Novel SiC/C Aerogels Through Pyrolysis of Polycarbosilane Precursors

Advanced Engineering Materials - Tập 16 Số 6 - Trang 814-819 - 2014
Emanuele Zera1, R. Campostrini1, Aravind Parakkulam Ramaswamy1, Yigal D. Blum2, Gian Domenico Sorarù1
1Dipartimento di Ingegneria Industriale Università di Trento Via Mesiano 77 Trento 38123 Italy
2SRI International, Menlo Park CA. USA

Tóm tắt

A new approach for forming aerogels with various silicon‐based compositions and hybrids between ceramics and carbon has been developed by combining efficient hydrosilylation as the hybridization‐crosslinking approach associated with gelation in the presence of solvent and followed by supercritical drying techniques. Highly porous carbon‐enriched SiC/C aerogels with adequate mechanical durability have been synthesized, pyrolyzed, and characterized. The “wet” gels were obtained by crosslinking a commercial polycarbosilane with divinylbenzene via Pt‐catalyzed hydrosilylation reaction in highly diluted condition (90 vol% of solvent). A supercritical drying was performed after exchanging the solvent (cyclohexane) with liquid CO2 forming undamaged aerogels. A subsequent pyrolysis and heat treatment (up to 1500 °C) in argon flow converted the polymeric aerogel into a SiC/C‐based material with bulk density of 166 kg m−3, SSA of 444 m2 g−1, a micro‐meso pore volume of 0.79 cm3 g−1, total porosity above 90 vol% and ultimate compressive strength of 1.6 MPa. The final product was compared to its cured gel and intermediates obtained during the pyrolysis process.

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Thông tin xuất bản

Advanced Engineering Materials

Tập 16 Số 6

814-819

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