JP2007518545A - Synthesis of ion-imprinted polymer particles - Google Patents

Abstract

  An ion imprinted polymer containing a metal ion recognition site is synthesized. These particles are synthesized by copolymerizing with functional and crosslinkable monomers in the presence of at least one imprinted metal ion in the form of a ternary complex. The polymerization was carried out by gamma irradiation (without initiator) or photochemistry and thermal polymerization (in the presence of initiator, AIBN). These materials were dried, pulverized and sieved to obtain erbium ion-imprinted polymer particles. Erbium ions were removed from the polymer particles by leaching with mineral acid leaving cavities / bonding sites in the polymer particles. The resulting polymer particles can be used as a solid phase extraction solvent for selective concentration of erbium ions from dilute aqueous solutions.

Description

  The present invention relates to the synthesis of ion-imprinted polymer particles for preconcentration of erbium ions prior to solid phase extraction, and a method thereof. Ion imprinted polymer particles have been prepared by radiation, photochemistry and thermal polymerization.

Monaz sand is processed through a series of beneficiation processes to produce light, medium and heavy rare earth chloride parts. The last part contains 55-60% Y ₂ O ₃ with Dy, Gd and Er as impurities. The preparation of 99.9-99.999% Y ₂ O ₃ is of increasing importance because it is widely used in the manufacture of lasers, superconducting materials and color television phosphors. Thus, the separation of Dy, Gd and Er is an essential prerequisite for preparing such high purity Y ₂ O ₃ . Three different polymerization methods described in this patent allow the separation of erbium from Y ₂ O ₃ .

Enantiomeric separations See Mark et al., 1998, WO 98/07671, which prepared imprinted polymers for the separation of optically active compounds of ibuprofen, naproxen and ketoprofen into their respective enantiomers. A Mosbach (Mussbach) prepared magnetically sensitive component by copolymerizing one or more functional monomers and a crosslinkable monomer in the presence of at least one imprinted molecule and at least one magnetically sensitive component such as iron oxide or nickel oxide. Mosbach et al., 2001, US Pat. No. 6,316,235. The imprint molecule was later removed to form a molecular memory recognition site. These particles are used for the selective separation of two different enantiomeric forms. In addition, Arnold (Arnold) prepared a solvent material for solid phase extraction comprising a polymer matrix containing one or more metal complexes by molecular imprinting that selectively binds only the enantiomers of optically active amino acids or peptides. ) Et al., 1998, US Pat. No. 5,786,427. See Fischer et al., 1995, US Pat. No. 5,461,175, which has synthesized chiral chromatographic materials for separating enantiomers of aryloxypropanol amine derivatives.

Sensor Arnold has developed a sensor consisting of a metal complex that contains an exchangeable ligand that binds to the target molecule and releases a proton, or exchanges with the target molecule during the binding interaction between the metal complex and the target molecule ( Arnold) et al., 2000, US Pat. No. 6,063,637. These sensors are meant for detecting the presence of sugars and other metal binding analytes. First, a molecular material is formed by forming a solution comprising a solvent and (a) a polymeric material capable of undergoing an addition reaction with nitrene, (b) a crosslinking agent, (c) a functional monomer, and (d) an imprint molecule. Reference is made to Yan et al., 1996, US Pat. No. 5,587,273, which prepared printed circuit boards and sensors.

Other applications of molecular imprinting Markovitz (Self-assembled surfactant analogues to synthesize molecularly imprinted porous structures to create at least one supramolecular structure with exposed imprinted groups, See Markowitz et al., 2001, US Pat. No. 6,310,110. An imprinted porous structure is formed by adding a reactive monomer to the mixture and allowing the monomer to polymerize with a supramolecular structure that serves as a template. In 2000, Sasaki et al. Developed a method for forming a molecularly imprinted metal oxide sol / gel material by molecular imprinting on the surface of the sol / gel material, solvent, and imprintable molecule. U.S. Pat. No. 6,057,377. Mossbach and Orof 2003, US Pat. No. 6,255, prepared a molecularly imprinted artificial antibody by mixing methacrylic acid, ethylene glycol dimethacrylate and corticosteroid print molecules to form an artificial antibody. , 461. These antibodies can be used in separation and analysis procedures. Reference is also made to Magnus et al., 2003, US Patent Application No. 2003-049970, which has prepared a selective adsorbent material that can be used for purification or analysis of biopolymers.

