315 results about "Ag nanoparticles" patented technology

A process for preparing the composite functional carbon nanotube / silver material features that the metallic salt reducing method is used to wrap to layer of Ag nanoparticles on the surface of carbon nanotube in order to make the carbon nanotube to bond with metallic base easily.

A medical antibacterial activated carbon fibre-nanoAg material used as wound dressing is prepared through activating the carbon-contained fibres by gasifying-activating method, immersing them in Ag-contained solution or spraying said solution onto them, and oscillating for embedding the Ag nanoparticles in fibres. Its advantages are high and durable antibacterial action.

An antibacterial silk protein carried nano-Ag powder used for cosmetics, health-care food, enzyme immobilizing materials, biosensor, artificial skin or muscle, etc is prepared proportionally from silk protein and Ag nanoparticles. Its preparing process is also disclosed.

A surface-enhanced Raman scattering method and apparatus to sequence polymeric biomolecules such as DNA, RNA, or proteins is introduced. The method uses metallic nanostructures such as, for example, spherical or cylindrical Au or Ag nanoparticles having characteristic lengths of 10-100 nm which when illuminated with light of the appropriate wavelength produce resonant oscillations of the conduction electrons (plasmon resonance). Electric field enhancements of 30-1000 near the particle surface resulting from such oscillations increase Raman scattering cross-sections by about 106-1015 due to the E4 dependence of the Raman scattering, wherein the largest enhancements occur in the gap / junction between novel closely spaced structures as disclosed herein.

The present invention provides for novel hydrogen sensors and methods for making same. In some embodiments, such novel hydrogen sensors are continuous-range hydrogen sensors comprising Pd—Ag nanoparticles arrayed as nanowires or two-dimensional shapes on a resistive surface. Such continuous-range hydrogen sensors are capable of measuring a wide range of hydrogen gas concentration over a wide temperature range. Unlike existing hydrogen sensors that experience a large change in resistance at a certain hydrogen concentration, the continuous-range hydrogen sensor of the present invention changes resistance continuously over a broad range of hydrogen concentration. This continuous change varies slowly with hydrogen concentration and is predictable such that the continuous-range hydrogen sensor can be used to measure hydrogen concentration continuously from a few ppm to 40,000 ppm level or higher over a broad range of temperatures (e.g., −40° C. to +150° C.).

The invention belongs to the field of nano material preparation, and relates to a method for comodifying a titanium dioxide nanotube array with silver and cadmium sulfide nanoparticles, which comprises the following steps: carrying out ultrasonic cleaning on a high-purity titanium sheet to remove oil, removing the natural oxide film, and carrying out secondary anodization to prepare an ordered titanium dioxide nanotube array; and treating the titanium dioxide nanotube array with a coupling agent, depositing Ag nanoparticles by an SILAR (successive ionic layer adsorption and reaction) process, and modifying the Ag-modified titanium dioxide nanotube array with CdS nanoparticles, thereby obtaining the Ag / CdS-nanoparticle-comodified titanium dioxide nanotube array. The invention is simple to operate and has the advantage of low cost; the noble metal and narrow-energy-gap semiconductor nanoparticles are utilized to comodify the titanium dioxide nanotube array, thereby effectively widening the absorption range of TiO2 in the visible light region and lowering the recombination rate of the electron-hole pair; and the invention has wide prospects in the aspects of solar cells, toxic or harmful pollutant degradation and the like.

The invention relates to an Ag / ZIF-8 antibacterial agent and a preparation method thereof, and belongs to the technical field of nano materials. The invention provides the Ag / ZIF-8 composite anti-bacterial agent and the preparation method. The Ag / ZIF-8 composite anti-bacterial agent is prepared by dispersing Ag nanoparticles onto ZIF-8 by impregnation and reduction. The used ZIF-8 material has a multi-stage pore structure and a large specific surface area, and has good stabilization and dispersion effects on Ag nanoparticles. According to the Ag / ZIF-8 anti-bacterial agent, the provided Ag / ZIF-8 nano anti-bacterial agent has small particles and a spherical or polyhedral structure with the particle diameter of 10-200nm, thereby being beneficial to increasing the adhesion of the Ag / ZIF-8 anti-bacterial agent to bacteria; the Ag nanoparticles and the ZIF-8 have a synergetic anti-bacterial effect, multiple indicating bacteria present efficient and board spectrum anti-bacterial effects; thepreparation method is simple in process, economical and feasible.

