783 results about "Negative charge" patented technology

The invention discloses an arginine decarboxylase diaA enzyme mutant and application thereof in preparation of butanediamine, and belongs to the field of bioengineering. According to the invention, rational charge overturning transformation is simultaneously carried out on a pentamer meridian oligomeric interface and a dimer latitudinal oligomeric interface, so that stable assembly and efficient catalysis of the decamer under the condition of neutral to alkaline pH (7.0-9.0) are realized. Wherein positive charges are introduced into a meridian interface to weaken electrostatic repulsion, and negative charges are introduced into a latitudinal interface to enhance dimer compactness and substrate transfer efficiency. The specific enzyme activity of the representative double mutant AdiAD110K / H736E at pH 8.0 is about 35 times that of a wild type, and the representative double mutant AdiAD110K / H736E keeps a complete decamer state in a pH range of 7.0-9.0. The yield of butanediamine is up to 145.9 g / L under the whole-cell catalysis of the mutant.

The invention discloses a rational copolymerization strategy for improving the stability of an oligomeric structure of acid-induced high-order oligomeric decarboxylase AdiA in a neutral to alkaline environment and application of the rational copolymerization strategy, and belongs to the field of bioengineering. According to the strategy, rational charge overturning transformation is carried out on a pentamer radial oligomeric interface and a dimer weft-wise oligomeric interface at the same time, and stable assembly and efficient catalysis of a decamer under the condition that the pH value is from 7.0 to 9.0 from neutral to alkaline are achieved. Wherein positive charges are introduced into a meridian interface to weaken electrostatic repulsion, and negative charges are introduced into a latitudinal interface to enhance dimer compactness and substrate transfer efficiency. The specific enzyme activity of the representative double mutant AdiAD471K / E467K / H736E is 45.5 times that of a wild type when the pH value is 8.0, and the representative double mutant AdiAD471K / E467K / H736E keeps a complete decamer state when the pH value is 7.0-9.0. The yield of butanediamine is up to 156.5 g / L by using the mutant to catalyze whole cells.

The invention belongs to the technical field of membrane separation, and aims to provide a preparation method and application of a covalent organic framework bipolar membrane. The method comprises the following steps: combining at least one amine, hydrazide or aldehyde monomer containing ionic groups with a monomer without ionic groups, and respectively synthesizing covalent organic framework COF nanosheets with positive charges and negative charges through a one-pot method under the condition of coexistence of an acid catalyst and an organic solvent; sequentially depositing COF nanosheets with positive and negative charges on the surface of the porous carrier by a hot solvent evaporation method; by constructing two COF separation layers with regular pore channels and opposite electrical properties, the covalent organic framework bipolar membrane with charge asymmetry is finally obtained. The product provided by the invention has high selectivity, can realize efficient separation of protons and metal cations, and significantly improves the extraction and recovery purity of hydrochloric acid; through charge repulsion and pore size screening mechanisms, separation of different anions can be further realized, and selective recovery of acid molecules is enhanced.

This invention belongs to the field of marine antifouling, and specifically relates to a transparent, self-lubricating organosilicon hybrid antifouling coating with a negatively charged surface and its preparation method. The antifouling coating is obtained by a sol-gel reaction of modified nanocellulose, hydroxy acid, and functional fluorine / siloxane monomers; the mass ratio of the hydroxy acid to the modified nanocellulose is 10–100:1; the mass ratio of the functional fluorine / siloxane monomer to the modified nanocellulose is 10–300:1. This invention, based on a multi-element green antifouling strategy, constructs a material surface with negative charge, self-lubrication, and low surface energy. The prepared antifouling coating exhibits excellent transparency, mechanical properties, and static antifouling performance. This antifouling coating is environmentally friendly and has broad application prospects in the field of marine antifouling.

The invention discloses an artificial SEI material and a preparation method thereof, an artificial SEI film and an artificial SEI film modified negative electrode. The artificial SEI material is an organic polymer brush (CNF-g-PSSX) prepared by grafting cellulose nanofibers with polystyrene sulfonate. The polymer brush is of a crystal structure and has a firm framework; and the side chain of polystyrene sulfonate has rich-SO3 functional groups which are matched with cations in sulfonate, so that a rapid ion transmission channel is provided, high-current-density circulation can be realized, and good interface contact is ensured. Due to a special molecular topological structure and a multi-component synergistic effect, when the organic polymer brush forms an artificial SEI film, high mechanical strength, high ionic conductivity and low interface impedance can be obtained at the same time, and through strong electrostatic repulsion between a negatively charged-SO3 group and the surface of a negatively charged lithium dendrite tip, the electrochemical performance of the artificial SEI film is improved. An obvious inhibition effect is shown on the continuous growth of dendritic crystals.

