Amine-functionalised poly(alkylene oxides) are used extensively as swelling inhibitors in water-based drilling fluids. This study will broaden our understanding of the mechanism of adsorption of these inhibitor molecules onto bentonite, a smectite mineral of the type that is responsible for clay swelling. The key objectives of this proposal are thus to determine how each of the following descriptors of polymer architecture influence their adsorption characteristics: molar mass, backbone hydrophobicity, number and protonation of amine substituents. Specifically the outcome in each case is to determine both the distribution and adsorbed amount of polymer.