CN114192196A - Preparation method of perfluorinated ion exchange membrane with high dimensional stability - Google Patents
Preparation method of perfluorinated ion exchange membrane with high dimensional stability Download PDFInfo
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- CN114192196A CN114192196A CN202111290012.9A CN202111290012A CN114192196A CN 114192196 A CN114192196 A CN 114192196A CN 202111290012 A CN202111290012 A CN 202111290012A CN 114192196 A CN114192196 A CN 114192196A
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- 239000003014 ion exchange membrane Substances 0.000 title claims abstract description 128
- 238000002360 preparation method Methods 0.000 title claims abstract description 21
- 206010042674 Swelling Diseases 0.000 claims abstract description 96
- 230000008961 swelling Effects 0.000 claims abstract description 96
- 238000011282 treatment Methods 0.000 claims abstract description 90
- 239000012528 membrane Substances 0.000 claims abstract description 71
- 238000000034 method Methods 0.000 claims abstract description 64
- 239000000243 solution Substances 0.000 claims abstract description 63
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 24
- 239000012670 alkaline solution Substances 0.000 claims abstract description 13
- 230000007935 neutral effect Effects 0.000 claims abstract description 7
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 claims description 84
- 238000002791 soaking Methods 0.000 claims description 42
- 239000007788 liquid Substances 0.000 claims description 16
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 12
- 238000000576 coating method Methods 0.000 claims description 7
- 229910052809 inorganic oxide Inorganic materials 0.000 claims description 6
- 239000011248 coating agent Substances 0.000 claims description 5
- YCKRFDGAMUMZLT-UHFFFAOYSA-N Fluorine atom Chemical compound [F] YCKRFDGAMUMZLT-UHFFFAOYSA-N 0.000 claims description 4
- WCUXLLCKKVVCTQ-UHFFFAOYSA-M Potassium chloride Chemical compound [Cl-].[K+] WCUXLLCKKVVCTQ-UHFFFAOYSA-M 0.000 claims description 4
- UIIMBOGNXHQVGW-UHFFFAOYSA-M Sodium bicarbonate Chemical compound [Na+].OC([O-])=O UIIMBOGNXHQVGW-UHFFFAOYSA-M 0.000 claims description 4
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 claims description 4
- MCMNRKCIXSYSNV-UHFFFAOYSA-N ZrO2 Inorganic materials O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 claims description 4
- 239000007864 aqueous solution Substances 0.000 claims description 4
- 229910052731 fluorine Inorganic materials 0.000 claims description 4
- 239000011737 fluorine Substances 0.000 claims description 4
- 238000007654 immersion Methods 0.000 claims description 4
- KWGKDLIKAYFUFQ-UHFFFAOYSA-M lithium chloride Chemical compound [Li+].[Cl-] KWGKDLIKAYFUFQ-UHFFFAOYSA-M 0.000 claims description 4
- INHCSSUBVCNVSK-UHFFFAOYSA-L lithium sulfate Chemical compound [Li+].[Li+].[O-]S([O-])(=O)=O INHCSSUBVCNVSK-UHFFFAOYSA-L 0.000 claims description 4
- 239000011347 resin Substances 0.000 claims description 4
- 229920005989 resin Polymers 0.000 claims description 4
- 150000003460 sulfonic acids Chemical class 0.000 claims description 4
- BVKZGUZCCUSVTD-UHFFFAOYSA-M Bicarbonate Chemical compound OC([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-M 0.000 claims description 2
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 claims description 2
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 claims description 2
- 239000007832 Na2SO4 Substances 0.000 claims description 2
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 claims description 2
- 150000001299 aldehydes Chemical class 0.000 claims description 2
- 125000004432 carbon atom Chemical group C* 0.000 claims description 2
- 150000001768 cations Chemical class 0.000 claims description 2
- 150000003841 chloride salts Chemical class 0.000 claims description 2
- 239000006185 dispersion Substances 0.000 claims description 2
- 238000001035 drying Methods 0.000 claims description 2
- 150000002576 ketones Chemical class 0.000 claims description 2
- 229910052744 lithium Inorganic materials 0.000 claims description 2
- 229910052700 potassium Inorganic materials 0.000 claims description 2
- 229910052939 potassium sulfate Inorganic materials 0.000 claims description 2
- BDERNNFJNOPAEC-UHFFFAOYSA-N propan-1-ol Chemical compound CCCO BDERNNFJNOPAEC-UHFFFAOYSA-N 0.000 claims description 2
- 229910052708 sodium Inorganic materials 0.000 claims description 2
- 239000011734 sodium Substances 0.000 claims description 2
- 235000017557 sodium bicarbonate Nutrition 0.000 claims description 2
- 229910000030 sodium bicarbonate Inorganic materials 0.000 claims description 2
- 239000011780 sodium chloride Substances 0.000 claims description 2
- 229910052938 sodium sulfate Inorganic materials 0.000 claims description 2
- 150000003467 sulfuric acid derivatives Chemical class 0.000 claims description 2
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N titanium dioxide Inorganic materials O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 claims description 2
- 229910052581 Si3N4 Inorganic materials 0.000 claims 1
- 239000011247 coating layer Substances 0.000 claims 1
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 claims 1
- 238000003860 storage Methods 0.000 abstract description 7
- 238000004519 manufacturing process Methods 0.000 abstract description 3
- 230000007774 longterm Effects 0.000 abstract description 2
- 238000003672 processing method Methods 0.000 abstract description 2
- 235000011121 sodium hydroxide Nutrition 0.000 description 27
- 230000000052 comparative effect Effects 0.000 description 18
