Membranes and Membrane Technologies最新文献

{"title":"Effect of Titanosilicate Mineral Natisite on Gas Transport Properties of Copolyimide P84","authors":"A. E. Mukhin,&nbsp;G. A. Polotskaya,&nbsp;E. B. Lodonova,&nbsp;I. S. Kuryndin,&nbsp;V. N. Yakovenchuk,&nbsp;G. O. Kalashnikova,&nbsp;A. Yu. Pulyalina","doi":"10.1134/S2517751625600037","DOIUrl":"10.1134/S2517751625600037","url":null,"abstract":"<p>The development of membrane processes requires new materials for the fabrication of highly efficient membranes. In this work, a composite based on copolyimide P84 with a novel modifier, the titanosilicate mineral natisite, used an additive has been created. For this purpose, natisite has been synthesized and identified. The composite P84/natisite (5 wt %) prepared in a DMF solution was used to obtain a flat film membrane. The physicochemical, mechanical, and gas transport properties of the P84/natisite membrane were studied in comparison with the P84 membrane. The transport properties were evaluated by the permeability of the membranes to He, O₂, N₂, and CO₂. The gas permeability through the membranes made of the composite is lower than that of the pure P84 membrane, and the H₂/N₂, CO₂/N₂, and O₂/N₂ selectivities are improved by including the modifier natisite. It is shown that the presence of 5 wt % natisite does not significantly alter the mechanical properties of the P84/natisite (5%) membrane, which meet the performance requirements.</p>","PeriodicalId":700,"journal":{"name":"Membranes and Membrane Technologies","volume":"6 6","pages":"424 - 432"},"PeriodicalIF":2.0,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143645634","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of Feed Solution pH on Efficiency of Electrodialysis Extraction of Tartrates","authors":"O. A. Yurchenko,&nbsp;K. V. Solonchenko,&nbsp;N. D. Pismenskaya","doi":"10.1134/S2517751625600049","DOIUrl":"10.1134/S2517751625600049","url":null,"abstract":"<p>Resource-efficient and environmentally sustainable electrodialysis (ED) is increasingly being used for the separation and purification of organic acids, including the extraction of their anions from wines, juices, and biochemically processed waste products. In this study, tartaric acid transport through the CJMA-3 anion-exchange membrane was investigated using voltammetry, chronopotentiometry, and ED experiments. It was shown that when using a Na_<i>x</i>H_{(2–<i>x</i>)}T solution at pH 9.0, which contains only divalent tartrate anions T²⁻, the transport patterns are similar to those well-known for strong electrolytes. However, at pH 2.5 or 3.0, the solution contains a mixture of undissociated tartaric acid molecules H₂T and monovalent anions HT⁻. Upon entering the membrane, some of the HT⁻ anions dissociate. Protons are expelled into the depleted solution due to the Donnan effect, while the newly formed divalent anions T²⁻ migrate through the CJMA-3 membrane. The reduction in HT⁻ concentration near the membrane stimulates the irreversible dissociation of H₂T. Under the influence of the electric field, protons are removed from the reaction zone and migrate into the solution, while anions move into the membrane. Thus, tartrate transport through the anion-exchange membrane occurs even when the feed solution primarily contains undissociated acid molecules. These mechanisms lead to empirical limiting currents significantly exceeding theoretical limiting current values. The energy consumption for extracting 20% of tartrates from a 0.022 M Na_<i>x</i>H_{(2–<i>x</i>)}T solution is 0.22 (pH 9.0), 0.32 (pH 3.0), and 0.57 kWh/kg (pH 2.5). The duration of ED increases in the following order: pH 3.0 <span>( ll )</span> pH 9.0 &lt; pH 2.5.</p>","PeriodicalId":700,"journal":{"name":"Membranes and Membrane Technologies","volume":"6 6","pages":"449 - 462"},"PeriodicalIF":2.0,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143645423","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structural Properties and Gas Permeation for PTMSP Films Treated by Elemental Fluorine in Liquid Perfluorodecalin","authors":"N. A. Belov,&nbsp;A. Yu. Alentiev,&nbsp;R. Yu. Nikiforov,&nbsp;D. A. Syrtsova,&nbsp;V. P. Makrushin,&nbsp;S. M. Matson,&nbsp;E. A. Skryleva,&nbsp;A. I. Gaidar,&nbsp;V. E. Ryzhikh","doi":"10.1134/S2517751625600104","DOIUrl":"10.1134/S2517751625600104","url":null,"abstract":"<p>A one-sided modification of homogeneous poly(1-trimethylsilylpropyne) (PTMSP) films was carried out by the method of liquid-phase fluorination with elemental fluorine in perfluorodecalin medium. The structure of the initial and modified samples was studied by X-ray photoelectron spectroscopy (XPS) and cross-sections of fluorinated films were tested by scanning electron microscopy (SEM). The differential gas chromatographic method was used to obtain the transport and separation characteristics of the studied samples for