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CN-117323822-B - Preparation method of high-temperature-resistant reverse osmosis membrane

CN117323822BCN 117323822 BCN117323822 BCN 117323822BCN-117323822-B

Abstract

The application relates to the technical field of membrane separation material preparation, in particular to a preparation method of a high-temperature-resistant reverse osmosis membrane, which comprises the following steps of preparing a casting solution, namely uniformly mixing and standing the above raw materials, defoaming and filtering the casting solution to obtain the casting solution, uniformly coating the casting solution on a base membrane, standing the base membrane, then placing the membrane in a water coagulation solution to obtain a porous support composite base membrane, coating an aqueous phase solution on the porous support composite base membrane, drying the porous support composite base membrane, coating an acyl chloride oil phase solution, and performing post-treatment to obtain the reverse osmosis composite membrane, wherein the casting solution comprises 8-14 parts by weight of solid polysulfone, 5-10 parts by weight of bismaleimide resin, 1-3 parts by weight of fumed silica, 75-82 parts by weight of N, N-dimethylformamide and 0.5-3 parts by weight of pore-forming agent. The reverse osmosis composite membrane in the application improves the heat resistance and the stability of the membrane under the condition that the membrane flux and the desalination rate are not obviously attenuated, reduces the running cost of high-temperature water treatment and prolongs the service life of the membrane to a certain extent.

Inventors

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Assignees

  • 苏州苏瑞膜纳米科技有限公司

Dates

Publication Date
20260505
Application Date
20231122

Claims (9)

  1. 1. The preparation method of the high-temperature-resistant reverse osmosis membrane is characterized by comprising the following steps of: The preparation method comprises the steps of S1, casting film liquid, S2, uniformly coating the casting film liquid on a porous base film, placing a film obtained after standing in a water solidification liquid to obtain a porous support composite base film, S3, contacting the porous support composite base film with an aqueous phase solution containing amine compounds in a coating mode, drying, S4, contacting the film obtained in the step S3 with an oil phase solution containing acyl chloride compounds in a coating mode to form a functional layer, and drying to obtain a reverse osmosis composite film, wherein the aqueous phase solution comprises the following components, by weight, 4-12 parts of diamine, 0.5-3 parts of silver nanoparticles, 2-2.5 parts of a pH regulator, 0.15-0.45 part of a surfactant, 0.15-1.15-2.4 parts of an acid acceptor, 2-2.5 parts of a sodium sulfonate, and 1-78 parts of a coupling agent, and further comprises 1-72 parts of hydrosulfide-1.5 parts of a hydrosulfide-1-2.
  2. 2. The method for preparing a high temperature reverse osmosis membrane according to claim 1, wherein the fumed silica has an average particle diameter of 6-8nm.
  3. 3. The method for producing a high temperature-resistant reverse osmosis membrane according to claim 1, wherein the mass ratio of the bismaleimide resin to the fumed silica is (2-5): 1.
  4. 4. The method for preparing the high-temperature-resistant reverse osmosis membrane according to claim 1, wherein the diamine is one or more of m-phenylenediamine, o-phenylenediamine, p-phenylenediamine, 4-chloro-1, 3-phenylenediamine and dimethylbenzenediamine, the pH regulator is one or more of camphorsulfonic acid, tannic acid and citric acid, the surfactant is one or more of sodium dodecyl sulfonate, sodium dodecyl benzene sulfonate, sodium lauryl sulfonate and sodium glycocholate, the acid acceptor is sodium hydroxide, and the modifier is N-methylpyrrolidone.
  5. 5. The method for preparing the high-temperature-resistant reverse osmosis membrane according to claim 1, wherein the oil phase solution comprises 1-4 parts by weight of acyl chloride monomer and 80-88 parts by weight of oil phase solvent, wherein the acyl chloride monomer is one or more of trimesoyl chloride, 4' -biphenyl dicarboxyl chloride, benzene disulfonyl chloride and terephthaloyl chloride, and the oil phase solvent is one or more of n-hexane, cyclohexane and heptane.
  6. 6. The method for preparing a high temperature resistant reverse osmosis membrane according to claim 1, wherein the mercaptosilane coupling agent is gamma-mercaptopropyl trimethoxysilane or gamma-mercaptopropyl triethoxysilane.
  7. 7. The method for preparing a high temperature resistant reverse osmosis membrane according to claim 1, wherein the pore-forming agent is one or more selected from polyethylene glycol, polyvinylpyrrolidone and 1, 4-dioxane.
  8. 8. The method for preparing a high temperature reverse osmosis membrane according to claim 1, wherein the temperature of the aqueous condensate is in the range of 8-16 ℃.
  9. 9. The method for preparing a high temperature-resistant reverse osmosis membrane according to claim 1, wherein after step S4, the obtained reverse osmosis membrane is cleaned with pure water, wetted with glycerol, coated with PVA on the surface of the composite membrane, and baked at 60-80 ℃.

