A reverse osmosis membrane for purified water after semiconductor cleaning

Abstract

The present invention relates to the field of reverse osmosis technology, and discloses a reverse osmosis membrane for purified water after semiconductor cleaning. The reverse osmosis membrane in the present invention is composed of a base layer, a support layer, and a functional layer, wherein the base layer is a non-woven fabric, the support layer is a composite polysulfone membrane layer, and the functional layer is a composite polyamide membrane layer; the NH2-MIL-125@MXene QDs nanomaterial introduced into the composite polysulfone membrane layer and the composite polyamide membrane layer not only improves the water flux, but also adsorbs metal ions entering the membrane layer, further improving the removal rate of metal ions, and has antibacterial properties, thereby improving the anti-pollution performance of the membrane layer; the composite polyamide membrane layer also introduces a PVA / CS composite material, which improves the removal rate of impurities in the solution by the membrane layer, and also improves the hydrophilicity of the membrane layer, thereby improving the water flux and anti-pollution performance.

Description

Technical Field

[0001] The present invention relates to the technical field of reverse osmosis, and in particular to a reverse osmosis membrane for purifying water after semiconductor cleaning. Background Art

[0002] Membrane separation technology is one of the most promising methods to remove metal ions from water. The advantages of membrane technology include high efficiency, easy operation, space saving and environmental friendliness. Membrane separation technology can be used to treat purified water after cleaning in the semiconductor industry to remove organic matter, metal ions and other impurities contained in the solution. However, the pore size of the nanofiltration membranes on the market may be larger than the hydrated ion size of the metal ions. These ions will easily pass through the membrane. Commercial porous membranes cannot effectively intercept and remove metal ions. Such membranes generally rely on chelation and ion exchange to effectively intercept metal ions. However, the connection force between the functional membrane and the support membrane of such composite membranes is physical. The functional membrane has poor stability and low water flux. There is also membrane surface contamination caused by chelation and adsorption.

[0003] The principle of metal removal by reverse osmosis membranes is similar to that of other pollutants, mainly based on the pore size and charge properties of the membrane. Metal ions, such as sodium, potassium, magnesium, lead, mercury, copper, nickel, etc., are positively charged, while the surface of the reverse osmosis membrane is negatively charged. During the reverse osmosis process, these positively charged metal ions are attracted by the negative charge on the membrane surface and are retained on one side of the membrane, thereby being removed. Therefore, based on this principle, researchers need to design a reverse osmosis membrane with high water flux, high retention rate and anti-pollution performance to meet the application of purified water after semiconductor cleaning. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention provides a reverse osmosis membrane for purifying water after semiconductor cleaning.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] A reverse osmosis membrane for purifying water after semiconductor cleaning, comprising a base layer, a support layer and a functional layer; the base layer is a non-woven fabric; the support layer is a composite polysulfone membrane layer; and the functional layer is a composite polyamide membrane layer.

[0007] The method for preparing a reverse osmosis membrane for purified water after semiconductor cleaning comprises the following steps:

[0008] Step S1: weighing raw materials by weight, mixing 15-20 parts of polysulfone resin and 3-6 parts of NH2-MIL-125@MXene QDs nanomaterial in 74-82 parts of N,N-dimethylformamide, stirring uniformly, degassing, to form a polysulfone casting solution, then evenly applying the polysulfone casting solution on a non-woven fabric, and then immersing it in deionized water to form a composite polysulfone membrane layer, thereby obtaining a reverse osmosis membrane precursor;

[0009] Step S2: 1-5 wt% m-phenylenediamine, 1-2 wt% PVA / CS composite material, 0.5-1.5 wt% NH2-MIL-125@MXene QDs nanomaterial, 0.5-1.2 wt% triethylamine, and the balance deionized water were mixed and stirred to form an aqueous phase solution; 0.15-0.25 wt% trimesoyl chloride and the balance cyclohexane were mixed and stirred to form an oil phase solution;

[0010] Step S3: Immerse the reverse osmosis membrane precursor in an aqueous solution for 1-3 minutes, take it out and remove the surface solution using a squeeze roller, then immerse it in an oil solution for 20-60 seconds, and finally heat treat it at 40-60°C for 15-25 minutes to form a composite polyamide membrane layer. Rinse it with deionized water and dry it to obtain a reverse osmosis membrane for purified water after semiconductor cleaning.

