CN113522042A

CN113522042A - Preparation method and application of homogeneous cation exchange membrane containing alkylbenzene sulfonate

Info

Publication number: CN113522042A
Application number: CN202110904749.9A
Authority: CN
Inventors: 王建友; 赵津礼
Original assignee: Nankai University
Current assignee: Nankai University
Priority date: 2021-08-07
Filing date: 2021-08-07
Publication date: 2021-10-22

Abstract

The invention discloses a preparation method of a homogeneous cation exchange membrane containing alkylbenzene sulfonate, which comprises the following steps: the invention further provides a homogeneous cation exchange membrane prepared by the preparation method, and the invention also provides application of the homogeneous cation exchange membrane prepared by the preparation method, and the homogeneous cation exchange membrane is applied to the field of electrodialysis concentration.

Description

Preparation method and application of homogeneous cation exchange membrane containing alkylbenzene sulfonate

Technical Field

The invention belongs to the technical field of exchange membranes, and particularly relates to a preparation method and application of a homogeneous cation exchange membrane containing alkylbenzene sulfonate.

Background

Cation exchange membranes are widely used as a key ionic membrane in the fields of electrodialysis, water treatment, fuel cells and the like. In some remote water-deficient areas, brackish water is the only available water source nearby, so in recent years, the brackish water desalination process also becomes a hot point of research in the field of desalination. Water containing Total Dissolved Solids (TDS) of 1000mg/L to 10000mg/L is generally called brackish water, depending on the salt content of the water, where TDS less than 5000mg/L is low to medium brackish water and above 5000mg/L is high brackish water. The brackish water can not be directly used due to high salt content, and the brackish water is suitable for being used as drinking water only if the salt content is lower than 500mg/L according to the requirements of the world health organization. Surveys have shown that 19% of the worldwide desalination processes are used to treat brackish water in the hope of obtaining acceptable drinking water. At present, the active development of unconventional water sources such as brackish water and the like and the improvement of the utilization efficiency become an important way for relieving water quality and water source shortage. At present, the brackish water mainly comprises a desalination process taking reverse osmosis, nanofiltration and electrodialysis as the core, and other processes comprise a distillation method, a membrane distillation method and the like. At present, two methods at the core of brackish water desalination are reverse osmosis and electrodialysis. The energy consumption is the main influence factor of the high or low of the two. Ionic membranes produced by foreign famous ionic membrane manufacturers are high in price, so that the use of the ionic membranes in the common field is limited, and although the price of the ionic membranes in China is low in price, the production process is not environment-friendly, and the development of a plurality of enterprises is also limited. The ion exchange membrane has a wide variety of substrate materials, and the functional group in the ion exchange membrane is the core of the ion exchange membrane and is the key point for realizing the selective permeability of the ion exchange membrane. Ion exchange of low functional density groups has been demonstrated to be feasible for brackish water desalination. Therefore, the development of the ion exchange membrane with low cost and good performance has very important practical significance for relieving the problem of desalting the bitter water at present.

Disclosure of Invention

Aiming at the situation, in order to overcome the defects of the prior art, the invention provides a preparation method and application of a homogeneous cation exchange membrane containing alkylbenzene sulfonate, the homogeneous cation exchange membrane is low in preparation cost and environment-friendly, the problem of high cost of an ED (immersion ED) process for brackish water desalination is solved, and the prepared membrane is low in resistance, good in desalination performance and capable of being stably used for a long time.

The technical scheme adopted by the invention is as follows: the preparation method of the homogeneous cation exchange membrane containing the alkylbenzene sulfonate comprises the following steps:

the method comprises the following steps: preparation of casting solution

Dissolving at least one matrix material in a proper solvent, adding at least one solubilizer, mechanically stirring for a period of time at a certain temperature to obtain a uniform solution, adding at least one fatty anionic surfactant, and continuously stirring and dissolving to a homogeneous phase, wherein the casting solution comprises the following components in percentage by mass: 3% -40% of sulfonated polymer matrix material; 2 to 30 percent of solvent; 1% -25% of anionic surfactant;

step two: film formation by evaporation of solvent

Carrying out ultrasonic treatment on the prepared casting solution at 25-95 ℃ for a period of time, standing for 12-24 hours until the defoaming is complete, scraping the homogeneous casting solution on a smooth flat plate, then putting the smooth flat plate into a blast oven, and adopting a gradient heating method: treating at 50-80 ℃ for 1-2 h, treating at 80-100 ℃ for 1-2 h, treating at 100-150 ℃ for 3-6 h, taking out the film, and cooling to room temperature in air;

step three: post-treatment

And (4) putting the cooled film into deionized water, automatically dropping the film from a smooth flat plate, changing water for many times, and storing for later use.

