A distinct structure of TiC for electromagnetic interference shielding and thermal stability of SiTiOC ceramic nanocomposites

Abstract

Materials capable of thermal stability electromagnetic interference (EMI) shielding have practical significance in the fields of aerospace. In this paper, a brand-new polymer-derived SiTiOC ceramic nanocomposites with tubular carbon was designed. The titanium atoms were uniformly introduced into the polysiloxane backbone by the transesterification between tetrabutyl titanate and silanol prepolymer, leading to excellent thermal stability properties. By controlling the pyrolysis temperature, a distinct structure of TiC was formed between the amorphous SiTiOC matrix and free carbon phase for enhanced electromagnetic interference shielding performance. More conductive paths were established, and the TiC structure initiated interfacial polarization and space charge polarization, contributing to the improvement of the dielectric loss and relaxation phenomena. Simultaneously, a total electromagnetic interference shielding efficiency of 27.85 dB at the entire X-band was reported for SiTiOC ceramic nanocomposites. A maximum SET of 38.59 dB was examined at around 12 GHz, suggesting that over 99.99% of the electromagnetic waves were shielded. The SiTiOC ceramic nanocomposites exhibited outstanding prospects in thermal stability electromagnetic interference shielding application in a severe environment.