Structure, stability, and rheological properties of zirconia suspensions in the presence of nanocrystals: Effects of ionic strength

Cellulose nanocrystals (CNCs) are used as a stabilizing agent in water-based zirconia suspensions at high concentration. The effects of CNC and NaCl concentrations were studied on the stability, adsorption, zeta potential, size, and rheology of slurries. We characterized samples and visualized CNCs at the surface of solid particles by scanning electron microscopy. The results confirm that the adsorption capacity of CNC on the surface of zirconia particles increases as salt concentration increases and causes an increase in the viscoelastic properties and a denser structure on the surface of adsorbent. The presence of counter-ions from the added electrolyte shortens the range of electrostatic repulsion between CNC particles through screening its electrical double layer resulting in more adsorption of adsorbate on the zirconia surface and, thus, provides stabilization.