Yong Zhou

Bio: Yong Zhou is an academic researcher from Chinese Academy of Sciences. The author has contributed to research in topics: Crystallization & Materials science. The author has an hindex of 18, co-authored 41 publications receiving 1267 citations.

Polypropylene/Graphene Oxide Nanocomposites Prepared by In Situ Ziegler−Natta Polymerization

Abstract: This paper reports the first example of preparation of polypropylene/graphene oxide (PP/GO) nanocomposites via in situ Ziegler−Natta polymerization. A Mg/Ti catalyst species was incorporated into GO via surface functional groups including −OH and −COOH, giving a supported catalyst system primarily structured by nanoscale, predominantly single GO sheet. Subsequent propylene polymerization led to the in situ formation of PP matrix, which was accompanied by the nanoscale exfoliation of GO, as well as its gradual dispersion. Morphological examination of the ultimate PP/GO nanocomposites by TEM and SEM techniques revealed effective dispersion in nanoscale of GO in PP matrix. High electrical conductivity was discovered with thus prepared PP/GO nanocomposites; for example, at a GO loading of 4.9 wt %, σc was measured at 0.3 S·m−1.

Frustrated crystallisation and hierarchical self-assembly behaviour of comb-like polymers

Abstract: Comb-like polymers with flexible side chains chemically pended onto a polymeric backbone afford some unusual properties due to their hierarchical structures, such as nanoscale confined crystallisation, phase transition and conformational variations, length scale effects, etc Considerable attention has been paid to these featured polymers, regarding their importance in understanding the correlation between hierarchical structure and the assembled morphologies In this review, we reviewed the recent research progress on the structure–property correlations of comb-like polymers This article brings together and highlights the fabrication, structure determination and morphology characterization for comb-like polymers, especially for nanostructured packing patterns and frustrated mobility of chain segments from the selected examples

Crystallization and aggregation behaviors of calcium carbonate in the presence of poly(vinylpyrrolidone) and sodium dodecyl sulfate.

Abstract: An anionic surfactant interacts strongly with a polymer molecule to form a self-assembled structure, due to the attractive force of the hydrophobic association and electrostatic repulsion. In this crystallization medium, the surfactant-stabilized inorganic particles adsorbed on the polymer chains, as well as the bridging effect of polymer molecules, controlled the aggregation behavior of colloidal particles.1 In this presentation, the spontaneous precipitation of calcium carbonate (CaCO3) was conducted from the aqueous systems containing a water-soluble polymer (poly(vinylpyrrolidone), PVP) and an anionic surfactant (sodium dodecyl sulfate, SDS). When the SDS concentrations were lower than the onset of interaction between PVP and SDS, the precipitated CaCO3 crystals were typically hexahedron-shaped calcite; the increasing SDS concentration caused the morphologies of CaCO3 aggregates to change from the flower-shaped calcite to hollow spherical calcite, then to solid spherical vaterite. These results indica...

Properties of amorphous calcium carbonate and the template action of vaterite spheres.

Abstract: The fast mixing of aqueous solutions of calcium chloride and sodium carbonate could immediately result in amorphous calcium carbonate (ACC). Under vigorous stirring, the formed ACC in the precipitation system will dissolve first and, then, transform within minutes to produce crystalline forms of vaterite and calcite. After that, the solution-mediated mechanism dominates the transformation of the thermodynamically unstable vaterite into the thermodynamically stable calcite. Although ACC is the least stable form of the six anhydrous phases of calcium carbonate (CaCO3), it could be, however, produced and stabilized by a variety of organisms. To better understand the formation−transformation mechanism of ACC and vaterite into calcite, ex-situ methods (i.e., scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction spectroscopy) were used to characterize the formation−transformation process of ACC and vaterite in aqueous systems without organic additives, showing that ACC sam...

Graphene based new energy materials

Abstract: Graphene, a one-atom layer of graphite, possesses a unique two-dimensional (2D) structure, high conductivity and charge carrier mobility, huge specific surface area, high transparency and great mechanical strength. Thus, it is expected to be an ideal material for energy storage and conversion. During the past several years, a variety of graphene based materials (GBMs) have been successfully prepared and applied in supercapacitors, lithium ion batteries, water splitting, electrocatalysts for fuel cells, and solar cells. In this review, we will summarize the recent advances in the synthesis and applications of GBMs in these energy related systems. The challenges and prospects of graphene based new energy materials are also discussed.