Hierarchically structured polymer-derived ceramic fibers by electrospinning and catalyst-assisted pyrolysis

Hierarchically structured polymer-derived ceramic fibers were successfully produced by electrospinning a commercially available preceramic polymer to which a cobalt-based catalyst precursor was added, followed by pyrolysis in nitrogen at temperatures ranging from 1250 to 1400 degrees C. The nanowires formed via the vapor liquid solid (VLS) mechanism, involving the reaction of SiO and CO gases, generated from the decomposition of the polymer-derived-ceramic at high temperature, with the heating atmosphere assisted by the presence of nano-sized CoSi droplets. The main crystalline phase for the nanowires was Si3N4 below 1350 degrees C, and Si2N2O at 1400 degrees C, and the amount of nanowires increased with increasing heating temperature. Hierarchically structured fiber mats possessed a higher specific surface area (14.45 m(2)/g) than that of a sample produced without the cobalt catalyst (4.37 m(2)/g). (C) 2013 Elsevier Ltd. All rights reserved.