WO2020139092A1

WO2020139092A1 - Method for modifying of the separation material surfaces

Info

Publication number: WO2020139092A1
Application number: PCT/PL2019/050077
Authority: WO
Inventors: Joanna Kujawa; Samer Al-Gharabli; Wojciech Kujawski
Original assignee: Uniwersytet Mikołaja Kopernika W Toruniu
Priority date: 2018-12-24
Filing date: 2019-12-16
Publication date: 2020-07-02
Also published as: PL428333A1

Abstract

A method comprising modifying of separation material surfaces, characterized by placing a flat membrane with generated hydroxyl groups, a modifying solution and dichloromethane in a glass vessel, tightly sealing said vessel and mixing said vessel's contents, preferably in a laminar flow cabinet in an atmosphere of inert gas, preferably argon or nitrogen, at a temperature of 20 to 40°C over a period of 1 to 6 h, wherein a solution is mixed throughout the entire reaction conduction time, the next step comprising removing said membrane from said glass vessel and washing said membrane with solvents by placing it, in order, in beakers filled with acetone, dichloromethane and water, and finally drying said membrane, preferably at a temperature of 40 to 60°C for 8 to 15 h.

Description

Method for modifying separation material surfaces

The subject of the invention is a method for modifying separation material surfaces, particularly for the purposes of water treatment via desalination, volatile organic compound removal, and the removal of pharmaceutical agents and hormone residues.

Controlled and selective transport through membranes is the key factor in membrane separation processes, whereas the interactions between the mixture undergoing separation and the membrane have a significant influence on the transport itself. The improvement of the separation transport efficiency can be accomplished in a number of ways, such as by seeking solutions inspired by nature. A method for regulating membrane separation in a membrane bioreactor is known from P. 414070, intended particularly for application in processes that exhibit significant fouling, that is the accumulation of great amounts of substances present in the separated mixture on the membrane surface, which make the process nonstationary, wherein the retentate is fed from a tank reactor by means of a pump to a membrane module, and the permeate is carried away from it as a stream with a volume that decreases over time as a consequence of membrane blockage, further comprising membrane backwashing of the membrane module, accomplished at determined intervals, characterized in that by having a determined maximum permissible time for conducting membrane separation, the separation is being conducted between backwash cycles, wherein the permeate in the form of a stream with a volume that decreases over time is carried away from the membrane module to a container from which it is subsequently carried away by means of a pump as a stream with a constant volume, wherein to guarantee the constant volume of the permeate stream being carried away from the container, a permeate stream with a decreasing volume is fed into the container proportionally to the volume carried away in excess, wherein said excess is evacuated via backwashing, wherein, in a situation where by maintaining the constant stream of the permeate being carried away from the container in the determined maximum time the container is not filled to the predetermined level, backwashing is initiated, emptying the partially filled container, and transmembrane pressure is subsequently increased, whereas should the container be filled to the predetermined level over a period shorter than the determined time interval directly preceding the maximum time then backwashing is initiated to empty the container, and transmembrane pressure is subsequently decreased, wherein the regulation according to the above two schemes is accomplished in situations where filling the container to the predetermined level and the backwashing initiated by said filling do not occur in the determined time interval directly preceding the determined maximum time, as well as until the determined maximum or achievable transmembrane pressure is achieved. The membrane bioreactor is formed from a tank reactor, which is coupled by a retentate channel by means of a pump to a membrane module comprising a transmembrane pressure control valve, wherein said module is further coupled to a permeate channel, wherein said permeate channel is further coupled to a backwash system, a stop valve and a pump, wherein said backwash system is characterized in that it is a container comprising a slidable piston moved by a coupled drive, wherein said container comprises a vent valve and a filling sensor, wherein said sensor is preferably formed from two conductometric electrodes, wherein one of said electrodes is installed at the bottom of said container and the other at the bottom of said piston.

A method for removing viral contaminants from a chemically defined cell culture medium is known from EP15275265. The membrane surfaces are modified using diacetone acrylamide and polyethylene glycol diacrylate.

The goal of the invention is to develop such a method of modifying surfaces that would make it possible to obtain nanocomposite porous membranes with inorganic filling material where the nanoparticles would exhibit magnetic properties.

The obtained membranes will exhibit organized surface nanoarchitectures due to the preparation by means of the chemical modification of the polymer base surface, and subsequently the covalent bonding of magnetic FesOi or lanthanide oxide nanoparticles by means of selected crosslinkers. The invention demonstrates a new method for modifying polymer membranes by means of the chemical bonding of magnetic nanoparticles to the activated surface with hydroxyl groups using crosslinkers with various lengths. This will ensure the free movement of the nanoparticles during the separation process, and will furthermore make it possible to reduce fouling as well as decrease concentration polarization, enabling a more turbulent flow.

The invention reveals a method for activating a polymer material (PVDF) exhibiting a naturally strong inert character in a simple, inexpensive and very effective way. The method is efficient and repeatable, which makes it possible to produce separation materials with specific properties, depending on their end purpose. This consequently makes it possible to greatly reduce membrane fouling during the separation process.

The goal is to produce a new type of hybrid organic-inorganic separation materials - heterogeneous polymer membranes based on activated polyvinylidene fluoride (PVDF) with inorganic nanofillers with magnetic properties - membranes with quantum dots, characterized by controlled physicochemical, tribological and separation properties. Materials prepared in this way have great potential for application in terms of membrane processes and in chemical sensors. The produced materials (porous membranes) will find application in membrane separation processes, in membrane distillation (MD) as well as in ultra- and microfiltration (UF/MF). The stability and fouling tendency of the produced hybrid membranes will be determined as well.

