757 results about "Silver nanoparticle" patented technology

The invention relates to the field of super-hydrophobic materials, in particular to a basalt fiber composite material as well as a preparation method and application thereof. According to the composite fabric material provided by the invention, a multistage micro-nano rough surface of the MoS2 nanoflowers and the silver nanoparticles is constructed on the fiber substrate, so that not only is super-hydrophobic self-cleaning realized, but also the anti-icing performance is relatively high, and particularly, rapid heating is realized by combining broadband absorption of the MoS2 nanoflowers and a local surface plasma resonance effect of the silver nanoparticles; and meanwhile, the silver nanoparticles accelerate heat conduction, so that excellent ice melting capability is obtained. The high conductivity of the silver nanoparticles constructs a conductive path, and the layered structure of MoS2 triggers interface polarization, so that the electromagnetic shielding effectiveness of the X wave band is improved. The dual antibacterial mechanism of the MoS2 nanoflowers and the silver nanoparticles also realizes broad-spectrum efficient antibiosis, the preparation method is green and environment-friendly, the cost is low, and the requirements of complex scenes such as wearable electronic equipment, medical protection, polar region protection and national defense can be met.

The invention discloses a gynecological antibacterial gel containing a carbomer component, and belongs to the technical field of gynecological nursing materials. The gel is prepared from 0.5 to 5 percent of plant extract microcapsules, 0.5 to 3 percent of carbomer, 2 to 10 percent of glycerol, 0.1 to 1.5 percent of triethanol and the balance of purified water. The plant extract microcapsule is prepared by compounding methacrylated silk fibroin and a caffeic acid hyaluronic acid graft, has temperature responsiveness, can improve the adhesive force on the surface of vaginal mucosa, and realizes slow release of the plant extract; the caffeic acid catechol hydroxyl is chelated with silver ions, a nano-silver monodisperse layer is formed on the surface of the microcapsule, and the antibacterial activity is improved. The composite plant extract can inhibit bacteria, repair mucous membranes and maintain the acidic microenvironment of the vagina. When the gel is prepared, the problem that the swelling efficiency of carbomer is low is solved through glycerol pre-grinding, and triethanolamine is added in three times to form a gradient cross-linked network. The problems that traditional gel is unstable in viscosity, poor in mucous membrane adhesiveness and prone to damaging vagina micro-ecology are solved, the antibacterial effect is good, and preservation is stable.

The invention discloses a paclitaxel drug resistance SERS (Surface Enhanced Raman Scattering) substrate and a detection method. Belongs to the technical field of drug resistance detection. The SERS substrate is mixed with ultrapure water after centrifuging a silver nanoparticle-sodium citrate suspension, and the mixture is dropwise added to a silicon wafer and dried to form a coffee ring structure. During detection, cancer tissue crushing liquid is dropwise added to the center of the substrate, SERS signals are collected through a Raman spectrometer and compared with a pre-established drug resistance / sensitivity spectrum database, and drug resistance is judged according to characteristic peaks at 820 cm <-1 >, 1180 cm <-1 >, 1270 cm <-1 > and 1450 cm <-1 >. The method is easy and convenient to operate, short in detection time (within 10 minutes), high in sensitivity and suitable for rapid screening of paclitaxel drug resistance of breast cancer patients.

The invention relates to the technical field of surface coating materials, in particular to a multifunctional surface coating which comprises the following raw materials: organic silicon modified acrylic resin, an intumescent flame retardant, hollow glass beads, nano titanium dioxide, an auxiliary agent, graphene, silver nanoparticles and flaky zinc powder. The intumescent flame retardant is formed by compounding melamine polyphosphate and pentaerythritol, and the auxiliary agent comprises a dispersing agent, a flatting agent and a plasticizer. By integrating multiple functions of fire prevention, water prevention, heat insulation, self-cleaning and the like into a whole, the complex requirements of different fields of buildings, industry, traffic and the like on material performance can be comprehensively met. In the application of building exterior walls, the fireproof safety, the waterproof sealing performance and the heat insulation performance of buildings can be effectively improved, and energy consumption is reduced; in the aspect of industrial equipment protection, equipment can be protected from being damaged by environmental factors such as high temperature, moisture and corrosion, and the service life of the equipment is prolonged.

