Estudo do mecanismo de crescimento de nanobastões de ouro em sistemas coloidais através de cálculos de dinâmica molecular

Abstract

Molecular dynamics simulations were carried out in order to help to elucidate the mechanism of the colloidal synthesis of gold nanorods (AuNRs) using the computational simulation data to complement to the growth mechanism proposed to these kinds of nanoparticles (soft template and zipping). In the stages of implementation, parameters of bromide ions were selected to choose the best contraíon model for the interaction with cetyltrimethylammonium cation (CTA+) for the formation of spherical micelles. Then, it was built adsorption surfactant systems on the gold surface (100) in a similar medium found on the surface of the growing gold nanorods. The studies related to the adsorption of the cetyltrimethylammonium bromide (CTAB) surfactant shows that the model obtained, produced a pattern of adsorption with cylindrical micelles very close to each other. This trend was also observed when different surfactant concentrations were employed. The results allow estimating the occurrence of the proposed mechanism and its consequences in interpretation, although it is still necessary to collect data from simulations in other facets also present in AuNRs.