Summary of the invention
Application hypovanadic oxide powder and hypovanadic oxide powder and the compound film of preparing of other materials, method is simple, is convenient to large-scale operation, not only can transform for the energy-saving of original glass port, and can be coated on different substrates, expands the applicability of vanadium dioxide.When but hypovanadic oxide powder is prepared into vanadium dioxide film and coating, pattern and particle diameter are all had to special requirement, require hypovanadic oxide powder to there is excellent dispersing property and chemical stability.
At this, the invention provides a kind of vanadium dioxide composite granule, comprise that chemical constitution is V
1-xm
xo
2vanadium dioxide nano powder, vanadium dioxide nano powder surface connects organically-modified long chain molecule, wherein M is doped element, 0≤x≤0.5.
Vanadium dioxide composite granule of the present invention, organically-modified to the surface process of vanadium dioxide and Dope nano-power thereof.It is different from the hypovanadic oxide powder of general unmodified or inorganic parcel and modification, and the mode by organic modifiers makes vanadium dioxide surface connect organically-modified long chain molecule, thereby greatly improves chemical stability and the dispersiveness of hypovanadic oxide powder.Apply vanadium dioxide composite granule stability provided by the invention and good dispersity, can preserve for a long time use, can be used as intelligent heat insulation powder and be applied to prepare intelligent energy-saving coating or coating, also can be used for the heat insulation occasions such as glass and exterior wall.It is different from general lagging material, and it can significantly intercept infrared light when transformation temperature is above, and can highly see through lower than transformation temperature infrared rays, and this variation is reversible, and the intelligence that can realize solar heat regulates.
Preferably, in vanadium dioxide composite granule of the present invention, the content of organically-modified long chain molecule is 0.1~50%.More preferably, organically-modified long chain molecule content is 1~10%.Organically-modified long chain molecule content is too small, cannot realize the abundant parcel of powder surface; Organically-modified long chain molecule content is excessive, can cause mutually tangling between organic molecule, affects on the contrary dispersion effect.
Preferably, organically-modified long chain molecule chain length is at 0.1nm~100nm.
The present invention relates to the organic surface modifying of vanadium dioxide nano particle, can effectively improve the dispersiveness of vanadium dioxide and Dope nano-power thereof and the chemical stability of powder.
Organically-modified long chain molecule is for comprising the functionalized organic long-chains such as chain alkyl, polyacrylic acid group, polyvinyl alcohol group, epoxide group, chain alkyl amine groups, halogenation chain alkyl, carboxylated chain alkyl.
Vanadium dioxide composite granule of the present invention, grafting by organically-modified properties-correcting agent on hypovanadic oxide powder surface, be wrapped in hypovanadic oxide powder surface, thereby can change the surface property of vanadium dioxide, according to the difference of selected group, can increase the dispersing property of vanadium dioxide composite particles in different solvents, expand the purposes of vanadium dioxide particle in intelligent temperature control coating or coating.
Preferably, the vanadium dioxide nano powder in vanadium dioxide composite granule of the present invention is Rutile Type, and phase transition temperature is adjustable at-20~70 ℃.The shared ratio of rutile phase hypovanadic oxide can, up to 80%, even can reach 100%.This vanadium dioxide nano powder has first-order phase transition characteristic, can induced environment temperature variation, and this variation of intelligent response realizes the band selective of sunlight is seen through or covered.Conventionally in envrionment temperature during lower than transformation temperature, the film that contains vanadium dioxide or coating are almost completely penetrating to the visible ray in sunlight and mid-infrared light; When temperature surpasses semi-conductor-metal phase change temperature of vanadium dioxide, vanadium dioxide undergoes phase transition and is converted into R phase, and now material can, to the blocking of mid-infrared light selectivity, reach the object of transparent (visible ray sees through) thermal resistance.Semi-conductor-the metal phase change of vanadium dioxide is thermoinducible reversible change, and its temperature switch effect can be used to the ultrared break-make of centering and carries out intelligent control.
The doped element M of regulation can be or arbitrary combination in the elements such as near 21~30 transition element vanadium in the periodic table of elements, tin and near element thereof and tungsten, molybdenum, ruthenium, niobium in the present invention.Wherein, near 21~30 transition element in the periodic table of elements vanadium comprise scandium, titanium, chromium, manganese, iron, cobalt, nickel, copper and zinc, and described tin and near element thereof comprise indium, antimony, tin, gallium, germanium, lead and bismuth.Preferred doped element is tungsten, molybdenum, bismuth, tin, iron, zinc and titanium.