The following polymer membranes can be utilized for the invention: polyvinylidene fluoride, polytetrafluoroethylene (PTFE), polydimethylsiloxane (PDMS) with spiral wounds and hollow fibers.

The invention makes it possible to prepare heterogeneous polymer membranes based on PVDF with inorganic filling material (FeiCh and selected lanthanide oxides) and to activate PVDF membranes using piranha solutions (acid - mixture of sulfuric(VI) acid and hydrogen peroxide, or basic - mixture of ammonium hydroxide and hydrogen peroxide) and to perform surface functionalization (activated PVDF and PDMS) using silane group modifiers with various molecular structures - various chain lengths (crosslinker function) - and subsequently to perform the covalent bonding of magnetic nanoparticles for the biomimicry of ciliary motion. It also makes it possible to provide detailed characterizations of the obtained functionalized materials with regard to their physicochemical, tribological and mechanical properties as well as to determine their stability by means of advanced instrumental and analytical methods (IR, NMR, Raman, TGA, HR-TEM, EELS, SEM, XRD, DCS, EPR, AFM, BET, BJH, static and dynamic goniometric measurements). It also makes it possible to identify the potential applications of the prepared materials and to define their suitability and efficiency by determining the selectivity and transport properties of the produced membranes in selected liquid mixture separation processes - membrane distillation and micro/ultrafiltration. The efficiency of the prepared membranes will be determined e.g. in the treatment of water containing microcontaminants (e.g. pharmaceutical agents) and the removal of volatile organic compounds (VOC) from water via membrane distillation. Furthermore, the membranes with built-in magnetic nanoparticles will be tested in the process of gas separation.

Producing membranes with controlled properties and determined surface nanoarchitecture:

- activating polyvinylidene fluoride membranes by generating hydroxyl groups (OH) (utilizing the oxidizing strength of a piranha solution originating from generated hydroxyl radicals through the decomposition of Caro’s acid (H₂SO₅) or H₂O₂). PVDF is naturally a very inert material, therefore its activation (giving it a labile character) is necessary.

- chemical modification with alkyl silanes with varied alkyl chain lengths (2-5 nm).

- bonding of magnetic nanoparticles (through valence bonds) to functionalized membranes.

The bonding of nanoparticles on appropriately long chains will enable the free movement of magnetic particles during separation (biomimicry of the ciliary motion of biological membranes). The ciliary motion on PVDF membranes will be further modulated by the absence/presence of a magnetic field (example of 3D modification by intervening in the membrane surface nanoarchitecture). The nature of the invention is a method comprising modifying of separation material surfaces, characterized by placing a flat membrane with generated hydroxyl groups, a modifying solution and dichloromethane in a glass vessel, tightly sealing said vessel and mixing said vessel’s contents, preferably in a laminar flow cabinet in an atmosphere of inert gas, preferably argon or nitrogen, at a temperature of 20 to 40°C over a period of 1 to 6 h, wherein a solution is mixed throughout the entire reaction conduction time, the next step comprising removing said membrane from said glass vessel and washing said membrane with solvents by placing it, in order, in beakers filled with acetone, dichloromethane and water, and finally drying said membrane, preferably at a temperature of 40 to 60°C for 8 to 15 h. Preferably the flat membrane is a polyvinylidene fluoride or polytetrafluoroethylene or polydimethylsiloxane membrane, preferably having a shape of a circle, preferably with a diameter of 25-65 mm. Preferably the modifying solution is obtained by placing a modifying agent, preferably at an amount of 0.3 to 1 g, in a volumetric flask, preferably with a volume of 10 to 40 ml, tightly sealing the volumetric flask and mixing its contents, preferably over a period of 3 to 20 minutes. Preferably the modifying agent is 3-isocyanatopropyltrimethoxysilane or 3- isocyanatopropyltrimethoxysilane or 3-isocyanatopropyltriethoxysilane or 3- isocyanatopropyldimethylchlorosilane or 3-isocyanatopropylmethyldichlorosilane. Preferably 10 to 65 ml of dichloromethane are added. Preferably each membrane washing in each of the solvents lasts 2 to 10 minutes, and the volume of each solvent is 10 to 30 ml.

