Preparation method of multi-crosslinking hydrophilic copper (II) ion imprinted polymer

Abstract

The invention relates to a preparation method of a multi-cross-linked hydrophilic copper (II) ion imprinted polymer, which belongs to the field of functional high polymer materials and comprises the following two steps: firstly, carrying out free radical copolymerization on an allyl tertiary amine salt modified salicylaldoxime copper (II) complex, a first tonality monomer, a first cross-linking agent and a water-based initiator in water, neutralizing after reaction, filtering and drying to obtain a second tonality monomer; a cross-linked polymer containing copper ions and tertiary amine groups is obtained; the preparation method comprises the following steps: firstly preparing a quaternary ammonium cation hydrophilic cross-linked polymer, then dissolving the quaternary ammonium cation hydrophilic cross-linked polymer in an organic solvent, reacting with an unsaturated alkylation reagent to generate a polymerizable quaternary ammonium cation hydrophilic cross-linked polymer, then adding a second tonality monomer, a second cross-linking agent and an initiator for secondary copolymerization, and finally preparing an imprinted polymer in a hollow resin ball, porous membrane or fiber form through a precipitation, membrane forming or spinning process. The solid-phase anion and cation dual-extraction agent for copper (II) ion imprinting and counter ions thereof is suitable for high-selectivity enrichment and deep extraction separation of copper (II) ions in various water systems, and has the function and characteristic of simultaneously extracting counter anions.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of functional polymer materials, and particularly relates to a preparation method of a multiple cross-linked hydrophilic copper (II) ion imprinted polymer, which is used as a solid-phase anion-cation double extractant for copper (II) ion imprinting and its counterion, and is suitable for high-selectivity enrichment and deep extraction separation of copper (II) ions in various water systems, and has the functions and characteristics of simultaneously extracting counter anions. BACKGROUND

[0002] 5-alkyl salicylaldehyde oxime is a high-selectivity extractant for liquid-liquid extraction separation of copper (II) in the current copper hydrometallurgy industry, and its copper-iron separation coefficient can reach 450-550, the extraction capacity is large, and the extraction performance is good. The high selectivity of 5-alkyl salicylaldehyde oxime for copper ions is due to the fact that the coordination atoms of 5-alkyl salicylaldehyde oxime are N and O, when two 5-alkyl salicylaldehyde oxime and Cu (II) form a chelate, a planar square structure is formed, and the H + of the phenolic hydroxyl group (O-H) of 5-alkyl salicylaldehyde oxime is exchanged with Cu (II) to form a neutral extract. In addition, the hydrogen bond between the oxime hydroxyl group (O-H) of 5-alkyl salicylaldehyde oxime and the phenolic oxygen anion further increases the stability of the chelate. Therefore, salicylaldehyde oxime extractant has high selectivity chelation performance for Cu (II). However, the 5-alkyl salicylaldehyde oxime has the following disadvantages: when the concentration of 5-alkyl salicylaldehyde oxime copper (II) chelate is high, precipitation easily occurs; and when the organic phase is regenerated by back extraction, free acid is entrained, and a small amount of emulsion also occurs, and the oil-water two-phase chromatographic separation time is long, so that the process control of copper hydrometallurgy is complex and variable, the production environment is poor, and waste pollution is serious. In addition, deep removal of Cu (II) is also an important application technology in other metal material refining industries.

[0003] In addition, the liquid-liquid extraction process is a proton exchange process of copper (II) ions and extractants, so when the extraction is recycled for many times, the acid concentration of the water phase of the extraction system gradually increases; at the same time, the anions (such as SO4 2− , PO4 3− , NO3 − and Cl -The waste acid liquid formed in the process of extracting copper (II) ions from the waste liquid of pickling and plating of copper (II) ions will also be discharged. In order to reduce the environmental pollution caused by the waste acid liquid, in recent years, scientists at home and abroad have studied a kind of salicylaldehyde oxime or salicylaldehyde Schiff base containing tertiary amine group in the molecular structure as a copper (II) ion solvent extraction agent or solid phase extraction agent, which is called a bidentate extraction agent of copper (II) ion. Compared with the traditional copper (II) ion solution extraction agent, the extraction agent can extract copper (II) ion and the counter anion accompanying it at the same time, so that the material balance in the extraction process can be more fully maintained. However, the synthesis technology of the tertiary amine group containing salicylaldehyde oxime or salicylaldehyde Schiff base as a copper (II) ion extraction agent is complex, the raw material price is high, and the performance needs to be improved.

[0004] Ion imprinted polymer is a branch of imprinted polymer, which has recognition, high selectivity and affinity for specific ions as a solid phase extraction agent, and has been used for the separation, enrichment and analysis of some trace heavy metal ions in medicine, food, drinking water and environment. The high selectivity of ion imprinted polymer for specific ions depends on the matching degree of the cavity size, valence state, coordination site number of the imprinted polymer and metal ions. However, the stability of the cavity size of the existing ion imprinted polymer is easily affected by environmental temperature, medium properties and mechanical action, and loses its high selectivity for specific ions.

