Super-hydrophobic functionalized vanadium dioxide film and preparation method and application thereof

Abstract

The invention provides a super-hydrophobic functionalized vanadium dioxide film as well as a preparation method and application thereof. The super-hydrophobic functionalized vanadium dioxide film is prepared from the following raw materials: cellulose and alpha-tocopherol modified M-phase vanadium dioxide. The alpha-tocopherol can be used for performing surface treatment on the VO2, so that the oxidation resistance and acid resistance of the VO2 and the stability of the VO2 in a film-forming reagent are effectively improved. Besides, after cellulose, alpha-tocopherol modified M-phase vanadium dioxide, an optional adhesive and other raw materials are mixed and laid on the base plate through a physical means, cellulose can be inserted into the surface layer of the base plate in a sowing and transplanting mode, and it can be ensured that alpha-tocopherol modified M-phase vanadium dioxide particles on the plane of the base plate do not shift; and a large number of cellulose and alpha-tocopherol modified M-phase vanadium dioxide particles can provide enough roughness for the coating, so that the super-hydrophobicity of the surface of the substrate is realized.

Description

Technical Field

[0001] The invention belongs to the technical field of vanadium dioxide materials, and in particular relates to a super-hydrophobic functionalized vanadium dioxide film, and a preparation method and application thereof. Background Art

[0002] VO 2 It has a relatively low phase transition temperature and exhibits special nonlinear electro-optical properties in the MIT phase transition. At the same time, due to its unique phase transition properties and excellent performance, from high transmittance of infrared light to high reflectivity before and after the phase transition, it is widely used in smart glass, optical storage, laser radiation protection film, lithium battery electrodes, high-sensitivity temperature sensors, adjustable microwave switching devices, infrared light modulation materials and other fields.

[0003] However, VO 2 During long-term outdoor use, the film will inevitably be corroded by acid rain, which will seriously shorten the service life of the film and destroy its functionality. 2 The stability of VO is poor, and the tetravalent vanadium is easily oxidized to pentavalent vanadium, which affects the thermochromic reaction performance. Common methods such as element doping and inorganic shell coating can make VO 2 Nanoparticles will bring the phase change temperature close to room temperature, but will cause irreversible effects on light transmittance and sunlight regulation capabilities. Summary of the invention

[0004] In view of this, the object of the present invention is to provide a super-hydrophobic functionalized vanadium dioxide film, and a preparation method and application thereof. The super-hydrophobic functionalized vanadium dioxide film has excellent hydrophobicity, oxidation resistance and stability.

[0005] To achieve this object, the present invention adopts the following technical solutions:

[0006] In a first aspect, the present invention provides a method for preparing a super-hydrophobic functionalized vanadium dioxide film, comprising the following steps:

[0007] S1: mixing an aqueous solution of a vanadium source with a precipitant, heating the mixture under boiling conditions to form a suspension with a precipitate, filtering the mixture to obtain a vanadium dioxide precursor, and calcining the mixture to obtain M-phase vanadium dioxide nanoparticles;

[0008] S2: mixing and reacting M-phase vanadium dioxide nanoparticles and α-tocopherol in the presence of a solvent to obtain α-tocopherol-modified M-phase vanadium dioxide;

[0009] S3: Mixing α-tocopherol-modified M-phase vanadium dioxide, cellulose, an optional binder and a solvent to obtain a mixed slurry, and preparing a film to obtain a super-hydrophobic functionalized vanadium dioxide film.

[0010] Preferably, the precipitant is selected from any one or more of urea, ammonia water or sodium hydroxide.

[0011] Preferably, the concentration of the aqueous solution of the vanadium source is 0.5-2M.

[0012] Preferably, the vanadium source is selected from vanadyl sulfate.

[0013] Preferably, the molar ratio of the precipitant to the vanadium source is (2-10):1.

[0014] Preferably, the heating temperature in the boiling state is 100° C. and the heating time is 1 to 3 hours.

[0015] Preferably, the calcination is vacuum calcination, the calcination temperature is 500-700° C., and the calcination time is 1-4 hours.

[0016] Preferably, the filtration further includes washing and drying steps.

[0017] Preferably, the washing is performed using anhydrous ethanol or deionized water.

[0018] Preferably, the drying is vacuum drying, the drying temperature is 35-60° C., and the drying time is 48-96 hours.

[0019] Preferably, the solvent in step S2 is selected from anhydrous ethanol.

[0020] Preferably, step S2 is: dispersing M-phase vanadium dioxide nanoparticles in a solvent to obtain a 6-12 wt% suspension, and then adding 1-3% by weight of α-tocopherol to the suspension to react and obtain α-tocopherol-modified M-phase vanadium dioxide.

[0021] Preferably, the reaction temperature in step S2 is 10-30° C. and the reaction time is 0.5-2 h.

[0022] Preferably, the reaction is carried out under stirring conditions.

[0023] Preferably, after the reaction is completed, the steps of ultrasonication, washing and drying are further included.

[0024] Preferably, the ultrasonication time is 10 to 60 minutes.

[0025] Preferably, the washing is performed using anhydrous ethanol or deionized water.

[0026] Preferably, the drying is vacuum drying, the drying temperature is 40-60° C., and the drying time is 4-20 hours.