Ion Imprint—Anions Prepared molecularly imprinted polymer membranes to selectively collect phosphate, nitrate and ferric ions, Murray 2003, US Patent Application 2003-2003. Reference is made to 113234. These membranes are prepared by copolymerizing a matrix monomer, a crosslinkable monomer, an ion imprint composite, a permeation agent and a polymerization initiator, and then removing ions from the ion imprint composite and the permeation agent. The permeant creates a channel in the membrane, allowing the membrane to communicate with the outer surface of the ion binding site in the membrane. Murray 2003, US Patent Application No. 2003-059346, addresses the removal of phosphate / nitrate anions using a selectively permeable polymer membrane. Selective binding sites are prepared by ferric ion imprint. Permeability is improved by using a polyester that binds metal ions; the polyester is removed from the membrane by the same acid treatment used to remove ferric ions. Polyester creates channels and directs ion migration to the imprint side, resulting in increased flux, but maintains selectivity.

Ion Imprint—Cation See, Singh et al., 2001, US Pat. No. 6,248,842, which produced a selectively crosslinked chelate polymer by replacing an acrylic chelator with a polymerizable functional group. The resulting substituted acrylic chelator is then complexed with the target metal ion, ie copper. Next, a crosslinkable monomer is added and the composite material is crosslinked. The complexed metal is then removed to provide a cross-linked polymeric chelator templated for the target metal ion. The complexing functional group relates to the detection and extraction of uranyl ions by polymer imprints consisting of the formula CTCOOH, wherein T is hydrogen or any halogen (preferably chlorine), their methyl and halogen substituents or COOH or PhCOOH, See John et al., 1999, WO 99/15707. Gladis and Rao are also ions for preconcentration / separation of uranyl ions from hosts of tetravalent, trivalent and divalent inorganic ions from both aqueous and synthetic seawater solutions. Teaches the synthesis of imprinted polymers. They form ternary mixed ligand complexes with imprinted ions quinolin-8-ol or its dihalo derivatives and 4-vinylpyridine in the presence of styrene and divinylbenzene as functional and crosslinkable monomers. Dai et al., 2001, prepared a mesophorous adsorbent material by ion imprint technology for the separation of minerals using bifunctional ligands such as amines, thiols, carboxylic acids, sulfonic acids and phosphonic acids. Reference is made to US Pat. No. 6,251,280. Carboxylic acid groups on the bifunctional ligand are used during the formation of mesophoric adsorbent materials specific for erbium template ions.

Lao et al. [Trends in Anal. Chem; 2003] has reviewed the preparation of custom materials for preconcentration / separation of metals with ion-imprinted polymers (IIP-SPE) for solid phase extraction. An ion-imprinted polymer (IIP) material with nanopores is formed using 2,2′-azo with the formation of a ternary complex of palladium imprinted ions with dimethyl glyoxime and 4-vinylpyridine and cyclohexanol as the porogen. Prepared by thermal copolymerization with styrene and divinylbenzene in the presence of bisisobutyronitrile [Sobhi et al., Anal. Chim. Acta, 488 (2003) 173-182]. Cationic imprinted SPE materials for the separation of La and Gd based on diethylenetriaminepentaacetic acid (DTPA) derivatives have been prepared. The imprint effect was observed with materials prepared in the presence of Gd salts and showed higher efficiency and selectivity than the corresponding blank polymer [Garcia et al., Tetrahedran Lett. 39 (1998) 8651]. The functionalized monomer of DTPA was copolymerized with commercially available divinylbenzene (DVB) containing 45% ethylstyrene in the presence of Gd ³⁺ salt. The resulting IIP was found to be more selective for Gd than La [Vigneau et al., Anal. Chim. Acta, 435 (2001) 75]. These selection studies were expanded to determine S _{Gd / Eu} and S _{Gd / Lu} using Gd imprinted IIP [Logneau et al., Chem. Lett. (2002) 202]. Biju et al. [Anal. Chim. Acta, 478 (2003) 43-51] describes Dy (III) IIP particles by copolymerizing styrene (functional monomer) in the presence of DVB as a crosslinkable monomer. Has been synthesized. Some authors [Talanta, 60 (2003) 747-754] have reported improved selectivity factors for Dy over La, Nd, Y and Lu after γ-irradiation of DyIIP particles.