- 238000011835 investigation Methods 0.000 description 8
- 239000003513 alkali Substances 0.000 description 7
- -1 perfluoro Chemical group 0.000 description 6
- 238000010521 absorption reaction Methods 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 238000013112 stability test Methods 0.000 description 2
- 229920003935 Flemion® Polymers 0.000 description 1
- 229920000557 Nafion® Polymers 0.000 description 1
- 206010038776 Retching Diseases 0.000 description 1
- 229910001514 alkali metal chloride Inorganic materials 0.000 description 1
- 239000012080 ambient air Substances 0.000 description 1
- 239000002585 base Substances 0.000 description 1
- ABDBNWQRPYOPDF-UHFFFAOYSA-N carbonofluoridic acid Chemical compound OC(F)=O ABDBNWQRPYOPDF-UHFFFAOYSA-N 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000005868 electrolysis reaction Methods 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- ZHPNWZCWUUJAJC-UHFFFAOYSA-N fluorosilicon Chemical compound [Si]F ZHPNWZCWUUJAJC-UHFFFAOYSA-N 0.000 description 1
- UQSQSQZYBQSBJZ-UHFFFAOYSA-N fluorosulfonic acid Chemical compound OS(F)(=O)=O UQSQSQZYBQSBJZ-UHFFFAOYSA-N 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 230000004936 stimulating effect Effects 0.000 description 1
- 230000037303 wrinkles Effects 0.000 description 1
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J47/00—Ion-exchange processes in general; Apparatus therefor
- B01J47/12—Ion-exchange processes in general; Apparatus therefor characterised by the use of ion-exchange material in the form of ribbons, filaments, fibres or sheets, e.g. membranes
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
- C25B1/00—Electrolytic production of inorganic compounds or non-metals
- C25B1/01—Products
- C25B1/34—Simultaneous production of alkali metal hydroxides and chlorine, oxyacids or salts of chlorine, e.g. by chlor-alkali electrolysis
- C25B1/46—Simultaneous production of alkali metal hydroxides and chlorine, oxyacids or salts of chlorine, e.g. by chlor-alkali electrolysis in diaphragm cells
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- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
- C25B13/00—Diaphragms; Spacing elements
- C25B13/02—Diaphragms; Spacing elements characterised by shape or form
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- Chemical Kinetics & Catalysis (AREA)
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- Inorganic Chemistry (AREA)
- Manufacture Of Macromolecular Shaped Articles (AREA)
Abstract
The invention provides a preparation method of a perfluorinated ion exchange membrane with high dimensional stability, which comprises the steps of firstly carrying out first low-temperature treatment on the perfluorinated ion exchange membrane by using a treatment solution, then carrying out high-temperature treatment by using the treatment solution, and finally carrying out second low-temperature treatment by using the treatment solution, wherein the high-temperature treatment temperature is higher than the low-temperature treatment temperature, and the treatment solution comprises one of water, a neutral solution or an alkaline solution. The perfluorinated ion exchange membrane treated by the method has higher dimensional stability, and avoids the problems of membrane surface relaxation and even wrinkling caused by secondary swelling of the membrane in the long-term storage process; the processing method provided by the invention is simple and easy to implement, does not need to greatly modify the existing equipment and production line, and saves the cost.
Description
Technical Field
The invention relates to a perfluorinated ion exchange membrane with high dimensional stability and provides a preparation method thereof.
Technical Field
Since the 70's of the 20 th century, the rapid development of chlor-alkali ion exchange membrane technology has revolutionized the chlor-alkali industry and even the global industry into motorways. Since DuPont (DuPont) and Asahi Glass (Asahi Glass) of Japan developed Nafion perfluorosulfonic acid ion exchange membranes and Flemion perfluorocarboxylic acid ion exchange membranes, respectively, from 1962 to 1975, ion membrane process alkali production has become a new fashion in the chlor-alkali industry. While the international chlor-alkali industry has been revolutionized, the domestic perfluorinated ion exchange membranes produced in China have been produced by retching and blood-draining of scientific researchers of several generations, and the rapid development of the international chlor-alkali industry is promoted. By the end of 2019, the ionic membrane caustic soda capacity of China reaches 4366.6 ten thousand tons, which accounts for 99.7 percent of the total caustic soda capacity of China.
Before the perfluorinated ion exchange membrane is used in a tank, after the membrane is stored for a certain time, the surface of the perfluorinated ion exchange membrane sometimes generates a phenomenon of looseness and even wrinkles, which seriously affects the appearance and the service performance of the membrane. The reason why the perfluorinated ion exchange membrane is loosened or wrinkled in the storage process is that the dimensional stability of the membrane is poor, and when the storage environment is unstable, the ambient temperature fluctuates, or the storage time is long, the dimension of the membrane is slowly changed, namely, secondary swelling occurs. How to improve the dimensional stability of the membrane, improve the apparent state of the membrane, and prolong the storage life thereof has become one of the hot subjects in the field of perfluorinated ion exchange membranes.