[0027] Preferably, the cellulose includes natural cellulose and / or artificial cellulose; and the particle size of the cellulose is 50 nm to 1 μm.

[0028] Preferably, the natural cellulose includes wood cellulose and / or cotton cellulose; and the artificial cellulose includes viscose cellulose and / or expanded cellulose.

[0029] Preferably, the adhesive is a mixture of component A and component B.

[0030] Preferably, the component A is selected from any one or more of anhydrous ethanol, glycerol, ethylene glycol or ethyl acetate.

[0031] Preferably, the component B is selected from thermosetting resins.

[0032] Preferably, the mass ratio of component A to component B is (1-10):1.

[0033] Preferably, the steps of obtaining the mixed slurry in step S3 are as follows: dispersing α-tocopherol-modified M-phase vanadium dioxide in an anhydrous ethanol solution, performing a first stirring to obtain a mixed solution with a concentration of 5 to 16 g / L; then dispersing cellulose in the mixed solution to obtain an initial slurry, wherein the concentration of cellulose in the mixed solution is 1 to 3 g / L, and simultaneously adding a binder, performing a second stirring to obtain a mixed slurry.

[0034] Preferably, the concentration of the mixed solution is 5 to 16 g / L.

[0035] Preferably, the concentration of the cellulose in the mixed solution is 1 to 3 g / L.

[0036] Preferably, the mass ratio of the adhesive to the initial slurry is (0.5-3):1.

[0037] Preferably, the speeds of the first stirring and the second stirring are independently 500-800 r / min.

[0038] Preferably, the first stirring time is 10 to 30 minutes.

[0039] Preferably, the second stirring time is 20 to 60 minutes.

[0040] Preferably, after the second stirring is completed, ultrasonic treatment is further included, and the time of the ultrasonic treatment is 40 to 120 minutes.

[0041] Preferably, the cellulose is subjected to a washing pretreatment.

[0042] Preferably, the washing pretreatment is: dispersing the cellulose in anhydrous ethanol and deionized water and performing centrifugal washing for 2 to 5 times.

[0043] In a second aspect, the present invention provides a super-hydrophobic functionalized vanadium dioxide film prepared by the above-mentioned preparation method, wherein the static contact angle of the super-hydrophobic functionalized vanadium dioxide film is greater than 150°. In a third aspect, the present invention also provides an application of the above-mentioned super-hydrophobic functionalized vanadium dioxide film in the exterior surface of a building, automobile glass or intelligent temperature control window.

[0044] Compared with the prior art, the present invention has the following beneficial effects:

[0045] The present invention provides a super-hydrophobic functionalized vanadium dioxide film, the preparation raw materials of which include: cellulose and α-tocopherol-modified M-phase vanadium dioxide. 2 Surface treatment can effectively improve VO 2 At the same time, α-tocopherol is not sensitive to heat and has strong acid resistance, so it does not affect the oxidizability of its particles when facing a huge temperature change, and can also increase VO 2 Acid resistance, thereby improving the stability of particles in film-forming agents (i.e., binders). In addition, cellulose, as a ring-shaped micro-nanostructured material, due to its small scale effect and good toughness, can be interspersed in the surface layer of the substrate in the manner of sowing and transplanting after being mixed with α-tocopherol-modified M-phase vanadium dioxide, optional binders and other raw materials and spread on the substrate by physical means, such as Figure 1 As shown in the figure, this interlaced pattern can ensure that the α-tocopherol modified M-phase vanadium dioxide particles on the substrate plane will not shift, and a large number of cellulose and α-tocopherol modified M-phase vanadium dioxide particles can provide sufficient roughness to the coating, thereby achieving super hydrophobicity on the substrate surface. Furthermore, this cellulose / α-tocopherol modified M-phase vanadium dioxide mixture interlaced structure makes the film more firmly on the substrate surface through organic agents such as adhesives, forming a firm transplanting structure on the substrate surface, with ultra-high mechanical stability.

[0046] After testing, the surface static contact angle of the super hydrophobic functionalized vanadium dioxide film provided by the present invention is 150°~170°, with super hydrophobic performance and certain self-cleaning function, low temperature visible light transmittance is 65~75%, high temperature visible light transmittance is 65~70%, and sunlight regulation efficiency is 16~18%. After aging at high temperature and high humidity for 240h, the static contact angle of the film surface is 150°~160°, the low temperature visible light transmittance is 70~75%, the high temperature visible light transmittance is 70~75%, and the sunlight regulation efficiency is 14~15.5%. It can be seen that the super hydrophobic functionalized vanadium dioxide film has stronger environmental adaptability and is expected to obtain a higher service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1A side view of a super-hydrophobic functionalized vanadium dioxide film on a substrate in the present invention;

[0048] Among them, 1 is a functionalized vanadium dioxide powder (i.e., α-tocopherol-VO 2 powder), 2 is cellulose, and 3 is substrate;

[0049] Figure 2 is a schematic diagram of the functionalized vanadium dioxide powder of the present invention;

[0050] Among them, 1.1 is VO 2 Kernel, 1.2 is in VO 2 Surface modified α-tocopherol. DETAILED DESCRIPTION

[0051] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0052] VO 2 The stability is poor, and the particles are easy to agglomerate in organic media, resulting in VO 2 The film has poor uniformity. The existing element doping process and inorganic shell coating process can solve some problems, but it will affect the visible light transmittance and sunlight regulation ability. 2 The film has poor water resistance and cannot meet the requirements of long-term outdoor use of the coating. At the same time, the reaction solution and the inevitable acid contact during the subsequent acid rain will corrode the VO to a certain extent. 2 Therefore, the present invention aims to prepare a functionalized vanadium dioxide film with super hydrophobicity, enhance its self-cleaning performance, improve its stability, weather resistance and optical properties, and enhance the super hydrophobicity, performance and service life of the film in the later application of the film to various glass products and building surfaces.

