CN-121972023-A - Copolymerization composite cation exchange membrane containing amino-functionalized inorganic phase, and preparation method and application thereof

CN121972023ACN 121972023 ACN121972023 ACN 121972023ACN-121972023-A

Abstract

The invention discloses a copolymerization composite cation exchange membrane containing amino functional inorganic phase, a preparation method and application thereof, wherein the preparation method of the cation exchange membrane comprises the following steps of (1) preparing the amino functional inorganic phase; the method comprises the steps of (1) preparing a rigid-flexible copolymerization-inorganic phase composite membrane solution, (3) defoaming and coating forming the composite membrane solution, and (4) protonating the composite membrane. The invention takes the rigid polymer containing active hydrogen as a structural support phase, the flexible polymer containing high-density amino groups as a functional site carrier, the amino functional inorganic phase as a synergistic enhancement phase, and a cross-linking agent is added, and the composite cation exchange membrane is prepared by the three-step core process of amino functional modification, rigid-flexible polymer copolymerization cross-linking and protonation activation, so that the composite cation exchange membrane has high ion exchange capacity, low surface resistance and low swelling rate, and also has excellent cycle performance.

Inventors

ZHANG PENG
JIA JIWU
MA YING
LI ZHIQIANG
GAO JIAMIN
SU YAN
WU HUOQIANG
ZHANG YIFENG
HUANG QIAN

Assignees

华能嘉祥发电有限公司
西安西热水务环保有限公司

Dates

Publication Date: 20260505
Application Date: 20260109

Claims (10)

1. The preparation method of the copolymerization composite cation exchange membrane containing amino functional inorganic phase is characterized by comprising the following steps: (1) Adding an inorganic material into an alcohol solvent, performing ultrasonic dispersion to form a first suspension, dropwise adding an aminosilane coupling agent into the first suspension, performing heating reaction, and centrifuging, washing and drying the obtained reaction product to obtain an amino functional inorganic phase; (2) Mixing and stirring the amino functional inorganic phase with a rigid polymer, an amino-containing flexible polymer and a polar organic solvent to form a second suspension, then adding a cross-linking agent into the second suspension, heating for reaction, then adding a defoaming agent into the obtained copolymerization system, and cooling and stirring to obtain a copolymerization-inorganic phase composite membrane solution; (3) The copolymerization-inorganic phase composite membrane liquid is subjected to deaeration treatment, then is coated on a pretreated substrate, and is subjected to standing and gradient drying after coating, so that a composite membrane is obtained; (4) And soaking the composite membrane in a protonation reagent, washing and drying to obtain the copolymerization composite cation exchange membrane containing the amino functional inorganic phase.
2. The method for preparing a copolymerized composite cation-exchange membrane containing an amino-functional inorganic phase according to claim 1, wherein in the step (1), the mass ratio of the inorganic material, the alcohol solvent and the aminosilane coupling agent is (3-4): 60-80): 5-8; Optionally, the inorganic material comprises at least one of hydroxyapatite, titanium dioxide and hydroxyapatite-silicon dioxide composite powder, and the particle size of the inorganic material is 50-100nm; optionally, the alcohol solvent comprises at least one of absolute ethyl alcohol, isopropanol and ethylene glycol; optionally, the aminosilane coupling agent comprises at least one of 3-aminopropyl triethoxysilane, 3-aminopropyl trimethoxysilane, N- (β -aminoethyl) - γ -aminopropyl trimethoxysilane.
3. The method for preparing an amino-functionalized inorganic phase-containing copolymerized composite cation-exchange membrane according to claim 1, wherein in the step (1), the power of ultrasonic dispersion is 200-300W, and the dispersion time is 40-50min; And/or the reaction temperature of the heating reaction is 75-85 ℃ and the reaction time is 8-10h; and/or the rotational speed of the centrifugation is 4000-4500r/min, and the time of each centrifugation is 20-25min; and/or the drying pressure is 0.06-0.1MPa, the drying temperature is 70-90 ℃ and the drying time is 16-20h.
4. The method for producing an amino group-containing functionalized inorganic phase-containing copolymerized composite cation-exchange membrane according to claim 1, wherein in the step (2), the mass ratio of the amino group-containing functionalized inorganic phase, the rigid polymer, the amino group-containing flexible polymer, the polar organic solvent, and the crosslinking agent is (4-9): 55-65): 25-35): 150-180): 3-5; Optionally, the rigid polymer comprises at least one of polyetheretherketone, polysulfone, polyethersulfone; Optionally, the amine-containing flexible polymer comprises at least one of polyallylamine, polyethylenimine, polylysine; optionally, the polar organic solvent comprises at least one of N-methylpyrrolidone, N-dimethylformamide, N-dimethylacetamide; optionally, the crosslinking agent comprises at least one of formaldehyde, glutaraldehyde, melamine formaldehyde resin; And/or, the defoamer is added in an amount of 0.4 to 0.7wt% of the copolymerization system; Optionally, the defoamer comprises at least one of polyether modified silicone oil, organic silicon defoamer and polyoxyethylene polyoxypropylene ether.
5. The method for preparing an amino-functionalized inorganic phase-containing copolymerized composite cation-exchange membrane according to claim 1, wherein in the step (2), the rotational speed of the mixing and stirring is 400-450r/min, the mixing temperature is 60-70 ℃, and the mixing time is 24-30h; And/or the reaction temperature of the heating reaction is 80-90 ℃ and the reaction time is 10-12h; and/or the temperature of the cooling and stirring is 30-35 ℃ and the stirring time is 25-35min.
6. The method for preparing an amino-functionalized inorganic phase-containing copolymerized composite cation exchange membrane according to claim 1, wherein in the step (3), the defoaming treatment is performed in a vacuum defoaming machine, and the vacuum degree of the vacuum defoaming machine is set to be-0.08 to-0.1 MPa, the temperature is 30-35 ℃, and the defoaming time is set to be 2-3 hours.
7. The method for producing an amino group-functionalized inorganic phase-containing copolymerized composite cation-exchange membrane according to claim 1, wherein in the step (3), the substrate is selected from any one of a glass plate, a polytetrafluoroethylene plate, and a stainless steel plate; and/or, the coating adopts an applicator with the thickness of 200-280 mu m, and the blade coating speed is 5-8cm/s; and/or, the standing time is 8-12min; and/or the gradient drying process is that the drying is carried out for 2.5-3.5h at 55-65 ℃, then for 2.5-3.5h at 80-90 ℃ and finally for 2-3h at 100-110 ℃ and 0.06-0.1 MPa.
8. The method for preparing a copolymerized composite cation-exchange membrane containing an amino-functional inorganic phase according to claim 1, wherein in the step (4), the protonating agent comprises at least one of hydrochloric acid solution, sulfuric acid solution and phosphoric acid solution, and the concentration of the protonating agent is 0.5-0.7mol/L; And/or the soaking temperature is 25-35 ℃ and the soaking time is 10-14h; And/or drying at 55-65deg.C under 0.06-0.1MPa for 8-12 hr.
9. A copolymerized composite cation-exchange membrane containing an amino-functional inorganic phase, characterized in that the copolymerized composite cation-exchange membrane containing an amino-functional inorganic phase is produced by the production method according to any one of claims 1 to 8.
10. Use of a copolyamide containing functionalized inorganic phase according to claim 9 in electrodialysis desalination.

