Pub Date : 2025-12-13DOI: 10.1016/j.memsci.2025.125059
Jiadi Ying , Zhen Cui , Lei Tu , Tiancun Liu , Song Lu , Qi Shen , Min Guo , Yeqing Wang , Zhen Yang , Minfeng Zeng , Zhixin Yu , Xingzhong Cao , Yuqing Lin
The development of high-performance cation exchange membranes (CEMs) with precise ion selectivity is crucial for electrodialysis applications, such as lithium extraction from salt-lake brines. However, conventional membrane materials often face a trade-off between high ion permeability and selectivity. In this work, we engineered a novel ionic cross-linked microporous membrane by blending sulfonated poly(ether ether ketone) (SPEEK) with a quaternized polymer of intrinsic microporosity (QPIM). This strategy leverages acid-base pair interactions between the sulfonic acid groups of SPEEK and the quaternary ammonium groups of QPIM to create well-defined sub-nanometer-scale ion transport channels. The optimized QPIM/SPEEK membrane (QPIM15) exhibits an exceptional Li+/Mg2+ selectivity of 6.98 and a high Li + permeation flux of 1.9 mol m−2 h−1, outperforming the pristine SPEEK and commercial CSO membranes. Comprehensive characterization and molecular dynamics simulations demonstrate that the enhanced performance originates from the synergy between size-sieving effects of narrowed microporous channels and electrostatic repulsion of cationic quaternary ammonium groups. This work provides a facile and effective approach for designing advanced ion-selective membranes, demonstrating great potential for efficient lithium-ion separation and other electrodialysis processes.
{"title":"Polymers with intrinsic microporosity engineered via acid-base pairs for highly selective lithium-ion transport channels","authors":"Jiadi Ying , Zhen Cui , Lei Tu , Tiancun Liu , Song Lu , Qi Shen , Min Guo , Yeqing Wang , Zhen Yang , Minfeng Zeng , Zhixin Yu , Xingzhong Cao , Yuqing Lin","doi":"10.1016/j.memsci.2025.125059","DOIUrl":"10.1016/j.memsci.2025.125059","url":null,"abstract":"<div><div>The development of high-performance cation exchange membranes (CEMs) with precise ion selectivity is crucial for electrodialysis applications, such as lithium extraction from salt-lake brines. However, conventional membrane materials often face a trade-off between high ion permeability and selectivity. In this work, we engineered a novel ionic cross-linked microporous membrane by blending sulfonated poly(ether ether ketone) (SPEEK) with a quaternized polymer of intrinsic microporosity (QPIM). This strategy leverages acid-base pair interactions between the sulfonic acid groups of SPEEK and the quaternary ammonium groups of QPIM to create well-defined sub-nanometer-scale ion transport channels. The optimized QPIM/SPEEK membrane (QPIM15) exhibits an exceptional Li<sup>+</sup>/Mg<sup>2+</sup> selectivity of 6.98 and a high Li <sup>+</sup> permeation flux of 1.9 mol m<sup>−2</sup> h<sup>−1</sup>, outperforming the pristine SPEEK and commercial CSO membranes. Comprehensive characterization and molecular dynamics simulations demonstrate that the enhanced performance originates from the synergy between size-sieving effects of narrowed microporous channels and electrostatic repulsion of cationic quaternary ammonium groups. This work provides a facile and effective approach for designing advanced ion-selective membranes, demonstrating great potential for efficient lithium-ion separation and other electrodialysis processes.</div></div>","PeriodicalId":368,"journal":{"name":"Journal of Membrane Science","volume":"741 ","pages":"Article 125059"},"PeriodicalIF":9.0,"publicationDate":"2025-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145787091","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}
Pub Date : 2025-12-13DOI: 10.1016/j.memsci.2025.125058
Huiyuan Chen , Qing Wang , Nong Xu , Qiao Liu , Fengshan Yu , Meng Guo , Bin Wang , Rongfei Zhou , Weihong Xing
Zeolite membranes used in pervaporation (PV) often present a trade-off between thickness and quality: thinner selective layers offer higher flux but are prone to nonselective defects. In this study, an ultradilute precursor solution combined with nanoseeds (15–25 nm) was employed for the first time to fabricate high-performance, ultrathin FAU zeolite membranes on tubular α-Al2O3 supports. The effects of synthesis parameters (precursor concentration, SiO2/Al2O3 ratio, crystallization temperature and time) on the membrane microstructure and PV performance were systematically investigated. The results show that the nanoseeds form a dense seed layer to effectively suppress defect formation, while the ultradilute precursor solution markedly reduces the rate of crystal growth, which thereby enables precise control over membrane thickness. Under optimized conditions (H2O/Al2O3 = 5,000, SiO2/Al2O3 = 9, 80 °C for 5 h), a pure-phase FAU membrane with an intergrown, defect-free microstructure was obtained at a thickness of approximately 1.61 μm. The membrane demonstrated excellent PV dehydration performance across representative water/organic solvent binary mixtures (ethanol, acetone, isopropanol, n-butanol, and dimethyl carbonate), which underscores its broad applicability. For example, the membrane achieved separation factors of 549 at 75 °C, 234 at 55 °C, and 1304 at 70 °C for binary mixtures containing 10 wt% water of ethanol, acetone, and isopropanol, respectively, with corresponding total fluxes of 2.29, 1.46, and 3.64 kg/(m2 h), respectively. In addition, the effect of operating parameters on PV performance was systematically examined and revealed that PV dehydration through the FAU membrane follows an adsorption-diffusion mechanism, with the hydrophilic FAU pores preferentially adsorbing water molecules to enable selective and rapid transport. In this study, high-quality ultrathin FAU membranes were successfully fabricated through the synergistic combination of an ultradilute precursor solution and nanoseeds. This strategy provides a promising route for the fabrication of zeolite membranes.