The invention relates to a preparation method of magnetic composite catalyst Ag / HNTs / Fe3O4, and belongs to the technical field of environmental function material preparation; a simple and effective chemical reduction method is used to prepare a Fe3O4 / Halloysite Nanotubes (HNTs / Fe3O4) magnetic composite material, then a silver nitrate solution and ammonia are mixed into a fresh silver ammonia solution as an oxidizing agent, glucose is used as a reducing agent, Ag nanoparticles are deposited on the magnetic composite material by a silver mirror reaction to prepare the magnetic composite catalyst Ag / HNTs / Fe3O4, and the magnetic composite catalyst Ag / HNTs / Fe3O4 is used for catalytic degradation of p-nitrophenol in a water solution.

The present invention discloses a polymeric polyamine which can be produced by polymerizing polyoxyalkylene-amine and a linker. The linker can be anhydride, carboxylic acid, epoxy, isocyanate or poly(styrene-co-maleic anhydride) copolymers (SMA). The present invention also discloses a method for stabilizing the Ag nanoparticles with polymeric polyamine. The polymeric polyamine serving as a stabilizer or dispersant is mixed with a water solution of silver salt and then a reducer is provided to reduce the silver ions and form an organic or a water solution of Ag nanoparticles. Water or solvent of this solution can be further removed through a heating, freezing or decompression process, and thus solid content of the solution can be increased. The concentrated solution also can be diluted to obtain a stable dispersion without aggregation.

The invention discloses a ZnO-Ag surface enhanced Raman scattering substrate and detection of organic pollutants with the substrate. The preparation method for the substrate comprises the following steps: the first step, ITO conductive glass is subjected to ultrasonic cleaning with acetone, alcohol and deionized water one by one and dried in the air; the second step, organic additives are added in a zinc nitrate solution, a first mixed liquid is formed, after the first mixed liquid is stirred for 30 min, an ammonia-water solution with a mass fraction of 25% is dropwisely added in the first mixed liquid, a second mixed liquid is formed, the processed ITO conductive glass from the first step is soaked in the second mixed liquid, after the water bath is at a constant temperature, the ITO conductive glass is placed in a baking box and baked for 60-100 min, a white and uniform ZnO layer is formed on the surface of the ITO conductive glass; the third step, Ag nanoparticles are deposited on the prepared ZnO nanolayer from the second step, and a ZnO-Ag surface enhanced Raman scattering substrate is obtained. The preparation method is simple. The prepared substrate has high sensitivity and good stability and can be used repeatedly.

This invention discloses a method for preparing metal dielectric composite particles of nanoscale Ag / SiO2. The method comprises: hydrolyzing tetraethyl orthosilicate by NH3 catalysis to prepare SiO2 microspheres, preparing AgClO4 electrolyte solutions with different concentrations, adding the prepared SiO2 microspheres into the AgClO4 electrolyte solutions, ultrasonicating in an electrolytic tank for 10min, inserting two electrodes into the electrolytic tank, applying DC to electrolyze and obtain the product, centrifuging to separate the product, washing with deionized water and ethanol repeatedly, and drying at 30-50 deg.C. This invention utilizes sonoelectrochemical method to deposit Ag nanoparticles onto the surface of SiO2 microspheres. The Ag nanoparticles are uniformly distributed onto the surface of SiO2 colloid, and have excellent potential applications.

The invention discloses a supported metal-organic framework composite material, and concretely discloses a noble-metal-loaded composite catalytic material based on a porous crystal metal organic framework material and application of the composite catalytic material to catalyze reduction of p-nitrophenol. A two-step synthesis method is employed and comprises firstly performing self-assembly on an organic ligand 3,5-di(2,5-dicarboxylphenyl)benzoic acid and zinc nitrate in a mixed solution of N,N-dimethylacetamide and water, so as to obtain a porous metal organic framework material, and enabling the matrix and holes of the metal organic framework material to be loaded with noble metal nanoparticles by utilizing a ultraviolet-light reduction technology, so as to finally obtain noble metal Ag nanoparticles which are uniformly distributed, uniform in size and has the diameter of 3-10 nm, wherein the loading amount of the noble metal is adjustable. The catalyst has stability and superior catalytic activity in catalyzing reduction of p-nitrophenol.