Description

Preparation method of high-temperature-resistant reverse osmosis membrane Technical Field The application relates to the technical field of membrane separation material preparation, in particular to a preparation method of a high-temperature-resistant reverse osmosis membrane. Background The membrane separation technology is one of the preferred technologies in the field of water pollution control engineering, and can be classified into a microfiltration membrane, an ultrafiltration membrane, a nanofiltration membrane and a reverse osmosis membrane according to its filtration accuracy. The reverse osmosis membrane technology has a plurality of advantages in the desalination of salt water, including the characteristics of low energy consumption, low investment cost, high recovery rate, small occupied area, high salt removal rate, stable water quality and the like. In addition, the reverse osmosis membrane system has long service life, so that the reverse osmosis membrane system is widely applied to the fields of drinking water purification, sewage and wastewater treatment and reuse. However, the application of reverse osmosis membranes in different fields is increasing, and higher requirements are put on the performance of the reverse osmosis membranes, especially in the fields of food, medicine, textile and the like, raw water is often high-temperature wastewater, and the temperature is usually higher than 45 ℃. Reverse osmosis membranes currently on the market are generally composed of a non-woven fabric, a porous support layer and a separation layer, and have the defects of low strength, easy deformation, easy breakage and easy stripping. In addition, the existing reverse osmosis membranes generally have a service temperature of less than 40 ℃ and thus cannot operate effectively under high temperature conditions. At high temperature, the desalination performance of the existing membrane can be rapidly reduced, so that the membrane flux and the desalination rate are reduced, the quality of produced water is affected, the running cost is increased, and the service life of the membrane is reduced. At present, the common method for industrially treating the high-temperature wastewater is to introduce the wastewater into a wastewater transfer tank for cooling treatment, and then use a reverse osmosis membrane system for water purification treatment. This method increases the treatment process, causes accumulation of wastewater, and is unfavorable for industrial production. Therefore, developing a high temperature resistant reverse osmosis membrane would greatly improve the application potential of reverse osmosis membranes in the field of drinking water purification and sewage/wastewater treatment. Improving the high temperature resistance and stability of membranes without significantly reducing membrane flux and desalination rates has become a major challenge in overcoming the challenges of membrane separation technologies in the areas of potable water purification and sewage/wastewater treatment. Disclosure of Invention In order to solve the stability and performance problems of the existing reverse osmosis membrane for treating high-temperature raw water, the application provides a preparation method of a high-temperature-resistant reverse osmosis membrane, which comprises the following steps: S1, preparing a casting solution, wherein the casting solution comprises 8-14 parts by weight of solid polysulfone, 5-10 parts by weight of bismaleimide resin, 1-3 parts by weight of fumed silica, 75-82 parts by weight of N, N-dimethylformamide and 0.5-3 parts by weight of pore-forming agent, uniformly mixing the above raw materials, standing, defoaming and filtering to obtain the casting solution; S2, uniformly coating the casting film liquid on the polyester non-woven fabric, and placing the film obtained after standing in water coagulating liquid to obtain a porous support composite base film; S3, contacting the porous support composite base film with an aqueous phase solution containing amine compounds in a coating mode, and drying; And S4, contacting the film obtained in the step S3 with an oil phase solution containing acyl chloride compounds in a coating mode to form a functional layer, and drying to obtain the reverse osmosis composite film. According to the technical scheme, the defects of lack of active groups and insufficient branching or crosslinking on polysulfone high-molecular chains are overcome by introducing bismaleimide resin containing benzene rings, imide heterocycle and having high crosslinking density into the porous support composite base membrane layer. In addition, the bismaleimide resin effectively disperses the nanomaterial between polysulfone molecular chains through a twisted non-coplanar structure, thereby enhancing the stability and mechanical properties of the membrane. Meanwhile, the strong electron-withdrawing effect of the carbonyl in the bismaleimide enables the bismaleimide to ea