{"title":"Ultrathin FAU zeolite membranes via an ultradilute precursor-nanoseed strategy: synthesis optimization and pervaporation dehydration performance","authors":"Huiyuan Chen , Qing Wang , Nong Xu , Qiao Liu , Fengshan Yu , Meng Guo , Bin Wang , Rongfei Zhou , Weihong Xing","doi":"10.1016/j.memsci.2025.125058","DOIUrl":"10.1016/j.memsci.2025.125058","url":null,"abstract":"<div><div>Zeolite membranes used in pervaporation (PV) often present a trade-off between thickness and quality: thinner selective layers offer higher flux but are prone to nonselective defects. In this study, an ultradilute precursor solution combined with nanoseeds (15–25 nm) was employed for the first time to fabricate high-performance, ultrathin FAU zeolite membranes on tubular α-Al<sub>2</sub>O<sub>3</sub> supports. The effects of synthesis parameters (precursor concentration, SiO<sub>2</sub>/Al<sub>2</sub>O<sub>3</sub> ratio, crystallization temperature and time) on the membrane microstructure and PV performance were systematically investigated. The results show that the nanoseeds form a dense seed layer to effectively suppress defect formation, while the ultradilute precursor solution markedly reduces the rate of crystal growth, which thereby enables precise control over membrane thickness. Under optimized conditions (H<sub>2</sub>O/Al<sub>2</sub>O<sub>3</sub> = 5,000, SiO<sub>2</sub>/Al<sub>2</sub>O<sub>3</sub> = 9, 80 °C for 5 h), a pure-phase FAU membrane with an intergrown, defect-free microstructure was obtained at a thickness of approximately 1.61 μm. The membrane demonstrated excellent PV dehydration performance across representative water/organic solvent binary mixtures (ethanol, acetone, isopropanol, n-butanol, and dimethyl carbonate), which underscores its broad applicability. For example, the membrane achieved separation factors of 549 at 75 °C, 234 at 55 °C, and 1304 at 70 °C for binary mixtures containing 10 wt% water of ethanol, acetone, and isopropanol, respectively, with corresponding total fluxes of 2.29, 1.46, and 3.64 kg/(m<sup>2</sup> h), respectively. In addition, the effect of operating parameters on PV performance was systematically examined and revealed that PV dehydration through the FAU membrane follows an adsorption-diffusion mechanism, with the hydrophilic FAU pores preferentially adsorbing water molecules to enable selective and rapid transport. In this study, high-quality ultrathin FAU membranes were successfully fabricated through the synergistic combination of an ultradilute precursor solution and nanoseeds. This strategy provides a promising route for the fabrication of zeolite membranes.</div></div>","PeriodicalId":368,"journal":{"name":"Journal of Membrane Science","volume":"741 ","pages":"Article 125058"},"PeriodicalIF":9.0,"publicationDate":"2025-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145787510","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}
Pub Date : 2025-12-12DOI: 10.1016/j.memsci.2025.125056
Qian Xu , Weijuan Guo , Ruonan Shi , Zhiling Yang , Xiaobin Wang , Feichao Wu
Developing advanced membrane materials, represented by MOF membranes, is crucial for the efficient separation of butane isomers, which are important petrochemical industrial raw materials. However, this area has received limited attention to date. In this work, MIL-140A series membranes were successfully prepared on α-Al2O3 ceramic substrates by metal precursor induction method, and were attempted for the separation of butane isomers. The developed MOF membranes exhibit impressive performance in separating n-butane/isobutane mixtures, which is attributed to their appropriate sieve apertures and preferential adsorption of n-butane. This mechanism can be described as size-based sieving assisted by preferential adsorption. Owing to its smaller sieve aperture, the performance of MIL-140A-NH2 membrane was superior to that of the MIL-140A membrane, showing a n-butane permeance of 136 GPU and an ideal selectivity of 25.4. The excellent separation performance was maintained under varying testing conditions, including operating temperature, operating pressure, feed composition, and testing duration. This work provides a useful reference for the development of membranes for industrial separation of butane isomers.
