The adsorption of acid dispersants on titanium dioxide pigments with different inorganic oxide treatments

The rheology and film gloss of latex coatings are strongly influenced by the interaction between thickener and disperse phases. Other coating components also participate in the complex interaction. Studies on individual components do not reflect the reality in a coating's formulation. The objective of this dissertation was to understand the complex interactions among dispersants, surfactants, associative thickeners, pigments, and latices in latex coatings.;This dissertation began with a study on the adsorption of acid dispersants on titanium dioxide (TiO;The competitive adsorption between surfactant and model Hydrophobe-modified Ethoxylate Urethane thickener (HEUR) was studied in Chapter 2. TiO;In Chapter 3, a unifying model was proposed to interpret the influence of model HEUR thickeners in waterborne coatings. This goal was approached by studying the adsorption of dispersant, surfactant, and associative thickener on latex. The HEUR adsorption studies were conducted alone and in competition with a nonionic surfactant. The effect of free surfactant level on latex rheology was discussed to elucidate the effect of HEUR associative thickener on rheology of latex coatings.;In Chapter 4, the effect of NaCl and sodium dodecylsulfate (SDS) on the rheology of commercial HASE solutions was investigated.;The effect of disperse phase/commercial HEUR associative thickener interaction on the rheology of disperse phases (pigment, latex) was studied in Chapter 5. Parallel studies was discussed in Chapter 6 with emphasis on Hydrophobe-modified Alkali-Swellable Emulsion (HASE) thickeners. The distinct rheological responses of HASE thickeners from HEUR thickeners were studied by both shear viscosity and oscillatory modulus measurements.;The component's influence on rheology and film gloss of latex coating formulation was addressed. These variables include thickeners, dispersant structures, latices, pigments, medium pH, and ionic strength. By integrating those parameters, a better understanding on the complex interactions in waterborne coatings can be achieved.