CN110828871A - Preparation method of proton exchange membrane with ordered hierarchical pore channels - Google Patents

Abstract

The invention relates to the field of fuel cells, and discloses a preparation method of a proton exchange membrane with an ordered multi-level pore structure, comprising the following steps: a single-ended silane functionalized with a mercapto group, a double-ended organic silane functionalized with a disulfide bond, The template agent and the photoacid generator are mixed uniformly and then coated on the substrate to form a liquid film; the liquid film is irradiated and polymerized under a high pressure mercury lamp to obtain mesopores with sulfhydryl groups inside the channel and disulfide bonds on the wall of the channel Organosilicon film; soak the mesoporous organosilicon film in absolute ethanol overnight to obtain a mesoporous organosilicon film without template agent; finally treat the mesoporous organosilicon film in hydrogen peroxide and dilute sulfuric acid respectively to obtain sulfonic acid Functionalized proton exchange membranes with hierarchical pore channels. The method uses single-head organosilane and double-head organosilane to synchronously self-assemble to form a proton exchange membrane with ordered multi-level pores, which can effectively increase proton transfer channels and improve proton conductivity, and has potential application value in proton exchange membrane fuel cells. .

Description

Preparation method of proton exchange membrane with ordered hierarchical pore channels

technical field

The invention relates to the technical field of fuel cells, in particular to a preparation method of a proton exchange membrane with ordered multi-level pore channels.

Background technique

Proton exchange membrane fuel cell is a kind of fuel cell system with proton exchange membrane as solid electrolyte. Among them, the proton exchange membrane is the core component of the fuel cell, which directly affects the performance and life of the cell. At present, the most important proton exchange membranes are perfluorosulfonic acid membrane, polyarylene ether membrane, polybenzimidazole membrane, etc. These organic membranes have poor heat resistance and aging resistance, and organic-inorganic composite proton exchange membranes are prepared. It is an important means to solve the above problems. Polyorganosilane hybrid materials have the advantages of strong structural design, diverse preparation processes, and excellent comprehensive properties of materials, and are important materials for proton exchange membrane substrates. In addition, the ordered pore structure in the proton exchange membrane can effectively increase the conduction rate of protons.

SUMMARY OF THE INVENTION

Purpose of the invention: In view of the problems existing in the prior art, the present invention provides a preparation method of a proton exchange membrane with an ordered multi-level pore structure. The prepared proton exchange membrane has an ordered multi-level pore structure, which can effectively increase the proton exchange rate Transfer channels to improve proton conductivity.

Technical solution: The present invention provides a preparation method of a proton exchange membrane with an ordered multi-level pore structure, including the following steps: S1: single-head organosilane functionalized with mercapto group, and double-head organosilane functionalized with disulfide bond , the template agent and the photoacid generator are evenly mixed and coated on the substrate to form a liquid film; S2: the liquid film is placed under a high-pressure mercury lamp for irradiation and polymerization for 30-60 minutes, to obtain a sulfhydryl group inside the channel, a channel Mesoporous organosilicon film with disulfide bonds on the wall; S3: soak the mesoporous organosilicon film in absolute ethanol overnight to obtain a mesoporous organosilicon film without template agent; S4: the mesoporous organosilicon film The membranes were sequentially treated in hydrogen peroxide and dilute sulfuric acid for 2 h to obtain sulfonic acid-functionalized proton exchange membranes with ordered hierarchical pore channels. ;

Preferably, the mass ratio of the thiol-functionalized single-ended organosilane, the disulfide-functionalized double-ended organosilane, the template agent, and the photoacid generator is 2:1:0.2-0.5:0.02-0.05.

Preferably, the mercapto-functional single-ended organosilane is any one of the following: 3-mercaptopropyltrimethoxysilane, 8-mercaptooctanetrimethoxysilane, and 11-mercaptoundecyltrimethoxysilane . More preferred is 8-mercaptooctanetrimethoxysilane.

Preferably, the disulfide functionalized double-headed organosilane is bis-[3-(triethoxysilyl)propyl]-disulfide.

Preferably, the photoacid generator is any one of the following: 4-isobutylphenyl-4'-methylphenyliodo hexafluorophosphate, diphenyl-(4-phenylthio)phenylsulfonium Hexafluorophosphate, 4-octyloxydiphenyliodonium hexafluoroantimonate. More preferred is 4-isobutylphenyl-4'-methylphenyliodo hexafluorophosphate.

