WO2018042060A1 - Offenporige membran mit innerem raumdurchspannendem polymerem strukturnetzwerk zur elektrophoretischen stoffselektiven separation sowie verfahren zu deren herstellung und anwendung - Google Patents

Offenporige membran mit innerem raumdurchspannendem polymerem strukturnetzwerk zur elektrophoretischen stoffselektiven separation sowie verfahren zu deren herstellung und anwendung Download PDF

Info

Publication number
WO2018042060A1
WO2018042060A1 PCT/EP2017/072271 EP2017072271W WO2018042060A1 WO 2018042060 A1 WO2018042060 A1 WO 2018042060A1 EP 2017072271 W EP2017072271 W EP 2017072271W WO 2018042060 A1 WO2018042060 A1 WO 2018042060A1
Authority
WO
WIPO (PCT)
Prior art keywords
open
membrane
alkyl
functionalized
pores
Prior art date
Application number
PCT/EP2017/072271
Other languages
English (en)
French (fr)
Inventor
Max DIETZ
Original Assignee
Drei Lilien Pvg Gmbh & Co. Kg
Nanoscience For Life Gmbh & Co. Kg
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from EP16187197.5A external-priority patent/EP3290101A1/de
Application filed by Drei Lilien Pvg Gmbh & Co. Kg, Nanoscience For Life Gmbh & Co. Kg filed Critical Drei Lilien Pvg Gmbh & Co. Kg
Priority to EP17764797.1A priority Critical patent/EP3506999A1/de
Publication of WO2018042060A1 publication Critical patent/WO2018042060A1/de

Links

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D71/00Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
    • B01D71/06Organic material
    • B01D71/74Natural macromolecular material or derivatives thereof
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D69/00Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor
    • B01D69/02Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor characterised by their properties
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D69/00Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor
    • B01D69/10Supported membranes; Membrane supports
    • B01D69/106Membranes in the pores of a support, e.g. polymerized in the pores or voids
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D69/00Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor
    • B01D69/12Composite membranes; Ultra-thin membranes
    • B01D69/125In situ manufacturing by polymerisation, polycondensation, cross-linking or chemical reaction
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D69/00Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor
    • B01D69/14Dynamic membranes
    • B01D69/141Heterogeneous membranes, e.g. containing dispersed material; Mixed matrix membranes
    • B01D69/142Heterogeneous membranes, e.g. containing dispersed material; Mixed matrix membranes with "carriers"
    • B01D69/144Heterogeneous membranes, e.g. containing dispersed material; Mixed matrix membranes with "carriers" containing embedded or bound biomolecules
    • CCHEMISTRY; METALLURGY
    • C07ORGANIC CHEMISTRY
    • C07CACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C51/00Preparation of carboxylic acids or their salts, halides or anhydrides
    • C07C51/42Separation; Purification; Stabilisation; Use of additives
    • C07C51/47Separation; Purification; Stabilisation; Use of additives by solid-liquid treatment; by chemisorption
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D2323/00Details relating to membrane preparation
    • B01D2323/40Details relating to membrane preparation in-situ membrane formation
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D2325/00Details relating to properties of membranes
    • B01D2325/20Specific permeability or cut-off range

Definitions

  • Open-pore membrane with internal space-spanning polymer structure network for electrophoretically selective separation
  • the present invention relates to an open-pore membrane having nanocavity polymer structures in solid separation media for separating off fatty and / or carboxylic acids from aqueous mixtures and to a process for their preparation.
  • Carboxylic or fatty acids are amphiphilic molecules that hardly dissolve in water and are therefore present in water only in small amounts in volatile form.
  • the most common form in which fatty acids occur in water is therefore in the form of micelles and emulsions which cause phase separation.
  • the amphiphilia causes them to precipitate on surfaces that are hydrophobic or lipophilic. If they are dissolved with detergents, they are present in an aqueous medium as micellar particles.
  • Most organic compounds adsorb carboxylic acids to some extent via electrostatic binding forces. Therefore, carboxylic acids are present in aqueous organic solutions for the most part in a bound form or as micelles with other organic compounds. Due to the small size of such micelles, a filtration of these structures is virtually impossible or there is an occupancy of the filter surfaces, which causes a closure of the filter surface (fouling).
  • liquid-gas extraction in which the molecule to be separated off is separated and separated from a liquid mixture by a compressed gas, e.g. in the form of supercritical CO2 extraction,
  • Analytical methods such as gas chromatography, which is a combination of the above-mentioned methods.
  • the listed extraction methods are used in analytical chemistry (here in particular chromatography) as well as in the pharmaceutical and chemical industries (in particular chromatography and liquid-liquid extraction) and petrochemistry (in particular distillation).
  • the methods which enable a high transport of substances are associated with a considerable input of energy and thus a cost. Separating membranes for the separation of carboxylic acids dissolved in an aqueous medium and membrane-based separation processes for carboxylic acids dissolved in an aqueous medium are nonexistent.
  • Carboxylic acids can only be separated discontinuously from an aqueous medium by the abovementioned processes. In the deprotonated state, carboxylic acids have a negative charge and can thus be moved in an electric field of tension. Therefore, in principle, an electrophoretic separation of carboxylic acids is possible. In the passage of carboxylic acids through an open-pore separation medium, such as e.g. a filter membrane, the surfaces are occupied by adhering carboxylic acids, it is irrelevant whether the surface properties of such membranes are hydrophobic or hydrophilic. Furthermore, compounds which are also present in the aqueous medium and which themselves have a negative charge and / or are loaded with deprotonated carboxylic acids, are transported along in an electrophoretic separation through a membrane. Therefore, a selective separation of carboxylic acids from aqueous organic mixtures by an open-cell membrane and methods of the prior art is not possible.
  • an open-pore separation medium such as e.g. a filter membrane
  • Membrane-based processes for material separation at the molecular level are carried out according to the state of the art with closed membranes, which allow a diffusive mass transfer of the molecular structures to be separated, and summarized under the term nanofiltration.
  • the disadvantage here is that the quantities of material that can be transported per membrane surface unit are only small and that a high energy requirement (eg for a pneumatic pressure build-up of 20-80 bar) is required for the separation (A comprehensive review of nanofiltration membranes: treatment, pretreatment, modeling, and atomic force microscopy, N. Hilal, H. Al-Zoubi, NA Darwish, AW Mohammad, M. Abu Arabi, Desalination 2004, 170: 281-308).
  • hydrophilic and hydrophobic compounds which are present together in an aqueous medium, can be selectively separated by diffusion through membranes, which have highly ordered nanoscale channels and were provided with a hydrophilic or hydrophobic surface coating (solvent extraction and Langmuir Adsorption-Based Transport in Chemically Functionalized Nanopore Membranes, Damian J. Odom, Lane A. Baker, and Charles R. Martin, J. Phys. Chem. B 2005, 109, 20887-20894).
  • the selectivity for the compounds to be separated is achieved by a surface coating of the channel walls. As a result, a selectivity index of up to five for a diffusive mass transfer could be documented for the separation of apolar compounds.
  • One aspect of the present invention relates to an open-cell membrane for the electrophoretic separation of carboxylic acids from a liquid mixture comprising or consisting of:
  • the present invention relates to an open-pored membrane for the electrophoretic separation of carboxylic acids from a liquid mixture comprising or consisting of:
  • space-spanning polymeric structural network spans the pores of the open cell membrane and is not a pure surface coating of the pores of the open cell membrane.
  • the present invention relates to an open-cell membrane for the selective electrophoretic separation of carboxylic acids from a mixture of substances in aqueous solution, comprising or consisting of: I) an open-porous carrier membrane having pores with a minimum diameter of 50 nm to 500 ⁇ and a maximum diameter of 1 ⁇ to 3 mm, and
  • space-spanning polymeric structural network spans the pores of the open cell membrane.
  • the present invention further relates to an open-cell membrane for the electrophoretic separation of carboxylic acids from a liquid mixture comprising or consisting of:
  • the underlying invention further relates to an open-cell membrane for the electrophoretic separation of carboxylic acids from a liquid mixture comprising or consisting of:
  • III means for generating a concentration gradient and / or an electrical gradient at the membrane.
  • a further aspect of the present invention relates to a process for producing an open-pored membrane according to the invention for the electrophoretic separation of carboxylic acids from a liquid mixture, comprising the steps:
  • step b) introducing a solution of polymerisable monomers and / or oligomers into the pores of the open-pore carrier membrane from step a), c) polymerization of the polymerizable monomers or oligomers in the pores of the open-pore carrier membrane to form a space-spanning polymeric structure network in the pores of the open-pore carrier membrane.
  • the polymerization resulted in complete closure of the channels and in part only in superficial coverage of the channels with a polymer layer. While membranes with fully buried channels could not be traversed by carboxylic acids, membranes that had a surface channel coating that could be quantified by scanning electron microscopy showed amplification of electroosmotic flow when an electrical voltage was applied in an electrodialysis cell.
  • Electro-osmotic flow is accomplished by occupying surfaces, e.g. in a membrane, with ions being moved in an electric field.
  • the superficially mobile ion layer is transported in the electric field, whereby the water sheath bound to the ions is transported and thus a water volume transport is created.
  • electrodialysis with membranes having microfluidic channels leads to the formation of an electroosmotic flow (EOF).
  • EEF electroosmotic flow
  • an EOF affects the effectiveness of a separation of carboxylic acids, which can be achieved with an electrodialysis
  • an embodiment of the invention is an open-pore membrane or an open-pore membrane available or obtained by a method according to the invention, wherein the open-cell membrane prevents an electro-osmotic flow through the open-cell membrane.
  • An embodiment of the underlying invention therefore relates to an open-cell membrane for the electrophoretic separation of carboxylic acids from a liquid mixture comprising or consisting of:
  • the open cell membrane prevents electro-osmotic flow through the open cell membranes.
  • a surprising result has been the use of compounds in the solutions containing reactive mono- / oligomers which can promote or cause a polymerization reaction of the reactive mono- / oligomers.
  • polymers formed on planar surfaces exhibited irregular electron-microscopic structures which had fabric-like textures but were fragile as an independent layer or mass. They were porous and could rapidly pick up liquid carboxylic acids in the three-dimensional network that had formed. They were not wettable with water. Such layers / masses were easily removed mechanically from the contact surface and disintegrated into the smallest particles.
  • a reaction activation e.g.
  • the reaction activation of the polymerizable monomers and / or oligomers is preferably carried out starting from the solvent phase. This means that by solvent, activators or physical means the polymerization reaction is initiated by components in the solvent phase and preferably not by an activator on the surface of the support membrane. However, this does not mean that an interaction or reaction with the surface of the support membrane may take place during or after polymerization.
  • Such treated membranes also received liquid carboxylic acids and did not allow uptake of water. Electron microscopy showed that in such membranes polymer structures were formed, which have textures that can be strand-like and form a three-dimensional network but can also be made of flat tissue structures that are parallel or in an irregular arrangement to each other and in which the polymeric tissue structures the entire Space that through the space-limiting internal structures of the support membrane was predetermined, filled. The resulting polymer structures were altered by physical measures that are not changed in their structure or properties by a pressure rinse with water or organic solvents, as well as by an ultrasonic bath.
  • another aspect of the present invention is directed to an open cell membrane for the electrophoretic separation of carboxylic acids from a liquid mixture obtainable or obtained by a process according to the invention.
  • another aspect of the present invention is an open-pore membrane for the electrophoretic separation of carboxylic acids from a liquid mixture obtainable or obtained by a process comprising the steps of: a) providing an open-pore carrier membrane with pores having a minimum diameter of 50 nm to 500 ⁇ and a maximum diameter of 1 ⁇ to 3 mm,
  • step b) introducing a solution of polymerizable monomers and / or oligomers into the pores of the open-pore carrier membrane from step a), c) polymerizing the polymerizable monomers or oligomers in the pores of the open-pored carrier membrane to form a space-spanning polymeric structural network in the pores of the open-pore carrier membrane.
  • the filling of the space-filling open-pore carrier membrane with a polymer which is polymerized was generated, so that thereby the pores, channels or slots are closed by the polymer formed.
  • the surface coating of the pores, channels or slots of the space-giving open-pore carrier membrane with a polymer is not according to the invention. Accordingly, an open-pore membrane, the interior spaces, pores, channels or slots of the space-giving open-pore carrier membrane are superficially coated, just as little according to the invention.
  • the space-filling or space-spanning open-pore polymer structures according to the invention are preferably achieved by "self-assembly" of mono- / oligomers into polymeric textures and are preferably covalently and / or electrostatically bonded to the surfaces of the open-pore carrier membrane in the pores of the porous support membrane, wherein the open-pore polymer structures are preferably nanocavity polymer structures.
  • the polymeric structural network is preferably the result of a "self-assembly" of monomers and / or oligomers, and the polymer structures or the polymeric structural network are preferably covalently bonded to the inner surfaces of the open-celled support membrane.
  • the polymeric structural network is covalently cross-linked in three dimensions.
  • One embodiment of the present invention thus relates to an open-pore membrane described herein for the electrophoretic separation of carboxylic acids from a liquid mixture, wherein the space-spanning polymeric structural network is nanocavitary.
  • an embodiment of the invention is an open-pore membrane for the electrophoretic separation of carboxylic acids from a liquid mixture
  • an open-pore carrier membrane having pores with a minimum diameter of 50 nm to 500 ⁇ and a maximum diameter of 1 ⁇ to 3 mm
  • space-spanning polymeric structure network is nanocavitary.
  • the underlying invention is directed to a process for the preparation of an open cell membrane according to the invention for the electrophoretic separation of carboxylic acids from a liquid mixture, comprising the steps:
  • the underlying invention relates to a process for producing an open-pored membrane according to the invention for the electrophoretic separation of carboxylic acids from a liquid mixture, comprising the steps:
  • open-pore membranes of the invention described herein are characterized in particular by the fact that they are suitable for the selective electrophoretic separation of carboxylic acids from a liquid mixture.
  • One embodiment of the present invention relates to an open-cell membrane for the selective electrophoretic separation of carboxylic acids from a liquid mixture comprising or consisting of:
  • open cell membrane is selective towards carboxylic acids.
  • an embodiment of the present invention is directed to a process for producing an open-pored membrane according to the invention for the selective electrophoretic separation of carboxylic acids from a liquid mixture, comprising the steps:
  • step b) introducing a solution of polymerizable monomers and / or oligomers into the pores of the open-pore carrier membrane from step a), c) polymerizing the polymerizable monomers or oligomers in the pores of the open-pored carrier membrane to form a space-spanning polymeric structural network in the pores of the open-pore carrier membrane.
  • Another embodiment of the present invention is directed to a process for producing an open cell membrane of the invention Electrophoretic separation of carboxylic acids from a liquid mixture, comprising the steps:
  • step b) introducing a solution of polymerisable monomers and / or oligomers into the pores of the open-pore carrier membrane from step a), c) polymerizing the polymerisable monomers or oligomers in the pores of the open-pore carrier membrane to form a space-spanning polymeric structural network in the pores of the open-pore carrier membrane,
  • open cell membrane is selective towards carboxylic acids.
  • the corresponding alcohol to hexanoic acid is e.g. Hexane-1-ol.
  • the open-cell membranes or open-pore membranes according to the invention are obtainable or obtained by a process according to the invention for the continuous separation of carboxylic acids, preferably of fatty acids, from liquid mixtures containing the carboxylic acids and preferably the fatty acids, this mixture being on one side of a membrane according to the invention with continuous pores, channels or slits and the carboxylic acids and preferably the fatty acids these continuous pores, channels or slits are transported to the other side of the membrane, with a selectivity index> 4 relative to that derived from the carboxylic acid by reduction ltlichen alcohol.
  • an embodiment of the present invention is an open-cell membrane for the electrophoretic separation of carboxylic acids from a liquid mixture consisting of: I) an open-pore carrier membrane having pores with a minimum diameter of 50 nm to 500 ⁇ and a maximum diameter of 1 ⁇ to 3 mm,
  • the open-pore membrane has a selectivity index for carboxylic acids over the corresponding alcohols of> 4.
  • reaction solution A high concentration of the monomers in the reaction solution was found to be advantageous for the formation of space-filling or space-spanning polymer structures.
  • this requires a high viscosity of the reaction solution, which makes incorporation into nano- or microchannels virtually impossible.
  • reaction solutions with a high content of monomers can be introduced into various separation media which have channel and / or slot structures in the micrometer to millimeter range and that radical or nucleophilic polymerization can be initiated by various starting reactions which lead to Formation of nanocavity polymer structures leads, preferably it is a multifocal radical or nucleophilic polymerization.
  • space-filling or more precisely space-spanning structural structures / textures are present in such membranes. These structural structures preferably form nanoscale cavities which are connected to one another.
  • Such membranes are porous, since a gas flow could pass through such membranes.
  • the polymer structures thus produced differ from those initiated by a start reaction due to contact with a coated surface, in the sense of a "grafting from” polymerization process and obtained by a self-sustained polymerization, characterized in that the polymer layer is not a closed mass, open-pore, with the formation of filamentous to membranous structures, which formed space-filling or space-spanning irregularly-restricted cleavage sites, thus initiating a radical or nucleophilic polymerization reaction in a monomer and / or oligomer solution by addition of a chemical initiator and / or physical reaction initiation Process for accelerating a polymerization reaction of a solution with reactive mono- / oligomers
  • the process for producing an open-pore membrane according to the invention for the electrophoretic separation of carboxylic acids from a liquid mixture comprises the steps:
  • the process for producing an open-pore membrane according to the invention for the electrophoretic separation of carboxylic acids from a liquid mixture comprises the steps:
  • step c) the solution of the polymerisable monomers and / or oligomers is heated and / or the solution contains a solvent which initiates a polymerization.
  • another preferred embodiment of the invention is an open-cell membrane for the electrophoretic separation of carboxylic acids a liquid mixture or obtained by a process comprising the steps:
  • step c) wherein the polymerization reaction in step c) is initiated by the addition or application of a chemical and / or physical initiator of a radical or nucleophilic polymerization.
  • a further preferred embodiment of the invention is an open-pore membrane for the electrophoretic separation of carboxylic acids from a liquid mixture obtainable or obtained by a process comprising the steps:
  • step c) the solution of the polymerisable monomers and / or oligomers is heated and / or the solution contains a solvent which initiates a polymerization.
