Pub Date : 2025-11-20DOI: 10.1016/j.memsci.2025.124977
Byung Kwan Lee , Juhyung Moon , Chaewon Youn , Young Jae Kim , Yu Jin Kim , Myung-Seok Lee , Jung-Hyun Lee , Chang Hyun Lee , Young Hoon Cho , Ho Bum Park
Thin-film composite (TFC) membranes are essential in water treatment, yet their fabrication often relies on toxic solvents (e.g., N-methyl-2-pyrrolidone, dimethylformamide, n-hexane) and petroleum-derived polymers (e.g., polysulfone and polyethersulfone), raising significant environmental concerns. In this study, we developed eco-friendly TFC membranes using biodegradable cellulose as the support and a bio-derived sugar-based monomer for the selective layer. Green solvents, PolarClean® and 2-methyltetrahydrofuran, were employed as sustainable alternatives to conventional solvents. The optimized membrane achieved outstanding performance, with a water permeance of 66.5 L m−2 h−1 bar−1 and 99.8 % CR rejection, while maintaining low salt rejection (4.4 % for NaCl and 9.3 % for Na2SO4). Moreover, the polyester selective layer exhibited excellent chlorine resistance and robust mechanical stability, emphasizing its potential for practical use. This work demonstrates a sustainable platform for fabricating green membranes tailored for dye/salt separation.
薄膜复合膜（TFC）在水处理中是必不可少的，但它们的制造通常依赖于有毒溶剂（例如，n-甲基-2-吡罗烷、二甲基甲酰胺、正己烷）和石油衍生聚合物（例如，聚砜和聚醚砜），这引起了严重的环境问题。在这项研究中，我们开发了生态友好的TFC膜，使用可生物降解的纤维素作为支撑，生物衍生的糖基单体作为选择层。绿色溶剂，PolarClean®和2-甲基四氢呋喃，被用作传统溶剂的可持续替代品。优化后的膜具有优异的性能，其透水性为66.5 L m−2 h−1 bar−1，CR截留率为99.8%，同时保持较低的盐截留率（NaCl为4.4%，Na2SO4为9.3%）。此外，聚酯选择层表现出优异的耐氯性和强大的机械稳定性，强调了其实际应用的潜力。这项工作展示了一个可持续的平台，用于制造适合染料/盐分离的绿色膜。
{"title":"Sustainable polyester loose nanofiltration membranes from bio-derived monomers and cellulose supports for efficient dye/salt separation","authors":"Byung Kwan Lee , Juhyung Moon , Chaewon Youn , Young Jae Kim , Yu Jin Kim , Myung-Seok Lee , Jung-Hyun Lee , Chang Hyun Lee , Young Hoon Cho , Ho Bum Park","doi":"10.1016/j.memsci.2025.124977","DOIUrl":"10.1016/j.memsci.2025.124977","url":null,"abstract":"<div><div>Thin-film composite (TFC) membranes are essential in water treatment, yet their fabrication often relies on toxic solvents (e.g., N-methyl-2-pyrrolidone, dimethylformamide, n-hexane) and petroleum-derived polymers (e.g., polysulfone and polyethersulfone), raising significant environmental concerns. In this study, we developed eco-friendly TFC membranes using biodegradable cellulose as the support and a bio-derived sugar-based monomer for the selective layer. Green solvents, PolarClean® and 2-methyltetrahydrofuran, were employed as sustainable alternatives to conventional solvents. The optimized membrane achieved outstanding performance, with a water permeance of 66.5 L m<sup>−2</sup> h<sup>−1</sup> bar<sup>−1</sup> and 99.8 % CR rejection, while maintaining low salt rejection (4.4 % for NaCl and 9.3 % for Na<sub>2</sub>SO<sub>4</sub>). Moreover, the polyester selective layer exhibited excellent chlorine resistance and robust mechanical stability, emphasizing its potential for practical use. This work demonstrates a sustainable platform for fabricating green membranes tailored for dye/salt separation.</div></div>","PeriodicalId":368,"journal":{"name":"Journal of Membrane Science","volume":"740 ","pages":"Article 124977"},"PeriodicalIF":9.0,"publicationDate":"2025-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145621606","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}
Hydrogen production by methanol steam reforming in membrane reactors is one of the most promising approaches due to convenient methanol transportation, high environmental friendliness of the method, and combination of hydrogen production with its deep purification. The hydrogen permeability of Pd–Cu alloy membranes of different thickness was studied including both unmodified membranes and those with surfaces modified with agglomerated palladium nanoneedles. The highest hydrogen permeability was achieved for 7 μm-thick membranes with a modified surface. The process of hydrogen production by steam methanol reforming was studied in a membrane reactor using Pd–Cu membranes of different thickness. The surface-modified membrane exhibites intrinsic catalytic activity, which significantly increases with the additional introduction of Cu–Ni catalyst with support based on TiO2–In2O3 or detonation nanodiamonds (DND). The hydrogen production rate in the steam reforming process increases by ∼2.5 times in a membrane reactor compared to a conventional flow reactor. The efficiency of the methanol steam reforming in the membrane reactor increases both with decreasing thickness of the Pd–Cu membranes from 30 to 7 μm and with surface modification by palladium nanoneedles. The highest hydrogen production rate in the permeate zone and alcohol conversion (91 %) were observed for the membrane-catalytic system with a modified 7 μm-thick Pd–Cu membrane and a Cu–Ni/DND catalyst. Moreover, no carbon monoxide impurities were detected when using the Cu–Ni/DND catalyst.
