High-temperature-resistant reverse osmosis membrane and preparation process thereof

Abstract

The invention discloses a high-temperature-resistant reverse osmosis membrane and a preparation process thereof, and relates to the technical field of membrane separation, and the high-temperature-resistant reverse osmosis membrane comprises a non-woven fabric layer, a support body layer and a functional membrane layer, the non-woven fabric layer is a plasma pretreatment non-woven fabric; the support body layer is obtained by curing a support body membrane casting solution on a plasma pretreatment non-woven fabric; the functional film layer is a polyamide layer doped with functional filler; the support casting solution is prepared from the following raw materials in percentage by mass: 12 to 21 percent of sulfonated polyaryletherketone sulfone copolymer, 3 to 7 percent of fluorinated titanium dioxide / metal organic framework modified graphite phase carbon nitride, 70 to 84 percent of N, N-dimethylformamide and 1 to 2 percent of pore-foaming agent. The reverse osmosis membrane provided by the invention has excellent high temperature resistance and hydrophilicity.

Description

Technical Field

[0001] The present application relates to the field of membrane separation technology, and in particular to a high-temperature resistant reverse osmosis membrane and a preparation process thereof. Background Art

[0002] With the rapid development of China's chemical industry and the continued advancement of urbanization, already scarce urban water resources are facing even more severe pollution challenges. Chemical wastewater, in particular, is complex in composition and high in pollutant concentrations, making it extremely difficult to treat and recycle. If discharged indiscriminately, chemical wastewater will cause irreversible pollution to lakes, rivers, and soil, posing a serious threat to the ecological environment and human health. To address water shortages and pollution, researchers have developed a variety of advanced water treatment technologies. Among these, reverse osmosis membrane separation technology stands out due to its significant advantages, including a small footprint, ease of operation, low energy consumption, and low cost. It is widely used in seawater desalination, drinking water production, and industrial wastewater treatment. Reverse osmosis is a membrane separation technology driven by pressure differentials. Its core principle is to use a semipermeable membrane to separate water molecules from salt and other soluble impurities by applying a pressure greater than the osmotic pressure of the salt solution.

[0003] Currently widely used composite reverse osmosis membranes typically operate only at temperatures below 50°C, significantly limiting their widespread industrial application. For example, in the textile printing and dyeing process, process requirements often require high wastewater outlet temperatures. In these situations, traditional reverse osmosis membranes require the wastewater to be cooled before subsequent filtration. This not only increases equipment investment and operating costs, but also reduces overall treatment efficiency. Using high-temperature resistant reverse osmosis membranes allows for direct filtration and separation of printing and dyeing wastewater at high temperatures, eliminating the need for additional cooling. This not only reduces equipment investment and energy consumption, but also increases the solubility of solutes in the wastewater at high temperatures. High-temperature filtration also accelerates the movement of water molecules, effectively improving membrane permeability and reducing the adhesion of pollutants to the membrane surface, minimizing membrane fouling and clogging, and extending membrane life. Therefore, the development and application of high-temperature resistant reverse osmosis membranes are of great significance for the treatment of chemical wastewater. Summary of the Invention

[0004] In order to provide a high-temperature resistant reverse osmosis membrane, the present application provides a high-temperature resistant reverse osmosis membrane and a preparation process thereof.

[0005] The present application provides a high-temperature resistant reverse osmosis membrane, which adopts the following technical solution:

[0006] A high-temperature resistant reverse osmosis membrane comprises a non-woven fabric layer, a support layer, and a functional membrane layer; the non-woven fabric layer is a plasma-pretreated non-woven fabric; the support layer is obtained by curing a support casting solution on the plasma-pretreated non-woven fabric; and the functional membrane layer is a polyamide layer doped with functional fillers.

[0007] The raw materials of the support casting solution include, by mass percentage, 12-21% of sulfonated polyaryletherketonesulfone copolymer, 3-7% of fluorinated titanium dioxide / metal organic framework modified graphite phase carbon nitride, 70-84% of N,N-dimethylformamide, and 1-2% of porogen.

[0008] Preferably, the raw materials of the polyamide layer doped with functional fillers include component A and component B; the raw materials of component A include 5-10% fatty amine, 0.01-0.03% fluorinated titanium dioxide / metal organic framework modified graphite phase carbon nitride, 0.04-0.06% 3-amino-1,2-propylene glycol, and the balance is water; the raw materials of component B include 5-10% fatty acid chloride, and the balance is an organic solvent.

[0009] Preferably, the sulfonated polyaryletherketonesulfone copolymer is prepared from the following raw materials in parts by weight: 6.4-9.6 parts of bisphenol A, 6-9 parts of 4,4'-difluorobenzophenone, 6-9 parts of 3,3'-disulfonated-4,4'-dichlorodiphenyl sulfone, 2.8-4.2 parts of 4-carboxyphenylhydroquinone, 16.6-24.9 parts of anhydrous potassium carbonate, 26-39 parts of toluene, and 54.6-81.9 parts of sulfolane.