According to the method, phosphomolybdic acid, copper chloride and ferric chloride serve as precursors, copper and iron-containing phosphomolybdic acid nano-enzyme (Cu, Fe-PMs) with peroxidase-like activity is synthesized through a microwave method, under the acidic condition, on one hand, the surface of Cu and Fe-PMs carries negative charges, high affinity is generated between Cu and Fe-PMs and a substrate TMB with positive charges, and on the other hand, the surface of Cu and Fe-PMs has negative charges; on the other hand, Cu / Fe / Mo three-metal redox couple accelerates the regeneration of Fe < 2 + > and plays an important role in the activity of peroxidase, and meanwhile, due to the introduction of sodium dehydroacetate, Cu and Fe in Cu and Fe-PMs and pyranoid ring and keto O in sodium dehydroacetate interact through coordinate bonds to cause electron interaction, so that the peroxidase-like activity of Cu and Fe-PMs is enhanced, and the peroxidase-like activity of Cu and Fe-PMs is improved. And the Fenton reaction is enhanced through transfer of electrons among the sodium dehydroacetate, the Cu and the Fe-PMs. When Cu and Fe-PMs oxidize TMB and H2O2, sodium dehydroacetate enhances the absorbance of the system, and on the basis, a novel colorimetric rapid detection method of sodium dehydroacetate is established.

The invention relates to the technical field of photoelectricity, in particular to a solar cell and a preparation method thereof, and aims to improve the passivation performance and ultraviolet induced degradation resistance of the solar cell. The solar cell comprises a substrate, the substrate is provided with a first surface and a second surface which are oppositely arranged in the thickness direction of the substrate, an emitter is formed on the first surface of the substrate, and the doping type of the emitter is opposite to that of the substrate; the first passivation layer is arranged on one side of the first surface of the substrate; the first passivation layer comprises an aluminum oxide layer, the fixed negative charge density of the aluminum oxide layer is larger than or equal to 4.0 * 10 < 12 > Qf / cm < 2 >, and the surface defect state density of the aluminum oxide layer is smaller than or equal to 0.9 * 10 < 12 > eV / cm < 2 >.

The embodiment of the invention provides a solar cell, a manufacturing method thereof and a photovoltaic module. The solar cell comprises a substrate, a chemical passivation layer, a first aluminum oxide layer, a barrier layer and a second aluminum oxide layer. The chemical passivation layer is located on the first side of the substrate and used for passivating the surface of the substrate; the first aluminum oxide layer is located on the surface, away from the substrate, of the chemical passivation layer and used for providing hydrogen atoms to the surface of the substrate; the barrier layer is located on the surface of the first alumina layer away from the chemical passivation layer; the second aluminum oxide layer is located on the surface, away from the first aluminum oxide layer, of the barrier layer and used for field passivation of the surface of the substrate; the first aluminum oxide layer contains negative charges and has a first charge density, the second aluminum oxide layer contains negative charges and has a second charge density, and the second charge density is larger than the first charge density. The surface passivation effect of the solar cell provided by the embodiment of the invention can be improved, so that the efficiency of the solar cell is improved.

The invention relates to the technical field of concrete admixtures, in particular to ultra-dispersed high-activity silica mortar, a preparation method and application thereof and a component, the ultra-dispersed high-activity silica mortar comprises silica mortar, the silica mortar contains polyelectrolyte, and the pH value of the silica mortar is 8-13; the polyelectrolyte is a linear carboxylic acid polymer and a salt thereof. The pH value of the silica fume slurry is adjusted to 8-13, and the dispersion effect of the polyelectrolyte containing carboxylic acid groups is combined, so that the charge property of the surfaces of silica fume particles is changed, the absolute value of the ZETA potential is increased, the highest absolute value of the ZETA potential can reach 50 mV or above, the strong negative electricity on the surfaces of the silica fume particles enables the particles to generate the electrostatic repulsion effect, and the particles are prevented from being damaged. The silicon ash particles can be effectively prevented from getting close to each other and being agglomerated by matching with the steric hindrance of the polyelectrolyte containing the carboxylic acid group, so that the dispersity of the silicon ash slurry is further improved, the dispersion stability is good, and the suspension rate in 30 days is basically 99.5% or above.

