Permeation of CO2 and N2 through glassy poly(dimethyl phenylene) oxide under steady‐ and presteady‐state conditions. Issue 9 (28th February 2020)

• Record Type: Journal Article
• Authors: Soniat, Marielle; Tesfaye, Meron; Mafi, Amirhossein; Brooks, Daniel J.; Humphrey, Nicholas D.; Weng, Lien‐Chun; Merinov, Boris; Goddard, William A.; Weber, Adam Z.; Houle, Frances A.
• Is Part Of: Journal of polymer science. Volume 58:Issue 9(2020)
• Page Start: 1207
• Page End: 1228
• Publication Date: 2020-02-28
• Subjects: multiscale simulations -- poly(dimethyl phenylene) oxide -- polymer permeation -- reaction–diffusion; Polymers -- Periodicals; Polymerization -- Periodicals; Polymerization; Polymers; Periodicals; 547.7
• DOI: 10.1002/pol.20200053
• Languages: English
• ISSNs: 2642-4150

Abstract

Abstract: Glassy polymers are often used for gas separations because of their high selectivity. Although the dual‐mode permeation model correctly fits their sorption and permeation isotherms, its physical interpretation is disputed, and it does not describe permeation far from steady state, a condition expected when separations involve intermittent renewable energy sources. To develop a more comprehensive permeation model, we combine experiment, molecular dynamics, and multiscale reaction–diffusion modeling to characterize the time‐dependent permeation of N2 and CO2 through a glassy poly(dimethyl phenylene oxide) membrane, a model system. Simulations of experimental time‐dependent permeation data for both gases in the presteady‐state and steady‐state regimes show that both single‐ and dual‐mode reaction–diffusion models reproduce the experimental observations, and that sorbed gas concentrations lag the external pressure rise. The results point to environment‐sensitive diffusion coefficients as a vital characteristic of transport in glassy polymers. Abstract : Multiscale reaction‐diffusion models of N2 and CO2 permeation through glassy poly(dimethyl phenylene oxide) are developed assuming either single‐ or dual‐mode transport and solved using a stochastic algorithm. Models for both transport modes predict pre‐steady‐state and steady‐state permeation curves that agree equally well with the experimental data. The simulations show that gas uptake can be delayed relative to the pressure rise, suggesting that even small molecules can perturb the polymer matrix during permeation.