CN105713597B - A kind of composite type heat mutagens mill base material and preparation method thereof - Google Patents

Abstract

The invention relates to a composite thermochromic slurry and a preparation method thereof. The composite thermochromic slurry comprises: vanadium dioxide nano-powder as an inorganic thermochromic material, an organic thermochromic material A ligand switch body, a polymer base material, and a dispersion medium, the ligand switch body comprising a switchable metal ion, a low-absorbance ligand capable of forming a low-absorbance complex with the switchable metal ion, and an energy A high absorbance ligand that forms a high absorbance complex with the switchable metal ion. The composite thermochromic paste of the present invention is characterized in that the thermochromic wavelength range covers the entire solar spectrum including visible light, and thus has a very high total solar regulation rate compared with traditional vanadium dioxide thermochromic materials.

Description

A kind of composite thermochromic paste and preparation method thereof

technical field

The invention belongs to the technical field of high-performance inorganic-organic composite materials, and in particular relates to thermochromic materials and their energy-saving and environment-friendly applications.

Background technique

The problem of global energy shortage is becoming more and more serious, and excessive carbon emissions are causing the environment to deteriorate day by day. Energy conservation and emission reduction have become the top priority of all countries. It is estimated that building energy consumption accounts for more than 30% of the total energy consumption in society. Therefore, promoting building energy conservation is one of the key measures for energy conservation, emission reduction, and sustainable development.

A large part of building energy consumption is used for air conditioning, and glass windows, as the main channel for heat exchange between buildings and the outside world, have become the main way for air conditioning energy loss. Therefore, the use of various types of energy-saving windows can effectively reduce energy consumption and achieve the purpose of energy conservation and environmental protection.

The mainstream products of energy-saving windows in the existing market are low-emissivity (Low-E) glass and heat-reflecting glass, etc., which are widely used in building energy conservation due to mature technology, low price and good heat insulation performance. However, since the optical properties of the above-mentioned energy-saving windows cannot be changed arbitrarily due to seasonal changes and perceived needs, it is difficult to meet the energy-saving needs of most cold winter and hot summer regions in my country and people's increasingly higher requirements for living environment comfort. As a result, new energy-saving products called "smart energy-saving windows" came into being.

Smart energy-saving windows use chromogenic materials with variable optical properties, and use their transflective performance changes to various physical stimuli to achieve controllable adjustment of indoor ambient light and heat. Obviously, smart energy-saving windows can adapt to the needs of most regions and different climatic conditions, and also make the indoor living environment more suitable for people.

According to the types of physical stimuli and the mechanism of discoloration, there are various types of smart energy-saving windows such as electrochromic, aerochromic, photochromic, and thermochromic.

Among various types of smart energy-saving windows, the thermochromic energy-saving window developed by using the semiconductor-metal reversible phase transition principle near room temperature of vanadium dioxide has the advantages of simple structure, less material consumption, and no need for switches or artificial energy control. Its remarkable advantages such as automatic light and heat regulation in response to changes in ambient temperature have gained attention and been developed in succession in various countries. Among them, the temperature-controlled intelligent energy-saving film technology using nano-vanadium dioxide has taken the lead in breaking through in my country, and the prepared vanadium dioxide-based temperature-controlled intelligent energy-saving film will be put on the market soon.

However, as the main inventor of the above-mentioned technology, at the same time, it is noticed that the above-mentioned vanadium dioxide temperature-controlled intelligent energy-saving window still has the following deficiencies:

(1) It has a relatively high adjustment range for the solar infrared band, but has almost no adjustment effect on the visible light band, which accounts for 50% of the total solar energy, and as a result reduces the total solar adjustment rate;

(2) Since there is no obvious adjustment effect in the visible light band, this adjustment cannot be used to produce sufficient visual changes, which is not conducive to a strong adjustment effect demonstration for customers, and has a decisive adverse effect on product publicity and promotion. ;

(3) It has a strong absorption effect on short-wavelength visible light, resulting in yellow coloring of the film.

So far, there is no mature technology to fundamentally solve the above-mentioned problems. Obviously, the solution to the above problems will mean a breakthrough in the application technology of vanadium dioxide-based thermochromic energy-saving windows.

Contents of the invention

Ligand Exchange Thermochromic (LETC for short) materials combine transformable metal ions with different ligands at different temperatures to form complexes with different absorption coefficients, thereby producing thermochromic effects. That is to say, at low temperature, metal ions combine with low absorption coefficient ligands to form low absorption coefficient complexes, which have higher transmittance; at high temperature, metal ions turn to combine with high absorption coefficient ligands to form high absorption complexes. Coefficient complexes have lower transmittance. This temperature-controlled optical change is reversible and mainly occurs in a specific wavelength range in the visible light band.

However, the thermochromism of common LETC materials only occurs in a very narrow band range in the vicinity of visible light, that is, in the full spectrum of sunlight, resulting in a relatively small adjustment ability. What's more, the middle and far infrared wave band, which is most sensitive to the human body's thermal sensation, cannot be adjusted, so it cannot be adjusted to ensure the comfortable feeling of the human body.

In addition, the LETC material can only achieve the adjustment purpose by absorbing light in the above-mentioned wavelength range, and the material itself has no reflection effect, so the adjustment effect is affected.

Based on the long-term research and development experience of thermochromic materials, the inventors discovered for the first time that by combining vanadium dioxide materials and LETC materials to form a new composite material, the thermochromic effects of the new materials can cover visible light and The full-band range of sunlight in the infrared band has made great progress in adjustment ability and comfort level, thus completing the present invention.

