Simultaneous Preparation and Dispersion of Regenerated Cellulose Nanoparticles Using a Facile Protocol of Dissolution–Gelation–Isolation–Melt Extrusion

Abstract

As a consequence of an inter- (or intra-) molecular hydrogen bond, cellulose molecular chains or cellulose nanoparticles have a strong force for aggregation. Therefore, on one hand the broad use of cellulose nanoparticles is stifled by the lack of effective methods for the preparation of them. On the other hand, researchers have been struggling to directly disperse nanocellulose in a polymeric matrix. Here a facile method of “dissolution–gelation–isolation–melt extrusion” is proposed to achieve regenerated cellulose (RC) nanoparticles from cellulose hydrogel and disperse them into a polymeric matrix simultaneously. A water-soluble poly(ethylene oxide) (PEO) molecular chain is used to isolate the cellulose nanoparticle precursors in the hydrogel. The following melt extrusion process provides a shear force to break up cellulose nanoparticles into smaller ones. By means of scanning electron microscopy and transmission electron microscopy, a hierarchical structure of cellulose aggregations with size in the ra...