433 results about "Poly(benzimidazole)" patented technology

The invention relates to the technical field of all-vanadium redox flow batteries, in particular to a sulfonated polybenzimidazole proton exchange membrane as well as a preparation method and application thereof. The proton exchange membrane structurally comprises a polybenzimidazole polymer main chain and a sulfonic acid group, the free volume of the polybenzimidazole polymer is regulated and controlled by synthesizing raw materials with different structures, and the polybenzimidazole proton exchange membrane is obtained by sulfonating the polybenzimidazole polymer. Aiming at the problems of cross permeation of vanadium ion electrolyte of a positive electrode and a negative electrode of the all-vanadium redox flow battery, capacity attenuation of the all-vanadium redox flow battery and low energy conversion efficiency, the preparation method comprises the following steps: constructing a polybenzimidazole polymer main chain by selecting raw materials with high rigidity and high free volume; the mechanical property of the polybenzimidazole membrane is improved while a rapid ion channel is constructed in the polymer membrane, and water molecules can be contained to limit swelling of a membrane material.

The invention discloses a lithium ion battery composite diaphragm, a preparation method and a lithium ion battery, and relates to the technical field of lithium ion batteries. The lithium ion battery composite diaphragm comprises a base membrane and a functional coating arranged on the negative electrode side of the base membrane, the functional coating sequentially comprises an ion conducting layer, a thermal barrier layer and a self-repairing layer from the position close to the base film to the position far away from the base film; wherein the base membrane is a polyimide and aramid nanofiber blended electrostatic spinning membrane; the ion conducting layer comprises a compound of a modified fast ion conductor and polyvinylidene fluoride-hexafluoropropylene; the thermal barrier layer comprises a cross-linked network of boron nitride nanosheets and polybenzimidazole; the self-repairing layer comprises polyurethane microspheres loaded with dynamic disulfide bonds. The composite diaphragm provided by the invention can remarkably inhibit a purple area on the surface of a negative electrode, and enhance high-temperature self-protection and interface self-repairing of the lithium ion battery, so that the cycle and safety performance of the lithium ion battery are remarkably improved.

The invention relates to a high-temperature proton exchange membrane, in particular to a high-temperature proton exchange membrane based on silica cross-linked polybenzimidazole and a preparation method of the high-temperature proton exchange membrane. The preparation method comprises the following steps: polymerizing 3, 3 '-diaminobenzidine, 4, 4'-diphenyl ether dicarboxylic acid and 5-hydroxyisophthalic acid to form a polybenzimidazole main chain containing an ether bond and a phenolic hydroxyl group, grafting a silane coupling agent on the polybenzimidazole main chain, and finally carrying out membrane formation and acid catalysis treatment to obtain the high-temperature proton exchange membrane based on silica crosslinked polybenzimidazole. A silicon-oxygen network structure is introduced into a polybenzimidazole main chain, so that the phosphoric acid retention rate and the oxidation resistance of the polymer film can be effectively improved, and the service life of the polymer film is prolonged.

The invention discloses a polybenzimidazole modified ion exchange membrane as well as preparation and application thereof. The polybenzimidazole modified ion exchange membrane comprises a polybenzimidazole-containing porous base membrane, the surface of the porous base membrane is grafted with a sulfonic acid modified layer, and the outer surface of the sulfonic acid modified layer is coated with an aluminum fluoride layer. The preparation method of the membrane comprises the following steps: immersing a polybenzimidazole-based membrane into an ammonium acetate aqueous solution for reaction, taking out the base membrane after the reaction, and drying to obtain a pretreated base membrane; immersing the pretreated base membrane into a sulfonic acid group grafting solution, heating for reaction, cleaning the base membrane after the reaction, and drying to obtain a sulfonic acid modified base membrane; and immersing the sulfonic acid modified base membrane into an ethanol solution of aluminum fluoride for reaction, taking out the membrane after the reaction, cleaning and drying to obtain the membrane. The membrane can be used for assembling a flow battery. According to the invention, the problem that a sulfonic acid modified layer is incompatible with metal fluoride is overcome, and a proper combination of a sulfonating agent and metal fluoride is screened, so that the high-performance ion exchange membrane which can be used for a flow battery is successfully obtained.

