Year: 2023
Type: article
Abstract: Porous polymer‐derived ceramics (PDCs) are outperforming materials when low‐density and thermal inertia are required. In this frame, thermal insulating foams such as silicon carbide (SiC) ones possess intriguing requisites for aerospace applications, but their thermal conductivity is affected by gas phase heat transfer and, in the high temperature region, by radiative mechanisms. Owing to the versatility of the PDC route, we present a synthesis pathway to embed PDC SiC aerogels within the open cells of a SiC foam, thus sensibly decreasing the thermal conductivity at 1000°C from 0.371 W·m −1 K −1 to 0.243 W·m −1 K −1 . In this way, it was possible to couple the mechanical properties of the foam with the insulating ability of the aerogels. The presented synthesis was optimized by selecting, among acetone, n‐hexane, and cyclohexane, the proper solvent for the gelation step of the aerogel formation to obtain a proper mesoporous colloidal structure that, after ceramization at 1000°C, presents a specific surface area of 193 m 2 ·g −1 . The so‐obtained ceramic composites present a lowest density of 0.18 g·cm −3 , a porosity of 90% and a compressive strength of 0.76 MPa.
DOI: 10.1111/jace.19118
Institutions: University of Trento, Technische Universität Darmstadt, Fraunhofer Research Institution for Materials Recycling and Resource Strategies IWKS, University of Naples Federico II, Izmir Institute of Technology, Institute of Condensed Matter Chemistry and Technologies for Energy, National Research Council
Language: English
Subfield: Ceramics and Composites
Field: Materials Science
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $4,070
Awards: G1523888516, G4516736450, G832006827
OpenAlex ID: W4362473990