阅读说明：本技术 适用于零极距电解槽的离子交换膜及其制备方法 (Ion exchange membrane suitable for zero-polar-distance electrolytic cell and preparation method thereof ) 是由 杨淼坤 张志浩 王玉顺 王丽 冯威 张江山 张永明 于 2020-09-24 设计创作，主要内容包括：本发明涉及一种适用于零极距电解槽的离子交换膜及其制备方法,属于全氟离子交换膜技术领域。本发明所述的离子交换膜,包括全氟离子交换树脂和增强材料,在全氟离子交换树脂膜层的至少一侧附着有具有微纳米级通道的多孔气体释放层；所述具有微纳米级通道的多孔气体释放层由分散液附着在离子交换膜层表面干燥而成；所述的分散液由中空微纳米颗粒分散在磺酸树脂水醇溶液中形成；所述的中空微纳米颗粒由全氟磺酸树脂加工而成的中空纤维膜破碎制得。本发明所述的适用于零极距电解槽的离子交换膜,其提高了膜与电极之间溶液的循环流动,更适合在高电流密度条件下的零极距电解槽中运行,具有更低的面电阻；本发明同时提供了简单易行的制备方法。(The invention relates to an ion exchange membrane suitable for a zero-polar-distance electrolytic cell and a preparation method thereof, belonging to the technical field of perfluorinated ion exchange membranes. The ion exchange membrane comprises perfluorinated ion exchange resin and a reinforcing material, wherein a porous gas release layer with a micro-nano channel is attached to at least one side of a perfluorinated ion exchange resin membrane layer; the porous gas release layer with the micro-nano channel is formed by attaching dispersion liquid on the surface of an ion exchange membrane and drying; the dispersion liquid is formed by dispersing hollow micro-nano particles in a sulfonic acid resin water-alcohol solution; the hollow micro-nano particles are prepared by crushing hollow fiber membranes processed by perfluorinated sulfonic acid resin. The ion exchange membrane suitable for the zero polar distance electrolytic cell improves the circular flow of solution between the membrane and the electrode, is more suitable for running in the zero polar distance electrolytic cell under the condition of high current density, and has lower surface resistance; the invention also provides a simple and feasible preparation method.)

1. An ion exchange membrane suitable for a zero-polar distance electrolytic cell comprises perfluorinated ion exchange resin and a reinforcing material, and is characterized in that: at least one side of the perfluorinated ion exchange resin film layer is attached with a porous gas release layer with micro-nano-scale channels;

the porous gas release layer with the micro-nano channel is formed by attaching dispersion liquid on the surface of an ion exchange membrane and drying;

the dispersion liquid is formed by dispersing hollow micro-nano particles in a sulfonic acid resin water-alcohol solution;

the hollow micro-nano particles are prepared by crushing hollow fiber membranes processed by perfluorinated sulfonic acid resin.

2. The ion exchange membrane suitable for use in a zero polar distance electrolysis cell according to claim 1, wherein: the preparation process of the hollow micro-nano particles is as follows: the perfluorinated sulfonic acid resin is melted and extruded into a hollow fiber membrane, is converted into a sodium type in NaOH solution, and is crushed by a grinder, so that micron-sized or nano-sized micro-nano particles are obtained.

3. The ion exchange membrane suitable for use in a zero polar distance electrolysis cell according to claim 1, wherein: the hollow micro-nano particles have an ion exchange capacity of 0.90-1.05 mmol/g, an outer diameter of 200-2000 nm, a wall thickness of 20-500 nm and a length of 50-500 nm.

4. The ion exchange membrane suitable for use in a zero polar distance electrolysis cell according to claim 1, wherein: the mass percentage of the hollow micro-nano particles in the dispersion liquid is 8-20%.

5. The ion exchange membrane suitable for use in a zero polar distance electrolysis cell according to claim 1, wherein: the mass percentage of the sulfonic acid resin in the sulfonic acid resin hydroalcoholic solution is 0.5-10%.

