Synthesis and characterization of a two-step reduced Graphene Oxide for antena applications in the microwave resime

Abstract

This thesis presents the development of a two-step reduced graphene oxide that is to be implemented as the radiating element for a patch antenna. The two-step reduced graphene oxide is prepared with graphite powder and is oxidized using the Tour’s method. The graphene oxide produced from this procedure is cleaned and neutralized before microwave irradiation procedure is carried out to begin the reduction process, by which oxygen containing functional groups are removed from the material. The second step of the reduction process consists of using the strongest hydrohalic acid, hydroiodic acid, to reduce graphene oxide in a reflux setup. The two-step reduced graphene oxide and its precursors are characterized using Field Emission Scanning Electron Microscopy (FESEM), Thermogravimetric analyzer (TGA), Ultraviolet-Visible Spectroscopy (UVVis), Fourier Transform Infrared Spectroscopy (FTIR), 4-Point Probe Conductivity Test, X-Ray Diffraction analyzer (XRD), and Energy Dispersive X-Ray analyzer (EDX). The results of the two-step reduction process yielded a reduced graphene oxide with a net conductivity measured at 4.8 x 102 Sm-1. The measured resistivity and electrical conductivity results were higher in the two-stepped method than any measurement yielded from its precursor materials. This thesis explains the effects that microwave irradiation and chemical reduction has on the degree of reduction and the overall structure of reduced graphene oxide. The two-step reduced graphene oxide was used as the radiating element in a microstrip patch antenna to determine the antenna performance in the microwave region.