Ion exchange resin for water treatment and preparation method thereof

Abstract

The invention relates to the technical field of ion exchange resin, and discloses ion exchange resin for water treatment and a preparation method thereof, the preparation method comprises the following preparation steps: uniformly mixing styrene, divinylbenzene, an initiator and composite nanoparticles as an organic phase; uniformly mixing polyvinyl alcohol and deionized water to serve as a water phase, mixing the organic phase and the water phase, stirring to form an emulsification system, continuously stirring to react, and filtering to obtain crosslinked spherical particles; mixing the cross-linked spherical particles with a sulfonation treatment agent, carrying out sulfonation reaction, washing with water, neutralizing, and drying to obtain a substance A; the preparation method comprises the following steps: mixing a substance A and a chloromethylation solvent, carrying out a chloromethylation reaction, adding an aminating agent, and carrying out a quaternization reaction, so that the obtained ion exchange resin has high adsorption capacity, heat resistance and compressive strength, and sulfonic acid groups and quaternary amine groups are introduced, so that the selectivity and hydrophilicity of the ion exchange resin are improved, and the water treatment efficiency is further improved.

Description

Technical Field

[0001] The present invention relates to the technical field of ion exchange resins, in particular to an ion exchange resin for water treatment and a preparation method thereof. Background Art

[0002] The ion exchange resin market is large, with an annual growth rate of more than 10%. The main growth points come from industries such as electronics, environmental protection, and power plant water treatment. National policies also actively encourage green manufacturing and the development of new materials. The "New Materials Industry Development Guide" lists high-performance resin materials as one of the key support directions. Currently, commonly used ion exchange resins are usually made into small bead-shaped particles. Their matrix is ​​mainly styrene-divinylbenzene copolymer, which has a good exchange capacity of 4-4.5mmol / g. It also has good versatility and is widely used in industrial circulating water, power plant condensate and other fields.

[0003] Ion exchange resins have insufficient thermal stability and an upper operating temperature limit of 120°C. During long-term operation and in environments with high organic pollution loads, they are prone to problems such as exchange capacity attenuation, resin breakage, and failure. The use of nanoparticles to participate in the polymerization reaction of ion exchange resins can enhance the compressive strength and thermal stability of ion exchange resins, but the compatibility of nanofillers with ion exchange resins is poor, which affects the thermal stability and mechanical properties of ion exchange resins. Summary of the Invention

[0004] The present invention provides an ion exchange resin for water treatment and a preparation method thereof, which solves the problems of insufficient thermal stability and poor compressive strength of the ion exchange resin.

[0005] The technical solution of the present invention: A method for preparing an ion exchange resin for water treatment comprises the following steps: S1. Styrene, divinylbenzene, an initiator, and composite nanoparticles are uniformly mixed to form an organic phase; polyvinyl alcohol and deionized water are uniformly mixed to form an aqueous phase. The organic and aqueous phases are mixed and stirred at 78-82°C to form an emulsified system. The mixture is reacted at 83-87°C for 5-7 hours and filtered to obtain cross-linked spherical particles. S2. The cross-linked spherical particles and the sulfonation agent are mixed, subjected to sulfonation reaction, neutralized by washing with water, and dried to obtain substance A; S3. Substance A and a chloromethylated solvent are mixed, and after chloromethylation, an aminating agent is added, and then a quaternization reaction is performed to obtain an ion exchange resin; The composite nanoparticles are obtained by reacting citric acid, 1-carboxyl-o-carborane and glycidyl methacrylate, and then mixing with modified nanoparticles. The modified nanoparticles are prepared by synthesizing porous carbon on the surface of nanoparticles and then subjecting the nanoparticles to surface treatment with carboxyl-polyethylene glycol-carboxyl groups.

[0006] Furthermore, the nanoparticles are selected from any one of nano-silicon dioxide, nano-titanium dioxide and nano-aluminum oxide.

[0007] Furthermore, the particle size of the nanoparticles is 50-100 nm.

[0008] Furthermore, in step S1, the mass ratio of styrene, divinylbenzene, initiator and composite nanoparticles is (80-90):(10-20):(0.4-0.7):(0.2-1).

[0009] Furthermore, the ratio of polyvinyl alcohol to deionized water is (1-3) g: (180-220) mL.

[0010] Furthermore, the initiator is selected from benzoyl peroxide or azobisisobutyronitrile.

[0011] Furthermore, in step S2, the mass ratio of the cross-linked spherical particles to the sulfonated treatment agent is 1:(30-50).

[0012] Furthermore, the sulfonation treatment agent includes chlorosulfonic acid / dichloroethane, trifluoromethanesulfonic acid, chlorosulfonic acid / acetic anhydride or acetylsulfonic acid / acetic acid.

[0013] Furthermore, the chlorosulfonic acid / dichloroethane sulfonation treatment temperature is 60° C., the time is 2 h, and the volume ratio of chlorosulfonic acid to dichloroethane is 1:2.

[0014] Furthermore, the trifluoromethanesulfonic acid sulfonation treatment temperature is 70° C. and the time is 1 h.

[0015] Furthermore, the chlorosulfonic acid / acetic anhydride sulfonation treatment temperature is 23° C., the time is 30 min, and the volume ratio of chlorosulfonic acid to acetic anhydride is 1:1.

[0016] Furthermore, the acetyl sulfonic acid / acetic acid sulfonation treatment temperature is 50° C., the time is 3 h, and the volume ratio of acetyl sulfonic acid to acetic acid is 1:1.

[0017] Furthermore, in step S3, the mass ratio of substance A, chloromethylation solvent and amination agent is 1:(30-40):(0.1-0.5).