[0053] Based on this, the present invention provides a method for preparing a super-hydrophobic functionalized vanadium dioxide film, comprising the following steps:

[0054] S1: mixing an aqueous solution of a vanadium source with a precipitant, heating the mixture under boiling conditions to form a suspension with a precipitate, filtering the mixture to obtain a vanadium dioxide precursor, and calcining the mixture to obtain M-phase vanadium dioxide nanoparticles;

[0055] S2: mixing and reacting M-phase vanadium dioxide nanoparticles and α-tocopherol in the presence of a solvent to obtain α-tocopherol-modified M-phase vanadium dioxide;

[0056] S3: Mixing α-tocopherol-modified M-phase vanadium dioxide, cellulose, an optional binder and a solvent to obtain a mixed slurry, and preparing a film to obtain a super-hydrophobic functionalized vanadium dioxide film.

[0057] According to the present invention, firstly, M-phase vanadium dioxide nanoparticles are provided, wherein the M-phase vanadium dioxide has phase change properties, which is beneficial to its subsequent application.

[0058] In some embodiments of the present invention, the preparation of M-phase vanadium dioxide nanoparticles comprises the following steps:

[0059] The aqueous solution of the vanadium source is mixed with the precipitant, and then heated in a boiling state to form a suspension with a precipitate, which is then filtered to obtain a vanadium dioxide precursor, and then calcined to obtain M-phase vanadium dioxide nanoparticles.

[0060] In the present invention, the vanadium source can be selected from vanadyl sulfate (or other tetravalent vanadium compounds). Vanadyl sulfate is preferably used in the present invention because of its good stability and easy storage and purchase. In the present invention, the concentration of the aqueous solution of the vanadium source is 0.5 to 2M, preferably 0.8 to 1.5M.

[0061] The purpose of the precipitant is to make the vanadium exist in a solid form, and the precipitant can be selected from any one or more of urea, ammonia water or sodium hydroxide.

[0062] In the present invention, the molar ratio of the precipitant to the vanadyl sulfate is (2-10):1, preferably (3-5):1.

[0063] The heating temperature under the boiling state is 100° C., the time is 1 to 3 hours, preferably 1.5 to 2.5 hours. The calcination is vacuum calcination, the calcination temperature is 500 to 700° C., preferably 550 to 650° C., and the time is 1 to 4 hours, preferably 2 to 3 hours.

[0064] In some preferred embodiments of the present invention, the filtration further includes washing and drying steps; the washing is carried out using anhydrous ethanol or deionized water; the drying is vacuum drying, the drying temperature is 35 to 60°C, preferably 40 to 55°C; the drying time is 48 to 96h, preferably 60 to 72h.

[0065] Illustratively, in some embodiments of the present invention, the M-phase vanadium dioxide is prepared according to the following method:

[0066] A certain amount of vanadium source is dispersed in a certain amount of deionized water, and the molar mass is controlled at 0.5-2M, preferably 0.8-1.5M; then a certain amount of precipitant is added, and the molar ratio of the precipitant to the vanadium sulfate is 2:1-10:1, preferably 3:1-5:1; then the suspension is heated in a water bath (100°C) and stirred for 1-3 hours under a boiling state to form a suspension with a precipitate, and the solid is taken by suction filtration, and repeatedly washed with anhydrous ethanol and deionized water, and vacuum dried (35-60°C) to obtain a vanadium dioxide precursor. Then the vanadium dioxide precursor is placed in a vacuum tube furnace and calcined for 1-4 hours, preferably 2-3 hours, and the calcination temperature is 500-700°C, preferably 550-650°C, to obtain M-phase vanadium dioxide nanoparticles.

[0067] Then, according to the present invention, the M-phase vanadium dioxide nanoparticles and α-tocopherol are mixed and reacted in the presence of a solvent to obtain α-tocopherol-modified M-phase vanadium dioxide.

[0068] In the present invention, in order to avoid the influence on the substance, the solvent is preferably selected from anhydrous ethanol.

[0069] In some embodiments of the present invention, preferably, M-phase vanadium dioxide nanoparticles are dispersed in a certain volume of anhydrous ethanol to form a suspension having a mass fraction of 6 to 12 wt%, to which 1 to 3% of the mass of the suspension is added α-tocopherol and mixed and reacted at room temperature (10 to 30° C.) for 0.5 to 2 hours, preferably at 15 to 25° C. for 0.8 to 1.5 hours, to obtain α-tocopherol-modified M-phase vanadium dioxide. The mixing and reaction are preferably carried out under stirring conditions.

