361 results about "Silver coating" patented technology

The invention belongs to the technical field of solar cell materials, and particularly relates to silver-coated copper powder and a preparation method thereof. A preparation method of silver-coated copper powder comprises the following steps that copper powder subjected to surface activation through an acid-base solution and a complexing agent are dissolved in water, and copper powder turbid liquid is obtained; dropwise adding a silver source solution into the copper powder turbid liquid to carry out a replacement reaction, and adjusting the pH value of the solution after the reaction to obtain a silver-coated copper powder precursor turbid liquid; and dropwise adding a reducing agent solution into the silver-coated copper powder precursor turbid liquid, then dropwise adding a silver source solution, carrying out oxidation-reduction reaction, carrying out solid-liquid separation, washing, and drying to obtain the silver-coated copper powder. According to the preparation method provided by the invention, in the chemical oxidation reduction process, the silver-coated copper powder with different silver layer distribution structures, compact silver coating structure and better performance is obtained by regulating and controlling the dropping sequence and dropping rate of the reducing agent solution and the silver source solution.

The invention provides a silver-coated copper material and a preparation method and application thereof. The silver-coated copper material comprises a base body and a silver layer coated on the surface of the base body, the base body comprises copper particles and a silver framework, the silver framework is provided with holes, the copper particles are distributed in the holes of the silver framework, and the silver layer is prepared by adopting a chemical plating method. The pore structure of the silver skeleton and the distribution of the copper particles are utilized, the separation of nucleation and growth of the silver coating is realized, the uniformity and compactness of the growth of the silver coating are ensured, the oxidation resistance and the conductivity of the silver-coated copper material are further improved, the use amount of precious metal silver is greatly reduced while the performance of the material is ensured, and the production cost is reduced. Cost control is realized; when the silver-coated copper material is applied to the fields of photovoltaic and electronic industry, the cost of raw materials can be remarkably reduced, the service life of the raw materials is prolonged, and large-scale use is facilitated.

The invention relates to the technical field of material detection, in particular to a silver coating adhesive force detection method based on multi-frequency impedance imaging, which comprises the following steps: applying a dual-mode multi-frequency excitation signal to the surface of a silver coating through an attached microelectrode array, synchronously acquiring voltage-current response data, and generating a dual-mode multi-frequency impedance original data set; performing time-varying impedance phase-locked separation on the dual-mode multi-frequency impedance original data set, extracting a dynamic impedance component of a coating-matrix interface region, and reconstructing a three-dimensional sub-interface impedance distribution diagram; and outputting an adhesive force quantized value through an oscillation frequency-adhesive force conversion model according to the spatial oscillation frequency characteristics of the impedance phase in the three-dimensional sub-interface impedance distribution diagram. According to the invention, a double-phase-locked loop system is adopted to realize the time-varying component demodulation of the impedance response of the silver coating-matrix interface, the low-frequency dynamic impedance signal modulated by silver ion migration is effectively extracted, and the weak change of the interface bonding state is sensitively reflected.

The invention discloses composite powder with a core-shell structure and a preparation method of the composite powder. The preparation method comprises the steps of pretreatment, titanium dioxide coating treatment, plating solution treatment and silver coating treatment. The titanium dioxide coating treatment comprises the following steps: after ultrasonically stirring butyl titanate and absolute ethyl alcohol, adding dilute acid to prepare a reaction solution; nickel powder is added into the reaction liquid for a constant-temperature reaction, and titanium dioxide coated nickel powder is obtained after the reaction; the plating solution treatment comprises the steps that titanium dioxide coated nickel powder, a solvent and a dispersing agent are subjected to ultrasonic stirring and then subjected to constant-temperature stirring, a reducing agent and a sodium hydroxide solution are added, and a dispersed solution is obtained after reaction; the silver coating treatment comprises the following steps: ultrasonically stirring and dispersing silver nitrate and deionized water, and then adding a complexing agent for complexing reaction; and pouring into the dispersion solution under a stirring state, and reacting to obtain the composite powder. According to the method, the stability of the nickel powder and the compactness of the coating layer in the preparation process of the composite powder can be effectively improved, and then the conductivity of the composite powder can be improved.