A method for larger-area fabrication of uniform silicon nanowire arrays is disclosed. The method includes forming a metal layer with a predetermined thickness on a substrate whose surface has a silicon material by a coating process, the metal layer selected from the group consisting of Ag, Au and Pt; and performing a metal-induced chemical etching for the silicon material by using an etching solution. Accordingly, a drawback that Ag nanoparticles are utilized to perform the metal-induced chemical etching in prior art is solved.

The invention discloses a preparation method of an SERS substrate of Au@Ag nanoparticles. According to the method, gold nanoparticles are prepared by reducing chloroauric acid with sodium citrate, thegold nanoparticles are modified with 4-sulfydryl aniline to link silver ions, and a certain proportion of ascorbic acid and sodium hydroxide are added to reduce a silver shell. Meanwhile, the form size of the core-shell structure is controllable, plasma resonance is realized through high coupling of the structure, and the so-called hotspots are formed in the core-shell structure, so that 4-sulfydryl aniline serving as an internal standard molecule has very high Raman signals. The Au@Ag core-shell structure is modified with 4-sulfydryl phenylboronic acid to capture glucose molecules, so that qualitative and quantitative detection of glucose is realized. The method has the advantages as follows: the internal standard substance is used for signal comparison, interference of complex substances in samples (such as urine) can be avoided, the detection sensitivity is improved, the preparation cost is low, and qualitative and quantitative detection of glucose is really realized.

The invention discloses a preparation method of a Z-type g-C3N4@Ag@Ag3PO4 composite photocatalyst. The preparation method comprises the following steps of firstly, putting urea into a ceramic crucible with a cover, putting into a muffle furnace, and calcining under air atmosphere, so as to obtain a g-C3N4 semiconductor material; by using the g-C3N4 as a carrier, respectively using silver nitrate and sodium dihydrogen phosphate as a silver ion source and a phosphate ion source, respectively using glucose and sodium borohydride as reduction agents, and using iron nitrate nonahydrate as an oxidant, finely preparing the Z-type g-C3N4@Ag@Ag3PO4 composite material with Ag nanoparticles between the g-C3N4 and Ag3PO4. The preparation method of the Z-type g-C3N4@Ag@Ag3PO4 composite photocatalyst has the advantages that the method is simple, the control is easy, the operation is convenient, the cost is low, the green and non-pollution effects of raw materials are realized, and the like; the spectrum absorbing range is effectively widened, the compounding of photon-generated carriers is effectively decreased, and the application prospect and potential practical value are good.

The present invention provides for novel hydrogen sensors and methods for making same. In some embodiments, such novel hydrogen sensors are continuous-range hydrogen sensors comprising Pd—Ag nanoparticles arrayed as nanowires or two-dimensional shapes on a resistive surface. Such continuous-range hydrogen sensors are capable of measuring a wide range of hydrogen gas concentration over a wide temperature range. Unlike existing hydrogen sensors that experience a large change in resistance at a certain hydrogen concentration, the continuous-range hydrogen sensor of the present invention changes resistance continuously over a broad range of hydrogen concentration. This continuous change varies slowly with hydrogen concentration and is predictable such that the continuous-range hydrogen sensor can be used to measure hydrogen concentration continuously from a few ppm to 40,000 ppm level or higher over a broad range of temperatures (e.g., −40° C. to +150° C.).

