Synthesis, Characterization and Anionic Dye Sequestration Capacity of Cellulose Nanocrystals Derived From Sugarcane Bagasse: Experimental and Regression Modelling

Abstract

This study reported the extraction of cellulose nanocrystals from sugarcane bagasse using acid hydrolysis method. Nanocrystals were characterized with scanning electron microscopy, energy dispersive X-ray, Fourier Transform Infra-Red spectroscopy and investigated for their adsorptive capacity for methyl orange (MO) sequestration. The disappearance of peaks at 1736 and 1429 cm-1 in addition to higher carbon content, greater crystallinity index from 1.09 to 1.21, predominantly nano range of particles (0.045 – 0.082 µm) and larger porosity are parameters that better-defined cellulose nanocrystals. A 2-fold improvement in monolayer adsorption capacity was obtained for cellulose nanocrystals (432.17mgg-1) described by Langmuir isotherm over bagasse (170.99 mgg-1) described by Freundlich isotherm. Adsorption processes on both adsorbents were spontaneous, exothermic and best fitted to pseudo second order kinetics ensuing chemisorption. Polynomial regression model appropriately predicted equations that best describe the effects of different batch adsorption parameters on MO removal with better fittingness than experimentally generated data.