阅读说明：本技术 无机片状材料及其制备方法 (Inorganic sheet material and method for producing same ) 是由 柳继成 穆彬 张海滨 郭永城 龚昌港 霍海元 李善云 温正助 郑洁 孔令利 于 2020-11-20 设计创作，主要内容包括：无机片状材料及其制备方法。所述无机片状材料的制备方法包括：在表面具有周期性排列微结构的模板上,涂覆无机片状材料前驱体溶液,所述微结构具有光子晶体结构性质；去除所述无机片状材料前驱体溶液的溶剂,得到无机片状材料涂层；将所述无机片状材料涂层从所述模板上剥离下来,得到所述无机片状材料。所述制备方法所制备的无机片状材料具有结构性颜色。(Inorganic sheet material and a method for preparing the same. The preparation method of the inorganic sheet material comprises the following steps: coating an inorganic flaky material precursor solution on a template with a periodically arranged microstructure on the surface, wherein the microstructure has the property of a photonic crystal structure; removing the solvent of the inorganic flaky material precursor solution to obtain an inorganic flaky material coating; and peeling the inorganic sheet material coating from the template to obtain the inorganic sheet material. The inorganic flaky material prepared by the preparation method has structural color.)

1. A method of making an inorganic sheet material, comprising:

coating an inorganic flaky material precursor solution on a template with a periodically arranged microstructure on the surface, wherein the microstructure has the property of a photonic crystal structure;

removing the solvent of the inorganic flaky material precursor solution to obtain an inorganic flaky material coating;

and peeling the inorganic sheet material coating from the template to obtain the inorganic sheet material.

2. The method of claim 1, wherein the template is a holographic laser film or a holographic laser metal plate.

3. The method of claim 1, wherein the microstructures have a size between 200nm and 1000nm, and wherein the photonic crystal structure property is a two-dimensional photonic crystal structure property.

4. The production method according to claim 1, wherein the inorganic flaky material precursor solution is a solution containing a metal oxide, a metal salt or a metal hydroxide; the precursor solution of the inorganic flaky material is aqueous solution or organic solution.

5. The method according to claim 1, wherein the inorganic sheet material precursor solution is one of the following solutions, or a mixed solution of two or more of the following solutions:

a silica precursor solution;

titanium dioxide precursor solution;

an aluminum oxide precursor solution;

zirconium dioxide precursor solution;

a tin dioxide precursor solution;

boron trioxide precursor solution;

indium oxide precursor solution;

a zinc oxide precursor solution;

ferric oxide precursor solution.

6. The method of claim 1, wherein the coating of inorganic sheet material is stripped from the template by scraping, rinsing, or sonication.

7. The method of claim 1, wherein prior to applying the inorganic sheet material precursor solution on the template, further comprising: and coating a stripping-assisting layer on the template.

8. The method of claim 7, wherein the peeling aid layer is a water-soluble polymer coating.

9. The method according to claim 8, wherein the water-soluble polymer coating layer is a polyvinylpyrrolidone coating layer or a polyvinyl alcohol coating layer.

10. The method of claim 1, wherein the method is a continuous process, wherein: the template is a continuous substrate, and all parts of the template are sequentially and continuously coated with the inorganic flaky material precursor solution, removed with the solvent and stripped.

11. An inorganic sheet material, wherein the surface of the inorganic sheet material has a periodically arranged microstructure having photonic crystal structure properties.

12. The inorganic sheet material of claim 11, wherein the microstructures have a size between 200nm and 1000nm, the photonic crystal structural property is a two-dimensional photonic crystal structural property, and the inorganic sheet material has a particle size distribution between 5 μ ι η and 1000 μ ι η.

Technical Field

The invention belongs to the field of inorganic powder materials, and particularly relates to an inorganic flaky material and a preparation method thereof.

Background

In recent times, due to the discovery of unique properties of ultrafine powder, more and more attention has been paid to the preparation and application of ultrafine powder, and meanwhile, the requirements of people on the diversification, functionalization and refinement of the powder are increasingly improved. The shape of the powder directly influences the practical application performance of the powder. The flaky powder has good adhesive force, obvious shielding effect and capability of reflecting light due to the special plane structure. The flaky powder has excellent performance superior to other conventional powders in the fields of pigments, coatings, conductive paste and the like. Especially in the pearlescent pigment industry, flake powder is a base material of various pearlescent pigments, such as: natural mica, synthetic mica, glass flake, flaky alumina, flaky silica, flaky aluminum powder and the like.

