Journal of Membrane Science最新文献

{"title":"In situ construction of fluorinated covalent organic framework membranes for high-efficiency nanofiltration","authors":"Zhidong Guo ,&nbsp;Jingwen Si ,&nbsp;Huijie Zheng ,&nbsp;Liangliang Dong ,&nbsp;Hao Li","doi":"10.1016/j.memsci.2026.125207","DOIUrl":"10.1016/j.memsci.2026.125207","url":null,"abstract":"<div><div>Efficient separation of organic molecules from inorganic salts in high-salt, multi-component systems remains a significant challenge in fine chemical processes. Traditional membrane materials often exhibit limitations in flux, selectivity, and chemical stability, which restrict their performance and applicability in industrial separation processes. Herein, this study proposes a strategy for fabricating COF membranes using fluorinated monomers to simultaneously enhance the flux, selectivity, and chemical stability. Specifically, a highly crystalline fluorinated COF membrane was synthesized on an alumina tube using a solvothermal method. This approach achieves three key goals: (i) creating low-surface-energy channels to facilitate the rapid transport of solvents, (ii) narrowing the pore size of the one-dimensional channels of the COF membrane to enhance sieving selectivity, and (iii) enhancing the framework stability to confer robust chemical stability to the membrane system. The resulting membrane demonstrated high permeability (102.34 L m⁻² h⁻¹ bar⁻¹) and an outstanding retention rate of over 99.9% for Congo red, corresponding to a CR/NaCl separation factor of 906. It also maintains a selective window for high antibiotic retention and low salt retention in antibiotic/salt system. This study offers an effective method for creating fluorinated COF membranes with high permeability and precise sieving capabilities, providing high-performance membrane materials suitable for high-salt dye desalination, antibiotic purification, and other specialized separation applications.</div></div>","PeriodicalId":368,"journal":{"name":"Journal of Membrane Science","volume":"745 ","pages":"Article 125207"},"PeriodicalIF":9.0,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146172390","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"In situ growth of a COF/MOF heterogeneous interlayer for high-performance reverse osmosis membranes","authors":"Siheng Zhao ,&nbsp;Xiaoqi Ma ,&nbsp;Shengchao Zhao ,&nbsp;Kuo Chen ,&nbsp;Jianquan Peng ,&nbsp;Zilong Huang ,&nbsp;Bingbing Yuan ,&nbsp;Q. Jason Niu","doi":"10.1016/j.memsci.2026.125269","DOIUrl":"10.1016/j.memsci.2026.125269","url":null,"abstract":"<div><div>The construction of functionalized interlayers has been identified as a highly effective strategy for the regulation of interfacial polymerization (IP) and the enhancement of the performance of thin-film composite (TFC) reverse osmosis (RO) membranes. However, most hydrophilic interlayers reported to date, although capable of improving monomer wetting and loading, tend to suppress the formation of the characteristic ridge-valley morphology, thereby reducing the effective mass-transfer area and ultimately limiting further enhancements in water permeability. Herein, a heterogeneous covalent organic framework (COF)/metal-organic framework (MOF) interlayer was constructed in situ on the surface of a polysulfone (PSF) support layer, in which an ultrathin COF layer was formed via sulfonic-acid-containing Pa-SO₃H and 2,4,6-triformylphloroglucinol to repair defects in the substrate. A ZIF-8 layer was subsequently grown in situ using the sulfonic acid groups on the COF as anchoring sites. Experimental results demonstrate that the COF/MOF interlayer structure significantly enhances the adsorption capacity of amine monomers and modulates their diffusion behavior, leading to a more pronounced leaf-like surface morphology, an optimized active-layer thickness, and an enhanced hydrophilicity of the polyamide (PA) layer. The i-TFC_C/M-T membrane, based on the rigid trimesoyl chloride monomer, exhibits a water permeance of approximately 5.20 L m⁻² h⁻¹ bar⁻¹, which is about 2.2 times higher than that of the control group, while maintaining a NaCl rejection of approximately 99.10%. The novel interlayer design was also proven to be suitable for the flexible cyclohexane-1,3,5-tricarbonyl trichloride system. This study demonstrates that the COF/MOF heterogeneous interlayer can shift the performance balance point of RO membrane flux without significantly compromising ion exclusion, thereby providing a general and effective strategy for designing high-performance aromatic PA RO membranes for brackish water desalination.