{"title":"Synthesis of robust MIL-140A series membranes for efficient butane isomer separation","authors":"Qian Xu , Weijuan Guo , Ruonan Shi , Zhiling Yang , Xiaobin Wang , Feichao Wu","doi":"10.1016/j.memsci.2025.125056","DOIUrl":"10.1016/j.memsci.2025.125056","url":null,"abstract":"<div><div>Developing advanced membrane materials, represented by MOF membranes, is crucial for the efficient separation of butane isomers, which are important petrochemical industrial raw materials. However, this area has received limited attention to date. In this work, MIL-140A series membranes were successfully prepared on α-Al<sub>2</sub>O<sub>3</sub> ceramic substrates by metal precursor induction method, and were attempted for the separation of butane isomers. The developed MOF membranes exhibit impressive performance in separating n-butane/isobutane mixtures, which is attributed to their appropriate sieve apertures and preferential adsorption of n-butane. This mechanism can be described as size-based sieving assisted by preferential adsorption. Owing to its smaller sieve aperture, the performance of MIL-140A-NH<sub>2</sub> membrane was superior to that of the MIL-140A membrane, showing a n-butane permeance of 136 GPU and an ideal selectivity of 25.4. The excellent separation performance was maintained under varying testing conditions, including operating temperature, operating pressure, feed composition, and testing duration. This work provides a useful reference for the development of membranes for industrial separation of butane isomers.</div></div>","PeriodicalId":368,"journal":{"name":"Journal of Membrane Science","volume":"741 ","pages":"Article 125056"},"PeriodicalIF":9.0,"publicationDate":"2025-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145787094","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}
Pub Date : 2025-12-12DOI: 10.1016/j.memsci.2025.125057
Kai Li , Yu-Ren Xue , Guang-Chang Xu , Hao-Cheng Yang , Zhi-Kang Xu
Supported ionic liquid membranes (SILMs) present exceptional selectivity in CO2 separation, but their practical application has been limited by extremely low permeance arising from high mass transfer resistance through the liquid phase. To overcome this limitation, we constructed an ultrathin ionic liquid (IL) selective layer by confining the liquid phase within a Janus substrate, referred to as Janus-confined ionic liquid membranes (JCILMs). The reduced IL thickness effectively lowers the transport resistance of CO2, thereby leading to a substantial enhancement in CO2 permeance. The Janus substrates were prepared via single-sided atomic layer deposition, where the thickness of the IL-philic layer could be adjusted by the deposition parameters such as the deposition cycle number and the precursor pulse time. The IL layer thickness is reduced from 180 μm to 30 μm. Corresponding JCILM performs a CO2 permeance of approximately 17 GPU with an ideal CO2/N2 selectivity of 70, representing a 19-fold permeance increase over the conventional SILM. The design of JCILMs broadens the application scope of Janus membranes and offers a novel strategy for the development of next-generation SILMs.
{"title":"Janus-confined ionic liquid membranes for boosted CO2 separation","authors":"Kai Li , Yu-Ren Xue , Guang-Chang Xu , Hao-Cheng Yang , Zhi-Kang Xu","doi":"10.1016/j.memsci.2025.125057","DOIUrl":"10.1016/j.memsci.2025.125057","url":null,"abstract":"<div><div>Supported ionic liquid membranes (SILMs) present exceptional selectivity in CO<sub>2</sub> separation, but their practical application has been limited by extremely low permeance arising from high mass transfer resistance through the liquid phase. To overcome this limitation, we constructed an ultrathin ionic liquid (IL) selective layer by confining the liquid phase within a Janus substrate, referred to as Janus-confined ionic liquid membranes (JCILMs). The reduced IL thickness effectively lowers the transport resistance of CO<sub>2</sub>, thereby leading to a substantial enhancement in CO<sub>2</sub> permeance. The Janus substrates were prepared via single-sided atomic layer deposition, where the thickness of the IL-philic layer could be adjusted by the deposition parameters such as the deposition cycle number and the precursor pulse time. The IL layer thickness is reduced from 180 μm to 30 μm. Corresponding JCILM performs a CO<sub>2</sub> permeance of approximately 17 GPU with an ideal CO<sub>2</sub>/N<sub>2</sub> selectivity of 70, representing a 19-fold permeance increase over the conventional SILM. The design of JCILMs broadens the application scope of Janus membranes and offers a novel strategy for the development of next-generation SILMs.</div></div>","PeriodicalId":368,"journal":{"name":"Journal of Membrane Science","volume":"741 ","pages":"Article 125057"},"PeriodicalIF":9.0,"publicationDate":"2025-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145787113","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}
Pub Date : 2025-12-11DOI: 10.1016/j.memsci.2025.125055
Hengxin Li , Kai Miao , Mei-ling Liu , Kecheng Guan , Dong Zou , Hideto Matsuyama
High-performance ceramic membranes are essential for membrane distillation (MD) treatment of high-salinity wastewater, yet achieving both high flux and strong rejection remains challenging. This study proposes a cross-layer construction strategy in which a polymer pre-filling approach is employed to fabricate a bi-layer silicon carbide (SiC) ceramic membrane without penetration, thereby significantly reducing mass-transfer resistance in vacuum membrane distillation (VMD). After optimization, the SiC support was sintered at 1350 °C, and a pre-filling concentration of 10 wt% PVB was identified as critical for preventing particle penetration and ensuring robust interfacial bonding. The membrane layer, prepared from a slurry with 15 wt% solid content and sintered at 1000 °C, exhibited a defect-free structure. Following fluorination, the membrane achieved a water contact angle of 139.6°. Computational fluid dynamics (CFD) simulations confirmed that the pre-filling strategy markedly reduces mass-transfer resistance compared with traditional intermediate-layer approaches. In VMD tests, the membrane delivered high fluxes of 34.89 and 28.40 kg·m-2·h-1 under feed salinities of 35 and 100 g·L-1 NaCl, respectively, while maintaining a salt rejection above 99.9 % and stable performance over 24 h. This work provides an effective pathway for designing high-flux ceramic membranes for MD.
