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Membranes
Volume 12
Issue 3
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Membranes, Volume 12, Issue 3 (March 2022) – 99 articles

Cover Story (view full-size image): A new approach is presented to describe the transport process by taking all the steps into explicit consideration and by including all the possible experiment-derived parameters. The algorithm simulates the experiments performed with lipid vesicles to assess the ion-transport ability of synthetic molecular carriers following a non-electrogenic uniport mechanism. While keeping calculation time affordable, the final goal is the curve-fitting of real experimental data, to obtain both an analysis and a predictive tool. The role and relative weight of different parameters are discussed and agreement with the literature is shown using simulations of a virtual benchmark case. The fitting of real experimental curves is also shown for two molecular carriers of different structural types. View this paper.
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13 pages, 2603 KiB  
Review
Research Progress of Polyvinyl Alcohol Water-Resistant Film Materials
by Baodong Liu, Jianhua Zhang and Hongge Guo
Membranes 2022, 12(3), 347; https://doi.org/10.3390/membranes12030347 - 20 Mar 2022
Cited by 43 | Viewed by 9238
Abstract
Polyvinyl alcohol (PVA) is one of the few biodegradable synthetic resins from petroleum-based sources that can alleviate white pollution in the environment. PVA film materials have excellent properties, such as high barrier, high transparency, high toughness, biocompatibility, and adjustable water solubility. However, due [...] Read more.
Polyvinyl alcohol (PVA) is one of the few biodegradable synthetic resins from petroleum-based sources that can alleviate white pollution in the environment. PVA film materials have excellent properties, such as high barrier, high transparency, high toughness, biocompatibility, and adjustable water solubility. However, due to the presence of hydrophilic hydroxyl groups in the side chain of PVA resin, when PVA film is placed in a humid or water environment, swelling or even dissolution will occur, which greatly limits its application. Therefore, it is necessary to modify PVA resin to improve water resistance without reducing other properties and can also impart various functionalities to it, thereby widening the application range. This paper reviews the water-resistant modification methods of polyvinyl alcohol and the application of water-resistant films and provides an outlook on the development trend of PVA water-resistant films. Full article
(This article belongs to the Special Issue Theoretical and Experimental Investigation of the Mass and Heat Transfers in Membrane Separation Processes)
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14 pages, 5582 KiB  
Article
Influence of Deposition Modes and Thermal Annealing on Residual Stresses in Magnetron-Sputtered YSZ Membranes
by Andrey Solovyev, Sergey Rabotkin, Anna Shipilova, Dmitrii Agarkov, Ilya Burmistrov and Alexander Shmakov
Membranes 2022, 12(3), 346; https://doi.org/10.3390/membranes12030346 - 19 Mar 2022
Cited by 3 | Viewed by 2143
Abstract
Thin-film electrolyte made of 8-mol% yttria stabilized zirconia (8YSZ) for solid oxide fuel cells (SOFCs) was fabricated on anode substrates using reactive magnetron sputtering of Zr-Y targets in a mixture of Ar and O2 gases. The deposition of 4–6 µm thin-film electrolyte [...] Read more.
Thin-film electrolyte made of 8-mol% yttria stabilized zirconia (8YSZ) for solid oxide fuel cells (SOFCs) was fabricated on anode substrates using reactive magnetron sputtering of Zr-Y targets in a mixture of Ar and O2 gases. The deposition of 4–6 µm thin-film electrolyte was in the transition or oxide modes differing by the oxygen concentration in the sputtering atmosphere. The half-cell bending of the anode-supported SOFCs was measured to determine the residual stresses in the electrolyte films after the deposition and thermal annealing in air. The dependences were studied between the deposition modes, residual stresses in the films, and the SOFC performance. At 800 °C, the maximum power density of SOFCs ranged between 0.58 and 1.2 W/cm2 depending on the electrolyte deposition mode. Scanning electron microscopy was carried out to investigate the surface morphology and structure of the YSZ electrolyte films after thermal annealing. Additionally, an X-ray diffraction analysis of the YSZ electrolyte films was conducted for the synchrotron radiation beam during thermal annealing at different temperatures up to 1300 °C. It was found that certain deposition modes provide the formation of the YSZ electrolyte films with acceptable residual stresses (<1 GPa) at room temperature, including films deposited on large area anodes (100 × 100 mm2). Full article
(This article belongs to the Special Issue Fabrication, Characterization and Application of Organic/Inorganic Film Membranes and Advanced Materials)
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22 pages, 7057 KiB  
Review
A Review of Titanium Dioxide (TiO2)-Based Photocatalyst for Oilfield-Produced Water Treatment
by Hadi Nugraha Cipta Dharma, Juhana Jaafar, Nurul Widiastuti, Hideto Matsuyama, Saied Rajabsadeh, Mohd Hafiz Dzarfan Othman, Mukhlis A Rahman, Nurul Natasha Mohammad Jafri, Nuor Sariyan Suhaimin, Atikah Mohd Nasir and Nur Hashimah Alias
Membranes 2022, 12(3), 345; https://doi.org/10.3390/membranes12030345 - 19 Mar 2022
Cited by 88 | Viewed by 8050
Abstract
Oilfield produced water (OPW) has become a primary environmental concern due to the high concentration of dissolved organic pollutants that lead to bioaccumulation with high toxicity, resistance to biodegradation, carcinogenicity, and the inhibition of reproduction, endocrine, and non-endocrine systems in aquatic biota. Photodegradation [...] Read more.
Oilfield produced water (OPW) has become a primary environmental concern due to the high concentration of dissolved organic pollutants that lead to bioaccumulation with high toxicity, resistance to biodegradation, carcinogenicity, and the inhibition of reproduction, endocrine, and non-endocrine systems in aquatic biota. Photodegradation using photocatalysts has been considered as a promising technology to sustainably resolve OPW pollutants due to its benefits, including not requiring additional chemicals and producing a harmless compound as the result of pollutant photodegradation. Currently, titanium dioxide (TiO2) has gained great attention as a promising photocatalyst due to its beneficial properties among the other photocatalysts, such as excellent optical and electronic properties, high chemical stability, low cost, non-toxicity, and eco-friendliness. However, the photoactivity of TiO2 is still inhibited because it has a wide band gap and a low quantum field. Hence, the modification approaches for TiO2 can improve its properties in terms of the photocatalytic ability, which would likely boost the charge carrier transfer, prevent the recombination of electrons and holes, and enhance the visible light response. In this review, we provide an overview of several routes for modifying TiO2. The as-improved photocatalytic performance of the modified TiO2 with regard to OPW treatment is reviewed. The stability of modified TiO2 was also studied. The future perspective and challenges in developing the modification of TiO2-based photocatalysts are explained. Full article
(This article belongs to the Section Biological Membrane Dynamics and Computation)
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23 pages, 7395 KiB  
Article
Proton Conductivity Enhancement at High Temperature on Polybenzimidazole Membrane Electrolyte with Acid-Functionalized Graphene Oxide Fillers
by Raja Rafidah Raja Sulaiman, Rashmi Walvekar, Wai Yin Wong, Mohammad Khalid and Ming Meng Pang
Membranes 2022, 12(3), 344; https://doi.org/10.3390/membranes12030344 - 19 Mar 2022
Cited by 18 | Viewed by 3217
Abstract
Graphene oxide (GO) and its acid-functionalized form are known to be effective in enhancing the proton transport properties of phosphoric-acid doped polybenzimidazole (PA-doped PBI) membranes utilized in high-temperature proton exchange membrane fuel cells (HTPEMFC) owing to the presence of proton-conducting functional groups. This [...] Read more.
