A ternary microemulsion polymerization was successfully used to prepare nanosized hollow polystyrene (PS) microlatexes with triblock copolymers of poly(oxyethyene)−poly(oxypropylene)−poly(oxyethylene)[(EO) x (PO) y (EO) x ]. Micelle formation using triblock copolymers is a useful nanoreactor in order to make polymer nanoparticles in oil/water (o/w) microemulsions. Poly(methyl methacrylate)/cross-linked polystyrene core/shell nanospheres have been fabricated by o/w microemulsion. PS hollow nanospheres were obtained using the polymer core etching technique. Water-soluble and oil-soluble initiators were used for the polymerization at 70 °C with moderate stirring and via modified buret feeding. After extraction of the surfactant matrix, the polymer particles contract considerably without the change of their spherical shape. The hollow sphere morphology and hollow image of the polymer particles were confirmed by field emission scanning electron microscope and transmission electron microscope. PS hollow spheres were fabricated with diameters in the range of ca. 15−30 nm, and the shell thickness was ca. 2−5 nm. The size of the hollow nanoparticle is dependent on the surfactant concentration and the weight ratio of [surfactant]/[monomer].

We report on the hydrolytic polymerization of zirconium in aqueous solution using the transient optical response of the fluorescent molecule 1-pyrenecarboxlyic acid (PCA) as a probe. We have measured the fluorescence lifetimes and rotational diffusion dynamics of PCA in “aged” aqueous solutions of tetravalent zirconium to understand the ability of fluorescent probes to report on the structural aspects of hydrous metal oxide self-assembly. The degree of polymerization, and therefore the extent of solute organization, is controlled by allowing the Zr4+ solutions to polymerize (age) for selected amounts of time at 85 °C. Fluorescence lifetimes and reorientation times measured for PCA in zirconium solutions increase rapidly, approaching a constant value after 30 h of aging. The data point to growth of polymers that achieve a maximum volume. The reorientation data place limits on the size and shape of polymers and provide insight into the mechanism for their growth.