Mixed-Matrix Membranes and Polymeric Membranes

A special issue of Membranes (ISSN 2077-0375). This special issue belongs to the section "Polymeric Membranes".

Deadline for manuscript submissions: closed (31 July 2022) | Viewed by 55214

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Guest Editor
Department of Chemical and Biomolecular Engineering, Sogang University, 35, Baekbeom-ro, Mapo-gu, Seoul 04107, Republic of Korea
Interests: organic and inorganic membranes; membrane nanostructure; bipolar membranes; biopolymer membranes; ion-conducting membranes; energy storage devices; fuel cell; reverse electrodialysis
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Special Issue Information

Dear Colleague,

The industrial application of polymeric membranes is increasing significantly day by day and has tremendous potential for delivering an efficient separation process. It has been almost 50 years since the first successful membrane was commercially utilized in the gas separation process. Considerable progress has been made in the development of high-performance membranes for separation and purification processes. Mixed-matrix membranes are a type of high-performance membrane technology that has taken the membrane separation process to new heights. It is essential to tune the physical and chemical properties of the polymeric material to enhance the perm-selectivity and efficient ion transport capacity. It is necessary to optimize the nano-material size and shape the polymer matrix to achieve a better interface. Therefore, several parameters must be taken into consideration for the development of a high homogeneity filler and matrix. This is the biggest challenge for researchers in order to overcome the poor selectivity of ions and mechanical strength under stress conditions. Enormous efforts have been made to identify highly compatible organic or inorganic fillers for the development of high-performance membranes for various applications.

The prime objective of this Special Issue is to provide a platform that allows authors to publish their findings on the nanoengineering aspects of mixed-matrix membranes. Authors working in designing advanced membrane material for separation and purification processes or energy storage applications can submit their findings to this issue. This issue will cover fundamental concepts and theories behind selecting appropriate filler material for use in a polymer matrix. Papers dealing with experimental observations or theoretical calculations for developing a defect-free interface between fillers andpolymer matrices are most welcome.

Dr. Rahul Singh
Guest Editor

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Keywords

  • mixed-matrix membrane
  • porous framework
  • organic fillers
  • inorganic fillers
  • polymer electrolyte membrane
  • ion separation
  • purification
  • electrochemical systems

Published Papers (21 papers)

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29 pages, 6975 KiB  
Article
Development and Investigation of Hierarchically Structured Thin-Film Nanocomposite Membranes from Polyamide/Chitosan Succinate Embedded with a Metal-Organic Framework (Fe-BTC) for Pervaporation
by Tatiana Plisko, Katsiaryna Burts, Andrey Zolotarev, Alexandr Bildyukevich, Mariia Dmitrenko, Anna Kuzminova, Sergey Ermakov and Anastasia Penkova
Membranes 2022, 12(10), 967; https://doi.org/10.3390/membranes12100967 - 2 Oct 2022
Cited by 5 | Viewed by 1727
Abstract
Thin-film composite membranes (TFC) obtained by the formation of a selective layer on a porous membrane-substrate via interfacial polymerization (IP) are indispensable for separation procedures in reverse osmosis, nanofiltration, pervaporation, and gas separation. Achieving high selectivity and permeability for TFC membranes is still [...] Read more.
Thin-film composite membranes (TFC) obtained by the formation of a selective layer on a porous membrane-substrate via interfacial polymerization (IP) are indispensable for separation procedures in reverse osmosis, nanofiltration, pervaporation, and gas separation. Achieving high selectivity and permeability for TFC membranes is still one of the main challenges in membrane science and technology. This study focuses on the development of thin film nanocomposite (TFN) membranes with a hierarchically structured polyamide (PA)/chitosan succinate (ChS) selective layer embedded with a metal–organic framework of iron 1,3,5-benzenetricarboxylate (Fe-BTC) for the enhanced pervaporation dehydration of isopropanol. The aim of this work was to study the effect of Fe-BTC incorporation into the ChS interlayer and PA selective layer, obtained via IP, on the structure, properties, and performance of pervaporation TFN membranes. The structure and hydrophilicity of the developed TFN membranes were investigated using scanning electron microscopy (SEM) and atomic force microscopy (AFM), along with water contact angle measurements. The developed TFN membranes were studied in the pervaporation dehydration of isopropanol (12–30 wt % water). It was found that incorporation of Fe-BTC into the ChS interlayer yielded the formation of a smoother, more uniform, and defect-free PA ultrathin selective layer via IP, due to the amorpho-crystalline structure of particles serving as the amine storage reservoir and led to an increase in membrane selectivity toward water, and a slight decrease in permeation flux compared to the ChS interlayered TFC membranes. The best pervaporation performance was demonstrated by the TFN membrane with a ChS-Fe-BTC interlayer and the addition of 0.03 wt % Fe-BTC in the PA layer, yielding a permeation flux of 197–826 g·m−2·h−1 and 98.50–99.99 wt % water in the permeate, in the pervaporation separation of isopropanol/water mixtures (12–30 wt % water). Full article
(This article belongs to the Special Issue Mixed-Matrix Membranes and Polymeric Membranes)
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15 pages, 4135 KiB  
Article
Chemical and Physical Ionic Liquids in CO2 Capture System Using Membrane Vacuum Regeneration
by José Manuel Vadillo, Guillermo Díaz-Sainz, Lucía Gómez-Coma, Aurora Garea and Angel Irabien
Membranes 2022, 12(8), 785; https://doi.org/10.3390/membranes12080785 - 15 Aug 2022
Cited by 7 | Viewed by 1889
Abstract
Carbon Capture Utilization and Storage technologies are essential mitigation options to reach net-zero CO2 emissions. However, this challenge requires the development of sustainable and economic separation technologies. This work presents a novel CO2 capture technology strategy based on non-dispersive CO2 [...] Read more.
