Photochromic functional ceramic material and application thereof

Abstract

The application relates to the technical field of functional ceramic preparation, and particularly discloses a photochromic functional ceramic material and application, which comprises the following steps: step S1, primary grinding; step S2, preparation of a photochromic material; step S3, preparation of a green body; and step S4, preparation of the photochromic functional ceramic material; the application is prepared from two aspects, one is that nano silicon dioxide is coated on the surface of nano aluminum oxide, and then the nano aluminum oxide is modified by using a silane coupling agent containing an amino group to obtain an enhanced component; through the coating, the agglomeration of the nano aluminum oxide particles caused by chemical bonding or hydrogen bonding is reduced; in the high-temperature sintering process, the aluminum oxide can generate mullite with the silicon dioxide; meanwhile, the amino group can also generate chemical crosslinking with a functionalized binder; the other aspect is that the functionalized binder is added, the functionalized binder is prepared by compounding dopamine, polyacrylic acid and silica sol; through the synergistic effect of the three, the mechanical properties of the functional ceramic material are improved.

Description

Technical Field

[0001] This invention relates to the field of functional ceramics preparation technology, and more specifically, to a photochromic functional ceramic material and its application. Background Technology

[0002] Photochromic materials, as an important component of functional ceramics, are widely used in functional ceramic parts and electronic components due to their unique photoinductive properties and superior photoresponse reversibility.

[0003] Sodium niobate-based compounds, as an important component of photochromic materials, possess excellent plasticity and high photoelectric conversion efficiency. However, although sodium niobate-based materials have high hardness, their toughness and bending strength are generally low. Currently, nano-alumina is used to toughen nano-sodium niobate-based materials, which can significantly improve the toughness and mechanical strength of nano-sodium niobate-based materials. However, during the sintering process, nano-alumina is prone to agglomeration, which leads to a decrease in the density of nano-sodium niobate-based materials and affects their mechanical strength.

[0004] Based on the above statements, the present invention provides a photochromic functional ceramic material with excellent mechanical properties and its application. Summary of the Invention

[0005] To address the problems mentioned in the background section, this invention provides a photochromic functional ceramic material and its application.

[0006] A photochromic functional ceramic material includes a photochromic material, a reinforcing component, a functionalized binder, and a solvent;

[0007] This invention also provides a method for preparing the photochromic functional ceramic material described in the above technical solution, comprising the following steps:

[0008] Step S1, Primary grinding: Niobium pentoxide, lithium carbonate, sodium carbonate, praseodymium oxide and anhydrous ethanol are mixed, wet ball milled, dried and sieved to obtain primary grinding material, wherein the mass ratio of niobium pentoxide, lithium carbonate, sodium carbonate, praseodymium oxide and anhydrous ethanol is 36.3:1-5:7.3-13.1:0.17-0.21:500-600;

[0009] Step S2: Preparation of photochromic material: Place the primary grinding material in a high-temperature sintering furnace for pre-sintering, cool to room temperature, and obtain the photochromic material;

[0010] Step S3: Preparation of green body: The photochromic material is added to the solvent and ground twice. Then, the reinforcing component, functionalized binder and catalyst are added and stirred evenly. The mixture is then placed in a mold and subjected to dry pressing and cold isostatic pressing to obtain the green body. The mass ratio of photochromic material, solvent, reinforcing component, functionalized binder and catalyst is 90-100:42-46:8-12:10-16:0.2-0.6.

[0011] Step S4: Preparation of photochromic functional ceramic material: Place the green blank in an alumina crucible, place it in a high-temperature box furnace, perform debinding treatment, then perform high-temperature sintering, and cool to room temperature to obtain photochromic functional ceramic material.

[0012] Application of a photochromic functional ceramic material prepared by the above method in functional ceramic parts.

[0013] Preferably, in step S1, the wet ball milling process specifically involves a ball milling speed of 480-540 rpm and a ball milling time of 22-26 h.

[0014] Preferably, in step S2, the pre-sintering process involves heating to 920-980℃ at a heating rate of 1-3℃ / min and holding at that temperature for 1.8-2.2 hours.

[0015] Preferably, in step S3, the solvent is an aqueous ethanol solution with a mass fraction of 8-12%.

[0016] Preferably, in step S3, the catalyst is p-toluenesulfonic acid or pyridine.

[0017] Preferably, in step S3, during the dry pressing process, the pressure is 6-8 MPa, the holding time is 1-2 min, the cold isostatic pressing pressure is 260-320 MPa, the cold isostatic pressing temperature is 64-72℃, and the cold isostatic pressing time is 2-4 min.