The invention discloses a negative charge leakage circuit, a rapid chip negative charge leakage method and a radio frequency chip. The negative charge leakage circuit comprises a leakage circuit module and a control signal module, the bleeder circuit module comprises a first PMOS (P-channel Metal Oxide Semiconductor) tube, the source electrode of the first PMOS tube is grounded, and the drain electrode of the first PMOS tube is connected with the negative voltage potential of the chip; the input end of the control signal module is used for receiving an enable signal, and the output end of the control signal module is connected with the grid electrode of the first PMOS tube; the control signal module is used for outputting a corresponding control signal according to the received enable signal so as to control the first PMOS tube to be in a conduction state or a cut-off state; the first PMOS tube is used for discharging negative charges in the chip when the first PMOS tube is in a conducting state. According to the invention, the discharge speed of negative pressure in the chip can be improved, and the reliability of the chip in repeated power-on and power-off starting is improved.

The invention provides an exosome enrichment method based on a modified cellulose material, which comprises the following steps: carrying out TEMPO oxidation on plant residue cellulose to prepare a cellulose material with a carboxyl structure; the cellulose structure is further refined by adopting mechanical shearing and high-pressure homogenizing means, so that the specific surface area and the dispersion stability are remarkably improved; through polyethyleneimine PEI grafting, a large number of amino functional groups are introduced, the surface electropositivity of the material is enhanced, and efficient adsorption and enrichment of exosomes with negative charges are achieved. The invention also provides the exosome prepared by the method. The modified cellulose material disclosed by the invention is wide in source, simple and convenient to prepare and mild in enrichment process, the separation purity and the enrichment efficiency of the exosome can be remarkably improved, and the modified cellulose material has good biocompatibility and environmental friendliness; compared with existing ultracentrifugation, density gradient centrifugation and immunoaffinity separation methods, the method has the advantages that the operation process is simplified, the equipment dependence and reagent cost are reduced, and the potential of large-scale production and clinical application is achieved.

The invention belongs to the technical field of semiconductor device simulation, and particularly relates to a method for rapidly calibrating BDTI surface potential and a related device. The method comprises the following steps: establishing a CIS BDTI device structure through simulation software; introducing silicon data, and calibrating an ion distribution curve in the device structure by taking a true value of SIMS concentration as a reference to obtain a device simulation model for concentration distribution calibration; replacing a surface high dielectric constant layer of the device simulation model for concentration distribution calibration with an electrode layer; and introducing the actually measured potential of the high dielectric constant layer of the device into the electrode layer to complete the surface potential calibration of the device. According to the invention, the surface high dielectric constant layer is directly replaced by the electrode layer, so that the potential of the surface high dielectric constant layer can be directly set as the potential of the actually measured high dielectric constant layer, the process of collecting, continuously increasing and adjusting positive and negative charges for many times and continuously adjusting the potential value of a High K material is avoided, and the calibration process is remarkably shortened.

The invention discloses a method for preparing a silicon-carbon composite negative electrode material through an electrostatic self-assembly technology, and belongs to the technical field of lithium ion battery negative electrode materials. According to the invention, lignin is used as a biomass carbon source and lauryl sodium sulfate (SDS) and poly (diallyldimethylammonium chloride) (PDDA) are used as activators through a simple electrostatic self-assembly technology; a proper amount of nano silicon and PDDA are subjected to in-situ adsorption, and lignin and SDS are subjected to in-situ adsorption; a self-assembly process is carried out through the positive and negative charge attraction effect among colloidal particles, so that effective compounding of the nano silicon particles and the biomass carbon is realized; and performing vacuum drying, and performing one-stage sintering in a tubular furnace to obtain the silicon-carbon composite negative electrode material. Based on the problems of non-uniform particle size, easy agglomeration and great abrasion of a silicon-carbon composite material in a traditional mechanical synthesis technology, the invention improves the compounding efficiency of the silicon-carbon material and improves the problems of volume expansion of a silicon negative electrode, slow migration rate of lithium ions, poor cycle performance and the like.

