Ultrahigh gas barrier poly (vinyl alcohol) nanocomposite film filled with congregated and oriented Fe3O4@GO sheets induced by magnetic-field

Graphene oxide nanosheets coated with magnetic ferroferric oxide nano-particles (Fe3O4@GO) were firstly in-situ synthesized and then employed as fillers to prepare a polyvinyl alcohol (PVA) nanocomposite film with ultrahigh gas barrier property under magnetic field. Fourier-transform infrared spectroscopy (FTIR) and Transmission Electron Microscope (TEM) showed that the magnetic Fe3O4 particles were homogenously absorbed onto the surface of GO sheets. Polarizing optical microscopy (POM) and Scanning Electron Microscopy (SEM) results proved that the PVA composite film containing congregated and oriented Fe3O4@GO nanosheets was facilely manufactured aided by the magnetic field. Due to dramatic decline of gas permeable areas along parallel direction of film, an unprecedented improvement on gas barrier property of PVA/Fe3O4@GO nanocomposite film was achieved. With the addition of only 0.072 vol% Fe3O4@GO, the oxygen permeability (PO2) of PVA film decreased from 21.17 × 10−15 to 0.2126 × 10−15 cm3 cm/(cm2 s Pa), showing about 99.0% improvement of gas barrier performance. The modified Bharadwaj model introduces a proportionality coefficient (k), giving better prediction of the PO2 of PVA/Fe3O4@GO nanocomposites. In addition, the prepared PVA/Fe3O4@GO nanocomposite film exhibited excellent tensile strength and Young's modulus. This congregated and oriented nanocomposite film with unprecedentedly excellent barrier performance could be perceived as a satisfying alternative for the traditional aluminum films applied in food and medicine packaging.