Adopt above-mentioned doped element, can controlled doping hypovanadic oxide powder size and pattern, doped element used equally also can regulate and control the phase transition temperature of vanadium dioxide.
In the present invention, doped vanadium dioxide powder is preferably particulate state, and the length-to-diameter ratio of particle is 1: 1~10: 1, is preferably 1: 1~5: 1, more preferably 1: 1~2: 1.Particle size is not more than 1um at least one dimension, preferably at least one dimension, is not more than 100nm, more preferably in three dimensions, is all not more than 100nm, most preferably in three dimensions, is all not more than 70nm.Described particulate state can be such as subsphaeroidal, oval, snowflake shape, cube, sheet shape etc.
The dispersiveness of hypovanadic oxide powder with above-mentioned size and pattern is better.The dispersiveness of the composite granule after modification also will be further enhanced.
The application also provides a kind of preparation method of vanadium dioxide composite granule, comprises that operation (1) is scattered in vanadium dioxide nano powder in dispersion medium, obtains mixture A; (2) in described mixture A, add dispersing auxiliary and the organic modifiers that is used to form hypovanadic oxide powder surface organic modification long chain molecule, be stirred to and fully mix to obtain mixture B; (3) mixture B is dried and makes organically-modified vanadium dioxide composite granule.
Hypovanadic oxide powder can be rutile phase hypovanadic oxide nanoparticle or doped rutile phase hypovanadic oxide nanoparticle.Can be the method preparation providing according to publication 2010PA011267CN, can be also rutile phase hypovanadic oxide nanoparticle or doped rutile phase hypovanadic oxide nanoparticle prepared by other known methods.Powder granule gravel size decision is below 200nm.The pattern of powder can be particle, nanometer rod and flakes particle.If prepare doped rutile phase hypovanadic oxide nanoparticle, before doped element, can adopt alkaline reagents to process presoma (the tetravalent vanadium ion aqueous solution), can obtain the controlled hypovanadic oxide powder size of size and pattern (being not more than 1um at least one dimension) and pattern (particulate state, length-to-diameter ratio is not more than 10: 1), the hypovanadic oxide powder grain-size of preparation is little, uniform particle diameter, and stable crystal form, it is at water, for example, in dispersion agent (polyvinylpyrrolidone) good dispersity, be easy to be coated on the matrixes such as glass, be suitable for preparing film and the coating of hypovanadic oxide powder.
The preparation method of vanadium dioxide composite granule provided by the invention, the dispersing auxiliary adding in operation (2) can be polyvinyl alcohol, one or more in polyvinylpyrrolidone, organic modified polyorganosiloxane dipropylene glycol monomethyl ether solution, organic silicon surfactant or fluorochemical surfactant or the dispersing auxiliary known altogether in the industry.
The preparation method of vanadium dioxide composite granule provided by the invention, the organic modifiers adding in operation (2) can be the organic modifiers such as stearic acid, polyacrylic acid, silane coupling agent, aluminate coupling agent or titanate coupling agent.Be preferably the silane coupling agent of pbz polymer long-chain.
Mode by coupling agent can make vanadium dioxide surface connect organic long-chain molecule, thereby greatly improves chemical stability and the dispersiveness of hypovanadic oxide powder.
In the preparation method of vanadium dioxide composite granule provided by the invention, dispersion medium used can be ethanol, one or more in the inert solvents such as Virahol, chloroform, dimethyl formamide, dimethyl sulfoxide (DMSO) ethylene dichloride or acetone.
In inert media, carry out organically-modifiedly, can prevent the sex change of vanadium dioxide, improve the chemical stability of powder.
The preparation method of vanadium dioxide composite granule provided by the invention, preparation technology's innovation, by the organic surface modifying process of organic modifiers, can effectively improve dispersiveness and the chemical stability of vanadium dioxide and Dope nano-power thereof.Vanadium dioxide composite granule of the present invention can be applicable to prepare intelligent energy-saving coating or coating, and the coating transparency of preparation is high, and low, the ageing-resistant ability of mist degree is strong, is mainly used in film, and the flexible materialss such as cloth also can be used for the heat insulation occasions such as glass and exterior wall.
Embodiment
Below, with reference to accompanying drawing, and further illustrate the present invention in conjunction with subordinate's embodiment.