Graphene oxide (GO) and its acid-functionalized form are known to be effective in enhancing the proton transport properties of phosphoric-acid doped polybenzimidazole (PA-doped PBI) membranes utilized in high-temperature proton exchange membrane fuel cells (HTPEMFC) owing to the presence of proton-conducting functional groups. This work aims to provide a comparison between the different effects of GO with the sulfonated GO (SGO) and phosphonated GO (PGO) on the properties of PA-doped PBI, with emphasis given on proton conductivity to understand which functional groups are suitable for proton transfer under high temperature and anhydrous conditions. Each filler was synthesized following existing methods and introduced into PBI at loadings of 0.25, 0.5, and 1 wt.%. Characterizations were carried out on the overall thermal stability, acid doping level (ADL), dimensional swelling, and proton conductivity. SGO and PGO-containing PBI exhibit better conductivity than those with GO at 180 °C under anhydrous conditions, despite a slight reduction in ADL. PBI with 0.5 wt.% SGO exhibits the highest conductivity at 23.8 mS/cm, followed by PBI with 0.5 wt.% PGO at 19.6 mS/cm. However, the membrane with PGO required a smaller activation energy for proton conduction, thus less energy was needed to initiate fast proton transfer. Additionally, the PGO-containing membrane also displayed an advantage in its thermal stability aspect. Therefore, considering these properties, it is shown that PGO is a potential filler for improving PBI properties for HTPEMFC applications. Full article
(This article belongs to the Special Issue Advanced Membrane Electrode Assembly (MEA) for Applications in Fuel Cell and Electrolyzer Based Systems)
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27 pages, 2805 KiB  
Review
Electro-Driven Materials and Processes for Lithium Recovery—A Review
by Anna Siekierka, Marek Bryjak, Amir Razmjou, Wojciech Kujawski, Aleksandar N. Nikoloski and Ludovic F. Dumée
Membranes 2022, 12(3), 343; https://doi.org/10.3390/membranes12030343 - 18 Mar 2022
Cited by 12 | Viewed by 5079
Abstract
The mass production of lithium-ion batteries and lithium-rich e-products that are required for electric vehicles, energy storage devices, and cloud-connected electronics is driving an unprecedented demand for lithium resources. Current lithium production technologies, in which extraction and purification are typically achieved by hydrometallurgical [...] Read more.
The mass production of lithium-ion batteries and lithium-rich e-products that are required for electric vehicles, energy storage devices, and cloud-connected electronics is driving an unprecedented demand for lithium resources. Current lithium production technologies, in which extraction and purification are typically achieved by hydrometallurgical routes, possess strong environmental impact but are also energy-intensive and require extensive operational capabilities. The emergence of selective membrane materials and associated electro-processes offers an avenue to reduce these energy and cost penalties and create more sustainable lithium production approaches. In this review, lithium recovery technologies are discussed considering the origin of the lithium, which can be primary sources such as minerals and brines or e-waste sources generated from recycling of batteries and other e-products. The relevance of electro-membrane processes for selective lithium recovery is discussed as well as the potential and shortfalls of current electro-membrane methods. Full article
(This article belongs to the Collection Feature Papers in Membrane Processing and Engineering)
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14 pages, 5319 KiB  
Article
Development of Free-Standing Titanium Dioxide Hollow Nanofibers Photocatalyst with Enhanced Recyclability
by Nurul Natasha Mohammad Jafri, Juhana Jaafar, Farhana Aziz, Wan Norharyati Wan Salleh, Norhaniza Yusof, Mohd Hafiz Dzarfan Othman, Mukhlis A. Rahman, Ahmad Fauzi Ismail, Roshanida A. Rahman and Watsa Khongnakorn
Membranes 2022, 12(3), 342; https://doi.org/10.3390/membranes12030342 - 18 Mar 2022
Cited by 2 | Viewed by 2053
Abstract
Titanium dioxide hollow nanofibers (THN) are excellent photocatalysts for the photodegradation of Bisphenol A (BPA) due to their extensive surface area and good optical properties. A template synthesis technique is typically employed to produce titanium dioxide hollow nanofibers. This process, however, involves a [...] Read more.
Titanium dioxide hollow nanofibers (THN) are excellent photocatalysts for the photodegradation of Bisphenol A (BPA) due to their extensive surface area and good optical properties. A template synthesis technique is typically employed to produce titanium dioxide hollow nanofibers. This process, however, involves a calcination procedure at high temperatures that yields powder-form photocatalysts that require post-recovery treatment before recycling. Meanwhile, the immobilization of photocatalysts on/into a membrane has been reported to reduce the active surface area. Novel free-standing TiO2 hollow nanofibers were developed to overcome those shortcomings. The free-standing photocatalyst containing 0.75 g of THN (FS-THN-75) exhibited good adherence and connectivity between the nanofibers. The recyclability of FS-THN-75 outperformed the THN calcined at 600 °C (THN-600), which retained 80% of its original weight while maintaining excellent degradation performance. This study recommends the potential application of free-standing TiO2 hollow nanofibers as high potential novel photocatalysts for the treatment of BPA in wastewater. Full article
(This article belongs to the Section Biological Membrane Dynamics and Computation)
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15 pages, 1815 KiB  
Article
Impact of Pre-Ozonation during Nanofiltration of MBR Effluent
by Zoulkifli Amadou-Yacouba, Julie Mendret, Geoffroy Lesage, François Zaviska and Stephan Brosillon
Membranes 2022, 12(3), 341; https://doi.org/10.3390/membranes12030341 - 18 Mar 2022
Cited by 3 | Viewed by 2067
Abstract
This study aimed to investigate the impact of real MBR effluent pre-ozonation on nanofiltration performances. Nanofiltration experiments were separately run with non-ozonated real MBR effluent, ozonated real MBR effluent and synthetic ionic solution mimicking the ionic composition of the real MBR effluent. The [...] Read more.
This study aimed to investigate the impact of real MBR effluent pre-ozonation on nanofiltration performances. Nanofiltration experiments were separately run with non-ozonated real MBR effluent, ozonated real MBR effluent and synthetic ionic solution mimicking the ionic composition of the real MBR effluent. The specific UV absorbance and the chemical oxygen demand were monitored during ozonation of real effluent, and the mineralization rate was calculated through the quantitative analysis of dissolved organic carbon. The membrane structure was characterized using SEM on virgin and fouled membrane surfaces and after different cleaning steps. The results confirm the low effect of the ozonation process in terms of organic carbon mineralization. However, the chemical oxygen demand and the specific UV absorbance were decreased by 50% after ozonation, demonstrating the efficiency of ozonation in degrading a specific part of the organic matter fraction. A benefic effect of pre-ozonation was observed, as it limits both fouling and flux decrease. This study shows that the partial mineralization of dissolved and colloidal organic matter by ozonation could have a positive effect on inorganic scaling and decrease severe NF membrane fouling. Full article
(This article belongs to the Special Issue Nanofiltration Membranes: Recent Advances and Environmental Applications)
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14 pages, 3340 KiB  
Article
Metal-Coordinated Nanofiltration Membranes Constructed on Metal Ions Blended Support toward Enhanced Dye/Salt Separation and Antifouling Performances
by Xiaofeng Fang, Shihao Wei, Shuai Liu, Ruo Li, Ziyi Zhang, Yanbiao Liu, Xingran Zhang, Mengmeng Lou, Gang Chen and Fang Li
Membranes 2022, 12(3), 340; https://doi.org/10.3390/membranes12030340 - 18 Mar 2022
Cited by 17 | Viewed by 3023
Abstract
Metal-phenol coordination is a widely used method to prepare nanofiltration membrane. However, the facile, controllable and scaled fabrication remains a great challenge. Herein, a novel strategy was developed to fabricate a loose nanofiltration membrane via integrating blending and interfacial coordination strategy. Specifically, iron [...] Read more.
