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Graphene oxide (GO) is a carbon‐based material, which is one atom thick sheet of graphite. The nanofillers have exceptional stiffness and strength owing to the presence of two‐dimensional graphene backbone. Especially owing to this reason, nanocomposites have been developed using GO for several applications. This review article explores the synthesis of GO from flake graphite. Main emphasis has been afforded on the preparation and characterization of GO nanocomposites, utilizing various industrial polymers for wide application in aerospace, biomedical, military, supercapacitors, electrical, sensor, and so on. Morphological characterization exploring the interaction and extent of dispersion of GO nanosheets in the polymer matrices is extensively accounted. From the reports, it is clear that exfoliation and strong interaction of GO tremendously improved the physical, mechanical, thermal, electrochemical, biocompatibility, and tribological properties of the added polymer. POLYM. COMPOS., 35:2297–2310, 2014. © 2014 Society of Plastics Engineers

In this contribution, we report studies of the nature of binding interactions and dynamics of protein histone I (H1) with ligands in solution and as a complex with DNA, an important biological process for the higher-order structure in chromatin. With femtosecond time resolution, we examined the role of solvation by water, the micropolarity at the interface of the binding site(s) of H1, and the rigidity of the complex structure. We used two biologically common fluorescent probes: 2-(p-toluidino)naphthalene-6-sulfonate (TNS) and 5-(dimethylamino)naphthalene-1-sulfonyl chloride (DC). By noncovalently attaching TNS and covalently adducting DC to the binding sites we found that the solvation dynamics, which occur within 1 ps, for the probe at the protein surface and in bulk solution are comparable, indicating the significant contribution of bulk water shells. However, the local polarity changes significantly, reflecting the change in dielectric properties at the protein/water interface. The binding structure of the protein ± DNA complex was examined by the local orientational motion of the probe. The covalently bound DC molecule, sandwiched between the protein and DNA, was found to be frozen, revealing the very rigid structure at the recognition site, while, for noncovalently bound TNS, the complexes displace the probe. The dynamical rigidity of the complex, and the role of solvation and interface polarity, elucidate the strong recognition mechanism between DNA and the protein by electrostatic interactions, which are important to the compactness and to chromatin condensation in the biological function.