Nanoscale high-purity aluminum oxide preparation method

A high-purity alumina, nano-scale technology, applied in the direction of alumina/aluminum hydroxide, nanotechnology, etc., can solve the problems of troublesome roasting process, alumina can not reach the nano-scale, long roasting time, etc., to achieve fine grain size , less agglomeration and better grain development

Active Publication Date: 2012-07-04
SHANGHAI HUAMING HI TECH GRP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0005] The Chinese patent "Preparation method of ultrafine high-purity alumina" (CN1062124A) controls the roasting temperature and speed of alumina monohydrate: it takes 4-6 hours to raise the temperature from room temperature to 500°C ± 50°C, from 500°C ± Raise to 50°C to burn γ or α alumina, the temperature is 3-6 hours, and maintain the firing temperature for 2-6 hours to obtain ultra-fine high-purity alumina with control

Method used

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  • Nanoscale high-purity aluminum oxide preparation method
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  • Nanoscale high-purity aluminum oxide preparation method

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Embodiment 1

[0032] Add 306g of aluminum isopropoxide and 282.6g of isopropanol into a 1000ml three-neck flask equipped with an electric stirring device and a reflux condenser, heat to 70°C, and stir evenly. Then add 81g of deionized water, 6.3g of nitric acid with a weight concentration of 68% and 235.5g of isopropanol, stir and reflux for 3h, and then spin dry the sol at a temperature of 60°C and a gauge pressure of -64kPa for 1.7h , to recover the solvent. The obtained hydrated alumina powder is heated from room temperature to 900°C at a constant rate of 2.9°C / min, and the holding time is 3h, and then cooled to room temperature with the furnace to obtain the nano-alumina product of the present invention.

[0033] The resulting product is shown in the X-diffraction pattern figure 1 , for γ-Al 2 o 3 , the grains are well developed; the TEM photos are shown in figure 2 , its primary particle size is 10-35nm, its shape is spherical, no large hard agglomerated particles are seen; its sp...

Embodiment 2

[0036] Add 306g of aluminum isopropoxide and 212g of isopropanol into a 1000ml three-necked flask equipped with an electric stirring device and a reflux condenser, heat to 50°C, and stir evenly. Then add 54g of deionized water, 6.3g of nitric acid with a weight concentration of 68% and 117.75g of isopropanol, stir and reflux for 4h, then spin dry the sol at a temperature of 70°C and a gauge pressure of -42kPa for 2.4h , Recovery of solvent. The obtained hydrated alumina powder is heated from room temperature to 750°C at a constant speed of 2.5°C / min, the holding time is 2h, and then cooled to room temperature with the furnace to obtain the nano-alumina product of the present invention.

[0037] The obtained product was analyzed as γ-Al by X-ray diffraction 2 o 3 ; The primary particle size is 6-22nm according to the transmission electron microscope photo, the shape is spherical, and no large hard agglomerated particles are seen; the specific surface area is 258m 2 / g; purit...

Embodiment 3

[0040] Add 306g of aluminum isopropoxide and 212g of isopropanol into a 1000ml three-necked flask equipped with an electric stirring device and a reflux condenser, heat to 80°C, and stir evenly. Then add 81g of deionized water, 6.3g of nitric acid and 157g of isopropanol with a weight concentration of 68% to it, stir and reflux for 2h, and then the sol is rotated and dried at a temperature of 50°C and a gauge pressure of -80kPa for 2h, and recovered solvent. The obtained hydrated alumina powder was heated from room temperature to 850 °C at a constant rate of 2.7 °C / min, the holding time was 0.5 h, and then cooled to room temperature with the furnace to obtain the product of the present invention.

[0041] The obtained product was analyzed as γ-Al by X-ray diffraction 2 o 3 ; According to the analysis of transmission electron microscope photos, the primary particle size is 7-25nm, the shape is spherical, and no large hard agglomerated particles are seen; the specific surface ...

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Abstract

The invention provides a nanoscale high-purity aluminum oxide preparation method. The method comprises the steps of (1) dissolving organic aluminum alkoxide in an ethanol solvent to obtain a aluminum alkoxide phase A; (2) adding a catalyst, water and the ethanol solvent to the aluminum alkoxide phase A, and refluxing at 50 to 85 DEG C for 2 to 5h for hydrolysis to obtain a sol; and (3) drying to obtain hydrated aluminum oxide powder, uniformly rising temperature at a speed of 2.4 to 2.9 DEG C/min to a phase inversion temperature, keeping the temperature for 0.5 to 4h, and cooling the product to room temperature to obtain nanoscale high-purity aluminum oxide, wherein the phase inversion temperature is 700 to 920 DEG C. The method provided by the invention has simple process and easy operation, can improve the property of gamma-Al2O3 by controlling the baking conditions, and can be industrialized easily. The gamma-Al2O3 nanoparticles prepared by the method have the advantages of fine primary grain, good grain development condition, less agglomeration and good dispersity.

Description

technical field [0001] The invention relates to a preparation method of nano-alumina, in particular to an alkoxide hydrolysis method. Background technique [0002] Nano-alumina refers to alumina products with a particle size of less than 100 nanometers. It has a series of excellent properties such as high chemical stability, thermal stability, high hardness and corrosion resistance. It is not only widely used in structural ceramics, catalyst carriers, and catalysts. , fine ceramics, microporous filtration, and in the field of new materials such as integrated circuit substrate materials, fast ion conductor composite materials, fluorescent materials, moisture-sensitive sensors and infrared absorption materials. Because the nano-alumina powder has high purity, fine and uniform particles, and good dispersion, it is easy to mix evenly with additives, so it has good transparency. Therefore, it can be used as a protective film coating for the phosphor layer in compact fluorescent l...

Claims

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Application Information

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IPC IPC(8): C01F7/02B82Y40/00
Inventor 吴秋芳潘婧余蓉蓉李鹏孔凡滔
Owner SHANGHAI HUAMING HI TECH GRP
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