The invention provides a composite thermochromic slurry, comprising: vanadium dioxide nanopowder as an inorganic thermochromic material, a ligand converter as an organic thermochromic material, a polymer substrate and a dispersed medium, the ligand switcher comprises a transformable metal ion, a low-absorbance ligand capable of forming a low-absorbance complex with the transformable metal ion, and a ligand capable of forming a high-absorbance complex with the transformable metal ion High absorbance ligands.

The composite thermochromic paste of the present invention is characterized in that the thermochromic wavelength range covers the entire solar spectrum including visible light, and thus has a very high total solar regulation rate compared with traditional vanadium dioxide thermochromic materials. At the same time, the large adjustment effect in the visible light band is transformed into an obvious visual change, which is of decisive significance to the effect display and promotion of the product. In addition, due to the increased absorption of longer wavelength bands of visible light, the intrinsic yellow color of vanadium dioxide has been greatly suppressed.

Preferably, the vanadium dioxide nanopowder is doped or non-doped rutile phase vanadium dioxide.

Preferably, the particle diameter of the vanadium dioxide nanopowder is 20-80 nm.

Preferably, the transformable metal ion is at least one of Fe(II), Co(II), Ni(II), Cu(II), and the low absorbance ligand is a dihydric alcohol, a ternary At least one of alcohols and polyols, preferably neopentyl glycol, trimethylolpropane, ethylene glycol, glycerol, at least one of 2-methyl-1,3-propanediol; the high absorbance The ligand comprises a coordinating group capable of forming a high-absorbance coordination compound with a transformable metal ion, preferably tetrabutylammonium bromide, tetrabutylammonium chloride, tetrabutylammonium iodide, choline chloride, tributylammonium At least one of phenylphosphine and tetrathiocyclotetradecane.

Preferably, the molar ratio of vanadium dioxide to the transformable metal ion in the ligand switching body is 9:1-1:9, preferably 2:1-1:6, more preferably 1:1-1:4.

Preferably, the polymer substrate is polyacrylamide, polyhydroxyethyl methacrylate, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polymethyl methacrylate, polyvinyl formaldehyde Ether, polyhydroxyethyl acrylate, polyvinylpyridine, polyglyceryl methacrylate, hydroxyethyl cellulose, polyurethane, poly 2-ethyl-2-oxazoline, polyvinylpyrrolidone, and polymers containing the above at least one of functional group copolymers.

Preferably, the dispersion medium is at least one of deionized water, ethanol, propanol, isopropanol, ethyl acetate, toluene, acetone, butanone, γ-butyrolactone, chloroform, and propylene glycol methyl ether acetate kind.

Preferably, in the composite thermochromic slurry, the concentration of vanadium dioxide nanopowder is 0.1-2mol/L; the concentration ratio of vanadium dioxide nanopowder to polymer substrate is 1:9～ 9:1, preferably 1:9-5:1, more preferably 1:5-1:1; the concentration of the transformable metal ion is 0.5-5 mol/L.

On the other hand, the present invention also provides a method for preparing any of the above composite thermochromic slurry coatings, comprising the following steps:

a. Prepare vanadium dioxide nanopowder and disperse it in the dispersion medium to obtain dispersion A;

b. Add soluble polymer to dispersion A, stir until the polymer is completely dissolved to obtain dispersion B;

c. Add the ligand conversion body into the dispersion B, and stir until completely dissolved to obtain the dispersion C;

d. Continuously stirring the dispersion C and heating, evaporating part of the excess dispersion medium to obtain the composite thermochromic slurry.

Preferably, the concentration of vanadium dioxide in dispersion A is 0.01-1 mol/L, preferably 0.05-0.5 mol/L, more preferably 0.1-0.2 mol/L; the concentration ratio of vanadium dioxide to polymer in dispersion B is 1:9 to 9:1, preferably 1:9 to 5:1, more preferably 1:5 to 1:1; the concentration of the transformable metal ion of the ligand switch in the dispersion C is 0.01 to 5 mol/L, 0.1-2 mol/L, more preferably 0.5-1 mol/L.

In another aspect, the present invention also provides a composite thermochromic coating, which is prepared from any one of the above composite thermochromic pastes.

In another aspect, the present invention also provides a composite thermochromic film, which is prepared by coating any one of the composite thermochromic pastes above on a substrate.

Description of drawings

Fig. 1 is the physical photograph of the vanadium dioxide-based composite film of embodiment 1 at 20 ℃ (left) and 80 ℃ (right);

Fig. 2 is the absorption curve of the vanadium dioxide-based composite thin film of embodiment 1 at 20 ℃ and 80 ℃;

Fig. 3 is the physical photograph of the vanadium dioxide-based composite film of embodiment 3 at 20 ℃ (left) and 80 ℃ (right);

Fig. 4 is the real photo of the vanadium dioxide thin film of Comparative Example 1 at 20°C (left) and 80°C (right).

Detailed ways

The present invention will be further described below in conjunction with the drawings and the following embodiments. It should be understood that the drawings and the following embodiments are only used to illustrate the present invention rather than limit the present invention.

The invention provides a high-performance vanadium dioxide-based thermochromic composite material. The composite material contains both an inorganic thermochromic material and an organic thermochromic material. The inorganic thermochromic material is vanadium dioxide, and the organic thermochromic material is vanadium dioxide. The thermochromic material is a ligand conversion body.