  The prepared molecularly imprinted polymer particles are widely used in the separation of enantiomers, structurally related drugs, amino acid derivatives, nucleotide base derivatives and the like. They therefore find wide application in the chemical and pharmaceutical industries, water purification and wastewater treatment. On the other hand, the preparation of ion-imprinted polymer particles is not well known for the separation of closely related inorganic ions. The patents by Die et al. [US Pat. No. 6,251,280; 2001] address this problem alone, but are too common and closely related to Er from lanthanide-based elements. Does not include separation.

  The main purpose of this study is to prepare erbium IIP materials by gamma irradiation in the presence of various amounts of methyl methacrylate (MMA) (functional monomer).

  It is another object of the present invention to provide a method for the preparation of erbium IIP material by photochemical polymerization as a function of exposure time.

  It is another object of the present invention to provide a method for the preparation of erbium IIP material by thermal polymerization as a function of EGDMA concentration (crosslinkable monomer).

  Yet another object of the present invention is to preconcentrate the separation of erbium from other selected lanthanide-based elements using IIP particles through solid phase extraction.

Thus, the present invention forms (a) a mixed ligand ternary complex of erbium imprinted ions with 5,7-dichloroquinolin-8-ol and 4-vinylpyridine,
(B) dissolving the ternary complex in a suitable porogen to form a prepolymerized mixture;
(C) combining the mixture of step (b) with a functional monomer and a crosslinkable monomer and polymerizing by gamma irradiation or by photochemistry and thermal polymerization to obtain a polymeric material;
(D) preparing erbium ion imprinted polymer particles by grinding and sieving the polymer material obtained in (c);
(E) selectively leaching the imprinted ion-embedded material in the polymer particles of (d) using a mineral acid, and a method of synthesizing ion-imprinted polymer particles for preconcentration of erbium ions for solid phase extraction. provide.

  In one embodiment of the invention, gamma irradiation is performed as a function of methyl methacrylate (functional monomer) concentration.

  In another embodiment of the invention, photochemical polymerization is performed as a function of UV irradiation time.

  In another embodiment of the invention, thermal polymerization is performed as a function of ethylene glycol dimethacrylate (crosslinkable monomer) concentration.

  In another embodiment of the invention, the functional monomer is selected from the group consisting of 4-vinylpyridine and methyl methacrylate.

  In another embodiment of the invention, the crosslinkable monomer comprises ethylene glycol dimethacrylate.

  In another embodiment of the invention, the reaction is carried out using 2,2'-azobisisobutyronitrile used as an initiator in step (c).

  In yet another embodiment of the invention, the grinding and sieving in step (d) is performed after drying the erbium ion imprinted polymer material.

  In another embodiment of the invention, the mineral acid used for leaching comprises HCl.

  The present invention provides a method for synthesizing selective erbium ion imprinted polymer particles with accessible and homogeneous imprinted sites for solid phase extraction from dilute aqueous solutions.

