Controlling Microstructure-Transport Interplay in Poly(ether-block-amide) Multiblock Copolymer Gas Separation Membranes

In this study, we investigated the effect of morphology on the gas-transport properties of a poly-(ether-block-amide) (PEBA) multiblock copolymer. We annealed the copolymer samples and varied the annealing temperature to evaluate the influence of changes in the microstructure on the gas transport properties of PEBA. In addition, we used time-resolved attenuated total reflection Fourier transform infrared spectroscopy to evaluate the diffusion coefficient of CO2 in PEBA based on the Fickian model. The effect of the annealing temperature on the microphase-separated structure of the multiblock copolymer is discussed in detail. Furthermore, the gas diffusivity was significantly affected by the purity of the soft domains. The annealed sample demonstrated a 38% increase in CO(2 )permeability while maintaining a high CO2/N-2 permselectivity of approximately 53. The findings of this study provide valuable insight into the design and optimization of PEBA membranes for gas separation applications.