Further, in the first step, the selected polymer matrix material is at least one of polysulfone, polyethersulfone 2010, polyethersulfone 3010, polyethersulfone 6020, polyphenylene oxide and polyethylene.

Further, in the first step, the solvent used for preparing the casting solution is at least one of N-methylpyrrolidone, dimethylacetamide, tetrahydrofuran and chloroform.

Further, in the first step, the solubilizer is at least one of acetone, polyvinylpyrrolidone (PVP) K60, PVP K90, polyvinyl alcohol (PVA), polyethylene glycol and ethylene glycol.

Further, in the first step, the alkylbenzene sulfonate anionic surfactant is at least one of sodium dodecylbenzene sulfonate, sodium octadecyl-p-xylene sulfonate, sodium lignin sulfonate, sodium p-methoxyfatty amido benzene sulfonate, sodium dodecylnaphthalene sulfonate, nonylbenzene sulfonic acid, sodium tridecylbenzene sulfonate, and sodium polystyrene sulfonate.

The invention also provides a homogeneous cation exchange membrane prepared by the preparation method, and the adopted technical scheme is that a polymer is directly used as a base material of the cation exchange membrane, and at least a solubilizer is dissolved in a proper solvent to prepare a membrane casting solution, and the cation exchange membrane is directly prepared by the processes of standing, defoaming, gradient temperature rise, solvent evaporation, cooling and stripping.

The invention also provides application of the homogeneous cation exchange membrane prepared by the method, and the homogeneous cation exchange membrane is applied to the field of electrodialysis concentration.

The cation exchange membrane is a flat membrane, is prepared by the preparation method of the alkylbenzene sulfonate-containing anionic surfactant, and can be applied to brackish water desalination.

The invention with the structure has the following beneficial effects: the preparation method and the application of the homogeneous cation exchange membrane containing the alkylbenzene sulfonate have the advantages that the adopted membrane matrix material is easy to obtain and low in cost, the membrane making process is simple, the membrane forming technology is mature and environment-friendly, and the industrial implementation is easy. Compared with the commercial ion exchange membrane with high price, the preparation cost of the cation membrane is obviously reduced on the whole, the cation membrane is applied to the brackish water desalination, the performance of the cation membrane is superior to that of the commercial ion exchange membrane, and the electrodialysis has important prospect in the brackish water desalination.

Drawings

FIG. 1 is an infrared spectrum of a cation exchange membrane prepared;

FIG. 2 is a practical diagram of the cation exchange membrane obtained in example 1;

FIG. 3 is a SEM image of the cross section of the cation exchange membrane obtained in example 1;

FIG. 4 is a practical diagram of the cation exchange membrane obtained in example 2;

FIG. 5 is a SEM image of the cross section of the cation exchange membrane obtained in example 2;

FIG. 6 is a practical diagram of the cation exchange membrane obtained in example 3;

FIG. 7 is a SEM image of the cross section of the cation exchange membrane obtained in example 3;

FIG. 8 is a practical diagram of the cation exchange membrane obtained in example 4;

FIG. 9 is a SEM image of the cross section of the cation exchange membrane obtained in example 4;

FIG. 10 is a practical diagram of the cation exchange membrane obtained in example 5;

FIG. 11 is a SEM image of the cross section of the cation exchange membrane obtained in example 5;

FIG. 12 is a practical diagram of the cation exchange membrane obtained in example 6;

FIG. 13 is a SEM image of a cross section of the cation exchange membrane obtained in example 6;

FIG. 14 is a practical diagram of the cation exchange membrane obtained in example 7;

FIG. 15 is a SEM image of the cross section of the cation exchange membrane obtained in example 7;

FIG. 16 is a practical diagram of the cation exchange membrane obtained in example 8;

FIG. 17 is a SEM image of a cross section of the cation exchange membrane obtained in example 8;

