Preparation method of a silica aerogel material loaded with a scintillation ceramic powder

Abstract

The present invention discloses a preparation method of a scintillation ceramic powder-supported silica aerogel material, which includes: preparing a mixed polymer gel from rare earth oxide Tb4O7 by the sol-gel method, drying and grinding the mixed polymer gel to obtain a precursor powder, and obtaining a scintillation ceramic powder through high-temperature sintering; placing tetraethyl orthosilicate, deionized water and ethanol in a container, mixing and stirring evenly, then adding scintillation ceramic powders with different doping ratios, adding ammonia water for catalysis after mixing and stirring, continuously stirring, and transferring to an appropriate mold when approaching the gel state to form a wet gel; soaking the wet gel in ethanol and then using supercritical drying with ethanol to obtain the scintillation ceramic powder-supported silica aerogel material. The scintillation ceramic powder-supported silica aerogel material prepared by the present invention has good luminescence performance and can be applied to military and civilian fields such as energy conservation and environmental protection, and luminescence lighting.

Description

Technical Field

[0001] The present invention belongs to the field of preparation of silica aerogel, and more specifically, the present invention relates to a method for preparing a scintillation ceramic powder loaded silica aerogel material. Background Art

[0002] Isotope energy is a new type of energy that is clean, highly safe and efficient. And a radiation light source prepared by exciting a fluorescent substance with β rays is one of the application forms of isotope energy. This self-luminous material system has stable light intensity, no external power supply, no maintenance, and is not affected by temperature, humidity, altitude and usage technology during use. Therefore, it is an excellent lighting system for dark conditions and small field of view lighting, and has good application prospects. Traditional surface radiation light sources have problems such as self-absorption of β rays by tritium gas, light-shielding property of phosphors and possible rupture of glass tubes, which affect the further improvement of the performance of radiation light sources and limit the expansion of their application fields.

[0003] An ideal radiation light source should be such that even if the light source breaks, it will not affect the luminescence performance, can effectively reduce the self-absorption of energy by the material, and at the same time is simple to operate and can meet large-scale industrial production. Summary of the Invention

[0004] An object of the present invention is to solve at least the above problems and / or defects and provide at least the advantages described hereinafter.

[0005] To achieve these objects and other advantages of the present invention, there is provided a method for preparing a scintillation ceramic powder loaded silica aerogel material, which is characterized by comprising the following steps:

[0006] Step 1: Prepare a light yellow mixed polymer gel from rare earth oxide Tb4O7 by the sol-gel method; dry and grind the obtained mixed polymer gel at 140-160 °C to obtain a precursor powder; then sinter the precursor powder at high temperature and finally cool it naturally to obtain a scintillation ceramic powder;

[0007] Step 2: Respectively take a certain amount of tetraethyl orthosilicate, deionized water and ethanol and place them in a container, mix and stir for 20-40 min; weigh the scintillation ceramic powder according to the doping ratio and add it to the container, mix and stir for 0.5-1.5 h; add ammonia water for catalysis and continue stirring. When it is close to the gel state, transfer it to an appropriate mold to form a wet gel; soak the obtained wet gel in ethanol for 22-26 h, and then use ethanol supercritical drying to obtain a scintillation ceramic powder loaded silica aerogel material.

[0008] Preferably, in the first step, the specific steps of the sol-gel method are as follows: Heat the HNO3 solution with a volume fraction of 40-60% to 80-100 °C, then weigh the rare earth oxide Tb4O7 and add it to the HNO3 solution, and mix and stir for 0.5-1.5 h until a colorless and transparent solution is obtained; perform acid drainage treatment on the solution; then, according to the molar amount of Tb4O7, weigh Al(NO3)3·9H2O, citric acid, and H3BO3 respectively according to the molar ratio, add them to the solution and stir for 1-2 h; react the solution at 70-90 °C for 3-4 h to obtain a pale yellow mixed polymer gel.

[0009] Preferably, the specific steps of the acid drainage treatment are as follows: Evaporate the solution to dryness, then add deionized water to dissolve it, repeat 2-4 times to remove excessive HNO3 until the pH of the solution is neutral.

[0010] Preferably, the volume-mass ratio of the HNO3 solution to Tb4O7 is 20-30 mL:0.5018 g.

[0011] Preferably, the molar ratio of Tb4O7, Al(NO3)3·9H2O, citric acid, and H3BO3 is 3:18-22:30-34:62-66.

