Validation of experimental results for graphene oxide-epoxy polymer nanocomposite through computational analysis

The change in interfacial interaction behavior of epoxy resin nanocomposites with the incorporation of graphene oxide (GO) was explored experimentally and computationally. GO with different weight (wt) loading was incorporated in epoxy resin by a three-way dispersion method. GO formed mechanical interlocking with epoxy resin, thereby resulting in a remarkable enhancement in mechanical and thermo-mechanical properties of GO-epoxy nanocomposite. In 0.3 wt% GO-epoxy nanocomposites, improvement of 26.7% in flexural strength and 39.2% in flexural modulus was reported. Using dynamic mechanical analysis (DMA), thermomechanical analysis (TMA) and differential scanning calorimetry (DSC), glass transition temperature (T_g) of 182.7°C and maximum thermal stability was reported for 0.3% GO-epoxy nanocomposite. The effect of GO on cross-linking in GO-epoxy nanocomposite was analyzed by DSC and Raman spectroscopy. The X-ray photoelectron spectroscopy (XPS) study was utilized to determine the interfacial interaction, and further was verified by density functional theory (DFT). By experimental and computational study, H-bonding was observed to improve interfacial interaction in GO-epoxy nanocomposite.