{"title":"Cross-layer construction of ceramic membranes with minimizing transfer resistance for membrane distillation","authors":"Hengxin Li , Kai Miao , Mei-ling Liu , Kecheng Guan , Dong Zou , Hideto Matsuyama","doi":"10.1016/j.memsci.2025.125055","DOIUrl":"10.1016/j.memsci.2025.125055","url":null,"abstract":"<div><div>High-performance ceramic membranes are essential for membrane distillation (MD) treatment of high-salinity wastewater, yet achieving both high flux and strong rejection remains challenging. This study proposes a cross-layer construction strategy in which a polymer pre-filling approach is employed to fabricate a bi-layer silicon carbide (SiC) ceramic membrane without penetration, thereby significantly reducing mass-transfer resistance in vacuum membrane distillation (VMD). After optimization, the SiC support was sintered at 1350 °C, and a pre-filling concentration of 10 wt% PVB was identified as critical for preventing particle penetration and ensuring robust interfacial bonding. The membrane layer, prepared from a slurry with 15 wt% solid content and sintered at 1000 °C, exhibited a defect-free structure. Following fluorination, the membrane achieved a water contact angle of 139.6°. Computational fluid dynamics (CFD) simulations confirmed that the pre-filling strategy markedly reduces mass-transfer resistance compared with traditional intermediate-layer approaches. In VMD tests, the membrane delivered high fluxes of 34.89 and 28.40 kg·m<sup>-2</sup>·h<sup>-1</sup> under feed salinities of 35 and 100 g·L<sup>-1</sup> NaCl, respectively, while maintaining a salt rejection above 99.9 % and stable performance over 24 h. This work provides an effective pathway for designing high-flux ceramic membranes for MD.</div></div>","PeriodicalId":368,"journal":{"name":"Journal of Membrane Science","volume":"741 ","pages":"Article 125055"},"PeriodicalIF":9.0,"publicationDate":"2025-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145787092","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}
Pub Date : 2025-12-11DOI: 10.1016/j.memsci.2025.125053
Qiang Li , Jiaqi Han , Saisai Li , Li Zhao , Qi Zhang , Shuyun Zheng , Dongjun Lv , Fucheng Wang , Huining Deng
Dually charged Janus nanofiltration (NF) membrane strongly breaks through the limitations of traditional polyamide-based membranes in indiscriminately removing divalent anions and cations. This report successfully constructs a high-performance quaternized polyethylenimine/lignin-polyamide (QPEI/PAL) composite NF membrane by the following strategy. Firstly, a highly negatively charged PAL separation layer on a polysulfone substrate is obtained by interfacial polymerization employing piperazine/alkaline lignin as an aqueous mixture and trimesoyl chloride (TMC) as an organic solution. Then, a loose upper surface of PEI polymer is constructed on the freshly formed PAL lower surface through a reaction with the residual acyl chloride groups. Subsequently, the amine and imine groups of the PEI upper surface are transformed into quaternary ammonium ions by CH3I fumigation. The experimental results show the obtained membrane shows high pure water permeance (11.0 L m−2 h−1 bar−1) and outstanding removal for various single-divalent salts (92.6 % for Na2SO4, 98.4 % for MgCl2, 97.0 % for CaCl2, etc.). It also possesses excellent separation selectivities for NaCl/Na2SO4 (81.7) and LiCl/MgCl2 (46.9) mixtures. Even under a high Mg2+/Li+ mass ratio of 80, the corresponding Li+/Mg2+ selectivity can still reach 43.0. The abundant negative charges on the PAL lower surface facilitates the rapid diffusion of Li+ ions within the Janus separation layer. This characteristic indicates the membrane shows outstanding Li+/Mg2+ separation capability. Furthermore, compared with the pristine polyamide NF membrane, the fabricated QPEI/PAL membrane exhibits an excellent hardness removal performance for various simulated hard waters with complex compositions. Additionally, the membrane exhibits high antibacterial properties and stable separation performance for Na2SO4 and MgCl2 removal in a long-term running (168 h).
