阅读说明：本技术 一种用于无膜电去离子系统的石墨烯复合离子交换树脂的制备方法 (Preparation method of graphene composite ion exchange resin for membraneless electrodeionization system ) 是由 申小兰 应雨枫 李�浩 彭振博 史海波 于 2020-11-30 设计创作，主要内容包括：本发明属于离子交换树脂制备领域,涉及用于无膜电去离子系统的石墨烯复合离子交换树脂的制备方法。本发明通过石墨烯复合共聚白球和磺化剂在60-150℃下混合反应,反应完成后降温至30-50℃,再经后处理制得的离子交换树脂制适用于无膜电去离子系统进行废水处理及高纯水制备,其较常规树脂交换容量、导电性得到大幅提高,且提升了无膜电去离子性能,有助于降低无膜电去离子系统再生电压和能耗。(The invention belongs to the field of ion exchange resin preparation, and relates to a preparation method of graphene composite ion exchange resin for a membraneless electrodeionization system. According to the invention, the graphene composite copolymerization white ball and the sulfonating agent are mixed and reacted at 60-150 ℃, the temperature is reduced to 30-50 ℃ after the reaction is finished, and the ion exchange resin prepared by post-treatment is suitable for wastewater treatment and high-purity water preparation of a membraneless electrodeionization system, the exchange capacity and the conductivity of the resin are greatly improved compared with those of the conventional resin, the membraneless electrodeionization performance is improved, and the regeneration voltage and the energy consumption of the membraneless electrodeionization system are reduced.)

1. The preparation method of the graphene composite ion exchange resin for the membrane-free electrodeionization system is characterized in that the graphene composite ion exchange resin is prepared by mixing and reacting graphene composite copolymerization white balls and a sulfonating agent at 60-150 ℃, cooling to 30-50 ℃ after the reaction is finished, and performing post-treatment.

2. The preparation method of the graphene composite ion exchange resin for the membraneless electrodeionization system according to claim 1, wherein the mass ratio of the graphene composite copolymerized white balls to the sulfonating agent in the mixing reaction is (1-1.5): (3-5).

3. The preparation method of the graphene composite ion exchange resin for the membraneless electrodeionization system according to claim 1 or 2, wherein the sulfonating agent is a sulfuric acid solution with a solute mass fraction of 30-99%.

4. The preparation method of the graphene composite ion exchange resin for the membraneless electrodeionization system according to claim 1 or 2, wherein the particle size of the graphene composite copolymerized white spheres is 0.4-0.8 mm.

5. The preparation method of the graphene composite ion exchange resin for the membraneless electrodeionization system according to claim 4, wherein the preparation method of the graphene composite copolymerized white spheres comprises the following steps:

(1) weighing 5-15 parts of graphene, 120 parts of styrene 100-containing material, 150 parts of divinylbenzene 100-containing material, 50-150 parts of dispersant, 3-8 parts of initiator, 10-30 parts of catalyst and 300 parts of pore-foaming agent 150-containing material;

(2) adding 20-60% of graphene into styrene for ultrasonic treatment, then adding the rest graphene and performing ultrasonic treatment to obtain a graphene/styrene suspension;

(3) and sequentially adding 10-50 parts of the graphene/styrene suspension, divinylbenzene, a dispersing agent, an initiator, a catalyst and a pore-foaming agent into pure water at the temperature of 40-60 ℃ to be uniformly stirred to form a mixed solution, heating the mixed solution to the temperature of 60-120 ℃, then carrying out heat preservation to carry out suspension polymerization reaction, cooling to the temperature of 30-50 ℃ after finishing heat preservation, and washing, filtering and drying to obtain the graphene composite copolymerization white ball.

6. The method for preparing the graphene composite ion exchange resin for the membraneless electrodeionization system according to claim 5, wherein the dispersing agent is one or more of polyvinyl alcohol and sodium chloride.

7. The preparation method of the graphene composite ion exchange resin for the membraneless electrodeionization system according to claim 5, wherein the initiator is one or more of benzoyl peroxide and lauroyl peroxide.

