Novel SiC/C Aerogels Through Pyrolysis of Polycarbosilane Precursors1. Issue 6 (28th April 2014)

• Record Type: Journal Article
• Authors: Zera, Emanuele; Campostrini, Renzo; Aravind, Parakkulam Ramaswamy; Blum, Yigal; Sorarù, Gian Domenico; Travitzky, Nahum; Medvedovski, Eugene
• Is Part Of: Advanced engineering materials. Volume 16:Issue 6(2014:Jun.)
• Page Start: 814
• Page End: 819
• Publication Date: 2014-04-28
• Subjects: Materials -- Periodicals; 620.11
• DOI: 10.1002/adem.201400134
• Languages: English
• ISSNs: 1438-1656

Abstract

<abstract abstract-type="main" xml:lang="en"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="adem201400134-sec-0001" sec-type="section"> <p>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.</p> </sec> </abstract>