The invention relates to double-layer integrated asymmetric viscous hydrogel as well as a preparation method and application thereof, and belongs to the technical field of hydrogel. The invention relates to a preparation method of double-layer integrated asymmetric viscous hydrogel, which comprises the following steps: adding natural macromolecular polysaccharide and a polymeric monomer into a salt solution, stirring at room temperature, then adding an initiator and a cross-linking agent, stirring and polymerizing to obtain the double-layer integrated asymmetric viscous hydrogel. Through a one-pot method, a salt component is introduced into a hydrogel system, and the hydrogel has a double-layer structure with asymmetric viscosity under the salting-out action; in addition, the hydrogel is doped with a carbon nanotube with the surface modified by polydopamine and silver nanoparticles, so that the mechanical property and the conductivity of the hydrogel are remarkably improved. The preparation method provided by the invention is simple, is suitable for various hydrogel systems, has good universality and is easy to popularize and apply.

The invention discloses composite conductive powder for preparing conductive silver paste and the conductive silver paste, and particularly relates to the technical field of electronic materials.The composite conductive powder is of a double-shell core-shell structure composed of a silver metal inner core, a silicon dioxide middle coating layer and a silver nanoparticle self-assembled outer layer and is subjected to ultraviolet irradiation treatment; the conductive silver paste is based on the composite conductive powder and is matched with cerium oxide modified glass powder, graphene nanosheets, thermoplastic polyurethane resin and a dibasic acid ester solvent to form a low-temperature environment-friendly formula. The volume resistivity of the conductive silver paste is as low as 1.2 * 10 <-6 > omega.cm, the curing temperature is reduced to 120 DEG C, the content of volatile organic compounds meets the environmental protection standard, meanwhile, the tensile strength is improved by 50%, the conductive silver paste can bear 500 times of bending circulation without breakage, the adhesive force reaches the level 0 of a cross-cut method, the strict requirement of a high-performance electronic device for the conductive silver paste is effectively met, and the conductive silver paste has wide application prospects.

The invention provides a micro-nano optical fiber probe for biochemical component detection based on infrared spectroscopy and detection equipment, and a preparation method of the micro-nano optical fiber probe comprises the following steps: S1, selecting one section of a multimode quartz optical fiber as a sensing area, and then removing a cladding layer and a coating layer of the sensing area to expose a bare fiber; s2, dripping a mixed acid solution prepared from hydrofluoric acid and citric acid to the bare fiber to corrode the bare fiber, and then cleaning and blow-drying; immersing the treated multimode quartz optical fiber into a silane coupling agent solution, reacting for 0.5-1 hour, and then drying; s3, immersing the multimode quartz optical fiber treated in the step S2 into a solution containing silver nanoparticles, and reacting for 10-20 minutes to obtain an optical fiber modified by the silver nanoparticles; and S4, sputtering a gold layer on the surface of the silver-modified optical fiber by adopting a vacuum magnetron sputtering technology to obtain the micro-nano optical fiber probe with the silver-gold film layer. After the surface of the silver nanostructure is covered with the gold film, oxygen, water, corrosive molecules and the like are effectively prevented from making direct contact with silver. In addition, both the gold and the silver can support a surface plasmon resonance (SPR) effect, and particularly, the prepared detection equipment can ensure the sensitivity of the SPR.

The invention discloses a preparation method of a sandwich structure immunosensor based on surface enhanced Raman scattering and application of the sandwich structure immunosensor to detection of an anti-phospholipase A2 receptor antibody, and is characterized by comprising the following steps: sputtering silver ions on a cotton swab / ZIF-67 prepared by an in-situ growth method by adopting an ion sputtering method to obtain a cotton swab / ZIF-67 / Ag NPs composite material; the preparation method comprises the following steps: preparing an antigen solution, then adding the antigen solution into the antigen solution to obtain an immune substrate, adding a methylene blue aqueous solution into a silver nanoparticle solution for reaction, then connecting an anti-human PLA2R IgG antibody to obtain an immune probe, and finally dropwise adding a phosphate buffer solution containing an antibody to be detected onto the immune substrate, and dropwise adding the immune probe solution to the immune substrate adsorbed with the antibody to be detected to obtain the sandwich structure immunosensor based on surface enhanced Raman scattering. The method has the advantages of high sensitivity, good selectivity and strong stability.

