(70p) Synthesis of Magnesium Hydroxide and Oxide Nanoparticles Using a High-Gravity Technique

The aim of this research was to synthesize magnesium hydroxide nanoparticles, which were further calcined to form magnesium oxide, using a spinning disk reactor, which is a type of high-gravity equipment. First, magnesium hydroxide was prepared by continuously pumping two aqueous solutions of MgCl2 and NaOH respectively into the chamber of the reactor, where a liquid-liquid reaction took place to form Mg(OH)2. The effects of operating variables, including rotating speed (N), reactant concentration, and liquid flow rate (L1, L2) on the size of magnesium hydroxide nanoparticles were investigated. Particle morphology and size of magnesium oxide calcined from produced magnesium hydroxide were also analyzed. The particle size of magnesium hydroxide increased with increasing flow rate, but remained quite constant as reactants concentration varied. As far as the size and uniformity were concerned, the best result of lamellar magnesium hydroxide particles was 50-80nm in length and 10nm in thickness. Polyhedral nanoparticles of 30-70nm magnesium oxide were obtained by calcinating lamellar hydroxide.