The invention relates to the technical field of biological detection, and discloses an instant staining lipoprotein sample separation method, which comprises the following steps: S1, lipoprotein staining: taking 10 [mu] L of a sample loading staining solution, adding 50 [mu] L of a plasma lipoprotein sample, and completing staining without waiting and heating incubation; s2, sample loading of dyed lipoprotein: assembling a sample density separation liquid pre-loading column in a disc electrophoresis tank, adding an electrophoresis buffer solution, and adding the lipoprotein sample dyed in the step S1 to the upper end of the sample density separation liquid pre-loading column; and S3, electrophoretic separation of the lipoprotein subtypes: switching on a power supply of an electrophoresis apparatus, enabling the lipoprotein with negative charges to migrate to a positive electrode under the action of an electric field, and realizing separation according to different particle sizes of the lipoprotein subtypes. The lipoprotein loading staining solution is good in dispersity and uniformity, and in the preparation process of the lipoprotein loading staining solution, the dye does not need to be filtered to remove insoluble substances and does not need to be heated; the staining solution is good in stability and can be stored at normal temperature.

The invention relates to the technical field of batteries, in particular to an all-vanadium redox flow battery SOC dual monitoring correction method and system. The method comprises the following steps: acquiring first SOC data through potential monitoring, wherein the first SOC data comprises a positive charge-discharge state SOC positive, n and a negative charge-discharge state SOC negative, n; second SOC data including SOC positive ', n and SOC negative', n are obtained through electrolyte valence state concentration monitoring; calculating correction coefficients kappa positive and kappa negative according to the first SOC data and the second SOC data; and finally, correcting the third SOC data by using the correction coefficient to obtain an actual SOC value. According to the method, a dual monitoring mode is adopted, the real-time online characteristic of potential monitoring is utilized, the high-precision advantage of electrolyte concentration monitoring is combined, the two monitoring methods are organically combined through a correction coefficient, and the problems that single potential monitoring is affected by hydrogen ion concentration and the electrolyte concentration monitoring cannot realize real-time online monitoring are solved. According to the method, the correction frequency of 0-10 days is designed, the correction timeliness and sampling interference are reasonably balanced, and the accuracy of SOC monitoring is improved.

The invention relates to the field of semiconductors, and discloses a wide bandgap semiconductor cellular structure and a semiconductor device.The wide bandgap semiconductor cellular structure comprises a substrate, an epitaxial layer and a hole injection layer; the epitaxial layer comprises a heterojunction structure, a hole collection layer and a hole barrier layer which are stacked in the first direction; the hole injection layer is stacked on the epitaxial layer; the source electrode is arranged on the side, back to the substrate, of the heterojunction structure, and the substrate is arranged in a floating mode; the drain electrode is arranged on the side, back to the substrate, of the heterojunction structure. In order to solve the problems of low breakdown voltage and poor stability of a cellular structure in the prior art, a leakage current path between a drain electrode and a source electrode is prolonged in the cellular structure through floating arrangement of a substrate, so that the breakdown voltage of a semiconductor device is reduced; and through the combined action of the hole injection layer, the hole collection layer and the hole blocking layer, holes are accumulated in the hole collection layer, accumulated negative charges are shielded, the substrate effect is inhibited, and the stability of the cellular structure is improved.

The invention discloses a CNT (at) Ti < 3 > C < 2 > T < x > MXene coupled porous g-C3N4 photocatalyst and a preparation method and application thereof. G-C3N4 is prepared through a one-step calcination method, and g-C3N4 which is good in dispersion and large in porosity is obtained through thermal stripping; and coupling the protonated porous g-C3N4 with a negatively charged CNT (at) Ti < 3 > C < 2 > T < x > MXene nanosheet through an electrostatic self-assembly method to form a heterostructure, so as to obtain the photocatalyst capable of efficiently degrading organic matters under a visible light illumination condition. An environment-friendly and safe pyrolysis method is adopted in the preparation process, operation is easy, the method is very suitable for large-scale production, and the method has good application prospects in the fields of sewage treatment, waste gas treatment and the like.

