Charged pore matrices prepared with and without template particles by computer simulations

Abstract

Series of Molecular Dynamics simulations to study the structure of different porous matrices were investigated. Matrices were prepared by two different processes. The first method consisted of charged particles simulated at a fixed density, and after equilibration, the matrix structure was taken from the last configuration. The second method was prepared from a binary mixture of charged particles where one of the components served as the template material and the other as the matrix. The final porous matrix configuration was obtained by removing template particles from the equilibrated mixture, and therefore only the matrix particles remained in the system. The volume distribution, the cluster formation, and the porosity in the pore matrix were investigated. The present results were compared with previous results of pore matrices prepared without electrostatic interactions. Therefore, electrostatic effects were analyzed in terms of the pore matrix preparation method. As a general trend, it was observed that matrices prepared with template presented smaller voids in the structure in comparison with matrices prepared without template. It was also found that porosity was higher in matrices without template than in matrices with template. When comparisons were made between matrices with and without electrostatic interactions, the porosity was higher in matrices with charge than in matrices without charge. Finally, at low and high temperatures, the porosity values were nearly the same.