Chinese patent document CN111378988A (202010244041.0) discloses a preparation method of a pre-swelling perfluorinated ion exchange membrane, which comprises the steps of carrying out pre-swelling treatment (the temperature is higher than the equilibrium temperature by 1-50 ℃ and the treatment time is 1-60 min) on a perfluorinated ion exchange membrane, and then carrying out equilibrium treatment (the temperature is 1-50 ℃ and the equilibrium time is 1-600 min) to obtain the pre-swelling perfluorinated ion exchange membrane. The solvent used in the pre-swelling is pure water or an alkaline solution with the mass concentration of 0.1-30.0%; the equilibrium solution is pure water or an alkaline solution with the mass concentration of 0.1-30.0%, and the pre-swelling solution and the equilibrium solution are different in types. The method can improve the size swelling ratio and the electrochemical performance of the perfluorinated ion exchange membrane, but cannot reduce the secondary swelling ratio.
Disclosure of Invention
The invention aims to solve the problems of high secondary swelling ratio and unstable size of a perfluorinated ion exchange membrane in the alkali metal chloride electrolysis industry, and provides a preparation method of the perfluorinated ion exchange membrane with high size stability.
In order to achieve the purpose, the invention adopts the following technical scheme:
a preparation method of a perfluorinated ion exchange membrane with high dimensional stability comprises the steps of firstly carrying out first low-temperature treatment on the perfluorinated ion exchange membrane by using a treatment liquid, then carrying out high-temperature treatment by using the treatment liquid, and finally carrying out second low-temperature treatment by using the treatment liquid, wherein the high-temperature treatment temperature is higher than the low-temperature treatment temperature, and the treatment liquid comprises one of water, a neutral solution or an alkaline solution.
Preferably, the average secondary swelling rate of the film in the transverse direction in a liquid environment at the temperature of below 60 ℃ is 0.015-0.700%, and the average secondary swelling rate in the longitudinal direction is 0.005-0.300%. Preferably, the average secondary swelling rate of the film in the transverse direction is 0.015-0.380%, and the average secondary swelling rate of the film in the longitudinal direction is 0.008-0.099%.
The method is adopted to measure the secondary swelling ratio of the membrane, and the average value of the results is the average secondary swelling ratio after multiple treatments and measurements.
Measuring the transverse dimension and the longitudinal dimension of the perfluorinated ion exchange membrane with high dimensional stability, and respectively marking as L0And L0' soaking the membranes in T1Immersion time t in liquid at temperature1Then transferred to T2Immersion time t in liquid at temperature2Measured in the transverse and longitudinal dimensions L respectively1And L1"the secondary swelling ratio of the membrane was calculated by the following formulas (1), (2):
The T is1Temperature higher than T2The temperature of (a); t is t110-600 min; t is t2Is 10-600 min.
Preferably, said T is1Is 30 to 50 ℃; t is2Is 15 to 25 ℃.
The liquid is water, NaOH solution with the mass fraction of 0.2-2.0 percent and NaHCO with the mass fraction of 0.2-2.0 percent3One or more of the solutions. The type and concentration of the liquid used for measuring the secondary swelling ratio of the membrane were the same as those of the treatment liquid for the membrane.
Further, the t is1Is 90-480 min; t is t2Is 120-480 min.
Preferably, the temperature of the first low-temperature treatment or the second low-temperature treatment is 15-30 ℃, and more preferably 15-25 ℃. The first low-temperature treatment or the second low-temperature treatment lasts for 90-1440 min.
Preferably, the high-temperature treatment temperature is 35-55 ℃, and preferably 35-50 ℃; the preferable high-temperature treatment time is 90-360 min. The high-temperature treatment temperature is 5-55 ℃ higher than the first low-temperature treatment temperature or the second low-temperature treatment temperature. The preferable high-temperature treatment temperature is 10-35 ℃ higher than the low-temperature treatment temperature.
Preferably, the neutral solution comprises one or more of alcohol, aldehyde, ketone, chloride or sulfate aqueous solutions with the mass concentration of 0.1-50.0%. Further preferably, the chloride salt is one of LiCl, NaCl or KCl; the sulfate salt comprises Li2SO4、Na2SO4Or K2SO4One kind of (1). Further preferably, the concentration of the neutral solution is 0.2-2 wt.%.
Preferably, the concentration of the alkaline solution is 0.2-2 wt.%. Preferably, the alkaline solution comprises one of an aqueous solution of a base, a carbonate, and a bicarbonate. Further preferably, the cation in the alkaline solution is one of Li, Na or K. More preferably, the alkaline solution is one of sodium hydroxide and sodium bicarbonate.
Preferably, the preparation method of the perfluorinated ion exchange membrane with high dimensional stability comprises the following steps: pre-soaking a perfluorinated ion exchange membrane in water at 15 ℃ for 120 min; soaking in 50 deg.C water for 90 min; and finally soaking in water of 15 ℃ for 120min to obtain the perfluorinated ion exchange membrane with high dimensional stability. The transverse average secondary swelling rate of the treated perfluorinated ion exchange membrane is 0.015-0.018%, and the longitudinal average secondary swelling rate is 0.006-0.010%.
Preferably, the perfluorinated ion exchange membrane is a fiber-reinforced multilayer fluorine-containing ion exchange membrane coated with hydrophilic coatings on two sides.
The thickness of the hydrophilic coating is 0-3 mu m.
Preferably, the fiber-reinforced multilayer fluorine-containing ion exchange membrane is a fiber-reinforced multilayer fluorine-containing ion exchange membrane described in chinese patent document CN101320818A (CN 200810138296.8).
