Cellulose Nanocrystals Prepared by TEMPO-mediated Oxidation of Wild Musa spp. Pseudostem

Abstract

Abstract: Valorization of agricultural waste to produce value-added products such as nanocellulose is important in bringing sustainable development and reduce our dependence on petroleumbased products which are harmful to our environment. The present work is carried out to investigate the potential of the pseudostems from the wild Musa spp. as a novel sustainable source of cellulose nanocrystal (CNCs). TEMPO-mediated oxidation and ultrasonication was followed in isolation of CNCs. The CNCs were characterized by various physicochemical parameters such as FTIR, TEM, Zeta potential, degree of oxidation, swelling and water retention value. TGA studies was performed to evaluate the thermal stability and percent crystallinity was determined by XRD spectroscopy. The final carboxylated CNC (cCNC) gel contains 5.56% w/w solid CNC exhibiting degree of oxidation of 34.91%. The CNC also showed high water retention value exhibiting ionic sensitivity to NaCl. The zeta potential value was determined to be -50.3 mV indicating its stability and particle size of the cCNC was less than 200 nm. The percent crystallinity was found to be 66.18% and TGA analysis showed the reduced thermal stability of the cCNCs. Carboxylated CNC was successfully isolated from the wild banana pseudostem following TEMPOoxidation method. Ultrasonication of the cCNC resulted in the formation of cCNCs with mostly spherical in shapes and the results from analysis indicate that the wild banana pseudostem could be a potential sustainable source of cellulose nanocrystals.