[0011] The NH2-MIL-125@MXene QDs nanomaterial is prepared by the following steps:

[0012] Step A1: 2-aminoterephthalic acid is dispersed in N,N-dimethylformamide and methanol, isopropyl titanate is added and stirred for 30 minutes, and then transferred to an autoclave and reacted at 100-120° C. for 48-72 hours. The mixture is centrifuged, washed, and dried to obtain NH2-MIL-125 nanomaterial.

[0013] Furthermore, in step A1, the ratio of 2-aminoterephthalic acid, N,N-dimethylformamide, methanol and isopropyl titanate is 2.9-5.8 g: 80 mL: 20 mL: 2.9-5.8 mL;

[0014] Step A2: MXene powder and ethanol were mixed and ground, placed on an 800-mesh sieve for sieving, the product was collected, and the product and NH2-MIL-125 nanomaterial were mixed evenly in 0.5 mol / L sodium hydroxide ethanol solution. The mixture was transferred to an autoclave and reacted at 100°C for 2.5-3.5 hours, ultrasonicated in a water bath for 2-3 hours, centrifuged, washed, and dried to obtain NH2-MIL-125@MXene QDs nanomaterial;

[0015] Furthermore, in step A2, the usage ratio of MXene powder, ethanol, NH2-MIL-125 nanomaterial and sodium hydroxide ethanol solution is 0.5-2 g: 3-5 mL: 0.2-1 g: 50 mL.

[0016] The PVA / CS composite material is prepared by the following steps:

[0017] Step B1, dispersing sodium hydroxide in deionized water, adding chitosan, mixing and stirring evenly, and refrigerating at -10°C for 24 hours. After thawing, centrifuging, collecting the precipitate, and drying to obtain pretreated chitosan;

[0018] Furthermore, in step B1, the ratio of sodium hydroxide, deionized water, and chitosan is 0.2-0.5 g:10 mL:3-6 g;

[0019] Step B2, diethylenetriamine pentaacetic acid was stirred in deionized water, and 1 mol / L sodium hydroxide solution was added and stirred for 15-35 minutes, then the temperature was raised to 35-45°C, EDC (1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride) and NHS (N-hydroxysuccinimide) were added in sequence and stirred for 2-3 hours, and then the pretreated chitosan was added and stirred for 3-5 hours, filtered, washed, and dried to obtain modified chitosan;

[0020] Furthermore, in step B2, the usage ratio of diethylenetriaminepentaacetic acid, deionized water, sodium hydroxide solution, EDC, NHS and pretreated chitosan is 0.6-1 g: 200 mL: 2-6 mL: 0.5-1 g: 0.32-0.64 g: 1.5-2.5 g;

[0021] Step B3, polyvinyl alcohol was mixed and stirred in deionized water, ultrasonically treated for 0.5-1.5 hours, and then modified chitosan was added and stirred for 12-24 hours, filtered, washed, and dried to obtain a PVA / CS composite material (polyvinyl alcohol / chitosan composite material);

[0022] Furthermore, in step B3, the usage ratio of polyvinyl alcohol, deionized water and modified chitosan is 5-10 g:100 mL:2-6 g.

[0023] Beneficial effects of the present invention:

[0024] The reverse osmosis membrane in the present invention consists of a base layer, a support layer and a functional layer, wherein the base layer is a non-woven fabric, the support layer is a composite polysulfone membrane layer, and the functional layer is a composite polyamide membrane layer; the NH2-MIL-125@MXene QDs nanomaterial introduced into the composite polysulfone membrane layer and the composite polyamide membrane layer not only improves the water flux, but also adsorbs metal ions entering the membrane layer, further improving the removal rate of metal ions, and has antibacterial properties, thereby improving the anti-pollution performance of the membrane layer; the PVA / CS composite material is also introduced into the composite polyamide membrane layer, which improves the removal rate of impurities in the solution of the membrane layer, and also improves the hydrophilicity of the membrane layer, thereby improving the water flux and anti-pollution performance.