However, the surfaces of the flaky powder are flat and smooth, so that the interference phenomenon of light cannot be generated when the incident light irradiates on the surface of the powder, and the color cannot be generated, but the surface of the flaky powder needs to be coated with oxides such as titanium dioxide or ferric oxide with different refractive indexes, and the interference phenomenon of the incident light at the boundary can be generated to display various colors.

Photonic crystals are formed by the ordered arrangement of periodic dielectric structures in two or three dimensions, and are called photonic crystals because the periodic dielectric materials on the scale of light waves have the capability of controlling light waves, which is very similar to the control of electrons by crystals. The photonic crystal has a wide range of applications, and on the one hand, can be used for miniaturization of microwave devices, improvement of light cycle efficiency, microchip formation of semiconductor electronics, magnetic effect and the like. On the other hand, by utilizing the property that the photonic crystal can reflect light waves, the structure of the photonic crystal can be designed to reflect light rays with corresponding wavelengths in a visible light range, and the photonic crystal shows gorgeous colors, does not need pigments or dyes when the colors are generated, has high reflectivity, never fades, is colors generated by the structure, and is called structural colors. In nature, there are many organisms whose colors are derived from photonic crystal structures, such as the scales on the wings of butterflies, which reflect gorgeous colors, not due to what pigments are on the scales, but due to their unique network-like cell wall structures, which are periodically arranged and ordered, forming typical photonic crystal structures. In addition, the color feathers of peacocks and parrots, the rainbow phenomenon of pigeon feathers and the like.

Disclosure of Invention

The problem to be solved by the present invention is to provide an inorganic sheet material having a structural color, and a method for producing the same.

In order to solve the above problems, the present invention provides a method for preparing an inorganic sheet material, comprising: coating an inorganic flaky material precursor solution on a template with a periodically arranged microstructure on the surface, wherein the microstructure has the property of a photonic crystal structure; removing the solvent of the inorganic flaky material precursor solution to obtain an inorganic flaky material coating; and stripping the inorganic flaky material coating from the template to obtain the inorganic flaky material.

Coating an inorganic flaky material precursor solution on a template with a periodically arranged microstructure on the surface, wherein the specific adopted method can be a coating method.

The preparation method has the beneficial effects that:

the preparation process does not need processes and equipment such as vacuum coating and the like, and has low production cost, low requirement on production conditions and high efficiency;

the prepared inorganic flaky material has good performance, the obtained inorganic flaky material (powder material) can be an inorganic flaky material (powder material) with a photonic crystal structure on the surface, light can generate interference phenomenon on the surface, and interference color can be generated, the inorganic flaky material is a structural color and has good angle-dependent color property, and the inorganic flaky material has excellent oxidation resistance and corrosion resistance and wide application range.

Optionally, the template is a holographic laser film or a holographic laser metal plate. The laser film can be a commercial holographic laser film or a commercial holographic laser metal plate. The holographic laser PET film is generally made of materials such as biaxially oriented polypropylene (BOPP), polyethylene terephthalate (PET), polyvinyl chloride (PVC), and the like, and is formed by generating a periodically arranged microstructure on the surface through a micro-imprinting technology. And the size of the microstructure on the surface of the template is selected to be between 200nm and 1000nm, so that the template has the typical two-dimensional photonic crystal structural property, has different diffraction angles under the irradiation of white light, can show gorgeous and colorful effects when being viewed at different angles, and provides a good template for the subsequent production of the structural color of the inorganic flaky material.

When the template is a thin metal plate having a surface with periodically arranged microstructures, further, the periodically arranged microstructures may be formed by laser etching or chemical etching, such as a stainless steel sheet.

Optionally, the inorganic sheet material precursor solution is a solution containing a metal oxide, a metal salt or a metal hydroxide; the precursor solution of the inorganic flaky material is aqueous solution or organic solution. The organic solution may further be an organic solution using a sol-gel method.

Optionally, the inorganic sheet material precursor solution is one of the following solutions, or a mixed solution of two or more of the following solutions: a silica precursor solution; titanium dioxide precursor solution; an aluminum oxide precursor solution; zirconium dioxide precursor solution; a tin dioxide precursor solution; boron trioxide precursor solution; indium oxide precursor solution; a zinc oxide precursor solution; ferric oxide precursor solution.

