Preparation process of a high refractive index glass microsphere

Abstract

The present invention discloses a preparation process of high refractive index glass microspheres, which relates to the technical field of glass. When preparing the high refractive index glass microspheres in the present invention, first, silica sol and titanium dioxide sol are prepared; secondly, mercaptopropyltrimethoxysilane is used to modify the silica sol, titanium dioxide sol, nano-aluminum sol, and nano-zirconia sol respectively to obtain modified silica sol, modified titanium dioxide sol, modified nano-aluminum sol, and modified nano-zirconia sol. The modified titanium dioxide sol and modified zirconia sol are mixed to obtain composite sol A, and the modified silica sol and modified nano-aluminum sol are mixed to obtain composite sol B; finally, composite sol A and composite sol B are successively used to modify the glass microspheres by the dip-coating method, and high refractive index glass microspheres are obtained after heat treatment. The high refractive index glass microspheres prepared by the present invention have good wear resistance and high refractive index.

Description

Technical Field

[0001] The present invention relates to the technical field of glass, and particularly to a preparation process of high-refractive-index glass microspheres. Background Art

[0002] High-refractive-index glass microspheres can be prepared by applying a high-refractive-index transparent coating on the surface of ordinary glass microspheres through special techniques. This coating endows the microspheres with a higher refractive index, enabling them to exhibit more excellent refraction and reflection effects under light irradiation without relying on special materials such as lead glass, titanate glass, or lanthanide glass; the refractive index of high-refractive-index glass microspheres is usually much higher than that of ordinary glass microspheres, and this characteristic makes them have wide application values in many fields.

[0003] In application scenarios, high-refractive-index glass microspheres are widely used to enhance the visual effects of products due to their unique optical properties. For example, in the coatings and inks industries, they can significantly improve the gloss and hiding power of coatings, making the coating surface more bright and plump; in the fields of plastics and rubber products, the addition of high-refractive-index glass microspheres can improve the transparency and texture of products, making their appearance more beautiful; in the optical field, they are even used to manufacture optical components such as mirrors and lenses, as well as for the encapsulation of LED light sources to improve the luminous efficiency and light uniformity;

[0004] However, traditional glass microspheres have limitations in some aspects, such as insufficient abrasion resistance and limited refractive index, which restricts their performance in high-end applications. Therefore, in order to overcome these shortcomings, researchers have developed high-abrasion-resistant and high-refractive-index glass microspheres. This new type of microspheres not only inherits the advantages of traditional glass microspheres but also achieves significant improvements in abrasion resistance and refractive index, meeting the market demand for high-quality optical materials and promoting the technological progress of multiple industries such as optics, coatings, and plastics. Summary of the Invention

[0005] The purpose of the present invention is to provide a preparation process of high-refractive-index glass microspheres to solve the problems existing in the prior art.

[0006] To solve the above technical problems, the present invention provides the following technical solutions:

[0007] A preparation method of high-refractive-index glass microspheres, comprising the following preparation steps:

[0008] (1) Mix tetraethyl orthosilicate and absolute ethanol at a volume ratio of 1:25 for 30 min to obtain a silicon solution. Mix 30 wt% ammonia water and absolute ethanol at a volume ratio of 1:10, stir at room temperature for 30 min, heat up to 50 °C, and dropwise add the silicon solution at a dropping rate of 1 mL / min. After the dropping is completed, stir for 1 h under sealed conditions. After the stirring is completed, obtain a silica sol; adjust the solid content of the silica sol to 2%-3% using absolute ethanol, adjust the pH to 3-4 using acetic acid, add mercaptopropyltrimethoxysilane with a mass 0.2-0.3 times that of the silica sol, and stir at room temperature for 30 min to obtain a modified silica sol;

[0009] (2) Mix tetrabutyl titanate, absolute ethanol, and pure water evenly, adjust the pH to 2-3 using a 36 wt% hydrochloric acid solution, and age at room temperature for 20 days to obtain a titanium dioxide sol; adjust the solid content of the titanium dioxide sol to 2%-3% using absolute ethanol, adjust the pH to 3-4 using acetic acid, add mercaptopropyltrimethoxysilane with a mass 0.2-0.3 times that of the titanium dioxide sol, and stir at room temperature for 30 min to obtain a modified titanium dioxide sol;

