1000 results about "Vanadium dioxide" patented technology

The invention relates to vanadium dioxide-doped powder, vanadium dioxide-doped dispersion, and a preparation method and application thereof. The chemical compositions of the vanadium dioxide-doped powder shown as V1-xMxO2 (x is more than 0 and less than or equal to 0.5, and M is a doped element used for controlling the size and appearance of the vanadium dioxide-doped powder.). The vanadium dioxide-doped powder has uniform grain size and high dispersibility.

The invention relates to a method of preparing vanadium dioxide by hydrothermal method. The method comprises the following steps: adding oxidant, reducing agent or acidity and alkalinity adjusting agent in a hydrothermal kettle containing proper amount of aqueous solution of the source of vanadium, then placing the hydrothermal kettle in a 40-300 DEG C of oven to perform heat preservation for 30 minutes to 5 days, and centrifuging to collect vanadium dioxide after the reaction is completely finished. The preparation method provided by the invention has simple process, low cost and high yield, the mass production can be realized and the purity of the obtained intelligent energy-saving vanadium dioxide nano-powder is high. Vanadium dioxide doped powder can further be obtained by adding proper amount of compound containing tungsten, molybdenum, manganese, chromium or titanium in the aqueous solution of the source of vanadium to realize wider industrial applications. The control of different appearances of vanadium dioxide nano-powder can be realized by controlling the categories of the source of vanadium and the dosage of oxidant, reducing agent or acidity and alkalinity adjusting agent.

The invention belongs to the technical field of material chemistry, in particular relates to a vanadium dioxide precursor liquid and a method for preparing a thin-film material by using the same. The vanadium dioxide precursor liquid of the invention comprises a soluble vanadium salt, a film forming accelerator and a solvent. The invention further provides a method for preparing a vanadium dioxide thin film by using the vanadium dioxide precursor liquid. The invention overcomes the shortages of the prior preparation technique of liquid-phase vanadium dioxide, reduces the cost of raw materials, and can previously reduce or oxidize the vanadium raw material in the raw materials to quadrivalence so that vanadium element is not necessarily subjected to an oxidation-reduction reaction in the process of thermal treatment. The vanadium dioxide thin film prepared by the invention has uniform phase, good purity and intelligent response to temperature. The vanadium dioxide thin film prepared ona glass substrate has a light transmittance peak value up to 70% at most in a visual light region and an infrared light regulating performance up to 60% at most, and has wide application prospect in the fields of optical functional materials and electric functional materials.

The invention relates to a method for preparing rutile-phase vanadium dioxide powder, in particular to a method for preparing rutile-phase vanadium dioxide powder through a hydrothermal method. The method for preparing rutile-phase vanadium dioxide powder adopts the conditions of different vanadium materials, dopants and doping ratios, and the like, to obtain rutile-phase vanadium dioxide powders with good crystallization performance and in shapes of grains, nanometer rods and snowflake-shaped grains. The temperature for transforming the powder from semiconductor phase to conductor phase can be reduced approximately to the room temperature.

The invention relates to an intelligent phase-change material with adjustable phase-change temperature and its preparing process, which comprises making doped vanadium dioxide precursor through liquid phase precipitation method, carrying out filtering, scouring, drying, heating and crystallizing. The crystal grain dimension of the obtained phase-change material is less than 100 nanometers, thus can be applied into intelligent window coating material and temperature measurement resistors.

The invention relates to a temperature-regulating intelligent tent fabric and a preparation method of the temperature-regulating intelligent tent fabric. The temperature-regulating intelligent tent fabric comprises a paulin matrix and a temperature-regulating coating, wherein the temperature-regulating coating comprises doped vanadium dioxide (V (1-x)Mx)O2 nanopowder or micelle, wherein 0 <= x <= 0.03. The preparation method of the temperature-regulating intelligent tent fabric comprises the following steps of: (1) preparing doped (V(1-x)Mx)O2; and (2) applying the doped (V(1-x)Mx)O2 to the paulin matrix by coating, padding or impregnating to obtain the temperature-regulating intelligent tent fabric. The temperature-regulating intelligent tent fabric can effectively improve the temperature in a tent, greatly improve the degree of comfort of a user and play a good role in the aspects of field construction, amusement and tourism, geological exploration, rescue and relief work, field hospitals and outdoor banquets, is easy to operate, is low in cost and has a good application prospect.

