Why is surface tension important in aqueous pigment dispersion?
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Senior Research Chemist
When preparing an aqueous pigment dispersion, it’s important to control the system surface tension to help enable adequate wetting of the hydrophobic pigment powders. Without proper surface tension control, it may be time and energy consuming to incorporate the powdered pigment into an aqueous solution. Then, even after incorporation, the pigment particles can remain inadequately “wetted,” leaving air pockets trapped on or in the agglomerates, thus causing foam and efficiency problems throughout the milling phase. While dispersing polymers and grind resins is useful to enable stabilization, they are typically inadequate in providing the surface tension control for optimal performance. Traditional surfactants, like APEs, can be used to help but often cause problems of their own, such as foam stabilization and competitive interactions with the dispersing polymers. By using a Gemini defoaming wetting agent, such as the Surfynol® AD01, Surfynol® 104, Surfynol 420, and Surfynol DF110 surfactants, you can control the system surface tension for optimal performance while minimizing any adverse effects such as foam or dispersion viscosity impact. In many systems, these products will even function as molecular defoamers, disrupting the foam caused by other chemistries.