[0018] Preferably, in step S4, the debinding process involves heating to 540-560°C at a heating rate of 1-3°C and holding for 4.5-5.5 hours, while the sintering process involves heating to 1220-1320°C at a heating rate of 3-5°C / min and holding for 3.6-4 hours.

[0019] Preferably, the reinforcing component is prepared by the following steps:

[0020] Step A1: While stirring, add saturated aluminum sulfate solution dropwise to sodium aluminate aqueous solution, controlling the addition to be completed within 15 minutes. After the addition is completed, continue stirring for 18-22 minutes to obtain a gel. Vacuum filter the gel to obtain a filter cake. Add the filter cake to an ethanol aqueous solution, stir evenly, adjust the pH value to 8.8-9.2, then add tetraethyl orthosilicate, heat to 50-66℃, and continue stirring for 1.2-1.6 hours. Centrifuge, precipitate, wash, and dry to obtain core-shell particles. The mass ratio of saturated aluminum sulfate solution, sodium aluminate aqueous solution, tetraethyl orthosilicate, and ethanol aqueous solution is 10-14:18-30:50-60:450-550. In the above reaction process, aluminum hydroxide gel is obtained by precipitation, and then the aluminum hydroxide gel is coated with silica obtained by hydrolysis of tetraethyl orthosilicate to obtain core-shell particles.

[0021] Step A2: Add core-shell particles to deionized water, heat to 35-45℃, sonicate for 8-12 minutes, and add a mixture of silane coupling agent and anhydrous ethanol dropwise while stirring, controlling the addition to be completed within 15 minutes. After the addition is completed, heat to 45-55℃, stir and react for 2.2-2.4 hours, centrifuge, wash and dry the precipitate to obtain the reinforcing component. The mass ratio of core-shell particles, deionized water and mixture a is 3-5:55-65:28-32, and the mass ratio of silane coupling agent and anhydrous ethanol in mixture a is 0.4-0.8:30. In the above reaction process, the core-shell particles are treated with silane coupling agent to obtain the reinforcing component.

[0022] Preferably, in step A1, the concentration of the sodium aluminate aqueous solution is 3-4M, and the mass fraction of the ethanol aqueous solution is 8-12%.

[0023] Preferably, in step A2, the silane coupling agent is γ-aminopropyltriethoxysilane or γ-aminopropylmethyldiethoxysilane.

[0024] Preferably, the functionalized adhesive is prepared by the following steps:

[0025] Dopamine and polyacrylic acid were added to a Tris-HCl buffer solution with a pH of 8-9 and stirred until homogeneous. Then silica sol was added, the temperature was raised to 34-40℃, and stirring was continued for 12-16 minutes to obtain a functionalized binder. The mass ratio of dopamine, polyacrylic acid, Tris-HCl buffer solution and silica sol was 2-3:10-14:50-60:0.8-1.2.

[0026] Preferably, the mass fraction of silica sol is 30-40%.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] To improve the mechanical properties of photochromic functional ceramic materials, this invention addresses the issue from two aspects. First, nano-silica is coated onto the surface of nano-alumina, and then modified using an amino-containing silane coupling agent to prepare a reinforcing component. This coating not only reduces the surface activity of the nano-alumina and decreases agglomeration between nano-alumina particles due to chemical bonding or hydrogen bonding, thus improving the mechanical properties of the ceramic material, but also allows the alumina to form a mullite phase with the silica during high-temperature sintering, further enhancing the mechanical properties. Simultaneously, the amino groups can chemically crosslink with the carboxyl groups in the functionalized binder, further improving the functional properties of the ceramic material. The mechanical properties of the ceramic material are improved; secondly, a functionalized binder is added. The functionalized binder is prepared by compounding dopamine, polyacrylic acid and silica sol. The phenolic hydroxyl structure of dopamine has good adhesion, and dopamine can self-polymerize in Tris-HCl buffer. The resulting polydopamine molecule contains abundant active amino groups, which can not only form hydrogen bonds with the hydroxyl groups in silica sol and the amino groups in the reinforcing components, but also form chemical bonds with polyacrylic acid. The presence of silica sol improves the compatibility between the functionalized binder and the reinforcing components. Introducing it into functional ceramic materials can work synergistically with the reinforcing components to jointly improve the mechanical properties of photochromic functional ceramics. Detailed Implementation

[0029] To make the embodiments of the present invention easier to understand, the present invention will be described in detail below with reference to specific embodiments. These embodiments are for illustrative purposes only and are not limited to the application scope of the present invention.