[0025] The NH2-MIL-125@MXene QDs nanomaterial of the present invention is first synthesized by a solvent thermal method using 2-aminoterephthalic acid and isopropyl titanate as raw materials; then, after the MXene powder is ground, MXene QDs (MXene quantum dots) are loaded on the NH2-MIL-125 nanomaterial by a solvent thermal-ultrasonic method to prepare the NH2-MIL-125@MXene QDs nanomaterial; the loading of MXene QDs significantly improves the dispersibility of the nanomaterial, so that it can be uniformly dispersed in the composite polysulfone membrane layer and the composite polyamide membrane layer, and then the high porosity of the nanomaterial is used to improve the permeability of the membrane layer to water molecules, thereby improving the water flux, and at the same time, the void structure can be used to adsorb small molecular metal ions (such as Na) entering the membrane layer. + , K + , Ca 2+ etc.), further improving the rejection rate of metal ions by the reverse osmosis membrane; in addition, the quantum dots in the nanomaterials also have a certain antibacterial effect, which can effectively improve the antibacterial properties of the reverse osmosis membrane surface, reduce the reduction in the service life of the membrane layer due to bacterial contamination, and increase the service life of the reverse osmosis membrane.

[0026] The PVA / CS composite material of the present invention first performs an alkali treatment on chitosan to obtain pretreated chitosan, thereby exposing more active groups (hydroxyl groups and amino groups) so that it can react with diethylenetriaminepentaacetic acid to obtain modified chitosan. Finally, polyvinyl alcohol and the modified chitosan are compounded by hydrogen bonding to obtain the PVA / CS composite material. The PVA / CS composite material introduced into the composite polyamide film layer can not only utilize the large number of active groups (amino groups, hydroxyl groups and carboxyl groups) contained in it to generate hydrogen bonding with amide bonds, thereby increasing the thickness and density of the film layer, thereby improving the removal of organic matter, metal ions and other impurities in the solution by the reverse osmosis membrane; it can also increase the hydrophilicity of the film layer, and the increase in hydrophilicity is conducive to the adsorption of water molecules on the surface of the film layer to form a hydration layer, which is conducive to the penetration of water molecules and increases water flux while maintaining a high rejection rate. It can also effectively reduce the adsorption and deposition of pollutants on the membrane surface, thereby improving the anti-pollution performance of the reverse osmosis membrane. In addition, the PVA / CS composite material contains a large number of carboxyl groups and has a certain negative charge, which can synergize with polyamide to improve the retention rate of metal ions in the membrane layer. DETAILED DESCRIPTION

[0027] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0028] Example 1: NH2-MIL-125@MXene QDs nanomaterials were prepared by the following steps:

[0029] Step A1: 2.9 g of 2-aminoterephthalic acid was dispersed in 80 mL of N,N-dimethylformamide and 20 mL of methanol, 2.9 mL of isopropyl titanate was added, and the mixture was stirred for 30 min. The mixture was then transferred to an autoclave and reacted at 100° C. for 48 h. The mixture was centrifuged, washed, and dried to obtain NH2-MIL-125 nanomaterial.

[0030] Step A2: 0.5 g of MXene powder and 3 mL of ethanol were mixed and ground, placed on an 800-mesh sieve for sieving, the product was collected, and the product and 0.2 g of NH2-MIL-125 nanomaterial were mixed evenly in 50 mL of 0.5 mol / L sodium hydroxide ethanol solution. The mixture was transferred to an autoclave and reacted at 100 ° C for 2.5 h. The mixture was ultrasonicated in a water bath for 2 h, centrifuged, washed, and dried to obtain NH2-MIL-125@MXene QDs nanomaterials.

[0031] The PVA / CS composite material is prepared by the following steps:

[0032] Step B1, dispersing 0.2 g of sodium hydroxide in 10 mL of deionized water, adding 3 g of chitosan, mixing and stirring evenly, and refrigerating at -10°C for 24 h. After thawing, centrifuging, collecting the precipitate, and drying to obtain pretreated chitosan;

[0033] Step B2, 0.6 g of diethylenetriaminepentaacetic acid was stirred in 200 mL of deionized water, and 2 mL of 1 mol / L sodium hydroxide solution was added and stirred for 15 min. Then, the temperature was raised to 35 ° C., 0.5 g of EDC and 0.32 g of NHS were added in sequence and stirred for 2 h. Then, 1.5 g of pretreated chitosan was added and stirred for 3 h. The mixture was filtered, washed, and dried to obtain modified chitosan;

[0034] Step B3: 5 g of polyvinyl alcohol was mixed and stirred in 100 mL of deionized water, and ultrasonic treatment was performed for 0.5 h. Then, 2 g of modified chitosan was added and stirred for 12 h. The mixture was filtered, washed, and dried to obtain a PVA / CS composite material.

