阅读说明：本技术 一种耐有机溶剂阳离子交换膜的制备方法 (Preparation method of organic solvent-resistant cation exchange membrane ) 是由 赵严 沈江南 沈鹏鑫 王利祥 于 2019-09-16 设计创作，主要内容包括：本发明公开了一种阳离子交换膜的制备方法,其包括：(1)将凯夫拉芳纶材料、氢氧化钾与二甲基亚砜溶剂按比例混合,并密封搅拌进行酰胺部分水解反应,将凯夫拉芳纶材料溶解成为带有氨基的纳米纤维铸膜液,并在水平放置的网布上刮制成膜；(2)将步骤(1)得到的膜立即放入0.1g/L～30g/L的对氨基苯磺酸钠水溶液中进行相转换,待相转换完成后,再转移至新配置的催化剂溶液中密封进行酰胺脱水缩合反应,所述的催化剂溶液为0.1～5g/L1-乙基-3-(3-二甲胺-亚硝酰基)碳二亚胺盐酸盐和0.05～3g/LN-羟基丁二酰亚胺的混合水溶液,充分反应后干燥得到阳离子交换膜。本发明制备工艺简便,操作易行,无毒环保；制备的阳离子交换膜对于有机溶剂具有良好的耐受性能。(The invention discloses a preparation method of a cation exchange membrane, which comprises the following steps: (1) mixing Kevlar aramid fiber material, potassium hydroxide and dimethyl sulfoxide solvent in proportion, sealing and stirring to perform amide partial hydrolysis reaction, dissolving the Kevlar aramid fiber material into nano-fiber casting solution with amino, and scraping the nano-fiber casting solution on a horizontally placed mesh to form a film; (2) immediately putting the membrane obtained in the step (1) into a 0.1-30 g/L sodium sulfanilate aqueous solution for phase conversion, transferring the membrane into a newly configured catalyst solution after the phase conversion is finished, sealing the membrane to perform an amide dehydration condensation reaction, wherein the catalyst solution is a mixed aqueous solution of 0.1-5 g/L1-ethyl-3- (3-dimethylamine-nitrosyl) carbodiimide hydrochloride and 0.05-3 g/L LN-hydroxysuccinimide, and drying the membrane after full reaction to obtain the cation exchange membrane. The preparation process is simple and convenient, the operation is easy, and the preparation method is non-toxic and environment-friendly; the prepared cation exchange membrane has good tolerance performance to organic solvents.)

1. A method of making a cation exchange membrane, the method comprising:

(1) the Kevlar aramid material, potassium hydroxide and a dimethyl sulfoxide solvent are mixed according to the mass percentage of 0.1-5%: 0.5% -10%: 85 to 99 percent of the mixture is mixed, sealed and stirred to carry out amide partial hydrolysis reaction, the Kevlar aramid fiber material is dissolved into nano-fiber casting solution with amino, and the nano-fiber casting solution is scraped into a film on a horizontally placed mesh;

(2) immediately putting the membrane obtained in the step (1) into a 0.1-30 g/L sodium sulfanilate aqueous solution for phase conversion, transferring the membrane into a newly configured catalyst solution after the phase conversion is finished, sealing the membrane to perform an amide dehydration condensation reaction, wherein the catalyst solution is a mixed aqueous solution of 1-ethyl-3- (3-dimethylamine-nitrosyl) carbodiimide hydrochloride and N-hydroxysuccinimide, the concentrations of the 1-ethyl-3- (3-dimethylamine-nitrosyl) carbodiimide hydrochloride and the N-hydroxysuccinimide in the mixed solution are respectively 0.1-5 g/L and 0.05-3 g/L, and drying the membrane after full reaction to obtain the cation exchange membrane.

2. The method of claim 1, wherein: in the step (1), the Kevlar aramid material, the potassium hydroxide and the dimethyl sulfoxide solvent are respectively 0.5-5 percent, 1-10 percent and 85-98 percent in percentage by mass.

3. The method of claim 1, wherein: in the step (1), the mass percentages of the Kevlar aramid fiber material, the potassium hydroxide and the dimethyl sulfoxide solvent are respectively 1-3%, 3-7% and 90-96%.

4. The method according to any one of claims 1 to 3, wherein: in the step (1), the conditions of the amide partial hydrolysis reaction are as follows: the reaction temperature is 20-90 ℃, and the reaction time is 3-7 days.