O₂, N₂, CO₂, CH₄, He, H₂. Fluorination of PTMSP films was shown to occur not only in the near-surface layer of the sample, but also to a depth of up to 50 µm. It was found that the gas permeability of the fluorinated films decreases, while the change in the flow through the membrane depends on the size of the penetrant molecule, as a result there is a significant increase in the selectivity of fluorinated PTMSP samples for H₂–CO₂, H₂–CH₄, H₂–N₂ and O₂–N₂ pairs relative to the virgin polymer. It was shown that in the process of liquid-phase fluorination PTMSP films are saturated with perfluorodecalin, which leads to a significant decrease in gas permeability. An approach is proposed to increase the flow of gases through a fluorinated membrane by removing perfluorodecalin by holding samples in hexafluorobenzene, leading to a significant increase in gas permeability while maintaining selectivity. The gas separation data for fluorinated PTMSP films after treatment in hexafluorobenzene are located significantly above the upper bound of 2008 in the permeability-selectivity plots. Thus, the method of liquid-phase fluorination followed by hexafluorobenzene treatment leads to a significant improvement in the gas separation characteristics of PTMSP.</p>","PeriodicalId":700,"journal":{"name":"Membranes and Membrane Technologies","volume":"6 6","pages":"409 - 423"},"PeriodicalIF":2.0,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143645532","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Treatment of Waste Solutions from Electrolytic-Plasma Polishing Decontamination to Remove Cr(III) Radionuclide Using Ultrafiltration Membranes","authors":"V. V. Torapava,&nbsp;A. M. Zaruba,&nbsp;D. A. Kazimirsky,&nbsp;A. V. Radkevich,&nbsp;P. K. Nahula,&nbsp;A. V. Bildyukevich,&nbsp;T. A. Hliavitskaya","doi":"10.1134/S2517751624600936","DOIUrl":"10.1134/S2517751624600936","url":null,"abstract":"<p>The paper presents the results of using ultrafiltration for purification of solutions simulating liquid radioactive waste, produced during decontamination of parts by electrolytic-plasma treatment, to remove chromium(III) radionuclides (⁵¹Cr(III)). The main performance characteristics and transport properties of ultrafiltration membranes made of hydrophilized polysulfone, polyethersulfone, and regenerated cellulose with different molecular weight cutoff (MWCO) values have been determined. The dependences of membrane flux and ⁵¹Cr(III) rejection coefficient on the pH of solutions and thermostatting time have been established. It has been shown that in 8% (NH₄)₂SO₄ solution at pH 7–8, the ⁵¹Cr(III) radionuclide occurs in the form of polynuclear hydroxo complexes, which are retained by ultrafiltration membranes and precipitate during centrifugation. A regenerated-cellulose membrane with MWCO = 10 is the most effective, rejecting ∼97% of ⁵¹Cr(III) at pH 8. Increasing the time of solution thermostatting before membrane separation leads to an increase in the rejection of ⁵¹Cr(III) due to a deeper hydrolysis process with the formation of polynuclear hydroxo complexes.</p>","PeriodicalId":700,"journal":{"name":"Membranes and Membrane Technologies","volume":"6 6","pages":"463 - 472"},"PeriodicalIF":2.0,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143645414","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Transport Properties of MF-4SK Perfluorinated Membranes Modified with Zirconium Hydrogen Phosphate","authors":"I. V. Falina,&nbsp;E. E. Meshcheryakova,&nbsp;K. M. Lyapishev,&nbsp;K. S. Demidenko,&nbsp;E. V. Titskaya,&nbsp;S. V. Timofeev,&nbsp;N. A. Kononenko","doi":"10.1134/S2517751624600948","DOIUrl":"10.1134/S2517751624600948","url":null,"abstract":"<p>The physicochemical and transport characteristics of cast and extruded MF-4SK perfluorinated membranes modified with zirconium hydrogen phosphate in an amount of 3–10% are studied. The inorganic phase is formed directly in the membrane volume by the pore-filling method. The effect of zirconium hydrogen phosphate content on the ion-exchange capacity, water content, diffusion permeability for electrolyte solution, hydrogen gas permeability, and electrical conductivity at the limited humidity of the MF-4SK membrane, as well as the efficiency of its use in a low-temperature proton-exchange membrane fuel cell, are investigated. A nonmonotonic change in the transport characteristics depending on the dopant content is demonstrated. The lowest diffusion permeability and maximum electrical conductivity at low humidity are exhibited by the membrane containing 6% of zirconium hydrogen phosphate. It is shown that zirconium hydrogen phosphate-modified membranes show promise as a polymer electrolyte in a hydrogen-air fuel cell membrane-electrode assembly due to a 17% higher maximum specific power compared to the original MF‑4SK membrane. This fact can be explained by an almost twofold lower ohmic resistance and reduced contribution of kinetic limitations of the membrane-electrode assembly (MEA) with the modified membranes, compared to the unmodified membrane, revealed by analysis of its impedance spectra.