The nature of the invention is also a method comprising modifying of separation material surfaces, characterized by placing a flat membrane with generated hydroxyl groups, a modifying solution and dichloromethane in a glass vessel, tightly sealing said vessel and mixing said vessel’s contents, preferably in a laminar flow cabinet in an atmosphere of inert gas, preferably argon or nitrogen, at a temperature of 20 to 40°C over a period of 1 to 6 h, wherein a solution is mixed throughout the entire reaction conduction time, the next step comprising removing said membrane from said glass vessel and washing said membrane with solvents by placing it, in order, in beakers filled with acetone, dichloromethane and water, and drying said membrane, preferably at a temperature of 40 to 60°C for 8 to 15 h, further comprising placing said membrane, magnetic nanoparticles, preferably at an amount of 1 to 5 g, and dichloromethane, preferably at a volume of 10 to 40 ml, in a glass vessel, tightly sealing said vessel and mixing said vessel’s contents, preferably over a period of 1 to 5 h at a temperature of 20 to 50°C, and drying said contents, preferably over a period of 20 to 30 h, wherein said magnetic nanoparticles are obtained by washing a metal oxide, preferably having a form of a powder, preferably at an amount of 1 to 5 g, in an order in solvents - acetone, dichloromethane and water - and drying said powder, preferably for 8 to 15 h at a temperature of 40 to 80°C. Preferably the flat membrane is a polyvinylidene fluoride or polytetrafluoroethylene or polydimethylsiloxane membrane, preferably having a shape of a circle, preferably with a diameter of 25-65 mm. Preferably the modifying solution is obtained by placing a modifying agent, preferably at an amount of 0.3 to 1 g, in a volumetric flask, preferably with a volume of 10 to 40 ml, tightly sealing the volumetric flask and mixing its contents, preferably over a period of 3 to 20 minutes. Preferably the modifying agent is 3-isocyanatopropyltrimethoxysilane or 3-isocyanatopropyltrimethoxysilane or 3- isocyanatopropyltriethoxysilane or 3-isocyanatopropyldimethylchlorosilane or 3- isocyanatopropylmethyldichlorosilane. Preferably 10 to 65 ml of dichloromethane are added. Preferably each membrane washing in each of the solvents lasts 2 to 10 minutes, and the volume of each solvent is 10 to 30 ml. Preferably the metal oxide is Fej0₄ or CeOi or GdzOj or Sm2C>3 or PreOi i or Nd₂0₃. Preferably each metal oxide washing in each of the solvents lasts 2 to 10 minutes, and the volume of each solvent is 10 to 30 ml.

The nature of the invention is also a method comprising modifying of separation material surfaces, characterized by placing a flat membrane with generated hydroxyl groups, a modifying solution and dichloromethane in a glass vessel, tightly sealing said vessel and mixing said vessel’s contents, preferably in a laminar flow cabinet in an atmosphere of inert gas, preferably argon or nitrogen, at a temperature of 20 to 40°C over a period of 1 to 6 h, wherein a solution is mixed throughout the entire reaction conduction time, the next step comprising removing said membrane from said glass vessel and washing said membrane with solvents by placing it, in order, in beakers filled with acetone, dichloromethane and water, and drying said membrane, preferably at a temperature of 40 to 60°C for 8 to 15 h, further comprising placing said membrane, magnetic nanoparticles, preferably at an amount of 1 to 5 g, and dichloromethane, preferably at a volume of 10 to 40 ml, in a glass vessel, tightly sealing said vessel and mixing said vessel’s contents, preferably over a period of 1 to 5 h at a temperature of 20 to 50°C, and drying said contents, preferably over a period of 20 to 30 h, wherein said magnetic nanoparticles are obtained by washing a metal oxide, preferably having a form of a powder, preferably at an amount of 1 to 5 g, in an order in solvents - acetone, dichloromethane and water - and drying said powder, preferably for 8 to 15 h at a temperature of 40 to 80°C, the next step comprising functionalizing of said powder by means of silanes with an amino terminus and reactive ethoxy groups by introducing said magnetic nanoparticles having a form of a powder, preferably at an amount of 1 to 5 g, to a silane solution, preferably with a concentration of 0.005 to 0.3 M, mixing and drying. Preferably the silane solution is obtained by mixing a modifier, preferably at an amount of 0.1 to 1 g, with dichloromethane, preferably at a volume of 10 to 40 ml, wherein said modifier is 3-Aminopropyldimethylethoxysilane or 3-Aminopropyltriethoxysilane. Preferably the flat membrane is a polyvinylidene fluoride or polytetrafluoroethylene or polydimethylsiloxane membrane, preferably having a shape of a circle, preferably with a diameter of 25-65 mm. Preferably the modifying solution is obtained by placing a modifying agent, preferably at an amount of 0.3 to 1 g, in a volumetric flask, preferably with a volume of 10 to 40 ml, tightly sealing the volumetric flask and mixing its contents, preferably over a period of 3 to 20 minutes. Preferably the modifying agent is 3-isocyanatopropyltrimethoxysilane or 3-isocyanatopropyltrimethoxysilane or 3- isocyanatopropyltriethoxysilane or 3-isocyanatopropyldimethylchlorosilane or 3- isocyanatopropylmethyldichlorosilane. Preferably 10 to 65 ml of dichloromethane are added. Preferably each membrane washing in each of the solvents lasts 2 to 10 minutes, and the volume of each solvent is 10 to 30 ml. Preferably the metal oxide is Fe₃04 or CeCh or Gd20₃ or S aCh or PreOi i or Nd₂0₃. Preferably each metal oxide washing in each of the solvents lasts 2 to 10 minutes, and the volume of each solvent is 10 to 30 ml.