</div></div>","PeriodicalId":368,"journal":{"name":"Journal of Membrane Science","volume":"745 ","pages":"Article 125269"},"PeriodicalIF":9.0,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146172381","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A crown ether-based sandwich supported liquid membrane contactor with long-term stable operation for lithium recovery from high-salinity brine","authors":"Junyuan Hua ,&nbsp;Jintao He ,&nbsp;Xiaohua Ma ,&nbsp;Hongchang Pei ,&nbsp;Xianhui Li ,&nbsp;Yujun Zhang ,&nbsp;Jianxin Li","doi":"10.1016/j.memsci.2026.125259","DOIUrl":"10.1016/j.memsci.2026.125259","url":null,"abstract":"<div><div>Supported Liquid Membrane (SLM) technology provides efficient lithium extraction from salt-lake brines via rapid ion transport, yet its stability is often compromised by organic phase leakage under transmembrane osmotic pressure. To overcome this, we prepared a crown ether-functionalized polyimide porous membrane (PI–14C4) via the nonsolvent-induced phase separation (NIPs) method and designed a sandwich-type SLM (S-SLM) contactor. The S-SLM features a double-layer PI-14C4 barrier with a ∼2 cm interlayer filled with TBP-NaNTf₂ (sodium bistrifluoromethylsulfonimide) organic phase, which effectively mitigates leakage and enhances operational robustness. In a continuous 156-h operation using high-concentration brine (∼90,000 ppm; containing LiCl 3.74 g/L, MgCl₂ 30.92 g/L, Na₂SO₄ 57.26 g/L; 10 L) as feed and 1 mol/L HCl (0.1 L) as stripping phase, Li⁺ concentrations on both sides reached equilibrium, while Mg²⁺ in the stripping phase remained only 19.22% of its initial concentration. The Mg/Li ratio decreased from 12.88 to 2.38, demonstrating outstanding Li selectivity and recovery. The S-SLM also retained high efficiency across 10 reuse cycles, confirming excellent cycling stability and reusability. Operating under a concentration gradient, the S-SLM leverages the capillary pore structure of PI-14C4 to retain a substantial organic phase. The crown ether moieties in the membrane, combined with the loaded and interlayer organic phases, establish an integrated and rapid transport pathway for Li⁺. This work presents a promising and stable S-SLM strategy for selective lithium recovery from high-salinity brines.</div></div>","PeriodicalId":368,"journal":{"name":"Journal of Membrane Science","volume":"745 ","pages":"Article 125259"},"PeriodicalIF":9.0,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146172460","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A two-dimensional network PBI membrane cross-linked through metal Ce-ligand bond for the high-temperature proton exchange membrane fuel cells","authors":"Zheng Zhao ,&nbsp;Hui-Biao You ,&nbsp;Bo Jiang ,&nbsp;Li-Na Jia ,&nbsp;Hui-Tao Yu ,&nbsp;Jin-Xiao Bao ,&nbsp;Gao-Fei Pan","doi":"10.1016/j.memsci.2026.125223","DOIUrl":"10.1016/j.memsci.2026.125223","url":null,"abstract":"<div><div>Here, A two-dimensional network polybenzimidazole (PBI) membrane was synthesized through metal Ce-ligand bond between the cerium trifluoromethanesulfonate and the modified PBI, which was synthesized by introduce the 2,2′-biquinoline-4,4′-dicarboxylic acid and 2,2′-bipyridine-4,4′-dicarboxylic acid into traditional <em>m</em>-PBI membranes. The two-dimensional network PBI membrane (named CO-PBI) demonstrates enhanced toughness, phosphoric acid (PA) retention, chemical stability. Upon PA doping, the CO-PBI membrane achieves a tensile strength of 42.42 MPa, a proton conductivity of 0.162 S cm⁻¹ at 160 °C, and a power density of 484.77 mW cm⁻² which is representing a 2.45 times enhancement compared to the pristine PBI membrane. This study presents a viable structural design framework to comprehensively improve the performance of PA-PBI proton exchange membranes.