Isolation of Nanocellulose by Enzymatic Hydrolysis of Bleached Musa textilis (Abaca) Pulp

Abstract

Nanocellulose is commonly isolated from cellulosic materials by chemical methods using strong acids. In this study, the enzymatic method was explored to isolate nanocellulose from commercial bleached S 2 grade abaca pulp. It was first disintegrated for 10 min and was subjected to enzyme hydrolysis while incubated with Bacillus sp. cellulase for 72 h at 50 °C and 120 revolutions/min. A clear liquid material was obtained after enzymatic hydrolysis after a series of centrifugation and ultrasonication. Results showed that the isolated nanocellulose had an average particle size of 375.9 nm ± 2.9 with a polydisperse index of 0.404 ± 0.059. Transmission electron and atomic force images showed that nanocellulose was longitudinal in size and highly aggregated and agglomerated. Through FTIR analysis, crystallinity indexes (i.e. lateral order index, total crystallinity index, and hydrogen bond intensity) of bleached abaca pulp and the isolated nanocellulose were compared. Results showed that the enzymatic hydrolysis of bleached abaca pulp resulted in higher cellulose crystallinity. Overall, nanocellulose can be isolated using biological methods using Bacillus sp. cellulase. These results could be used as a baseline to isolate smaller particle sizes, highly monodisperse, and stable nanocellulose that could be further applied in packaging, papermaking, cosmetics, medicine, and numerous other applications.