Atomistic simulation of nanoporous layered double hydroxide materials and their properties.

摘要

The goal of this study was to develop a new approach to atomistic simulation that would improve microscopic analysis of its properties for nanoporous layered double hydroxides materials. Energy minimization and molecular dynamics simulation techniques were used to develop atomistic models of LDH materials and to study diffusion and adsorption isotherms. Various morphological properties of LDH were computed, including their vibrational frequency, X-ray diffraction and basal spacing distances. These results were found to be in good agreement with the experimental data at various temperatures. The self-diffusivity were also computed and compared with the experimental data. The sorption isotherms of carbon dioxide in LDH material were computed. Both computed diffusivities and sorption isotherms were in good quantitative agreement with experimental data from our group in USC. In this study, we tried to carry out different kinds of structural approach for improving atomistic simulation methodology. Polycrystalline LDH structure was generated based on single crystalline simulation to compute the diffusivity and adsorption isotherms. The results were presented same tendency with experimental data and also proposed the optimal number of particles in the polycrystalline LDHs simulation. Binary-crystalline LDH structure was developed to compute the concentration profile of arsenate molecules in aqueous solution and it was compared with the experimental concentration changes.