[0012] Preferably, in the first step, the heating rate of high-temperature sintering is 5-15 °C / min, heat up to 550-650 °C and hold for 0.5-1.5 h, then heat up to 900-1100 °C and hold for 1.5-2.5 h.

[0013] Preferably, in the second step, the concentration of ammonia water is 1.5-2.5 mol / L.

[0014] Preferably, in the second step, the volume ratio of tetraethyl orthosilicate, deionized water, ethanol, and ammonia water is 1:0.5-1.5:3.5-4.5:0.19-0.32.

[0015] Preferably, in the second step, the doping ratio of the scintillation ceramic powder is 10%-15% of the total mass of tetraethyl orthosilicate and the scintillation ceramic powder, and the mass of tetraethyl orthosilicate is V 正硅酸乙酯 *0.51.

[0016] Preferably, the application of the scintillation ceramic powder-supported silica aerogel material prepared by the above preparation method in luminescence lighting.

[0017] The present invention has at least the following beneficial effects: The present invention prepares a scintillation ceramic powder by a simple sol-gel method, and prepares a silica aerogel material loaded with the scintillation ceramic powder by using tetraethyl orthosilicate as a silicon source in combination with an ethanol supercritical drying process. It has good luminescence performance, and even if the light source is broken, it will not affect the luminescence performance. It can also effectively reduce the self-absorption of the material for energy, and the process is simple, low in cost, energy-saving and environmentally friendly, and can meet large-scale industrial production.

[0018] Other advantages, objects and features of the present invention will be partly reflected by the following description, and partly will be understood by those skilled in the art through the research and practice of the present invention. Brief Description of the Drawings

[0019] Figure 1 PL spectrum (excitation wavelength 275 nm) of the scintillation ceramic powder prepared in Example 1;

[0020] Figure 2 Sample diagram of the silica aerogel material loaded with 10% doped scintillation ceramic powder prepared in Example 2;

[0021] Figure 3 Scanning electron microscope image of the silica aerogel material loaded with 10% doped scintillation ceramic powder prepared in Example 2;

[0022] Figure 4 Quantum yield comparison diagram of the test blank sample, the scintillation ceramic powder prepared in Example 1, the silica aerogel material loaded with 10% doped scintillation ceramic powder prepared in Example 2, and the silica aerogel material loaded with 15% doped scintillation ceramic powder prepared in Example 3;

[0023] Figure 5 For Figure 4 Partial enlarged view of. Detailed Description of the Embodiments

[0024] The following further describes the present invention in detail with reference to the drawings, so that those skilled in the art can implement it according to the description in the specification.

[0025] It should be understood that the terms such as "having", "comprising" and "including" used herein do not exclude the existence or addition of one or more other elements or their combinations.

[0026] Example 1

[0027] Prepare a scintillation ceramic powder, including the following steps:

[0028] Measure 20 mL of HNO3 solution with a volume fraction of 50% and heat it to 90 °C. Then weigh 0.5018 g of rare earth oxide Tb4O7 and add it to the HNO3 solution. Mix and stir for 1 h until a colorless and transparent solution is obtained. Evaporate the solution to dryness, add deionized water to dissolve it, repeat 2 - 3 times to remove the excess HNO3 until the pH of the solution is neutral. Then weigh 1.6778 g of Al(NO3)3·9H2O, 1.5033 g of citric acid, and 0.8877 g of H3BO3 respectively, add them to the solution and stir for 1 h. React the solution at 80 °C for 3 - 4 h to obtain a pale yellow mixed polymer gel. Dry and grind the mixed polymer gel at 150 °C to obtain a precursor powder. The precursor powder is sintered under high-temperature sintering conditions with a heating rate of 10 °C / min, heated to 600 °C and held for 1 h, then heated to 1000 °C and held for 3 h, and finally cooled naturally to obtain the scintillation ceramic powder;

[0029] Perform PL spectroscopy (excitation wavelength 275 nm) testing on the scintillation ceramic powder prepared in this example, and the results are as Figure 1 shown.