The invention discloses a preparation method of a heat conduction and electromagnetic shielding self-healing polyurethane composite material, which comprises the following steps: modifying nano cellulose CNF (denoted as CNF-coated PPA) by using polyphenol amine PPA, and depositing silver nanoparticles on the surface of the CNF-coated PPA in situ to obtain a deposited material; the preparation method comprises the following steps: preparing a polyamide epichlorohydrin PAE solution, modifying graphene nanosheets GNP by using the PAE solution, and recording the modified graphene nanosheets GNP as PAE-GNP suspension liquid; cNF (at) PPA (at) Ag is dispersed into the PAE-GNP suspension liquid, and the CNF (at) PPA (at) Ag suspension liquid is marked as CNF-GNP suspension liquid; and preparing waterborne polyurethane WPU, dispersing the CNF-GNP suspension into the WPU, and carrying out vacuum filtration, drying and hot pressing on the mixed solution to obtain the polyurethane composite material. The method is simple in preparation process, mild in reaction condition and stable in product quality, and the polyurethane composite material prepared according to the method has excellent heat conduction, electromagnetic shielding and self-healing performance.

The present invention deals with a heat and moisture exchange filter with biocidal activity for medical ventilation equipment that comprises polymeric cellulose fibers impregnated with silver nanoparticles (AgNPs). The heat and moisture exchanger filter can be used in intubated patients under artificial ventilation in anesthesiology and intensive care and allows robust replacement, a fundamental utility for protection against nosocomial cross-contamination infections caused by microorganisms, such as bacteria, fungi, yeasts and viruses.The invention also deals with the method of preparing the heat and moisture exchange filter with biocidal activity and the use of silver nanoparticles.

The invention belongs to the field of biomedical materials, and discloses a composite hydrogel dressing and application. The composite hydrogel dressing is prepared by the following steps: blending 4-aminophenylboronic acid grafted hyaluronic acid and gallic acid grafted collagen, adjusting the pH value, carrying out a cross-linking reaction to obtain a cross-linking product, and stirring and mixing the cross-linking product with a gallic acid reduced silver nanoparticle solution. The antibacterial and self-healing composite hydrogel dressing for promoting wound repair has proper adhesion, mechanical properties and free radical scavenging ability, and excellent antibacterial property, biocompatibility and self-healing ability.

The invention discloses a preparation method of an environment-friendly degradable single-sided perspective sticker, and belongs to the technical field of modified nano materials. The method comprises the following steps: (1) preparation of a multi-layer composite structure: mixing polylactic acid and poly (butylene succinate), adding nano-montmorillonite and a surface modifier, and carrying out melt blending to form a first-layer melt; stirring poly (butylene adipate-co-terephthalate) and fluorescent carbon nanodots to form a second layer of melt; the first layer, the pressure-sensitive adhesive layer and the second layer are co-extruded and compounded to form a film blank. And (2) construction of the nano-film: biaxially stretching the film blank, imprinting a micropore array, dipping in the silver nanoparticle suspension, and drying to obtain the nano-film. And (3) coating functionalization treatment: immersing into a fluorine-containing nano coating solution, and curing. And (4) post-treatment: carrying out secondary curing. The obtained single-sided perspective sticker is suitable for the fields of buildings, vehicle privacy films and the like, and solves the problems of serious pollution and slow degradation of a traditional sticker.