{"title":"Synergy between membrane and catalyst design for efficient hydrogen generation via methanol steam reforming","authors":"Elena Mironova , Valeria Zarubina , Iliya Petriev , Polina Pushankina , Natalia Zhilyaeva , Irina Stenina , Andrey Yaroslavtsev","doi":"10.1016/j.memsci.2025.124974","DOIUrl":"10.1016/j.memsci.2025.124974","url":null,"abstract":"<div><div>Hydrogen production by methanol steam reforming in membrane reactors is one of the most promising approaches due to convenient methanol transportation, high environmental friendliness of the method, and combination of hydrogen production with its deep purification. The hydrogen permeability of Pd–Cu alloy membranes of different thickness was studied including both unmodified membranes and those with surfaces modified with agglomerated palladium nanoneedles. The highest hydrogen permeability was achieved for 7 μm-thick membranes with a modified surface. The process of hydrogen production by steam methanol reforming was studied in a membrane reactor using Pd–Cu membranes of different thickness. The surface-modified membrane exhibites intrinsic catalytic activity, which significantly increases with the additional introduction of Cu–Ni catalyst with support based on TiO<sub>2</sub>–In<sub>2</sub>O<sub>3</sub> or detonation nanodiamonds (DND). The hydrogen production rate in the steam reforming process increases by ∼2.5 times in a membrane reactor compared to a conventional flow reactor. The efficiency of the methanol steam reforming in the membrane reactor increases both with decreasing thickness of the Pd–Cu membranes from 30 to 7 μm and with surface modification by palladium nanoneedles. The highest hydrogen production rate in the permeate zone and alcohol conversion (91 %) were observed for the membrane-catalytic system with a modified 7 μm-thick Pd–Cu membrane and a Cu–Ni/DND catalyst. Moreover, no carbon monoxide impurities were detected when using the Cu–Ni/DND catalyst.</div></div>","PeriodicalId":368,"journal":{"name":"Journal of Membrane Science","volume":"740 ","pages":"Article 124974"},"PeriodicalIF":9.0,"publicationDate":"2025-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145578002","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}
Oil-water separation is a vital process across various industries, where membrane separation stands out as a promising, energy-efficient solution. Despite its potential, the widespread application is hindered by the limited durability of existing membrane surface engineering effects. This study introduces an innovative fabrication strategy to create a superhydrophobic and durable nanofibrous membrane for efficient oil-water separation. Utilizing electrospinning and a two-step sequential covalent-bonding dip-coating process, the membrane was chemically decorated with vinyl trichlorosilane, followed by a thiol-ene “Click” reaction with 1H, 1H, 2H, 2H-perfluorodecanethiol, resulting in a stable superhydrophobic and oleophilic surface. The membrane exhibited high permeation fluxes for various organic solvents, achieving separation efficiencies exceeding 99.5 % for non-emulsified mixtures (oil:water = 1:1) and over 99.7 % for hydrocarbon oil/water emulsions (oil:water = 99:1). Furthermore, the membrane demonstrated remarkable stability, enduring multiple filtration cycles and harsh chemical environments, including extended exposure to NaOH solutions. To validate its industrial applicability, the nanofibrous membrane was employed in a membrane extraction process post amide synthesis, successfully separating dichloromethane and water, thereby streamlining the extraction process. This work showcases a robust membrane surface engineering strategy for efficient oil-water separation.