[0030] Example 2

[0031] A preparation method of a scintillation ceramic powder-supported silica aerogel material, comprising the following steps:

[0032] Step 1: Measure 20 mL of HNO3 solution with a volume fraction of 50% and heat it to 90 °C. Then weigh 0.5018 g of rare earth oxide Tb4O7 and add it to the HNO3 solution. Mix and stir for 1 h until a colorless and transparent solution is obtained. Evaporate the solution to dryness, add deionized water to dissolve it, repeat 2 - 3 times to remove the excess HNO3 until the pH of the solution is neutral. Then weigh 1.6778 g of Al(NO3)3·9H2O, 1.5033 g of citric acid, and 0.8877 g of H3BO3 respectively, add them to the solution and stir for 1 h. React the solution at 80 °C for 3 - 4 h to obtain a pale yellow mixed polymer gel. Dry and grind the mixed polymer gel at 150 °C to obtain a precursor powder. The precursor powder is sintered under high-temperature sintering conditions with a heating rate of 10 °C / min, heated to 600 °C and held for 1 h, then heated to 1000 °C and held for 3 h, and finally cooled naturally to obtain the scintillation ceramic powder;

[0033] Step 2: Take 25 mL of tetraethyl orthosilicate, 25 mL of deionized water, and 100 mL of ethanol and place them in a container. Mix and stir for 30 min. Weigh 1.4167 g of scintillating ceramic powder and add it to the container. Mix and stir for 1 h. Add 6 mL of 2 mol / L ammonia water for catalysis and keep stirring. When it is close to the gel state, transfer it to a mold to obtain 8 cylindrical wet gels with a diameter of 25 mm and a height of 20 mm at one time. Immerse the obtained wet gels in ethanol for 24 h, and then use ethanol supercritical drying to obtain a 10% doped ratio of scintillating ceramic powder-loaded silica aerogel material, as Figure 2 shown.

[0034] The scanning electron microscope image of the scintillating ceramic powder-loaded silica aerogel material prepared in this example is as Figure 3 shown.

[0035] Example 3

[0036] A preparation method of a scintillating ceramic powder-loaded silica aerogel material includes the following steps:

[0037] Step 1: Measure 20 mL of HNO3 solution with a volume fraction of 50% and heat it to 90 °C. Then weigh 0.5018 g of rare earth oxide Tb4O7 and add it to the HNO3 solution. Mix and stir for 1 h until a colorless and transparent solution is obtained. Evaporate the solution to dryness, add deionized water to dissolve it, and repeat 2 - 3 times to remove the excess HNO3 until the pH of the solution is neutral. Then weigh 1.6778 g of Al(NO3)3·9H2O, 1.5033 g of citric acid, and 0.8877 g of H3BO3 respectively, add them to the solution and stir for 1 h. React the solution at 80 °C for 3 - 4 h to obtain a pale yellow mixed polymer gel. Dry and grind the mixed polymer gel at 150 °C to obtain a precursor powder. The precursor powder is sintered under the high-temperature sintering conditions of a heating rate of 10 °C / min, heating to 600 °C and holding for 1 h, and then heating to 1000 °C and holding for 3 h, and finally naturally cooled to obtain a scintillating ceramic powder;

[0038] Step 2: Take 25 mL of tetraethyl orthosilicate, 25 mL of deionized water, and 100 mL of ethanol and place them in a container. Mix and stir for 30 min. Weigh 2.2504 g of scintillating ceramic powder and add it to the container. Mix and stir for 1 h. Add 6 mL of 2 mol / L ammonia water for catalysis and keep stirring. When it is close to the gel state, transfer it to a mold to obtain 8 cylindrical wet gels with a diameter of 25 mm and a height of 20 mm at one time. Immerse the obtained wet gels in ethanol for 24 h, and then use ethanol supercritical drying to obtain a 15% doped ratio of scintillating ceramic powder-loaded silica aerogel material.

[0039] The quantum yields of the scintillation ceramic powder prepared in Example 1, the silica aerogel material loaded with the 10% doped ratio scintillation ceramic powder prepared in Example 2, and the silica aerogel material loaded with the 15% doped ratio scintillation ceramic powder prepared in Example 3 were tested, with the blank sample as the control. The results are as Figure 4 shown. The quantum yield of the scintillation ceramic powder material prepared in Example 1 was 53.61%, the quantum yield of the silica aerogel material loaded with the 10% doped ratio scintillation ceramic powder prepared in Example 2 was 63.64%, and the quantum yield of the silica aerogel material loaded with the 15% doped ratio scintillation ceramic powder prepared in Example 3 was 23.07%. The different quantum yields indicate that there are differences in the energy utilization efficiency of each sample; the quantum yield of the silica aerogel material loaded with the 10% doped ratio scintillation ceramic powder is higher than that of the scintillation ceramic powder, indicating that the self-absorption effect of this sample on energy is lower and the energy utilization efficiency is higher; the quantum yield of the silica aerogel material loaded with the 15% doped ratio scintillation ceramic powder is lower than that of the scintillation ceramic powder, indicating that the self-absorption effect of this sample on energy is stronger and the energy utilization efficiency is lower.

