Water-assisted synthesis of phenolic aerogel with superior compression and thermal insulation performance enabled by thick-united nano-structure

The applications of traditional organic aerogels are commonly restricted by their powder falling, expensive preparation, and poor mechanical property. Herein, we report a phenolic resin aerogel based on the nanostructure of thick-united phenolic particles instead of the traditional thin-united connection. The aerogels fabricated through sol-gel reaction and interfacial polymerization are endowed with superior mechanical and outstanding thermal insulation performances. The 3D networks of phenolic resin aerogel obtained through the water-assisted method (PRAW) with domain sizes below 90 nm result from the phase separation in nanoscale. The highly porous PRAW exhibits excellent compressive properties with the compressive strength and modulus reaching 18.3 and 62.23 MPa, respectively, when the strain exceeds 50% without catastrophic collapse. Furthermore, it possesses excellent high temperature protection ability: a 20 mm thick sample can resist the temperature of 1200 degrees C for 5 min, with a final back-side temperature of 57.7 degrees C. This newly inexpensive and environmental-friendly methodology for PRAW preparation provide a broad application prospect in the field of thermal insulation under harsh environments.