Carbon Capture Utilization and Storage technologies are essential mitigation options to reach net-zero CO2 emissions. However, this challenge requires the development of sustainable and economic separation technologies. This work presents a novel CO2 capture technology strategy based on non-dispersive CO2 absorption and membrane vacuum regeneration (MVR) technology, and employs two imidazolium ionic liquids (ILs), [emim][Ac] and [emim][MS], with different behavior to absorb CO2. Continuous absorption–desorption experiments were carried out using polypropylene hollow fiber membrane contactors. The results show the highest desorption behavior in the case of [emim][Ac], with a MVR performance efficiency of 92% at 313 K and vacuum pressure of 0.04 bar. On the other hand, the IL [emim][MS] reached an efficiency of 83% under the same conditions. The MVR technology could increase the overall CO2 capture performance by up to 61% for [emim][Ac] and 21% for [emim][MS], which represents an increase of 26% and 9%, respectively. Moreover, adding 30%vol. demonstrates that the process was only favorable by using the physical IL. The results presented here indicate the interest in membrane vacuum regeneration technology based on chemical ILs, but further techno-economic evaluation is needed to ensure the competitiveness of this novel CO2 desorption approach for large-scale application. Full article
(This article belongs to the Special Issue Mixed-Matrix Membranes and Polymeric Membranes)
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16 pages, 9000 KiB  
Article
The Effect of Solution Casting Temperature and Ultrasound Treatment on PEBAX MH-1657/ZIF-8 Mixed Matrix Membranes Morphology and Performance
by Elsa Lasseuguette, Louise Fielder-Dunton, Qian Jian and Maria-Chiara Ferrari
Membranes 2022, 12(6), 584; https://doi.org/10.3390/membranes12060584 - 31 May 2022
Cited by 4 | Viewed by 2206
Abstract
Approximately two-thirds of anthropogenic emissions causing global warming are from carbon dioxide. Carbon capture is essential, with membranes proving to be a low cost and energy-efficient solution to alternative technologies. In particular, mixed matrix membranes (MMMs) can have higher permeability and selectivity than [...] Read more.
Approximately two-thirds of anthropogenic emissions causing global warming are from carbon dioxide. Carbon capture is essential, with membranes proving to be a low cost and energy-efficient solution to alternative technologies. In particular, mixed matrix membranes (MMMs) can have higher permeability and selectivity than pure polymer membranes. The fabrication conditions affect the formation of defects within the membranes. In this work, MMMs were created using a PEBAX MH-1657 polymer and a ZIF-8 filler. The effect of casting plate temperature, varying from −5 °C to 50 °C, and the effect of ultrasound treatment time (80–400 min) and method (filler solution only, filler and polymer combined solution only and filler solution followed by combined solution) were investigated, aiming to reduce defect formations hence improving the performance of the MMMs. SEM images and permeation tests using pure CO2 and N2 gas, replicating flue gas for carbon capture, were used to investigate and compare the membranes morphology and performance. The results indicated that the MMMs maintained their permeabilities and selectivities at all tested casting temperatures. However, the neat PEBAX membranes demonstrated increased phase separation of the polyamide and polyether oxide phases at higher temperatures, causing a reduction in permeability due to the higher crystallinity degree, confirmed by DSC experiment. The MMMs fabricated at low ultrasound times displayed a large amount of aggregation with large particle size causing channeling. At high ultrasound times, a well-dispersed filler with small filler diameters was observed, providing a high membrane performance. Overall, defect-free membranes were successfully fabricated, leading to improved performance, with the best membrane resulting from the longest ultrasound time reaching the Robeson bound upper limits. Full article
(This article belongs to the Special Issue Mixed-Matrix Membranes and Polymeric Membranes)
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10 pages, 3993 KiB  
Article
Dual-Structure PVDF/SDS Nanofibrous Membranes for Highly Efficient Personal Protection in Mines
by Gang Zhou, Rulin Liu, Qingfeng Xu, Kaili Wang, Yongmei Wang and Seeram Ramakrishna
Membranes 2022, 12(5), 482; https://doi.org/10.3390/membranes12050482 - 29 Apr 2022
Cited by 1 | Viewed by 1741
Abstract
Pneumoconiosis in miners is considered a global problem. Improving the performance of individual protective materials can effectively reduce the incidence of pneumoconiosis. In this study, the blend membrane of sodium dodecyl sulfate and polyvinylidene fluoride with a dual structure was prepared using electrospinning [...] Read more.