The invention relates to the technical field of all-vanadium redox flow batteries, in particular to a covalent organic framework cross-linked sulfonated polybenzimidazole proton exchange membrane as well as a preparation method and application thereof. The proton exchange membrane structurally comprises a polymer main chain, a sulfonic acid group, a connecting agent and a cross-linking agent molecule, a sulfonated polybenzimidazole polymer, a COF cross-linking agent and the connecting agent are dissolved in N-methyl pyrrolidone, and the COF cross-linked sulfonated polybenzimidazole proton exchange membrane is obtained after treatment. Aiming at the problems that vanadium ions of a positive electrode and a negative electrode of an all-vanadium redox flow battery are crossed, the capacity of the all-vanadium redox flow battery fades and the energy efficiency is low, the hydrophilicity of the sulfonated polybenzimidazole proton exchange membrane is improved through sulfonation treatment, and the mass transfer resistance is reduced. After the covalent organic framework is introduced, the increased free volume is beneficial to construction of a rapid proton transmission channel and can accommodate water molecules to limit swelling of the membrane material.

The invention provides a phosphoric acid doped polybenzimidazole high-temperature proton exchange membrane and a preparation method thereof. In the membrane material, the range of the mass fraction of the phosphoric acid in the polybenzimidazole polymer is greater than 0 wt.% and not greater than 3000 wt.%. The membrane is prepared by the following steps: S1, dissolving a polybenzimidazole polymer in a solvent, and adding phosphoric acid to obtain a composite solution; and S2, casting the composite solution onto a membrane forming container, and drying to obtain the phosphoric acid doped polybenzimidazole high-temperature proton exchange membrane. The phosphoric acid doped polybenzimidazole high-temperature proton exchange membrane not only can be used for preparing HT-PEM without internal stress so as to prevent loss of phosphoric acid, but also can be used for randomly and accurately controlling the phosphoric acid doping amount and thickness of the prepared membrane through the composition and volume of the solution; therefore, the phosphoric acid doped polybenzimidazole composite HT-PEM without internal stress, which has high stability and ultrahigh specific proton conductivity, is prepared.

The invention relates to the field of multifunctional coatings, in particular to a multifunctional coating based on acrylic resin and a production process of the multifunctional coating. Comprising the following raw materials in parts by weight: 40-60 parts of water-based acrylic resin emulsion, 0.3-0.6 part of a defoaming agent, 3-5 parts of modified nano hydroxyapatite, 0.3-0.5 part of a flatting agent, 2-5 parts of a dispersing agent, 1-3 parts of a curing agent, 3-5 parts of modified nano aluminum oxide and 30-50 parts of deionized water. The grafted chloroprene rubber can improve the interfacial compatibility of the nano-hydroxyapatite and a matrix and endows the coating with wear resistance, and after the nano-alumina is grafted with polybenzimidazole, a benzimidazole ring interacts with the matrix to enhance the interfacial compatibility of the nano-alumina and the matrix, so that the nano-alumina forms a high-temperature-resistant structure in the coating, and the wear resistance of the coating is improved. And the aromatic heterocyclic structure of the polybenzimidazole can endow the coating with higher thermal decomposition temperature, so that the coating has high temperature resistance.

The invention discloses a water-soluble phosphonated polybenzimidazole polymer and a preparation method thereof, and particularly, under the protection of nitrogen flow, 3, 3 '-diaminobenzidine and diphosphonic acid substituted aromatic dicarboxylic acid react for 6-30 hours at 180-250 DEG C by taking polyphosphoric acid as a medium, and the phosphonated polybenzimidazole polymer is obtained through polycondensation. The phosphonated polybenzimidazole polymer disclosed by the invention has good solubility in water under an alkaline condition, can be used as a solvent in subsequent processing, has the characteristics of no pollution and environmental protection, is easy to recover and has a wide application prospect.

The invention discloses a carboxyl-containing Troger base and a preparation method of an anion exchange membrane of the carboxyl-containing Troger base, and relates to the technical field of ion exchange membrane preparation. The preparation method of the anion exchange membrane containing the carboxyl comprises the following steps: synthesizing a Troger base containing the carboxyl, synthesizing a polybenzimidazole polymer containing the Troger base, synthesizing an anion exchange membrane polymer containing the Troger base, and preparing the compact anion exchange membrane containing the Troger base. Compared with the prior art, the preparation method has the advantages that the carboxyl-containing Troger base is synthesized through the reaction of specific aminomethyl benzoic acid and dimethoxymethane and by using trifluoroacetic acid as a solvent and a catalyst, so that the purity and the stability of a product are improved, the carboxyl-containing Troger base is more effectively introduced into a polybenzimidazole polymer, and the polybenzimidazole polymer is prepared. The porosity of the polybenzimidazole polymer is improved, so that the electrochemical performance and the mechanical stability of the anion exchange membrane are improved.