The invention belongs to the field of flexible electronic devices, and discloses a preparation method of a high-performance strain sensor based on a nano-silver nano-cellulose seepage network. According to the hydrogel, polyvinyl alcohol is used as a matrix, a seepage network formed by polydopamine anchored nano-silver / nano-cellulose PCNF is used as a conductive phase, glycerin is used as an anti-freezing humectant, and through the synergistic effect of a three-dimensional seepage conductive network and a dynamic hydrogen bond network, the defects that traditional hydrogel is poor in sensing stability, poor in environmental stability and low in mechanical strength are overcome. The preparation process is simple, the conductive hydrogel is high in tensile strength, high in sensitivity and good in cycling stability and has an antibacterial function, and an assembled strain sensor can monitor a human motion signal in real time and is suitable for the fields of wearable equipment, electronic skin and medical monitoring in an extreme environment. Through material system and process innovation, integration of high performance and multiple functions is achieved, and wide application prospects are achieved.

A membrane includes a polysulfone-based support, a polydopamine (PDA) layer disposed on a surface of the polysulfone-based support, and a silver / polydopamine (Ag / PDA) composite layer disposed on a surface of the polydopamine layer. The polysulfone-based support has a pore size of up to 600 nanometers (nm). The Ag / PDA composite layer contains core-shell structure particles and spherical particles. The core-shell structure particles have a silver nanoparticle core and a polydopamine shell. The spherical particles are silver-decorated polydopamine particles. The membrane can at least partially separate an Erichrome Black T (EBT) dye from an EBT dye / salt containing mixture by rejecting the EBT dye and allowing the EBT dye / salt containing mixture to pass through the membrane.

The invention provides a method for detecting an external vesicle marker through high-flux nano plasma exciting light immune color development, and belongs to the technical field of human extracellular vesicles. After a serum sample is subjected to centrifugal treatment, the serum sample and a CD81 capture antibody substrate are incubated, and the particle size distribution of the vesicles is monitored in real time; a zwitterionic polymer modified gold nanoparticle LAM detection probe and a polyethylene glycol modified silver nanoparticle LprG detection probe are prepared to be specifically combined with a vesicle surface antigen, a chromogenic enhancement solution is adopted to induce a plasma resonance signal, and full-hole scanning imaging is carried out; and constructing a double-layer game optimization model to cooperatively optimize the detection sensitivity and the signal stability, carrying out weighted summation on normalized signals of the particle size subgroups to obtain comprehensive detection signal intensity, comparing the comprehensive detection signal intensity with a threshold value, and outputting a final judgment result. The technical problem that quantitative accuracy is affected by signal intensity deviation caused by vesicle particle size difference in outer vesicle marker detection is solved.

The invention provides a graphene-based capacitive sensor for detecting the moisture content in lubricating oil, a preparation method of the graphene-based capacitive sensor and a method for detecting the moisture content in the lubricating oil, and belongs to the technical field of moisture content detection. The graphene-based capacitive sensor for detecting the moisture content in the lubricating oil comprises a graphene-based electrode and a gold nanoparticle layer which are arranged in a laminated manner, the graphene-based electrode comprises a laser-induced graphene film and doped nanoparticles loaded on the surface and in pores of the laser-induced graphene film, and the doped nanoparticles are silver nanoparticles and copper oxide particle clusters; array holes are formed in the gold nanoparticle layer, the diameter of holes in the array holes is larger than the diameter of water molecules and smaller than the diameter of lubricating oil molecules, and the depth of the holes in the array holes is consistent with the thickness of the gold nanoparticle layer. The graphene-based capacitive sensor can realize real-time online detection of the moisture content in the lubricating oil, and is high in detection sensitivity and simple to operate.

The invention relates to the field of solder materials, and provides a non-ferrous metal solder for low-temperature brazing and application, the solder is composed of carbon-coated copper nanorods, tin-bismuth alloy-coated silver nanoparticles, 2-mercaptobenzimidazole, rosin resin, an organic active agent, a dispersing agent, ionic liquid, hydroxyethyl cellulose, indium nitrate and citric acid. The silver particles are of a core-shell structure and are coated with tin-bismuth alloy layers, and continuous carbon layers are formed on the surfaces of the copper nanorods, so that the conductivity and the interface stability of the solder are effectively improved. The non-ferrous metal solder with excellent conductivity, low melting point and good wettability is prepared through step-by-step mixing, hot press molding and low-temperature heat treatment processes, and is suitable for electronic device packaging, power device connection and flexible circuit interconnection, and the defects of existing solder in the aspects of low-temperature welding and high conductivity are overcome.