[0005] The functional monomer for preparing ion imprinted polymer is a polymerizable ligand or chelating ligand. The polymerizable ligand or chelating ligand can form a stable complex with transition metal ions. The ionic bond and coordination bond between the polymerizable ligand or chelating ligand and transition metal ions have stronger force than hydrogen bond, van der Waals force, hydrophobic interaction, etc., and have strong chelation directionality, which is conducive to the preparation of imprinted polymer with high selectivity and stable imprinted function; the recognition process through coordination has the advantages of rapid and reversible combination; the coordination between metal ions and ligand or chelating ligand has good thermodynamic stability, and it is relatively easy to reach kinetic equilibrium, and has a wide range of applications; however, since the crosslinking agent used is mostly ethylene glycol bisacrylate or bisacrylamide methane, etc., the ion imprinted polymer material prepared is prone to hydrolysis reaction in acid and alkaline aqueous solution, causing the ion imprinted polymer material to lose its structural stability, and cannot be used for a long time in the absorption-desorption cycle under acid and alkaline environmental conditions. At the same time, the ion imprinted polymer material has less imprinted sites and small saturated adsorption capacity; the ion imprinted polymer material has deep pore channels, and the diffusion resistance of template ions close to the recognition site is large, which prolongs the equilibrium ion exchange time of the ion imprinted polymer material.

[0006] Based on the defects of the prior art, the team of the present inventors has developed a kind of transition metal ion imprinted polymer material containing quaternary ammonium cation and salicylaldehyde Schiff base according to the principle of molecular synthesis design, CN102924656, CN103193928, CN104356298, CN105646827 and CN105126909, the transition metal ion imprinted polymer structure contains salicylaldehyde oxime, amine group and quaternary ammonium cation three kinds of functional groups, as a solid phase imprinting bidentate extractant of copper (II), which can quickly extract copper (II) ion and its accompanying anion, realize the material balance in the extraction process, eliminate the environmental pollution factors such as SO4 2− , PO4 3− , NO3 − and Cl - ; at the same time, compared with the existing solution extractant, it is convenient to use, low loss and small pollution. In order to improve the rapid ion exchange capacity of copper (II) ion imprinted resin, CN107573462B discloses a copper (II) ion surface imprinted polymer with polystyrene as the base material, and the saturation adsorption time is less than 2 minutes. SUMMARY

[0007] On the basis of the above research work, in order to further improve the stability of the copper (II) ion imprinted polymer cavity space under various conditions, ensure the high selectivity of the copper (II) ion imprinted polymer, and realize the short saturation adsorption and desorption time, large adsorption capacity, the present application provides a kind of multiple crosslinking hydrophilic copper (II) ion imprinted polymer, which is used as a copper (II) ion solid phase imprinting bidentate extractant, used for high selectivity enrichment, deep extraction separation and persistent circulation of copper (II) ion in various water systems, and has the functions and characteristics of extracting anion at the same time.

[0008] This invention provides a method for preparing a hydrophilic copper(II) ion-imprinted polymer with multiple crosslinks in its polymer chain. The polymer chemistry principle involves using an allyl tertiary amine salt-modified salicylaldehyde oxime copper(II) complex as a functional monomer, an allyl ammonium salt as the first modulating monomer, and a polyallyl ammonium salt as the first crosslinking agent to complete the first free radical copolymerization in aqueous solution, thereby obtaining a polymer chain containing copper(II). A water-soluble crosslinked polymer containing copper(II) ions and tertiary amine salts is first prepared. Then, after alkali neutralization, the tertiary amine groups on the polymer chain undergo a quaternization reaction with an unsaturated alkylating agent to obtain a hydrophilic crosslinked polymer containing vinylbenzene, copper(II) ions, tertiary amine salts, and polymerizable quaternary ammonium cations. Next, the hydrophilic crosslinked polymer containing styrene groups, copper(II) ions, tertiary amine salts, and polymerizable quaternary ammonium cations is further subjected to a second free radical solution polymerization in an organic solution with styrene, acrylonitrile, or acrylate as the second modulating monomer and divinylbenzene as the second crosslinking agent to obtain a hydrophilic copper(II) ion-imprinted polymer with a multi-crosslinked polymer chain. The allyl tertiary amine salt modified salicylaldehyde copper(II) complex is selected from the structure shown in general formula (1):

[0009] General formula (1) In the general formula (1), R1 is selected from C1 to C2. 18 One of the hydrocarbon groups, where X is selected from Cl, Br, CH3COO, or p One of -CH3C6H4SO3.

[0010] The allylammonium salt used as the first modulating monomer refers to one of the hydrochloride, hydrobromide, acetate, or p-toluenesulfonate of N-alkyl-N,N-diallylamine; wherein the alkyl group is selected from C1 to C2. 18 One of the hydrocarbon groups.

[0011] The polyallyl ammonium salt used as the first crosslinking agent refers to one or more of the following: N,N,N-triallylamine, N,N,N',N'-tetraallylethylenediamine, N,N'-dimethyl-N,N'-diallylethylenediamine, N,N'-diethyl-N,N'-diallylethylenediamine, N,N'-dibenzyl-N,N'-diallylethylenediamine, or N,N'-diallylpiperazine hydrochloride, hydrobromide, acetate, or p-toluenesulfonate.