The invention discloses a screen cloth enhanced polybenzimidazole porous membrane as well as a preparation method and application thereof. The preparation method comprises the following steps: fully mixing polybenzimidazole, a polar solvent and a template to obtain a mixed solution, coating a base material with the mixed solution, placing a polymer mesh on the previous base material, and carrying out in-situ compounding, polar solvent removal and film formation to obtain a compact mesh reinforced polybenzimidazole film; and then carrying out in-situ etching treatment to prepare the screen cloth enhanced polybenzimidazole porous membrane. The size and connectivity of ion channels in the membrane can be regulated and controlled by regulating and controlling the type and content of templates in the membrane casting process, and the polybenzimidazole porous layer can be ultrathin by combining the effect of enhancing the mechanical property of the polymer mesh cloth, so that the mass transfer resistance of the polybenzimidazole porous separation layer is remarkably reduced, and the performance of the membrane is improved. The mesh-reinforced polybenzimidazole porous membrane has good dimensional stability and pore uniformity, and has the characteristics of high ion selectivity, high ion conductivity and high stability.

The invention relates to the technical field of high-molecular compounds, and discloses an epoxy resin material for a high-pressure conduit and a preparation method of the epoxy resin material. The preparation method comprises the following steps: preparing the following raw materials in parts by mass: 65-70 parts of bisphenol A epoxy resin; 55-60 parts of a curing agent; 0.1 to 0.2 part of an imidazole accelerant; 10 to 15 parts of a reactive diluent; and 8 to 15 parts of epoxy silicon dioxide. The diluent is prepared from N, N, N ', N'-tetraepoxypropyl-4, 4 '-diaminodiphenylmethane and ethylene glycol diglycidyl ether according to the mass ratio of 1 to (4 to 5); the curing agent comprises a polybenzimidazole curing agent, a polyethylene glycol curing agent and methyl tetrahydrophthalic anhydride in a mass ratio of (2-3): (2-3): (5-6). The epoxy resin material prepared by the invention has excellent electrical properties and mechanical properties.

The invention provides a cross-linked polybenzimidazole membrane as well as a preparation method and application thereof. The cross-linked polybenzimidazole membrane comprises a cross-linked network structure, main raw materials of the crosslinked polybenzimidazole membrane comprise polybenzimidazole, a crosslinking agent and a pore forming agent, the crosslinking agent is a diepoxy compound or a silane coupling agent with an epoxy bond, and the addition amount of the crosslinking agent relative to the polybenzimidazole is 2wt%-10wt%. The cross-linked polybenzimidazole membrane is high in mechanical strength, good in mechanical stability, low in swelling rate in electrolyte and high in durability; the cross-linking agent and the pore-forming agent selected in the invention can ensure that the cross-linked polybenzimidazole membrane forms a cross-linked network structure.

The invention provides a polybenzimidazole / porous SiO2 microsphere hybrid high-temperature membrane as well as a preparation method and application thereof, and belongs to the field of high-temperature proton exchange membranes. The preparation method comprises the following steps: synthesizing mesoporous SiO2 by using a template method, modifying and oxidizing the surface of the mesoporous SiO2 by using a silane coupling agent to obtain sulfonated SiO2 microspheres, filling imidazole into the sulfonated SiO2 microspheres by using an evaporation method to obtain porous SiO2 microspheres, adding the porous SiO2 microspheres into a soluble arylether type polybenzimidazole solution, fully and uniformly mixing, pouring on a glass plate, and carrying out vacuum drying to obtain the composite material. And removing the solvent by adopting a heating method to obtain the hybrid membrane. The hybrid membrane is soaked in a phosphoric acid solution to obtain the polybenzimidazole / porous SiO2 microsphere hybrid high-temperature membrane, the special structure of the polybenzimidazole / porous SiO2 microsphere hybrid high-temperature membrane can adsorb and retain more phosphoric acid molecules, and the phosphoric acid doping level and the proton conductivity are improved; therefore, the material has important application in the field of high-temperature proton exchange membrane fuel cells.