{"title":"Engineering electrospun hydrophobic SiO2 nanofibers via organosilica-based click chemistry modification for ultrafast oil-water separation","authors":"Hongmiao Wu , Xiao Shen , Mingjie Wei , Feng Zhang , Ze-Xian Low , Weihong Xing","doi":"10.1016/j.memsci.2025.124964","DOIUrl":"10.1016/j.memsci.2025.124964","url":null,"abstract":"<div><div>Oil-water separation is a vital process across various industries, where membrane separation stands out as a promising, energy-efficient solution. Despite its potential, the widespread application is hindered by the limited durability of existing membrane surface engineering effects. This study introduces an innovative fabrication strategy to create a superhydrophobic and durable nanofibrous membrane for efficient oil-water separation. Utilizing electrospinning and a two-step sequential covalent-bonding dip-coating process, the membrane was chemically decorated with vinyl trichlorosilane, followed by a thiol-ene “Click” reaction with 1H, 1H, 2H, 2H-perfluorodecanethiol, resulting in a stable superhydrophobic and oleophilic surface. The membrane exhibited high permeation fluxes for various organic solvents, achieving separation efficiencies exceeding 99.5 % for non-emulsified mixtures (oil:water = 1:1) and over 99.7 % for hydrocarbon oil/water emulsions (oil:water = 99:1). Furthermore, the membrane demonstrated remarkable stability, enduring multiple filtration cycles and harsh chemical environments, including extended exposure to NaOH solutions. To validate its industrial applicability, the nanofibrous membrane was employed in a membrane extraction process post amide synthesis, successfully separating dichloromethane and water, thereby streamlining the extraction process. This work showcases a robust membrane surface engineering strategy for efficient oil-water separation.</div></div>","PeriodicalId":368,"journal":{"name":"Journal of Membrane Science","volume":"740 ","pages":"Article 124964"},"PeriodicalIF":9.0,"publicationDate":"2025-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145578268","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 : 2025-11-19DOI: 10.1016/j.memsci.2025.124968
Menghao Liu , Jiwei Chen , Yanhong Ji , Zhenyu Cui , Jinjin Liu , Benqiao He
The water-soluble macromolecular porogens usually have a small amount of residue in the membrane material and would be slowly released to pose adverse effects for production ultrahigh-purity permeate. In this work, a reactive porogen, azodicarbonamide (AC), was used to prepare polyethersulfone (PES) hollow fiber loose nanofiltration membranes (LNF-HFM) with low DOC leaching for the first time in this work. NaOH solution was used as the core solution, coagulation bath, and post-treatment solutions. During the membrane formation, AC molecules were reacted with NaOH to generate nanobubbles and completely disappeared from the membranes. By adjusting the AC dosage, the structure and performance of the LNF-HFMs were modulated. It was found that M12 membrane exhibited an excellent separation performance with a pure water flux of 203.3 ± 1.6 L/(m2·h) and a rejection of 99.9 % for Congo Red. The rejection of 5 nm standard nano gold colloidal solutions was above 99.9 %. The DOC leaching from M12 was only about 1/9 from the membrane using PEG20000 (water-soluble macromolecules) as porogen, indicating that M12 released significantly less DOC. This work provides a novel strategy for preparing membranes with low DOC release.
{"title":"Preparation and performance of low dissolved organic carbon leaching hollow fiber loose nanofiltration membranes using a reactive porogen","authors":"Menghao Liu , Jiwei Chen , Yanhong Ji , Zhenyu Cui , Jinjin Liu , Benqiao He","doi":"10.1016/j.memsci.2025.124968","DOIUrl":"10.1016/j.memsci.2025.124968","url":null,"abstract":"<div><div>The water-soluble macromolecular porogens usually have a small amount of residue in the membrane material and would be slowly released to pose adverse effects for production ultrahigh-purity permeate. In this work, a reactive porogen, azodicarbonamide (AC), was used to prepare polyethersulfone (PES) hollow fiber loose nanofiltration membranes (LNF-HFM) with low DOC leaching for the first time in this work. NaOH solution was used as the core solution, coagulation bath, and post-treatment solutions. During the membrane formation, AC molecules were reacted with NaOH to generate nanobubbles and completely disappeared from the membranes. By adjusting the AC dosage, the structure and performance of the LNF-HFMs were modulated. It was found that M12 membrane exhibited an excellent separation performance with a pure water flux of 203.3 ± 1.6 L/(m<sup>2</sup>·h) and a rejection of 99.9 % for Congo Red. The rejection of 5 nm standard nano gold colloidal solutions was above 99.9 %. The DOC leaching from M12 was only about 1/9 from the membrane using PEG20000 (water-soluble macromolecules) as porogen, indicating that M12 released significantly less DOC. This work provides a novel strategy for preparing membranes with low DOC release.</div></div>","PeriodicalId":368,"journal":{"name":"Journal of Membrane Science","volume":"740 ","pages":"Article 124968"},"PeriodicalIF":9.0,"publicationDate":"2025-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145577882","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 : 2025-11-19DOI: 10.1016/j.memsci.2025.124972
Benfa Chu , Zhenle Gan , Xuhao Wei , Song Ge , Xu He , Zhongbiao Zhang , Chunli Song
Redox flow batteries (RFBs) hold great potential for large-scale sustainable energy storage, where ion exchange membranes serve as key components that critically influence energy efficiency and cycling stability. Nevertheless, the development of high-performance membranes via precise molecular engineering remains an outstanding challenge. Herein, we prepared two types of sulfonated polymers: poly(aryl indole ketone)s (SPAIKs) and poly(aryl indole sulfone)s (SPAIEs), by incorporating indole into poly(aryl ketone)s and precisely controlling the sulfonation degree. Benefiting from this structural design, an alkaline zinc-iron flow battery (AZIFB) delivers a cycling stability for more than 700 cycles (SPAIKs) and 500 cycles (SPAIEs) at 200 mA cm−2, along with an EE of above 85 %. The acidized membrane enables an acidic vanadium flow battery (VFB) to exhibit excellent performance, sustaining over 300 cycles (SPAIKs-H) and 150 cycles (SPAIEs-H) at 120 mA cm−2 with EE exceeding 80 %. In this study, we propose a cost-effective and straightforward fabrication approach for high-performance membranes applicable to a wide-pH-range redox flow batteries.