[0018] Furthermore, the chloromethylation solvent includes a zinc chloride aqueous solution or benzyl chloride with a mass fraction of 1%.

[0019] Furthermore, the chloromethylation reaction temperature of the zinc chloride aqueous solution is 50° C. and the reaction time is 4 h.

[0020] Furthermore, the chloromethylation reaction temperature of benzyl chloride is 30° C. and the reaction time is 6 h.

[0021] Furthermore, the aminating agent includes a 30% by mass trimethylamine ethanol solution, a 25% by mass triethanolamine solution, or trimethylamine / dimethylethanolamine.

[0022] Furthermore, the quaternization reaction temperature of the trimethylamine ethanol solution is 25° C. and the reaction time is 3 hours.

[0023] Furthermore, the quaternization reaction temperature of the triethanolamine solution with a mass fraction of 25% is 40° C. and the time is 2 h.

[0024] Furthermore, the trimethylamine / dimethylethanolamine quaternization reaction temperature is 23° C., the time is 3 h, and the volume ratio of trimethylamine to dimethylethanolamine is 1:1.

[0025] Furthermore, the composite nanoparticles are specifically prepared by the following steps: A1. Nanoparticles, glucose, and tannic acid were added to ethanol, stirred, filtered, washed, dried, and placed in a tube furnace. Potassium hydroxide solution was added and nitrogen was introduced. After high-temperature carbonization, the mixture was cooled to room temperature, removed, washed, and dried to obtain porous carbon-loaded nanoparticles. A2. The porous carbon nanoparticles and carboxyl-polyethylene glycol-carboxyl groups were added to ethanol, stirred, and the particles were collected by centrifugation to obtain modified nanoparticles; A3. 1-carboxyl-o-carborane and citric acid were added to ethanol, stirred evenly, and an aqueous sodium hydroxide solution was added to adjust the pH to 2-3. After stirring, the reaction was cooled to 80-100 ° C, glycidyl methacrylate was added, and after stirring, the reaction was completed, washed, and dried to obtain a modifier; A4. The modified nanoparticles and the modifier are mixed and stirred evenly, and a sodium hydroxide aqueous solution is added. After the reaction is completed, the mixture is filtered, washed, and dried to obtain composite nanoparticles.

[0026] Furthermore, in the above-mentioned A1 reaction process, tannic acid acts as a binder and contains a large number of hydroxyl groups, which can be combined with rigid nanoparticles through hydrogen bonds. Tannic acid can also be combined with glucose through chemical bonds, so that glucose adheres to the surface of the nanoparticles through tannic acid. After high-temperature carbonization, glucose decomposes under heat to form a dense carbon layer. Potassium hydroxide solution acts as an activator and can form pores on the surface of the dense carbon layer, thereby realizing the synthesis of a porous carbon structure on the surface of the nanoparticles, and obtaining nanoparticles loaded with porous carbon.

[0027] Furthermore, during the above-mentioned A2 reaction process, the carboxyl group contained in the carboxyl-polyethylene glycol-carboxyl group can be chemically bonded with the oxygen-containing functional groups contained on the surface of the porous carbon-loaded nanoparticles, so that the carboxyl-polyethylene glycol-carboxyl group is grafted on the surface of the porous carbon-loaded nanoparticles to obtain modified nanoparticles.

[0028] Furthermore, during the above-mentioned reaction A3, the carboxyl group of 1-carboxy-o-carborane can undergo an esterification reaction with the hydroxyl group of citric acid, so that citric acid is grafted onto 1-carboxy-o-carborane, and the oxygen-containing functional group contained in citric acid can undergo a ring-opening reaction with the epoxy group of glycidyl methacrylate, so that glycidyl methacrylate is grafted onto 1-carboxy-o-carborane through citric acid to obtain a modifier.

[0029] Furthermore, during the above reaction A4, the modifier and the modified nanoparticles are mixed, and the hydroxyl groups contained in the modifier can react with the carboxyl groups in the modified nanoparticles, so that the modifier is coated on the surface of the modified nanoparticles to obtain composite nanoparticles.

[0030] Furthermore, in step A1, the ratio of the amount of nanoparticles, glucose, tannic acid, ethanol and potassium hydroxide solution is (5-6):(2-3):(0.3-0.7):(180-220)mL:(4-6)mL.

[0031] Furthermore, in step A2, the ratio of the amount of porous carbon-loaded nanoparticles, carboxyl-polyethylene glycol-carboxyl and ethanol is (2-2.6) g: (0.8-1.2) g: (80-120) mL.

[0032] Furthermore, in step A3, the ratio of 1-carboxy-o-carborane, citric acid, ethanol and glycidyl methacrylate is (1-1.4) g: (0.8-1.2) g: (25-35) mL: (1.2-1.4) g.

[0033] Furthermore, in step A4, the ratio of the modified nanoparticles, the modifier and the sodium hydroxide aqueous solution is (2-3) g: (15-25) mL: (0.5-1.5) mL.

[0034] Furthermore, the nanoparticles are selected from any one of nano-silicon dioxide, nano-titanium dioxide and nano-aluminum oxide.

[0035] Furthermore, the particle size of the nanoparticles is 50-100 nm.

[0036] The present invention has the following beneficial effects: (1) In the technical solution of the present invention, a porous carbon structure is synthesized on the surface of nanoparticles. On the one hand, the rigid nanoparticles serve as the skeleton structure of the ion exchange resin and are dispersed in the ion exchange resin matrix, which can absorb external stress and hinder the expansion of microcracks. In addition, the nanoparticles have high thermal stability and can improve the heat resistance of the ion exchange resin. On the other hand, the synthesized porous carbon has high adsorption performance and pore capacity, which can improve the exchange capacity and adsorption performance of the ion exchange resin. The synthesized porous carbon can also improve the compressive strength and heat resistance of the ion exchange resin.

