Microporous and functional group Co-designed polyesteramide membranes for efficient and broad-spectrum organic solvent nanofiltration

Organic solvent nanofiltration (OSN) is an emerging energy-efficient separations technology, which urgently requires easily processable OSN membranes with high selectivity and broad-spectrum organic solvent applicability to facilitate enhanced industrial applications. Herein, we describe the preparation of microporous polyesteramide (PEA) membranes through interfacial polymerization (IP) between amino-diphenol monomers and trimesoyl chloride (TMC) on a poly(ether ether ketone) (PEEK) support. The crosslinked network structures and large twisted monomers enhance the microporosity of PEA membranes, leading to a significant improvement in solvent permeance while maintaining high selectivity. The optimized PEA membrane demonstrates exceptional permeance for acetone (21.0 ​L ​m⁻² ​h⁻¹ bar⁻¹) and methanol (14.3 ​L ​m⁻² ​h⁻¹·bar⁻¹), with a molecular weight cut-off of 296 ​g ​mol⁻¹. Additionally, the PEA/APH-diphenol membrane exhibits ultrafast permeance for the nonpolar solvent toluene (8.3 ​L ​m⁻² ​h⁻¹·bar⁻¹), owing to the introduction of a large number of ester groups. Overall, PEA membranes prepared through the molecular-level structure design of IP monomers possess enormous industrial application potential owing to their high performance and broad-spectrum applications.