氧化还原液流电池（rfb）具有大规模可持续储能的巨大潜力，其中离子交换膜是影响能源效率和循环稳定性的关键部件。然而，通过精确的分子工程开发高性能膜仍然是一个突出的挑战。本文通过将吲哚掺入到聚芳基酮中，并精确控制磺化程度，制备了聚芳基吲哚酮（SPAIKs）和聚芳基吲哚砜（SPAIEs）两种磺化聚合物。得益于这种结构设计，碱性锌铁液流电池（AZIFB）在200 mA cm - 2下可提供超过700次循环（SPAIKs）和500次循环（SPAIEs）的循环稳定性，以及超过85%的EE。酸化膜使酸性钒液流电池（VFB）表现出优异的性能，在120 mA cm - 2下维持超过300次循环（SPAIKs-H）和150次循环（SPAIKs-H）， EE超过80%。在这项研究中，我们提出了一种成本效益高且直接的制造方法，用于适用于宽ph范围氧化还原液流电池的高性能膜。
{"title":"Molecular engineering of indole-stabilized membranes enables high-performance wide-pH-range redox flow batteries","authors":"Benfa Chu , Zhenle Gan , Xuhao Wei , Song Ge , Xu He , Zhongbiao Zhang , Chunli Song","doi":"10.1016/j.memsci.2025.124972","DOIUrl":"10.1016/j.memsci.2025.124972","url":null,"abstract":"<div><div>Redox flow batteries (RFBs) hold great potential for large-scale sustainable energy storage, where ion exchange membranes serve as key components that critically influence energy efficiency and cycling stability. Nevertheless, the development of high-performance membranes via precise molecular engineering remains an outstanding challenge. Herein, we prepared two types of sulfonated polymers: poly(aryl indole ketone)s (SPAIKs) and poly(aryl indole sulfone)s (SPAIEs), by incorporating indole into poly(aryl ketone)s and precisely controlling the sulfonation degree. Benefiting from this structural design, an alkaline zinc-iron flow battery (AZIFB) delivers a cycling stability for more than 700 cycles (SPAIKs) and 500 cycles (SPAIEs) at 200 mA cm<sup>−2</sup>, along with an EE of above 85 %. The acidized membrane enables an acidic vanadium flow battery (VFB) to exhibit excellent performance, sustaining over 300 cycles (SPAIKs-H) and 150 cycles (SPAIEs-H) at 120 mA cm<sup>−2</sup> with EE exceeding 80 %. In this study, we propose a cost-effective and straightforward fabrication approach for high-performance membranes applicable to a wide-pH-range redox flow batteries.</div></div>","PeriodicalId":368,"journal":{"name":"Journal of Membrane Science","volume":"740 ","pages":"Article 124972"},"PeriodicalIF":9.0,"publicationDate":"2025-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145621600","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 : 2025-11-18DOI: 10.1016/j.memsci.2025.124969
Kang Hee Yun, Seungbo Sim, Chorok Jeong, Ki Jun Jeong, Tae-Hyun Bae
The growing demand for reliable sterile filtration in pharmaceutical manufacturing underscores the need for advanced microfiltration (MF) membranes that ensure excellent bacterial removal while minimizing protein loss. This study demonstrates the importance of imparting hydrophilicity throughout the entire porous structure—not just the surface—to effectively suppress protein adsorption. Polyethersulfone (PES) membranes were fabricated via an optimized vapor-induced phase separation (VIPS) process to yield symmetric structures with a mean pore size of 0.22 μm, followed by functionalization with tannic acid (TA) coatings (TA-PES) or co-deposition of TA–silica nano-microspheres (TA/Si-PES). Both modified membranes achieved outstanding bacterial rejection (>99.99999 %), confirming their suitability for sterile filtration. The TA/Si-PES membrane exhibited superior antifouling performance, with minimal bovine serum albumin (BSA) adsorption and nearly complete flux recovery after simple water rinsing, whereas the TA-PES membrane showed moderate fouling control but limited stability during extended operation. These results highlight the TA/Si-PES membrane as a promising candidate for biopharmaceutical sterile filtration, offering robust bacterial removal, reduced protein loss, and improved long-term performance.
