CN111715309A - Preparation method of amphoteric ion exchange membrane and amphoteric ion exchange membrane - Google Patents

Preparation method of amphoteric ion exchange membrane and amphoteric ion exchange membrane Download PDF

Info

Publication number
CN111715309A
CN111715309A CN202010624087.5A CN202010624087A CN111715309A CN 111715309 A CN111715309 A CN 111715309A CN 202010624087 A CN202010624087 A CN 202010624087A CN 111715309 A CN111715309 A CN 111715309A
Authority
CN
China
Prior art keywords
exchange membrane
solution
mass
ion exchange
zwitterionic
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CN202010624087.5A
Other languages
Chinese (zh)
Other versions
CN111715309B (en
Inventor
徐铜文
葛亮
阿福
赵璋
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Institute of Advanced Technology University of Science and Technology of China
Original Assignee
Institute of Advanced Technology University of Science and Technology of China
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Institute of Advanced Technology University of Science and Technology of China filed Critical Institute of Advanced Technology University of Science and Technology of China
Priority to CN202010624087.5A priority Critical patent/CN111715309B/en
Publication of CN111715309A publication Critical patent/CN111715309A/en
Application granted granted Critical
Publication of CN111715309B publication Critical patent/CN111715309B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • 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
    • B01J43/00—Amphoteric ion-exchange, i.e. using ion-exchangers having cationic and anionic groups; Use of material as amphoteric ion-exchangers; Treatment of material for improving their amphoteric ion-exchange properties
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/30—Hydrogen technology
    • Y02E60/50—Fuel cells
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P10/00—Technologies related to metal processing
    • Y02P10/20—Recycling

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Manufacture Of Macromolecular Shaped Articles (AREA)

Abstract

The invention discloses a preparation method of a zwitter-ion exchange membrane, which comprises the following steps: dissolving a quaternized polymer, an amino polycarboxylic acid compound, alkyl orthosilicate and an inorganic acid solution in a first organic solvent to obtain a first solution, processing the first solution into a film, and annealing the film to obtain the amphoteric ion exchange membrane. The invention also provides a zwitterionic exchange membrane. The quaternary ammonium group is introduced into the side chain of the polymer, so that the polymer has good selectivity to strong electrostatic repulsion force of high-valence cations, carboxylic acid groups are introduced to assist the transfer of the cations in a channel, the flux of the cations is improved, different proportions of the carboxylic acid groups are adjusted based on the balance of the selectivity and the flux, the structure of the amphoteric ion exchange membrane is further regulated and controlled by annealing treatment, the mechanical strength of the amphoteric ion exchange membrane is increased, and the obtained amphoteric ion exchange membrane has the beneficial effects of good mechanical strength and performance and high selectivity to single-polyvalent cations.