[0070] In some preferred embodiments of the present invention, in order to make the product after the reaction dispersed uniformly, it is preferred that the reaction be subjected to ultrasonic treatment for 10 to 60 minutes, preferably 20 to 40 minutes. After the ultrasonic treatment, the obtained product is centrifuged and washed with anhydrous ethanol and deionized water. After the washing, the product is dried in a vacuum drying oven at 40 to 60° C. for 4 to 20 hours, preferably at 45 to 55° C. for 5 to 15 hours, to obtain α-tocopherol-modified M-phase vanadium dioxide (abbreviated as “α-tocopherol-VO 2 ”), which is in the form of powder.

[0071] In the present invention, α-tocopherol is a light yellow mucus, and α-tocopherol is used to 2 Surface treatment can effectively improve VO 2 At the same time, α-tocopherol is not sensitive to heat and has strong acid resistance, so it does not affect the oxidizability of its particles when facing a huge temperature change, and can also increase VO 2 Acid resistance, thus improving the stability of particles in film-forming agents.

[0072] Obtain α-tocopherol-VO 2 After the powder, according to the present invention, α-tocopherol-VO 2 The powder, cellulose, an optional binder and a solvent are mixed to obtain a mixed slurry.

[0073] In the present invention, the solvent is selected from any one or more of anhydrous ethanol, glycerol, ethylene glycol or ethyl acetate, preferably anhydrous ethanol.

[0074] In the present invention, the cellulose includes natural cellulose and / or artificial cellulose; the natural cellulose includes wood cellulose and / or cotton cellulose; the artificial cellulose includes viscose cellulose and / or expanded cellulose. Since the particle size of cellulose has an effect on the formation of the film, if the particle size is too large, it is difficult to form a film. Therefore, the present invention preferably has a particle size of 50nm to 1μm, preferably 100 to 800nm, and more preferably 300 to 500nm.

[0075] It should be noted that in order to ensure that cellulose and α-tocopherol-modified M-phase vanadium dioxide are mixed and dispersed uniformly, and in order to be easier to form a film, a super-hydrophobic functionalized vanadium dioxide film with excellent stability is obtained. In some preferred embodiments of the present invention, an adhesive is introduced into the system of α-tocopherol-modified M-phase vanadium dioxide and cellulose. The adhesive is a mixture of component A and component B, which is an organic adhesive. Among them, the component A is selected from any one or more of anhydrous ethanol, glycerol, ethylene glycol or ethyl acetate, which is used to promote the uniform fusion of each component; the component B is selected from a thermosetting resin, and can be specifically selected from any one or more of epoxy resin, phenolic resin or polyimide resin, and its function is to adjust the product into a later curable colloid, which is convenient for later coating. In some embodiments of the present invention, the mass ratio of component A and component B is (1 to 10): 1, preferably (2 to 8): 1, and more preferably (3 to 5): 1.

[0076] In some embodiments of the present invention, the steps of obtaining the mixed slurry in step S3 are as follows: dispersing the α-tocopherol-modified M-phase vanadium dioxide in an anhydrous ethanol solution, performing a first stirring to obtain a mixed solution; then dispersing cellulose in the mixed solution to obtain an initial slurry, and adding a binder at the same time, performing a second stirring to obtain a mixed slurry. In some preferred embodiments of the present invention, the cellulose is subjected to a washing pretreatment; the washing pretreatment is: dispersing the cellulose in anhydrous ethanol and deionized water and performing centrifugal washing for 2 to 5 times.

[0077] Among them, the concentration of the mixed solution is 5-16 g / L, preferably 6-10 g / L; the concentration of the cellulose in the mixed solution is 1-3 g / L, preferably 1.5-2.5 g / L; the mass ratio of the adhesive to the initial pulp is (0.5-3):1, preferably (1-2):1.

[0078] In the present invention, the speeds of the first stirring and the second stirring are independently 500-800 r / min, preferably 600-700 r / min; the time of the first stirring is 10-30 min, preferably 15-25 min; the time of the second stirring is 20-60 min, preferably 30-40 min.

[0079] In some embodiments of the present invention, after the second stirring is completed, ultrasonic treatment is further included, and the time of the ultrasonic treatment is 40 to 120 minutes, preferably 50 to 100 minutes. In the present invention, the power of the ultrasonic treatment is generally 40 to 70W, preferably 60W, and the frequency is 30 to 60kHz, preferably 40 to 50kHz.

[0080] It should be noted that cellulose has a small scale effect and good toughness. 2 After the powder, adhesive and other raw materials are mixed and spread on the substrate by physical means, cellulose is interspersed in the surface layer of the substrate in the manner of sowing and transplanting. This interspersing mode can ensure that the α-tocopherol modified vanadium dioxide particles will not shift on the substrate plane. A large amount of cellulose and α-tocopherol modified vanadium dioxide particles can provide sufficient roughness for the coating, thereby achieving super hydrophobicity on the substrate surface. At the same time, it will not affect the original transmittance of the film, and can extend the service life of the film in the later application of various glass products and building surfaces.