As used herein, the term “ion imprint polymer (IIP)” refers to a cavity or “imprint site” that is complementary to the shape and size of the imprint ion when the imprint ion is removed from the material. It refers to a material polymerized around imprint ions in such a way that it remains in the material. When IIP material is added to a dilute solution containing imprint ions, the imprint sites selectively bind the imprint ions. Such binding allows the use of the ordered material for its concentration / separation from other such ions similar to imprinted ions. The salient features of the present invention include the following:
i) Synthesis of custom-made IIP particles by thermal, light and □ -irradiation polymerization,
ii) polymer pretreatment to leach imprint ions;
iii) Concentration from dilute aqueous solution.

i) Synthesis of erbium IIP particles as ordered.
The synthesis of custom erbium IIP materials involves two main steps: (I) formation of a ternary mixed ligand complex with imprinted ions (erbium) and (ii) MMA and EGDMA of the ternary mixed ligand complex. There is polymerization. The formation of the ternary complex was performed in 2-methoxyethanol (porogen). The evidence of complex formation was monitored by recording the UV-visible spectrum. FIG. 1 shows the absorption spectra of 5,7-dichloroquinolin-8-ol (DCQ), 4-vinylpyridine (VP), DCQ + VP, Er ³⁺ + DCQ, Er ³⁺ + VP, and Er ³⁺ + DCQ + VP. These spectra clearly show ternary complex formation in methoxyethanol solution (see FIG. 2).

The ternary composite was imprinted upon addition of functional (MMA) and crosslinkable (EGDMA) monomers. In the case of thermal and photochemical polymerization, only 2,2′-azobisisobutyronitrile is added as a polymerization initiator. The resulting IIP material was dried in an oven at 50 ° C. to obtain an erbium IIP material. FIG. 3 shows a schematic diagram of the polymer imprint method. These materials were pulverized and sieved to obtain erbium IIP particles. 4, 5 and 6 show the effect of MMA concentration, UV irradiation time and EGDMA concentration on Er ³⁺ concentration using IIPs synthesized by □ -irradiation, photochemistry and thermal polymerization, respectively.

ii) Pretreatment of IIP material to leach imprint ions Imprint ions, Er ³⁺ leached from the polymer by stirring with 5N HCl solution for 6 hours. The resulting IIP particles were dried in an oven at 50 ° C. to obtain IIP-SPE particles that could be used for selective concentration of erbium ions from dilute aqueous solution.

iii) Concentration of Er ³⁺ from dilute aqueous solution The concentration of erbium ions from dilute aqueous solution using erbium IIP particles has been studied in detail. FIG. 4 shows the effect of methyl methacrylate (MMA) concentration on the percent concentration of erbium ions using Er ³⁺ IIPs polymerized by gamma irradiation. The effect of UV irradiation time on the percent concentration of erbium using IIP particles synthesized by photochemical polymerization is shown in FIG. The effect of crosslinkable monomer (EGDMA) concentration during erbium ion concentration using IIP particles synthesized by thermal polymerization is shown in FIG.

Accordingly, the present invention provides a “synthesized custom-made IIP-SPE particles for erbium ion incorporation and method” comprising the following related steps:
(I) Preparation of IIP particles by γ-ray irradiation, photochemistry and thermal polymerization,
(Ii) concentration of erbium ions from the dilute aqueous solution,
(Iii) Separation of erbium from other lanthanide elements.

  The following examples illustrate the synthesis of ion imprinted polymeric materials for selective solid phase extraction of erbium ions.

Example 1: Polymerization by gamma irradiation Erbium chloride 1.0 mM (0.44 g), DCQ 3.0 mM (0.64 g) and VP2 mM (0.21 g) in 50 ml R.D. B. The flask was placed in a flask and dissolved in 5 or 10 ml of 2-methoxyethanol by stirring. MMA 4 (0.4 g) or 8 (0.8 g) and 12 (1.2 g) mM and EGDMA 16 (3.17 g) or 32 (6.34 g) and 48 (9.52 g) mM added And stirred until a homogeneous solution was obtained. The monomer mixture was transferred into a test tube, cooled to 0 ° C., purged with N ₂ for 10 minutes, and sealed.

These solutions were exposed to 1 megarad of gamma irradiation using a Co ⁶⁰ source for 4 hours. The formed solid was washed with water and dried in an oven at 50 ° C. This resulted in 5.70, 9.43 and 14.27 g of polymer material with 4, 8 and 12 mM functional monomer, respectively. Polymer embedded erbium ions were leached with 50% (v / v) HCl with stirring for 6 hours. This resulted in 4.14, 7.52 and 11.29 g of polymer material with 4,8 and 12 mM functional monomer, respectively, after drying in an oven at 50 ° C.