Description

Preparation method of amphoteric ion exchange membrane and amphoteric ion exchange membrane
Technical Field
The invention relates to the technical field of membrane separation, in particular to a preparation method of a zwitterionic exchange membrane and the zwitterionic exchange membrane.
Background
Lithium is a silver white alkali metal and has a wide range of applications, such as lithium batteries, ceramics, and glass. As society develops, the demand for lithium is increasing. Lithium is usually extracted from high salt lakes in the form of lithium ions, but the extraction of lithium is hindered due to the interference of magnesium, calcium and other ions, and how to extract lithium in a mixed system becomes a key problem in the recovery field.
The membrane technology has low cost and low energy consumption, and has better application prospect in lithium recovery because the flux of monovalent ions is higher than that of high-valence ions. In the prior art, a modified active membrane is obtained by modifying a commercialized base membrane, but the commercialized base membrane has high cost and is difficult to popularize industrially.
The above is only for the purpose of assisting understanding of the technical aspects of the present invention, and does not represent an admission that the above is prior art.
Disclosure of Invention
The embodiment of the invention mainly aims to provide a preparation method of a zwitterionic exchange membrane, and aims to solve the technical problems that a commercialized base membrane in the prior art is high in cost and difficult to popularize industrially.
In order to solve the above problems, an embodiment of the present invention provides a method for preparing a zwitterionic exchange membrane, including the following steps:
preparing a first solution: dissolving 5-20% by mass of quaternized polymer, 1-2% by mass of aminopolycarboxylic acid compound, 1-2% by mass of alkyl orthosilicate and 5-15% by mass of inorganic acid solution in 61-88% by mass of first organic solvent to obtain first solution, wherein the concentration of the inorganic acid solution is 0.01-0.1 mol/L;
preparing a zwitterionic exchange membrane: and processing the first solution into a film, and heating the film at 60-120 ℃ for 5-8 h to obtain the zwitter-ion exchange membrane.
Optionally, the step of preparing the first solution comprises:
dissolving 10-20% by mass of quaternized polymer, 1.5-2% by mass of aminopolycarboxylic acid compound, 1.5-2% by mass of alkyl orthosilicate and 10-15% by mass of inorganic acid solution in 61-77% by mass of first organic solvent to obtain the first solution, wherein the concentration of the inorganic acid solution is 0.05-0.1 mol/L.
Optionally, the step of preparing the first solution comprises:
dissolving 10 mass percent of quaternized polymer, 2 mass percent of aminopolycarboxylic acid compound, 2 mass percent of alkyl orthosilicate and 10 mass percent of inorganic acid solution in 76 mass percent of first organic solvent to obtain first solution, wherein the concentration of the inorganic acid solution is 0.1 mol/L.
Optionally, the step of preparing the zwitterionic exchange membrane comprises:
processing said first solution into said film;
and (3) increasing the heating temperature of the film in a step manner within the temperature range of 60-120 ℃ according to a preset time interval, and continuously heating for 5-8 h to obtain the amphoteric ion exchange membrane.
Optionally, the step of processing the first solution into a film comprises:
dropping the first solution on a flat plate;
and heating the flat plate at 60-80 ℃ for 4-12 h to obtain the film.
Alternatively, the aminopolycarboxylic acid compound comprises at least one of 5-aminoisophthalic acid, 2-aminoterephthalic acid, 3-aminophthalic acid, and 5-amino-1, 2, 3-benzenetricarboxylic acid.
Optionally, the first organic solvent comprises at least one of dimethyl sulfoxide, N-methylpyrrolidone, and N, N-dimethylformamide.
Alternatively, the preparation of the quaternized polymer comprises the steps of:
dissolving 10-20% of halomethylated polymer in a second organic solvent in a mass percentage of 77-89%, adding 1-3% of N-methyldiethanolamine in the second organic solvent, and reacting at 40-60 ℃ for 12-24 h to obtain a second solution, wherein the second organic solvent comprises at least one of dimethyl sulfoxide, N-methylpyrrolidone and N, N-dimethylformamide;
adding 10-20 mL of toluene into the second solution, and collecting the precipitated precipitate;
washing the precipitate with diethyl ether to obtain the quaternized polymer.
Optionally, the halomethylated polymer comprises at least one of halomethyl polyphenylene ether, halomethyl polyethersulfone, halomethyl polystyrene, and halomethyl polyetherketone, wherein the halomethyl comprises at least one of chloromethyl, bromomethyl, and iodomethyl.
In addition, in order to solve the above problems, embodiments of the present invention further provide a zwitterionic exchange membrane prepared by the above preparation method of the zwitterionic exchange membrane.
According to the preparation method of the amphoteric ion exchange membrane provided by the embodiment of the invention, the quaternary ammonium group is introduced into the side chain of the polymer, so that the polymer has better selectivity to stronger electrostatic repulsive force of high-valence cations, the carboxylic acid group is introduced to assist the transfer of the cations in a channel, the flux of the cations is improved, different proportions of the carboxylic acid group are adjusted based on the balance of the selectivity and the flux, the structure of the amphoteric ion exchange membrane is further regulated and controlled by annealing treatment, the mechanical strength of the amphoteric ion exchange membrane is increased, the obtained amphoteric ion exchange membrane with good mechanical strength and performance and high single-polyvalent cation selectivity is obtained, and the preparation method is suitable for different single-polyvalent cation separation systems.
Drawings
FIG. 1 is a nuclear magnetic resonance hydrogen spectrum of a brominated polyphenylene ether according to an example of the present invention;
FIG. 2 is a nuclear magnetic resonance hydrogen spectrum of a quaternized polyphenylene ether of an embodiment of the invention;
FIG. 3 is an infrared spectrum of a quaternized polyphenylene ether and a zwitterionic exchange membrane of an embodiment of the invention;
FIG. 4 is a chemical reaction equation relating to an embodiment of the present invention;
FIG. 5 is a pictorial view of a zwitterionic ion-exchange membrane prepared in accordance with example 1 of the present invention;
FIG. 6 is a scanning electron microscope image of the surface of the zwitterionic exchange membrane in accordance with the present invention;
FIG. 7 is a scanning electron micrograph of a cross section of a zwitterionic exchange membrane according to an embodiment of the present invention;
FIG. 8 is a schematic diagram of a device for testing a limiting current density according to an embodiment of the present invention;
FIG. 9 is a schematic view of an electrodialysis testing apparatus according to an embodiment of the present invention;
FIG. 10 is a graph of current density versus voltage for the zwitterionic exchange membrane of example 1 in accordance with the present invention;
