Modeling of nitrogen adsorption phenomena in amorphous silica using molecular dynamics method

Abstract

Nitrogen, as a widely element found in nature, is used to characterize the surface of materials. Brunauer-Emmett-Teller (BET) is a principle in which nitrogen is used as a characterization of materials because of its properties that can interact with solid and inert elements. BET can only produce quantitative data and does not show adsorption phenomena. Molecular dynamics simulation is conducted to observe the phenomena that occur during nitrogen adsorption in amorphous silica. In this study, the molecular dynamics simulation is arranged in a state of the isotherm, where the temperatures used are 77K, and applied pressures 1, 3, 5, 7, and 10 atm for each equilibrium. Lennard-Jones Potential is used in molecular dynamics simulation to simulate the interaction between atoms based on Coulomb force. Based on the results obtained from the simulation, it was found that 77°K is an optimal condition to adsorb nitrogen. The higher the pressure given in system, the amount of nitrogen adsorbed increases.