[0012] As is well known to those skilled in the art, the proportions of the functional monomer of general formula (1), the first modulating monomer, the first crosslinking agent, the second modulating monomer, and the second crosslinking agent used in the preparation of the multi-crosslinked hydrophilic copper(II) ion-imprinted polymer of the present invention control the pore size, saturated adsorption capacity, equilibrium adsorption time, and stability of the copper(II) ion-imprinted polymer. A higher proportion of the functional monomer of general formula (1) is beneficial to increasing the saturated adsorption capacity of the copper(II) ion-imprinted polymer; an increased proportion of the first modulating monomer and the second modulating monomer is beneficial to increasing the pore size of the copper(II) ion-imprinted polymer and shortening the ion exchange equilibrium time; an increased proportion of the first crosslinking agent and the second crosslinking agent increases the pore stability of the condensed pores of the copper(II) ion-imprinted polymer, reduces the pore size of the copper(II) ion-imprinted polymer, and makes ion exchange diffusion the main factor.

[0013] As is well known to those skilled in the art, the condensed state of the multi-crosslinked hydrophilic copper(II) ion-imprinted polymer, whether it is foam-like, fibrous, thin-film-like, or hollow spherical, can significantly increase the specific surface area of ​​the copper(II) ion-imprinted polymer, effectively demonstrating its adsorption capacity and shortening the equilibrium adsorption time. Therefore, the addition of a porogen is essential in the preparation of the multi-crosslinked hydrophilic copper(II) ion-imprinted polymer of this invention. The porogen is selected from one or more of N-methylpyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, dimethyl sulfoxide, or hexamethylphosphoramide, and is also the organic solvent selected in the preparation of the multi-crosslinked hydrophilic copper(II) ion-imprinted polymer of this invention.

[0014] In summary, the optimized ratio of general formula (1) / first modulating monomer / first crosslinking agent / second modulating monomer / second crosslinking agent, as well as suitable preparation technology, are key to preparing the multi-crosslinked hydrophilic copper(II) ion imprinted polymer with excellent comprehensive performance (high selectivity for copper(II) ion adsorption, high ion exchange capacity, short saturation adsorption time, long-lasting cycle performance, and convenient, safe and effective use).

[0015] The specific preparation method of the aforementioned multi-crosslinked hydrophilic copper(II) ion-imprinted polymer is as follows: Step 1: Preparation of cross-linked polymers containing copper(II) ions and tertiary amine groups on the polymer chain Weigh out the salicylaldehyde oxime copper(II) complex modified with general formula (1), the first modulating monomer, the first crosslinking agent, and the aqueous initiator in sequence, and mix them together in a reactor containing deionized water. After stirring evenly, purge with nitrogen to remove oxygen for 30 min, raise the temperature to 50~90℃, and complete the free radical copolymerization reaction in the aqueous solution after 6~12 h to obtain an aqueous solution of crosslinked polymer containing copper(II) ions and tertiary amine salt. After the temperature of the aqueous solution of crosslinked polymer containing copper(II) ions and tertiary amine salt drops to room temperature, slowly add an appropriate amount of saturated sodium bicarbonate aqueous solution for alkali treatment. After precipitation is complete, filter and dry to obtain a crosslinked polymer containing copper(II) ions and tertiary amine groups on the polymer chain.

[0016] The allyl tertiary amine salt-modified salicylaldehyde oxime copper(II) complex has the structure shown in general formula (1):

[0017] General formula (1) In general formula (1), R1 is selected from C1 to C2. 18 One of the hydrocarbon groups, X is selected from Cl, Br, CH3COO or p One of -CH3C6H4SO3.

[0018] The allyl ammonium salt is a first-modifying monomer, referring to one of the hydrochloride, hydrobromide, acetate, or p-toluenesulfonate salts of N-alkyl-N,N-diallylamine; wherein the alkyl group is selected from C1 to C2. 18 One of the hydrocarbon groups.

[0019] The polyallyl ammonium salt as the first crosslinking agent refers to one or more of the following: hydrochloride, hydrobromide, acetate, or p-toluenesulfonate of N,N,N-triallylamine, N,N'-diallylpiperazine, N,N,N',N'-tetraallylethylenediamine, N,N'-dimethyl-N,N'-diallylethylenediamine, N,N'-diethyl-N,N'-diallylethylenediamine, or N,N'-dibenzyl-N,N'-diallylethylenediamine. The mass ratio of the functional monomer of the general formula (1) to the first modulating monomer to the first crosslinking agent to the deionized water is 1:0.2~2:0.05~0.5:2~200.

[0020] The aqueous initiator is selected from one or more of hydrogen peroxide, sodium persulfate, potassium persulfate, ammonium persulfate, azobisisobutylamidine hydrochloride, azobisisobutylimidazoline hydrochloride, 4,4'-azobis(cyanopentarate sodium), or azobisisopropylimidazoline hydrochloride. The amount of the aqueous initiator is 1 to 13% of the total mass of the functional monomer of general formula (1), the first modulating monomer, and the first crosslinking agent.