6. The ion exchange membrane suitable for use in a zero polar distance electrolysis cell according to claim 1, wherein: the distribution amount of the hollow micro-nano particles on the surface of the ion exchange membrane is 0.5-3mg/cm²。

7. The ion exchange membrane suitable for use in a zero polar distance electrolysis cell according to claim 1, wherein: the roughness Ra of the porous gas release layer with the micro-nano channel is 3.00-20.00 mu m.

8. The ion exchange membrane suitable for use in a zero polar distance electrolysis cell according to claim 1, wherein: the thickness of the porous gas release layer with the micro-nano scale channels attached is 1.0-5.0 μm.

9. The ion exchange membrane suitable for use in a zero polar distance electrolysis cell according to claim 1, wherein: the reinforcing material is a net material, a fiber material, a non-woven fabric material or a porous membrane material prepared from one of polytetrafluoroethylene, polyperfluoroalkoxy resin, polyperfluoroethylpropylene or ethylene-tetrafluoroethylene copolymer.

10. A method for preparing an ion exchange membrane suitable for use in a zero pole pitch electrolyzer as recited in any one of claims 1 to 9, wherein: the preparation method comprises the following preparation steps:

(1) performing melt casting on a perfluorinated ion exchange resin precursor to form a single-layer film or a multilayer composite film in a mode of coextrusion by a screw extruder, introducing a reinforcing material between film forming press rollers, and pressing the reinforcing material into a film body under the action of pressure between the rollers to form a polymer film;

(2) soaking the polymer membrane in the step (1) in a mixed aqueous solution of dimethyl sulfoxide and strong base to convert the polymer membrane into an ion exchange membrane with an ion exchange function;

(3) dissolving perfluorinated sulfonic acid resin into a water-alcohol mixed solution to form a sulfonic acid resin water-alcohol solution, adding hollow micro-nano particles, and homogenizing in a ball mill to form a dispersion liquid;

(4) and (3) attaching the dispersion liquid to the surface of the ion exchange membrane obtained in the step (2) by adopting a surface coating manufacturing method, and drying to form a porous gas release layer with a micro-nano channel attached to at least one side of the ion exchange membrane, so as to obtain the target product.

Technical Field

The invention relates to an ion exchange membrane suitable for a zero-polar-distance electrolytic cell and a preparation method thereof, belonging to the technical field of perfluorinated ion exchange membranes.

Background

In the production of chlor-alkali by ion membrane method, in order to realize electrolysis under the conditions of high current density, low cell voltage and high alkali liquor concentration to achieve the purposes of improving productivity and reducing power consumption, the key point is to shorten the distance between the ion membrane and the electrode to reduce the cell voltage, so that the narrow polar distance type ion membrane electrolysis process is put into practical use. With the continuous progress of the technology, zero-pole-pitch electrolyzers have been widely used, but when the distance between the electrodes is reduced to less than 2mm, hydrogen bubbles adhered to the membrane surface are difficult to release because the membrane is in close contact with the cathode, and a large amount of hydrogen bubbles accumulate on the membrane surface facing the cathode. The bubbles obstruct the current channel, so that the effective electrolysis area of the membrane is reduced, the current distribution on the membrane surface is uneven, and the local polarization effect is obviously increased. This, in turn, sharply increases the membrane resistance and cell voltage, and the power consumption of electrolysis significantly increases.