Preferably, the hydrophilic coating is prepared by coating and drying a lower alcohol dispersion liquid containing perfluorinated sulfonic acid resin and nano inorganic oxide; the mass fraction of the perfluorinated sulfonic acid resin is 3-13%, and the mass fraction of the nano inorganic oxide is 5-15%.
More preferably, the lower alcohol is a monohydric alcohol having 1 to 4 carbon atoms. Preferably ethanol or propanol.
Further preferably, the nano inorganic oxide comprises nano ZnO and ZrO2Or TiO2ZrO is preferred2。
The principle of the invention is as follows: the method of the invention comprises the steps of fully balancing the ion exchange membrane at room temperature, enabling the membrane to absorb water at room temperature to be saturated and expand to a certain level, then placing the membrane in a balancing solution at a higher temperature, stimulating the internal pore passages of the membrane to stretch at a high temperature, simultaneously opening internal molecular chains, improving the water absorption capacity of the membrane, and enabling the membrane to further absorb water by heating. The film treated by the method of the invention is fully stretched, so that the sensitivity of the size to the temperature is reduced, and the stability is improved.
However, when the perfluorinated ion exchange membrane is in a dry state, the size of the perfluorinated ion exchange membrane corresponds to the current ambient air humidity and temperature, and at this time, if the membrane is directly soaked in a balancing solution with a higher temperature, the size of the membrane is suddenly increased, the balance among partial molecules in the membrane is instantly broken, and the full absorption of the membrane for the treatment solution is influenced. Therefore, the membrane treated by the method does not reach a real equilibrium and stable state, and when the membrane is subjected to high-temperature change again in the storage process, the membrane still undergoes large swelling and has poor dimensional stability.
Compared with the traditional perfluorinated ion exchange membrane which is soaked in the treatment solution and then directly packaged, the perfluorinated ion exchange membrane has the advantages that: (1) the perfluorinated ion exchange membrane treated by the method has higher dimensional stability, and avoids the problems of membrane surface relaxation and even wrinkling caused by secondary swelling of the membrane in the long-term storage process; (2) the processing method is simple and easy to implement, does not need to greatly modify the existing equipment and production line, and saves the cost.
Drawings
FIG. 1 is the longitudinal dimension L of the film after the treatment described in example 10A perspective and partial enlargement of (a);
FIG. 2 is the longitudinal dimension L of the film after the treatment described in example 11A perspective and partial enlargement of (a);
FIG. 3 is the longitudinal dimension L of the treated film described in comparative example 10A perspective and partial enlargement of (a);
FIG. 4 longitudinal dimension L of treated film as described in comparative example 11A real map and a partial enlarged view.
Detailed Description
The present invention will be further described by the following examples, however, the scope of the present invention is not limited to the following examples. It will be understood by those skilled in the art that various changes and modifications may be made to the invention without departing from the spirit and scope of the invention.
The perfluorinated ion exchange membranes used in the embodiment of the invention are all chlor-alkali ion exchange membranes DF2807 produced by the fluorine silicon technology group of east Shandong Yue. However, the applicable objects of the treatment method provided by the present invention are not limited to the ion exchange membrane.
Example 1
A preparation method of a perfluorinated ion exchange membrane with high dimensional stability comprises the following steps:
firstly, pre-soaking a perfluorinated ion exchange membrane in NaOH solution with mass fraction of 0.2% at 16 ℃ for 240min, and taking out; soaking in NaOH solution with mass fraction of 0.2% at 35 deg.C for 240min, and taking out; and finally soaking the membrane into NaOH solution with the mass fraction of 0.2% at 16 ℃ for balancing treatment for 240min to obtain the perfluorinated ion exchange membrane with high dimensional stability.
The types and concentrations of the treatment liquids used for the high-temperature treatment and the low-temperature treatment are the same.
Investigation of the dimensional stability of the perfluorinated ion exchange membrane:
the transverse dimension and the longitudinal dimension of the perfluorinated ion exchange membrane treated as described above are measured and are respectively denoted as L0And L0Soaking the treated membrane in NaOH solution with mass fraction of 0.2% at 35 deg.C for 240min, transferring to NaOH solution with mass fraction of 0.2% at 16 deg.C, balancing for 240min, and measuring transverse dimension and longitudinal dimension as L1And L1"the secondary swelling ratio of the membrane was calculated by the following formulas (1), (2):
TABLE 1 change in size and Secondary swelling Rate of Perfluoroion exchange membranes treated by the method of the invention
The method disclosed by the invention is used for treating the same batch of perfluorinated ion exchange membrane samples 1-4 (see table 1), and the obtained longitudinal secondary swelling ratio and transverse secondary swelling ratio are averaged. The average secondary swelling ratio in the transverse direction was 0.377%, and the average secondary swelling ratio in the longitudinal direction was 0.099%.
Comparative example 1
A stability treatment method of a perfluorinated ion exchange membrane comprises the following steps: soaking in a treatment solution (NaOH solution with mass fraction of 0.2%) at 16 deg.C for 240min, and taking out.
The dimensional stability of the perfluorinated ion exchange membrane treated by the method is investigated: the dimensional stability examination conditions and equations were followed in example 1.
