Open Access

ARTICLE

Computational Studies of Molecular Diffusion through Carbon Nanotube Based Membranes

by Susan B. Sinnott¹, Zugang Mao,², Ki-Ho Lee

1 Corresponding author, University of Florida, Deptarment of Materials Science and Engineering, Gainesville, Florida 32611-6400, sinnott@mse.ufl.edu
2 Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208

Computer Modeling in Engineering & Sciences 2002, 3(5), 575-588. https://doi.org/10.3970/cmes.2002.003.575

Abstract

Nanofluidics is an area that has been under study for some time in zeolites and ideal nanoporous systems. Computational studies of the behavior of molecules in nanoporous structures have played an important role in understanding this phenomenon as experimental studies of molecular behavior in nanometer-scale pores are difficult to perform. In this paper computational work to study molecular motion and the separation of molecular mixtures in carbon nanotube systems is reported. The systems examined include organic molecules, such as CH₄, C₂H₆, n-C₄H₁₀, and i-C₄H₁₀, and inorganic molecules, such as CO₂. The interatomic forces in the molecular dynamics simulations are calculated using a classical reactive empirical bond-order hydrocarbon potential coupled to Lennard-Jones and Coulombic potentials. Molecules moving at thermal velocities corresponding to 300 K are predicted to diffuse from areas of high density to areas of low density through the nanotubes. The simulations indicate how the structure and size of the molecules and the nanotubes influence molecular diffusion through the nanotubes and the separation of the molecular mixtures.

---