Ultralight and resilient Al 2 O 3 nanotube aerogels with low thermal conductivity

Abstract This report describes a novel method to produce fluffy and resilient nanotube aerogels by combining solution blow spinning and Atom Layer Deposition ( ALD ). Polyvinylpyrrolidone ( PVP ) sponges obtained by blow spinning are used as templates and are deposited in ALD . After removal of template, semitransparent aerogels whose density can be as low as 0.68 mg/cm 3 were obtained. The product is heat‐stable, with the ability to retain original shape and keep elastic after being kept at 900°C for 2 hours. It is also heat‐insulated, with a thermal conductivity of 0.022 W/K∙m at room temperature. Additionally, when compressed to 60% of the original height for 100 cycles during in‐situ mechanical test, the sponges recovered to around 80% of the original shape, further indicating excellent mechanically elasticity of the aerogel.