This proposal continues our work on polyoxometallates (POM)-headed surfactants. POMs are well defined transition metal clusters with a range of interesting catalytic, magnetic and optical properties. In applications POMs are often supported on other materials to provide a high surface area open network, allowing access to the POMs. The use of solution self-assembly to structure POMs within a silica matrix is therefore attractive, so we are studying the synthesis and organisation of POM-headed surfactants. Electrostatic screening is commonly used to influence micelle-templated silica and is expected to strongly alter the phase diagram, given the high charge (-6) on the POM headgroups. Therefore here we propose to study the size and shape of C12 and C16 POM-amphiphiles micelles in the presence of salt, using contrast variation to determine the details of the micelle structures.