Metal-phenol coordination is a widely used method to prepare nanofiltration membrane. However, the facile, controllable and scaled fabrication remains a great challenge. Herein, a novel strategy was developed to fabricate a loose nanofiltration membrane via integrating blending and interfacial coordination strategy. Specifically, iron acetylacetonate was firstly blended in Polyether sulfone (PES) substrate via non-solvent induced phase separation (NIPS), and then the loose selective layer was formed on the membrane surface with tannic acid (TA) crosslinking reaction with Fe3+. The surface properties, morphologies, permeability and selectivity of the membranes were carefully investigated. The introduction of TA improved the surface hydrophilicity and negative charge. Moreover, the thickness of top layer increased about from ~30 nm to 119 nm with the increase of TA assembly time. Under the optimum preparation condition, the membrane with assembly 3 h (PES/Fe-TA3h) showed pure water flux of 175.8 L·m−2·h−1, dye rejections of 97.7%, 97.1% and 95.0% for Congo red (CR), Methyl blue (MB) and Eriochrome Black T (EBT), along with a salt penetration rate of 93.8%, 95.1%, 97.4% and 98.1% for Na2SO4, MgSO4, NaCl and MgCl2 at 0.2 MPa, respectively. Both static adhesion tests and dynamic fouling experiments implied that the TA modified membranes showed significantly reduced adsorption and high FRR for the dye solutions separation. The PES/Fe-TA3h membrane exhibited high FRR of 90.3%, 87.5% and 81.6% for CR, EBT and MB in the fouling test, stable CR rejection (>97.2%) and NaCl permeation (>94.6%) in 24 h continuous filtration test. The combination of blending and interfacial coordination assembly method could be expected to be a universal way to fabricate the loose nanofiltration membrane for effective fractionation of dyes and salts in the saline textile wastewater. Full article
(This article belongs to the Special Issue Advanced Membrane Technologies for Wastewater Treatment and Recycling)
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14 pages, 3033 KiB  
Article
Integration of Nanofiltration and Reverse Osmosis Technologies in Polyphenols Recovery Schemes from Winery and Olive Mill Wastes by Aqueous-Based Processing
by Paulina Tapia-Quirós, María Fernanda Montenegro-Landívar, Mònica Reig, Xanel Vecino, Javier Saurina, Mercè Granados and José Luis Cortina
Membranes 2022, 12(3), 339; https://doi.org/10.3390/membranes12030339 - 18 Mar 2022
Cited by 12 | Viewed by 3034
Abstract
More sustainable waste management in the winery and olive oil industries has become a major challenge. Therefore, waste valorization to obtain value-added products (e.g., polyphenols) is an efficient alternative that contributes to circular approaches and sustainable environmental protection. In this work, an integration [...] Read more.
More sustainable waste management in the winery and olive oil industries has become a major challenge. Therefore, waste valorization to obtain value-added products (e.g., polyphenols) is an efficient alternative that contributes to circular approaches and sustainable environmental protection. In this work, an integration scheme was purposed based on sustainable extraction and membrane separation processes, such as nanofiltration (NF) and reverse osmosis (RO), for the recovery of polyphenols from winery and olive mill wastes. Membrane processes were evaluated in a closed-loop system and with a flat-sheet membrane configuration (NF270, NF90, and Duracid as NF membranes, and BW30LE as RO membrane). The separation and concentration efficiency were evaluated in terms of the total polyphenol content (TPC), and by polyphenol families (hydroxybenzoic acids, hydroxycinnamic acids, and flavonoids), using high-performance liquid chromatography. The water trans-membrane flux was dependent on the trans-membrane pressure for the NF and RO processes. NF90 membrane rejected around 91% of TPC for the lees filters extracts while NF270 membrane rejected about 99% of TPC for the olive pomace extracts. Otherwise, RO membranes rejected more than 99.9% of TPC for both types of agri-food wastes. Hence, NF and RO techniques could be used to obtain polyphenol-rich streams, and clean water for reuse purposes. Full article
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26 pages, 4948 KiB  
Article
Chemical Reaction and Internal Heating Effects on the Double Diffusive Convection in Porous Membrane Enclosures Soaked with Maxwell Fluid
by Dhananjay Yadav, Maimouna Al-Siyabi, Mukesh Kumar Awasthi, Salma Al-Nadhairi, Amna Al-Rahbi, Maryam Al-Subhi, Ravi Ragoju and Krishnendu Bhattacharyya
Membranes 2022, 12(3), 338; https://doi.org/10.3390/membranes12030338 - 18 Mar 2022
Cited by 11 | Viewed by 2178
Abstract
In this paper, the joint impact of the interior heating and chemical reaction on the double diffusive convective flow in porous membrane enclosures soaked by a non-Newtonian Maxwell fluid is investigated applying linear and nonlinear stability techniques. The porous enclosures are square, slender [...] Read more.
In this paper, the joint impact of the interior heating and chemical reaction on the double diffusive convective flow in porous membrane enclosures soaked by a non-Newtonian Maxwell fluid is investigated applying linear and nonlinear stability techniques. The porous enclosures are square, slender and rectangular. Using the linear stability analysis, the expression for the critical thermal Rayleigh–Darcy number, above which the convective movement occurs, is derived analytically in terms of associated physical parameters. A nonlinear stability examination reliant on the Fourier double series is executed to calculate the convective heat and mass transports of the arrangement. It is observed that the pattern of convective activity is oscillatory only in the occurrence of a relaxation parameter and the threshold value of the relaxation parameter for the occurrence of the oscillatory pattern depends on the other physical parameters. The onset of convective instability accelerates with the increasing chemical reacting parameter, the interior heating parameter, the solute Rayleigh–Darcy number, the Lewis number, the Vadasz number, and the relaxation parameter, while it delays with the heat capacity ratio. The convective heat and mass transfers increase with the solute Rayleigh–Darcy number, the Vadasz number, the relaxation parameter, and the aspect ratio (for rectangular enclosure), while it decreases with the heat capacity ratio and the aspect ratio (for slender enclosure). Additionally, the convective heat transfer enhances with the interior heating parameter, while the convective mass transfer enhances with the chemical reacting parameter and the Lewis number. The effects of Vadasz number, heat capacity ratio, and relaxation parameter are witnessed only on the oscillatory pattern of convection and unsteady convective heat and mass transfers. Further, some existing literature results are compared with the current findings. Full article
(This article belongs to the Special Issue Computational Modeling and Digitalisation in Membranes Process: Simulation, Design and Application)
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12 pages, 1385 KiB  
Article
Anion-Conducting Polymer Electrolyte without Ether Linkages and with Ionic Groups Grafted on Long Side Chains: Poly(Alkylene Biphenyl Butyltrimethyl Ammonium) (ABBA)
by Riccardo Narducci, Raul Andres Becerra-Arciniegas, Luca Pasquini, Gianfranco Ercolani, Philippe Knauth and Maria Luisa Di Vona
Membranes 2022, 12(3), 337; https://doi.org/10.3390/membranes12030337 - 18 Mar 2022
Cited by 2 | Viewed by 2236
Abstract
In this work we report the synthesis of the new ionomer poly(alkylene biphenyl butyltrimethyl ammonium) (ABBA) with a backbone devoid of alkaline-labile C-O-C bonds and with quaternary ammonium groups grafted on long side chains. The ionomer was achieved by metalation reaction with n [...] Read more.
In this work we report the synthesis of the new ionomer poly(alkylene biphenyl butyltrimethyl ammonium) (ABBA) with a backbone devoid of alkaline-labile C-O-C bonds and with quaternary ammonium groups grafted on long side chains. The ionomer was achieved by metalation reaction with n-butyllithium of 2-bromobiphenyl, followed by the introduction of the long chain with 1,4-dibromobutane. The reaction steps were followed by 1H-NMR spectroscopy showing the characteristic signals of the Br-butyl chain and indicating the complete functionalization of the biphenyl moiety. The precursor was polycondensed with 1,1,1-trifluoroacetone and then quaternized using trimethylamine (TMA). After the acid catalyzed polycondensation, the stoichiometric ratio between the precursors was respected. The quaternization with TMA gave a final degree of amination of 0.83 in agreement with the thermogravimetric analysis and with the ion exchange capacity of 2.5 meq/g determined by acid–base titration. The new ionomer blended with poly(vinylalcohol) (PVA) or poly(vinylidene difluoride) (PVDF) was also characterized by water uptake (WU) and ionic conductivity measurements. The higher water uptake and ionic conductivity observed with the PVDF blend might be related to a better nanophase separation. Full article
(This article belongs to the Collection Feature Papers in Membrane Chemistry)
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16 pages, 5230 KiB  
Article
Tribological Performance of Diamond Films with Different Roughnesses of Silicon Nitride Substrates and Carbon Source Concentrations
by Feng Lu, Tianwei Liu, Xu Bai, Yuhou Wu, He Wang and Guangyu Yan
Membranes 2022, 12(3), 336; https://doi.org/10.3390/membranes12030336 - 18 Mar 2022
Cited by 3 | Viewed by 1775
Abstract
Diamond films were deposited on silicon nitride (Si3N4) substrates with three different roughnesses using the method of hot-filament chemical vapor deposition (HFCVD). The tribological properties of the film were studied by changing the deposition time, deposition distance, and methane [...] Read more.
