Anisotropic electrical conductivity in polymer derived ceramics induced by graphene aerogels

This article reports the fabrication of bulk polymer derived ceramics (PDCs) with anisotropic electrical properties attributed to embedded anisotropic reduced graphene oxide aerogels (rGOAs). The rGOAs function as a reinforcing frame to produce a bulk ceramic composite, and as a conductive network to improve the charge transport efficiency. 1 wt% embedded rGOAs increase the conductivity of PDC by more than eight orders of magnitude. The highly aligned graphene sheets also generate different electrical conductivity values in the longitudinal and transversal directions. The electrical conductivity along longitudinal direction is ten times higher than that along transversal direction. In addition, Raman spectroscopy and X-ray diffraction studies of PDCs with and without graphene indicate that graphene facilitates the transition of amorphous carbon to graphitic carbon in the PDCs. The SiCN/rGOA composites demonstrated high electrical conductivity at high temperature and good mechanical properties, leading to potential applications as electronics at high temperature.