Effect of Ethanol on Controlling Synthesis of MgO Modified Silica Hollow Spheres

Using Gemini surfactants GEM16-6-16 as template and ethanol as controlling agent, MgO-SiO2 complexes hollow spheres were synthesized by co-condensation or impregnation methods. As observed by XRD, SEM and TEM, the complexes are hollow spheres with diameter of 600 to 700 nm, and some of the MgO crystals grow on the surface of hollow spheres. The synthesis mechanism of hollow spheres was tentatively elucidated by studying the change of micelle structures of GEM16-6-16 in ethanol aqueous solutions with different molar ratios of ethanol to water, and also the effects of ethanol on the competition between hydrolysis and condensation of TEOS.