Title
Extraction and characterization of cellulose nanocrystals from corn stover
Authors
LARISSA A. DE S. COSTA ANANDA F. FONSECA FABIANO V. PEREIRA and JANICE I. DRUZIAN

Received October 14, 2013
Published Volume 49 Issue 2 February
Keywords corn stover, cellulose nanocrystals, acid hydrolysis

Abstract
The aim of this study was to explore the utilization of corn stover as a source of raw material for the production of cellulose nanocrystals. Corn stover was first purified using chemical extraction and bleaching and then separated into nanocrystals by acid hydrolysis. The chemical composition and characteristics of corn stover were studied before and after purification according to a TAPPI standard and by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). Morphological features of the nanostructures were studied using transmission electron microscopy (TEM). The chemical composition of the employed corn stover was 45.5 wt% cellulose, 27.6 wt% hemicellulose and 6.8 wt% lignin. The crystallinity of the corn stover was 25.3%, and it increased to more than 43% after the acid hydrolysis. Changes in the peaks of the FTIR spectrum at 1731, 1556 and 1244 cm-1 indicated that the alkali treatment partly removed hemicelluloses and lignin from the fiber surface. The corn stover had better thermal stability than those of the cellulose obtained after the bleaching treatment and of the nanocrystals isolated following acid hydrolysis. The TEM study indicated that the nanosized crystals had an average diameter and length of 6.9 nm and 356 nm, respectively, leading to an aspect ratio of approximately 54.7. Therefore, the produced corn stover nanocrystals possessed great potential as strengthening agents in nanocomposites.