Diamond films were deposited on silicon nitride (Si3N4) substrates with three different roughnesses using the method of hot-filament chemical vapor deposition (HFCVD). The tribological properties of the film were studied by changing the deposition time, deposition distance, and methane (CH4) concentration. The friction coefficient, delamination threshold load, and wear rate of the diamond films were tested and calculated using the reciprocating friction and wear test under dry friction conditions. The results show that, when the deposition time is 12 h, the bonding force of the film is the lowest and the friction coefficient is the largest (0.175, 0.438, and 0.342); the deposition distance has little effect on the friction performance. The friction coefficients (0.064, 0.107, and 0.093) of nano-diamond films (NCD) prepared at a 40 sccm CH4 concentration are smaller than those of micro-diamond films (MCD) prepared at a 16 sccm CH4 concentration. The load thresholds before delamination of Ra 0.4 μm substrate diamond film are as high as 40 N and 80 N, whereas the diamond films deposited on Ra 0.03 μm substrates have lower wear rates (4.68 × 10−4 mm3/mN, 5.34 × 10−4 mm3/mN) and low friction coefficients (0.119, 0.074, 0.175, and 0.064). Within a certain load range, the deposition of a diamond film on a Ra 0.03 μm Si3N4 substrate significantly reduces the friction coefficient and improves wear resistance. Diamond film can improve the friction performance of a workpiece and prolong its service life. Full article
(This article belongs to the Collection Feature Papers in Inorganic Membranes and Hybrid Materials)
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18 pages, 7585 KiB  
Article
Permeation Increases Biofilm Development in Nanofiltration Membranes Operated with Varying Feed Water Phosphorous Concentrations
by Luisa Javier, Laura Pulido-Beltran, Johannes S. Vrouwenvelder and Nadia M. Farhat
Membranes 2022, 12(3), 335; https://doi.org/10.3390/membranes12030335 - 18 Mar 2022
Cited by 4 | Viewed by 2093
Abstract
Nutrient limitation has been proposed as a biofouling control strategy for membrane systems. However, the impact of permeation on biofilm development under phosphorus-limited and enriched conditions is poorly understood. This study analyzed biofilm development in membrane fouling simulators (MFSs) with and without permeation [...] Read more.
Nutrient limitation has been proposed as a biofouling control strategy for membrane systems. However, the impact of permeation on biofilm development under phosphorus-limited and enriched conditions is poorly understood. This study analyzed biofilm development in membrane fouling simulators (MFSs) with and without permeation supplied with water varying dosed phosphorus concentrations (0 and 25 μg P·L−1). The MFSs operated under permeation conditions were run at a constant flux of 15.6 L·m2·h−1 for 4.7 days. Feed channel pressure drop, transmembrane pressure, and flux were used as performance indicators. Optical coherence tomography (OCT) images and biomass quantification were used to analyze the developed biofilms. The total phosphorus concentration that accumulated on the membrane and spacer was quantified by using microwave digestion and inductively coupled plasma atomic emission spectroscopy (ICP-OES). Results show that permeation impacts biofilm development depending on nutrient condition with a stronger impact at low P concentration (pressure drop increase: 282%; flux decline: 11%) compared to a higher P condition (pressure drop increase: 206%; flux decline: 2%). The biofilm that developed at 0 μg P·L−1 under permeation conditions resulted in a higher performance decline due to biofilm localization and spread in the MFS. A thicker biofilm developed on the membrane for biofilms grown at 0 μg P·L−1 under permeation conditions, causing a stronger effect on flux decline (11%) compared to non-permeation conditions (5%). The difference in the biofilm thickness on the membrane was attributed to a higher phosphorus concentration in the membrane biofilm under permeation conditions. Permeation has an impact on biofilm development and, therefore, should not be excluded in biofouling studies. Full article
(This article belongs to the Special Issue Honorary Issue for Prof. Dr. Anastasios Karabelas)
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14 pages, 5859 KiB  
Article
New Facility for Membrane Fouling Investigations under Customizable Hydrodynamics: Validation and Preliminary Experiments with Pulsating Cross-Flow
by Roberto Bert, Costantino Manes and Alberto Tiraferri
Membranes 2022, 12(3), 334; https://doi.org/10.3390/membranes12030334 - 17 Mar 2022
Cited by 3 | Viewed by 1781
Abstract
Flux reduction induced by fouling is arguably the most adverse phenomenon in membrane-based separation systems. In this respect, many laboratory-scale filtration studies have shown that an appropriate use of hydrodynamic perturbations can improve both performance and durability of the membrane; however, to fully [...] Read more.
Flux reduction induced by fouling is arguably the most adverse phenomenon in membrane-based separation systems. In this respect, many laboratory-scale filtration studies have shown that an appropriate use of hydrodynamic perturbations can improve both performance and durability of the membrane; however, to fully understand and hence appropriately exploit such effects, it is necessary to understand the underpinning flow processes. Towards this end, in this work we propose and validate a new module-scale laboratory facility with the aim of investigating, at very well-controlled flow conditions, how hydrodynamics affects mass transport phenomena at the feed/membrane interface. The proposed facility was designed to obtain a fully developed and uniform flow inside the test section and to impose both steady and pulsating flow conditions. The walls of the facility were made transparent to grant optical accessibility to the flow. In this paper, we discuss data coming from particle image velocimetry (PIV) measurements and preliminary ultrafiltration tests both under steady and pulsating flow conditions. PIV data indicate that the proposed facility allows for excellent flow control from a purely hydrodynamic standpoint. Results from filtration tests provide promising results pointing towards pulsating flows as a viable technique to reduce fouling in membrane systems. Full article
(This article belongs to the Special Issue Water and Wastewater Treatment Technologies with Membrane Filtration)
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13 pages, 33439 KiB  
Article
Nanofiltration Membranes Formed through Interfacial Polymerization Involving Cycloalkane Amine Monomer and Trimesoyl Chloride Showing Some Tolerance to Chlorine during Dye Desalination
by Micah Belle Marie Yap Ang, Yi-Ling Wu, Min-Yi Chu, Ping-Han Wu, Yu-Hsuan Chiao, Jeremiah C. Millare, Shu-Hsien Huang, Hui-An Tsai and Kueir-Rarn Lee
Membranes 2022, 12(3), 333; https://doi.org/10.3390/membranes12030333 - 17 Mar 2022
Cited by 4 | Viewed by 2705
Abstract
Wastewater effluents containing high concentrations of dyes are highly toxic to the environment and aquatic organisms. Recycle and reuse of both water and dye in textile industries can save energy and costs. Thus, new materials are being explored to fabricate highly efficient nanofiltration [...] Read more.