</p>","PeriodicalId":700,"journal":{"name":"Membranes and Membrane Technologies","volume":"6 6","pages":"383 - 390"},"PeriodicalIF":2.0,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143645419","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Li3–2xNbxCr2–x(PO4)3 Complex Phosphates with the NASICON Structure: Synthesis and Ionic Conductivity","authors":"S. A. Novikova,&nbsp;A. B. Yaroslavtsev","doi":"10.1134/S2517751624600924","DOIUrl":"10.1134/S2517751624600924","url":null,"abstract":"<p>One of the main trends in the development of metal-ion batteries concerns the transition to lithium anodes, the safe use of which is impossible without replacing liquid membranes with solid ones, primarily inorganic membranes. Lithium–niobium–chromium phosphates with calculated compositions Li_{3–2<i>x</i>}Nb_<i>x</i>Cr_2–<i>x</i>(PO₄)₃ (<i>х</i> = 0.95, 1.00, 1.05) were obtained by solid-state synthesis and characterized by XRD analysis and impedance spectroscopy. The obtained complex lithium-niobium-chromium phosphates with the NASICON structure crystallize in hexagonal modification. The unit cell parameters of crystal lattice of the synthesized materials decrease with increasing chromium content. The highest ionic conductivity and the lowest activation energy are exhibited by the material of composition Li_1.1Nb_0.95Cr_1.05(PO₄)₃ (3 × 10^–5 S/cm at 25°С), which indicates a greater mobility of lithium ions by the interstitial mechanism even in the region of its own disorderliness.</p>","PeriodicalId":700,"journal":{"name":"Membranes and Membrane Technologies","volume":"6 6","pages":"433 - 438"},"PeriodicalIF":2.0,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143645421","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of Operations of MF-4SC Membrane In Situ Modification with Zirconium Hydrogen Phosphate on Its Transport Properties and PEMFC Characteristics","authors":"J. Loza,&nbsp;N. Loza,&nbsp;I. Falina","doi":"10.1134/S2517751624600729","DOIUrl":"10.1134/S2517751624600729","url":null,"abstract":"<p>This work is aimed at studying the characteristics of a homogeneous perfluorinated membrane at various stages of introducing zirconium hydrogen phosphate (ZrHP) in situ. A sample modified with ZrHP by pore-filling method, a sample processed the same as the first one, excluding treating with ZrHP precursor solution, and a sample of initial membrane are studied. A significant increase in the diffusion permeability and specific conductivity of the membrane in the solutions of hydrochloric acid after its treatment with heated immersion solutions is observed. This effect reduces after ZrHP nanoparticles appearance. The transport-structural parameters of the microheterogeneous model have been calculated. Both the internal equilibrium solution volume and the mobility of coions and counterions in the gel phase increase after treating with immersion solutions, due to greater swelling of the gel phase in alcohols. The specific power density of the PEMFC MEA with the ZrHP-modified membrane used as a polymeric electrolyte is significantly lower compared to the initial membrane, but annealing the membrane compensates this effect.</p>","PeriodicalId":700,"journal":{"name":"Membranes and Membrane Technologies","volume":"6 6","pages":"391 - 399"},"PeriodicalIF":2.0,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143645418","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hydrogen Permeability through Surface-Modified Pd76Ag14Au10 Membranes","authors":"P. D. Pushankina,&nbsp;A. I. Simonov,&nbsp;S. S. Dzhimak,&nbsp;I. S. Petriev","doi":"10.1134/S2517751624600900","DOIUrl":"10.1134/S2517751624600900","url":null,"abstract":"<p>t—Palladium-containing membranes are used for hydrogen separation and purification. However, for sufficiently thin membranes permeation flux can be limited by the kinetics of surface processes. In the present study, in order to overcome the limitation of transition through the surface, the developed Pd₇₆Ag₁₄Au₁₀ alloy membranes were modified with a nanostructured surface layer. The modification was carried out by the deposition of penta-branched bimetallic Pd–Pt nanoparticles on the membrane surface. An increase in hydrogen flux was observed in a wide temperature range (25–400°C). The highest values of permeation flux density were demonstrated for membranes with a penta-branched modifier, up to 52.43 mmol s^–1 m^–2 at 400°С. It is assumed that the complex morphology of the nanoparticles, as well as the presence of synergistic effect from the combination of Pd and Pt, contribute to a decrease in activation barriers and an increase in catalytic activity. The developed membranes demonstrated high and stable selectivity over time, which opens up wide possibilities for their use in steam reforming reactors for producing high-purity hydrogen.