阅读说明：本技术 一种高强度防冻型三维多孔水凝胶吸附材料及其制法 (High-strength anti-freezing three-dimensional porous hydrogel adsorption material and preparation method thereof ) 是由 黄春美 于 2019-11-25 设计创作，主要内容包括：本发明涉及水凝胶吸附材料技术领域,且公开了一种高强度防冻型三维多孔水凝胶吸附材料及其制法,包括以下配方原料：丙烯酰胺、丙烯酸、复合引发剂、防冻剂、交联剂、羧基化石墨烯、壳聚糖、脱胶蚕丝蛋白。该一种高强度防冻型三维多孔水凝胶吸附材料及其制法,羧基化石墨烯均匀地掺杂进入水凝胶的内部,产生丰富的孔隙,形成三维多孔结构,含有大量的极性羟基的壳聚糖接枝改性聚(丙烯酰胺-丙烯酸),降低了水凝胶材料的冰点,提高了其防冻性能,改性共聚物含有大量的羧基、氨基和羟基,可以与铜、镉等重金属络合形成螯合物,蚕丝蛋白具有优异的拉伸强度和弹性模量,增强了水凝胶吸附材料的弹性膨胀性能和断裂强度。(The invention relates to the technical field of hydrogel adsorption materials, and discloses a high-strength anti-freezing three-dimensional porous hydrogel adsorption material and a preparation method thereof, wherein the high-strength anti-freezing three-dimensional porous hydrogel adsorption material comprises the following formula raw materials: acrylamide, acrylic acid, a composite initiator, an antifreezing agent, a cross-linking agent, carboxylated graphene, chitosan and degummed fibroin. According to the high-strength anti-freezing type three-dimensional porous hydrogel adsorption material and the preparation method thereof, the carboxylated graphene is uniformly doped into the hydrogel to generate abundant pores to form a three-dimensional porous structure, chitosan grafted modified poly (acrylamide-acrylic acid) containing a large amount of polar hydroxyl groups reduces the freezing point of the hydrogel material and improves the anti-freezing performance of the hydrogel material, the modified copolymer contains a large amount of carboxyl groups, amino groups and hydroxyl groups and can be complexed with heavy metals such as copper, cadmium and the like to form chelates, and the fibroin has excellent tensile strength and elastic modulus and enhances the elastic expansion performance and breaking strength of the hydrogel adsorption material.)

1. The high-strength antifreezing three-dimensional porous hydrogel adsorption material comprises the following formula raw materials in parts by weight, and is characterized in that: 20-24 parts of acrylamide, 36-55 parts of acrylic acid, 1-2 parts of composite initiator, 2-4 parts of antifreezing agent, 1-1.5 parts of cross-linking agent, 3-5.5 parts of carboxylated graphene, 10-15 parts of chitosan and 8-12 parts of degummed silk protein.

2. The high-strength antifreezing three-dimensional porous hydrogel adsorbing material as set forth in claim 1, wherein: the carboxylated graphene has the sheet diameter of 0.5-5 um, the thickness of 0.8-1.2 nm and the carboxyl content of 4.5-5.5%.

3. The high-strength antifreezing three-dimensional porous hydrogel adsorbing material as set forth in claim 1, wherein: the composite initiator is potassium persulfate and ammonium persulfate, and the mass molar ratio of the potassium persulfate to the ammonium persulfate is 3-4: 1.

4. According to claimThe high-strength antifreezing three-dimensional porous hydrogel adsorbing material disclosed by claim 1 is characterized in that: the cross-linking agent isN,N-methylenebisacrylamide.

5. The high-strength antifreezing three-dimensional porous hydrogel adsorbing material as set forth in claim 1, wherein: the antifreeze is prepared from CaCl₂And MgCl₂The weight molar ratio of the two substances is 3-5: 1.

6. The high-strength antifreezing three-dimensional porous hydrogel adsorbing material as set forth in claim 1, wherein: the preparation method of the degummed fibroin comprises the following steps:

(1) adding appropriate amount of silk into 0.5-0.8 g/L sodium carbonate solution, heating to 95-100 deg.C, soaking for 1-2 hr for degumming, filtering, washing solid product, and drying to obtain fibroin;

(2) adding fibroin into NaCl solution with mass fraction of 20-25%, transferring the solution into a dialysis bag, dialyzing with distilled water, filtering the solution, washing the solid product, and drying to obtain degummed fibroin.

