Miscanthus Giganteus: A commercially viable sustainable source of cellulose nanocrystals

With a goal of identifying a new scalable source for cellulose nanocrystals (CNCs), we successfully isolated CNCs from a sustainable, non-invasive grass, Miscanthus x. Giganteus (MxG). Subjecting MxG stalks to base hydrolysis, bleaching and acid hydrolysis allowed access to cellulose nanocrystals (MxG-CNC) in high yields. X-ray diffraction studies showed the crystallinity of the MxG-CNCs increased with subsequent treatment conditions (>90% after HCl hydrolysis). Transmission electron microscopy showed that the MxG-CNC exhibit relatively high aspect ratios (60-70), and small angle neutron scattering showed the crystals were ribbon-like with a width and thickness of 8.5 and 2.8nm respectively. As expected, thermomechanical analysis of nanocomposites fabricated with carboxylic acid functionalized MxG-CNC (MxG-CNC-COOH) and PVAc showed an increase in modulus (above T_g) as filler content was increased. Comparing the properties to PVAc nanocomposites containing CNCs from wood showed at least as good, if not slightly better, reinforcement at the same loading level.