Two-dimensional materials modified layered double hydroxides: A series of fillers for improving gas barrier and permselectivity of poly(vinyl alcohol)

Abstract

Abstract A series of modified 2D nanosheets (graphene oxide-layered double hydroxide, GO-LDH; boron nitride-LDH, BN-LDH; and molybdenum disulfide-LDH, MoS2-LDH) are prepared via a cost-effective, environmentally-friendly, and effortless method based on the concept of electrostatic interaction. The modified 2D nanosheet/Poly(vinyl alcohol) (PVA) nanocomposite films show a comprehensive improvement of physicochemical properties. Among the synthesized films, the O2 barrier performance of the 1% GO-LDH/PVA nanocomposite film (1.44\u202f×\u202f10−13\u202fcm3\u202fcm/cm2·s·cmHg) is 25-fold higher than that of the pure PVA film (3.68\u202f×\u202f10−12\u202fcm3\u202fcm/cm2·s·cmHg). The 1% GO-LDH/PVA shows tremendous improvement in tensile strength (84.7\u202fMPa) and modulus (3032\u202fMPa) values than the PVA film (46.7 and 371\u202fMPa). Furthermore, the 2% BN-LDH/PVA nanocomposite shows the H2/CO2 permselectivity value of 102.5, which is superior to the Robeson upper bound and most reported separation films. In addition to the improved gas barrier and permselectivity performances, an exceptional combination of the thermal stability, tensile strength/modulus, flexibility, and transparency of the nanocomposite film could lead to applications in food packaging, H2 purification, and CO2 capture.