FIG. 11 shows the stability test results of the selectivity of the zwitterionic exchange membrane to Li/Mg ions in accordance with the present invention;
FIG. 12 shows the results of selectivity tests on different single high valence cation systems for the zwitterionic exchange membrane in accordance with the example of the present invention;
FIG. 13 is a pictorial view of a zwitterionic exchange membrane prepared in accordance with example 2 of the present invention;
FIG. 14 is a current density-voltage curve for a zwitterionic exchange membrane prepared in accordance with example 2 of the present invention;
FIG. 15 is a pictorial view of a zwitterionic exchange membrane prepared in accordance with example 3 of the present invention;
FIG. 16 is a current density-voltage curve for a zwitterionic exchange membrane prepared in accordance with example 3 of the present invention.
The implementation, functional features and advantages of the objects of the present invention will be further explained with reference to the accompanying drawings.
Detailed Description
It should be understood that the detailed description and specific examples, while indicating the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.
In this embodiment, a method for preparing a zwitterionic ion-exchange membrane with simple preparation process and low cost is provided, which does not need a commercialized base membrane, and the first solution is processed into the zwitterionic ion-exchange membrane by preparing the first solution.
The amphoteric ion exchange membrane can use at least one of polyphenyl ether, polyether sulfone, polystyrene and polyether ketone as a main chain structure and a hydrophobic structure unit, quaternary ammonium groups are introduced on branched chains to improve the selectivity of low-valent cations, such as monovalent ions such as hydrogen ions, sodium ions, lithium ions and the like, and multi-hydroxyl groups are introduced through the quaternary ammonium groups to further introduce hydrophilic groups such as amino groups, carboxyl groups and the like, so that a cation transmission channel is provided.
In one embodiment, a first solution is prepared: dissolving 5-20% by mass of quaternized polymer, 1-2% by mass of aminopolycarboxylic acid compound, 1-2% by mass of alkyl orthosilicate and 5-15% by mass of inorganic acid solution in 61-88% by mass of first organic solvent to obtain first solution, wherein the concentration of the inorganic acid solution is 0.01-0.1 mol/L; preparing a zwitterionic exchange membrane: and processing the first solution into a film, and heating the film at 60-120 ℃ for 5-8 h to obtain the zwitter-ion exchange membrane.
The mass percent of the quaternary ammonium polymer is less than 5%, the film forming capability of the prepared first solution is influenced, and the film forming capability is poor; the mass percent of the quaternary ammonium polymer is more than 15 percent, and the viscosity of the first solution is higher.
The amino polycarboxylic acid compound provides amino and carboxylic acid groups, a connecting bridge is formed by the amino and the quaternized polymer, a negatively charged group is formed by the carboxylic acid groups, and a cation-extracting transmission channel is 1-2% in mass ratio.
Alkyl orthosilicate is used as a catalyst and a crosslinking structural group, and hydrolysis is carried out under hydrochloric acid, so that crosslinking among polymer chains can be promoted. The alkyl orthosilicate can be ethyl orthosilicate, butyl orthosilicate or methyl orthosilicate.
The inorganic acid solution may be one of a hydrochloric acid solution and a sulfuric acid solution.
Hydrochloric acid provides an acidic environment that facilitates the hydrolysis of the alkyl orthosilicate.
Hydroxyl connected with quaternary ammonium groups of the quaternary ammonium polymer can perform substitution reaction with an aminopolycarboxylic acid compound, alkyl orthosilicate can be hydrolyzed under acidic condition to release hydroxyl, the released hydroxyl can perform dehydration condensation reaction with the hydroxyl connected with the quaternary ammonium groups, and carboxyl on a polybasic carboxyl compound can perform esterification reaction with the hydroxyl under heating condition to form a cross-linking structure between chains. In addition, the hydroxyl group of the hydrolyzed alkyl orthosilicate can react with the hydroxyl group on the polymer chain, and can also react with the silicon hydroxyl group connected with other chains to form a cross-linking structure between chains through dehydration condensation reaction.
The main chain of the polymer cross-linked membrane is hydrophobic, and the side chain has hydrophilic groups such as carboxylic acid group and quaternary ammonium group, so the hydrophilic groups are converged together to form an ion transmission channel, but the hydrophobic limit of the skeleton makes the area not very large, ions with different hydration radiuses can be screened through the pore size, and the micro-phase structure of the membrane can be further adjusted after the membrane is annealed. At higher temperature, molecular chains have larger kinetic energy, so molecular weight can be further rearranged and moved to obtain a membrane with a regular structure, the size of an ion transmission channel on the membrane can be reduced, and the size sieving performance is further enhanced. Due to the fact that the temperature is high, the crosslinking degree of the membrane is also high, a more compact membrane structure is formed, and the membrane has stronger ion selectivity and mechanical strength and is beneficial to application of the membrane in the field of ion separation.
In one embodiment, the step of preparing the first solution comprises: dissolving 10-20% by mass of quaternized polymer, 1.5-2% by mass of aminopolycarboxylic acid compound, 1.5-2% by mass of alkyl orthosilicate and 10-15% by mass of inorganic acid solution in 61-77% by mass of first organic solvent to obtain the first solution, wherein the concentration of the inorganic acid solution is 0.05-0.1 mol/L.
In one embodiment, the step of preparing the first solution comprises: dissolving 10 mass percent of quaternized polymer, 2 mass percent of aminopolycarboxylic acid compound, 2 mass percent of alkyl orthosilicate and 10 mass percent of inorganic acid solution in 76 mass percent of first organic solvent to obtain first solution, wherein the concentration of the inorganic acid solution is 0.1 mol/L.
Alternatively, the first organic solvent may be a polar solvent, which readily disperses the quaternized polymer.
In one embodiment, the first organic solvent may be at least one of dimethylsulfoxide, N-methylpyrrolidone, and N, N-dimethylformamide.
In one embodiment, the step of preparing the zwitterionic exchange membrane comprises:
processing said first solution into said film;
and (3) increasing the heating temperature of the film in a step manner within the temperature range of 60-120 ℃ according to a preset time interval, and continuously heating for 5-8 h to obtain the amphoteric ion exchange membrane.
