Model reduction for molecular diffusion in nanoporous media

Gonzalez, Gaston A.; Fritz, Ruben A.; Colon, Yamil J.; Herrera, Felipe

Abstract

Porous materials are widely used for applications in gas storage and separation. The diffusive properties of a variety of gases in porous media can be modeled using molecular dynamics simulations that can be computationally demanding depending on the pore geometry, complexity, and amount of gas adsorbed. We explore a dimensionality reduction approach for estimating the self-diffusion coefficient of gases in simple pores using Langevin dynamics, such that the three-dimensional (3D) atomistic interactions that determine the diffusion properties of realistic systems can be reduced to an effective one-dimensional (1D) diffusion problem along the pore axis. We demonstrate the approach by modeling the transport of nitrogen molecules in single-walled carbon nanotubes of different radii, showing that 1D Langevin models can be parametrized with a few single-particle 3D atomistic simulations. The reduced 1D model predicts accurate diffusion coefficients over a broad range of temperatures and gas densities. Our work paves the way for studying the diffusion process of more general porous materials such as zeolites or metal-organics frameworks with effective models of reduced complexity.

Más información

Título según WOS: ID WOS:000957708700001 Not found in local WOS DB
Título de la Revista: PHYSICAL REVIEW MATERIALS
Volumen: 7
Número: 3
Editorial: AMER PHYSICAL SOC
Fecha de publicación: 2023
DOI:

10.1103/PhysRevMaterials.7.036001

Notas: ISI