Journal of Membrane Science最新文献

{"title":"Impact of the porous support disc of a gas permeation cell on the estimation of the membrane transport properties","authors":"Zheng Cao,&nbsp;Boguslaw Kruczek,&nbsp;Jules Thibault","doi":"10.1016/j.memsci.2025.123831","DOIUrl":"10.1016/j.memsci.2025.123831","url":null,"abstract":"<div><div>The rapid development of polymeric membranes for gas separation requires an accurate and suitable method for promptly assessing their performance. The time-lag method is one of the most commonly used methods to estimate the permeation parameters (permeability, diffusivity, and solubility) of single gases in membranes. However, a membrane is not evaluated in isolation; it is placed in a permeation cell, which may impact the determination of these parameters. This paper explores the effect of using a porous support disc on estimating the membrane permeation parameters. The impact of a porous disc supporting an ideal membrane was assessed by solving Fick's second law of diffusion. Results clearly show that the membrane thickness, along with the pore size and the porosity of the porous disc, may significantly influence the estimation of the diffusivity and permeability of the membrane using the time-lag method. Interestingly, the observed effect was not dependent on the intrinsic diffusivity of the membrane. The relative diffusivity and relative permeability are strictly a function of the porosity of the porous disc and the ratio of the pore diameter to the membrane thickness. Results can be used to correct the impact of the porous plate and recover the intrinsic membrane properties.</div></div>","PeriodicalId":368,"journal":{"name":"Journal of Membrane Science","volume":"721 ","pages":"Article 123831"},"PeriodicalIF":8.4,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143419379","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":"Molecule transport behaviors in ultrathin and porous membranes: The role of pore size","authors":"Aokun Li ,&nbsp;Siyu Liu ,&nbsp;Ruilong Li ,&nbsp;Jingjing Chen ,&nbsp;Chongchong Chen ,&nbsp;Jie Zhang ,&nbsp;Wenpeng Li ,&nbsp;Xiaoli Wu ,&nbsp;Jingtao Wang","doi":"10.1016/j.memsci.2025.123835","DOIUrl":"10.1016/j.memsci.2025.123835","url":null,"abstract":"<div><div>Ultrathin (&lt;100 nm) and porous membranes exhibit rapid molecule transport due to the high porosity and short transport path. However, molecule transport behaviors in terms of pore size (<em>r</em>) remain unclear. Herein, four kinds of porous MOF membranes with ultrathin thickness (∼20 nm) are prepared on the support layers. The pore sizes of MOF membranes are subtly adjusted (0.66, 0.81, 1.12, and 1.90 nm) by selecting carboxyl ligands with varied benzene-ring numbers. Based on these platforms, we demonstrate that the transport of both polar and non-polar molecules obeys the typical Hagen-Poiseuille model for ultrathin membrane with pore size larger than 1.0 nm. The permeance of solvents obeys <span><math><mrow><mi>P</mi><mo>=</mo><msub><mi>k</mi><mn>1</mn></msub><mfrac><msup><mi>r</mi><mn>4</mn></msup><mi>μ</mi></mfrac></mrow></math></span> (<em>μ</em>, viscosity; <em>k</em>_{<em>1,1.90</em>} = 126.84 and <em>k</em>_{<em>1,1.12</em>} = 580.64). In contrast, for the pore size smaller than 1.0 nm, other factors such as molecule polarity and diameter count. Specifically, for the membrane with pore size of 0.81 nm, the transport of polar and non-polar molecules follows the Hagen-Poiseuille model, but with distinct slopes: <span><math><mrow><mi>P</mi><mo>=</mo><msub><mi>k</mi><mn>2</mn></msub><mfrac><msup><mi>r</mi><mn>4</mn></msup><mi>μ</mi></mfrac></mrow></math></span> and <span><math><mrow><mi>P</mi><mo>=</mo><msub><mi>k</mi><mn>3</mn></msub><mfrac><msup><mi>r</mi><mn>4</mn></msup><mi>μ</mi></mfrac></mrow></math></span>, respectively. While for the membrane with pore size of 0.66 nm, new phenomenal equations are respectively proposed to describe the transport of polar and non-polar molecules. The permeance of polar and non-polar solvents obeys <span><math><mrow><mi>P</mi><mo>=</mo><msub><mi>k</mi><mn>4</mn></msub><mfrac><msup><mi>r</mi><mn>4</mn></msup><mrow><msup><mi>R</mi><mn>2</mn></msup><mi>D</mi><mi>μ</mi></mrow></mfrac></mrow></math></span> and <span><math><mrow><mi>P</mi><mo>=</mo><msub><mi>k</mi><mn>5</mn></msub><mfrac><msup><mi>r</mi><mn>4</mn></msup><mrow><msup><mi>R</mi><mn>2</mn></msup><mi>μ</mi></mrow></mfrac></mrow></math></span>, respectively (<em>R</em> and <em>D</em> represent molecule diameter and dipole moment, respectively). These findings should shed light on the molecule transport mechanism in porous and ultrathin membranes with confined nanochannels.