8. The preparation method of the graphene composite ion exchange resin for the membraneless electrodeionization system according to claim 5, wherein the catalyst is one or more of zinc chloride and nickel chloride.

9. The preparation method of the graphene composite ion exchange resin for the membraneless electrodeionization system according to claim 5, wherein the pore-foaming agent is one or more of toluene, ethylbenzene and propylbenzene.

Technical Field

The invention belongs to the field of ion exchange resin preparation, and relates to a preparation method of graphene composite ion exchange resin for a membraneless electrodeionization system.

Background

The non-membrane electrodeionization method is a new type of water treatment method, which is divided into two stages of treatment and regeneration, the treatment is similar to the ordinary ion exchange process, when the ion exchange resin is failed, the two ends of the resin are electrified with high-voltage direct current to regenerate, and the failed ion exchange resin is regenerated by hydrogen ions and hydroxyl ions generated by electrolysis and water cracking. Compared with the traditional ion exchange method, the method does not need to use acid-base agents, and can realize in-situ electric regeneration of the ion exchange resin; compared with the traditional electrodeionization technology, the method does not need to use an ion exchange membrane, and has the advantages of simple device structure, difficult polarization and scaling, convenient assembly and disassembly and the like. The membrane-free electrodeionization has wide application prospect in the fields of wastewater treatment and high-purity water preparation.

The ion exchange resin is a core material of a membraneless electrodeionization system, and has great influence on effluent quality, energy consumption, water recovery rate and the like of membraneless electrodeionization. The ideal resin should have excellent adsorption performance, electrical regeneration performance, exchange capacity and electrical conductivity at the same time. However, since adsorption and regeneration are in a pair of contradictions, strong adsorption capacity makes regeneration difficult, and easy regeneration makes adsorption capacity weak, while conductivity and exchange capacity are in a pair of contradictions, strong conductivity makes exchange capacity small, and large exchange capacity makes conductivity weak, it is almost impossible to find an ideal resin that meets the above-mentioned conditions among ordinary anion and cation resins.

Chinese patent application document (publication number: CN111097555A) discloses a strong-base graphene composite ion exchange resin material and a preparation method thereof, wherein the prepared basic graphene composite ion exchange resin material is uniformly dispersed in a polymer matrix in a covalent bond form and has good thermal stability and swelling resistance, but the basic anion exchange resin prepared by the method can not be used for treating cations such as heavy metals.

Disclosure of Invention

The invention aims to solve the problems in the prior art, and provides a preparation method of graphene composite ion exchange resin, which can be used for preparing the graphene composite ion exchange resin with large exchange capacity and excellent conductivity and used for a membraneless electrodeionization system.

The purpose of the invention can be realized by the following technical scheme: a preparation method of graphene composite ion exchange resin for a membrane-free electrodeionization system is characterized in that the graphene composite ion exchange resin is prepared by mixing and reacting graphene composite copolymerization white balls and a sulfonating agent at 60-150 ℃, cooling to 30-50 ℃ after the reaction is finished, and performing post-treatment.

The sulfonation reaction can load functional group-sulfonic group on the resin, the sulfonic group can effectively adsorb cations such as heavy metal, and the sulfonic group can be easily dissociated to obtain H in the solution⁺SO strongly acidic, the negatively charged groups, e.g. SO, contained in the bulk after dissociation of the resin^3-The adsorption agent can adsorb other cations in the binding solution, and the adsorption capacity of the adsorption agent is greatly improved after a large number of sulfonic groups are loaded.

In the above preparation method of the graphene composite ion exchange resin for the membraneless electrodeionization system, the mass ratio of the graphene composite copolymerized white balls to the sulfonating agent in the mixing reaction is (1-1.5): (3-5). The proportional relation between the graphene composite copolymerization white ball and the sulfonating agent directly influences the contents of graphene and functional groups on the resin, the proportion is too high, the graphene content is high, but the functional group content is low; if the ratio is too low, the functional group content is high, but the graphene content is low.