[0030] Where specific techniques or conditions are not specified in the examples, they shall be performed in accordance with the techniques or conditions described in the literature in this field, or in accordance with the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased through legitimate channels.

[0031] The silica sol is industrial-grade silica sol produced by Guangdong Kening Technology Co., Ltd., the polyacrylic acid is premium-grade polyacrylic acid sold by Jinan Xinguang Chemical Products Co., Ltd., CAS number 659-98-01, and the polyvinyl alcohol is produced by Shandong Jinyufeng New Materials Co., Ltd., CAS number 9002-89-5.

[0032] The present invention will be further described in detail below with reference to embodiments and comparative examples.

[0033] Preparation Examples 1-3 and Comparative Preparation Examples 1-3 provide an enhancing component.

[0034] Preparation Example 1

[0035] This preparation example provides a reinforcing component, which is prepared by the following steps:

[0036] Step A1: At a speed of 540 rpm, saturated aluminum sulfate solution is added dropwise to sodium aluminate aqueous solution while stirring, and the addition is completed within 15 minutes. After the addition is completed, the speed is kept constant and stirring is continued for 18 minutes to obtain a gel. The gel is vacuum filtered to obtain a filter cake. The filter cake is added to an 8% (w / w) ethanol aqueous solution and stirred at a speed of 600 rpm for 16 minutes until homogeneous. The pH value is adjusted to 8.8 with a 0.002% (w / w) sodium hydroxide aqueous solution. Then, tetraethyl orthosilicate is added, the temperature is raised to 50℃, and the stirring is continued for 1.2 hours while maintaining a constant speed. The mixture is centrifuged, and the precipitate is washed three times each with anhydrous ethanol and deionized water. It is then dried at 55℃ to constant weight to obtain core-shell particles. The mass ratio of saturated aluminum sulfate solution, sodium aluminate aqueous solution, tetraethyl orthosilicate, and ethanol aqueous solution is 10:18:50:450.

[0037] Step A2: The core-shell particles were added to deionized water and heated to 35°C. The mixture was ultrasonically treated for 8 minutes at a frequency of 30 kHz and a power of 450 W until homogeneous. The stirring speed was controlled at 460 rpm. A mixture of γ-aminopropyltriethoxysilane and anhydrous ethanol (a) was added dropwise while stirring, completing the addition within 15 minutes. After addition, the temperature was raised to 45°C, and the stirring speed was maintained. The reaction was continued for 2.2 hours. The mixture was centrifuged, and the precipitate was washed three times each with anhydrous ethanol and deionized water. It was then dried at 58°C to constant weight to obtain the reinforcing component. The mass ratio of core-shell particles, deionized water, and mixture a was 3:55:28. In mixture a, the mass ratio of γ-aminopropyltriethoxysilane to anhydrous ethanol was 0.4:30.

[0038] Preparation Example 2

[0039] This preparation example provides a reinforcing component, which is prepared by the following steps:

[0040] Step A1: While stirring at 560 rpm, saturated aluminum sulfate solution is added dropwise to sodium aluminate aqueous solution, and the addition is completed within 15 minutes. After the addition is completed, the stirring speed is maintained and the mixture is stirred for another 20 minutes to obtain a gel. The gel is then vacuum filtered to obtain a filter cake. The filter cake is added to a 10% ethanol aqueous solution and stirred at 630 rpm for 18 minutes until homogeneous. The pH value is adjusted to 9.0 with a 0.004% sodium hydroxide aqueous solution, and then tetraethyl orthosilicate is added. The temperature is raised to 58°C and the reaction is stirred for another 1.4 hours. The mixture is then centrifuged, and the precipitate is washed four times each with anhydrous ethanol and deionized water. The precipitate is then dried at 60°C to constant weight to obtain core-shell particles. The mass ratio of saturated aluminum sulfate solution, sodium aluminate aqueous solution, tetraethyl orthosilicate, and ethanol aqueous solution is 12:24:55:500.

[0041] Step A2: The core-shell particles are added to deionized water and heated to 40°C. The mixture is ultrasonically treated for 10 minutes at a frequency of 35 kHz and a power of 500 W until homogeneous. While stirring, a mixture of γ-aminopropylmethyldiethoxysilane and anhydrous ethanol (a) is added dropwise over 15 minutes. After addition, the temperature is raised to 50°C, and the stirring speed is maintained. The reaction continues for 2.3 hours. The mixture is then centrifuged, and the precipitate is washed four times each with anhydrous ethanol and deionized water. It is then dried at 62°C to constant weight to obtain the reinforcing component. The mass ratio of core-shell particles, deionized water, and mixture a is 4:60:30. In mixture a, the mass ratio of γ-aminopropylmethyldiethoxysilane to anhydrous ethanol is 0.8:30.