The invention discloses a stainless steel material for a food-grade straw and a preparation process of the stainless steel material, and relates to the technical field of stainless steel material plating. The silver coating and the antibacterial coating are arranged on the surface of the stainless steel material, and the stainless steel material has good wear resistance and antibacterial performance through the action of the double protective layers. Sulfonated polyphenylene sulfide is added into a silver plating solution, a plating layer is formed after electroplating, the surface of a stainless steel material is not prone to being scratched, the wear resistance of stainless steel is improved, quaternary ammonium salt modified tea polyphenol-nano-silver composite particles are added into the antibacterial coating, and through the synergistic antibacterial effect of quaternary ammonium salt, tea polyphenol and nano-silver, the wear resistance of the stainless steel material is improved. The broad-spectrum antibacterial property is realized, and the efficient antibacterial effect is achieved.

The invention discloses a preparation method of silver-coated copper powder. The preparation method comprises the following steps: reacting copper-containing complexing mother liquor, a silver source and a reducing agent; the copper-containing complexing mother liquor is prepared from the following raw materials: copper powder, a chelating agent, a dispersing agent and a modification additive; the modification additive comprises at least one of ethylenediamine, ammonium carbonate, ammonia water, tetraethylenepentamine, polyethylene polyamine, imidazole, pyridazine, pyrimidine and pyrazine. According to the preparation method of the silver-coated copper powder, the silver coating layer of the prepared silver-coated copper powder is uniform and compact, and controllable preparation of the silver-coated copper powder with different appearances is achieved.

The invention discloses a humidifying structure, an air conditioner applying the humidifying structure and an air conditioner control method, and belongs to the technical field of air conditioner humidifying, the humidifying structure comprises a wet film humidifier and a humidifying circulating mechanism arranged on the lower portion of the wet film humidifier, the humidifying circulating mechanism comprises a water storage tank, a top cover, a water pump and a water conveying pipe, and the interior of the water storage tank is connected with a blocking plate; the top of the water treatment tank body is provided with a downward concave-convex cambered-surface concave part, the center of the cambered-surface concave part is provided with a large notch part, and the water treatment tank body, the inner wall surface of the water outlet and the surface of the cambered-surface concave part are each coated with a nano-silver coating. Before the humidification structure releases water vapor for humidification into a room, water in the humidification structure can be subjected to surrounding type sterilization treatment, so that the number of bacteria released into a newborn ward of a hospital can be greatly reduced in the humidification process of the air conditioner, the sterile requirement of the newborn ward is met, and the health and safety of newborns are ensured.

The invention belongs to the technical field of metal powder materials, and particularly relates to a preparation and surface modification method of silver-coated copper powder. Comprising the following steps that copper powder activated through a mixed acid solution and a dispersing agent are dissolved in ethyl alcohol, and copper powder turbid liquid is obtained; dropwise adding the silver complexing solution into the copper powder turbid liquid under the condition of water bath heating for reaction to obtain silver-coated copper powder turbid liquid; then, a reducing agent solution is dropwise added into the silver-coated copper powder turbid liquid, silver ions in the solution are further reduced, solid-liquid separation, washing and drying are conducted, and primary silver-coated copper powder is obtained; and finally, the silver-coated copper powder is subjected to surface modification, and the dispersity of the silver-coated copper powder is improved. The preparation method of the silver-coated copper powder provided by the invention is simple in process, and in the chemical oxidation reduction process, the prepared silver-coated copper powder is compact in silver coating, complete in coating, low in resistivity and good in oxidation resistance by regulating and controlling the concentration of silver ions and the complexing agent, the reaction temperature, the type of the dispersing agent, the dripping rate and the type of the surface modifier.

The invention relates to a multifunctional water-based low-temperature paint double-coating structure which comprises a first coating and a second coating, the first coating comprises a metal sheet pigment and inorganic oxide pigment mixture, and the second coating comprises transparent organic color paste. A first coating paint composition used for the first coating and a second coating paint composition used for the second coating are both mixtures containing acrylic resin emulsion and polyurethane dispersoid. The double-coating structure adopts the technical scheme of mixed pigment, curing agents such as isocyanate are not contained, and the obtained double-coating structure has high radar wave transmission performance, high infrared reflection performance and high reflection and heat insulation capacity, is particularly suitable for black or silver coating systems, adopts water-based low-temperature coating, and has the advantages that the water-based low-temperature coating is adopted, so that the water-based low-temperature coating is more environment-friendly; the paint has the characteristics of remarkable low-temperature quick-drying film formation, thin coating and low VOC (volatile organic compound), and can realize low energy consumption, health and environmental protection of a coating process. The invention further comprises a multifunctional water-based low-temperature paint coating system and application.