[0037] (2) In the technical solution of the present invention, carboxyl-polyethylene glycol-carboxyl is grafted onto the surface of the porous carbon-loaded nanoparticles, giving the porous carbon-loaded nanoparticles an active functional group carboxyl, which is conducive to grafting a modifier onto the surface of the porous carbon-loaded nanoparticles, participating in the polymerization reaction of the ion exchange resin, improving the compatibility of the nanoparticles and the ion exchange resin, and avoiding the poor compatibility of the nanoparticles and the ion exchange resin, which affects the thermal stability and mechanical properties of the ion exchange resin.

[0038] (3) In the technical solution of the present invention, glycidyl methacrylate is grafted onto 1-carboxyl-o-carborane through citric acid to form a modifier, which is then coated on the surface of the modified nanoparticles to obtain composite nanoparticles. On the one hand, the double bonds contained in glycidyl methacrylate can participate in the polymerization reaction of the ion exchange resin, so that the composite nanoparticles are dispersed in the ion exchange resin through chemical bonds, thereby improving the bonding strength between the composite nanoparticles and the ion exchange resin. On the other hand, 1-carboxyl-o-carborane contains a stable cage structure and has high thermal stability, which further enhances the heat resistance of the ion exchange resin, increases the operating temperature of the ion exchange resin, and avoids the problems of exchange capacity attenuation, resin damage, and failure of the ion exchange resin in long-term operation and in an environment with high organic pollution load.

[0039] (4) In the technical solution of the present invention, divinylbenzene is used as a cross-linking agent and composite nanoparticles are used as a reinforcing agent to prepare styrene-divinylbenzene microspheres. After the styrene-divinylbenzene microspheres are subjected to a sulfonation reaction, an ion exchange resin for water treatment is obtained through a chloromethylation reaction and an amination reaction. The ion exchange resin has high adsorption capacity, heat resistance and compressive strength, and the introduction of sulfonic acid groups and quaternary amine groups improves the selectivity and hydrophilicity of the ion exchange resin, thereby improving the water treatment efficiency. DETAILED DESCRIPTION

[0040] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0041] The raw materials used in the examples of the present invention are as follows, and all reagents used are of analytical grade.

[0042] Wherein, the nanoparticles are selected from nano-silicon dioxide, and the particle size is 80nm.

[0043] Example 1

[0044] The composite nanoparticles are specifically prepared by the following steps: A1. 5.6 g of nanoparticles, 2.5 g of glucose, and 0.5 g of tannic acid were added to 200 mL of ethanol and stirred at 70°C for 30 min. The mixture was filtered, washed three times with deionized water, and dried in a 70°C oven for 10 min. The mixture was then placed in a tube furnace, and 5 mL of 30% potassium hydroxide solution was added. Nitrogen was introduced and carbonized at 800°C for 4 h. The mixture was cooled to room temperature, removed, washed three times with deionized water, and dried in a 70°C oven for 10 min to obtain porous carbon-loaded nanoparticles. A2. 2.3 g of porous carbon-loaded nanoparticles and 1 g of carboxyl-polyethylene glycol-carboxyl were added to 100 mL of ethanol, stirred at 65 ° C for 30 min, and centrifuged at 10,000 r / min to collect the particles to obtain modified nanoparticles; A3. 1.2 g of 1-carboxyl-o-carborane and 1 g of citric acid were added to 30 mL of ethanol and stirred. A 1 mol / L aqueous sodium hydroxide solution was added to adjust the pH to 2.5. The mixture was stirred at 130°C for 1.5 h. After cooling to 90°C, 1.3 g of glycidyl methacrylate was added and stirred for 4 h. The mixture was then washed three times with ethanol to remove any unreacted citric acid and dried in an oven at 80°C for 10 min to obtain the modifier. A4. Mix 2.5 g of modified nanoparticles with 20 mL of the modifier, stir evenly, add 1 mL of a 1 mol / L sodium hydroxide solution, and stir at 70°C for 20 min. Filter, wash three times with deionized water, and dry in an oven at 70°C for 10 min to obtain composite nanoparticles.

[0045] Comparative Example 1 The difference between this comparative example and Example 1 is that the nanoparticles loaded with porous carbon are replaced by nanoparticles, and the remaining steps and raw materials are the same as those in Example 1.

[0046] A1. 2.3 g of nanoparticles and 1 g of carboxyl-polyethylene glycol-carboxyl were added to 100 mL of ethanol, stirred at 65 ° C for 30 min, and centrifuged at 10,000 rpm to collect the particles to obtain modified nanoparticles; A2. 1.2 g of 1-carboxy-o-carborane and 1 g of citric acid were added to 30 mL of ethanol and stirred. A 1 mol / L aqueous sodium hydroxide solution was added to adjust the pH to 2.5. The mixture was stirred at 130°C for 1.5 h. After cooling to 90°C, 1.3 g of glycidyl methacrylate was added and stirred for 4 h. The mixture was then washed three times with ethanol to remove unreacted citric acid and dried in an oven at 80°C for 10 min to obtain the modifier. A3. Mix 2.5 g of modified nanoparticles with 20 mL of the modifier, stir evenly, add 1 mL of a 1 mol / L sodium hydroxide aqueous solution, and stir at 70°C for 20 min. Filter, wash three times with deionized water, and dry in an oven at 70°C for 10 min to obtain composite nanoparticles.

