Stable nonspherical fluorine-containing colloidal dispersions: Synthesis and film formation

A simple synthetic method for preparing stable colloidal dispersions that form polymeric films containing fluorinated acrylates is presented. The simultaneous presence of the dual tail anionic fluorosurfactant phosphoric acid bis(tridecafluorooctyl) ester ammonium salt (FSP) and sodium dodecyl sulfate (SDS) surfactants facilitates a suitable environment for the aqueous polymerization of methyl methacrylate/n-butyl acrylate/heptadecafluorodecyl methacrylate (MMA/nBA/FMA) colloidal particles. Polyermerization is achieved by a low-sheer monomer-starved emulsion polymerization process in which the FSP/SDS surfactant mixture significantly reduces the surface tension of the aqueous phase, thus facilitating mobility and subsequent polymerization of FMA along with MMA and nBA momomers. Using this approach, it is possible to obtain stable nonspherical MMA/nBA/FMA colloidal dispersions containing up to a 8.5% (W/W) copolymer content of FMA. These studies illustrate that the incorporation of FMA into MMA/nBA particle morphologies facilitates surface phase separation during coalescence, resulting in F-containing film-air (F-A) interfaces. Thus, surface properties with a significant decrease in the kinetic coefficient of friction as well as high contact angles can be produced.