The invention discloses application of biological silver nanoparticles synthesized based on bacillus velezensis in prevention and treatment of tomato gray mold, and relates to the technical field of prevention and treatment of tomato gray mold. Researches find that the biological silver nanoparticles Bio-AgNPs have a relatively strong inhibition effect on the growth of botrytis cinerea hyphae, and when the concentration of the biological silver nanoparticles Bio-AgNPs is 100 mu g / mL, the growth inhibition rate of the botrytis cinerea hyphae is 100%. The Bio-AgNPs shows a good prevention and treatment effect on the tomato gray mold, after 40 [mu] g / mL of Bio-AgNPs is used for treating tomato fruits and leaves, the scab of the tomato fruits is obviously reduced by 52.21%, and the prevention and treatment effect on the tomato leaf gray mold is 40.19%.

The invention relates to the technical field of functional coatings of medical instruments, in particular to a temperature-sensitive response type sodium polyacrylate catheter leakage-proof coating, a preparation method and application thereof, and the coating is of a three-layer composite structure. And the bottom bonding layer adopts a polydopamine modified silane coupling agent system, contains silver nanoparticles, has the thickness of 5-15 microns, and ensures strong bonding and antibiosis of the substrate. The middle functional layer is a three-dimensional cross-linking degree gradient interpenetrating network polymer, is composed of a plurality of monomers and nano materials, and is 50-100 [mu] m in thickness, the cross-linking degree of the middle functional layer is gradually increased from inside to outside, gradient transition of mechanical properties is achieved, the outer protective layer is composed of a copolymer, is 3-8 [mu] m in thickness, and provides excellent anti-fouling and biocompatibility. The coating is endowed with strong adhesive force, gradient mechanical property and surface stability, the sodium polyacrylate component absorbs water and expands in urine to form sealing, and the expansion degree of the sodium polyacrylate component is regulated and controlled by the pH value and ionic strength of the urine.

The invention discloses a hybrid Ag / MXene / Fe-Co MOF surface enhanced Raman scattering sensor and an application of the hybrid Ag / MXene / Fe-Co MOF surface enhanced Raman scattering sensor in rapid detection of bacteria. According to the sensor, silver nanoparticles are prepared through a sodium citrate reduction method, a two-dimensional material MXene and a bimetal organic framework are combined, and a surface enhanced Raman scattering spectrum detection platform with high sensitivity, stability and anti-interference performance is constructed. The conductive network of MXene and the local surface plasmon resonance effect of silver nanoparticles synergistically enhance an electromagnetic field, and the porous structure of Fe-Co MOF enriches target molecules and forms dense hot spots, so that the Raman signal intensity is remarkably improved. Experiments show that the detection limit of the sensor to 4-mercaptobenzoic acid is as low as 10 <-12 > M, and the signal stability can last for 7 days; the detection limit on common pathogenic bacteria such as escherichia coli and staphylococcus aureus reaches 10 CFU / mL, and the linear correlation coefficient is superior to 0.96. The sensor has hydrophobicity and biocompatibility, can efficiently capture bacteria through capillary force, is suitable for trace detection of complex samples, and provides a new strategy for rapid diagnosis of clinical drug-resistant bacteria.

The invention discloses a preparation method of a high-stability manual buffer solution, which comprises the following steps of: introducing two types of slow-release porous particle structures, namely a first type of particles loaded with acidic or alkaline components and a second type of particles loaded with silver nanoparticles, so that continuous slow release and dynamic adjustment of the components in the buffer solution are realized; the pH drift and the aging of a buffer system are effectively delayed; meanwhile, slow release of the silver nanoparticles endows the buffer solution with lasting antibacterial protection, microbial growth is remarkably inhibited, and due to the structural design, the long-term pH stability and storage safety of the buffer solution are remarkably improved, the clarity and physicochemical properties of the buffer solution are guaranteed, and the stability of the buffer solution is improved. The method greatly expands the application range in the fields of high-requirement biological experiments, medical detection, long-term sample storage and the like, the particle addition amount and the component proportion can be flexibly adjusted according to actual requirements, the method adapts to different pH ranges and application scenes, and various experiment requirements of protein purification, long-term sample storage, high-sensitivity analysis and detection are met.