[0040] It can be seen that compared with the scintillation ceramic powder, the quantum yield and the energy utilization efficiency of the silica aerogel loaded with the scintillation ceramic powder can be regulated by controlling the doping ratio. The 10% - 15% doping ratio is the result of the inventor's multiple experiments and creative work, and it has a better luminescence effect compared with samples with a lower doping ratio and is easier to control in the preparation process compared with samples with a higher doping ratio.

[0041] Although the embodiments of the present invention have been disclosed as above, it is not limited to the applications listed in the specification and embodiments. It can be fully applied to various fields suitable for the present invention. For those familiar with the field, additional modifications can be easily made. Therefore, without departing from the general concept defined by the claims and the equivalent scope, the present invention is not limited to the specific details and the examples shown and described herein.

Claims

1. A preparation method of a silica aerogel material loaded with a scintillation ceramic powder, characterized in that, It includes the following steps: Step 1: Prepare a pale yellow mixed polymer gel from rare earth oxide Tb4O7 by sol-gel method; dry and grind the obtained mixed polymer gel at 140 - 160 °C to obtain a precursor powder; then sinter the precursor powder at high temperature and finally cool it naturally to obtain a scintillation ceramic powder; the heating rate of the high-temperature sintering is 10 °C / min, heat up to 600 °C and hold for 0.5 - 1.5 h, then heat up to 1000 °C and hold for 1.5 - 2.5 h; Step 2: Respectively take a certain amount of tetraethyl orthosilicate, deionized water and ethanol and place them in a container, mix and stir for 20 - 40 min; weigh the scintillation ceramic powder according to the doping ratio and add it to the container, mix and stir for 0.5 - 1.5 h; add ammonia water for catalysis, continue stirring, and transfer it to an appropriate mold when it is close to the gel state to form a wet gel; Soak the obtained wet gel in ethanol for 22 - 26 h, and then use ethanol supercritical drying to obtain a scintillation ceramic powder-supported silica aerogel material; In the said Step 1, the specific steps of the sol-gel method are: heat the HNO3 solution with a volume fraction of 40 - 60% to 80 - 100 °C, then weigh the rare earth oxide Tb4O7 and add it to the HNO3 solution, mix and stir for 0.5 - 1.5 h until it becomes a colorless transparent solution; perform acid drainage treatment on the solution; then, according to the molar amount of Tb4O7, weigh Al(NO3)3·9H2O, citric acid and H3BO3 respectively according to the molar ratio, add them to the solution and stir for 1 - 2 h; react the solution at 70 - 90 °C for 3 - 4 h to obtain a pale yellow mixed polymer gel; among them, the volume-mass ratio of the HNO3 solution to Tb4O7 is 20 - 30 mL:0.5018 g; the molar ratio of Tb4O7, Al(NO3)3·9H2O, citric acid and H3BO3 is 3:18 - 22:30 - 34:62 - 66; the specific steps of the acid drainage treatment are: evaporate the solution to dryness, then add deionized water to dissolve it, repeat 2 - 4 times to remove the excessive HNO3 until the pH of the solution is neutral; In the second step, the doping ratio of the scintillating ceramic powder is 10% of the total mass of tetraethyl orthosilicate and the scintillating ceramic powder, and the mass of tetraethyl orthosilicate is .

2. The preparation method of a silica aerogel material loaded with a scintillation ceramic powder as described in claim 1, characterized in that, In the said Step 2, the concentration of ammonia water is 1.5 - 2.5 mol / L.

3. The preparation method of a silica aerogel material loaded with a scintillation ceramic powder as described in claim 1, characterized in that, In the said Step 2, the volume ratio of tetraethyl orthosilicate, deionized water, ethanol and ammonia water is 1:0.5 - 1.5:3.5 - 4.5:0.19 - 0.

32.

4. Application of a scintillation ceramic powder-supported silica aerogel material prepared by the preparation method according to any one of claims 1 - 3 in luminescent lighting.

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