The Influence of Pre-treatment Time and Sulfuric Acid on Cellulose Nanocrystals

Abstract

Cellulose nanocrystals (CNCs) were produced with different pre-mixing times between the cotton fiber and the sulfuric acid at room temperature, prior to the reaction at 45 °C. The CNC0 and CNC60 films were prepared using vacuum filtration methods. Based on transmission electron microscopy observations, the dimension and yield of CNCs gradually decreased with increasing pre-mixing time. Considering the balance of yield and quality of CNCs, CNC0 was chosen as the optimal product. The synthetic process played an important role in the production of CNCs. Various CNCs had similar crystallinity index values with the increased pre- mixing time. The decreased contact angle was the result of decreased dimensions of CNCs or the additional sulfate group at the surface of the CNCs. Both thermogravimetric and contact angle analysis are sensitive for the constituents of CNCs.