Evaluation of crosslinking and surface coating on the moisture resistance of freeze‐dried clay aerogel

Moisture resistance, referring to the stability of compressive strength and thermal conductivity against the exposure of moisture, is critical to thermal insulation products. So far, seldom reports placed their attentions on the comprehensive investigation of crosslinking and surface coating on the performance of freeze‐dried clay aerogel for the purpose of thermal insulation. In this study, the strategies of crosslinking and surface coating have been applied on freeze‐dried PVA/clay aerogel, respectively. Both strategies are demonstrated to be effective on the improvement of the moisture resistance of aerogel. In comparison, surface coating endows aerogel with higher compressive strength, thermal resistance and thermal stability owing to the well‐preserved house‐card structure and rigid silica layers on the surfaces of laminas and bridges. The current results indicate surface coating has a great potential in the preparation of freeze‐dried aerogel for the purpose of thermal insulation. POLYM. COMPOS., 39:3810–3816, 2018. © 2017 Society of Plastics Engineers