In the above preparation method of the graphene composite ion exchange resin for the membraneless electrodeionization system, the sulfonating agent is a sulfuric acid solution with a solute mass fraction of 30-99%. When the sulfuric acid concentration is too low, the carried sulfonic acid group is small, resulting in insufficient adsorption ability.

In the above preparation method of the graphene composite ion exchange resin for the membraneless electrodeionization system, the particle size of the graphene composite copolymerized white spheres is 0.4-0.8 mm. The particle size is mainly determined by micropores in the resin, the more micropores, the larger particle size, the faster resin exchange speed and the easier regeneration, but the conductivity is reduced; the smaller the number of micropores, the smaller the particle size, the slower the resin exchange rate, and the regeneration is difficult, but the conductivity is increased. When the particle size is 0.4-0.8mm, the regeneration capability and the conductivity of the graphene composite copolymerized white ball reach the highest cost performance, the requirement of the regeneration capability is met, and the graphene composite copolymerized white ball also has excellent conductivity.

In the above method for preparing the graphene composite ion exchange resin for the membraneless electrodeionization system, the method for preparing the graphene composite copolymerized white spheres comprises the following steps:

(1) weighing 5-15 parts of graphene, 120 parts of styrene 100-containing material, 150 parts of divinylbenzene 100-containing material, 50-150 parts of dispersant, 3-8 parts of initiator, 10-30 parts of catalyst and 300 parts of pore-foaming agent 150-containing material;

(2) adding 20-60% of graphene into styrene for ultrasonic treatment, then adding the rest graphene and performing ultrasonic treatment to obtain a graphene/styrene suspension;

(3) and sequentially adding 10-50 parts of the graphene/styrene suspension, divinylbenzene, a dispersing agent, an initiator, a catalyst and a pore-foaming agent into pure water at the temperature of 40-60 ℃ to be uniformly stirred to form a mixed solution, heating the mixed solution to the temperature of 60-120 ℃, then carrying out heat preservation to carry out suspension polymerization reaction, cooling to the temperature of 30-50 ℃ after finishing heat preservation, and washing, filtering and drying to obtain the graphene composite copolymerization white ball.

According to the invention, the conductivity and exchange capacity of the resin are greatly increased by adding graphene, the graphene is uniformly dispersed into the suspension by using ultrasonic oscillation, and the dispersibility of the graphene is further improved by a two-step graphene adding method.

In the above preparation method of the graphene composite ion exchange resin for the membraneless electrodeionization system, the dispersant is one or two of polyvinyl alcohol and sodium chloride.

In the above preparation method of the graphene composite ion exchange resin for the membraneless electrodeionization system, the initiator is one or two of benzoyl peroxide and lauroyl peroxide.

In the above preparation method of the graphene composite ion exchange resin for the membraneless electrodeionization system, the catalyst is one or two of zinc chloride and nickel chloride. The zinc chloride and the nickel chloride are used as catalysts, so that the reaction speed can be accelerated, the polymerization reaction and the functional group reaction can be promoted, and the adsorption and regeneration performance of the ion exchange resin can be improved.

In the above preparation method of the graphene composite ion exchange resin for the membraneless electrodeionization system, the pore-foaming agent is one or two of toluene, ethylbenzene and propylbenzene. The pore-forming agent can increase the specific surface area of the resin, thereby increasing the point position of the functional group and improving the exchange capacity of the resin.

Compared with the prior art, the invention has the following beneficial effects: the graphene composite ion exchange resin prepared by the sulfonation reaction is suitable for wastewater treatment and high-purity water preparation of a membrane-free electrodeionization system, the exchange capacity and the conductivity of the graphene composite ion exchange resin are greatly improved compared with those of the conventional resin, the membrane-free electrodeionization performance is improved, and the regeneration voltage and the energy consumption of the membrane-free electrodeionization system are reduced.

Detailed Description

The following are specific examples of the present invention and further describe the technical solutions of the present invention, but the present invention is not limited to these examples.

