EP1989146A1

EP1989146A1 - Molecularly imprinted polymer, process for production thereof and process for the selective treatment of poorly degradable and/or toxic compounds in liquids

Info

Publication number: EP1989146A1
Application number: EP07722869A
Authority: EP
Inventors: Ute Steinfeld; Barbara Palm
Original assignee: Korea Institute of Science and Technology Europe Forschungs GmbH
Current assignee: Korea Institute of Science and Technology Europe Forschungs GmbH
Priority date: 2006-02-20
Filing date: 2007-02-20
Publication date: 2008-11-12
Also published as: WO2007096135A1; DE102006007796B3; JP2009529066A; KR20080110590A; US20100036188A1

Abstract

The present invention relates to a molecularly imprinted polymer and also to a production process therefor and a process for selective treatment of poorly degradable and/or toxic compounds in liquids using the molecularly imprinted polymers. Such polymers and processes are required for selective removal and/or degradation of biological, poorly degradable pollutants or toxic compounds, for example from wastewaters. Consequently, a molecularly imprinted polymer suitable for the selective treatment of at least one poorly degradable and/or toxic compound is provided having a polymeric network which is made up of monomers and has cavities of predetermined size, wherein the cavities are arranged at predetermined spacings and have specific binding sites and/or patterns for the poorly degradable and/or toxic compounds.

Description

Molecularly embossed polymer, process for its preparation and process for the selective treatment of hardly degradable and / or toxic compounds in

liquids

The present invention relates to a molecularly imprinted polymer and a production process therefor and to a process for selectively treating sparingly degradable and / or toxic compounds in liquids using the molecularly imprinted polymers. Such polymers and processes will be needed to selectively remove and / or degrade biologically degradable pollutants or toxic compounds, for example, from effluents.

Conventional biological wastewater treatment in sewage treatment plants achieves inadequate degradation for a number of biologically degradable pollutants or substances with a certain degree of persistence. For the purpose of a more extensive The elimination of these substances from waste water or water is also used on a large scale, including so-called Advanced Oxidation Processes (AOP), which are highly reactive free-radical species, mainly of the hydroxyl radical with a redox potential of +2.80 V. , as an oxidizer to effectively remove degradable pollutants, even up to a possible complete mineralization of organic substances to carbon dioxide and water. Because of this high reactivity, however, the majority of organic compounds in the water, including the easily degradable attacked. This nonspecific attack then results in an unnecessarily high demand for oxidant and / or energy to produce the reacting species, depending on the type of "Advanced Oxidation" process used furthermore, the underlying process itself loses effectiveness.

It is therefore an object of the present invention to provide molecularly imprinted polymers and a process for the selective treatment of sparingly degradable and / or toxic compounds in liquids, in which the selective treatment can be made more specific and therefore more cost-effective.

This object is achieved by the molecularly imprinted polymer of claim 1, the process for its preparation according to claim 3 and the method for the selective treatment of at least one persistent and / or toxic compound in liquids

Claim 5 solved. Advantageous developments of Polymers according to the invention, the preparation process according to the invention and the treatment process according to the invention are given in the respective dependent claims. The method according to the invention for the selective treatment of compounds has several individual steps, which will be explained in more detail below. First, the inclusion of the compound, ie a substance or a specific group of substances from the liquid, such as water or wastewater, in a molecularly imprinted polymer, as described for example in claim 1.

The specific or selective uptake of the target molecule and similar compounds in the solution takes place on the one hand via the molecular shape, on the other by defined molecular recognition mechanisms or specific binding interactions (such as ionic interactions or salt bridges, hydrogen bonds, hydrophobic interactions and others) With the bonding groups on the Kavitäts- surfaces, It can be the inclusion of the respective scaffle or the relevant substance group rniccels adsorption (attachment) on the surface as well as by absorption (storage) inside the material (in the further course is therefore generally of "sorption "or" sorb "spoken).

A combination or successive arrangement of different selective polymer materials for each of the relevant hardly degradable substances that are present in the wastewater concerned, is conceivable.