In the present invention, the ligand switching body comprises two kinds of ligands, namely a transformable metal ion, a low-absorbance ligand capable of forming a low-absorbance complex with it, and a high-absorbance ligand capable of forming a high-absorbance complex with it. Material. Through the combination of metal ions and different ligands at different temperatures, complexes with different absorption coefficients are formed, resulting in thermochromic effects. At low temperatures, metal ions combine with low-absorbance ligands to form complexes with low absorption coefficients. At high temperature, metal ions combine with high-absorbance ligands to form high-absorption complexes, which have low transmittance. This temperature-controlled optical change is reversible and mainly occurs in a specific wavelength range in the visible light band.

The transformable metal ion may be a transition metal ion, preferably at least one of Fe(II), Co(II), Ni(II), and Cu(II). At least one of them is selected to combine with different ligands, and specific absorption can be obtained in different wave bands as required.

The light absorption ability of the ligand switching body can be expressed by absorbance. The low absorbance means that the absorbance is less than 0.2 in the wavelength range of 400-1400nm, and the high absorbance means that the absorbance is above 0.8 in the wavelength range of 400-1400nm.

The low-absorbance ligands include but are not limited to at least one of diols, triols, and polyols, preferably neopentyl glycol, trimethylolpropane, ethylene glycol, glycerol, 2-methyl- At least one of 1,3-propanediol. The high-absorbance ligand comprises a coordination group capable of forming a high-absorbance coordination compound with a transformable metal ion, for example, may contain at least one of N, P, and S atoms, and/or be selected from chloride, bromide, At least one of iodide and halide-like compounds, preferably tetrabutylammonium bromide, tetrabutylammonium chloride, tetrabutylammonium iodide, choline chloride, triphenylphosphine, tetrathiocyclotetradecine at least one of alkanes.

In the ligand switch body, the molar ratio of the switchable metal ion to the ligand with low absorbance and the ligand with high absorbance can be (0.1-1):(1-10):(4-10).

In addition, polymers may also be included in the ligand switching body to serve as a bridge for ligand switching. In addition, it should be understood that the ligand switching body does not necessarily contain a polymer, and the polymer is not required when there is a solvent, and the solvent and the polymer can replace each other as a ligand switching bridge. Such polymers include, but are not limited to, polyacrylamide, polyhydroxyethyl methacrylate, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polymethyl methacrylate, polyvinyl methyl ether, poly Methyl hydroxyethyl acrylate, polyvinylpyridine, polyglyceryl methacrylate, hydroxyethyl cellulose, polyurethane, poly-2-ethyl-2-oxazoline, polyvinylpyrrolidone, and copolymers containing functional groups of the above polymers at least one of the

The vanadium dioxide in the present invention may be non-doped vanadium dioxide or vanadium dioxide with doping elements. The vanadium dioxide may be in the rutile phase. Vanadium dioxide crystals have a reversible phase transition and a huge change in optical properties at 68 °C. However, by element doping and other means, the transition temperature can be precisely controlled near room temperature. The vanadium dioxide in the present invention includes various elements of traditional vanadium dioxide-based thermochromic energy-saving windows such as doped vanadium dioxide.

The chemical composition of the doped vanadium dioxide powder can be V _1-x M _x O ₂ , where 0<x≤0.5. The dopant element can be one or any combination of the 21-30 transition elements near vanadium in the periodic table of elements, tin and its nearby elements, tungsten, molybdenum, ruthenium, niobium, tantalum, magnesium and other elements. Among them, the 21-30 transition elements near vanadium in the periodic table of elements include scandium, titanium, chromium, manganese, iron, cobalt, nickel, copper and zinc, and the tin and its nearby elements include indium, antimony, tin, gallium, Germanium, lead and bismuth, preferred doping elements are tungsten, molybdenum, bismuth, tin, niobium, tantalum, magnesium, iron, zinc and titanium. By using the above-mentioned doping elements, the size and shape of the doped vanadium dioxide powder can be controlled, or at the same time the phase transition temperature of the vanadium dioxide can also be adjusted.

In the present invention, vanadium dioxide can be powder, preferably granular, that is, exists in the form of vanadium dioxide nanoparticles. The aspect ratio of the particles may be 1:1-10:1, preferably 1:1-5:1, more preferably 1:1-2:1. The particle size is not greater than 1 μm in at least one dimension, preferably not greater than 100 nm in at least one dimension, more preferably not greater than 100 nm in all three dimensions, for example, 20-80 nm. The granular shape can be nearly spherical, oval, snowflake, cubic, flake, etc.

In addition, the vanadium dioxide nanoparticles may also have an outer coating. The outer cladding layer is preferably transparent, which can improve the stability of the vanadium dioxide particles without affecting the overall visible light transmittance of the vanadium dioxide particles. The material of the outer cladding layer includes, but is not limited to, one or more of carbon, silicon oxide, magnesium oxide, and aluminum oxide. The thickness of the outer cladding layer can range from 2 to 20 nm.

In principle, vanadium dioxide and the ligand converter can be compounded in any ratio according to needs, but a large number of experiments have shown that the molar ratio of vanadium dioxide to metal ions in the LETC material is preferably 9:1 to 1:9, more preferably 2: 1-1:6, most preferably 1:1-1:4.

The present invention constitutes a brand-new composite material by combining vanadium dioxide material and LETC material, so that the thermochromic effect of the new material covers the full range of sunlight including visible light and infrared bands, and has both adjustment ability and comfort made leaps forward.