双荷电Janus纳滤膜强有力地突破了传统聚酰胺基膜不加区分地去除二价阴离子和阳离子的局限性。本文采用以下策略成功构建了高性能季铵化聚乙烯亚胺/木质素聚酰胺（QPEI/PAL）复合纳滤膜。首先，以哌嗪/碱性木质素为水溶液，三甲基氯（TMC）为有机溶液，通过界面聚合在聚砜基底上获得了高负电荷的PAL分离层。然后，通过与残留的酰氯基团反应，在新形成的PAL下表面上构建松散的PEI聚合物上表面。随后，PEI上表面的胺基和亚胺基通过CH3I熏蒸转化为季铵离子。实验结果表明，所制备的膜具有较高的纯水渗透率（11.0 L m−2 h−1 bar−1）和对各种单二价盐的去除率（Na2SO4去除率92.6%，MgCl2去除率98.4%，CaCl2去除率97.0%等）。它对NaCl/Na2SO4（81.7）和LiCl/MgCl2（46.9）混合物也有很好的分离选择性。即使在Mg2+/Li+质量比高达80的情况下，相应的Li+/Mg2+选择性仍可达到43.0。PAL下表面丰富的负电荷有利于Li+离子在Janus分离层内的快速扩散。这一特性表明该膜具有优异的Li+/Mg2+分离能力。此外，与原始聚酰胺纳滤膜相比，制备的QPEI/PAL膜对各种复杂成分的模拟硬水具有优异的去除硬度性能。此外，该膜具有较高的抗菌性能和稳定的分离性能，可以长期运行（168 h）去除Na2SO4和MgCl2。
{"title":"Dually charged quaternized PEI/lignin-polyamide composite nanofiltration membrane toward highly efficient di-/monovalent ion separation","authors":"Qiang Li , Jiaqi Han , Saisai Li , Li Zhao , Qi Zhang , Shuyun Zheng , Dongjun Lv , Fucheng Wang , Huining Deng","doi":"10.1016/j.memsci.2025.125053","DOIUrl":"10.1016/j.memsci.2025.125053","url":null,"abstract":"<div><div>Dually charged Janus nanofiltration (NF) membrane strongly breaks through the limitations of traditional polyamide-based membranes in indiscriminately removing divalent anions and cations. This report successfully constructs a high-performance quaternized polyethylenimine/lignin-polyamide (QPEI/PAL) composite NF membrane by the following strategy. Firstly, a highly negatively charged PAL separation layer on a polysulfone substrate is obtained by interfacial polymerization employing piperazine/alkaline lignin as an aqueous mixture and trimesoyl chloride (TMC) as an organic solution. Then, a loose upper surface of PEI polymer is constructed on the freshly formed PAL lower surface through a reaction with the residual acyl chloride groups. Subsequently, the amine and imine groups of the PEI upper surface are transformed into quaternary ammonium ions by CH<sub>3</sub>I fumigation. The experimental results show the obtained membrane shows high pure water permeance (11.0 L m<sup>−2</sup> h<sup>−1</sup> bar<sup>−1</sup>) and outstanding removal for various single-divalent salts (92.6 % for Na<sub>2</sub>SO<sub>4</sub>, 98.4 % for MgCl<sub>2</sub>, 97.0 % for CaCl<sub>2</sub>, <em>etc.</em>). It also possesses excellent separation selectivities for NaCl/Na<sub>2</sub>SO<sub>4</sub> (81.7) and LiCl/MgCl<sub>2</sub> (46.9) mixtures. Even under a high Mg<sup>2+</sup>/Li<sup>+</sup> mass ratio of 80, the corresponding Li<sup>+</sup>/Mg<sup>2+</sup> selectivity can still reach 43.0. The abundant negative charges on the PAL lower surface facilitates the rapid diffusion of Li<sup>+</sup> ions within the Janus separation layer. This characteristic indicates the membrane shows outstanding Li<sup>+</sup>/Mg<sup>2+</sup> separation capability. Furthermore, compared with the pristine polyamide NF membrane, the fabricated QPEI/PAL membrane exhibits an excellent hardness removal performance for various simulated hard waters with complex compositions. Additionally, the membrane exhibits high antibacterial properties and stable separation performance for Na<sub>2</sub>SO<sub>4</sub> and MgCl<sub>2</sub> removal in a long-term running (168 h).</div></div>","PeriodicalId":368,"journal":{"name":"Journal of Membrane Science","volume":"741 ","pages":"Article 125053"},"PeriodicalIF":9.0,"publicationDate":"2025-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145787155","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}
Pub Date : 2025-12-11DOI: 10.1016/j.memsci.2025.125054
Tingting Tang , Wenyi Zhang , Yucheng Liu , Xuewei Li , Kaibo Hu , Yinhua Wan , Jiuyang Lin
Yttrium (Y), the most abundant heavy rare earth element (HREE) in ion-adsorption type rare earth ores (IATREO), is essential for various innovative functional materials. This study employed hollow fiber renewal liquid membrane (HFRLM) technology combined with a novel phosphorus-containing extractant Cextrant322 (C322) to establish a C322-HFRLM system for the selective separation of Y3+ from Y-rich HREEs solution of IATREO. Under the optimized conditions of 0.5 mol L−1 C322, feed phase pH of 3, flow rate of 550 mL min−1, and stripping-to-feed volume ratio (VS/VF) of 1.6, the results demonstrated that the purity of Y3+ in the feed phase increased from 61.90 % to 97.69 % after a single-step simultaneous extraction-stripping process. The maximum separation factor (SF) values between Ho3+-Lu3+ and Y3+ (i.e., SFHo/Y, SFEr/Y, SFTm/Y, SFYb/Y, and SFLu/Y) were 1.32, 2.41, 5.71, 8.60, and 9.80 at 0.25-h operation, respectively. Compared with the traditional hollow fiber supported liquid membrane (HFSLM) system, the C322-HFRLM system achieved 1.29 times increase in Y3+ purity, demonstrating significantly enhanced separation efficiency and stability. Therefore, HFRLM presents substantial potential as an advanced membrane separation technology for the efficient industrial-scale separation and enrichment of Y3+.