[0047] Comparative Example 2 The difference between this comparative example and Example 1 is that the modified nanoparticles are replaced by nanoparticles loaded with porous carbon, and the remaining steps and raw materials are the same as those in Example 1.

[0048] A1. 5.6 g of nanoparticles, 2.5 g of glucose, and 0.5 g of tannic acid were added to 200 mL of ethanol and stirred at 70°C for 30 min. The mixture was filtered, washed three times with deionized water, and dried in a 70°C oven for 10 min. The mixture was then placed in a tube furnace, and 5 mL of 30% potassium hydroxide solution was added. Nitrogen was introduced and carbonized at 800°C for 4 h. The mixture was cooled to room temperature, removed, washed three times with deionized water, and dried in a 70°C oven for 10 min to obtain porous carbon-loaded nanoparticles. A2. 1.2 g of 1-carboxy-o-carborane and 1 g of citric acid were added to 30 mL of ethanol and stirred. A 1 mol / L aqueous sodium hydroxide solution was added to adjust the pH to 2.5. The mixture was stirred at 130°C for 1.5 h. After cooling to 90°C, 1.3 g of glycidyl methacrylate was added and stirred for 4 h. The mixture was then washed three times with ethanol to remove unreacted citric acid and dried in an oven at 80°C for 10 min to obtain the modifier. A3. Mix 2.5 g of porous carbon-loaded nanoparticles with 20 mL of the modifier, stir evenly, add 1 mL of a 1 mol / L sodium hydroxide aqueous solution, and stir at 70°C for 20 min. Filter, wash three times with deionized water, and dry in an oven at 70°C for 10 min to obtain composite nanoparticles.

[0049] Comparative Example 3 The difference between this comparative example and Example 1 is that glycidyl methacrylate was not added, and the remaining steps and raw materials were the same as those in Example 1.

[0050] A1. 5.6 g of nanoparticles, 2.5 g of glucose, and 0.5 g of tannic acid were added to 200 mL of ethanol and stirred at 70°C for 30 min. The mixture was filtered, washed three times with deionized water, and dried in a 70°C oven for 10 min. The mixture was then placed in a tube furnace, and 5 mL of 30% potassium hydroxide solution was added. Nitrogen was introduced and carbonized at 800°C for 4 h. The mixture was cooled to room temperature, removed, washed three times with deionized water, and dried in a 70°C oven for 10 min to obtain porous carbon-loaded nanoparticles. A2. 2.3 g of porous carbon-loaded nanoparticles and 1 g of carboxyl-polyethylene glycol-carboxyl were added to 100 mL of ethanol, stirred at 65 ° C for 30 min, and centrifuged at 10,000 r / min to collect the particles to obtain modified nanoparticles; A3. 1.2 g of 1-carboxyl-o-carborane and 1 g of citric acid were added to 30 mL of ethanol and stirred. A 1 mol / L aqueous sodium hydroxide solution was added to adjust the pH to 2.5. The mixture was stirred at 130°C for 1.5 h. The mixture was washed three times with ethanol to remove unreacted citric acid and dried in an oven at 80°C for 10 min to obtain the modifier. A4. Mix 2.5 g of modified nanoparticles with 20 mL of the modifier, stir evenly, add 1 mL of a 1 mol / L sodium hydroxide solution, and stir at 70°C for 20 min. Filter, wash three times with deionized water, and dry in an oven at 70°C for 10 min to obtain composite nanoparticles.

[0051] Comparative Example 4 The difference between this comparative example and Example 1 is that 1-carboxyl o-carborane was not added, and the remaining steps and raw materials were the same as those in Example 1.

[0052] A1. 5.6 g of nanoparticles, 2.5 g of glucose, and 0.5 g of tannic acid were added to 200 mL of ethanol and stirred at 70°C for 30 min. The mixture was filtered, washed three times with deionized water, and dried in a 70°C oven for 10 min. The mixture was then placed in a tube furnace, and 5 mL of 30% potassium hydroxide solution was added. Nitrogen was introduced and carbonized at 800°C for 4 h. The mixture was cooled to room temperature, removed, washed three times with deionized water, and dried in a 70°C oven for 10 min to obtain porous carbon-loaded nanoparticles. A2. 2.3 g of porous carbon-loaded nanoparticles and 1 g of carboxyl-polyethylene glycol-carboxyl were added to 100 mL of ethanol, stirred at 65 ° C for 30 min, and centrifuged at 10,000 r / min to collect the particles to obtain modified nanoparticles; A3. Add 1 g of citric acid to 30 mL of ethanol and stir. Adjust the pH to 2.5 with 1 mol / L sodium hydroxide solution. Add 1.3 g of glycidyl methacrylate and react at 90°C with stirring for 4 h. Wash three times with ethanol to remove unreacted citric acid and dry in an oven at 80°C for 10 min to obtain a modifier. A4. Mix 2.5 g of modified nanoparticles with 20 mL of the modifier, stir evenly, add 1 mL of a 1 mol / L sodium hydroxide solution, and stir at 70°C for 20 min. Filter, wash three times with deionized water, and dry in an oven at 70°C for 10 min to obtain composite nanoparticles.