The invention discloses a coating and a method for recovering precious metals in a physical vapor deposition process. The coating mainly comprises a silver coating positioned on the lower layer and an organic silicon modified layer positioned on the surface of the silver coating. Before precious metal is recycled, the coating is prepared on the surface of the position where precious metal needs to be recycled in the physical vapor deposition process, after physical vapor deposition is completed, an adhesive tape is adopted to be pasted to the surface of the coating, and then the precious metal is stripped from the surface of the coating in a mode of tearing the adhesive tape; or scraping the surface of the coating by adopting a tool, so that the noble metal is stripped from the surface of the coating, and stripped noble metal chips are collected; and finally, the adhesive tape with the precious metal or the collected precious metal scraps are heated, and the precious metal is recycled from a heating product. According to the method, efficient stripping and efficient recycling of the precious metal can be achieved, the coating has no influence on physical vapor deposition equipment and the technological process, and the method is simple in technology, high in operability, environmentally friendly, free of pollution and high in economical efficiency when the precious metal is recycled and can be applied to the recycling process of the precious metal on a large scale.

The invention belongs to the technical field of water-based organic resin, and particularly relates to a preparation method of resin for an environment-friendly water-based electrosilvering coating. According to the environment-friendly water-based electrosilvering coating resin and the preparation method thereof, the acrylic acid monomer and the carboxylic acid monomer containing various functional groups are added into the raw materials in the prior art, and the environment-friendly water-based electrosilvering coating resin prepared through co-modification of the epoxy resin, the silanized graphene oxide and the silane coupling agent is good in adhesive force with a substrate and has good salt fog resistance and scratch resistance; the organic solvent used in the preparation process does not contain triphenyl organic solvents and is low in toxicity and environmentally friendly, the raw materials of the resin are wide in source and relatively low in cost, and the prepared environment-friendly water-based electrosilvering coating resin has good fluidity, controllable viscosity and easy construction.

The invention discloses high-oxidation-resistance flaky silver-coated copper particles and a preparation method thereof, and relates to the technical field of silver-coated copper powder. The process comprises the steps of flaky copper powder preparation, copper powder pretreatment, silver coating plating and post-treatment. The surface of the copper powder is pretreated, and active sites on the surface of the copper powder are reduced; secondly, a zinc phosphate plated film is formed, full coverage of a silver layer is achieved by adding nano-silver to assist in a silver ammonia solution, meanwhile, micropores of the silver layer are filled, and the compactness of the silver-coated copper powder is improved; besides, the silver content of the silver-coated copper powder is controlled to be 8.7-14.6%, and the normal-temperature oxidation resistance of the silver-coated copper powder is improved, so that the optimal anti-oxidation effect is achieved, and performance deterioration caused by oxidation is reduced.

The invention belongs to the technical field of metal surface treatment, and discloses a high-uniformity metal surface silver plating process and a corrosion-resistant treatment method thereof.The high-uniformity metal surface silver plating process comprises the following steps that firstly, pretreatment is conducted; step 2, activating treatment; step 3, pre-plating a bottom layer; step 4, electrosilvering; step 5, post-processing; according to the method, pre-plating of the bottom layer and electroplating of silver are combined, a layer of thin nickel or copper is pre-plated firstly, and then electroplating of silver is performed, so that the binding force and uniformity of the silver plating layer are effectively improved, and in the electroplating process, the mode of stirring and circulating the electroplating liquid is adopted, so that silver ions in the electroplating liquid are uniformly distributed, and the uniformity of the plating layer is improved; and a thin aluminum oxide protective film is deposited on the surface of the silver plating layer by adopting a chemical vapor deposition technology, so that the corrosion resistance of the silver plating layer is further improved.