Description

Copolymerization composite cation exchange membrane containing amino-functionalized inorganic phase, and preparation method and application thereof Technical Field The invention belongs to the technical field of ion exchange membrane materials, and particularly relates to a copolymerization composite cation exchange membrane containing amino-functionalized inorganic phases, and a preparation method and application thereof. Background The cation exchange membrane is used as a core functional material for electrodialysis, membrane Capacitance Deionization (MCDI), electrorefining and other technologies, the performance of the cation exchange membrane directly determines the desalination efficiency, the energy consumption level and the long-term stability of the system, and the cation exchange membrane has irreplaceable functions in the fields of sea water desalination, industrial wastewater treatment, pure water preparation, chemical separation and the like. The ideal cation exchange membrane needs to have high Ion Exchange Capacity (IEC), low surface resistance, low swelling rate, excellent mechanical strength and chemical stability, however, the prior art still faces the bottleneck of multi-performance collaborative optimization, and is difficult to meet the requirements of industrial application on high efficiency, long-acting and environmental protection. The traditional cation exchange membrane preparation mainly relies on two major technical paths of single polymer modification or simple inorganic-organic blending, and has obvious defects. In the polymer modification route, the prior art introduces ion exchange groups (such as-SO 3H、-PO3H2) on the polymer chain through chemical modification means such as sulfonation, phosphorylation and the like, and typically represents sulfonated polyether ether ketone (SPEEK) and Sulfonated Polysulfone (SPSF) membranes. Although the membrane can provide a certain ion exchange capacity, the membrane has two main core problems that firstly, functional groups are not enough in stability, sulfonic groups and phosphoric groups are easy to hydrolyze and fall off in aqueous solution, so that the membrane performance is fast attenuated along with the service time, secondly, the modification process is harsh, the sulfonation/phosphorylation reaction needs to be carried out under the conditions of high temperature (80-120 ℃) and strong acid, the energy consumption is high, the polymer chain is easy to degrade, a large amount of acid waste liquid is generated, and the environmental pollution risk is high. Furthermore, "ionic conduction and structural stabilization" of a single polymer film are naturally contradictory. In order to increase the ionic capacity, the content of hydrophilic groups needs to be increased, but excessive hydrophilic groups can cause excessive swelling of the membrane in an aqueous solution, damage the regularity of an ion transmission channel, further increase the surface resistance and even cause mechanical rupture of the membrane. To improve structural stability, the prior art attempts to modify by chemical crosslinking or blending with inorganic phases. The chemical crosslinking modification mostly adopts crosslinking agents such as epichlorohydrin and the like to inhibit the swelling of polymer chain segments by constructing a covalent network, but the crosslinking reaction needs to accurately control the temperature and time, the reaction condition is sensitive, and the ion channel is blocked by excessive crosslinking to reduce the ion exchange capacity, and in addition, part of the crosslinking agents have toxicity residual risks, so that the application of the membrane in the fields of drinking water treatment and the like is limited. The simple inorganic-organic blend membrane is prepared by physically mixing inorganic particles such as silicon dioxide and montmorillonite with a polymer, and inhibiting swelling by utilizing the physical supporting effect of an inorganic phase. The inorganic particles are easy to fall off from the membrane matrix after long-term soaking or recycling, so that the membrane performance is attenuated sharply, for example, the ion exchange capacity of the existing SPEEK/inorganic particle blending membrane is usually lower than 1.6mmol/g, the surface resistance exceeds 5.5Ω & cm 2, the swelling rate is higher than 18%, the performance retention rate is lower than 80% after 100 times of recycling, and the requirements of electrodialysis and other scenes on high efficiency and long-term effect are difficult to be met. In addition, the existing cation exchange membrane preparation process has the problems of low economy and environmental protection, that part of the process depends on expensive functional monomers, rare inorganic fillers or toxic solvents (such as fluorine-containing solvents) which are difficult to recycle, so that the production cost is high, the high-temperature and high-pressure reaction conditions and