[0021] Step 2: Preparation of multi-crosslinked hydrophilic copper(II) ion-imprinted polymer The cross-linked polymer containing copper(II) ions and tertiary amine groups on the polymer chain is dissolved in an organic solvent, and an unsaturated alkylating agent and a polymerization inhibitor are added. The mixture is stirred and reacted at 20-80°C for 6-24 h to obtain a hydrophilic cross-linked polymer solution containing copper(II) ions and polymerizable quaternary ammonium cations on the polymer chain. After the temperature of the hydrophilic cross-linked polymer solution containing copper(II) ions and polymerizable quaternary ammonium cations on the polymer chain drops to room temperature, a second modulating monomer, a second cross-linking agent, and an initiator are added. The mixture is stirred evenly and purged with nitrogen for 30 min. The temperature is then raised to 50-90°C, and a free radical copolymerization reaction in an organic solution is carried out for 6-12 h to obtain a multi-cross-linked polymer solution containing copper(II) ions and quaternary ammonium cations on the polymer chain. Hollow resin spheres, porous membranes, or fiber materials of the multi-cross-linked hydrophilic copper(II) ion imprinted polymer are obtained by solvent precipitation, drop coating, wet spinning, and other processes. The organic solvent mentioned therein refers to one or more of N-methylpyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, dimethyl sulfoxide, or hexamethylphosphoramide; the amount of the organic solvent used is 2 to 200 times the total mass of the general formula (1), the unsaturated alkylating agent, the first modulating monomer, the first crosslinking agent, the second modulating monomer, and the second crosslinking agent.

[0022] The unsaturated alkylating agent refers to one of 3-chloropropene, 3-bromopropene, and p-chloromethylstyrene; the amount of the unsaturated alkylating agent is 20-80% of the sum of the molar amounts of N atoms in general formula (1), the first modulating monomer, and the first crosslinking agent.

[0023] The polymerization inhibitor refers to one or more of hydroquinone, p-methoxyphenol, tert-butylhydroquinone, 2,6-dibutylhydroquinone, 2,6-di-tert-butyl-p-cresol, and 2,4,6-tri-tert-butylphenol; the amount of the polymerization inhibitor is 0.2 to 12% of the mass of the unsaturated alkylating agent.

[0024] The second modulating monomer refers to one or more of styrene, acrylonitrile or acrylate, and the amount of the second modulating monomer is 0.1 to 10 times the mass of general formula (1); The second crosslinking agent refers to divinylbenzene, and the amount of the second crosslinking agent is 0.05 to 5 times the mass of general formula (1).

[0025] The initiator refers to one or more of benzoyl peroxide, lauroyl peroxide, methyl ethyl ketone peroxide, azobisisobutyronitrile, azobisisoheptanenitrile, or dimethyl azobisisobutyrate, and the amount of the initiator is 1 to 13% of the total mass of the unsaturated alkylating agent, the second modulating monomer, and the second crosslinking agent.

[0026] The copper(II) ion-imprinted polymer of this invention is prepared using a two-stage solution polymerization process. The first stage involves copolymerization in an aqueous solution to obtain a water-soluble crosslinked polymer containing copper(II) ions and tertiary amine salts on the crosslinked polyallyl ammonium salt backbone. The second stage involves copolymerization in an organic solution to obtain a hydrophilic copper(II) ion-imprinted polymer containing copper(II) ions, tertiary amine groups, and quaternary ammonium cations on the crosslinked polyallyl ammonium backbone, as well as a crosslinked polystyrene backbone, with the two crosslinked backbones linked by bonding. Compared to existing ion-imprinted materials, the three-dimensional network structure of the two crosslinked backbones linked by bonding in this invention significantly improves the cavity space stability of the copper(II) ion-imprinted polymer and reduces its susceptibility to environmental, media, and mechanical influences. This is crucial for ensuring high selectivity of copper(II) ion exchange during the recycling process of the copper(II) ion-imprinted polymer.

[0027] The beneficial effects of this invention are: The main chain or side chain structure of the multi-crosslinked hydrophilic copper(II) ion-imprinted polymer of the present invention does not contain ester bonds or amide bonds, and it has high stability in acid and alkaline media, and can continuously maintain the acid and alkaline chemical stability of the copper(II) ion-imprinted polymer during the adsorption-desorption cycle.

[0028] The multi-crosslinked hydrophilic copper(II) ion-imprinted polymer structure of the present invention employs the multi-crosslinking effect of dual polymer chains. The copper(II) ion-imprinted polymer exhibits high environmental stability, media stability, and mechanical stability during recycling, which is of great significance for ensuring the high selectivity of the copper(II) ion-imprinted polymer.

[0029] The multi-crosslinked hydrophilic copper(II) ion-imprinted polymer of this invention features a uniformly distributed quaternary ammonium cation unit structure, significantly improving its water wettability. This facilitates the rapid diffusion of free copper(II) ions in aqueous solutions, resulting in a shorter time to reach adsorption equilibrium and overcoming the shortcomings of existing cation exchange resins, such as strong hydrophobicity within the cavities and long equilibrium adsorption times. Furthermore, the copper(II) ion-imprinted polymer also possesses acid-base neutralization and anion exchange capabilities.