Vanadium dioxide material has first-order phase transition characteristic, can induced environment temperature variation, and this variation of intelligent response realizes the band selective of sunlight is seen through or covered.Vanadium dioxide nano powder is scattered in to other matrix, as transparent polymer, can retain on the basis of vanadium dioxide optics performance of control, improve visible light transmissivity to realistic scale, can carry out reducing energy consumption to the outside surface of the transportation means such as in commission glass, metope and car and boat.But because nanoparticle specific surface area is little and surface free energy is high, between particle, be easy to reunite, this specific character has determined direct vanadium dioxide nano particle to be joined in coating, be difficult to the performance of real performance nano material, and easily reunite, affect optical property and the outward appearance of coating, thereby limited the application of material on adhering film to glass and transparent glass.The present invention relates to the organic surface modifying process of vanadium dioxide nano particle, can effectively improve the dispersiveness of vanadium dioxide and Dope nano-power thereof and the chemical stability of powder.
Method of the present invention, comprises, vanadium dioxide nano powder is scattered in dispersion medium, obtains the operation of mixture A; In described mixture A, add dispersing auxiliary and be used to form the organic modifiers of hypovanadic oxide powder surface organic modification long chain molecule, be stirred to and fully mix to obtain the operation of mixture B; By the dry operation that makes organically-modified vanadium dioxide composite granule of mixture B.
Particularly, the first high-speed stirring dispersing and mixing of the hypovanadic oxide powder that can be 1~50% by weight percent content and 50~99% dispersion medium, and the ultrasonic mixture that disperses to obtain, in mixture, add again afterwards dispersing auxiliary and organic modifiers, at 0~200 ℃ of constant temperature, stir, by modes such as ultrasonic, sand milling or ball millings, disperse, centrifugation again, under certain temperature, vacuum-drying obtains organically-modified vanadium dioxide composite granule.
Wherein, in the operation that vanadium dioxide nano powder is mixed with dispersion medium, the weight ratio of vanadium dioxide nano powder and dispersion medium can be 1: 1~1: 1000.Preferably, the weight ratio of vanadium dioxide nano powder and dispersion medium is 1: 5~1: 100.When weight ratio is too small, hypovanadic oxide powder is low with organic modifiers contact probability, jitter time that need to be longer and larger properties-correcting agent consumption; Weight ratio is excessive, is unfavorable for the abundant dispersion of powder in dispersion medium and wetting, affects the modified effect in later stage.
The rotating speed of high-speed stirring can be 1000~3000rad/min.Ultrasonic power can be 50~5000W, and frequency is 21KHz.
In addition, drum's speed of rotation can be chosen as 10~2000rad/min.
Again, the rotating speed of sand mill can be 10~2000rad/min.
Grinding medium can be selected zirconia balls, and particle diameter, at 0.02mm~50mm, is preferably the grinding medium of small particle size.
Above-mentioned surface organic modification technique organic modifiers used can be the organic modifiers such as stearic acid, polyacrylic acid, silane coupling agent, aluminate coupling agent or titanate coupling agent, is preferably the silane coupling agent of pbz polymer long-chain.It can be 0.05~5 % by weight that organic modifiers adds the amount in mixture; Be preferably 0.1~2 % by weight.Organically-modified long chain molecule content is too small, cannot realize the abundant parcel of powder surface; Organically-modified long chain molecule content is excessive, can cause mutually tangling between organic molecule, affects on the contrary dispersion effect.Mode by coupling agent can make vanadium dioxide surface connect organic long-chain molecule, thereby greatly improves chemical stability and the dispersiveness of hypovanadic oxide powder.
Above-mentioned surface organic modification technique dispersing auxiliary used is polyvinyl alcohol, one or more in polyvinylpyrrolidone, organic modified polyorganosiloxane dipropylene glycol monomethyl ether solution, organic silicon surfactant or fluorochemical surfactant or the dispersing auxiliary known altogether in the industry.Dispersing auxiliary is mainly used in reducing the surface tension of solution, and raising solvent is wetting powder surface, thereby improves dispersion effect.It can be 0.02~2 % by weight that dispersing auxiliary adds the amount in mixture; Be preferably 0.05~1 % by weight.Few add-on can reach needed dispersion effect.If add, too much can affect the surface organic modification of powder process.
Should be understood that the above-mentioned embodiment that the present invention describes in detail, and following examples only for being described, the present invention being not used in and limiting the scope of the invention.The raw material adopting, reagent can be synthesized and be made by purchase marketable material or traditional chemical transform mode.Unless otherwise defined or described herein, the familiar same meaning of all specialties used herein and scientific words and those skilled in the art.In addition any method and material similar to described content or that be equal to all can be applicable in the inventive method.Other aspects of the present invention, due to disclosure herein, are that appearance is intelligible to those skilled in the art.
Below, by embodiment, the present invention is described in more details.