7. The high-strength antifreezing three-dimensional porous hydrogel adsorbing material as set forth in claim 1, wherein: the preparation method of the high-strength antifreezing three-dimensional porous hydrogel adsorption material comprises the following steps:

(1) adding 20-24 parts of acrylamide, 36-55 parts of acrylic acid, 2-4 parts of antifreezing agent and 3-5.5 parts of carboxylated graphene into a distilled water solvent, carrying out ultrasonic treatment on the solution at 50-60 ℃ for 2-3 h at the ultrasonic frequency of 20-22KHz, and then adding 1-2 parts of composite initiator and 1-1.5 parts of cross-linking agentN,NHeating the solution to 70-80 ℃, reacting for 6-8 h, cooling the solution to room temperature, filtering, washing a solid product, and drying to prepare a poly (acrylamide-acrylic acid) copolymer;

(2) adding a sulfuric acid solution into an ethylene glycol solvent, adjusting the pH value of the solution to 3-4, adding 10-15 parts of chitosan and the poly (acrylamide-acrylic acid) copolymer prepared in the step (1), transferring the solution into a hydrothermal reaction kettle, heating to 160 ℃ and 170 ℃, reacting for 10-15 h, cooling the solution to room temperature, removing the solvent through a high-speed centrifuge, washing a solid product, and drying to prepare a poly-chitosan grafted (acrylamide-acrylic acid) copolymer;

(3) adding 8-12 parts of degummed fibroin and the chitosan graft (acrylamide-acrylic acid) copolymer prepared in the step (2) into an ethanol solvent, carrying out ultrasonic dispersion treatment on the solution at 35-45 ℃ for 3-4 h, wherein the ultrasonic frequency is 20-22KHz, standing the solution in a drying oven, heating to 60-70 ℃, and slowly drying ethanol to prepare the chitosan graft (acrylamide-acrylic acid) copolymer-fibroin composite material, namely the high-strength anti-freezing three-dimensional porous hydrogel adsorption material.

Technical Field

The invention relates to the technical field of hydrogel adsorption materials, in particular to a high-strength anti-freezing three-dimensional porous hydrogel adsorption material and a preparation method thereof.

Background

The hydrogel is a three-dimensional network structure gel with strong hydrophilicity, the hydrogel material can rapidly swell in water, a crosslinking network exists in the hydrogel, the hydrogel can swell and retain a large amount of water and can not dissolve or decompose, the water absorption capacity is related to the crosslinking degree of the hydrogel, the higher the crosslinking degree is, the lower the water absorption capacity is, the aggregation state of the hydrogel is a state between an incomplete solid and an incomplete liquid, the solid can maintain a certain shape and volume under certain conditions, and the liquid can diffuse or permeate solute from the hydrogel.

The hydrogel is used as a high-water-absorption high-water-retention material and is widely applied to the fields of drought resistance in arid regions, cosmetic masks, agricultural films, building material condensation preventers, mining dust depressants, food preservatives, medical drug carriers and the like, the hydrogel contains a large number of active groups such as hydroxyl, amino and the like, and can form a complex with heavy metals and ions thereof, so that the effect of adsorbing heavy metal pollutants is achieved, the hydrogel adsorbent has the characteristics of easy regeneration, recycling and the like, but the conventional acrylic acid derivative hydrogel is easy to lose and decompose due to poor self stability and mechanical property in the long-time continuous water absorption swelling process, and the acrylic acid derivative hydrogel has poor low-temperature resistance, high freezing point and poor anti-freezing property, so that the swelling effect of the hydrogel material on water is reduced in the low-temperature state, inhibits the complexation with heavy metal and reduces the practicability of the hydrogel adsorption material.

Disclosure of Invention

Technical problem to be solved

Aiming at the defects of the prior art, the invention provides a high-strength anti-freezing type three-dimensional porous hydrogel adsorption material and a preparation method thereof, solves the problems that the matrix is easy to lose and decompose due to poor self stability and mechanical properties of acrylic acid derivative hydrogel, and simultaneously solves the problems that the hydrogel has poor low temperature resistance and poor anti-freezing property, the swelling property of the hydrogel material to water is reduced in a low temperature state, and the complexing effect with heavy metal is inhibited.

(II) technical scheme

In order to achieve the purpose, the invention provides the following technical scheme: the high-strength antifreezing three-dimensional porous hydrogel adsorption material comprises the following formula raw materials in parts by weight: 20-24 parts of acrylamide, 36-55 parts of acrylic acid, 1-2 parts of composite initiator, 2-4 parts of antifreezing agent, 1-1.5 parts of cross-linking agent, 3-5.5 parts of carboxylated graphene, 10-15 parts of chitosan and 8-12 parts of degummed silk protein.

