Síntese de nanoplaquetas de óxido de grafeno reduzido (rGO) por diferentes rotas para aplicação em tintas condutoras

Abstract

Graphene, a two-dimensional material with excellent properties, is one of the allotropic forms of carbon. Graphite, the precursor that gives rise to graphene, is made up of several layers of hexagonally bonded carbons, each of which characterizes a graphene sheet. Separating these layers would ensure that graphene is obtained and, to this end, chemical exfoliation followed by reduction has emerged as a large-scale synthesis method. Obtaining graphene oxide (GO) involves inserting oxygenated functional groups between the graphite chains, and its reduction partially removes these groups, making it possible to improve its properties. Reduced graphene oxide (rGO), the product of the reduction of the material, has properties similar to graphene and, among them, high electrical conductivity. The excellent properties of graphene guarantee this material and its derivatives wide applicability, especially in the field of electronic equipment and in the production of conductive inks. The main difficulty for this application is related to the difficulty of producing these materials on a large scale and with a morphology that favors their electrical properties. Another difficulty lies in choosing the ideal formulation for a possible conductive ink, evaluating aspects such as the quality of the dispersion of the material in the chosen base, the properties obtained and the related cost-benefit ratio. In this work, the synthesis of GO and nanoplatelets of rGO was addressed, and two reduction methods were chosen, thermal reduction and chemical reduction using ascorbic acid as a reducing agent. Scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy analyses were carried out, confirming the quality of the materials synthesized using different routes. Satisfactory results were obtained by evaluating the hydrophilic behavior, the adhesion of the different ink compositions to the substrate, and the electrical conductivity analyses of the inks produced with GO and nanoplatelets of rGO.