Effects of xonotlite additive and forming pressure on the properties of the SiO2-based nanoporous thermal insulation materials

Abstract

Nanoporous thermal insulation materials prepared with fumed SiO2 possess excellent thermal insulation property, and havebeen attracted much attention, but their mechanical properties are poor. Adding a small amount of fiber materials as atoughening material can improve the mechanical properties of the nanoporous thermal insulation materials. However, toomuch fiber materials additives will seriously affect the thermal insulation property. In this study, SiO2-based nanoporousthermal insulation materials were prepared, and the effects of addition amounts of xonotlite and forming pressure on themechanical performance and thermal insulation performance of as-prepared thermal insulation materials were investigated. It was found that addition of 10% xonotlite and forming pressure of 2MPa were proper for the preparation of SiO2-basednanoporous thermal insulation materials. The compressive strength and thermal conductivity of as-prepared materials were0.34 MPa and 0.031 W·m−1·K−1, respectively.