Super-low thermal conductivity fibrous nanocomposite membrane of hollow silica/polyacrylonitrile

Abstract

Global warming aggravates mainly due to human activities, such as the massive use of fossil energy and excessive deforestation. Thus, reducing energy waste becomes has gained more importance. Thermal insulation materials with superlow thermal conductivity show notable potential in energy saving. Herein, an adiabatic hollow silica/polyacrylonitrile (SiO2-PAN) fibrous nanocomposite membrane was prepared via electrospinning. Hollow SiO2 spheres were prepared by using tetraethyl orthosilicate as a silica source and hydrothermal carbon spheres as the template. The thermal insulation property of PAN fibrous nanocomposite membrane can be enhanced by appending hollow SiO2 spheres. The solid conduction of the fibrous nanocomposite membrane was reduced by the addition of hollow SiO2 spheres. The composite fibrous nanocomposite membrane is flexible and achieves an optimal thermal conductivity of 16 mW/(m·K). The fibrous nanocomposite membrane can maintain its thermal insulation property and becomes hydrophobic after treatment with silicone oil. The developed membrane provides a new idea for the future development of thermal insulation materials.