Pneumoconiosis in miners is considered a global problem. Improving the performance of individual protective materials can effectively reduce the incidence of pneumoconiosis. In this study, the blend membrane of sodium dodecyl sulfate and polyvinylidene fluoride with a dual structure was prepared using electrospinning techniques, and the morphological structure, fiber diameter, and filtration performance of the nanofiber membranes were optimized by adjusting the PVDF concentration and SDS content. The results show that the incorporation of SDS enabled the nanofiber membranes to show tree-like and beaded fibers. Compared with the original PVDF membrane, the small content of tree-like fibers and beaded fibers can improve the filtration efficiency and reduce the resistance of the fiber membrane. The prepared nanofiber membrane has excellent comprehensive filtration performance, and the quality factor is 0.042 pa1 when the concentration of PVDF is 10 wt% and the addition of SDS is 0.1 wt%. Furthermore, after high-temperature treatment, the membrane could still maintain good filtration performance. The PVDF/SDS blend nanofiber membrane has outstanding filtration efficiency and good thermal stability and can fully meet the personal protection of miners in underground high-temperature operation environments. Full article
(This article belongs to the Special Issue Mixed-Matrix Membranes and Polymeric Membranes)
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16 pages, 3560 KiB  
Article
Development of Chitosan/Rice Husk-Based Silica Composite Membranes for Biodiesel Purification
by Saiful, Ulfa Riana, Muliadi Ramli, Muhammad Iqrammullah, Yanuardi Raharjo and Yusuf Wibisono
Membranes 2022, 12(4), 435; https://doi.org/10.3390/membranes12040435 - 17 Apr 2022
Cited by 6 | Viewed by 2429
Abstract
Inorganic–organic composite membranes (IOCMs) are an alternative separation method developed for their straightforward process, economic benefits, and ease of scaling up. The IOCMs in this study were prepared from a biopolymer chitosan matrix and rice husk-based silica filler to remove impurities from crude [...] Read more.
Inorganic–organic composite membranes (IOCMs) are an alternative separation method developed for their straightforward process, economic benefits, and ease of scaling up. The IOCMs in this study were prepared from a biopolymer chitosan matrix and rice husk-based silica filler to remove impurities from crude biodiesel. The IOCMs were prepared through phase inversions, in which the priorly prepared silica particles were dispersed in the dope solution of chitosan. The maximum loading of the silica particles was 60%, capable of reducing the soap level, free glycerol level, and acid number from 547.9 to 12.2 mg/L, 54 to 0.041%, and 2.02 to 1.12 mgKOH/g. These reduced impurity values have satisfied the standardized quality. The chemical composition and morphology of the IOCM was characterized using Fourier-transform infrared spectroscopy and scanning electron microscope–energy dispersive X-Ray spectroscopy. The IOCM water absorption-based porosity and swelling degree were studied as well. Further investigation using isothermal modeling revealed the adsorption dependency against the Sips model equation (R2 = 0.99 and root-mean-square errors = 1.77 × 10−8). Even though regeneration is still a challenging factor in this study, the IOCM prepared from chitosan and rice husk-derived silica particles could be used in crude biodiesel purification. Full article
(This article belongs to the Special Issue Mixed-Matrix Membranes and Polymeric Membranes)
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19 pages, 5911 KiB  
Article
Supported Liquid Membranes Based on Bifunctional Ionic Liquids for Selective Recovery of Gallium
by Haitao Zhou, Yuxi Ye, Yuefei Tan, Kailun Zhu, Xinmin Liu, Hongjing Tian, Qingjie Guo, Lingyun Wang, Shuju Zhao and Yang Liu
Membranes 2022, 12(4), 376; https://doi.org/10.3390/membranes12040376 - 30 Mar 2022
Cited by 5 | Viewed by 1759
Abstract
In this work, separation and recovery of gallium from aqueous solutions was examined using acid-base bifunctional ionic liquids (Bif-ILs) in both solvent extraction and supported liquid membrane (SLM) processes. The influence of a variety of parameters, such as feed acidity, extractant concentration and [...] Read more.
In this work, separation and recovery of gallium from aqueous solutions was examined using acid-base bifunctional ionic liquids (Bif-ILs) in both solvent extraction and supported liquid membrane (SLM) processes. The influence of a variety of parameters, such as feed acidity, extractant concentration and metal concentration on the solvent extraction behavior were evaluated. The slope method combined with FTIR spectroscopy was utilized to determine possible extraction mechanisms. The SLM containing Bif-ILs demonstrated highly selective facilitated transport of 96.2% Ga(III) from feed to stripping solution after optimization. During the evaluation of the separation performance of SLM for the transport of Ga(III), in the presence of Al(III), Mg(II), Cu(II) and Fe(II), 88.5% Ga(III) could be transported with only 6% Fe(II) and a nil quantity of other metals co-transported. SLM exhibited excellent long-time stability in five repeated transport cycles. Highly selective transport and separation performance was achieved using the SLM containing Bif-ILs, indicating considerable potential for application in Ga(III) recovery. Full article
(This article belongs to the Special Issue Mixed-Matrix Membranes and Polymeric Membranes)
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17 pages, 26053 KiB  
Article
Preparation of Polyvinylidene Fluoride Nano-Filtration Membranes Modified with Functionalized Graphene Oxide for Textile Dye Removal
by Hirra Ahmad, Muhammad Zahid, Zulfiqar Ahmad Rehan, Anum Rashid, Saba Akram, Meshari M. H. Aljohani, Syed Khalid Mustafa, Tayyaba Khalid, Nader R. Abdelsalam, Rehab Y. Ghareeb and Mohammad S. AL-Harbi
Membranes 2022, 12(2), 224; https://doi.org/10.3390/membranes12020224 - 15 Feb 2022
Cited by 16 | Viewed by 2961
Abstract
Water scarcity has become one of the most significant problems globally. Membrane technology has gained considerable attention in water treatment technologies. Polymeric nanocomposite membranes are based on several properties, with enhanced water flux, high hydrophilicity and anti-biofouling behavior, improving the membrane performance, flexibility, [...] Read more.
