We request NR beam time on SURF to study the impact of multivalent counterions on the surface adsorption of alkyloxyethylene sulfate surfactants and alkyloxyethylene sulphate / nonionic mixed surfactants. This proposal is part of a broader collaborative research programme between Oxford, STFC, and Unilever on the nature of adsorption and self-assembly in surfactant mixtures. It relates critically to other major themes in our broad programme, on the adsorption and self-assembly of biosurfactant / conventional surfactant mixtures and on the development of novel optimised delivery mechanisms for active benefits such as perfumes. This proposal complements a similar proposal submitted to LOQ, that addresses the self-assembly properties.