The invention discloses a modified polybenzimidazole blended polyvinylpyrrolidone high-temperature proton exchange membrane, a preparation method of the modified polybenzimidazole blended polyvinylpyrrolidone high-temperature proton exchange membrane, a membrane electrode and a fuel cell. The modified polybenzimidazole blended polyvinylpyrrolidone high-temperature proton exchange membrane comprises modified polybenzimidazole and polyvinylpyrrolidone, the mass ratio of the modified polybenzimidazole to the polyvinylpyrrolidone is (3 to 1): (1 to 2); the structure of the modified polybenzimidazole is # imgabs0 #, wherein the value range of n is 500 to 1000. According to the high-temperature proton exchange membrane provided by the invention, the proton conductivity is remarkably improved on the premise of ensuring the mechanical strength, and the high-temperature proton exchange membrane is expected to be applied to the field of high-temperature proton exchange membrane fuel cells on a large scale.

The present invention relates to ion exchange functionalized polymer molecules comprising repeating units having a benzimidazole unit as a backbone, a side chain, or at least a portion of both. The ion exchange functionalized polymer molecule further includes an ion exchange group attached to the repeating unit. The ion exchange group may be a tetravalent boron group or a metal fluoride, and the metal fluoride may be a multivalent metal atom.

The invention discloses a multi-layer enhanced proton exchange membrane for a flow battery and a preparation method of the multi-layer enhanced proton exchange membrane, and belongs to the field of high polymer materials. Sulfonated polybenzimidazole serves as a middle reinforcing layer, fluorine-containing sulfonic acid resin serves as functional resin layers on the two sides, the reinforcing layers can be prevented from being corroded and degraded by electrolyte in a strong acid and alkali environment, the reinforcing material is prevented from being exposed, meanwhile, the porous reinforcing layer can be better combined with fluorine-containing sulfonic acid resin solutions on the two sides, and the service life of the composite material is prolonged. The resin solution is infiltrated into the porous layer, so that the swelling of the membrane is better limited; the thickness of the sulfonated polybenzimidazole porous enhancement layer accounts for 10%-40% of the thickness of the multi-layer enhanced proton exchange membrane, so that the transmission capacity, the strength performance and the dimensional stability of protons can be improved, and the comprehensive improvement of the sulfonic acid resin membrane in the aspects of ion permeation blocking, the dimensional change rate, the electric conductivity, the mechanical performance and the puncture resistance strength is realized.

The invention belongs to the technical field of waterproof and moisture permeable membrane materials, and particularly relates to a bio-based microporous membrane based on a template and a preparation method and application thereof, and the preparation method comprises the following steps: dispersing one of polybenzimidazole, aminated PI and carboxylated PBO and modified CNF into a DMF / water system; performing electrostatic spinning on the high-viscosity spinning solution; carrying out low-temperature vacuum drying treatment on the modified nanofiber self-supporting framework; coating and filling the bio-based polyurethane resin into the bio-based microporous membrane template, and carrying out negative pressure adsorption until the filling is uniform; and carrying out gradient drying on the bio-based wet membrane to obtain the bio-based microporous membrane. Compared with the prior art, the problems that in the prior art, the mechanical property or stability of bio-based polyurethane is insufficient, and a nanofiber reinforcing technology is difficult to combine with the bio-based polyurethane are solved. A nanofiber self-supporting framework with a stable structure is prepared through an electrostatic spinning technology, and then the nanofiber self-supporting framework is compounded with bio-based polyurethane to form a microporous membrane layer with waterproof and moisture permeable functions.