[0035] Example 2: NH2-MIL-125@MXene QDs nanomaterials were prepared by the following steps:

[0036] Step A1: Disperse 4.4 g of 2-aminoterephthalic acid in 80 mL of N,N-dimethylformamide and 20 mL of methanol, add 4.4 mL of isopropyl titanate, and stir for 30 min. Then, transfer the mixture to an autoclave, react at 110° C. for 60 h, centrifuge, wash, and dry to obtain NH2-MIL-125 nanomaterial.

[0037] Step A2: 1 g of MXene powder and 4 mL of ethanol were mixed and ground, placed on an 800-mesh sieve for sieving, the product was collected, and the product and 0.6 g of NH2-MIL-125 nanomaterial were mixed evenly in 50 mL of 0.5 mol / L sodium hydroxide ethanol solution. The mixture was transferred to an autoclave and reacted at 100 ° C for 3 h. The mixture was ultrasonicated in a water bath for 2.5 h, centrifuged, washed, and dried to obtain NH2-MIL-125@MXene QDs nanomaterials.

[0038] The PVA / CS composite material is prepared by the following steps:

[0039] Step B1, dispersing 0.35 g of sodium hydroxide in 10 mL of deionized water, adding 4.5 g of chitosan, mixing and stirring evenly, and refrigerating at -10°C for 24 h. After thawing, centrifuging, collecting the precipitate, and drying to obtain pretreated chitosan;

[0040] Step B2, 0.8 g of diethylenetriaminepentaacetic acid was stirred in 200 mL of deionized water, and 4 mL of 1 mol / L sodium hydroxide solution was added and stirred for 25 min. The temperature was then raised to 40 ° C. 0.75 g of EDC and 0.48 g of NHS were added in sequence and stirred for 2.5 h. Then 2 g of pretreated chitosan was added and stirred for 4 h. The mixture was filtered, washed, and dried to obtain modified chitosan.

[0041] Step B3: 7.5 g of polyvinyl alcohol was mixed and stirred in 100 mL of deionized water, and ultrasonically treated for 1 h. Then, 4 g of modified chitosan was added and stirred for 18 h. The mixture was filtered, washed, and dried to obtain a PVA / CS composite material.

[0042] Example 3: NH2-MIL-125@MXene QDs nanomaterials were prepared by the following steps:

[0043] Step A1: 5.8 g of 2-aminoterephthalic acid was dispersed in 80 mL of N,N-dimethylformamide and 20 mL of methanol, 5.8 mL of isopropyl titanate was added, and the mixture was stirred for 30 min. The mixture was then transferred to an autoclave and reacted at 120° C. for 72 h. The mixture was centrifuged, washed, and dried to obtain NH2-MIL-125 nanomaterial.

[0044] Step A2: 2 g of MXene powder and 5 mL of ethanol were mixed and ground, placed on an 800-mesh sieve for sieving, the product was collected, and the product and 1 g of NH2-MIL-125 nanomaterial were mixed evenly in 50 mL of 0.5 mol / L sodium hydroxide ethanol solution. The mixture was transferred to an autoclave and reacted at 100 ° C for 3.5 h. The mixture was ultrasonicated in a water bath for 3 h, centrifuged, washed, and dried to obtain NH2-MIL-125@MXene QDs nanomaterials.

[0045] The PVA / CS composite material is prepared by the following steps:

[0046] Step B1, dispersing 0.5 g of sodium hydroxide in 10 mL of deionized water, adding 6 g of chitosan, mixing and stirring evenly, and refrigerating at -10°C for 24 h. After thawing, centrifuging, collecting the precipitate, and drying to obtain pretreated chitosan;

[0047] Step B2, 1 g of diethylenetriaminepentaacetic acid was stirred in 200 mL of deionized water, and 6 mL of 1 mol / L sodium hydroxide solution was added and stirred for 35 min. Then, the temperature was raised to 45 ° C. 1 g of EDC and 0.64 g of NHS were added in sequence and stirred for 3 h. Then, 2.5 g of pretreated chitosan was added and stirred for 5 h. The mixture was filtered, washed, and dried to obtain modified chitosan.

[0048] Step B3: 10 g of polyvinyl alcohol was mixed and stirred in 100 mL of deionized water, and ultrasonic treatment was performed for 1.5 h. Then, 6 g of modified chitosan was added and stirred for 24 h. The mixture was filtered, washed, and dried to obtain a PVA / CS composite material.