Following the incorporation of the target compound in the polymer, foreign substances, which to some extent are incorporated into the polymer, washed out with suitable solvents or solvent mixtures. Water, all imaginable aqueous solutions and organic solvents may be used as solvents, also in combination with one another and also with water or with dissolved organic or inorganic compounds. This step is not necessarily required but may be done.

In a further step, the target compounds are liberated or desorbed as preferred compounds or their degradation products with suitable solvents or solvent mixtures. Here too, water, all imaginable aqueous solutions and organic solvents can be used, even in mixtures with one another and with water or else with dissolved organic or inorganic compounds.

Subsequently, the process according to the invention, in which the target compounds are separated in this way, can also be combined or coupled with various degradation processes, in particular so-called "advanced oxidation" processes (AOP = advanced oxidation processes) be reduced.

A further improvement results when materials or substances are used which have a catalytically active reaction-accelerating effect. These can be used in addition or else coupled to the polymer, for example. Coupling with the AOPs is also possible, but only the activation energy for the formation of certain oxidation products can be reduced. It is It is also possible to control the reaction by means of such materials or substances in such a way that biodegradable products are already formed by partial oxidation and that thus the oxidizing agent or oxidation process of the AOP can be used more effectively.

Furthermore, a combination with a biological disinfection is advantageous.

As already indicated above, the washing step for removing the foreign substances taken up and / or the release of the substance or compound (compound) which has been taken up in preference can be avoided or omitted. This is possible if the molecularly imprinted polymer (MGP) loaded with the respective substance is integrated directly into a subsequent AOP. The reagents required for the AOP can be directly: injected into the polymer material or passed through. Direct coupling with catalysts is also possible.

In this case, the selectively to be treated compound is already degraded directly in the polymer and then the degradation products with suitable

Solvents or solvent mixtures as described above removed from the polymer again or sorbierc.

Another possibility or variant of the method is that the catalytically active center is incorporated into the structure of the molecularly imprinted polymer (MIP) and thus serves as an artificial enzyme analogue.

The catalytic activity of the polymers can by the correct organization of the catalytic groups in the molecularly imprinted binding sites is achieved. As catalytic groups may serve structures which generate hydroxyl radicals and / or other oxygen-containing oxidants.

In a previously known fixed catalytic mechanism for the degradation of the subject substances, it is possible to use transition state analogs in the preparation of the molecularly imprinted polymers

(TSAs) which stabilizes the transition state of the particular degradation reaction and increases the rate of product formation and / or controls product formation either directly or indirectly.

Typical degradation reactions may be, for example: hydrolysis of esters, amides, ethers; Ring cleavage, aromatic substitution and other reactions whose transition states can be used as transition state analogues in the manufacturing processes.

A further possibility is the use of Coenzyi Ti analogs or coordinating compounds to catalytically assist the reactions. Other catalytic centers can also be used.

The release of the degradation products then takes place after the degradation reaction as mentioned above with the appropriate solvents or solvent mixtures.

With the polymers according to the invention and the process according to the invention for the selective treatment of compounds in liquids, a large number of advantages over conventional processes can be achieved. On the one hand, easy and cost-effective removal of harmful substances from readily degradable constituents or matrix compounds, which interfere with the treatment of water by means of AOP, is possible. Even an accumulation and concentration of poorly degradable compounds or classes of compounds is possible to achieve a cost reduction of the AOP or ^'an increase removals by reducing the volume of liquid.

Furthermore, in the method according to the invention, only the predetermined selected and relevant hardly degradable or toxic compounds or classes of compounds are specifically taken up from the liquid, whereby an extension of the operating time of the selective filter component (polymer) is made possible. The relevant pollutants, in contrast to the use with activated carbon, can also be degraded later or at the same time to less harmful products, e.g. by an AOP integrated into the polymer or by separation downstream of the polymer.

In particular, the process according to the invention makes it possible to flexibly use individually tailored molecularly imprinted polymers for a large number of different critical pollutants. The molecularly imprinted polymers used in this way can be regenerated and reused. It is also possible, instead of degrading the hardly degradable compound, to recover them from the polymer, especially in the case of rare compounds. Overall, there is thus a wide range of possible variations and adaptations of the liquid-keying treatment system according to the present invention to the particular problem at hand. The process can be used to treat liquid media such as water or wastewater that is contaminated or contaminated with special pollutants. Examples include, among other areas:

Industrial wastewater, such as Process waste water of the chemical or pharmaceutical industry or the pulp and paper industry, municipal wastewater,

Hospital wastewater or treatment of its partial flows, as well as remediation of contaminated sites and landfills. The method is suitable for the treatment of waste water with a high AOX content.

