Novel self-reinforcing ZrO2–SiO2 aerogels with high mechanical strength and ultralow thermal conductivity

Abstract

Novel self-reinforcing ZrO2–SiO2 aerogels with high mechanical strength and ultralow thermal conductivity are fabricated by impregnating hydrolyzed ZrO2–SiO2 sol into wet gel matrix and drying. The ZrO2–SiO2 sol fills the macropores and defects of ZrO2–SiO2 aerogel matrix generating during the gelation process, which contributes to the improvement of the mechanical properties of the ZrO2–SiO2 aerogel matrix. The mechanical and thermal properties of the as-prepared ZrO2–SiO2 aerogel are investigated and discussed. The results show that the mechanical strength of the self-reinforcing aerogels obviously increases from 0.51 to 3.11 MPa with the increase of impregnation times, while the thermal conductivity of the aerogels slightly increases from 0.0235 to 0.0306 W m−1 K−1. The novel self-reinforcing ZrO2–SiO2 aerogel could have interesting applications in aerospace and energy because of its outstanding mechanical and thermal properties.