Effect of tourmaline addition on the structure of silica hollow microspheres prepared by a novel template method

Abstract

In this article, the silica hollow microspheres were prepared through the sol-gel method, using conglobate synechocystis sp. as the template with addition of tourmaline. The pretreated synechocystis sp. was implanted into the silica precursor, and then solidified into shell on the surface of synechocystis sp. template by means of condensation polymerization reaction along with base catalysts. Meanwhile, the effect of tourmaline addition on the structure of silica hollow microspheres was studied systematically. Results show that regular spherical silica hollow microspheres have been prepared with average particle size of about 2 μm and have a shell-thickness of about 80 nm. The addition of tourmaline is propitious to accelerate the sol-gel process of tetraethyl orthosilicate (TEOS), leading to the agglomeration degree decrease of silica hollow microspheres. The above phenomenon could be ascribed to enhancement of water molecules ionization due to spontaneous polarization and far infrared properties of tourmaline mineral materials, which accelerates the hydrolysis-condensation rate of TEOS. The silica hollow microspheres as prepared exhibited regular hollow spherical structure, so they could be applicated in the field of thermal insulation materials.