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Amphiphilic polystyrene-block-polyethylene oxide (PS-b-PEO) block copolymers (BCPs) have been demonstrated to be effective in directing organization of colloidal Au nanoparticles (NPs). Au NPs have been incorporated into the polymer and the different chemical affinity between the NP surface and the two blocks of the BCP has been used as a driving force of the assembling procedure. The morphology of the nanocomposites, prepared and fabricated as thin films, has been investigated by means of atomic force and scanning electron microscopies as a function of the NP content and BCP molecular weight. NPs have been effectively dispersed in PS-b-PEO hosts at any investigated content (up to 17 wt%) and a clear effect of the BCP properties on the final nanocomposite morphology has been highlighted. Finally, electrostatic force microscopy has demonstrated the conductive properties of the nanocomposite films, showing that the embedded Au NPs effectively convey their conductive properties to the film. The overall investigation has confirmed the selective confinement of the as-prepared surfactant-coated metal NPs in the PS block of PS-b-PEO, thus proposing a very simple and prompt assembling tool for nanopatterning, potentially suitable for optoelectronic, sensing and catalysis applications.

As-synthesized organic-capped TiO2 nanorods were incorporated into polystyrene-block-poly(methyl methacrylate) (PS-b-PMMA) diblock copolymer to achieve TiO2/PS-b-PMMA nanocomposites with enhanced optical and conductive properties. The specific surface chemistry of TiO2 nanorods derived from the colloidal synthetic approach allowed their prompt incorporation in the PS-b-PMMA block copolymer template up to 50 wt %, which resulted in films with an extended coverage of highly dispersed nanoparticles for contents higher than 30 wt %. At such high nanorod contents, the films fabricated by the prepared nanocomposites demonstrated enhanced optical properties. Atomic force microscopy investigation of the nanocomposite films showed a cylindrical morphology for low nanorod contents. Conversely, higher nanorod contents resulted upon removal of the organic component in the nanocomposites with UV treatment in overall nanorod coverage of the film surface with the concomitant formation of charge percolation paths, which led to noticeable conductivity values. EFM and PF-TUNA measurements confirmed the conductive properties of the composites at nanoscale, whereas semiconductor analyzer measurements provided their macroscale characterization. In addition, an increase in the UV-vis absorption was observed with the increase in the nanorod content along with a remarkable conductivity of the overall film.

Nanocomposites based on a self-assembled polystyrene-block-polymethyl methacrylate (PS-b-PMMA) diblock copolymer and rutile titanium dioxide (TiO2) nanoparticles covered by stearic acid were investigated. Different amounts of TiO2 nanoparticles were added to the PS-b-PMMA matrix to study the effect of the TiO2 nanoparticles content on the final properties of TiO2/PS-b-PMMA nanocomposites. A good dispersion of TiO2 nanoparticles was achieved even in the case of a high (more than 3 wt %) TiO2 nanoparticles content in the matrix. Atomic force microscopy (AFM) results indicated that TiO2 nanoparticles were confined in the microseparated PS-block of the block copolymer due to the affinity between nanoparticles covered by stearic acid and PS-block. The addition of TiO2 nanoparticles changed the final morphology of the designed nanocomposites, from worm-like to cylindrical structure, without losing the ability of the block copolymer to self-assemble even for high TiO2 nanoparticles content. TiO2 nanoparticles transferred their electrical and optical properties to the designed TiO2/PS-b-PMMA nanocomposites.