Hebei Messi Biology Co., Ltd. stated that magnesium hydroxide whiskers are divided into two types: natural and synthetic. Fibrous brucite is a natural fibrous magnesium hydroxide. It has the advantages of white color, easy splitting, and high velvet yield. It is a variant of brucite ore. There are reserves of fibrous brucite ore in many areas of China. Traditional methods for preparing magnesium hydroxide whiskers mostly use high-temperature pyrolysis or simple hydrothermal methods. This method consumes a lot of energy, is costly, and the process is complex and difficult to reproduce.
Using Qinghai Dongtai brucite as the raw material, using sodium hydroxide solution containing a certain amount of organic solvent as the precipitant, using the microwave-hydrothermal method, the hydrothermal temperature is 180°C, the reaction time is 1.5h, and the mass of the organic solvent in the reaction system The fraction is 30%, and a magnesium hydroxide whisker product with good crystal shape, good dispersion and high purity is obtained, with a yield of 80%.
Add anionic surfactants such as sodium oleate and potassium oleate or a compound of nonionic surfactant OP-10 to an aqueous solution containing magnesium ions (including magnesium chloride, magnesium nitrate or magnesium sulfate). After stirring evenly, stir for 10 seconds. Add alkali solution dropwise at ℃ ~ 60 ℃ to perform precipitation reaction, and the resulting paste is dried at 70 ℃. The magnesium hydroxide product is a needle-shaped crystal with a short axis direction of 3nm~6nm and a long axis direction of 50nm~100nm.
Hebei Messi Biology Co., Ltd. stated that under stirring conditions, slowly add a certain amount of calcium hydroxide powder to the magnesium chloride solution and place it in a 45°C water bath to obtain a suspension. After the precipitate is filtered, it is filtered with distilled water, ethanol, and After rinsing with isopropyl alcohol and drying, a certain amount of ethanol aqueous solution and sodium hydroxide solution with a volume ratio of 3:1 were added, and stirred at a constant temperature of 62°C for 3 hours to obtain magnesium hydroxide whiskers.