TABLE 2 Perfluoroion exchange Membrane size and Secondary swelling Rate Change not according to the Process of the invention
The average secondary swelling ratio of the transverse direction of the perfluorinated ion exchange membrane which is not treated by the method is 1.610%, and the average secondary swelling ratio of the longitudinal direction is 0.460%. It can be seen that the secondary swelling ratio of comparative example 1 is significantly greater than that of example 1. The treatment method can reduce the secondary swelling rate of the membrane and improve the dimensional stability of the membrane.
Example 2
A preparation method of a perfluorinated ion exchange membrane with high dimensional stability comprises the following steps:
firstly, pre-soaking a perfluorinated ion exchange membrane in a NaOH solution with the mass fraction of 2.0% at 25 ℃ for 360min, and taking out; soaking in 2.0 wt% NaOH solution at 35 deg.C for 360min, and taking out; and finally soaking the membrane in NaOH solution with the mass fraction of 2.0% at 25 ℃ for balancing treatment for 360min to obtain the perfluorinated ion exchange membrane with high dimensional stability.
Investigation of the dimensional stability of the perfluorinated ion exchange membrane:
measuring the transverse dimension and the longitudinal dimension of the perfluorinated ion exchange membrane treated by the methodSize, respectively denoted as L0And L0Soaking the treated membrane in 2.0% NaOH solution at 35 deg.C for 120min, transferring to 2.0% NaOH solution at 25 deg.C, balancing for 360min, and measuring transverse and longitudinal dimensions L1And L1"the secondary swelling ratio of the membrane was calculated by the formula (1). The results are shown in table 3 below:
TABLE 3 changes in the size and Secondary swelling Rate of Perfluoroion exchange membranes treated by the method of the invention
The perfluoro ion exchange membrane treated by the method has the average transverse secondary swelling rate of 0.125 percent and the average longitudinal secondary swelling rate of 0.026 percent.
Comparative example 2
A stability treatment method of a perfluorinated ion exchange membrane comprises the following steps: soaking in 25 deg.C treatment solution (2.0% NaOH solution) for 360min, and taking out.
The dimensional stability of the perfluorinated ion exchange membrane treated by the method is investigated: the dimensional stability examination conditions and equations were followed in example 2. The results are shown in table 4 below:
TABLE 4 change in size and Secondary swelling Rate of perfluoroion exchange membranes untreated according to the Process of the invention
The average secondary swelling ratio in the transverse direction of the perfluorinated ion exchange membrane which is not treated by the method is 0.593 percent, and the average secondary swelling ratio in the longitudinal direction is 0.177 percent. The secondary swelling ratio of comparative example 2 was significantly larger than that of example 2.
Example 3
A preparation method of a perfluorinated ion exchange membrane with high dimensional stability comprises the following steps:
firstly, a perfluorinated ion exchange membrane is subjected to NaHCO with the mass fraction of 0.2% at the temperature of 20 DEG C3Pre-soaking in the solution for 180min, and taking out; then NaHCO with the mass fraction of 0.2 percent at the temperature of 40 DEG C3Soaking in the solution for 180min, and taking out; finally soaking the mixture into NaHCO with the mass fraction of 0.2 percent at the temperature of 20 DEG C3And (4) carrying out equilibrium treatment in the solution for 180min to obtain the perfluorinated ion exchange membrane with high dimensional stability.
Investigation of the dimensional stability of the perfluorinated ion exchange membrane:
the transverse dimension and the longitudinal dimension of the perfluorinated ion exchange membrane treated as described above are measured and are respectively denoted as L0And L0Soaking the treated membrane in 0.2% NaHCO at 40 deg.C3The solution is put for 180min and then transferred to NaHCO with the mass fraction of 0.2 percent at 20 DEG C3Equilibrating in solution for 180min, and determining the transverse dimension and the longitudinal dimension as L respectively1And L1"the secondary swelling ratio of the membrane was calculated by the formula (1). The results are shown in table 5 below:
TABLE 5 changes in the size and Secondary swelling Rate of Perfluoroion exchange membranes treated by the method of the invention
The perfluoro ion exchange membrane treated by the method has the average secondary swelling rate of 0.290 percent in the transverse direction and 0.049 percent in the longitudinal direction.
Comparative example 3
A stability treatment method of a perfluorinated ion exchange membrane comprises the following steps: treating fluid (0.2% NaHCO by mass) at 20 deg.C3Solution) and taken out after 180 min.
The dimensional stability of the perfluorinated ion exchange membrane treated by the method is investigated: the dimensional stability examination conditions and equations were followed in example 3. The results are shown in table 6 below:
TABLE 6 change in size and Secondary swelling Rate of perfluoroion exchange membranes untreated according to the Process of the invention
The average secondary swelling rate of the transverse direction of the perfluorinated ion exchange membrane which is not treated by the method is 1.287 percent, and the average secondary swelling rate of the longitudinal direction of the perfluorinated ion exchange membrane is 0.459 percent. The secondary swelling ratio of comparative example 3 was significantly larger than that of example 3.
Example 4
A preparation method of a perfluorinated ion exchange membrane with high dimensional stability comprises the following steps:
firstly, pre-soaking a perfluorinated ion exchange membrane in a NaOH solution with the mass fraction of 1.1% at 25 ℃ for 480min, and taking out; soaking in NaOH solution with mass fraction of 1.1% at 35 deg.C for 240min, and taking out; and finally soaking the membrane in NaOH solution with the mass fraction of 1.1% at 25 ℃ for balancing treatment for 240min to obtain the perfluorinated ion exchange membrane with high dimensional stability.