{"title":"Hydrophilic modification of PES microfiltration membranes via tannic acid/silica coating for enhanced sterile filtration","authors":"Kang Hee Yun, Seungbo Sim, Chorok Jeong, Ki Jun Jeong, Tae-Hyun Bae","doi":"10.1016/j.memsci.2025.124969","DOIUrl":"10.1016/j.memsci.2025.124969","url":null,"abstract":"<div><div>The growing demand for reliable sterile filtration in pharmaceutical manufacturing underscores the need for advanced microfiltration (MF) membranes that ensure excellent bacterial removal while minimizing protein loss. This study demonstrates the importance of imparting hydrophilicity throughout the entire porous structure—not just the surface—to effectively suppress protein adsorption. Polyethersulfone (PES) membranes were fabricated via an optimized vapor-induced phase separation (VIPS) process to yield symmetric structures with a mean pore size of 0.22 μm, followed by functionalization with tannic acid (TA) coatings (TA-PES) or co-deposition of TA–silica nano-microspheres (TA/Si-PES). Both modified membranes achieved outstanding bacterial rejection (>99.99999 %), confirming their suitability for sterile filtration. The TA/Si-PES membrane exhibited superior antifouling performance, with minimal bovine serum albumin (BSA) adsorption and nearly complete flux recovery after simple water rinsing, whereas the TA-PES membrane showed moderate fouling control but limited stability during extended operation. These results highlight the TA/Si-PES membrane as a promising candidate for biopharmaceutical sterile filtration, offering robust bacterial removal, reduced protein loss, and improved long-term performance.</div></div>","PeriodicalId":368,"journal":{"name":"Journal of Membrane Science","volume":"740 ","pages":"Article 124969"},"PeriodicalIF":9.0,"publicationDate":"2025-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145578269","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 : 2025-11-18DOI: 10.1016/j.memsci.2025.124970
Jingjing Kong , Anguo Xiao , Ning Qi , Zhiquan Chen
A series of carbon molecular sieve (CMS) membranes were prepared by crosslinkable rearrangable 6FDA-based polyimide precursors to study the effects of crosslinked and rearranged structures on the pore structure and gas separation performance of CMS membranes after pyrolysis. Fourier transform infrared (FT-IR) and thermogravimetric-mass spectrum (TG-MS) show that the precursor releases small molecules during pyrolysis to form an oxygen and nitrogen-containing aromatic heterocyclic structure. X-ray diffraction (XRD) showed that the stacking efficiency of the heterocyclic planar structure was improved with the decrease of the rearrangement part and the increase of the crosslinking part, resulting in the decrease of the chain spacing. Positron annihilation lifetime measurements reveal that the CMS membranes have similar structure with that of graphite containing high density of ultramicropores with size in the range of 5.7–6.1 Å. The size of ultramicropore decreases gradually with the increase of the crosslinking ratio, which is in agreement with the results of nitrogen adsorption and XRD measurements. Compared with the polyimide precursors, the gas permeability of the CMS membranes is greatly enhanced. The CMS-DABA-0 membrane has an ultra-high CO permeability up to 18,265 barrer. A positive correlation between the gas diffusivity and the ultramicropore volume of the CMS membranes was found. The gas permeability deteriorates with the increase in the crosslinking ratio, while the gas selectivity increases significantly. Notably the permeability selectivity of CO/N and CO/CH pairs in CMS-DABA-0.5 exceeds the 2019 upper bound due to the modulation of ultramicroporous structure by structure of PI precursors, suggesting the potential application of CMS membranes for future CO separation.
采用可交联重排的6fda基聚酰亚胺前驱体制备了一系列碳分子筛（CMS）膜，研究了交联和重排结构对CMS膜热解后孔隙结构和气体分离性能的影响。傅里叶红外（FT-IR）和热重质谱（TG-MS）分析表明，前驱体在热解过程中释放小分子，形成含氧、含氮的芳香杂环结构。x射线衍射（XRD）表明，杂环平面结构的堆积效率随着重排部分的减少和交联部分的增加而提高，导致链间距减小。正电子湮没寿命测量表明，CMS膜具有与石墨膜相似的结构，含有高密度的超微孔，尺寸在5.7 ~ 6.1 Å之间。随着交联率的增加，超微孔的尺寸逐渐减小，这与氮吸附和XRD测量结果一致。与聚酰亚胺前驱体相比，CMS膜的透气性大大提高。CMS-DABA-0膜具有高达18265巴的超高CO2渗透率。气体扩散率与CMS膜的超微孔体积呈正相关。随着交联率的增加，透气性变差，而气体选择性显著提高。值得注意的是，由于PI前驱体结构对超微孔结构的调制，CMS- daba -0.5中CO2/N2和CO2/CH4对的渗透选择性超过了2019年的上限，这表明CMS膜在未来CO2分离中的潜在应用。