The invention discloses a triazinyl porous polymer material. The triazinyl porous polymer material is an acetylene bond-functionalized triazinyl porous polymer. The invention also relates to an application of an Ag / triazinyl porous polymer catalyst in catalysis of a carboxylation reaction of the aromatic terminal alkyne and CO2. The triazinyl porous polymer material with high CO2 adsorption capacity is designed and synthesized, and Ag nanoparticles are loaded through using the coordination characteristic of a triazine ring in order to introduce a catalytic active unit to the triazinyl porous organic material skeleton and obtain the Ag / triazinyl porous polymer catalyst. The catalyst can catalyze the direct carboxylation of the aromatic terminal alkyne and CO2 to synthesize acetylenic acid, that is, the catalyst converts CO2 into a chemical substance with high added values.

The invention provides a preparation method for an Ag-doped modified manganese-based mullite catalyst and an application of the Ag-doped modified manganese-based mullite catalyst in a motor vehicle exhaust gas purification aftertreatment system. The catalyst is prepared through an in-situ complexing combustion method; and the method achieves uniform mixing of Ag and mullite, Ag modification of manganese-based mullite is achieved through high-temperature roasting, and the Ag-doped modified manganese-based mullite catalyst with high oxidation activity is obtained. The process has the following advantages: (1) by adopting the in-situ complexing combustion method, the dispersity of Ag nanoparticles in a mullite matrix can be improved; (2) the generation and transfer of an active oxygen speciescan be accelerated by Ag doped modification, and thus, the catalytic oxidation of NO and soot activity of the manganese-based mullite are further improved; and (3) the catalyst has excellent hydrothermal stability and sulfur oxide poisoning resistance. The catalyst is simple in preparation method, short in preparation cycle and low in cost, is applicable to oxidation of soot particles and nitrogen oxides in motor vehicle exhaust gases and has a good application prospect.

The invention discloses a three-terminal parallel polymer solar cell based on metal nanoparticle doping and a preparation method of the solar cell, and belongs to the technical field of polymer solar cells. The solar cell sequentially consists of ITO (Indium Tin Oxide) conductive glass serving as a substrate and a cathode, a TiO2 electronic transmission layer, a PSBTBT:PC70BM:NPs active layer, an MoO3 hole transmission layer, an Ag anode, a WO3 hole transmission layer, a P3HT:PC70BM:NPs active layer, an LiF electronic transmission layer and an Al cathode, wherein a mass ratio of the P3HT:PC70BM:NPs active layer is 1:1:(0.02-0.05), and NPs represents Au or Ag nanoparticles. According to the solar cell and the preparation method, two subcells form a parallel structure, light absorbing ranges of active layers of the subcells are complementary, metal nanoparticles are doped in the active layer of each subcell, and a utilization ratio of sunlight by the solar cell is increased by utilizing a plasma enhancement effect nearby the metal nanoparticles, so that the performance of the solar cell is improved.

The invention discloses a porous CeO2 nanomaterial preparation method and application in paper-based sensors with snowflake shaped Ag nanoparticles. Wax printing and laser cutter techniques are adopted for preparing a hydrophobic area, a semi-hydrophilic area, a hydrophilic area and a hollow passage on paper, and a paper chip is modified by printing corresponding electrodes on the paper and functionalizing operating areas. The obtained paper chip is folded to form a three-electrode system, and primary detection is performed. Pb<2+> activates DNA chain enzymes and catalyzes substrate chain breaking to promote fixation of a porous CeO2 nanomaterial on the paper-based sensors, and inhibition of electrochemical luminescence is substituted with the catalysis effect. The prepared paper chip is folded and subjected to secondary detection, and ultra-sensitive detection of a to-be-detected article is realized through luminous intensity difference of twice detection.

The invention relates to a self-assembly material based on silver nanoparticles and a preparation method thereof. The constitution is characterized in that the center is a self-assembly body of Ag nanoparticles, the center is decorated with a layer of tannin, and an outermost layer is a sol gel SiO2 layer; the constitution is further characterized in that during a cladding process of silicon dioxide, by controlling the injection sequence of tetraethyl orthosilicate, a mononuclear composite structure or a multinuclear composite structure can be obtained, mononuclear silver nanoparticles or multinuclear silver nanoparticles are prepared, and the thichness of the SiO2 layer in outer layer is adjustable. The preparation method comprises the steps that first, the silver nanoparticles with tannin serving as a reducing agent and ligand are compounded, and then silicon dioxide cladding is conducted to the silver nanoparticles through a sol-gel method. The self-assembly material based on the silver nanoparticles and the preparation method thereof has the advantages that the method is simple, the mononuclear composite structure and the multinuclear composite structure are easy to achieve, and the composite structures are stable.