Obviously, by adjusting the visible light band, which accounts for 50% of the total solar energy, compared with traditional vanadium dioxide materials, the total solar radiation regulation rate has been decisively improved.

At the same time, due to the sufficient visual changes produced by the obvious adjustment effect of the visible light band, it is helpful to carry out a powerful effect demonstration to customers and play a decisive role in promoting the promotion of products. It overcomes the problem that the adjustment range of vanadium dioxide is mainly limited to the infrared band, and there is almost no visually obvious adjustment effect in the visible light band.

At the same time, the absorption of specific wavelengths of visible light by LETC materials plays a beneficial role in harmonizing the inherent color development of vanadium dioxide.

At the same time, vanadium dioxide has a strong blocking effect on solar ultraviolet wavelengths, and can be used as a natural ultraviolet absorber in composite materials, which greatly improves the anti-ultraviolet ability of LETC materials.

The thermochromic range of the composite material of the invention covers the full band of 300-2500nm solar radiation, and has obvious visual effects. The thermochromism is reversible between 10°C and 100°C.

The composite materials of the present invention may exist in a variety of forms including, but not limited to, slurries, coatings, films, and the like. Among them, there may be various relationships between the inorganic thermochromic material (vanadium dioxide) and the organic thermochromic material (ligand switch), as long as both exist at the same time. In one example, the two can exist in a slurry, paint, or film in a mixed state. In another example, the inorganic thermochromic material and the organic thermochromic material exist in a non-mixed state. Such a non-mixed state includes each being layered but having contact between layers, or being each being layered and having no contact between layers. For example, the composite material of the present invention may be a composite film formed by laminating a vanadium dioxide film and a ligand converter film. In the composite film, the two films may each have one or more layers. The two films can be stacked adjacently, or can be separated by other layers between them. The layer may be, for example, a flexible PET (polyethylene terephthalate) film, rigid glass, or the like.

In addition, a polymer matrix may also be included in the composite material of the present invention. On the one hand, the polymer substrate serves as a bridge for ligand conversion, and on the other hand, it can play a role in dispersion and support in composite materials, such as a film-forming agent in thin films. In one example, vanadium dioxide (preferably nano-sized vanadium dioxide powder) is compounded with an appropriate LETC material in an appropriate ratio, and uniformly dispersed in a polymer matrix to form a thermally controlled optical modulation characteristic with high temperature control. Chromogenic composite film material. In addition, the polymer base material is preferably compatible with the vanadium dioxide and the ligand switching body in the composite material, so as to keep the slurry from precipitation and maintain the transparency of the film. As examples, the polymer substrate may be polyacrylamide, polyhydroxyethylmethacrylate, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polymethylmethacrylate, polyvinyl Methyl ether, polyhydroxyethyl acrylate, polyvinylpyridine, polyglycerol methacrylate, hydroxyethyl cellulose, polyurethane, poly 2-ethyl-2-oxazoline, polyvinylpyrrolidone, and polymers containing the above At least one of the copolymers with functional groups.

In one embodiment, the composite material of the present invention is a composite thermochromic slurry, which contains vanadium dioxide nanopowder as an inorganic thermochromic material, and a ligand as an organic thermochromic material. Transformers, polymer substrates and dispersion media.

The dispersion medium includes but is not limited to one of deionized water, ethanol, propanol, isopropanol, ethyl acetate, toluene, acetone, methyl ethyl ketone, γ-butyrolactone, chloroform, and propylene glycol methyl ether acetate or more, preferably one or more of ethanol, isopropanol, acetone, and γ-butyrolactone.

In the slurry, the concentration of vanadium dioxide nanopowder may be 0.1-2 mol/L, preferably 0.1-0.5 mol/L. The concentration ratio of the vanadium dioxide nanopowder to the polymer substrate may be 1:9-9:1, preferably 1:9-5:1, more preferably 1:5-1:1. The concentration of the transformable metal ions may be 0.5-5 mol/L, preferably 0.5-2 mol/L. As mentioned above, the molar ratio of vanadium dioxide to the transformable metal ion in the ligand switching body may be 9:1-1:9, preferably 2:1-1:6, more preferably 1:1-1:4.

Described slurry can also comprise dispersing aid, and this dispersing aid can be selected from polyethylene glycol, oleic acid, triethylhexyl phosphoric acid, silane coupling agent, sodium lauryl sulfate, methyl amyl alcohol, One or more of fatty acid polyethylene glycol ester, polyacrylate, polyacrylamide, polyphosphate, polyvinyl alcohol, polyvinylpyrrolidone, modified polyester, modified polyurethane and modified acrylic dispersant.

In addition, one or more of UV absorbers, light stabilizers, heat stabilizers and plasticizers can also be added.

Hereinafter, the preparation method of the said slurry is demonstrated as an example.

Prepare vanadium dioxide nanopowder and disperse it in a dispersion medium to obtain dispersion A. The vanadium dioxide nanopowder can be prepared by a hydrothermal method. It may be vanadium dioxide in the rutile phase. The concentration of vanadium dioxide in the dispersion A may be 0.01-1 mol/L, preferably 0.05-0.5 mol/L, more preferably 0.1-0.2 mol/L. In addition, a dispersing aid can also be added to the dispersion A to promote the dispersion of the vanadium dioxide nanopowder. The dispersion method can be ball milling and the like. The ball milling speed can be 500-1000r/min, and the ball milling time can be 1-3 hours.