[0010] Preferably, the preparation method of the sulfonated polyaryletherketonesulfone copolymer comprises the following steps:

[0011] 6.4-9.6 parts of bisphenol A are dried, mixed with 6-9 parts of 4,4'-difluorobenzophenone, 6-9 parts of 3,3'-disulfonated-4,4'-dichlorodiphenyl sulfone, 2.8-4.2 parts of 4-carboxyphenyl hydroquinone, and 16.6-24.9 parts of anhydrous potassium carbonate, and stirred uniformly. Subsequently, 26-39 parts of toluene and 54.6-81.9 parts of sulfolane are added, and the mixture is heated to 40-50°C and stirred uniformly. The mixture is then heated to 125-145°C, refluxed for 4-6 hours, and then toluene is removed by distillation at 125-145°C. The mixture is then heated to 185-195°C and stirred for 24-30 hours. After the reaction, the mixture is removed from water, washed under boiling conditions until the water is clear, and then dried to obtain a sulfonated polyaryletherketonesulfone copolymer.

[0012] Preferably, the fluorinated titanium dioxide / metal organic framework modified graphite phase carbon nitride is prepared from the following raw materials in parts by weight: 0.03-0.06 parts of fluorinated titanium dioxide / metal organic framework composite material, 48-96 parts of ethanol, and 0.5-1 part of graphite phase carbon nitride.

[0013] Preferably, the fluorinated titanium dioxide / metal organic framework composite material is prepared from the following raw materials in parts by weight: 0.2-0.3 parts of fluorinated titanium dioxide, 60-90 parts of water, 1-1.5 parts of trimesic acid, and 0.25-0.3 parts of tetrabutyl titanate;

[0014] The preparation method of the fluorinated titanium dioxide / metal organic framework composite material comprises the following steps:

[0015] 0.2-0.3 parts of fluorinated titanium dioxide are added to 40-60 parts of water, stirred evenly, and then 0.25-0.3 parts of tetrabutyl titanate are added; the mixture is stirred in an oil bath at 70-80°C for 3-4 hours; the precipitate is separated by centrifugation and rinsed to eliminate pollutants to obtain a clean precipitate, 0.25-0.3 parts of trimesic acid are mixed with the washed precipitate, 20-30 water are added, and ultrasonic treatment is performed for 15-25 minutes. The mixture is transferred to a hydrothermal reactor and heated in an oven at 150-180°C for 8-10 hours; after the reaction is completed, the mixture is cooled to room temperature, the precipitate is separated by centrifugation, and the precipitate is washed. Then, the precipitate is dried at 80-90°C to obtain a fluorinated titanium dioxide / metal organic framework composite material.

[0016] Preferably, the preparation method of the fluorinated titanium dioxide comprises the following steps:

[0017] By weight, 40-60 parts of water are added to 2.4-3.6 parts of titanium sulfate and stirred until completely dissolved, and then 20.4-30.7 parts of hydrofluoric acid are added under stirring, and stirred for 5-10 minutes after all are added; then the pH value of the system is adjusted to 8-9, and stirring is continued for 15-20 minutes, and then it is allowed to stand and age for 20-25 minutes; then it is washed by water centrifugation multiple times, and the treated sample is dried at 75-85°C; the dried material is ground into a powder form, loaded into a crucible, and heat-treated in a muffle furnace at 520-580°C for 2-4 hours. After the heat treatment is completed, it is naturally cooled to ambient temperature to obtain fluorinated titanium dioxide.

[0018] Preferably, the preparation method of the fluorinated titanium dioxide / metal organic framework modified graphite phase carbon nitride comprises the following steps:

[0019] 0.03-0.06 parts of fluorinated titanium dioxide / metal organic framework composite material are added to 8-16 parts of ethanol and ultrasonically dispersed uniformly, and then 0.5-1 parts of graphite phase carbon nitride are added to 40-80 parts of ethanol and ultrasonically dispersed uniformly; then, the fluorinated titanium dioxide / metal organic framework composite material dispersion is dropwise added to the graphite phase carbon nitride dispersion, ultrasonically dispersed for 60-80 minutes, stirred at 60-65°C for 5-7 hours, and then the temperature is increased to evaporate the remaining ethanol to obtain fluorinated titanium dioxide / metal organic framework modified graphite phase carbon nitride.

[0020] The present application provides a process for preparing a high-temperature resistant reverse osmosis membrane, which adopts the following technical solution:

[0021] A process for preparing a high-temperature resistant reverse osmosis membrane comprises the following steps:

[0022] S1. The nonwoven fabric was soaked in an isopropanol solution for 0.5-1h, and the isopropanol on the surface of the membrane was rinsed with water and placed in an oven for drying; the dried nonwoven fabric was placed flat on the workbench for plasma treatment to obtain a plasma pretreated nonwoven fabric;

[0023] S2. After mixing 12-21% sulfonated poly(aryletherketonesulfone) copolymer, 3-7% fluorinated titanium dioxide / metal organic framework modified graphite carbon nitride, 70-84% N,N-dimethylformamide, and 1-2% porogen by mass percentage, stirring evenly, standing for 1-3h, and then ultrasonically degassing for 10-30min to obtain a support casting solution;