[0010] (3) Mix nano-aluminum sol and absolute ethanol at a volume ratio of 1:10, adjust the pH to 3-4 using acetic acid, add mercaptopropyltrimethoxysilane with a mass 0.2-0.3 times that of the nano-aluminum sol, and stir at room temperature for 30 min to obtain a modified nano-aluminum sol; mix nano-zirconia sol and absolute ethanol at a volume ratio of 1:10, adjust the pH to 3-4 using acetic acid, add mercaptopropyltrimethoxysilane with a mass 0.2-0.3 times that of the nano-aluminum sol, and stir at room temperature for 30 min to obtain a nano-zirconia sol;

[0011] (4) Mix the modified zirconia sol, absolute ethanol, the modified titanium dioxide sol, tetrabutylammonium iodide, and 30 wt% hydrogen peroxide, and stir at room temperature for 30 min to obtain a composite sol A; mix the modified nano-aluminum sol, absolute ethanol, the modified silica sol, tetrabutylammonium iodide, and 30 wt% hydrogen peroxide, and stir at room temperature for 30 min to obtain a composite sol B;

[0012] (5) Immerse the glass microspheres in acetone and ultrasonicate for 10-20 min, then immerse in absolute ethanol and ultrasonicate for 10-20 min, wash with pure water 3-4 times, dry at 50-60 °C for 2-3 h, cool to room temperature, impregnate and lift the film using the composite sol A, heat-treat at 100-110 °C for 1-2 h, and cool to room temperature; impregnate and lift the film using the composite sol B, heat-treat at 100-110 °C for 1-2 h to obtain high-refractive-index glass microspheres.

[0013] As an optimization, the volume ratio of the 30 wt% ammonia water to tetraethyl orthosilicate described in step (1) is 1:1.

[0014] As an optimization, the volume ratio of tetrabutyl titanate, absolute ethanol, and pure water described in step (2) is 2:1:25.

[0015] As an optimization, the parameters of the nano-zirconia sol described in step (3) are: particle size 20 - 30 nm, solid content 30%, and pH 4 - 6.

[0016] As an optimization, the parameters of the nano-aluminum sol described in step (3) are: particle size 10 - 20 nm, solid content 20%, and pH 3 - 5.

[0017] As an optimization, the mass ratio of the modified zirconia sol, absolute ethanol, modified titanium dioxide sol, tetrabutylammonium iodide, and 30 wt% hydrogen peroxide described in step (4) is 1:10:10:0.02:1.

[0018] As an optimization, the mass ratio of the modified nano-aluminum sol, absolute ethanol, modified silica sol, tetrabutylammonium iodide, and 30 wt% hydrogen peroxide described in step (4) is 1:10:10:0.02:1.

[0019] As an optimization, the model of the glass microspheres described in step (5) is HL20.

[0020] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0021] In the preparation of high-refractive-index glass microspheres by the present invention, first, silica sol and titanium dioxide sol are prepared; secondly, mercaptopropyltrimethoxysilane is used to modify the silica sol, titanium dioxide sol, nano-aluminum sol, and nano-zirconia sol respectively to obtain modified silica sol, modified titanium dioxide sol, modified nano-aluminum sol, and modified nano-zirconia sol. The modified titanium dioxide sol and modified zirconia sol are mixed to obtain composite sol A, and the modified silica sol and modified nano-aluminum sol are mixed to obtain composite sol B; finally, composite sol A and composite sol B are used in sequence to modify the glass microspheres by the dip-coating method, and high-refractive-index glass microspheres are obtained after heat treatment.

[0022] First, by adjusting the ratios among ammonia water, tetraethyl orthosilicate, and absolute ethanol, silica sol with large particle size is prepared; by adjusting the ratios among tetrabutyl titanate, absolute ethanol, hydrochloric acid, and pure water and then through aging, anatase titanium dioxide sol with large particle size is prepared. The anatase titanium dioxide sol has a relatively high refractive index. Secondly, mercaptopropyltrimethoxysilane is used to modify the silica sol, titanium dioxide sol, nanoaluminum sol, and nanometer zirconia sol respectively. Through the modification of mercaptopropyltrimethoxysilane, the surfaces of the sols are all provided with mercapto groups. The modified titanium dioxide sol and the modified zirconia sol are mixed to obtain composite sol A. Both zirconia and titanium dioxide in the composite sol A are substances with relatively high refractive indices, which can increase the refractive index of glass microspheres. The modified silica sol and the modified nanoaluminum sol are mixed to obtain composite sol B. The two sols in the composite sol are polymerized by generating disulfide bonds under the action of a tetrabutylammonium iodide-hydrogen peroxide oxidation system, and the two sol particles are tightly bound together, ultimately generating particulate composite particles. The introduction of sulfur elements can also increase the refractive index of the material.

