Molecular dynamics analysis of the AOT/water/isooctane system: Effect of simulation time, initial configuration, and model salts

摘要

We present preliminary molecular dynamics results showing the effect of simulation time, initial configuration, and presence of model salts for the AOT/water/isooctane system. Reverse micelles, in particular the ones formed by this system, are commonly used as nanoreactors for nanoparticle synthesis. We are interested in the synthesis of ZrO2 or similar, and how these particles affect the dynamics and structure of the reverse micelles. At first, we explore the structure and dynamics of regular reverse micelles formed in the AOT-water system in isooctane, without the presence of nanoparticle precursors. The morphological characteristics of reverse micelles at different water/surfactant ratios is still not well understood. We find that there are significant variations in the morphology as a function of the water/surfactant ratio. The most significant geometrical variability is found in the low end of the water/surfactant ratio. Additional preliminary results are presented showing the effect of nanoparticle precursors in the core of the reverse micelles by incorporating metal-salt ions into the system. We find that the behavior within the water/surfactant ratios studied is similar to the regular reverse micelles with an increase in micellar size and slightly improved stability of the geometrical structures. Also, our findings show that longer simulation times than previously done are required to understand the dynamics of these systems. We suggest simulation times in order of hundreds of nanoseconds. (c) 2007 Elsevier B.V. All fights reserved.