A facile direct spray-coating of Pebax® 1657: Towards large-scale thin-film composite membranes for efficient CO2/N2 separation

High-efficient CO2 capture using membrane separation technology is a promising approach towards environmental redemption in recent years. Thin-film composite (TFC) membrane with selective layer made of CO2-philic materials is the preferred membrane type for industrial-scale application, owing to its high permselectivity and good processability. Herein, we propose a facile direct spray-coating method to fabricate Pebax® 1657 thin-film on a porous polysulfone (PSF) substrate. Unlike most conventional multilayer TFC membranes, the unnecessary need for gutter layer in this work greatly simplifies the membrane fabrication process. Pebax® 1657 thin films were deposited through direct spraying of the polymer solution containing Pebax® 1657 on PSF substrate under ambient temperature. The as-prepared Pebax®1657 TFC membranes showed decent separation performances with CO2 permeance of >200 GPU and CO2/N2 selectivity of >50 for mixed gas (vol. (CO2)/vol. (N2) = 20/80) tests. The facile TFC membrane fabrication and good CO2 separation performances make the direct spray coated Pebax®1657 membranes a promising strategy for large-scale CO2 capture applications. [Display omitted] •TFC membranes are fabricated through direct spray of Pebax® 1657 solution on PSF ultrafiltration substrate.•The unnecessary need for gutter layer greatly improved the simplicity of TFC membrane preparation process.•The obtained Pebax® 1657 TFC membranes exhibit competitive CO2 permeance (>200 GPU) and CO2/N2 selectivity (>50).•The successful fabrication of A4-sized TFC membrane demonstrates the scale-up potential of the direct spray coating method.