The preparation of monodisperse colloidal microlatex particles of polystyrene and poly(styrene butene diacid) by the use of microwave radiation and under normal ambient pressure is reported. There is no surfactant in ...The preparation of monodisperse colloidal microlatex particles of polystyrene and poly(styrene butene diacid) by the use of microwave radiation and under normal ambient pressure is reported. There is no surfactant in the system.The total synthesis time has been reduced from more then 10h(conventional method) to less than 1 h(microwave mothod). The dynamic experimental results indicate that the reaction proecss is very sharp in comparison with conventional polymerization. No constant rate stage existed.展开更多
In this paper, we have successfully fabricated the colloidal crystals of monodispersed polystyrene latex. Styrene was polymerized in degassed water at 75 ℃, using potassium persulfate as an initiator. The surfactant ...In this paper, we have successfully fabricated the colloidal crystals of monodispersed polystyrene latex. Styrene was polymerized in degassed water at 75 ℃, using potassium persulfate as an initiator. The surfactant was sodium dodecyl sulfate(SDS). Firstly, the monodispersed polystyrene latex with an average diameter of some nanometers was synthesized via emulsion polymerization, then these small latex particles were used to act as seeds for further growth. The size of polystyrene latex was controlled between 50 nm and 400 nm via diversifying the condition of polymerization. The resulted emulsion solution could accumulate slowly to form three dimensional ordered structure, which was induced by capillary as the solvent evaporating at room temperature. The opal is close packed face center cubic(f.c.c) lattice of polystyrene latex. Defects such as vacancies, dislocations or grain boundaries could be obviously observed from the SEM images. Reflectance spectra showed the red shift of specular reflectivity peak for the polystyrene colloidal crystal as the size of polystyrene latex increasing. It was demonstrated that the reflectance is intrinsic property of these colloidal crystals. This provides ideal model for the research and application of photonic crystals and form useful template for growth of various ordered macroporous materials.展开更多
In this paper, the self-assembly of PS 43-b-PEO 45-b-PS 43 triblcok copolymer was investigated. The colloids were made by firstly dissolving the copolymer in the common solvents, including THF, 1,4-dioxane, and DMF, t...In this paper, the self-assembly of PS 43-b-PEO 45-b-PS 43 triblcok copolymer was investigated. The colloids were made by firstly dissolving the copolymer in the common solvents, including THF, 1,4-dioxane, and DMF, then droping water into the corresponding copolymer solution to induce the self-assembly. The aggregates prepared were characterized with TEM and AFM techniques. The experimental results demonstrated that the self-assembled vesicles were formed when THF and 1,4-dioxane were used as the common solvents to dissolve the copolymer, comparatively, using DMF as the common solvent resulted in the formation of spherical aggregates. The self-assembled aggregates observed, possessing hierarchical structures, could be used as either the nanostructures themselves for drug delivery systems, separations, catalysts, and so on, or templates or building blocks for more complex structures.展开更多
文摘The preparation of monodisperse colloidal microlatex particles of polystyrene and poly(styrene butene diacid) by the use of microwave radiation and under normal ambient pressure is reported. There is no surfactant in the system.The total synthesis time has been reduced from more then 10h(conventional method) to less than 1 h(microwave mothod). The dynamic experimental results indicate that the reaction proecss is very sharp in comparison with conventional polymerization. No constant rate stage existed.
文摘In this paper, we have successfully fabricated the colloidal crystals of monodispersed polystyrene latex. Styrene was polymerized in degassed water at 75 ℃, using potassium persulfate as an initiator. The surfactant was sodium dodecyl sulfate(SDS). Firstly, the monodispersed polystyrene latex with an average diameter of some nanometers was synthesized via emulsion polymerization, then these small latex particles were used to act as seeds for further growth. The size of polystyrene latex was controlled between 50 nm and 400 nm via diversifying the condition of polymerization. The resulted emulsion solution could accumulate slowly to form three dimensional ordered structure, which was induced by capillary as the solvent evaporating at room temperature. The opal is close packed face center cubic(f.c.c) lattice of polystyrene latex. Defects such as vacancies, dislocations or grain boundaries could be obviously observed from the SEM images. Reflectance spectra showed the red shift of specular reflectivity peak for the polystyrene colloidal crystal as the size of polystyrene latex increasing. It was demonstrated that the reflectance is intrinsic property of these colloidal crystals. This provides ideal model for the research and application of photonic crystals and form useful template for growth of various ordered macroporous materials.
文摘In this paper, the self-assembly of PS 43-b-PEO 45-b-PS 43 triblcok copolymer was investigated. The colloids were made by firstly dissolving the copolymer in the common solvents, including THF, 1,4-dioxane, and DMF, then droping water into the corresponding copolymer solution to induce the self-assembly. The aggregates prepared were characterized with TEM and AFM techniques. The experimental results demonstrated that the self-assembled vesicles were formed when THF and 1,4-dioxane were used as the common solvents to dissolve the copolymer, comparatively, using DMF as the common solvent resulted in the formation of spherical aggregates. The self-assembled aggregates observed, possessing hierarchical structures, could be used as either the nanostructures themselves for drug delivery systems, separations, catalysts, and so on, or templates or building blocks for more complex structures.