{"title":"Highly selective separation of yttrium from heavy rare earth elements by hollow fiber renewal liquid membrane","authors":"Tingting Tang , Wenyi Zhang , Yucheng Liu , Xuewei Li , Kaibo Hu , Yinhua Wan , Jiuyang Lin","doi":"10.1016/j.memsci.2025.125054","DOIUrl":"10.1016/j.memsci.2025.125054","url":null,"abstract":"<div><div>Yttrium (Y), the most abundant heavy rare earth element (HREE) in ion-adsorption type rare earth ores (IATREO), is essential for various innovative functional materials. This study employed hollow fiber renewal liquid membrane (HFRLM) technology combined with a novel phosphorus-containing extractant Cextrant322 (C322) to establish a C322-HFRLM system for the selective separation of Y<sup>3+</sup> from Y-rich HREEs solution of IATREO. Under the optimized conditions of 0.5 mol L<sup>−1</sup> C322, feed phase pH of 3, flow rate of 550 mL min<sup>−1</sup>, and stripping-to-feed volume ratio (<em>V</em><sub>S</sub>/<em>V</em><sub>F</sub>) of 1.6, the results demonstrated that the purity of Y<sup>3+</sup> in the feed phase increased from 61.90 % to 97.69 % after a single-step simultaneous extraction-stripping process. The maximum separation factor (<em>SF</em>) values between Ho<sup>3+</sup>-Lu<sup>3+</sup> and Y<sup>3+</sup> (i.e., <em>SF</em><sub>Ho/Y</sub>, <em>SF</em><sub>Er/Y</sub>, <em>SF</em><sub>Tm/Y</sub>, <em>SF</em><sub>Yb/Y</sub>, and <em>SF</em><sub>Lu/Y</sub>) were 1.32, 2.41, 5.71, 8.60, and 9.80 at 0.25-h operation, respectively. Compared with the traditional hollow fiber supported liquid membrane (HFSLM) system, the C322-HFRLM system achieved 1.29 times increase in Y<sup>3+</sup> purity, demonstrating significantly enhanced separation efficiency and stability. Therefore, HFRLM presents substantial potential as an advanced membrane separation technology for the efficient industrial-scale separation and enrichment of Y<sup>3+</sup>.</div></div>","PeriodicalId":368,"journal":{"name":"Journal of Membrane Science","volume":"741 ","pages":"Article 125054"},"PeriodicalIF":9.0,"publicationDate":"2025-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145734430","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}
Pub Date : 2025-12-10DOI: 10.1016/j.memsci.2025.125040
Junkai Gong , Zhiwei Zhou , Hao Wang , Chuang Lei , Qiangqiang Yang , Xiaoguang Wang , Lu Shao , Yanqiu Zhang
Covalent organic framework (COF)-based membranes exhibit exceptional potential for molecular separation owing to their well-defined nanoporosity, tailorable pore apertures, and high surface-to-volume ratios. However, achieving precise pore-size regulation remains a critical challenge in membrane design. Herein, we report a defect-engineering strategy for COF membranes through in-situ polydopamine (PDA) incorporation during interfacial polymerization. Dopamine undergoes oxidative self-polymerization in the p-phenylenediamine (Pa) aqueous phase, generating PDA that simultaneously reacts with Pa monomers and infiltrates TpPa-COF framework defects via Schiff-base chemistry. This dual-function modification not only repairs structural imperfections, but also introduces hydrophilic moieties that enhance surface wettability. The optimized PDA-TpPa membrane demonstrates superior separation performance, achieving 99 % rejection of organic dyes while maintaining a high water permeance of 117.3 L m−2 h−1 bar−1. Furthermore, the membrane exhibits considerable permeance towards various organic solvents, notably for n-hexane, which reached as high as 337 L m−2 h−1 bar−1. This work establishes a novel paradigm for fabricating high-performance COF membranes.
共价有机骨架（COF）基膜由于具有明确的纳米孔隙度、可定制的孔径和高表面体积比，表现出非凡的分子分离潜力。然而，实现精确的孔径调节仍然是膜设计中的一个关键挑战。在此，我们报告了在界面聚合过程中通过原位聚多巴胺（PDA）掺入COF膜的缺陷工程策略。多巴胺在对苯二胺（Pa）水相中进行氧化自聚合，生成PDA，该PDA同时与Pa单体反应，并通过希夫碱化学渗透TpPa-COF框架缺陷。这种双重功能的修饰不仅修复了结构缺陷，而且还引入了增强表面润湿性的亲水部分。优化后的PDA-TpPa膜具有优异的分离性能，对有机染料的去除率达到99%，同时保持了117.3 L m−2 h−1 bar−1的高透水性。此外，该膜对各种有机溶剂表现出相当大的渗透性，特别是对正己烷，其渗透性高达337 L m−2 h−1 bar−1。这项工作为制造高性能碳纤维膜建立了一个新的范例。
{"title":"Molecular welded interface engineering to synthesize covalent organic framework membranes for ultrafast molecular sieving","authors":"Junkai Gong , Zhiwei Zhou , Hao Wang , Chuang Lei , Qiangqiang Yang , Xiaoguang Wang , Lu Shao , Yanqiu Zhang","doi":"10.1016/j.memsci.2025.125040","DOIUrl":"10.1016/j.memsci.2025.125040","url":null,"abstract":"<div><div>Covalent organic framework (COF)-based membranes exhibit exceptional potential for molecular separation owing to their well-defined nanoporosity, tailorable pore apertures, and high surface-to-volume ratios. However, achieving precise pore-size regulation remains a critical challenge in membrane design. Herein, we report a defect-engineering strategy for COF membranes through in-situ polydopamine (PDA) incorporation during interfacial polymerization. Dopamine undergoes oxidative self-polymerization in the <em>p</em>-phenylenediamine (Pa) aqueous phase, generating PDA that simultaneously reacts with Pa monomers and infiltrates TpPa-COF framework defects via Schiff-base chemistry. This dual-function modification not only repairs structural imperfections, but also introduces hydrophilic moieties that enhance surface wettability. The optimized PDA-TpPa membrane demonstrates superior separation performance, achieving 99 % rejection of organic dyes while maintaining a high water permeance of 117.3 L m<sup>−2</sup> h<sup>−1</sup> bar<sup>−1</sup>. Furthermore, the membrane exhibits considerable permeance towards various organic solvents, notably for n-hexane, which reached as high as 337 L m<sup>−2</sup> h<sup>−1</sup> bar<sup>−1</sup>. This work establishes a novel paradigm for fabricating high-performance COF membranes.