The nature of the invention is also a method comprising modifying of separation material surfaces, characterized by placing a flat membrane with generated hydroxyl groups, a modifying solution and dichloromethane in a glass vessel, tightly sealing said vessel and mixing said vessel’s contents, preferably in a laminar flow cabinet in an atmosphere of inert gas, preferably argon or nitrogen, at a temperature of 20 to 40°C over a period of 1 to 6 h, wherein a solution is mixed throughout the entire reaction conduction time, the next step comprising removing said membrane from said glass vessel and washing said membrane with solvents by placing it, in order, in beakers filled with acetone, dichloromethane and water, and drying said membrane, preferably at a temperature of 40 to 60°C for 8 to 15 h, further comprising placing said membrane, magnetic nanoparticles, preferably at an amount of 1 to 5 g, and dichloromethane, preferably at a volume of 10 to 40 ml, in a glass vessel, tightly sealing said vessel and mixing said vessel’s contents, preferably over a period of 1 to 5 h at a temperature of 20 to 50°C, and drying said contents, preferably over a period of 20 to 30 h, wherein said magnetic nanoparticles are obtained by washing a metal oxide, preferably having a form of a powder, preferably at an amount of 1 to 5 g, in an order in solvents - acetone, dichloromethane and water - and drying said powder, preferably for 8 to 15 h at a temperature of 40 to 80°C, the next step comprising functionalizing of said powder by means of silanes with an amino terminus and reactive ethoxy groups by introducing said magnetic nanoparticles having a form of a powder, preferably at an amount of 1 to 5 g, to a silane solution, preferably with a concentration of 0.005 to 0.3 M, the next step comprising mixing, drying and placing said powder at an amount of 1 to 5 g in a glass vessel containing 0.4 mmol of a modifying agent containing a Fmoc group, 1 ml of 0.45 M HBTU (O- (Benzotriazol-l-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate) in dichloromethane and 0.5 ml of 33% DIPEA (N,N-Diisopropylethylamine) in dichloromethane at a volume of 20 ml, tightly sealing and mixing, preferably over a period of 0.5 to 3 h at a temperature of 20 to 50°C, removing the solvent and washing with dichloromethane. Preferably immediately after washing, the modified nanoparticles are incubated in a 20% piperidine solution in dichloromethane, preferably over a period of 5 to 15 minutes. Preferably the silane solution is obtained by mixing a modifier, preferably at an amount of 0.1 to 1 g, with dichloromethane, preferably at a volume of 10 to 40 ml, wherein said modifier is 3-Aminopropyldimethylethoxysilane or 3-Aminopropyltriethoxysilane. Preferably the flat membrane is a polyvinylidene fluoride or polytetrafluoroethylene or polydimethylsiloxane membrane, preferably having a shape of a circle, preferably with a diameter of 25-65 mm. Preferably the modifying solution is obtained by placing a modifying agent, preferably at an amount of 0.3 to 1 g, in a volumetric flask, preferably with a volume of 10 to 40 ml, tightly sealing the volumetric flask and mixing its contents, preferably over a period of 3 to 20 minutes. Preferably the modifying agent is 3-isocyanatopropyltrimethoxysilane or 3-isocyanatopropyltrimethoxysilane or 3- isocyanatopropyltriethoxysilane or 3-isocyanatopropyldimethylchlorosilane or 3- isocyanatopropylmethyldichlorosilane. Preferably 10 to 65 ml of dichloromethane are added. Preferably each membrane washing in each of the solvents lasts 2 to 10 minutes, and the volume of each solvent is 10 to 30 ml. Preferably the metal oxide is Fe

or CeCh or Gd (¾ or SimC or RGbOi _I or Nd C> . Preferably each metal oxide washing in each of the solvents lasts 2 to 10 minutes, and the volume of each solvent is 10 to 30 ml. Preferably the modifying agent is [Nl-(9- fluorenylmethoxycarbonyl)-l,13-diamino-4,7,10-trioxatridecan-succinamic acid or l-(9- fluorenylmethyloxycarbonyl-amino)-4,7,10-trioxa-13-tridecanamine hydrochloride with an amino terminus and a Fmoc group or 4-[(2,4-dimethoxyphenyl)(Fmoc-amino)methyl]-phenoxyacetic acid. The invention is presented in the following examples of implementation.

Example 1.

The modification in the example of implementation utilizes a flat polyvinylidene fluoride membrane in the shape of a circle with a diameter of 47 mm. The membrane contains generated hydroxyl groups. The modifying solution is prepared by placing a modifying agent in the form of 3- isocyanatopropyltrimethoxysilane at an amount of 0.411 g in a 20-ml volumetric flask in order to produce a solution with a concentration of 0.1 M.

Afterwards the volumetric flask is filled with 20 ml of dichloromethane. The solution preparation and the modification process are conducted in an atmosphere of an inert gas, argon, in order to eliminate the potential problem of solution polycondensation as a result of the presence of moisture in the air. The modification and preparation process is conducted in a laminar flow cabinet filled with the inert gas. The obtained solution is mixed over a period of 5 minutes.

The membrane is placed in a sealable glass vessel in the form of a bottle and 20 ml of the modifying agent are added.

The modification is conducted in a sealed glass vessel, at a temperature of 30°C over a period of 3 h, and the solution is mixed throughout the entire reaction conduction time.

Afterwards the membrane is removed from the reaction vessel and washed in solvents by placing it, in order, in beakers filled with acetone, dichloromethane and water. Each washing in each solvent lasts 5 minutes, and the volume of each solvent is 20 ml. Afterwards the membrane is dried at a temperature of 60°C over a period of 12 h. The product of the reaction is a polymer material (PVDF) with reactive isocyanate groups on the surface.

Example 2.

Example 2 is different from example 1 in that the modifying agent is 3- isocyanatopropyltrimethoxysilane at an amount of 0.411 g, and the modification process itself is conducted in an atmosphere of an inert gas in the form of nitrogen. The membrane utilized in the example is a polytetrafluoroethylene (PTFE) membrane.

Example 3.

Example 3 is different from example 1 in that the modifying agent is 3- isocyanatopropyltriethoxysilane (CAS: 15396-00-6, Mw=205.29 g/mol) = 0.483 g. The membrane utilized in the example is a polydimethylsiloxane (PDMS) membrane with spiral wounds and hollow fibers.

Example 4.