[0049] Example 4: A reverse osmosis membrane for purified water after semiconductor cleaning is prepared by the following steps:

[0050] Step S1: Weigh the raw materials by weight, mix 15 parts of polysulfone resin and 3 parts of NH2-MIL-125@MXene QDs nanomaterial prepared in Example 1 in 82 parts of N,N-dimethylformamide, stir evenly, and degas to form a polysulfone casting solution, then evenly apply the polysulfone casting solution on a non-woven fabric, and then immerse it in deionized water to form a composite polysulfone membrane layer, thereby obtaining a reverse osmosis membrane precursor;

[0051] Step S2: 1 wt% of m-phenylenediamine, 1 wt% of the PVA / CS composite material prepared in Example 1, 0.5 wt% of the NH2-MIL-125@MXene QDs nanomaterial prepared in Example 1, 0.5 wt% of triethylamine, and the remainder of deionized water were mixed and stirred to obtain a water phase solution; 0.15 wt% of trimesoyl chloride and the remainder of cyclohexane were mixed and stirred to obtain an oil phase solution;

[0052] Step S3: The reverse osmosis membrane precursor is first immersed in the aqueous solution for 1 minute, taken out and the surface solution is removed by squeezing rollers, then immersed in the oil phase solution for 20 seconds, and finally heat-treated at 40°C for 15 minutes to form a composite polyamide membrane layer, which is then rinsed with deionized water and dried to obtain a reverse osmosis membrane for purified water after semiconductor cleaning.

[0053] Example 5: A reverse osmosis membrane for purified water after semiconductor cleaning, comprising the following steps:

[0054] Step S1: Weigh the raw materials by weight, mix 17 parts of polysulfone resin and 5 parts of NH2-MIL-125@MXene QDs nanomaterial prepared in Example 2 in 78 parts of N,N-dimethylformamide, stir evenly, degas, and form a polysulfone casting solution. Then, evenly apply the polysulfone casting solution on a non-woven fabric, and then immerse it in deionized water to form a composite polysulfone membrane layer, thereby obtaining a reverse osmosis membrane precursor;

[0055] Step S2: 3 wt% of m-phenylenediamine, 1.5 wt% of the PVA / CS composite material prepared in Example 2, 1 wt% of the NH2-MIL-125@MXene QDs nanomaterial prepared in Example 2, 0.8 wt% of triethylamine, and the remainder of deionized water were mixed and stirred to obtain a water phase solution; 0.2 wt% of trimesoyl chloride and the remainder of cyclohexane were mixed and stirred to obtain an oil phase solution;

[0056] Step S3: The reverse osmosis membrane precursor is first immersed in an aqueous solution for 2 minutes, taken out and the surface solution is removed using a squeeze roller, then immersed in an oil phase solution for 40 seconds, and finally heat-treated at 50°C for 20 minutes to form a composite polyamide membrane layer, which is then rinsed with deionized water and dried to obtain a reverse osmosis membrane for purified water after semiconductor cleaning.

[0057] Example 6: A reverse osmosis membrane for purified water after semiconductor cleaning is prepared by the following steps:

[0058] Step S1: Weigh the raw materials by weight, mix 20 parts of polysulfone resin and 6 parts of NH2-MIL-125@MXene QDs nanomaterials prepared in Example 3 in 74 parts of N,N-dimethylformamide, stir them evenly, and degas to form a polysulfone casting solution. Then, apply the polysulfone casting solution evenly on a non-woven fabric, and then immerse it in deionized water to form a composite polysulfone membrane layer, thereby obtaining a reverse osmosis membrane precursor;

[0059] Step S2: 5 wt% of m-phenylenediamine, 2 wt% of the PVA / CS composite material prepared in Example 3, 1.5 wt% of the NH2-MIL-125@MXene QDs nanomaterial prepared in Example 3, 1.2 wt% of triethylamine, and the remainder of deionized water were mixed and stirred to form an aqueous phase solution; 0.25 wt% of trimesoyl chloride and the remainder of cyclohexane were mixed and stirred to form an oil phase solution;

[0060] Step S3: The reverse osmosis membrane precursor is first immersed in an aqueous solution for 3 minutes, taken out and the surface solution is removed using a squeeze roller, then immersed in an oil phase solution for 60 seconds, and finally heat-treated at 60°C for 25 minutes to form a composite polyamide membrane layer, which is then rinsed with deionized water and dried to obtain a reverse osmosis membrane for purified water after semiconductor cleaning.