[0030] The multi-crosslinked hydrophilic copper(II) ion imprinted polymer of the present invention, after elution and recovery of copper(II), is easily transformed into a zwitterionic imprinted polymer in an alkaline solution. It can not only selectively chelate and extract copper(II) ions, but also adsorb counter anions, thus maintaining the balance of anions and cations in the extracted solution during the extraction process. Detailed Implementation

[0031] The following examples further illustrate the multi-crosslinked hydrophilic copper(II) ion-imprinted polymer and its preparation method provided by the present invention, with the aim of providing a better understanding of the content of the present invention.

[0032] 56 g of bis(N,N-diallylamylmethyl)salicylaldehyde oxime copper(II)·2H₂O, 32 g of N,N-diallyl-N-benzylamine hydrochloride, 12 g of N,N,N-triallylamylamine hydrochloride, 8.8 g of azobisisobutylamidine hydrochloride, and 500 g of deionized water were weighed into a reactor. After stirring evenly, the reactor was purged with nitrogen for 30 min to remove oxygen. The temperature was then raised to 60-65℃ for aqueous solution polymerization for 4 h. The polymerization temperature was then increased to 80-90℃ and polymerization was continued for 4 h. After cooling to room temperature, a saturated sodium bicarbonate aqueous solution was slowly added. After complete precipitation, the solution was filtered, washed with water, and vacuum dried to obtain 90.7 g of greenish-yellow solid resin. The 90.7 g of greenish-yellow solid resin was dissolved in 860 g of N,N-dimethylacetamide. After purging with nitrogen for 30 min to remove oxygen, 57 g of p-chloromethylstyrene and 1.5 g of [unclear text - likely a continuation of the previous sentence] were added. Hydroquinone was stirred at room temperature for 20 h, followed by the addition of 53 g styrene, 48 g acrylonitrile, 22 g divinylbenzene, 3.5 g benzoyl peroxide, and 4.5 g azobisisobutyronitrile. After stirring until homogeneous, the mixture was heated to 60-65 °C for polymerization for 4 h. As the viscosity of the reaction system increased, 500 g N,N-dimethylacetamide was continuously added to dilute the mixture. The polymerization temperature was then increased to 80-90 °C, and polymerization was continued for 4 h to obtain a copper(II) ion-imprinted polymer (1-1) solution. The copper(II) ion-imprinted polymer (1-1) solution was continuously sprayed into 8% dilute ammonia water for treatment. After filtration and washing, the spherical resin was subjected to Soxhlet extraction with tetrahydrofuran and water for 24 h to remove N,N-dimethylacetamide and unreacted monomers, resulting in spherical resin with a particle size of 0.3-0.8 mm. The spherical resin with a particle size of 0.3~0.8 mm was rinsed with 1.5 mol / L hydrochloric acid to remove copper(II) ions; then the spherical resin was neutralized and rinsed with 5 mol / L ammonia water. After centrifugation at a constant speed of 2000±200 r / min for 5 min, 600.3 g of pale yellow copper(II) imprinted polymer (1-1) spherical resin was obtained.

[0033] Thermogravimetric analysis showed that 600.3 g of the pale yellow copper(II) imprinted polymer (1-1) contained 328.5 g of water, with an initial thermal decomposition temperature of 197℃. At a constant temperature of 25℃, the 600.3 g of the pale yellow copper(II) imprinted polymer (1-1) was continuously leached with a copper sulfate solution with a pH of 4.5. The results showed that the time for saturation adsorption of copper(II) ions by the copper(II) imprinted polymer (1-1) was 2.8 min, and the saturation adsorption capacity of copper(II) ions was 1.55 mg / g. These results indicate that the copper(II) imprinted polymer (1-1) has high hydrophilicity and a fast copper(II) ion exchange rate.

[0034] Comparative Example 1: Preparation of Copper(II) Ion Imprinted Polymer (1-1) Film The copper(II) ion imprinted polymer (1-1) solution prepared in Example 1 was drop-coated onto a clean glass plate. Then, 8% (w / w) dilute ammonia solution was sprayed onto the glass plate. After 2 h, the film was formed. The film was washed with deionized water and isopropanol and then subjected to Soxhlet extraction for 24 h to remove N,N-dimethylacetamide and unreacted monomers. The film was then rinsed with 1.5 mol / L hydrochloric acid to remove copper(II) ions. Finally, the spherical resin was neutralized and rinsed with 5 mol / L ammonia water. After drying, a pale yellow copper(II) imprinted polymer film (1-1) was obtained. The average thickness of the pale yellow copper(II) imprinted polymer membrane (1-1) was measured to be 0.8 mm. Under constant temperature of 25℃, the membrane was continuously immersed in a copper sulfate solution with a pH of 4.5. The results showed that the time for saturation adsorption of copper(II) ions by the copper(II) imprinted polymer membrane (1-1) was 1.5 min, and the saturation adsorption capacity of copper(II) ions was 1.62 mg / g. These results indicate that the copper(II) imprinted polymer membrane (1-1) has high hydrophilicity and a relatively faster copper(II) ion exchange rate.

