Banca de QUALIFICAÇÃO: NEUBI FRANCISCO XAVIER JUNIOR
Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.DISCENTE : NEUBI FRANCISCO XAVIER JUNIOR
DATA : 11/12/2019
HORA: 10:00
LOCAL: PQ sala 50
TÍTULO:
ANTICORROSIVE ACTIVITY OF CHALCONE DERIVATIVE IMINES ON IRON SURFACE BY CAR-PARINELLO MOLECULAR DYNAMICS
PALAVRAS-CHAVES:
corrosion; inhibitor; dynamics; Car-Parinello; adsorption; surface
PÁGINAS: 20
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Química
SUBÁREA: Físico-Química
ESPECIALIDADE: Química Teórica
RESUMO:
Corrosion is a phenomenon commonly defined as the deterioration of a material (usually metallic) or its properties because of a reaction with aggressive agents present in the environment in which such material is inserted. Losses from deteriorating metals / alloys worldwide are estimated to cost the equivalent of 3% of world GDP ($ 2.2 trillion). Some of the factors that favor corrosion are pH, temperature and the presence of species that accelerate the corrosive process, such as O2, H2S and CO2and the surface structure subject to corrosion. In general, corrosion control techniques should be applied to prevent or reduce corrosive action, increasing the longevity and stability of the material structure. Among all forms of prevention, the most cost-effective is achieved by the use of efficient corrosion inhibitors (CIs), allowing the use of a low-grade quality metals, reducing operating costs. The use of organic molecules as corrosion inhibitors is one of the most efficient methods for preventing deterioration of metallic materials. However, due to the huge amount of interactions present in the corrosive environment, the corrosion inhibition mechanism is not established. Therefore, a model performing simulations by ab initio molecule dynamics, considering all active degrees of freedom, give a consistent picture of the chemical phenomenon that occurs on the surface and can fill several gaps in the theoretical model of the global corrosive process. The objective of this work is to elucidate the anti-corrosive activity of CIs, particularly imines derived from chalcones, on a carbon steel surface in an HCl medium. Three new compounds, recently synthesized by the laboratory NUSQUIMED (Nucleus of Synthesis and Medicinal Chemistry), from UFRRJ, coordinated by Prof. Dra. Aurea Echevarria, will be tested in a theoretical model as potential corrosion inhibitors: [(1Z, 2E) -1,3-diphenylprop-2-en-1-ylidene] phenylamine (IM-A), [(1Z, 2E ) -1,3-diphenylprop-2-en-1-ylidene] -1-phenylmethanamine (IM-B) and [(1Z, 2E) -1,3-diphenylprop-2-en-1-ylidene] -2- phenylethanamine (IM-F). Specifically, three steps will be performed: (I) conformational analysis of the CIs, seeking the lowest energy structure for each of the three compounds, with implicit solvent effects included in the calculation; (II) study of the adsorption of CIs on a Fe surface (110), starting from the structures characterized in the previous step, through periodic calculations. The aim of this step is to describe the interactions between the inhibitor and the surface, as well as to relate the inhibition efficiency with adsorption energy values; (III) analysis of the effect of surface adsorbed corrosion inhibitor in relation to the species that participate in the corrosive process (H2O, H3O + and Cl-), through Car-Parinello ab initio molecular dynamics simulations. In this step, it is intended to start from the surface adsorbed structure, calculated in the previous step, and include the reactive species, quantifying the total interaction energy of the system. Finally, a correlation will be made between the adsorption and interaction energy values obtained in step (II) and (III), respectively, with the inhibition efficiency of each studied compound, thus evaluating the effects of the surface and the species on the theoretical model. At the end of the project, a significant contribution to the understanding of the anticorrosive activity of ICs on metallic surfaces is expected, not only of chalcone-derived compounds, but of aromatic compounds as a whole. With an established theoretical model, it may be possible to make better proposals for new Cis, generating positive developments in the prevention of operating costs and the maintenance of metallic equipment at industrial level.
MEMBROS DA BANCA:
Interno - 1220404 - CARLOS MAURICIO RABELLO DE SANTANNA
Externo ao Programa - 1808284 - MARCIO SOARES PEREIRA
Externo ao Programa - 2324368 - FILIPE ARANTES FURTADO