Cadmium sulfide nanoparticle/polymer composites have been produced using a one-system reverse micellar synthesis. A monomer, methyl methacrylate (MMA), was used as the oil and polymerized following formation of 2-3 nm CdS particles in the fluid medium. When Aerosol OT (AOT) was employed as the surfactant, opaque solids containing 20-80 nm aggregates of the CdS nanoparticles were obtained. The aggregates were fairly uniform in size, their diameter depending on the AOT concentration. With a 1:1 weight ratio of MMA and a polyethylene diacrylate, 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 nonaggregated CdS particles.

Changes in the microstructure of oil-in-water microemulsions were identified electrochemically by using ferrocene derivatives, methyl viologen, and ferricyanide as the electroactive probes. Microdroplets as well as the bicontinuous microstructure were detected. This was accomplished by determining diffusion coefficients of the probes. Use of probes of different hydrophobicity/hydrophilicity and charge made it possible to investigate different microenvironments of microemulsions including oil, water, and surfactant/cosurfactant interface. Electrochemical reversibility of the probes was affected by the structure and appeared to reflect the ease of mobility across interphases. Reaction potential (E1/2) of the probes depended on the composition of the microemulsion.

The influence of cationic polyelectrolytes, poly[(diallyldimethylammonium chloride)-co-(N-methyl-Nvinylacetamide)] (poly(DADMAC-co-NMVA)) of different charge density in contrast to that of a noncharged polymer, poly(N-methyl-N-vinylacetamide) (polyNMVA), on the lamellar liquid crystalline system sodium dodecyl sulfate (SDS)/decanol/water was investigated by means of microscopy observation between crossed polarizers, by small angle X-ray diffraction, and by rheology. The lamellar liquid crystal remained stable in all investigated formulations. The results depended on the charge density as well as the concentration of the incorporated polymer. For the polymer with the highest charge two lamellar structures existed concurrently. In excess of a certain concentration the highest charged polymer adsorbed flat onto the SDS-decanol bilayer as shown by its changed interlayer spacing, whereas at lower concentration the polymer did not have a discernible effect on the X-ray diffraction pattern. The results obtained for mixtures of the lowest charged polymer are in accordance with a loop adsorption of the polymer onto the SDSdecanol bilayer. Incorporation of the noncharged polymer did not lead to such adsorption structures and a conclusion of the importance of electrostatic interactions depending on the charge density of the polymer is reasonable. The results obtained by SAXS measurements were supported by the results of rheological measurements.