Water scarcity has become one of the most significant problems globally. Membrane technology has gained considerable attention in water treatment technologies. Polymeric nanocomposite membranes are based on several properties, with enhanced water flux, high hydrophilicity and anti-biofouling behavior, improving the membrane performance, flexibility, cost-effectiveness and excellent separation properties. In this study, aminated graphene oxide (NH2-GO)-based PVDF membranes were fabricated using a phase-inversion method for textile dye removal. These fabricated membranes showed the highest water flux at about 170.2 (J/L.h−1.m−2) and 98.2% BSA rejection. Moreover, these membranes removed about 96.6% and 88.5% of methylene blue and methyl orange, respectively. Aminated graphene oxide-based polyvinylidene fluoride (PVDF) membranes emerge as a good membrane material that enhances the membrane performance. Full article
(This article belongs to the Special Issue Mixed-Matrix Membranes and Polymeric Membranes)
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16 pages, 6230 KiB  
Article
Preparation and Separation Properties of Electrospinning Modified Membrane with Ionic Liquid Terminating Polyimide/Polyvinylpyrrolidone@Polydopamine
by Peng Qi, Hongge Jia, Shuangping Xu, Qingji Wang, Guiming Su, Guoxing Yang, Mingyu Zhang, Yanqing Qu and Fuying Pei
Membranes 2022, 12(2), 189; https://doi.org/10.3390/membranes12020189 - 5 Feb 2022
Cited by 3 | Viewed by 2003
Abstract
In this paper, superhydrophilic polyimide (PI) membranes were prepared using the electrostatic spinning method, capped with a hydrophilic ionic liquid (IL), and blended with polyvinylpyrrolidone (PVP). Using this preparation, the surface of the fiber membranes was coated in polydopamine (PDA) by means of [...] Read more.
In this paper, superhydrophilic polyimide (PI) membranes were prepared using the electrostatic spinning method, capped with a hydrophilic ionic liquid (IL), and blended with polyvinylpyrrolidone (PVP). Using this preparation, the surface of the fiber membranes was coated in polydopamine (PDA) by means of an in-growth method. Scanning electron micrographs showed prepared blend films can form continuous fibers, for whom the distributions of diameter and pore were uniform. Post-modification (carried out by adding hydrophilic substances), the ability of the membrane surface to adhere to water was also significantly improved. The water contact angle was reduced from 128.97 ± 3.86° in unmodified PI to 30.26 ± 2.16°. In addition, they displayed a good separation effect on emulsified oil/water mixtures. The membrane flux reached a maximum value of 290 L·m−2·h−1, with a maximum separation efficiency reached of more than 99%. After being recycled 10 times, the separation efficiency maintained a level exceeding 95%. The purpose of this study is to demonstrate the simplicity and efficiency of this experiment, thereby providing new ideas for the future application of membrane separation technology in wastewater treatment. Full article
(This article belongs to the Special Issue Mixed-Matrix Membranes and Polymeric Membranes)
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18 pages, 3123 KiB  
Article
Optimal Water Backwashing Condition in Combined Water Treatment of Alumina Microfiltration and PP Beads
by Hyungmin Cho, Gihoon Yoon, Minjae Kim and Jin Yong Park
Membranes 2022, 12(1), 92; https://doi.org/10.3390/membranes12010092 - 15 Jan 2022
Cited by 2 | Viewed by 1832
Abstract
Membrane fouling is a dominant limit of the membrane separation process. In this research, the optimal water backwashing to solve the membrane fouling problem was investigated in the combined water treatment process of alumina MF and pure polypropylene (PP) beads. Additionally, the influence [...] Read more.
Membrane fouling is a dominant limit of the membrane separation process. In this research, the optimal water backwashing to solve the membrane fouling problem was investigated in the combined water treatment process of alumina MF and pure polypropylene (PP) beads. Additionally, the influence of membrane shape (tubular or seven channel) was examined, depending on the water backwashing period. The optimal backwashing time (BT) could be 20 s in the combined water treatment process, because of the highest total treated volume (VT) in our BT 6–30 s conditions. The optimal backwashing period (BP) could be 6 min, because of the minimum membrane fouling and the maximum VT in the combined process of tubular alumina MF and PP beads. The resistance of reversible membrane fouling (Rrf) showed a major resistance of total membrane fouling, and that of irreversible membrane fouling (Rif) was a minor one, in the combined process using tubular or seven channel MF. The Rif showed a decreasing trend obviously, as decreasing BT from NBW to 2 min for seven channel MF. It means that the more frequent water backwashing could be more effective to control the membrane fouling, especially irreversible fouling, for seven channel membranes than tubular membranes. Full article
(This article belongs to the Special Issue Mixed-Matrix Membranes and Polymeric Membranes)
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23 pages, 5074 KiB  
Article
The Optimization of Dispersion and Application Techniques for Nanocarbon-Doped Mixed Matrix Gas Separation Membranes
by Ruben Hammerstein, Tim Schubert, Gerd Braun, Tobias Wolf, Stéphan Barbe, Antje Quade, Rüdiger Foest, Dionysios S. Karousos and Evangelos P. Favvas
Membranes 2022, 12(1), 87; https://doi.org/10.3390/membranes12010087 - 13 Jan 2022
Cited by 7 | Viewed by 1857
Abstract
In this work, supported cellulose acetate (CA) mixed matrix membranes (MMMs) were prepared and studied concerning their gas separation behaviors. The dispersion of carbon nanotube fillers were studied as a factor of polymer and filler concentrations using the mixing methods of the rotor–stator [...] Read more.
