Tunable Porous Membranes: A Comprehensive Review of Stimuli-Responsive Mechanisms, Polymer Systems, Fabrication Methods, and Advanced Applications

Tunable porous membranes have emerged as a transformative class of separation materials capable of dynamically adjusting pore size, surface charge, and selectivity in response to external stimuli. This review provides a comprehensive overview of tunable porous membranes based on an analysis of key articles in the field. Nanofiltration (NF) membranes, with molecular weight cutoffs ranging from ۱۰۰ to ۲۰۰۰ Da and pore sizes of approximately ۱ nm, primarily achieve separation through pore sieving and Donnan exclusion. However, conventional NF membranes suffer from broad pore size distributions and limited ion selectivity. To address these challenges, ten distinct stimuli-responsive mechanisms are presented, including pH-responsive, thermo-responsive, mechanical stress-responsive (negative Poisson's ratio), selective chemical adsorption, photo-responsive (localized surface plasmon resonance), ionic strength-responsive, electro-responsive, solid-state chemical conversion, glucose-responsive, and phase separation mechanisms. Nine classes of polymers are described, including PAA, P۲VP, P۴VP, PDMA, alginate, auxetic PDMS, functionalized COFs, functionalized POPs (PAF-۱), and pGMA. Thirteen fabrication methods are detailed, such as SNIPS, template synthesis, phase separation, iCVD, electrospinning, and interfacial polymerization. The roles of various porogens (hard and soft templates) and nanoparticles (ZnO, La₂O₃, Au, Ag, TiO₂) as functional additives are also discussed. Applications in water treatment, pharmaceutical and biomedical engineering, industrial separations, and sensing are summarized. This review aims to provide researchers with a structured understanding of tunable porous membranes and to guide future developments in material design, fabrication, and application.

کلیدواژه ها:

Tunable porous membranes ، Nanofiltration ، Stimuli-responsive mechanisms ، Smart polymers ، Nanoparticles