The effect of drying process of cellulose nanofiber from oil palm empty fruit bunches on morphology

Abstract

One major manufacturing challenge in nanocellulose production is getting the dry form of nanocellulose while maintaining its nano-size dimensions. Different drying techniques will produce nanocellulose with different sizes and morphologies. Each has its own specific application. This study performed three methods to dry nanocellulose suspension, specifically cellulose nanofiber, including freeze-drying, spray-drying, and oven drying. The morphology and particle size of the dried CNF were analyzed using Field Emission Scanning Electron Microscope (FE SEM). Sponge-like material, also known as aerogel with low density (0.01 - 0.02 g/cm3) and high porosity (98%), was obtained via freeze-drying. Meanwhile, finely grounded solidly in a spherical and irregular form has resulted from the spray drying process of CNF, with an average diameter of less than 2 μm. Oven-dried CNF formed rigid thin film with a rough surface. However, the FE-SEM micrograph indicated that the nanoscale dimension of the oven-dried CNF has no longer existed. Therefore, oven-drying is not suggested as a drying method for nanocellulose.