1477 results about "Interfacial polymerization" patented technology

The invention discloses a p-type or n-type COF film, the film thickness is 50 nm to 5 m, the aperture is 0.7 nm to 4 nm, and the film has a regular pore channel structure and light response performance. According to the invention, proper monomers are selected, and liquid-solid interface polymerization reaction is carried out, so that COF membranes grow along the tube wall, and p-type and n-type COF membranes are respectively prepared. The growth direction of the film is inconsistent with the transmission direction of the monomer and the catalyst, and the process can effectively promote the dissolution growth and self-repair of the COF film, so that the crystallinity and stacking orientation of the film are improved, and the structural characteristics of the COF film are optimized. The obtained COF film has a remarkable advantage of light-driven ion pump performance. The obtained COF membrane is used for preparing a desalting device.

The invention discloses a nanofiltration membrane for extracting lithium from salt lake brine with a high magnesium-lithium ratio and a preparation method of the nanofiltration membrane, and belongs to the technical field of nanofiltration composite membranes. The preparation method of the nanofiltration membrane comprises the following steps: first-time interfacial polymerization treatment, second-time interfacial polymerization treatment and post-treatment. The nanofiltration membrane with a double-layer lithium ion permeation channel is constructed through coupling of secondary interfacial polymerization and a B15C5 modification process, and stable permeation performance of the membrane is guaranteed while high magnesium ion rejection rate and high magnesium-lithium separation factor are realized through synergistic modification of crown ether and secondary interfacial polymerization. The nanofiltration membrane disclosed by the invention shows excellent performance in a real salt lake brine test, and in practical application, the membrane can effectively treat a complex brine system with a high magnesium-lithium ratio; and in a 24-hour continuous test, long-term stability is also shown, and an efficient, stable and feasible solution is provided for lithium extraction of the salt lake brine with the high magnesium-lithium ratio.

The invention discloses a pillararene-based supramolecular polymer membrane, a preparation method thereof and application of the pillararene-based supramolecular polymer membrane in dye separation. The preparation method utilizes interfacial polymerization, and comprises the following steps: mixing a CH2Cl2 solution containing MeP5Bpy with an aqueous solution containing tetra (4-aminophenyl) methane and acetic acid, and standing to obtain the pillararene-based supramolecular polymer membrane at the interface of CH2Cl2 and the aqueous solution. The dye separation process is simple to operate and low in equipment requirement; rectification operation is not needed in the separation process, energy consumption is low, energy is saved, and the production cost is reduced.

The invention provides a preparation method of a polyester loose nanofiltration membrane, and belongs to the technical field of nanofiltration membrane preparation. The preparation method provided by the invention comprises the following steps: dissolving a water-phase monomer in a sodium hydroxide solution to obtain a NaOH solution containing the water-phase monomer; soaking an ultrafiltration membrane in the NaOH solution containing the aqueous phase monomer to obtain an ultrafiltration membrane supporting layer; contacting the ultrafiltration membrane supporting layer with a trimesoyl chloride solution, and carrying out interfacial polymerization reaction to obtain a primary nanofiltration membrane; and carrying out heat treatment on the primary nanofiltration membrane to obtain the polyester loose nanofiltration membrane. The water-phase monomer is a compound which has a non-planar distorted structure and simultaneously contains phenolic hydroxyl groups and alcoholic hydroxyl groups. The method provided by the invention is simple and easy to implement, relatively low in required cost and beneficial to realizing large-scale industrial production of the high-efficiency nanofiltration membrane. The polyester loose nanofiltration membrane prepared by the preparation method disclosed by the invention has relatively high permeation flux, and meanwhile, a relatively high Na2SO4 retention rate can be kept.

The invention discloses a high-selectivity magnesium-lithium separation nanofiltration membrane based on a polyolefin base membrane and a preparation method and application of the high-selectivity magnesium-lithium separation nanofiltration membrane based on the polyolefin base membrane. The preparation method comprises the steps that the polyolefin base membrane is in single-face contact with an organic phase monomer solution containing an isophthaloyl chloride monomer or a paraphthaloyl chloride monomer, and the redundant solution is poured out; one side, contacted with the organic phase monomer solution, of the obtained membrane is contacted with a polyethyleneimine-containing aqueous phase monomer solution, an interfacial polymerization reaction is carried out, the obtained membrane is placed in a drying oven for heat treatment, then the membrane is soaked in an organic solution for activation, and the polyvinyl composite nanofiltration membrane is obtained. The nanofiltration membrane has high magnesium ion interception and high magnesium-lithium separation selectivity in a mixed solution with a high magnesium-lithium ratio, the preparation process is simple, conditions are mild, amplification and industrial production are easy to realize, and the nanofiltration membrane has good long-term operation stability.