</p>","PeriodicalId":700,"journal":{"name":"Membranes and Membrane Technologies","volume":"6 6","pages":"400 - 408"},"PeriodicalIF":2.0,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143645635","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Selective Limiting Concentration of Electrolyte Solutions with Singly and Doubly Charged Cations","authors":"N. O. Kovalchuk,&nbsp;A. A. Minenko,&nbsp;N. A. Romanyuk,&nbsp;N. V. Smirnova,&nbsp;S. A. Loza,&nbsp;V. I. Zabolotsky","doi":"10.1134/S2517751625600050","DOIUrl":"10.1134/S2517751625600050","url":null,"abstract":"<p>The effect of the anion-exchange layer of the copolymer <i>N</i>,<i>N</i>-diallyl-<i>N</i>,<i>N</i>-dimethylammonium chloride and ethyl methacrylate on the electrochemical properties of a homogeneous cation-exchange membrane based on perfluorosulfonic polymer has been studied. The application of a modifying layer with a thickness of 5 µm onto a 215 µm-thick membrane leads to a reduction in electrical conductivity by no more than 35%, while the diffusion permeability decreases more than fivefold and becomes independent of concentration. During testing of both cation-exchange and bilayer membranes in the process of limiting concentration of sodium chloride solution, comparable degrees of concentration have been achieved. The effectiveness of the bilayer membrane for selective limiting electrodialysis concentration has been demonstrated. When concentrating a solution containing sodium and calcium chlorides, the specific selective permeability coefficient <i>P</i>(Na⁺/Ca²⁺) for the cation-exchange membrane has ranged from 0.5 to 1.2. The use of the bilayer membrane significantly increase the specific selective permeability coefficient to 1.5–2.7, depending on the current density, allowing for efficient separation of electrolytes containing singly and doubly charged cations.</p>","PeriodicalId":700,"journal":{"name":"Membranes and Membrane Technologies","volume":"6 6","pages":"439 - 448"},"PeriodicalIF":2.0,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143645420","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"PVDF Membrane Formation via NIPS in Isothermal and Non-Isothermal Conditions: Thermodynamics, Structure, and Properties","authors":"K. V. Pochivalov,&nbsp;A. V. Basko,&nbsp;T. N. Lebedeva,&nbsp;M. Y. Yurov,&nbsp;A. A. Yushkin,&nbsp;S. V. Bronnikov,&nbsp;A. V. Volkov","doi":"10.1134/S2517751625600074","DOIUrl":"10.1134/S2517751625600074","url":null,"abstract":"<p>Previously published experimental data and new data on cloud points were used to plot ternary phase diagram with temperature axis for the poly(vinylidene fluoride) (PVDF)–dimethyl acetamide (DMAc)–water system. The topology of the plotted diagram is different from the published previously. It shows that an increase in temperature leads to a shift of the boundary curves (liquid equilibrium binodal, polymer crystallization curve and swelling curve) to the composition range enriched by the non-solvent. At the same time, a decrease in temperature leads to degeneration of liquid equilibrium binodal. Taking into account the plotted diagram, the expected morphologies of the membranes prepared via non-solvent induced phase separation (NIPS) in both isothermal and non-isothermal conditions were derived. Morphology and properties of the samples prepared from the dope solution of defined composition via NIPS at different temperatures and via thermally assisted non-solvent induced phase separation, T-NIPS (or NIPS in non-isothermal conditions) were studied. It was shown that an increase in temperature leads to formation of cellular structure, resulting from the liquid–liquid phase separation; a decrease in through pore size and improvement of the mechanical properties. Decrease in pore size from 110 to 35 nm accompanied with decrease in permeance from 8.1 to 0.25 L/(m² h bar) and increase in blue dextran rejection from 20 to 94%. A decrease in temperature changes the structure formation process from liquid–liquid phase separation (induced by the mass transfer processes) to solid–liquid phase separation (induced by temperature decrease). In the T-NIPS process (cooling) layers with finger-like pores and sponge-like structure between them, with spherulites surrounded by sponge-like structure and with spherulites connected with each other were formed in the structure of the membrane. T-NIPS process allows to obtain membranes with permeance 6.1 L/(m² h bar) and Blue dextran rejection of 91%.</p>","PeriodicalId":700,"journal":{"name":"Membranes and Membrane Technologies","volume":"6 6","pages":"473 - 490"},"PeriodicalIF":2.0,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143645424","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}