Fluoromethacrylate-containing colloidal dispersions: Phospholipid-assisted synthesis, particle morphology, and temperature-responsive stratification
Because of unique properties of fluoropolymers, F-containing water dispersible colloidal dispersions continue to be of great interest and represent significant scientific challenges. These studies focus on the development and understanding of morphologies of F-containing colloidal particles synthesized in an aqueous phase in the presence of bioactive dispersing agents. When methyl methacrylate (MMA), n-butyl acrylate (n-BA), and heptadecafluorodecyl methacrylate (FMA) monomers are copolymerized in an aqueous phase, in the presence of phospholipids (PL), nonspherical particle morphologies are obtained. Their morphologies depend upon MMA/nBA ratios and lead to significantly different coalescence mechanisms and consequently surface properties. For higher MMA content, the particles are spherical, but at higher nBA contents, nonspherical morphologies are produced. This behavior is attributed to monomer starved conditions and the differences in reactivity ratios which forces copolymerization of FMA on the surface of p-MMA/n-BA particles, giving rise to nonspherical morphologies in the presence of biologically active PLs. Such prepared aqueous dispersions upon coalescence form films that exhibit ultralow static and kinetic coefficients of frictions which are attributed to internal phase stratification during coalescence.