Example 4 is different from example 1 in that the modifying agent is 3- isocyanatopropyldimethylchlorosilane (CAS: 17070-70-1 , Mw=l 77.71 g/mol) at an amount of 0.355 g·

Example 5.

Example 5 is different from example 1 in that the modifying agent is 3- isocyanatopropylmethyldichlorosilane (CAS: 17070-69-8, Mw=198.12 g/mol) at an amount of 0.396 g·

Example 6.

The polymer material with reactive isocyanate groups on the surface, obtained according to example 1, is placed in a glass vessel together with magnetic nanoparticles.

The method of obtaining the magnetic nanoparticles is as follows.

2 g of metal oxide, Fe30₄, in the form of a powder are washed with solvents in the following order: acetone, dichloromethane and water, 5 minutes per each solvent, using 20 ml of each solvent. Afterwards the powder is dried for 12 h at a temperature of 60°C to remove any contaminants from its surface.

The polymer material and magnetic nanoparticles in the form of 2 g of nanopowder prepared as described above are placed in a glass reaction vessel. 20 ml of dichloromethane are added to the vessel, and the reaction is conducted for 3 h at a temperature of 40°C, with constant mixing. A direct reaction occurs between the hydroxyl groups (OH) of the magnetic nanoparticles and the isocyanate groups (CNO) present on the PVDF membrane, forming a urethane bond as per the following reaction:

After mixing, the membrane with the bonded nanoparticles is removed from the vessel and left to dry for 24 h.

The effect of the modification is a polymer PVDF membrane with a modified surface nanoarchitecture and a stable bonding of magnetic nanoparticles on crosslinkers with freedom of movement under the influence of an external magnetic field.

Example 7.

Example 7 differs from example 6 in that the nanoparticle with magnetic properties is a lanthanide oxide, CeCfy and the drying is conducted in a drier at 60°C for 12 h.

Example 8.

Example 8 differs from example 6 in that the nanoparticle with magnetic properties is a lanthanide oxide, GdiO .

Example 9.

Example 9 differs from example 6 in that the nanoparticle with magnetic properties is a lanthanide oxide, SimCb.

Example 10.

Example 10 differs from example 6 in that the nanoparticle with magnetic properties is a lanthanide oxide, Pr₆O_n.

Example 11.

Example 11 differs from example 6 in that the nanoparticle with magnetic properties is a lanthanide oxide, Nd C> .

Example 12.

Modifying the surface using crosslinkers with isocyanate groups (CNO) and nanoparticles with magnetic properties subjected to additional surface modification.

The method of obtaining the magnetic nanoparticles is as follows.

2 g of metal oxide, FesCfr, in the form of a powder are washed with solvents in the following order: acetone, dichloromethane and water, 5 minutes per each solvent, using 20 ml of each solvent. Afterwards the powder is dried for 12 h at a temperature of 60°C to remove any contaminants from its surface. The nanoparticles undergo functionalization by means of silanes with an amino terminus and reactive ethoxy groups.

2 g of the dried powder are introduced into a 0.1 M silane solution.

The silane solution is obtained by mixing 0.323 g of 3-Aminopropyldimethylethoxysilane (CAS: 18306-79-1, Mw = 161.32 g/mol), a modifier, with 20 ml of dichloromethane. The modification process is conducted in a sealed glass vessel for 3 h at a temperature of 30°C. The solution is then removed and the material is cleaned by washing it with solvents— acetone, dichloromethane and water - each time subjecting it to centrifugation for 5 minutes at 500 rpm. Afterwards the material is dried for 12 h at 60°C.

During the final step, the magnetic nanoparticles with amino groups (N¾) are bonded to the PVDF membrane surfaces with isocyanate groups (CNO).

The materials thus prepared, i.e. the 47 mm diameter membrane and the 2 g of modified nanopowder, are placed in a glass reaction vessel and 20 ml of dichloromethane are added. The reaction is conducted at a temperature of 40°C for 3 h, with constant mixing.

A direct reaction occurs between the amino groups (Nth) of the magnetic nanoparticles and the isocyanate groups (CNO) present on the PVDF membrane, forming a urea bond as per the following reaction:

R-NH2 + R’NCO -» R-NH-CO-NH-R’

After mixing, the membrane with the bonded nanoparticles is removed and left to dry for 24 h.

Example 13.

Example 13 is different from example 12 in that the modifying agent is 3- Aminopropyltriethoxysilane (CAS: 919-30-2, Mw = 221.47 g/mol) at an amount of 0.443 g, and drying is conducted in a drier at 60°C for 12 h.

Example 14.

Example 14 differs from example 12 in that the nanoparticle with magnetic properties is a lanthanide oxide, GdaCft.

Example 15.

Example 15 differs from example 12 in that the nanoparticle with magnetic properties is a lanthanide oxide, SimCfi.

Example 16.

Example 16 differs from example 12 in that the nanoparticle with magnetic properties is a lanthanide oxide, PreOn.

Example 17.

Example 17 differs from example 12 in that the nanoparticle with magnetic properties is a lanthanide oxide, NdoCfi.

Example 18. The polymer material with reactive isocyanate groups on the surface, obtained according to example 1 , is placed in a glass vessel together with magnetic nanoparticles.

The method of obtaining the magnetic nanoparticles is as follows.

2 g of metal oxide, FeaCh, in the form of a powder are washed with solvents in the following order: acetone, dichloromethane and water, 5 minutes per each solvent, using 20 ml of each solvent. Afterwards the powder is dried for 12 h at a temperature of 60°C to remove any contaminants from its surface. The nanoparticles undergo functionalization by means of silanes with an amino terminus and reactive ethoxy groups.