[0023] Finally, composite sol A and composite sol B are successively used to modify glass microspheres by the dip-coating method to obtain high-refractive-index glass microspheres. The addition of zirconia and titanium dioxide sols contained in the composite sol A helps to improve the refractive index and hardness of the material, and a functional layer will be formed on the glass surface. The composite sol B contains silica and nanoaluminum components. The nanoaluminum sol has good adhesiveness and film-forming property and has strong adhesive force during drying and curing, which can improve the friction resistance and scratch resistance of the film surface, and a wear-resistant layer will be formed on the glass surface. Then, through heat treatment, high-refractive-index glass microspheres are obtained. As a reversible bond, the disulfide bond breaks during high-temperature treatment and will recover at room temperature. When heat-treating the glass microspheres, the broken disulfide bonds in the composite sol A and the broken disulfide bonds in the composite sol B will crosslink, so that the functional layer and the wear-resistant layer are crosslinked through disulfide bonds, forming a denser network and enhancing the wear resistance and mechanical properties. Specific embodiments

[0024] The technical solutions in the embodiments 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 a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

[0025] The parameters of the nanometer zirconia sol used in the following examples and comparative examples are: particle size 20 - 30 nm, solid content 30%, pH 4 - 6; the parameters of the nanoaluminum sol used are: particle size 10 - 20 nm, solid content 20%, pH 3 - 5; the model of the glass microspheres used is HL20.

[0026] Example 1:

[0027] A preparation method of high refractive index glass microspheres, the preparation method of the high refractive index glass microspheres comprising the following preparation steps:

[0028] (1) Weigh 30wt% ammonia water and tetraethyl orthosilicate according to a volume ratio of 1:1, mix tetraethyl orthosilicate and absolute ethanol according to a volume ratio of 1:25 for 30 min to obtain a silicon solution, mix 30wt% ammonia water and absolute ethanol according to a volume ratio of 1:10, stir at room temperature for 30 min, heat up to 50 °C, dropwise add the silicon solution at a dropping rate of 1 mL / min. After the dropping is completed, stir for 1 h under sealed conditions. After the stirring is completed, obtain silica sol; adjust the solid content of the silica sol to 2% using absolute ethanol, adjust the pH to 4 using acetic acid, add mercaptopropyltrimethoxysilane which is 0.2 times the mass of the silica sol, and stir at room temperature for 30 min to obtain modified silica sol;

[0029] (2) Weigh tetrabutyl titanate, absolute ethanol, and pure water according to a volume ratio of 2:1:25 and mix them evenly. Adjust the pH to 3 using a 36wt% hydrochloric acid solution, and age at room temperature for 20 days to obtain titanium dioxide sol; adjust the solid content of the titanium dioxide sol to 2% using absolute ethanol, adjust the pH to 4 using acetic acid, add mercaptopropyltrimethoxysilane which is 0.2 times the mass of the titanium dioxide sol, and stir at room temperature for 30 min to obtain modified titanium dioxide sol;

[0030] (3) Mix nano-aluminum sol and absolute ethanol according to a volume ratio of 1:10, adjust the pH to 4 using acetic acid, add mercaptopropyltrimethoxysilane which is 0.3 times the mass of the nano-aluminum sol, and stir at room temperature for 30 min to obtain modified nano-aluminum sol; mix nano-zirconia sol and absolute ethanol according to a volume ratio of 1:10, adjust the pH to 4 using acetic acid, add mercaptopropyltrimethoxysilane which is 0.2 times the mass of the nano-aluminum sol, and stir at room temperature for 30 min to obtain nano-zirconia sol;