  • a reactive monomer solution is fully incorporated into a microporous and / or macroporous support membrane and the polymerization initiated by the solvent phase, ie, the polymerization in step c) is characterized by a solution contained in the solution Solvent initiated. Therefore, a further preferred embodiment of the present invention is a process for producing an open-pore membrane for the electrophoretic separation of carboxylic acids from liquid mixtures comprising the steps: a) providing an open-pore carrier membrane with pores having a minimum diameter of 50 nm to 500 ⁇ m and a maximum diameter from 1 ⁇ to 3 mm,
  • step c) the solution contains a solvent which initiates the polymerization.
  • an open-pored membrane is obtainable or obtained by a process for the production of open-pore membranes comprising a self-assembled nanocavity room-spanning polymeric structural network for the reduction / elimination of an electro-osmotic flow.
  • an open-celled membrane described herein which has a self-assembled nanocavity spanning polymeric structural network for reducing / eliminating electro-osmotic flow.
  • the membrane of the invention and / or a separate membrane is / is coated with a polycation. Suitable polycations are described in more detail in the section "Post-polymerization Functionalization.”
  • the coating can be used in Form of adsorption and / or covalent bonding or physiosorptive and / or chemisorptive carried to the surface of the support material.
  • the coating can be applied on the surface, preferably on the side facing the acceptor medium.
  • the coating can also be introduced into the cleavage spaces of the membrane, which in turn can take place in the form of an adsorption and / or a covalent bond or physiosorptive and / or chemisorptive.
  • a free-bearing layer consisting of polycationic compounds is used by bringing them together with a membrane according to the invention.
  • This bringing together means a close spatial contact, the z. B. is achieved by the membranes are pressed together by a suitable holding device to each other, whereby a gap formation between the two membranes is prevented.
  • a suitable holding device to each other, whereby a gap formation between the two membranes is prevented.
  • an open-pore membrane according to the invention is obtainable or obtained by a process in which a suppression of an electro-osmotic flow takes place by at least one polycationic compound being applied in the optional step d2) to the surfaces of the space-spanning polymer structure network in a physiosorptive and / or chemosorptive manner.
  • an open-pored membrane according to the invention is furthermore preferably also comprising a functionalization of the surfaces of the space-spanning polymeric structural network.
  • the open-pore membrane comprises or consists for the electrophoretic separation of carboxylic acids from a liquid mixture of substances:
  • an open-pored membrane according to the invention is furthermore preferably further comprising a functionalization of the surfaces of the nanocavity-spanning polymeric structural network.
  • the open-pore membrane comprises or consists for the electrophoretic separation of carboxylic acids from a liquid mixture of substances:
  • open-pore membranes wherein the surface of the space-spanning polymeric structural network is functionalized with at least one hydrophobic polycationic compound.
  • Hydrophobic herein means that the polycationic compound preferably has a K ow of> 0.3, more preferably of 0.4, more preferably of 0.4, more preferably of 0.5, even more preferably of 0.6, even more preferably from 0.7, more preferably from> 0.8 and most preferably> 1. Hydrophobic does not mean that the compounds can not be dissolved in one part in an aqueous medium. Therefore, in a preferred embodiment, the open-pored membrane for electrophoretic separation of carboxylic acids from a liquid mixture of substances comprises or consists of:
  • surfaces of the space-spanning polymeric structural network is functionalized with at least one hydrophobic polycationic compound.
  • a membrane according to the invention described herein further comprising a coating on the surfaces of the space-spanning polymeric structural network comprising at least one compound selected from the group consisting of or consisting of amphiphilic and / or cationic and / or polycationic compound.
  • a preferred embodiment of the present invention is an open cell membrane for the electrophoretic separation of carboxylic acids from a liquid mixture comprising or consisting of:
  • the surfaces of the space-spanning polymeric structural network comprises a coating comprising at least one compound selected from the group consisting of or consisting of amphiphilic and / or cationic and / or polycationic compounds.
  • a coating comprising at least one compound selected from the group consisting of or consisting of amphiphilic and / or cationic and / or polycationic compounds.
  • a further membrane which has been adsorptively and / or chemosorptively coated with a polycationic compound (s) is brought into close spatial contact with the separation membrane in order to obtain an electrochemical to reduce osmotic flow.
  • Another aspect of the present invention relates to a method for suppressing the electro-osmotic flow, which is achieved by the separation membrane and / or another membrane is adsorptively and / or chemosorptively coated with a polycationic compound (s) In the case of a separate membrane, this is brought into close spatial contact with the separation membrane.
  • a polycationic compound s
  • a preferred embodiment of the invention therefore relates to a process for producing an open-pore membrane for the electrophoretic separation of carboxylic acids from a liquid mixture, preferably a mixture of substances in aqueous solution, comprising the steps:
  • Another aspect of the invention relates to the surface charge of the space-spanning polymeric structural network in the membranes produced according to the invention.
  • the surface charge can be determined by a transmembrane determination of the zeta potential.
  • the zeta potential of the membrane according to the invention is preferably 0 mV.
  • the membranes according to the invention have a zeta potential which is not equal to 0 mV and lies in a range between + 40 mV and -80 mV.
  • the ionic or ionizable compounds are provided with a protective group and added to the reaction mixture in stage b). In another embodiment, these protecting groups are cleaved in optional step d1) by appropriate reagents or physical means and subsequently removed from the membrane.
  • ionic and / or ionizable compounds in the optional process step d2) are attached to the surfaces of the nanocavitamin polymer structures in a physio- and / or chemosorptive manner. For this it may be necessary to first prepare reactive groups on the polymer structures. Methods for this are known in the art. After a subsequent physio- and / or chemosorptive addition of ionic or ionizable compounds and after the removal of protective groups such membranes are carefully cleaned of unreacted or eliminated compounds.
  • Scalable surface charges of the membranes of the present invention can be made in these optional process steps, preferably in the range of + 0.1mV to + 40mV, as long as a positive zeta potential is desired and in the range of -0.1mV to -80mV if a negative zeta potential is required.
  • a preferred embodiment of the present invention is a process for producing an open-pored membrane for the electrophoretic separation of carboxylic acids from a liquid mixture, comprising the steps: a) providing an open-pore carrier membrane with pores having a minimum diameter of 50 nm to 500 ⁇ m and a maximum diameter of 1 ⁇ m to 3 mm,
  • the introduced mono and / or oligomer solution contains protected monomers and / or protected oligomers and the monomers and / or oligomers are ionic and / or ionizable.
  • a preferred embodiment of the present invention is a process for producing an open-pored membrane for the electrophoretic separation of carboxylic acids from a liquid mixture, comprising the steps:
  • step b) introducing a solution of polymerisable monomers and / or oligomers into the pores of the open-pore carrier membrane from step a), wherein the introduced mono- and / or oligomer solution contains protected monomers and / or protected oligomers,
  • d2) binding of an ionic and / or ionizable compound to the deprotected, open-pore, space-spanning polymeric structural network.
  • the process for producing an open-pore membrane for the electrophoretic separation of carboxylic acids from a liquid mixture comprises the steps:
  • the nanocavity polymer structures according to the invention are prepared by a polymerization process which is started in situ by nucleophilic reaction initiation of a monomer solution. This initiation is referred to herein as "reaction activation" or “reaction initiation.” This includes nucleophilic and free-radical reactions involving covalent bonding between one or more mono- / oligomers, or covalent bonding with other compounds (eg, organic compounds on surfaces of the bulk support membrane).
  • reaction products additionally promote the formation of the nanocavitaminic polymer structures.
  • reaction initiation also means suitable measures for a multifocal start of the polymerization so that nanocavitary spatial structures within the space-giving open-pore open pores are formed In other words, reaction initiation prevents / prevents a uniform layer buildup or the formation of compact dressings of the forming polymers by a multifocal polymer growth.
  • Suitable reaction activation means include adding initiators of polymerization reactions, raising the temperature, lowering the temperature, adding a solvent, irradiating, increasing or decreasing the pressure, as well as known methods of the prior art.
  • reaction activation prevents the formation of a compact layer of the polymer on the surfaces of the supporting fabric and a closure of the pores of a porous membrane.
  • a preferred embodiment of the invention thus relates to a process for producing an open-pore membrane for the electrophoretic separation of carboxylic acids from a liquid mixture comprising the steps:
  • step c) wherein the formation of the space-spanning, polymeric structural network in step c) takes place via a multifocal polymer growth.
  • the process for producing an open-pored membrane for the electrophoretic separation of carboxylic acids from a liquid mixture comprising the steps:
  • step b) introducing a solution of polymerisable monomers and / or oligomers into the pores of the open-pore carrier membrane from step a), c) polymerisation of the polymerisable monomers or oligomers in the pores of the open-pored carrier membrane to form a space-spanning polymer structure network in the pores of the open-pored carrier membrane,
  • the mono- or oligomers are in the form of a solution or suspension in a suitable solvent.
  • suitable solvents are, acetonitrile, THF, 1, 4-dioxane, ⁇ , ⁇ -dimethylformamide (DMF) dichloromethane, chloroform, methyl tert-butyl ether or similar solvents, such as. N, N-dimethylacetamide (DMA) and N-methylpyrrolidone (NMP), DMSO, water, methanol, toluene, xylene, anisole and other organic solvents and combinations thereof or hereby.
  • DMA N-dimethylacetamide
  • NMP N-methylpyrrolidone
  • the choice of monomer / oligomer concentration will depend on the resulting physical properties and solubility.
  • the concentration is to be selected from a range between 1 mmol / l and 3 mol / l, more preferably between 10 mmol / l and 1 mol / l and more preferably between 100 mmol / l and 0.5 mol / l.
  • the process for producing an open-pore membrane for the electrophoretic separation of carboxylic acids from a liquid mixture comprises the steps:
  • the monomer and / or oligomer concentration of said mono and / or oligomer solution is between 1 mmol / l and 3 mol / l.
  • a further preferred embodiment of the present invention is an open-pore membrane for the electrophoretic separation of carboxylic acids from a liquid mixture obtainable or obtained by a process comprising the steps: Providing an open-pore carrier membrane with pores having a minimum diameter of 50 nm to 500 ⁇ m and a maximum diameter of 1 ⁇ m to 3 mm,
  • the monomer and / or oligomer concentration of said mono and / or oligomer solution is between 1 mmol / l and 3 mol / l.
  • the preparation of nanocavitation polymer structures by a suitable and prepared structure and space-giving membrane is filled to saturation with the reactive mono- / oligomer solution.
  • the filling can be carried out by impregnation, pouring, loading with / in the monomer / oligomer solution or by a continuous or discontinuous volume flow of the mono- / oligomer solution through the membrane. It may be necessary to lower or raise the temperature.
  • the introduction of the mono- / oligomer solution in the structuring membrane at a temperature of -10 to 100 ° C, more preferably between 0 ° C and 80 ° C and more preferably between 10 ° C and 40 ° C.
  • the nanocavity polymer structures according to the invention are prepared by a polymerization process which is started in situ by a free-radical or nucleophilic reaction initiation of a monomer and / or oligomer solution.
  • the process for producing an open-pore membrane for the electrophoretic separation of carboxylic acids from a liquid mixture comprises the steps:
  • Initiators of a reaction of the mono- / oligomers are substances that can initiate a ring-opening or free-radical polymerization, as known from the prior art. These include solvents such as water, DMF, NMP, DMSO, tetramethylurea.
  • Nucleophiles such as amines, amides, alcoholates, hydroxide ions, thiolates, triethylamine, ammonia, pyridines, such as 4-dimethylaminopyridine, phosphines, carbenes, such as imidazol-2-ylidenes and imidazolin-2-ylidenes or thiazol-2-ylidenes.
  • Cationic catalysts such as trifluoromethanesulfonic acid and methyltrifluoromethanesulfonate, bifunctional organocatalysts, such as [1- (3,5-bis (trifluoromethyl) phenyl) -3- (2-dimethylamino-cyclohexyl) thiourea] or [1, 5,7-triazabicyclo ( 4.4.0) dec-5-ene (TBD).
  • Catalysts such as Grubb's catalyst, metal ions such as copper, tin, for example as tin octanoate (Sn (Oct) 2 ), aluminum alkoxides Al (OR) 3, titanium alkoxides (Ti (OR) 4 ), cobalt or nickel, acids such as ascorbic acid, sulfuric acid or phosphoric acid, furthermore azo compounds, such as AIBN or peroxides, such as benzoyl peroxide.
  • metal ions such as copper, tin, for example as tin octanoate (Sn (Oct) 2 ), aluminum alkoxides Al (OR) 3, titanium alkoxides (Ti (OR) 4 ), cobalt or nickel, acids such as ascorbic acid, sulfuric acid or phosphoric acid, furthermore azo compounds, such as AIBN or peroxides, such as benzoyl peroxide.
  • the substances / compounds which initiate a starting reaction are added to a carrier structure of the mono- / oligomer solution immediately before the introduction of the monomer / oligomer solution and / or have been previously applied to the surfaces of the carrier structure.
  • the ring-opening polymerization is preferably carried out with a nucleophile-induced polymerization, preferably previously amines are applied to the surfaces of the carrier structures.
  • the initiator of a free-radical or nucleophilic polymerization is added to the mono- / oligomer solution immediately prior to introduction into the supporting tissue.
  • solvents which can initiate a nucleophilic reaction such as DMF, DMA or NMP.
  • solvent combinations are particularly preferred.
  • a ring-opening polymerization of amino acid monomers dissolved in THF can be initiated by the addition of 10% by volume DMF.
  • the initiation of the free-radical or ring-opening reaction in the solvent phase is by physical means.
  • the polymerization reaction takes place at an overpressure or at a reduced pressure.
  • a negative pressure between 10 and 900 mbar.
  • Further preferred is the application of a pressure curve.
  • initially an increased pressure can be applied and in the course of this is lowered continuously or stepwise.
  • the solvent-induced polymerization initiation takes place in a container with a controllable inlet / outlet valve.
  • the temperature of the membrane filled with the reaction solution takes place according to a two-stage or multistage or continuous flow pattern with different temperatures. Preferred is a duration of a temperature increase between 10 minutes and 72 hours, more preferably between 30 minutes and 48 hours and more preferably between 2 and 24 hours.
  • the reaction initiation of the mono- / polymer solution takes place in a space-providing supporting fabric by a polycondensation in the form of a melt.
  • temperatures are chosen here which are around or above the individual melting point of the monomers used. Preference is given to heating to 40 to 200 ° C, more preferably to 80 ° to 140 ° C and more preferably to 90 ° to 140 ° C.
  • Another preferred method for initiating polymerization is exposure of the open-celled membrane impregnated with a mono- / oligomer solution to long or short wave radiation. Particularly preferred is the application of microwaves.
  • the reactive mono- / oligomers are concentrated in the internal spatial structures of the porous support membrane prior to reaction activation. In one embodiment, this can be done by introducing the solution with the reactive mono- / oligomers into the support membrane and then evaporating the solvent by appropriate means, preferably without causing a reaction activation. This can be achieved, for example, by performing the evaporation at a reduced temperature and an applied vacuum. This process can be repeated in the required number. It is preferred to carry out thereafter a melt or irradiation of the accumulated reactive mono- / oligomers.
  • nano-cavitation spaces formed during the polymerization can be influenced by additionally adding to the solution with mono- and / or oligomers compounds which do not participate in a polymerization reaction.
  • additional connections are inert to the reaction conditions.
  • These compounds which may also be referred to as release agents, are preferably hydrophobic and low molecular weight compounds.
  • a low-molecular compound preferably means a compound having a molecular mass of at most 1000 g / mol.
  • Hydrophobic here means that the compound preferably has a K ow of> 0.3, more preferably of 0.4, more preferably of 0.4, more preferably of 0.5, even more preferably of 0.6, even more preferably of 0.7, more preferably> 0.8 and most preferably> 1. Hydrophobic does not mean that the compounds can not be dissolved in one part in an aqueous medium. Furthermore, they are preferably oleophilic and can be completely removed again after the multifocal polymerization according to the invention by means of a suitable solvent from the membrane with a space-spanning polymer structure network. Mixtures of release agents may also be used.
  • Preferred compounds which can be used as release agents in a multifocal polymerization in particular aliphatic or aromatic hydrocarbons, such as alkanes, alkenes, alkynes, cycloalkanes, cycloalkenes, cycloalkynes, isoprenes, terpenes, alcohols, phenols, carboxylic acids or their salts, carboxylic acid alkyl esters , Fatty alcohols or their salts, carbonic acid dialkyl esters, ethers, alkylsulfonic acids or their salts, alkylsulfuric esters, dialkylsulfoxides, dialkylsulfones, amides, carbamates and organic phosphorus compounds.
  • alkanes alkenes, alkynes, cycloalkanes, cycloalkenes, cycloalkynes, isoprenes, terpenes
  • alcohols phenols
  • carboxylic acids or their salts carboxylic acid
  • the molar ratio between the release agent and the monomer or oligomer is preferably in the range of 1: 100-1: 1, preferably 1: 100-1: 2, more preferably between 1: 80-1: 3, more preferably between 1: 60-1: 4, more preferably between 1: 40-1: 5 and even more preferably between 1: 30-1: 6 and even more preferably between 1:20 -1:10.
  • alkyl also means aryl or alkylaryl compounds
  • an "alkyl” radical comprises 1 to 30 carbon atoms (C 1 -C 30 -alkyl), more preferably 4 to 22 carbon atoms and even more preferably 6 - 22 carbon atoms.
  • an "aryl” radical comprises from 6 to 14 carbon atoms of (Ce-Ci 4 -aryl)
  • an "alkylaryl” radical comprises from 7 to 15 carbon atoms (C 7 -C 15 -alkylaryl).
  • the process of making an open cell membrane for the electrophoretic separation of carboxylic acids from a liquid mixture comprises the steps of: a) providing an open-pore carrier membrane with pores having a minimum diameter of 50 nm to 500 ⁇ m and a maximum diameter of 1 ⁇ m to 3 mm,
  • step b) further contains a release agent.
  • a ring-opening polymerization which takes place while heating the substrate.
  • step c) the formation of a space-spanning polymeric structural network by ring-opening polymerization takes place, wherein the solution of the polymerizable monomers and / or oligomers is heated and / or the solution contains a solvent which is a ring-opening or free-radical polymerization initiated. Therefore, open-cell membranes are also available or obtained by the method just described.
  • the process for producing an open-pore membrane for the electrophoretic separation of carboxylic acids from liquid mixtures therefore comprises the steps of: a) providing an open-pore carrier membrane having pores with a minimum diameter of 50 nm to 500 ⁇ m and a maximum diameter from 1 ⁇ to 3 mm,
  • step c) the formation of a space-spanning polymeric structural network is carried out by ring-opening polymerization, wherein the solution of polymerizable monomers and / or oligomers is heated and / or the Solution contains a solvent that initiates a ring-opening or radical polymerization.
