Effects of silica sources on the properties of magnetic hollow silica

In this paper, magnetic hollow silica was synthesized through Pickering emulsion route with polymethyltriethoxysilane (PMTS) and tetraethoxysilane (TEOS) as silica sources. The effects of silica sources on the mechanical strength and adsorption ability of magnetic hollow silica were investigated. The formation process of magnetic hollow silica was discussed. The magnetic hollow silica prepared from PMTS has small size, smooth surface, good dispersivity and high mechanical strength. In contrast with TEOS as silica source, the slower hydrolysis and polymerization rates and lower hydrolysis degree of PMTS are beneficial to create compact silica layer, moreover, the weaker penetrability and better hydrophobicity lead the Fe3O4 particles to be wrapped in silica layers. In addition, as a coating material, the elasticity and toughness of PMTS and its polymer result in the improvements of mechanical strength and adsorption ability of magnetic hollow silica.