5. The method of claim 4, wherein: the conditions for the amide partial hydrolysis reaction are: the mixture is stirred and reacted for 2 to 4 days at the temperature of between 40 and 90 ℃, and then the temperature is reduced to between 20 and 30 ℃ for reaction for 1 to 3 days.

6. The method according to any one of claims 1 to 3, wherein: in the step (1), the conditions for scraping the film are as follows: the temperature is 0-40 ℃, the humidity is 4-40%, the thickness of the film scraping knife is 50-500 mu m, and the preferable film scraping conditions are as follows: the temperature was 20 ℃, the humidity was 20%, and the thickness of the doctor blade was 250 μm.

7. The method according to any one of claims 1 to 3, wherein: in the step (2), the concentration of the sodium sulfanilate aqueous solution is 1-6g/L, and the most preferable concentration is 6 g/L.

8. The method according to any one of claims 1 to 3, wherein: in the step (2), the phase inversion time is 10-20min, more preferably 15 min.

9. The method according to any one of claims 1 to 3, wherein: in the step (2), the amide dehydration reaction conditions are as follows: soaking at room temperature for 10-20 days.

10. The method according to any one of claims 1 to 3, wherein: in the step (2), the drying temperature is 40-70 ℃.

Technical Field

The invention relates to a preparation method of an organic solvent resistant cation exchange membrane.

Technical Field

With the rapid development of society, water pollution and water resource shortage have become the most urgent global problems, and the sustainable development of human beings is directly restricted. In particular, agricultural wastewater and industrial wastewater have been receiving attention because they contain a large amount of harmful metal ions and other compounds which are difficult to treat. Currently, ion exchange membranes are used as the core component of electrodialysis, and the treatment of salt removal in the desalination direction of water treatment has irreplaceable advantages. But the traditional cation exchange membrane material cannot meet the metal salt ion removal of the current complex water environment. Especially in the aqueous solution mixed with a large amount of organic solvent, the ion exchange membrane material is chemically degraded, the ion exchange capacity is reduced, and the ion desalting performance is greatly influenced. Therefore, finding and designing suitable membrane materials for organic solvent cation exchange membranes has become an urgent research hotspot. The discovery opens up a wide application prospect for applying the cation exchange membrane to the metal ion removal treatment of the sewage mixed with the organic solvent at present.

The Kevlar aramid material synthesized by the poly dimethyl terephthalate (PPTA) has excellent tolerance to the most common organic solvent due to the highly ordered and asymmetric alternating structure of long molecular chains and intermolecular hydrogen bonds, thereby having extremely high application prospect. The industrial aramid product is dissolved in a mixed solution of dimethyl sulfoxide and potassium hydroxide, and provides an ideal material basis for designing an organic solvent-resistant ion exchange membrane.

Disclosure of Invention

The invention aims to provide a preparation method of an organic solvent resistant cation exchange membrane.

In order to achieve the purpose, the invention adopts the following technical scheme:

a method of making a cation exchange membrane, the method comprising:

(1) the Kevlar aramid material, potassium hydroxide and a dimethyl sulfoxide solvent are mixed according to the mass percentage of 0.1-5%: 0.5% -10%: 85% -99% (the sum of the weight of Kevlar aramid fiber material, potassium hydroxide and dimethyl sulfoxide solvent is 100%), sealing and stirring to perform amide partial hydrolysis reaction, dissolving the Kevlar aramid fiber material into nanofiber membrane casting solution with amino, and scraping the nanofiber membrane casting solution on a horizontally placed mesh to form a membrane;

(2) immediately putting the membrane obtained in the step (1) into a 0.1-30 g/L sodium sulfanilate aqueous solution for phase conversion, transferring the membrane into a newly configured catalyst solution after the phase conversion is finished, sealing the membrane to perform an amide dehydration condensation reaction, wherein the catalyst solution is a mixed aqueous solution of 1-ethyl-3- (3-dimethylamine-nitrosyl) carbodiimide hydrochloride and N-hydroxysuccinimide, the concentrations of the 1-ethyl-3- (3-dimethylamine-nitrosyl) carbodiimide hydrochloride and the N-hydroxysuccinimide in the mixed solution are respectively 0.1-5 g/L and 0.05-3 g/L, and drying the membrane after full reaction to obtain the cation exchange membrane.

