Ultrathin Freestanding Nanocellulose Film Prepared from TEMPO-Mediated Oxidation and Homogenized Hydrogel

This paper presents a versatile method to fabricate ultrathin nanofibrillated cellulose (NFC) films as thin as 800 nm by blade coating, which is compatible with a roll-to-roll process on a large scale. Our approach allows obtaining a dried nanocellulose film within a span of 1 h subsequent to 2,2,6,6-tetramethylpiperidine-1-oxyl radical-assisted oxidation and homogenization procedures. One of the thinnest freestanding NFC films with a thickness of 800 nm is achieved using a blade coating of nanocellulose after 72 h of oxidation followed by homogenization with a channel size of 65 μm. Incorporating water-soluble CdTe core-type quantum dots into the nanocellulose film led to a uniform emission under 385 nm UV irradiation, indicating excellent material compatibility. We anticipate nanocellulose developed in our study to be beneficial in biomimicry flying objects, environmentally friendly encapsulation, color filters, and energy storage device membranes, to name a few.