The process can be used in the sewage treatment plant as a replacement for activated carbon or the use of ultrafiltranion as final cleaning.

Furthermore, the method of treatment of

Pollutant-contaminated animal excretions, e.g. of livestock. Also, the recovery of rare chemicals absorbed in the selective filter component is conceivable.

In the following, the process for preparing the molecularly imprinted polymers (embossing procedure of the MIP) will now be briefly described. This consists u.a.

β from a complex formation of the target molecule (template, print molecule) dissolved in a suitable solvent (porogen) or its molecular units or functional groups with the so-called functional monomer (polymerizable unit which interacts with the print molecule) via specific interactions . Followed by the polymerization step together with the cross-linker (unit having two or more linkages with the functional monomers) for establishing a network of wells of defined size and specific binding sites and binding patterns at defined intervals, β and finally washing out the template molecule. küls. '-

The subject of the present invention is the use in connection with environmental fluid media, e.g. Water or wastewater, and with: the selective removal and degradation of ingredients of these liquid media. Relevant here is the selection and modification of the functional monomers or of a mixture of functional monomers, cross-linkers or a mixture of crosslinkers, porogen or porogen mixtures and of radical initiators and suitable catalytic groups for particular target molecules or target molecule groups or their Derivatives and the preparation of a suitable washing and purification protocol for newly prepared polymers. The invention relates in addition to the production of novel functional monomers, by the inventive method for the selective treatment of liquids with recording, washing, desorption and degradation step with the materials and reagents or technologies used, if necessary, the method can all listed

Steps or just selected ones included.

Typical functional monomers used (polymerizable moiety that interacts with the print molecule) may be: Carboxylic acids, such as acrylic acid, methacrylic acid, Triflu- or methacrylic acid, vinyl benzoic acid, itaconic acid, and their amides;

Sulfonic acids such as acrylamidomethylpropanesulfonic acid;

heteroaromatic or weak bases, such as substituted or unsubstituted vinylpyridines, vinylpyrimidines, vinylpyrazoles, vinylimidazoles, vinyltriazines, vinylpurines, -indoles, -quinolines, -acridines, -phenanthridines, bis (acrylamido) pyridine;

aliphatic or aromatic vinyl derivatives, such as substituted or unsubstituted styrenes, vinylnaphthalenes, vinylnaphthalenecarboxylic acids, vinylnaphthols, vinylanthracenes, vinylanthracenecarboxylic acids, vinylphenanthrenes, vinylphenanthrenecarboxylic acids, and similar fused aromatics, vinylbenzamidine; Acryloylamino-benzamidine, (amidinoalkyl) -styrene, where the alkyl may be methyl, ethyl or propyl, N-acryloyl- (amidinoalkyl) -aniline, vinyl derivatives with chelating groups, such as iminodiacetic acid, ethylenediamine tetraacetic acid, inter alia, for complexing metal ions , Silanes, as well as mixtures of such monomers. Other functional monomers can also be used.

As a crosslinker (unity mic two or more linkage possibilities with the functional monomers) can serve:

Isomers of divinylbenzene;

Bis (acryloyl) alkanes, ethane, propane and butane being suitable as aikans; Systems based on acrylic acid or methacrylic acid, such as, for example, ethylene glycol dimethacrylate (EDMA) and trimethylolpropane trimethacrylate (TRIM);

tri- and tetrafunctional acrylate cross-linkers, e.g. Pentaerythritol triacrylate (PETRA) and pentaerythritol tetraacrylate (PETEA) as well as

Crosslinkers containing functional groups, e.g. Acrylamide units which are linked to the amide nitrogens by means of aliphatic (methylene-a.a.), aromatic (phenylene and the like) or heteroaromatic (pyridinyl and the like) spacers. Other cross-linkers can also be used, for example also cross-linkers that are stable against UV light or ozone.