Investigation of the dimensional stability of the perfluorinated ion exchange membrane:
the transverse dimension and the longitudinal dimension of the perfluorinated ion exchange membrane treated as described above are measured and are respectively denoted as L0And L0Further soaking the treated membrane in NaOH solution with mass fraction of 1.1% at 35 deg.C for 240min, transferring to NaOH solution with mass fraction of 1.1% at 25 deg.C, balancing for 240min, and determining transverse and longitudinal dimensions as L1And L1"the secondary swelling ratio of the membrane was calculated by the formula (1). The results are shown in table 7 below:
TABLE 7 changes in size and Secondary swelling Rate of Perfluoroion exchange membranes treated according to conventional methods
The average transverse secondary swelling rate of the perfluorinated ion exchange membrane treated by the method is 0.029%, and the average longitudinal secondary swelling rate of the perfluorinated ion exchange membrane is 0.013%.
Comparative example 4
A traditional stability treatment method of a perfluorinated ion exchange membrane comprises the following steps of: soaking in 25 deg.C treatment solution (NaOH solution with mass fraction of 1.1%), and taking out after 240 min.
The dimensional stability of the perfluorinated ion exchange membrane treated by the traditional method is investigated: the dimensional stability examination conditions and equations were followed in example 4. The results are shown in table 8 below:
TABLE 8 changes in size and Secondary swelling Rate of perfluoroion exchange membranes untreated according to the Process of the invention
The perfluorinated ion exchange membrane which is not treated by the method has the average secondary swelling rate of 1.035% in the transverse direction and the average secondary swelling rate of 0.365% in the longitudinal direction. The secondary swelling ratio of comparative example 4 was significantly larger than that of example 4.
Example 5
A preparation method of a perfluorinated ion exchange membrane with high dimensional stability comprises the following steps:
firstly, a perfluorinated ion exchange membrane is subjected to NaHCO with the mass fraction of 2.0% at the temperature of 20 DEG C3Pre-soaking in the solution for 1440min, and taking out; then NaHCO with the mass fraction of 2.0 percent at the temperature of 40 DEG C3Soaking in the solution for 240min, and taking out; finally, the mixture is soaked into NaHCO with the mass fraction of 2.0 percent at the temperature of 20 DEG C3And (4) equilibrium processing is carried out for 1440min in the solution, and the perfluorinated ion exchange membrane with high dimensional stability is obtained.
Investigation of the dimensional stability of the perfluorinated ion exchange membrane:
measuring the transverse dimension and the longitudinal dimension of the perfluorinated ion exchange membrane treated by the methodIs marked as L0And L0Soaking the treated membrane in 2.0% NaHCO at 40 deg.C3480min in solution, then transferring to NaHCO with 2.0% mass fraction at 20 DEG C3Equilibrating in solution for 480min, and determining the transverse dimension and the longitudinal dimension as L respectively1And L1"the secondary swelling ratio of the membrane was calculated by the formula (1). The results are shown in table 9 below:
TABLE 9 change in size and Secondary swelling Rate of Perfluoroion exchange membranes treated according to the method of the present invention
The perfluoro ion-exchange membrane treated in this example had an average secondary swelling ratio in the transverse direction of 0.250% and an average secondary swelling ratio in the longitudinal direction of 0.078%.
Comparative example 5
A traditional stability treatment method of a perfluorinated ion exchange membrane comprises the following steps of: treatment solution (NaHCO 2.0% by mass) at 20 deg.C3Solution), and taken out after 1440 min.
Dimensional stability investigation of perfluorinated ion exchange membranes treated by the above method: the dimensional stability examination conditions and equations were followed in example 5. The results are shown in table 10 below:
TABLE 10 changes in size and Secondary swelling Rate of perfluoroion exchange membranes untreated according to the Process of the invention
The average secondary swelling ratio in the transverse direction of the perfluorinated ion exchange membrane which is not treated by the method is 0.754 percent, and the average secondary swelling ratio in the longitudinal direction is 0.249 percent. The secondary swelling ratio of comparative example 5 was significantly larger than that of example 5.
Example 6
A preparation method of a perfluorinated ion exchange membrane with high dimensional stability comprises the following steps:
soaking a perfluorinated ion exchange membrane in water at 16 ℃ for 240min, and taking out; soaking in 40 deg.C water for 240min, and taking out; and finally soaking the membrane in water at the temperature of 16 ℃ for balancing treatment for 240min to obtain the perfluorinated ion exchange membrane with high dimensional stability.
Investigation of the dimensional stability of the perfluorinated ion exchange membrane:
the longitudinal dimension and the transverse dimension of the perfluorinated ion exchange membrane treated in the way are measured and are respectively marked as L0And L0Soaking the treated membrane in 35 deg.C water for 240min, transferring to 16 deg.C water, and balancing for 240min to determine the longitudinal and transverse dimensions as L1And L1"the secondary swelling ratio of the membrane was calculated by the formulas (1) and (2). The results are shown in Table 11:
TABLE 11 changes in the size and Secondary swelling Rate of the Perfluoroion exchange Membrane treated according to the method of the present invention
The perfluorinated ion exchange membrane treated in this example had an average secondary swelling ratio of 0.656% in the transverse direction and 0.253% in the longitudinal direction.
