TiO2 Pigment Post Treatment and Its Influence on Electrostatic Stability of Technical Dispersion
Titanium dioxide can be utilized in various applications such as a pigment base in paints, coatings, plastics and laminates. During both the production process at the TiO2 producer and the manufacturing process of paints, coatings and composite materials, avoiding the coagulation and agglomeration of the TiO2 dispersion is important. Surface chemistry of the TiO2 dispersion can be controlled during the measurement of Electrokinetic Sonic Amplitude (ESA) by regulating the pH value, e.g. for avoiding flocculation of dispersion. This means the zeta potential of the dispersion should not be or close to zero. Zeta potential is a dimension of the effective surface charge of particles and the interaction between the particles with ions in solution and particles among each other. Characterizing the absolute surface charge (in an aqueous dispersion) of the TiO2 pigment, negative or positive in the unit (mV), gives a decisive parameter for an ultimate application of the product. The zeta potential depends on the kind of solvent, the nature and amount of the ions in solution (specific conductivity) and the pH value. It is also the main factor determining the stability of the whole dispersion.