The invention provides a PVDF (Polyvinylidene Fluoride) nanofiltration membrane constructed on the basis of microwave-enhanced bridging interfacial polymerization as well as a preparation method and application of the PVDF nanofiltration membrane. The method comprises the following steps: reacting PVDF powder with an organic alkali to prepare a modified film-forming solution, blade-coating the modified film-forming solution on a non-woven fabric supporting layer, placing the non-woven fabric supporting layer in an ethanol-water or methanol-water coagulating bath, and preparing a PVDF supporting film by virtue of assistance of an ice template; weighing the functionalized nano material and an amino silane coupling agent, performing ultrasonic dispersion, and adding a catalyst for reaction to obtain dispersion liquid; immersing a PVDF support membrane into the dispersion liquid to obtain a modified membrane; immersing the modified membrane into an aqueous solution containing an amine monomer and an organic solution containing an acyl chloride monomer, and carrying out microwave radiation. The interface reaction rate and selectivity are enhanced through the microwave excitation effect, and meanwhile, the hydrophilicity and reaction activity of the PVDF base membrane are cooperatively regulated and controlled, so that the separation efficiency and the anti-pollution capacity of the membrane are remarkably improved. The obtained PVDF nanofiltration membrane has high flux, high selectivity and excellent structural stability, and is suitable for efficient purification and resource recovery application in a complex water system.

The invention discloses a desalting membrane as well as a preparation method and application thereof, and relates to the technical field of membrane separation. The desalting membrane comprises a porous ultrafiltration base membrane and a functional layer formed on the surface of the porous ultrafiltration base membrane; the functional layer is formed by copolymerizing and cross-linking a polyamine monomer, a zwitterionic multi-element hydroxyl monomer and an acyl chloride monomer through an interfacial polymerization reaction. The preparation method comprises the following steps: providing the porous ultrafiltration base membrane; coating the surface of the porous ultrafiltration base membrane with an alkaline water-phase solution containing a polyamine monomer and a zwitterionic multi-hydroxyl monomer to form a water-phase solution layer; coating an oil-phase solution containing an acyl chloride monomer on the surface of the water-phase solution layer to form a functional layer; and performing heat treatment. The invention also provides application of the desalination membrane in any one of seawater desalination, brackish water desalination, wastewater treatment and material separation and concentration. According to the invention, zwitter-ion-based multi-hydroxyl monomers are introduced into water-phase monomers to participate in interfacial polymerization, and a super-hydrophilic nano-channel is constructed in a separation layer, so that the water flux and the desalination rate of the membrane are remarkably improved.

The invention discloses a preparation method and application of a ternary multifunctional three-dimensional framework mediated high ammonia nitrogen selectivity polyamide reverse osmosis membrane, and belongs to the technical field of membrane separation. The method comprises the following steps: 1, preparing a high-molecular copolymer; 2, preparing a polysulfone support layer by adopting a non-solvent induced phase inversion method; 3, preparing a polyamide reverse osmosis membrane by adopting an interfacial polymerization method; and 4, preparing the polyamide reverse osmosis membrane with high ammonia nitrogen selectivity. Through reasonable design of the structure and distribution of the group of the ternary multifunctional three-dimensional structure high-molecular copolymer, the copolymer can react with the acyl chloride group on the surface of the polyamide active layer to form a covalent amido bond, and the covalent amido bond is anchored on the surface of the polyamide layer in situ to construct the functional layer. The functional layer not only can significantly improve the surface potential of the membrane, but also can increase the inherent concentration of ammonia nitrogen on the surface of the membrane, thereby increasing the diffusion resistance, finally realizing the repulsive force to the ammonia nitrogen, and improving the interception capability of the grafted membrane to the ammonia nitrogen. The operation process is simple and mild, the whole membrane preparation process is not changed, and industrialization is easy.