As porogens (solvents that serve as solvents for the polymerization reaction and induce porosity in the imprinted polymer), solvents of different dielectric constants can be used, the parameters such as different swelling properties of the polymer, different morphologies of the polymer with different structures and pore diameters / porosity or influence different inductive strengths of noncovalent interactions, in particular aliphatic or alicyclic hydrocarbons such as hexane, heptane or cyclohexane,

aromatic hydrocarbons, such as toluene;

halogenated hydrocarbons, such as chloroform, dichloromethane or 1,2-dichloro-anhane;

short-chain alcohols, such as methanol, ethanol, propanol; Ether, acetonitrile, tetrahydrofuran, ethyl acetate, acetone, dimethylformamide, dioxane, dimethyl sulfoxide;

also in mixtures with each other and with water.

As initiators (radical initiators) 2,2'-azobisisobutyronitrile (AIBN), 2,2'-azobis (2,4-dimethyl valeronicril) (ADVN) and others can be used, including the use of UV light possible.

The molecularly imprinted polymers can be present in the following forms after the production process:

^β preparation of polymer monoliths and subsequent fragmentation,

Grafting of the embossed polymer onto preformed particles, production of polymer beads from suspension, emulsion or dispersion polymerization,

* Polymer particles bound to thin films or polyraer membranes,

* Polymer membranes, ^θ Surface-embossed polymer phases: The formed complexes of the template molecules with the functional monomers bind to activated surfaces, such as silicon or glass surfaces, and after washing, give defined embossed structures.

The polymer can be introduced into a separation column or into a filter device made of plastic, glass, stainless steel or other materials; or bonded to thin films, surfaces of different materials or polymer membranes or else itself can be used as a membrane. Alternatively, the particles can be freely floating in the liquid phase. Other devices for receiving the polymer can be used.

A combination or successive arrangement of several sorption steps with the same or different selective polymer materials is conceivable. The reactor shape can also vary.

The flow of contaminated with the substance or group of substances concerned. Water can be passed through both the separation column, filter device, membrane, etc., and also be conducted past the sorbent material almost in parallel. Other methods can also be used.

In the following, some examples of polymers embossed with molecules of the group chlorophenoxy compounds are presented. These are in the table in

Fig. 1 shown. This table represents the relevant substances used for the preparation of the molecularly imprinted polymers.

The individual components were mixed together in 50 ml test tubes with ice cooling, purged with nitrogen for 5 min, sealed with parafilm and left at 60 ^° C. for 19 h.

For workup, the polymer blocks were crushed until particles with a particle size <250 microns are formed; then triturated four times with 50 ml of acetone and filtered through a 20 micron sieve.

The purification of the polymers was carried out: at polymer 1 and 5_:

β four times with acetonitrile: acetic acid (99: 1) and

Methanol: Acetic acid (90:10) at 65 ⁰ C, then wash five times with 50 ml of water,

at polymer 4_:

each twice with: 50 ml of acetic acid (glacial acetic acid), 50 ml of acetonitrile: acetic acid (1: 1), 50 ml of acetonitrile: acetic acid: (90:10), 50 ml of methanol: acetic acid (80:20), 50 ml of methanol and wash five times with 50 ml of water each time.

FIG. 2 now shows the proportion of sorbed (in%) and concentration of clofibric acid remaining in the aqueous phase (in mol / l) after one or two sorption reactions per 300 mg of the molecularly imprinted polymer in MIP 1 treated wastewater 10 ml landfill leachate with the addition of 1.2 * 10 ^"4 M clofibric acid, 300 mg MIP 1 was added to this effluent to be treated and stirred for 30 minutes.

It can be seen immediately that more than 60% of the clofibric acid was removed from the wastewater even with a single sorption. With double sorption, a sorption rate of over 80% will be achieved.

3 shows in table form the fraction (in%) of the sorbed clofibric acid (initial concentration c = 1.2 * 10 ^"4 M in landfill leachate) after one (column 2) or twice sorption (column 3) with 300 tng molecularly imprinted Polymer after incubation for 30 minutes with stirring Column 2 gives the used molecularly imprinted polymer according to the table shown in Fig. 1.

