Preparation of aerogel-like SiOC ceramic with honeycomb structure and its high-temperature performance

Development of lightweight ceramic aerogel with enhanced thermal insulation and high temperature re-sistance is required in the field of thermal insulation. Here, a aerogel-like SiOC ceramic with honeycomb structure was prepared by solvothermal method using polyhydromethylsiloxane (PHMS) as precursor and divinylbenzene (DVB) as cross-linker followed by freeze-drying and pyrolysis. The pore size and homo-geneity of the honeycomb structure could be further controlled by the content of DVB through adjusting the crosslinking degree of the PSO wet gel. The aerogel-like SiOC possessing uniform honeycomb structure with the pore size of 20-50 mu m and the wall thickness of 3-6 mu m is obtained at the mass ratio of DVB:PHMS of 2:1. The aerogel-like SiOC exhibits low density (0.14 g center dot cm-3) and low thermal conductivity (0.0577 W center dot m-1 center dot K-1). Moreover, it maintains the honeycomb structure after high temperature treatment at 1400 degrees C in argon and 800 degrees C in air indicating its good thermal stability. This work provides a novel route for the preparation of the aerogel-like SiOC ceramic with honeycomb structure and designable overall per-formance, further expanding its application in thermal insulation. (c) 2022 Elsevier B.V. All rights reserved.