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[Display omitted] • High-porosity SOD/GO interlayer was used to modulate i-TFC membrane. • The SOD/GO interlayer slowed down the diffusion of the amine monomers. • The i-TFC membrane with stripe morphology and narrow pore size was prepared. • The i-TFC membrane possessed a 2.5-fold water permeance of the controlled TFC. Controllable preparation of high-performance polyamide nanofiltration (NF) membranes that can be used in various applications such as seawater desalination and wastewater treatment is very promising. In this work, a high-performance polyamide NF membrane was designed using high-porosity hydroxy sodalite/graphene oxide (SOD/GO) composite interlayer to slow down the diffusion of amine monomer and control the interfacial polymerization (IP) process. The unique tortuous effect and hydrogen bonds with amine monomers caused by the dense interlayer significantly inhibit the diffusion of amine monomers (reduction of 50 % in diffusion rate), thereby resulting in the controllable slow IP process. The slowing IP process facilitates the formation of thinner dense polyamide (PA) layer with stripe morphology and narrow pore size. Consequently, the optimal polyamide membrane with composite interlayer possesses a superior water permeability of 22.05 L m-2h−1⋅bar−1, nearly 2.5 fold that of the controlled one, while retaining an excellent rejection of Na 2 SO 4 (97.25 ± 0.81 %). Moreover, the polyamide membrane depicts outstanding antifouling propensity (flux-recovery ratio (FRR) = 82 %), long-term stability (80 h) and pressure resistance (9 bar). This work provides a novel strategy for controllable construction of high-performance NF membrane and deepens the slights into the interlayer influences IP process. [ABSTRACT FROM AUTHOR]

Ultra-thin nanofiltration (NF) membranes exhibit excellent potential in the high-efficiency removal of ions due to their superior water permeability and selectivity. However, the stability of these membranes under pressure still poses a significant challenge. In this study, we have developed an innovative polyMOF interlayer using trimesoyl chloride (TMC) cross-linked UiO-66-NH 2 (denoted as UiO-66-NH 2 -TMC) to bolster the construction of a pressure-resistant and ultra-thin polyamide (PA) membrane, achieving stable and high-permeance desalination performance. The introduced hydrophilic and structurally reinforced UiO-66-NH 2 -TMC interlayer with high pore density and narrow pore size distribution provides essential benefits: (1) it ensures a uniform distribution of amine monomers, which are critical for creating defect-free PA membranes; (2) it optimizes the diffusion of amine monomers, encouraging the formation of an ultra-thin PA membrane; and (3) it enhances the overall compatibility and structural support of the membrane, significantly improving pressure resistance. Consequently, our interlayer-modulated thin-film composite (i-TFC) membrane, with 13 nm thickness, demonstrates exceptional water permeance at 25 L m−2 h−1⋅bar−1 and maintains a high sodium sulfate (Na 2 SO 4) rejection of 96 %. Moreover, the i-TFC membranes exhibit stable performance under pressures ranging from 2 to 10 bar, display excellent long-term operational stability over 36 h, and show an anti-fouling propensity with a notable flux recovery ratio of 81.5 %. This research offers a novel approach to polyMOF interlayer application, carving a path toward designing and fabricating ultra-thin NF membranes with efficient and stable desalination properties. The preparation of i-TFC membranes with the polyMOF interlayer and an ultra-thin pressure-resistant PA layer for efficient desalination. [Display omitted] • A polyMOF interlayer of TMC cross-linked UiO-66-NH 2 was prepared. • The interlayer regulates the IP process and enhances the membrane stability. • The ultra-thin (13 nm) PA membrane has excellent nanofiltration performance. [ABSTRACT FROM AUTHOR]

The preparation of MOF composite membranes with the interfacial polymerization method and the functional modification with PEI to enhance Li+/Mg2+ sieving properties. [Display omitted] • MOF "monomers" are constructed into membranes via interfacial polymerization. • The surface charge and pore size are regulated by PEI post-modification. • The high MOF ratio provides more transport channels for ions. Advanced ion transportation channels aided by charge and suitable aperture play a crucial role in achieving precise separation of ions. Here, we report a MOF composite membrane with electropositive surface and sub-nanometer-sized ion transport channels for efficient Li+/Mg2+ separation. The membranes were fabricated using MOF "porous monomers" and trimesoyl chloride (TMC) through interfacial polymerization, and subsequently modified with amino-functionalized polyethyleneimine (PEI). The abundant porosity of the MOFs composite membrane includes the inner and the intergranular pores of MOF provided a rapid transport channel for Li+ ions, and a superior Li+ permeation rate of 0.68 mol m−2h−1 (a 10 times enhancement compared to the currently leading MOF membranes). Moreover, the improved positively charged surface (from −78 mV to + 4 mV at pH = 7) and reduced mean pore diameter (from 1.13 nm to 0.8 nm) of the membrane caused a remarkable selectivity of 13.2 for Li+/Mg2+. The design concept of the above MOFs based membrane provides a novel approach for developing high-quality MOF composite membranes for improving Li+/Mg2+ separation performance. [ABSTRACT FROM AUTHOR]