Polymer-grafted nanoparticles homopolymer

Among the two ionic polymerization techniques mentioned above, a living anionic polymerization should show the best possible control of polymer architecture and composition. Mono dispersed homopolymers, complex-block, graft, star, and miktoarm architectures have been accessible primarily by anionic polymerization methods [22]. They have been used to grow polymer brushes from various small particles such as silica gels graphite,carbon black, and flat surfaces [23-26]. Recent results have been reported on living anionic polymerizations on clay [27] and silica nanoparticles [28,29]. 

The linear viscoelastic properties in the melt state of highly grafted polymers on spherical silica nanoparticles are probed using linear dynamic oscillatory measurements and linear stress relaxation measurements. While the pure silica tethered polymer nanocomposite exhibits solid-like response, the addition of a matched molecular weight free matrix homopolymer chains to this hybrid material, initially lowers the modulus and later changes the viscoelastic response to that of a liquid. These results are consistent with the breakdown of the ordered mesoscale structure, characteristic of the pure hybrid and the high hybrid concentration blends, by the addition of homopolymers with matched molecular weights. 

Recently, the synthesis of polymer nanocomposite OLEDs based on a new series of sulfide-containing polyfluorene homopolymers and copolymers and CdSe/ZnS nanocrystals was described by Yang et al. [38]. CdSe/ZnS nanoparticles were grafted to sulfur atoms by a ligand-exchanging reaction. The EL efficiency of nanocomposite OLEDs was effectively improved by QD nanocrystals incorporated in the polymers [38]. 

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