The invention discloses a preparation method for vanadium dioxide and doped powder thereof. The method comprises the following steps: 1, weighing vanadium pentoxide, hydrogen peroxide and distilled water, preparing the materials into a V<5+>-containing complex aqueous solution; 2, adding a reducing agent, a surfactant and a dopant to the complex aqueous solution, and stirring to form a clear solution; 3, transferring the resulting solution from the step 2 to a hydrothermal reaction kettle, and carrying out a reaction for 1-168 hours at a temperature of 140-220 DEG C to obtain the doped powderof the VO2(B); 4, placing the resulting doped powder of the VO2(B) from the step 3 in high pure argon atmosphere or nitrogen atmosphere, and annealing for 10-720 minutes at the temperature of 400-700DEG C to obtain the doped powder of the VO2(M). The method of the present invention has characteristics of low cost, simple process and easy control, and is suitable for the large-scale industrial production. With the method of the present invention, the doping of the VO2 powder material can be realized, and the doped atoms can be uniformly dispersed in the VO2.

The invention provides a method for preparing nano powder of monoclinic phase vanadium dioxide by using a hydrothermal-high temperature solid phase synthesis method. The method comprises the following steps of: a) reacting a vanadium source with a reducing agent to obtain vanadium dioxide (VO2)(B), VO2(A) or VO2 (paramontroseite) by using a hydrothermal method; b) washing the VO2(B), the VO2(A) or the VO2 (paramontroseite) and then thoroughly drying the VO2(B), the VO2(A) or the VO2 (paramontroseite) to form powder; c) vacuum-packaging the powder of the VO2(B), the VO2(A) or the VO2 (paramontroseite) in an airtight and high-temperature resistant container; and d) annealing the container at the temperature of between 350 and 1,200 DEG C for over 3 hours to obtain the nano powder of the monoclinic phase vanadium dioxide. The method has the characteristics of simple production technology, low production cost, environmental friendliness, higher product yield, higher product purity and easy industrial mass production.

A process for preparing VO2 nanoparticles includes such steps as proportionally adding V2O5 and oxalic acid to reactor, adding water, stirring at 40-70 deg.C while reaction, evaporating to obtain solid vanadium oxalate, vacuum heating to 350-500 deg.C, holding the temp for 20-40 min for thermodecomposing, and cooling. It is possible to add MoO3 or N5H37W6O24 for preparing the doped product.

The invention discloses a preparation method of monodispersed M-phase vanadium dioxide nanoparticles. The preparation method comprises the following steps: mixing vanadium pentoxide, oxalate dihydrate and water according to a molar ratio of (1-2.5) : 1 : (500-800) to obtain mixed liquid, adding 4%-6% of a surfactant based on the volume of the mixed liquid into the mixed liquid, and stirring for at least 2 hours to obtain a precursor solution; reacting the precursor solution in a sealed state at 200-260 DEG C for at least 1 day to obtain reaction liquid; performing solid-liquid separation and washing on the reaction liquid in sequence to obtain orthogonal vanadium dioxide powder; annealing the orthogonal vanadium dioxide powder in a nitrogen atmosphere at 300-600 DEG C for 0.5 hour to obtain the monodispersed M-phase vanadium dioxide nanoparticles with particle sizes of 60nm-80nm. The preparation method has the advantages of environmental protection and no temperature gradient control during annealing, and can be widely used for preparing the M-phase vanadium dioxide nanoparticles with very good dispersity.