Add the soluble polymer to the dispersion A, stir until the polymer is completely dissolved to obtain the dispersion B. The concentration ratio of vanadium dioxide to polymer in the dispersion B is 1:9-9:1, preferably 1:9-5:1, more preferably 1:5-1:1. Soluble polymers can be polyacrylamide, polyhydroxyethyl methacrylate, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polymethyl methacrylate, polyvinyl methyl ether, polyhydroxyethyl Methyl acrylate, polyvinylidene fluoride, polyvinylpyridine, polyglyceryl methacrylate, hydroxyethyl cellulose, polyurethane, poly 2-ethyl-2-oxazoline, polyvinylpyrrolidone, and polymers containing the above functional groups At least one of the copolymers. According to the selected dispersion medium, select the corresponding polymer that can be dissolved in the dispersion medium as a film-forming agent and a bridge for ligand conversion.

Add the ligand conversion body into the dispersion B, stir until completely dissolved to obtain the dispersion C, and obtain the slurry. The ligand switcher may be a mixture of a switchable metal ion source, the aforementioned low-absorbance ligand, and the aforementioned high-absorbance ligand. These three can be added at the same time or separately. As a source of switchable metal ions, there may be corresponding metal salts, such as metal halides, metal nitrates, metal tetrafluoroborates, metal acetates, metal carbonates, metal perchlorates, and the like. The concentration of the ligand converter in the dispersion C may be 0.01-5 mol/L, preferably 0.1-2 mol/L, more preferably 0.5-1 mol/L.

According to the requirements of the slurry concentration, the dispersion liquid C can also be continuously stirred and heated to evaporate part of the excess dispersion medium.

The composite thermochromic slurry of the present invention can be prepared into thermochromic coatings, various pasting films or intermediate films and other thermochromic films as required. As a preparation method of the thermochromic thin film, it may be formed by coating the slurry on a substrate. The coating method can be sprayed, scraped, brushed, flow coated or roller coated. Substrates include, but are not limited to, glass, or polypropylene (PP), polyethylene (PE), polyamide (PA), polyvinyl chloride (PVC), polyethylene terephthalate (PET), and polymethyl Plastic films such as methyl acrylate (PMMA).

By applying the above slurry, coating and film to different types of transparent substrates, thermochromic energy-saving windows for buildings and vehicles can be prepared.

For example, to meet the energy-saving requirements of buildings or vehicles, the huge optical effect produced by the thermochromic composite film can be reversible between 10°C and 100°C by doping vanadium dioxide or selecting different LETC materials.

The high-performance vanadium dioxide-based thermochromic composite material of the present invention is characterized in that the thermochromic wavelength range covers the entire sunlight spectrum. Compared with the traditional thermochromic material of vanadium dioxide, the invention has higher solar regulation efficiency. At the same time, due to the large adjustment effect in the visible light band, it produces obvious visual changes, which is of decisive significance for the effect display and promotion of products. The invention has low cost, is suitable for mass industrial production, and can be widely used in energy-saving and environment-friendly fields such as intelligent energy-saving windows.

Below in conjunction with specific embodiment, further illustrate the present invention. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention, and some non-essential improvements and adjustments made by those skilled in the art according to the above contents of the present invention belong to the protection scope of the present invention. The specific process parameters and the like in the following examples are only examples of suitable ranges, that is, those skilled in the art can make a selection within a suitable range through the description herein, and are not limited to the specific values exemplified below.

Example 1

First prepare 100ml of vanadium pentoxide solution containing 0.01mol/L, add 0.01g of oxalic acid and stir to form a uniform solution. Put the above solution into the reaction kettle and seal it, and react at 240°C for 24h. After cooling, take it out, centrifuge, wash and dry to obtain vanadium dioxide powder.

Take 0.5g of the vanadium dioxide nano-powder and 0.25g of polyvinylpyrrolidone prepared by the above-mentioned hydrothermal treatment, add them into 100g of ethanol, stir and ultrasonically disperse for 30min, transfer the dispersion to a ball mill tank, and ball mill for 1h under the condition of 900r/min to obtain two vanadium oxide ethanol dispersion; add 10g polyvinyl butyral to the above dispersion, stir until dissolved; continue to add 6.5g nickel perchlorate, 6g neopentyl glycol and 24g tetrabutylammonium bromide, stir until completely dissolved and Mix evenly; keep stirring the above-mentioned dispersion liquid at 90°C for 30 minutes to obtain a composite thermochromic slurry of vanadium dioxide and a ligand converter. The above slurry is evenly coated on the surface of commercially available common glass to obtain vanadium dioxide-based thermochromic glass.

A spectrophotometer (Hitachi U-3010) with a heating accessory was used to measure the spectral transmittance spectrum of the thermochromic glass at low temperature (20°C) and high temperature (80°C), and then calculated according to the formula The visible light transmittance of glass (T _lum : 380-780nm) and the solar energy transmittance in different wavelength bands (T _sol , 260-380nm, 380-780nm, 780-2600nm) are calculated as follows:

Among them, T(λ) represents the transmittance at the wavelength λ, φ _lum (λ) is the relative spectral luminous efficiency of the human eye, and φ _sol (λ) is the solar radiation spectral curve.

The test and calculation results are shown in Table 1. It can be seen that compared with common vanadium dioxide thermochromic glass, the glass of the present invention has a very high visible light transmittance; The light regulation rate exceeds 18%. At the same time, the color of the glass changes from light to dark, and the color changes from yellowish brown to dark green (Figure 1, the text in the picture is the background set to show the transparency of the film). That is, the visual changes accompanying the dimming process are noticeable. Figure 2 shows the absorption curves of films made of composite thermochromic paste at 20°C and 80°C. It can be seen that the absorption of the film is significantly enhanced at high temperatures, and characteristic absorption peaks appear near the wavelengths of 750nm and 1300nm, respectively. Corresponds to LETC and _VO2 .

