The apparent structural hydrophobicity of cellulose nanocrystals

The Teas graph of wood-based sulfuric acid-hydrolyzed cellulose nanocrystals (CNCs) was plotted based on sedimentation tests in a set of 25 common solvents. Comparisons with those of sucrose and dextran, taken as equivalents for cellobiose (cellulose repeating unit) and amorphous cellulose, respectively, highlighted the amphiphilic nature of CNCs. In the absence of any chemical arguments, the hydrophobic behavior displayed is thought to be caused by the exposition of (200) lattice planes at the CNC surface. This apparent structural hydrophobicity may be exploited to achieve the dispersion of CNCs in some mildly-non polar matrices such as poly(ethylene glycol) and poly(lactic acid). The Teas graph is a useful tool to predict the dispersibility potential of CNCs and to select a proper solvent for nanocomposite preparation