FIG. 18 is a practical diagram of the cation exchange membrane obtained in example 9;

FIG. 19 is a SEM image of a cross section of the cation exchange membrane obtained in example 9;

FIG. 20 is a practical diagram of the cation exchange membrane obtained in example 10;

FIG. 21 is a SEM image of the cross section of the cation exchange membrane obtained in example 10;

FIG. 22 is a schematic representation of the cation exchange membrane obtained in example 11;

FIG. 23 is a SEM image of a cross section of the cation exchange membrane obtained in example 11;

FIG. 24 is a schematic representation of a cation exchange membrane obtained in example 12;

FIG. 25 is a SEM image of a cross section of the cation exchange membrane obtained in example 12.

Wherein, A, sulfonic acid group, B, contrast film, C, cation exchange film, D, sodium dodecyl benzene sulfonate.

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention and not to limit the invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments; all other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The homogeneous cation exchange membrane is prepared by blending a polymer, a solubilizer and an alkylbenzene sulfonate anionic surfactant. The mechanical property of the membrane is maintained by a polymer, the alkylbenzene sulfonate anionic surfactant provides a functional group of the cation exchange membrane, the alkylbenzene sulfonate anionic surfactant and the alkylbenzene sulfonate anionic surfactant cannot be well compatible in a solvent to form a homogeneous system, and a solubilizer is added to form a good homogeneous system, and then the good homogeneous system is defoamed, preserved at constant temperature, scraped, dried and shed to prepare the cation exchange membrane which can be applied to desalination of high-concentration brackish water (TDS is more than 5000 mg/L).

Example 1:

mixing 10g of polysulfone, 10g of PVP K60 and 70g of trichloromethane, stirring for 10 hours at 60 ℃, adding 10g of sodium lignosulfonate after complete dissolution at 50 ℃ to fully dissolve and form a homogeneous solution, performing ultrasonic defoaming for 4 hours at 80 ℃ in an ultrasonic instrument, standing and defoaming for 24 hours, scraping the casting solution on a dry, smooth and clean glass plate, putting the glass plate into an oven, and performing gradient temperature rise: evaporating the solvent for 5h at 50 ℃, heating to 90 ℃ for 5h, heating to 120 ℃ for 3h, taking out from the oven, cooling, immersing in deionized water, and automatically dropping the ion membrane from the glass plate to obtain the ion exchange membrane. The test shows that the thickness of the cationic membrane is 183um, the water absorption is 32 percent, and the ion exchange capacity is 1.06 mmol/g. Designing a desalination process, applying a miniature ED device self-made by a laboratory to desalinate brackish water, wherein the initial NaCl concentration of a diluent and a concentrated solution is 7500mg/L, and compared with a certain commercial ionic membrane, the desalination rate reaches 90%, and the energy consumption of the prepared membrane and the commercial membrane is 16.2 kW.h/m 3 respectively.

Example 2

Mixing 10g of polyether sulfone 2010, 8g of acetone and 100g of trichloromethane, stirring for 10 hours at 60 ℃, adding 15g of sodium dodecyl benzene sulfonate after complete dissolution, fully dissolving at 60 ℃ to form a homogeneous solution, performing ultrasonic defoaming for 4 hours at 60 ℃ in an ultrasonic instrument, standing for defoaming for 24 hours, scraping the casting solution on a dry, smooth and clean glass plate, putting the glass plate into an oven, and performing gradient temperature rise: evaporating the solvent for 5h at 50 ℃, heating to 80 ℃ for evaporating the solvent for 4h, heating to 130 ℃ for evaporating the solvent for 4h, taking out the solution from the oven, cooling, immersing the solution into deionized water, and automatically dropping the ion membrane from the glass plate to obtain the ion exchange membrane. The test shows that the thickness of the cationic membrane is 201um, the water absorption is 33 percent, and the ion exchange capacity is 0.92 mmol/g. Designing a desalination process, applying a miniature ED device manufactured by a laboratory for desalination, wherein the initial NaCl concentration of a diluent and a concentrated solution is 7500mg/L, and when the desalination rate reaches 90% compared with a certain commercial ionic membrane, the energy consumption of the prepared membrane and the energy consumption of the commercial membrane are 15.2 kW.h/m 3 respectively.