In order to overcome the defects caused by the bubble effect and quickly release the adhered hydrogen bubbles from the membrane surface with small hydrophilicity, a modification method of the hydrophilic coating on the surface of the ionic membrane is developed. After the surface of the membrane is covered with a porous non-electrode coating which can be permeated by gas and liquid and has no electrocatalytic activity, the hydrophilicity of the membrane surface is obviously increased, and the anti-foaming capability is obviously improved. The ion membrane modified by the hydrophilic coating can be tightly attached to an electrode, so that the cell voltage is greatly reduced, and the ion membrane modified by the hydrophilic coating is widely applied to a zero-polar-distance type ion membrane electrolysis process at present. The hydrophilic coating modification process needs to cover the surface of the ionic membrane by an electrolytic deposition method, a particle embedding method and the like after inorganic components and a special binder are mixed, and the coating process is specifically introduced in patents CA2446448 and CA 2444585; however, although this modification method has a significant effect, the process is relatively complicated. In addition, the ionic membrane can be subjected to continuous scouring of alkaline liquor flow and continuous oscillation caused by turbulent flow in the electrolytic operation process, the hydrophilic coating attached to the surface of the ionic membrane can gradually fall off, and the anti-foaming function is gradually reduced to be ineffective.

The patent US 4502931 mentions that the ion film surface is modified by surface roughening by ion etching, but this method is not only not easy to implement in large area, but also has low anti-foaming ability, when the interpolar distance is reduced to a certain extent, the groove pressure is still greater than 3.5V, and the current efficiency is lower than 90%.

Patent CN104018180B disperses fine particles of perfluoro sulfonic acid resin with ion exchange capacity in a non-electrode porous gas release layer, and is applied to an electrolytic cell with high current density and zero polar distance, so as to realize extremely low surface resistance. However, because the perfluorosulfonic acid resin microparticles have a solid structure and high hardness, if the sizes of the perfluorosulfonic acid resin microparticles are in the range of 20nm to 50 μm, a special refrigerating device and grinding equipment are needed, and the preparation is relatively difficult. And the non-electrode porous gas release layer constructed by the patent can not solve the problems of poor solution flow and uneven concentration in a narrow membrane polar space caused by zero polar distance, so that certain resistance still exists in ion conduction.

Therefore, the ion membrane surface treatment method which is easy to realize and effective for a long time is developed, the ion membrane can continuously provide lower tank voltage and lower sheet resistance in the zero-polar distance electrolysis process, the energy consumption is further reduced, and the method has very important significance.

Disclosure of Invention

The invention aims to solve the technical problem of overcoming the defects in the prior art and providing an ion exchange membrane suitable for a zero-polar-distance electrolytic cell, which improves the circulating flow of solution between the membrane and an electrode, is more suitable for running in the zero-polar-distance electrolytic cell under the condition of high current density and has lower surface resistance; the invention also provides a simple and feasible preparation method.

The ion exchange membrane suitable for the zero polar distance electrolytic cell comprises perfluorinated ion exchange resin and a reinforcing material, wherein a porous gas release layer with a micro-nano channel is attached to at least one side of a perfluorinated ion exchange resin membrane layer;

the porous gas release layer with the micro-nano channel is formed by attaching dispersion liquid on the surface of an ion exchange membrane and drying;

the dispersion liquid is formed by dispersing hollow micro-nano particles in a sulfonic acid resin water-alcohol solution;

the hollow micro-nano particles are prepared by crushing hollow fiber membranes processed by perfluorinated sulfonic acid resin.

The preparation process of the hollow micro-nano particles is as follows: the perfluorinated sulfonic acid resin is melted and extruded into a hollow fiber membrane, is converted into a sodium type in NaOH solution, and is crushed by a grinder, so that the crushing is easier to carry out and micro-nano particles are easier to obtain due to the hollow structure of the hollow fiber membrane. The hollow micro-nano particles have an ion exchange function.

Preferably, the ion exchange capacity of the hollow micro-nano particles is 0.90-1.05 mmol/g, the outer diameter size is 200-2000 nm, the wall thickness is 20-500 nm, and the length is 50-500 nm.

Preferably, the mass percentage of the hollow micro-nano particles in the dispersion liquid is 8-20%.