[0031] (4) Mix the modified zirconia sol, absolute ethanol, modified titanium dioxide sol, tetrabutylammonium iodide, and 30wt% hydrogen peroxide according to a mass ratio of 1:10:10:0.02:1, and stir at room temperature for 30 min to obtain composite sol A; mix the modified nano-aluminum sol, absolute ethanol, modified silica sol, tetrabutylammonium iodide, and 30wt% hydrogen peroxide according to a mass ratio of 1:10:10:0.02:1, and stir at room temperature for 30 min to obtain composite sol B;

[0032] (5) Immerse the glass microspheres in acetone and ultrasonically treat them for 20 min, then immerse them in absolute ethanol and ultrasonically treat them for 20 min. Wash them 4 times with pure water, dry them at 60 °C for 3 h, cool them to room temperature, impregnate and dip-coat them with composite sol A, and heat-treat them at 110 °C for 2 h. Then cool them to room temperature; impregnate and dip-coat them with composite sol B, and heat-treat them at 110 °C for 2 h to obtain high-refractive-index glass microspheres.

[0033] Example 2:

[0034] A preparation method of high-refractive-index glass microspheres, the preparation method of the high-refractive-index glass microspheres comprising the following preparation steps:

[0035] (1) Weigh 30 wt% ammonia water and tetraethyl orthosilicate according to a volume ratio of 1:1. Mix tetraethyl orthosilicate and absolute ethanol according to a volume ratio of 1:25 for 30 min to obtain a silicon solution. Mix 30 wt% ammonia water and absolute ethanol according to a volume ratio of 1:10, stir at room temperature for 30 min, heat up to 50 °C, and dropwise add the silicon solution at a dropping rate of 1 mL / min. After the dropping is completed, stir for 1 h under sealed conditions. After the stirring is completed, obtain silica sol; adjust the solid content of the silica sol to 2.5% with absolute ethanol, adjust the pH to 3.5 with acetic acid, add mercaptopropyltrimethoxysilane with a mass 0.25 times that of the silica sol, and stir at room temperature for 30 min to obtain modified silica sol;

[0036] (2) Weigh tetrabutyl titanate, absolute ethanol, and pure water according to a volume ratio of 2:1:25 and mix them evenly. Adjust the pH to 2.5 with 36 wt% hydrochloric acid solution, and age at room temperature for 20 days to obtain titanium dioxide sol; adjust the solid content of the titanium dioxide sol to 2.5% with absolute ethanol, adjust the pH to 3.5 with acetic acid, add mercaptopropyltrimethoxysilane with a mass 0.25 times that of the titanium dioxide sol, and stir at room temperature for 30 min to obtain modified titanium dioxide sol;

[0037] (3) Mix nano-aluminum sol and absolute ethanol according to a volume ratio of 1:10, adjust the pH to 3.5 with acetic acid, add mercaptopropyltrimethoxysilane with a mass 0.25 times that of the nano-aluminum sol, and stir at room temperature for 30 min to obtain modified nano-aluminum sol; mix nano-zirconia sol and absolute ethanol according to a volume ratio of 1:10, adjust the pH to 3.5 with acetic acid, add mercaptopropyltrimethoxysilane with a mass 0.25 times that of the nano-aluminum sol, and stir at room temperature for 30 min to obtain nano-zirconia sol;

[0038] (4) Mix the modified zirconia sol, absolute ethanol, modified titanium dioxide sol, tetrabutylammonium iodide, and 30 wt% hydrogen peroxide in a mass ratio of 1:10:10:0.02:1, and stir for 30 min at room temperature to obtain composite sol A; mix the modified nano-aluminum sol, absolute ethanol, modified silica sol, tetrabutylammonium iodide, and 30 wt% hydrogen peroxide in a mass ratio of 1:10:10:0.02:1, and stir for 30 min at room temperature to obtain composite sol B.

[0039] (5) Immerse the glass microspheres in acetone and ultrasonicate for 15 min, then immerse them in absolute ethanol and ultrasonicate for 15 min, wash them 3 times with pure water, dry them at 55 °C for 2.5 h, cool them to room temperature, dip-coat them with composite sol A, heat-treat them at 105 °C for 1.5 h, and cool them to room temperature; dip-coat them with composite sol B, heat-treat them at 105 °C for 1.5 h to obtain high-refractive-index glass microspheres.