Wastewater effluents containing high concentrations of dyes are highly toxic to the environment and aquatic organisms. Recycle and reuse of both water and dye in textile industries can save energy and costs. Thus, new materials are being explored to fabricate highly efficient nanofiltration membranes for fulfilling industrial needs. In this work, three diamines, 1,4-cyclohexanediamine (CHD), ethylenediamine (EDA), and p-phenylenediamine (PPD), are reacted with TMC separately to fabricate a thin film composite polyamide membrane for dye desalination. Their chemical structures are different, with the difference located in the middle of two terminal amines. The surface morphology, roughness, and thickness of the polyamide layer are dependent on the reactivity of the diamines with TMC. EDA has a short linear alkane chain, which can easily react with TMC, forming a very dense selective layer. CHD has a cyclohexane ring, making it more sterically hindered than EDA. As such, CHD’s reaction with TMC is slower than EDA’s, leading to a thinner polyamide layer. PPD has a benzene ring, which should make it the most sterically hindered structure; however, its benzene ring has a pi-pi interaction with TMC that can facilitate a faster reaction between PPD and TMC, leading to a thicker polyamide layer. Among the TFC membranes, TFCCHD exhibited the highest separation efficiency (pure water flux = 192.13 ± 7.11 L∙m−2∙h−1, dye rejection = 99.92 ± 0.10%, and NaCl rejection = 15.46 ± 1.68% at 6 bar and 1000 ppm salt or 50 ppm of dye solution). After exposure at 12,000 ppm∙h of active chlorine, the flux of TFCCHD was enhanced with maintained high dye rejection. Therefore, the TFCCHD membrane has a potential application for dye desalination process. Full article
(This article belongs to the Special Issue Membranes for Resource, Energy, and Water Recovery)
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20 pages, 10490 KiB  
Article
Electrospinning of Quaternized Chitosan-Poly(vinyl alcohol) Composite Nanofiber Membrane: Processing Optimization and Antibacterial Efficacy
by Jheng-Yu Wu, Chi-Yun Wang, Kuei-Hsiang Chen, You-Ren Lai, Chen-Yaw Chiu, Hung-Che Lee and Yu-Kaung Chang
Membranes 2022, 12(3), 332; https://doi.org/10.3390/membranes12030332 - 17 Mar 2022
Cited by 14 | Viewed by 2512
Abstract
N-(2-hydroxy) propyl-3-trimethylammonium chitosan chloride (HTCC) is a type of quaternary ammonium chitosan derivative with an antibacterial activity superior to the pristine chitosan, but its electrospinnability is limited. In this study, polyvinyl alcohol (PVA) was blended with HTCC to improve the electrospinnability of [...] Read more.
N-(2-hydroxy) propyl-3-trimethylammonium chitosan chloride (HTCC) is a type of quaternary ammonium chitosan derivative with an antibacterial activity superior to the pristine chitosan, but its electrospinnability is limited. In this study, polyvinyl alcohol (PVA) was blended with HTCC to improve the electrospinnability of nanofibers. The electrospinning of PVA–HTCC nanofiber membranes was optimized in terms of structural stability and antimicrobial performance. Based on scanning electron microscopic analysis, the morphology and diameter of the produced nanofibers were influenced by the applied voltage, flow rate of the feed solution, and weight ratio of the polymer blend. An increase in the HTCC content decreased the average nanofiber diameter. The maximum water solubility of the PVA–HTCC nanofibers reached the maximum value of 70.92% at 12 h and 25 °C. The antibacterial activity of PVA–HTCC nanofiber membranes against Escherichia coli was ~90%, which is significantly higher than that of PVA–chitosan nanofiber membrane. Moreover, the antibacterial efficiency of PVA–HTCC nanofiber membranes remained unaffected after 5 cycles of antibacterial treatment. The good antibacterial performance and biocompatibility of PVA–HTCC nanofiber membrane makes them attractive for biomedical and biochemical applications that necessitate sterile conditions. Full article
(This article belongs to the Section Membrane Applications)
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17 pages, 1656 KiB  
Article
In Silico Drug Design of Benzothiadiazine Derivatives Interacting with Phospholipid Cell Membranes
by Zheyao Hu and Jordi Marti
Membranes 2022, 12(3), 331; https://doi.org/10.3390/membranes12030331 - 17 Mar 2022
Cited by 6 | Viewed by 2078
Abstract
The use of drugs derived from benzothiadiazine, a bicyclic heterocyclic benzene derivative, has become a widespread treatment for diseases such as hypertension, low blood sugar or the human immunodeficiency virus, among others. In this work we have investigated the interactions of benzothiadiazine and [...] Read more.
The use of drugs derived from benzothiadiazine, a bicyclic heterocyclic benzene derivative, has become a widespread treatment for diseases such as hypertension, low blood sugar or the human immunodeficiency virus, among others. In this work we have investigated the interactions of benzothiadiazine and four of its derivatives designed in silico with model zwitterionic cell membranes formed by dioleoylphosphatidylcholine, 1,2-dioleoyl-sn-glycero-3-phosphoserine and cholesterol at the liquid–crystal phase inside aqueous potassium chloride solution. We have elucidated the local structure of benzothiadiazine by means of microsecond molecular dynamics simulations of systems including a benzothiadiazine molecule or one of its derivatives. Such derivatives were obtained by the substitution of a single hydrogen site of benzothiadiazine by two different classes of chemical groups, one of them electron-donating groups (methyl and ethyl) and another one by electron-accepting groups (fluorine and trifluoromethyl). Our data have revealed that benzothiadiazine derivatives have a strong affinity to stay at the cell membrane interface although their solvation characteristics can vary significantly—they can be fully solvated by water in short periods of time or continuously attached to specific lipid sites during intervals of 10–70 ns. Furthermore, benzothiadiazines are able to bind lipids and cholesterol chains by means of single and double hydrogen-bonds of characteristic lengths between 1.6 and 2.1 Å. Full article
(This article belongs to the Special Issue Modeling and Simulation of Lipid Membranes)
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12 pages, 2695 KiB  
Article
Lithium Salt Catalyzed Ring-Opening Polymerized Solid-State Electrolyte with Comparable Ionic Conductivity and Better Interface Compatibility for Li-Ion Batteries
by Wei Zhang, Sujin Yoon, Lei Jin, Hyunmin Lim, Minhyuk Jeon, Hohyoun Jang, Faiz Ahmed and Whangi Kim
Membranes 2022, 12(3), 330; https://doi.org/10.3390/membranes12030330 - 16 Mar 2022
Cited by 5 | Viewed by 2716
Abstract
Rechargeable lithium-ion batteries have drawn extensive attention owing to increasing demands in applications from portable electronic devices to energy storage systems. In situ polymerization is considered one of the most promising approaches for enabling interfacial issues and improving compatibility between electrolytes and electrodes [...] Read more.
Rechargeable lithium-ion batteries have drawn extensive attention owing to increasing demands in applications from portable electronic devices to energy storage systems. In situ polymerization is considered one of the most promising approaches for enabling interfacial issues and improving compatibility between electrolytes and electrodes in batteries. Herein, we observed in situ thermally induced electrolytes based on an oxetane group with LiFSI as an initiator, and investigated structural characteristics, physicochemical properties, contacting interface, and electrochemical performances of as-prepared SPEs with a variety of technologies, such as FTIR, 1H-NMR, FE-SEM, EIS, LSV, and chronoamperometry. The as-prepared SPEs exhibited good thermal stability (stable up to 210 °C), lower activation energy, and high ionic conductivity (>0.1 mS/cm) at 30 °C. Specifically, SPE-2.5 displayed a comparable ionic conductivity (1.3 mS/cm at 80 °C), better interfacial compatibility, and a high Li-ion transference number. The SPE-2.5 electrolyte had comparable coulombic efficiency with a half-cell configuration at 0.1 C for 50 cycles. Obtained results could provide the possibility of high ionic conductivity and good compatibility through in situ polymerization for the development of Li-ion batteries. Full article
(This article belongs to the Special Issue Polymer Electrolyte for Energy Devices)
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20 pages, 8650 KiB  
Article
Dual Optimized Sulfonated Polyethersulfone and Functionalized Multiwall Carbon Tube Based Composites High Fouling Resistance Membrane for Protein Separation
by Muhammad Irfan, Masooma Irfan, Ani Idris, Abdullah Saad Alsubaie, Khaled H. Mahmoud, Noordin Mohd Yusof and Naeem Akhtar
Membranes 2022, 12(3), 329; https://doi.org/10.3390/membranes12030329 - 16 Mar 2022
Cited by 4 | Viewed by 2574
Abstract
Commercial grade sulfonated-Polyethersulfone (S-PES) and functionalized multiwall carbon nanotube (f-MWCNT)/polyvinylpyrrolidone (PVP) nanocomposites (NCs) were used to enhance and optimize the antifouling, protein resistance and protein separation properties of the S-PES ultrafiltration membranes. The polarities of sulfonic groups of S-PES, carbonyl carbon of pyrrolidone, [...] Read more.
