Pigment stability in water using a toolbox for stability

Well-suspended and stabilized pigment is critical to ensure the long-term stability of many commercial products, including paint formulations as well as food and cosmetic products. Here, we discuss the effect of pH and pigment grade on pigment stability in water. We studied pigment stability using a novel 'stability toolbox' that consisted rheological measurements, zeta potential, and quantifying sedimentation/coalescence by light transmission and scattering. We show that each of these techniques provide unique information, enabling us to map out the structure-property-performance relationships of pigments in water. We showed that for inorganic pigments in water, electrostatic interactions dominate the rheological response and the sedimentation behavior. This stability toolbox can be broadly applied to colloidal as well as polymeric suspensions.