Example 1

(1) Adding 5 parts of graphene into 120 parts of styrene, performing ultrasonic oscillation for 2 hours, then adding 4 parts of graphene, and performing ultrasonic oscillation for 1 hour to obtain a suspension. Adding 30 parts of graphene/styrene suspension, 120 parts of divinylbenzene, 120 parts of polyvinyl alcohol, 5 parts of benzoyl peroxide, 20 parts of zinc chloride and 200 parts of toluene into pure water at 50 ℃ and uniformly stirring to form a mixed solution, heating the mixed solution to 80 ℃, then preserving heat to perform suspension polymerization reaction, cooling to 40 ℃ after heat preservation, washing, filtering and drying to obtain graphene composite copolymerized white balls with the particle size of 0.5 mm;

(2) compounding a graphene composite copolymerization white ball and a sulfonating agent in a ratio of 1: 4 at 80 ℃, the sulfonating agent is sulfuric acid with the mass fraction of 99%, the temperature is reduced to 30 ℃ after the reaction is finished, and the graphene composite ion exchange resin is obtained after dilution by dilute sulfuric acid and washing to neutrality.

Example 2:

(1) adding 2 parts of graphene into 120 parts of styrene, performing ultrasonic oscillation for 2 hours, then adding 3 parts of graphene, and performing ultrasonic oscillation for 1-2 hours to obtain a suspension. Adding 10 parts of graphene/styrene suspension, 100 parts of divinylbenzene, 50 parts of sodium chloride, 3 parts of lauroyl peroxide, 10 parts of nickel chloride and 150 parts of ethylbenzene into pure water at 40 ℃ and uniformly stirring to form a mixed solution, heating the mixed solution to 60 ℃, then preserving heat to perform suspension polymerization reaction, cooling to 30 ℃ after heat preservation, washing with water, filtering and drying to obtain graphene composite copolymerized white spheres with the particle size of 0.4 mm;

(2) compounding a graphene composite copolymerization white ball and a sulfonating agent in a ratio of 1: 2 at 60 ℃, the sulfonating agent is sulfuric acid with the mass fraction of 30%, the temperature is reduced to 30 ℃ after the reaction is finished, and the graphene composite ion exchange resin is obtained after dilution by dilute sulfuric acid and washing to neutrality.

Example 3:

(1) firstly, adding 5 parts of graphene into 120 parts of styrene, performing ultrasonic oscillation for 2 hours, then adding 8 parts of graphene, and performing ultrasonic oscillation for 2 hours to obtain a suspension. Adding 50 parts of graphene/styrene suspension, 150 parts of divinylbenzene, 150 parts of polyvinyl alcohol, 8 parts of benzoyl peroxide, 30 parts of zinc chloride and 300 parts of toluene into pure water at 60 ℃ and uniformly stirring to form a mixed solution, heating the mixed solution to 120 ℃, then preserving heat to perform suspension polymerization reaction, cooling to 50 ℃ after heat preservation, washing with water, filtering and drying to obtain graphene composite copolymerized white balls with the particle size of 0.8 mm;

(2) compounding a graphene composite copolymerization white ball and a sulfonating agent in a ratio of 1: 5 at 150 ℃, the sulfonating agent is sulfuric acid with the mass fraction of 60%, the temperature is reduced to 50 ℃ after the reaction is finished, and the graphene composite ion exchange resin is obtained after dilution by dilute sulfuric acid and washing to neutrality.

Example 4:

(1) adding 3 parts of graphene into 110 parts of styrene, performing ultrasonic oscillation for 1 hour, then adding 4 parts of graphene, and performing ultrasonic oscillation for 2 hours to obtain a suspension. Adding 20 parts of graphene/styrene suspension, 120 parts of divinylbenzene, 60 parts of polyvinyl alcohol, 7 parts of benzoyl peroxide and 20 parts of zinc chloride, and 180 parts of toluene into pure water at 55 ℃, uniformly stirring to form a mixed solution, heating the mixed solution to 100 ℃, then preserving heat, carrying out suspension polymerization reaction, cooling to 45 ℃ after heat preservation, washing, filtering and drying to obtain graphene composite copolymerized white balls with the particle size of 0.5 mm;

(2) compounding a graphene composite copolymerization white ball and a sulfonating agent in a ratio of 1: 6 at 80 ℃, the sulfonating agent is sulfuric acid with the mass fraction of 60%, the temperature is reduced to 35 ℃ after the reaction is finished, and the graphene composite ion exchange resin is obtained after dilution by dilute sulfuric acid and washing to neutrality.

