Improving the colloidal stability of Cellulose nano-crystals by surface chemical grafting with polyacrylic acid

Cellulose nano-crystals (CNC) can be tailored for various value-added applications. However, its use in aqueous systems is hampered by its limited dispersability, especially at a high CNC concentration. In this study, the improvement of CNC colloidal stability by surface chemical grafting with polyacrylic acid (PAA) was investigated, and the zeta potential and the charge density of the chemically modified CNC were analyzed. The results showed that an acrylic dosage of 1% (based on the dry weight of CNC) was sufficient to significantly enhance the colloidal stability. CNC, after chemical grafting with PAA, showed better stability against the increase in storage time or solid content of the aqueous medium, compared with the un-modified CNC.