Again, it can be seen again that excellent sorption rates are achieved by means of the molecularly imprinted polymers according to the invention.

Claims

claims

A molecularly imprinted polymer suitable for the selective treatment of at least one poorly degradable and / or toxic compound with a monomeric polymeric network having predetermined size cavities, said cavities being arranged at predetermined intervals and being specific for the hardly degradable and / or toxic compounds Have binding sites and / or patterns.

2. Polymer according to claim 1, characterized in that as monomers, carboxylic acids such as acrylic acid, methacrylic acid, trifluoromethacrylic acid, vinylbenzoic acid, itaconic acid, and their amides; Sulfonic acids, such as acrylamidomethylpropanesulfonic acid; heteroaromatic or weak bases, such as substituted or unsubstituted vinylpyridines, vinylpyrimidines, vinylpirazoles, vinylimidazoles, vinyltriazines, vinylpurines, vinylindoles, vinylquinolines, vinylacridines, vinylphenanthridines, bis (acrylamido) pyridine; aliphatic or aromatic vinyl derivatives, such as substituted or unsubstituted styrenes, vinylnaphthalenes, vinylnaphthalenecarboxylic acids, vinylnaphthols, vinylanthracenes, vinylanthracenecarboxylic acids, vinylphenanthrenes, vinylphenantantecarboxylic acids, and similar fused aromatics, vinylbenzamidine; Acryloylaminobenzamidine, (amidinoalkyl) -stryol, preferably with methyl, ethyl or propyl as alkyl, N-acryloyl- (amidinoalkyl) -aniline, vinyl derivatives with chelating groups, such as iminodiacetic acid, ethylenediamineturaacetic acid, etc., for complexing metal ions, silanes and also

Mixtures of such monomers, and / or as crosslinking agents isomers of divinylbenzene, bis (acryloyl) alkanes, preferably with ethane, propane or butane as alkane; Systems based on acrylic acid or methacrylic acid, such as e.g. Ethylene glycol dimethacrylate (EDMA) and trimethylolpropane trimethacrylate (TRIM); tri- and tetrafunctional acrylate cross-linkers, e.g. Pentaerythritol triacrylate (PETRA) and

Pentaerythritol tetraacrylate (PETEA) and crosslinkers containing functional groups, e.g. Acrylamide units which are attached to the amide nitrogens via aliphatic (methylene etc.), aromatic (phenylene and the like) or heteroaromatic (pyridinyl etc.) spacers.

3. A process for preparing a molecularly imprinted polymer according to any one of claims 1 or 2, characterized in that a complex of one or more poorly degradable and / or toxic compounds (target molecule, template, Princmolekül) or their MoIe- külteilen or their Scrukturanaloga and one or more Polyτπerisxerbaren monomers in a solvent (porogen) or solvent mixture is formed, the complex is polymerized together with a cross-linker to form a polymer network with cavities of defined size and / or for the hardly degradable and / or toxic compound, specific binding sites and / or patterns in predetermined patterns, and washing out of the hardly degradable and / or toxic compound.

4. The method according to claim 3, characterized in that as carboxylic acids carboxylic acids, such as acrylic acid, methacrylic acid, trifluoromethacrylic acid, vinylbenzene acid, itaconic acid, and their amides; Sulfonic acids, such as acrylamidomethylpropanesulfonic acid; heteroaromatic or weak bases, such as substituted or unsubstituted vinylpyridines,

Vinylpyrimidines, vinylpyrazoles, vinylimidazoles, vinyltriazines, vinylpurines, vinylindoles, vinylquinolines, vinylacridines, vinylphenanthridines, bis (acrylamido) pyridine; aliphatic or aromatic vinyl derivatives such as substituted or unsubstituted styrenes, vinylnaphthalenes, vinylnaphthalenecarboxylic acids, vinylnaphthols, vinylanthracenes, vinylanthracene carboxylic acids, vinylphenanthrenes, vinylphenantantecarboxylic acids, and the like condensed