In this work, supported cellulose acetate (CA) mixed matrix membranes (MMMs) were prepared and studied concerning their gas separation behaviors. The dispersion of carbon nanotube fillers were studied as a factor of polymer and filler concentrations using the mixing methods of the rotor–stator system (RS) and the three-roll-mill system (TRM). Compared to the dispersion quality achieved by RS, samples prepared using the TRM seem to have slightly bigger, but fewer and more homogenously distributed, agglomerates. The green γ-butyrolactone (GBL) was chosen as a polyimide (PI) polymer-solvent, whereas diacetone alcohol (DAA) was used for preparing the CA solutions. The coating of the thin CA separation layer was applied using a spin coater. For coating on the PP carriers, a short parameter study was conducted regarding the plasma treatment to affect the wettability, the coating speed, and the volume of dispersion that was applied to the carrier. As predicted by the parameter study, the amount of dispersion that remained on the carriers decreased with an increasing rotational speed during the spin coating process. The dry separation layer thickness was varied between about 1.4 and 4.7 μm. Electrically conductive additives in a non-conductive matrix showed a steeply increasing electrical conductivity after passing the so-called percolation threshold. This was used to evaluate the agglomeration behavior in suspension and in the applied layer. Gas permeation tests were performed using a constant volume apparatus at feed pressures of 5, 10, and 15 bar. The highest calculated CO2/N2 selectivity (ideal), 21, was achieved for the CA membrane and corresponded to a CO2 permeability of 49.6 Barrer. Full article
(This article belongs to the Special Issue Mixed-Matrix Membranes and Polymeric Membranes)
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12 pages, 4996 KiB  
Article
Optimization of a MOF Blended with Modified Polyimide Membrane for High-Performance Gas Separation
by Yushu Zhang, Hongge Jia, Qingji Wang, Wenqiang Ma, Guoxing Yang, Shuangping Xu, Shaobin Li, Guiming Su, Yanqing Qu, Mingyu Zhang and Pengfei Jiang
Membranes 2022, 12(1), 34; https://doi.org/10.3390/membranes12010034 - 27 Dec 2021
Cited by 13 | Viewed by 3338
Abstract
The preparation, characterization and gas separation properties of mixed matrix membranes (MMMs) were obtained from polyimide capped with ionic liquid and blended with metal-organic frameworks (MOFs). The synthesized MOF was amine functionalized to produce UiO-66-NH2, and its amino group has a [...] Read more.
The preparation, characterization and gas separation properties of mixed matrix membranes (MMMs) were obtained from polyimide capped with ionic liquid and blended with metal-organic frameworks (MOFs). The synthesized MOF was amine functionalized to produce UiO-66-NH2, and its amino group has a higher affinity for CO2. Mixed matrix membranes exhibited good membrane forming ability, heat resistance and mechanical properties. The polyimide membrane exclusively capped by ionic liquid exhibited good permselectivity of 74.1 for CO2/CH4, which was 6.2 times that of the pure polyimide membrane. It is worth noting that MMM blended with UiO-66-NH2 demonstrated the highest ideal selectivity for CO2/CH4 (95.1) with a CO2 permeability of 7.61 Barrer, which is close to the 2008 Robeson upper bound. The addition of UiO-66-NH2 and ionic liquid enhanced the permselectivity of MMMs, which may be one of the promising technologies for high performance CO2/CH4 gas separation. Full article
(This article belongs to the Special Issue Mixed-Matrix Membranes and Polymeric Membranes)
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32 pages, 13930 KiB  
Article
Impact of Ionic Liquid Structure and Loading on Gas Sorption and Permeation for ZIF-8-Based Composites and Mixed Matrix Membranes
by Paloma Ortiz-Albo, Tiago J. Ferreira, Carla F. Martins, Vitor Alves, Isabel A. A. C. Esteves, Luís Cunha-Silva, Izumi Kumakiri, João Crespo and Luísa A. Neves
Membranes 2022, 12(1), 13; https://doi.org/10.3390/membranes12010013 - 23 Dec 2021
Cited by 10 | Viewed by 3355
Abstract
Carbon dioxide (CO2) capture has become of great importance for industrial processes due to the adverse environmental effects of gas emissions. Mixed matrix membranes (MMMs) have been studied as an alternative to traditional technologies, especially due to their potential to overcome [...] Read more.