[0040] Example 3:

[0041] A method for preparing high-refractive-index glass microspheres, the method for preparing the high-refractive-index glass microspheres comprising the following preparation steps:

[0042] (1) Weigh 30 wt% ammonia water and tetraethyl orthosilicate at a volume ratio of 1:1, mix tetraethyl orthosilicate and absolute ethanol at a volume ratio of 1:25 for 30 min to obtain a silicon solution, mix 30 wt% ammonia water and absolute ethanol at a volume ratio of 1:10, stir at room temperature for 30 min, heat up to 50 °C, and dropwise add the silicon solution at a dropping rate of 1 mL / min. After the dropping is completed, stir for 1 h under sealed conditions. After the stirring is completed, obtain a silica sol; adjust the solid content of the silica sol to 3% using absolute ethanol, adjust the pH to 3 using acetic acid, add 0.3 times the mass of the silica sol of mercaptopropyltrimethoxysilane, and stir at room temperature for 30 min to obtain a modified silica sol.

[0043] (2) Weigh tetrabutyl titanate, absolute ethanol, and pure water at a volume ratio of 2:1:25 and mix them evenly, adjust the pH to 3 using a 36 wt% hydrochloric acid solution, and age at room temperature for 20 days to obtain a titanium dioxide sol; adjust the solid content of the titanium dioxide sol to 3% using absolute ethanol, adjust the pH to 3 using acetic acid, add 0.3 times the mass of the titanium dioxide sol of mercaptopropyltrimethoxysilane, and stir at room temperature for 30 min to obtain a modified titanium dioxide sol.

[0044] (3) Mix nano-aluminium sol and absolute ethanol at a volume ratio of 1:10, adjust the pH to 3 using acetic acid, add 0.3 times the mass of nano-aluminium sol of mercaptopropyltrimethoxysilane, and stir at room temperature for 30 min to obtain modified nano-aluminium sol; Mix nano-zirconia sol and absolute ethanol at a volume ratio of 1:10, adjust the pH to 3 using acetic acid, add 0.3 times the mass of nano-aluminium sol of mercaptopropyltrimethoxysilane, and stir at room temperature for 30 min to obtain nano-zirconia sol;

[0045] (4) Mix modified zirconia sol, absolute ethanol, modified titanium dioxide sol, tetrabutylammonium iodide, and 30 wt% hydrogen peroxide at a mass ratio of 1:10:10:0.02:1, and stir at room temperature for 30 min to obtain composite sol A; Mix modified nano-aluminium sol, absolute ethanol, modified silica sol, tetrabutylammonium iodide, and 30 wt% hydrogen peroxide at a mass ratio of 1:10:10:0.02:1, and stir at room temperature for 30 min to obtain composite sol B;

[0046] (5) Immerse the glass microspheres in acetone and sonicate for 10 min, then immerse in absolute ethanol and sonicate for 10 min, wash 3 times with pure water, dry at 50 °C for 2 h, cool to room temperature, dip-coat with composite sol A, and heat-treat at 100 °C for 1 h, then cool to room temperature; Dip-coat with composite sol B, and heat-treat at 100 °C for 1 h to obtain high-refractive-index glass microspheres.

[0047] Comparative Example 1:

[0048] The preparation method of the high-refractive-index glass microspheres in Comparative Example 1 is different from that in Example 2 in that step (5) is modified to: Immerse the glass microspheres in acetone and sonicate for 15 min, then immerse in absolute ethanol and sonicate for 15 min, wash 3 times with pure water, dry at 55 °C for 2.5 h, cool to room temperature, dip-coat with composite sol B, and heat-treat at 105 °C for 1.5 h to obtain high-refractive-index glass microspheres.

[0049] Comparative Example 2:

[0050] The preparation method of the high-refractive-index glass microspheres in Comparative Example 2 is different from that in Example 2 in that step (5) is modified to: Immerse the glass microspheres in acetone and sonicate for 15 min, then immerse in absolute ethanol and sonicate for 15 min, wash 3 times with pure water, dry at 55 °C for 2.5 h, cool to room temperature, dip-coat with composite sol A, and heat-treat at 105 °C for 1.5 h to obtain high-refractive-index glass microspheres.