The invention discloses a preparation method of a vanadium battery electrolyte oxidation corrosion resistant composite membrane, which comprises the following steps: S1, uniformly dispersing graphene oxide nanosheets on the surface of an SPEEK (sulfonated polyether ether ketone) matrix by using sulfonated polyether ether ketone as a substrate to obtain an SPEEK / GO (graphene oxide) substrate; s2, treating the SPEEK / GO substrate in oxygen plasma treatment equipment, and ultrasonically cleaning the SPEEK / GO substrate with isopropanol for 10-20 minutes; s3, dissolving polybenzimidazole in N, N-dimethylacetamide (the concentration is 3-5wt%), and magnetically stirring until the polybenzimidazole is completely dissolved; the preparation method comprises the following steps: adding TiO2 nanoparticles (the particle size is 20-25nm, and the TiO2 nanoparticles are pretreated by a silane coupling agent KH-570) according to the mass ratio of 15-20%, ultrasonically dispersing and carrying out ice bath to obtain PBI-TiO2 dispersion liquid; s4, the SPEEK / GO substrate treated in the step S1 is vertically immersed in PBI-TiO2 dispersion liquid, the final coating thickness is 1.5 + / -0.2 [mu] m, and a pretreated film is obtained; and S5, carrying out hot pressing on the pretreated membrane by using a hot press, and then carrying out gradient cooling to room temperature to obtain the final composite membrane. The vanadium battery is better in vanadium resistance and corrosion resistance and suitable for high-power-density vanadium batteries.

The invention provides a preparation method of a fiber bragg grating humidity sensor based on a polyimide and MXene composite coating. The preparation method comprises the following steps: preparing a surface hydrophobic modification solution according to an MPTMS solution, a PAA aqueous solution and a nano SiO2 ethanol dispersion liquid; the method comprises the following steps: sequentially coating polybenzimidazole amic acid, MXene and polybenzimidazole amic acid on the surface of a gate region of the fiber bragg grating, so that a polybenzimidazole amic acid inner layer, an MXene middle layer and a polybenzimidazole amic acid outer layer are sequentially formed on the surface of the gate region from the surface to the outer layer; immersing the coated fiber bragg grating into a surface hydrophobic modification solution to carry out surface hydrophobic modification treatment on the outer layer of the polybenzimidazole amic acid; and carrying out annealing curing treatment on the fiber bragg grating subjected to surface hydrophobic modification treatment to obtain the fiber bragg grating humidity sensor based on the polyimide and MXene composite coating. According to the sandwich structure, through material function layering and interface optimization, collaborative improvement of sensitivity, response speed, stability and environmental adaptability is achieved.

The invention relates to the technical field of special polymer functional membranes, and discloses a polybenzimidazole gas separation membrane as well as a preparation method and application thereof, the polybenzimidazole gas separation membrane has an interpenetrating network-shaped pore structure, and the polybenzimidazole gas separation membrane has a nanoscale pore structure. The pore size distribution of the nanoscale pore structure is 0.1-30 nm, and the average pore size of the nanoscale pore structure is 1-80 nm. The polybenzimidazole gas separation membrane has an interpenetrating network-shaped pore structure and a nanoscale pore structure, so that the polybenzimidazole gas separation membrane has relatively high gas selectivity and permeability coefficient and also has relatively good mechanical properties.

The invention relates to a preparation method of a high-temperature proton exchange membrane, in particular to a preparation method of a phosphoric acid / cystine functionalized MXene / polybenzimidazole composite high-temperature proton exchange membrane for a high-temperature fuel cell. The invention aims to solve the problem of insufficient oxidation resistance of the existing fuel cell proton exchange membrane. The method comprises the following steps: 1, preparing polybenzimidazole; (2) preparing cystine functionalized MXene; and 3, preparing a cystine functionalized MXenen and OPBI compounded proton exchange membrane, and then dipping in a phosphoric acid solution. According to the application of the cystine functionalized MXene / polybenzimidazole composite membrane for the high-temperature fuel cell in HT-PEM, the conductivity and oxidation resistance of a proton exchange membrane are improved, a basis is provided for developing novel efficient HT-PEM, and the cystine functionalized MXene / polybenzimidazole composite membrane is applied to the technical field of proton exchange membrane fuel cells.

The invention is applicable to the technical field of fuel cells, and provides a blending modified polybenzimidazole proton exchange membrane and a preparation method thereof, and the preparation method comprises the following steps: S1, preparing 4-methyl-N-toluenesulfonyl benzene sulfonamide; s2, preparing 4, 4 '-[imino bis (sulfonyl)] dibenzoic acid; s3, preparation of PSI: dissolving CBSI and a proper amount of anhydrous lithium chloride in a proper amount of a mixed solution of pyridine, triphenyl phosphite and pyrrolidone, adding diamino molecules after complete dissolution, heating and stirring the solution for 12 h, pouring the solution into methanol, filtering and collecting a product, washing with water, and drying to obtain the product PSI; and S4, preparing the PSI / OPBI blended membrane. The blended membrane prepared by the invention has excellent proton conductivity and good mechanical properties, and meets the performance requirements of the proton exchange membrane of the fuel cell; moreover, the raw materials are low in cost and easy to obtain, the synthesis conditions are mature, the yield is high, the feasibility is high, and the application prospect is wide.