The invention discloses a high-performance composite solvent-resistant nanofiltration membrane with a rigid twisted non-planar structure polyamide layer and a preparation method of the high-performance composite solvent-resistant nanofiltration membrane. The preparation method comprises the steps of preparation of the rigid twisted non-planar structure polyamide layer and surface modification. A water phase solution containing adamantane diamine and m-phenylenediamine and an organic phase solution containing 1, 3, 5-trimesoyl chloride and acetone are subjected to interfacial polymerization reaction to prepare a polyamide layer with a rigid twisted non-planar structure, and then a polyphenol modifier is used for carrying out hydrophilic modification on the polyamide layer, so that the rigid twisted non-planar structure is obtained. The pure water permeability and retention rate of the solvent-resistant nanofiltration membrane are obviously improved; due to the introduction of adamantane diamine, the interfacial polymerization process and the formation of a polyamide layer are remarkably regulated and controlled, and the separation performance of the solvent-resistant membrane is greatly improved on the premise that the interception performance of the membrane is hardly reduced; the preparation process is simple, and the prepared membrane is excellent in performance and has a good application prospect in the aspect of organic solvent separation.

The invention discloses a preparation method of a high-performance magnesium-lithium separation membrane. The preparation method comprises the following steps: forming a polyamide film; mixing small molecular quaternary ammonium salt and amine monomer to serve as a solution for secondary interfacial polymerization; performing secondary interfacial polymerization to form a positive charge separation layer; and finally, promoting the reaction through high-temperature curing to obtain the nanofiltration membrane. According to the invention, the quaternary ammonium group with strong positive charges is introduced into the membrane in an in-situ grafting manner, the positive electricity of the membrane is increased, meanwhile, a transmission pore channel with positive charges is constructed, the operation is simple, the effect is obvious, the separation capacity of the membrane is greatly improved, and the method has a wide large-scale application prospect.

The invention relates to the technical field of phase change microcapsules, in particular to a polyurea / polyacrylate double-layer shell material phase change microcapsule and a preparation method thereof. The microcapsule sequentially comprises a phase change material core material, a polyacrylate shell material and a polyurea shell material from inside to outside, and is prepared from the following raw materials: a polyisocyanate monomer, an acrylate monomer, an acrylate functional monomer, an acrylate cross-linking agent, a chain extender, an initiator, a surfactant, a phase change material and water. According to the invention, polyurea interfacial polymerization and polyacrylate suspension polymerization are combined to form a double-layer shell material for coating to prepare the phase change microcapsule, so that the phase change microcapsule has excellent sealing property, durability and high enthalpy value performance.

The present invention relates to the technical field of nanofiltration membranes, and particularly relates to a preparation method for a positively charged nanofiltration membrane for improving a "trade-off" effect. The preparation method comprises the following process: sequentially adding a water phase and an oil phase to the surface of a support layer to perform a reaction, so as to prepare a polyamide layer; pouring in a functionalized graphene dispersion; and sequentially placing same into an N,N-dimethyl propane diamine solution, a sodium borohydride solution and an iodomethane solution to perform a reaction, so as to obtain a nanofiltration membrane, wherein the functionalized graphene is pyrrolidone-based graphene. According to the present invention, a mixture of piperazine and polyethyleneimine is used as a water phase and is subjected to interfacial polymerization with an oil phase 1,3,5-trimesoyl chloride on the surface of the support membrane; and by means of the compounding of micromolecular piperazine and macromolecular polyethyleneimine, the rapid formation of a polyamide layer is promoted, the distance of a system cross-linked network is increased, a positively charged polyamide layer having a large pore diameter and good hydrophilicity is formed, and a good water flux and a good rejection rate are achieved, thereby improving the "trade-off" effect.

The invention discloses a preparation method of a high-activity hierarchical pore boric acid imprinted hydrogel microsphere adsorbent and application of the adsorbent to selective adsorption of a flavonoid compound naringin NRG. According to the invention, dopamine is used for modifying COFs so as to enhance surface functionalization of COFs; preparing a sulfydryl functionalized covalent organic framework microsphere; synthesizing sulfydryl microspheres by utilizing an emulsion interfacial polymerization method; preparing a COFs boron affinity imprinting microsphere adsorbent based on boron affinity interaction; the adsorbent is applied to selective adsorption of NRG in agricultural wastewater. The prepared adsorbent has a remarkable multilayer adsorption effect, and the adsorption capacity is remarkably improved through the boron affinity effect. The multi-stage pore structure of the COFs microspheres provides abundant sites for adsorption, and the mass transfer rate is remarkably improved. In addition, the prepared adsorbent shows remarkable specificity in the aspects of adsorption and separation of NRG, and a promising adsorption material is provided for industrial separation of NRG.

