Physico-chemical characteristics of nanocellulose at the variation of catalytic hydrolysis process

Abstract

In this work, the influence of various sulfuric acid (H2SO4) concentration is studied towards the crystallinity, particle size distribution, thermal stability, and morphology of the synthesized nanocellulose (NCC) during the esterification process. Different concentrations of H2SO4 (40%, 58%, 64% and 78%) was utilized to achieve the optimal properties of NCC. The as-produced NCC was characterized by Fourier Transmission Infra-Red (FTIR) analysis that confirmed the attachment of sulphate ions (SO4−3) to C-6 of the glucose ring. Moreover, the hydrogen ions (H+) weakened the C-6 of cellulose chains by attacking the glycosidic linkages resulting in the formation of NCC. The X-Ray Diffraction (XRD) analysis revealed an increase in the crystallinity index with increasing H2SO4 concentration till 78%. NCC represented a needle shaped like structure having a particle size of 10–18 nm in diameter as observed under Atomic Force Microscopy (AFM) and Fourier Emission Scanning Electron Microscopy (FESEM). Furthermore, Dynamic Light Scattering (DSL) analysis recorded the particle size of the NCC as less than 20 nm in diameter. Thus, owing to various H2SO4 concentration the particle size, crystallinity, and features of NCC are substantially affected.