SiC-Coated Carbon Nanotubes with Enhanced Oxidation Resistance and Stable Dielectric Properties

• Main Authors: Rong Li, Yuchang Qing, Juanjuan Zhao, Shiwen Huang
• Format: Article
• Language: English
• Published: MDPI AG 2021-05-01
• Series: Materials
• Subjects: carbon nanotubes; polycarbosilane; pyrolysis; antioxidation; dielectric properties
• Online Access: https://www.mdpi.com/1996-1944/14/11/2770

Carbon nanotubes (CNTs) coated with SiC coating was successfully prepared by pyrolysis of polycarbosilane (PCS) used as a precursor. The function of pyrolysis temperature on the oxidation resistance and the dielectric properties of CNTs/SiC were studied in X-band. The results demonstrate that the obtained dense SiC film can prevent the oxidation of CNTs when the pyrolysis temperature reaches 600 °C. Correspondingly, after heat treatment is at 400 °C for 200 h, the mass loss of P-600 is less than 1.86%, and the real and imaginary parts of the dielectric constant nearly keep constant (ε′ from 14.2 to 14, and ε″ from 5.7 to 5.5). SiC-coated CNTs have a better oxidation resistance than pristine CNTs. Therefore, this work, with a facile preparation process, enhances the oxidation resistance of CNTs at high temperature for a long time and maintains a stable dielectric property, which means CNTs/SiC composites can be good candidates for applications in the field of high-temperature absorbers.