</div></div>","PeriodicalId":368,"journal":{"name":"Journal of Membrane Science","volume":"744 ","pages":"Article 125223"},"PeriodicalIF":9.0,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146185549","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fluidization PAC- MnOx combined ceramic membrane reactor for manganese removal: In-situ growth pathway of MnOx and supersession of water flux","authors":"Mengyao Xiao ,&nbsp;Dachao Lin ,&nbsp;Yang Zou ,&nbsp;Jiaqi Chen ,&nbsp;Zhihong Wang ,&nbsp;Jinxu Nie ,&nbsp;Yunlong Luo ,&nbsp;Xinglin Lu ,&nbsp;Xing Du","doi":"10.1016/j.memsci.2026.125201","DOIUrl":"10.1016/j.memsci.2026.125201","url":null,"abstract":"<div><div>Groundwater containing dissolved manganese (II) poses a significant challenge to the drinking water treatment process. Ceramic membrane technology enhances manganese removal, but its low permeate flux constrains its practical implementation. To improve efficiency, an integral aeration-MnOx fluidized bed system coupled with ceramic membrane filtration (A-MFB-CF) was developed and operated continuously for 176 days. It demonstrated efficient manganese removal, reducing Mn²⁺ concentrations from 0.5–1.5 mg/L to &lt;0.02 mg/L while maintaining a high water flux (60–120 LMH). Mn-oxidizing bacteria (MnOBs), including <em>Ralstonia, Hyphomicrobium,</em> and <em>Pseudomonas</em>, in PAC-MnOx particles, were identified using microbial community analysis. An increased abundance of MnOBs led to stronger resistance to Mn(II) shock loading. Continuous operation of A-MFB-CF filtration accelerated the conversion of MnOx, as evidenced by surface morphology evolution showing dynamic restructuring and bio-chemical synergy. The MnOx transformation pathway transitioned from dissolved Mn(II) species, to small 3D particles [Mn(III)/Mn(IV)] and large-sized 3D aggregates, eventually evolving into 2D layered sheets. The presence of birnessite with low crystallinity was confirmed using Raman and X-ray diffraction (XRD) analysis, and this structure contributes to its superb catalytic oxidation efficiency and high Mn(II) adsorption capacity. X-ray photoelectron spectroscopy (XPS) analysis further demonstrated the formation of catalytically active birnessite, characterized by mixed valence states of Mn (III) and Mn (IV). Electron Paramagnetic Resonance (EPR) indicated that MnOx formation was initially dominated by biologically mediated conversion, followed by a shift to physicochemical processes during prolonged operation. Additionally, PAC-MnOx fluidization in ceramic membrane tank effectively mitigated cake layer deposition and thus reduce membrane fouling. Our findings demonstrate an effective and space-efficient water treatment strategy, particularly suitable for decentralized water supply scenarios with stringent footprint constraints.</div></div>","PeriodicalId":368,"journal":{"name":"Journal of Membrane Science","volume":"744 ","pages":"Article 125201"},"PeriodicalIF":9.0,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146185550","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bimetallic-tuned Prussian blue analogue crystalline membranes for hydrogen purification","authors":"Wei Zhang ,&nbsp;Lianhao Li ,&nbsp;Yaxin Zhang ,&nbsp;Haonan Yang ,&nbsp;Zhuo Yang ,&nbsp;Guozhen Liu ,&nbsp;Gongping Liu ,&nbsp;Wanqin Jin","doi":"10.1016/j.memsci.2026.125228","DOIUrl":"10.1016/j.memsci.2026.125228","url":null,"abstract":"<div><div>Prussian blue (PB) and its analogues (PBA) crystals with regular and straight nanochannels are promising building blocks for molecular separation membranes. However, it remains a challenge to construct well-intergrown PB/PBA membranes due to their excessively rapid nucleation rate. Herein, we report a new type of bimetallic PBA crystalline membranes with tunable pore microenvironment for hydrogen purification. The membrane was prepared using an interfacial growth process, wherein two metal ion precursors slowly diffuse in opposite directions to react on the surface of porous substrate. This interfacial growth approach reduced the coordination reaction rate and facilitated the intergrowth of PBA membrane. Regulating the metal ions compositions (Fe–Co, Co–Co, Ni–Co) was further utilized to synergistically tuned pore size and interaction with CO₂. The resulting membranes exhibited excellent H₂/CO₂ separation performance with H₂ permeability of 1985–2935 Barrer and selectivity of 27–38, beyond the limits for state-of-the-art membranes. This work provides a facile strategy for developing high-performance crystalline molecular separation membranes.