Spin-echo SANS measurements of PMMA latexes with AOT in dodecane

PHSA-stabilized PMMA latexes are an essential system in the field of colloid science. They are considered the best model system for hard sphere spheres and can have functionality added to infer result in interesting soft materials. There are numerous examples of these complex materials formed from micron sized latexes with structural features of a commensurate size. This is larger than conventional SANS could study, but it is an ideal size range for the technique spin-echo SANS (SESANS). Before studying complex soft materials, the ability to determine the size and shape of individual PMMA latexes (in the dilute, non-interacting regime) needs to be established first. Previous SESANS results on ~2 µm latexes showed the ability to measure these using SESANS, but multimer aggregation in the samples prevent determining the single-particle form factor. In this proposal, scattering from selected dispersions will be repeated with the addition of AOT surfactant to provide a small degree of particle repulsion to avoid aggregation formation (as is known in the literature).