[0081] In some more specific embodiments of the present invention, cellulose is preferably dispersed in anhydrous ethanol and deionized water and centrifuged for 2 to 5 times to remove surface impurities to obtain clean cellulose. 2 The powder is dispersed in anhydrous ethanol solution to prepare α-tocopherol-VO with a concentration of 5-16 g / L. 2 The ethanol mixed solution was stirred rapidly at 500-800 r / min. Then the washed cellulose was dispersed in α-tocopherol-VO 2 An ethanol mixed solution, wherein the concentration of cellulose in the mixed solution is 1 to 3 g / L. At the same time, a binder is added, and the binder and the slurry (i.e., cellulose and α-tocopherol-VO 2The mixture of α-tocopherol and ethanol mixed solution has a mass ratio of 0.5:1 to 3:1, and after stirring in a stirrer for 20 to 60 minutes, it is dispersed in an ultrasonic crusher for 40 to 120 minutes to obtain a mixed slurry, that is, α-tocopherol-VO 2 - Cellulose pulp.

[0082] Obtain α-tocopherol-VO 2 After the cellulose pulp is prepared, a super-hydrophobic functionalized vanadium dioxide thin film is obtained by film-forming according to the present invention. The present invention has no particular limitation on the film-forming method, which can be carried out according to methods well known to those skilled in the art.

[0083] In some embodiments of the present invention, a certain amount of uniformly stirred α-tocopherol-VO 2 - The cellulose slurry is placed on a glass substrate, and is evenly spin-coated onto the glass substrate under the action of centrifugation, and dried at room temperature (10-30° C., preferably 15-25° C.) for 15-80 min, preferably 30-50 min.

[0084] Alternatively, α-tocopherol-VO 2 - Cellulose pulp is placed in a magnetron sputtering or electrostatic spinning machine to prepare a vanadium dioxide film on a substrate glass. The magnetron sputtering and electrostatic spinning processes can be carried out according to methods well known to those skilled in the art.

[0085] The preparation method provided by the present invention is simple, convenient, easy to implement, and conducive to industrial or industrialized production.

[0086] In the present invention, the super-hydrophobic functionalized vanadium dioxide film obtained by the above preparation method is an intelligent temperature film material with an autonomous regulation function of infrared radiation changing with temperature, which can be applied to scenes such as building exterior surfaces, glass surfaces, and car rearview mirrors, and can effectively solve the problem of single VO 2 The coating material is easily oxidized and has poor weather resistance stability, which makes it difficult to meet the performance requirements of the intelligent temperature control film. In order to increase its super-hydrophobic properties, extend its later service life and expand its usage scenarios.

[0087] Further, after testing, the surface static contact angle of the super-hydrophobic functionalized vanadium dioxide film prepared by the above-mentioned preparation method of the present invention is 150°~170°, with super-hydrophobic performance and certain self-cleaning function, low-temperature visible light transmittance is 65~75%, high-temperature visible light transmittance is 65~70%, and sunlight regulation efficiency is 16~18%. After aging at high temperature and high humidity for 240h, the static contact angle of the film surface is 150°~160°, the low-temperature visible light transmittance is 70~75%, the high-temperature visible light transmittance is 70~75%, and the sunlight regulation efficiency is 14~15.5%. It can be seen that the super-hydrophobic functionalized vanadium dioxide film has stronger environmental adaptability and is expected to obtain a longer service life.

[0088] In summary, the super-hydrophobic functionalized vanadium dioxide film provided by the present invention has better stability, super-hydrophobicity, and more environmental applicability than traditional vanadium dioxide films.

[0089] Based on this, the present invention provides an application of a super-hydrophobic functionalized vanadium dioxide film in building exterior surfaces, automobile glass or intelligent temperature-controlled windows.

[0090] In order to further illustrate the present invention, the following examples are provided for detailed description. The experimental raw materials used in the following examples of the present invention are all common commercially available products.

[0091] Example 1

[0092] Step 1:

[0093] A certain amount of vanadium sulfate powder was dispersed in a certain amount of deionized water with a molar concentration of 1M, and then a certain amount of precipitant urea was added, with a molar ratio of precipitant to vanadium sulfate of 4:1, and then heated in a water bath (100°C) and stirred for 2h under boiling state to form a suspension with precipitation, and the solid was taken by suction filtration, and washed repeatedly twice with anhydrous ethanol and deionized water, and vacuum dried (50°C) for 12h to obtain vanadium dioxide precursor A. Precursor A was then placed in a vacuum tube furnace and calcined for 3h at a calcination temperature of 500°C to obtain M-phase vanadium dioxide nanoparticles B.

[0094] Step 2:

[0095] The M-phase vanadium dioxide B was dispersed in a certain volume of anhydrous ethanol to prepare a suspension with a mass fraction of 10%. α-tocopherol (2% by mass of the suspension) was added thereto and stirred for 1 hour at room temperature (20°C) and ultrasonicated for 15 minutes. Then, the product α-tocopherol-VO was obtained after centrifugation washing twice with anhydrous ethanol and deionized water and drying at 50°C in a vacuum drying oven for 8 hours. 2 Powder C.

[0096] Step 3:

[0097] First, lignocellulose was dispersed in anhydrous ethanol and deionized water and centrifuged twice to remove surface impurities; then α-tocopherol-VO 2 Nanoparticles C were dispersed in anhydrous ethanol solution to prepare α-tocopherol-VO 2 The ethanol mixed solution concentration was 8 g / L and stirred rapidly at 600 r / min. The washed cellulose was then dispersed in α-tocopherol-VO 2 An ethanol mixed solution, wherein the concentration of cellulose in the mixed solution is 1.5 g / L, and an organic binder (ethyl acetate: phenolic resin = 6:1, mass ratio) is added at the same time, and the mass ratio of the binder to the original slurry is 0.5:1. After stirring in a blender for 30 minutes, the mixture is dispersed in an ultrasonic crusher for 60 minutes to obtain α-tocopherol-VO2-cellulose slurry D.