Preferably, the mass percentage of the sulfonic acid resin in the sulfonic acid resin hydroalcoholic solution is 0.5-10%. Researches show that the viscosity of the dispersion liquid is high due to the fact that the content of the sulfonic acid resin is too high, the preparation of the porous coating is not facilitated, and in addition, the dispersion effect of the perfluorinated sulfonic acid resin hollow micro-nano particles in the dispersion liquid is influenced by the sulfonic acid resin hydroalcoholic solution with the too high viscosity, so that the gas release effect and the solution flow are reduced.

The ratio of water to alcohol in the sulfonic acid resin hydroalcoholic solution can be selected according to the conventional selection in the field, and the alcohol is preferably methanol, ethanol, propanol, ethylene glycol or isopropanol. Preferably, the weight ratio of water to alcohol is 1: 1.

Preferably, the distribution quantity of the hollow micro-nano particles on the surface of the ion exchange membrane is 0.5-3mg/cm²。

The above-mentionedThe roughness Ra of the porous gas release layer with the micro-nano channel is 3.00-20.00 mu m. The larger Ra is, the rougher the surface is, and the more space is for gas desorption; the surface resistance of the ion exchange membrane is lower than 1.1 omega cm²。

Preferably, the porous gas release layer having the micro-nano-scale channels attached thereto has a thickness of 1.0 to 5.0 μm, and may be attached to one side of the ion-exchange membrane or both sides of the ion-exchange membrane. The ion exchange membrane is used as a separation membrane in an electrolytic cell in the chlor-alkali industry, wherein one side of the porous gas release layer attached with the micro-nano channel is preferentially arranged on the cathode side of the electrolytic cell, so that the attachment of bubbles can be effectively avoided, the flow and ion conduction of solution between the polar distances of the membrane can be increased, and the surface resistance and the cell voltage can be obviously reduced. The surface resistance of the ion exchange membrane attached with the porous gas release layer with the micro-nano-scale channels is lower than 1.1 omega cm²。

The perfluorinated sulfonic acid resin hollow micro-nano particles are dispersed in a sulfonic acid resin hydroalcoholic solution to prepare a dispersion solution, and on the premise of meeting the surface gas desorption function, the hollow micro-nano particles with ion exchange capacity have an internal hollow structure, so that more spaces can be provided for electrolyte solution flowing and ion conduction between a membrane and an electrode, and the reduction of surface resistance and cell voltage is facilitated.

Preferably, the reinforcing material is a mesh material, a fiber material, a non-woven fabric material or a porous membrane material made of one of Polytetrafluoroethylene (PTFE), polyperfluoroalkoxy resin (PFA), polyperfluoroethylpropylene (FEP) or ethylene-tetrafluoroethylene copolymer (ETFE).

The formation process of the porous gas release layer on the surface of the ion exchange membrane is various, and the conventional surface coating preparation method comprises the following steps: spraying, brushing, roll coating, dipping, transfer printing, spin coating, and the like, with spraying being preferred. The process operation is carried out according to the prior art.

The perfluorinated ion exchange resin is a single-layer film or a composite film prepared by one or more perfluorinated ion exchange resins containing one or two functional groups of sulfonic acid or carboxylic acid by a single-machine or multi-machine co-extrusion method, and can be a sulfonic acid single-layer film, a sulfonic acid-carboxylic acid blended single-layer film, a sulfonic acid/sulfonic acid composite film, a sulfonic acid/carboxylic acid composite film, a sulfonic acid/sulfonic acid-carboxylic acid copolymer/carboxylic acid composite film, a sulfonic acid/sulfonic acid-carboxylic acid blended/carboxylic acid composite film and the like. The various perfluorinated ion exchange resins are prepared according to the prior art.