  • Preferred is a process for ring-opening polymerization in which the substrate is heated with the mono- / oligomer solution.
  • the process for producing an open-pored membrane for the electrophoretic separation of carboxylic acids from a liquid mixture comprises the steps:
  • step c) a polycondensation of a thermal melt of the polymerizable monomers and / or oligomers takes place.
  • the polymerization is initiated by a start reaction initiated from the surface of the support materials. Preference is given to surfaces which have a functionalization with a starter for a free-radical or ring-opening polymerization.
  • polymerizations which are carried out by means of a "grafting through” process In the grafting through process, two or more polymer compounds are bonded together, one of the compounds forming a longer-chain backbone and the other compounds being used in the reaction with this backbone.
  • a polymerization takes place in the form of a "grafting to" process. Initially, polymers are produced in suitable reaction mixtures.
  • the resulting polymers are subsequently purified and obtained in a specified form or with a defined molar mass by suitable separation techniques. These polymers are then with Surfaces or other polymers brought into contact and connected to these by means of a condensation, addition or substitution reaction.
  • Polymerization processes with which the nanocavity polymer structures according to the invention can be prepared include processes from the prior art, such as atom transfer radical polymerization (ATRP), ring-opening metathesis polymerization (ROMP), anionic or cationic polymerization, as well as free living radical polymerization, but also the radiation-induced polymerization, the ring-opening olefin metathesis polymerization, the reversible addition-fragmentation chain transfer polymerization, the nitroxide-mediated polymerization, polycondensation reactions and an inferior-induced polymerization.
  • ATRP atom transfer radical polymerization
  • RRP ring-opening metathesis polymerization
  • anionic or cationic polymerization as well as free living radical polymerization, but also the radiation-induced polymerization, the ring-opening olefin metathesis polymerization, the reversible addition-fragmentation chain transfer polymerization, the nitroxide-mediated polymerization, polycondensation reactions and an inferior-
  • reaction conditions required in the various processes for the preparation of nanocavity space-filling or space-spanning polymer structures can be very different.
  • a reaction time between 1 minute and 10 days, more preferably between 10 minutes and 3 days and more preferably between 15 minutes and 24 hours.
  • a reaction temperature between 0 ° and 270 ° C, more preferably between 10 ° and 180 ° C and more preferably between 20 ° and 130 ° C.
  • step b) a solution containing reactive monooligomers is introduced into a spatially open porous carrier membrane and polymerization initiation in step c) results in the formation of polymer structures which form nanocavityy cleavage spaces.
  • an open-pore membrane is also available or obtained according to the method of the invention just described.
  • step c) takes place chemically, physico-chemically or physically by polymerization initiation.
  • Preference is also given to obtaining an open-pore membrane for the electrophoretic separation of carboxylic acids from a liquid substance mixture or obtained by the process according to the invention which has just been described.
  • Preference is given to a process in which the polymerization is initiated in step c) by increasing the temperature. Preference is also given to obtaining an open-pore membrane for the electrophoretic separation of carboxylic acids from a liquid substance mixture or obtained by the process according to the invention which has just been described.
  • the room-spanning polymeric structural network may comprise at least one polymer such as polyvinylidene chloride, polyvinyl butyral, polyvinylpyridine, polycarbonates, polyamides, polyimides, polybenzimidazoles, polyethers, polystyrene, polydivinylbenzene, polyvinyltoluene, polyvinylbenzyl chloride, Polymethylmethacrylate, polyethylene, polypropylene, polyvinylacetate, polyacrylonitrile, polyacrolein, polybutadiene, polychlorobutadiene, polyisoprene, polyvinylchloride, polyvinylalcohol, polyacrylonitrile.
  • polymer such as polyvinylidene chloride, polyvinyl butyral, polyvinylpyridine, polycarbonates, polyamides, polyimides, polybenzimidazoles, polyethers, polystyrene, polydivinylbenzene, polyvinyltoluen
  • Polyhydroxybutyrate co-valerates, poly (1,4-dioxane-2,3-diones), poly (1,3-dioxan-2-ones), poly-para-dioxanones, polyanhydrides, polymaleic anhydrides,
  • Polyvinyl alcohols polyester amides, glycolated polyesters, polyphosphoesters, polyphosphazenes, poly [p-carboxyphenoxy) propane], polyhydroxypentanoic acid, polyanhydrides, polyethylene oxide-propylene oxide, polyether esters such as polyethylene oxide, polyalkene oxalates, polyorthoesters and their copolymers, lipids, waxes, oils, polyunsaturated fatty acids, eicosapentaenoic acid, Timnodonic acid, docosahexaenoic acid, arachidonic acid, linoleic acid, ⁇ -linolenic acid, ⁇ -linolenic acid, carrageenans, fibrinogen, agar-agar, starch, collagen, protein-based polymers, polyamino acids, synthetic polyamino acids, zein, polyhydroxyalkanoates, pectinic acid, actinic acid, carboxymethylsulfate,
  • lipophilic polymers Particularly preferred are lipophilic polymers. Particularly preferred are lipophilic polymers having amide bonds, such as polyamino acids and preferably polyamino acids of the same amino acid monomer, such as polyisoleucine, polyphenylalanine, polyvaline.
  • the space-spanning polymeric structural network of the open-pore membranes according to the invention described hereinbefore preferably comprises or comprises the electrophoretic separation of carboxylic acids from a liquid mixture of polyvinyl polymers or polyamino acids.
  • space-spanning polymeric structural network consists of vinyl polymers or polyamino acids, preferably lipophilic polyamino acids.
  • the space-spanning polymeric structural network of the open-pore membranes according to the invention described hereinbefore preferably comprises or comprises the electrophoretic separation of carboxylic acids from homopolyamino acids.
  • a particularly preferred embodiment according to the invention is therefore directed to an open-pored membrane for the electrophoretic separation of carboxylic acids from a liquid mixture of substances comprising or consisting of:
  • space-spanning polymeric structural network consists of homopoly-a-amino acids, preferably lipophilic homopoly-a-amino acids.
  • homopoly-a-amino acids refers to polymers of the same a-amino acid as e.g. Polyphenylalanine.
  • the space-spanning polymeric structural network of the present invention open-celled membranes for the electrophoretic separation of carboxylic acids from a liquid mixture preferably comprises or consists of vinyl polymers selected from the group consisting of or consisting of polyvinyl chloride, polyvinylidene chloride, polyacrylic acid, polyacrylamide, polyvinyl butyral, polyvinylpyridine, polyvinylamine, polyvinyl ethers, polystyrene , Polydivinylbenzene, polyvinyltoluene, polyvinylbenzylchloride, polymethylmethacrylate, polyethylene, polypropylene, polyvinylacetate, polyacrylonitrile, polyacrolein, polybutadiene, polychlorobutadiene, polyisoprene, polyvinylalcohol, alkylated
  • the space-spanning polymeric structural network consists of vinyl polymers and the vinyl polymers are selected from the group consisting of or consisting of polyvinyl chloride, polyvinylidene chloride, polyacrylic acid, polyacrylamide, polyvinyl butyral, polyvinyl pyridine, polyvinylamines, polyvinyl ethers, polystyrene, polydivinylbenzene, polyvinyltoluene, polyvinylbenzylchloride, polymethylmethacrylate, polyethylene, polypropylene , Polyvinyl acetate, polyacrylonitrile, polyacrolein, Polybutadiene, polychlorobutadiene, polyisoprene, polyvinyl alcohol, alkylated or acylated polyvinyl alcohol.
  • organic compound units known from the prior art can be used for the production of the open-pore nanocavitic space-filling or space-spanning polymer structures according to the invention.
  • organic compound units are ethylene, propylene, vinyl chloride, caprolactam, isoprene, 1,3-butadiene, 4-vinylbenzyl chloride (VBC) or ammonium salts thereof, carbonates, arylates, caprolactone, tetrafluoroethylene, oxazolines, imidazoles, carboxylic acid esters or ethers, 1 -thio-2,3-dihydroxypropyl thioether, 1-diglycerol ether, 1, 2 dihydroxy 3-thiopropyl-1-ether, 1-glycerol ether, 1-glycerol ether having a substituent at position 3, such as. B. 1, 3 glycerol.
  • imides for example m- or p-phenyleneisophthalamide
  • paraphenylenes for example m- or p-phenyleneisophthalamide
  • terephthalamides for example m- or p-phenyleneisophthalamide
  • paraphenylenes for example m- or p-phenyleneisophthalamide
  • terephthalamides for example m- or p-phenyleneisophthalamide
  • paraphenylenes for example m- or p-phenyleneisophthalamide
  • terephthalamides for example m- or p-phenyleneisophthalamide
  • paraphenylenes for example m- or p-phenyleneisophthalamide
  • terephthalamides for example m- or p-phenyleneisophthalamide
  • paraphenylenes for
  • aromatic polyamides such as vinylpyrrolidone or mixed esters thereof, urethane, urea or biologically produced or degradable mono- or polymers, preferably from lactic acid, hydroxyalkanoate, hydroxybutyrate, hydroxyvalerate, cellulose or mixtures thereof or copolymers thereof.
  • Various polymerization mechanisms can be selected for the preparation of the nanocavity polymer structures according to the invention.
  • monomers containing free-radical, cationic or anionic centers to produce.
  • Techniques for making reactive mono- / oligomers are known in the art.
  • Halogens and halides such as bromine or chloride, cyclic olefins, such as norbornenes and cyclopentenes, negatively charged vinyl groups, isocyanates, amines, aldehydes, ketones, carboxylic acids, epoxides, electron-rich aromatics, such as phenols, hydroxy compounds, such as phenols, are particularly useful as reactive centers or alcohols, Michael systems such as ⁇ , ⁇ -unsaturated esters, amides, nitriles, nitroolefins, carbonic acids and derivatives.
  • Particularly preferred is the use of monomers that are physiologically occurring and / or biodegradable.
  • Particularly suitable amino acids and derivatives thereof are suitable for this purpose. These may be carbamic acid, alpha-, beta- or gamma-amino acids as well as L- or D-forms as well Mixtures of these.
  • Further amino acid derivatives such as. As tyrosine, cinnamic acid or 3- (4-hydroxyphenyl) propionic acid.
  • protected amino acids are used, i.
  • Reactive major or pendant groups are protected from reaction turnover by reversible saturation with a non-reactive compound.
  • protecting group for the functionality to be protected it is preferred to use fluorenylmethoxycarbonyl (Fmoc), tert-butyloxycarbonyl (Boc), benzyloxycarbonyl (Cbz, Z) or acetyl groups, more preferred are triphenylmethyl (Trt), benzyloxymethyl (Born), benzyl -, phenyl, dinitrophenyl (Dnp), toluenesulfony-1 (Tos), mesitylenesulfonyl (Mts), acetamidomethyl (Acm), tert-Butylmercapto weakness (tBum) used.
  • Methods are known in the prior art with which the protective groups can be removed again following polymerization.
  • the space-spanning polymeric structural network of the open-cell membranes of the invention described herein comprise or comprise electrophoretic separation of carboxylic acids from polyamino acids, and wherein the polyamino acids consist of amino acid monomer units selected from the group consisting of or consisting of proteinogens Amino acids and their derivatives, in particular their lipophilic derivatives such as alkylated or acylated derivatives or derivatives with lipophilic protective groups.
  • space-spanning polymeric structure network in the pores of the support membrane, wherein the space-spanning polymeric structural network consists of or comprises polyamino acids, and wherein the polyamino acids consist of amino acid monomer units selected from the group consisting of or consisting of proteinogenic amino acids and their derivatives.
  • the polyamino acids consist of amino acid monomer units selected from the group consisting of or consisting of proteinogenic amino acids and their derivatives.
  • the polyamino acids consist of amino acid monomer units selected from the group consisting of or consisting of proteinogenic amino acids and their derivatives.
  • amino acid monomer units selected from the group consisting of or consisting of proteinogenic amino acids and their derivatives.
  • alkylated proteinogen amino acids alkylated proteinogen amino acids
  • acylated proteinogenic amino acids or proteinogenic amino acids with protective groups in particular lipophilic protective groups.
  • Proteinogenic amino acids include alanine, arginine, asparagine, aspartic acid, cysteine, glutamine, glutamic acid, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, thryptophan, tyrosine and valine.
  • the functional group of the respective proteinogenic amino acid which is present in addition to the ⁇ -aminocarboxylic acid unit, is preferably functionalized by a further lipophilic group.
  • the ⁇ -amino unit can also be monoalkylated. There is also the possibility that the proteinogenic amino acid in the carbon chain or the carbon ring carries additional functionalities.
  • the open-pore membranes according to the invention for the electrophoretic separation of carboxylic acids from a liquid mixture whose space-spanning polymeric structural network consists of poly-a-amino acids and preferably homopoly-a-amino acids described herein are the monomer units of poly-a-amino acids selected from the group comprising or consisting of alanine, phenylalanine, valine, isoleucine, leucine, proline, ⁇ -functionalized arginine, O-functionalized serine, asparagine functionalized on the ß-amide moiety, aspartic acid functionalized on the ß-carbonyl moiety, glutamic acid functionalized on the ⁇ -carbonyl moiety, glutamine functionalized functionalized on the ⁇ -carbonyl moiety, histidine functionalized on the imidazole moiety, O-functionalized threonine, thryptophan functionalized on the indole moiety, S-functionalized cysteine, or ⁇ - ⁇ -functionalized
  • the monomer units of the polyamino acids are selected from the group consisting of or consisting of alanine, phenylalanine, valine, isoleucine, leucine, proline, ⁇ , ⁇ ' ⁇ -dialkyl-arginine, ⁇ , ⁇ -dialkyl-arginine, ⁇ -alkyl-arginine , ⁇ -carbamate-functionalized-arginine, ⁇ -carbamate-functionalized, ⁇ ' ⁇ -alkyl-arginine, ⁇ -acyl-arginine, ⁇ -alkyl, ⁇ '-acyl-arginine, ⁇ -alkylsulfonyl-arginine, ⁇ -alkylsulfonyl , ⁇ -alkyl-arginine, ⁇ -amide-alkylated asparagine, aspartic acid- ⁇ -alkylester, -glutamic acid-y-alkylester, ⁇ -amide-alkylated glutamine
  • alkyl or alkylated also means aryl or alkylaryl compounds
  • an "alkyl” radical comprises 1 to 10 carbon atoms (C 1 -C 10 -alkyl).
  • an "acyl” group comprises 1 to 10 carbon atoms (Ci-Cio-acyl).
  • an "aryl” group comprises from 6 to 14 carbon atoms (C6-Ci 4 aryl).
  • an "alkylaryl” radical comprises 7 to 15 carbon atoms (C 7 -C 5 -alkylaryl).
  • the simplest alkylaryl radical is benzyl (-CH 2 Ph).
  • radicals are preferred: alanine, phenylalanine, valine, isoleucine, leucine, proline, ⁇ , ⁇ ' ⁇ -di-Ci-Cio-alkyl-arginine, ⁇ , ⁇ -di-Ci-Cio-alkyl-arginine, ⁇ - Ci-Cio-alkyl-arginine, ⁇ -carbamate-functionalized-arginine, ⁇ -carbamate-functionalized, ⁇ ' ⁇ -Ci-Cio-alkyl-arginine, ⁇ -Ci-Cio-acyl-arginine, ⁇ -Ci-Cio Alkyl, ⁇ ' ⁇ -Ci-Cio-acyl-arginine, ⁇ -Ci-Cio-alkylsulfonyl-arginine, ⁇ -Ci-Cio-alkylsulfonyl, N * -Ci-Cio-alkyl
  • the amino acids are selected from the group consisting of or consisting of phenylalanine, valine, isoleucine, leucine, proline, ⁇ , ⁇ '-dialkyl-arginine, ⁇ , ⁇ -dialkyl-arginine, ⁇ -alkyl-arginine, ⁇ -carbamate - functionalized-arginine, N-carbamate-functionalized, N'-alkyl-arginine, ⁇ -acyl-arginine, ⁇ -alkyl, ⁇ ' ⁇ -acyl-arginine, ⁇ -alkylsulfonyl-arginine, ⁇ -alkylsulfonyl, N * -alkyl -Arginine, y-alkyl glutamate, ⁇ - ⁇ -alkyl-lysine, ⁇ - ⁇ , ⁇ -dialkyl-lysine, ⁇ - ⁇ -acyl-lysine, ⁇ - ⁇ - ⁇ -acyl-lysine, ⁇ - ⁇
  • amino acids are selected from the group comprising or consisting of phenylalanine, ⁇ -Boc-arginine, ⁇ -Cbz-arginine, ⁇ -Fmoc-arginine glutamic acid-Y-benzyl ester.
  • another particularly preferred embodiment of the underlying invention is an open-pore membrane for the electrophoretic separation of carboxylic acids from a liquid mixture comprising or consisting of:
  • the space-spanning polymeric structural network consists of or comprises polyamino acids
  • the polyamino acids consist of amino acid monomer units, alanine, phenylalanine, valine, isoleucine, leucine, proline, ⁇ -functionalized arginine, O-functionalized serine, asparagine functionalized on the ⁇ -amide moiety
  • Aspartic acid functionalizes at the ⁇ -carbonyl moiety
  • glutamic acid functionalizes at the ⁇ -carbonyl unit
  • glutamine functionalizes at the ⁇ -carbonyl unit
  • histidine functionalizes at the imidazole unit
  • O-functionalized threonine thryptophan functionalizes at the indole unit
  • S-functionalized cysteine or ⁇ - ⁇ -functionalized lysine S-functionalized cysteine or ⁇ - ⁇ -functionalized lysine.