Table 1

Example 2

First prepare 100ml of vanadyl sulfate solution containing 0.01mol/L, add 5g of hydrazine monohydrate with a mass fraction of 10%, then use sodium hydroxide to titrate to pH 7 to form a suspension, filter and wash the precipitate and disperse it again in 100mL Stir in water to form a homogeneous solution. Put the above solution into the reaction kettle and seal it, and react at 260°C for 24h. Take it out after cooling, add 0.1g of glucose into the reactor, close the reactor, react at 180°C for 8h and cool to room temperature, centrifuge, wash and dry to obtain carbon-coated vanadium dioxide powder.

Take 1g of carbon-coated vanadium dioxide nanopowder and 0.5g of polyvinylpyrrolidone prepared by the above-mentioned hydrothermal treatment, add them into 100g of acetone, stir and ultrasonically disperse for 30min, then transfer the dispersion to a ball mill tank, and ball mill for 1h under the condition of 900r/min Obtain vanadium dioxide acetone dispersion liquid; 10g polymethyl methacrylate is added above-mentioned dispersion liquid, stir to dissolve; Continue to add 15g nickel perchlorate, 12g trimethylol propane and 52g tetrabutylammonium bromide, stir until Completely dissolve and mix evenly; keep stirring the above dispersion liquid at 90°C for 30 minutes to obtain a composite thermochromic slurry of vanadium dioxide and ligand conversion body. The above slurry is evenly coated on the surface of commercially available common glass to obtain vanadium dioxide-based thermochromic glass.

The performance of the glass was evaluated in the same manner as in Example 1, and the results are shown in Table 2. It can be seen that the solar light regulation rate of the glass of the present invention reaches 24.59% on the premise that the visible light transmittance exceeds 50%. The color change is more pronounced due to the increased modulation rate.

Table 2

Example 3

First prepare 100 ml of vanadium pentoxide solution containing 0.01 mol/L, add 0.005 g of tungsten trioxide and 0.5 g of hydrazine monohydrate with a mass fraction of 10%, and stir to form a uniform solution. Put the above solution into the reaction kettle and seal it, and react at 260°C for 24h. After cooling, take it out, centrifuge, wash and dry to obtain vanadium dioxide powder.

Take 0.5g of the vanadium dioxide nano-powder and 0.25g of polyvinylpyrrolidone prepared by the above-mentioned hydrothermal treatment, add them into 100g of acetone, stir and ultrasonically disperse for 30min, then transfer the dispersion to a ball mill tank, and ball mill for 1h under the condition of 900r/min to obtain two Vanadium oxide acetone dispersion; add 10g polymethyl methacrylate to the above dispersion, stir until dissolved; continue to add 4g cobalt bromide, 5g trimethylolpropane and 24g tetrabutylammonium bromide, stir until completely dissolved and Mix evenly; keep stirring the above-mentioned dispersion liquid at 90°C for 30 minutes to obtain a composite thermochromic slurry of vanadium dioxide and a ligand converter. The above slurry is evenly coated on the surface of commercially available common glass to obtain vanadium dioxide-based thermochromic glass.

The properties of the glass were evaluated in the same manner as in Example 1, and the results are shown in Table 3. It can be seen that, compared with common vanadium dioxide thermochromic glass, the glass of the present invention has a very high visible light transmittance; The light regulation rate exceeds 18%. At the same time, the glass tone changes from light to dark, and the color also changes from yellowish brown to dark green (Figure 3, the text in the picture is the background set to show the transparency of the film). That is, the visual changes accompanying the dimming process are noticeable.

table 3

Example 4

First prepare 100ml of vanadyl sulfate solution containing 0.01mol/L, add 5g of hydrazine monohydrate with a mass fraction of 10%, then use sodium hydroxide to titrate to pH 7 to form a suspension, filter and wash the precipitate and disperse it again in 100mL Stir in water to form a homogeneous solution. Put the above solution into the reaction kettle and seal it, and react at 260°C for 24h. Take it out after cooling, add the reaction solution into 100mL of absolute ethanol, then add 10mL of deionized water and 5mL of ammonia water and stir evenly, then add 2.5mL of tetraethyl orthosilicate dropwise, stir at room temperature for 5h, filter, wash, and dry. Annealed to obtain silicon oxide-coated vanadium dioxide powder.

Take 1g of the above hydrothermally prepared silica-coated vanadium dioxide nanopowder and 0.5g of polyvinylpyrrolidone, add it to 100g of ethanol, stir and ultrasonically disperse for 30min, transfer the dispersion to a ball mill tank, and ball mill at 900r/min 1h to obtain vanadium dioxide ethanol dispersion; add 10g polyvinyl butyral to the above dispersion, stir until dissolved; continue to add 9g cobalt bromide, 14g neopentyl glycol and 52g tetrabutylammonium bromide, stir until completely dissolved And mix evenly; keep stirring the above dispersion liquid at 90° C. for 30 minutes to obtain the composite thermochromic paste of vanadium dioxide and ligand conversion body. The above slurry is evenly coated on the surface of commercially available common glass to obtain vanadium dioxide-based thermochromic glass.

The properties of the glass were evaluated in the same manner as in Example 1, and the results are shown in Table 4. It can be seen that the solar light regulation rate of the glass of the present invention reaches 21.91% on the premise that the visible light transmittance exceeds 50%. The color change is more pronounced due to the increased modulation rate.