The invention discloses a simulation self-cleaning decorative cloth UV printing ink coating device, and relates to the technical field of printing, the simulation self-cleaning decorative cloth UV printing ink coating device comprises a bearing base, a conveying roller set is fixedly installed at the right end of the upper portion of the top of the bearing base, and through cooperation of a powder particle adsorption assembly, an ink transfer printing assembly and a vibration assembly, the powder particle adsorption assembly and the ink transfer printing assembly are matched; positive and negative charges generated by the positive and negative conductive metal plates cover the peripheral side of the surface of the coating rod, the adsorbability of charge particles on the surface of the printing fabric is improved, a direct-current electromagnetic field is formed outside the coating rod through the feeding motor, the lead screw and the three sets of magnetic rings, and the titanium dioxide is further made to be evenly dispersed in the coating rod under the matching of the mass of the titanium dioxide. The titanium dioxide can be singly captured by charges covering the surface of the fabric to be printed, accumulation of titanium dioxide on the surface of the printed fabric is reduced, and the phenomenon that in the subsequent printing operation process, due to the fact that gaps exist between ink and the printed fabric, ink blocks fall off in the subsequent printing and drying operation is reduced.

The invention relates to the technical field of pharmaceutical preparations, and provides double-shell JAK inhibitor nanoparticles, a preparation method thereof and targeted delivery eye drops. The double-shell JAK inhibitor nanoparticle provided by the invention comprises a core, an inner shell and an outer shell, wherein the core comprises a nanostructure lipid carrier and a JAK inhibitor; the inner shell layer is a cationic polymer, and the outer shell layer is hyaluronic acid. Through the design of the positive charge inner shell layer and the negative charge outer shell layer, the dual functions of mucosa adhesion and active targeting are achieved, the surface of the nanoparticle is electronegative finally, cytotoxicity possibly caused by direct exposure of a cationic polymer is reduced, non-specific aggregation of the cationic polymer and electronegative protein in tears is avoided, and the stability of tears is improved. And the stability of the preparation is improved. The eye drops provided by the invention can obviously prolong the residence time of the JAK inhibitor on the ocular surface, enhance the cornea permeability, can actively target to ocular inflammatory cells, and have a wide application prospect.

The present invention addresses the problem of how to effectively and efficiently extract, separate, and recover high-concentration PFAS contained in water regardless of the type of PFAS. An organic fluorine compound is converted to a chemical species having a negative charge on the basis of ionization by acid dissociation of the organic fluorine compound, molecularization of protonation-type hydrophobic cations, or both of these items, the distribution of the organic fluorine compound to an aqueous phase is promoted, and the organic fluorine compound is recovered.

The method is based on a core idea of unifying a field theory and an interference field theory, is devoted to exploration and expansion of an artificial field frontier technology, and covers an artificial field plus quality technology, an artificial field interference technology and an artificial field control space-time technology. In the research process, mutual verification of experiments and theories is paid attention to. Theoretically, internal correlation among Planck mass, electron mass, gravitational force, electric field force, magnetic field force and fine structure constants is deeply analyzed, a conclusion that the gravitational force, the electric field force and the magnetic field force are equal when a substance reaches a light velocity is obtained, and a unique quantum effect is presented. In the aspect of experiments, a simple verification method is adopted, and substances are placed in a positive electrode area and a negative electrode area respectively. Along with the enhancement of the electric field intensity and the action time, the substance mass in the positive electrode area is gradually reduced, and the substance mass in the negative electrode area is correspondingly increased. The phenomenon can be explained as that the space where the positive charges are located has divergence characteristics and the space where the negative charges are located has convergence characteristics, so that the masses of the substances in the positive and negative electrode areas are changed alternately.

The invention discloses a preparation method of stable spray granulation silicon nitride slurry and granulation powder, and belongs to the technical field of ceramic materials. According to the invention, absolute ethyl alcohol is adopted as a solvent, so that the problem that silicon nitride slurry is easy to hydrolyze is solved, and the temperature during spray granulation is reduced. On the basis that a dispersing agent is added into slurry, tetramethylammonium hydroxide is added into the slurry, the Zeta potential value of the slurry is increased, the slurry is made to be in an alkaline environment, dissociation of Si-OH groups is promoted, more negative charges are carried on the surface of silicon nitride, meanwhile, zwitterions released by the tetramethylammonium hydroxide form a double-electron layer around silicon nitride particles, and therefore the conductivity of the silicon nitride particles is improved. The dispersity of the particles in the slurry is improved. The silicon nitride powder is more uniformly distributed in a medium such as a binder due to the improvement of the dispersibility, and the silicon nitride slurry with low viscosity, good dispersibility, good stability and good fluidity can be prepared. The slurry can be more symmetrically gathered and formed in the spray granulation process, and the sphericity degree and apparent density of granulation powder are improved.