  • the monomer units of the polyamino acids are selected from the group consisting of or consisting of alanine, phenylalanine, valine, isoleucine, leucine, proline, ⁇ , ⁇ ' ⁇ -dialkyl-arginine, ⁇ , ⁇ -dialkyl-arginine, ⁇ -alkyl-arginine , ⁇ -carbamate-functionalized-arginine, N-carbamate-functionalized, N'-alkyl-arginine, ⁇ -acyl-arginine, ⁇ -alkyl, ⁇ '-acyl-arginine, ⁇ -alkylsulfonyl-arginine, ⁇ -alkylsulfonyl, ⁇ -alkyl-arginine, ⁇ -amide-alkylated asparagine, aspartic acid- ⁇ -alkyl ester, glutamic acid-Y-alkyl ester, ⁇ -amide-alkylated glutamine, imidazo
  • a particular preferred embodiment of the present invention is a process for the preparation of an open-celled membrane for the electrophoretic separation of carboxylic acids from a liquid mixture, comprising the steps: a) providing an open-pore carrier membrane with pores having a minimum diameter of 50 nm to 500 ⁇ m and a maximum diameter of 1 ⁇ m to 3 mm,
  • polymerizable monomers or the units of the polymerizable oligomers are selected from the group consisting of or consisting of alanine, phenylalanine, valine, isoleucine, leucine, proline, ⁇ -functionalized arginine, O-functionalized serine, asparagine functionalized on the ⁇ -amide unit, Aspartic acid functionalized on the ⁇ -carbonyl moiety, glutamic acid functionalized on the ⁇ -carbonyl unit, glutamine functionalized on the ⁇ -carbonyl unit, histidine functionalized on the imidazole moiety, O-functionalized threonine, thryptophan functionalized on the indole moiety, S-functionalized cysteine or ⁇ - ⁇ - functionalized lysine.
  • the monomer units of the polyamino acids are selected from the group consisting of or consisting of phenylalanine, valine, isoleucine, leucine, proline, ⁇ , ⁇ '-dialkyl-arginine, ⁇ , ⁇ -dialkyl-arginine, ⁇ -alkyl-arginine, ⁇ Carbamate-functionalized arginine, N-carbamate-functionalized, N'-alkyl-arginine, ⁇ -acyl-arginine, ⁇ -alkyl, ⁇ ' ⁇ -acyl-arginine, ⁇ -alkylsulfonyl-arginine, ⁇ -alkylsulfonyl, ⁇ - Alkyl arginine, ⁇ -amide alkylated asparagine, aspartic acid ⁇ -alkyl ester, ⁇ -alkyl glutamate, ⁇ -amide-alkylated glutamine, imidazole-alkylated histidine, O
  • an open-pored membrane is obtainable or obtained by the process just mentioned.
  • monomers of ⁇ -amino acid N-carboxyanhydrides Particularly preferred is phenylalanine NCA as a reactive monomer.
  • di-, tri- or polypeptides having at least one reactive group which allows polymerization Also referred to herein as "reactive monomers” are di-, tri- or oligomers, as well as copolymers or block polymers which have one or more reactive groups which enable or permit polymerization with other reactive monomers Copolymers, such as styrene.
  • the polymerization reactions of the invention can be prepared with reactive monomers or alone or together from / with reactive oligomers.
  • oligomer is meant herein a molecule consisting of 2, 3 or more like or similar molecular moieties covalently bonded together.
  • the oligomers of the invention preferably have up to 500 subunits, more preferably up to 250, and more preferably up to 100 subunits.
  • the molecular subunits of the oligomers of the invention preferably consist of the same compounds as the reactive monomers described herein.
  • polypeptides consisting of 2, 3 or more identical or different amino acids linearly linked in the form of a chain or in cyclic formation and also falling within the term oligomer as used herein.
  • the reactive oligomers have one or more reactive centers which allow a nucleophilic or free-radical reaction, preferably these consist of one or more of the compounds listed herein.
  • the reactive oligomers can be polymerized by the same methods as the reactive monomers.
  • the membranes according to the invention are also resistant to fouling by compounds which, due to their physico-chemical properties and their dimensions, can enter and prove the membranes according to the invention.
  • Another very advantageous effect, which is accomplished with the membranes according to the invention, is a very good biocompatibility.
  • contact with biological fluids only leads to a small to barely measurable adhesion of biomolecules.
  • no attachment of living cells was observed.
  • This also leads to an inhibition of otherwise common fouling processes that in separation membranes that are used in biological fluids occur.
  • the anti-fouling effect is assisted by separating the carboxylic acids without pressurizing the donor medium.
  • the surfaces of the membranes of the invention also have a very good biocompatibility and hemocompatibility.
  • the membranes of the invention are also bio- or hemocompatible.
  • an open-pore membrane having a spatially tension-spanning polymeric structural network or its preparation the subunits preferably being> 25% by weight, more preferably> 50% by weight, more preferably> 75% by weight and particularly preferably> 90% by weight of phenylalanine and / or phenylalanine derivatives are constructed.
  • Preferred is a process for the production of bio- and hemocompatible membranes.
  • the process for producing an open-pore biocompatible and hemocompatible membrane for the electrophoretic separation of carboxylic acids from a liquid mixture comprises the steps:
  • an open cell membrane for electrophoretic separation of carboxylic acids which are bio- and hemocompatible
  • Another preferred embodiment of the present invention is an open-pore biocompatible and hemocompatible membrane for the electrophoretic separation of carboxylic acids from a liquid mixture consisting of:
  • the process for producing an open-pore membrane for the electrophoretic separation of carboxylic acids from a liquid mixture comprises the steps:
  • the mono- and / or oligomer solution contains biomonomers and / or biooligomers.
  • membranes which were polymerized with polyphenylalanine or benzylglutamate monomers by a process of the present invention had no structural changes by electron microscopy when placed in THF or hexane for 3 weeks.
  • Preferred is a process for the preparation of solvent resistant membranes.
  • the mono- and / or oligomeric compounds used to make the nanocavity polymer structures may have pendant functional groups.
  • the functional side groups may be polar or apolar and / or reactive and / or ionic compounds contain.
  • apolar groups are aliphatic or cyclic hydrocarbons.
  • polar side groups are alcohols or carboxylic acids.
  • reactive side groups are amines, thiols, olefins, alkynes, aldehydes.
  • these pendant functional groups are protected by protecting groups known in the art during the polymerization reaction.
  • the protecting groups are cleaved off after the polymerization reaction and removed from the membrane by suitable means.
  • the membranes are liberated from residual residues of monomers and / or catalysts and / or by-products by flushing the membranes with a suitable sequence of solvents.
  • Preference is given to a process in which residues of monomers and / or catalysts and / or by-products present in stage d) are removed from the membrane.
  • the polymers according to the invention which form nanocavity polymer networks are biopolymers. These include physiological compounds such as amino acids, carboxylic acids, polysaccharides, nucleic acids, polyphenols, phenylpropane derivatives, saccharides, and their derivatives. Particularly preferred are phenylalanine, lysine, arginine and benzylglutamate.
  • Preferred carboxylic acids are stearic acid, oleic acid, linoleic acid and linolenic acid.
  • Preferred is a process for the preparation of nanocavitrich polymer structures of polyphenylalanine.
  • a preferred embodiment of the present invention relates to methods for surface functionalization of the nanocavity polymer structures with compounds that are bifunctional lipophilic and cationic.
  • the coating consists of amphiphilic molecules having a positively charged group and having a lipophilic moiety, such as a longer alkyl moiety.
  • Suitable molecules for surface functionalization are therefore in particular tetraalkylammonium compounds or alkylated imidazole compounds having at least one alkyl radical or a longer carbon chain, which may also contain aromatics or double bonds or heteroatoms, and the positively charged nitrogen atom, so that lipophilic and cationic properties are present in one molecule.
  • Preferred compounds are Tetradecyltrimethylammonium oxalate, Denatoniumbenzoat or tetramethyl-2-methylene-1 H-imidazole.
  • An alternative is to use two different molecules, one having the cationic properties and the other the lipophilic properties, such as ammonium polyols or a trimethylpropylammonium group having cationic properties and a dodecyl moiety having the lipophilic properties.
  • stage d2 Preference is given to a process in which the surface functionalization of the polymer structures, obtainable from stage c), with amphiphilic compounds takes place in stage d2).
  • step d2) functionalizing the surface of the space-spanning polymeric structural network from step c) with at least one amphiphilic one
  • the polymerization of mono- / oligomers takes place in a space-providing supporting fabric.
  • the supporting tissue is preferably an open-pored carrier membrane.
  • "Spontaneous" in this context means that the open-pore carrier membrane is porous and open-pored and that the pores, channels or slots have a diameter between 10nm to 500 ⁇ , preferably between 20nm to 500 ⁇ , more preferably between 30nm to 500 ⁇ , more preferably between 50nm up to 500 ⁇ m, more preferably between 10 nm to 300 ⁇ m, more preferably between 30 to 300 ⁇ m, more preferably between 40 nm to 300 ⁇ m, more preferably between 50 nm to 300 ⁇ m, more preferably between 100 nm and 10 ⁇ m and most preferably between 200 nm and 5 ⁇ have.
  • the space-giving open-pore carrier membrane has a large specific surface or large inner surface, the space limiting and shaping is for the nanocavitation polymer structures, which abut the inner surfaces, or with which they are connected.
  • the space-giving open-pore carrier membrane has open cavities in the form of open, continuous pores, channels or slots and is therefore not only able to absorb substances and molecules into its open cavities, but also viscous solutions with a solids concentration of 1 mmol / L to 3 mol / L.
  • the open-pore carrier membrane is also characterized by the fact that it has a high mechanical stability. The open cavities remain stable in external pressure effects in shape and in particular do not coincide.
  • Suitable open cell backing fabrics for coating can be any durable membranes, fabrics or materials having a preferred open porosity of> 15%, more preferably> 25%, more preferably> 50%, even more preferably> 70% and most preferably> 80%.
  • Suitable materials are both organic and inorganic materials, provided they are resistant to the solvent used for the solution of monomers and aqueous media with which they are brought into contact in an application.
  • Suitable organic materials include natural and synthetic polymers, in particular cellulose and cellulose derivatives, for example cellulose acetates, melamines, polyethylene, polypropylene, PMMA, polycarbonate, polyurethane, Nafion, polyethylene, terephthalate (PET) or polysulfones.
  • cellulose and cellulose derivatives for example cellulose acetates, melamines, polyethylene, polypropylene, PMMA, polycarbonate, polyurethane, Nafion, polyethylene, terephthalate (PET) or polysulfones.
  • Polymeric materials may be in the form of fibers, fabrics or foams, and may form a structural network in any arrangement. Particularly preferred are hollow chamber fibers. Furthermore, polymer membranes are suitable, which were first prepared as a closed film and then perforated mechanically or chemically.
  • nanoscale polymer structures are also suitable in which, after an electron bombardment, channels which pass through the membrane are produced by chemical etching along the polymer dressing dissolved by the electron bombardment
  • films of polymers which are porous by means of multidimensional warping are suitable Particularly suitable for this purpose is PTFE and also suitable are films made of block copolymers in which polymer components are dissolved by physical or chemical methods after production, whereby the films become porous which may also already contain chemical bonding groups, so that a surface functionalization for the inventive production of space-filling or space-spanning polymers is no longer required.
  • the nanoscale polymer structures are prepared by applying films or strips to the monomer solution and stacking them in multiple layers.
  • the films serve as support framework, the composite can be sliced after the polymerization.
  • the transport of carboxylic acids is not carried out by the carrier film, but along this through the space-filling or space-spanning polymer structures.
  • different geometries of a separation medium can be produced. So rings or tubes can be made by cutting.
  • strips can be produced which are superimposed and joined together to form a solid composite.
  • the carrier material consists of carbon fibers. These have the advantage of a high chemical and thermal resistance and a very good mechanical strength. Carbon fibers can be made in thin strips or fibers and can be z. B. process into tissues.
  • Suitable inorganic materials preferably include ceramic or metallic materials such as, for example, alumina, aluminum, titanium oxide, titanium, tantalum, zirconium, zirconium oxide, zeolites or glass.
  • Suitable ceramic membranes can be produced from a pressing or sintering of particles, which are then thermally treated, whereby a stable composite is formed. It may be necessary to use organic or inorganic additives which are physically or chemically wholly or partly discharged or degraded after or during the production of the membrane. Ceramic membranes can also be obtained by a melt of particles. This method is particularly suitable for silicon compounds.
  • fiber textures can also be produced from inorganic materials. These can be put together to fabric associations, z. B. as a glass fiber fabric.
  • the voids of suitable porous materials may have any configuration as long as they are interconnected in plurality and allow the passage of a liquid medium through the material.
  • the gap dimensions are preferably for minimum diameters between 10nm to ⁇ ⁇ , more preferably between 100nm and 10 ⁇ and more preferably between 200nm and 1 ⁇ .
  • maximum diameters of the gaps are between 1 ⁇ m and 3 mm, more preferably between 10 ⁇ m and 1 mm in diameter, and more preferably between 10 ⁇ m and ⁇ m.
  • the length of the connections between the two outer sides is preferably between 5 ⁇ and 10mm, more preferably between 50 ⁇ and 3mm and more preferably between ⁇ ⁇ and 1 mm.
  • the structure or structure of the space-giving supporting tissue, resp. the open-pore carrier membrane is arbitrary. It may be a layered structure of fibers or fabrics or consist of a sintered material or of a cast or compressed continuously or discontinuously related material.
  • the thickness of the carrier material, resp. the open-pore carrier membrane is preferably between 5 ⁇ and 10mm, more preferably between 50 ⁇ and 3mm and more preferably between ⁇ ⁇ and 1 mm.
  • the outer shape of the space-giving support structure can have any desired geometry, preferably a flat design and a tubular shape.
  • the space-giving open-pore carrier membrane is a hollow fiber capillary.
  • the space-giving open-pore carrier membrane of step a) consists of a porous, free-carrying membrane, fabrics or textures and porous materials which are present in a composite structure.
  • Preferred is a method in which the space-giving open-pore carrier membrane of stage a) consists of inorganic and / or organic compounds.
  • the space-giving open-pore carrier membrane of stage a) has the form of planar membranes, tubes or hollow-chamber capillaries.
  • Open-cell membrane for the electrophoretic separation of carboxylic acids from a liquid mixture consisting of:
  • the open-celled support membrane consists of a porous, free-carrying membrane, a woven fabric or textures, or porous materials that are in a composite structure.
  • the nanocavitates Polymer structures are space-filling or space-spanning as well as a full-surface composite with the inner surfaces of the spatial structure fabric is achieved. Therefore, it is advantageous to achieve a full-surface occupancy / binding of the inner space-defining boundary surfaces of the open-pore carrier membrane with the polymer structures according to the invention.
  • reaction-forming groups are already present on the spatial support structure, these can be applied to the inner surfaces of the support material using techniques known in the art. Suitable compounds which should be available on the surface for high-density reaction formation have functional groups, such as. As amines, epoxides, thiols, alkyl halides or carboxyl groups.
  • the surfaces of the open-pore carrier membrane are to be prepared with suitable measures from the prior art.
  • the binding can be chemosorptive or physiosorptive.
  • Preferred compounds with which a full-surface covering of the surfaces of the open-pore carrier membrane can be effected by means of a covalent bond are, for example, aminosilanes, such as (3-aminopropyl) triethoxysilane (APTS) or and (3-trimethoxysilylpropyl) diethylenetriamine (TAPTES).
  • Examples of compounds with which a physiosorptive coating of the surfaces is possible for example, dopamine, polyethyleneimine, polyvinylamine, polyvinylimidazole, polyvinylpyridine, polyvinylpyrrolidone, polylysine or polyacrylic acid.
  • step a1 Preference is given to a process in which the surface treatment in step a1) is carried out with a starter for free-radical or nucleophilic polymerization.
  • residues of solvent and / or by-products of the reaction may remain in the open-celled membrane produced according to the invention. These residues can be removed from the membrane in a separate cleaning step, eg by rinsing or washing. It may be necessary to clean the membranes with various solvents and in a sequential sequence, preferred are methanol, H2O2 or THF. Furthermore, it may be necessary residues of Solvents, including, for example, the insertion in a vacuum drying cabinet or heating are suitable methods.
  • the process for preparing an open-cell membrane for the electrophoretic separation of carboxylic acids from a liquid mixture comprising the steps:
  • step d) purifying the membrane from step c) of solvents and / or reaction by-products.
  • the membranes according to the invention are distinguished in particular by different physical properties. These include, in particular, that they are permeable to gases and carboxylic acids.
  • the membranes according to the invention are further characterized by measurable surface properties, such as, for example, a lipophilicity, or a hydrophobicity, or a charge carrier density, which are indicated by the determination of the contact angles for water or a carboxylic acid.
  • the measurement method aims at the wettability of surfaces, measuring the angle between a drop of liquid on a surface and the solid surface.
  • the membranes according to the invention exhibited water contact angles of preferably> 70 °, more preferably of> 100 ° and more preferably of> 120 °, both on the outer surfaces and on the surfaces of breaklines.
  • the membranes of the invention further preferably had contact angles for oleic acid on outer and inner surfaces, which are preferably ⁇ 30 °, more preferably ⁇ 20 ° and more preferably ⁇ 10 °.
  • Further preferred is a method according to the invention described herein, wherein the functionalized or coated surfaces of the pores, channels or slots have a contact angle for water of> 70 °, preferably> 100 °, particularly preferably> 120 ° and a contact angle for the carboxylic acid to be separated of ⁇ 30 ° have.
  • an open-cell membrane according to the invention for the electrophoretic separation of carboxylic acids from a liquid mixture described herein characterized in that the contact angle for water on the surface of the inner pores, channels or slits of the open-pore membrane is> 70 °.
  • the contact angle for water on the surface of the inner pores, channels or slots of the open-pore membrane is> 70 °.
  • the membrane is lipophilic and / or the space-spanning polymeric structural network is lipophilic.
  • the membranes of the invention are characterized in that they absorb carboxylic acids against a hydrostatic gradient.
  • This gradient is preferably> 10 mm H 2 O, more preferably> 30 mm H 2 O and more preferably> 60 mm H 2 O. This can be determined by adding to closed and completely filled with a carboxylic acid container with a membrane lying therein, a corresponding negative pressure is applied.
  • the membranes of the invention are resistant to most organic solvents. Preference is given to a resistance to toluene, ethanol, methanol, xylene, acetonitrile, THF, dimethylformamide, acetone, methyl ester, ethyl ester, propylene carbonate, NMP, DMSO, dichloromethane, chloroform, dichloroethane, perchlorethylene, trichlorethylene, carbon tetrachloride, chlorobenzene, benzyl alcohol, glycols, glycol ethers , Isopropyl acetate, butanone, methyl isobutyl ketone, methoxypropyl acetate, butyl acetate, tetrahydrofuran, diethyl ether, diisopropyl ether, MTBE, butanol, isopropanol, trifluoroethanol, hexafluoroisopropanol.
  • Preferred is a process for the preparation of membranes with nanocavity polymer structures that are resistant to organic solvents.
  • the membrane according to the invention has a high biocompatibility. High compatibility is ensured in particular by a low activation of the coagulation and complement system occurs upon contact with the membrane of the invention. Another aspect of high biocompatibility is due to low adsorption of proteins and living cells.
