Micelle formation in tetrahydrofuran-methanol, 1,2-dichloroethane-methanol, tetrahydrofuranwater, and water solutions by PS-PEO diblock copolymers was studied by the fluorescence spectroscopy. For this purpose, a series of PS-PEO copolymers was labeled by the phenanthrene or anthracene groups at the block junctions. The chromophore contents in copolymers were determined by the absorbance spectroscopy using suitable model compounds. When micelles were present, intramicellar nonradiative energy transfer could be observed. For the PS-PEO copolymer (M" = 114 000,93 weight % PEO) we find the onset of micelle formation in water in the range of 10 X 10-3 g/L (9 X -8 M).
Polystyrene-block-poly(4-vinylpyridine) diblock copolymer micelles of various compositions and molecular weights were characterized in toluene. Static light scattering, quasielastic light scattering and viscosity measurements were used to determine the basic micellar characteristics (aggregation number, micellar size, geometry and polydispersity). Depending on the copolymer under investigation, two different geometries (spherical and non-spherical geometry) were observed. The micelles which are spherical in shape have aggregation numbers in the range 200-600 while the non-spherical micelles have a much larger aggregation number (ranging between 600-1000). The sizes of the micelles remain unchanged in our concentration range g/mL) and no critical micelle concentration could be detected in the concentration range from to g/mL. A detailed analysis of the structural parameters of the micelles which are spherical in shape, reveals that the core-shell interfacial area per copolymer chain as well as the volume fraction of the copolymer in the shell are relatively constant, and that the core is almost not swollen by the solvent. Mixed uniform micelles were observed after mixing equal amounts of two solutions containing micelles differing in size and molecular weight. The reequilibration rate was found to be very fast.-5 *
In this article, we describe the synthesis of a PMMA-g-PDMS graft copolymer via a miniemulsion process. A highly hydrophobic PDMS macromonomer was copolymerized in the presence of MMA. Latex particles were obtained with a high yield and a complete incorporation of the macromonomer by using AIBN as initiator, SDS as a surfactant and a PMMA-b-PEO block copolymer as a cosurfactant, with a given amount of methanol in order to reduce the interfacial tension. The characterization of the resulting latex by 1 H NMR and QELS evidenced the interest of such a process in order to copolymerize monomers with very different solubilities and to obtain directly a graft copolymer in aqueous dispersion.
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