Desarrollo de simulaciones de dinámica molecular para el estudio de la interacción de átomos de metales pesados con la magnetita

Abstract

This work deals with the simulations of Molecular Dynamics for the study of lead adsorption in magnetite nanoparticles with the purpose of removing this heavy metal from water sources. The adsorbent model is ionic magnetite with a Buckingham-Coulomb potential because it reproduces physical parameters observed in different investigations of magnetite both experimentally and theoretically. Adding to the above, the calculated physical parameters are the network parameter, the parameters of the Birch-Murnaghan equation of state, the surface energy, adsorption points and energies, in addition it tries to emulate magnetite under real conditions of temperature and pressure, which is why the coefficient of thermal expansion and diffusion is calculated. The magnetite with which we work presents isotropy in the xy plane while there is anisotropy in the plane perpendicular to it and the diffusion coefficient is progressively reduced as we go layer by layer into the structure, because of how the model itself is structured. Finally, certain considerations were taken for the study of adsorption, concluding that the lead cations remained adhered to the magnetite surface, demonstrating that this crystal presents adsorbance.