Example 3:

mixing 15g of polyether sulfone 3010, 12g of PVP K120 and 90g of dimethylacetamide, stirring for 4 hours at 50 ℃, adding 12g of octadecyl-p-xylene sodium sulfonate after complete dissolution at 70 ℃ to form a homogeneous solution, performing ultrasonic defoaming for 5 hours at 80 ℃ in an ultrasonic instrument, standing and defoaming for 24 hours, scraping the casting solution on a dry, smooth and clean glass plate, putting the glass plate into an oven, and performing gradient temperature rise: evaporating the solvent for 5h at 60 ℃, heating to 90 ℃ for 5h, heating to 120 ℃ for 3h, taking out from the oven, cooling, immersing in deionized water, and automatically dropping the ion membrane from the glass plate to obtain the ion exchange membrane. The test shows that the thickness of the cationic membrane is 163um, the water absorption is 30 percent, and the ion exchange capacity is 0.96 mmol/g. Designing a desalination process, and concentrating by using a miniature ED device manufactured by a laboratory, wherein the initial NaCl concentration of a diluent and a concentrated solution is 7500mg/L, and compared with a certain commercial ionic membrane, the desalination rate reaches 90%, and the energy consumption of the prepared membrane and the commercial membrane is 15.7 kW.h/m 3 respectively.

Example 4:

mixing 10g of polyethersulfone 6020, 10g of polyvinyl alcohol and 70g of dichloromethane, stirring for 10 hours at 40 ℃, adding 10g of p-methoxy fatty acid amide sodium benzenesulfonate after complete dissolution to form a homogeneous solution at 50 ℃, performing ultrasonic defoaming for 6 hours at 50 ℃ in an ultrasonic instrument, standing and defoaming for 24 hours, scraping the casting solution on a dry, smooth and clean glass plate, putting the glass plate into an oven, and performing gradient temperature rise: evaporating the solvent for 5h at 50 ℃, heating to 100 ℃ for 5h, heating to 120 ℃ for 3h, taking out from the oven, cooling, immersing in deionized water, and automatically dropping the ion membrane from the glass plate to obtain the ion exchange membrane. The test shows that the thickness of the cationic membrane is 191um, the water absorption is 39 percent, and the ion exchange capacity is 0.86 mmol/g. Designing a desalination process, and concentrating by using a miniature ED device manufactured by a laboratory, wherein the initial NaCl concentration of a diluent and a concentrated solution is 7500mg/L, and compared with a certain commercial ionic membrane, the desalination rate reaches 90%, and the energy consumption of the prepared membrane and the commercial membrane is 16.9 kW.h/m 3 respectively.

Example 5:

mixing 10g of polyethylene, 5g of polyether sulfone 2010, 5g of PVP K90 and 100g of tetrahydrofuran, stirring for 10 hours at 60 ℃, adding 15g of sodium dodecyl naphthalene sulfonate after complete dissolution at 50 ℃ to form a homogeneous solution, performing ultrasonic defoaming for 4 hours at 80 ℃ in an ultrasonic instrument, standing for 24 hours for defoaming, scraping the casting solution on a dry, smooth and clean glass plate, putting the glass plate into an oven, and performing gradient temperature rise: evaporating the solvent for 5h at 50 ℃, heating to 90 ℃ for 5h, heating to 110 ℃ for 3h, taking out from the oven, cooling, immersing in deionized water, and automatically dropping the ion membrane from the glass plate to obtain the ion exchange membrane. The test shows that the thickness of the cationic membrane is 193um, the water absorption is 35 percent, and the ion exchange capacity is 0.83 mmol/g. Designing a desalination process, and concentrating by using a miniature ED device self-made in a laboratory, wherein the initial NaCl concentration of a diluent and a concentrated solution is 7500mg/L, and compared with a certain commercial ionic membrane, the desalination rate reaches 90%, and the energy consumption of the prepared membrane and the commercial membrane is 15.3 kW.h/m 3 respectively. .

