STUDIES ON NOVEL SURFACTANT-FREE POLYSTYRENE NANOPARTICLES FORMED IN MICROPHASE INVERSION

Randomly carboxylated polystyrene ionomers are insoluble in water. How ever, we found that when their tetrahydrofuran (THF) solutions are add ed into an excess of water or vice versa, the ionomer chains can under go a microphase inversion to form surfactant free colloidal nanopartic les stable in water. In this study, a combination of static and dynami c laser light scattering (LLS) was used to study the influence of vari ous experiment conditions, such as the initial ionomer concentration i n THF, the degree of carboxylation, the type of counterion, the compos ition of the THF/water mixture, and the order of mixing the ionomer TH F solution with water, on the formation and size distribution of the n anoparticles.