Study on required energy to deagglomerate pigmentary titanium dioxide in water

The dispersion process is used in various industries, including coatings, paper manufacturing, and food processing. All of these industries base their developments and technology of particle dispersion on theories that consider spherical particles in simple systems. The objective of this study was to improve understanding of the impact of these theories when applied to nonspherical/nonideal particles. Effective dispersion allows for a reduction in the use of the powder to achieve the specified final properties. This paper reports experimental results on the required energy (RE) used to disperse five different titanium dioxide (TiO2) samples into liquids with different values of surface tension [deionized (DI) water and DI water containing surfactants]. The selection of the TiO2 samples was based on different particle sizes with the same surface properties, and similar sizes with different surface properties. The results showed that the particle shape is fundamental in determining the RE for dispersion, once it defines the number of interactions among the particles. The larger the number of interactions, the more energy is required to deagglomerate the particles. An empirical equation was developed to describe the energy required for pigment dispersion as a function of the ratio between the liquid and the particle surface tensions and the particle shape factor.