Preferably, the carboxylated graphene has the sheet diameter of 0.5-5 um, the thickness of 0.8-1.2 nm and the carboxyl content of 4.5-5.5%.

Preferably, the composite initiator is potassium persulfate and ammonium persulfate, and the molar ratio of the two substances is 3-4: 1.

Preferably, the crosslinking agent isN,N-methylenebisacrylamide.

Preferably, the antifreeze is CaCl₂And MgCl₂The weight molar ratio of the two substances is 3-5: 1.

Preferably, the preparation method of the degummed fibroin comprises the following steps:

(1) adding appropriate amount of silk into 0.5-0.8 g/L sodium carbonate solution, heating to 95-100 deg.C, soaking for 1-2 hr for degumming, filtering, washing solid product, and drying to obtain fibroin.

(2) Adding fibroin into NaCl solution with mass fraction of 20-25%, transferring the solution into a dialysis bag, dialyzing with distilled water, filtering the solution, washing the solid product, and drying to obtain degummed fibroin.

Preferably, the preparation method of the high-strength antifreezing three-dimensional porous hydrogel adsorption material comprises the following steps:

(1) adding 20-24 parts of acrylamide, 36-55 parts of acrylic acid, 2-4 parts of antifreezing agent and 3-5.5 parts of carboxylated graphene into a distilled water solvent, carrying out ultrasonic treatment on the solution at 50-60 ℃ for 2-3 h at the ultrasonic frequency of 20-22KHz, and then adding 1-2 parts of composite initiator and 1-1.5 parts of cross-linking agentN,NAnd (2) heating the solution to 70-80 ℃, reacting for 6-8 h, cooling the solution to room temperature, filtering, washing a solid product, and drying to obtain the poly (acrylamide-acrylic acid) copolymer.

(2) Adding a sulfuric acid solution into an ethylene glycol solvent, adjusting the pH value of the solution to 3-4, adding 10-15 parts of chitosan and the poly (acrylamide-acrylic acid) copolymer prepared in the step (1), transferring the solution into a hydrothermal reaction kettle, heating to 160 ℃ and 170 ℃, reacting for 10-15 h, cooling the solution to room temperature, removing the solvent through a high-speed centrifuge, washing a solid product, and drying to prepare the chitosan grafted (acrylamide-acrylic acid) copolymer.

(3) Adding 8-12 parts of degummed fibroin and the chitosan graft (acrylamide-acrylic acid) copolymer prepared in the step (2) into an ethanol solvent, carrying out ultrasonic dispersion treatment on the solution at 35-45 ℃ for 3-4 h, wherein the ultrasonic frequency is 20-22KHz, standing the solution in a drying oven, heating to 60-70 ℃, and slowly drying ethanol to prepare the chitosan graft (acrylamide-acrylic acid) copolymer-fibroin composite material, namely the high-strength anti-freezing three-dimensional porous hydrogel adsorption material.

(III) advantageous technical effects

Compared with the prior art, the invention has the following beneficial technical effects:

according to the high-strength anti-freezing three-dimensional porous hydrogel adsorption material and the preparation method thereof, the poly (acrylamide-acrylic acid) copolymer is used as a matrix part of the hydrogel, the copolymer has a large number of hydrophilic groups of carboxyl and amino, the water absorption of the hydrogel is enhanced, and the carboxylated graphene is bonded with the amino in the copolymer and forms a hydrogen bond, so that the graphene can be uniformly doped into the hydrogel, the graphene agglomeration is avoided, meanwhile, rich pores are generated in the hydrogel, a three-dimensional porous structure is formed, and the water absorption capacity of the hydrogel material is greatly increased.

According to the high-strength anti-freezing three-dimensional porous hydrogel adsorption material and the preparation method thereof, chitosan is used for grafting and modifying the poly (acrylamide-acrylic acid) copolymer, the chitosan has good chemical resistance, the chemical stability of the hydrogel material is enhanced, meanwhile, a large number of polar hydroxyl groups of the chitosan reduce the freezing point of the hydrogel material, and in an anti-freezing agent CaCl₂And MgCl₂Under the combined action of the components, the antifreezing performance of the hydrogel material is improved.

According to the high-strength anti-freezing three-dimensional porous hydrogel adsorption material and the preparation method thereof, the chitosan grafted modified poly (acrylamide-acrylic acid) copolymer contains a large amount of carboxyl, amino and hydroxyl, and can be complexed with heavy metals such as copper, cadmium and ions thereof to form a chelate, so that the adsorption performance of the hydrogel material is greatly enhanced, and the three-dimensional porous structure of the hydrogel material can play a good role in storing heavy metal pollutants.