The films obtained directly can be strengthened by heat treatment, since they are brittle and have low mechanical strength. According to a preset time interval such as 1h, the heating temperature of the film is increased in a stepwise manner within the temperature range of 60-120 ℃, and the film is continuously heated for 5-8 h to obtain the amphoteric ion exchange membrane. Through the mode of cascaded heating to promote the active group fully reaction between the polymer, form the crosslinked structure, obtain suitable compact structure, strengthen zwitterion exchange membrane's mechanical strength, can greatly promote zwitterion exchange membrane's selectivity simultaneously.
In one embodiment, the step of processing the first solution into a film comprises:
dropping the first solution on a flat plate;
and heating the flat plate at 60-80 ℃ for 4-12 h to obtain the film.
And (3) dropwise adding the first solution on a flat plate to uniformly distribute the first solution on the flat plate, and heating the flat plate dropwise added with the first solution at 60-80 ℃ for 4-12 h to volatilize the first organic solvent in the first solution to obtain the film. The film was a brown-yellow, homogeneous film with a smooth surface and no significant bubble particles.
Optionally, the flat plate may be glass, a rectangular area may be formed on the cleaned glass by using adhesive tape, the glass plate is placed on the heating table, the first solution is dropped on the glass plate by using a dropper, so that the rectangular area is uniformly dispersed by the first solution, and then the heating plate is opened for drying, so as to obtain the film.
Alternatively, the flat plate to which the first solution is added may be placed in an oven and heated to volatilize the solvent, thereby obtaining a film.
In one embodiment, the aminopolycarboxylic acid compound comprises at least one of 5-aminoisophthalic acid, 2-aminoterephthalic acid, 3-aminophthalic acid, and 5-amino-1, 2, 3-benzenetricarboxylic acid.
In one embodiment, the preparation of the quaternized polymer comprises the steps of:
dissolving 10-20% of halomethylated polymer in a second organic solvent in a mass percentage of 77-89%, adding 1-3% of N-methyldiethanolamine in the second organic solvent, and reacting at 40-60 ℃ for 12-24 h to obtain a second solution, wherein the second organic solvent comprises at least one of dimethyl sulfoxide, N-methylpyrrolidone and N, N-dimethylformamide;
adding 10-20 mL of toluene into the second solution, and collecting the precipitated precipitate;
washing the precipitate with diethyl ether to obtain the quaternized polymer.
Reacting a halomethylated polymer with N-methyldiethanolamine under heating to generate a strongly polar quaternized polymer, adding toluene with weak polarity, separating out off-white precipitate from the quaternized polymer due to low solubility in the toluene, and washing the precipitate by using diethyl ether to obtain the quaternized polymer.
Taking a halomethylated polymer as an example of a brominated polyphenylene ether, after the brominated polyphenylene ether has reacted sufficiently with N-methyldiethanolamine, the-CH of the brominated polyphenylene ether can be seen by comparing the nuclear magnetic resonance spectrum (see FIG. 2) of the brominated polyphenylene ether (see FIG. 1) with that of a quaternized polyphenylene ether2In the Br radicalThe chemical shift of H is 4.5ppm, and in the nuclear magnetic resonance spectrum of the quaternized polyphenylene ether, a peak with the chemical shift of 4.5ppm does not exist, indicating that bromine groups in the brominated polyphenylene ether are converted into quaternary ammonium groups.
As an alternative embodiment, the halomethylated polymer comprises at least one of halomethyl polyphenylene ether, halomethyl polyethersulfone, halomethyl polystyrene, and halomethyl polyetherketone, wherein the halomethyl comprises at least one of chloromethyl, bromomethyl, and iodomethyl groups.
The amphoteric ion exchange membrane is prepared by the preparation method of the amphoteric ion exchange membrane. Wherein, the amphoteric ion exchange membrane is provided with a positively charged quaternary ammonium group, and has good selectivity to low-valence cations due to strong repulsion to high-valence cations by the same polarity repulsion; the amphoteric ion exchange membrane has negatively charged carboxylic acid groups, so that the channels of cations are enlarged.
Taking quaternized polyphenyl ether as an example, the prepared zwitterionic exchange membrane is subjected to structural characterization, referring to fig. 3, fig. 3 is an infrared spectrum diagram of the quaternized polyphenyl ether (upper) and the zwitterionic exchange membrane (lower), and compared with the quaternized polyphenyl ether, the zwitterionic exchange membrane is 1784cm-1～1652cm-1The absorption peak in the wavelength region is the oscillation peak of carboxylic acid group; amphoteric ion exchange membrane 1558cm-1The small peak of (a) is the peak of-RNH, indicating the inclusion of a secondary amine in the zwitterionic exchange membrane, indicating that the quaternized polymer reacts with N-methyldiethanolamine such that the amino group in the N-methyldiethanolamine becomes a secondary amine; and the amphoteric ion exchange membrane is 1089cm-1The peak becomes wider, and the structure of Si-O-C and Si-O-Si is introduced when the peak becomes larger, and the changes indicate that the crosslinking reaction occurs.
In this embodiment, hydroxyl groups on the quaternized polymer react with amino groups of aminopolycarboxylic acid, negatively charged carboxylic acid groups are introduced on side chains of the polymer, alkyl orthosilicate is hydrolyzed under acidic conditions to obtain silicon hydroxyl groups, the silicon hydroxyl groups and the hydroxyl groups on the quaternized polymer undergo dehydration condensation reaction to form a cross-linked structure between the polymers, after a film is heated, a zwitterionic exchange membrane with good mechanical strength is obtained, cations are assisted to pass through the zwitterionic exchange membrane through electrostatic interaction of a large number of carboxylic acid groups and the cations, so that the flux of the cations is increased, and quaternary ammonium groups in the zwitterionic exchange membrane have different electrostatic repulsive forces to different cations, so that the selectivity to the cations is improved.
Example 1
The following examples are given by way of illustration of a quaternized polymer being a quaternized polyphenylene ether.
The preparation method of the quaternized polyphenylene ether comprises the following steps: 1.0g of brominated polyphenylene ether was dissolved in 9ml of N-methylpyrrolidone to obtain a yellow transparent solution, and 0.2g of N-methyldiethanolamine was added and stirred at 40 ℃ for reaction for 18 hours to obtain a second solution. Adding 10mL of toluene into the second solution to precipitate an off-white polymer precipitate, collecting the precipitated precipitate, fully washing the precipitate with excessive diethyl ether, and drying to obtain white powder to obtain the quaternized polyphenylene ether.
The preparation step of the first solution: dissolving 1.0g of quaternized polyphenylene ether in 9ml of dimethyl sulfoxide, adding 0.2g of 5-aminoisophthalic acid after complete dissolution, adding 0.2g of tetraethoxysilane, dropwise adding 1ml of hydrochloric acid with the concentration of 0.1mol/L, and reacting for 6 hours under stirring to obtain a first solution. Wherein a chemical reaction equation of the chemical reaction performed in the preparation step of the first solution is shown in fig. 4.