</div></div>","PeriodicalId":368,"journal":{"name":"Journal of Membrane Science","volume":"741 ","pages":"Article 125040"},"PeriodicalIF":9.0,"publicationDate":"2025-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145787153","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}
Pub Date : 2025-12-10DOI: 10.1016/j.memsci.2025.125050
Lei Huang , Xueting Zhao , Jinmao Lv , Xinliang Zhang , Zhihong Dong , Anqi Liu , Jiefeng Pan , Xiaocheng Lin
Controllable assembly of covalent organic framework (COF) nanosheets into two-dimensional (2D) layered membranes is crucial to prepare advanced membranes. However, the prevalence of disordered stacking of COF nanosheets often leads to tortuous or overlapped pores and sacrifices membrane permeability. Further, membrane stability is often questioned due to weak interlayer interactions. Herein, a three-dimensional (3D) polyphenol-mediated interlayer engineering strategy was proposed for manipulating the interlayer channels and interactions of COF membranes for simultaneous enhancement of membrane permeability and stability. The COF membranes (TTSBI/TFTA-TG(Cl)) were prepared via vacuum-assisted self-assembly method with TFTA-TG(Cl) COF nanosheets as the building host and 3D polyphenols 5,5′,6,6′-Tetrahydroxy-3,3,3′,3′-tetramethyl-1,1′-spirobiindane (TTSBI) as intercalating guests. The stereoscopic spirocyclic architecture of TTSBI provides rigid interlayer support to expand the 2D nanochannels within the COF membranes, which optimizes the water molecule transport pathway to enhance water permeance. The multiple interactions (e.g., electrostatic and cation-π interactions) between TTSBI and COF nanosheets strengthen the interlayer combination, thereby enhancing the structural stability of the COF membrane. The as-prepared TTSBI/TFTA-TG(Cl) membrane exhibited water permeance of 77.3 L m−2 h−1·bar−1 (approximately 2.5 times that of the pristine TFTA-TG(Cl) membrane) with methylene blue rejection above 91 %. Furthermore, the TTSBI/TFTA-TG(Cl) membrane can effectively reject dye molecules with molecular weight of ≥800 Da, and simultaneously demonstrate superior stability. This polyphenol-mediated interlayer engineering strategy may provide new insights into the construction and manipulation of the channels in COF membranes for high-permeability separation application.
{"title":"3D polyphenol-intercalated covalent organic framework membranes: Toward interlayer manipulation for high-permeability nanofiltration","authors":"Lei Huang , Xueting Zhao , Jinmao Lv , Xinliang Zhang , Zhihong Dong , Anqi Liu , Jiefeng Pan , Xiaocheng Lin","doi":"10.1016/j.memsci.2025.125050","DOIUrl":"10.1016/j.memsci.2025.125050","url":null,"abstract":"<div><div>Controllable assembly of covalent organic framework (COF) nanosheets into two-dimensional (2D) layered membranes is crucial to prepare advanced membranes. However, the prevalence of disordered stacking of COF nanosheets often leads to tortuous or overlapped pores and sacrifices membrane permeability. Further, membrane stability is often questioned due to weak interlayer interactions. Herein, a three-dimensional (3D) polyphenol-mediated interlayer engineering strategy was proposed for manipulating the interlayer channels and interactions of COF membranes for simultaneous enhancement of membrane permeability and stability. The COF membranes (TTSBI/TFTA-TG<sub>(Cl)</sub>) were prepared via vacuum-assisted self-assembly method with TFTA-TG<sub>(Cl)</sub> COF nanosheets as the building host and 3D polyphenols 5,5′,6,6′-Tetrahydroxy-3,3,3′,3′-tetramethyl-1,1′-spirobiindane (TTSBI) as intercalating guests. The stereoscopic spirocyclic architecture of TTSBI provides rigid interlayer support to expand the 2D nanochannels within the COF membranes, which optimizes the water molecule transport pathway to enhance water permeance. The multiple interactions (e.g., electrostatic and cation-π interactions) between TTSBI and COF nanosheets strengthen the interlayer combination, thereby enhancing the structural stability of the COF membrane. The as-prepared TTSBI/TFTA-TG<sub>(Cl)</sub> membrane exhibited water permeance of 77.3 L m<sup>−2</sup> h<sup>−1</sup>·bar<sup>−1</sup> (approximately 2.5 times that of the pristine TFTA-TG<sub>(Cl)</sub> membrane) with methylene blue rejection above 91 %. Furthermore, the TTSBI/TFTA-TG<sub>(Cl)</sub> membrane can effectively reject dye molecules with molecular weight of ≥800 Da, and simultaneously demonstrate superior stability. This polyphenol-mediated interlayer engineering strategy may provide new insights into the construction and manipulation of the channels in COF membranes for high-permeability separation application.</div></div>","PeriodicalId":368,"journal":{"name":"Journal of Membrane Science","volume":"741 ","pages":"Article 125050"},"PeriodicalIF":9.0,"publicationDate":"2025-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145734326","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}
