Graphene-based multifunctional iron oxide nanosheets with tunable properties.

We report the synthesis of graphenes with tunable properties due to the growth of needlelike iron oxide (IO) nanoparticles on their surfaces. The electrical conductivity, flexibility, and magnetic properties of graphene nanosheets (GNSs) could be tuned on demand by fine controlling both the surface coverage and the length of the IO nanoneedles. The degree of coverage of the IO nanoparticles on the surface of the GNSs made it possible to control the resulting properties of the IO/GNSs on demand.

Electrical properties of imidazole-modified MWNT/polyphenylenesulfide composites prepared by melt mixing.

The electrical conductivity of surface-modified multiwalled carbon nanotubes (MWNTs)/poly-phenylenesulfide (PPS) composites prepared by melt processing is measured as a function of frequency with the MWNTs content and evaluated in terms of percolation behavior. The imidazoledithiocarboyxlic acid (imidazole) is grafted from the oxidized MWNTs, and the results of surface analysis, HRTEM and thermal analysis reveal that the MWNTs are successfully modified by imidazole. Although the imidazole-modified MWNTs are most damaged during the modification reaction of imidazole with carboxylic group onto the MWNTs as well as during the oxidation, so that the modified MWNTs are significantly shortened, the imidazole modification of MWNTs enables the PPS composites to have the lower percolation threshold and the higher electrical conductivity than the oxidized MWNTs/PPS composites.