[0024] S3. The support film obtained by S2 is applied to the plasma pretreated nonwoven fabric obtained by S1 to a thickness of 50-150μm; then evaporated at room temperature for 10-30s and immersed in 15-25 ℃ water to form a gel film, and then dried in an oven at 50-70 ℃ for 5-8 hours to obtain a support layer;

[0025] S4. After uniformly mixing 5-10% fatty amine, 0.01-0.03% fluorinated titanium dioxide / metal organic framework modified graphite carbon nitride, 0.04-0.06% 3-amino-1,2-propanediol, and the balance water, component A is obtained; after uniformly mixing 5-10% fatty acid chloride and the balance organic solvent, component B is obtained;

[0026] S5. The surface of the support layer prepared in S3 is first immersed in component A for 30-60 seconds, and then allowed to stand at room temperature for 5-30 seconds; then immersed in component B for 10-30 seconds, and then allowed to stand at room temperature for reaction for 8-12 minutes, and then placed in a drying oven and dried at 40-60°C for 2-6 hours to obtain a functional membrane layer, thereby obtaining a high-temperature resistant reverse osmosis membrane.

[0027] Preferably, the plasma treatment conditions are as follows: the radio frequency power applied is 40-50 W, the discharge gas is air, and the treatment time is 20-30 min.

[0028] In summary, this application includes at least one of the following beneficial technical effects:

[0029] 1. This application utilizes air plasma to treat the surface of a non-woven fabric to generate carboxyl groups on its surface, thereby effectively improving the hydrophilicity of the non-woven fabric and effectively improving the adhesion between the non-woven fabric and the support casting liquid, thereby improving the performance and durability of the reverse osmosis membrane.

[0030] 2. In the present application, bisphenol A, 4,4'-difluorobenzophenone, 3,3'-disulfonated-4,4'-dichlorodiphenyl sulfone, and 4-carboxyphenyl hydroquinone are used as raw materials to undergo a polycondensation reaction under the catalysis of anhydrous potassium carbonate to synthesize a sulfonated polyaryletherketonesulfone copolymer, which also contains carboxyl groups on its surface. The introduction of carboxyl and sulfonic acid groups not only effectively enhances the thermal stability and mechanical properties of the polymer material, but also effectively increases the hydrophilicity of the polymer material, thereby significantly enhancing the water flux of the reverse osmosis membrane.

[0031] 3. This application uses a simple precipitation method to prepare fluorinated titanium dioxide, and further uses a hydrothermal reaction to synthesize a fluorinated titanium dioxide / metal organic framework MIL-125 (Ti) composite material; then, a simple water bath stirring method is used to electrostatically self-assemble the graphite phase carbon nitride and the fluorinated titanium dioxide / metal organic framework MIL-125 (Ti) composite material through π-π conjugation to obtain fluorinated titanium dioxide / metal organic framework modified graphite phase titanium nitride, which has excellent thermal stability and anti-fouling properties. It is doped into the support casting liquid and the polyamide layer, which significantly enhances the high temperature resistance, chemical stability and hydrophilic properties of the reverse osmosis membrane. The obtained reverse osmosis membrane also has excellent anti-fouling and pollution resistance, effectively improving the durability of the reverse osmosis membrane. DETAILED DESCRIPTION

[0032] The present application is further described in detail below with reference to the embodiments.

[0033] The chemical reagents used in the preparation examples, embodiments and comparative examples provided by the present invention are all commercially available products, and their brands and manufacturers are as follows:

[0034] 3-Amino-1,2-propanediol, Weifang Qianjin Fine Chemical Co., Ltd.;

[0035] Bisphenol A, Panhua Chemical (Shanghai) Co., Ltd.;

[0036] Graphitic carbon nitride, Henan Lavoisier Chemical Products Co., Ltd.;

[0037] Polyvinyl alcohol, Shanghai Aladdin Biochemical Technology Co., Ltd., P139549.

[0038] Preparation Example 1 Preparation of sulfonated polyaryletherketonesulfone copolymer

[0039] Preparation Example 1.1

[0040] 6.4 g of bisphenol A was dried and mixed with 6 g of 4,4'-difluorobenzophenone, 6 g of 3,3'-disulfonated-4,4'-dichlorodiphenyl sulfone, 2.8 g of 4-carboxyphenyl hydroquinone, and 16.6 g of anhydrous potassium carbonate, and stirred uniformly. Subsequently, 26 g of toluene and 54.6 g of sulfolane were added, and the mixture was heated to 40° C. and stirred uniformly. The mixture was then heated to 125° C. and refluxed for 4 hours. Toluene was then removed by distillation at 125° C. The mixture was then heated to 185° C. and stirred for 24 hours. After the reaction, the mixture was taken out of deionized water, washed under boiling conditions until the water was clear, and then dried to obtain a sulfonated polyaryletherketonesulfone copolymer.