The invention belongs to the technical field of aluminum alloy electroplating, and particularly relates to a preparation method of a silver coating of aluminum and aluminum alloy. The preparation method of the silver plating layer of the aluminum and the aluminum alloy comprises the following steps that the aluminum or the aluminum alloy is sequentially subjected to alkali etching, primary acid pickling, primary zinc dipping, secondary acid pickling, secondary zinc dipping, copper plating, silver pre-plating and cyaniding silver plating; wherein during copper plating, a copper plating solution comprises 30 g / L to 40 g / L of CuCN and 50 g / L to 60 g / L of NaCN; a silver pre-plating solution in the silver pre-plating process comprises 2-3 g / L of AgCN and 90-100 g / L of KCN, the current density in the silver pre-plating process is 0.3-0.6 A / dm < 2 >, and the silver pre-plating time is 1-2 min. And by controlling electroplating process parameters of copper plating and silver pre-plating in the electroplating process, the compactness of the plating layer is improved, the capability of resisting water vapor and the like is effectively enhanced, and then the corrosion resistance of the silver plating layer is improved.

The invention discloses a methane sensor based on a micro-nano optical fiber coupler and a methane concentration measuring method. The methane sensor comprises a broadband light source, a sensing unit and an oscilloscope which are sequentially connected from front to back, the sensing unit comprises a micro-nano optical fiber coupler, an indium oxide coating and a silver coating, and the silver coating and the indium oxide coating are sequentially arranged in the middle of the micro-nano optical fiber coupler from inside to outside; one end of the micro-nano optical fiber coupler is provided with a P1 port and a P2 port which are used as input ends, and the other end of the micro-nano optical fiber coupler is provided with a P3 port and a P4 port which are used as output ends. Ports P1 and P2 of the micro-nano optical fiber coupler are connected with the output end of the broadband light source, and a port P3 of the micro-nano optical fiber coupler is connected with the oscilloscope. The methane concentration is calculated based on the optical interference principle of the micro-nano optical fiber coupler, and the influence of external factors such as volume, pressure and temperature is eliminated. The device has the advantages of being small in size, high in external interference resistance and good in corrosion resistance, can better adapt to various environments, and has wide development space and good practicability.

The invention provides fine grid slurry and a preparation method thereof, a solar cell and a photovoltaic module. The fine grid slurry is prepared from the following components in parts by weight: 50 to 65 parts of silver powder, 15 to 25 parts of silver modified nickel-coated copper powder, 2 to 5 parts of alloy powder, 2 to 5 parts of glass powder, 0.5 to 2 parts of aluminum oxide, 10.5 to 17.5 parts of organic carrier and 0.5 to 1.8 parts of additive, the silver-modified nickel-coated copper powder comprises a copper inner core, a nickel coating layer and a silver coating layer, wherein the outer surface of the copper inner core is sequentially coated with the nickel coating layer and the silver coating layer from inside to outside. The alloy powder comprises Ni element, B element and Si element; the aluminum oxide is spherical nano aluminum oxide; the organic carrier comprises organic silicon modified acrylic resin and epoxy resin. According to the fine grid slurry, the raw material cost is remarkably reduced, the process compatibility is good, silk-screen printing can be better supported, and the photoelectric conversion efficiency of a photovoltaic module can be better improved.

The invention belongs to the technical field of metal powder, and particularly relates to a preparation method of silver-coated copper powder, which comprises the following steps: mixing copper salt, a dispersing agent, a reducing agent, an auxiliary agent and a solvent, reacting to obtain a copper solution, mixing silver salt, the dispersing agent, a complexing agent and the solvent to obtain a silver-ammonia solution, mixing the silver-ammonia solution and the copper solution, reacting to obtain the silver-coated copper powder, the preparation method of the silver-coated copper powder is simple, economical and reliable, the glutamic acid additive is added in the silver coating process, the conversion rate of a silver layer reaches up to 100%, and the prepared silver-coated copper powder is good in dispersity and high in compactness.