Alternatively, the method of removing the solvent may be a heating method. The heating may be performed by heating the template (film) or by baking the template as a whole, for example, by drying in an oven to volatilize the solvent.

Optionally, the inorganic sheet material coating is peeled off the template by scraping, rinsing or ultrasonic methods. The template with the inorganic flaky material coating may be soaked in water and then the inorganic flaky material coating (flaky oxide coating) is peeled off by scraping, rinsing or ultrasonic (vibration) methods.

Optionally, before the step of coating the inorganic sheet material precursor solution on the template, the method further includes: and coating a stripping-assisting layer on the template. The stripping-assisting layer is used for facilitating stripping of the inorganic flaky material coating.

Optionally, the peeling-assisting layer is a water-soluble polymer coating.

Optionally, the water-soluble polymer coating is a polyvinylpyrrolidone (PVP) coating or a polyvinyl alcohol (PVA) coating.

Optionally, the preparation method is a continuous production method, wherein: the template is a continuous substrate, and all parts of the template are sequentially and continuously coated with the inorganic flaky material precursor solution, removed with the solvent and stripped.

Optionally, after the inorganic sheet material coating is peeled off from the template to obtain the inorganic sheet material, the collected inorganic sheet material may be further filtered, washed and dried, or calcined.

The invention also provides an inorganic flaky material, wherein the surface of the inorganic flaky material is provided with a periodically arranged microstructure which has the property of a photonic crystal structure.

The inorganic flaky material provided by the invention has the beneficial effects that:

the light rays irradiate the surface of the inorganic flaky material, so that the interference phenomenon of the light rays can be generated among the periodically arranged microstructures, and the different sizes of the microstructures reflect various light rays with different specific wavelengths, thereby generating structural colors; along with the difference of incident light angles, the inorganic flaky material has different colors and good angle-dependent color variation performance;

the inorganic flaky material (powder material) has the advantages that the surface does not need to be further coated with other oxides like the traditional pearlescent pigment to generate the interference phenomenon of light (so as to generate color);

if the holographic laser template is used for preparation, the inorganic sheet material can also have the color effect of holographic laser under white light, and the selected oxide is high-temperature resistant, acid-base resistant and wide in applicability.

Optionally, the size of the microstructure is between 200nm and 1000nm, the photonic crystal structural property is a two-dimensional photonic crystal structural property, and the particle size distribution of the inorganic sheet material is between 5 μm and 1000 μm.

Optionally, the inorganic sheet material is one of the following inorganic materials, or the inorganic sheet material is a mixture of two or more of the following inorganic materials: silicon dioxide; titanium dioxide; aluminum oxide; zirconium dioxide; boron trioxide; tin dioxide; indium oxide; zinc oxide; ferric oxide.

Drawings

FIG. 1 is a scanning electron micrograph of an inorganic sheet material produced in example one;

FIG. 2 is a scanning electron micrograph of an inorganic platelet material produced in example one at another magnification.

Detailed Description

Therefore, the invention provides a novel inorganic flaky material and a preparation method thereof, provides a preparation method of an inorganic flaky material with a photonic crystal structure on the surface, and further, the inorganic flaky material can have a holographic laser effect.

For a more clear presentation, the invention is described in detail below with reference to the accompanying drawings.

EXAMPLE one preparation of a platy silica

Preparing a flaky silicon dioxide precursor solution:

diluting concentrated water glass solution (silica content 28%) with water to silica content of 10%, and passing the solution through chromatographic column filled with strong acid cation exchange resin (001 × 7 type, southern opening university chemical plant) to remove sodium ions to obtain silica sol; 100 g of the prepared silica sol was added with 0.2 g of wetting agent UNIQ FLOW 487U (Youka chemical Co., Ltd.), and subjected to ultrasonic dispersion treatment until the solution was clear for use.

Preparation of the flaky silica:

adopting a holographic laser PET film produced by Wenzhou Futwin company as a template, and scraping a layer of coating of the prepared silicon dioxide precursor solution on the holographic laser PET film by using a wet film preparation device, wherein the thickness of the wet film is 100 mu m; drying in an oven at 80 deg.C for 5 min to remove solvent; then washing the coating with a 3% hydrochloric acid solution to wash the flaky silica material off for peeling, and collecting in a beaker; after filtering and drying, the flaky silicon dioxide powder with obvious laser rainbow effect under white light is obtained.