[0035] Following the preparation method and operating steps of Example 1, the functional monomer bis5-(N,N-diallylamylmethyl)salicylaldehyde oxime copper(II) of Example 1 was replaced with bis5-(N-benzyl-N-allylamylmethyl)salicylaldehyde oxime copper(II) to prepare an N,N-dimethylacetamide solution of copper(II) ion imprinted polymer (2-1). This solution was then neutralized with 8% (w / w) dilute ammonia water, filtered, washed with water, and dried to obtain spherical resin. The spherical resin was subjected to Soxhlet extraction with water and tetrahydrofuran for 24 h sequentially to remove N,N-dimethylacetamide and unreacted monomers. The resin was then eluted with 1.5 mol / L hydrochloric acid to remove copper(II) ions. After neutralization and elution with 5 mol / L ammonia water, and drying, pale yellow copper(II) ion imprinted polymer (2-1) resin spheres were obtained. The results showed that at a constant temperature of 25℃, the time for the hollow resin balls of the copper(II) ion imprinted polymer (2-1) to saturate and adsorb copper(II) ions was 3.7 min, and the saturated adsorption capacity of copper(II) ions was 1.53 mg / g.

[0036] Comparative Example 2: Preparation of Copper(II) Ion Imprinted Polymer (2-1) Film The copper(II) ion imprinted polymer (2-1) solution prepared in Example 2 was drop-coated onto a clean glass plate. Then, 8% (w / w) dilute ammonia solution was sprayed onto the glass plate. After 2 hours, the film was formed. The film was washed with deionized water and isopropanol and then subjected to Soxhlet extraction for 24 hours to remove N,N-dimethylacetamide and unreacted monomers. The film was then rinsed with 1.5 mol / L hydrochloric acid to remove copper(II) ions. Finally, the spherical resin was neutralized and rinsed with 5 mol / L ammonia water. After drying, a pale yellow copper(II) ion imprinted polymer film (2-1) was obtained. The average thickness of the pale yellow copper(II) ion-imprinted polymer membrane (2-1) was measured to be 0.8 mm. The membrane was continuously immersed in a copper sulfate solution with a pH of 4.5 at a constant temperature of 25℃. The results showed that the time for the copper(II) ion-imprinted polymer membrane (2-1) to saturate and adsorb copper(II) ions was 1.6 min, and the saturated adsorption capacity of copper(II) ions was 1.68 mg / g.

[0037] Following the preparation method and operating steps of Example 1, the functional monomer bis5-(N,N-diallylamylmethyl)salicylaldehyde oxime copper(II) of Example 1 was replaced with bis5-(N-dodecyl-N-allylamylmethyl)salicylaldehyde oxime copper(II) to prepare an N,N-dimethylacetamide solution of copper(II) ion-imprinted polymer (2-2). This solution was then neutralized with 8% (w / w) dilute ammonia water, filtered, washed with water, and dried to obtain spherical resin. The spherical resin was subjected to Soxhlet extraction with water and tetrahydrofuran for 24 h sequentially to remove N,N-dimethylacetamide and unreacted monomers. The resin was then eluted with 1.5 mol / L hydrochloric acid to remove copper(II) ions. After neutralization and elution with 5 mol / L ammonia water, and drying, pale yellow copper(II) ion-imprinted polymer (2-2) resin spheres were obtained. The results showed that at a constant temperature of 25℃, the time for the hollow resin balls of the copper(II) ion imprinted polymer (2-2) to saturate and adsorb copper(II) ions was 3.8 min, and the saturated adsorption capacity of copper(II) ions was 1.46 mg / g.

[0038] The N,N-dimethylacetamide solution of the copper(II) ion imprinted polymer (2-2) prepared in Example 2 was drop-coated onto a clean glass plate. Then, 8% (w / w) dilute ammonia solution was sprayed onto the glass plate. After 2 h, the film was formed. The film was washed with deionized water and isopropanol and then subjected to Soxhlet extraction for 24 h to remove N,N-dimethylacetamide and unreacted monomers. The film was then rinsed with 1.5 mol / L hydrochloric acid to remove copper(II) ions. Finally, the spherical resin was neutralized and rinsed with 5 mol / L ammonia water. After drying, a pale yellow copper(II) ion imprinted polymer film (2-2) was obtained. The average thickness of the pale yellow copper(II) ion-imprinted polymer membrane (2-2) was measured to be 0.8 mm. The membrane was continuously immersed in a copper sulfate solution with a pH of 4.5 at a constant temperature of 25℃. The results showed that the time for the copper(II) ion-imprinted polymer membrane (2-2) to saturate and adsorb copper(II) ions was 1.9 min, and the saturated adsorption capacity of copper(II) ions was 1.62 mg / g.