The preparation method of the ion exchange membrane suitable for the zero polar distance electrolytic cell comprises the following preparation steps:

(1) performing melt casting on a perfluorinated ion exchange resin precursor to form a single-layer film or a multilayer composite film in a mode of coextrusion by a screw extruder, introducing a reinforcing material between film forming press rollers, and pressing the reinforcing material into a film body under the action of pressure between the rollers to form a polymer film;

(2) soaking the polymer membrane in the step (1) in a mixed aqueous solution of dimethyl sulfoxide and strong base to convert the polymer membrane into an ion exchange membrane with an ion exchange function;

(3) dissolving perfluorinated sulfonic acid resin into a water-alcohol mixed solution to form a sulfonic acid resin water-alcohol solution, adding hollow micro-nano particles, and homogenizing in a ball mill to form a dispersion liquid;

(4) and (3) attaching the dispersion liquid to the surface of the ion exchange membrane obtained in the step (2) by adopting a surface coating manufacturing method, and drying to form a porous gas release layer with a micro-nano channel attached to at least one side of the ion exchange membrane, so as to obtain the target product.

Wherein: the perfluorinated ion exchange resin in the step (1) can be one or more, one or more screw extruders can be selected, and the extrusion mode can be a single-layer or multi-layer coextrusion mode.

The forming process of the porous gas release layer with the micro-nano channel on the surface of the ion exchange membrane is various, and the surface coating preparation method in the step (4) comprises the following steps: spraying, brushing, roll coating, dipping, transfer printing, spin coating, and the like, with spraying being preferred. The process operation is carried out according to the prior art.

The ion exchange membrane prepared by the invention is suitable for the zero-polar-distance electrolytic cell, can improve the circulating flow of solution between the membrane and the electrode when being used in the chlor-alkali industry, is more suitable for running in the zero-polar-distance electrolytic cell under the condition of high current density, and has lower surface resistance.

Compared with the prior art, the invention has the following beneficial effects:

(1) the perfluorinated sulfonic acid resin hollow micro-nano particles have an ion exchange function, cannot form ion barrier when attached to the surface of an ion exchange membrane, and are particularly suitable for running under the condition of high current density;

(2) the surface roughness Ra of the ion exchange membrane attached with the gas release layer is 3.00-20.00 mu m, and in a zero-polar-distance electrolytic cell, a certain gap exists between the surface of the coating and an electrode mesh, so that bubbles can escape easily, and the surface resistance and the cell voltage can be reduced remarkably;

(3) the perfluorinated sulfonic acid resin hollow micro-nano particles have hollow structures, so that the flow and ion conduction of solutions in a membrane body and in a limited space between membrane polar distances are facilitated, and the surface resistance and the cell voltage are further remarkably reduced;

(4) the perfluorinated sulfonic acid resin hollow micro-nano particles have good compatibility with ion exchange membrane layers, are not easy to desorb, and the function of inhibiting the generation of bubbles cannot be attenuated along with the time extension in the service life and the service life of the whole membrane;

(5) the zero-polar-distance proton exchange membrane prepared by the invention can achieve the following technical indexes in a zero-polar-distance electrolytic tank: at a current density of 6kA/m²Even higher, the surface resistance is less than or equal to 1.10 omega cm²The average groove pressure is less than or equal to 2.75V.

(6) The ion exchange membrane prepared by the invention is suitable for the zero polar distance electrolytic cell, and can continuously provide a good anti-foaming effect, reduce the cell voltage, improve the current efficiency and reduce the power consumption in the zero polar distance electrolysis process.

Detailed Description

The present invention is further illustrated by the following examples, which are not intended to limit the practice of the invention.

The concentrations in the examples are given in mass percent unless otherwise specified.