  • Preferred is a process for the preparation of membranes with nanocavity polymer structures that are biocompatible.
  • So z For example, it can be shown that a selectivity for fatty acids to fatty alcohols or fatty sulfates having an equal number of carbon atoms, with a selectivity index CIOH based on fatty alcohols of 400-800 and a selectivity index ⁇ based on fatty sulfates of 160, when using an aqueous Medium (Example 3).
  • the membranes of the invention also a selectivity to other organic compounds having negative charge groups is found. Proteins usually have one under physiological conditions negative surface charge and can be transported electrophoretically. With uncoated porous membranes, the achievable transport amount of carboxylic acids and proteins through the membrane is proportional to each other. In diffusion and electrodialysis, which were carried out with the membranes of the invention, there was virtually no transport of proteins through the membrane, whereas compared to uncoated membranes, the transport rate for carboxylic acids was increased (Example 3). But also small anionic compounds were retained, such as chloride and sulfate ions. Thus, the membranes according to the invention ensure a high selectivity for the separation of carboxylic acids from aqueous media or aqueous mixtures of substances.
  • a solubilization of carboxylic acids is carried out prior to the separation of the carboxylic and / or fatty acids.
  • Effective solubilization techniques of carboxylic and / or fatty acids are described in the literature.
  • alkali formers such as NaOH
  • cationic water-soluble compounds such as guadinine or amidine-bearing compounds or quaternary ammonium compounds.
  • solutions or emulsions containing carboxylic acids which can be separated include industrial oils, vegetable oils, dairy products, phospholipid and glycolipid purification fluids, fuel purification, biodiesel production, biomass separation, biotechnological process fluids, blood, blood plasma, process fluids, effluents , pharmaceutical synthesis mixtures and liquids of chemical analysis and wastewater. Since the separation membranes according to the invention are not based on the principle of a molecular size selection and the effective channel diameters are usually much larger than the molecules of the substance mixture to be scavenged, it is preferable to apply no or only a small transmembrane pressure gradient. To achieve this, it may be necessary to monitor the pressure at the donor and acceptor side and to provide pressure equalization.
  • a preferred embodiment of the membranes of the invention relates to a separation process in which no elevated pressure is applied to the liquid mixture containing at least one carboxylic acid for the passage of the at least one carboxylic acid through the membrane.
  • a hydrostatic pressure is applied to the donor chamber. This is particularly advantageous to counteract any existing EOF.
  • the transport of carboxylic acids through the membranes according to the invention is carried out by a diffusion due to a concentration gradient or a thermal gradient and / or electro-kinetically by an electrical gradient.
  • An electrical gradient is preferably produced by the application of a DC voltage between the donor and acceptor sides.
  • a voltage of between 1 ⁇ V and 500V, more preferably between 100mV and 100V, and more preferably between 1V and 50V is preferred.
  • a current strength between 0.01 mA and 5 A, more preferably between 0.1 mA and 0, is preferred. 5A and more preferably between 1 mA and 0.5A.
  • a preferred method for carrying out the diffusion dialysis are cross-flow methods, using a suitable acceptor medium, in which a recording of the carboxylic acids to be separated can take place.
  • a particularly preferred embodiment relates to a method according to the invention, wherein an electrochemical gradient is applied from the inlet side to the outlet side of the membrane for separating the at least one carboxylic acid.
  • the invention therefore also relates to a process for the continuous separation of carboxylic acids from liquid mixtures, comprising the steps:
  • the separation has a selectivity index of> 4 over the alcohol obtainable by reduction of the corresponding carboxylic acid.
  • Another aspect of the invention relates to methods that can be optionally used to counteract the generation of an electro-osmotic flow that can occur at high electrical voltages.
  • the presence of dissolved polycationic compounds in the acceptor medium, in which the transported carboxylic acids are taken up makes this possible. This can lead to the formation of viscous layers come from the membrane surface, which contain carboxylic acids derived from the donor medium. These layers are permeable to carboxylic acids.
  • Polycationic compounds are described in greater detail using the example of polyethyleneimine in the section Post-polymerization functionalization.
  • the concentration of the polycationic compounds in the acceptor medium is preferably between 0.1 ⁇ / ⁇ to 2mol / l, more preferably between 1 ⁇ / ⁇ and 0.1 mol / l and more preferably between 10 ⁇ / ⁇ and 50 mmol / l.
  • Preference is given to a method in which an inhibition of the electro-osmotic flow during electrodialysis is achieved by the use of polycationic compounds in the acceptor medium.
  • Carboxylic acids are a very common class of compounds extracted from organic substrates in many industrial sectors.
  • the carboxyl groups essentially cause the chemical but also the physicochemical properties of the carboxylic acids. Lipophilic carbon compounds are thereby given amphiphilic properties.
  • the solubility in aqueous or organic mixtures is decisively changed compared to a same molecular structure without a carboxyl group. As a rule, this also results in a reduced extractability of these molecules from a mixture of substances, especially if they are present in emulsions.
  • Many carboxylic acids are important building and building materials in various industries, which they often have to be present in a high degree of purity. The extraction takes place by digestion of organic organic products and fossil materials or by a substance synthesis.
  • the membranes of the invention are also bio- and hemocompatible, so that they can be used in biological solutions or in blood and blood products. It is particularly advantageous that the membranes of the invention can be prepared with different support materials that are available from the prior art. Thus, different designs are easy to implement and the different requirements for different applications can be guaranteed.
  • open pore refers to continuous pores extending from one side of the membrane to the other side. This means that there is an association of individual pores, which communicate with one another via at least one pore entrance and at least one pore outlet and the combination also has at least one pore entrance on one side of the membrane and at least one pore exit on the other side of the membrane. They thus establish a connection from one side of the membrane to the other and allow a mass transport through the membrane. In other words, one side of the membrane may be in fluid communication with the other side of the membrane. Open pore therefore does not mean that a pore has only one opening on one side of the membrane. Open pore therefore does not mean that a pore has only one opening (dead end pore) or two or more openings on only one side of the membrane. Open pores include pores, channels, slots and any other forms of continuous connections between the two membrane sides.
  • Open-poredness also means porosity.
  • the total porosity of a substance is made up of the sum of the voids that are related to each other and to the environment (open porosity, useful porosity) and the unconnected voids (closed or dead-end porosity).
  • the porosity here means only the open porosity, ie the Nutzporostician, which can be used for mass transfer.
  • the closed porosity is unimportant to the present invention.
  • the open-pore membrane is therefore preferably ideally open-pored, ie preferably has only useful porosity.
  • High open porosity refers to open-pore material or, ideally, a honeycomb structure, while pure closed-pore character is referred to as foam.
  • the open-pore membrane as well as the space-spanning polymeric structural network is not made of foam or a foam-like structure.
  • open-pored carrier membrane means space and structural porous support webs or solids having continuous open connections between both (or more) outsides, ie, no foam or foamy formation
  • structuring refers to the outer shape and geometry of the open-pore carrier membrane.
  • the open connections can be plane-parallel to completely irregular
  • the contours may have any dimensions, preferably, minimum diameters of the internal cavities (pores) are between 10 nm and 500 ⁇ m, more preferably wall contours or progression shapes of the inner boundary surfaces which bound the cavities (pores) preferably between 10nm to 400 ⁇ , more preferably between 10nm to 300 ⁇ , more preferably between 10nm to 200 ⁇ , more preferably between 10nm to ⁇ ⁇ , more preferably between 20nm to ⁇ ⁇ , more preferably between 30nm to ⁇ ⁇ , more preferably
  • the spatial structures of the open-pore carrier membrane are not nanocavitary.
  • the maximum diameter of the inner cavities of the support membrane between 1 and 3mm ⁇ , more preferably between 10 ⁇ diameter and 1 mm and more preferably between 10 ⁇ and ⁇ ⁇ .
  • minimum diameter of the internal cavities (pores) refers to the minimum distance that the plane-parallel or completely irregular wall contours or progress forms of the inner boundary surfaces of the support membrane, which delimit the cavities (pores)
  • Maximum diameter is the largest distance between the plano-parallel or completely irregular wall contours or progress forms of the inner boundary surface.
  • the thickness of the support membrane and / or the length of the open connections between the outer sides is preferably between 5 ⁇ and 10mm, more preferably between 50 ⁇ and 3mm and more preferably between ⁇ ⁇ and 1 mm.
  • the structure or structure of the space-giving open-pore carrier membrane are arbitrary. It may be a layered structure of fibers or fabrics or consist of a sintered or cast or pressed, continuous or discontinuous contiguous material.
  • the material of the space-giving open-pored carrier membrane can have any external or internal surface finish (eg smooth or rough) and consist of substances or compounds including, among others, natural polymers such as cellulose, synthetic polymers such as polyethylene glycol, and inorganic compounds such as alumina or silica.
  • polymeric structural network refers to the entirety of the polymer structures in the pores of the support membrane.
  • the polymer structures may be in various configurations and categorized, preferably as filament, ribbon, mesh, sheet or nodular, but other geometries and combinations thereof are possible.
  • the polymer structures are connected to each other covalently and / or electrostatically and are preferably connected physiologically and / or chemosorptively to the interfaces of the open-pore carrier membrane.
  • nano-cavitation spaces are also referred to herein as “nanocavity spatial structures” because they may have different geometric shapes, being round, polygonal or slot-shaped.
  • Nanonocavitary means the minimum distance between two nanometer-scale polymeric interfaces between 0 , 01 to 1000 nm, preferably between 0.01 and 100 nm, more preferably between 0.1 and 50 nm and more preferably between 1 and 10 nm
  • the maximum distance between two polymeric boundary surfaces is preferably between 1 and 500 nm, more preferably between 5 and 10 nm 200nm and more preferably between 10 and 100nm
  • the nanocavity spatial structures are interconnected and can be traversed by a gas or carboxylic acids Nanocavitation the polymer structures form nanocavitary gap spaces, which interconnected and open are. Thus, there is still an open connection between the outer boundary surfaces of the membrane.
  • the support membrane remains open-pore with ideally only useful porosity, because the space-spanning polymeric structure network (definition see below) is also porous and does not adversely affect the useful porosity of the support membrane.
  • the pores in the carrier membrane remain open and are not closed by the space-spanning polymeric structure network.
  • the length of a transmembrane path through the interconnected or not directly interconnected nanocavity spatial structures between 1 ⁇ and 30mm, more preferably between 5 ⁇ and 3mm and more preferably between 50 ⁇ and 1 mm.
  • open-pore space-spanning polymeric structure network is nanocavitary and the continuous compounds have a maximum diameter between 1 nm and 500 nm.
  • space-spanning is to be understood as meaning that the polymer structures, which are, for example, in a thread-like, band-shaped or net-like configuration, extend, for example through the cavity of the pores of the carrier membrane, from one boundary surface of one cavity toward another boundary surface.
  • room-spanning suggests, the polymeric structure network extends into the space of the pores in a naturally random and arbitrary manner.
  • the polymer structures and the polymeric structural network do not close the pores.
  • the polymer structures and the polymeric structural network do not provide a coating on the surfaces of the pores in the support membrane which would ultimately only lead to a reduction in the maximum and minimum pore diameters.
  • the Polymer structures and the polymeric structural network are therefore not a surface modification of the pore surfaces, but are three-dimensional structures that use the interior of the pores, ie extend in the interior of the pores and partially abut the surfaces of the pores, these touch or are bound to them.
  • the space-spanning polymeric structure network expands in the pores of the support membrane in a three-dimensional direction. It is open-pored. It is preferably nanocavitary. It is preferably produced by multifocal
  • Polymer growth It may partially cover, adhere to or touch the surfaces of the pores, but is not a pure surface coating. It preferably expands in the available space of the pores.
  • the "polymeric structure network” is composed of the entirety of the polymer structures already defined above, which extend in the cavities of the support membrane, and thus occupy the space within the space-giving, open-pore support membrane in three dimensions.
  • the “polymeric structure network” of polymers is built up.
  • the structure network should have a high open porosity and ideally have only useful porosity.
  • the term “room-spanning polymer structure network” therefore refers to the entirety of the polymer structures that are located in the pores of the support membrane and thus occupy the space within the space-giving, open-pore support membrane in three dimensions ) produced by the polymer structures allow fluid communication of the outer interfaces of the membrane through the open, interconnected nanocavity fractures.
  • the polymeric structural network is not a pure surface layer coating wherein the space-spanning polymeric structural network may cover and / or adhere to the surfaces of the support membrane pores.
  • the term is also not to be understood as meaning a layer structure which extends from the surfaces of the pores into the interior of the pores.
  • a coating of surfaces for example by a polymer, is not a space-spanning polymeric structural network.
  • the room-spanning polymers produced according to the invention are Structural network not to surface coatings, although they cover the surface of the space-giving open-pore carrier membrane, in contact with it or may be directly or indirectly physiologically and / or chemosorptively bound to it.
  • the polymer structures limit the gap or cavities within the open-pore carrier membrane and form the space-spanning polymeric structure network.
  • the term "self-assembly” as used herein refers to the formation of three-dimensional molecular contiguous structures that result from a polymerization reaction.
  • the polymerization can be carried out starting from monomers or oligomers.
  • the polymer growth is multifocal.
  • multifocal polymer growth is understood to mean that the space-spanning polymeric structural network is formed by polymerization in the pores of the support membrane at a plurality of locations within the support membrane and the resulting polymer structures grow together, intertwine and / or bond together ,
  • the space-spanning polymer structure network according to the invention is preferably produced on the basis of a multifocal polymer growth which self-assembles during formation from various structure formations.
  • the selectivity index a refers to the amount of substance of a carboxylic or fatty acid as compared to an organic compound (ref) of comparable molecular weight ( ⁇ 30%), which is not a carboxylic or fatty acid, through a membrane of the invention is transported per unit time by applying an electrical gradient or a concentration gradient.
  • v is the transport speed in mol / s
  • n is the transported amount of substance
  • t is the time.
  • membranes according to the invention which have a selectivity index ⁇ of> 4, preferably of> 6, more preferably of> 8 and most preferably of> 10.
  • the selectivity index aoH between a carboxylic acid and the corresponding alcohol is determined: Preference is given to membranes according to the invention which have a selectivity index CIOH of> 4, preferably of> 6, more preferably of> 8 and most preferably of> 10.
  • the selectivity index characterizes the transport of carboxylic or fatty acids through a separating membrane according to the invention in comparison with a hydrophilic molecule (Kow ⁇ 1) with a comparable molecular weight (+/- 30%).
  • the selectivity index ⁇ characterizes the transport of carboxylic or fatty acids through a separating membrane according to the invention in comparison to a hydrophobic molecule (K 0 w> 1) with a comparable molecular weight (+/- 30%), which carries no carboxyl group.
  • Kow refers to the distribution quotient of a compound in a mixture of octanol and water.
  • membranes according to the invention which have a selectivity index of> 8, more preferably of> 12 and most preferably of> 20.
  • membranes according to the invention which have a selectivity index ⁇ of> 8, more preferably of> 10 and most preferably of> 15.
  • carboxylic acids includes organic molecules having as a common feature one or more carboxyl group (s) (-COOH).
  • the most common forms of carboxylic acids include compounds of the general formula R-COOH where R is an aliphatic radical CH 3 - (CH 2 ) n-.
  • R is an aliphatic radical CH 3 - (CH 2 ) n-.
  • R is an aliphatic radical CH 3 - (CH 2 ) n-.
  • R is an aliphatic radical CH 3 - (CH 2 ) n-.
  • R is an aliphatic radical CH 3 - (CH 2 ) n-.
  • alkenyl or alkynyl radicals as well as cyclic or heterocyclic carbon radicals may carry a carboxyl group.
  • the term includes compounds having multiple carboxyl groups.
  • Fatty acids are carboxylic acids having at least 4 carbon atoms.
  • PUFA polyunsaturated fatty acids
  • Linoleic acid is a typical member of this group. Some other polyunsaturated fatty acids exhibit a shift in one of their double bonds, which are not separated again by a methylene group and are known as conjugated fatty acids. Some unusual fatty acids do not have the regular structure with one methylene group between two double bonds, but are polyolefins separated by several methylene groups.
  • Representatives of this group are linoleic acid, linolenic acid, arachidonic acid, stearidonic acid, EPA, DPA, DHA and meadklare.
  • the most common polyolefinic acids are octadecatrienoic acids.
  • carboxylic acids include, for. B. the cyclopropanoic acids, such as.
  • the lactobacillic acid (1 1, 12-methylene-octadecanoic)
  • cyclopropanoic acids epoxy acids, eg. B. 9,10-Epoxystearin- and 9,10-epoxy-octadec-12-en- (coronaric) acid.
  • acetylene fatty acids also known as harmony acids, such as tartric acid (6-octadecic acid).
  • hydroxy fatty acids wherein the hydroxyl group may occur at various positions in the carbon chain, which may be saturated or monounsaturated.
  • Examples are ricinoleic acid (12-hydroxy-9-octadecenoic acid), and lesquerolic acid, the C20 homolog of ricinoleic acid (14-hydroxy-1-1-eicosenoic acid).
  • di- or tricarboxylic acids examples of which are adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, brassylic acid and thapsic acid.
  • the fatty acids are carboxylic acids having at least 6 carbon atoms, i. Fatty acids having a carbon chain length of 6 to 30, more preferably having a carbon chain length of 6 to 28, even more preferably having a carbon chain length of 6 to 26, even more preferably having a carbon chain length of 6 to 24, even more preferably having a carbon chain length of 8; 22 and most preferably having a carbon chain length of 10 - 22.
  • a liquid composition having a carbon chain length of 6 to 30, more preferably having a carbon chain length of 6 to 28, even more preferably having a carbon chain length of 6 to 26, even more preferably having a carbon chain length of 6 to 24, even more preferably having a carbon chain length of 8; 22 and most preferably having a carbon chain length of 10 - 22.
  • Liquid mixture means a mixture of at least one solvent and at least one carboxylic acid, preferably at least one fatty acid and at least one other substance which is not a carboxylic acid, wherein the solvent may be at least one organic solvent or water or mixtures of organic solvents or in a mixture of at least one organic solvent and water, therefore, in the embodiments described herein, the liquid mixture preferably comprises at least one organic solvent or water or a mixture of solvents, more preferably water or water having a volume of up to 20 vol % of organic solvents which are preferably miscible with water, such as acetone, THF or ethanol
  • the liquid mixture may be either a solution or an emulsion.
