High strength, excellent thermal stability and high temperature insulation HNTs/Al 2 O 3 dual network aerogels

Abstract

Abstract Al2O3 aerogels are attractive for thermal insulation due to their low thermal conductivity at room temperature and high heat resistance performance. However, poor mechanical properties and high thermal conductivity at high-temperatures limit their practical applications. Herein, HNTs/Al2O3 interpenetrating dual network aerogels was successfully prepared by vacuum impregnation, sol-gel process and CO2 supercritical drying technology. The unique interpenetrating dual network structure of the HNTs/Al2O3 aerogels endows it with integrated performances of the excellent mechanical strength (1.85-2.06 MPa), good thermal stability (~1000 ℃) and ultralow thermal conductivity at high temperature (~0.055 W m-1 K-1, 1000 ℃). These favorable multi-features of aerogels are expected to be widely applied in aerospace and other high temperature environments.