The invention discloses a high-salt-rejection and pollution-resistant polyamide reverse osmosis membrane, which is characterized in that an aromatic cationic surfactant containing two benzene ring structures is adopted to regulate and control the interfacial polymerization reaction of a polyamine monomer and a polyacyl chloride monomer, and a high-salt-rejection and pollution-resistant polyamide functional layer is generated on a porous ultrafiltration base membrane. The effective specific surface area of the polyamide functional layer of the reverse osmosis membrane is gt; 1.2, the surface potential gt when the pH is equal to 7; -20 mV; the molecular weight cut-off of the polyamide reverse osmosis membrane is 1t; the molecular weight is 100Da, and the retention rate for 2000ppm of NaCl is gt; the anti-fouling coating has the advantages of good hydrophilicity and excellent anti-fouling performance. The preparation process of the polyamide reverse osmosis membrane is simple and efficient, and has industrial application potential. The polyamide reverse osmosis membrane can be used for purification and treatment of different types of water, and has important application value.

The invention discloses a preparation method of a photocatalytic nanofiltration membrane based on IL-GQDs. The method comprises the following steps: pretreating bagasse, and applying the pretreated bagasse and imidazole ionic liquid (IL) to preparation of ionic liquid functionalized graphene quantum dots (IL-GQDs); the IL-GQDs are uniformly distributed on the surface of the base membrane by utilizing a vacuum-assisted low-temperature interfacial polymerization technology to form an ultrathin photocatalytic active layer; and finally, curing and cleaning to obtain the photocatalytic nanofiltration membrane based on the IL-GQDs. According to the prepared IL-GQDs, the membrane surface is endowed with high specific surface area and excellent photocatalytic activity, and meanwhile, an additional water transmission channel can be established under the condition that the pore diameter of the membrane is not changed, so that the problem of trade-off of a traditional membrane is solved. In addition, through combination of low-temperature and vacuum-assisted interfacial polymerization technologies, the membrane structure is more uniform and compact, defects on the surface of the membrane are reduced, and the stability and the anti-pollution capacity of the membrane are improved. The membrane disclosed by the invention shows relatively high water flux, salt recovery rate and long-term stability in water treatment application.

The invention discloses a polyamide composite membrane based on a nanobubble-assisted free interface polymerization strategy and a preparation method and application of the polyamide composite membrane. Nanobubble precursors of different types and concentrations are loaded in a water-phase solution by a chemical method, and the polyamide composite membrane is prepared by means of reaction between the precursors and water or self-decomposition of the precursors. Nanometer bubbles are pre-constructed in a water phase solution, and under a free interface polymerization process, by utilizing upward migration of the nanometer bubbles at a neutralization phase interface of the water phase solution, hierarchical regulation and control of a polyamide separation layer structure are realized from bottom to top; according to the polyamide composite membrane, the bottom opening characteristic, the internal nano-cavity structure and the surface morphological characteristic of the polyamide separation layer are effectively improved, the transmembrane transmission rate of water molecules is remarkably increased, the hydraulic resistance is reduced, and the water flux of the membrane is remarkably improved on the premise that the salt rejection rate of the polyamide composite membrane is not sacrificed.

The invention discloses a preparation method and application of a polyamide composite nanofiltration membrane containing a graphdiyne middle layer, and belongs to the technical field of membrane separation. Comprising a porous substrate, a graphdiyne middle layer and a polyamide layer. The graphdiyne is selected from graphdiyne, graphdiyne, hydrogen-substituted graphdiyne and other graphdiyne derivatives. The specific preparation method comprises the following steps: carrying out suction filtration on graphdiyne dispersion liquid to a porous substrate, respectively dipping the graphdiyne dispersion liquid in a water phase and an oil phase, carrying out interfacial polymerization to generate a polyamide membrane, and finally, drying the membrane in a constant-temperature and constant-humidity drying oven to obtain the polyamide composite nanofiltration membrane containing the graphdiyne middle layer. The preparation method disclosed by the invention is simple and efficient, and the prepared composite membrane can effectively intercept divalent salt and organic matters in water and has excellent water permeability, ion separation and antibiotic desalination effects.