[0039] Example 4 Preparation of hollow resin spherical copper(II) ion-imprinted polymers (1-2) Following the preparation method and operating steps of Example 1, 12 g of N,N,N-triallylammonium hydrochloride in Example 1 was replaced with 25 g of N,N,N-triallylammonium hydrochloride to prepare an N,N-dimethylacetamide solution of copper(II) ion imprinted polymer (1-2). This solution was then neutralized with 8% (w / w) dilute ammonia water, filtered, washed with water, and dried to obtain spherical resin. The spherical resin was subjected to Soxhlet extraction with water and tetrahydrofuran for 24 h sequentially to remove N,N-dimethylacetamide and unreacted monomers. The resin was then eluted with 1.5 mol / L hydrochloric acid to remove copper(II) ions. After neutralization and elution with 5 mol / L ammonia water, and drying, pale yellow copper(II) ion imprinted polymer (1-2) resin spheres were obtained. The results showed that at a constant temperature of 25℃, the time for the hollow resin balls of the copper(II) ion imprinted polymer (1-2) to saturate and adsorb copper(II) ions was 2.8 min, and the saturated adsorption capacity of copper(II) ions was 1.47 mg / g.

[0040] Following the preparation method and operating steps of Example 1, 22 g of divinylbenzene in Example 1 was replaced with 40 g of divinylbenzene to prepare an N,N-dimethylacetamide solution of copper(II) ion imprinted polymer (1-3). The solution was then neutralized and deposited using 8% (w / w) dilute ammonia water. After filtration, washing with water, and drying, spherical resins were obtained. The spherical resins were subjected to Soxhlet extraction with water and tetrahydrofuran for 24 h sequentially to remove N,N-dimethylacetamide and unreacted monomers. The resins were then eluted with 1.5 mol / L hydrochloric acid to remove copper(II) ions. Finally, the resins were neutralized and eluted with 5 mol / L ammonia water, and dried to obtain pale yellow copper(II) ion imprinted polymer (1-3) resin spheres. The results showed that at a constant temperature of 25℃, the time for the hollow resin balls of the copper(II) ion imprinted polymer (1-3) to saturate and adsorb copper(II) ions was 5.5 min, and the saturated adsorption capacity of copper(II) ions was 1.56 mg / g.

[0041] Following the preparation method and operating steps of Example 1, the p-chloromethylstyrene in Example 1 was replaced with 3-bromopropene to prepare an N,N-dimethylacetamide solution of copper(II) ion imprinted polymer (1-4). The solution was then neutralized and deposited using 8% (w / w) dilute ammonia water. After filtration, washing with water, and drying, spherical resins were obtained. The spherical resins were subjected to Soxhlet extraction with water and tetrahydrofuran for 24 h sequentially to remove N,N-dimethylacetamide and unreacted monomers. The resins were then eluted with 1.5 mol / L hydrochloric acid to remove copper(II) ions. After neutralization and elution with 5 mol / L ammonia water, and drying, pale yellow copper(II) ion imprinted polymer (1-4) resin spheres were obtained. Measurements showed that at a constant temperature of 25°C, the time for the hollow resin spheres of copper(II) ion imprinted polymer (1-4) to saturate and adsorb copper(II) ions was 2.3 min, and the saturated adsorption capacity for copper(II) ions was 1.61 mg / g.

[0042] Compared with the copper(II) ion imprinted polymers of Examples 1-6 and Comparative Examples 1-3, the condensed state morphology significantly affected the saturation adsorption time and adsorption capacity of copper(II) ions. The amount of the first crosslinking agent had no significant effect on the saturation adsorption time and adsorption capacity of copper(II) ions, while the amount of the second crosslinking agent had a relatively significant effect on the saturation adsorption time and adsorption capacity of copper(II) ions.