The invention belongs to the technical field of high polymer materials, and particularly relates to a composite proton exchange membrane and a preparation method thereof. According to the prepared composite proton exchange membrane, the perfluorosulfonic acid resin capable of being industrially applied is selected as a base membrane material, and the modified polybenzimidazole polymer resin is added, so that the problem of high ion permeation rate of a perfluorosulfonic acid proton exchange membrane in the prior art is solved; interpenetration and permeation of the electrolyte in the use process of the perfluorosulfonic acid proton exchange membrane can be reduced, cross contamination of positive and negative electrolyte is greatly reduced, and the service life of the electrolyte is prolonged. The PBI is functionalized, so that the proton transmission capacity of the PBI is improved, and the proton exchange membrane formed by blending the functionalized PBI and the perfluorinated sulfonic acid resin can keep excellent vanadium resistance, excellent proton transmission capacity and relatively high ion selectivity at the same time. The preparation process is simple, and the prepared proton exchange membrane can meet the performance and long-term stability use requirements of a flow battery.

The invention relates to a preparation method of a modified nanocellulose lithium metal battery diaphragm, which comprises the following steps: by taking a natural degradable high polymer material cellulose as a matrix material, modifying polybenzimidazole by using polyethyleneimine by adopting an electrostatic self-assembly synergistic phase inversion method, and doping the modified polybenzimidazole into nanocellulose in a colloid particle manner, so as to obtain the modified nanocellulose lithium metal battery diaphragm. And carrying out vacuum filtration to prepare the polybenzimidazole / polyethyleneimine composite modified nano cellulose diaphragm. The method has the advantages that the filling of the colloid particles plays a role in supporting the fiber structure and improving the porosity. And polybenzimidazole is modified by polyethyleneimine, so that the transmission rate of lithium ions is improved. The process is simple and environment-friendly, and the obtained diaphragm shows good electrochemical performance when being applied to the lithium metal battery and has a wide application prospect in the field of the lithium metal battery.

The invention belongs to the technical field of fuel cell proton exchange membranes, and discloses a hydroxyl-containing modified polybenzimidazole proton exchange membrane and a preparation method thereof. According to the modified polybenzimidazole, a monomer (5-hydroxyisophthalic acid) containing a hydroxyl structure is added during polymerization of a raw material monomer, and the novel hydroxyl-containing modified polybenzimidazole is obtained through an imidazole forming reaction. The hydroxyl-containing modified polybenzimidazole can be prepared into the modified polybenzimidazole proton exchange membrane by using a solution casting method. According to the modified polybenzimidazole disclosed by the invention, stable doping of phosphoric acid in the membrane is facilitated by introducing hydroxyl and ether bonds, so that more proton carriers are kept under an anhydrous condition, the phosphoric acid doping rate of the prepared proton exchange membrane is further improved, and construction of a proton transmission channel is facilitated. The novel hydroxyl-containing modified polybenzimidazole proton exchange membrane has a good application prospect in the aspect of proton exchange membrane fuel cells.

The invention relates to the technical field of polyaryletherketone composite materials, in particular to a modified carbon fiber reinforced polyaryletherketone composite material and a preparation method thereof.The preparation method comprises the following steps that S1, polybenzimidazole is attached to the surface of phosphorus-containing group functionalized carbon fiber; s2, in a protective atmosphere, preheating polyaryletherketone in a mold pressing mold, then uniformly laying the phosphorus-containing group functionalized carbon fibers treated in the step S1 on a preheated polyaryletherketone material, and carrying out stepped mold pressing forming, so as to obtain the modified carbon fiber reinforced polyaryletherketone composite material. The interface shear strength of the carbon fiber reinforced polyaryletherketone composite material is greatly improved through the action of surface modification of the phosphoric acid on the carbon fiber and interface transition of the polybenzimidazole.