[0053] Example 2

[0054] A method for preparing an ion exchange resin for water treatment comprises the following steps: S1. 80 g of styrene, 10 g of divinylbenzene, 0.4 g of initiator, and 0.2 g of composite nanoparticles were mixed to form the organic phase; 1 g of polyvinyl alcohol and 180 mL of deionized water were mixed to form the aqueous phase. The organic and aqueous phases were mixed and stirred at 78°C to form an emulsion. The mixture was then reacted at 83°C for 5 h and filtered to obtain cross-linked spherical particles. S2. The cross-linked spherical particles were mixed with chlorosulfonic acid / dichloroethane and subjected to a sulfonation reaction at 60°C for 2 h. The mixture was then washed and neutralized with a 5% sodium hydroxide solution and dried to obtain substance A. The mass ratio of the cross-linked spherical particles to the chlorosulfonic acid / dichloroethane was 1:30, and the volume ratio of the chlorosulfonic acid / dichloroethane was 1:2. S3. Mix substance A with a 1% (mass fraction) zinc chloride aqueous solution, conduct a chloromethylation reaction at 50°C for 4 hours, add a 30% (mass fraction) trimethylamine ethanol solution, and conduct a quaternization reaction at 40°C for 2 hours to obtain an ion exchange resin; the mass ratio of substance A, 1% (mass fraction) zinc chloride aqueous solution, and 30% (mass fraction) trimethylamine ethanol solution is 1:30:0.1.

[0055] Example 3

[0056] A method for preparing an ion exchange resin for water treatment comprises the following steps: S1. 85 g of styrene, 15 g of divinylbenzene, 0.5 g of initiator, and 0.5 g of composite nanoparticles were mixed to form an organic phase; 2 g of polyvinyl alcohol and 200 mL of deionized water were mixed to form an aqueous phase. The organic and aqueous phases were mixed and stirred at 80°C to form an emulsion system. The mixture was reacted at 85°C for 6 h and filtered to obtain cross-linked spherical particles. S2. The cross-linked spherical particles were mixed with chlorosulfonic acid / dichloroethane and subjected to a sulfonation reaction at 60°C for 2 h. The mixture was then washed and neutralized with a 5% sodium hydroxide solution and dried to obtain substance A. The mass ratio of the cross-linked spherical particles to the chlorosulfonic acid / dichloroethane was 1:30, and the volume ratio of the chlorosulfonic acid / dichloroethane was 1:2. S3. Mix substance A with a 1% (mass fraction) zinc chloride aqueous solution, conduct a chloromethylation reaction at 50°C for 4 hours, add a 30% (mass fraction) trimethylamine ethanol solution, and conduct a quaternization reaction at 40°C for 2 hours to obtain an ion exchange resin; the mass ratio of substance A, 1% (mass fraction) zinc chloride aqueous solution, and 30% (mass fraction) trimethylamine ethanol solution is 1:30:0.1.

[0057] Example 4

[0058] A method for preparing an ion exchange resin for water treatment comprises the following steps: S1. 90 g of styrene, 20 g of divinylbenzene, 0.7 g of initiator, and 1 composite nanoparticle were uniformly mixed to form the organic phase; 3 g of polyvinyl alcohol and 220 mL of deionized water were uniformly mixed to form the aqueous phase. The organic and aqueous phases were mixed and stirred at 82°C to form an emulsion system. The mixture was reacted at 87°C for 7 h and filtered to obtain cross-linked spherical particles. S2. The cross-linked spherical particles were mixed with chlorosulfonic acid / dichloroethane and subjected to a sulfonation reaction at 60°C for 2 h. The mixture was then washed and neutralized with a 5% sodium hydroxide solution and dried to obtain substance A. The mass ratio of the cross-linked spherical particles to the chlorosulfonic acid / dichloroethane was 1:30, and the volume ratio of the chlorosulfonic acid / dichloroethane was 1:2. S3. Mix substance A with a 1% (mass fraction) zinc chloride aqueous solution, conduct a chloromethylation reaction at 50°C for 4 hours, add a 30% (mass fraction) trimethylamine ethanol solution, and conduct a quaternization reaction at 40°C for 2 hours to obtain an ion exchange resin; the mass ratio of substance A, 1% (mass fraction) zinc chloride aqueous solution, and 30% (mass fraction) trimethylamine ethanol solution is 1:30:0.1.

[0059] Example 5

[0060] A method for preparing an ion exchange resin for water treatment comprises the following steps: S1. 85 g of styrene, 15 g of divinylbenzene, 0.5 g of initiator, and 0.5 g of composite nanoparticles were mixed to form an organic phase; 2 g of polyvinyl alcohol and 200 mL of deionized water were mixed to form an aqueous phase. The organic and aqueous phases were mixed and stirred at 80°C to form an emulsion system. The mixture was reacted at 85°C for 6 h and filtered to obtain cross-linked spherical particles. S2. The cross-linked spherical particles were mixed with trifluoromethanesulfonic acid and subjected to a sulfonation reaction at 70°C for 1 hour. The mixture was then washed with a 5% sodium hydroxide solution for neutralization and dried to obtain substance A. The mass ratio of the cross-linked spherical particles to trifluoromethanesulfonic acid was 1:30. S3. Mix substance A with a 1% (mass fraction) zinc chloride aqueous solution, conduct a chloromethylation reaction at 50°C for 4 hours, add a 30% (mass fraction) trimethylamine ethanol solution, and conduct a quaternization reaction at 40°C for 2 hours to obtain an ion exchange resin; the mass ratio of substance A, 1% (mass fraction) zinc chloride aqueous solution, and 30% (mass fraction) trimethylamine ethanol solution is 1:30:0.1.

