Method for controlling the dispersibility and barrier properties of dry nanocrystalline cellulose in solutions of various pH and ionic strength

摘要

A new method to control the dispersibility of dried nanocrystalline cellulose (NCC) by controlling solution pH and ionic strength is provided; when stable, non-reswellable acid-form NCC (H-NCC) films are placed in concentrated sodium hydroxide solutions, they swell but do not disperse; while sodium-form NCC (Na-NCC) or other NCC films having neutral monovalent counterions readily disperse in pure water, Na-NCC films placed in hydrochloric acid and sodium chloride as well as sodium hydroxide solutions of sufficient ionic strength swell, but do not disperse; similar properties are observed for freeze-dried NCC products. The dispersibility of these NCC films is a function of the ionic strength and the identity of the electrolyte solutions to which they are exposed. NCC films are envisaged that have barrier properties in an electrolyte solution but that disintegrate or disperse when rinsed with pure water at the end of their useful lifespan.