44results about How to "Excellent salt rejection" patented technology

The invention discloses a reverse osmosis membrane and a preparation method thereof. The reverse osmosis membrane comprises a non-woven support layer, a polysulfone base membrane layer, a polyamide desalination layer and a transition layer, wherein the non-woven support layer is coated with the polysulfone base membrane layer; the transition layer is a hydrophilic membrane layer and is arranged between the polysulfone base membrane layer and the polyamide desalination layer. According to the reverse osmosis membrane, as the hydrophilic transition layer is inserted between the polysulfone base membrane layer and the polyamide desalination layer, the hydrophilic transition layer improves dispersion uniformity of a polyamine solution on the surface of the polysulfone base membrane layer, a binding force of the hydrophilic polyamide desalination layer with the polysulfone base membrane layer is increased greatly, the reverse osmosis membrane is high in desalinization ratio, uniformity and water flux, and long in service life, and can bear at least 0.5 MPa backpressure, and significantly lower engineering cost and manufacturing cost.

The invention relates to the technical field of reverse osmosis membrane performance improving, in particular to a method for increasing the performance of a reverse osmosis membrane. The method includes: using a pickling agent to perform acid pickling on the reverse osmosis membrane after interface polymerization is completed, then using a chemical surface treating agent to perform chemical surface treatment, and using a humectant to perform moisturizing treatment on the reverse osmosis membrane. The method has the advantages that the charge density and chemical components of the polyamide desalting layer of the reverse osmosis membrane can be precisely regulated, the desalting rate and water flux of the reverse osmosis membrane are improved at the same time, the hydrophilicity of the reverse osmosis membrane is increased, pollution occurrence frequency is lowered, the cleaning recovery ability of the reverse osmosis membrane during the actual operation of the reverse osmosis membrane is increased, the defect of an imperfect desalting layer network structure caused by the interface polymerization is overcome, the content of residual monomer is reduced, the desalting rate is increased by 0.5%, and the flux is increased by 20-60%.

The invention provides a preparation method of an oxidized graphene doped hollow fiber nanofiltration membrane. The preparation method comprises the steps that a plurality of hollow fiber nanofiltration membrane serve as basic membranes to be packaged into a component shell to obtain a membrane component for usage; oxidized graphene, an active monomer and an acid absorbing agent are added into a solvent A for uniform ultrasonic mixing to obtain a solution A; multielementacyl chloride is dissolved in a solvent B to obtain a solution B; the solution A is introduced into the inner cavity of the hollow fiber nanofiltration membrane of the membrane component for full infiltration, the solution A is removed, drying is performed, the solvent B is introduced into the inner cavity of the membrane for interfacial polymerization reaction, then the solution B is removed, drying is performed, andpure-water rinsing and drying are performed to obtain the membrane. The oxidized graphene is added in the membrane preparation process and has the very good effect on the aspects of surface hydrophilicity improvement, membrane flux increase and pollution resistance. The product is good in mechanical strength andcontamination resistance and is higher than an oxidized-graphene-free pure polyamide nanofiltration membraneindesalting rate and water flux.

The invention discloses a hydrophobic porous MXene membrane as well as a preparation method and application thereof. The preparation method comprises the following steps: (1) etching three-dimensional layered MAX by using a mixed solution of LiF and HCl, performing washing, adding water, and carrying out ultrasonic dispersion to obtain a two-dimensional layered MXene suspension; (2) preparing a hydrolysis solution from a substance with low surface energy, mixing the hydrolysis solution with the two-dimensional layered MXene suspension in the step (1), and carrying out a hydrolysis reaction; and (3) carrying out vacuum filtration on the modified MXene solution obtained in the step (2) on a porous substrate membrane, and carrying out vacuum drying to obtain the hydrophobic porous MXene membrane. The prepared membrane has a porous MXene layer, and a large interlayer spacing and a gap generated by stacking provide a plurality of channels for the transmission of water molecules. The preparation method is simple, mild in condition, easy to operate and environment-friendly; the prepared membrane is acid-resistant, alkali-resistant and good in flexibility; and the membrane is used for water treatment, and has excellent durability and competitive flux.

The invention discloses a preparation method of an alkali-resistant composite nanofiltration membrane. Polyethyleneimine is used as a composite layer material, multi-component epoxy is used as a crosslinking agent, and the composite nanofiltration membrane is obtained by a gradient crosslinking process. In the membrane filtration process, protonated amino groups on a polyethyleneimine molecular chain enable the surface of the membrane to be positively charged, and the membrane has high selectivity to multivalent cations. Due to the fact that amino and epoxy groups carry out ring-opening reactions to form carbon-carbon saturated bonds and hydroxyl groups, the composite layer has good stability and permeability in an alkaline environment. The preparation process is simple, and the compositemembrane is good in permeability and can be widely applied to graded removal of micromolecular organic matters in alkaline wastewater.

