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Organic-inorganic nanocomposites composed of polymers and nanoparticles offer a vast design space of potential material properties, depending heavily on the properties of these two constituents and their spatial arrangement. The ability to place polymers in direct contact with functional nanoparticles via strong bonding, that is, stable chemical interaction without the dissociation of surface capping polymers, provides a means of preventing nanoparticles from aggregation and increasing their dispersibility in nanocomposites, and promises opportunities to explore new properties and construction of miniaturized devices. However, this is still a challenging issue and has not yet been largely explored. Here, we report an unconventional strategy to create in situ organic-inorganic nanocomposites comprising monodisperse ferroelectric nanoparticles directly and permanently tethered with ferroelectric polymers by capitalizing on rationally designed amphiphilic star-like diblock copolymer as nanoreactors. The diameter of ferroelectric nanoparticles and the chain length of ferroelectric polymers can be precisely tuned. The dielectric and ferroelectric properties of nanocomposites containing different sizes of ferroelectric nanoparticles were scrutinized. Such bottom-up crafting of intimate organic-inorganic nanocomposites offers new levels of tailorability to nanostructured materials and promises new opportunities for achieving exquisite control over the surface chemistry and properties of nanocomposites with engineered functionality for diverse applications in energy conversion and storage, catalysis, electronics, nanotechnology, and biotechnology. [ABSTRACT FROM AUTHOR]

Atom transfer radical polymerization (ATRP) of 4-vinylpyridine, t-butyl acrylate, and styrene in sequential order from a β-cyclodextrin core yielded an amphiphilic star-like triblock copolymer, poly(4-vinylpyridine)-block-poly(t-butyl acrylate)-block-polystyrene (P4VP-b-PtBA-b-PS). Subsequently, star-like triblock copolymer composed of inner hydrophilic P4VP blocks, central hydrophobic PtBA blocks, and outer hydrophobic PS blocks with well-defined molecular architecture and molecular weight of each block was judiciously exploited as nanoreactor for synthesis of precisely shaped hairy plasmonic/semiconductor Au/TiO2 core/shell nanoparticles. The resulting Au/TiO2 nanoparticles were intimately and permanently tethered with outer PS chains that enabled the superior solubility of nanoparticles in nonpolar solvents. The PS chains on the surface of these bifunctional nanoparticles were carbonized by annealing in an inert atmosphere (i.e., yielding carbon-coated Au/TiO2 nanoparticles). In comparison to a widely used TiO2 network film (i.e., P25)-based device, dye-sensitized solar cells assembled by incorporating a thin layer of carbonized Au/TiO2 nanoparticles on the top of P25 film as photoanode exhibited largely improved short-circuit current density, JSC (18.4% increase), and power conversion efficiency, PCE (13.6% increase), respectively. Such improvements were attributed to the surface plasmon-enabled light harvesting enhancement of Au core and fast electron transport promoted by the carbon layer coating on Au/TiO2 nanoparticles, as revealed by external quantum efficiency (EQE), UVâ€"vis spectroscopy, and electrochemical impedance spectroscopy measurements, respectively. [ABSTRACT FROM AUTHOR]

A series of novel amphiphilic 21-arm, starlike diblock copolymers, poly(acrylic acid)-b-poly(3-hexylthiophene) (PAA-b-P3HT), based on β-cyclodextrin (β-CD) with well-defined molecular architectures and ratio of two chemically distinct blocks were prepared, for the first time, via a combination of quasi-living Grignard metathesis method (GRIM), click reaction, and atom transfer radical polymerization (ATRP). The starlike PAA-b-P3HT diblock copolymers consist of hydrophilic coil-like PAA cores and hydrophobic rodlike P3HT shells with narrow molecular weight distribution and well-defined molecular weight of each block. Owing to the compact structure, the amphiphilic starlike PAA-b-P3HT formed a unimolecular micelle. Emulsion based on these novel amphiphilic starlike, coil–rod diblock copolymers were readily produced by cross-linking hydrophilic coil-like PAA cores with a bifunctional cross-linker, ethylenediamine. [ABSTRACT FROM AUTHOR]