Chemical shift tensor analysis of uniaxially oriented cellulose microcrystals

Abstract

Chemical shift tensor of cellulose Ia was investigated via line-shape simulations of solid-state 13C NMR spectra obtained for uniaxially oriented cellulose nanocrystals (CNCs). The cellulose film composed of highly oriented CNCs was obtained by shearing of a CNC/water suspension. The solid-state 13C NMR measurements were performed at different angles (b Ls), which are defined as angles between the static magnetic field and the direction of uniaxial orientation of CNC. The shape of the obtained NMR spectra varied depending on the b L. The line-shape simulations for the series of the solid-state 13C NMR spectra indicate that the directions of d33 axis of C2-C6 locate almost parallel to the directions of C-O bonds.