Extreme Thermal Shielding Effects in Nanopaper Based on Multilayers of Aligned Clay Nanoplatelets in Cellulose Nanofiber Matrix

Thin films consisting of highly aligned clay nanoplatelets embedded in cellulose nanofiber matrix can withstand the penetration of a flame torch (temperature ≈ 900 °C) with a stable temperature drop >600 °C on the unexposed side. Clay nanoplatelets provide high through-thickness interface density and thermal shielding properties, while nanocellulose expands to form thermally stable carbonaceous residue connecting clay platelets.