Viscoelastic characteristics of all cellulose suspension and nanocomposite.

We prepared cellulose nanocrystal (CNC)/carboxymethyl cellulose (CMC) suspensions and nanocomposites and carried out rheological analysis of the all-cellulose samples. Morphological observation of the prepared CNCs was conducted using transmission electron microscopy (TEM) and atomic force microscopy (AFM). The electrokinetic characteristic of the CNCs was evaluated from zeta potential measurement. A simple shear test, an oscillatory shear test, and dynamic mechanical analysis (DMA) were carried out, and their results were compared. The findings revealed that the greater shear-thinning behavior and more solid-like rheological behavior were observed with an increase in the content of CNCs embedded in both the suspensions and nanocomposites. In addition, the viscoelastic properties acquired in different experimental modes (i.e., shear and extension) were compared from a rheological perspective.