{"title":"Tailored ultramicroporous structure in CMS membranes through crosslinking and rearrangement of polyimide precursor for efficient gas separation","authors":"Jingjing Kong , Anguo Xiao , Ning Qi , Zhiquan Chen","doi":"10.1016/j.memsci.2025.124970","DOIUrl":"10.1016/j.memsci.2025.124970","url":null,"abstract":"<div><div>A series of carbon molecular sieve (CMS) membranes were prepared by crosslinkable rearrangable 6FDA-based polyimide precursors to study the effects of crosslinked and rearranged structures on the pore structure and gas separation performance of CMS membranes after pyrolysis. Fourier transform infrared (FT-IR) and thermogravimetric-mass spectrum (TG-MS) show that the precursor releases small molecules during pyrolysis to form an oxygen and nitrogen-containing aromatic heterocyclic structure. X-ray diffraction (XRD) showed that the stacking efficiency of the heterocyclic planar structure was improved with the decrease of the rearrangement part and the increase of the crosslinking part, resulting in the decrease of the chain spacing. Positron annihilation lifetime measurements reveal that the CMS membranes have similar structure with that of graphite containing high density of ultramicropores with size in the range of 5.7–6.1 Å. The size of ultramicropore decreases gradually with the increase of the crosslinking ratio, which is in agreement with the results of nitrogen adsorption and XRD measurements. Compared with the polyimide precursors, the gas permeability of the CMS membranes is greatly enhanced. The CMS-DABA-0 membrane has an ultra-high CO<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> permeability up to 18,265 barrer. A positive correlation between the gas diffusivity and the ultramicropore volume of the CMS membranes was found. The gas permeability deteriorates with the increase in the crosslinking ratio, while the gas selectivity increases significantly. Notably the permeability selectivity of CO<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>/N<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> and CO<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>/CH<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span> pairs in CMS-DABA-0.5 exceeds the 2019 upper bound due to the modulation of ultramicroporous structure by structure of PI precursors, suggesting the potential application of CMS membranes for future CO<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> separation.</div></div>","PeriodicalId":368,"journal":{"name":"Journal of Membrane Science","volume":"740 ","pages":"Article 124970"},"PeriodicalIF":9.0,"publicationDate":"2025-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145578270","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 : 2025-11-18DOI: 10.1016/j.memsci.2025.124954
Jung Hun Han , Sang Yoon Song , Ju-Hyun Baek , Jeong Hoon Nam , Gunjick Lee , Jin-Yoo Suh , Seok Su Sohn
Vanadium-based alloys are promising candidates for hydrogen separation membranes due to their high hydrogen permeability and cost-effectiveness, but their practical application is hindered by hydrogen embrittlement and limited malleability. Among various alloy systems, dual-phase V–Cu alloys have emerged as promising alternatives, offering improved ductility and embrittlement resistance. However, while compositional design has been extensively investigated, the influence of thermally induced microstructural evolution on hydrogen transport remains insufficiently understood. In this study, a V76Cu15Ni2Al7 (at%) alloy was systematically examined to clarify how post-deformation annealing at 600–800 °C affects dislocation density, grain boundary character, and Cu precipitate morphology, and how these microstructural changes govern hydrogen diffusivity, solubility, and embrittlement behavior. Progressive recovery and partial recrystallization reduced dislocation density, while Cu precipitates underwent spheroidization and redistribution. These changes markedly enhanced hydrogen diffusivity (from 0.23 to 2.45 × 10−9 m2 s−1 at 400 °C) and permeability, while slightly reducing total solubility. Furthermore, the reduced hardness mismatch between the V and Cu phases alleviated interfacial stress concentration, thereby improving resistance to hydrogen embrittlement. Notably, membranes annealed at 800 °C maintained stable hydrogen permeation down to 125 °C without fracture. These findings establish that recovery, recrystallization, and precipitate redistribution are key microstructural levers for optimizing both hydrogen transport and long-term durability in V-based hydrogen separation membranes.
{"title":"Recovery and recrystallization effects on hydrogen transport behavior of V–Cu–Ni–Al hydrogen separation membranes","authors":"Jung Hun Han , Sang Yoon Song , Ju-Hyun Baek , Jeong Hoon Nam , Gunjick Lee , Jin-Yoo Suh , Seok Su Sohn","doi":"10.1016/j.memsci.2025.124954","DOIUrl":"10.1016/j.memsci.2025.124954","url":null,"abstract":"<div><div>Vanadium-based alloys are promising candidates for hydrogen separation membranes due to their high hydrogen permeability and cost-effectiveness, but their practical application is hindered by hydrogen embrittlement and limited malleability. Among various alloy systems, dual-phase V–Cu alloys have emerged as promising alternatives, offering improved ductility and embrittlement resistance. However, while compositional design has been extensively investigated, the influence of thermally induced microstructural evolution on hydrogen transport remains insufficiently understood. In this study, a