[0051] Comparative Example 3:

[0052] The difference between the preparation method of the high refractive index glass microspheres of Comparative Example 3 and that of Example 2 is that step (4) is modified as follows: zirconia sol, absolute ethanol, and titania sol are mixed at a mass ratio of 1:10:10 and stirred at room temperature for 30 min to obtain composite sol A; nano-aluminum sol, absolute ethanol, and silica sol are mixed at a mass ratio of 1:10:10 and stirred at room temperature for 30 min to obtain composite sol B.

[0053] Test Example 1:

[0054] Test method:

[0055] Test of wear resistance: The wear resistance of the protective layer was tested using an abrasion tester. The rotational speed of the carrier stage of the abrasion tester was set to 100 r / min, and the high refractive index glass microspheres prepared in the examples and comparative examples were subjected to wear tests until the protective layer was worn and the matrix glass microspheres were exposed, and the time taken for this process was recorded. The results are shown in Table 1.

[0056] Test of refractive index: Its refractive index was measured by the oil immersion method. The results are shown in Table 1.

[0057] Table 1

[0058] Duration (h) Refractive index Example 1 824 1.91 Example 2 825 1.92 Example 3 825 1.92 Comparative Example 1 482 1.71 Comparative Example 2 531 1.89 Comparative Example 3 757 1.87

[0059] From the comparison of the experimental data of Examples 1 to 3 and Comparative Examples 1 to 3 in Table 1, it can be found that the high refractive index glass microspheres prepared by the present invention have good wear resistance and relatively high refractive index.

[0060] By comparison, the wear resistance of Examples 1 to 3 is better than that of Comparative Examples 1 to 3, indicating that the composite sol B contains silica and nano-aluminum components. The nano-aluminum sol has good adhesiveness and film-forming properties, and has strong adhesive force during drying and curing, which can improve the friction and scratch resistance of the film surface, and will modify a wear-resistant layer on the glass surface. Then, through heat treatment, high refractive index glass microspheres are obtained. As a reversible bond, the disulfide bond breaks during high-temperature treatment and will recover at room temperature. When heat-treating the glass microspheres, the broken disulfide bonds in composite sol A and the broken disulfide bonds in composite sol B will crosslink, enabling the functional layer and the wear-resistant layer to crosslink through disulfide bonds, forming a denser network and enhancing wear resistance and mechanical properties.

[0061] By comparison, the refractive indices of Examples 1 to 3 are superior to those of Comparative Examples 1 to 3. This shows that, firstly, by adjusting the ratios among ammonia water, tetraethyl orthosilicate, and absolute ethanol, silica sols with large particle sizes are prepared; by adjusting the ratios among tetrabutyl titanate, absolute ethanol, hydrochloric acid, and pure water, and then through aging, anatase-type titanium dioxide sols with large particle sizes are prepared, and the anatase-type titanium dioxide sols have relatively high refractive indices; secondly, mercaptopropyltrimethoxysilane is used to modify the silica sols, titanium dioxide sols, nanoaluminum sols, and nanozirconia sols respectively. Through the modification of mercaptopropyltrimethoxysilane, the surfaces of the sols are all provided with mercapto groups. The modified titanium dioxide sols and modified zirconia sols are mixed to obtain composite sol A. Both zirconia and titanium dioxide in composite sol A are substances with relatively high refractive indices, which can increase the refractive index of glass microspheres; the modified silica sols and modified nanoaluminum sols are mixed to obtain composite sol B; under the action of the tetrabutylammonium iodide-hydrogen peroxide oxidation system, the two sols in the composite sol polymerize by forming disulfide bonds, and the introduction of sulfur elements can also increase the refractive index of the material.

[0062] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above-described exemplary embodiments, and without departing from the spirit or basic characteristics of the present invention, the present invention can be implemented in other specific forms. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be embraced within the present invention. Any reference signs in the claims should not be construed as limiting the claimed elements.

