Fabrication and characterization of silicon oxycarbide fibre-mats via electrospinning for high temperature applications

Abstract

Electrospinning is an emerging technique for synthesizing micron to submicron-sized polymer fibre supports for applications in energy storage, catalysis, filtration, drug delivery and so on. However, fabrication of electrospun ceramic fibre mats for use as a reinforcement phase in ceramic matrix composites or CMCs for aerospace applications remains largely unexplored. This is mainly due to stringent operating requirements that require a combination of properties such as low mass density, high strength, and ultrahigh temperature resistance. Herein we report fabrication of molecular precursor-derived silicon oxycarbide or SiOC fibre mats via electrospinning and pyrolysis of cyclic polysiloxanes-based precursors at significantly lower weight loadings of organic co-spin agent. Ceramic fibre mats, which were free of wrapping, were prepared by a one-step spinning (in air) and post heat-treatment for crosslinking and pyrolysis (in argon at 800 °C). The pyrolyzed fibre mats were revealed to be amorphous and a few microns in diameter. Four siloxane-based pre-ceramic polymers were used to study the influence of precursor molecular structure on the compositional and morphological differences of cross-linked and pyrolyzed products. Further thermal characterization suggested the potential of electrospun ceramic mats in high temperature applications.