Peculiarities in the Hydration of Cellulose in Air and Water Suspensions as Studied by H NMR Spectroscopy

Abstract

Bound water layers in hydrated powders and aqueous suspensions of microcrystalline cellulose were investigated by 1 H NMR methods. The characteristics of such layers were calculated and the magnitude of the interfacial energy (γ s ) at the cellulose/water interface in an aqueous environment determined. It was found that the concentration of strongly bound water and the value of γ s were strongly dependent on the concentration of cellulose in suspension. This is probably due to the strong interaction between cellulose particles. At very high suspension concentrations, the concentration of water inside the cellulose filament decreased by more than three-times while the value of γ s decreased from 31 J/g to 9 J/g as a result of surface forces.