  • liquid mixture in all embodiments disclosed herein may be replaced by the term "aqueous solution of a mixture of substances" wherein the mixture of substances consists of at least one carboxylic acid, preferably at least one fatty acid and at least one further substance , which is not a carboxylic acid.
  • the further substance can be selected from the group comprising or consisting of alcohols such as octadecanol, alkyl sulfates such as octadecyl sulfate, possibly alkylsulfonic acids asulfonates such as octadecanesulfonate, proteins such as albumin, .beta.-thromboglobuhn, glycoproteins such as fibrinogen, fibronectin, lipoproteins, enzymes such as LDH, phospholipids, Glycolipids, dyes, platelets, leukocytes, surfactants, inorganic salts or ions such as sulfates, and thrombin-antithrombin complex.
  • the further substances preferably comprise all substances occurring in the blood or in the blood plasma.
  • liquid mixtures of substances comprising or consisting of at least one fatty acid, arginine and at least one solvent.
  • liquid mixtures in the form of a nanoemulsion comprising or consisting of at least one fatty acid and arginine.
  • Another preferred liquid mixture is whole blood or blood plasma.
  • the viscosity of the liquid mixture should be below 1 10 mPa * s, preferably below 100 mPa * s, more preferably below 90 mPa * s, more preferably below 80 mPa * s, more preferably below 70 mPa * s, more preferably below 60 mPa * s, more preferably below 50 mPa * s, more preferably below 40 mPa * s, more preferably below 30 mPa * s, more preferably below 20 mPa * s, more preferably below 10 mPa * s, even more preferably below 5 mPa * s and most preferably less than 2 mPa * s.
  • surface functionalization for the present invention, the change in the surface properties by introducing chemical radicals, preferably with functional groups, on the surface of the space-limiting structures of the open-pore carrier membrane, both on its outer surface as well as on the surface of the space-giving structures understood.
  • the introduction of chemical residues can be physio- or chemosorptive as well as a combination of both.
  • mono- to multilayers of molecules can be applied to the surfaces of a support structure.
  • Typical compounds for physiosorptive attachments are e.g. Polymers with many different charge groups and amphiphilic molecules, e.g. Phospholipids or carboxylic acids and hydrophilic compounds, such as electrolytes or polyelectrolytes.
  • SAM SAM on various substrates (eg gold, oxides of aluminum, zirconium, titanium or silicon) via reactive groups on the molecules to be bound HS-R (thiols), R-SS-R '(disulfides), RSR (dialky
  • ALD Atomic Layer Deposition
  • CVD Chemical Vapor Deposition
  • PECVD Plasma-Enhanced Chemical Vapor Deposition
  • CVI Chemical Vapor Infiltration
  • Gas separation processes are particularly suitable for applying monolayers of the gas phase compound, but multiple layers and polymerization processes can be achieved. Also known are coatings with silanes and organic molecules. a) Surface pretreatment / activation methods
  • Another method of cleaning and activating the substrate surfaces is the application of radiant energy, for example in the UV range.
  • Plasma processes can be used both for cleaning surfaces and for activating them.
  • Plasma is a complex gas state of matter consisting of free radicals, electrons, ions, photons, etc.
  • Plasma can be formed by continuous electrical discharge in either an inert gas or a reactive gas.
  • plasma can improve the properties of both the porous substance and a polymer film for gas separation.
  • Porous membranes can be subjected to a plasma treatment to achieve the following effects:
  • inert gases such as argon or helium are suitable.
  • a second application is the introduction of functional groups.
  • Plasma treatment with air, oxygen, or water vapor introduces oxygen-containing functional groups on the surface.
  • Nitrogen, ammonia and alkylamine plasma introduce nitrogen-containing functional groups.
  • Ammonia plasma was used to measure the flow and selectivity of UF
  • Polysulfone membranes improve. Nitrogen and oxygen plasma was used to improve the hydrophilicity of polyvinylchloride membranes.
  • Hydrophilization can also be achieved by plasma-induced deposition polymerization including hydrophilic monomers.
  • the plasma is then formed by gaseous organic molecules that polymerize and on the
  • plasma is used to remove polymer structures on one or both outer sides of the membranes produced according to the invention.
  • the production of nanocavityer polymer structures is carried out by in situ polymerization within the spatial structures open-pore carrier membranes.
  • the manner of introducing a solution / suspension with reactive mono- / oligomers into the spatial structures of the open-pore carrier membrane depends inter alia on their viscosity, the dimensions of the spatial structures and the reaction conditions and can therefore vary considerably.
  • the type of introduction of the monomer / oligomer solution can be carried out by impregnation, pouring, inserting the open-pore carrier membrane or by a continuous or discontinuous volume flow of the mono- / oligomer solution, which is passed through the membrane.
  • a preferred embodiment of the present invention is directed to a process for preparing an open cell membrane for the electrophoretic separation of carboxylic acids from a liquid mixture, comprising the steps:
  • a particularly preferred embodiment of the present invention is directed to a process for the preparation of an open-pore membrane for the electrophoretic separation of carboxylic acids from a liquid mixture, comprising the steps:
  • the solution of polymerizable monomers and / or oligomers is introduced into the open-celled support membrane immediately after adding a multifocal polymerization initiator and the polymerization is carried out under static conditions.
  • the introduction of the mono- / oligomer solutions is preferably carried out at a temperature of -10 to 100 ° C, more preferably this is between 0 ° C and 80 ° C and more preferably between 10 ° C and 40 ° C.
  • the polymerization is carried out by a radical or nucleophilic reaction of reactive monomer and / or oligomers.
  • the polymerization process is preferably initiated immediately before, during and / or after the introduction of the mono- / oligomer solution into the open-pore carrier membrane.
  • the polymerization to nanocavitation polymer structures then takes place in situ. It is initiated and / or maintained by a chemical reaction involving compounds located on the surfaces of the open cell support membrane and / or contained in the mono- / oligomer solution.
  • Such compounds include nucleophiles such as amines, amides, alcoholates, hydroxide ions, thiolates, triethylamine, ammonia, pyridines such as 4-dimethylaminopyridine, phosphines, carbenes, such as imidazole 2-ylidenes and imidazolin-2-ylidenes or thiazol-2-ylidenes.
  • nucleophiles such as amines, amides, alcoholates, hydroxide ions, thiolates, triethylamine, ammonia
  • pyridines such as 4-dimethylaminopyridine
  • phosphines such as imidazole 2-ylidenes and imidazolin-2-ylidenes or thiazol-2-ylidenes.
  • Cationic catalysts such as trifluoromethanesulfonic acid and methyl fluoromethanesulfonate
  • bifunctional organocatalysts such as [1- (3,5-bis (trifluoromethyl) phenyl) -3- (2-dimethylannino-cyclohexyl) thiourea] or [1, 5,7-triazabicyclo (4.4 .0) dec-5-ene (TBD).
  • Catalysts such as Grubb's catalyst, metal ions, such as copper, tin, such as tin octanoate (Sn (Oct) 2), aluminum alkoxide AI (OR) 3, titanium alkoxides (Ti (OR) 4), cobalt or nickel, acids, such as ascorbic acid, sulfuric acid or Phosphoric acid, furthermore azo compounds, such as AIBN or peroxides, such as benzoyl peroxide.
  • Initiators of a polymerization reaction are also solvents such as water, DMF, NMP, DMA, NMP, DMSO, tetramethylurea.
  • Polymerization processes that can be used to obtain nanocavity polymer structures include process steps known by the terms “grafting from”, “grafting through”, or “grafting to”.
  • nucleophilic reaction initiation such as atom transfer radical polymerization (ATRP), ring-opening metathesis polymerization (ROMP), anionic or cationic polymerization, and free living radical polymerization, but also radiation induced polymerization, ring-opening olefin metathesis polymerization, reversible addition-fragmentation chain transfer polymerization, nitroxide-mediated polymerization, polycondensation reactions, and iniferter-induced polymerization.
  • ATRP atom transfer radical polymerization
  • RDP ring-opening metathesis polymerization
  • anionic or cationic polymerization anionic or cationic polymerization
  • free living radical polymerization but also radiation induced polymerization, ring-opening olefin metathesis polymerization, reversible addition-fragmentation chain transfer polymerization, nitroxide-mediated polymerization, polycondensation reactions, and iniferter-induced polymerization.
  • Preferred reactive mono- / oligomers are benzyl-L-glutamate-NCA, phenylalanine-NCA, H-Lys (Z) -NCA, alanine-NCA, valine-NCA, or combinations thereof.
  • the reactive mono- / oligomers are introduced into the open-pore carrier membranes in the form of solutions or suspensions having a preferred concentration of between 1 mmol / l and 3 mol / l.
  • the initiation / catalysis of the polymerization reaction leading to nanocavity polymer structures can also be accomplished by or in combination with physical (n) reaction conditions.
  • the polymerization reaction can be carried out at different ambient pressures.
  • An overpressure can be used, for example, with a temperature increase of the substrate. Preference is given to the application of a pressure between 1, 1 bar and 10bar. Further preferred is the installation of a negative pressure between 10 and 900 mbar.
  • the temperature and the ambient pressure of the substrate can be varied during the course of the polymerization.
  • the substrate initially be subjected to an increased pressure and in the course of this is lowered continuously or stepwise.
  • the duration of a pressure which is changed with respect to the ambient temperature and the environment is preferably over 10 minutes to 72 hours, more preferably over 30 minutes and 48 hours and more preferably over 2 and 24 hours.
  • the production according to the invention of nanocavitary polymer structures can also be achieved by a polycondensation of the mono- / oligomers, in the form of a melt, introduced into the spatial structures of the open-pore carrier membrane. Preference is given here to temperatures which are above or above the individual melting point of the monomers used, preferably heating to 40 to 200 ° C., more preferably 80 ° to 140 ° C. and more preferably 90 ° to 140 ° C.
  • Another preferred method for polymerization initiation is exposure of the mono- / oligomer solution impregnated membrane to long or short wavelength radiation. Particularly preferred is the application of microwaves.
  • compounds of reactive mono and / or oligomers are added to the solution which preferably do not react with the mono and / or oligomers and / or influence the polymerization reaction. They serve to stabilize the space of the nanocavitational space structures forming in the course of the multifocal polymerization, in which they are located after polymerization.
  • These preferred apolar and low molecular weight compounds can be rinsed out of the nanocavity pore system after polymerization with suitable solvents. Suitable compounds are i.a.
  • linear or cyclic hydrocarbon compounds or aromatic hydrocarbons such as alcohols, fatty alcohols, fatty acid methyl esters, alkanes, isoprenes, terpenes, alkenes, alkynes, cycloalkanes, cycloalkenes, cycloalkynes, phenols, carboxylic acids or their salts, alkyl carboxylates, fatty alcohols, fatty acids or their salts, Carbonic acid dialkyl esters, ethers, alkylsulfonic acids or their salts, alkyl sulfates, dialkylsulfoxides, dialkylsulfones, amides, carbamates and organic phosphorus compounds.
  • release agent and “compounds used for space stabilization” are used synonymously herein.
  • the purification of the membranes after polymerization is carried out by placing in preferably THF, DMF or DCM.
  • the successful polymerization is achieved by analytical methods, such as contact angle measurement,
  • a particular preferred embodiment of the present invention is a process for the preparation of an open-celled membrane for the electrophoretic separation of carboxylic acids from a liquid mixture, comprising the steps:
  • solution of the polymerisable monomers and / or oligomers is at least one amino acid and / or at least one oligopeptide in a solvent.
  • the solution of the polymerisable monomers and / or oligomers is at least one amino acid and / or at least one oligopeptide in an organic solvent.
  • a particularly particular preferred embodiment of the present invention is a process for the preparation of an open-celled membrane for the electrophoretic separation of carboxylic acids from a liquid mixture, comprising the steps:
  • step b) introducing a solution of polymerisable monomers and / or oligomers into the pores of the open-pore carrier membrane from step a), c) polymerisation of the polymerisable monomers or oligomers in the pores of the open-pored carrier membrane to form a space-spanning polymer structure network in the pores of the open-pored carrier membrane,
  • solution of the polymerisable monomers and / or oligomers is at least one amino acid and / or at least one oligopeptide in an organic solvent.
  • functional groups A / compounds can be applied to the polymer structures and / or introduced into the cavities and / or brought to / on one or both outer surfaces of the membranes.
  • the preferred compounds are covalently bonded to the nanocavity polymer structures.
  • Preferred compounds which allow cationic or polycationic surface properties by physisorption or chemisorption are amines. These include u.a.
  • aliphatic and cycloaliphatic amines preferably methylamine, ethylamine, propylamine, butylamine, pentylamine, hexylamine, heptylamine, octylamine, nonylamine, decylamine, undecylamine, dodecylamine, tridecylamine, stearylamine, palmitylamine, 2-ethylhexylamine, isononylamine, hexamethyleneimine, dimethylamine, diethylamine, dipropylamine, Dibutylamine, dihexylamine, ditridecylamine, N-methylbutylamine, N-ethylbutylamine; alicyclic amines, preferably cyclopentylamine, cyclohexylamine, N-methylcyclohexylamine, N-ethylcyclohexylamine, dicyclohexylamine; Diamines,
  • Aminopropyl piperazine N, N-bis (aminopropyl) methylamine, N, N-bis (aminopropyl) ethylamine, N, N-bis (aminopropyl) hexylamine, N, N-bis (aminopropyl) octylamine, N, N-dimethyldipropylenetriamine, N, N-bis (3-dimethylaminopropyl) amine, N, N'-1, 2-ethanediylbis (1, 3-propanediamine), N- (aminoethyl) piperazine, N- (2-imidazole) piperazine, N- Ethyl piperazine, N- (hydroxyethyl) piperazine, N- (aminoethyl) piperazine, N- (aminopropyl) piperazine, N- (aminoethyl) n-morpholine, N- (aminopropyl)
  • Preferred amines are selected from hexamethylenediamine, octylamine, monoethanolamine, octamethylenediamine, diaminododecane, decylamine, dodecylamine, betaines such as polycarboxybetaines, arginine and mixtures thereof.
  • Polycationic in this context means that a functionalization with a plurality of cationic charge carriers, wherein a single compound or single compound unit may contain a singular cationic charge group.
  • Particularly preferred is a post-functionalization with hydrophobized polycationic electrolytes. Positive charge groups are provided predominantly by quaternized nitrogen compounds.
  • charge carriers are also suitable, for example amines, amides, ammonium, imines, azanes, triazines, tetrazanes or nitrones.
  • the nitrogen-based cationic charge groups may be, for example, guanidine or amidine or imidazole groups.
  • DE10124387A1 discloses methods with which hydrophilic cationic polyelectrolytes can be hydrophobically functionalized.
  • the cationic charge group consists of a quaternized nitrogen compound.
  • the hydrogen atoms of primary and secondary amino groups are partially substituted by linear or branched alkyl, alkenyl, hydroxyalkyl or alkylcarboxy radicals having 10 to 22 C atoms, preferably 14 to 18 C atoms in the alkyl radical, the further substituents, as carboxyl groups, can carry replace.
  • Suitable quaternizing agents are alkylating agents such as dimethyl sulfate, diethyl sulfate, methyl chloride, methyl iodide, ethyl chloride or benzyl chloride. Also preferred are hydrophobic Polyethyleninnine. These may be homopolymers of ethyleneimine (aziridine) or its higher homologs, as well as the graft polymers of polyamidoamines or polyvinylamines with ethyleneimine or its higher homologs. The polyethyleneimines can be uncrosslinked or crosslinked, quaternized and / or modified by reaction with alkylene oxides, dialkyl or alkylene carbonates or C 1 - to C 6 -carboxylic acids.
  • Grafted polyamidoamines are known, for example, from US Pat. No. 4,144,123 or DE-B-2,434,816.
  • Hydrophobic polyethyleneimines can also consist of polymers which have been prepared from ethyleneimine units and polyamidoamines by grafting. Particularly preferred are hydrophobic compounds of polyamidoamine (PAMAM), polyethylenimine (PEI) and polypropylenimine (PPI).
  • PAMAM polyamidoamine
  • PEI polyethylenimine
  • PPI polypropylenimine
  • APTS Aminosilanes (aminopropyl) triethoxysilane
  • amino-functionalized polymers polylysine, polyvinylamine
  • polycarboxylic acids polyacrylic acid, polyglutamic acid
  • polyamides and polyacrylic acid esters are preferred to carry out further functionalizations and corresponding couplings. This is preferably done by converting the amino functionalities with cyclic acid anhydride (e.g., glutaric anhydride) to the carboxylic acid.
  • cyclic acid anhydride e.g., glutaric anhydride
  • the carboxyl groups require activation by various reagents, e.g.
  • Pentafluorophenol N-hydroxysuccinimide, thionyl chloride, 1-ethyl-3- (3-dimethylaminopropyl) carbodiimide.
  • attachment directly to functional silanes such as (3-glycidoxypropyl) trimethoxysilane, (3-iodopropyl) trimethoxysilane, (3-
  • the membranes of the invention are preferably used in conjunction with a diffusive or electro-kinetic separation process.
  • Diffusion dialysis DD
  • DD diffusion dialysis
  • electroosmosis electroosmosis
  • ED Electrodialysis
  • ED is an electrochemically driven membrane process in which ion-selective membranes in combination with an electrical potential difference can be used to remove ionic species from uncharged compounds from a solution.
  • the starting solution is in a chamber (donor chamber), which preferably has the largest possible contact surface of the volume of space with the at least two sides limiting membranes filled.
  • the separation membranes preferably have a selectivity that is selective to anions on the anode-facing side and cationic on the cathode-facing side. These membranes are preferably aligned parallel to each other and allow a preferably straight-line flow of electrons between an anode and a cathode and are not directly electrically connected to each other.
  • an ED unit may consist of repeating units of a cation acceptor chamber, a donor chamber, and an anion acceptor chamber which may be arranged in a serial sequence between a DC voltage generator.
  • the separation of the ions from the starting solution is carried out by applying a DC voltage to an anode and a cathode. The process can be carried out in a continuous flow mode or under static conditions.
  • the cathode and / or the anode are in liquid-filled spaces, the cathode or the anode chamber, preferably by an anion- or cation-selective membrane, with a cut-off region, preferably ⁇ 100D, are electrically separated from the donor and acceptor chambers, respectively. Between the donor and the acceptor chamber is the membrane of the invention.
  • a serial arrangement consisting of a cation-selective membrane which delimits a donor chamber to the cathode, a membrane according to the invention, which defines the anode chamber and the anode-side anode chamber an acceptor.
  • a plurality of this sequence is to be arranged in series.