The invention discloses a zwitter-ion modified acrylate dielectric elastomer film and a preparation method thereof. Zwitter-ions can be selected from sulfobetaine methacrylate (SBMA), carboxyl betaine methacrylate (CBMA), sulfobetaine acrylamide (SBAA) and the like. The acrylate monomer can be butyl acrylate (BA), dodecyl acrylate (LA), isoamyl acrylate (EHA) and the like. Zwitterions (special compounds which simultaneously carry equal positive and negative charges on the same molecule and are electrically neutral on the whole) are copolymerized into an acrylate dielectric elastomer through photo-initiated free radical polymerization reaction, zwitterionic clusters uniformly distributed in the dielectric elastomer can construct traps for capturing high-energy electrons, the leakage current of the material is reduced, and the dielectric property of the material is improved. And the intrinsic breakdown field strength of the material is improved. In addition, the mutual attraction effect between dipole ions with positive and negative charges in the structure provides driving force for intrinsic self-repairing. And after being electrically and mechanically damaged, the material can be self-recovered, so that the service life of the material is prolonged.

The invention discloses a covalent organic framework with oxidation-reduction activity and a bionic nano-channel structure as well as a preparation method and application of the covalent organic framework, and belongs to the technical field of environmental protection. According to the preparation method, 2, 4-dihydroxybenzene-1, 3, 5-tricarboxaldehyde and 2, 5-bis (allyloxy) terephthaloyl hydrazine are taken as raw materials, a two-dimensional covalent organic framework with oxidation-reduction activity is synthesized, and then a sulfonic acid group with negative charges is covalently grafted, so that a functional material with a bionic nano-channel structure is formed. The material has regular porous channels and rich functional sites, the porous channels provide efficient mass transfer paths and adsorption spaces for uranyl ions, and the functional sites realize specific recognition of the uranyl ions through oxidation-reduction reaction and electrostatic interaction, so that the material shows synergistic advantages of strong selectivity, high adsorption capacity and rapid adsorption kinetics on uranium. The method is simple and low in cost, and the prepared material is clear in structure, good in hydrophilicity, capable of efficiently adsorbing uranyl ions and good in application prospect.

The invention provides a cation exchange membrane chromatography medium and a preparation method and application thereof, the cation exchange membrane chromatography medium comprises a homo-porous membrane, polydopamine is loaded on two side surfaces and in a pore structure of the homo-porous membrane, and a cation exchange functional ligand is grafted on the polydopamine; a homogeneous pore membrane is selected as a matrix membrane, polydopamine is loaded on the surface and in an internal pore structure of the homogeneous pore membrane, and then a cation exchange functional ligand is further grafted, so that the surface of a chromatography medium of the obtained cation exchange membrane has relatively strong negative charges, and biomolecules with positive charges can be effectively adsorbed, thereby being separated from biomolecules with negative charges; meanwhile, the membrane is relatively low in transmembrane pressure and relatively high in separation degree, also has the characteristics of high permeability and high selectivity, and is suitable for being applied to separation and purification of biological drug macromolecules.

Provided is a fluid injection device (10) capable of efficiently administering a drug. A first transport body (11) has a first transport flow path through which a first fluid (21) flows, and a second transport body (12) has a second transport flow path through which a second fluid (22) flows. Positive-side microneedles (13) provided to the first transport body (11) have a first opening and a first flow path to which a positive charge is fixed. Negative-side microneedles (14) provided to the second transport body (12) have a second opening and a second flow path to which a negative charge is fixed. When a current / voltage application means (15) applies a current or voltage between a first electrode (24) disposed in the first transport flow path and a second electrode (25) disposed in the second transport flow path, an ion current flows through the first fluid (21) and the second fluid (22), and the first fluid (21) flows from the first opening toward the outside and the second fluid (22) flows from the second opening toward the outside by electroosmotic flow.