Example 6:

mixing 5g of polyethersulfone 6020, 8g of polyethylene, 10g of polyvinyl alcohol and 80g of trichloromethane, stirring for 10 hours at 40 ℃, adding 10g of sodium tridecylbenzenesulfonate after complete dissolution at 50 ℃ to form a homogeneous solution, performing ultrasonic defoaming for 4 hours at 70 ℃ in an ultrasonic instrument, standing for 24 hours for defoaming, scraping the casting solution on a dry, smooth and clean glass plate, putting the glass plate into an oven, and performing gradient temperature rise: evaporating the solvent for 5h at 60 ℃, heating to 90 ℃ for 5h, heating to 120 ℃ for 3h, taking out from the oven, cooling, immersing in deionized water, and automatically dropping the ion membrane from the glass plate to obtain the ion exchange membrane. The test shows that the thickness of the cationic membrane is 197um, the water absorption is 43 percent, and the ion exchange capacity is 0.76 mmol/g. Designing a desalination process, and concentrating by using a miniature ED device self-made in a laboratory, wherein the initial NaCl concentration of a diluent and a concentrated solution is 7500mg/L, and compared with a certain commercial ionic membrane, the desalination rate reaches 90%, and the energy consumption of the prepared membrane and the commercial membrane is 16.5 kW.h/m 3 respectively.

Example 7:

mixing 10g of polysulfone, 5g of polyethylene, 6g of acetone and 70g N-methyl pyrrolidone, stirring for 8 hours at 60 ℃, adding 10g of sodium polystyrene sulfonate after complete dissolution at 50 ℃ to form a homogeneous solution, performing ultrasonic defoaming for 4 hours at 70 ℃ in an ultrasonic instrument, standing for 24 hours for defoaming, scraping the casting solution on a dry, smooth and clean glass plate, putting the glass plate into an oven, and performing gradient temperature rise: evaporating the solvent for 5h at 40 ℃, heating to 90 ℃ for 5h, heating to 110 ℃ for 5h, taking out from the oven, cooling, immersing in deionized water, and automatically dropping the ion membrane from the glass plate to obtain the ion exchange membrane. The test shows that the thickness of the cationic membrane is 182um, the water absorption is 38 percent, and the ion exchange capacity is 0.85 mmol/g. Designing a desalination process, and concentrating by using a miniature ED device self-made in a laboratory, wherein the initial NaCl concentration of a diluent and a concentrated solution is 5000mg/L, and compared with a certain commercial ionic membrane, the desalination rate reaches 90%, and the energy consumption of the prepared membrane and the commercial membrane is 11.5 kW.h/m 3 respectively.

Example 8:

mixing 10g of polyether sulfone 3010, 5g of polyethylene, 6g of polyethylene glycol and 70g of trichloromethane, stirring for 8 hours at 60 ℃, adding 10g of sodium polystyrene sulfonate after complete dissolution at 50 ℃ to form a homogeneous solution, performing ultrasonic defoaming for 4 hours at 50 ℃ in an ultrasonic instrument, standing for defoaming for 24 hours, scraping the casting solution on a dry, smooth and clean glass plate, putting the glass plate into an oven, and performing gradient temperature rise: evaporating the solvent for 5h at 60 ℃, heating to 90 ℃ for 5h, heating to 110 ℃ for 5h, taking out from the oven, cooling, immersing in deionized water, and automatically dropping the ion membrane from the glass plate to obtain the ion exchange membrane. The test shows that the thickness of the cationic membrane is 172um, the water absorption is 36 percent, and the ion exchange capacity is 0.82 mmol/g. Designing a desalination process, and concentrating by using a miniature ED device self-made in a laboratory, wherein the initial NaCl concentration of a diluent and a concentrated solution is 5000mg/L, and compared with a certain commercial ionic membrane, the desalination rate reaches 90%, and the energy consumption of the prepared membrane and the commercial membrane is 11.7 kW.h/m 3 respectively.

Example 9:

mixing 10g of polysulfone, 10g of polyphenylene oxide, 6g of polyethylene glycol and 70g N-methyl pyrrolidone, stirring for 8 hours at 60 ℃, adding 6g of sodium polystyrene sulfonate after complete dissolution at 50 ℃ to form a homogeneous solution, performing ultrasonic defoaming for 4 hours at 70 ℃ in an ultrasonic instrument, standing and defoaming for 24 hours, scraping the casting solution on a dry, smooth and clean glass plate, putting the glass plate into an oven, and performing gradient temperature rise: evaporating the solvent for 5h at 40 ℃, heating to 90 ℃ for 5h, heating to 110 ℃ for 5h, taking out from the oven, cooling, immersing in deionized water, and automatically dropping the ion membrane from the glass plate to obtain the ion exchange membrane. The test shows that the thickness of the cationic membrane is 182um, the water absorption is 38 percent, and the ion exchange capacity is 0.75 mmol/g. Designing a desalination process, and concentrating by using a miniature ED device self-made in a laboratory, wherein the initial NaCl concentration of a diluent and a concentrated solution is 5000mg/L, and compared with a certain commercial ionic membrane, the desalination rate reaches 90%, and the energy consumption of the prepared membrane and the commercial membrane is 11.8 kW.h/m 3 respectively.