Example 2: Polymerization by light means Erbium chloride 1.0 mM (0.44 g), DCQ 3.0 mM (0.64 g) and VP2 mM (0.21 g) in 50 ml R.D. B. It put in the flask and melt | dissolved by stirring in 10 ml of 2-methoxyethanol. MMA 8 mM (0.8 g), EGDMA 32 mM (6.35 g) and AIBN 50 mg were added and stirred until a homogeneous solution was obtained. The monomer mixture was then transferred into a test tube, cooled to 0 ° C., purged with N ₂ for 10 minutes, and sealed. These solutions were polymerized by exposure to UV irradiation (300 nm) for 4, 8 and 16 hours. The formed solid was washed with water and dried in an oven at 50 ° C. This resulted in 7.55, 9.85 and 9.95 g of polymer material with 4, 8 and 16 hours of UV irradiation (300 nm). Polymer embedded erbium ions were leached with 50% (v / v) HCl with stirring for 6 hours. This resulted in 5.35, 7.31 and 7.36 g of polymer material after 4, 8 and 16 hours of UV irradiation, respectively, after drying in an oven at 50 ° C.

Example 3 Polymerization by Thermal Means Erbium chloride 1.0 mM (0.44 g), DCQ 3.0 mM (0.64 g) and VP 2.0 mM (0.21 g) in 50 ml R.D. B. It put in the flask and melt | dissolved by stirring in 10 ml of 2-methoxyethanol. MMA 8.0 mM (0.8 g); and 8, 16 and 32 mM EGDMA (1.59, 3.17 and 6.34 g) and 50 mg AIBN were added and stirred until a homogeneous solution was obtained. The polymerization mixture was cooled to 0 ° C., purged with N ₂ for 10 minutes, sealed and heated in an oil bath at ˜80 ° C. by stirring for 2 hours. The formed solid was washed with water and dried in an oven at 50 ° C. This resulted in 4.32, 5.50 and 8.84 g of polymer material with 50, 66 and 80% crosslinkable monomer. The polymer-embedded erbium ions were leached with 50 ml (v / v) HCl, 100 ml with stirring for 6 hours, filtered and dried in an oven at 50 ° C. This resulted in 2.59, 3.90 and 7.90 g of erbium ion imprinted polymer material.

Advantages of the Invention The liquid-liquid extraction method replaces the conventional ion exchange method because it is highly reliable and easy to expand. However, the liquid-liquid extraction method requires 40-50 stages of countercurrent extraction because the Er separation factor for Y is closer to 1.0. In addition, the use of large amounts of hazardous chemicals, ie solvents and extraction solvents, is essential. On the other hand, separations based on ion-imprinted polymer particles described in the present invention are environmentally more manageable and include reduced costs due to lower consumption of chemicals, as well as Y, Dy, Gd, Tb, etc. Provides a better selection factor for Er with respect to

References:
Patent document WO9807671 Mark et al.
Separating enatiomers by molecular imprinting
US Pat. No. 6,316,235 Mosbach et al.
Preparation and use of magnetically susceptible polymer particles
U.S. Pat. No. 5,786,428 Arnold et al.
Adsorbents for amino acids and neptide separation

US Pat. No. 5,461,175 Fisher et al.
Method for separating enantiomers of aryloxipropanolamine derivatives and chiral solid phase chromatography material for use in the method
U.S. Patent No. 6,063,637 Arnold et al.
Sensors for sugars and other metal binding analytes
US Patent No. 5,587,273 Yang et al.
Molecularly imprinted materials, method for their preparation and devices including such materials

US Patent No. 6,310,110 Markowitz et al.
Molecularly imprinted material made by template directed synthesis
US Patent No. 6,057,377 Sasaki et al.
Molecular receptors in metal oxide sol-gel materials
US Pat. No. 6,255,461 Mosbach et al.
Artificial antibodies to corticosteroids prepared by molecular imprinting
US Patent No. 20030487070 Magnus et al.
Selective affinity material, preparation there of by molecular imprinting, and use of the same.