The invention discloses a preparation method of an acid-resistant polyquaternary ammonium membrane based on a Porxitch interfacial polymerization reaction. The preparation method comprises the following steps: dissolving an amine monomer in a water-phase solvent to form a water-phase solution; dissolving a bromomethyl monomer in an organic phase solvent to form an organic phase solution; after the base membrane is soaked in the water phase solution for a period of time, the water phase solution is removed, and the water phase solution remaining on the surface of the base membrane is removed; coating the organic phase solution on the surface of a base membrane, and carrying out interfacial polymerization reaction for 1-15 minutes at the high temperature of 50-90 DEG C, so as to prepare a polyquaternary ammonium membrane on the base membrane; and washing the surface of the polyquaternary ammonium membrane with an organic solvent to remove residual reactants, and then carrying out heat treatment in a drying oven to obtain the acid-resistant polyquaternary ammonium membrane.

The invention relates to a preparation method of a nanofiltration membrane containing a covalent organic framework (COF) interlayer. The nanofiltration membrane (NF) comprises a base membrane, an interlayer and a separation surface layer. The interlayer is formed by in-situ growth of polyphenol and diamine under the action of an oxidizing agent, and the separation surface layer is formed by an aqueous-phase active monomer and multi-element acyl chloride through an interfacial polymerization reaction. According to the invention, an imino covalent organic framework (TpPa-COF) film interlayer is introduced, and a surface polyamide layer is prepared through interfacial polymerization, so that the hydrophilicity of the film and the ability of removing divalent cations are improved. The invention aims to solve the problem of balance between low flux and high separation effect of an NF membrane in separation of monovalent / divalent cations, maintain ideal water flux while ensuring high separation effect, and solve the problem that a traditional NF membrane separation layer has defects. The two-dimensional TpPa-COF material can effectively control the pore size distribution and hydrophilicity of the surface of the substrate and improve the separation performance of the composite membrane. The preparation method is simple, and the obtained nanofiltration membrane has a wide application prospect.

The invention discloses a chlorine-resistant and acid-resistant composite nanofiltration membrane and a preparation method thereof, and belongs to the technical field of membrane separation. A polyhydric alcohol or / phenol compound monomer containing no less than two hydroxyl groups is subjected to interfacial polymerization with cyanuric chloride, so that a relatively loose network structure can be formed, and selective separation of dye and salt is realized. As a hydrochloric acid (HCl) byproduct can be generated in the reaction process, an alkaline compound is added as an acid-binding agent to neutralize HCl and promote the interfacial polymerization reaction, the formed composite nanofiltration membrane structure does not contain amino groups and polyamide bonds sensitive to active chlorine, the reaction sites of the active chlorine are reduced, and the chlorine-resistant stability of the membrane is good. Meanwhile, the polymer film contains a triazine ring structure, and a formed ether bond has good chemical stability, so that the acid-resistant stability of the film is good. The prepared composite nanofiltration membrane has good nanofiltration separation performance, shows good chlorine-resistant and acid-resistant stability, and can be used for separation of dyes / salts.

The invention relates to the technical field of dye separation, and discloses a loose nanofiltration membrane and a preparation method and application thereof.The loose nanofiltration membrane is prepared from a multi-acyl chloride organic solution and an amine monomer water-phase solution on the surface of a porous supporting membrane through a one-step interfacial polymerization method, and the rejection rate of the loose nanofiltration membrane to methyl blue, Congo red and other dyes is 95% or above; meanwhile, the loose nanofiltration membrane has high water permeability and excellent dye / inorganic salt separation selectivity, and is expected to have wide application prospects in the fields of dye production and purification and dye wastewater desalination.