[0098] Step 4:

[0099] Take a certain amount of α-tocopherol-VO 2 -Cellulose slurry D is placed on a glass substrate, and is evenly spin-coated onto the glass substrate under the action of centrifugation, and dried at room temperature for 15 minutes to obtain a super-hydrophobic functionalized vanadium dioxide film E.

[0100] To detect the E effect of superhydrophobic functionalized vanadium dioxide film, relevant performance tests are required.

[0101] The test results are as follows: The static contact angle of the surface of the super-hydrophobic functionalized vanadium dioxide film E is 155°, indicating that it has super-hydrophobic properties and a certain self-cleaning function, the low-temperature visible light transmittance is 68%, the high-temperature visible light transmittance is 65%, and the sunlight regulation efficiency is 17.1%. After aging at high temperature and high humidity for 240 hours, the static contact angle of the surface of the super-hydrophobic functionalized vanadium dioxide film E is still 150°, the low-temperature visible light transmittance is 72%, the high-temperature visible light transmittance is 70%, and the sunlight regulation efficiency is 15.2%.

[0102] Example 2

[0103] Step 1:

[0104] A certain amount of vanadium sulfate powder was dispersed in a certain amount of deionized water with a molar concentration of 1.5M, and then a certain amount of precipitant ammonia water was added, with a molar ratio of precipitant ammonia water to vanadium sulfate of 6:1, and then heated in a water bath (100°C) and stirred for 1h under boiling state to form a suspension with precipitation, and the solid was taken by suction filtration, and washed repeatedly with anhydrous ethanol and deionized water twice, and vacuum dried (60°C) for 14h to obtain vanadium dioxide precursor A. Precursor A was then placed in a vacuum tube furnace and calcined for 2h at a calcination temperature of 550°C to obtain M-phase vanadium dioxide nanoparticles B.

[0105] Step 2:

[0106] The M-phase vanadium dioxide B was dispersed in a certain volume of anhydrous ethanol to prepare a suspension with a mass fraction of 8%. α-tocopherol of 1.5% of the mass of the suspension was added thereto and stirred for 1.5 hours at room temperature (20°C) and ultrasonicated for 20 minutes. Then, the product α-tocopherol-VO was obtained after centrifugation washing twice with anhydrous ethanol and deionized water and drying at 60°C in a vacuum drying oven for 12 hours. 2 Powder C.

[0107] Step 3:

[0108] First, the swollen cellulose was dispersed in anhydrous ethanol and deionized water and centrifuged twice to remove surface impurities; then α-tocopherol-VO 2 Nanoparticles C were dispersed in anhydrous ethanol solution to prepare α-tocopherol-VO 2 The ethanol mixed solution, with a concentration of 10 g / L, was rapidly stirred at 500 r / min; then the washed cellulose was dispersed in α-tocopherol-VO 2 An ethanol mixed solution, wherein the concentration of cellulose in the mixed solution is 2 g / L, and an organic binder (ethylene glycol + ethyl acetate (mass ratio, 1:1): polyimide resin = 8:1, mass ratio) is added at the same time, the ratio of the binder to the original slurry is 2:1, and the mixture is stirred in a blender for 40 minutes and then dispersed in an ultrasonic crusher for 40 minutes, thereby obtaining α-tocopherol-VO 2 - Cellulose pulp D.

[0109] Step 4:

[0110] Take a certain amount of α-tocopherol-VO 2 -Cellulose slurry D is placed on a glass substrate, and is evenly spin-coated onto the glass substrate under the action of centrifugation, and dried at room temperature for 40 minutes to obtain a super-hydrophobic functionalized vanadium dioxide film E.

[0111] With reference to Example 1, relevant performance tests were performed on the obtained super-hydrophobic functionalized vanadium dioxide film E.

[0112] The results are as follows: The static contact angle of the surface of the super-hydrophobic functionalized vanadium dioxide film E is 160°, which has super-hydrophobic properties and certain self-cleaning functions, the low-temperature visible light transmittance is 71%, the high-temperature visible light transmittance is 68%, and the sunlight regulation efficiency is 16.2%. After aging at high temperature and high humidity for 240 hours, the static contact angle of the surface of the super-hydrophobic functionalized vanadium dioxide film E is still 152°, the low-temperature visible light transmittance is 74%, the high-temperature visible light transmittance is 71%, and the sunlight regulation efficiency is 14.8%.

[0113] Example 3

[0114] Step 1:

[0115] A certain amount of vanadium sulfate powder is dispersed in a certain amount of deionized water with a molar concentration of 0.5M, and then a certain amount of precipitant sodium hydroxide is added dropwise, with a molar ratio of precipitant sodium hydroxide to vanadium sulfate of 2:1, and then heated in a water bath (100°C) and stirred for 1h under boiling state to form a suspension with precipitation, and the solid is taken by suction filtration, and washed repeatedly twice with anhydrous ethanol and deionized water, and vacuum dried (45°C) for 10h to obtain vanadium dioxide precursor A. Precursor A is then placed in a vacuum tube furnace and calcined for 1h at a calcination temperature of 600°C to obtain M-phase vanadium dioxide nanoparticles B.

