Silica microcapsules and microtubes prepared from rod-like and needle-like polyaniline templates

Rod-like or needle-like particles of polyanilinium p-toluene sulfonate have been used as templates for the formation of silica microcapsules or microtubes. Thus, an alkaline aqueous suspension of the needles was treated with tetraethyl orthosilicate to form silica-coated needles, which were subsequently calcined to remove the polyanilinium templates. The rod-like or needle-like polyaniline particles, their silica-coated derivatives and silica microcapsules or microtubes have been characterized by thermogravimetric analysis, Fourier transformation infrared spectroscopy, scanning electron microscopy (SEM), field emission scanning electron microscopy (FE-SEM), and transmission electron microscopy.