[0061] Comparative Example 1: This comparative example is a reverse osmosis membrane. The difference from Example 6 is that MXene QDs are used instead of the NH2-MIL-125@MXene QDs nanomaterial prepared in Example 3, and the rest are the same.

[0062] Comparative Example 2: This comparative example is a reverse osmosis membrane. The difference from Example 6 is that NH2-MIL-125 nanomaterial is used instead of the NH2-MIL-125@MXene QDs nanomaterial prepared in Example 3, and the rest are the same.

[0063] Comparative Example 3: This comparative example is a reverse osmosis membrane. The difference from Example 6 is that polyvinyl alcohol is used instead of the PVA / CS composite material prepared in Example 3, and the rest are the same.

[0064] Comparative Example 4: This comparative example is a reverse osmosis membrane. The difference from Example 6 is that chitosan is used instead of the PVA / CS composite material prepared in Example 3, and the rest are the same.

[0065] The reverse osmosis membranes prepared in Examples 4-6 and Comparative Examples 1-4 were subjected to performance tests:

[0066] Contact angle test: After repeatedly rinsing the film sample (1 cm × 5 cm) with pure water, it was dried in a vacuum oven at 40°C for 24 hours. The contact angles were measured at 10 random locations on the film sample surface, and the average value was calculated.

[0067] Permeation selectivity test: The feed solution used to test the membrane permeation selectivity was a 2000 mg / L NaCl aqueous solution. The test temperature and pressure were 25°C and 1.55 MPa, respectively. The flux and salt rejection were tested at 9 sites and the average value was taken.

[0068] Antibacterial performance test: The membrane was immersed in Escherichia coli culture medium (CFU = 1 × 10 6 / mL) and cultured at 37°C for 24 h. Then, the sample solution was taken for viable bacterial culture counting, and the inhibition rate of the membrane against Escherichia coli was calculated (inhibition rate = (AB) / A×100%, where A is the number of viable bacteria at time 0 and B is the number of viable bacteria after 24 h).

[0069] Metal ion retention rate test: The test was carried out using a membrane permeation device and an inductively coupled plasma mass spectrometer was used to test the concentration of metal ions. R% = (1-C f / C p )×100%, where R is the retention rate, C p and C f (mg / L) are the metal ions in the original liquid tank (K + and Na + ) and the metal ion concentration in the draw solution after the infiltration is completed;

[0070] Particle retention rate test: The test was conducted using a membrane permeation device and a liquid particle counter was used to test the particle concentration (the particle size in the test solution was 0.1-0.5 μm). R1% = (1-C f1 / C p1 )×100%, where R1 is the particle retention rate, C p1 and C f1 (particles / mL) are the initial concentration of particles (0.1-0.5 μm) in the original solution tank and the concentration of particles in the draw solution after the infiltration is completed;

[0071] The test results are shown in Table 1:

[0072] Table 1: Performance test results

[0073]

[0074] As can be seen from Table 1, the reverse osmosis membrane prepared by the present invention has excellent water flux, permeability, desalination rate, antibacterial rate, metal ion retention rate and particulate matter retention rate after performance testing.

[0075] The above content is merely an example and explanation of the concept of the present invention. Those skilled in the art may make various modifications or additions to the described specific embodiments or replace them in a similar manner. As long as they do not deviate from the scope defined by the concept of the invention, they should all fall within the scope of protection of the present invention.