The invention discloses ultra-large-particle-size silver-coated copper powder particles and a preparation process thereof, and relates to the technical field of electronic metal materials. The process comprises the steps of atomization preparation of copper powder particles, acid washing, alkali washing, silver coating plating, cleaning and drying and the like. According to the method, the copper powder particles are prepared through the atomization technology, the atomization pressure and the medium flow speed are accurately controlled to crush molten copper into liquid drops with the proper granularity, then the liquid drops are rapidly condensed into the copper powder particles, the particle size of the prepared copper powder particles is stabilized between 7.5 micrometers and 8 micrometers, the particle size is uniform, the yield is high, and the production rate is extremely high; in addition, the silver layer on the particle surface of the silver-coated copper powder prepared by the method is densely and uniformly covered, the average thickness is controlled below 100nm, and the particle performance is ensured on the basis of reducing the cost.

The invention discloses an incision protection sleeve for medical engineering and a production process thereof, the incision protection sleeve comprises an outer layer protection film and an inner layer protection film, the outer layer protection film is composed of a polytetrafluoroethylene base material and a nano-silver composite layer coated on the surface, the density of the nano-silver composite layer is 1.5-3.0 mg / cm, the thickness of the nano-silver composite layer is 0.1-0.3 mm, the diameter of hollow microspheres is 50-200 [mu] m, the wall thickness of the hollow microspheres is 5-15 [mu] m, and the filling rate of the hollow microspheres is 10-30% of the volume of a buffer ring; according to the material innovation, the PTFE-nano-silver composite layer gives consideration to antibacterial performance and durability, the collagen-silica gel buffer layer promotes tissue repair, the structure innovation is that magnetic fixation and a shape memory support achieve one-key type rapid installation, the operation time in an operation is shortened by more than 20%, the process innovation is that laser welding and plasma spraying technologies are combined, the product consistency (tolerance + / -0.05 mm) is ensured, and the production efficiency is improved. Clinical values are as follows: animal experiments prove that the postoperative infection rate is reduced to 1.2% (8.7% in a control group), and the incision healing time is shortened by 3-5 days.

The invention relates to the technical field of composite metal materials, in particular to a silver-coated graphene copper composite material and a preparation method thereof, and aims at solving the problems that traditional silver-coated copper powder is high in silver consumption, copper is oxidized due to the fact that a silver layer is prone to being damaged, and conductivity is insufficient. The method comprises the steps that a graphene coating layer is formed on a copper powder substrate in situ through chemical vapor deposition, and graphene copper powder is obtained; performing etching treatment on the graphene copper powder to controllably expose part of the copper substrate so as to form anchoring points for silver ion deposition; carrying out reduction treatment on the etched graphene copper powder so as to ensure that an anchoring site has chemical activity; in a reductive liquid phase environment, enabling a chemical silver plating solution to react with the graphene copper powder subjected to reduction treatment, and guiding silver ion deposition by utilizing an anchoring point, so as to form a silver coating layer on the surface of the graphene coating layer; and separating and drying the reacted system to obtain the silver-coated graphene copper composite material. The material is better in oxidation resistance and conductivity, and the process is free of waste liquid.

The invention provides a device for assisting an Ommaya bag in extracting cerebrospinal fluid, and belongs to the technical field of medical instruments. Comprising an annular sterile positioning base and an injector, a through hole is formed in the middle of the annular sterile positioning base, a fixing cylinder concentric with the through hole is fixedly connected to the upper surface of the annular sterile positioning base, a stretching assembly is arranged on the right side of the fixing cylinder, and a tightening assembly is arranged in the fixing cylinder; elastic assemblies are arranged on the left side and the right side of the upper surface of the fixing cylinder. The operation sterile area is enlarged through the sterile adhesive layer and the transparent soft plate, the sterile adhesive layer composed of the nano-silver coating can achieve 72-hour continuous antibiosis, infection prevention and pathogen invasion risk reduction, the center position is located through concentric circle cross scales of the sterile semi-transparent film, guiding and visual positioning of the syringe needle are achieved, and the operation safety of the syringe needle is improved. The needle head can vertically penetrate into the center of a capsule cavity, and hematoma or capsule wall damage caused by puncture deviation is avoided.