Provided are thermochromic microparticles that comprise particles of rutile (R-phase) vanadium dioxide (VO2) and rutile titanium dioxide (TiO2). At least one of the vanadium dioxide (VO2) particles is grown on the titanium dioxide (TiO2) particles so as to be larger than said titanium dioxide (TiO2) particles and in a rod form.

The invention discloses a terahertz modulator, and a preparation method and a tuning method of the terahertz modulator. The terahertz modulator comprises a copper resonance ring array (1), a vanadium dioxide film (2), a silicon dioxide substrate (3), a broadband terahertz source (4) and a pumping laser source (5), wherein the copper resonance ring array (1) and the silicon dioxide substrate (3) form a metamaterial; and the rear surface of the silicon dioxide substrate (3) is plated with the vanadium dioxide film (2). The terahertz modulator disclosed by the invention is capable of modulating the terahertz intensity of an optically controlled high-speed broadband.

The invention provides a preparation method of intelligent nano transparent insulating glass coating comprising organic silicon resin, nano-tin indium oxide or nano-tin antimony oxide pulp, nano-silica or nano-aluminium oxide pulp, doped nano-vanadium dioxide pulp, a diluent and an addition agent. The preparation method comprises the following steps of: mixing the pulp, respectively dripping the pulp, the diluent and the addition agent into the organic silicon resin, and stirring for 10-30 minutes to obtain synthetic intelligent nano transparent insulating glass coating. The test shows that after the intelligent nano transparent insulating glass coating is coated on a white glass with thickness of 5mm, the heat-insulating property of the white glass is greatly increased, and the corresponding transmittance of visible light is higher; after the intelligent nano transparent insulating glass coating is coated on the glass, the transmission of near infrared rays of the glass can be reduced at the temperature above 35DEG C, and the transmission of near infrared rays of the glass can be increased at the temperature below 35DEG C, thereby the automatic regulation of the near infrared ray transmission of the glass along with the temperature variation can be realized and the contradiction of heating in winter and shading in summer is overcome so that the thermal property of the energy-saving glass can be intelligently regulated along with climatic change. The intelligent nano transparent insulating glass coating realizes the functions of insulating heat in winter and shading, lighting and insulting in summer and has higher energy-saving effect.

The invention relates to the field of metamaterial devices and provides a switching-controllable THz wave metamaterial perfect absorber (MPA) and a control method thereof. The switching-controllable THz wave metamaterial perfect absorber comprises a substrate, an MIT (metal-insulator transition) layer positioned on the substrate, a dielectric layer positioned on the MIT phase change layer and metal opening resonance units positioned on the dielectric layer and being in cyclic arrangement, and the on/off of the absorber at the resonance frequencies of the metal opening resonance units is realized through changing the conductivity of the MIT phase change layer. According to the invention, the variation of the conductivities of the MIT phase-change material before and after phase change is utilized to change the absorptivity of the absorber, so that the THz MPA can be turned on/off near the resonance frequency of the metal opening resonance units, initiative control of the electromagnetic transfer characteristics of THz wave bands at the specific frequency, and accordingly, a larger on-off ratio or modulation depth can be obtained; and the switching-controllable MPA adopting the substrate-vanadium dioxide-dielectric layer-SRRs (Split Ring Resonators) four-layer structure can control the conductivity of vanadium dioxide through an external field so as to control the absorptivity of the MPA.

The present invention present invention relates to one kind of intelligent solar heat temperature controlling phase change paint of vanadium dioxide and dopant. The paint consists of polymer filming material, dispersant, composite pigment, color regulator, solvent and plasticizer. Being different from traditional solar heat reflecting paint, it can reflect the infrared light of whole waveband at the temperature over the phase change temperature Tc of (V1-xMx)O2 to result in high reflecting efficiency and high temperature-lowering effect; and can pass the infrared light of whole waveband at the temperature below the phase change temperature Tc to result in high heating effect, so as to realize intelligent temperature control. The paint of the present invention may be coated to the surface metal, concrete, timber, foamed plastic, etc. and widely used for building, vehicle, ship, oil reservoir and other facilities exposed to sunlight.