Example 10:

mixing 10g of polysulfone, 5g of polyethylene, 6g of acetone and 70g N-methyl pyrrolidone, stirring for 8 hours at 60 ℃, adding 9g of sodium polystyrene sulfonate after complete dissolution at 50 ℃ to form a homogeneous solution, performing ultrasonic defoaming for 4 hours at 70 ℃ in an ultrasonic instrument, standing for 24 hours, scraping the casting solution on a dry, smooth and clean glass plate, putting the glass plate into an oven, and performing gradient temperature rise: evaporating the solvent for 5h at 40 ℃, heating to 90 ℃ for 5h, heating to 110 ℃ for 5h, taking out from the oven, cooling, immersing in deionized water, and automatically dropping the ion membrane from the glass plate to obtain the ion exchange membrane. The test shows that the thickness of the cationic membrane is 182um, the water absorption is 38 percent, and the ion exchange capacity is 0.85 mmol/g. Designing a desalination process, and concentrating by using a miniature ED device self-made in a laboratory, wherein the initial NaCl concentration of a diluent and a concentrated solution is 5000mg/L, and compared with a certain commercial ionic membrane, the desalination rate reaches 90%, and the energy consumption of the prepared membrane and the commercial membrane is 11.5 kW.h/m 3 respectively.

Example 11:

mixing 12g of polyether sulfone 2010, 7g of polyethylene, 6g of polyethylene glycol and 90g N-methyl pyrrolidone, stirring for 9 hours at 60 ℃, adding 5g of octadecyl-p-xylene sodium sulfonate after complete dissolution to form a homogeneous solution at 50 ℃, ultrasonically defoaming for 4 hours at 70 ℃ in an ultrasonic instrument, standing and defoaming for 24 hours, scraping the casting solution on a dry, smooth and clean glass plate, putting the glass plate into an oven, and performing gradient temperature rise: evaporating the solvent for 5h at 40 ℃, heating to 90 ℃ for 5h, heating to 110 ℃ for 5h, taking out from the oven, cooling, immersing in deionized water, and automatically dropping the ion membrane from the glass plate to obtain the ion exchange membrane. The test shows that the thickness of the cationic membrane is 182um, the water absorption is 38 percent, and the ion exchange capacity is 0.85 mmol/g. Designing a desalination process, and concentrating by using a miniature ED device self-made in a laboratory, wherein the initial NaCl concentration of a diluent and a concentrated solution is 5000mg/L, and compared with a certain commercial ionic membrane, the desalination rate reaches 90%, and the energy consumption of the prepared membrane and the commercial membrane is 11.9 kW.h/m 3 respectively.

Example 12:

mixing 10g of polysulfone, 5g of polyethylene, 6g of polyethylene glycol and 70g N-methyl pyrrolidone, stirring for 8 hours at 60 ℃, adding 10g of sodium lignosulfonate after completely dissolving at 50 ℃ to fully dissolve to form a homogeneous solution, performing ultrasonic defoaming for 4 hours at 70 ℃ in an ultrasonic instrument, standing for 24 hours for defoaming, scraping the casting solution on a dry, smooth and clean glass plate, putting the glass plate into an oven, and performing gradient temperature rise: evaporating the solvent for 5h at 60 ℃, heating to 80 ℃ for 5h, heating to 110 ℃ for 4h, taking out from the oven, cooling, immersing in deionized water, and automatically dropping the ion membrane from the glass plate to obtain the ion exchange membrane. The test shows that the thickness of the cationic membrane is 211um, the water absorption is 35 percent, and the ion exchange capacity is 0.79 mmol/g. Designing a desalination process, and concentrating by using a miniature ED device self-made in a laboratory, wherein the initial NaCl concentration of a diluent and a concentrated solution is 5000mg/L, and compared with a certain commercial ionic membrane, the desalination rate reaches 90%, and the energy consumption of the prepared membrane and the commercial membrane is 12.5 kW.h/m 3 respectively.