[0061] Example 6

[0062] A method for preparing an ion exchange resin for water treatment comprises the following steps: S1. 85 g of styrene, 15 g of divinylbenzene, 0.5 g of initiator, and 0.5 g of composite nanoparticles were mixed to form an organic phase; 2 g of polyvinyl alcohol and 200 mL of deionized water were mixed to form an aqueous phase. The organic and aqueous phases were mixed and stirred at 80°C to form an emulsion system. The mixture was reacted at 85°C for 6 h and filtered to obtain cross-linked spherical particles. S2. The cross-linked spherical particles were mixed with chlorosulfonic acid / acetic anhydride and subjected to a sulfonation reaction at 23°C for 30 minutes. The mixture was then washed with a 5% sodium hydroxide solution for neutralization and dried to obtain substance A. The mass ratio of the cross-linked spherical particles to the chlorosulfonic acid / acetic anhydride was 1:30, and the volume ratio of the chlorosulfonic acid to the acetic anhydride was 1:1. S3. Mix substance A with a 1% (mass fraction) zinc chloride aqueous solution, conduct a chloromethylation reaction at 50°C for 4 hours, add a 30% (mass fraction) trimethylamine ethanol solution, and conduct a quaternization reaction at 40°C for 2 hours to obtain an ion exchange resin; the mass ratio of substance A, 1% (mass fraction) zinc chloride aqueous solution, and 30% (mass fraction) trimethylamine ethanol solution is 1:30:0.1.

[0063] Example 7

[0064] A method for preparing an ion exchange resin for water treatment comprises the following steps: S1. 85 g of styrene, 15 g of divinylbenzene, 0.5 g of initiator, and 0.5 g of composite nanoparticles were mixed to form an organic phase; 2 g of polyvinyl alcohol and 200 mL of deionized water were mixed to form an aqueous phase. The organic and aqueous phases were mixed and stirred at 80°C to form an emulsion system. The mixture was reacted at 85°C for 6 h and filtered to obtain cross-linked spherical particles. S2. The cross-linked spherical particles were mixed with acetylsulfonic acid / acetic acid, and the mixture was subjected to a sulfonation reaction at 50°C for 3 hours. The mixture was then washed with a 5% sodium hydroxide solution for neutralization and dried to obtain substance A. The mass ratio of the cross-linked spherical particles to acetylsulfonic acid / acetic acid was 1:30, and the volume ratio of acetylsulfonic acid to acetic acid was 1:1. S3. Mix substance A with a 1% (mass fraction) zinc chloride aqueous solution, conduct a chloromethylation reaction at 50°C for 4 hours, add a 30% (mass fraction) trimethylamine ethanol solution, and conduct a quaternization reaction at 40°C for 2 hours to obtain an ion exchange resin; the mass ratio of substance A, 1% (mass fraction) zinc chloride aqueous solution, and 30% (mass fraction) trimethylamine ethanol solution is 1:30:0.1.

[0065] Example 8

[0066] A method for preparing an ion exchange resin for water treatment comprises the following steps: S1. 85 g of styrene, 15 g of divinylbenzene, 0.5 g of initiator, and 0.5 g of composite nanoparticles were mixed to form an organic phase; 2 g of polyvinyl alcohol and 200 mL of deionized water were mixed to form an aqueous phase. The organic and aqueous phases were mixed and stirred at 80°C to form an emulsion system. The mixture was reacted at 85°C for 6 h and filtered to obtain cross-linked spherical particles. S2. The cross-linked spherical particles were mixed with chlorosulfonic acid / dichloroethane and subjected to a sulfonation reaction at 60°C for 2 h. The mixture was then washed and neutralized with a 5% sodium hydroxide solution and dried to obtain substance A. The mass ratio of the cross-linked spherical particles to the chlorosulfonic acid / dichloroethane was 1:30, and the volume ratio of the chlorosulfonic acid / dichloroethane was 1:2. S3. Substance A and benzyl chloride were mixed and subjected to chloromethylation reaction at 30°C for 6 hours. A 30% trimethylamine ethanol solution was added and quaternization reaction was carried out at 40°C for 2 hours to obtain an ion exchange resin; the mass ratio of substance A, benzyl chloride, and 30% trimethylamine ethanol solution was 1:30:0.1.

[0067] Example 9

[0068] A method for preparing an ion exchange resin for water treatment comprises the following steps: S1. 85 g of styrene, 15 g of divinylbenzene, 0.5 g of initiator, and 0.5 g of composite nanoparticles were mixed to form an organic phase; 2 g of polyvinyl alcohol and 200 mL of deionized water were mixed to form an aqueous phase. The organic and aqueous phases were mixed and stirred at 80°C to form an emulsion system. The mixture was reacted at 85°C for 6 h and filtered to obtain cross-linked spherical particles. S2. The cross-linked spherical particles were mixed with chlorosulfonic acid / dichloroethane and subjected to a sulfonation reaction at 60°C for 2 h. The mixture was then washed and neutralized with a 5% sodium hydroxide solution and dried to obtain substance A. The mass ratio of the cross-linked spherical particles to the chlorosulfonic acid / dichloroethane was 1:30, and the volume ratio of the chlorosulfonic acid / dichloroethane was 1:2. S3. Mix substance A with a 1% (mass fraction) zinc chloride aqueous solution, conduct a chloromethylation reaction at 40°C for 2 hours, add a 25% (mass fraction) triethanolamine solution, and conduct a quaternization reaction at 40°C for 2 hours to obtain an ion exchange resin; the mass ratio of substance A, 1% (mass fraction) zinc chloride aqueous solution, and 25% (mass fraction) triethanolamine solution is 1:30:0.1.