The invention relates to a method for electrochemically depositing silver nanoparticles in a titanium dioxide nanotube array. The method comprises the following steps: (a) titanium sheet pretreatment: removing oil stain and impurities on the surface of a titanium sheet, burnishing the surface of the titanium sheet, carrying out polishing treatment, cleaning, and drying for later use; (b) preparing a TiO2 nanotube array on the surface of the titanium sheet by virtue of an anodic oxidation method; (c) deposition of silver nanoparticles: cleaning the titanium sheet on which the titanium dioxide nanotube array is formed on the surface for removing the impurities, then dipping the titanium sheet into mixed liquid of Ag ion-containing ethanol and water, connecting the titanium sheet to a cathode of a power supply, applying a voltage between the titanium sheet processed in the step (a) as an anode and the cathode, and electrochemically depositing silver; and (d) sample treatment: cleaning the sample prepared in the step (c), drying, and calcining. By virtue of the method, Ag nanoparticles can be deposited into a nanotube, so that the SPR effect of the silver nanoparticles can be effectively enhanced, and the photocatalytic performance of the TiO2 nanotube array can be further improved.

The invention discloses a preparation method of polyimide / CCTO@Ag nanoparticle composite material with high dielectric and low loss. According to the method, polyimide is used as matrix, the prepared CCTO@Ag nanoparticles are ultrasonically dispersed in absolute ethyl alcohol, then is blended with polyimide monomer in solvent, then in situ polymerization reaction is carried out on the monomer at room temperature to simultaneously realize copolymerization of polyimide and intercalation recombination with the CCTO@Ag nanoparticles, obtained stock solution is subjected to gradient annealing according to a coating method to finally obtain the polyimide / CCTO@Ag nanoparticle composite film. Compared with pure polyimide, the polyimide / CCTO@Ag nanoparticle composite material prepared according to the preparation method has the dielectric constant (103) increased by 30 times, also has low dielectric loss (0.006) and can be widely applied in fields of high energy storage capacitors, artificial organs, high speed integrated circuits, and the like.

The invention discloses a method for preparing size-controllable silver nanoparticles. The method includes steps of adding sodium hydroxide or potassium hydroxide aqueous solution into mixed liquor comprising protective agents, water and weak reducing agents containing aldehyde groups and regulating a pH (potential of hydrogen) value of the mixed liquor until the pH value of the mixed liquor ranges from 8 to 10; adding Au seed crystal aqueous solution into the mixed liquor; then dripping silver and ammonia solution into the mixed liquor to carry out silver and ammonia reaction on the basis of gold seed crystals; acquiring sol containing the silver nanoparticles after reaction is completed. The method has the advantage that continuous growth of the Ag nanoparticles is controlled by a seed crystal growth process, so that the Ag nanoparticles with narrow size distribution (with relative standard deviation smaller than 20%) and the particle sizes which are continuously controllable within the range from 20nm to 120nm can be acquired.

A composite photolytic antibacterial agent for antibacterial polymer, fiber and fabrics contains proportionally the nanoparticles of TiO2, SiO2 and Ag. It features that the TiO2 and Ag nanoparticles are wrapped by SiO2 nanoparticles to form a special porous layer.

The invention relates to preparation and high-efficiency hydrogen production of a novel surface plasma enhanced high-efficiency photocatalytic water splitting composite catalyst Au / CdX (X refers to S, Se and the like). The Au / Cd core-shell structure nanocrystalline consists of Au particles serving as a core and a CdX semiconductor serving as a shell layer, wherein the size of the Au particles is 20-45nm; the CdX shell layer is a single crystalline layer of 2-12nm; and the crystal form is a hexagonal phase of wurtzite. The preparation method comprises the following steps: adding a precursor into hydrosol of the Au / Ag nanoparticles to be converted into Au / AgX; adding a cadmium salt and a phosphine ligand, reacting at the temperature of 50 to 80 DEG C to generate the Au / CdX catalyst. The photocatalytic water splitting hydrogen production efficiency of the catalyst is 20-30mol / g / h and is higher than that of pure CdS quantum dots of the same mass by over 1000 times. The water solubility is high, the inverted phase is not needed during the test, the operating device is simplified, and the time is shortened. Meanwhile, the material utilization rate is improved, the synthesis condition is mild, and the catalyst is environmentally friendly, feasible and low in cost and has wide application prospects in the field of photocatalysis.

