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

Abstract

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.

Preparation of Pt/CNT catalyst with high dispersion structure via plasma jet

“…The improved stability of Pt/CNT was attributed to a large number of defects caused by the high temperature effect of free arc on the surface of CNT, which forms a strong interface function between Pt-NP and CNT. As well as CNTs carriers have better oxidation resistance and are less susceptible to etching during redox reactions that cause Pt-NP to detach from the carrier, so Pt/CNT has higher durability [23] .…”

High temperature microwave absorbing materials

“…78 Ceramics are often utilized as the matrix of CNT-based HTMAMs, which can improve the thermal stability of the CNTs. Li et al 79 fabricated CNT/SiC composites via pyrolysis of polycarbosilane and investigated the dielectric and oxidation resistance properties of the composite at different pyrolysis temperatures. The CNTs could be prevented from the high temperature oxidation by coating SiC ceramics.…”

Advances in Carbon-Based Microwave Absorbing Materials

“…It is common to produce dielectric-magnetic synergy by decorating CNTs/CNFs with magnetic nanoparticles, while the synergy from two dielectric components is also concerned in recent advances. For example, Li et al coated CNTs with SiC, and the resultant composite (P-600) displayed much better oxidation resistance and stable dielectric properties than pristine CNTs [4]. After heat treatment at 400 • C for 200 h, the mass loss of P-600 was less than 1.86%, and the complex permittivity was almost unchanged.…”