The polymer membrane described in the examples was processed using a perfluorinated ion exchange resin of the following structure, wherein the sulfonic acid resin has the repeating unit:

the repeating units of the carboxylic acid resin are:

the sulfonic acid carboxylic acid copolymer repeating units are:

example 1

The preparation method of the ion exchange membrane suitable for the zero polar distance electrolytic cell comprises the following steps:

(1) the composite membrane is compounded by a coextrusion casting mode by using perfluorinated sulfonic acid resin with IEC (1.10 mmol/g), perfluorinated sulfonic acid carboxylic acid copolymer resin with IEC (1.05 mmol/g) and perfluorinated carboxylic acid resin with IEC (0.95 mmol/g) according to the mass part ratio of 100:5:10, and the total thickness is 110 mu m. And simultaneously, introducing a PTFE (polytetrafluoroethylene) reinforced net between film forming compression rollers, and rolling and compounding the PTFE reinforced net into a film body to form a polymer film.

(2) And (2) soaking the polymer membrane in the step (1) in a mixed aqueous solution containing 15 wt% of dimethyl sulfoxide and 20 wt% of NaOH at 75 ℃ for 70 minutes to convert the polymer membrane into an ion exchange membrane with an ion exchange function.

(3) Preparing water and ethanol into a mixed solution according to the weight ratio of 1:1, and then dissolving perfluorinated sulfonic acid resin with IEC (IEC) of 0.90mmol/g into the water-alcohol mixed solution to form a sulfonic acid resin solution with the concentration of 0.5 wt%; and adding perfluorinated sulfonic acid resin hollow micro-nano particles with IEC (0.90 mmol/g), the average outer diameter size of 200nm, the average wall thickness of 20nm and the length of about 50nm into the solution, and homogenizing in a ball mill to form a dispersion liquid with the content of 8 wt%.

(4) By sprayingAttaching the dispersion liquid to the two side surfaces of the ion exchange membrane obtained in the step (2), drying to form a porous gas release layer with the surface roughness Ra of 3 mu m, wherein the distribution amount of the perfluorinated sulfonic acid resin hollow micro-nano particles on the surface of the composite membrane is 0.5mg/cm²。

And (3) performance testing:

carrying out an electrolysis test of a sodium chloride aqueous solution in an electrolytic cell by using the prepared ion exchange membrane attached with the porous gas release layer with the micro-nano-scale channel, supplying 300g/L of the sodium chloride aqueous solution to an anode chamber, supplying 32% by mass of a sodium hydroxide solution and pure water to a cathode chamber, and ensuring that the concentration of the sodium chloride discharged from the anode chamber is 200g/L and the mass fraction of the sodium hydroxide solution discharged from the cathode chamber is 32%; the test temperature is 85 ℃, and the current density is 6kA/m²After 30 days of electrolysis experiments, the average cell pressure was 2.74V. Thereafter, the sheet resistance of the resulting film was measured to be 1.08. omega. cm by the standard SJ/T10171.5 method²。

Comparative example 1

An ion exchange membrane having an ion exchange function was prepared in the same manner as in example 1, and then a dispersion was prepared in the same manner, except that hollow micro-nano particles of perfluorosulfonic acid resin in the dispersion were replaced with zirconia particles having an average particle size of 500nm, and the resulting mixture was homogenized in a ball mill to form a dispersion having a content of 8 wt%. An ion-exchange membrane having porous gas release layers attached to both sides thereof was obtained in the same manner as in example 1, and the amount of distribution of zirconia particles on the surface of the composite membrane was also 0.5mg/cm². The film formed had a surface roughness Ra of about 25.00 μm.

An electrolytic test of a sodium chloride solution was carried out under the same conditions as in example 1, and after an electrolysis test for 30 days, the average cell pressure was 3.05V and the sheet resistance was 2.4. omega. cm²。

Example 2

An ion exchange membrane having an ion exchange function was prepared in the same manner as in example 1.

