writer：Chunjia Luo, Wenyan Duan, Xiaowei Yin and Jie Kong*
keywords：Microwave Absorbing, Polymer-Derived Ceramics
source：期刊
specific source：J. Phys. Chem. C, 2016, 120, 18721–18732
Issue time：2016年

Chunjia Luo, Wenyan Duan, Xiaowei Yin and Jie Kong*, Microwave AbsorbingPolymer-Derived Ceramics from Cobalt CoordinatedPoly(dimethylsilylene)diacetylenes, J. Phys. Chem. C, 2016, 120, 18721–18732

http://pubs.acs.org/doi/abs/10.1021/acs.jpcc.6b03995

Abstract: The microwave absorption materials in X-band with high-temperature resistance are the important and urgency topic in functional materials. In this contribution, we presented a useful and promising strategy to prepare cobalt-containing microwave absorption ceramics with high-temperature resistance. The polymer-derived ceramics were obtained via pyrolysis of carbon-rich poly(dimethylsilylene)diacetylenes coordinated with octacarbonyldicobalt. The XRD and Roman spectra revealed that the introduction of cobalt led to in situ formation of cobalt silicide nanocrystals and crystallized carbons (graphitic and tubular carbons), resulting in an enhanced microwave absorption property. The microwave absorption property and bandwidth could be tuned by controlling the cobalt content and annealing temperature of ceramics. When the average real permittivity, imaginary permittivity and loss tangent of materials increased to 8.06, 3.10 and 0.39, the reflection coefficient (RC) value of as-synthesized ceramics was lower than -10 dB almost across the whole X-band (8.46-12.4 GHz). The minimum RC value of -42.43 dB at 10.55 GHz showed over 99.99% absorption of electromagnetic waves. The high-performance cobalt-containing microwave absorption ceramics possess a promising potential in the field of electromagnetic interference protection.