Advances in rigid and flexible multi-functional nanocomposites based on perovskites modified with reduced graphen oxide for electro-electronic applications

• Grant number: 19/27053-3
• Support Opportunities: Regular Research Grants
• Start date: May 01, 2022
• End date: April 30, 2024
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Nonmetallic Materials
• Principal Investigator: Miguel Ángel Ramírez Gil
• Grantee: Miguel Ángel Ramírez Gil
• Host Institution: Faculdade de Engenharia (FEG). Universidade Estadual Paulista (UNESP). Campus de Guaratinguetá. Guaratinguetá , SP, Brazil
• Associated researchers: Alex Arbey Lopera Sepúlveda ; Edgar Andrés Chavarriaga Miranda ; Johan Alexander Cortes Suarez ; Leandro Alfredo Ramajo ; Miriam Susana Castro ; Ronaldo Spezia Nunes

Abstract

Recent studies have been explored the manufacture of nanocomposites by the addition of carbonaceous materials in order to improve properties. Reduced graphene oxide (RGO) presents a rich structure of active sites, which give this material a high reactivity as well as high conductivity and good mechanical properties. These characteristics may enhance the properties of the multifunctional perovskites CaCu3Ti4O12 (CCTO) and CaSnO3 (CSO), allowing the development of new rigid and flexible electronic devices. Given these aspects, the main objective of this project is to prepare and characterize the multifunctional nanocomposites of CCTO-RGO and CSO-RGO in the form of nanopowders, bulks, and employ these materials as fillers in the polydimethylsiloxane matrix (PDMS) for the manufacture of flexible nanocomposites. The nanoparticles of the CCTO and CSO will be obtained by the combustion in solution method and the RGO by the modified Hummers method. The effect of the addition of RGO to the CCTO and SCO on the optical behavior of the nanopowders and (di)electric bulks, as well as the analysis of the percentage of filler in the PDMS matrix in the electrical and mechanical response of the flexible nanocomposites will be evaluated. The structure of nanoporous will be studied using X-ray diffractometry (XRD / Rietveld), XANES / EXAFS, Raman spectroscopy, and visible ultraviolet (UV-vis) optical response, photoluminescence (PL) and photocatalytic tests. A comparative study of the (micro-nano) structure and dielectric and non-ohmic properties of the ceramic nanocomposites will be carried out. The structure of the nanocomposites in bulk form will be evaluated by XRD / Rietveld, and the microstructure of the interfaces CCTO-RGO and CSO-RGO will be studied using Raman confocal electron microscopy. Current-voltage measurements (I-V) and impedance spectroscopy (IS) will be performed to determine the parameters that define the non-ohmic and dielectric properties. The flexible nanocomposites will be made of PDMS matrix incorporating CCTO-RGO nanoparticles (PDMS / CCTO-RGO) and SCO-RGO nanoparticles (PDMS / SCO-RGO) with different fillers (10 to 60% by volume). The dielectric response of the flexible nanocomposites will be studied by impedance measurements as function of temperature, and theoretical models will be used to simulate the dielectric behavior of nanocomposites. The mechanical behavior of the nanocomposites will be evaluated by dynamical-mechanical analysis and tests according to the technical standards to determine the mechanical tensile strength and modulus of elasticity, which will be correlated with variations of density, microporosity, and composition. (AU)