Claims

1. A reverse osmosis membrane for purified water after semiconductor cleaning, characterized in that: It includes a base layer, a support layer and a functional layer; the base layer is a non-woven fabric; the support layer is a composite polysulfone membrane layer; and the functional layer is a composite polyamide membrane layer. The method for preparing a reverse osmosis membrane for purified water after semiconductor cleaning comprises the following steps: Step S1: weighing raw materials by weight, mixing 15-20 parts of polysulfone resin and 3-6 parts of NH2-MIL-125@MXene QDs nanomaterial in 74-82 parts of N,N-dimethylformamide, stirring uniformly, degassing, to form a polysulfone casting solution, then evenly applying the polysulfone casting solution on a non-woven fabric, and then immersing it in deionized water to form a composite polysulfone membrane layer, thereby obtaining a reverse osmosis membrane precursor; Step S2: 1-5 wt% m-phenylenediamine, 1-2 wt% PVA / CS composite material, 0.5-1.5 wt% NH2-MIL-125@MXene QDs nanomaterial, 0.5-1.2 wt% triethylamine, and the balance deionized water were mixed and stirred to form an aqueous phase solution; 0.15-0.25 wt% trimesoyl chloride and the balance cyclohexane were mixed and stirred to form an oil phase solution; Step S3: Immerse the reverse osmosis membrane precursor in an aqueous solution for 1-3 minutes, take it out and remove the surface solution using a squeeze roller, then immerse it in an oil solution for 20-60 seconds, and finally heat treat it at 40-60°C for 15-25 minutes to form a composite polyamide membrane layer. Rinse it with deionized water and dry it to obtain a reverse osmosis membrane for purified water after semiconductor cleaning.

2. The reverse osmosis membrane for purified water after semiconductor cleaning according to claim 1, characterized in that: The NH2-MIL-125@MXene QDs nanomaterial is prepared by the following steps: Step A1: 2-aminoterephthalic acid is dispersed in N,N-dimethylformamide and methanol, isopropyl titanate is added and stirred for 30 minutes, and then transferred to an autoclave and reacted at 100-120° C. for 48-72 hours. The mixture is centrifuged, washed, and dried to obtain NH2-MIL-125 nanomaterial. Step A2: Mix and grind the MXene powder and ethanol, place it on an 800-mesh sieve for sieving, collect the product, and evenly mix the product and NH2-MIL-125 nanomaterial in 0.5 mol / L sodium hydroxide ethanol solution. Transfer it to an autoclave, react at 100°C for 2.5-3.5 hours, ultrasonicate in a water bath for 2-3 hours, centrifuge, wash, and dry to obtain NH2-MIL-125@MXene QDs nanomaterial.

3. The reverse osmosis membrane for purified water after semiconductor cleaning according to claim 2, characterized in that: In step A1, the usage ratio of 2-aminoterephthalic acid, N,N-dimethylformamide, methanol and isopropyl titanate is 2.9-5.8 g:80 mL:20 mL:2.9-5.8 mL.

4. The reverse osmosis membrane for purified water after semiconductor cleaning according to claim 2, characterized in that: In step A2, the usage ratio of MXene powder, ethanol, NH2-MIL-125 nanomaterial and sodium hydroxide ethanol solution is 0.5-2 g: 3-5 mL: 0.2-1 g: 50 mL.

5. The reverse osmosis membrane for purified water after semiconductor cleaning according to claim 1, characterized in that: The PVA / CS composite material is prepared by the following steps: Step B1, dispersing sodium hydroxide in deionized water, adding chitosan, mixing and stirring evenly, and refrigerating at -10°C for 24 hours. After thawing, centrifuging, collecting the precipitate, and drying to obtain pretreated chitosan; Step B2, diethylenetriaminepentaacetic acid was stirred in deionized water, and 1 mol / L sodium hydroxide solution was added and stirred for 15-35 minutes, then the temperature was raised to 35-45°C, EDC and NHS were added in sequence and stirred for 2-3 hours, and then the pretreated chitosan was added and stirred for 3-5 hours, filtered, washed, and dried to obtain modified chitosan; Step B3: Mix polyvinyl alcohol in deionized water and stir evenly, perform ultrasonic treatment for 0.5-1.5 hours, then add modified chitosan and stir for 12-24 hours, filter, wash, and dry to obtain a PVA / CS composite material.

6. The reverse osmosis membrane for purified water after semiconductor cleaning according to claim 5, characterized in that: In step B1, the usage ratio of sodium hydroxide, deionized water and chitosan is 0.2-0.5 g:10 mL:3-6 g.

7. The reverse osmosis membrane for purified water after semiconductor cleaning according to claim 5, characterized in that: In step B2, the usage ratio of diethylenetriaminepentaacetic acid, deionized water, sodium hydroxide solution, EDC, NHS and pretreated chitosan is 0.6-1 g: 200 mL: 2-6 mL: 0.5-1 g: 0.32-0.64 g: 1.5-2.5 g.

8. The reverse osmosis membrane for purified water after semiconductor cleaning according to claim 5, characterized in that: In step B3, the usage ratio of polyvinyl alcohol, deionized water and modified chitosan is 5-10 g:100 mL:2-6 g.

Images