Pub Date : 2025-12-09DOI: 10.1016/j.memsci.2025.125019
Jinmao Lv , Xueting Zhao , Lei Huang , Xuexi Zhang , Yu Sun , Jiefeng Pan , Xiaocheng Lin
Electrodialysis technology, an energy-efficient membrane separation technique, relies on the performance of its core component—ion exchange membranes (IEMs). However, anion exchange membranes (AEMs) still lag behind cation exchange membranes (CEMs, e.g., Nafion), primarily due to the trade-off between minimizing area resistance and maintaining dimensional stability. To tackle this issue, we leveraged 1-vinylimidazole (1-VIm) as a dual-functional agent by grafting it onto chloromethylated polysulfone (CMPSF) via N-alkylation and subsequently employing its vinyl group for in-situ self-polymerization to form the crosslinked structure. Results demonstrate that the 1-VIm self-crosslinked structure enables the coexistence of a high ion exchange capacity (IEC) for low area resistance and outstanding dimensional stability (suppressed swelling). The optimal VIPSF-3 membrane exhibits a swelling ratio of only 8.0 ± 0.5 % at 60 °C, while significantly enhancing membrane selectivity with an ion transport number () as high as 0.990 ± 0.002. During a 140-min electrodialysis desalination test, the optimized VIPSF-3 membrane outperformed the commercial AMV AEM by achieving a salt removal rate () of 90.5 ± 0.8 %, a current efficiency (η) of 98.3 ± 0.8 %, and an energy consumption (EC) of 4.04 ± 0.13 kWh·kg−1. These values surpass those of AMV ( = 82.4 ± 1.0 %, η = 88.3 ± 1.1 %, EC = 5.20 ± 0.17 kWh·kg−1). This study provides a novel strategy for preparing high-performance AEMs for electrodialysis applications.
{"title":"Preparation of polysulfone-based imidazole-functionalized self-crosslinked anion exchange membranes for electrodialysis","authors":"Jinmao Lv , Xueting Zhao , Lei Huang , Xuexi Zhang , Yu Sun , Jiefeng Pan , Xiaocheng Lin","doi":"10.1016/j.memsci.2025.125019","DOIUrl":"10.1016/j.memsci.2025.125019","url":null,"abstract":"<div><div>Electrodialysis technology, an energy-efficient membrane separation technique, relies on the performance of its core component—ion exchange membranes (IEMs). However, anion exchange membranes (AEMs) still lag behind cation exchange membranes (CEMs, e.g., Nafion), primarily due to the trade-off between minimizing area resistance and maintaining dimensional stability. To tackle this issue, we leveraged 1-vinylimidazole (1-VIm) as a dual-functional agent by grafting it onto chloromethylated polysulfone (CMPSF) via N-alkylation and subsequently employing its vinyl group for in-situ self-polymerization to form the crosslinked structure. Results demonstrate that the 1-VIm self-crosslinked structure enables the coexistence of a high ion exchange capacity (<em>IEC</em>) for low area resistance and outstanding dimensional stability (suppressed swelling). The optimal VIPSF-3 membrane exhibits a swelling ratio of only 8.0 ± 0.5 % at 60 °C, while significantly enhancing membrane selectivity with an ion transport number (<span><math><mrow><msub><mi>t</mi><mi>i</mi></msub></mrow></math></span>) as high as 0.990 ± 0.002. During a 140-min electrodialysis desalination test, the optimized VIPSF-3 membrane outperformed the commercial AMV AEM by achieving a salt removal rate (<span><math><mrow><msub><mi>R</mi><mrow><mi>s</mi><mi>a</mi><mi>l</mi><mi>t</mi></mrow></msub></mrow></math></span>) of 90.5 ± 0.8 %, a current efficiency (<em>η</em>) of 98.3 ± 0.8 %, and an energy consumption (<em>EC</em>) of 4.04 ± 0.13 kWh·kg<sup>−1</sup>. These values surpass those of AMV (<span><math><mrow><msub><mi>R</mi><mrow><mi>s</mi><mi>a</mi><mi>l</mi><mi>t</mi></mrow></msub></mrow></math></span> = 82.4 ± 1.0 %, <em>η</em> = 88.3 ± 1.1 %, <em>EC</em> = 5.20 ± 0.17 kWh·kg<sup>−1</sup>). This study provides a novel strategy for preparing high-performance AEMs for electrodialysis applications.</div></div>","PeriodicalId":368,"journal":{"name":"Journal of Membrane Science","volume":"741 ","pages":"Article 125019"},"PeriodicalIF":9.0,"publicationDate":"2025-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145734434","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}
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