Preferably, the templating agent is any one of the following: octadecyl polyoxyethylene ether, polyethylene glycol-polypropylene glycol-polyethylene glycol triblock polymer, cetyltrimethyl bromide Ammonium. Polyethylene glycol-polypropylene glycol-polyethylene glycol triblock polymers are more preferred.

Preferably, the mass fraction of the hydrogen peroxide is 20%-30%; the concentration of the dilute sulfuric acid is 0.1-0.5 mol/L; the power of the high-pressure mercury lamp is 100 w.

Beneficial effects: the present invention utilizes a high pressure mercury lamp to induce the decomposition of the photoacid generator to generate an acid catalyst, and in-situ catalyzes the hydrolysis of the organosilane to generate a hydrophilic silanol structure. At this time, a single-ended organosilane forms a hydrophilic silanol structure , the other end of the hydrophobic mercaptoalkyl structure; at the same time, the two ends of the organosilane form a hydrophilic silanol structure at both ends and a hydrophobic disulfide structure in the middle. At the same time, the template agent self-assembles into a hexahedral pore structure with a hydrophobic structure inside and a hydrophilic structure outside. The hydrolyzed hydrophilic end of the single-ended organosilane is polycondensed and cross-linked on the outside of the Si-O-Si pore wall structure, and the hydrophobic end extends to the inside of the hexahedral pore. -O-Si pore wall structure, the hydrophobic end is forcibly confined on the pore wall due to the effect of size confinement, forming an organic silicon film with an ordered structure of sulfhydryl groups in the pore channels and disulfide bond groups on the pore wall. After removing the template agent and oxidizing disulfide bonds and sulfhydryl groups to sulfonate groups, the pore walls are micropores (formed by microphase separation after the disulfide bonds are broken and oxidized to sulfonate groups) and the pore channels are mesopores (formed after the template agent is removed). ) of the hierarchically porous proton transport channel.

Due to the application of the above-mentioned technical solutions, the present invention has the following advantages compared with the prior art:

1) The present invention uses single-ended organosilane and double-ended organosilane to synchronously self-assemble under the induction of a template agent to form a proton exchange membrane with ordered multi-level pores, which can effectively increase proton transfer channels and improve proton conductivity. It has potential application value in fuel cells.

2) The photo-induced self-assembly method of the present invention prepares the proton exchange membrane, which is a green and efficient preparation method without the participation of a solvent in the preparation process and has a high reaction rate.

Detailed ways

The present invention will be described in detail below with reference to specific embodiments.

Embodiment 1:

0.5 g of 8-mercaptooctane trimethoxysilane, 0.25 g of bis-[3-(triethoxysilyl)propyl]-disulfide, 0.1 g of polyethylene glycol-polypropylene glycol-polyethylene glycol tri- After mixing the block polymer and 0.02 g photoacid generator α-benzoylbenzyl carbamate, place it on a stirrer to stir and mix evenly to obtain a coating solution; uniformly coat the obtained coating solution on a polytetrafluoroethylene base A liquid film was formed on the substrate; after irradiating the liquid film on the substrate with a high-pressure mercury lamp for 30 minutes, an organic silicon film with an ordered pore structure was obtained; the organic silicon film with an ordered pore structure was peeled off from the substrate, and the organic silicon film was The silicon film was treated in 30% hydrogen peroxide and 0.2 mol/L dilute sulfuric acid for 2 h in turn, and dried to obtain a proton exchange membrane with an ordered hierarchical pore structure.

Embodiment 2:

0.5 g of 3-mercaptooctane trimethoxysilane, 0.25 g of bis-[3-(triethoxysilyl)propyl]-disulfide, 0.1 g of octadecyl polyoxyethylene ether, and 0.02 g of light After the acid generator diphenyl-(4-phenylthio)phenylsulfonium hexafluorophosphate is mixed, it is placed on a stirrer to stir and mix evenly to obtain a coating solution; the obtained coating solution is uniformly coated on the polytetrafluoroethylene base. forming a liquid film; after irradiating the liquid film on the substrate with a high-pressure mercury lamp for 40 minutes, an organosilicon film with an ordered pore structure was obtained; after being peeled off from the substrate, an organosilicon film with an ordered pore structure was obtained, and the The organosilicon films were sequentially treated in 25% hydrogen peroxide and 0.3 mol/L dilute sulfuric acid for 2 h, and dried to obtain a proton exchange membrane with an ordered hierarchical pore structure.