The invention discloses a preparation method of high-oxidation-resistance silver-coated copper composite powder, which comprises the following steps: (1) pretreatment of copper powder: sequentially putting the copper powder into alkali liquor and acid liquor for pretreatment to obtain the pretreated copper powder; (2) preparation of copper powder suspension: dispersing the pretreated copper powder in a mixed solvent of water and alcohol, then adding a dispersing agent, a reducing agent and a surface tension additive, and adjusting the pH value to 9-11 to obtain the copper powder suspension; and (3) a coating reaction is conducted, specifically, the silver complex solution is dropwise added into the copper powder suspension obtained in the step (2) for the coating reaction, the reaction continues to be sufficient after dropwise adding is completed, the high-oxidation-resistance silver-coated copper composite powder is obtained, and the thickness of a silver coating layer is 150-200 nm. The prepared silver-coated copper composite powder has the advantages of being good in dispersity, uniform and compact in silver coating layer and high in oxidation resistance.

The invention relates to a preparation method of silver-coated mica powder, and belongs to the technical field of conductive powder materials, the silver-coated mica powder comprises modified mica powder and a silver coating layer coating the modified mica powder; wherein a silane coupling agent structure in the Schiff base polymer intermediate can react with hydroxyl on the surface of the mica powder, so that on one hand, the mica powder can be modified, and on the other hand, an organic polymer transition layer is formed on the surface of the mica powder; silver ions are enriched through sulfur and nitrogen multi-reaction active sites in a Schiff base polymer intermediate, so that an organic polymer transition layer and chelated silver ions can be stably attached to the surface of mica powder, and a compact coating layer is formed. And after high-temperature calcination, the silver elementary substance promotes the coating layer to be connected into a sheet through a metal bond between Ag and Ag, the mica powder can be completely coated, and the oxidation resistance of the silver-coated mica powder is improved.

This invention relates to the field of photovoltaic technology and discloses a conductive silver-coated copper micropowder for photovoltaic applications and its preparation method. This preparation method aims to solve the problem of balancing performance and cost in existing silver-coated copper micropowders for photovoltaic applications. In this invention, during the pretreatment stage, the base copper powder is acid-washed but not water-washed. It undergoes pH adjustment, organic pre-bonding treatment, and gradient ammoniation to retain the activity of the copper powder and construct a uniform copper-ammonia complex layer. In the chemical silver plating stage, the pretreatment solution is added to a composite base liquid containing a complexing agent, organic amine, dispersant, and combined reducing agent. A silver-ammonia solution is then added dropwise under ultrasonic dispersion and nitrogen protection. In the post-treatment stage, the product undergoes ethanol reflux desorption, antioxidant treatment, vacuum drying, and low-temperature plasma activation, followed by sieving to obtain the final product. This method can achieve uniform and complete silver coating even with low silver content, providing a feasible path for the large-scale replacement of pure silver powder for photovoltaic applications with silver-coated copper micropowder.

The present application belongs to a kind of anti-tarnish sealant, for the technical problem that existing anti-tarnish agent can only extend the tarnish time, reduce the degree of tarnish, and the high temperature stability is poor, the silver-plated parts after treatment poor acid and salt fog ability, provide a kind of silver coating water-based anti-tarnish sealant, anti-tarnish film and its preparation method, anti-tarnish sealant includes yttrium zirconium composite sol, silane coupling agent, alkyl mercaptan, emulsifier, wetting agent, penetrant and water, it is proved to have the dual role of anti-tarnish and sealing silver coating hole, can significantly improve the anti-tarnish ability and acid and salt fog resistance of silver coating, and has very high high-temperature stability, can withstand 900 ℃ high-temperature baking.

The invention discloses a triboelectric nano-generator prepared by spraying MXene on stretchable polyurethane fibers, a preparation method and an application of the triboelectric nano-generator. The triboelectric nano-generator is integrally of a layered coaxial linear structure and comprises a stretchable layer, a conductive layer, a triboelectric layer and a two-dimensional material layer from inside to outside. The stretchable layer is a polyurethane (PU) layer; the conductive layer is formed by tightly winding a silver wire or a silver-coated nylon wire on the stretchable layer; the triboelectric layer is a polyamide (PA) layer and is used for generating a triboelectric effect; the two-dimensional material layer is used for improving the electrical output performance. According to the method, the production of the triboelectric nano generator FM-TENG with the stretchable polyurethane fiber sprayed with the MXene is realized through a two-step weaving process; the prepared triboelectric nano generator FM-TENG has excellent mechanical performance, stable electrical performance and high customizability, and can be widely applied to the fields of human motion recognition, energy collection, self-powered sensing and the like.