Comparative example:

mixing 18g of polysulfone, 10g of ethylene glycol and 70g of dimethylacetamide, stirring for 10 hours at 40 ℃, ultrasonically defoaming for 2 hours in an ultrasonic instrument after complete dissolution, standing for defoaming for 24 hours, scraping the casting solution on a dry, smooth and clean glass plate, putting the glass plate into an oven, and carrying out gradient temperature rise: evaporating the solvent for 1h at 60 ℃, heating to 70 ℃ for evaporating the solvent for 1h, heating to 120 ℃ for evaporating the solvent for 6h, taking out the film from the oven, cooling, immersing the film into deionized water for 48h, and automatically dropping the ionic film from the glass plate to obtain the contrast film.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, 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.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

The present invention and its embodiments have been described above, and the description is not intended to be limiting, and the drawings are only one embodiment of the present invention, and the actual structure is not limited thereto. In summary, those skilled in the art should appreciate that they can readily use the disclosed conception and specific embodiments as a basis for designing or modifying other structures for carrying out the same purposes of the present invention without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. The preparation method of the homogeneous cation exchange membrane containing the alkylbenzene sulfonate is characterized by comprising the following steps: the method comprises the following steps:

the method comprises the following steps: preparation of casting solution

Dissolving at least one matrix material in a proper solvent, adding at least one solubilizer, mechanically stirring for a period of time at a certain temperature to obtain a uniform solution, adding at least one fatty anionic surfactant, and continuously stirring and dissolving to obtain a homogeneous phase;

step two: film formation by evaporation of solvent

step three: post-treatment

2. The process of claim 1 for the preparation of a homogeneous cation exchange membrane comprising alkylbenzene sulfonates characterised in that: in the first step, the casting solution comprises the following components in percentage by mass: 3% -40% of polymer matrix material; 2 to 30 percent of solvent; 1 to 25 percent of anionic surfactant; 50-75% of solvent, and the sum of the mass percentages of the components is 100%.

3. The process of claim 1 for the preparation of a homogeneous cation exchange membrane comprising alkylbenzene sulfonates characterised in that: in the first step, the selected polymer matrix material is at least one of polysulfone, polyethersulfone 2010, polyethersulfone 3010, polyethersulfone 6020, polyphenylene oxide and polyethylene.

4. The process of claim 1 for the preparation of a homogeneous cation exchange membrane comprising alkylbenzene sulfonates characterised in that: in the first step, the solvent used for preparing the casting solution is at least one of N-methylpyrrolidone, dimethylacetamide, tetrahydrofuran and trichloromethane.

5. The process of claim 1 for the preparation of a homogeneous cation exchange membrane comprising alkylbenzene sulfonates characterised in that: in the first step, the solubilizer is at least one of acetone, polyvinylpyrrolidone (PVP) K60, PVP K90, polyvinyl alcohol (PVA), polyethylene glycol and ethylene glycol.

6. The process of claim 1 for the preparation of a homogeneous cation exchange membrane comprising alkylbenzene sulfonates characterised in that: in the first step, the alkylbenzene sulfonate anionic surfactant is at least one of sodium dodecyl benzene sulfonate, sodium octadecyl-p-xylene sulfonate, sodium lignin sulfonate, sodium p-methoxy fatty amide benzene sulfonate, sodium dodecyl naphthalene sulfonate, nonylbenzene sulfonic acid, sodium tridecylbenzene sulfonate and sodium polystyrene sulfonate.

7. The process of claim 1 for the preparation of a homogeneous cation exchange membrane comprising alkylbenzene sulfonates characterised in that: the homogeneous cation exchange membrane is prepared according to the preparation method.

8. The application of homogeneous cation exchange membrane containing alkyl benzene sulfonate is characterized in that: is applied to the field of electrodialysis concentration.

9. Use of a homogeneous cation exchange membrane comprising alkylbenzene sulfonates according to claim 8, wherein: the initial salt solution concentration of the bitter salt water desalination process is 5000-10000 mg/L.