The preparation steps of the film are as follows: and (2) circling an area on a glass plate by using adhesive tape paper, horizontally placing the area on a heating plate, dripping the first solution cooled to the normal temperature on the glass plate until the first solution is uniformly paved on the whole circling area, controlling the heating plate to heat to 60 ℃, and continuously heating for 12 hours to obtain the film.
The preparation method of the amphoteric ion exchange membrane comprises the following steps: the film is placed on a glass plate and is placed in a muffle furnace, and the heating program arranged on the muffle furnace comprises the following steps: heating to 70 deg.C for 45 min; heating to 70 deg.C for 60 min; heating to 80 deg.C for 10 min; heating to 80 deg.C for 60 min; heating to 90 deg.C for 10 min; heating to 90 deg.C for 60 min; heating to 100 deg.C for 10 min; heating to 100 deg.C for 60 min; heating to 120 deg.C, and taking 20 min; heating to 120 deg.C for 180 min; and finishing heating. After the reaction is finished, cooling to normal temperature, taking out the film, and finishing the thermal crosslinking to obtain the zwitterion exchange membrane 1, referring to fig. 5, wherein fig. 5 is a real object diagram of the zwitterion exchange membrane 1. Referring to fig. 6 and 7, fig. 6 and 7 are a surface scanning electron microscope image and a cross-sectional scanning electron microscope image of the zwitterionic exchange membrane, respectively, it can be seen that the zwitterionic exchange membrane has a regular and dense structure and forms a pore diameter as a cation transmission channel.
Characterization of the performance of the zwitterionic exchange membrane:
(1) cation Exchange Capacity (CEC): firstly weighing the mass of a dry film, soaking the dry film for 24 hours by hydrochloric acid with the concentration of 1mol/L to convert the film into an H type, washing the film by water, soaking the film by 2mol/L sodium chloride solution for 24 hours to completely replace hydrogen ions on ion exchange groups in the film, using phenolphthalein as an indicator, titrating the replaced H + by 0.05mol/L sodium hydroxide, calculating the amount of sodium hydroxide substances consumed by titration, and taking the ratio of the amount of the sodium hydroxide substances to the dry weight of a zwitter-ion exchange membrane as a ratio to obtain CEC of the zwitter-ion exchange membrane in unit of mmol/g;
(2) the water content is measured by accurately weighing the dry mass W of the amphoteric ion exchange membrane1And wet mass W2Then with the formula WU ═ W (W)2-W1)/W1Obtaining a value of water content WU by 100%;
(3) limiting current density. The test was carried out in a four-electrode chamber method, where 0.3mol/L sodium sulfate was used in the chamber outside the commercial membrane Nafion and 0.5mol/L sodium chloride solution was used in the chamber around the membrane, as shown in FIG. 8. Gradually increasing current, observing transmembrane voltage drop with multimeter and a pair of silver/silver chloride electrodes, drawing I-V curve, recording limiting current density, and effective membrane area of 7.07cm2。
(4) Ion separation performance. The test was carried out using an electrodialysis apparatus, the principle of which is shown in FIG. 9, the solution in the anode and cathode compartments being 0.3mol/L Na2SO4The solution and the solution in the desalting chamber have different compositions for different systems (the Li/Mg, Na/Mg and K/Mg systems are respectively 0.1mol/L of chloride, and for H/Fe, 1mol/L of H and0.25mol/L Fe), the concentration chamber is 0.01mol/L KCl, and the volumes are all 100 ml. The anion exchange membrane used was AMX of ASTOM corporation of Japan, and the amphoteric ion exchange membrane prepared in the example of the present invention was used as a separation membrane, and the test time was 1h, wherein the cation concentration of the concentration chamber was measured using ICP-AES, and the flux and selectivity of each cation were calculated from the concentration of each ion.
And (3) testing results: the CEC of the zwitterionic exchange membrane 1 is 0.24; the water content of the amphoteric ion exchange membrane 1 is 30%, wherein the water content of the corresponding quaternized polyphenylene ether is 43%. According to the current density-voltage curve in FIG. 10, the limiting current density was 9mA/cm2(ii) a The amphoteric ion exchange membrane 1 separates the Li/Mg system, and the lithium ion flux is 33.46 x 10-10mol·cm-2·s-1The magnesium ion flux was 4.18 x 10-10mol·cm-2·s-1The selectivity to Li/Mg was 8.1, with better flux and selectivity compared to commercial membranes. To verify the stability of the zwitterionic exchange membrane 1, reference is made to figure 11, which shows that the zwitterionic exchange membrane has excellent performance and good stability.
In addition, different cation combination systems were tested for the zwitterionic membrane 1, with reference to FIG. 12, for Na/Mg, K/Mg and H/Fe systems, the selectivities were 41.3, 25 and 246, respectively, and the fluxes of monovalent cations in each system were 309.64 x 10, respectively-10mol·cm-2·s-1，130.29*10-10mol·cm-2·s-1And 402.03 x 10-10mol·cm-2·s-1The result shows that the amphoteric ion exchange membrane 1 has higher separation performance for different types of cation systems, and has the characteristics of high flux and high selectivity.
Example 2
The preparation method of the quaternized polyphenylene ether comprises the following steps: 1.0g of brominated polyphenylene ether was dissolved in 8ml of N-methylpyrrolidone to obtain a yellow transparent solution, and 0.2g of N-methyldiethanolamine was added and stirred at 50 ℃ for 12 hours to obtain a second solution. Adding 15mL of toluene into the second solution to precipitate an off-white polymer precipitate, collecting the precipitated precipitate, fully washing the precipitate with excessive diethyl ether, and drying to obtain white powder to obtain the quaternized polyphenylene ether.
The preparation step of the first solution: 1.0g of quaternized polyphenylene ether is dissolved in 8ml of N-methylpyrrolidone, 0.15g of 5-aminoisophthalic acid is added after complete dissolution, 0.15g of ethyl orthosilicate is added, 1ml of hydrochloric acid with the concentration of 0.05mol/L is added dropwise, and reaction is carried out for 5.5h under the stirring condition, so as to obtain a first solution.
The preparation steps of the film are as follows: and (2) circling an area on a glass plate by using adhesive tape paper, horizontally placing the area on a heating plate, dropwise adding the first solution cooled to normal temperature on the glass plate until the first solution is uniformly paved on the whole circling area, controlling the heating plate to heat to 70 ℃, and continuously heating for 6 hours to obtain the film.