[0042] Preparation Example 3

[0043] This preparation example provides a reinforcing component, which is prepared by the following steps:

[0044] Step A1: At a speed of 580 rpm, saturated aluminum sulfate solution is added dropwise to sodium aluminate aqueous solution while stirring, and the addition is completed within 15 minutes. After the addition is completed, the speed is kept constant and stirring is continued for 22 minutes to obtain a gel. The gel is vacuum filtered to obtain a filter cake. The filter cake is added to a 12% ethanol aqueous solution and stirred at a speed of 660 rpm for 20 minutes until homogeneous. The pH value is adjusted to 9.2 with a 0.006% sodium hydroxide aqueous solution. Then, tetraethyl orthosilicate is added, the temperature is raised to 66℃, and the reaction is continued to be stirred for 1.6 hours. After centrifugation, the precipitate is washed 5 times each with anhydrous ethanol and deionized water, and dried at 65℃ to constant weight to obtain core-shell particles. The mass ratio of saturated aluminum sulfate solution, sodium aluminate aqueous solution, tetraethyl orthosilicate, and ethanol aqueous solution is 14:30:60:550.

[0045] Step A2: The core-shell particles were added to deionized water and heated to 45°C. The mixture was ultrasonically treated for 12 minutes at an ultrasonic frequency of 40 kHz and an ultrasonic power of 550 W until homogeneous. The stirring speed was controlled at 540 rpm. A mixture of γ-aminopropyltriethoxysilane and anhydrous ethanol (a) was added dropwise while stirring, completing the addition within 15 minutes. After addition, the temperature was raised to 55°C, and the stirring speed was maintained. The reaction was continued for 2.4 hours. The mixture was centrifuged, and the precipitate was washed five times each with anhydrous ethanol and deionized water. It was then dried at 66°C to constant weight to obtain the reinforcing component. The mass ratio of core-shell particles, deionized water, and mixture a was 5:65:32. In mixture a, the mass ratio of γ-aminopropyltriethoxysilane to anhydrous ethanol was 0.8:30.

[0046] Comparative Preparation Example 1

[0047] This comparative preparation example provides a reinforcing component, which is prepared by the following steps:

[0048] Step A1: At a speed of 540 rpm, saturated aluminum sulfate solution is added dropwise to sodium aluminate aqueous solution while stirring, and the addition is completed within 15 minutes. After the addition is completed, the speed is kept constant and stirring is continued for 18 minutes to obtain a gel. The gel is vacuum filtered to obtain a filter cake. The filter cake is added to an 8% (w / w) ethanol aqueous solution and stirred at 600 rpm for 16 minutes until homogeneous. The pH value is adjusted to 8.8 with a 0.002% (w / w) sodium hydroxide aqueous solution. Then tetrabutyl titanate is added, the temperature is raised to 50℃, and the stirring is continued for 1.2 hours while keeping the speed constant. The mixture is centrifuged and the precipitate is washed three times each with anhydrous ethanol and deionized water. It is then dried at 55℃ to constant weight to obtain core-shell particles. The mass ratio of saturated aluminum sulfate solution, sodium aluminate aqueous solution, tetrabutyl titanate, and ethanol aqueous solution is 10:18:50:450.

[0049] Step A2: The core-shell particles were added to deionized water and heated to 35°C. The mixture was ultrasonically treated for 8 minutes at a frequency of 30 kHz and a power of 450 W until homogeneous. The stirring speed was controlled at 460 rpm. A mixture of γ-aminopropyltriethoxysilane and anhydrous ethanol (a) was added dropwise while stirring, completing the addition within 15 minutes. After addition, the temperature was raised to 45°C, and the stirring speed was maintained. The reaction was continued for 2.2 hours. The mixture was centrifuged, and the precipitate was washed three times each with anhydrous ethanol and deionized water. It was then dried at 58°C to constant weight to obtain the reinforcing component. The mass ratio of core-shell particles, deionized water, and mixture a was 3:55:28. In mixture a, the mass ratio of γ-aminopropyltriethoxysilane to anhydrous ethanol was 0.4:30.