Comparative example 6
A stability treatment method of a perfluorinated ion exchange membrane comprises the following steps: soaking in 16 deg.C water for 240min, and taking out.
Dimensional stability study of the treated perfluorinated ion exchange membranes: following the dimensional stability test conditions and equations of example 6, the results are shown in Table 12 below:
TABLE 12 changes in size and Secondary swelling Rate of perfluoroion exchange membranes untreated according to the method of the invention
The average secondary swelling rate of the transverse direction of the perfluorinated ion exchange membrane which is not treated by the method is 0.914%, and the average secondary swelling rate of the longitudinal direction of the perfluorinated ion exchange membrane is 0.320%. The secondary swelling ratio of comparative example 6 was significantly larger than that of example 6.
Example 7
A preparation method of a perfluorinated ion exchange membrane with high dimensional stability comprises the following steps:
soaking a perfluorinated ion exchange membrane in water at 15 ℃ for 120min, and taking out; soaking in 50 deg.C water for 90min, and taking out; and finally soaking the membrane in water at 15 ℃ for balancing treatment for 120min to obtain the perfluorinated ion exchange membrane with high dimensional stability.
Investigation of the dimensional stability of the perfluorinated ion exchange membrane:
the longitudinal dimension and the transverse dimension of the perfluorinated ion exchange membrane treated in the way are measured and are respectively marked as L0And L0Soaking the treated membrane in 50 deg.C water for 90min, transferring to 15 deg.C water, and balancing for 120min to determine the longitudinal and transverse dimensions as L1And L1"the secondary swelling ratio of the membrane was calculated by the formulas (1) and (2). The results are shown in Table 13:
TABLE 13 change in size and Secondary swelling Rate of Perfluoroion exchange membranes treated according to the method of the present invention
The average transverse secondary swelling rate of the perfluorinated ion exchange membrane treated by the method is 0.017%, and the average longitudinal secondary swelling rate of the perfluorinated ion exchange membrane is 0.008%.
Comparative example 7
A stability treatment method of a perfluorinated ion exchange membrane comprises the following steps: soaking in 15 deg.C water for 120min, and taking out.
Dimensional stability study of the treated perfluorinated ion exchange membranes: following the dimensional stability test conditions and equations of example 7, the results are shown in Table 14 below:
TABLE 14 change in size and Secondary swelling Rate of perfluoroion exchange membranes untreated according to the Process of the invention
The average transverse secondary swelling rate of the perfluorinated ion exchange membrane which is not treated by the method is 1.869 percent, and the average longitudinal secondary swelling rate of the perfluorinated ion exchange membrane is 0.607 percent. The secondary swelling ratio of the perfluorinated ion-exchange membrane treated in comparative example 7 was significantly greater than that of example 7.
Example 8
A preparation method of a perfluorinated ion exchange membrane with high dimensional stability comprises the following steps:
firstly, pre-soaking a perfluorinated ion exchange membrane in NaOH solution with mass fraction of 0.2% at 16 ℃ for 240min, and taking out; soaking in 0.2 wt% NaOH solution at 45 deg.C for 240min, and taking out; and finally soaking the membrane into NaOH solution with the mass fraction of 0.2% at 16 ℃ for balancing treatment for 240min to obtain the perfluorinated ion exchange membrane with high dimensional stability.
For a consideration of the dimensional stability of the perfluoroion exchange membrane, reference is made to example 1.
TABLE 15 change in size and Secondary swelling Rate of Perfluoroion exchange membranes treated by the method of the present invention
The perfluoro ion exchange membrane treated by the method has the transverse average secondary swelling rate of 0.101 percent and the longitudinal average secondary swelling rate of 0.021 percent. Example 8 compared with example 1, the temperature difference between the high temperature treatment and the low temperature treatment was changed, and it is shown that within a certain range, the larger the temperature difference, the lower the secondary swelling ratio of the perfluorinated ion exchange membrane after treatment.
Comparative example 8
The difference between the preparation method of the perfluorinated ion exchange membrane and the embodiment 1 is that: the method does not carry out first low-temperature treatment and comprises the following steps:
soaking a perfluorinated ion exchange membrane in a NaOH solution with the mass fraction of 0.2% at 35 ℃ for 240min, and taking out; and finally soaking the membrane into NaOH solution with the mass fraction of 0.2% at 16 ℃ for balancing treatment for 240min to obtain the treated perfluorinated ion exchange membrane.
The dimensional stability of the perfluorinated ion exchange membrane was examined according to the method of example 1, and the results are shown in Table 16:
TABLE 16 change in size and Secondary swelling ratio of directly heat-treated perfluoro ion exchange membranes
The perfluorinated ion exchange membrane is not subjected to first low-temperature treatment, is subjected to high-temperature treatment and then subjected to low-temperature treatment, and has the average transverse secondary swelling rate of 8.658% and the average longitudinal secondary swelling rate of 5.905%. Comparative example 8 has a significantly greater secondary swelling ratio than example 1.
The average secondary swelling ratio in the transverse direction and the longitudinal direction of the perfluorinated ion exchange membrane treated by the method disclosed by the invention is reduced, and the specific data pair table 17 shows.
TABLE 17 comparison of Secondary swelling ratios of perfluoroion exchange Membrane treated versus untreated samples
As can be seen from the comparison in Table 13, the perfluoro ion exchange membrane treated by the method of the present invention has the advantages of significantly reduced secondary swelling rate and effectively improved dimensional stability.