[0116] Step 2:

[0117] The M-phase vanadium dioxide B was dispersed in a certain volume of anhydrous ethanol to prepare a suspension with a mass fraction of 8%, and 1% of the mass of the suspension was added to it and stirred for 2 hours at room temperature (20°C) and ultrasonicated for 20 minutes. Then, it was centrifuged and washed twice with anhydrous ethanol and deionized water, and dried in a vacuum drying oven at 60°C for 14 hours to obtain the product α-tocopherol-VO 2 Powder C.

[0118] Step 3:

[0119] First, the swollen cellulose was dispersed in anhydrous ethanol and deionized water and centrifuged three times to remove surface impurities; then, α-tocopherol-VO 2 Nanoparticles C were dispersed in anhydrous ethanol solution to prepare α-tocopherol-VO 2 The ethanol mixed solution concentration was 12 g / L and stirred rapidly at 600 r / min. The washed cellulose was then dispersed in α-tocopherol-VO 2 An ethanol mixed solution, wherein the concentration of cellulose in the mixed solution is 1.5 g / L, and an organic binder (ethylene glycol: epoxy resin = 5:1, mass ratio) is added, and the ratio of the binder to the original slurry is 1.5:1. After stirring in a blender for 30 minutes, the mixture is dispersed in an ultrasonic crusher for 40 minutes to obtain α-tocopherol-VO 2 - Cellulose pulp D.

[0120] Step 4:

[0121] Take a certain amount of α-tocopherol-VO 2 -Cellulose slurry D is placed on a glass substrate, and is evenly spin-coated onto the glass substrate under the action of centrifugation, and dried at room temperature for 60 minutes to obtain a super-hydrophobic functionalized vanadium dioxide film E.

[0122] With reference to Example 1, relevant performance tests were performed on the obtained super-hydrophobic functionalized vanadium dioxide film E.

[0123] The results are as follows: The static contact angle of the surface of the super-hydrophobic functionalized vanadium dioxide film E is 162°, which has super-hydrophobic properties and certain self-cleaning functions, the low-temperature visible light transmittance is 72%, the high-temperature visible light transmittance is 67%, and the sunlight regulation efficiency is 17.5%. After aging at high temperature and high humidity for 240 hours, the static contact angle of the surface of the super-hydrophobic functionalized vanadium dioxide film E is still 157°, the low-temperature visible light transmittance is 76%, the high-temperature visible light transmittance is 72%, and the sunlight regulation efficiency is 14.6%.

[0124] Schematically, in the present invention, the side view of the super-hydrophobic functionalized vanadium dioxide film obtained in the above embodiment on the substrate (ie, the base glass in the corresponding embodiment) is as shown in FIG. Figure 1 As shown. Among them, 1 is a functionalized vanadium dioxide powder (α-tocopherol-VI 2 1 is cellulose, and 2 is a substrate.

[0125] Functionalized vanadium dioxide powder (α-tocopherol-VO 2 The schematic diagram of powder is as follows Figure 2 As shown. Among them, 1.1 is VO 2 Kernel, 1.2 is in VO 2 Surface modified α-tocopherol. Note that Figure 2 This is only a schematic diagram. The α-tocopherol shown in the figure does not represent the actual number of grafted functional groups of α-tocopherol.

[0126] Comparative Example 1

[0127] Step 1:

[0128] Take a certain amount of vanadium sulfate powder and disperse it in a certain amount of deionized water with a molar concentration of 0.8M, then add a certain amount of precipitant sodium hydroxide, the molar ratio of precipitant sodium hydroxide to vanadium sulfate is 3:1, then heat in a water bath (100°C) and stir for 1h under boiling state to form a suspension with precipitation, take the solid by suction filtration, wash it repeatedly with anhydrous ethanol and deionized water twice, and vacuum dry it (45°C) for 10h to obtain a vanadium dioxide precursor. Then, the precursor A is placed in a vacuum tube furnace and calcined for 1h at a calcination temperature of 600°C to obtain M-phase vanadium dioxide nanoparticles.

[0129] Step 2: Disperse the M-phase vanadium dioxide nanoparticles in anhydrous ethanol solution to prepare VO 2 The ethanol mixed solution concentration was 12 g / L, and it was rapidly stirred at 600 r / min. Then an organic binder (ethylene glycol: epoxy resin = 5:1, mass ratio) was added, and the ratio of the binder to the original slurry was 1.5:1. After stirring in a blender for 30 min, it was dispersed in an ultrasonic crusher for 40 min to obtain VO 2 Slurry.

[0130] Step 3:

[0131] Take a certain amount of VO 2 The slurry was placed on a glass substrate, and was evenly spin-coated onto the glass substrate under the action of centrifugation. The slurry was dried at room temperature for 60 minutes to obtain a vanadium dioxide film E.

[0132] With reference to Example 1, relevant performance tests were performed on the obtained super-hydrophobic functionalized vanadium dioxide film E.

