Existing polyamide (PA) membrane synthesis protocols are underpinned by controlling diffusion-dominant liquid-phase reactions that yield subpar spatial architectures and ionization behavior. We report an ice-confined interfacial polymerization strategy to enable the effective kinetic control of the interfacial reaction and thermodynamic manipulation of the hexagonal polytype ( I _h ) ice phase containing monomers to rationally synthesize a three-dimensional quasilayered PA membrane for nanofiltration. Experiments and molecular simulations confirmed the underlying membrane formation mechanism. Our ice-confined PA nanofiltration membrane features high-density ionized structure and exceptional transport channels, realizing superior water permeance and excellent ion selectivity.

COF membrane was synthesized using a molecularly soldered strategy toward precise-sieving angstrom-sized contaminants.

Although covalent organic frameworks (COFs) demonstrate notable potential for developing advanced separation membranes, contemporary COF membranes still lack controlled stacking and highly efficient sieving. Here, Turing-architecture COF membranes were constructed by engineering a reaction-diffusion assembly process via heterogeneous nucleation synthesis with tannic acid (TA). TA covalently binds with amine monomers to form a composite precursor with increased reactivity and decreased diffusivity. This altered the pathway of Schiff base reactions with aldehyde monomers, fulfilling suitable reaction-diffusion conditions, and ultimately formed the labyrinthine stripe or spot-patterned Turing COF film with controlled stacking and uniform pore structure. This endows our COF membrane with highly efficient molecule sieving ability for organic solvent nanofiltration while exhibiting a flux that is 621% greater than that of commercial membranes. Thus, this study provides a paradigm for the in situ synthesis of highly efficient COF membranes for diversely sustainable separations.

Nanofiltration membranes with confined nanopores are vital for energy-efficient molecular and ionic sieving towards sustainable ecosystems. However, the production of contemporary nanofiltration membranes still relies on hazardous petrochemical-based chemicals, raising serious water contamination concerns and complicating after-usage disposal. This phenomenon contradicts the sustainability of membranes derived from green chemistry principles, emphasizing not only their eco-friendly application but also their preparation and end of life. Here we report the synthesis of a sustainable nanofiltration membrane (SNFM) with superior performance for water treatment and an inherent natural soil degradation mechanism through a safer approach utilizing integrated low-hazard chemicals. Experiments and simulations confirmed that our SNFM can be fabricated in an environmentally friendly manner and decomposed by natural soil microorganisms, contributing to its distinctive eco-friendliness. Notably, the SNFM demonstrated both exceptional water permeance and molecular and ionic sieving capability, outperforming commercial and state-of-the-art membranes. This approach establishes a new paradigm for next-generation water recycling and sustainable chemical processes.