Individually Dispersed Wood-Based Cellulose Nanocrystals

Abstract

Good\ndispersion of cellulose nanocrystals (CNCs) in the polymer\nmatrix is one of the key factors to obtaining good properties in the\nresulting nanocomposites. However, the preparation of individually\ndispersed CNCs in solvents or in polymer matrices has been a challenge.\nIn this study, individually dispersed wood-based CNCs have been successfully\nprepared in solvents, including dimethylformamide (DMF), H₂O, and a mixture of H₂O/DMF, by sonication of moisture-containing\nCNCs. The CNCs dispersions were characterized by dynamic light scattering\n(DLS). It is found that CNCs containing above about 3.8 wt % moisture\nis critical for achieving individually dispersed CNC in solvents.\nHydrodynamic radius (<i>R</i>_h) of CNCs is smaller\nin H₂O/DMF co-solvent mixture than that in pure DMF or\nin pure H₂O under same sonication treatment conditions.\nExperimental results have been corroborated using molecular simulation\nstudy.