Acrylonitrile-butadiene-styrene resin (ABS)/graphene nanocomposites were prepared through a facile coagulation method. Because the chemical reduction of graphene oxide was in situ conducted in the presence of ABS at the dispersion stage, the aggregation of the graphene nanosheets was avoided. It was shown by transmission electron microscopy that the graphene nanosheets were selectively located and homogeneously dispersed in the styrene-acrylonitrile (SAN) phase. The electrical conductivity and linear viscoelastic behavior of the nanocomposites were systematically studied. With increasing filler content, graphene networks were established in the SAN phase. Consequently, the nanocomposites underwent a transition from electrical insulator to conductor at a percolation threshold of 0.13 vol %, which is smaller than that of other ABS composites. Such a low percolation threshold results from extreme geometry, selective localization, and homogeneous dispersion of the graphene nanosheets in SAN phase. Similarly, the rheological response of the nanocomposites also showed a transition to solid-like behavior. Due to the thermal reduction of graphene nanosheets and structure improvement of graphene networks, enhanced electrical conductivity of the nanocomposites was obtained after annealing.

Mass production of two-dimensional quantum sheets (2D QSs) is highly desired to fully exploit their properties. Herein, we present a general strategy for the high-yield production of molybdenum disulfide (MoS) and tungsten disulfide (WS) QSs by a sequential combination of salt-assisted ball-milling and sonication-assisted solvent exfoliation of their bulk materials. Such a strategy enables reproducible production of intrinsic and defect-free MoS and WS QSs with exceedingly high yields of 25.5 and 20.1 wt %, respectively. By precipitation-redispersion treatment, the QSs can be redispersed in a wide range of solvents with redispersion concentration up to 20 mg/mL or even higher. Remarkable nonlinear absorption saturation is demonstrated in the QSs-poly(methyl methacrylate) (PMMA) hybrid thin film with loading content of merely 0.1 wt %. Our method provides an avenue toward mass production and full exploration of 2D QSs.