The present disclosure provides a method of manufacturing a water-treatment separation membrane having improved salt rejection rate and permeable flux properties, the method including: forming an aqueous solution layer containing an amine compound on a porous support; forming a polyamide active layer by bringing an organic solution containing an acyl halide compound and a first organic solvent into contact with the aqueous solution layer; and coating a second organic solvent having a degree of volatility lower than that of the first organic solvent on the polyamide active layer, and a water-treatment separation membrane manufactured by the manufacturing method.

The invention discloses a reverse osmosis membrane, a preparation method of the reverse osmosis membrane and application of the reverse osmosis membrane to the field of water treatment. The reverse osmosis membrane comprises a support layer and a separation layer which is positioned on the surface of the support layer, wherein the separation layer comprises polyhedral oligomeric silsesquioxane and sulfonated poly ether sulfone which has a structure as shown in any one of formula (I) to formula (III). The reverse osmosis membrane provided by the invention has excellent chlorine resistance and relatively high water flux and desalination ratio at the same time.

The invention discloses a method for preparing a reverse osmosis membrane capable of resisting biological pollution. The method comprises the following steps: putting a reverse osmosis membrane substrate into an organic phase containing an antibacterial additive, wherein the organic phase is ethylene glycol ethyl acrylate or acrylic amino-2-methyl-propanesulfonic acid; then, treating the reverse osmosis membrane substrate by using a water phase containing an initiator; carrying out drying treatment to obtain the reverse osmosis membrane capable of resisting the biological pollution. The invention also discloses a device for preparing the reverse osmosis membrane capable of resisting the biological pollution. The reverse osmosis membrane prepared by the method not only has good pure water flux and salt removing rate, but also has excellent biological pollution resistance.

The invention relates to a method for preparing multi-channel hollow fiber nano-filtration membranes. The method includes steps of (1), adding polymers, organic solvents and additives into a reaction kettle according to certain proportions, stirring the polymers, the organic solvents and the additives to form uniform and stable membrane casting solution, defoaming the membrane casting solution under a vacuum condition, ejecting the membrane casting solution via multi-channel hollow fiber molds under the driving effects of air pressures, feeding the membrane casting solution into external coagulating bath under certain core solution flow rate and air spacing conditions, carrying out phase transformation to form multi-channel hollow fiber basement membranes, sufficiently soaking the multi-channel hollow fiber basement membranes, then taking out the multi-channel hollow fiber basement membranes, airing the multi-channel hollow fiber basement membranes at certain temperatures, packaging the multi-channel hollow fiber basement membranes in stainless steel assemblies, plugging two ends of each stainless steel assembly by the aid of cotton and sealing the stainless steel assemblies by glue; (2), preparing aqueous-phase solution with certain concentration and oil-phase solution with certain concentration, injecting the aqueous-phase solution in multi-channel inner holes, reserving the aqueous-phase solution in the multi-channel inner holes for a certain period of time, purging the aqueous-phase solution by the aid of strong airflow, injecting the oil-phase solution into the multi-channel inner holes, reserving the oil-phase solution in the multi-channel inner holes for a certain period of time, purging the oil-phase solution by little airflow, arranging the multi-channel inner holes in an oven, carrying out reaction and taking the multi-channel inner holes out of the oven to obtain the multi-channel hollow fiber nano-filtration membranes. The method for preparing the multi-channel hollow fiber nano-filtration membranes has the advantages of high toughness and strength.

The invention relates to a preparation method of a hollow fiber composite nano-filtration membrane. According to the method, a polysulfone hollow fiber basic membrane is adopted and is subjected to dip-coating in a membrane forming solution, which takes acrylic resin, carboxyl type vinyl chloride-vinyl acetate resin and diphenylmethane diisocyanate as solutes and butyl acetate and dimethyl carbonate as solvents, to form a dense membrane, so as to prepare the hollow fiber composite nano-filtration membrane; the disadvantages that an organic hollow fiber composite nano-filtration membrane is easy to swell and has low mechanical strength, and an assembly is difficult to seal are overcome; meanwhile, the nano-filtration membrane has a good desalting rate and relatively high water flux and chemical stability, and can realize continuous industrial production.

The invention discloses a novel reverse osmosis membrane and a preparation method thereof. The preparation method of the membrane disclosed by the invention comprises the steps of blade coating of a support layer, preparation of a function layer, preparation of a protection layer, etc. Through the means such as surface grafting modification, ultrasonic preparation of the function layer and mixed acid washing in aftertreatment, the problems of mutual restriction of flux and desalination rate and relatively short service life caused by pollution are overcome to a certain degree. The reverse osmosis membrane provided by the invention can realize a good effect in practical application.

