Fabrication of ultra-permeable micelle-based isoporous membranes

Abstract

Membrane separation technology has garnered significant interest due to its energy efficiency, environmental benefits, and molecular sieving capabilities. Polymeric membranes, despite their cost-effectiveness and processability, face challenges in balancing water permeance and selectivity, primarily due to non-uniform or sparse pore structures. Block copolymer (BCP)-based isoporous membranes, fabricated via strategies like the self-assembly and non-solvent-induced phase separation (SNIPS), offer improved pore uniformity and separation performance. This work introduces an alternative strategy to produce isoporous membranes by combining phase separation and surface tension driven micelle spreading at the air/water interface. The resulting membranes feature ordered isopores (ca. 10 nm) and exceptional water permeance (ca. 1450 L m⁻² h⁻¹ bar⁻¹), enabling precise nanoparticle separation. The membrane demonstrates stability under 20 psi pressure, with tunable thickness (via micellar solution volume) and pore size (via water temperature). The work advances the design of high-performance isoporous membranes, offering potential applications in ultrafiltration, biotechnology, and environmental remediation.