ABSTRACT
Most ag-based materials are amphiphilic because they comprise polar and non-polar groups within the same molecule. One of the major categories of amphiphilic agbased materials are seed oils, which have been actively investigated as substitutes for petroleum in a wide variety of consumer and industrial applications. Due to their amphiphilicity, seed oils adsorb on surfaces and alter various surface and interfacial properties. The adsorption properties of seed oils at metal-metal, starch-metal, hexadecane-water interfaces were investigated as a function of seed oil chemical structure, seed oil concentration, and substrate surface properties. The effect of vegetable oil adsorption on surface properties was monitored using interfacial tension and boundary friction measurements. The data were then analyzed using various adsorption models to estimate the free energies of adsorption of the vegetable oils as a function of vegetable oil and substrate characteristics. The result showed that the estimated free energies of adsorptions were independent of the method used to probe the adsorption of the vegetable oil at the interface (interfacial tension vs. boundary friction). However, the estimated free energies of adsorption were found to be functions of vegetable oil chemical structure, substrate surface properties, and the adsorption model used to analyze the adsorption data.