  • the last arrangement with such a sequence is closed on the anode side by an anion-selective membrane which adjoins an acceptor chamber.
  • the acceptor and / or the donor chambers can in each case be connected to one another via external connections or can be filled individually from a receiver vessel of the starting solution or of the acceptor medium.
  • it is particularly advantageous to initiate the starting solution (donor solution) preferably on the cathode side in the donor chamber system of the ED unit and admit the acceptor solution on the anode side in the acceptor chamber system.
  • a particularly advantageous cross-flow separation is achieved in which carboxylic acids are transported from the starting solution into the acceptor medium.
  • a further particularly preferred method application of the membranes according to the invention takes place in the form of a hollow-chamber dialyzer, as is known, for example, in medical technology.
  • a starting solution is passed through a distribution system in tubes or capillaries, which have emerged from a manufacturing process according to the invention and can be used as a separation membrane by these are finally connected to the distribution device.
  • the preferred tubes or capillaries preferably have a diameter between 50 ⁇ and 3cm, more preferably between ⁇ ⁇ and 1 cm and more preferably between 1 mm and 5mm and have a length which is preferably between 1 cm and 10m, more preferably this is between 5cm and 2m and more preferably between 10cm and 100cm.
  • the tubes or capillaries are finally connected at the other end to one or more catcher (s).
  • An electric field can be introduced to the liquid medium in the distributor and / or the collecting device, preferably by a connection to a cathode chamber or by placing it within the distributor or collecting system.
  • the cathode chambers are electrically separated from the starting medium by a cation-selective membrane.
  • the tubes / capillaries are in an open or closed container, which receives an acceptor medium or which can be passed through the container.
  • the acceptor medium is electrically connected to an anode, which is preferably electrically separated from the acceptor medium by an anion selective membrane.
  • the flow rate (s) of the starting and / or accepting medium is preferably between 1 mm / min and 100 m / min, more preferably between 5 cm / min and 50 m / min and more preferably between 10 cm / min and 1 m / min. But also a reverse separation direction for carboxylic acids is conceivable.
  • one or more cathodes may be placed in the distributor or collecting device and one or more anodes may be placed in the surrounding container and / or the Meetingmediunn is passed on the outer sides of the tubes or capillaries and the acceptor medium flows through the tubes / capillaries.
  • Such applications are preferably carried out at temperatures of the solutions between 5 ° C and 120 ° C, more preferably between 10 ° C and 75 ° C, and more preferably between 15 ° C and 45 ° C.
  • the pressure prevailing in the chamber systems e.g. monitored by pressure sensors, and monitors the differential pressure between the chamber systems.
  • pressure equalization takes place between the donor and acceptor chamber systems.
  • a differential pressure between the chamber systems is adjustable.
  • other parameters of the acceptor and / or donor medium are monitored, such as. PH, conductivity, temperature, ion concentrations or viscosity.
  • the material of which the usable electrodes are made can be taken from the prior art. However, electrodes are preferred, consisting of or with a permanent coating of carbon, platinum, gold or silver.
  • the solutions filled the anode and cathode compartments preferably contain ionic or ionizable compounds suitable for charge transport. Such compounds are known in the art.
  • a concentration gradient existing between the starting and accepting medium is used to transport carboxylic acids through one of the membranes of the present invention.
  • the acceptor medium is an organic solvent.
  • the membranes according to the invention are carried out together with cationic compounds which are bound and / or unbound in the acceptor chamber.
  • carboxylic acids that pass through the membrane into the acceptor chamber can be bound by these compounds, thereby increasing the solubility of the carboxylic acids (eg, by arginine and triethylamine) or lowering them (eg, by sodium, calcium, Polycations) can be.
  • polycationic compounds which are capable of simultaneously binding a multiplicity of carboxylic acids Particularly preferred is polyethyleneimine.
  • carboxylic acids which have been passed from the donor solution through the separation membrane can be immobilized / bound by means of cationic and / or polycationic compounds and can be removed and obtained in complexed form directly from the acceptor medium.
  • the membranes of the invention are used in a DD or ED process to produce carboxylic acids from a Donormediunn transport in an acceptor mediated and to win the separated carboxylic acids in one or more further process steps.
  • the carboxylic acid-enriched acceptor solution can be separated and the carboxylic acids dissolved therein can be protonated by a pH reduction, which can be adjusted by means of an acid, whereby a phase separation is achieved and the carboxylic acid phase can be separated.
  • Membranes of the invention may be used for product recovery or purification of media.
  • carboxylic acids which are present by a chemical or bio-technological process or by a purification in an aqueous medium can be separated off.
  • fatty acids can be selectively obtained, find an application, for example as food or a biodiesel, lubricant or soap production are supplied.
  • starting materials or products from chemical or pharmaceutical synthesis can be recovered or separated in pure form.
  • Carboxylic acids are furthermore to be separated off, for example, in the dairy industry, the beverage industry, from mixtures of a chemical reaction or synthesis, from cleaning solutions which, for. B.
  • oils are industrial oils, vegetable oils, fuels, used cooking oils.
  • Other applications are possible in bio-diesel production, biomass separation, bio-technological process technology, purification of blood plasma, process fluids, pharmaceutical synthesis mixtures and liquids in chemical analysis.
  • the method according to the invention is particularly suitable for separating carboxylic acids and in particular fatty acids from the blood of a human by way of dialysis.
  • Another aspect of the present invention is directed to a method which is a dialysis method and which serves to separate fatty acids from blood.
  • step a) comprises providing blood.
  • a dialysis method for separating fatty acids from ex vivo blood comprising the step of a) providing blood or blood products.
  • fluids can be used as the starting medium, such as blood or blood products, Dairy products, beverages, aqueous synthesis media or aqueous extractions of synthesis mixtures, cleaning media or effluents of industrial or municipal origin, but are not limited thereto.
  • a further aspect of the present invention relates to the use of the open-cell membranes according to the invention or the open-pore membranes according to the invention obtainable or obtained by one of the inventive methods described herein for the electrophoretic separation of carboxylic acids from liquid mixtures.
  • the open-celled membranes according to the invention or the open-pored membranes according to the invention are obtainable or obtained by one of the methods according to the invention described herein for the electrophoretic separation of carboxylic acids from liquid mixtures.
  • the open-pored membranes according to the invention or the open-pore membranes according to the invention are obtainable or obtained by one of the methods according to the invention described herein for the electrophoretic separation of carboxylic acids from liquid mixtures.
  • the open-cell membranes according to the invention or the open-pore membranes according to the invention are obtainable or obtained by one of the methods according to the invention described herein for the electrophoretic separation of carboxylic acids from aqueous media.
  • open-pored membranes according to the invention or the open-pore membranes according to the invention are obtainable or obtained by one of the inventive methods described herein for the electrophoretic separation of carboxylic acids from aqueous media, wherein the aqueous media are blood and blood products, used.
  • NCA ⁇ -amino acid-N-carboxyanhydrides
  • ROP ring-opening polymerization
  • ultrafiltration membranes of (a) zirconium oxide ceramic with an asymmetric pore size distribution (Kerafol, Germany), (b) PTFE membrane, average pore diameter 1, 0 ⁇ (Emflon, Pall, Germany), (c ) Glass frit, grade D (Schott, Germany), (d) polyethersulfone membrane (Supor, ⁇ , ⁇ , Pall, USA) and (e) anodized aluminum oxide membranes with channel diameters of 200 nm (Anodisc, Whatman, Germany).
  • the membranes (a) - (d) were purified by means of a basic cleaning solution consisting of deionized H 2 O, H 2 O 2 (35%) and NH 3 (30%) in a ratio of 5: 1: 1 (v: v: v). cleaned at 80 ° C for 10 minutes. The procedure was repeated 5 times, finally cleaning with methanol. Thereafter, the membranes were stored in a solution of H 2 SO and H 2 O 2 (7: 3) at 80 ° C for 10 minutes. Final purification with deionized H 2 O and methanol. Membranes (e) were cleaned with H 2 O 2 (35%) at 80 ° C for 10 minutes. Final purification with deionized H 2 O and drying at 70 ° C for 2 hours.
  • aminosilanes 3-aminopropyltriethoxysilane (APTS) and 3-trimethoxysilylpropyl-diethylenetriamine (TAPTES) (Sigma-Aldrich, USA) were dissolved in toluene and heated to 75 ° C.
  • the coating objects were stored for 4 minutes and then rinsed with toluene and dichloromethane and then dried in a vacuum oven at 80 ° C for 24 hours. Quality control by means of contact angle measurements.
  • the membranes were placed in an aminosilane solution at a concentration of 1% by volume to 5% by volume in toluene at 120 ° C for 4 hours. Then clean the membranes with toluene and dry in a vacuum oven at 70 ° C.
  • the covalent coupling of the activated carboxylic acids to the membrane surfaces was carried out by placing in a 60 mmolare solution of pentafluorophenyl ester in DMF for 15 hours and 24 hours at temperatures between 0 ° C and 80 ° C.
  • the volume flow through the membrane was 1 mL / h to 2 mL / h.
  • a filament ceramic of Kerafol was placed in 5% v / v TAPTES or APTES in 5 mL of absolute toluene and refluxed for 4 h at 95-120 ° C.
  • the reaction was carried out with phenylalanine, sarcosine, alanine, cysteine, valine, benzylglutamate, Cbz-lysine, Boc-arginine-NCA (guanidine-protecting group) and lysine NCAs.
  • the resulting support membrane with Cbz-lysine and Boc-arginine NCA had similar properties in the following experiments compared to phenylalanine-NCA.
  • a filament ceramic of Kerafol was placed in 5% v / v TAPTES or APTES in 5 mL of absolute toluene and refluxed for 4 h at 95-120 ° C.
  • 1 g of one or more NCA was weighed into a 50 ml Erlenmeyer flask under argon.
  • Solvent-induced polycondensations were carried out by adding 250 mmolar solutions of phenylalanine, arginine, Boc-arginine, lysine, Cbz-lysine,
  • Benzylglutamate and valine NCAs and combinations of these were prepared in dimethylformamide.
  • the support material (with or without amino functionality) was immersed in the solutions in an inert gas atmosphere. After 72 hours at room temperature or 60 ° C, the membrane was rinsed with 5 mL of THF. Supplementary studies were carried out in the same way with solvent mixtures of THF and DMF (80:20 v: v, and 50:50 v: v).
  • the polymerization was investigated by means of contact angle measurement, infrared spectroscopy and scanning electron microscopy. For membranes in which SEMs were polymer structures on the outer surfaces of the membranes, they were treated with argon plasma.
  • the resulting support membrane with Cbz-lysine and Boc-arginine NCA had comparable properties in the following experiments compared to phenylalanine-NCA.
  • Membranes pretreated according to steps A) to E) or native membranes were placed in a 10 wt% polyethylenimine solution (methanol) at 25 ° C for 24 hours. For purification, the membranes were placed in methanol and then dried. This step was repeated three times. The functionalization was checked by infrared spectroscopy.
  • Table 1 Examples of membranes, their surface functionalization and polymerization process.
  • Coatings with alkylsilanes reached water contact angles (HPC) of 59 ° to 79 °.
  • the WKW of the amino acid polymers were between 68 ° and 17 ° and those of the alkyl imidazole silanes between 66 ° and 92 °.
  • the guanidine silanes showed WKW by 68 °.
  • HPCs 95 ° - 10 ° resulted.
  • the fatty acid contact angles (HFCs) for coatings with alkanesilanes were between 10 ° and 25 °, for amino acid polymers between 0 ° to 20 °, for the alkyl imidazole silane functionalization between 0 and 10 °, and for surfaces with guanidine silanes around 30 °.
  • the HFCs were below 10 °.
  • the two chambers had a filling volume of 25 ml each and were separated from an outside adjoining anolyte or catholyte chamber by further Teflon SEAPs, into which a cation- or anion-selective membrane (Fumasep FKS or FAS, Fumatech, Germany) was pressure-tight.
  • anolyte and catholyte chambers were platinum electrodes connected to a DC power source.
  • a lid sealed the chambers against each other and against the atmosphere. Through a pneumatic connection, which was through the lid in the donor chamber, the pressure in this chamber could be monitored by means of a pressure transducer.
  • Experiment D1 NaCl 1% by weight + caproic acid 100 mmol / l in 2% ammoniacal solution
  • the acceptor chamber was filled in experiments D1 and D2 with a 10Ommolaren arginine solution and in the experiments D3 and D4 with a NaOH solution (0.1%) in which dissolved 0.5Gew% of polyethyleneimine.
  • Magnetic stir bars were inserted in both chambers, which were rotated by an external magnetic stirrer at 100rpm during the investigations.
  • Table 2 Results of translocation experiments on diffusion DD and electrophoresis ED.
  • Membranes with nanocavity polymer structures were not permeable to hydrophilic compounds, while these membranes were permeable to both diffusive and electrophoretic mass transport of carboxylic acids.
  • the electrophoretic mass transfer for carboxylic acids was increased compared to the native carrier membranes.
  • carboxylic acids compared to sulfates which had a comparable molecular weight, a selective mass transport with a selectivity index ⁇ of 158 for M1 .8 and 164 for M2.5.
  • v is the transport velocity through the membrane
  • n is the transported amount of substance
  • the selectivity in electrodialysis was even higher.
  • the selectivity index CIOH was 395 for M1 .8 and 820 for M2.5.
  • 6-lauroleic acid (C12: 1) was added to the following organic media at a concentration of 100 mmol / L: V1 calf serum, V2 sludge (10 wt% dry matter), V3 buttermilk and V4 beer fermentation solution ,
  • the acceptor chamber was filled with a 200 mm arginine solution.
  • the electrodialysis was carried out at a voltage of 15 V with a current of 100 mA for 6 hours. Every 15 minutes, a sample was taken from the acceptor chamber to determine the lauric acid concentration and to detect proteins. The time to reach a lauroleinic acid concentration of 10mnol / l was determined (duration 1). Subsequently, both chambers were emptied and then filled with the same starting solutions as in the previous experiment, and started an identical experimental procedure. Again, the duration was determined until reaching a lauroleinic acid concentration of 10mnnol / l (duration 2). Thereafter, the membranes were swirled in a water bath and then dried.
  • aDuration 1 duration in minutes until a lauroleinic acid concentration in the acceptor chamber of 10 mmol / l is reached during the first test run;
  • b duration 2 duration in minutes until lauric acid concentration in the acceptor chamber reaches 10 mmol / l during the second test run;
  • c Protein 1 Semiquative detection of protein in the acceptor chamber solution at the end of the first trial run, detection limit 0.5 g / l;
  • d Protein 2 Semiquative detection of protein in the acceptor chamber solution at the end of the second run, detection limit 0.5 g / l
  • the separation of the membranes with nanocavitation polymer structures was comparable in the investigated starting solutions.
  • the following membranes from Example 2 were tested: M1 .1, M1 .12, M4.2, and M4.8 and the native membranes M1 .0 and M4.0.
  • the experiment was carried out according to Example 3.
  • the donor chamber was in the test series A) with whole blood, which was anticoagulated with heparin in a concentration of 1, 1 IU / ml and in the experiment B) filled with blood serum.
  • the investigations were carried out at a temperature of 37 ° C.
  • the acceptor chamber contained a 10 molar arginine solution.
  • a DC voltage of 5V at 50mA was applied to the electrodes.
  • the test duration was 120 minutes.
  • the whole blood (VB) or the serum (S) from the donor chamber were separated and further analyzed.
  • EDTA or citrate were added to the VB to reach final concentrations of 4 and 13 mM, respectively.
  • the number of platelets was determined with a Coulter AcT diff TM haematology analyzer (Coulter Corporation, USA).
  • the EDTA-primed VB was centrifuged at 2.200 g for 10 min. At 41 ° C and the citrated VB was centrifuged for 10 min at 1.000 g and for 10 min at 10,000 g at 41 ° C.
  • thrombin-anti-thrombin complex TAT
  • factor XIIa-AT - Complex formation was quantified with an enzyme immunoassay (EIA) (Enzygnosts, Behringwerke, Germany). Further, quantification was by an EIA for ⁇ -thromboglobulin ( ⁇ -TG) and the complement factors C5b and sC5b-9. The values obtained were compared with those from a reference sample in which the VB or S had been stored in a PTFE container of the same duration and agitation as in the electrodialysis apparatus.
  • EIA enzyme immunoassay
  • the membranes used were briefly swirled after the experiments in a water bath and then divided. A portion of the membrane pieces were dried and examined for the protein adsorption carried out. The other part of the membrane pieces was immediately further processed for the analysis of the cell occupancy of the surfaces.
  • the adsorbed protein content was determined by enzyme linked immunosorbent assays for fibrinogen, fibronectin and albumin.
  • the mean coverage densities of hydrophobized membranes and membranes with nanocavity polymer structures were related to the staining index, which was determined for an unused starting membrane.
  • the extent of adhesion of platelets and leukocytes was determined by fluorescence microscopic analysis after staining with calcein AM and propidium iodide and is reported as relative surface coverage to total surface area. Cytotoxicity was determined by determining the LDB levels of VB after electrodialysis and is reported as a relative increase over the value of a reference sample stored under agitation in a PTFE container over the duration of the experiment.
  • Membranes with nanocavity polymer structures caused only minimal activation of the coagulation and complement system during electrodialysis compared to a native membrane or a membrane with a hydrophobic surface functionalization. Furthermore, there was a significantly lower superficial occupancy of serum proteins and blood cells than was the case with native membranes and membranes with a hydrophobic surface functionalization. While there was evidence of surface cytotoxicity in electrodialyses using native membranes and membranes with hydrophobic surface functionalities, those were not found in membranes with nanocavity polymer structures. Table 4: Results of bio- and hemocompatibility studies.
  • TAT thrombin-antithrombin complex
  • b ß-TG beta-thromboglobulin
  • c platelets / leukocytes area occupied by platelets or leucocytes in relation to the total area.
  • Ceramic zirconia sintered membranes with a mean channel width of ⁇ , ⁇ , a material thickness of 3 mm and dimensions of 30 ⁇ 30 cm were supplied to a surface pretreatment according to Example 2 (M1 .1 1 or M1 .12).
  • the presence of nanocavity tissue-like polymer structures that occupy space or space throughout the lumen system, i. the pores of the membranes could be documented electron microscopically.
  • the stack as well as the outside anolyte and catholyte compartments were pressed together by an external device so that the chambers were pressure sealed against the environment.
  • Another identical ED unit was manufactured using native ceramic zirconium oxide membranes. During ED, a DC voltage of 40V was applied at 0.3A.
