Effect of graphene oxide on thermal, optical, and gas permeability of graphene oxide/poly(vinyl alcohol) hybrid films using the boric acid

We prepared graphene oxide (GO)/poly(vinyl alcohol) (PVA) hybrid films using boric acid (BA) as a cross-linking agent for barrier films. The variations of thermal properties, optical transparency, and gas permeability of GO/B-PVA hybrid films were studied in relation to increase in the GO content from 0 to 5 wt%. The intercalations of polymer chains in the PVA were examined with wide angle X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR). In addition, the thermal properties were investigated using a differential scanning calorimeter (DSC) and thermogravimetric analyzer (TGA). As a result, with increasing GO content, the crystallinity and glass transition temperature (T_g) of the GO/B-PVA hybrid films were increased. The oxygen permeability rate (P_O2) values were increased by about 97% at 5 wt% GO content. Enhanced oxygen transmission performance was attributed to the outstanding impermeability of GO as well as the strong interfacial adhesion between GO and the PVA matrix.