The invention discloses a preparation method and application of a novel chloride ion removal material Ti3C2Tx / Ag. The method includes: etching a block Ti3AlC2 to obtain laminar Ti3C2Tx-MXene; ultrasonically stripping the Ti3C2Tx-MXene solution, and taking a supernatant to obtain a few-lamella Ti3C2Tx-MXene solution; dissolving a certain amount of AgNO3 in deionized water, and adding a certain amount of hydrochloric acid under an ultrasonic condition to obtain an AgCl colloidal solution; adding the obtained AgCl colloid into the few-lamella Ti3C2Tx-MXene solution, and performing oscillation fora certain time under the conditions of constant temperature and constant rotating speed; and carrying out vacuum filtration and separation on the reacted mixed solution, performing washing with deionized water for several times, and conducting natural drying at room temperature to obtain the Ti3C2Tx / Ag film. An in-situ self-reduction technology is utilized, AgCl colloid is used as an oxidizing agent, Ti3C2Tx-MXene is used as a reducing agent, the loading capacity and the particle size of Ag are regulated and controlled by controlling the reaction time, and the synthesis method is simple and practicable; based on the battery effect (conversion reaction) of Ag nanoparticles and the pseudocapacitance behavior (ion intercalation) of Ti3C2Tx, the prepared and synthesized Ti3C2Tx / Ag film showsexcellent chloride ion removal capability and good desalination performance.

The invention provides a SiC high-temperature pressure sensor without lead package and a manufacturing method thereof. The manufacturing method comprises the steps: a p-SiC wafer sheet is thinned, anda p-SiC layer and an n-SiC layer are sequentially grown on the Si surface; a sensitive membrane of a square emboss structure is formed on the C surface; an imaging masking layer is formed on the n-SiC layer, and shallow etching and acid pickling are conducted to form a sensitive pressure resistance strip; a blocking layer is formed on the Si surface through thermal oxidation and selectively corroded, and a contact window is obtained in the upper part of the sensitive pressure resistance strip; an Ni / Ti / Ni / Ni / Pt metal layer is formed on the Si surface and imaged, and makes contact with the sensitive pressure resistance strip through the contact window to form an electrode and a bonding pad; high-temperature annealing is conducted to enable the sensitive pressure resistance strip and the metal electrode to form Ohm contact to form a static pressure compensation unit; and a package base body is manufactured, Ag nanoparticles are deposited at the chip bonding pad, a Pt lead penetrates through a lead hole to be sintered with the Ag nanoparticles, and then gaps are filled with glass collosol.

The invention provides a photocatalyst material for absorbing a full sunlight spectrum and a preparation method thereof and relates to the technical field of composite micro-nano materials. The material uses an upconversion material NaYF4: Yb,Er as a template, and the surface of the template is sequentially modified with TiO2 and Ag nanoparticles. Firstly, the upconversion material is obtained through hydro-thermal synthesis reaction, then is used as the template and is successively modified with the TiO2 and Ag nanoparticles through reduction reaction, and the UC / TiO2 / Ag composite micro-nano photocatalyst material is obtained. The photocatalyst material retains the advantage of efficiently absorbing ultraviolet and visible wavebands of high-energy excitation of a traditional photocatalyst material, meanwhile can also convert long-wave radiation of an infrared waveband in sunlight into visible waveband shortwave radiation which can be directly absorbed by the material, the sunlight utilization rate is further improved, full spectrum utilization of sunlight is achieved, and the photocatalyst material is hopeful to serve as a photocatalyst for sunlight-based efficient catalytic degradation of organic pollutants.