The invention discloses a composite medical suture and a preparation method thereof, and belongs to the field of biomedicine. In order to solve the problems that an existing medical suture is poor in antibacterial effect and biological safety, the composite medical suture comprises a core layer, a degradation regulation and control layer, a slow release layer and an antibacterial layer which are sequentially arranged from inside to outside; the core layer is prepared from a blend fiber of poly (hydroxybutyrate-hydroxyvalerate) and polycaprolactone-co-polyglycolide; the degradation regulation and control layer comprises a mixture of at least two kinds of polyethylene glycol with different molecular weights; the slow release layer comprises quaternary ammonium salt loaded graphene oxide nanofibers; the antibacterial layer comprises titanium dioxide loaded with silver nanoparticles. Through the synergistic effect of the four layers, the comprehensive optimization of mechanical properties, degradation rate, drug sustained release and antibacterial function is realized; the purposes of improving the slow-release antibacterial performance, reducing damage to the human body, reducing inflammation and the like are achieved, and the antibacterial and degradation effects meet the recovery requirements.

The invention discloses a dressing for promoting pain relief and regeneration of burn wounds and a preparation method of the dressing. The dressing comprises a drug delivery carrier and slow-release multi-effect hydrogel loaded on the drug delivery carrier, the slow-release multi-effect hydrogel is prepared from the following raw materials in parts by weight: 100 parts of water, 7 to 35 parts of multi-effect slow-release microspheres, 3.5 to 10 parts of sodium carboxymethyl cellulose, 2.5 to 8 parts of sodium hyaluronate and 0.5 to 4 parts of glycerol. The dressing provided by the invention has the effects of relieving wound pain, promoting wound regeneration and inhibiting and killing bacteria, the effect of the dressing is long-acting by realizing slow release of various active components (antibacterial carbon dots, silver nanoparticles and bletilla striata polysaccharide), and the dressing has a good application prospect by virtue of matching of the active components and the slow-release effect of the active components. The nursing and treatment effects of burn wounds can be effectively improved, and the application prospect is very good.

The invention provides a super-lubricity antibacterial coating material and a preparation method and application thereof, and relates to the technical field of medical implant materials, and the preparation method comprises the following steps: S1, respectively pretreating silver nanoparticles and polyethylene glycol; s2, the pretreated silver nanoparticles are placed in a first solvent, a silver nanoparticle solution is obtained, then a silane reagent and a catalyst are added, a silanization reaction is carried out, and activated silver nanoparticles are obtained; s3, placing a hydrophilic monomer in a second solvent, and then adding the activated silver nanoparticles to obtain a silver nanoparticle modified hydrophilic monomer; s4, putting the pretreated polyethylene glycol and an activating agent into a third solvent, and carrying out activating treatment to obtain an activated polyethylene glycol solution; and S5, putting the hydrophilic monomer modified by the silver nanoparticles into the activated polyethylene glycol solution to obtain the super-lubricity antibacterial coating material. When the surface of a silica gel catheter is coated with the super-lubricity antibacterial coating material, the lubricity and antibacterial property of the catheter are remarkably improved.

The invention belongs to the technical field of gas analysis, and relates to a surface-enhanced Raman scattering flexible substrate material as well as a preparation method and application thereof. The surface-enhanced Raman scattering flexible substrate material comprises a three-dimensional network structure and silver nanoparticles, the three-dimensional network structure is composed of hydroxypropyl methyl cellulose nanofibers, the silver nanoparticles are wrapped in the hydroxypropyl methyl cellulose nanofibers, and the silver nanoparticles are of a polyhedral structure. The surface-enhanced Raman scattering flexible substrate material is used for detecting thiol compounds in a solution, and the detection limit can reach 10 <-19 > M level; after the surface of the silver nanoparticle is modified with the probe, the material can detect trace substances in exhaled air. In addition, after the material is stored for 6 months at room temperature, the SERS signal intensity attenuation is less than or equal to 4%, and the relative standard deviation detected by 20 random sites is only 4.04%.