The invention relates to the field of surface treatment of electrical materials for electric power system application equipment, and discloses a silver plating method for an outdoor high-voltage switch conductive part. The invention relates to a silver plating method for a conductive part of an outdoor high-voltage switch. The silver plating method comprises the steps of pre-plating treatment, organic solvent oil removal, chemical oil removal, acid etching, acid pickling passivation, wax brushing (soaking), acid pickling and film removal, cleaning and polishing of a to-be-plated surface, silver pre-plating, cyaniding silver plating, alkali boiling for wax removal, acid etching for bright dipping, acrylic varnish coating of a non-silver-plated part and silver layer anti-discoloration treatment. By optimizing the silver plating step and the formula of the silver plating electroplating solution, the hardness, adhesive force and weather resistance of the silver plating layer of the copper base material and copper alloy base material conductive part of the high-voltage switch are improved, so that the high-voltage switch can adapt to different working conditions and environments.

The invention discloses a preparation method of an alkali-resistant silver coating, which comprises the following steps: (1) adding pretreated aluminum powder into a solvent, and then adding chitosan and inorganic metal salt for reaction to prepare chitosan and metal salt coated aluminum powder; the preparation method comprises the following steps: adding a template agent and carbon microspheres into an alkali solution, uniformly dispersing, adding organic silicate ester into an obtained mixture, and reacting to obtain silicon dioxide extinction powder; adding the prepared silicon dioxide matting powder and a modifier into toluene for reflux reaction to prepare surface-modified silicon dioxide matting powder; the preparation method comprises the following steps: uniformly mixing the chitosan with the metal salt coated aluminum powder, the surface modified silicon dioxide matting powder, the accelerant, the flame retardant, the auxiliary agent and the filler, feeding into an extruder for melt extrusion, cooling after extrusion, crushing and sieving to obtain the alkali-resistant silver coating. A coating prepared from the alkali-resistant silver paint provided by the invention on a metal surface can keep stable color and complete in a strong alkaline environment.

The invention relates to the technical field of odor-absorbing towels, in particular to a bacillus subtilis-based biological enzyme odor-absorbing towel and a preparation method thereof.The bacillus subtilis-based biological enzyme odor-absorbing towel comprises the following four layers: a surface layer, a breathable anti-reverse-osmosis non-woven fabric or nano-silver coating material, the pore diameter of the surface layer is smaller than or equal to 0.1 micron, and the surface layer is used for gas adsorption and liquid blocking; the biological enzyme filter membrane layer is formed by loading bacillus subtilis spores (greater than or equal to 108 CFU / g) and immobilized enzymes (lipase and protease) by a sodium alginate / chitosan composite hydrogel membrane; the specific surface area of the adsorption layer is larger than or equal to 1200 m < 2 > / g, the H2S adsorption capacity of the adsorption layer is larger than or equal to 200 mg / g, and the adsorption layer is used for pre-adsorbing high-concentration sulfides; the bottom layer is a microporous PE leakage-proof film, and the humidity is maintained at 60%-80% RH. According to the invention, peculiar smell molecules can be effectively degraded, liquid reverse osmosis can be prevented, and good air permeability and humidity regulation and control capability can be realized.

The present invention relates to the technical field of decorative films, and in particular to an antibacterial and mildew-proof high-flash glitter powder film material and a preparation method thereof, comprising the following steps: S1, taking a biaxially oriented PET film substrate, cleaning and dusting the surface, corona treating it, preheating it, vacuum evaporating a silver layer, cooling it, and removing it from the chamber to obtain a silver-plated PET film; S2, adding a terpolymer to deionized water, ultrasonically dispersing it, adding a water-based polyurethane binder, stirring it, adding glitter powder, and continuing to stir it to obtain a functional coating slurry; S3, evenly coating the functional coating slurry on the surface of the silver-plated PET film, drying it with hot air, curing the coating with UV light, heat-setting it in a nitrogen atmosphere, and winding it up to obtain the antibacterial and mildew-proof high-flash glitter powder film material prepared by the present invention has good optical properties and good antibacterial properties.