[0041] Preparation Example 1.2

[0042] 8 g of bisphenol A was dried and mixed with 7.5 g of 4,4'-difluorobenzophenone, 7.5 g of 3,3'-disulfonated-4,4'-dichlorodiphenyl sulfone, 3.5 g of 4-carboxyphenyl hydroquinone, and 20.8 g of anhydrous potassium carbonate, and stirred uniformly. Subsequently, 32.5 g of toluene and 68 g of sulfolane were added, and the mixture was heated to 45° C. and stirred uniformly. The mixture was then heated to 135° C. and refluxed for 5 hours. Toluene was then removed by distillation at 135° C. The mixture was then heated to 190° C. and stirred for 27 hours. After the reaction, the mixture was taken out of deionized water, washed under boiling conditions until the water was clear, and then dried to obtain a sulfonated polyaryletherketonesulfone copolymer.

[0043] Preparation Example 1.3

[0044] 9.6 g of bisphenol A was dried and mixed with 9 g of 4,4'-difluorobenzophenone, 9 g of 3,3'-disulfonated-4,4'-dichlorodiphenyl sulfone, 4.2 g of 4-carboxyphenyl hydroquinone, and 24.9 g of anhydrous potassium carbonate, and stirred uniformly. Subsequently, 39 g of toluene and 81.9 g of sulfolane were added, and the mixture was heated to 50° C. and stirred uniformly. The mixture was then heated to 145° C. and refluxed for 6 hours. Toluene was then removed by distillation at 145° C. The mixture was then heated to 195° C. and stirred for 30 hours. After the reaction, the mixture was taken out of deionized water, washed under boiling conditions until the water was clear, and then dried to obtain a sulfonated polyaryletherketonesulfone copolymer.

[0045] Preparation Example 2 Preparation of Fluorinated Titanium Dioxide / Metal Organic Framework Modified Graphite Phase Carbon Nitride Preparation Example 2.1

[0046] S1. To 2.4 g of titanium sulfate, 40 g of deionized water was added and stirred until completely dissolved, followed by the addition of 20.4 g of hydrofluoric acid with stirring, and the mixture was stirred for 5 min after all the addition was completed; the pH value of the system was then adjusted to 8, and stirring was continued for 15 min, followed by aging for 20 min; the treated sample was then washed by centrifugation with deionized water several times, and dried at 75 ° C; the dried material was ground into a powder form, placed in a crucible, and heat-treated in a muffle furnace at 520 ° C for 2 h. After the heat treatment, it was naturally cooled to ambient temperature to obtain fluorinated titanium dioxide;

[0047] S2. 0.2 g of the fluorinated titanium dioxide prepared in S1 was added to 40 g of deionized water, stirred evenly, and then 0.25 g of tetrabutyl titanate was added; the mixture was stirred in a 70°C oil bath for 3 h; the precipitate was separated by centrifugation and rinsed with deionized water to remove contaminants to obtain a clean precipitate, 0.25 g of trimesic acid was mixed with the clean precipitate, 20 g of deionized water was added, and after ultrasonic treatment for 15 min, the mixture was transferred to a hydrothermal reactor and heated in an oven at 150°C for 8 h; after the reaction was completed, the mixture was cooled to room temperature, the precipitate was separated by centrifugation, and the precipitate was washed and then dried at 80°C to obtain a fluorinated titanium dioxide / metal organic framework composite material;

[0048] S3. Add 0.03 g of the fluorinated titanium dioxide / metal organic framework composite material prepared by S2 to 8 g of ethanol and ultrasonically disperse it evenly, then add 0.5 g of graphite phase carbon nitride to 40 g of ethanol and ultrasonically disperse it evenly; then add the fluorinated titanium dioxide / metal organic framework composite material dispersion dropwise to the graphite phase carbon nitride dispersion, ultrasonically disperse it for 60 minutes, stir it at 60°C for 5 hours, and then raise the temperature to 80°C to evaporate the remaining ethanol to obtain fluorinated titanium dioxide / metal organic framework modified graphite phase carbon nitride.

[0049] Preparation Example 2.2

[0050] S1. To 3 g of titanium sulfate, 50 g of deionized water was added and stirred until completely dissolved, followed by the addition of 25.7 g of hydrofluoric acid with stirring, and the mixture was stirred for 7.5 min after all the addition; the pH value of the system was then adjusted to 8.5, and stirring was continued for 17.5 min, followed by aging for 22.5 min; the treated sample was then washed by centrifugation with deionized water several times, and dried at 80 ° C; the dried material was ground into a powder form, placed in a crucible, and heat-treated in a muffle furnace at 550 ° C for 3 h. After the heat treatment, it was naturally cooled to ambient temperature to obtain fluorinated titanium dioxide;