US Patent No. 2003113234 Murray
Polymer based permeable membrane for removal of ions
US Patent No. 2003059346 Murray
Method and apparatus for environmental phosphate / nitrate pollution removal using a selectively permeable molecularly imprinted polymer membrane
US Pat. No. 6,248,842 Shin et al.
Synthetic polymer matrices including pre-organised chelation sites for the selective and reversible binding of metals.

WO9915,707 John et al.
Detection and extraction of an ion in a solution, particularly uranium ion.
US Pat. No. 6,251,280 Dai et al.
Imprint coating synthesis of selective functionalized ordered mesoporous sorbents for separation and sensors

Non-patent literature Garcia et al., Tetrahedron Lett., 39 (1998) 8651.
Ionic imprinting effect in gadolinium / lanthanum separation
Bignew et al., Anal. Chim. Acta, 435 (2001) 75.
Ionic imprinted resins based on EDTA and DTPA derivatives for lanthanides (III) separation
Bignew et al., Chem. Lett. (2002) 202.
Solid-Liquid separation of lanthanide / lanthanide and lanthanide / actinide using ionic imprinted polymer based on a DTPA derivative

Bijou et al., Anal. Chim. Acta, 478 (2003) 43.
Ion imprinted polymer particles: synthesis.Characterization and dysprosium ion uptake properties suitable for analytical applications.
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Effect of γ-irradiation of ion imprinted polymer (IIP) particles for preconcentrative separation of dysprosium from other selected lanthanides.

The UV-visible absorption spectra of 5,7-dichloroquinolin-8-ol (DCQ), 4-vinylpyridine (VP), DCQ + VP, Er ³⁺ + DCQ + Er, Er ³⁺ + VP, and Er ³⁺ + DCQ + VP are shown. It is a schematic diagram of ternary mixed ligand complex formation. It is a schematic diagram of a polymer imprint method. -Shows the effect of methyl methacrylate (MMA) (functional monomer) concentration on the preconcentration of Er3 ⁺ using IIP particles synthesized by irradiation. The effect of UV irradiation time on the preconcentration of Er ³⁺ using IIP particles synthesized by photochemical polymerization is shown. Figure 6 shows the effect of ethylene glycol dimethacrylate (EGDMA) (crosslinkable monomer) concentration on preconcentration of Er3 ⁺ using IIP particles synthesized by thermal polymerization.

Claims (9)

(A) forming a mixed ligand ternary complex of erbium imprinted ions with 5,7-dichloroquinolin-8-ol and 4-vinylpyridine;
(B) dissolving the ternary complex in a suitable porogen to form a pre-polymerizing mixture;
(C) combining the mixture of step (b) with a functional monomer and a crosslinkable monomer and polymerizing by gamma irradiation or by photochemical and thermal polymerization to obtain a polymeric material;
(D) preparing erbium ion imprinted polymer particles by grinding and sieving the polymer material obtained in (c) above,
(E) ion imprint for solid phase extraction preconcentration of erbium ions, comprising selectively leaching the imprinted ion implant material in the polymer particles of (d) with a mineral acid ion imprinted) A method for synthesizing polymer particles.   The method according to claim 1, wherein the gamma irradiation is performed as a function of the methyl methacrylate (functional monomer) concentration.   The method of claim 1 wherein the photochemical polymerization is performed as a function of UV irradiation time.   The method of claim 1 wherein the thermal polymerization is performed as a function of ethylene glycol dimethacrylate (crosslinkable monomer) concentration.   The method of claim 1, wherein the functional monomer is selected from the group consisting of 4-vinylpyridine and methyl methacrylate.   The method of claim 1, wherein the crosslinkable monomer comprises ethylene glycol dimethacrylate.   The process according to claim 1, wherein the reaction is carried out using 2,2'-azobisisobutyronitrile used as an initiator in step (c).   The process according to claim 1, wherein the grinding and sieving in step (d) is performed after drying the erbium ion imprinted polymer material.   The process according to claim 1, wherein the mineral acid used for leaching comprises HCl.

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