</div></div>","PeriodicalId":368,"journal":{"name":"Journal of Membrane Science","volume":"744 ","pages":"Article 125228"},"PeriodicalIF":9.0,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146185552","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nanofiltration of synthetic HTL-AP: rejection, fouling analysis, and membrane autopsy","authors":"Soorena Gharibian ,&nbsp;Knud Villy Christensen ,&nbsp;Rime Bahij ,&nbsp;Morten Enggrob Simonsen ,&nbsp;Massimiliano Errico","doi":"10.1016/j.memsci.2026.125178","DOIUrl":"10.1016/j.memsci.2026.125178","url":null,"abstract":"<div><div>Valorization or recycling of the hydrothermal liquefaction aqueous phase (HTL-AP) pose a substantial obstacle to the commercial use of the HTL process for biomass (especially algal). This is due to its high concentration of organic constituents and nutrients. This article focus on nanofiltration (NF) of acidic and basic synthetic HTL-AP using a DuPont FilmTec™ NF90 membrane in a batch crossflow module. The emphasis is on rejection performance and fouling behavior, supported by membrane autopsy. Overall, almost 90 % rejection of COD, NH₄⁺, and PO₄³⁻, and TDS/conductivity was achieved. HTL-AP(pH = 4) led to higher NH₄⁺ rejection (94 ± 1 %) compared with pH = 8.5 (83 ± 3 %). This can be attributed to the formation of a gel layer and the equilibrium between NH₄⁺ and NH_3, favoring the more permeable NH₃ at higher pH. Flux monitoring revealed that NF90 performs better (J_{30 wt% recovery}/J₀ ca. 0.77 ± 0.02) with HTL-AP(pH = 8.5) than at pH = 4 (0.56 ± 0.06) since at pH = 8.5 most of the small organic compounds are deprotonated and therefore exhibit weaker interactions with the negatively charged NF90 surface. At both HTL-AP pH levels irreversible fouling is negligible while gel layer and concentration polarization are major contributors which are reversible through water flushing. Resistance due to the gel layer formation was more prominent for HTL-AP(pH = 4). The presence of a thin gel layer was confirmed through attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), scanning electron microscopy (SEM), water contact angle measurements, and thermal gravimetric analysis (TGA). In addition, fouling resistance due to pore blockage and persistent adsorbed foulants inside the membrane matrix is also a significant contributor. This was removed successfully by basic cleaning (NaOH).</div></div>","PeriodicalId":368,"journal":{"name":"Journal of Membrane Science","volume":"744 ","pages":"Article 125178"},"PeriodicalIF":9.0,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146076320","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Emerging next-generation adsorptive hollow fiber membrane for selective separation of ultra-trace arsenic from aquatic stream and its recovery","authors":"Anil R. Gupta ,&nbsp;Nayan Nandha ,&nbsp;Pranay Kumar ,&nbsp;Mrinmoy Mondal ,&nbsp;Puyam S. Singh ,&nbsp;Saroj Sharma","doi":"10.1016/j.memsci.2026.125181","DOIUrl":"10.1016/j.memsci.2026.125181","url":null,"abstract":"<div><div>To combat arsenic contamination in water, a novel polymeric hollow fibre (HF) membrane indicated as [FeTMA@HF] was developed by incorporating an integrated iron precursor. The presence of cohesive iron within the polymer matrix of the HF membrane exhibits a prominent impact over the conventional mixed matrix membranes on its overall performance. The FeTMA@HF5 has shown absolute rejection of arsenic [As(V):100%, As(III): 98.6%] from 100 μg L⁻¹ feed arsenic in the HF module (module area: 0.02 m²), with a permeability of 48 Lm⁻²h⁻¹ bar⁻¹, at neutral pH (7.0±0.2) at 0.5 bar TMP, 30 L h⁻¹ CFR. The FeTMA@HF membranes were evaluated for their surface morphology, porosity, pore size, surface potential/charge, molecular weight cut-off, permeability, and contact angle. The domestic scale membrane module (area: 0.3 m²) was able to treat 7400 L of arsenic-contaminated groundwater (100 μg L⁻¹) at neutral pH with 0.5 bar pressure. The safety of treated water was validated by verifying the non-leaching behaviour of the HF membrane through toxicity assessments. This ensures that the water is safe to drink while also recovering arsenic at the end, allowing the filter to be reused multiple times after backwashing. This technique is unique in its ability to eradicate and retrieve arsenic in an environmentally sustainable manner.