Then, water and ethanol were mixed at a weight ratio of 1:1 to prepare a mixed solution, and IEC was 0.90mmol/g of a fluorosulfonic acid resinDissolving the mixture into a water-alcohol mixed solution to form a sulfonic acid resin solution with the concentration of 10.0 wt%; and adding perfluorinated sulfonic acid resin hollow micro-nano particles with IEC (1.05 mmol/g), average outer diameter size of 2000nm, average wall thickness of 500nm and length of about 500nm into the solution, and homogenizing in a ball mill to form a dispersion with the content of 20 wt%. By adopting a spraying method, the dispersion liquid is attached to the surfaces of the two sides of the ion exchange membrane with the ion exchange function, a porous gas release layer with the surface roughness Ra of 20 mu m is formed after drying, and the distribution quantity of the perfluorinated sulfonic acid resin hollow micro-nano particles on the surface of the composite membrane is 3mg/cm²。

Carrying out an electrolysis test of a sodium chloride aqueous solution in an electrolytic cell by using the prepared ion exchange membrane attached with the porous gas release layer with the micro-nano-scale channel, supplying 300g/L of the sodium chloride aqueous solution to an anode chamber, supplying 32% by mass of a sodium hydroxide solution and pure water to a cathode chamber, and ensuring that the concentration of the sodium chloride discharged from the anode chamber is 200g/L and the mass fraction of the sodium hydroxide solution discharged from the cathode chamber is 32%; the test temperature is 85 ℃, and the current density is 6kA/m²After 30 days of electrolysis experiments, the average cell pressure was 2.68V. Thereafter, the sheet resistance of the obtained film was measured to be 0.95. omega. cm by the standard SJ/T10171.5 method²。

Example 3

An ion exchange membrane having an ion exchange function was prepared in the same manner as in example 1.

Then, preparing water and propanol into a mixed solution according to the weight ratio of 1:1, and then dissolving the fluorine-containing sulfonic acid resin with IEC being 0.90mmol/g into the water-alcohol mixed solution to form a sulfonic acid resin solution with the concentration of 2.5 wt%; and adding perfluorinated sulfonic acid resin hollow micro-nano particles with IEC (0.97 mmol/g), average outer diameter size of 1000nm, average wall thickness of 500nm and length of about 300nm into the solution, and homogenizing in a ball mill to form a dispersion with the content of 10.5 wt%. Adopting a roller coating method, attaching the dispersion liquid to the two side surfaces of the ion exchange membrane with the ion exchange function, drying to form a porous gas release layer with the surface roughness Ra of 11 mu m, and distributing perfluorinated sulfonic acid resin hollow micro-nano particles on the surface of the composite membraneThe amount was 2.6mg/cm²。

Carrying out an electrolysis test of a sodium chloride aqueous solution in an electrolytic cell by using the prepared ion exchange membrane attached with the porous gas release layer with the micro-nano-scale channel, supplying 300g/L of the sodium chloride aqueous solution to an anode chamber, supplying 32% by mass of a sodium hydroxide solution and pure water to a cathode chamber, and ensuring that the concentration of the sodium chloride discharged from the anode chamber is 200g/L and the mass fraction of the sodium hydroxide solution discharged from the cathode chamber is 32%; the test temperature is 85 ℃, and the current density is 6kA/m²After 30 days of electrolysis experiments, the average cell pressure was 2.70V. Thereafter, the sheet resistance of the resulting film was measured to be 0.98. omega. cm by a standard SJ/T10171.5 method²。

Example 4

The difference from example 3 is that:

roll-coating the dispersion prepared in example 3 on one side of the ion exchange membrane with ion exchange function mentioned in example 3, installing the side on the cathode side of the electrobath, drying to form a porous gas release layer with surface roughness Ra of 11 μm, wherein the distribution amount of the perfluorinated sulfonic acid resin hollow micro-nano particles on the surface of the composite membrane is 2.6mg/cm²。

The resulting membrane was subjected to an electrolysis test with an aqueous solution of sodium chloride in the electrolytic cell described in example 1, at a current density of 6kA/m²After 30 days of electrolysis experiments, the average cell pressure was 2.72V. Thereafter, the sheet resistance of the obtained film was measured to be 1.00. omega. cm by the standard SJ/T10171.5 method²。