[0051] S2. 0.25 g of the fluorinated titanium dioxide prepared in S1 was added to 50 g of deionized water, stirred evenly, and then 0.275 g of tetrabutyl titanate was added; the mixture was stirred in a 75°C oil bath for 3.5 h; the precipitate was separated by centrifugation and rinsed with deionized water to remove contaminants to obtain a clean precipitate, 0.275 g of trimesic acid was mixed with the clean precipitate, 25 g of deionized water was added, and after ultrasonic treatment for 20 min, the mixture was transferred to a hydrothermal reactor and heated in an oven at 175°C for 9 h; after the reaction was completed, the mixture was cooled to room temperature, the precipitate was separated by centrifugation, and the precipitate was washed and then dried at 85°C to obtain a fluorinated titanium dioxide / metal organic framework composite material;

[0052] S3. Add 0.045 g of the fluorinated titanium dioxide / metal organic framework composite material prepared by S2 into 12 g of ethanol and ultrasonically disperse it evenly, then add 0.75 g of graphite phase carbon nitride into 60 g of ethanol and ultrasonically disperse it evenly; then add the fluorinated titanium dioxide / metal organic framework composite material dispersion dropwise into the graphite phase carbon nitride dispersion, ultrasonically disperse it for 70 minutes, stir it at 62.5°C for 6 hours, and then raise the temperature to 80°C to evaporate the remaining ethanol to obtain fluorinated titanium dioxide / metal organic framework modified graphite phase carbon nitride.

[0053] Preparation Example 2.3

[0054] S1. To 3.6 g of titanium sulfate, 60 g of deionized water was added and stirred until completely dissolved, followed by the addition of 30.7 g of hydrofluoric acid with stirring, and the mixture was stirred for 10 min after all the addition; the pH value of the system was then adjusted to 9, and stirring was continued for 20 min, followed by aging for 25 min; the treated sample was then washed by centrifugation with deionized water several times, and dried at 85 ° C; the dried material was ground into a powder form, placed in a crucible, and heat-treated in a muffle furnace at 580 ° C for 4 h. After the heat treatment, it was naturally cooled to ambient temperature to obtain fluorinated titanium dioxide;

[0055] S2. 0.3 g of the fluorinated titanium dioxide prepared in S1 was added to 60 g of deionized water, stirred evenly, and then 0.25 g of tetrabutyl titanate was added; the mixture was stirred in a 70°C oil bath for 3 h; the precipitate was separated by centrifugation and rinsed with deionized water to remove contaminants to obtain a clean precipitate, 0.3 g of trimesic acid was mixed with the clean precipitate, 30 g of deionized water was added, and after ultrasonic treatment for 25 min, the mixture was transferred to a hydrothermal reactor and heated in an oven at 180°C for 10 h; after the reaction was completed, the mixture was cooled to room temperature, the precipitate was separated by centrifugation, and the precipitate was washed and then dried at 90°C to obtain a fluorinated titanium dioxide / metal-organic framework composite material;

[0056] S3. Add 0.06 g of the fluorinated titanium dioxide / metal organic framework composite material prepared by S2 to 16 g of ethanol and ultrasonically disperse it evenly, then add 1 g of graphite phase carbon nitride to 80 g of ethanol and ultrasonically disperse it evenly; then add the fluorinated titanium dioxide / metal organic framework composite material dispersion dropwise to the graphite phase carbon nitride dispersion, ultrasonically disperse it for 80 minutes, stir it at 65°C for 7 hours, and then raise the temperature to 80°C to evaporate the remaining ethanol to obtain fluorinated titanium dioxide / metal organic framework modified graphite phase carbon nitride.

[0057] Example 1

[0058] S1. Soak a polyester nonwoven fabric in a 25% by mass isopropyl alcohol solution for 0.5 h. Rinse the isopropyl alcohol off the surface of the fabric with deionized water and dry it in an oven. The dried nonwoven fabric was then placed flat on a workbench and plasma treated with air as the discharge gas, applying 40 W of RF power, for 20 min. This yielded a plasma-pretreated nonwoven fabric.

[0059] S2. 12% by mass of the sulfonated poly(aryletherketonesulfone) copolymer prepared in Preparation Example 1.1, 3% by mass of the fluorinated titanium dioxide / metal-organic framework-modified graphite carbon nitride prepared in Preparation Example 2.1, 84% by mass of N,N-dimethylformamide, and 1% by mass of the porogen polyvinyl alcohol were mixed and stirred uniformly. The mixture was allowed to stand for 1 hour and then ultrasonically degassed for 10 minutes to obtain a support casting solution.

[0060] S3. The support casting solution prepared in S2 was applied to the plasma pretreated nonwoven fabric obtained in S1 to a thickness of 50 μm; then evaporated at room temperature for 10 seconds and immersed in 15 ° C deionized water to form a gel-cured film, which was then dried in an oven at 50 ° C for 5 hours to obtain a support layer;

[0061] S4. 5% butanediamine, 0.01% fluorinated titanium dioxide / metal organic framework-modified graphite carbon nitride prepared in Preparation Example 2.1, 0.04% 3-amino-1,2-propylene glycol, and 94.95% deionized water were mixed uniformly by mass to obtain component A; 5% succinyl chloride and 95% N,N-dimethylformamide were mixed uniformly by mass to obtain component B;

[0062] S5. The surface of the support layer prepared in S3 is first immersed in component A for 30 seconds, and then allowed to stand at room temperature for 5 seconds; then immersed in component B for 10 seconds, and then allowed to stand at room temperature for reaction for 8 minutes, and then placed in a drying oven and dried at 40°C for 6 hours to obtain a functional membrane layer, thereby obtaining a high-temperature resistant reverse osmosis membrane.