The particle size distribution of the flaky silica is between 30 and 120 mu m, the thickness is 900nm, and the electron microscope scanning photographs can refer to fig. 1 and fig. 2. Meanwhile, the flaky silicon dioxide can see the effect similar to holographic laser under white light, and has the rainbow effect of color variation along with angles.

In the embodiment, a holographic laser film with periodically arranged microstructures on the surface is used as a template, the surface of the template is coated with a film, and the periodically arranged microstructures are transferred to an inorganic sheet material after the coating is dried. Compared with the prior vacuum coating method, the preparation method has the advantages of simple method, easily obtained equipment and raw materials and low cost.

The inorganic sheet material prepared by the embodiment has the characteristic of two-dimensional photonic crystals due to the periodically arranged microstructures on the surface, and can generate strong interference colors and holographic laser effects under the irradiation of white light.

The inorganic flaky material prepared by the embodiment shows a structural color, and the selected inorganic material is high-temperature resistant, acid-base resistant and stable in structure, and never fades as long as the periodically arranged microstructures are not damaged. Can be applied to the fields of paint, cosmetics, plastics, printing ink and the like, and has wide application range.

The inorganic flaky material prepared by the embodiment can be used as a base material of pearlescent pigment due to the surface of the inorganic flaky material with the periodically arranged microstructures, and the subsequent surface can be continuously coated with oxides such as titanium dioxide, ferric oxide and the like, or the surface can be plated with metal silver, so that a stronger holographic laser effect can be generated.

EXAMPLE two preparation of platy titanium dioxide

Preparing a flaky titanium dioxide precursor solution:

100 g of titanium tetrachloride aqueous solution with a concentration of 1.2 mol/l were added with 0.2 g of wetting agent UNIQ FLOW 487U (Youcai chemical Co., Ltd.) and subjected to ultrasonic dispersion treatment until the solution was clarified for use.

Preparation of flaky titanium dioxide:

adopting a holographic laser PET film produced by Wenzhou Futwin company as a template, and scraping a layer of coating of the prepared titanium dioxide precursor solution on the holographic laser PET film by using a wet film preparation device, wherein the thickness of the wet film is 50 mu m; drying in an oven at 80 deg.C for 5 min to remove solvent; then washing the coating with deionized water, washing the flaky titanium dioxide material, and collecting the flaky titanium dioxide material in a beaker; and (3) after filtering and drying, putting the titanium dioxide into a muffle furnace, and calcining for 15 minutes at 850 ℃ to obtain the flaky titanium dioxide material.

The flaky titanium dioxide material has an obvious laser rainbow effect under white light. The particle size distribution of the sheet material is between 40 μm and 120 μm, and the thickness is 500 nm.

EXAMPLE III preparation of flaky alumina

Preparing a flaky aluminum oxide precursor solution:

dissolving 15 g of triethanol aluminum in 30 g of absolute ethyl alcohol, adding 9 g of deionized water under stirring, continuing stirring at room temperature for 2 hours, adding 0.11 g of wetting agent ZY-R877 (Shanghai catalpi chemical Co., Ltd.), and performing ultrasonic dispersion treatment until the solution is clear for later use.

Preparing flaky aluminum oxide:

adopting a holographic laser PET film produced by Wenzhou Futwin company as a template, and scraping a coating of the prepared aluminum oxide precursor solution on the holographic laser PET film by using a wet film preparation device, wherein the thickness of the wet film is 50 mu m; drying in an oven at 80 deg.C for 5 min to remove solvent, soaking in water, stripping the coating by ultrasonic vibration, stripping off the aluminum oxide sheet, and collecting in a beaker; and (3) after filtering and drying, putting the mixture into a muffle furnace, and calcining the mixture for 15 minutes at the temperature of 750 ℃ to obtain the flaky alumina material.

The flaky alumina material has obvious laser rainbow effect under white light. The particle size distribution of the flaky material is between 30 and 110 mu m, and the thickness of the flaky material is 500 nm.

EXAMPLE IV preparation of platy zirconium dioxide

Preparing a flaky zirconium dioxide precursor solution:

26 g of zirconium oxychloride octahydrate is dissolved in a mixed solution of 54 g of water and 20 g of concentrated hydrochloric acid, and after the solution is clarified, 0.2 g of wetting agent UNIQ FLOW 487U (Youcai chemical Co., Ltd.) is added, and ultrasonic dispersion treatment is carried out until the solution is clarified for later use.