[0069] Example 10

[0070] A method for preparing an ion exchange resin for water treatment comprises the following steps: S1. 85 g of styrene, 15 g of divinylbenzene, 0.5 g of initiator, and 0.5 g of composite nanoparticles were mixed to form an organic phase; 2 g of polyvinyl alcohol and 200 mL of deionized water were mixed to form an aqueous phase. The organic and aqueous phases were mixed and stirred at 80°C to form an emulsion system. The mixture was reacted at 85°C for 6 h and filtered to obtain cross-linked spherical particles. S2. The cross-linked spherical particles were mixed with chlorosulfonic acid / dichloroethane and subjected to a sulfonation reaction at 60°C for 2 h. The mixture was then washed and neutralized with a 5% sodium hydroxide solution and dried to obtain substance A. The mass ratio of the cross-linked spherical particles to the chlorosulfonic acid / dichloroethane was 1:30, and the volume ratio of the chlorosulfonic acid / dichloroethane was 1:2. S3. Mix substance A with a 1% by mass aqueous zinc chloride solution, conduct a chloromethylation reaction at 40°C for 2 hours, add trimethylamine / dimethylethanolamine, and conduct a quaternization reaction at 23°C for 3 hours to obtain an ion exchange resin; the mass ratio of substance A, 1% by mass aqueous zinc chloride solution, and trimethylamine / dimethylethanolamine is 1:30:0.1, and the volume ratio of trimethylamine / dimethylethanolamine is 1:1.

[0071] Comparative Example 5 The difference between this comparative example and Example 3 is that the composite nanoparticles are replaced by the material prepared in Comparative Example 1, and the remaining steps are synchronized with Example 3.

[0072] Comparative Example 6 The difference between this comparative example and Example 3 is that the composite nanoparticles are replaced by the material prepared in Comparative Example 2, and the remaining steps are synchronized with Example 3.

[0073] Comparative Example 7 The difference between this comparative example and Example 3 is that the composite nanoparticles are replaced by the material prepared in Comparative Example 3, and the remaining steps are synchronized with Example 3.

[0074] Comparative Example 8 The difference between this comparative example and Example 3 is that the composite nanoparticles are replaced by the material prepared in Comparative Example 4, and the remaining steps are synchronized with Example 3.

[0075] The performance of the ion exchange resins prepared in Examples 2-10 and Comparative Examples 5-8 was tested.

[0076] Adsorption capacity test: Prepare 200 mL of sodium DSD solution (4,4-diaminostilbene-2,2-disulfonic acid in Chinese) with a concentration of 1000 mg / L and a pH of 7, add 0.1 g of the prepared ion exchange resin, and oscillate and adsorb at 25°C for 24 h with an oscillation frequency of 150 rpm until adsorption equilibrium is reached. Use HPLC to determine the concentration of residual sodium DSD in the solution and calculate the adsorption capacity.

[0077] Exchange capacity performance test: The exchange capacity of the ion exchange resin prepared above was tested according to GB / T 13659-2008 and GB / T 11992-2008 standards.

[0078] Thermal stability test: The ion exchange resin prepared above was placed in a heater, and the heater was heated at a rate of 10°C / min. The initial decomposition temperature was recorded, which was the maximum operating temperature of the ion exchange resin.

[0079] Compressive strength performance test: Take the ion exchange resin particles prepared above (particle size 0.8 mm), use a universal material testing machine to apply vertical pressure at a rate of 5 mm / min until the particles break, and record the compressive strength value.

[0080] The test results are shown in Table 1 below.

[0081] Table 1 Performance test of ion exchange resins prepared in Examples 2-10 and Comparative Examples 5-8 project Adsorption capacity mg / g Exchange capacity mmol / g Heat-resistant temperature / ℃ Compressive strength / N Example 2 4.7 455.3 145 85 Example 3 4.8 459.2 148 87 Example 4 4.5 450.9 141 83 Example 5 4.2 448.6 142 83 Example 6 4.1 449.9 143 82 Example 7 4.0 448.2 144 84 Example 8 3.8 440.5 140 83 Example 9 3.6 441.3 142 86 Example 10 3.2 439.6 145 85 Comparative Example 5 1.7 193.6 103 56 Comparative Example 6 1.9 203.6 115 62 Comparative Example 7 2.1 223.4 123 66 Comparative Example 8 1.6 190.3 101 53 It can be seen from the data in Table 1 that the ion exchange resins prepared in Examples 2-10 have high thermal stability, compressive strength and exchange capacity.

[0082] In Comparative Example 5, the nanoparticles loaded with porous carbon are replaced with composite nanoparticles prepared from nanoparticles and added to the ion exchange resin. Its thermal stability, mechanical properties and exchange capacity decrease, which proves that the porous carbon structure synthesized on the surface of the nanoparticles can absorb external stress and hinder the expansion of microcracks. The nanoparticles have high thermal stability and can improve the heat resistance of the ion exchange resin. In addition, the synthesized porous carbon has high adsorption performance and pore capacity, which can improve the adsorption capacity and adsorption performance of the ion exchange resin.

[0083] In Comparative Example 6, the modified nanoparticles were replaced with composite nanoparticles prepared by nanoparticles loaded with porous carbon, and the composite nanoparticles were added to the ion exchange resin. The thermal stability, mechanical properties and exchange capacity of the composite nanoparticles decreased, which proved that the carboxyl-polyethylene glycol-carboxyl group was given the active functional group carboxyl of the nanoparticles loaded with porous carbon, which was beneficial to grafting the modifier on the surface of the nanoparticles loaded with porous carbon, participating in the polymerization reaction of the ion exchange resin, improving the compatibility of the nanoparticles with the ion exchange resin, and avoiding the poor compatibility of the nanoparticles with the ion exchange resin, which affected the thermal stability and mechanical properties of the ion exchange resin.