Example 5:

(1) adding 5 parts of graphene into 120 parts of styrene, performing ultrasonic oscillation for 1 hour, then adding 3 parts of graphene, and performing ultrasonic oscillation for 1 hour to obtain a suspension. Adding 12 parts of graphene/styrene suspension, 100 parts of divinylbenzene, 60 parts of polyvinyl alcohol, 5 parts of benzoyl peroxide, 28 parts of zinc chloride and 155 parts of toluene into pure water at 45 ℃ and uniformly stirring to form a mixed solution, heating the mixed solution to 65 ℃, then preserving heat to perform suspension polymerization reaction, cooling to 42 ℃ after heat preservation, washing with water, filtering and drying to obtain graphene composite copolymerized white spheres with the particle size of 0.6 mm;

(2) compounding a graphene composite copolymerization white ball and a sulfonating agent in a ratio of 1: 1 at 70 ℃, the sulfonating agent is sulfuric acid with the mass fraction of 60%, the temperature is reduced to 40 ℃ after the reaction is finished, and the graphene composite ion exchange resin is obtained after dilution by dilute sulfuric acid and washing to neutrality.

Comparative example 1:

according to the method in Chinese patent application document (CN: CN111097555A), dichloroethane, trimethylamine hydrochloride and sodium hydroxide solution are added into the graphene composite copolymerized white ball to react for 6h at 30 ℃.

Comparative example 2:

the difference from the example 1 is only that the graphene composite copolymerized white ball is not mixed with the sulfonating agent to react in the process of preparing the composite ion exchange resin in the comparative example 2, but is mixed with the conventional aminating agent to react.

Comparative example 3:

the only difference from example 1 is that this comparative example does not add graphene.

The graphene composite ion exchange resins prepared by the methods of examples 1 to 5 and comparative examples 1 to 3 were subjected to capacity change and conductivity tests.

Table 1: performance testing of graphene composite ion exchange resins prepared by the methods described in examples 1-5 and comparative examples 1-3

Examples	Cation exchange capacity (eq/L)	Conductivity (S/m)
			Example 1	3.1	1.9
Example 2	1.5	1.5
			Example 3	2.2	2.1
Example 4	2.9	1.3
			Example 5	1.3	1.8
Comparative example 1	0	1.0
			Comparative example 2	0	0.1
Comparative example 3	0.2	0.2

In conclusion, the graphene composite ion exchange resin prepared by the sulfonation reaction is suitable for wastewater treatment and high-purity water preparation of a membrane-free electrodeionization system, the exchange capacity and the conductivity of the graphene composite ion exchange resin are greatly improved, the membrane-free electrodeionization performance is improved, and the regeneration voltage and the energy consumption can be reduced.

The technical scope of the invention claimed by the embodiments of the present application is not exhaustive, and new technical solutions formed by equivalent replacement of single or multiple technical features in the technical solutions of the embodiments are also within the scope of the invention claimed by the present application; in all the embodiments of the present invention, which are listed or not listed, each parameter in the same embodiment only represents an example (i.e., a feasible embodiment) of the technical solution, and there is no strict matching and limiting relationship between the parameters, wherein the parameters may be replaced with each other without departing from the axiom and the requirements of the present invention, unless otherwise specified.

The technical means disclosed by the scheme of the invention are not limited to the technical means disclosed by the technical means, and the technical scheme also comprises the technical scheme formed by any combination of the technical characteristics. While the foregoing is directed to embodiments of the present invention, it will be appreciated by those skilled in the art that various changes may be made in the embodiments without departing from the principles of the invention, and that such changes and modifications are intended to be included within the scope of the invention.

The specific embodiments described herein are merely illustrative of the spirit of the invention. Various modifications or additions may be made to the described embodiments or alternatives may be employed by those skilled in the art without departing from the spirit or ambit of the invention as defined in the appended claims.