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Poly(vinylalcohol)/reduced graphite oxide nanocomposites have been synthesised by reducing graphite oxide in the presence of the polymer matrix and coagulating the system with 2-propanol. It has been observed that some interactions occur between the polymer and the reduced graphite oxide layers, mainly by hydrogen bonding. These interactions are responsible for a remarkable change in the thermal behaviour of the nanocomposites. In addition, high electrical conductivity has been achieved at concentrations beyond 7.5 wt% of reduced graphite oxide ($0.1 S cm À1 ), with a percolation threshold between 0.5 and 1 wt%.

Covalent binding of polymers to graphene represents an interesting alternative for the development of novel composite materials with a compendium of interfacial interactions. Through covalent linking, the concept of interface changes from a traditional view of interactions between components, such as van der Waals, hydrogen bonding, and so on, that is to say, at a polymer-filler interface, to a single compound concept where graphene forms an integral part of the polymeric chains. This feature article provides an overview of the strategies currently employed to functionalize graphene with polymers. We focus on the grafting-from and grafting-to methods used to bind polymers to graphene. The advantages and drawbacks, as well as the influence of each method on the final properties, are highlighted.

Gallium oxide (Ga2O3) thin films were produced by sputter deposition by varying the substrate temperature (T s) in a wide range (T s = 25–800 °C). The structural characteristics and optical properties of Ga2O3 films were evaluated using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectrometry (EDS), Rutherford backscattering spectrometry (RBS), and spectrophotometric measurements. The effect of growth temperature is significant on the chemistry, crystal structure, and morphology of Ga2O3 films. XRD and SEM analyses indicate that the Ga2O3 films grown at lower temperatures were amorphous, while those grown at T s ≥ 500 °C were nanocrystalline. RBS measurements indicate the well-maintained stoichiometry of Ga2O3 films at T s = 300–800 °C. The spectral transmission of the films increased with increasing temperature. The band gap of the films varied from 4.96 to 5.17 eV for a variation in T s in the range 25–800 °C. A relationship between microstructure and optical property is discussed.