[0063] Example 2

[0064] S1. Soak a polyester nonwoven fabric in a 25% by mass isopropyl alcohol solution for 0.75 h. Rinse the isopropyl alcohol off the surface of the fabric with deionized water and dry it in an oven. The dried nonwoven fabric was then placed flat on a workbench and plasma treated with air as the discharge gas, applying 45 W of RF power, for 25 min. This yielded a plasma-pretreated nonwoven fabric.

[0065] S2. 16% by mass of the sulfonated poly(aryletherketonesulfone) copolymer prepared in Preparation Example 1.2, 5% by mass of the fluorinated titanium dioxide / metal-organic framework-modified graphite carbon nitride prepared in Preparation Example 2.2, 77.5% by mass of N,N-dimethylformamide, and 1.5% by mass of the porogen polyvinyl alcohol were mixed and stirred uniformly. The mixture was allowed to stand for 2 h and then ultrasonically degassed for 20 min to obtain a support casting solution.

[0066] S3. The support film casting solution prepared in S2 was applied to the plasma pretreated nonwoven fabric obtained in S1 to a thickness of 100 μm; the film was then evaporated at room temperature for 20 seconds and then immersed in 20 ° C deionized water to form a gel film, which was then dried in an oven at 60 ° C for 6.5 hours to obtain a support layer;

[0067] S4. 7.5% butanediamine, 0.02% fluorinated titanium dioxide / metal organic framework modified graphite carbon nitride prepared in Preparation Example 2.2, 0.05% 3-amino-1,2-propylene glycol, and 91.8% deionized water were mixed uniformly to obtain component A; 7.5% succinyl chloride and 92.5% N,N-dimethylformamide were mixed uniformly to obtain component B;

[0068] S5. The surface of the support layer prepared in S3 is first immersed in component A for 45 seconds, and then allowed to stand at room temperature for 20 seconds; then immersed in component B for 20 seconds, and then allowed to stand at room temperature for reaction for 10 minutes, and then placed in a drying oven and dried at 50°C for 4 hours to obtain a functional membrane layer, thereby obtaining a high-temperature resistant reverse osmosis membrane.

[0069] Example 3

[0070] S1. Soak a polyester nonwoven fabric in a 25% by mass isopropyl alcohol solution for 1 hour. Rinse the isopropyl alcohol off the surface of the fabric with deionized water and dry it in an oven. The dried nonwoven fabric was then placed flat on a workbench and plasma treated with air as the discharge gas, applying 50 W of RF power, for 30 minutes. This yielded a plasma-pretreated nonwoven fabric.

[0071] S2. 21% of the sulfonated poly(aryl ether ketone sulfone) copolymer prepared in Preparation Example 1.3, 7% of the fluorinated titanium dioxide / metal organic framework-modified graphite carbon nitride prepared in Preparation Example 2.3, 70% of N,N-dimethylformamide, and 2% of the porogen polyvinyl alcohol were mixed by mass percentage, stirred evenly, allowed to stand for 3 h, and then ultrasonically degassed for 30 min to obtain a support casting solution;

[0072] S3. The support casting solution prepared in S2 was applied to the plasma pretreated nonwoven fabric obtained in S1 to a thickness of 150 μm; the solution was then evaporated at room temperature for 30 seconds and then immersed in 25 ° C deionized water to form a gel-cured film, which was then dried in an oven at 70 ° C for 8 hours to obtain a support layer;

[0073] S4. 10% butanediamine, 0.03% fluorinated titanium dioxide / metal organic framework-modified graphite carbon nitride prepared in Preparation Example 2.3, 0.06% 3-amino-1,2-propylene glycol, and 89.91% deionized water were mixed uniformly to obtain component A; 10% succinyl chloride and 90% N,N-dimethylformamide were mixed uniformly to obtain component B;

[0074] S5. The surface of the support layer prepared in S3 is first immersed in component A for 60 seconds, and then allowed to stand at room temperature for 30 seconds; then immersed in component B for 30 seconds, and then allowed to stand at room temperature for reaction for 12 minutes, and then placed in a drying oven and dried at 60°C for 2 hours to obtain a functional membrane layer, thereby obtaining a high-temperature resistant reverse osmosis membrane.

[0075] Comparative Example 1

[0076] The difference between Comparative Example 1 and Example 1 is that in Comparative Example 1, the polyester non-woven fabric is not subjected to plasma treatment.

[0077] Comparative Example 2

[0078] The difference between Comparative Example 2 and Example 1 is that in Comparative Example 2, an equal amount of trifluoromethane polyarylether is used to replace the sulfonated polyaryletherketonesulfone copolymer prepared in Preparation Example 1.1.

