Designing Titanium Dioxide Aqueous Dispersion with High Solid Content and Low Viscosity

Titanium dioxide (TiO₂) is the most widely used white coating additive, and the solid content of the aqueous dispersion system is an important factor affecting productivity during its processing sanding. Achieving high solid content dispersion with low viscosity and high stability is crucial for enhancing its productivity; however, this objective currently presents a significant challenge. In this work, we propose a simple strategy for the use of low-molecular-weight poly(acrylic acid) sodium salt (PAAS) as an efficient dispersant for TiO₂ dispersion. We quantitatively characterized the stability of TiO₂ dispersions when different molecular weights of PAAS were used as a dispersant using a Turbiscan analyzer based on the multiple light scattering technique, and also investigated the viscosity and ζ potential. It was found that through the steric hindrance and electrostatic repulsion provided by PAAS, the PAAS with a molecular weight of 6000 g·mol^-1 could afford TiO₂ dispersion with solid content as high as 50%, exceptional dispersive stability, and low viscosity as 43 mPa·s at the shear rate of 100 s^-1. Owing to the high TiO₂ content, high stability, and low viscosity, this PAAS-dispersed aqueous dispersion shows great potential in TiO₂ production industry.