Etching process to selectively remove copper

Abstract

Advanced aerogel materials have great potential for applications in areas such as thermal insulation. However, the creation of a low-temperature resistant elastic aerogel remains a considerable challenge. Herein, we demonstrate an organic and inorganic hybrid strategy to develop a wood-based composite aerogel (wood/silica aerogels) by freeze drying. The silica nanoparticles are in situ grafted onto the wood nanofibers through the sol-gel method. The obtained wood/silica aerogels exhibit excellent hydrophobic (127°), flame-retardant (LOI = 44%), and thermal insulation performances (0.032 W m−1 K−1). More notably, wood/silica aerogels demonstrated elasticity and flexibility, performing torsion and elastic recovery even in liquid nitrogen (−196 °C). The successful synthesis of wood/silica aerogel provides a new idea for designing flexible thermal insulation materials with low temperature resistance.