Claims (10)
1. A preparation method of a perfluorinated ion exchange membrane with high dimensional stability is characterized in that the perfluorinated ion exchange membrane is subjected to first low-temperature treatment by using a treatment solution, then subjected to high-temperature treatment by using the treatment solution, and finally subjected to second low-temperature treatment by using the treatment solution, wherein the high-temperature treatment temperature is higher than the low-temperature treatment temperature, and the treatment solution comprises one of water, a neutral solution or an alkaline solution.
2. The preparation method of claim 1, wherein the high-dimensional-stability perfluorinated ion exchange membrane has a transverse average secondary swelling rate of 0.015 to 0.700% and a longitudinal average secondary swelling rate of 0.005 to 0.300% in a liquid environment at a temperature of below 60 ℃; preferably, the average secondary swelling rate of the film in the transverse direction is 0.015-0.380%, and the average secondary swelling rate of the film in the longitudinal direction is 0.008-0.099%.
Preferably, the method for measuring the secondary swelling ratio is as follows: measuring the transverse dimension and the longitudinal dimension of the perfluorinated ion exchange membrane with high dimensional stability, and respectively marking as L0And L0' soaking the membranes in T1Immersion time t in liquid at temperature1Then transferred to T2Immersion time t in liquid at temperature2Measured in the transverse and longitudinal dimensions L respectively1And L1"the secondary swelling ratio of the membrane was calculated by the following formulas (1), (2):
The T is1Temperature higher than T2，t110-600 min; t is t2Is 10-600 min.
3. The method according to claim 1, wherein the high-temperature treatment temperature is 5 to 55 ℃ higher than the first low-temperature treatment temperature and 5 to 55 ℃ higher than the second low-temperature treatment temperature; the preferable high-temperature treatment temperature is 10-35 ℃ higher than the first low-temperature treatment temperature; and the temperature is 10-35 ℃ higher than the temperature of the second low-temperature treatment.
4. The method according to claim 1 or 3, wherein the temperature of the first low-temperature treatment or the second low-temperature treatment is 15 to 30 ℃, and more preferably 15 to 25 ℃;
preferably, the time of the first low-temperature treatment or the second low-temperature treatment is 90-1440 min.
5. The method for preparing the silicon nitride according to claim 4, wherein the high-temperature treatment temperature is 35-55 ℃, preferably 35-50 ℃; preferably, the high-temperature treatment time is 90-360 min.
6. The preparation method according to claim 1, wherein the neutral solution comprises one or more of an aqueous solution of alcohol, aldehyde, ketone, chloride or sulfate with a mass concentration of 0.1-50.0%. Preferably, the chloride salt is one of LiCl, NaCl or KCl; the sulfate salt comprises Li2SO4、Na2SO4Or K2SO4One kind of (1). Further preferably, the concentration of the neutral solution is 0.2-2 wt.%.
7. The method according to claim 1, wherein the concentration of the alkaline solution is 0.2 to 2 wt.%.
8. The method of claim 1 or 7, wherein the alkaline solution comprises one of an aqueous solution of a base, a carbonate, and a bicarbonate. Preferably, the cation in the alkaline solution is one of Li, Na or K. More preferably, the alkaline solution is one of sodium hydroxide and sodium bicarbonate.
9. The preparation method according to claim 1, wherein the perfluorinated ion exchange membrane is a fiber-reinforced multilayer fluorine-containing ion exchange membrane coated with hydrophilic coatings on both sides.
10. The method according to claim 9, wherein the hydrophilic coating layer has a thickness of 0 to 3 μm.
Preferably, the hydrophilic coating is prepared by coating and drying a lower alcohol dispersion liquid containing perfluorinated sulfonic acid resin and nano inorganic oxide; the mass fraction of the perfluorinated sulfonic acid resin is 3-13%, and the mass fraction of the nano inorganic oxide is 5-15%.
More preferably, the lower alcohol is a monohydric alcohol having 1-4 carbon atoms; preferably ethanol or propanol.
Further preferably, the nano inorganic oxide comprises nano ZnO and ZrO2Or TiO2Is preferably ZrO2。
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN101320818A (en) * | 2008-07-15 | 2008-12-10 | 山东东岳神舟新材料有限公司 | Fibre reinforced multi-layer fluorine-contained ionic exchange film |
| CN101350420A (en) * | 2008-07-22 | 2009-01-21 | 山东东岳神舟新材料有限公司 | Inorganics doping multi-layer fluorine-containing ion-exchange film |
| CN111378988A (en) * | 2020-03-31 | 2020-07-07 | 山东东岳高分子材料有限公司 | Preparation method of pre-swelling perfluorinated ion exchange membrane |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101320818A (en) * | 2008-07-15 | 2008-12-10 | 山东东岳神舟新材料有限公司 | Fibre reinforced multi-layer fluorine-contained ionic exchange film |
| CN101350420A (en) * | 2008-07-22 | 2009-01-21 | 山东东岳神舟新材料有限公司 | Inorganics doping multi-layer fluorine-containing ion-exchange film |
| CN111378988A (en) * | 2020-03-31 | 2020-07-07 | 山东东岳高分子材料有限公司 | Preparation method of pre-swelling perfluorinated ion exchange membrane |
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