Highly selective multilayer polymer thin films for CO₂/N₂ separation

Abstract

ABSTRACT Multilayer thin films of poly(ethylene oxide) (PEO) and poly(methacrylic acid) (PMAA), deposited via layer‐by‐layer (LbL) assembly from aqueous solutions, are investigated for CO 2 /N 2 separation. Eight and ten bilayer (217 and 389 nm thick, respectively) PEO/PMAA thin films deposited on a 25 μm polystyrene substrate exhibit CO 2 /N 2 selectivities of 142 and 136, respectively. These are the highest reported to‐date for this gas pair separation using a homogeneous polymer film. While further work remains to improve CO 2 permeability, these results indicate the potential of LbL assemblies as standalone CO 2 separation membranes for low‐flux/high‐purity applications, or as part of a composite and/or mixed‐matrix membrane for high‐flux applications. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017 , 55 , 1730–1737