[0079] Comparative Example 3

[0080] The difference between Comparative Example 3 and Example 1 is that in Comparative Example 3, no fluorinated titanium dioxide / metal organic framework modified graphite phase carbon nitride is added to S2.

[0081] Comparative Example 4

[0082] The difference between Comparative Example 4 and Example 1 is that in Comparative Example 4, no fluorinated titanium dioxide / metal organic framework modified graphite phase carbon nitride is added to S2.

[0083] Performance testing

[0084] 1. The high-temperature resistant reverse osmosis membranes obtained in Examples 1-3 and Comparative Examples 1-4 were continuously operated for 72 hours in a 2000 ppm sodium chloride solution at operating temperatures of 25, 50, and 85°C, respectively, and an operating pressure of 1.55 MPa. The desalination and water permeation performances were tested. The results are shown in Table 1.

[0085] The specific test results are as follows:

[0086] Table 1 Performance test results

[0087]

[0088] It can be seen from the detection method in Table 1 that after the high-temperature resistant reverse osmosis membrane provided by the present application has been continuously operated at 25, 50, and 85°C for 72 hours, the reverse osmosis composite membrane in the embodiment has an increased water flux as the test temperature increases, and the desalination rate changes little, and has always maintained a very high desalination rate, while the desalination rate of the reverse osmosis composite membrane in the comparative example decreases significantly as the treatment temperature increases. Therefore, the high-temperature resistant reverse osmosis composite membrane provided by the present application always maintains a relatively high desalination rate and water flux, and the reverse osmosis composite membrane does not deform, break or peel off during high-temperature operation, and can effectively improve its excellent heat resistance and mechanical properties.

[0089] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A high temperature resistant reverse osmosis membrane, characterized in that: It includes a non-woven fabric layer, a support layer, and a functional film layer; the non-woven fabric layer is a plasma pretreated non-woven fabric; The support layer is obtained by solidifying a support casting liquid on a plasma pre-treated non-woven fabric; the functional membrane layer is a polyamide layer doped with functional fillers; The raw materials of the support casting solution include, by mass percentage, 12-21% of sulfonated polyaryletherketonesulfone copolymer, 3-7% of fluorinated titanium dioxide / metal organic framework modified graphite phase carbon nitride, 70-84% of N,N-dimethylformamide, and 1-2% of porogen.

2. A high temperature resistant reverse osmosis membrane according to claim 1, characterized in that: The raw materials of the polyamide layer doped with functional fillers include component A and component B; the raw materials of component A include 5-10% fatty amine, 0.01-0.03% fluorinated titanium dioxide / metal organic framework modified graphite phase carbon nitride, 0.04-0.06% 3-amino-1,2-propylene glycol, and the balance is water; the raw materials of component B include 5-10% fatty acid chloride, and the balance is an organic solvent.

3. The high temperature resistant reverse osmosis membrane according to claim 1, characterized in that: The sulfonated polyaryletherketonesulfone copolymer is prepared from the following raw materials in parts by weight: 6.4-9.6 parts of bisphenol A, 6-9 parts of 4,4'-difluorobenzophenone, 6-9 parts of 3,3'-disulfonated-4,4'-dichlorodiphenyl sulfone, 2.8-4.2 parts of 4-carboxyphenylhydroquinone, 16.6-24.9 parts of anhydrous potassium carbonate, 26-39 parts of toluene, and 54.6-81.9 parts of sulfolane.

4. A high temperature resistant reverse osmosis membrane according to claim 3, characterized in that: The preparation method of the sulfonated polyaryletherketonesulfone copolymer comprises the following steps: 6.4-9.6 parts of bisphenol A are dried, mixed with 6-9 parts of 4,4'-difluorobenzophenone, 6-9 parts of 3,3'-disulfonated-4,4'-dichlorodiphenyl sulfone, 2.8-4.2 parts of 4-carboxyphenyl hydroquinone, and 16.6-24.9 parts of anhydrous potassium carbonate, and stirred uniformly. Subsequently, 26-39 parts of toluene and 54.6-81.9 parts of sulfolane are added, and the mixture is heated to 40-50°C and stirred uniformly. The mixture is then heated to 125-145°C, refluxed for 4-6 hours, and then toluene is removed by distillation at 125-145°C. The mixture is then heated to 185-195°C and stirred for 24-30 hours. After the reaction, the mixture is removed from water, washed under boiling conditions until the water is clear, and then dried to obtain a sulfonated polyaryletherketonesulfone copolymer.

5. A high temperature resistant reverse osmosis membrane according to claim 1 or 2, characterized in that: The fluorinated titanium dioxide / metal organic framework modified graphite phase carbon nitride is prepared from the following raw materials in parts by weight: 0.03-0.06 parts of fluorinated titanium dioxide / metal organic framework composite material, 48-96 parts of ethanol, and 0.5-1 part of graphite phase carbon nitride.