Aromatics, vinylbenzamidine; Acryloylaminobenzamidine ,. (Amidinoalkyl) -styrene, preferably with methyl, ethyl or propyl as Al-kyl _. , N-acryloyl- (amidinoalkyl) -aniline, vinyl derivatives having chelating groups, such as iminodiacetic acid, ethylenediaminetetraacetic acid, inter alia, for complexing metal ions, silanes, and also mixtures of such monomers and / or cross-linking agents of the polymerization. ^• Isomers of divinylbenzene, bis (acryloyl ) - alkanes, preferably with ethane, propane and butane as alkane; Systems based on acrylic acid or methacrylic acid, such as ethylene glycol dimethacrylate (EDMA) and trimethylolpropane trimethacrylate

(TRIM); tri- and tetrafunctional acrylate cross-linkers, e.g. Pentaerythritol triacrylate (PETRA) and pentaerythritol tetraacrylate (PETEA) as well as crosslinkers containing functional groups, e.g. Acrylamide units, which are linked to the amide nitrogens via aliphatic (methylene and the like), aromatic (phenylene, etc.) or heteroaromatic (pyridinyl, etc.) spacers and / or used as solvent solvents of different dielectric constant, the parameters, such as different Swelling properties of the polymer, different morphologies of the polymer with different structures and pore diameters / porosity or different binding scores of the noncovalent interactions influence, in particular aliphatic or alicyclic hydrocarbons such as hexane, heptene or cyclohekanane; aromatic hydrocarbons, such as toluene; halogenated hydrocarbons, such as chloroform, dichloromethane or 1,2-dichloroethane, - short-chain alcohols, such as methanoi, ethanol, propanol;

Ethers, acetonitrile, tetrahydrofuran, ethyl acetate, acetone, dimethylformamide, dioxane, dimethyl sulfoxide; also in mixtures with one another and with water and / or as a radical initiator of the polymerization

2,2'-azobisisobutyronitrile (AIBN), 2,2'-azobis (2,4-dimethyl-valeronitrile) (ADVN) and used otherwise.

5. A process for the selective treatment of at least one poorly degradable and / or toxic compounds in liquids, characterized in that the liquid is contacted with at least one on the compound to be treated or one of its degradation products molecularly imprinted polymer, the compound to be treated in the molecular imprinted polymer is removed, optionally some or all of the non-treated compounds are removed from the molecularly imprinted polymer and the compound to be treated or its degradation products are removed from the molecularly imprinted polymer.

6. The method according to claim 5, characterized marked nee that the molecularly imprinted polymer is coupled with a degradation of the scaffold to be treated accelerating catalyst material.

7. The method according to any one of claims 5 and 6, character- ized in that as catalyst mate rial CoenΣym analogs or coordinating compounds λ ^ erwendeü v / earth.

5. The method according to any one of claims 5 to 7, characterized in that the degradation by means of advanced oxidation processes (AOP), plasma treatment, photocatalysis, ozonation, ultraviolet radiation, Fenton processes and the like takes place.

9. The method according to any one of the preceding claims, characterized in that as the catalyst material titanium, iridium oxide, iron and / or diamond is introduced into the polymers, advantageously in / on the cavities which the

Target molecules of the ^'advanced oxidation processes bind.

10. The method according to one of the two preceding claims, characterized in that free radical - is introduced, advantageously titanium oxide, in "dissolved form and the molecular embossed polymers washed around.

11. The method according to any one of claims 5 to 10, characterized in that at least two different molecularly imprinted polymers for the treatment of at least two poorly degradable and / or toxic compounds are used.

12.- Method according to one of claims 5 to 11, character- ized in that molecularly imprinted

Polymers according to one of claims 1 or 2 are used.

13. Use of a molecularly imprinted polymer and / or process according to one of the preceding claims in the environment, for the treatment,

Purification and / or quality improvement of liquids, in particular of effluents, such as industrial wastewater, process waters of the chemical or pharmaceutical industry or of the paper and pulp industry, municipal wastewaters, hospital effluents, excretions of animals, in particular livestock, also in connection with microbial treatment processes. ren, in particular as a replacement of activated carbon or UlLrafiltration as final cleaning.

14. Use of a molecularly imprinted polymer and / or a method according to any one of claims 1 to 12 for the recovery of rare chemicals or their degradation products.

15. Use according to claim 13 or 14 for remediation and landfill drainage and / or landfill remediation.