Claims

1. A method for preparing high refractive index glass microspheres, characterized in that, It includes the following preparation steps: (1) Mix tetraethyl orthosilicate and absolute ethanol at a volume ratio of 1:25 for 30 min to obtain a silicon solution. Mix 30 wt% ammonia water and absolute ethanol at a volume ratio of 1:10, stir at room temperature for 30 min, heat up to 50 °C, and dropwise add the silicon solution at a dropping rate of 1 mL / min. After the dropping is completed, stir for 1 h under sealed conditions. After the stirring is completed, obtain silica sol. Adjust the solid content of the silica sol to 2% - 3% using absolute ethanol, adjust the pH to 3 - 4 using acetic acid, add 0.2 - 0.3 times the mass of the silica sol of mercaptopropyltrimethoxysilane, and stir at room temperature for 30 min to obtain modified silica sol; (2) Mix tetrabutyl titanate, absolute ethanol, and pure water evenly, adjust the pH to 2 - 3 using 36 wt% hydrochloric acid solution, and age at room temperature for 20 days to obtain titanium dioxide sol. Adjust the solid content of the titanium dioxide sol to 2% - 3% using absolute ethanol, adjust the pH to 3 - 4 using acetic acid, add 0.2 - 0.3 times the mass of the titanium dioxide sol of mercaptopropyltrimethoxysilane, and stir at room temperature for 30 min to obtain modified titanium dioxide sol; (3) Mix nano-aluminum sol and absolute ethanol at a volume ratio of 1:10, adjust the pH to 3 - 4 using acetic acid, add 0.2 - 0.3 times the mass of the nano-aluminum sol of mercaptopropyltrimethoxysilane, and stir at room temperature for 30 min to obtain modified nano-aluminum sol; Mix nano-zirconia sol and absolute ethanol at a volume ratio of 1:10, adjust the pH to 3 - 4 using acetic acid, add 0.2 - 0.3 times the mass of the nano-aluminum sol of mercaptopropyltrimethoxysilane, and stir at room temperature for 30 min to obtain nano-zirconia sol; (4) Mix modified zirconia sol, absolute ethanol, modified titanium dioxide sol, tetrabutylammonium iodide, and 30 wt% hydrogen peroxide, and stir at room temperature for 30 min to obtain composite sol A; Mix modified nano-aluminum sol, absolute ethanol, modified silica sol, tetrabutylammonium iodide, and 30 wt% hydrogen peroxide, and stir at room temperature for 30 min to obtain composite sol B; (5) Immerse the glass microspheres in acetone and ultrasonicate for 10 - 20 min, then immerse them in absolute ethanol and ultrasonicate for 10 - 20 min, wash them with pure water 3 - 4 times, dry them at 50 - 60 °C for 2 - 3 h, cool them to room temperature, impregnate and lift the film using composite sol A, heat-treat at 100 - 110 °C for 1 - 2 h, and cool to room temperature; Impregnate and lift the film using composite sol B, heat-treat at 100 - 110 °C for 1 - 2 h to obtain high-refractive-index glass microspheres.

2. The preparation method of a high-refractive-index glass microsphere according to claim 1, wherein, In step (1), the volume ratio of the 30 wt% ammonia water to tetraethyl orthosilicate is 1:

1.

3. The preparation method of a high-refractive-index glass microsphere according to claim 1, characterized in that, In step (2), the volume ratio of tetrabutyl titanate, absolute ethanol, and pure water is 2:1:

25.

4. The preparation method of a high-refractive-index glass bead according to claim 1, characterized in that, The parameters of the nano-zirconia sol in step (3) are: particle size 20 - 30 nm, solid content 30%, pH 4 - 6.

5. The preparation method of a high-refractive-index glass microsphere according to claim 1, characterized in that, The parameters of the nano-aluminum sol in step (3) are: particle size 10 - 20 nm, solid content 20%, pH 3 - 5.

6. The preparation method of a high-refractive-index glass microsphere according to claim 1, wherein, The mass ratio of the modified zirconia sol, absolute ethanol, modified titanium dioxide sol, tetrabutylammonium iodide, and 30 wt% hydrogen peroxide described in step (4) is 1:10:10:0.02:

1.

7. The preparation method of a high-refractive-index glass microsphere according to claim 1, characterized in that, The mass ratio of the modified nanoaluminum sol, absolute ethanol, modified silica sol, tetrabutylammonium iodide, and 30 wt% hydrogen peroxide described in step (4) is 1:10:10:0.02:

1.

8. The preparation method of a high refractive index glass bead according to claim 1, characterized in that, The model of the glass microspheres described in step (5) is HL20.