[0084] In Comparative Example 7, when the composite nanoparticles prepared without the addition of glycidyl methacrylate were added to the ion exchange resin, their thermal stability, mechanical properties and exchange capacity decreased, proving that the double bonds contained in glycidyl methacrylate can participate in the polymerization reaction of the ion exchange resin, allowing the composite nanoparticles to be dispersed in the ion exchange resin through chemical bonds, thereby improving the bonding strength between the composite nanoparticles and the ion exchange resin.

[0085] In Comparative Example 8, the composite nanoparticles prepared without adding 1-carboxy-o-carborane were added to the ion exchange resin, and its thermal stability decreased, proving that 1-carboxy-o-carborane contains a stable cage structure and has high thermal stability, further enhancing the heat resistance of the ion exchange resin, increasing the operating temperature of the ion exchange resin, and avoiding the problems of exchange capacity attenuation, resin damage, and failure of the ion exchange resin during long-term operation and in an environment with a high organic pollution load.

[0086] Throughout the specification, references to terms such as "one embodiment," "example," or "specific example" indicate that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0087] The above contents are merely examples and explanations of the present invention. Those skilled in the art may make various modifications or additions to the described specific embodiments or replace them in similar ways. As long as they do not deviate from the invention or exceed the scope defined by the claims, they should all fall within the scope of protection of the present invention.

Claims

1. A method for preparing an ion exchange resin for water treatment, characterized in that: The method comprises the following preparation steps: S1. Styrene, divinylbenzene, an initiator, and composite nanoparticles are uniformly mixed to form an organic phase; polyvinyl alcohol and deionized water are uniformly mixed to form an aqueous phase. The organic and aqueous phases are mixed and stirred at 78-82°C to form an emulsified system. The mixture is reacted at 83-87°C for 5-7 hours and filtered to obtain cross-linked spherical particles. S2. The cross-linked spherical particles and the sulfonation agent are mixed, subjected to sulfonation reaction, neutralized by washing with water, and dried to obtain substance A; S3. Substance A and a chloromethylated solvent are mixed, and after chloromethylation, an aminating agent is added, and then a quaternization reaction is performed to obtain an ion exchange resin; The composite nanoparticles are obtained by reacting citric acid, 1-carboxyl o-carborane and glycidyl methacrylate, and then mixing and reacting with modified nanoparticles; The modified nanoparticles are obtained by synthesizing porous carbon on the surface of nanoparticles and then subjecting the nanoparticles to surface treatment with carboxyl-polyethylene glycol-carboxyl.

2. The method for preparing an ion exchange resin for water treatment according to claim 1, wherein The composite nanoparticles are specifically prepared by the following steps: A1. Nanoparticles, glucose, and tannic acid were added to ethanol, stirred, filtered, washed, dried, and placed in a tube furnace. Potassium hydroxide solution was added and nitrogen was introduced. After high-temperature carbonization, the mixture was cooled to room temperature, removed, washed, and dried to obtain porous carbon-loaded nanoparticles. A2. The porous carbon nanoparticles and carboxyl-polyethylene glycol-carboxyl groups were added to ethanol, stirred, and the particles were collected by centrifugation to obtain modified nanoparticles; A3. 1-carboxyl-o-carborane and citric acid were added to ethanol, stirred evenly, and an aqueous sodium hydroxide solution was added to adjust the pH to 2-3. After stirring, the reaction was cooled to 80-100 ° C, glycidyl methacrylate was added, and after stirring, the reaction was completed, washed, and dried to obtain a modifier; A4. The modified nanoparticles and the modifier are mixed and stirred evenly, and a sodium hydroxide aqueous solution is added. After the reaction is completed, the mixture is filtered, washed, and dried to obtain composite nanoparticles.

3. The method for preparing an ion exchange resin for water treatment according to claim 2, wherein: In step A1, the dosage ratio of the nanoparticles, glucose, tannic acid, ethanol and potassium hydroxide solution is (5-6):(2-3):(0.3-0.7):(180-220) mL:(4-6) mL.

4. The method for preparing an ion exchange resin for water treatment according to claim 2, wherein: In step A2, the ratio of the porous carbon-loaded nanoparticles, carboxyl-polyethylene glycol-carboxyl and ethanol is (2-2.6) g: (0.8-1.2) g: (80-120) mL.

5. The method for preparing an ion exchange resin for water treatment according to claim 2, wherein: In step A3, the ratio of the amount of 1-carboxyl o-carborane, citric acid, ethanol and glycidyl methacrylate is (1-1.4) g: (0.8-1.2) g: (25-35) mL: (1.2-1.4) g.

6. The method for preparing an ion exchange resin for water treatment according to claim 2, wherein: In step A4, the ratio of the modified nanoparticles, the modifier and the sodium hydroxide aqueous solution is (2-3) g: (15-25) mL: (0.5-1.5) mL.

7. The method for preparing an ion exchange resin for water treatment according to claim 1, wherein: In step S1, the mass ratio of styrene, divinylbenzene, initiator and composite nanoparticles is (80-90):(10-20):(0.4-0.7):(0.2-1); The ratio of polyvinyl alcohol to deionized water is (1-3) g: (180-220) mL; The initiator is selected from benzoyl peroxide or azobisisobutyronitrile.

8. The method for preparing an ion exchange resin for water treatment according to claim 1, wherein: In step S2, the mass ratio of the cross-linked spherical particles to the sulfonated treatment agent is 1:(30-50).

9. The method for preparing an ion exchange resin for water treatment according to claim 1, wherein: In step S3, the mass ratio of substance A, chloromethylated solvent and aminating agent is 1:(30-40):(0.1-0.5).

10. An ion exchange resin obtained by the method for preparing an ion exchange resin for water treatment according to any one of claims 1 to 9.