The invention discloses a multilayer reverse osmosis composite membrane which is provided with a photo-initiation polymer protective layer, and comprises a base layer playing a supporting role, a transition layer, a separation layer and a protection layer; the transition layer is located on the base layer, the separation layer is located on the transition layer, the protection layer is located onthe separation layer, and the protection layer is of a three-dimensional network structure formed by a photo-induced polymerization reaction. According to the multilayer reverse osmosis composite membrane, the protective layer with the three-dimensional network structure is formed on the surface of a composite membrane through photo-induced polymerization reaction, and under the condition that requirements on the desalination rate and flux of the multilayer reverse osmosis composite membrane are met, the composite membrane separation layer can be effectively prevented from being damaged and abraded by the outside, the service life of the composite membrane is greatly prolonged, and the anti-pollution performance of the composite membrane can be effectively improved.

The invention relates to a preparation method of an anti-pollution reverse osmosis membrane, the preparation method comprises the following steps: adding a surfactant and a water-soluble cross-linking agent into an aqueous solution of a polymer, and uniformly mixing to obtain an aqueous phase solution, wherein the surfactant is an anionic surfactant and/or a cationic surfactant; the polymer is a neutral water-soluble polymer and/or a charged water-soluble polymer; coating the composite membrane with the aqueous phase solution, standing, and removing the residual aqueous phase solution on the composite membrane; and reacting the composite membrane under a microwave condition to obtain the anti-pollution reverse osmosis membrane. According to the preparation method of the anti-pollution reverse osmosis membrane, a uniform and thin anti-pollution layer is prepared through a surface coating method. According to the method, the composite membrane has good anti-pollution performance, and the water flux of the composite membrane is improved by about 30%. In addition, the preparation method is simple, easy to control, good in reproducibility, low in preparation cost and suitable for large-scale production.

The invention discloses a reverse osmosis membrane, and a preparation method and application thereof, belonging to the field of separating membranes. The reverse osmosis membrane comprises a supporting layer, a separating layer, an intermediate connecting layer and a cross-linking layer which are successively laminated, wherein the separating layer is formed by sulfonated polyether sulphone as shown in a formula (1) which is described in the specification; the intermediate connecting layer is formed by polyethylene glycol; the cross-linking layer is formed by cross-linking alginate; and in theformula (1), M is K, Na or Li, and n is in a range of 10 to 100. The reverse osmosis membrane provided by the invention has excellent salt rejection rate, water permeability and chlorine resistance and good industrial application prospects.

The invention provides a method for preparing a reverse osmosis membrane and a reverse osmosis membrane prepared by the method. The method includes: forming a polysulfone layer by applying a solution containing a mixed solvent containing two or more solvents having different solubility parameter values ​​to the surface of a porous support; and forming a polysulfone layer on the polysulfone layer. active layer.

The present invention relates to a reverse osmosis membrane including: a porous support; a polysulfone layer formed on the porous support; and a polyamide active layer formed on the polysulfone layer, wherein the polyamide active layer is formed through interfacial polymerization between an amine compound and an acyl halide compound, and the acyl halide compound includes a monofunctional acyl halide and a polyfunctional acyl halide, and a method of manufacturing the same.

The invention discloses a preparation method of a high-efficiency anti-pollution reverse osmosis membrane. The preparation method comprises the following steps of treating a base material of the reverse osmosis membrane by plasma; treating by an organic phase containing an additive, wherein the organic phase is polystyrene sulfamic acid or polyvinyl sulfamic acid, the additive is a polyvinyl pyrrolidone and dimethylformamide mixture, and the mixing volume ratio is 1:4; then, drying the base material of the reverse osmosis membrane, so as to obtain the high-efficiency anti-pollution reverse osmosis membrane. The invention also discloses a preparation device of the high-efficiency anti-pollution reverse osmosis membrane. The prepared reverse osmosis membrane has the advantages that the pure water flux and desalting rate are good, the high-efficiency anti-pollution effect is realized, and the service life of the reverse osmosis membrane is prolonged.

The invention relates to a method for preparing a reverse osmosis composite membrane with high salt rejection rate and high flux by reforming a polyamide separation layer. The method is characterized in that after interfacial polymerization membrane preparation, the membrane is soaked in a modified solution containing a nucleophilic catalyst to prepare the reverse osmosis composite membrane with high salt rejection rate and high flux. The mass percentage concentration of the nucleophilic catalyst in the modified solution is 0.01%-5%. The modified nucleophilic catalyst is prepared from 4-dimethylaminopyridine, 4-pyrrolidinyl pyridine and N-methylimidazole. The solvent comprises water, normal hexane and normal heptane. After modification, a sodium chloride solution with the concentration of 2000 mg/L is adopted for testing the salt rejection rate and the water flux of the membrane, and under the operation pressure of 15.5 bar, the water flux of the membrane is 38.46-84.90 L.m<-2>. h<-1>, and the salt rejection rate is 98.00-99.54%. The whole membrane preparation process is simple and easy to amplify.

The present invention relates to a reverse osmosis membrane including: a porous support; a polysulfone layer formed on the porous support; and a polyamide active layer formed on the polysulfone layer, wherein the polyamide active layer is formed through interfacial polymerization between an amine compound and an acyl halide compound, and the acyl halide compound includes a monofunctional acyl halide and a polyfunctional acyl halide, and a method of manufacturing the same.