[0133] The results are as follows: the static contact angle of the surface of the unmodified vanadium dioxide film E is 120°, the hydrophobicity decreases, the low-temperature visible light transmittance is 78%, the high-temperature visible light transmittance is 65%, and the sunlight regulation efficiency is 12.5%. After aging at high temperature and high humidity for 240 hours, the static contact angle of the surface of the vanadium dioxide film E is about 110°, the low-temperature visible light transmittance is 80%, the high-temperature visible light transmittance is 68%, and the sunlight regulation efficiency is 11.2%. It can be seen that the overall performance of the comparative example is far worse than that of the embodiment and does not have super hydrophobic properties.

[0134] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing a super-hydrophobic functionalized vanadium dioxide film, characterized in that: The following steps are involved: S1: After mixing the aqueous solution of the vanadium source and the precipitant, heating them under boiling conditions to form a suspension with a precipitate, filtering to obtain a vanadium dioxide precursor, and calcining to obtain M-phase vanadium dioxide nanoparticles; S2: mixing and reacting M-phase vanadium dioxide nanoparticles and α-tocopherol in the presence of a solvent to obtain α-tocopherol-modified M-phase vanadium dioxide; S3: Mixing α-tocopherol-modified M-phase vanadium dioxide, cellulose, an optional binder and a solvent to obtain a mixed slurry, and preparing a film to obtain a super-hydrophobic functionalized vanadium dioxide film.

2. The preparation method according to claim 1, characterized in that: The precipitant is selected from any one or more of urea, ammonia water or sodium hydroxide; The concentration of the aqueous solution of the vanadium source is 0.5 to 2 M; The vanadium source is selected from vanadyl sulfate; The molar ratio of the precipitant to the vanadium source is (2-10):

1.

3. The preparation method according to claim 1 or 2, characterized in that: The heating temperature under the boiling state is 100° C. and the heating time is 1 to 3 hours; The calcination is vacuum calcination, the calcination temperature is 500-700° C., and the calcination time is 1-4 hours.

4. The preparation method according to any one of claims 1 to 3, characterized in that The filtration also includes washing and drying steps; The washing is carried out using anhydrous ethanol or deionized water; The drying is vacuum drying, the drying temperature is 35-60° C., and the drying time is 48-96 hours.

5. The preparation method according to any one of claims 1 to 4, characterized in that: The solvent in step S2 is selected from anhydrous ethanol; Step S2 is: dispersing M-phase vanadium dioxide nanoparticles in a solvent to obtain a 6-12 wt% suspension, and then adding 1-3 wt% of α-tocopherol to the suspension to react and obtain α-tocopherol-modified M-phase vanadium dioxide.

6. The preparation method according to any one of claims 1 to 5, characterized in that The reaction temperature in step S2 is 10-30°C and the reaction time is 0.5-2h; The reaction is carried out under stirring conditions; After the reaction is completed, the steps of ultrasonication, washing and drying are also included; The ultrasonic time is 10 to 60 minutes; The washing is carried out using anhydrous ethanol or deionized water; The drying is vacuum drying, the drying temperature is 40-60° C., and the drying time is 4-20 hours.

7. The preparation method according to any one of claims 1 to 6, characterized in that: The cellulose includes natural cellulose and / or artificial cellulose; the particle size of the cellulose is 50nm to 1μm; The natural cellulose includes wood cellulose and / or cotton cellulose; the artificial cellulose includes viscose cellulose and / or expanded cellulose; The adhesive is a mixture of component A and component B; The component A is selected from any one or more of anhydrous ethanol, glycerol, ethylene glycol or ethyl acetate; The component B is selected from thermosetting resins; The mass ratio of component A to component B is (1-10):

1.

8. The preparation method according to any one of claims 1 to 7, characterized in that The steps of obtaining the mixed slurry in step S3 are as follows: dispersing the α-tocopherol-modified M-phase vanadium dioxide in an anhydrous ethanol solution, performing a first stirring to obtain a mixed solution; then dispersing cellulose in the mixed solution to obtain an initial slurry, and adding a binder at the same time, performing a second stirring to obtain a mixed slurry.

9. The preparation method according to claim 8, characterized in that: The concentration of the mixed solution is 5 to 16 g / L; The concentration of the cellulose in the mixed solution is 1 to 3 g / L; The mass ratio of the adhesive to the initial slurry is (0.5-3):

1.

10. The preparation method according to claim 8 or 9, characterized in that: The speeds of the first stirring and the second stirring are independently 500 to 800 r / min; The first stirring time is 10 to 30 minutes; The second stirring time is 20 to 60 minutes; After the second stirring is completed, ultrasonic treatment is also included, and the time of the ultrasonic treatment is 40 to 120 minutes.

11. The preparation method according to any one of claims 1 to 10, characterized in that: The cellulose is subjected to washing pretreatment; The washing pretreatment is as follows: dispersing the cellulose in anhydrous ethanol and deionized water and performing centrifugal washing for 2 to 5 times.

12. The super-hydrophobic functionalized vanadium dioxide film prepared by the preparation method according to any one of claims 1 to 11, characterized in that: The static contact angle of the super-hydrophobic functionalized vanadium dioxide film is greater than 150°.

13. Use of a super-hydrophobic functionalized vanadium dioxide film prepared by the preparation method according to any one of claims 1 to 11 or a super-hydrophobic functionalized vanadium dioxide film according to claim 12 in building exterior surfaces, automobile glass or intelligent temperature-controlled windows.

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