Carbon dioxide (CO2) capture has become of great importance for industrial processes due to the adverse environmental effects of gas emissions. Mixed matrix membranes (MMMs) have been studied as an alternative to traditional technologies, especially due to their potential to overcome the practical limitations of conventional polymeric and inorganic membranes. In this work, the effect of using different ionic liquids (ILs) with the stable metal–organic framework (MOF) ZIF-8 was evaluated. Several IL@ZIF-8 composites and IL@ZIF-8 MMMs were prepared to improve the selective CO2 sorption and permeation over other gases such as methane (CH4) and nitrogen (N2). Different ILs and two distinct loadings were prepared to study not only the effect of IL concentration, but also the impact of the IL structure and affinity towards a specific gas mixture separation. Single gas sorption studies showed an improvement in CO2/CH4 and CO2/N2 selectivities, compared with the ones for the pristine ZIF-8, increasing with IL loading. In addition, the prepared IL@ZIF-8 MMMs showed improved CO2 selective behavior and mechanical strength with respect to ZIF-8 MMMs, with a strong dependence on the intrinsic IL CO2 selectivity. Therefore, the selection of high affinity ILs can lead to the improvement of CO2 selective separation for IL@ZIF-8 MMMs. Full article
(This article belongs to the Special Issue Mixed-Matrix Membranes and Polymeric Membranes)
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17 pages, 53365 KiB  
Article
Organo-Functionalization: An Effective Method in Enhancing the Separation and Antifouling Performance of Thin-Film Nanocomposite Membranes by Improving the Uniform Dispersion of Palygorskite Nanoparticles
by Liu Yang, Qianwen Zhang, Qikun Wang, Wande Ding and Kefeng Zhang
Membranes 2021, 11(11), 889; https://doi.org/10.3390/membranes11110889 - 19 Nov 2021
Cited by 5 | Viewed by 1722
Abstract
Recently, palygorskite (Pal) has become a promising new membrane additive in flux enhancement and fouling reduction, which is an environmentally friendly nanoclay material under the 2:1 layer composition with 1D tubular structure. However, the aggregation of Pal due to the intermolecular forces is [...] Read more.
Recently, palygorskite (Pal) has become a promising new membrane additive in flux enhancement and fouling reduction, which is an environmentally friendly nanoclay material under the 2:1 layer composition with 1D tubular structure. However, the aggregation of Pal due to the intermolecular forces is still an obstacle to be solved in improving membrane performance. Herein, Pal nanoparticles were chemically modified by KH550 to weaken the aggregation and improve the dispersibility, and then incorporated into the organic phase to prepare thin-film nanocomposite (TFN) membranes. The results showed that the organo-functionalization could effectively improve the membrane hydrophilicity and dispersion of Pal nanoparticles in the polyamide layer, which contributed to the enhanced water flux (from 25 to 38 L/m2·h), unchanged salt rejection (98.0%) and better antifouling capacity (91% flux recovery rate), which suggested that the organo-functionalization of nanoparticles was an efficient method in further enhancing membrane performance Full article
(This article belongs to the Special Issue Mixed-Matrix Membranes and Polymeric Membranes)
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24 pages, 3155 KiB  
Article
CO2/CH4 and H2/CH4 Gas Separation Performance of CTA-TNT@CNT Hybrid Mixed Matrix Membranes
by Chhabilal Regmi, Saeed Ashtiani, Zdeněk Hrdlička and Karel Friess
Membranes 2021, 11(11), 862; https://doi.org/10.3390/membranes11110862 - 9 Nov 2021
Cited by 16 | Viewed by 3096
Abstract
This study explored the underlying synergy between titanium dioxide nanotube (TNT) and carbon nanotube (CNT) hybrid fillers in cellulose triacetate (CTA)-based mixed matrix membranes (MMMs) for natural gas purification. The CNT@TNT hybrid nanofillers were blended with CTA polymer and cast as a thin [...] Read more.
This study explored the underlying synergy between titanium dioxide nanotube (TNT) and carbon nanotube (CNT) hybrid fillers in cellulose triacetate (CTA)-based mixed matrix membranes (MMMs) for natural gas purification. The CNT@TNT hybrid nanofillers were blended with CTA polymer and cast as a thin film by a facile casting technique, after which they were used for single gas separation. The hybrid filler-based membrane depicted a higher CO2 uptake affinity than the single filler (CNT/TNT)-based membrane. The gas separation results indicate that the hybrid fillers (TNT@CNT) are strongly selective for CO2 over CH4 and H2 over CH4. The increment in the CO2/CH4 and H2/CH4 selectivities compared to the pristine CTA membrane was 42.98 from 25.08 and 48.43 from 36.58, respectively. Similarly, the CO2 and H2 permeability of the CTA-TNT@CNT membrane increased by six- and five-fold, respectively, compared to the pristine CTA membrane. Such significant improvements in CO2/CH4 and H2/CH4 separation performance and thermal and mechanical properties suggest a feasible and practical approach for potential biogas upgrading and natural gas purification. Full article
(This article belongs to the Special Issue Mixed-Matrix Membranes and Polymeric Membranes)
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17 pages, 17592 KiB  
Article
Application of Response Surface Methodology (RSM) for the Optimization of Chromium(III) Synergistic Extraction by Supported Liquid Membrane
by Jakub Rajewski and Agnieszka Dobrzyńska-Inger
Membranes 2021, 11(11), 854; https://doi.org/10.3390/membranes11110854 - 4 Nov 2021
Cited by 24 | Viewed by 2554
Abstract
In this paper, the response surface methodology (RSM) was proposed for studying the synergistic extraction of chromium(III) ions by double-carrier supported liquid membrane (DCSLM) with organophosphorus carriers (D2EHPA/Cyanex272). At first, the optimization method of “one-factor-at-a-time” was adopted for determination of the best conditions [...] Read more.