2 g of the dried powder are introduced into a 0.1 M silane solution.

The silane solution is obtained by mixing 0.323 g of 3-Aminopropyldimethylethoxysilane (CAS: 18306-79-1, Mw = 161.32 g/mol), a modifier, with 20 ml of dichloromethane. The process is conducted in a sealed glass vessel for 3 h at a temperature of 30°C. The solution is then removed and the material is cleaned by washing it with solvents - acetone, dichloromethane and water— each time subjecting it to centrifugation for 5 minutes at 500 rpm. Afterwards the material is dried for 12 h at 60°C. The obtained material is a nanopowder with amino groups (NFh).

The nanopowder with amino groups (Nth) at an amount of 2 g is placed in a glass reaction vessel containing 10 ml of a modifying agent with a concentration of 0.4 mmol containing a Fmoc group in the form of [Nl-(9-fhiorenylmethoxycarbonyl)-l,13-diamino-4,7,10-trioxatridecan-succinamic acid, 1 ml of 0.45 M HBTU (0-(Benzotriazol-l-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate) in dichloromethane and 0.5 ml of 33% DIPEA (N,N-Diisopropylethylamine) in dichloromethane. The goal is to activate the available amino groups. Thus prepared, the solution is mixed for 1 h at 40°C, followed by removing the solvent and washing with dichloromethane. The product constitutes nanoparticles with long crosslinkers on their surfaces that contain an amino group protected by the fluorenylmethyloxycarbonyl group.

In order to prepare the material for bonding with CNO groups, the protecting group must be removed from the membrane surface and the amino group (NFh) must be activated.

To accomplish this, immediately after washing the modified nanoparticles are incubated for 10 minutes in a 20% v/v piperidine solution in dichloromethane. The material is ready for nanoparticle bonding or for introducing another modifier segment. In order to introduce another segment, a procedure analogous to the one described above is performed.

The membrane and the modified nanoparticles are placed in a glass vessel and 20 ml of dichloromethane are added. The reaction is conducted for 30 minutes at a temperature of 40°C, with constant mixing. A direct reaction occurs between the amino groups (NFh) of the magnetic nanoparticles and the isocyanate groups (CNO) present on the PVDF membrane, forming a urea bond as per the following reaction:

The effect of the modification is a polymer PVDF membrane with a modified surface nanoarchitecture and a stable bonding of magnetic nanoparticles on very long crosslinkers with freedom of movement under the influence of an external magnetic field.

Example 19.

Example 19 differs from example 18 in that the modifying agent is l-(9- fluorenylmethyloxycarbonyl-amino)-4,7,10-trioxa-13-tridecanamine hydrochloride with an amino terminus and a Fmoc group.

Example 20.

Example 20 differs from example 18 in that the modifying agent is 4-[(2,4-dimethoxyphenyl)(Fmoc- amino)methyl]-phenoxyacetic acid (known as the Rink amide linker).

Example 21.

Example 21 differs from example 19 in that the nanoparticle with magnetic properties is a lanthanide oxide, Gd C> .

Example 22.

Example 22 differs from example 19 in that the nanoparticle with magnetic properties is a lanthanide oxide, SimO .

Example 23.

Example 23 differs from example 19 in that the nanoparticle with magnetic properties is a lanthanide oxide, PreOn.

Example 24.

Example 24 differs from example 19 in that the nanoparticle with magnetic properties is a lanthanide oxide, Nd C> .

Claims

Patent claims

1. A method comprising modifying of separation material surfaces, characterized by placing a flat membrane with generated hydroxyl groups, a modifying solution and dichloromethane in a glass vessel, tightly sealing said vessel and mixing said vessel’s contents, preferably in a laminar flow cabinet in an atmosphere of inert gas, preferably argon or nitrogen, at a temperature of 20 to 40°C over a period of 1 to 6 h, wherein a solution is mixed throughout the entire reaction conduction time, the next step comprising removing said membrane from said glass vessel and washing said membrane with solvents by placing it, in order, in beakers filled with acetone, dichloromethane and water, and finally drying said membrane, preferably at a temperature of 40 to 60°C for 8 to 15 h.

2. The method of claim 1 , characterized in that said flat membrane is a polyvinylidene fluoride or polytetrafluoroethylene or polydimethylsiloxane membrane, preferably having a shape of a circle, preferably with a diameter of 25-65 mm.

3. The method of claim 1 or 2, characterized in that said modifying solution is obtained by placing a modifying agent, preferably at an amount of 0.3 to 1 g, in a volumetric flask, preferably with a volume of 10 to 40 ml, tightly sealing said volumetric flask and mixing said volumetric flask’s contents, preferably over a period of 3 to 20 minutes.

4. The method of claim 1, 2 or 3, characterized in that said modifying agent is 3- isocyanatopropyltrimethoxy silane or 3-isocyanatopropyltrimethoxysilane or 3- isocyanatopropyltriethoxysilane or 3-isocyanatopropyldimethylchlorosilane or 3- isocyanatopropylmethyldichlorosilane.

5. The method of claim 1, 2, 3 or 4, characterized in that dichloromethane is added at a volume of 10 to 65 ml.

6. The method of claims 1 to 5, characterized in that each membrane washing in each of said solvents lasts 2 to 10 minutes, each solvent having a volume of 10 to 30 ml.

