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Abstract: Polystyrene nanoparticles, cross-linked with divinylbenzene (PS-(DVB) x ) and having radii, R p ≤ 10 nm, have been synthesized using batch and semi-batch radical microemulsion polymerizations. The nanoparticles were characterized thoroughly using 1H NMR, size exclusion chromatography, differential scanning calorimetry, and various small-angle scattering techniques (light, X-rays, and neutrons). Control over network and interface morphologies of the PS-(DVB) x nanoparticles is readily achieved by varying the concentration of divinylbenzene and the polymerization technique (batch vs. semi-batch). Small-angle neutron scattering (SANS) allowed us to identify three distinct nanoparticle morphologies: (i) fuzzy soft gels with flexible chain-segments tethered/looped at the interface of a homogeneous core, (ii) smooth soft gels without a fuzzy interfacial layer, and (iii) dendritic glassy gels exhibiting an inhomogeneous core with an ill-defined interface. Atomic force microscopy imaging supports the morphologies and the softness of the nanoparticles as indicated by SANS. [Copyright &y& Elsevier]

Abstract: The synthesis via anionic polymerization of six linear triblock terpolymers with various sequences of blocks such as PS (polystyrene), PB [poly(butadiene)], PI [(poly(isoprene)] and PCHD [poly(1,3-cyclohexadiene)] is reported. The synthesis of the terpolymers was carried out by the use of anionic polymerization with high-vacuum techniques and sequential monomer addition. Molecular characterization of the samples was performed via size exclusion chromatography (SEC) and membrane osmometry (MO) to measure the polydispersity indices and the number-average molecular weights, respectively. Proton nuclear magnetic resonance spectroscopy (1H NMR) was employed to verify the microstructure type for the polydienes, as well as, to calculate the molar composition. Structural characterization of the terpolymers was performed via transmission electron microscopy (TEM) and small angle X-ray scattering (SAXS), and several morphologies were observed including one which has not been reported previously. Real-space self-consistent field theory (SCFT) without a priori knowledge about the symmetry of the periodic structures was used to elucidate the thermodynamics of the synthesized triblock copolymers. [Copyright &y& Elsevier]