</div></div>","PeriodicalId":368,"journal":{"name":"Journal of Membrane Science","volume":"721 ","pages":"Article 123835"},"PeriodicalIF":8.4,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143395265","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":"Broad range thickness dependence of gas separation properties for carbon molecular sieve membranes based on a hydroxyl-functionalized microporous polyimide","authors":"Wojciech Ogieglo ,&nbsp;Tiara Puspasari ,&nbsp;Merza Al Karam,&nbsp;Yingge Wang,&nbsp;Xiaofan Hu,&nbsp;Ingo Pinnau","doi":"10.1016/j.memsci.2025.123828","DOIUrl":"10.1016/j.memsci.2025.123828","url":null,"abstract":"<div><div>Carbon molecular sieves (CMS) are a promising class of membrane materials that exhibit excellent gas separation properties originating from their well-developed structures containing micropores (&lt;20 Å), ultramicropores (&lt;7 Å) and submicropores (&lt;4 Å). In the first stage of a membrane development process CMS materials are usually characterized in form of thick (50–100 μm), self-standing isotropic membrane films. For practical applications, however, CMS materials need to be converted into thin, selective layers with thicknesses on the order of several micrometers or less. Reduction of the film thickness can often lead to significant differences in the gas separation performance of the CMS materials similar to the well-known deviations from bulk behavior found in glassy polymers (e.g. glass transition temperatures, density, chain dynamics, physical aging rate, etc.). However, despite its practical importance the thickness-dependence of CMS membranes has been rarely studied systematically. Here, we present a detailed study of the gas separation properties of CMS films derived from a promising intrinsically microporous polyimide precursor (6FDA-HTB) over a broad thickness range of 0.55–100 μm, including free standing (10–100 μm) and supported &lt;1 μm samples. This allows us to directly compare the properties of thick, self-standing films with those of thin, supported films representative of practical CMS membranes. Our results indicate a strong but relatively regular reduction of permeability with decreasing film thickness that suggests a similar mechanism of microporosity evolution for thick and thin films. Despite the reduction of permeability, the thin films still possess quite favorable combinations of permeances and selectivities even after 28 days of physical aging, e.g. O₂/N₂ &gt; 8, O₂ permeance ∼20–30 GPU, CO₂/CH₄ &gt; 100, CO₂ permeance ∼150–300 GPU. The presented results are of significant importance for the design of efficient molecularly sieving membranes based on amorphous microporous CMS materials.</div></div>","PeriodicalId":368,"journal":{"name":"Journal of Membrane Science","volume":"721 ","pages":"Article 123828"},"PeriodicalIF":8.4,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143419279","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 synthesis of Prussian blue@MXene membranes for high-efficient ion sieving in desalination","authors":"Jian Zhao ,&nbsp;Tao Liu ,&nbsp;Guozhen Liu ,&nbsp;Danfeng Jiang ,&nbsp;Yingguo Li ,&nbsp;Xiao Chen ,&nbsp;Zhenyu Chu ,&nbsp;Chao Yu ,&nbsp;Gongping Liu ,&nbsp;Wanqin Jin","doi":"10.1016/j.memsci.2025.123832","DOIUrl":"10.1016/j.memsci.2025.123832","url":null,"abstract":"<div><div>Two-dimensional (2D) materials membranes show great potential for water desalination, whose performance can be further improved by introducing nanoporous crystals into the narrow and tortuous interlayer channels. Here, we constructed a new membrane using Prussian blue (PB)@MXene nanosheets synthesized in situ at room temperature as building blocks, presenting a significantly enhanced water desalination performance. Briefly, the negatively charged MXene nanosheets anchored Fe³⁺ as nucleation sites through electrostatic interactions, and then coordinated with [Fe(CN)₆]^4- at room temperature to produce PB crystals. By utilizing microfluidic synthesis approach, the residence time and reaction amount of Fe³⁺ and [Fe(CN)₆]^4- in the flow channel were precisely controlled, which was beneficial for regulating crystal size to tune the interlayer spacing. The