[0050] Comparative Preparation Example 2

[0051] This comparative preparation example provides a reinforcing component, which is prepared by the following steps:

[0052] This preparation example provides a reinforcing component, which is prepared by the following steps:

[0053] Step A1: At a speed of 540 rpm, saturated aluminum sulfate solution is added dropwise to sodium aluminate aqueous solution while stirring, and the addition is completed within 15 minutes. After the addition is completed, the speed is kept constant and stirring is continued for 18 minutes to obtain a gel. The gel is vacuum filtered to obtain a filter cake. The filter cake is added to an 8% (w / w) ethanol aqueous solution and stirred at a speed of 600 rpm for 16 minutes until homogeneous. The pH value is adjusted to 8.8 with a 0.002% (w / w) sodium hydroxide aqueous solution. Then, tetraethyl orthosilicate is added, the temperature is raised to 50℃, and the stirring is continued for 1.2 hours while maintaining a constant speed. The mixture is centrifuged, and the precipitate is washed three times each with anhydrous ethanol and deionized water. It is then dried at 55℃ to constant weight to obtain core-shell particles. The mass ratio of saturated aluminum sulfate solution, sodium aluminate aqueous solution, tetraethyl orthosilicate, and ethanol aqueous solution is 10:18:50:450.

[0054] Step A2: The core-shell particles were added to deionized water and heated to 35°C. The mixture was ultrasonically treated for 8 minutes at a frequency of 30 kHz and a power of 450 W until homogeneous. While stirring, a mixture of γ-glycidoxypropyltrimethoxysilane and anhydrous ethanol (a) was added dropwise over 15 minutes. After addition, the temperature was raised to 45°C, and the stirring speed was maintained. The reaction was continued for 2.2 hours. The mixture was centrifuged, the precipitate was washed, and dried at 58°C to constant weight to obtain the reinforcing component. The mass ratio of core-shell particles, deionized water, and mixture a was 3:55:28. In mixture a, the mass ratio of γ-glycidoxypropyltrimethoxysilane to anhydrous ethanol was 0.4:30.

[0055] Preparation Examples 4-6 and Comparative Preparation Examples 3-4 provide a functionalized adhesive.

[0056] Preparation Example 4

[0057] This preparation example provides a functionalized adhesive, which is prepared by the following steps:

[0058] Dopamine and polyacrylic acid were added to Tris-HCl buffer solution at pH 8 and stirred at 600 rpm for 5 min until homogeneous. Then, 30% by mass of silica sol was added, the stirring speed was adjusted to 1000 rpm, the temperature was raised to 34℃, and stirring was continued for 12 min to obtain the functionalized binder. The mass ratio of dopamine, polyacrylic acid, Tris-HCl buffer solution and silica sol was 2:10:50:0.8.

[0059] Preparation Example 5

[0060] This preparation example provides a functionalized adhesive, which is prepared by the following steps:

[0061] Dopamine and polyacrylic acid were added to Tris-HCl buffer solution with pH 8.5 and stirred at 620 rpm for 7 min until homogeneous. Then, 35% by mass of silica sol was added, the stirring speed was adjusted to 1100 rpm, and stirring was continued for 14 min to obtain the functionalized binder. The mass ratio of dopamine, polyacrylic acid, Tris-HCl buffer solution and silica sol was 2.5:12:55:1.0.

[0062] Preparation Example 6

[0063] This preparation example provides a functionalized adhesive, which is prepared by the following steps:

[0064] Dopamine and polyacrylic acid were added to Tris-HCl buffer solution with pH 9 and stirred at 640 rpm for 9 min until homogeneous. Then, 40% by mass of silica sol was added, the stirring speed was adjusted to 1200 rpm, the temperature was raised to 37°C, and stirring was continued for 16 min to obtain the functionalized binder. The mass ratio of dopamine, polyacrylic acid, Tris-HCl buffer solution and silica sol was 3:14:60:1.2.

[0065] Comparative preparation example 3

[0066] This comparative preparation example provides a functionalized adhesive, which is prepared by the following steps:

[0067] Polyacrylic acid was added to Tris-HCl buffer solution with pH 8 and stirred at 600 rpm for 5 min until homogeneous. Then, 20% by mass of silica sol was added, the stirring speed was adjusted to 1000 rpm, the temperature was raised to 40℃, and stirring was continued for 12 min to obtain the functionalized adhesive. The mass ratio of polyacrylic acid, Tris-HCl buffer solution and silica sol was 10:50:0.8.

