Nanoporous fibers built with carbon-bound SiO2 nanospheres via electrospinning and calcination

Porous silica fibers were fabricated aiming to broaden the applications of SiO 2 nanosphere materials. The fibers were built with SiO 2 nanospheres via electrospinning and calcinations . At first, SiO 2 nanospheres (synthesized by Stober method) were surface-modified using γ-aminopropyltriethoxysilane to obtain SiO 2 -NH 2 nanospheres, which dispersed homogeneously in the solvent. Then, polyacrylonitrile (PAN) and polymethylmethacrylate (PMMA) were introduced in different weight ratios into the suspension. Subsequently, PAN/PMMA/SiO 2 composites were electrospun , followed by preoxidization and calcination to transfer PAN into carbon form and to remove PMMA component. Thus, porous silica fibers were fabricated with SiO 2 nanospheres binding together during carbonization and porous structure was formed. The porosity, pore size and pore volume of porous silica fibers were controllable by adjusting the content of SiO 2 nanospheres and the weight ratio of PAN/PMMA. Accordingly, the drug adsorption and release performance of these porous silica fibers depended on their micro-structural features. The thus-obtained porous silica fibers displayed great potentials in applications such as drug carriers and adsorbents.