  • the donor and acceptor chambers were each serially connected by a tube system. The inlet and the flow direction of the chamber systems were opposite, the introduction of the starting medium was in the first cell, the Cathode chamber adjoined. Both systems were designed with a flow rate of 1 liter / min. applied.
  • untreated ceramic membranes were used with the same experimental setup.
  • the acceptor solution consisted of a 0.5 molar arginine solution introduced from a storage vessel into the acceptor chamber system. After exiting the ED unit, the fatty acid-enriched acceptor solution was collected in a vessel and the volume determined. Furthermore, samples were taken for analysis. There was a quantitative determination of iron, magnesium and phosphorus, as well as a semiquantitative determination of glycolipids.
  • a hexane-extracted rapeseed oil was degummed with an aqueous arginine solution.
  • the aqueous phase contained 12% by weight free fatty acids, 8% by weight phospholipids and 6% by weight glycolipids, as well as lipoproteins and dyes, as well as iron, magnesium, sodium, calcium and potassium ions. This WP was a greenish cloudy emulsion and was introduced into the donor chamber system with a peristaltic pump.
  • a track-etch polycarbonate membrane (Nuclepore, Whatman, USA, pore diameter 20 nm, thickness 5 ⁇ m), whose inner and outer surfaces had been coated over the entire surface according to Example 2 M1.1, was investigated (PC1.1).
  • the selectivity of the transport properties was compared with membranes that had room-filling or space-spanning nanocavity polymer structures (M5.12 and M1 .8 from Example 2).
  • the hydrophobized nanofiltration membranes had a water contact angle between 1 10 ° and 1 18 °. After the experiments, all membranes were removed and visually assessed.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Organic Chemistry (AREA)
  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Biochemistry (AREA)
  • Molecular Biology (AREA)
  • Dispersion Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Manufacture Of Porous Articles, And Recovery And Treatment Of Waste Products (AREA)
  • Separation Using Semi-Permeable Membranes (AREA)

Abstract

Die vorliegende Erfindung betrifft eine offenporige Membran mit nanocavitären Polymerstrukturen in soliden Trennmedien zur Abtrennung von Fett-und/oder Carbonsäuren aus vornehmlich wässrigen Gemischensowie ein Verfahren zu deren Herstellung.

Description

Offenporige Membran mit innerem raumdurchspannendem polymerem Strukturnetzwerk zur elektrophoretischen stoffselektiven Separation
sowie Verfahren zu deren Herstellung und Anwendung Die vorliegende Erfindung betrifft eine offenporige Membran mit nanocavitären Polymerstrukturen in soliden Trennmedien zur Abtrennung von Fett- und/oder Carbonsäuren aus wässrigen Gemischen sowie ein Verfahren zu deren Herstellung.
Beschreibung
Carbon- bzw. Fettsäuren sind amphiphile Moleküle, die sich kaum in Wasser lösen und daher in Wasser lediglich nur in geringen Mengen in volatiler Form vorliegen. Die häufigste Form, in der Fettsäuren in Wasser vorkommen, besteht daher in Form von Micellen und Emulsionen, die eine Phasentrennung bewirken. Die Amphiphilie bedingt, dass sie sich an Oberflächen abscheiden, die hydrophob oder lipophil sind. Sofern sie mit Detergenzien gelöst sind, liegen sie in einem wässrigen Medium als micellare Partikel vor. Die meisten organischen Verbindungen adsorbieren Carbonsäuren bis zu einem gewissen Anteil über elektrostatische Bindungskräfte. Daher liegen Carbonsäuren in wässrigen organischen Lösungen zum überwiegenden Teil in einer gebundenen Form bzw. als Micellen mit anderen organischen Verbindungen vor. Aufgrund der Kleinheit derartiger Micellen ist eine Filtration dieser Gebilde praktisch nicht möglich oder es kommt zu einer Belegung der Filteroberflächen, die einen Verschluss der Filterfläche bedingt (Fouling).
Daher werden klassische Extraktionsverfahren, wie die Filtration oder Dialyse, für eine Abtrennung von Carbonsäuren praktisch nicht angewandt.
Zur Abtrennung von Carbonsäuren können grundsätzlich klassische Extraktionsverfahren angewandt werden.
Hierzu gehören
- die Fest-Flüssig-Extraktionsverfahren, bei denen eine Adsorption der abzutrennenden Moleküle an Oberflächen erfolgt, z.B. bei der Chromatographie, - die Flüssig-Flüssig-Extraktion, bei der sich das abzutrennende Molekül in einem flüssigen Extraktionsmittel, z.B. einem Alkohol oder einem unpolaren Lösungsmittel aus einem flüssigen Stoffgemisch anreichert,
- die Flüssig-Gas-Extraktion, bei der das abzutrennende Molekül durch ein komprimiertes Gas aus einem flüssigen Stoffgemisch herausgelöst und abgetrennt wird, z.B. in Form der überkritischen CO2-Extraktion,
- die Destillation, bei der das abzutrennende Molekül aus einem flüssigen Stoffgemisch verdampft und in einer Kühlkolonne wieder kondensiert wird, sowie
- analytische Verfahren, wie die Gaschromatographie, die eine Kombination der o. g. Verfahren darstellt. Die aufgeführten Extraktionsverfahren werden in der Analytischen Chemie (hier insb. die Chromatographie) sowie in der Pharmazie und Chemischen Industrie (hier insb. die Chromatographie und Flüssig-Flüssig-Extraktion) und der Petrochemie (hier insb. die Destillation) angewandt. Dabei sind die Verfahren, die einen hohen Stoffmengentransport ermöglichen, mit einem erheblichen Energieeintrag und damit Kostenaufwand verbunden. Trennmembranen zur Abtrennung von in einem wassrigen Medium gelösten Carbonsäuren sowie membranbasierte Abtrennverfahren für in einem wassrigen Medium gelöste Carbonsäuren sind nicht existent.
Detaillierte Beschreibung
Carbonsäuren lassen sich mit den vorgenannten Verfahren nur diskontinuierlich aus einem wässrigen Medium separieren. Im deprotonierten Zustand weisen Carbonsäuren eine negative Ladung auf und können somit in einem elektrischen Spannungsfeld bewegt werden. Daher ist grundsätzlich eine elektrophoretische Separation von Carbonsäuren möglich. Beim Durchtritt von Carbonsäuren durch ein offenporiges Separationsmedium, wie z.B. einer Filtermembran, werden die Oberflächen durch hieran adhärierende Carbonsäuren belegt, dabei ist es unerheblich, ob die Oberflächeneigenschaften derartiger Membranen hydrophob oder hydrophil sind. Ferner werden Verbindungen, die sich ebenfalls in dem wässrigen Medium befinden und die selbst eine negative Ladung aufweisen und/oder mit deprotonierten Carbonsäuren beladen sind, bei einer elektrophoretischen Abtrennung durch eine Membran mittransportiert. Daher ist eine selektive Abtrennung von Carbonsäuren aus wässrigen organischen Gemischen durch eine offenporige Membran und Methoden aus dem Stand der Technik nicht möglich.
Membranbasierte Verfahren zur stofflichen Trennung auf molekularer Ebene werden nach dem Stand der Technik mit geschlossenen Membranen, die einen diffusiven Stofftransport der abzutrennenden molekularen Strukturen ermöglichen, durchgeführt und unter dem Begriff Nanofiltration zusammengefasst. Nachteilig ist dabei, dass die pro Membranflächeneinheit transportierbaren Stoffmengen nur gering sind und für die Abtrennung ein hoher Energiebedarf (z.B. für einen pneumatischen Druckaufbau von 20 - 80 bar) erforderlich ist (A comprehensive review of nanofiltration membranes: Treatment, pretreatment, modelling, and atomic force microscopy. N. Hilal, H. Al-Zoubi, N.A. Darwish, A.W. Mohammad, M. Abu Arabi. Desalination 2004,170:281-308). Daher eignen sich Trennverfahren mit geschlossenen Membranen nicht, wenn große Stoffmengen abgetrennt werden sollen. Zur Separation von Stoffklassen wurde in jüngerer Zeit die Verwendung offenporiger Membranen mit nanoskalierten Kanaldurchmessern vorgeschlagen, womit theoretisch ein wesentlich höherer Stofftransport möglich ist, als mit geschlossenen Membranen (Molecular Sieving Using Nanofilters: Past, Present and Future. Jongyoon Han, Jianping Fu, Reto B. Schoch. Lab Chip. 2008, 8(1 ): 23-33). In neuerer Zeit wurden hierzu mikro- und nanofluidische Verfahren zur selektiven Trennung von Stoffgemischen vorgestellt. Dabei konnte gezeigt werden, dass hydrophile und hydrophobe Verbindungen, die zusammen in einem wässrigen Medium vorliegen, durch Membranen, die hoch geordnete nanoskalierte Kanäle aufweisen und mit einer hydrophilen oder hydrophoben Oberflachenbeschichtung versehen worden waren, mittels Diffusion selektiv abgetrennt werden können (Solvent-Extraction and Langmuir-Adsorption-Based Transport in Chemically Functionalized Nanopore Membranes. Damian J. Odom, Lane A. Baker, and Charles R. Martin. J. Phys. Chem. B 2005, 109, 20887-20894). Die Selektivität für die abzutrennenden Verbindungen wird dabei durch eine Oberflächenbeschichtung der Kanalwände erreicht. Hierdurch konnte für die Separation von apolaren Verbindungen ein Selektivitätsindex von bis zu fünf für einen diffusiven Stofftransport dokumentiert werden. Es wurde jetzt gefunden, dass die mit einer alleinigen Oberflächenbeschichtung von nanoskalierten Kanälen erreichbaren Eigenschaften nicht geeignet sind, um eine ausreichende Selektivität für die Separation von Carbonsäuren gegenüber anderen organischen Verbindungen, die Carbonsäuren ähnlich sind, in einem diffusiven Separationsprozess zu gewährleisten. Ferner besteht bei derartigen Membranen keine Selektivität für die Separation von unterschiedlichen organischen Verbindungen, wenn an die Trennmembran ein elektrischer Gradient angelegt wird. So zeigte sich, dass sich aus einer Lösung, die Albumin und gelöste Fettsäuren enthielt, Fettsäuren durch eine Membran, die Kanäle von 100nm aufwies und deren Oberflächen mit Alcylsilanen beschichtet waren, durch eine Diffusion in ein Akzeptormedium abtrennen lassen, wobei ein minimaler Transport von Albumin durch die Membran stattfindet. Wurde der gleiche Versuch mit Anlage eines transmembranösen elektrischen Gradienten durchgeführt, so kam es zu einem Durchtritt von Albumin und Fettsäuren durch eine solche Membran, der in gleichem Maße stattfand, eine Selektivität des Stofftransports bestand dann nicht mehr. Somit lässt sich durch eine Oberflächenbeschichtung, wie z. B. durch eine Hydrophobisierung der Filtermembranoberflächen, alleine ein selektiver elektrophoretischer Stofftransport für amphiphile Carbonsäuren nicht herstellen. Für elektrophoretische Separationen von organischen Verbindungen mit Membranen ist bekannt, dass es zu starken Foulingprozessen, insbesondere an anionenselektiven Membranen, kommt (Fouling of electrodialysis membranes by organic substances. Lindstrand, V; Sundstrom, G und Jönsson, Ann-Sofi LU (2000), in Desalination 128(1 ). p.102-91 .) Ferner ist die Entstehung elektro-osmotischer Fluss-Phänomene bei einer Spannungsanlage an Membranen mit mikro- und nanofluidischen Kanälen beschrieben. Aus dem bisherigen Stand der Technik ist demnach nicht ersichtlich, wie man stoffgruppenspezifische Trenneigenschaften für Carbonsäuren in eine offenporige Trennapparatur implementieren könnte. Daher ist es Aufgabe der vorliegenden Erfindung, eine offenporige Trennmembran und ein Verfahren zur Abtrennung von Carbonsäuren und/oder Fettsäuren aus einer Lösung oder einer Emulsion durch eine Membran bereitzustellen. Ferner ist es Aufgabe der Erfindung, Verfahren zur Herstellung solcher Trennmembranen und Verfahren zur Trennung von Carbonsäuren und/oder Fettsäuren unter Verwendung solcher Trennmembranen bereitzustellen.
Diese Aufgabe wird erfindungsgemäß durch die technische Lehre der unabhängigen Ansprüche gelöst. Weitere vorteilhafte Ausgestaltungen der Erfindung ergeben sich aus den abhängigen Ansprüchen, der Beschreibung, den Figuren sowie den Beispielen.
Ein Aspekt der vorliegenden Erfindung betrifft eine offenporige Membran zur elektrophoretischen Abtrennung von Carbonsäuren aus einem flüssigen Stoffgemisch umfassend oder bestehend aus:
I) einer offenporigen Trägermembran aufweisend Poren mit einem minimalen Durchmesser von 50 nm bis 500 μιτι und einem maximalen Durchmesser von 1 μιτι bis 3 mm, und
II) einem raumdurchspannenden polymeren Strukturnetzwerk in den Poren der Trägermembran.
Mit anderen Worten betrifft die vorliegende Erfindung eine offenporige Membran zur elektrophoretischen Abtrennung von Carbonsäuren aus einem flüssigen Stoffgemisch umfassend oder bestehend aus:
I) einer offenporigen Trägermembran aufweisend Poren mit einem minimalen Durchmesser von 50 nm bis 500 μιτι und einem maximalen
Durchmesser von 1 μιτι bis 3 mm, und
II) einem raumdurchspannenden polymeren Strukturnetzwerk in den Poren der Trägermembran,
wobei das raumdurchspannende polymere Strukturnetzwerk die Poren der offenporigen Membran durchspannt und keine reine Oberflächenbeschichtung der Poren der offenporigen Membran ist.
Noch anders formuliert betrifft die vorliegende Erfindung eine offenporige Membran zur selektiven elektrophoretischen Abtrennung von Carbonsäuren aus einem Gemisch von Stoffen in wässriger Lösung umfassend oder bestehend aus: I) einer offenporigen Trägermembran aufweisend Poren mit einem minimalen Durchmesser von 50 nm bis 500 μιτι und einem maximalen Durchmesser von 1 μιτι bis 3 mm, und
II) einem raumdurchspannenden polymeren Strukturnetzwerk in den Poren der Trägermembran,
wobei das raumdurchspannende polymere Strukturnetzwerk die Poren der offenporigen Membran durchspannt.
Die vorliegende Erfindung betrifft ferner eine offenporige Membran zur elektrophoretischen Abtrennung von Carbonsäuren aus einem flüssigen Stoffgemisch umfassend oder bestehend aus:
I) einer offenporigen Trägermembran aufweisend Poren mit einem minimalen Durchmesser von 50 nm bis 500 μιτι und einem maximalen Durchmesser von 1 μιτι bis 3 mm, und
II) einem raumdurchspannenden polymeren Strukturnetzwerk in den
Poren der Trägermembran,
wobei zur Separation der Carbonsäuren ein Konzentrationsgradient und/oder elektrischer Gradient an der Membran eingerichtet wird. Mit anderen Worten betrifft die zugrundeliegende Erfindung ferner eine offenporige Membran zur elektrophoretischen Abtrennung von Carbonsäuren aus einem flüssigen Stoffgemisch umfassend oder bestehend aus:
I) einer offenporigen Trägermembran aufweisend Poren mit einem minimalen Durchmesser von 50 nm bis 500 μιτι und einem maximalen Durchmesser von 1 μιτι bis 3 mm, und
II) einem raumdurchspannenden polymeren Strukturnetzwerk in den Poren der Trägermembran, und
III) Mittel zur Erzeugung eines Konzentrationsgradient und/oder eines elektrischen Gradienten an der Membran.
Ein weiterer Aspekt der vorliegenden Erfindung betrifft ein Verfahren zur Herstellung einer erfindungsgemäßen offenporigen Membran zur elektrophoretischen Abtrennung von Carbonsäuren aus einem flüssigen Stoffgemisch, umfassend die Schritte:
a) Bereitstellen einer offenporigen Trägermembran mit Poren mit einem minimalen Durchmesser von 50 nm bis 500 μιτι und einem maximalen Durchmesser von 1 μιτι bis 3 mm,
b) Einbringen einer Lösung von polymerisierbaren Monomeren und/oder Oligomeren in die Poren der offenporigen Trägermembran aus Schritt a), c) Polymerisation der polymerisierbaren Monomeren oder Oligomeren in den Poren der offenporigen Trägermembran zur Ausbildung eines raumdurchspannenden polymeren Strukturnetzwerkes in den Poren der offenporigen Trägermembran.
Ausgehend von Lösungen mit reaktionsfähigen Aminosäure-Monomeren kam es nach Einleitung einer nukleophilen Polymerisationsreaktion zur Ausbildung von kompakten, aber offenporigen Massen, die ein großes Aufnahmevermögen für Fettsäuren zeigten und aufgrund der Hydrophobie nicht mit Wasser benetzbar waren. Derartige Polymergebilde sind allerdings spröde und fragil, da offenbar keine ausreichende Quervernetzung zwischen den Polymerketten während der Selbstassemblierung stattfindet. Es wurde daher versucht eine derartige Selbstassemblierung in vorgegebenen nanoskalierten Kanälen einzurichten, indem die Kanaloberflächen zunächst mit einer reaktionsinitiierenden Beschichtung, wie z.B. Aminosilanen, vollflächig beschichtet wurden. Eine statische oder dynamische Beschickung der Membrankanäle mit einer Monomer-Lösung brachte unterschiedliche Ergebnisse. Zum Teil kam es durch die Polymerisation zu einem vollständigen Verschluss der Kanäle und zum Teil nur zu einer oberflächlichen Belegung der Kanäle mit einer Polymerschicht. Während Membranen mit vollständig verlegten Kanälen nicht von Carbonsäuren passiert werden konnten, zeigten Membranen, bei denen eine oberflächliche Kanalbeschichtung erfolgt war, die mittels Raster-Elektronenmikroskopie quantifiziert werden konnte, eine Verstärkung des elektroosmotischen Flusses, bei Anlage einer elektrischen Spannung in einer Elektrodialyse-Zelle.
Ein elektro-osmotischer Fluss kommt zustande durch eine Belegung von Oberflächen, z.B. in einer Membran, mit Ionen, die in einem elektrischen Feld bewegt werden. Die oberflächlich bewegliche lonenschicht wird im elektrischen Feld transportiert, wodurch die an die Ionen gebundene Wasserhülle mittransportiert wird und somit ein W