V<sub>76</sub>Cu<sub>15</sub>Ni<sub>2</sub>Al<sub>7</sub> (at%) alloy was systematically examined to clarify how post-deformation annealing at 600–800 °C affects dislocation density, grain boundary character, and Cu precipitate morphology, and how these microstructural changes govern hydrogen diffusivity, solubility, and embrittlement behavior. Progressive recovery and partial recrystallization reduced dislocation density, while Cu precipitates underwent spheroidization and redistribution. These changes markedly enhanced hydrogen diffusivity (from 0.23 to 2.45 × 10<sup>−9</sup> m<sup>2</sup> s<sup>−1</sup> at 400 °C) and permeability, while slightly reducing total solubility. Furthermore, the reduced hardness mismatch between the V and Cu phases alleviated interfacial stress concentration, thereby improving resistance to hydrogen embrittlement. Notably, membranes annealed at 800 °C maintained stable hydrogen permeation down to 125 °C without fracture. These findings establish that recovery, recrystallization, and precipitate redistribution are key microstructural levers for optimizing both hydrogen transport and long-term durability in V-based hydrogen separation membranes.</div></div>","PeriodicalId":368,"journal":{"name":"Journal of Membrane Science","volume":"740 ","pages":"Article 124954"},"PeriodicalIF":9.0,"publicationDate":"2025-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145577877","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 : 2025-11-17DOI: 10.1016/j.memsci.2025.124966
Chaoyi Ma , Hui Yang , Shuyun Gu , Linlong Zhou , Siyao Li , Zhi Xu
Membrane-based separation presents a promising and energy-efficient alternative to conventional energy-intensive processes for separation in hydrocarbon systems. However, the current practical application of membrane separation is hindered by the poor stability and insufficient sieving capability in non-polar organic solvents. In this work, a series of aldehyde monomers with tunable alkyl side chains were adopted and combined with tetrahedral amine monomer to prepare covalent organic polymer nanofilms with sub-10 nm thickness via interfacial polymerization. The extension of alkyl side chains precisely regulated the pore nanostructure and chemical properties of the membranes, optimizing transport pathways for hydrocarbons. The resulting TAM-C4 nanofilm demonstrated an exceptional solvent permeance in hydrocarbon systems, with a toluene permeance of 23.9 L m−2 h−1 bar−1 and a hexane permeance of 22.0 L m−2 h−1 bar−1, while maintaining accurate molecular sieving for small molecules with molecular weight <440 Da. Moreover, the TAM-C4 nanofilm achieved 5.2-fold enrichment of active pharmaceutical ingredients within 5 h, outperforming commercial membranes due to its remarkable selectivity and efficient solvent transport capabilities in hexane. Their tunable nanostructure and robust separation performance position them as promising alternatives for separating small molecules in hydrocarbon systems, offering a feasible energy-saving separation method for pharmaceutical industry.
膜基分离为碳氢化合物系统中传统的能源密集型分离工艺提供了一种有前途的、节能的替代方法。然而，膜分离在非极性有机溶剂中的稳定性差、筛分能力不足，阻碍了目前膜分离的实际应用。本研究采用一系列烷基侧链可调的醛类单体与四面体胺单体结合，通过界面聚合制备了厚度在10 nm以下的共价有机聚合物纳米膜。烷基侧链的延伸精确地调节了膜的孔纳米结构和化学性质，优化了碳氢化合物的运输途径。所得TAM-C4纳米膜在碳氢化合物体系中表现出优异的溶剂渗透性，甲苯的渗透性为23.9 L m−2 h−1 bar−1，己烷的渗透性为22.0 L m−2 h−1 bar−1，同时对分子量为440 Da的小分子保持精确的分子筛分。此外，TAM-C4纳米膜在5小时内实现了5.2倍的活性药物成分富集，优于商业膜，因为它具有显著的选择性和高效的己烷溶剂运输能力。其可调的纳米结构和强大的分离性能使其成为分离碳氢化合物系统中小分子的有希望的替代品，为制药工业提供了一种可行的节能分离方法。
{"title":"Ultrathin alkyl-chain functionalized covalent organic polymer nanofilms for separation in hydrocarbon system","authors":"Chaoyi Ma , Hui Yang , Shuyun Gu , Linlong Zhou , Siyao Li , Zhi Xu","doi":"10.1016/j.memsci.2025.124966","DOIUrl":"10.1016/j.memsci.2025.124966","url":null,"abstract":"<div><div>Membrane-based separation presents a promising and energy-efficient alternative to conventional energy-intensive processes for separation in hydrocarbon systems. However, the current practical application of membrane separation is hindered by the poor stability and insufficient sieving capability in non-polar organic solvents. In this work, a series of aldehyde monomers with tunable alkyl side chains were adopted and combined with tetrahedral amine monomer to prepare covalent organic polymer nanofilms with sub-10 nm thickness via interfacial polymerization. The extension of alkyl side chains precisely regulated the pore nanostructure and chemical properties of the membranes, optimizing transport pathways for hydrocarbons. The resulting TAM-C4 nanofilm demonstrated an exceptional solvent permeance in hydrocarbon systems, with a toluene permeance of 23.9 L m<sup>−2</sup> h<sup>−1</sup> bar<sup>−1</sup> and a hexane permeance of 22.0 L m<sup>−2</sup> h<sup>−1</sup> bar<sup>−1</sup>, while maintaining accurate molecular sieving for small molecules with molecular weight <440 Da. Moreover, the TAM-C4 nanofilm achieved 5.2-fold enrichment of active pharmaceutical ingredients within 5 h, outperforming commercial membranes due to its remarkable selectivity and efficient solvent transport capabilities in hexane. Their tunable nanostructure and robust separation performance position them as promising alternatives for separating small molecules in hydrocarbon systems, offering a feasible energy-saving separation method for pharmaceutical industry.</div></div>","PeriodicalId":368,"journal":{"name":"Journal of Membrane Science","volume":"740 ","pages":"Article 124966"},"PeriodicalIF":9.0,"publicationDate":"2025-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145621597","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 : 2025-11-17DOI: 10.1016/j.memsci.2025.124962