[0068] Comparative preparation example 4

[0069] This comparative preparation example provides a functionalized adhesive, which is prepared by the following steps:

[0070] Dopamine and polyvinyl alcohol were added to a Tris-HCl buffer solution with a pH of 8 and stirred at 600 rpm for 5 minutes until homogeneous. Then, 20% silica sol was added, the stirring speed was adjusted to 1000 rpm, the temperature was raised to 34°C, and stirring was continued for 12 minutes to obtain a functionalized binder. The mass ratio of dopamine, polyvinyl alcohol, Tris-HCl buffer solution and silica sol was 2:10:50:0.8.

[0071] Examples 1-3 and Comparative Examples 1-4 provide a method for preparing photochromic functional ceramic materials.

[0072] Example 1

[0073] This embodiment provides a method for preparing photochromic functional ceramic materials, including the following steps:

[0074] Step S1, Primary grinding: Niobium pentoxide, lithium carbonate, sodium carbonate, praseodymium oxide and anhydrous ethanol are mixed, the ball mill speed is controlled at 480 rpm, the ball milling time is 26 h, dried at 60℃, and passed through a 300 mesh sieve to obtain primary grinding material, wherein the mass ratio of niobium pentoxide, lithium carbonate, sodium carbonate, praseodymium oxide and anhydrous ethanol is 36.3:1:7.3:0.17:500;

[0075] Step S2: Preparation of photochromic material: Place the primary grinding material in a high-temperature sintering furnace, heat it to 920°C at a heating rate of 1°C / min, and cool it to room temperature to obtain the photochromic material.

[0076] Step S3: Preparation of green body: The photochromic material is added to an 8% (w / w) ethanol aqueous solution and ground twice for 14 min. Then, the reinforcing component prepared in Preparation Example 1, the functionalized binder prepared in Preparation Example 4, and p-toluenesulfonic acid are added. The mixture is stirred at 900 rpm for 12 min until homogeneous. The mixture is then placed in a mold and dry-pressed at a pressure of 6 MPa for 1 min. Finally, it is cold-pressed at a pressure of 260 MPa, a temperature of 64°C, and a time of 2 min to obtain the green body. The mass ratio of the photochromic material, ethanol aqueous solution, reinforcing component, functionalized binder, and p-toluenesulfonic acid is 90:42:8:10:0.2.

[0077] Step S4: Preparation of photochromic functional ceramic material: Place the green body in an alumina crucible, place it in a high-temperature box furnace, heat it to 540℃ at a heating rate of 1℃, hold it at that temperature for 4.5h, then heat it to 1220℃ at a heating rate of 3℃ / min, hold it at that temperature for 3.6h, and cool it to room temperature to obtain the photochromic functional ceramic material.

[0078] Example 2

[0079] This embodiment provides a method for preparing photochromic functional ceramic materials, including the following steps:

[0080] Step S1, Primary grinding: Niobium pentoxide, lithium carbonate, sodium carbonate, praseodymium oxide and anhydrous ethanol are mixed, the ball mill speed is controlled at 510 rpm, the ball milling time is 24 h, dried at 64℃, and passed through a 320 mesh sieve to obtain primary grinding material, wherein the mass ratio of niobium pentoxide, lithium carbonate, sodium carbonate, praseodymium oxide and anhydrous ethanol is 36.3:3:10.2:0.19:550;

[0081] Step S2: Preparation of photochromic material: Place the primary grinding material in a high-temperature sintering furnace, heat it to 950℃ at a heating rate of 2℃ / min, hold it at that temperature for 2.0h, and cool it to room temperature to obtain the photochromic material;

[0082] Step S3: Preparation of green body: The photochromic material is added to a 10% (w / w) ethanol aqueous solution and ground twice for 18 min. The reinforcing component prepared in Preparation Example 2 and the functionalized binder prepared in Preparation Example 5 are then added and stirred at 940 rpm for 14 min until homogeneous. The mixture is then placed in a mold and dry-pressed at a pressure of 7 MPa for 1.5 min. Cold isostatic pressing is then performed at a pressure of 290 MPa, a temperature of 68°C, and a time of 3 min to obtain the green body. The mass ratio of the photochromic material, ethanol aqueous solution, reinforcing component, functionalized binder, and pyridine is 95:44:10:13:0.4.

[0083] Step S4: Preparation of photochromic functional ceramic material: Place the green body in an alumina crucible, place it in a high-temperature box furnace, heat it to 550℃ at a heating rate of 2℃, hold it for 5h, then heat it to 1240℃ at a heating rate of 4℃ / min, hold it for 3.8h, and cool it to room temperature to obtain the photochromic functional ceramic material.