</div></div>","PeriodicalId":368,"journal":{"name":"Journal of Membrane Science","volume":"744 ","pages":"Article 125181"},"PeriodicalIF":9.0,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146076314","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Highly flexible bimetallic ZIF membranes fabricated via support-induced assisted confined counter-diffusion for efficient hydrogen purification","authors":"Lu Liu,&nbsp;Wenxiu Zhang,&nbsp;Tengfei Yang,&nbsp;Feiyu Yan,&nbsp;Xiaobin Wang","doi":"10.1016/j.memsci.2026.125265","DOIUrl":"10.1016/j.memsci.2026.125265","url":null,"abstract":"<div><div>Bimetallic metal organic frameworks (MOFs) hold significant promise for gas separation applications owing to the synergistic effects of dual-metal centers; however, the fabrication of defect-free and mechanically robust bimetallic MOF membranes remains significant challenges. This study developed a novel support-induced assisted confined counter-diffusion strategy to fabricate highly flexible bimetallic Zn/Co-zeolitic imidazolate framework (ZIF) membranes on rationally designed ZnO-PVDF (polyvinylidene fluoride)/PVDF dual-layer polymeric-supports. The bottom PVDF layer (42.0 μm) provided essential mechanical strength to composite membrane, while its well-developed finger-like channels facilitated efficient mass transport, minimizing diffusion resistance. The top ZnO-PVDF layer, thin (9.0 μm) and featuring fine pores, not only offered abundant heterogeneous nucleation sites through uniformly dispersed ZnO-nanoparticles but also regulated the diffusion of Co²⁺ ions and 2-methylimidazole (Hmim) ligands, enabling spatially confined membrane growth. The bimetallic Zn/Co-ZIF membrane with 1.2 μm-thickness exhibited high H₂ permeance (4.3 × 10⁻⁷ mol m⁻² s⁻¹·Pa⁻¹) and excellent selectivities for H₂/CH₄ (26) and H₂/N₂ (22), demonstrating outstanding molecular sieving capability. Notably, mechanical stability tests under bending stress (curvature: 300 m⁻¹) revealed that the membrane remained structural integrity and maintained nearly constant gas permeation after bending, indicating superior flexibility and mechanical durability. Moreover, the H₂/CH₄ selectivity remained stable over 120-h of continuous operation, confirming outstanding long-term operational stability. Furthermore, a series of membranes with consistent performance were successfully fabricated on a large-area ZnO-PVDF/PVDF support (127.5 cm²), highlighting high reproducibility and scalability. This work establishes a robust foundation for the controllable synthesis of high-performance bimetallic MOF membranes toward industrial-scale gas separation processes.</div></div>","PeriodicalId":368,"journal":{"name":"Journal of Membrane Science","volume":"745 ","pages":"Article 125265"},"PeriodicalIF":9.0,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146172389","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Co-ion diffusion through bipolar membranes governs efficiency and stability in acid-base flow batteries","authors":"Pavel A. Loktionov ,&nbsp;Letian Li ,&nbsp;Vojtech Konderla ,&nbsp;Yorick Baljeu ,&nbsp;Ayesha Nawaz ,&nbsp;Sander Looman ,&nbsp;David A. Vermaas","doi":"10.1016/j.memsci.2026.125239","DOIUrl":"10.1016/j.memsci.2026.125239","url":null,"abstract":"<div><div>Salt-ion crossover through bipolar membranes (BPMs) is a major source of capacity fade and efficiency loss in acid-base flow batteries (ABFBs), yet its mechanisms remain poorly understood. Here, we quantify Na⁺ and Cl⁻ crossover in a five-cell ABFB stack under varying electrolyte composition, state of charge (SoC), current density, and temperature. The results show that crossover occurs predominantly through BPMs and is governed by diffusion assisted by H⁺/OH⁻ neutralization. At ambient conditions, Cl⁻ crossover exceeds Na⁺ by roughly twofold, with apparent activation energies of 15 kJ mol⁻¹ (Cl⁻) and 33 kJ mol⁻¹ (Na⁺), reflecting asymmetric co-ion diffusion within the cation- and anion-exchange layers. Increasing current density reduces the relative contribution of crossover, whereas higher electrolyte concentration, SoC, and temperature increase it. Based on the combined voltage efficiency and crossover analysis, we recommend operating ABFBs under conditions corresponding to BPM efficiencies above 80% - that is, with dilute electrolytes (≤0.25 M), near-equimolar acid and base (SoC ≈ 50%), and cycling current densities exceeding 5 mA cm⁻². These insights clarify the interplay between salt-ion transport and BPM operation, and provide design guidelines for next-generation ABFBs and other BPM-based electrochemical systems.</div></div>","PeriodicalId":368,"journal":{"name":"Journal of Membrane Science","volume":"745 ","pages":"Article 125239"},"PeriodicalIF":9.0,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146172376","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}