The invention discloses a structural material for the modulation of terahertz waves, which belongs to the technical field of electronics. The structural material comprises a medium substrate (2) and a vibratron array (1) attached to the surface of the medium substrate (2), wherein the medium substrate (2) is the medium material substrate highly transparent to the terahertz waves; the vibratron array (1) consists of a plurality of vibratron units with the same shape and size; and each vibratron unit is formed by a vanadium dioxide thin film on deposited on the surface of the medium substrate (2). The structural material adopts a medium material highly transparent to the terahertz waves as the substrate to achieve little and stable terahertz wave absorption loss, adopts the vanadium dioxide thin film which is a high-speed phase change material to manufacture the vibratron array, realizes the modulation of the terahertz waves by triggering the phase change of the vanadium dioxide thin film by thermal or laser modulation, and compared with a conventional metal vibratron array-based terahertz modulator, has greater modulation depth.

The invention belongs to the field of inorganic functional material, relating to a preparation method of rutile phase vanadium dioxide nanowire. In the preparation method, vanadium ion aqueous solution or suspension of which the molar concentration is 0.005-0.2 mol/L is prepared firstly; then, doping agent is added to carry out ultrasonic dispersion; the obtained liquid is added into a hydrothermal kettle and is synthetized by a hydrothermal reaction; the hydrothermal kettle is taken out and is naturally cooled to room temperature after being quickly chilled; the obtained product is decentralized, washed and dried to obtain the rutile phase vanadium dioxide nanowire. The rutile phase vanadium dioxide nanowire with favourable crystallinity can be obtained by changing vanadium ion compound and density thereof and controlling conditions, such as reaction temperature and time, packing ratio, doping agent addition, cooling speed and the like. The length-diameter ratio of the prepared rutile phase vanadium dioxide nanowire can be controllably adjusted between dozens and thousands. The obtained nanowire can be applied in the fields of intelligent window coatings, temperature control devices, optoelectronic switches, thermistors, optical information storage and the like.

The invention relates to a vanadium dioxide-based composite film with adjustable radiance as well as a preparation method and the application thereof. The vanadium dioxide-based composite film with adjustable radiance comprises a vanadium dioxide film layer and a transparent conductive film layer, wherein, the transparent conductive film layer is composited to the vanadium dioxide film layer and can reduce the radiance of the vanadium dioxide-based composite film; and the radiance of the vanadium dioxide-based composite film is below 0.70. The vanadium dioxide-based composite film integrates the advantages of thermochromic intelligent energy-saving glass and low-emissivity glass, also has higher visible light transmittance, and improves the thermal insulation performance of vanadium dioxide-based intelligent energy-saving glass.

The invention discloses a method for preparing a vanadium dioxide film. According to the method, metal vanadium or low-valence vanadium oxide film is annealed in oxygen and vacuum to obtain a phase-transition vanadium dioxide film; the most proper oxygen partial pressure, the annealing temperature and the annealing time are selected according to the type and thickness of the low-valence vanadium oxide to obtain a vanadium dioxide film with excellent performance, wherein the infrared regulation rate at 2,400nm can be 58 percent, and the visible light transmittance can be 43 percent; the doped low-valence vanadium oxide film is oxidized to obtain the doped vanadium dioxide film, and the phase transition temperature of the vanadium dioxide can be regulated by means of doping to adapt to different requirements. The vanadium dioxide film can be applied to optical information storage, photoelectric switches, intelligent windows and uncooled infrared focal plane imaging; the method is compatible with large-scale coated glass production process, and a vanadium dioxide film with excellent performance can grow on amorphous glass.

The invention relates to a preparation method of vanadium dioxide powder, comprising a precursor treatment procedure of treating a tetravalent vanadium ion water solution with an alkali reagent to obtain suspension. The preparation method provided by the invention has the advantages of simplicity and convenience for operation, low cost, high yield and suitability to scale production, and the vanadium dioxide powder prepared with the preparation method provided by the invention has uniform particle size and good dispersibility.

