| The results of an attempt to obtain a well-dispersed and, preferably, transparent polymer blend using as a starting system a microemulsion in which both phases were liquid monomers, stabilized only by a surfactant, and without any cosurfactant present are reported. The monomers used in our research were acrylic acid (AA), methyl methacrylate (MMA), and styrene (Sty). The initial attempt was to polymerize the monomer-droplets and then the monomer that formed the continuous phase. Since we were unable to separate the polymerization of the two monomers, the next approach was to polymerize the monomer-droplets in an unpolymerizable medium, and then to redisperse the latex particles in the second liquid monomer, followed by its polymerization. The solids obtained were opaque, and phase separated at various degrees. Rather than devote additional efforts to the characterization of these materials, another approach was investigated.; The second approach involves the preparation of composites of CdS nanoparticles in a MMA polymer matrix using a one-system reverse micellar synthesis. Methyl methacrylate was used as the oil and polymerized following formation of 2--3nm CdS particles in the fluid medium. When Aerosol OT (AOT) was employed as the surfactant, opaque solids containing 20--80nm aggregates of the CdS nanoparticles were obtained. When a crosslinker, polyethylene diacrylate, was used aggregation was eliminated but the solid remained opaque. Replacing the AOT by the polymerizable surfactant didecyldimethylammonium methacrylate with MMA as the oil led to the formation of a transparent solid matrix containing non-aggregated CdS particles. |