[0084] Example 3

[0085] This embodiment provides a method for preparing photochromic functional ceramic materials, including the following steps:

[0086] Step S1, Primary grinding: Niobium pentoxide, lithium carbonate, sodium carbonate, praseodymium oxide and anhydrous ethanol are mixed, the ball mill speed is controlled at 540 rpm, the ball milling time is 22 h, dried at 68℃, and passed through a 340 mesh sieve to obtain primary grinding material, wherein the mass ratio of niobium pentoxide, lithium carbonate, sodium carbonate, praseodymium oxide and anhydrous ethanol is 36.3:3:10.2:0.19:550;

[0087] Step S2: Preparation of photochromic material: Place the primary grinding material in a high-temperature sintering furnace and heat it to 980°C at a heating rate of 3°C / min. Cool it to room temperature to obtain the photochromic material.

[0088] Step S3: Preparation of green body: The photochromic material is added to a 12% (w / w) ethanol aqueous solution and ground twice for 22 min. The reinforcing component prepared in Preparation Example 3, the functionalized binder prepared in Preparation Example 6, and p-toluenesulfonic acid are then added. The mixture is stirred at 980 rpm for 16 min until homogeneous. The mixture is then placed in a mold and dry-pressed at a pressure of 8 MPa for 2 min. Cold isostatic pressing is then performed at a pressure of 320 MPa, a temperature of 72°C, and a time of 4 min to obtain the green body. The mass ratio of the photochromic material, ethanol aqueous solution, reinforcing component, functionalized binder, and p-toluenesulfonic acid is 100:46:12:16:0.6.

[0089] Step S4: Preparation of photochromic functional ceramic material: Place the green body in an alumina crucible, place it in a high-temperature box furnace, heat it to 560℃ at a heating rate of 3℃, hold it for 5.5h, then heat it to 1320℃ at a heating rate of 5℃ / min, hold it for 4h, and cool it to room temperature to obtain the photochromic functional ceramic material.

[0090] Comparative Example 1

[0091] Comparative Example 1 is the same as Example 1, except that the reinforcing component in Example 1 is replaced with the reinforcing component prepared in Comparative Preparation Example 1.

[0092] Comparative Example 2

[0093] Comparative Example 2 is the same as Example 1, except that the reinforcing component in Example 1 is replaced with the reinforcing component prepared in Comparative Preparation Example 2.

[0094] Comparative Example 3

[0095] Comparative Example 3 is the same as Example 1, except that the functionalized adhesive in Example 1 is replaced with the functionalized adhesive prepared in Comparative Preparation Example 3.

[0096] Comparative Example 4

[0097] Comparative Example 4 is the same as Example 1, except that the functionalized adhesive in Example 1 is replaced with the functionalized adhesive prepared in Comparative Preparation Example 4.

[0098] Performance testing

[0099] The performance of the photochromic functional ceramic materials prepared in Examples 1-3 and Comparative Examples 1-4 was tested.

[0100] Vickers hardness test: The Vickers hardness of the photochromic functional ceramic material prepared above was tested according to GB / T 16534-2009 "Test method for room temperature hardness of fine ceramics".

[0101] Bending strength test: The bending strength of the photochromic functional ceramic material prepared above was tested according to GB / T6569-2006 "Test Method for Bending Strength of Fine Ceramics";

[0102] Fracture toughness test: The fracture toughness value of the photochromic functional ceramic material prepared above was tested according to GB / T 23806-2009 "Test method for fracture toughness of fine ceramics - single-sided pre-cracked beam (SEPB) method".

[0103] Table 1 Performance parameters of the photochromic functional ceramic materials prepared in Examples 1-3 and Comparative Examples 1-4

[0104] Test performance Vickers hardness / GPa Flexural strength / MPa <![CDATA[Fracture toughness / MPa•m 1 / 2 > Example 1 5.52 268 2.6 Example 2 5.61 274 2.9 Example 3 5.57 265 2.4 Comparative Example 1 4.86 245 1.9 Comparative Example 2 5.26 236 2.1 Comparative Example 3 4.63 181 1.6 Comparative Example 4 4.74 206 1.7

[0105] As shown in Table 1, compared with Comparative Examples 1-4, the photochromic functional ceramic materials prepared in Examples 1-3 have superior mechanical strength.

[0106] This specific embodiment is merely an explanation of the present invention and is not intended to limit the invention. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they are within the scope of the claims of the present invention.