The preparation method of the amphoteric ion exchange membrane comprises the following steps: the film is placed on a glass plate and is placed in a muffle furnace, and the heating program arranged on the muffle furnace comprises the following steps: heating to 80 deg.C for 60 min; heating to 80 deg.C for 60 min; heating to 90 deg.C for 10 min; heating to 90 deg.C for 60 min; heating to 100 deg.C for 10 min; heating to 100 deg.C for 60 min; heating to 120 deg.C for 15 min; heating to 120 deg.C for 180 min; and finishing heating. After the reaction is finished, cooling to normal temperature, taking out the film, and finishing the thermal crosslinking to obtain the zwitterion exchange membrane 2, referring to fig. 13, wherein fig. 13 is a real object diagram of the zwitterion exchange membrane 2.
And (3) testing results: the CEC of the zwitterionic exchange membrane 1 is 0.14; the water content of the amphoteric ion exchange membrane 2 was 24%, and the water content of the corresponding quaternized polyphenylene ether was 43%. According to the current density-voltage curve in FIG. 14, the limiting current density of the amphoteric ion-exchange membrane 2 is 22mA/cm2(ii) a The amphoteric ion exchange membrane 1 separates the Li/Mg system, and the lithium ion flux is 3.63 x 10-10mol·cm-2·s-1The flux of magnesium ions was 0.18 x 10-10mol·cm-2·s-1The selectivity to Li/Mg was 19.7, with better flux and selectivity compared to commercial membranes.
Higher selectivity towards monovalent cations, relative to example 1, promotes a reduction in the content of carboxylic acid groups in the zwitterionic exchange membrane 2 due to the reduced content of aminopolycarboxylic acid added, resulting in a reduced flux of monovalent cations.
Example 3
The preparation method of the quaternized polyphenylene ether comprises the following steps: 1.0g of brominated polyphenylene ether was dissolved in 10ml of N-methylpyrrolidone to obtain a yellow transparent solution, and 0.2g of N-methyldiethanolamine was added and stirred at 60 ℃ for 10 hours to obtain a second solution. Adding 20mL of toluene into the second solution to precipitate an off-white polymer precipitate, collecting the precipitated precipitate, fully washing the precipitate with excessive diethyl ether, and drying to obtain white powder to obtain the quaternized polyphenylene ether.
The preparation step of the first solution: 1.0g of quaternized polyphenylene ether is dissolved in 8ml of N-methylpyrrolidone, 0.1g of 5-aminoisophthalic acid is added after complete dissolution, 0.1g of ethyl orthosilicate is added, 1ml of hydrochloric acid with the concentration of 0.01mol/L is added dropwise, and reaction is carried out for 5 hours under stirring conditions, so as to obtain a first solution.
The preparation steps of the film are as follows: and (2) circling an area on a glass plate by using adhesive tape paper, horizontally placing the area on a heating plate, dropwise adding the first solution cooled to normal temperature on the glass plate until the first solution is uniformly paved on the whole circling area, controlling the heating plate to heat to 80 ℃, and continuously heating for 6 hours to obtain the film.
The preparation method of the amphoteric ion exchange membrane comprises the following steps: the film is placed on a glass plate and is placed in a muffle furnace, and the heating program arranged on the muffle furnace comprises the following steps: heating to 90 deg.C for 60 min; heating to 90 deg.C for 60 min; heating to 100 deg.C for 10 min; heating to 100 deg.C for 60 min; heating to 120 deg.C for 15 min; heating to 120 deg.C for 180 min; and finishing heating. After the completion of the cooling to room temperature, the membrane is taken out, and the thermal crosslinking is completed to obtain the zwitterionic exchange membrane 3, referring to fig. 15, fig. 15 is a real object diagram of the zwitterionic exchange membrane 3.
And (3) testing results: the CEC of the zwitterionic exchange membrane 1 is 0.13; the water content of the amphoteric ion exchange membrane 3 was 26%, and the water content of the corresponding quaternized polyphenylene ether was 43%. According to the current density-voltage curve in FIG. 16, sinceThe current density-voltage curve of the amphoteric ion exchange membrane 3 has no platform period in the test range, so that the limit current density cannot be calculated; the amphoteric ion exchange membrane 1 separates the Li/Mg system, and the lithium ion flux is 1.66 x 10-10mol·cm-2·s-1The flux of magnesium ions was 0.32 x 10-10mol·cm-2·s-1The selectivity to Li/Mg was 5.4, with better flux and selectivity compared to commercial membranes.
Compared with the examples 1 and 2, the selectivity and the flux of the cation are reduced, mainly because the carboxylic acid groups in the amphoteric ion exchange membrane 3 are reduced due to the reduction of the amount of the aminopolycarboxylic acid, the cross-linked structure in the membrane is reduced, the compactness of the membrane is reduced, and the selectivity and the flux of the cation are reduced.
In summary, the experimental methods used in examples 1 to 3 differ only slightly, mainly by varying the amount of aminopolycarboxylic acid used. Can prepare homogeneous amphoteric ion exchange membranes with excellent performance, and has better selectivity and flux in single-multivalent cation separation systems. The quaternary ammonium group is introduced into the side chain of the polymer, so that the polymer has better selectivity to stronger electrostatic repulsion force of high-valence cations, the carboxylic acid group is introduced to assist the transfer of the cations in a channel, the flux of the cations is improved, different proportions of the carboxylic acid group are adjusted based on the balance of the selectivity and the flux, the annealing treatment is used for further regulating and controlling the structure of the amphoteric ion exchange membrane, the mechanical strength of the amphoteric ion exchange membrane is increased, and the obtained amphoteric ion exchange membrane with good mechanical strength and high single-polyvalent cation selectivity is suitable for different single-polyvalent cation separation systems and has good application prospects in the aspects of seawater desalination and the like.
The above-mentioned serial numbers of the embodiments of the present invention are merely for description and do not represent the merits of the embodiments.
It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.
Through the above description of the embodiments, those skilled in the art will clearly understand that the method of the above embodiments can be implemented by software plus a necessary general hardware platform, and certainly can also be implemented by hardware, but in many cases, the former is a better implementation manner. Based on such understanding, the technical solution of the present invention may be embodied in the form of a software product, which is stored in a computer-readable storage medium (such as ROM/RAM, magnetic disk, optical disk) as described above, and includes several instructions for enabling a terminal device (such as a mobile phone, a computer, a server, an air conditioner, or a network device) to execute the method according to the embodiments of the present invention.
The above description is only a preferred embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications of equivalent structures and equivalent processes, which are made by using the contents of the present specification and the accompanying drawings, or directly or indirectly applied to other related technical fields, are included in the scope of the present invention.