The invention discloses an intelligent temperature controlling coating with an oriented structure. The intelligent temperature controlling coating is formed by mixing a vanadium dioxide composite powder sizing agent, coating resin, a solvent and an orientational agent and coating a substrate with the mixture. The vanadium dioxide composite powder sizing agent comprises vanadium dioxide composite powder, a dispersing agent and a dispersion medium, wherein the vanadium dioxide composite powder comprises vanadium dioxide nano powder with chemical constitution of V1-xMx O2, wherein the M is an alloying element, 0</=x</=0.5. By a suitable orientational agent being used by the intelligent temperature controlling coating, the vanadium dioxide nano powder can be directionally aligned in the coating, and the performance of nano-material can be really played. Due to the directional alignment of the vanadium dioxide nano powder, the visible light transmittance, transparency and intelligent adjustment performance of the coating can be improved; the haze of the coating can be reduced, ultraviolet light can almost be shielded completely, and infrared ray with higher energy in the sunlight can be intelligently adjusted.

The present invention provides a method for preparing B phase vanadium dioxide nano rod by means of rheological phase reaction and self-assembly process combination, and is characterized by that said method includes the following steps: mixing inorganic vanadium oxide powder and cationic surfactant according to the mole ratio of 2:1, magnetic stirring for 1 hr. in absolute ethyl alcohol medium, adding proper quantity of deionized water, stirring and ageing for 48 hr to form rheological product, moving it into the stainless reactor still with teflon lining bottom, making hydrothermal reaction for 6-8 days at 180 deg.C, water-washing and filtering for 3 times, drying for 12 hr at 80 deg.C so as to obtain B phasek vanadium dioxide nano rod product with high surface activity.

The invention relates to thermochromic composite powder with a core-shell structure and a preparation method of the powder. The thermochromic composite powder is a core-shell structure, wherein a core is M-phase vanadium dioxide, the shell is a transparent oxide and the shell and the core are separated by using air or in a vacuum manner.

The invention relates to a thermochromic laminated glass. The thermochromic laminated glass comprises two pieces of glass and a thermochromic film which is clamped between the two pieces of glass, wherein the thermochromic film comprises a polyvinyl butyral base film and tungsten oxide-doped vanadium dioxide powder which is dispersed in the polyvinyl butyral base film. The invention also relates to a manufacturing method for the thermochromic laminated glass. The thermochromic laminated glass adopts the tungsten oxide-doped vanadium dioxide powder which is dispersed in the polyvinyl butyral base film to form the thermochromic film, the basic structure of the conventional laminated glass is not changed, the investment is low, and a high-efficient color change effect is achieved. Due to the adoption of metal oxides, the thermochromic laminated glass is non-toxic, green, environment-friendly and non-flammable, has high safety and meets the current requirements of energy saving and emission reduction. In addition, the thermochromic laminated glass does not basically change the conventional preparation process when manufactured, is simple in preparation process and low in cost, and is suitable for the fields of building glass, automobile sunroof glass, side window glass and the like.

A process for preparing the doped composite VO2 nanoparticles with low phase-change temp (25-30 deg.C) and improved physical propoerties includes such steps as preparing the metal element and non-metal element doped solid vanadium oxalate as precursor from V2O5 and oxalic acid, and vacuum thermodecomposing. Its molecular formula is V1-xMxO2-yZy, where x=0-0.08, y=0-0.1, M is metal element and Z is non-metal element.

This invention discloses a method for preparing controllable phase-transformation and tungsten-doped vanadium dioxide powder. In this invention, controlled, strictly, is the pH value (being at 7-9) of the solution for preparing prodecessor; selected is combined reductant containing organic amine and formic acid; protected by inert gas during whole process. By using this inventive method, obtained is high pureness single-phase VO2 nanometer powder. Due to the activity of white tungstic acid is far higher than that of other tungsten compounds, the adulteration of W6+ in VO2 crystal lattice is increased greatly, to achieve the effective adulteration, and then to realize controllable phase transformation temperature.