This proposal continues our research on ion binding to surfactant micelles. Our recent work demonstrates that the details of water structure around micelles are now accessible using Empirical Potential Structure Refinement methods combined with neutron scattering data. NIMROD is ideal to study large micelles simultaneously with the water structures around them. Here we wish to probe the molecular basis of the Hofmeister series, which ranks anions in order of their strength of binding to colloids such as micelles. Initially this was proposed to arise from water structuring/disordering but more recently it has been suggested that anion shape and charge distribution is more important. These experiments will enable us to probe both the water structure and the micelle surface layers, to directly study the extent of binding, molecular orientation and water structure for a series of anions.