SYNTHESIS OF SILICA BASED MATERIALS FOR APPLICATIONS IN FOAM INHIBITION

Abstract

Foam is often an undesired side effect that occurs during the production and application of paint systems. Hence, a defoamer is added to prevent formation of foam and/or destroys existing foam. In this thesis, we focused on solid-in-oil type of defoamer formulation where the solid particles are the active components performing defoaming capabilities. The ability to control the physical and chemical properties of these solid particles is an important aspect in the exploration of their effects on defoaming efficiencies. Thus, wet-chemical approaches are developed to render silica particles with specific surface functionality and structural properties. With the successful synthesis of spiky particles, we investigated the pin effect of solid particles on defoaming which showed improved defoaming efficiency compared to other morphologies. We also observed that defoamer is most efficient at optimal hydrophobicity of silica particles. In addition, the use of diblock copolymer-grafted particles as defoamers, namely PE-b-PEG/silica nanocomposites, was explored.