Preparation of flaky zirconium dioxide:

the method comprises the following steps of (1) coating a stripping-assisting layer on a template by using a holographic laser PET (polyethylene terephthalate) film produced by Wenzhoufu twin company as the template, wherein the stripping-assisting layer can be a water-soluble polymer coating, and the water-soluble polymer coating can be a polyvinylpyrrolidone coating or a polyvinyl alcohol coating;

and scraping a layer of coating of the prepared zirconium dioxide precursor solution on a holographic laser PET film by using a wet film preparation device, wherein the thickness of the wet film is 50 microns, putting the holographic laser PET film into an oven at 80 ℃ for drying for 5 minutes, then washing the coating by using deionized water, washing the flaky zirconium dioxide material, collecting the flaky zirconium dioxide material in a beaker, filtering and drying the flaky zirconium dioxide material, putting the dried product into a muffle furnace, and calcining the product at 850 ℃ for 15 minutes to obtain the flaky zirconium dioxide material.

The sheet zirconium dioxide material has obvious laser rainbow effect under white light. The particle size distribution of the sheet material is between 40 μm and 120 μm, and the thickness is 600 nm.

EXAMPLE V preparation of flaky tin dioxide

Preparing a flaky tin dioxide precursor solution:

preparing tin tetrachloride pentahydrate into 100 ml of 0.13 mol/L aqueous solution of tin tetrachloride, adding 0.6 g of citric acid, heating the solution to 65 ℃, slowly adding 0.5 mol/L ammonia water under stirring to hydrolyze the solution into tin hydroxide precipitate, stopping adding the ammonia water when the pH value is 2, cooling to room temperature, and aging for 24 hours. Filtering the precipitate, fully washing, adding 50 g of deionized water, adjusting the pH to 1.8 by using dilute hydrochloric acid, and heating to 60 ℃ to obtain transparent tin hydroxide hydrosol. 50 g of hydrosol was taken, 0.1 g of wetting agent UNIQ FLOW 487U (Youcai chemical Co., Ltd.) was added, and ultrasonic dispersion treatment was carried out until the solution was clear for use.

Preparation of flaky tin dioxide:

a holographic laser PET film produced by Wenzhou Futwin company is used as a template, a wet film preparation device is used for scraping a coating of the prepared tin dioxide precursor solution on the holographic laser PET film, the thickness of the wet film is 50 micrometers, the holographic laser PET film is placed in an oven at 80 ℃ for drying for 5 minutes, then the coating is washed by deionized water, the flaky tin dioxide material is washed, collected in a beaker, filtered and dried, then placed in a muffle furnace for calcining at 850 ℃ for 15 minutes, and the flaky tin dioxide material is obtained and has an obvious laser rainbow effect under white light. The particle size distribution of the flaky material is between 30 and 140 mu m, and the thickness of the flaky material is 500 nm.

EXAMPLE six continuous Process for producing a platy silica Material

The holographic laser PET film produced by Wenzhou Futwin company is taken as a continuous template coiled material (namely, the holographic laser PET film is coiled on a corresponding roller body for output for example), and is coated by a coating machine, the running speed of the coating machine is 5 m/s, the precursor solution prepared in the first embodiment is continuously coated on the PET film (specifically, for example, one section, namely one part, on the coating surface) by the coating machine, and the thickness of the wet film can be 50 μm; then the coated holographic laser PET film enters a 10-meter oven area, the temperature in the oven is 100 ℃, and a hot air system can be arranged for staying in the oven for 2 seconds; and (3) after the drying is finished, the dried holographic laser PET film enters a water tank, a water flow washing system is arranged in the water tank, the flaky silicon dioxide is washed from the PET film, and the filtration, washing and drying can be carried out to obtain flaky silicon dioxide powder with an obvious laser rainbow effect under white light.

The holographic laser PET film is washed by the water purifying tank and then enters an oven area for drying, a new production process is started, and the holographic laser PET film can be conveyed back to the original position by another roller, so that the holographic laser PET film does not need to be long, only one circle of holographic laser PET film is needed, the circular use can be realized, and the continuous production can be realized by the method.

It should be noted that in other embodiments of the present invention, other specific production equipment and systems may be used to implement the continuous process.

Although the present invention is disclosed above, the present invention is not limited thereto. Various changes and modifications may be effected therein by one skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.