Claims (10)

1. The preparation method of the zwitter-ion exchange membrane is characterized by comprising the following steps of:
preparing a first solution: dissolving 5-20% by mass of quaternized polymer, 1-2% by mass of aminopolycarboxylic acid compound, 1-2% by mass of alkyl orthosilicate and 5-15% by mass of inorganic acid solution in 61-88% by mass of first organic solvent to obtain first solution, wherein the concentration of the inorganic acid solution is 0.01-0.1 mol/L;
preparing a zwitterionic exchange membrane: and processing the first solution into a film, and heating the film at 60-120 ℃ for 5-8 h to obtain the zwitter-ion exchange membrane.
2. The method of preparing a zwitterionic ion-exchange membrane according to claim 1 wherein said step of preparing a first solution comprises:
dissolving 10-20% by mass of quaternized polymer, 1.5-2% by mass of aminopolycarboxylic acid compound, 1.5-2% by mass of alkyl orthosilicate and 10-15% by mass of inorganic acid solution in 61-77% by mass of first organic solvent to obtain the first solution, wherein the concentration of the inorganic acid solution is 0.05-0.1 mol/L.
3. The method of preparing a zwitterionic ion-exchange membrane according to claim 1 wherein said step of preparing a first solution comprises:
dissolving 10 mass percent of quaternized polymer, 2 mass percent of aminopolycarboxylic acid compound, 2 mass percent of alkyl orthosilicate and 10 mass percent of inorganic acid solution in 76 mass percent of first organic solvent to obtain first solution, wherein the concentration of the inorganic acid solution is 0.1 mol/L.
4. The process for preparing a zwitterionic exchange membrane according to claim 1 wherein said step of preparing a zwitterionic exchange membrane comprises:
processing said first solution into said film;
and (3) increasing the heating temperature of the film in a step manner within the temperature range of 60-120 ℃ according to a preset time interval, and continuously heating for 5-8 h to obtain the amphoteric ion exchange membrane.
5. The method of preparing a zwitterionic exchange membrane according to claim 1 wherein said step of processing said first solution into a thin film comprises:
dropping the first solution on a flat plate;
and heating the flat plate at 60-80 ℃ for 4-12 h to obtain the film.
6. The method of claim 1, wherein the aminopolycarboxylic acid compound comprises at least one of 5-aminoisophthalic acid, 2-aminoterephthalic acid, 3-aminophthalic acid, and 5-amino-1, 2, 3-benzenetricarboxylic acid.
7. The method of claim 1, wherein the first organic solvent comprises at least one of dimethyl sulfoxide, N-methylpyrrolidone, and N, N-dimethylformamide.
8. The process for preparing a zwitterionic exchange membrane according to claim 1 wherein said quaternized polymer is prepared by the steps of:
dissolving 10-20% of halomethylated polymer in a second organic solvent in a mass percentage of 77-89%, adding 1-3% of N-methyldiethanolamine in the second organic solvent, and reacting at 40-60 ℃ for 12-24 h to obtain a second solution, wherein the second organic solvent comprises at least one of dimethyl sulfoxide, N-methylpyrrolidone and N, N-dimethylformamide;
adding 10-20 mL of toluene into the second solution, and collecting the precipitated precipitate;
washing the precipitate with diethyl ether to obtain the quaternized polymer.
9. The method of claim 8, wherein the halomethylated polymer comprises at least one of halomethyl polyphenylene ether, halomethyl polyethersulfone, halomethyl polystyrene, and halomethyl polyetherketone, wherein the halomethyl comprises at least one of chloromethyl, bromomethyl, and iodomethyl groups.
10. A zwitterionic exchange membrane prepared by the process for the preparation of a zwitterionic exchange membrane according to any one of claims 1 to 9.
CN202010624087.5A 2020-07-01 2020-07-01 Preparation method of amphoteric ion exchange membrane and amphoteric ion exchange membrane Active CN111715309B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202010624087.5A CN111715309B (en) 2020-07-01 2020-07-01 Preparation method of amphoteric ion exchange membrane and amphoteric ion exchange membrane