The invention provides a self-repairing modified graphene water-based coating composition as well as a preparation method and application thereof. Graphene is modified through free radical polymerization of 4-styrylpyridine (BPP) on the surface of graphene, and then coulomb interaction between protonated positive charges of BPP polymer graphene and negative charges of phosphotungstic acid anions is realized, so that the self-repairing modified graphene water-based coating composition is obtained. According to the present invention, the combination effect needs to be optimized by regulating the pH value of the solution, the obtained coating material has characteristics of high corrosion resistance, high self-repairing ability and high mechanical property, and the coating can be used in the fields of self-building cleaning exterior walls, automobile finishing paints, sea-crossing bridges, offshore wind power towers, chemical pipelines, and mobile phone / computer shell antistatic coatings.

The invention provides an electrostatic chuck and semiconductor equipment, and belongs to the technical field of semiconductor preparation. According to the electrostatic chuck, the charge generator is connected with the ejector pin assembly, when the wafer needs to be desorbed on the electrostatic chuck, the charge generator is started, due to residual positive charges on the upper surface of the dielectric layer, set charges generated by the charge generator are negative charges, and the charge generator conducts the generated negative charges to the ejector pin assembly. When the ejector pin assembly jacks up the wafer, the ejector pin assembly is full of negative charges, and the negative charges counteract the positive charges on the upper surface of the dielectric layer, so that the adsorption force between the wafer and the electrostatic chuck is reduced, and the wafer and the electrostatic chuck can be better desorbed in the desorption process; the situation that the wafer and the electrostatic chuck cannot complete smooth desorption and the wafer is damaged is avoided, and the technical problem that in the prior art, the wafer is damaged in the desorption process due to poor electricity removal in a J-R type electrostatic chuck is solved.

The invention relates to a preparation method of a carboxylate dispersant and an application of the carboxylate dispersant in a suspending agent, and belongs to the technical field of dispersants.The carboxylate polymer containing carboxyl, polyethylene glycol and slow-release chelating agent nanoparticles are polymerized together to form a comb-shaped structure; the sulfonic acid group on the carboxylate dispersant is ionized into-SO3-, the surfaces of pesticide particles are negatively charged, the electrostatic repulsion in the system is enhanced, the collision among the softened pesticide particles can be weakened, the sedimentation trend of the pesticide nanoparticles is weakened to a certain extent, and the stability of the suspension system is improved. Meanwhile, sodium ethylene diamine tetracetate in the slow-release chelating agent nano-microspheres can be slowly released, the sodium ethylene diamine tetracetate is preferentially chelated with calcium ions and magnesium ions in water, the calcium ions and the magnesium ions are prevented from being combined with sulfonic acid and carboxylic acid groups on the carboxylate dispersing agent, and the comb-shaped structure of the carboxylate dispersing agent has strong steric hindrance, so that the carboxylate dispersing agent can be used for dispersing calcium ions and magnesium ions in water. The effect of physically blocking calcium and magnesium ions can be achieved.

The invention discloses a high-performance Mg < 2 + > / Li < + > separation nanofiltration membrane and a preparation method thereof, the Mg < 2 + > / Li < + > separation nanofiltration membrane is a polymer composite membrane, and is composed of a surface separation layer and a support layer; the surface separation layer is formed by self-assembling a polycation electrolyte and a polyanion electrolyte layer by layer, the supporting layer is formed by ultraviolet grafting of any one or two of sodium polystyrene sulfonate, polymethylacrylic acid 3-sulfonic acid propyl ester potassium salt and polyacrylic acid on the surface of a hydrophobic polymeric membrane, and the surface of the supporting layer is negatively charged. The negative charge amount of the supporting layer is gradually reduced from top to bottom; the whole separation membrane has the characteristics that the upper layer is hydrophilic and the lower layer is hydrophobic. By adjusting the charge density and aperture of the supporting layer, the structure of the surface separation layer is influenced, the charge repulsion effect, aperture screening effect and built-in electric field intensity of the whole membrane are enhanced, and the Mg < 2 + > / Li < + > separation factor is increased. Permeation and rapid transportation of water are promoted by virtue of a hydrophilic upper-layer and hydrophobic lower-layer structure, and the membrane flux is improved; the preparation process is simple, and the used solvent is water, so that the method is green and environment-friendly and has a good application prospect.