Speaker
Description
Desalination of seawater and brackish water is one possible response to water crises and shortages. In our work we have explored one of the desalination methods based on Reverse Osmosis, using a layer of a two-dimensional material as a membrane in the filtration process of this fluid.These criteria led us to choose a material from the Transition Metal Dichalcogenide (TMD) family, the chosen material being molybdenum disulphide.
Given the size of the particles and the simulation time required, the ideal method is based on molecular dynamics. The simulation will therefore describe the system on an atomic scale by describing the movement of the atoms (chlorine and sodium) and molecules (water) that make up our system. We used the Lenard Jones and Coulombian potentials to describe the interactions between the water molecules and the chlorine and sodium atoms respectively. The hardware we used to model our system was VESTA (Visualization for Electronic and Structural Analysis) and Packmol, and for the simulation code we used LAMMPS (Large-Scale Atomic/Molecular Massively Parallel Simulator) and some basic tools for representing the results. For the simulations we chose pressures of 50MPa, 100MPa, 150MPa, 200MPa, 250MPa and 1000MPa respectively and simulation times ranging from 0ns to 10ns with a composition of 900 water molecules and 32 salt ions (16 chlorine and sodium atoms). The simulation was carried out on a molybdenum disulphide monolayer with a pore size of 1nm.
In short, our study shows that molybdenum disulphide is a very good material for the water desalination process. The results obtained in the study of a monolayer of this material are highly relevant, as the performance of molybdenum disulphide allows us to predict that this study could well be developed on a large industrial scale to solve the problem of access to drinking water for a large proportion of the world's population.