Claims

1. A method for preparing a multi-crosslinked hydrophilic copper(II) ion-imprinted polymer, characterized in that, The following preparation method is used: Step 1: Preparation of cross-linked polymers containing copper(II) ions and tertiary amine groups on the polymer chain Weigh out the salicylaldehyde oxime copper(II) complex modified with general formula (1), the first modulating monomer, the first crosslinking agent, and the aqueous initiator in sequence, and mix them together in a reactor containing deionized water. After stirring evenly, purge with nitrogen to remove oxygen for 30 min, raise the temperature to 50~90℃, and complete the free radical copolymerization reaction in the aqueous solution after 6~12 h to obtain an aqueous solution of crosslinked polymer containing copper(II) ions and tertiary amine salt. After the temperature of the aqueous solution of crosslinked polymer containing copper(II) ions and tertiary amine salt drops to room temperature, slowly add an appropriate amount of saturated sodium bicarbonate aqueous solution for neutralization. After precipitation is complete, stop the neutralization process, filter, and dry to obtain a crosslinked polymer containing copper(II) ions and tertiary amine groups on the polymer chain. The mass ratio of the salicylaldehyde oxime copper(II) complex modified with general formula (1) / first modulating monomer / first crosslinking agent / deionized water is 1:0.2~2:0.05~0.5:2~200; the amount of the aqueous initiator is 1~13% of the total mass of general formula (1), first modulating monomer, and first crosslinking agent. The allyl tertiary amine salt-modified salicylaldehyde oxime copper(II) complex has the structure shown in general formula (1): General formula (1) where R1 in general formula (1) is selected from C1 to C2. 18 One of the hydrocarbon groups, X is selected from Cl, Br, CH3COO or p One of -CH3C6H4SO3; Step 2: Preparation of multi-crosslinked hydrophilic copper(II) ion-imprinted polymer The cross-linked polymer containing copper(II) ions and tertiary amine groups on the polymer chain obtained in step one is dissolved in an organic solvent. An unsaturated alkylating agent and a polymerization inhibitor are added, and the mixture is stirred at 20-80°C for 6-24 h to obtain a hydrophilic cross-linked polymer solution containing copper(II) ions and polymerizable quaternary ammonium cations on the polymer chain. After the temperature of the hydrophilic cross-linked polymer solution containing copper(II) ions and polymerizable quaternary ammonium cations on the polymer chain drops to room temperature, a second modulating monomer, a second cross-linking agent, and an initiator are added. The mixture is stirred evenly and purged with nitrogen for 30 min to remove oxygen. Then, the temperature is raised to 50-90°C to carry out a free radical copolymerization reaction in an organic solution for 6-12 h to obtain a multi-cross-linked polymer solution containing copper(II) ions and quaternary ammonium cations on the polymer chain. Hollow resin spheres, porous membranes, or fiber materials of the multi-cross-linked hydrophilic copper(II) ion imprinted polymer are obtained by solvent precipitation, drop coating, and wet spinning processes, respectively. The amount of the unsaturated alkylating agent used is 20-80% of the sum of the molar amounts of nitrogen atoms in general formula (1), the first modulating monomer, and the first crosslinking agent; The amount of polymerization inhibitor used is 0.2~12% of the mass of the unsaturated alkylating agent; The amount of the second tonality monomer is 0.1 to 10 times the mass of the general formula (1); The amount of the second crosslinking agent is 0.05 to 5 times the mass of general formula (1); The amount of initiator used is 1-13% of the total mass of the unsaturated alkylating agent, the second modulating monomer, and the second crosslinking agent; The amount of organic solvent used is 2 to 200 times the total mass of general formula (1), unsaturated alkylating agent, first modulating monomer, first crosslinking agent, second modulating monomer, and second crosslinking agent.

2. The method for preparing the multi-crosslinked hydrophilic copper(II) ion-imprinted polymer according to claim 1, characterized in that: The first modulating monomer refers to any one of the hydrochloride, hydrobromide, acetate, or p-toluenesulfonate of N-alkyl-N,N-diallylamine; wherein the alkyl group is selected from C1 to C2. 18 One of the hydrocarbon groups.

3. The method for preparing the multi-crosslinked hydrophilic copper(II) ion-imprinted polymer according to claim 1, characterized in that: The first crosslinking agent refers to one or more of the hydrochloride, hydrobromide, acetate or p-toluenesulfonate of N,N,N-triallylamine, N,N'-diallylpiperazine, N,N,N',N'-tetraallylethylenediamine, N,N'-dimethyl-N,N'-diallylethylenediamine, N,N'-diethyl-N,N'-diallylethylenediamine or N,N'-dibenzyl-N,N'-diallylethylenediamine.

4. The method for preparing a multi-crosslinked hydrophilic copper(II) ion-imprinted polymer according to claim 1, characterized in that: The aqueous initiator is selected from one or more of hydrogen peroxide, sodium persulfate, potassium persulfate, ammonium persulfate, azobisisobutylamidine hydrochloride, azobisisobutylimidazoline hydrochloride, 4,4'-azobis(cyanopentarate sodium), or azobisisopropylimidazoline hydrochloride.

5. The method for preparing the multi-crosslinked hydrophilic copper(II) ion-imprinted polymer according to claim 1, characterized in that: The unsaturated alkylating agent is one of 3-chloropropene, 3-bromopropene, and p-chloromethylstyrene.

6. The method for preparing the multi-crosslinked hydrophilic copper(II) ion-imprinted polymer according to claim 1, characterized in that: The polymerization inhibitor is one or more of hydroquinone, p-methoxyphenol, tert-butylhydroquinone, 2,6-dibutylhydroquinone, 2,6-di-tert-butyl-p-cresol, and 2,4,6-tri-tert-butylphenol.

7. The method for preparing the multi-crosslinked hydrophilic copper(II) ion-imprinted polymer according to claim 1, characterized in that: The second modulating monomer is one or more of styrene, acrylonitrile, or acrylate.

8. The method for preparing the multi-crosslinked hydrophilic copper(II) ion-imprinted polymer according to claim 1, characterized in that: The initiator is one or more of benzoyl peroxide, lauroyl peroxide, methyl ethyl ketone peroxide, azobisisobutyronitrile, azobisisoheptanenitrile, or dimethyl azobisisobutyrate.

9. The method for preparing the multi-crosslinked hydrophilic copper(II) ion-imprinted polymer according to claim 1, characterized in that: The organic solvent is one or more of N-methylpyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, dimethyl sulfoxide, or hexamethylphosphoramide.

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