Nanoscale high-purity aluminum oxide preparation method

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...

AI Technical Summary

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 controllable particle size, but the two-stage calcination process is more troublesome. And the roasting time is longer; the Chinese patent "Preparation of high-purity ultra-fine alumina powder technology by aluminum alcohol hydrolysis" (CN1316382A) roasts hydrated alumina at 750-1180°C for 200-220min, and the heating rate is 3-4°C / min. Obtain ultra-fine high-purity alumina, but the obtained alumina cannot reach the nanometer level

Images