membranes were fabricated by vacuum filtration of PB@MXene nanosheets on the surface of porous substrate. The resulting PB@MXene membrane exhibited an enhanced water permeance of up to 61.6 mol m⁻² h⁻¹ and salt rejection of 98.1 %, increasing by 63.4 % and 13.9 % respectively compared with those of MXene membrane. Interestingly, the iron ions could be replaced with other metal ions such as cobalt and nickel atoms, to generate Prussian blue analogs, thereby varying the pore size of crystal to improve water permeance. Such a facile fabrication approach for PB@MXene membranes provides new insights into the development of advanced materials to construct 2D membrane for desalination.</div></div>","PeriodicalId":368,"journal":{"name":"Journal of Membrane Science","volume":"721 ","pages":"Article 123832"},"PeriodicalIF":8.4,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143419280","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":"Bio-inspired AS1411-Functionalized membrane for specific and non-destructive capture of tumor cells","authors":"Yangyang Li ,&nbsp;Riyue Shu ,&nbsp;Cheng Zeng ,&nbsp;Jing Wang ,&nbsp;Lin Zhang ,&nbsp;Zhe Tang","doi":"10.1016/j.memsci.2025.123833","DOIUrl":"10.1016/j.memsci.2025.123833","url":null,"abstract":"<div><div>The morphological characteristics of tumor cells can provide valuable visual insights into the degree of cell differentiation, which is crucial for accurate cancer grading and diagnosis. The development of biomaterials that can selectively capture these cells while preserving their morphology is essential for advancing cancer diagnosis and treatment. However, designing anti-adhesion biomaterials that possess the ability to capture tumor cells and maintain their structure is still a challenge. Inspired by the dynamic interactions between extracellular matrix and cellular receptors, we propose a versatile nanofibrous membrane functionalized with aptamers and protein binding. Fabricated through a facile polydopamine (PDA) coating on a polyurethane (PU) membrane, this platform provides a bioactive surface for binding functional molecules. The covalent chemistry of PDA allows for the binding of streptavidin (SA) and bovine serum albumin (BSA), forming a highly hydrophilic BSA/SA/PDA@PU membrane. Subsequently, a biotin-modified aptamer (AS1411), which specifically targets tumor cells, were further bound with SA to obtain the AS/BSA/SA/PDA@PU membrane. This modified membrane demonstrates high specificity in capturing tumor cells while preserving cell morphology, providing a promising approach for enhanced cancer diagnostics and therapeutic interventions.</div></div>","PeriodicalId":368,"journal":{"name":"Journal of Membrane Science","volume":"721 ","pages":"Article 123833"},"PeriodicalIF":8.4,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143419278","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":"Organic solvent nanofiltration membranes with tunable selectivity using meta-aramid supports: Effects of PDMS coating, interfacial polymerization, and hybrid PDMS-interfacial polymerization process","authors":"Eun-Bi Kim ,&nbsp;Da-Seul Lim ,&nbsp;Hee Joo ,&nbsp;Hye-Jin Lee ,&nbsp;Hak-Yong Lee ,&nbsp;Ho Bum Park ,&nbsp;Jae-Chang Lee ,&nbsp;Suwan Myung","doi":"10.1016/j.memsci.2025.123824","DOIUrl":"10.1016/j.memsci.2025.123824","url":null,"abstract":"<div><div>Organic solvent nanofiltration (OSN) membranes face significant challenges in maintaining chemical stability and separation performance, particularly in solvents with diverse polarities, viscosities, and molar volumes. To address these limitations, this study developed three types of OSN membranes using hydrophilic meta-aramid–based supports, renowned for their exceptional solvent resistance. Distinct fabrication methods, including dip-coating, interfacial polymerization (IP), and a hybrid approach combining both techniques, were employed to tailor membrane properties for diverse separation applications. The dip-coated membrane with polydimethylsiloxane (PDMS) exhibited high permeance in low-viscosity solvents, including hexane (36.2 Lm⁻²h⁻¹ bar⁻¹), ethyl acetate (30.3 Lm⁻²h⁻¹ bar⁻¹), acetone (21.6 Lm⁻²h⁻¹ bar⁻¹), and toluene (26.9 Lm⁻²h⁻¹ bar⁻¹), with an MWCO of 980 g mol⁻¹ in acetone, making it suitable for separating solutes in such systems. The IP-fabricated membrane, utilizing piperazine and trimesoyl chloride, demonstrated superior separation performance