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202010624087.5A CN111715309B (en) 2020-07-01 2020-07-01 Preparation method of amphoteric ion exchange membrane and amphoteric ion exchange membrane

Publications (2)

Publication Number Publication Date
CN111715309A true CN111715309A (en) 2020-09-29
CN111715309B CN111715309B (en) 2023-01-17

Family

ID=72571127

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202010624087.5A Active CN111715309B (en) 2020-07-01 2020-07-01 Preparation method of amphoteric ion exchange membrane and amphoteric ion exchange membrane

Country Status (1)

Country Link
CN (1) CN111715309B (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113621158A (en) * 2021-09-02 2021-11-09 浙江工业大学 Preparation method of ion exchange membrane with mono/divalent anion separation cross-linking type amphoteric structure
CN114405286A (en) * 2021-12-08 2022-04-29 华东理工大学 Ion-crosslinked amphoteric ion exchange membrane, preparation method and application thereof in selective electrodialysis

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH07241443A (en) * 1994-03-04 1995-09-19 Asahi Glass Co Ltd Method for selectively electrodialyzing monovalent cation
CN103736405A (en) * 2013-12-17 2014-04-23 中国科学技术大学 Preparation method of cation exchange membrane with function of selectively separating monovalent and multivalent cations
CN106512969A (en) * 2016-11-03 2017-03-22 浙江大学 Preparation and chemical modification method of polymer graphene composite chromatographic filling material
CN109012761A (en) * 2018-08-29 2018-12-18 中国科学技术大学先进技术研究院 A kind of monovalent anion selective diffusion barrier and preparation method thereof
CN110465212A (en) * 2019-08-26 2019-11-19 中国科学技术大学 A kind of preparation method of univalent cation selective diffusion barrier

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH07241443A (en) * 1994-03-04 1995-09-19 Asahi Glass Co Ltd Method for selectively electrodialyzing monovalent cation
CN103736405A (en) * 2013-12-17 2014-04-23 中国科学技术大学 Preparation method of cation exchange membrane with function of selectively separating monovalent and multivalent cations
CN106512969A (en) * 2016-11-03 2017-03-22 浙江大学 Preparation and chemical modification method of polymer graphene composite chromatographic filling material
CN109012761A (en) * 2018-08-29 2018-12-18 中国科学技术大学先进技术研究院 A kind of monovalent anion selective diffusion barrier and preparation method thereof
CN110465212A (en) * 2019-08-26 2019-11-19 中国科学技术大学 A kind of preparation method of univalent cation selective diffusion barrier

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
LIANG GE ET AL.: "Preparation of monovalent cation selective membranes through annealing treatment", 《JOURNAL OF MEMBRANE SCIENCE》 *
NOOR UI AFSAR ET AL.: "Cation exchange membrane integrated with cationic and anionic layers for selective ion separation via electrodialysis", 《DESALINATION》 *
YUBIN HE ET AL.: "Monovalent cations permselective membranes with zwitterionic side chains", 《JOURNAL OF MEMBRANE SCIENCE》 *

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113621158A (en) * 2021-09-02 2021-11-09 浙江工业大学 Preparation method of ion exchange membrane with mono/divalent anion separation cross-linking type amphoteric structure
CN114405286A (en) * 2021-12-08 2022-04-29 华东理工大学 Ion-crosslinked amphoteric ion exchange membrane, preparation method and application thereof in selective electrodialysis
CN114405286B (en) * 2021-12-08 2024-06-28 华东理工大学 Ion crosslinking type amphoteric ion exchange membrane, preparation method and application thereof in selective electrodialysis

Also Published As

Publication number Publication date
CN111715309B (en) 2023-01-17

Similar Documents

Publication Publication Date Title
EP0309259B1 (en) Immobilized electrolyte membrane and method of preparation thereof
CN111715309B (en) Preparation method of amphoteric ion exchange membrane and amphoteric ion exchange membrane
CN105504284B (en) A kind of polymer containing quaternary ammonium group, anion-exchange membrane and preparation method thereof
US9707722B2 (en) Method for producing porous polyimide film, and porous polyimide film
KR101330571B1 (en) Manufacturing method of hybride ion exchange membrane
DE102009020129A1 (en) Proton-conducting polymer electrolytes and fuel cells
CN108110290B (en) Cross-linked imidazole type polyether-ether-ketone anion exchange membrane for fuel cell and preparation method thereof
Hao et al. A simple and green preparation of PVA-based cation exchange hybrid membranes for alkali recovery
Hao et al. Alkali recovery using PVA/SiO2 cation exchange membranes with different–COOH contents
US9790339B2 (en) Crosslinked speek cation exchange membrane having improved chemical stability by radiation and method of preparing the same
CN108148213B (en) Preparation method of carbon nitride doped anion exchange membrane
JP2016183273A (en) Porous polyimide film
CN110400898B (en) Lithium battery diaphragm and preparation method thereof
WO2017178447A1 (en) Inorganic/organic compositions
JP6747091B2 (en) Porous film and method for producing the same
Song et al. Rational Materials and Structure Design for Improving the Performance and Durability of High Temperature Proton Exchange Membranes (HT‐PEMs)
US9905872B2 (en) Process for preparing an ion-exchange composite material comprising a specific polymer matrix and a filler consisting of ion-exchange particles
Ye et al. 3-Glycidoxy-propylthrimethoxysilane improved anion exchange membranes based on quaternized poly (2, 6-dimethyl-1, 4-phenyleneoxide)
CN103864977B (en) The preparation method of a kind of many silicon linking agent and the special anionic membrane of diffusion dialysis thereof
CN111613831A (en) All-solid-state battery
CN111729694B (en) Preparation method of anion exchange membrane and anion exchange membrane
CN109675448A (en) A kind of preparation method of antifouling anion-exchange membrane
US9065109B2 (en) Method for preparing a composite material comprising a polymeric matrix and a filler consisting in ion exchange inorganic particles
Nagarale et al. Polyaniline derivatized anion exchange membrane for acid recovery
KR102019887B1 (en) Ionic block copolymer and preparation method thereof

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant