Advanced thermal insulation and absorption properties of recycled cellulose aerogels

A cost effective and scalable recipe for fabricating biodegradable cellulose aerogels from paper waste has been realized. The green aerogel is macroporous and has extremely low density and thermal conductivity: 0.04 g cm−3 and 0.029–0.032 Wm−1K−1, respectively. It is highly absorbent, absorbing 18–20 times its weight in liquid. Up to 99.8% of the liquid is recovered simply by squeezing the aerogel. The fabrication can be optimized for absorbing polar (water) or non-polar liquids (oil). Coating the aerogel with methyltrimethoxysilane improves its hydrophobicity without affecting its absorbency. Mechanically, the aerogel is flexible yet strong making a wide range of applications possible.