This Ph.D. study investigates the adsorption of monomeric (isostearic acid, ISA) and oligomeric fatty acids (poly(hydroxystearic acid), PHS 1400 and PHS 3500) to nanoparticles of industrial interest in carriers with different solvent properties. It was found that it was necessary to apply a number of methods to study the adsorption and subsequent stabilisation of the particles by the dispersing molecules, namely adsorption isotherm methods, rheological techniques, atomic force microscopy and

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... vis spectroscopy. The particles (surface) studied consist of uncoated titania and a commercially available titania coated with a combination of alumina and silica. The use of gel permeation chromatography (GPC) to study the adsorption behaviour of polydisperse dispersants provided information not only about the amount of the dispersant adsorbed to the surface, but also the preferential adsorption of low molecular weight components. The displacement of large molecules by smaller ones could be monitored in order to gain insight into the types of adsorption mechanisms at work. It was found that small molecules were unable to fully displace their larger counterparts, suggesting that there was more than one adsorption mechanism in effect. This was supported by the adsorption study of one of the fatty acid dispersants which was esterified with methanol to remove the acid functionality. Adsorption at the particle surface still occurred, but at a much reduced rate. The preferential adsorption of the smaller molecules was also found to be largely eliminated. Adsorption isotherms showed Langmuir-like adsorption behaviour of the molecules to the surface, probably through a combination of acid-base interaction and other specific interactions between surfactant molecule and surface. Adsorption of the dispersant molecules at the particle surface was found to vary with solvent properties reflecting the equilibrium which is established between solubility of the dispersant in solution (χ) and that adsorbed on the surface (г) as a result of [...]