Isolation and characterization of cellulose nanofibers from cassava root bagasse and peelings

This work aimed to obtain and characterize nanofibers from cassava bagasse and peelings, which are waste originating from cassava starch extraction. To isolate the nanofibers, a combination of pre-treatments (alkaline treatment, Q-chelating treatment, bleaching), acid hydrolysis, and a final ultrasonic disintegration step were used. Acidic hydrolysis was conducted at a constant temperature of 60 degrees C; the acid concentration (30, 40, and 50%) and the treatment time (30, 60, and 90 min) were varied. The nanofibers were characterized for their morphology, surface charge, crystallinity index (XRD), and functional groups (FTIR). The diameters of the nanofibers ranged from 2.3 nm to 5.4 nm. The zeta potential values were lower than -47.7 mV. As expected, all the products derived from acid hydrolysis displayed high crystallinity index. Finally, FTIR analysis confirmed that the isolation processes effectively removed amorphous materials such as lignin and hemicellulose from the nanofibers. (C) 2016 Elsevier Ltd. All rights reserved.