Preparation and characterization of magnesia-coated silica particles by surface-induced precipitation method using magnesia alcoholate precursor

Monodispersed magnesia-coated silica particles were prepared by surface-induced precipitation method using two different magnesia precursors (magnesium alcoholate and magnesium hydroxide) and then calcined at 700 °C. The influence of the alkoxy group on the thermal decomposition behavior and morphological properties of magnesia coated on the surface of silica particles was investigated. The results showed that the degree of the crystallinity of magnesia coating from the alcoholate was significantly higher than that of the hydroxide. Furthermore, the magnesia-coated silica particles obtained from alcoholate exhibited spherical shape without the formation of hard aggregate in spite of heat treatment in comparison to that obtained from hydroxide. XPS investigation also confirmed that the magnesia coating layer and core silica particle were connected through the Mg–O–Si chemical bonding at the interface.