in high-polarity solvents, such as acetonitrile (2.2 Lm⁻²h⁻¹ bar⁻¹) and methanol (1.6 Lm⁻²h⁻¹ bar⁻¹), as well as in water (3.3 Lm⁻²h⁻¹ bar⁻¹), achieving an MWCO of 275 g mol⁻¹ in acetone. Lastly, the hybrid membrane, combining PDMS coating with interfacial polymerization (IP), offered tunable MWCOs ranging from 624 to 248 g mol⁻¹, while maintaining high permeance in solvents such as acetone (1.5 Lm⁻²h⁻¹ bar⁻¹), acetonitrile (0.8 Lm⁻²h⁻¹ bar⁻¹), and ethyl acetate (0.7 Lm⁻²h⁻¹ bar⁻¹), demonstrating its versatility for a wide range of separation applications. This study provides critical insights into the design and optimization of meta-aramid–based OSN membranes, highlighting their potential to enable precise and efficient separation in pharmaceutical, chemical, and industrial applications.</div></div>","PeriodicalId":368,"journal":{"name":"Journal of Membrane Science","volume":"721 ","pages":"Article 123824"},"PeriodicalIF":8.4,"publicationDate":"2025-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143387989","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"3D simulation of the electrodialysis process. Unobvious spacer filaments placement to increase the limiting current","authors":"Mikhail Petryakov ,&nbsp;Andrey Gorobchenko ,&nbsp;Artem Mareev ,&nbsp;Ilya Moroz ,&nbsp;Andrey Kislyi ,&nbsp;Vikky Anand ,&nbsp;Semyon Mareev","doi":"10.1016/j.memsci.2025.123829","DOIUrl":"10.1016/j.memsci.2025.123829","url":null,"abstract":"<div><div>In the electrodialysis process, the concentration polarization phenomenon determines the value of the limiting current density and, consequently, significantly affects energy consumption. Commercial spacers are commonly used to mix the solution and enhance ion delivery to ion-exchange membranes, and its shape has a crucial impact on the electrodialysis optimization. The target features of spacers development are better mixing and lower shadow effect.</div><div>In a binary NaCl electrolyte solution with different diffusion coefficients of ions (<em>D</em>_Na≈1.5 <em>D</em>_Cl) the limiting current is determined by the cation-exchange membrane, according to Peers' equation, because its counterion has the minimal value of <em>D</em> in the solution. Recently using 2D simulation and corresponding experiment it was found that the limiting current of an electrodialysis channel with NaCl solution may be increased by displacing the spacer filaments towards the anion-exchange membrane. This arrangement increases the flow velocity of the solution near the surface of the cation-exchange membrane, thus, thereby reducing the boundary layer thickness near it.</div><div>In this work, using 3D simulation, we investigated several types of spacers. For the first time, an unobvious result was found: displacing the filaments toward the cation-exchange membrane in NaCl solution leads to an increase in the total limiting current and the effect is more pronounced then in the case of displacement toward the anion-exchange membrane. It is theoretically shown that in 3D systems, better solution mixing and ion delivery may be achieved in nonintuitive ways and the comprehensive analysis should be done to predict the system behavior.</div></div>","PeriodicalId":368,"journal":{"name":"Journal of Membrane Science","volume":"721 ","pages":"Article 123829"},"PeriodicalIF":8.4,"publicationDate":"2025-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143419377","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":"Polyamide-based nanofiltration membranes with acicular leaf-like structure for rapid and selective separation of mono-divalent salts","authors":"Bo Zhu ,&nbsp;Tiefan Huang ,&nbsp;Lelin Zeng ,&nbsp;Nan Li ,&nbsp;Zhiwei Xu ,&nbsp;Jianxian Zeng ,&nbsp;Hu Zhou","doi":"10.1016/j.memsci.2025.123822","DOIUrl":"10.1016/j.memsci.2025.123822","url":null,"abstract":"<div><div>Conventional polyamide-based nanofiltration (NF) membranes frequently encounter significant trade-off constraints between selectivity and permeability, which impedes their widespread adoption. In this study, we present a method for the construction of membrane surfaces with regular acicular leaf-like structures via interfacial polymerization reactions. This approach involves the induction of KCl crystal growth and the sacrifice of crystal templates, resulting in the formation of NF membranes with enhanced water permeability and pleasing mono-divalent salts selectivity. The molecular