Table 4

Comparative example 1

First prepare 100ml of vanadium pentoxide solution containing 0.01mol/L, add 0.01g of oxalic acid and stir to form a uniform solution. Put the above solution into the reaction kettle and seal it, and react at 240°C for 24h. Take it out after cooling, and centrifugally dry to obtain vanadium dioxide powder. Take 0.5g of the vanadium dioxide nano-powder and 0.25g of polyvinylpyrrolidone prepared by the above-mentioned hydrothermal treatment, add them into 100g of ethanol, stir and ultrasonically disperse for 30min, transfer the dispersion to a ball mill tank, and ball mill for 1h under the condition of 900r/min to obtain two Ethanol dispersion of vanadium oxide; add 9g of polyvinyl butyral to the above dispersion and stir until dissolved; keep stirring the above dispersion at 90°C for 30min to obtain vanadium dioxide thermochromic slurry. The above slurry is evenly coated on the surface of commercially available common glass to obtain vanadium dioxide-based thermochromic glass.

The properties of the glass were evaluated in the same manner as in Example 1, and the results are shown in Table 5. It can be seen that, on the premise that only vanadium dioxide is used as the thermochromic material, in order to obtain the visible light transmittance equivalent to Example 1, the solar light regulation rate is only about half of that of Example 1. At the same time, it can be seen from Figure 4 that the glass does not produce visual hue changes during dimming.

table 5

Comparative example 2

First prepare 100 ml of vanadium pentoxide solution containing 0.01 mol/L, add 0.005 g of tungsten trioxide and 0.5 g of hydrazine monohydrate with a mass fraction of 10%, and stir to form a uniform solution. Put the above solution into the reaction kettle and seal it, and react at 260°C for 24h. After cooling, take it out, centrifuge, wash and dry to obtain vanadium dioxide powder. Take 1g of the vanadium dioxide nanopowder and 0.5g of polyvinylpyrrolidone prepared by the above-mentioned hydrothermal treatment, add them into 100g of ethanol, stir and ultrasonically disperse for 30min, then transfer the dispersion to a ball mill tank, and ball mill for 1h under the condition of 900r/min to obtain the carbon dioxide Ethanol dispersion of vanadium; add 9g of polyvinyl butyral to the above dispersion, stir until dissolved; keep stirring the above dispersion at 90°C for 30min to obtain vanadium dioxide thermochromic slurry. The above slurry is evenly coated on the surface of commercially available common glass to obtain vanadium dioxide-based thermochromic glass.

The properties of the glass were evaluated in the same manner as in Example 1, and the results are shown in Table 6. It can be seen that under the premise of only using vanadium dioxide as a thermochromic material, if the solid content of vanadium dioxide is increased, the solar light regulation rate also increases to 12.23%, but its visible light transmittance drops rapidly to only About 40%. Furthermore, no noticeable hue change was observed upon dimming.

Table 6

Comparative example 3

Add 10g of polymethyl methacrylate to 100g of acetone and stir until dissolved, then sequentially add 15g of nickel perchlorate, 14g of neopentyl glycol and 52g of tetrabutylammonium bromide, stir until dissolved to obtain a dispersion. The dispersion liquid is coated on the surface of a commercially available common glass by a spin coating method to obtain a thermochromic glass containing only polymer groups.

The properties of the glass were evaluated in the same manner as in Example 1, and the results are shown in Table 7. It can be seen that under the condition of using LETC thermochromic material alone, although the coated glass has a high visible light transmittance and obvious temperature control visual changes, the temperature control adjustment range in the solar infrared band is very weak. 2.75%, does not have a good infrared adjustment effect. At the same time, the overall infrared transmittance of the glass is too high, and it does not have a good infrared blocking effect in summer.

Table 7

The present invention constitutes a brand-new composite material by combining vanadium dioxide material and LETC material, so that the thermochromic effect of the new material covers the full range of sunlight including visible light and infrared bands, and has both adjustment ability and comfort It has made great progress and can be widely used in energy-saving and environmental protection fields such as smart energy-saving windows.

Claims (21)

1. a kind of composite type heat mutagens mill base material, which is characterized in that including：Vanadium dioxide as inorganic system's thermochromic material Nano-powder, dentate conversion body, polymeric substrate and decentralized medium as organic system thermochromic material, the dentate Conversion body includes that can change metal ion, can be formed in 400~1400nm wave-length coverage interior suctions with the metal ion that changes Luminosity is less than the low absorbance ligand of 0.2 complex and can be formed in 400~1400nm with the metal ion that changes The high absorbance ligand for the complex that wave-length coverage internal absorbance is 0.8 or more, the metal ion that changes are selected from Fe (II), at least one of Co (II), Ni (II), Cu (II),

The vanadium dioxide exists in the form of vanadium dioxide nano particle, and the particle size range of the vanadium dioxide nano particle is 20~80nm,

The composite type heat mutagens mill base material is prepared via a method which：

A. preparing vanadium dioxide nano powder and be scattered in decentralized medium, ball milling, rotational speed of ball-mill is 500~1000r/min, Obtain dispersion liquid A；

B. soluble polymer is added in dispersion liquid A, stirring is completely dissolved to polymer, obtains dispersion liquid B；

C. dentate conversion body is added in dispersion liquid B, stirs to being completely dissolved, obtains dispersion liquid C；