Commercial grade sulfonated-Polyethersulfone (S-PES) and functionalized multiwall carbon nanotube (f-MWCNT)/polyvinylpyrrolidone (PVP) nanocomposites (NCs) were used to enhance and optimize the antifouling, protein resistance and protein separation properties of the S-PES ultrafiltration membranes. The polarities of sulfonic groups of S-PES, carbonyl carbon of pyrrolidone, hydroxyl and carboxyl groups of f-MWCNT in the membrane composition helped to strongly bind each other through hydrogen bonding, as shown by Fourier-transform infrared spectroscopy (FTIR). These binding forces greatly reduced the leaching of NCs and developed long finger-like projection, as confirmed by elution ratio and cross-sectional studies of the membranes via field emission scanning electron microscope (FESEM). The contact angle was reduced up to 48% more than pristine PES. Atomic force microscopy (AFM) was employed to study the various parameters of surface roughness with 3d diagrams, while grain analysis of membrane surface provided a quantitative estimation about volume, area, perimeter, length, radius and diameter. The NCs/S-PES enhanced the flux rate with an impressive (80–84%) flux recovery ratio and (58–62%) reversible resistance (Rr) value in situ, with 60% and 54.4% lesser dynamic and static protein adsorption. The best performing membrane were reported to remove 31.8%, 66.3%, 83.6% and 99.9% for lysozyme-(14.6 kDa), trypsin-(20 kDa), pepsin-(34.6 kDa) and bovine serum albumin (BSA-66 kDa), respectively. Full article
(This article belongs to the Special Issue Nanotechnology and Hybrid Membranes)
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19 pages, 3827 KiB  
Article
Influence of Y Doping on WO3 Membranes Applied in Electrolyte-Insulator-Semiconductor Structures
by Chyuan-Haur Kao, Yu-Ching Liao, Chi-Chih Chuang, Yi-Hsuan Huang, Chang-Hsueh Lee, Shih-Ming Chen, Ming-Ling Lee and Hsiang Chen
Membranes 2022, 12(3), 328; https://doi.org/10.3390/membranes12030328 - 15 Mar 2022
Cited by 1 | Viewed by 1960
Abstract
In this paper, tungsten oxide (WO3) is deposited on a silicon substrate applied in electrolyte-insulator-semiconductor structures for pH sensing devices. To boost the sensing performance, yttrium (Y) is doped into WO3 membranes, and annealing is incorporated in the fabrication process. [...] Read more.
In this paper, tungsten oxide (WO3) is deposited on a silicon substrate applied in electrolyte-insulator-semiconductor structures for pH sensing devices. To boost the sensing performance, yttrium (Y) is doped into WO3 membranes, and annealing is incorporated in the fabrication process. To investigate the effects of Y doping and annealing, multiple material characterizations including X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), atom force microscopy (AFM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) are performed. Material analysis results indicate that annealing and Y doping can increase crystallinity, suppress defects, and enhance grainization, thereby strengthening membrane sensing capabilities in terms of sensitivity, linearity, and reliability. Because of their stable response, high reliability, and compact size, Y-doped WO3 membranes are promising for future biomedical applications. Full article
(This article belongs to the Section Membrane Applications)
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23 pages, 4960 KiB  
Article
Comparative Study of Polycaprolactone Electrospun Fibers and Casting Films Enriched with Carbon and Nitrogen Sources and Their Potential Use in Water Bioremediation
by Daniella Alejandra Pompa-Monroy, Ana Leticia Iglesias, Syed Gulam Dastager, Meghana Namdeo Thorat, Amelia Olivas-Sarabia, Ricardo Valdez-Castro, Lilia Angélica Hurtado-Ayala, José Manuel Cornejo-Bravo, Graciela Lizeth Pérez-González and Luis Jesús Villarreal-Gómez
Membranes 2022, 12(3), 327; https://doi.org/10.3390/membranes12030327 - 15 Mar 2022
Cited by 2 | Viewed by 2502
Abstract
Augmenting bacterial growth is of great interest to the biotechnological industry. Hence, the effect of poly (caprolactone) fibrous scaffolds to promote the growth of different bacterial strains of biological and industrial interest was evaluated. Furthermore, different types of carbon (glucose, fructose, lactose and [...] Read more.
Augmenting bacterial growth is of great interest to the biotechnological industry. Hence, the effect of poly (caprolactone) fibrous scaffolds to promote the growth of different bacterial strains of biological and industrial interest was evaluated. Furthermore, different types of carbon (glucose, fructose, lactose and galactose) and nitrogen sources (yeast extract, glycine, peptone and urea) were added to the scaffold to determinate their influence in bacterial growth. Bacterial growth was observed by scanning electron microscopy; thermal characteristics were also evaluated; bacterial cell growth was measured by ultraviolet-visible spectrophotometry at 600-nm. Fibers produced have an average diameter between 313 to 766 nm, with 44% superficial porosity of the scaffolds, a glass transition around ~64 °C and a critical temperature of ~338 °C. The fibrous scaffold increased the cell growth of Escherichia coli by 23% at 72 h, while Pseudomonas aeruginosa and Staphylococcus aureus increased by 36% and 95% respectively at 48 h, when compared to the normal growth of their respective bacterial cultures. However, no significant difference in bacterial growth between the scaffolds and the casted films could be observed. Cell growth depended on a combination of several factors: type of bacteria, carbon or nitrogen sources, casted films or 3D scaffolds. Microscopy showed traces of a biofilm formation around 3 h in culture of P. aeruginosa. Water bioremediation studies showed that P. aeruginosa on poly (caprolactone)/Glucose fibers was effective in removing 87% of chromium in 8 h. Full article
(This article belongs to the Special Issue Electrospun Nanofiber Membranes: From Synthesis to Applications)
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20 pages, 3851 KiB  
Article
Efficacy of Two Stabilizers in Nanoemulsions with Whey Proteins and Thyme Essential Oil as Edible Coatings for Zucchini
by Iulia Bleoanca, Andreea Lanciu, Livia Patrașcu, Alina Ceoromila and Daniela Borda
Membranes 2022, 12(3), 326; https://doi.org/10.3390/membranes12030326 - 15 Mar 2022
Cited by 8 | Viewed by 2318
Abstract
Edible coatings are important for horticulture crops preservation and reducing food waste. Application of edible coatings followed by low-temperature storage prolongs the storability, preserves quality, and decreases the overall postharvest losses. This study evaluated the efficacy of two nanoemulsions formulae containing thyme essential [...] Read more.