In this paper, the response surface methodology (RSM) was proposed for studying the synergistic extraction of chromium(III) ions by double-carrier supported liquid membrane (DCSLM) with organophosphorus carriers (D2EHPA/Cyanex272). At first, the optimization method of “one-factor-at-a-time” was adopted for determination of the best conditions for Cr(III) extraction by SLM with only one carrier (D2EHPA). The optimum/threshold D2EHPA concentration in the membrane phase increased linearly with initial concentration of Cr(III) ions in the feed phase. After the addition the second carrier (Cyanex272), the synergistic effect was observed. The largest percentage of extraction and the shorter time was obtained. The optimization of the synergistic extraction in DCSLM system by RSM using Box–Behnken design (BBD) for three variables (concentration and proportions of the carriers, initial concentration of Cr(III), and time of the process) was studied. The statistical model was verified with the analysis of variance (ANOVA) for the response surface quadratic model. The reduced quadratic model showed that the predicted values were in agreement with those obtained experimentally, as well as the fact that the concentrations and proportions of the carriers had a significant influence on the response. The developed model was considered to be verified and can be used to predict the optimal condition for the chromium ions extraction. Full article
(This article belongs to the Special Issue Mixed-Matrix Membranes and Polymeric Membranes)
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11 pages, 1795 KiB  
Article
Biphenyl-Based Covalent Triazine Framework/Matrimid® Mixed-Matrix Membranes for CO2/CH4 Separation
by Stefanie Bügel, Quang-Dien Hoang, Alex Spieß, Yangyang Sun, Shanghua Xing and Christoph Janiak
Membranes 2021, 11(10), 795; https://doi.org/10.3390/membranes11100795 - 19 Oct 2021
Cited by 6 | Viewed by 2796
Abstract
Processes, such as biogas upgrading and natural gas sweetening, make CO2/CH4 separation an environmentally relevant and current topic. One way to overcome this separation issue is the application of membranes. An increase in separation efficiency can be achieved by applying [...] Read more.
Processes, such as biogas upgrading and natural gas sweetening, make CO2/CH4 separation an environmentally relevant and current topic. One way to overcome this separation issue is the application of membranes. An increase in separation efficiency can be achieved by applying mixed-matrix membranes, in which filler materials are introduced into polymer matrices. In this work, we report the covalent triazine framework CTF-biphenyl as filler material in a matrix of the glassy polyimide Matrimid®. MMMs with 8, 16, and 24 wt% of the filler material are applied for CO2/CH4 mixed-gas separation measurements. With a CTF-biphenyl loading of only 16 wt%, the CO2 permeability is more than doubled compared to the pure polymer membrane, while maintaining the high CO2/CH4 selectivity of Matrimid®. Full article
(This article belongs to the Special Issue Mixed-Matrix Membranes and Polymeric Membranes)
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16 pages, 4428 KiB  
Article
Fabrication and Characterization of Sulfonated Graphene Oxide (SGO) Doped PVDF Nanocomposite Membranes with Improved Anti-Biofouling Performance
by Muhammad Zahid, Tayyaba Khalid, Zulfiqar Ahmad Rehan, Talha Javed, Saba Akram, Anum Rashid, Syed Khalid Mustafa, Rubab Shabbir, Freddy Mora-Poblete, Muhammad Shoaib Asad, Rida Liaquat, Mohamed M. Hassan, Mohammed A. Amin and Hafiz Abdul Shakoor
Membranes 2021, 11(10), 749; https://doi.org/10.3390/membranes11100749 - 29 Sep 2021
Cited by 12 | Viewed by 2333
Abstract
Emergence of membrane technology for effective performance is qualified due to its low energy consumption, no use of chemicals, high removal capacity and easy accessibility of membrane material. The hydrophobic nature of polymeric membranes limits their applications due to biofouling (assemblage of microorganisms [...] Read more.
Emergence of membrane technology for effective performance is qualified due to its low energy consumption, no use of chemicals, high removal capacity and easy accessibility of membrane material. The hydrophobic nature of polymeric membranes limits their applications due to biofouling (assemblage of microorganisms on surface of membrane). Polymeric nanocomposite membranes emerge to alleviate this issue. The current research work was concerned with the fabrication of sulfonated graphene oxide doped polyvinylidene fluoride (PVDF) membrane and investigation of its anti-biofouling and anti-bacterial behavior. The membrane was fabricated through phase inversion method, and its structure and morphology were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-rays diffraction (XRD) and thermo gravimetric analysis (TGA) techniques. Performance of the membrane was evaluated via pure water flux; anti-biofouling behavior was determined through Bovine Serum albumin (BSA) rejection. Our results revealed that the highest water flux was shown by M7 membrane about 308.7 Lm−2h−1/bar having (0.5%) concentration of SGO with improved BSA rejection. Furthermore, these fabricated membranes showed high antibacterial activity, more hydrophilicity and mechanical strength as compared to pristine PVDF membranes. It was concluded that SGO addition within PVDF polymer matrix enhanced the properties and performance of membranes. Therefore, SGO was found to be a promising material for the fabrication of nanocomposite membranes. Full article
(This article belongs to the Special Issue Mixed-Matrix Membranes and Polymeric Membranes)
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Review

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15 pages, 67175 KiB  
Review
A Review of the Application of Modified Separators in Inhibiting the “shuttle effect” of Lithium–Sulfur Batteries
by Bo-Wen Zhang, Bo Sun, Pei Fu, Feng Liu, Chen Zhu, Bao-Ming Xu, Yong Pan and Chi Chen
Membranes 2022, 12(8), 790; https://doi.org/10.3390/membranes12080790 - 17 Aug 2022
Cited by 16 | Viewed by 3122
Abstract
Lithium-sulfur batteries with high theoretical specific capacity and high energy density are considered to be one of the most promising energy storage devices. However, the “shuttle effect” caused by the soluble polysulphide intermediates migrating back and forth between the positive and negative electrodes [...] Read more.