Comparative example 1
Get each constituent mass as follows:
Vanadium dioxide nano powder (Doped Tungsten, particle diameter 20~100nm), 20g
Ethanol (dispersion medium), 80g
Polyvinylpyrrolidone (dispersing auxiliary), 0.05g;
First by vanadium dioxide nano powder and dispersion medium, high-speed stirring under 1500rad/min is disperseed 30min, and ultrasonic dispersion 30min, again dispersing auxiliary is added wherein, on homogenizer, at 70 ℃ of constant temperature, stir 2h, centrifugation again, vacuum-drying obtains the vanadium dioxide composite granule of organo-silicon coupling agent modification at 60 ℃;
The salient features of resulting vanadium dioxide and doped and compounded powder thereof is in Table 1.
As shown in Figure 1, without the pattern of organically-modified vanadium dioxide particle, diameter of particle 10~100nm not etc., is not that agglomerating particles exists but comparatively loose between particle.
Embodiment 1
Get each constituent mass as follows:
Vanadium dioxide nano powder (Doped Tungsten, particle diameter 20~100nm), 20g
Ethanol (dispersion medium), 80g
Silane coupling agent (containing polyvinyl alcohol group, organic modifiers), 1g
Polyvinylpyrrolidone (dispersing auxiliary), 0.05g;
First by vanadium dioxide nano powder and dispersion medium, under 1500rad/min, high-speed stirring is disperseed 30min, and ultrasonic dispersion 30min, again dispersing auxiliary and silane coupling agent are added wherein, on homogenizer, at 70 ℃ of constant temperature, stir 2h, centrifugation again, vacuum-drying obtains the vanadium dioxide composite granule of organo-silicon coupling agent modification at 60 ℃;
The salient features of resulting vanadium dioxide and doped and compounded powder thereof is in Table 1.
As shown in Figure 2, through the pattern of the vanadium dioxide composite granule of organic surface modifying, not etc., powder is not because be coated with machine group for diameter of particle 10~100nm, and the more not organically-modified particle of particle diameter increases slightly, but presents dispersion state between powder.
Embodiment 2
Get each constituent mass as follows:
Vanadium dioxide nano powder (undoping, particle diameter 20~60nm), 10g
Ethanol (dispersion medium), 90g
Stearic acid, 1g
Polyvinyl alcohol (dispersing auxiliary), 0.05g
First by vanadium dioxide nano powder and dispersion medium, under 1500rad/min, high-speed stirring is disperseed 30min, and ultrasonic dispersion 30min, again dispersing auxiliary and stearic acid are added wherein, on homogenizer, at 60 ℃ of constant temperature, stir 2h, centrifugation again, vacuum-drying obtains stearic acid modified vanadium dioxide nano composite granule at 60 ℃;
The salient features of resulting vanadium dioxide and doped and compounded powder thereof is in Table 1.
Embodiment 3
Get each constituent mass as follows:
Vanadium dioxide nano powder (Doped Tungsten, particle diameter 20~100nm), 15g
Virahol (dispersion medium), 85g
Silane coupling agent (containing chain alkyl, organic modifiers), 1g
Organic modified polyorganosiloxane dipropylene glycol monomethyl ether solution (dispersing auxiliary), 0.08g
First by vanadium dioxide nano powder and dispersion medium, under 1000rad/min, high-speed stirring is disperseed 20min, and ultrasonic dispersion 60min, again dispersing auxiliary and silane coupling agent are added wherein, on homogenizer, at 80 ℃ of constant temperature, stir 2h, centrifugation again, vacuum-drying obtains the vanadium dioxide nano composite granule that surface is connected to chain alkyl at 60 ℃;
The salient features of resulting vanadium dioxide and doped and compounded powder thereof is in Table 1.
Embodiment 4
Get each constituent mass as follows:
Vanadium dioxide nano powder (doping molybdenum, particle diameter 20~100nm), 25g
Virahol (dispersion medium), 75g
Titanate coupling agent (containing epoxide group, organic modifiers), 1g
Polyvinyl alcohol (dispersing auxiliary), 0.15g
First by vanadium dioxide nano powder and dispersion medium, high-speed stirring under 1500rad/min is disperseed 20min, and ultrasonic dispersion 60min, again dispersing auxiliary and titanate coupling agent are added wherein, on homogenizer, at 80 ℃ of constant temperature, stir 2h, centrifugation again, vacuum-drying obtains the vanadium dioxide nano composite granule that surface is connected to epoxide group at 70 ℃;
The salient features of resulting vanadium dioxide and doped and compounded powder thereof is in Table 1.