Edible coatings are important for horticulture crops preservation and reducing food waste. Application of edible coatings followed by low-temperature storage prolongs the storability, preserves quality, and decreases the overall postharvest losses. This study evaluated the efficacy of two nanoemulsions formulae containing thyme essential oil and whey proteins as coatings for zucchini, with the purpose of extending their shelf-life. The nanoemulsions were rheologically evaluated and the formula with guar and arabic gum mix stabilizer (S) showed a better capacity to restructure after strain compared to the formulae with Tween 20 (T). The S coating material had a better capacity to integrate nanoparticles compared to T. However, when applied on zucchini, T coating was more effective in reducing weight loss showing 16% weight loss compared to 21% in S, after 42 days. At the end of storage at 10 °C, the T-coated zucchini had better firmness (p < 0.05) compared with S and both coatings were superior to control (p < 0.05). POD (peroxidase) activity was high in peel at the end of storage when also CAT (catalase) showed a sudden increase. On the 42nd day of storage, the highest enzymes activity (CAT, POD, and APX (ascorbate peroxidase)) was present in the S-coated zucchini peel. The most abundant volatile in T coating was α-pinene and 4-carene in S. Sensory analysis showed that T coating delayed the appearance of senescence while S exhibited surface cracks. Full article
(This article belongs to the Special Issue Multifunctional Hybrid Nanostructured Membranes)
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15 pages, 508 KiB  
Review
Dialysis Membranes for Acute Kidney Injury
by Yanuardi Raharjo, Muhammad Nidzhom Zainol Abidin, Ahmad Fauzi Ismail, Mochamad Zakki Fahmi, Saiful, Muthia Elma, Djoko Santoso, Hamizah Haula’ and Ahlan Riwahyu Habibi
Membranes 2022, 12(3), 325; https://doi.org/10.3390/membranes12030325 - 15 Mar 2022
Cited by 10 | Viewed by 5201
Abstract
Mortality and morbidity rates among critically ill septic patients having acute kidney injury (AKI) are very high, considering the total number of deaths after their admission. Inappropriate selection of the type of continuous renal replacement therapy and inadequate therapy become the immediate causes [...] Read more.
Mortality and morbidity rates among critically ill septic patients having acute kidney injury (AKI) are very high, considering the total number of deaths after their admission. Inappropriate selection of the type of continuous renal replacement therapy and inadequate therapy become the immediate causes of these issues. Dialysis is a commonly used treatment intended to prolong the life of AKI patients. Dialysis membranes, which are the core of dialysis treatment, must be properly selected to ensure fair treatment to the patients. The accumulation of certain types of molecules must be dealt with using the right membrane. Whether it is low-flux, high-flux, or adsorptive type, the dialysis membrane should be chosen depending on the condition of the patients. The selection of dialysis membranes should also be based on their effect on the treatment outcomes and well-being. All these options are needed to serve the patients of different clinical settings. The use of dialysis membranes is not restricted to conventional haemodialysis, but rather they can be employed in haemoperfusion, haemofiltration, haemodiafiltration, or a combination of any two of them. This review focuses in-depth on different types of dialysis membranes, their characteristics, and approaches in addressing the issues encountered in patients having AKI with sepsis and/or multiorgan failure in intensive care units. Full article
(This article belongs to the Special Issue Mixed Matrix Membranes for Molecular Separations)
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14 pages, 788 KiB  
Review
The Role of Extracellular Vesicles in Osteoporosis: A Scoping Review
by Weifei Zhang, Pengzhou Huang, Jianjing Lin and Hui Zeng
Membranes 2022, 12(3), 324; https://doi.org/10.3390/membranes12030324 - 14 Mar 2022
Cited by 10 | Viewed by 3441
Abstract
As an insidious metabolic bone disease, osteoporosis plagues the world, with high incidence rates. Patients with osteoporosis are prone to falls and becoming disabled, and their cone fractures and hip fractures are very serious, so the diagnosis and treatment of osteoporosis is very [...] Read more.
As an insidious metabolic bone disease, osteoporosis plagues the world, with high incidence rates. Patients with osteoporosis are prone to falls and becoming disabled, and their cone fractures and hip fractures are very serious, so the diagnosis and treatment of osteoporosis is very urgent. Extracellular vesicles (EVs) are particles secreted from cells to the outside of the cell and they are wrapped in a bilayer of phospholipids. According to the size of the particles, they can be divided into three categories, namely exosomes, microvesicles, and apoptotic bodies. The diameter of exosomes is 30–150 nm, the diameter of microvesicles is 100–1000 nm, and the diameter of apoptotic bodies is about 50–5000 nm. EVs play an important role in various biological process and diseases including osteoporosis. In this review, the role of EVs in osteoporosis is systematically reviewed and some insights for the prevention and treatment of osteoporosis are provided. Full article
(This article belongs to the Special Issue Shedding New Light on the Cell Biology and Medicine of Extracellular Vesicles)
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26 pages, 4954 KiB  
Article
Can Large-Scale Offshore Membrane Desalination Cost-Effectively and Ecologically Address Water Scarcity in the Middle East?
by Daniel Janowitz, Sophie Groche, Süleyman Yüce, Thomas Melin and Thomas Wintgens
Membranes 2022, 12(3), 323; https://doi.org/10.3390/membranes12030323 - 14 Mar 2022
Cited by 7 | Viewed by 5982
Abstract
The Middle East will face tremendous water scarcity by 2050, which can only be mitigated by large-scale reverse osmosis seawater desalination. However, the coastal land in the region is rare and costly, so outsourcing the desalination facility to artificial islands could become a [...] Read more.
The Middle East will face tremendous water scarcity by 2050, which can only be mitigated by large-scale reverse osmosis seawater desalination. However, the coastal land in the region is rare and costly, so outsourcing the desalination facility to artificial islands could become a realistic scenario. This study investigated the ecological and economic challenges and possible advantages of that water supply option by analysing conceptual alternatives for offshore membrane-based desalination plants of up to 600 MCM/y capacity. Key environmental impacts and mitigation strategies were identified, and a detailed economic analysis was conducted to compare the new approach to state-of-the-art. The economic analysis included calculating the cost of water production (WPC) and discussing the differences between offshore alternatives and a conventional onshore desalination plant. In addition, the study investigated the impact of a changing energy mix and potential carbon tax levels on the WPC until 2050. The results indicate that offshore desalination plants have ecological advantages compared to onshore desalination plants. Furthermore, the construction cost for the artificial islands has a much lower effect on the WPC than energy cost. In contrast, the impact of potential carbon tax levels on the WPC is significant. The specific construction cost ranges between 287 $/m2 and 1507 $/m2 depending on the artificial island type and distance to the shoreline, resulting in a WPC between 0.51 $/m3 and 0.59 $/m3. This work is the first to discuss the environmental and economic effects of locating large-scale seawater desalination plants on artificial islands. Full article
(This article belongs to the Special Issue Honorary Issue for Prof. Dr. Anastasios Karabelas)
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15 pages, 5259 KiB  
Article
MOF-Derived Nanoporous Carbon Incorporated in the Cation Exchange Membrane for Gradient Power Generation
by Xia Sun, Ying Liu, Ruibo Xu and Yongsheng Chen
Membranes 2022, 12(3), 322; https://doi.org/10.3390/membranes12030322 - 14 Mar 2022
Cited by 6 | Viewed by 3276
Abstract
Ion exchange membranes (IEMs), as a part of the reverse electrodialysis (RED) system, play an important role in salinity gradient power (SGP) generation. Structure optimization of IEMs is critical to increase the power production by RED. In this work, metal organic framework (MOF)-derived [...] Read more.
Ion exchange membranes (IEMs), as a part of the reverse electrodialysis (RED) system, play an important role in salinity gradient power (SGP) generation. Structure optimization of IEMs is critical to increase the power production by RED. In this work, metal organic framework (MOF)-derived nanoporous carbons (hollow zeolitic imidazolate framework (ZIF)-derived nanoporous carbons, HZCs) were incorporated in a sulfonated poly (2, 6-dimethyl-1,4-phenylene oxide) (sPPO) membrane to prepare an organic−inorganic nanocomposite cation exchange membrane (CEM). Physicochemical properties, electrochemical properties, and power generation of the synthesized nanocomposite membranes with different HZCs loading were characterized. The results show that the incorporated HZCs could tailor the microstructure of the membrane matrix, providing a superior performance of the nanocomposite membrane. With a HZCs loading of 1.0 wt.%, the nanocomposite membrane possessed the highest permselectivity of 77.61% and the lowest area resistance of 0.42 Ω·cm2, along with a super gross power density of 0.45 W/m2, which was 87.5% (about 1.87 times) higher than that of the blank sPPO membrane. Therefore, incorporating of an appropriate amount of HZCs in the ion-exchange membrane can improve the performance of the membrane, providing a promising method to increase the power generation of the RED system. Full article
(This article belongs to the Special Issue Membrane Processes for Liquid and Gas Separations: Opportunities and Challenges)
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13 pages, 3404 KiB  
Article
Synthesis of Nanocomposite TiSiCN Coatings by Titanium Evaporation and Organosilicon Compound Activation in Hollow Cathode Arc Discharge
by Andrey I. Menshakov, Yulia A. Bruhanova, Andrey I. Kukharenko and Ivan S. Zhidkov
Membranes 2022, 12(3), 321; https://doi.org/10.3390/membranes12030321 - 12 Mar 2022
Cited by 3 | Viewed by 2313
Abstract
TiSiCN coatings have been obtained by anode evaporation of titanium and the decomposition of hexamethyldisilazane in an arc discharge, using a self-heated hollow cathode, at the pressure rate of 1 mTorr of the Ar+N2 gas mixture. The proposed method makes it possible [...] Read more.
