The epoxy resin employed in this study was a difunctional diglycidyl ether of bisphenol A (DGEBA) with an equivalent weight of 175–180 g/equiv. and a hydroxyl/epoxy ratio of 0.03, supplied by Sigma-Aldrich (St. Louis, MI, USA). The hardener was a solid tetrafunctional aromatic amine, 4,4′-diaminodiphenylmethane (DDM), from Sigma-Aldrich, with a molecular weight of 198 g/mol and an amine equivalent weight of 49.5 g/mol.
Commercial powder graphite containing 99 wt % minimum of carbon, 0.8 wt % maximum of ash, and 0.05 wt % maximum of sulfur from Acros Organic was selected for the preparation of GO and rGO. For the oxidation of graphite, sodium nitrate was purchased from Acros Organic, whereas sulfuric acid (95–97%), potassium permanganate (extra pure) and hydrogen peroxide (30 wt %) were purchased from Scharlau. For the GO reduction, monohydrated hydrazine (64–65%) from Sigma Aldrich was used. Pure water by ELIX Advantages (type II) was employed in the current work. All reagents have been used without further purification.
Commercial powder graphite containing 99 wt % minimum of carbon, 0.8 wt % maximum of ash, and 0.05 wt % maximum of sulfur from Acros Organic was selected for the preparation of GO and rGO. For the oxidation of graphite, sodium nitrate was purchased from Acros Organic, whereas sulfuric acid (95–97%), potassium permanganate (extra pure) and hydrogen peroxide (30 wt %) were purchased from Scharlau. For the GO reduction, monohydrated hydrazine (64–65%) from Sigma Aldrich was used. Pure water by ELIX Advantages (type II) was employed in the current work. All reagents have been used without further purification.