The invention provides a high-flux chlorine-resistant anti-pollution composite nanofiltration membrane and a preparation method and application thereof, and the preparation method comprises the following steps: immersing a porous base membrane into a water-phase monomer solution, taking out the porous base membrane, removing a surface solution, and immersing the porous base membrane into an organic-phase monomer solution to complete interfacial polymerization to obtain an initial polyamide active layer; immersing the prepared initial polyamide active layer in a mixed solution containing sodium lignin sulfonate, a surfactant and a catalyst to complete surface modification; and carrying out thermocuring on the prepared surface-modified polyamide active layer to obtain the high-flux chlorine-resistant anti-pollution composite nanofiltration membrane. The anti-pollution performance and water flux of the prepared composite nanofiltration membrane are obviously improved, the composite nanofiltration membrane is suitable for being used as drinking water terminal treatment, and softening and purification of drinking water are achieved.

The invention relates to the technical field of membrane separation, in particular to an optical isomerization metal organic framework interlayer forward osmosis membrane and a preparation method thereof. The preparation method of the photo-isomerization metal organic framework interlayer forward osmosis membrane comprises the following steps: loading a UiO-67-SP nano material dispersion liquid on the surface of a nylon support layer under a light source irradiation condition or a dark condition to form a composite interlayer; under a light source irradiation condition or a dark condition, adding an amine monomer aqueous phase solution and an acyl chloride organic phase solution to the surface of the composite intermediate layer, so that an amine monomer in the amine monomer aqueous phase solution and an acyl chloride monomer in the acyl chloride organic phase solution are subjected to an interfacial polymerization reaction and a separation layer is formed; the spiropyrane / zirconium-based photo-isomerization metal organic framework intermediate layer forward osmosis membrane is obtained. According to the prepared forward osmosis membrane, the water flux and the salt ion interception effect are remarkably improved, namely, the reverse salt flux is reduced, and the problems that an existing forward osmosis membrane is poor in water permeability and ion recovery performance due to the fact that a separation layer is too thick and non-selective holes exist can be solved.

The invention relates to the technical field of seawater desalination, in particular to a seawater desalination reverse osmosis membrane, a preparation method and application. The seawater desalination reverse osmosis membrane is prepared by the preparation method. The preparation method comprises the following steps: immersing the prepared support layer into a water phase solution, and then taking out the support layer adsorbing the water phase solution; immersing the support layer adsorbing the water phase solution into a first oil phase solution, and forming a primary reverse osmosis membrane through a first interfacial polymerization reaction; then, taking out the primary reverse osmosis membrane, and carrying out first drying treatment under a steam condition; and immersing the primary reverse osmosis membrane into a second oil phase solution, and carrying out a second interfacial polymerization reaction to form the seawater desalination reverse osmosis membrane. The application refers to the application of the reverse osmosis membrane for seawater desalination in the aspects of reclaimed water reuse, seawater desalination and brackish water desalination. According to the invention, the seawater desalination reverse osmosis membrane which simultaneously meets high desalination rate and high water flux can be prepared.

The invention discloses a piezoelectric nanofiltration membrane with an electric anti-scaling function and a preparation method and application thereof, and belongs to the technical field of membrane method water treatment. Two-dimensional conductive nanosheets are doped in a traditional PVDF piezoelectric membrane, phase separation is performed in an alternating electric field, then a piezoelectric base membrane with high beta-PVDF content and a crystal orientation structure is prepared, and then interfacial polymerization is performed on the piezoelectric base membrane to form the nanofiltration membrane with piezoelectric activity. By adding the two-dimensional conductive nanosheets into the base film, on one hand, the content of beta-phase PVDF in the base film is increased, so that the piezoelectric property of the base film is enhanced; on the other hand, the two-dimensional conductive nanosheets are induced to be directionally arranged and form conductive synapses on the surface of the base membrane by synchronously applying an alternating electric field in the membrane preparation process, so that after interfacial polymerization, the conductive synapses can penetrate into a polyamide layer and form a conductive network, and finally a piezoelectric signal of the base membrane is conducted to the surface of the nanofiltration membrane; therefore, the nanofiltration membrane is endowed with piezoelectric characteristics and an electric anti-scaling function.

