Multi-step microwave reduction of graphite oxide and its use in the formation of electrically conductive graphene/epoxy composites

• Published in: Composites. Part B, Engineering Vol. 64; pp. 187 - 193
• Main Authors: Pokharel, Pashupati, Truong, Quang-Trung, Lee, Dai Soo
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.08.2014; Elsevier
• Subjects: A. Polymer–matrix composites (PMCs); Applied sciences; B. Electrical properties; Composites; E. Cure; Electrically conductive; Exact sciences and technology; Forms of application and semi-finished materials; Graphene; Irradiation; Microwaves; Oxides; Percolation; Polymer industry, paints, wood; Polymer matrix composites; Reduction; Technology of polymers; B. Electrical properties; E. Cure; A. Polymer–matrix composites (PMCs); Conducting material; Electrical conductivity; Electrical properties; Epoxy resin; Microwave heating; Experimental study; Glass transition temperature; Composite material; Polymer filler interaction; Thermal properties; Chemical reduction; A. Polymer-matrix composites (PMCs); Shear viscosity; Graphene; Morphology; Concentration effect; Graphite Oxides; Percolation; Rheological properties
• ISSN: 1359-8368; 1879-1069
• DOI: 10.1016/j.compositesb.2014.04.013

The multi-step MW reduction technique was developed in this study to obtain reduced graphene oxides; EG, RGO-1, and RGO-2 with MW irradiation time of 1, 2, and 3min, respectively. Results of TGA, IR, and elemental analysis demonstrated that the degree of reduction of GO increased with increasing the MW irradiation time. Overall, 3min of MW irradiation of GO in 3 steps was sufficient to obtain highly reduced GO (C/O ratio 10.38 by elemental analysis). The electrical percolation threshold of composites was observed as 1wt% and 0.3wt% for RGO-1 and RGO-2, respectively. Even at 0.5wt% loading of RGO-2 in epoxy, the Tg value of the composite increased by 10°C, indicating a strong interfacial interaction between graphene and epoxy resin.