According to the high-strength anti-freezing three-dimensional porous hydrogel adsorption material and the preparation method thereof, the poly (acrylamide-acrylic acid) copolymer and degummed fibroin are used to form a composite material, the fibroin has excellent toughness, tensile strength and high elastic modulus, the mechanical properties such as elastic expansion of the hydrogel adsorption material are greatly enhanced, and the problems of matrix loss and decomposition caused by reduction of the mechanical properties of the hydrogel material due to long-time continuous water adsorption are solved.

Detailed Description

To achieve the above object, the present invention provides the following embodimentsModes and examples: the high-strength antifreezing three-dimensional porous hydrogel adsorption material comprises the following formula raw materials in parts by weight: 20-24 parts of acrylamide, 36-55 parts of acrylic acid, 1-2 parts of a composite initiator, 2-4 parts of an antifreezing agent, 1-1.5 parts of a cross-linking agent, 3-5.5 parts of carboxylated graphene, 10-15 parts of chitosan, 8-12 parts of degummed fibroin, wherein the sheet diameter of the carboxylated graphene is 0.5-5 mu m, the thickness of the carboxylated graphene is 0.8-1.2 nm, the carboxyl content of the carboxylated graphene is 4.5-5.5%, the composite initiator is potassium persulfate and ammonium persulfate, the molar ratio of the potassium persulfate to the ammonium persulfate is 3-4:1, and the cross-linking agent is potassium persulfateN,NMethylene bisacrylamide, antifreeze agent from CaCl₂And MgCl₂The weight molar ratio of the two substances is 3-5: 1.

The preparation method of the degummed silk protein comprises the following steps:

(1) adding appropriate amount of silk into 0.5-0.8 g/L sodium carbonate solution, heating to 95-100 deg.C, soaking for 1-2 hr for degumming, filtering to remove solvent, washing solid product with appropriate amount of distilled water, and drying thoroughly to obtain fibroin.

(2) Adding an ethanol solution of NaCl with the mass fraction of 20-25% into a reaction bottle, adding fibroin, stirring for dissolving, transferring the solution into a dialysis bag, dialyzing with distilled water, filtering the solution to remove the solvent, washing a solid product, and fully drying to prepare the degummed fibroin.

The preparation method of the high-strength anti-freezing three-dimensional porous hydrogel adsorption material comprises the following steps:

(1) adding a proper amount of distilled water solvent into a reaction bottle, adding 20-24 parts of acrylamide, 36-55 parts of acrylic acid, 2-4 parts of antifreezing agent and 3-5.5 parts of carboxylated graphene, placing the reaction bottle into an ultrasonic dispersion instrument, heating to 50-60 ℃, carrying out ultrasonic treatment for 2-3 h at the ultrasonic frequency of 20-22KHz, adding 1-2 parts of composite initiator and 1-1.5 parts of cross-linking agentN,NPutting a reaction bottle in a constant-temperature water bath kettle, heating to 70-80 ℃, uniformly stirring for reaction for 6-8 h, cooling the solution to room temperature, filtering to remove the solvent, washing the solid product with a proper amount of distilled water, putting the solid product in an oven, heating to 75-85 ℃, fully drying, and preparing the methylene bisacrylamideTo poly (acrylamide-acrylic acid) copolymers.

(2) Adding an ethylene glycol solvent into a reaction bottle, adding a sulfuric acid solution, adjusting the pH value of the solution to 3-4, sequentially adding 10-15 parts of chitosan and the poly (acrylamide-acrylic acid) copolymer prepared in the step (1), transferring the solution into a hydrothermal reaction kettle, placing the hydrothermal reaction kettle in a reaction kettle heating box, heating to 160-170 ℃, reacting for 10-15 h, cooling the solution to room temperature, removing the solvent through a high-speed centrifuge, washing a solid product with a proper amount of distilled water, placing the solid product in an oven, heating to 80-90 ℃, and fully drying to prepare the chitosan grafted (acrylamide-acrylic acid) copolymer.

(3) Adding an ethanol solvent into a reaction bottle, adding 8-12 parts of degummed fibroin and the chitosan graft (acrylamide-acrylic acid) copolymer prepared in the step (2), placing the reaction bottle in an ultrasonic dispersion instrument, heating to 35-45 ℃, wherein the ultrasonic frequency is 20-22KHz, performing ultrasonic dispersion treatment for 3-4 h, standing the reaction bottle in an oven, heating to 60-70 ℃, and slowly drying ethanol to prepare the chitosan graft (acrylamide-acrylic acid) copolymer-fibroin composite material, namely the high-strength anti-freezing three-dimensional porous hydrogel adsorption material.