TiSiCN coatings have been obtained by anode evaporation of titanium and the decomposition of hexamethyldisilazane in an arc discharge, using a self-heated hollow cathode, at the pressure rate of 1 mTorr of the Ar+N2 gas mixture. The proposed method makes it possible to independently and widely change the amount of metal and precursor vapor flows, the pressure and composition of the vapor-gas mixture and the degree of ionic interaction on the surface of the growing coating within a single discharge system. The paper presents the method and the results of the effect of a current discharge (10–50 A), and the flux of precursor vapours (0–1 g/h), on deposition rates, compositions, and properties of TiSiCN coatings deposited by an advanced combined PVD+PECVD method. Dense homogeneous TiSiCN coatings up to 6 µm thick and up to 27.5 GPa in hardness were obtained at 7.5 µm/h. The composition of the obtained coatings has been studied by X-ray diffraction and X-ray photoelectron spectroscopy, and it has been shown that the presented methods can form nanocomposite coatings with nanocrystallites TiC, TiN, and TiCxN1−x 3–10 nm in the amorphous matrix based on SiCN. Full article
(This article belongs to the Special Issue Fabrication, Characterization and Application of Organic/Inorganic Film Membranes and Advanced Materials)
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27 pages, 3082 KiB  
Review
Lignocellulosic Biomass-Derived Nanocellulose Crystals as Fillers in Membranes for Water and Wastewater Treatment: A Review
by Olawumi O. Sadare, Kelvin O. Yoro, Kapil Moothi and Michael O. Daramola
Membranes 2022, 12(3), 320; https://doi.org/10.3390/membranes12030320 - 11 Mar 2022
Cited by 14 | Viewed by 3813
Abstract
The improvement of membrane applications for wastewater treatment has been a focal point of research in recent times, with a wide variety of efforts being made to enhance the performance, integrity and environmental friendliness of the existing membrane materials. Cellulose nanocrystals (CNCs) are [...] Read more.
The improvement of membrane applications for wastewater treatment has been a focal point of research in recent times, with a wide variety of efforts being made to enhance the performance, integrity and environmental friendliness of the existing membrane materials. Cellulose nanocrystals (CNCs) are sustainable nanomaterials derived from microorganisms and plants with promising potential in wastewater treatment. Cellulose nanomaterials offer a satisfactory alternative to other environmentally harmful nanomaterials. However, only a few review articles on this important field are available in the open literature, especially in membrane applications for wastewater treatment. This review briefly highlights the circular economy of waste lignocellulosic biomass and the isolation of CNCs from waste lignocellulosic biomass for membrane applications. The surface chemical functionalization technique for the preparation of CNC-based materials with the desired functional groups and properties is outlined. Recent uses of CNC-based materials in membrane applications for wastewater treatment are presented. In addition, the assessment of the environmental impacts of CNCs, cellulose extraction, the production techniques of cellulose products, cellulose product utilization, and their end-of-life disposal are briefly discussed. Furthermore, the challenges and prospects for the development of CNC from waste biomass for application in wastewater treatment are discussed extensively. Finally, this review unraveled some important perceptions on the prospects of CNC-based materials, especially in membrane applications for the treatment of wastewater. Full article
(This article belongs to the Special Issue Nanotechnology and Hybrid Membranes)
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17 pages, 2223 KiB  
Article
Versatile Encapsulation and Synthesis of Potent Liposomes by Thermal Equilibration
by Steven A. Roberts, Chaebin Lee, Shrishti Singh and Nitin Agrawal
Membranes 2022, 12(3), 319; https://doi.org/10.3390/membranes12030319 - 11 Mar 2022
Cited by 4 | Viewed by 2695
Abstract
The wide-scale use of liposomal delivery systems is challenged by difficulties in obtaining potent liposomal suspensions. Passive and active loading strategies have been proposed to formulate drug encapsulated liposomes but are limited by low efficiencies (passive) or high drug specificities (active). Here, we [...] Read more.
The wide-scale use of liposomal delivery systems is challenged by difficulties in obtaining potent liposomal suspensions. Passive and active loading strategies have been proposed to formulate drug encapsulated liposomes but are limited by low efficiencies (passive) or high drug specificities (active). Here, we present an efficient and universal loading strategy for synthesizing therapeutic liposomes. Integrating a thermal equilibration technique with our unique liposome synthesis approach, co-loaded targeting nanovesicles can be engineered in a scalable manner with potencies 200-fold higher than typical passive encapsulation techniques. We demonstrate this capability through simultaneous co-loading of hydrophilic and hydrophobic small molecules and targeted delivery of liposomal Doxorubicin to metastatic breast cancer cell line MDA-MB-231. Molecular dynamic simulations are used to explain interactions between Doxorubicin and liposome membrane during thermal equilibration. By addressing the existing challenges, we have developed an unparalleled approach that will facilitate the formulation of novel theranostic and pharmaceutical strategies. Full article
(This article belongs to the Special Issue Modern Studies on Drug-Membrane Interactions)
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14 pages, 864 KiB  
Review
The Peritoneal Membrane—A Potential Mediator of Fibrosis and Inflammation among Heart Failure Patients on Peritoneal Dialysis
by Margarita Kunin and Pazit Beckerman
Membranes 2022, 12(3), 318; https://doi.org/10.3390/membranes12030318 - 11 Mar 2022
Cited by 3 | Viewed by 9083
Abstract
Peritoneal dialysis is a feasible, cost-effective, home-based treatment of renal replacement therapy, based on the dialytic properties of the peritoneal membrane. As compared with hemodialysis, peritoneal dialysis is cheaper, survival rate is similar, residual kidney function is better preserved, fluid and solutes are [...] Read more.
Peritoneal dialysis is a feasible, cost-effective, home-based treatment of renal replacement therapy, based on the dialytic properties of the peritoneal membrane. As compared with hemodialysis, peritoneal dialysis is cheaper, survival rate is similar, residual kidney function is better preserved, fluid and solutes are removed more gradually and continuously leading to minimal impact on hemodynamics, and risks related to a vascular access are avoided. Those features of peritoneal dialysis are useful to treat refractory congestive heart failure patients with fluid overload. It was shown that in such patients, peritoneal dialysis improves functional status and quality of life, reduces hospitalization rate, and may decrease mortality rate. High levels of serum proinflammatory cytokines and fibrosis markers, among other factors, play an important part in congestive heart failure pathogenesis and progression. We demonstrated that those levels decreased following peritoneal dialysis treatment in refractory congestive heart failure patients. The exact mechanism of beneficial effect of peritoneal dialysis in refractory congestive heart failure is currently unknown. Maintenance of fluid balance, leading to resetting of neurohumoral activation towards a more physiological condition, reduced remodeling due to the decrease in mechanical pressure on the heart, decreased inflammatory cytokine levels and oxidative stress, and a potential impact on uremic toxins could play a role in this regard. In this paper, we describe the unique characteristics of the peritoneal membrane, principals of peritoneal dialysis and its role in heart failure patients. Full article
(This article belongs to the Special Issue Membranes in Renal Replacement Therapy)
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