Improvement of the thermal stability of silicone-based aerogels without deteriorating their flexibility via the incorporation of well-dispersed carbon nanotubes

• Published in: Journal of sol-gel science and technology 2023-06, Vol.106 (3), p.663-671
• Main Authors: Shimizu, Taiyo, Yamada, Takeo, Matsumoto, Naoyuki, Kokubo, Ken, Hata, Kenji
• Format: Article
• Language: English
• Subjects: Aerogels; Carbon; Carbon nanotubes; Ceramics; Chemistry and Materials Science; Composites; Compressive properties; cryogels; etc.; Flexibility; Glass; High temperature; Inorganic Chemistry; Materials Science; Modulus of elasticity; Nanotechnology; Natural Materials; Optical and Electronic Materials; Original Paper: Nano- and macroporous materials (aerogels; Scavenging; Silicones; Thermal stability; Thermogravimetric analysis; Weight loss; xerogels
• ISSN: 0928-0707; 1573-4846
• DOI: 10.1007/s10971-023-06110-0

This study reports on the successful improvement of the thermal stability of silicone-based aerogels by incorporating carbon nanotubes (CNTs) without sacrificing their mechanical flexibility. Organic-inorganic hybrid aerogels, such as silicone-based aerogels, offer superior mechanical flexibilities compared to inorganic aerogels, but exhibit lower thermal stability at high temperatures. Our results show that CNT/polymethylsilsesquixoane (PMSQ, CH 3 SiO 3/2 ) composite aerogels exhibit improved high-temperature stability, with a 70 °C increase in the temperature for 10% weight loss, revealed by thermogravimetric analysis. Judging from the results of the analysis of the gas evolved during heating, this improvement in thermal stability is likely due to the radical scavenging activities of CNTs. Furthermore, these CNT/PMSQ composite aerogels demonstrated comparable or even better deformation behavior under uniaxial compression. It was found that the use of centrifugation process can preserve the native properties of PMSQ such as mechanical flexibilities and thermally insulating properties, and even enhance compressive modulus and resilience against compression. Our findings highlight the potential of CNTs for improving the thermal stability of organic-inorganic hybrid aerogels without sacrificing their inherent properties. Graphical Abstract The thermal stability of polymethylsilsesquioxane aerogels in an atmospheric condition can be improved by the incorporation of well-dispersed carbon nanotubes. Highlights Carbon nanotube-incorporated silicone-based composite aerogels exhibited better thermal stability. Obtained composite aerogels exhibited comparable or even better compressive behavior. Centrifugation process is of critical importance to the resultant properties of composite aerogels.