dynamics simulation and the observation of the membrane surface morphology revealed that the orderly grown KCl crystal templates successfully helped to form a regular acicular leaf-like structure on the membrane surface after the sacrificial treatment. As a result, polyamide-based NF membranes with a high permeable area were produced. The enhanced permeable area, diminished membrane thickness, and concentrated pore size distribution were identified as the key factors for the high permeability of 14.6 LMH/bar. And the mono-divalent salts separation coefficients (α(NaCl/Na₂SO₄)) of the membranes reached 97.8, which is outstanding compared to most currently reported polyamide-based NF membranes. The ultrahigh permselectivity NF membranes prepared by means of crystal template sacrifice are expected to provide a powerful aid for ion separation, desalination and drinking water treatment.</div></div>","PeriodicalId":368,"journal":{"name":"Journal of Membrane Science","volume":"721 ","pages":"Article 123822"},"PeriodicalIF":8.4,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143378790","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":"Effect of substrate pore size and physical gelation on the performance of BTESE-derived silica membranes for gas separation","authors":"Xiaoheng Jin,&nbsp;Derrick Ng,&nbsp;Xing Wu,&nbsp;Durga Acharya,&nbsp;Celesta Fong,&nbsp;Zongli Xie","doi":"10.1016/j.memsci.2025.123826","DOIUrl":"10.1016/j.memsci.2025.123826","url":null,"abstract":"<div><div>Hydrogen-selective membranes are pivotal in advancing sustainable energy technologies. Organosilica, due to its hydrothermal stability, has shown promise as a gas separation membrane, but its fabrication requires stringent substrate pore control. This study investigates the influence of substrate pore size and rheological property on bis(triethoxysilyl)ethane (BTESE)-derived membranes. Through sol-gel synthesis modifications, including surfactant-induced gelation, pore filling was reduced while gas selectivity was enhanced on larger-pore substrates (20–50 nm). Rheological analyses confirmed that interparticle force modulation enables shear thickening behavior and results in defect-free membranes with superior hydrogen sieving. These findings expand the scope of BTESE-derived silica membranes for industrial gas separation, highlighting the role of substrate interaction and rheological control in membrane performance.</div></div>","PeriodicalId":368,"journal":{"name":"Journal of Membrane Science","volume":"721 ","pages":"Article 123826"},"PeriodicalIF":8.4,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143419285","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ion uptake and pairing in membranes: The pore model","authors":"Viatcheslav Freger","doi":"10.1016/j.memsci.2025.123795","DOIUrl":"10.1016/j.memsci.2025.123795","url":null,"abstract":"<div><div>Ion uptake plays a critical role in membrane separations used for water purification and electro-membrane processes. Although models of ion uptake usually consider free dissociated ions, ion-pairing was suggested to play an important role as well and but its understanding in the context of membrane transport is still insufficient. The paper systematically develops the pore model of ion-pairing in membranes, which considers the membrane as a micro-heterogeneous system, composed of interspersed water-rich domains (pores accommodating ions) and a low-dielectric matrix. It is shown that this picture significantly departs from the predictions of the primitive model of the membrane as a uniform dielectric, in which dielectric exclusion and pairing of ions are rigidly related thus pairing of mobile ions is always negligible. Within the pore model, the effect of the ion-pairing constant enhanced by the low-dielectric properties of the matrix may outweigh the opposite effect of dielectric exclusion thereby mobile ions may be present within the membrane mainly as ion-pairs rather than free ions. We discuss various implications of this result for salt and ion uptake, transport, and conductance in neutral and charged membranes and outline needs for further research towards predictive modeling.</div></div>","PeriodicalId":368,"journal":{"name":"Journal of Membrane Science","volume":"722 ","pages":"Article 123795"},"PeriodicalIF":8.4,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143445883","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}