Massively Parallel Mesoscopic Simulations of Gas Permeability of Thin Films Composed of Carbon Nanotubes

A mesoscopic computational model for simulation of gas flow through carbon nanotube (CNT) films is developed. The model is implemented in a parallel computational code enabling massively parallel dynamic simulations of CNT materials at length scales relevant to experimental studies. Self-diffusivity of Ar within CNT films with 9% volume fraction of the nanotubes and the effective diffusivity of Ar through the films are calculated for two different structures of the films: a continuous network of CNT bundles and a layered arrangement of dispersed individual CNTs. The results of the simulations suggest a moderate structural sensitivity of the gas diffusivity, with about 3–4.5 times lower values of self-diffusivity predicted for films with dispersed CNTs, and a smaller difference in the values of the effective diffusivity that are found to be on the order of 10−6 m2s−1 for both film structures.