The invention provides a polyimide multilayer composite membrane material as well as a preparation method and application thereof, and belongs to the technical field of gas separation. According to the method, through collaborative design of a functional support layer, a gradient MOF layer and an ultrathin selection layer structure, the problems of support layer pore seepage, MOF agglomeration, weak interface bonding and the like in an existing composite membrane material are solved. The preparation method comprises the following steps: firstly, carrying out electrostatic spinning on a polyamide acid glue solution, and synchronously introducing dopamine by adopting a chemical imidization method to prepare a functionalized polyimide fiber membrane containing hydroxyl and amino on the surface, so that the mechanical property of a supporting layer and the MOF anchoring capability are remarkably improved; growing MOF layers with different particle sizes on the surface of the fiber membrane by regulating and controlling the concentration gradient of ligand / metal salt and the reaction time, and passivating through a silane coupling agent after each step of growth so as to avoid heterogeneous nucleation and construct a gradient structure; after the MOF gradient layer is subjected to Ar plasma pretreatment to introduce hydroxyl, the ultrathin polyamide selection layer is formed by utilizing interfacial polymerization of fluorine-containing acyl chloride and a macrocyclic amine monomer, and the ultrathin polyamide selection layer is suitable for gas separation work.

The invention discloses a pH response type pesticide microcapsule and a preparation method thereof, and the preparation method comprises the following steps: mixing a pesticide raw material, an organic cosolvent and a diisocyanate monomer to obtain an oil phase; mixing a surfactant with water to obtain a water phase; adding the oil phase into the water phase, and carrying out shear emulsification to obtain O / W type emulsion; and mixing the O / W type emulsion with an aqueous solution of polyamine containing the vanillyl Schiff base structure, and carrying out an interfacial polymerization reaction to obtain the pH response type polyurethane pesticide microcapsule with the vanillyl Schiff base structure. According to the invention, the organic cosolvent and diisocyanate are used as oil phase components, can dissolve the raw pesticide and do not react with the raw pesticide, has good pH responsiveness, can realize stimulation response to an acid environment caused by pathogenic bacteria infected crops, improves the utilization rate of the pesticide, and reduces the usage amount of the pesticide.

A method for preparing a self-supporting composite nanofiltration membrane is provided. A porous graphene-based two-dimensional sheet material is prepared by taking amino graphene quantum dots as the main body and subjecting them to an interfacial polymerization reaction with polyacyl chloride, and then the porous graphene-based two-dimensional sheet material is encapsulated in-situ with polyamide by an in-situ encapsulating technology to prepare a self-supporting porous graphene / polyamide separation layer with excellent permeability and high selectivity.

The invention discloses a surface-enhanced tryptophan modified nanofiltration membrane as well as a preparation method and application thereof. Belongs to the field of water treatment membrane preparation. The invention aims to solve the technical problems of non-uniform pore size distribution and surface hydrophobicity of the conventional nanofiltration membrane. The method comprises the following steps: adding tryptophan into a piperazine water-phase solution, and carrying out interfacial polymerization with oil-phase trimesoyl chloride to prepare the tryptophan modified nanofiltration membrane. According to the preparation method, the diffusion rate of the piperazine monomer can be adjusted in the interfacial polymerization process by utilizing a similar surfactant structure of tryptophan, meanwhile, the tryptophan has hydrophilicity and can improve the hydrophilicity of the surface of an active layer, and the prepared modified nanofiltration membrane is reduced in molecular weight cut-off, improved in surface hydrophilicity and good in water resistance. The retention rate of organic micro-pollutants is improved, and meanwhile, good anti-pollution performance is achieved.

According to the method for preparing the polyamide / sulfonated COFs reverse osmosis membrane through in-situ copolymerization, a polysulfone ultrafiltration membrane is used as a supporting layer, a water-phase monomer solution and an organic-phase monomer solution are subjected to a one-step in-situ copolymerization reaction on a water-phase / organic interface on the supporting layer, and the polyamide / sulfonated COFs reverse osmosis membrane is prepared. The preparation method is simple in technological process and low in cost, the sulfonated COFs material is introduced into a polyamide layer through one-step interface in-situ copolymerization, the dispersity and compatibility of the sulfonated COFs can be well enhanced, the interface polymerization process is regulated and controlled by fully utilizing a porous structure, hydrophilicity and indirect control of monomer diffusion, and the like, and the preparation method is suitable for large-scale industrial production. The trade-off effect of a traditional polyamide reverse osmosis membrane is broken through, the salt rejection rate is increased while high water flux is guaranteed, and the polyamide reverse osmosis membrane has very high practical application value.