Lithium-sulfur batteries with high theoretical specific capacity and high energy density are considered to be one of the most promising energy storage devices. However, the “shuttle effect” caused by the soluble polysulphide intermediates migrating back and forth between the positive and negative electrodes significantly reduces the active substance content of the battery and hinders the commercial applications of lithium–sulfur batteries. The separator being far from the electrochemical reaction interface and in close contact with the electrode poses an important barrier to polysulfide shuttle. Therefore, the electrochemical performance including coulombic efficiency and cycle stability of lithium–sulfur batteries can be effectively improved by rationally designing the separator. In this paper, the research progress of the modification of lithium–sulfur battery separators is reviewed from the perspectives of adsorption effect, electrostatic effect, and steric hindrance effect, and a novel modification of the lithium–sulfur battery separator is prospected. Full article
(This article belongs to the Special Issue Mixed-Matrix Membranes and Polymeric Membranes)
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10 pages, 2204 KiB  
Review
Recent Progress of Adsorptive Ultrafiltration Membranes in Water Treatment—A Mini Review
by Tong Yu, Jing Zhou, Feng Liu, Bao-Ming Xu and Yong Pan
Membranes 2022, 12(5), 519; https://doi.org/10.3390/membranes12050519 - 13 May 2022
Cited by 18 | Viewed by 3564
Abstract
Adsorptive ultrafiltration mixed matrix membranes (MMMs) are a new strategy, developed in recent years, to remove harmful cations and small-molecule organics from wastewater and drinking water, which achieve ultrafiltration and adsorption functions in one unit and are considered to be among the promising [...] Read more.
Adsorptive ultrafiltration mixed matrix membranes (MMMs) are a new strategy, developed in recent years, to remove harmful cations and small-molecule organics from wastewater and drinking water, which achieve ultrafiltration and adsorption functions in one unit and are considered to be among the promising technologies that have exhibited efficiency and competence in water reuse. This mini review concerns the research progress of adsorptive ultrafiltration MMMs for removing heavy metal ions and small-molecule organics. We firstly introduce the types and classifications of adsorptive ultrafiltration MMMs (their classifications can be established based on the type of the adsorbent used). Furthermore, we discuss the removal mechanism of adsorptive ultrafiltration MMMs, as well as summarizing the main fabrication techniques for adsorptive ultrafiltration membranes. In addition, we identified some of the issues and challenges of the practical application for adsorptive ultrafiltration. Full article
(This article belongs to the Special Issue Mixed-Matrix Membranes and Polymeric Membranes)
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20 pages, 5033 KiB  
Review
Complementary Powerful Techniques for Investigating the Interactions of Proteins with Porous TiO2 and Its Hybrid Materials: A Tutorial Review
by Yihui Dong, Weifeng Lin, Aatto Laaksonen and Xiaoyan Ji
Membranes 2022, 12(4), 415; https://doi.org/10.3390/membranes12040415 - 11 Apr 2022
Viewed by 3170
Abstract
Understanding the adsorption and interaction between porous materials and protein is of great importance in biomedical and interface sciences. Among the studied porous materials, TiO2 and its hybrid materials, featuring distinct, well-defined pore sizes, structural stability and excellent biocompatibility, are widely used. [...] Read more.
Understanding the adsorption and interaction between porous materials and protein is of great importance in biomedical and interface sciences. Among the studied porous materials, TiO2 and its hybrid materials, featuring distinct, well-defined pore sizes, structural stability and excellent biocompatibility, are widely used. In this review, the use of four powerful, synergetic and complementary techniques to study protein-TiO2-based porous materials interactions at different scales is summarized, including high-performance liquid chromatography (HPLC), atomic force microscopy (AFM), surface-enhanced Raman scattering (SERS), and Molecular Dynamics (MD) simulations. We expect that this review could be helpful in optimizing the commonly used techniques to characterize the interfacial behavior of protein on porous TiO2 materials in different applications. Full article
(This article belongs to the Special Issue Mixed-Matrix Membranes and Polymeric Membranes)
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16 pages, 1926 KiB  
Review
Enhanced Specific Mechanism of Separation by Polymeric Membrane Modification—A Short Review
by Anna Siekierka, Katarzyna Smolińska-Kempisty and Joanna Wolska
Membranes 2021, 11(12), 942; https://doi.org/10.3390/membranes11120942 - 29 Nov 2021
Cited by 11 | Viewed by 2742
Abstract
Membrane technologies have found a significant application in separation processes in an exceeding range of industrial fields. The crucial part that is decided regarding the efficiency and effectivity of separation is the type of membrane. The membranes deal with separation problems, working under [...] Read more.
Membrane technologies have found a significant application in separation processes in an exceeding range of industrial fields. The crucial part that is decided regarding the efficiency and effectivity of separation is the type of membrane. The membranes deal with separation problems, working under the various mechanisms of transportation of selected species. This review compares significant types of entrapped matter (ions, compounds, and particles) within membrane technology. The ion-exchange membranes, molecularly imprinted membranes, smart membranes, and adsorptive membranes are investigated. Here, we focus on the selective separation through the above types of membranes and detect their preparation methods. Firstly, the explanation of transportation and preparation of each type of membrane evaluated is provided. Next, the working and application phenomena are evaluated. Finally, the review discusses the membrane modification methods and briefly provides differences in the properties that occurred depending on the type of materials used and the modification protocol. Full article
(This article belongs to the Special Issue Mixed-Matrix Membranes and Polymeric Membranes)
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