Embodiment 5
Get each constituent mass as follows:
Vanadium dioxide nano powder (doping molybdenum, particle diameter 20~100nm), 5g
Virahol (dispersion medium), 95g
Aluminate coupling agent (containing chain alkyl, organic modifiers), 0.7g
Polyvinylpyrrolidone (dispersing auxiliary), 0.04g
First by vanadium dioxide nano powder and dispersion medium, under 1500rad/min, high-speed stirring is disperseed 20min, and ultrasonic dispersion 60min, again dispersing auxiliary and aluminate coupling agent are added wherein, on homogenizer, at 80 ℃ of constant temperature, stir 2h, centrifugation again, vacuum-drying obtains the vanadium dioxide nano powder that surface is connected to chain alkyl at 60 ℃;
The salient features of resulting vanadium dioxide and doped and compounded powder thereof is in Table 1.
Embodiment 6
Get each constituent mass as follows:
Vanadium dioxide nano powder (Doped Tungsten, particle diameter 20~100nm), 10g
Dimethyl formamide (dispersion medium), 90g
Polyacrylic acid, 1.5g
Fluorochemical surfactant (dispersing auxiliary), 0.1g
First by vanadium dioxide nano powder and dispersion medium, under 1000rad/min, high-speed stirring is disperseed 20min, and ultrasonic dispersion 60min, again dispersing auxiliary and polyacrylic acid are added wherein, on homogenizer, at 80 ℃ of constant temperature, stir 2h, centrifugation again, vacuum-drying obtains surface and is connected to polyacrylic vanadium dioxide nano composite granule at 60 ℃;
The salient features of resulting vanadium dioxide and doped and compounded powder thereof is in Table 1.
Embodiment 7
Get each constituent mass as follows:
Vanadium dioxide nano powder (Doped Tungsten, particle diameter 20~100nm), 20g
Ethanol (dispersion medium), 80g
Silane coupling agent (containing chain alkyl amido, organic modifiers), 2.5g
Organic surface active agent (dispersing auxiliary), 0.07g
First by vanadium dioxide nano powder and dispersion medium, under 1500rad/min, high-speed stirring is disperseed 40min, and ultrasonic dispersion 30min, again dispersing auxiliary and silane coupling agent are added wherein, on homogenizer, at 80 ℃ of constant temperature, stir 2h, centrifugation again, vacuum-drying obtains the vanadium dioxide nano composite granule that surface is connected to chain alkyl amido at 70 ℃;
The salient features of resulting vanadium dioxide and doped and compounded powder thereof is in Table 1.
Embodiment 8
Get each constituent mass as follows:
Vanadium dioxide nano powder (Doped Tungsten, particle diameter 20~100nm), 10g
Dimethyl formamide (dispersion medium), 90g
Silane coupling agent (containing halogenation chain alkyl, organic modifiers), 1.5g
Fluorochemical surfactant (dispersing auxiliary), 0.06g
First by vanadium dioxide nano powder and dispersion medium, under 1000rad/min, high-speed stirring is disperseed 20min, and ultrasonic dispersion 60min, again dispersing auxiliary and silane coupling agent are added wherein, on homogenizer, at 80 ℃ of constant temperature, stir 2h, centrifugation again, vacuum-drying obtains the vanadium dioxide nano composite granule that surface is connected to halogenation chain alkyl at 60 ℃;
The salient features of resulting vanadium dioxide and doped and compounded powder thereof is in Table 1.
Referring to following table 1, from this table, organically-modified vanadium dioxide and the dopen Nano composite granule thereof that method provided by the invention obtains can be described, its particle diameter is significantly less than unmodified powder, and BET specific surface area is greater than unmodified powder, and Stability of Slurry also will be significantly better than unmodified powdery pulp.By 300 ℃ of weightless data, can find out by surface organic modification process, can connect at nano powder surface 5~11% organic long-chain, thereby greatly improve chemical stability and the dispersiveness of hypovanadic oxide powder.
Table 1:
Industrial applicability: vanadium dioxide composite granule of the present invention can be applicable to prepare intelligent energy-saving coating or coating, the coating transparency of preparation is high, and low, the ageing-resistant ability of mist degree is strong, is mainly used in film, the flexible materialss such as cloth, also can be used for the heat insulation occasions such as glass and exterior wall.Also can be widely used in energy-saving and emission-reduction equipment, for example energy-conservation film, energy-saving coatings, sun power temperature control unit; Or energy information equipment, for example, micro photo electric switch device, thermistor, battery material and optical information storage part.The preparation method of vanadium dioxide composite granule provided by the invention, preparation technology's innovation, by the organic surface modifying process of organic modifiers, can effectively improve dispersiveness and the chemical stability of vanadium dioxide (vanadium dioxide) and Dope nano-power thereof.