He was among the first to apply photon correlation techniques and, with colleagues, developed the now standard method of cumulant analysis for particle sizing.
With his work on the Brownian motions of strongly interacting particles, Pusey was one of the first to apply microscopic approaches to colloidal suspensions.
His research exploited analogies and differences between concentrated suspensions of hard-sphere colloids and atomic materials, to investigate such fundamental phenomena as crystallisation, the glass transition and the formation of ordered binary superlattices.
With Eric Jakeman, Pusey also introduced K-distributions; these have proved powerful in describing the statistical properties of, for example, microwaves scattered by the sea surface and laser light propagating through the atmosphere.
[6] In 2005, he was awarded the Rhodia Prize by the European Colloid and Interface Society for his Outstanding contributions in the experimental study of dynamically arrested (glassy) particulate matter, especially in relation to hard sphere fluids with added polymer.