Highly ordered dispersions of charged polymer particles that are tens or hundreds of nanometres diameter can be prepared. These are useful model systems for self-assembly and provide interesting routes to preparation of new materials such as photonic devices. The different effects of the screened Coulomb interactions and the constraint of a hard wall are important in determining nucleation and growth of crystals and interface structures. This proposal is to continue previous succesful experiments using the spin-echo techniques SERGIS (interfacial structure) and SESANS (bulk correlations) to study specifically the effects of particle size and concentration. These will be used to study large latex particles at a buried interface (sapphire substrate/dispersion) and within the bulk of the same samples.