Polymer inorganic nanosheet composites hold great promise in enhancing their physical and mechanical properties by increasing the interfacial area. Herein, we demonstrate the nanoinclusion effects of two-dimensional (2D) molybdenum disulfide (MoS₂) and tungsten disulfide (WS₂) nanosheets on the mechanical properties of the poly(vinyl alcohol) (PVA) polymer. At very small amounts of nanosheets (0.9 wt% for MoS₂ and 2.0 wt% for WS₂), nanocomposite films exhibit up to 65% improved mechanical properties than the neat PVA film because of strong non-covalent polymer–filler interactions by means of large contact area induced by the 2D geometry of nanosheets. As demonstrated by the decrease in the crystallinity of PVA and the increase in the glass transition temperature, 2D MoS₂ is a more attractive filler than 2D WS₂ in terms of reinforcing mechanical properties of PVA. These findings fit well with a modified Halpin–Tsai (H–T) model including a nanoscale interfacial layer that can support the observed reinforcements with extremely small 2D filler loadings. This study highlights the strong interplay between the polymer and inorganic nanosheets which plays an important role in greatly improving the mechanical stability of nanocomposites.

We report the structural, electronic, optical and thermoelectric (TE) properties of X ₃ PbO (X = Ca, Sr, Ba) anti-perovskites as a function of X cations belonging to the group IIA. The computations are done by using the most recently introduced modified Becke–Johnson potential. It has been observed that the cubic lattice constant increases as the cations change from Ca to Ba, consequently, the bulk modulus reduces. The bottom of conduction band shows strong hybridization between Pb-6p, O-2p and X-s states, in contrast, valence band maxima are mainly manufactured by Pb-6p states. The anti-perovskites exhibit narrow direct band gap that show an inverse relation to the static real dielectric constants that verifies Penn’s model. In addition, the X cations induced tuning of the absorption edge in the visible and the ultraviolet energy suggest optical device applications. The computed TE parameters have been found sensitive to the X cations and have been demonstrated to be best suited for the TE devices operating at high temperatures.