D. it is persistently dispersed with stirring liquid C and heats, the extra decentralized medium of evaporation section obtains the composite type heat mutagens mill base material；

Wherein, in step a,

Vanadium dioxide nano powder is the vanadium dioxide nano particle with external coating, and the thickness range of the external coating is The material of 2~20nm, the external coating are at least one of carbon, silica, magnesia and aluminium oxide；And/or

Vanadium dioxide nano powder and dispersing aid are scattered in decentralized medium, the dispersing aid is selected from polyethylene glycol, oil Acid, triethyl group hexyl phosphoric acid, silane coupling agent, lauryl sodium sulfate, methyl anyl alcohol, fatty acid polyethylene glycol ester, polypropylene Hydrochlorate, polyacrylamide, polyphosphate, polyvinyl alcohol, polyvinylpyrrolidone, modified poly ester, modified polyurethane and modification One or more of acrylic acid dispersant.

2. composite type heat mutagens mill base material according to claim 1, which is characterized in that the vanadium dioxide nano powder is Doped or non-doped rutile phase hypovanadic oxide.

3. composite type heat mutagens mill base material according to claim 1, which is characterized in that the low absorbance ligand is more At least one of first alcohol；The high absorbance ligand includes that can form high absorbance coordinationization with that can change metal ion Close object coordinating group, the high absorbance ligand be selected from tetrabutylammonium bromide, tetrabutylammonium chloride, tetrabutylammonium iodide, At least one of choline chloride, triphenylphosphine, tetrathiacyclotetradecane.

4. composite type heat mutagens mill base material according to claim 3, which is characterized in that the low absorbance ligand is two At least one of first alcohol, trihydroxylic alcohol.

5. composite type heat mutagens mill base material according to claim 4, which is characterized in that the low absorbance ligand is new At least one of pentanediol, trimethylolpropane, ethylene glycol, glycerine, 2- methyl-1,3-propanediols.

6. composite type heat mutagens mill base material according to claim 1, which is characterized in that vanadium dioxide and dentate conversion body In the molar ratio for changing metal ion be 9:1~1:9.

7. composite type heat mutagens mill base material according to claim 6, which is characterized in that vanadium dioxide and dentate conversion body In the molar ratio for changing metal ion be 2:1~1:6.

8. composite type heat mutagens mill base material according to claim 7, which is characterized in that vanadium dioxide and dentate conversion body In the molar ratio for changing metal ion be 1:1~1:4.

9. composite type heat mutagens mill base material according to claim 1, which is characterized in that the polymeric substrate is polypropylene Amide, poly hydroxy ethyl acrylate, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, poly-methyl methacrylate Ester, polyvinylmethyl ethers, poly-hydroxyethyl methyl acrylate, polyvinylpyridine, polyglycerolmethacrylate, hydroxy ethyl fiber In element, polyurethane, poly- 2- ethyl-2-oxazolines, polyvinylpyrrolidone and copolymer containing above-mentioned polymers functionality At least one.

10. composite type heat mutagens mill base material according to claim 1, which is characterized in that the decentralized medium is deionization In water, ethyl alcohol, propyl alcohol, isopropanol, ethyl acetate, toluene, acetone, butanone, gamma-butyrolacton, chloroform, propylene glycol methyl ether acetate At least one.

11. composite type heat mutagens mill base material according to any one of claim 1 to 10, which is characterized in that described multiple In mould assembly thermochromism slurry, a concentration of 0.1~2mol/L of vanadium dioxide nano powder；Vanadium dioxide nano powder with polymerize The concentration ratio of object base material is 1:9~9:1；A concentration of 0.5~5mol/L of metal ion can be changed.

12. composite type heat mutagens mill base material according to claim 11, which is characterized in that vanadium dioxide nano powder with it is poly- The concentration ratio for closing object base material is 1:9~5:1.

13. composite type heat mutagens mill base material according to claim 12, which is characterized in that vanadium dioxide nano powder with it is poly- The concentration ratio for closing object base material is 1:5~1:1.

14. composite type heat mutagens mill base material according to claim 1, which is characterized in that vanadium dioxide concentration in dispersion liquid A For 0.01~1 mol/L；The concentration ratio of vanadium dioxide and polymer is 1 in dispersion liquid B:9~9:1；Dentate turns in dispersion liquid C Change a concentration of 0.01~5 mol/L for changing metal ion of body.

15. composite type heat mutagens mill base material according to claim 14, which is characterized in that vanadium dioxide is dense in dispersion liquid A Degree is 0.05~0.5 mol/L.

16. composite type heat mutagens mill base material according to claim 15, which is characterized in that vanadium dioxide is dense in dispersion liquid A Degree is 0.1~0.2 mol/L.

17. composite type heat mutagens mill base material according to claim 14, which is characterized in that in dispersion liquid B vanadium dioxide with The concentration ratio of polymer is 1:9~5:1.

18. composite type heat mutagens mill base material according to claim 17, which is characterized in that in dispersion liquid B vanadium dioxide with The concentration ratio of polymer is 1:5~1:1.

19. composite type heat mutagens mill base material according to claim 14, which is characterized in that dentate is converted in dispersion liquid C A concentration of 0.1~2 mol/L for changing metal ion of body.

20. composite type heat mutagens mill base material according to claim 19, which is characterized in that dentate is converted in dispersion liquid C A concentration of 0.5~1 mol/L for changing metal ion of body.

21. a kind of compound thermochromic thin film, which is characterized in that by compound described in any one of claim 1 to 20 Thermochromism slurry is made coated on matrix.