7. A method comprising modifying of separation material surfaces, characterized by placing a flat membrane with generated hydroxyl groups, a modifying solution and dichloromethane in a glass vessel, tightly sealing said vessel and mixing said vessel’s contents, preferably in a laminar flow cabinet in an atmosphere of inert gas, preferably argon or nitrogen, at a temperature of 20 to 40°C over a period of 1 to 6 h, wherein a solution is mixed throughout the entire reaction conduction time, the next step comprising removing said membrane from said glass vessel and washing said membrane with solvents by placing it, in order, in beakers filled with acetone, dichloromethane and water, and drying said membrane, preferably at a temperature of 40 to 60°C for 8 to 15 h, further comprising placing said membrane, magnetic nanoparticles, preferably at an amount of 1 to 5 g, and dichloromethane, preferably at a volume of 10 to 40 ml, in a glass vessel, tightly sealing said vessel and mixing said vessel’s contents, preferably over a period of 1 to 5 h at a temperature of 20 to 50°C, and drying said contents, preferably over a period of 20 to 30 h, wherein said magnetic nanoparticles are obtained by washing a metal oxide, preferably having a form of a powder, preferably at an amount of 1 to 5 g, in an order in solvents - acetone, dichloromethane and water - and drying said powder, preferably for 8 to 15 h at a temperature of 40 to 80°C.

8. The method of claim 7, characterized in that said flat membrane is a polyvinylidene fluoride or polytetrafluoroethylene or polydimethylsiloxane membrane, preferably having a shape of a circle, preferably with a diameter of 25-65 mm.

9. The method of claim 7 or 8, characterized in that said modifying solution is obtained by placing a modifying agent, preferably at an amount of 0.3 to 1 g, in a volumetric flask, preferably with a volume of 10 to 40 ml, tightly sealing said volumetric flask and mixing said volumetric flask’s contents, preferably over a period of 3 to 20 minutes.

10. The method of claim 7, 8 or 9, characterized in that said modifying agent is 3- isocyanatopropyltrimethoxysilane or 3-isocyanatopropyltrimethoxysilane or 3- isocyanatopropyltriethoxysilane or 3-isocyanatopropyldimethylchlorosilane or 3- isocyanatopropylmethyldichlorosilane.

11. The method of claim 7, 8, 9 or 10, characterized in that dichloromethane is added at a volume of 10 to 65 ml.

12. The method of claims 7 to 11, characterized in that each membrane washing in each of said solvents lasts 2 to 10 minutes, each solvent having a volume of 10 to 30 ml.

13. The method of claims 7 to 12, characterized in that said metal oxide is Fe₃C>₄ or CeCh or Gd₂C>₃ or Sn^Cb or PreOn or Nd2C .

14. The method of claims 7 to 13, characterized in that each metal oxide washing in each of said solvents lasts 2 to 10 minutes, each solvent having a volume of 10 to 30 ml.

15. A method comprising modifying of separation material surfaces, characterized by placing a flat membrane with generated hydroxyl groups, a modifying solution and dichloromethane in a glass vessel, tightly sealing said vessel and mixing said vessel’s contents, preferably in a laminar flow cabinet in an atmosphere of inert gas, preferably argon or nitrogen, at a temperature of 20 to 40°C over a period of 1 to 6 h, wherein a solution is mixed throughout the entire reaction conduction time, the next step comprising removing said membrane from said glass vessel and washing said membrane with solvents by placing it, in order, in beakers filled with acetone, dichloromethane and water, and drying said membrane, preferably at a temperature of 40 to 60°C for 8 to 15 h, further comprising placing said membrane, magnetic nanoparticles, preferably at an amount of 1 to 5 g, and dichloromethane, preferably at a volume of 10 to 40 ml, in a glass vessel, tightly sealing said vessel and mixing said vessel’s contents, preferably over a period of 1 to 5 h at a temperature of 20 to 50°C, and drying said contents, preferably over a period of 20 to 30 h, wherein said magnetic nanoparticles are obtained by washing a metal oxide, preferably having a form of a powder, preferably at an amount of 1 to 5 g, in an order in solvents - acetone, dichloromethane and water - and drying said powder, preferably for 8 to 15 h at a temperature of 40 to 80°C, the next step comprising functionalizing of said powder by means of silanes with an amino terminus and reactive ethoxy groups by introducing said magnetic nanoparticles having a form of a powder, preferably at an amount of 1 to 5 g, to a silane solution, preferably with a concentration of 0.005 to 0.3 M, mixing and drying.

16. The method of claim 15, characterized in that said silane solution is obtained by mixing a modifier, preferably at an amount of 0.1 to 1 g, with dichloromethane, preferably at a volume of 10 to 40 ml, wherein said modifier is 3-Aminopropyldimethylethoxysilane or 3- Aminopropyltriethoxysilane.

17. The method of claims 15 and 16, characterized in that said flat membrane is a polyvinylidene fluoride or polytetrafluoroethylene or polydimethylsiloxane membrane, preferably having a shape of a circle, preferably with a diameter of 25-65 mm.

18. The method of claims 15, 16 and 17 , characterized in that said modifying solution is obtained by placing a modifying agent, preferably at an amount of 0.3 to 1 g, in a volumetric flask, preferably with a volume of 10 to 40 ml, tightly sealing said volumetric flask and mixing said volumetric flask’s contents, preferably over a period of 3 to 20 minutes.

