Thin Cellulose Nanofiber from Corncob Cellulose and Its Performance in Transparent Nanopaper

Abstract

Cellulose separated from corncob was used as a new cellulose resource to produce esterified cellulose nanofiber (E-CNF) with hexanoyl chloride through one-step mechanochemical esterification by ball milling. The result showed that corncob cellulose was easily disintegrated and esterified to achevie a high DS, and then, thin nanofiber was compared to the common pulp cellulose resource. The DS of E-CNF was as high as 0.95, and the diameter was about 1.5–2.8 nm. Then, E-CNF was formed to nanopaper by vacuum filtration showing high optical transparency up to 89% at 550 nm. The transparent nanopaper had a Young’s modulus of 5.5 GPa and tensile strength of 110–125 MPa. Due to the introduction of alkyl chain, the wetting property of the nanopaper was changed from hydrophilicity to hydrophobicty. So, it may still work well in a humid environment.