Junxia Deng , Wei Guo , Congcong Wu , Aqib Riaz , Xingfeng Lei , Xiaohua Ma
Precisely controlling the properties of carbon molecular sieve membranes (CMSMs) is a major challenge in developing advanced gas separation membranes. Here, a series of high-performance CMSMs for gas separation were prepared by adjusting the crosslinking density of polyimide precursors. These precursors were synthesized by introducing a three-dimensional 2,6,13(14)-triamino-triptycene as a crosslinker at different content. After carbonization at 550 °C, the resulting CMSMs showed an increased specific surface area (744–829 m2 g−1), pore volume (0.31–0.39 cm3 g−1 Å−1), and pore size (5.07–5.27 Å) as the crosslinking density of the precursor increased from 0 to 10 %. As a result, the SPI-10 %-CMS membrane demonstrated a fivefold higher CO2 permeability (21,638 vs. 3688 Barrer) than that of the SPI-0 %-CMS membrane, while maintained a high CO2/CH4 selectivity of 47.1. Its overall performance surpassed the latest 2019 trade-off curve. Moreover, wonderful mixed-gas separation properties were observed for the SPI-5 %-CMS membrane, which showed a CO2 permeability of 6692 Barrer and CO2/CH4 selectivity of 51.5 even under the upstream CO2/CH4 mixed-gas pressure of 15 bar (1 bar = 100,000 Pa), outperforming the latest 2018 CO2/CH4 mixed-gas upper limit. It showed 5 times enhanced CO2 permeability while maintain high selectivity of SPI-10 %-CMS, which is attributed to the crosslinked precursor improved micropore volume during carbonization step that increases the diffusion and solubility coefficient. Conclusively, increasing the crosslinking density of the polyimide precursor is a viable strategy for developing high-performance CMSMs.
{"title":"Enhanced gas separation performance of carbon molecular sieve membranes by increasing the crosslinking density of polyimide precursors","authors":"Junxia Deng , Wei Guo , Congcong Wu , Aqib Riaz , Xingfeng Lei , Xiaohua Ma","doi":"10.1016/j.memsci.2025.124962","DOIUrl":"10.1016/j.memsci.2025.124962","url":null,"abstract":"<div><div>Precisely controlling the properties of carbon molecular sieve membranes (CMSMs) is a major challenge in developing advanced gas separation membranes. Here, a series of high-performance CMSMs for gas separation were prepared by adjusting the crosslinking density of polyimide precursors. These precursors were synthesized by introducing a three-dimensional 2,6,13(14)-triamino-triptycene as a crosslinker at different content. After carbonization at 550 °C, the resulting CMSMs showed an increased specific surface area (744–829 m<sup>2</sup> g<sup>−1</sup>), pore volume (0.31–0.39 cm<sup>3</sup> g<sup>−1</sup> Å<sup>−1</sup>), and pore size (5.07–5.27 Å) as the crosslinking density of the precursor increased from 0 to 10 %. As a result, the SPI-10 %-CMS membrane demonstrated a fivefold higher CO<sub>2</sub> permeability (21,638 vs. 3688 Barrer) than that of the SPI-0 %-CMS membrane, while maintained a high CO<sub>2</sub>/CH<sub>4</sub> selectivity of 47.1. Its overall performance surpassed the latest 2019 trade-off curve. Moreover, wonderful mixed-gas separation properties were observed for the SPI-5 %-CMS membrane, which showed a CO<sub>2</sub> permeability of 6692 Barrer and CO<sub>2</sub>/CH<sub>4</sub> selectivity of 51.5 even under the upstream CO<sub>2</sub>/CH<sub>4</sub> mixed-gas pressure of 15 bar (1 bar = 100,000 Pa), outperforming the latest 2018 CO<sub>2</sub>/CH<sub>4</sub> mixed-gas upper limit. It showed 5 times enhanced CO<sub>2</sub> permeability while maintain high selectivity of SPI-10 %-CMS, which is attributed to the crosslinked precursor improved micropore volume during carbonization step that increases the diffusion and solubility coefficient. Conclusively, increasing the crosslinking density of the polyimide precursor is a viable strategy for developing high-performance CMSMs.</div></div>","PeriodicalId":368,"journal":{"name":"Journal of Membrane Science","volume":"740 ","pages":"Article 124962"},"PeriodicalIF":9.0,"publicationDate":"2025-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145578267","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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