Pore structure, thermal insulation and compressive property of ZrO2 nanofiber aerogels with carbon junction fabricated by freeze drying

Abstract

ZrO2 nanofiber aerogels with carbon as fiber junction were fabricated by freeze drying. The effects of resorcinol-formaldehyde (RF) content and fiber content on the pore structure, thermal property and compressive property of ZrO2/C nanofiber aerogels were systematically investigated. ZrO2/C nanofiber aerogels have ultra-high porosity above 99.4%, and possess hierarchical pore structure with honeycomb pores in the micro-scale and minor pores in the nano-scale. Both RF content and fiber content have effects on the porosity, thermal conductivity and plateau stress of ZrO2/C nanofiber aerogels. Thermal conductivity is in the range of 0.0332–0.036 W·m−1·K−1. With the increase in RF content or fiber content, both thermal conductivity and plateau stress increase. The thermal transfer mode and compressive deformation mode were analyzed. Fiber junctions play a significant role during the thermal transfer and compression of ZrO2/C nanofiber aerogels.