The invention discloses a loose nanofiltration membrane with a slow-release sterilization function and a preparation method of the loose nanofiltration membrane. The nanofiltration membrane can realize slow release and long-acting antibiosis of silver ions. The preparation method of the membrane comprises the following steps: synthesizing UiO-66-NH2 nano particles by a hydrothermal method, mixing the UiO-66-NH2 nano particles with an AgNO3 solution, and reducing by using NaBH4 to prepare Ag-coated UiO-66-NH2 nano particles; the preparation method comprises the following steps: blending Ag-coated UiO-66-NH2 and polybenzimidazole, preparing a PBI-based mixed matrix membrane by using a non-solvent induced phase inversion method, and then crosslinking the PBI-based mixed matrix membrane by using trimesoyl chloride to obtain the biological pollution resistant loose nanofiltration membrane. Test results show that the loose nanofiltration membrane prepared by the method has excellent dye desalination performance and antibacterial performance. The salt retention rate is less than 1% while the crystal violet dye retention rate is kept to be 99% or above. An antibacterial experiment shows that after the membrane is co-cultured for 36 hours, the antibacterial rates of the membrane on escherichia coli and staphylococcus aureus respectively reach 97.4% and 96.3%. Slow-release experiments show that the prepared loose nanofiltration membrane can stably maintain the release amount at 0.1 [mu] g.L <-1 >. Day <-1 >, and can realize long-term effective sterilization.

The invention relates to a high-temperature proton exchange membrane, in particular to a semi-interpenetrating high-temperature proton exchange membrane based on imidazolyl polyion liquid and a preparation method of the semi-interpenetrating high-temperature proton exchange membrane. The preparation method comprises the following steps: dissolving polybenzimidazole, a silane coupling agent and the imidazolyl polyionic liquid in dimethyl sulfoxide to obtain a mixture, spreading and drying the mixture to prepare a membrane, and performing acid catalysis to form a silicon-oxygen cross-linked structure, thereby obtaining the semi-interpenetrating high-temperature proton exchange membrane based on the imidazolyl polyionic liquid. A silicon-oxygen cross-linked network structure is introduced into the proton exchange membrane, so that the oxidation resistance and tensile strength of the membrane can be improved, and the swelling rate of the acid-doped membrane can be reduced; the phosphoric acid adsorption rate can be improved by introducing the imidazolyl polyion liquid, so that the proton conductivity is improved.

The invention relates to the technical field of ion exchange membranes of all-vanadium redox flow batteries, and discloses a cross-linked amino type polybenzimidazole composite membrane for a vanadium battery and a preparation method of the cross-linked amino type polybenzimidazole composite membrane. The preparation method comprises the following steps: S1, preparing an imidazole functional monomer 1 containing double bonds; s2, preparing a functional monomer 2 containing double bonds; step S3, preparing a cross-linked amino type polybenzimidazole solution; and step S4, preparing the cross-linked amino polybenzimidazole composite membrane. The composite membrane disclosed by the invention has a cross-linked structure, so that the acid absorption rate and the proton conductivity can be improved, the voltage efficiency of the vanadium battery can be improved, and the tensile strength and the mechanical stability of the membrane can also be improved; the nitrogen heterocyclic structure in the chain segment can inhibit vanadium ion permeation and improve coulombic efficiency.

The invention discloses a preparation method of a branched polybenzimidazole side chain grafted monovalent / divalent high-selectivity cationic membrane, which is characterized in that a branched unit is introduced into a main chain to construct a microcavity structure based on the unique tight stacking and rich hydrogen bond network characteristics of polybenzimidazole (PBI), and the pore diameter in the membrane and the free volume of a polymer are regulated and controlled to prepare the branched polybenzimidazole side chain grafted monovalent / divalent high-selectivity cationic membrane. The stable and rapid transmission of monovalent ions is promoted, and a high interception effect on divalent ions is kept. Then molecules containing sulfonic acid groups and hydrophobic side chain molecules are grafted to the branched PBI, the ionic conduction performance is improved, meanwhile, a microphase separation structure can be constructed, the ionic transmembrane energy barrier difference is increased through the ionic hydration energy difference of monovalent and divalent ions, selective transmission of ions is achieved, and the ionic conductivity is improved. Finally, the ion separation membrane with outstanding stability and excellent comprehensive performance of selectivity and flux is obtained.