Claims

1. A photochromic functional ceramic material, characterized in that, The mixture includes reinforcing components, photochromic materials, functionalized binders, catalysts, and solvents, wherein the mass ratio of the photochromic materials, solvents, reinforcing components, functionalized binders, and catalysts is 90-100:42-46:8-12:10-16:0.2-0.

6. The reinforcing component is first obtained by precipitation of saturated aluminum sulfate solution and sodium aluminate aqueous solution to obtain a gel, which is then coated with nano-silica obtained by hydrolysis of tetraethyl orthosilicate to obtain core-shell particles, and then modified with a silane coupling agent. The silane coupling agent is γ-aminopropyltriethoxysilane or γ-aminopropylmethyldiethoxysilane; The photochromic material is prepared by calcining niobium pentoxide, lithium carbonate, sodium carbonate, and praseodymium oxide. The functionalized adhesive is prepared by the following steps: Dopamine and polyacrylic acid were added to Tris-HCl buffer solution with pH 8-9 and stirred until homogeneous. Then silica sol was added, the temperature was raised to 34-40℃, and stirring was continued for 12-16 minutes to obtain the functionalized adhesive.

2. The photochromic functional ceramic material according to claim 1, characterized in that, The reinforcing component is prepared by the following steps: Step A1: While stirring, add saturated aluminum sulfate solution dropwise to sodium aluminate aqueous solution, controlling the addition to be completed within 15 minutes. After the addition is completed, continue stirring for 18-22 minutes to obtain a gel. Vacuum filter the gel to obtain a filter cake. Add the filter cake to an ethanol aqueous solution, stir evenly, adjust the pH value to 8.8-9.2, then add tetraethyl orthosilicate, heat to 50-66℃, continue stirring and reacting for 1.2-1.6 hours, centrifuge, wash the precipitate, and dry to obtain core-shell particles. Step A2: Add the core-shell particles to deionized water, heat to 35-45℃, sonicate for 8-12 minutes, and add a mixture of silane coupling agent and anhydrous ethanol dropwise while stirring, completing the addition within 15 minutes. After the addition is complete, heat to 45-55℃ and stir the reaction for 2.2-2.4 hours. Centrifugation, washing and drying of the precipitate yields the reinforcing component.

3. The photochromic functional ceramic material according to claim 2, characterized in that, In step A1, the mass ratio of saturated aluminum sulfate solution, sodium aluminate aqueous solution, tetraethyl orthosilicate and ethanol aqueous solution is 10-14:18-30:50-60:450-550.

4. The photochromic functional ceramic material according to claim 2, characterized in that, In step A2, the mass ratio of core-shell particles, deionized water, and mixture a is 3-5:55-65:28-32, and the mass ratio of silane coupling agent and anhydrous ethanol in mixture a is 0.4-0.8:

30.

5. The photochromic functional ceramic material according to claim 1, characterized in that, The mass ratio of dopamine, polyacrylic acid, Tris-HCl buffer, and silica sol is 2-3:10-14:50-60:0.8-1.

2.

6. The photochromic functional ceramic material according to any one of claims 1-5, characterized in that, Specifically, it is prepared by the following steps: Step S1, Primary grinding: Niobium pentoxide, lithium carbonate, sodium carbonate, praseodymium oxide and anhydrous ethanol are mixed, wet ball milled, dried and sieved to obtain primary grinding material; Step S2: Preparation of photochromic material: Place the primary grinding material in a high-temperature sintering furnace for pre-sintering, cool to room temperature, and obtain the photochromic material; Step S3: Preparation of green body: Add the photochromic material to the solvent, grind it twice, then add the reinforcing component, functionalized binder and catalyst, stir evenly, place it in the mold, dry press and cold isostatic pressing to obtain the green body; Step S4: Preparation of photochromic functional ceramic material: Place the green blank in an alumina crucible, place it in a high-temperature box furnace, perform debinding treatment, then perform high-temperature sintering, and cool to room temperature to obtain photochromic functional ceramic material.

7. The photochromic functional ceramic material according to claim 6, characterized in that, In step S1, the mass ratio of niobium pentoxide, lithium carbonate, sodium carbonate, praseodymium oxide, and anhydrous ethanol is 36.3:1-5:7.3-13.1:0.17-0.21:500-600. The wet ball milling process is specifically as follows: the ball milling speed is 480-540 rpm, and the ball milling time is 22-26 h.

8. The application of the photochromic functional ceramic material as described in claim 6 in functional ceramic parts.