6. A high temperature resistant reverse osmosis membrane according to claim 5, characterized in that: The fluorinated titanium dioxide / metal organic framework composite material is prepared from the following raw materials in parts by weight: 0.2-0.3 parts of fluorinated titanium dioxide, 60-90 parts of water, 1-1.5 parts of trimesic acid, and 0.25-0.3 parts of tetrabutyl titanate; The preparation method of the fluorinated titanium dioxide / metal organic framework composite material comprises the following steps: 0.2-0.3 parts of fluorinated titanium dioxide are added to 40-60 parts of water, stirred evenly, and then 0.25-0.3 parts of tetrabutyl titanate are added; the mixture is stirred in an oil bath at 70-80°C for 3-4 hours; the precipitate is separated by centrifugation and rinsed to eliminate pollutants to obtain a clean precipitate, 0.25-0.3 parts of trimesic acid are mixed with the washed precipitate, 20-30 water are added, and ultrasonic treatment is performed for 15-25 minutes. The mixture is transferred to a hydrothermal reactor and heated in an oven at 150-180°C for 8-10 hours; after the reaction is completed, the mixture is cooled to room temperature, the precipitate is separated by centrifugation, and the precipitate is washed. Then, the precipitate is dried at 80-90°C to obtain a fluorinated titanium dioxide / metal organic framework composite material.

7. A high temperature resistant reverse osmosis membrane according to claim 6, characterized in that: The preparation method of the fluorinated titanium dioxide comprises the following steps: By weight, 40-60 parts of water are added to 2.4-3.6 parts of titanium sulfate and stirred until completely dissolved, and then 20.4-30.7 parts of hydrofluoric acid are added under stirring, and stirred for 5-10 minutes after all are added; then the pH value of the system is adjusted to 8-9, and stirring is continued for 15-20 minutes, and then it is allowed to stand and age for 20-25 minutes; then it is washed by water centrifugation multiple times, and the treated sample is dried at 75-85°C; the dried material is ground into a powder form, loaded into a crucible, and heat-treated in a muffle furnace at 520-580°C for 2-4 hours. After the heat treatment is completed, it is naturally cooled to ambient temperature to obtain fluorinated titanium dioxide.

8. The high temperature resistant reverse osmosis membrane according to claim 5, characterized in that: The preparation method of the fluorinated titanium dioxide / metal organic framework modified graphite phase carbon nitride comprises the following steps: 0.03-0.06 parts of fluorinated titanium dioxide / metal organic framework composite material are added to 8-16 parts of ethanol and ultrasonically dispersed uniformly, and then 0.5-1 parts of graphite phase carbon nitride are added to 40-80 parts of ethanol and ultrasonically dispersed uniformly; then, the fluorinated titanium dioxide / metal organic framework composite material dispersion is dropwise added to the graphite phase carbon nitride dispersion, ultrasonically dispersed for 60-80 minutes, stirred at 60-65°C for 5-7 hours, and then the temperature is increased to evaporate the remaining ethanol to obtain fluorinated titanium dioxide / metal organic framework modified graphite phase carbon nitride.

9. A process for preparing a high temperature resistant reverse osmosis membrane according to any one of claims 1 to 8, comprising the following steps: S1. The nonwoven fabric was soaked in an isopropanol solution for 0.5-1h, and the isopropanol on the surface of the membrane was rinsed with water and placed in an oven for drying; the dried nonwoven fabric was placed flat on the workbench for plasma treatment to obtain a plasma pretreated nonwoven fabric; S2. After mixing 12-21% sulfonated poly(aryletherketonesulfone) copolymer, 3-7% fluorinated titanium dioxide / metal organic framework modified graphite carbon nitride, 70-84% N,N-dimethylformamide, and 1-2% porogen by mass percentage, stirring evenly, standing for 1-3h, and then ultrasonically degassing for 10-30min to obtain a support casting solution; S3. The support film obtained by S2 is applied to the plasma pretreated nonwoven fabric obtained by S1 to a thickness of 50-150μm; then evaporated at room temperature for 10-30s and immersed in 15-25 ℃ water to form a gel film, and then dried in an oven at 50-70 ℃ for 5-8 hours to obtain a support layer; S4. After uniformly mixing 5-10% fatty amine, 0.01-0.03% fluorinated titanium dioxide / metal organic framework modified graphite carbon nitride, 0.04-0.06% 3-amino-1,2-propanediol, and the balance water, component A is obtained; after uniformly mixing 5-10% fatty acid chloride and the balance organic solvent, component B is obtained; S5. The surface of the support layer prepared in S3 is first immersed in component A for 30-60 seconds, and then allowed to stand at room temperature for 5-30 seconds; then immersed in component B for 10-30 seconds, and then allowed to stand at room temperature for reaction for 8-12 minutes, and then placed in a drying oven and dried at 40-60°C for 2-6 hours to obtain a functional membrane layer, thereby obtaining a high-temperature resistant reverse osmosis membrane.

10. The process for preparing a high temperature resistant reverse osmosis membrane according to claim 9, characterized in that: The plasma treatment conditions are as follows: the radio frequency power applied is 40-50W, the discharge gas is air, and the treatment time is 20-30 minutes.

Images