In the invention, the Kevlar aramid fiber material can be aramid nanofiber with models of AP, K29, K49, 100, 119, 129, KM2, KM2Plus and the like.

Preferably, in the step (1), the Kevlar aramid material, the potassium hydroxide and the dimethyl sulfoxide solvent are mixed according to the mass percentage of 0.5-5%: 1% -10%: 85% to 98%, more preferably 1% to 3%: 3% -7%: 90 to 96 percent.

Preferably, in step (1), the amide partial hydrolysis reaction conditions are: the reaction temperature is 20-90 ℃, and the reaction time is 3-7 days. As a further preference, the conditions of the amide partial hydrolysis reaction are: the mixture is stirred and reacted for 2 to 4 days at the temperature of between 40 and 90 ℃, and then the temperature is reduced to between 20 and 30 ℃ for reaction for 1 to 3 days.

Preferably, in the step (1), the conditions for scraping the film are as follows: the temperature is 0-40 ℃, the humidity is 4-40%, and the thickness of the film scraping knife is 50-500 mu m; more preferred knifing conditions are: the temperature was 20 ℃, the humidity was 20%, and the thickness of the doctor blade was 250 μm.

Preferably, in step (2), the concentration of the sodium sulfanilate aqueous solution is 1 to 6g/L, and most preferably 6 g/L.

Preferably, in step (2), the phase inversion time is 10-20min, more preferably 15 min.

Preferably, in the step (2), the amide dehydration reaction conditions are as follows: soaking at room temperature for 10-20 days.

Preferably, in the step (2), the drying temperature is 40 to 70 ℃.

Compared with the prior art, the invention has the beneficial effects that: the preparation process is simple and convenient, the operation is easy, and the preparation method is non-toxic and environment-friendly; the prepared cation exchange membrane has good tolerance performance to organic solvents.

Drawings

Fig. 1 shows the membrane ion exchange capacity of the prepared cation exchange membrane, and it can be seen that the membrane ion exchange capacity is improved along with the increase of the dosage of the sodium sulfanilate.

Fig. 2 shows the water content of the prepared cation exchange membrane, and it can be seen that the water content of the membrane is firstly reduced and then improved along with the increase of the dosage of the sodium sulfanilate.

Fig. 3 is a film surface resistance of the prepared cation exchange membrane, and it can be seen that the membrane ion exchange capacity is reduced along with the increase of the dosage of the sodium sulfanilate.

FIG. 4 is a scanning electron micrograph of the cation exchange membrane prepared.

FIG. 5 is a plot of polarization current versus voltage for the prepared K-CEM-0 in 0.1M NaCl.

FIG. 6 is a plot of polarization current versus voltage for the prepared K-CEM-1 in 0.1M NaCl.

Fig. 7 is a schematic view of an electrodialysis unit.

FIG. 8 shows that the effective membrane area of K-CEM-1 membrane is 20cm at 15.0V ²Desalting chamber in the lower desalting chamber.

FIG. 9 is a plot of polarization current versus voltage for the prepared K-CEM-2 in 0.1M NaCl.

FIG. 10 shows K-CEM-2 films at 15.0V withThe effective membrane area is 20cm ²Desalting chamber in the lower desalting chamber.

FIG. 11 is a plot of polarization current versus voltage for the prepared K-CEM-3 in 0.1M NaCl.

FIG. 12 shows that the effective membrane area of K-CEM-3 membrane is 20cm at 15.0V ²Desalting chamber in the lower desalting chamber.

FIG. 13 shows the desalination of electrodialysis desalination and concentration compartment after soaking K-CEM-3 membrane in 25% acetone aqueous solution for 48 hours.

FIG. 14 shows the desalination of electrodialysis desalination chamber and concentration chamber after soaking K-CEM-3 membrane in 50% acetone aqueous solution for 48 hr.

FIG. 15 shows the desalination of electrodialysis desalination and concentration desalination of K-CEM-3 membrane in 75% acetone solution after soaking in water for 48 hr.

FIG. 16 shows the desalination of electrodialysis desalination chamber and concentration chamber after soaking K-CEM-3 membrane in 100% acetone for 48 hours.

Detailed Description

The invention is described in further detail below with reference to the following figures and embodiments: