CN-122006512-A - Ion solvation microporous membrane resistant to high temperature and high concentration alkali, preparation method and application thereof

Abstract

The invention discloses an ion solvation microporous membrane resistant to high temperature and high concentration alkali, a preparation method and application thereof, and relates to the technical field of separation membranes; meanwhile, stable oxindole/OH ‑ complex ion pairs are constructed in situ, and a continuous ion solvation micropore channel is formed, so that not only is a rich transmission site provided for OH < - >, but also a selective transmission path penetrating through the film thickness direction is constructed, and excellent ion selectivity and chemical stability can be maintained under the conditions of high-concentration alkali liquor and high temperature.

Inventors

• GU JINGJING
• MA WEI
• XIA YOUFU
• ZHANG MENGJUAN
• GE XIAOLAN
• XU JUNKAI
• CHEN SIQI

Assignees

• 亳州学院

Dates

Publication Date

20260512

Application Date

20260225

Claims (10)

1. 1. A method of preparing an ion solvated microporous membrane comprising the steps of: S1, synthesizing an isatoic-arene copolymer by an aromatic hydrocarbon and isatoic through a super acid catalytic reaction; s2, preparing the isatin-arene copolymer into a polymer film; s3, forming a super-crosslinked microporous membrane by a super-crosslinking reaction of the polymer membrane; s4, soaking the super-crosslinked microporous membrane in an alkaline solution to obtain the ion solvated microporous membrane.
2. 2. The method according to claim 1, wherein the aromatic hydrocarbon is at least one of biphenyl, para-terphenyl, meta-terphenyl, and tetra-biphenyl.
3. 3. The method according to claim 1, wherein the molar ratio of the aromatic hydrocarbon to the isatin is 1 (1-1.3).
4. 4. The method according to claim 1, wherein the catalyst for the super acid catalytic reaction is a mixed acid of trifluoroacetic acid and trifluoromethanesulfonic acid; preferably, the molar ratio of the aromatic hydrocarbon to the trifluoroacetic acid is 1 (1-1.5); preferably, the molar ratio of the trifluoroacetic acid to the trifluoromethanesulfonic acid is 1 (7-12). Preferably, the reaction solvent of the super acid catalytic reaction is at least one of dichloromethane, chloroform and tetrahydrofuran.
5. 5. The method according to claim 1, wherein the polymer film is prepared by at least one of solution casting, knife coating, and spin coating, and comprises at least one of N-methylpyrrolidone, dimethyl sulfoxide, and N, N-dimethylformamide as a solvent.
6. 6. The method according to claim 1, wherein the reaction solvent of the super-crosslinking reaction is at least one of 1, 2-dichloroethane, N-dimethylformamide and carbon tetrachloride; Preferably, the catalyst of the super-crosslinking reaction is at least one of ferric chloride, stannous chloride, aluminum trichloride, boron fluoride and ferric bromide; preferably, the cross-linking agent of the super cross-linking reaction is at least one of dimethanol formal, chlorodimethyl ether, dichloroxylene and 4,4' -bis (chloromethyl) biphenyl; preferably, the mol ratio of the reaction solvent to the catalyst to the cross-linking agent is (5-20): 1 (0.5-3); preferably, the reaction temperature of the super-crosslinking reaction is 25-80 ℃.
7. 7. The method according to claim 1, wherein the alkaline solution is one of sodium hydroxide, potassium hydroxide, lithium hydroxide and calcium hydroxide solution; Preferably, the concentration of the alkaline solution is 1-10 mol L -1 ; Preferably, the soaking temperature of the alkaline solution is 20-80 ℃ and the soaking time is 7-10 days.
8. 8. An ion solvated microporous membrane prepared by the method of any one of claims 1-7.
9. 9. Use of the ion solvated microporous membrane of claim 8 in OH - /multivalent anion separation.
10. 10. The method of claim 9, wherein the OH - /multivalent anion comprises at least one of OH - /WO 4 2- 、OH - /MoO 4 2-- 、OH - /SO 4 2-- 、OH - /CO 3 2- ; preferably, the OH - /multivalent anion separation is by electrodialysis.

Description

Ion solvation microporous membrane resistant to high temperature and high concentration alkali, preparation method and application thereof Technical Field The invention relates to the technical field of separation membranes, in particular to an ion solvation microporous membrane resistant to high temperature and high concentration alkali, a preparation method and application thereof. Background The high-temperature high-concentration alkali wastewater is a typical wastewater generated in the industrial continuous production processes of metallurgy, metal surface treatment, printing, dyeing, spinning and the like. For example, in textile dyeing, cotton mercerization and alkaline extraction processes of cellulose from agricultural straw, the wastewater temperature generated by these processes is 25-75 ℃, where the OH - concentration is as high as 5mol L -1. Membrane separation technology has made significant progress in the field of alkali recovery, however, under extreme conditions of high temperature, high alkali concentration, etc., the stability of membrane materials still faces significant challenges, and only a few membranes can meet such requirements at present. Most of the anion exchange membranes developed so far have insufficient chemical stability in high-temperature high-concentration alkali, mainly because quaternary ammonium groups in the OH - membrane undergo nucleophilic substitution or Hofmann elimination reaction to cause degradation of membrane materials, so that the stability of the anion exchange membrane in high-temperature high-concentration alkali is greatly reduced, and the performance stability and the service life of the anion exchange membrane are further influenced. The ion solvating membrane achieves OH - conduction by absorbing electrolyte in the aqueous hydroxide solution. In terms of chemical stability, ion solvated membranes exhibit excellent alkali resistance stability due to the absence of quaternary ammonium groups compared to conventional quaternized hydrocarbon polymers. In terms of structural stability, channels formed by the conventional microphase separation structure are easy to swell, and the selectivity of ions is reduced. The super-crosslinked polymer has unique advantages in the aspect of swelling resistance, and the super-crosslinked polymer constructs a permanent rigid microporous structure through Friedel-Crafts reaction, and the rigid network microporous structure provides favorable conditions for ion selective transmission due to excellent pore connectivity and extremely low swelling degree. German application (ANGEWANDTE CHEMIE International Edition, 2024, e 202407372) reports a method for preparing a microporous anion exchange membrane by hypercrosslinking, which effectively overcomes the swelling problem of the microphase separated ion exchange membrane, realizes high transmission rate of Cl - ions and high selectivity of Na +/Cl- ions, but contains quaternary ammonium groups and is easy to degrade in high-concentration alkali liquor. Natural energy (Nature energy, 2024, 401-410) reports that poly (oxindole-biphenyl) based ion solvated membranes with highly stable oxindole/KOH complex ion pairs are useful in water electrolysis devices. These ion solvation membranes exhibit good alkaline stability at 80 ℃, but the membranes are dense membranes, non-porous structures, and ion transport channels are realized by ion exchange only, which is detrimental to the improvement of ion transport rate. Patent CN 110903449a discloses a preparation method of isatin aromatic hydrocarbon copolymer, which is characterized in that the isatin aromatic hydrocarbon copolymer containing quaternary ammonium cations is synthesized by carrying out hydroxyalkylation polycondensation reaction on substituted isatin, methyl piperidone and aromatic hydrocarbon under the catalysis of super-strong acid, and an anion exchange membrane is further prepared, so that the isatin aromatic hydrocarbon copolymer can be used for electrochemical devices such as fuel cells, energy storage cells, electrolyzed water and the like. However, the membrane depends on quaternary ammonium groups as cation conduction sites, and has potential stability hazards when realizing ion transmission function, namely, on one hand, the quaternized structure is easy to absorb water and swell to influence the dimensional stability of the membrane, and on the other hand, under the working conditions of high temperature and high concentration and alkalinity, the quaternary ammonium groups are easy to undergo reactions such as Hofmann degradation or nucleophilic substitution, and the like, so that the chemical structure is damaged, and the durability of the membrane in long-term operation is limited. Patent CN 119039574a discloses a self-contained microporous polymer based on indole-2, 3-dione, and uses it in the field of ion solvation membrane preparation and alkaline water electrolysis hydrogen production. The patent uses s