19. The method of claims 15 to 18, characterized in that said modifying agent is 3- isocyanatopropyltrimethoxysilane or 3-isocyanatopropyltrimethoxysilane or 3- isocyanatopropyltriethoxysilane or 3-isocyanatopropyldimethylchlorosilane or 3- isocyanatopropylmethyldichlorosilane.

20. The method of claims 15 to 19, characterized in that dichloromethane is added at a volume of 10 to 65 ml.

21. The method of claims 15 to 20, characterized in that each membrane washing in each of said solvents lasts 2 to 10 minutes, each solvent having a volume of 10 to 30 ml.

22. The method of claims 15 to 21, characterized in that said metal oxide is Fe₃C>₄ or CeCh or Gd2C>3 or Sn^C or PrgOn or NdaC .

23. The method of claims 15 to 22, characterized in that each metal oxide washing in each of said solvents lasts 2 to 10 minutes, each solvent having a volume of 10 to 30 ml.

24. A method comprising modifying of separation material surfaces, characterized by placing a flat membrane with generated hydroxyl groups, a modifying solution and dichloromethane in a glass vessel, tightly sealing said vessel and mixing said vessel’s contents, preferably in a laminar flow cabinet in an atmosphere of inert gas, preferably argon or nitrogen, at a temperature of 20 to 40°C over a period of 1 to 6 h, wherein a solution is mixed throughout the entire reaction conduction time, the next step comprising removing said membrane from said glass vessel and washing said membrane with solvents by placing it, in order, in beakers filled with acetone, dichloromethane and water, and drying said membrane, preferably at a temperature of 40 to 60°C for 8 to 15 h, further comprising placing said membrane, magnetic nanoparticles, preferably at an amount of 1 to 5 g, and dichloromethane, preferably at a volume of 10 to 40 ml, in a glass vessel, tightly sealing said vessel and mixing said vessel’s contents, preferably over a period of 1 to 5 h at a temperature of 20 to 50°C, and drying said contents, preferably over a period of 20 to 30 h, wherein said magnetic nanoparticles are obtained by washing a metal oxide, preferably having a form of a powder, preferably at an amount of 1 to 5 g, in an order in solvents - acetone, dichloromethane and water - and drying said powder, preferably for 8 to 15 h at a temperature of 40 to 80°C, the next step comprising functionalizing of said powder by means of silanes with an amino terminus and reactive ethoxy groups by introducing said magnetic nanoparticles having a form of a powder, preferably at an amount of 1 to 5 g, to a silane solution, preferably with a concentration of 0.005 to 0.3 M, the next step comprising mixing, drying and placing said powder at an amount of 1 to 5 g in a glass vessel containing 0.4 mmol of a modifying agent containing a Fmoc group, 1 ml of 0.45 M HBTU (0-(Benzotriazol-l-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate) in dichloromethane and 0.5 ml of 33% DIPEA (N,N- Diisopropylethylamine) in dichloromethane as a solvent at a volume of 20 ml, tightly sealing and mixing, preferably over a period of 0.5 to 3 h at a temperature of 20 to 50°C, removing said solvent and washing with dichloromethane.

25. The method of claim 24, characterized in that immediately after washing, modified nanoparticles are incubated in a 20% piperidine solution in dichloromethane, preferably over a period of 5 to 15 minutes.

26. The method of claim 25, characterized in that said silane solution is obtained by mixing a modifier, preferably at an amount of 0.1 to 1 g, with dichloromethane, preferably at a volume of 10 to 40 ml, wherein said modifier is 3-Aminopropyldimethylethoxysilane or 3- Aminopropyltriethoxysilane.

27. The method of claims 25 and 26, characterized in that said flat membrane is a polyvinylidene fluoride or polytetrafluoroethylene or polydimethylsiloxane membrane, preferably having a shape of a circle, preferably with a diameter of 25-65 mm.

28. The method of claims 25, 26 and 27, characterized in that said modifying solution is obtained by placing a modifying agent, preferably at an amount of 0.3 to 1 g, in a volumetric flask, preferably with a volume of 10 to 40 ml, tightly sealing said volumetric flask and mixing said volumetric flask’s contents, preferably over a period of 3 to 20 minutes.

29. The method of claims 25 to 28, characterized in that said modifying agent is 3- isocyanatopropyltrimethoxysilane or 3-isocyanatopropyltrimethoxysilane or 3- isocyanatopropyltriethoxysilane or 3-isocyanatopropyldimethylchlorosilane or 3- isocyanatopropylmethyldichlorosilane.

30. The method of claims 25 to 29, characterized in that dichloromethane is added at a volume of 10 to 65 ml.

31. The method of claims 25 to 30, characterized in that each membrane washing in each of said solvents lasts 2 to 10 minutes, each solvent having a volume of 10 to 30 ml.

32. The method of claims 25 to 31, characterized in that said metal oxide is Fe3C>4 or CeCh or Gd2C>3 or Sni203 or PreOn or NdiCb.

33. The method of claims 25 to 32, characterized in that each metal oxide washing in each of said solvents lasts 2 to 10 minutes, each solvent having a volume of 10 to 30 ml.

34. The method of claims 25 to 33, characterized in that said modifying agent is [Nl-(9- fluorenylmethoxycarbonyl)-l,13-diamino-4,7,10-trioxatridecan-succinamic acid or l-(9- fluorenylmethyloxycarbonyl-amino)-4,7,10-trioxa-13-tridecanamine hydrochloride with an amino terminus and a Fmoc group or 4-[(2,4-dimethoxyphenyl)(Fmoc-amino)methyl]- phenoxyacetic acid.