Efficient synthesis of hollow silica microspheres useful for porous silica ceramics.

Hollow silica microspheres (HSMs) have been successfully synthesized in large quantities using colloidal carbon spheres (CCSs) as template, cetyltrimethylammonium bromide (CTAB) as modifying agent and tetraethylorthosilicate (TEOS) as silicon source. The CCSs are fabricated by a simple hydrothermal treatment of D -glucose, which exhibit well monodisperse and homogeneous in dimension. The CTAB effectively modifies the surface charge characteristics of CCSs, which provides a favorable circumstance for the deposition of TEOS hydrolysis products. The HSMs can be eventually obtained after CCSs and CTAB being removed by sintering. The as-prepared HSMs are nearly uniform in dimension with particle size of about 500 nm. Porous silica ceramics with a three-dimensional network structure is prepared using these HSMs as raw material. Such ceramics possesses low density and dielectric constant, which make it very potential in the application of lightweight or low dielectric materials. [ABSTRACT FROM AUTHOR]