期刊
JOURNAL OF MATERIALS CHEMISTRY C
卷 2, 期 6, 页码 1057-1067出版社
ROYAL SOC CHEMISTRY
DOI: 10.1039/c3tc32088j
关键词
-
资金
- NSFC [50802079, 51072169]
- Natural Science Foundation of Fujian Province of China [2011J01330]
Hydrosilylation of vinyl ferrocene with allylhydridopolycarbosilane was used to synthesize a processable hyperbranched polyferrocenylcarbosilane (HBPFCS), which was characterized by combination of gel permeation chromatography, Fourier transform infrared (FT-IR) spectroscopy, and nuclear magnetic resonance (NMR) spectroscopy. The polymer-to-ceramic transformation of the HBPFCSs was then investigated by FT-IR and C-13 MAS NMR spectroscopy as well as by thermal gravimetric analysis (TGA). A self-catalytic effect of ferrocenyl units in the HBPFCS skeleton on dehydrocoupling was found during a curing process at 170 degrees C resulting in a high ceramic yield of ca. 80% at 1200 degrees C in Ar. Finally, microstructures and magnetic properties of the final ceramics were studied by techniques such as X-ray diffraction, energy dispersive spectroscopy, Raman spectroscopy, transmission electron microscopy and vibrating sample magnetometry. The final ceramic (pyrolysis temperature >= 900 degrees C) is characterized by a microstructure comprised of a SiC/C/Fe nanocomposite. Turbostratic carbon layers located at the segregated alpha-Fe crystal boundary avoid interdiffusion and explain the exclusive existence of alpha-Fe in a SiC/C matrix even at 1300 degrees C. Variations of the iron content in the HBPFCSs and of the pyrolysis conditions facilitate the control of the composition and ceramic micro/nanostructure, influencing in particular magnetic properties of the final SiC/C/Fe nanocomposite ceramic.
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