Preparation of ultra-fine silica fibers using electrospun poly(vinyl alcohol)/silatrane composite fibers as precursor

Ultra-fine composite fibers made from poly(vinyl alcohol) (PVA)/silatrane, an inexpensive and moisture-stable silicon-containing compound, were prepared by a combined sol-gel processing and electrospinning technique with average diameters ranging between 119 and 405 nm. These fibers were subsequently converted to ultrafine silica fibers by calcination treatment, with the aim of producing a silica structure with a high surface area-to-mass ratio. Upon calcination at 500 degrees C, the PVA/silica composite fibers were converted into amorphous silica fibers, while calcination of the composite fibers at temperatures >= 700 degrees C resulted in the formation of cristobalite fibers. The average diameter of these silica fibers ranged between 162 and 213 nm.