Embodiment 3:

Combine 0.5 g of 11-mercaptoundecyltrimethoxysilane, 0.25 g of bis-[3-(triethoxysilyl)propyl]-disulfide, 0.2 g of cetyltrimethylammonium bromide and After mixing 0.02 g of photoacid generator diphenyl-(4-phenylthio)phenylsulfonium hexafluorophosphate, place it on a stirrer to stir and mix evenly to obtain a coating solution; uniformly coat the obtained coating solution on polytetrafluoroethylene A liquid film is formed on the vinyl substrate; after irradiating the liquid film on the substrate with a high-pressure mercury lamp for 30 minutes, an organosilicon film with an ordered pore structure is obtained; the organosilicon film with an ordered pore structure is peeled off from the substrate, and the The organosilicon film was sequentially treated in 30% hydrogen peroxide and 0.4 mol/L dilute sulfuric acid for 2 h, and dried to obtain a proton exchange membrane with an ordered hierarchical pore structure.

Table 1 Performance test results of the proton exchange membranes prepared in Embodiments 1 to 3

It can be seen from Table 1 that the proton exchange membrane prepared by this method has good mechanical strength and dimensional stability, high ion exchange capacity and proton conductivity. Among them, the proton exchange membrane prepared in Example 1 has outstanding comprehensive performance and has potential application value.

The above-mentioned embodiments are only intended to illustrate the technical concept and features of the present invention, and the purpose is to enable those who are familiar with the art to understand the content of the present invention and implement it accordingly, and cannot limit the protection scope of the present invention. All equivalent transformations or modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.

Claims (9)

1. A preparation method of a proton exchange membrane with ordered multi-stage pore channels is characterized by comprising the following steps:

s1: uniformly mixing sulfydryl functionalized single-head organosilane, disulfide bond functionalized double-head organosilane, a template agent and a photoacid generator, and coating the mixture on a substrate to form a liquid film;

s2: irradiating and polymerizing the liquid film for 30-60 minutes under a high-pressure mercury lamp to obtain a mesoporous organic silicon film with mercapto groups in the pore canal and disulfide bonds on the wall of the pore canal;

s3: soaking the mesoporous organic silicon film in absolute ethyl alcohol overnight to obtain a mesoporous organic silicon film without a template agent;

s4: and (3) sequentially treating the mesoporous organic silicon film in hydrogen peroxide and dilute sulfuric acid for 2 hours to obtain the sulfonic acid functionalized proton exchange membrane with the ordered multi-stage pore channel.

2. The preparation method of the proton exchange membrane with the ordered multi-stage pore channels as claimed in claim 1, wherein the mass ratio of the mercapto-functionalized single-headed organosilane, the disulfide-bond functionalized double-headed organosilane, the templating agent and the photoacid generator is 2: 1: 0.2-0.5: 0.02-0.05.

3. The method for preparing a proton exchange membrane having ordered multi-stage pore channels as claimed in claim 1, wherein the mercapto-functionalized single-headed organosilane is any one of the following:

3-mercaptopropyltrimethoxysilane, 8-mercaptooctane-trimethoxysilane and 11-mercaptoundecyltrimethoxysilane.

4. The method of claim 1, wherein the disulfide-functionalized double-headed organosilane is bis- [3- (triethoxysilyl) propyl ] -disulfide.

5. The method for preparing a proton exchange membrane having an ordered multi-stage pore channel as claimed in claim 1, wherein the photoacid generator is any one of:

4-isobutylphenyl-4' -methylphenyliodohexafluorophosphate, diphenyl- (4-phenylsulfide) phenylsulfonium hexafluorophosphate, 4-octyloxydiphenyliodonium hexafluoroantimonate.

6. The method for preparing a proton exchange membrane with ordered multi-stage pore channels according to claim 1, wherein the template is any one of the following:

octadecyl polyoxyethylene ether, polyethylene glycol-polypropylene glycol-polyethylene glycol triblock polymer, and hexadecyl trimethyl ammonium bromide.

7. The preparation method of the proton exchange membrane with the ordered multi-stage pore channels according to any one of claims 1 to 6, wherein the mass fraction of the hydrogen peroxide is 20-30%.

8. The method for preparing a proton exchange membrane having an ordered multi-stage pore channel as claimed in any one of claims 1 to 6, wherein the concentration of the dilute sulfuric acid is 0.1-0.5 mol/L.

9. The process for the preparation of a proton exchange membrane with ordered multi-stage pore channels according to any one of claims 1 to 6, wherein the power of the mercury high-pressure lamp is 100 w.