The invention discloses an adipose-derived stem cell exosome compound loaded with silver nanoparticles and application of the adipose-derived stem cell exosome compound loaded with the silver nanoparticles, and ADSC-Exos loaded with the silver nanoparticles is developed by integrating AgNPs into an exosome of ADSCs. In vivo, the Exo-AgNPs can accelerate healing of infected wounds by reducing bacterial colonization and promoting collagen deposition, angiogenesis and M2 type macrophage polarization. In vitro, the Exo-AgNPs activates the functions of fibroblasts and vascular endothelial cells, and shows an excellent antibacterial property. In addition, the Exo-AgNPs induces polarization of M2 type macrophages and inhibits secretion of proinflammatory cytokines by activating autophagy. The results show that Exo-AgNPs is expected to become an ideal biological material for treating infected wounds.

The invention discloses a multi-layer composite pipe as well as a preparation method and application thereof, and relates to the technical field of high polymer materials. The multi-layer composite pipe sequentially comprises a PEXB layer, a composite coating, a PTFE layer and a self-repairing layer from outside to inside, the composite coating comprises graphene, silver nanoparticles loaded on the surface of the graphene and a bio-based material crosslinked with the silver nanoparticles, and the self-repairing layer comprises polyurethane / epoxy resin microcapsules; the mass ratio of the graphene to the bio-based material to the silver nanoparticles in the composite coating is (85-89): 10: (1-5); the bio-based material is selected from one of carboxymethyl chitosan and sodium alginate. The multi-layer composite pipe has excellent chlorine resistance, antibacterial property, corrosion resistance and self-repairing function.

The invention discloses composite hydrogel with a photo-thermal antibacterial effect and a preparation method of the composite hydrogel. The composite hydrogel is prepared from the following components: gold nanorods with a photo-thermal effect; silver nanoparticles grow on the surface of a gold nanorod through a reduction deposition method, and a silver-coated gold nanorod of a core-shell structure is formed; oxidized hyaluronic acid and carboxymethyl chitosan are subjected to Schiff base reaction and cross-linking to form a self-healing hydrogel matrix; the advantages of the Au-Ag-PEG nanoparticles and the hydrogel are combined, so that the Au-Ag-PEG hydrogel has an excellent antibacterial effect in vitro and in vivo; therefore, the nano composite hydrogel wound dressing has huge application potential in the aspect of treating infectious skin wounds.

The invention provides a method and system for detecting organophosphorus pesticide residues and a storage medium, and relates to the technical field of organophosphorus pesticide residue detection.The method comprises the steps that a micro-fluidic chip is used for removing impurities from surface flushing liquid and homogeneous sample liquid, pesticide molecules are enriched through magnetic microspheres, the target molecule concentration is increased, and the detection sensitivity is high; the method comprises the following steps: firstly, preparing a surface-enhanced Raman scattering substrate, dropwise adding the enriched liquid onto the surface-enhanced Raman scattering substrate, enhancing Raman signals through a silver nanoparticle array, acquiring spectral data by using a portable Raman spectrometer, removing fluorescence background interference through polynomial fitting, extracting the characteristic peak intensity of target molecules, and calculating a comprehensive characteristic index by combining spectral characteristic parameters; finally, an SVM (support vector machine) model is trained based on historical sample data, the concentration of the sample to be detected is accurately predicted, and whether the concentration meets the food safety standard or not is judged.

This invention discloses a method for preparing ultrafine spherical silver-coated copper powder. A dense film is formed on the surface of copper powder using a specific activator, and this film can quickly form a complex with silver ions in the solution. At the same time, under the action of a specific reducing agent, silver ions are reduced to fine silver nanoparticles and adsorbed on the surface of copper powder. Silver ions in the solution form a dense silver layer on the surface of copper powder through two-dimensional nucleation, resulting in silver-coated copper powder with high density, high conductivity, and high oxidation resistance.