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Composite Conducting Membranes: Preparation, Properties, and Applications

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

Deadline for manuscript submissions: closed (15 November 2021) | Viewed by 32589

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Special Issue Editors

Prof. Dr. Mohammad Rezaul Karim

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Guest Editor

Center of Excellence for Research in Engineering Materials (CEREM), Deanship of Scientific Research (DSR), College of Engineering, King Saud University, P.O. Box 800, Riyadh 11421, Saudi Arabia
Interests: nanomaterials; graphene; conducting polymers; carbon nanotubes; composites materials; material characterizations; biomaterials; quantum dots; nanofibers membranes; renewable energy; water treatments; drug delivery
Special Issues, Collections and Topics in MDPI journals

Dr. Muhammad Omer Aijaz

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Center of Excellence for Research in Engineering Materials (CEREM), Deanship of Scientific Research (DSR), College of Engineering, King Saud University, P.O. Box 800, Riyadh 11421, Saudi Arabia
Interests: electrospun nanofiber membranes; hydrogels for water treatment by adsorption of pollutants (such as metal ions and dyes); antibiotic activities and drug delivery
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

The preparation, characterization, and applications of composite conducting membranes have been widely studied due to their fascinating properties. An important use of nanoparticles and conducting polymers or ceramics is in composites, materials that combine one or more separate components and which are designed to exhibit, overall, the best properties of each component. This multifunctionality applies not only to electrical properties but extends to mechanical, optical, and magnetic ones. The exceptional physicochemical properties rendered by nanomaterials at molecular level hold great potential to address the limitations and bottlenecks of conventionally used polymeric and ceramic membranes. Currently, the major development in this field is focused on the innovative design of composite conducting membranes in which membrane structures and properties have been carefully tailored and controlled through the incorporation of a wide range of engineered nanomaterials.

In this Special Issue, we invite researchers to share their works by submitting reviews or communications and articles on topics concerning the development of composite conducting membranes. The issue will specifically cover all aspects associated with the synthesis of nanomaterials, fabrication of composite conducting membranes, their modifications, and applications in various membrane-based processes, including desalination, wastewater treatment, biomedical, energy, and environmental remediation.

Prof. Dr. Mohammad Rezaul Karim
Dr. Muhammad Omer Aijaz
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Membranes is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2700 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

composites
conducting polymers
nanofiber membranes
functional nanomaterials
physical and chemical modifications
wastewater treatments
biomedical applications
environmental remediation
energy applications
desalination

Published Papers (12 papers)

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Research

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18 pages, 4077 KiB

Open AccessArticle

Carbon Nanodots-Embedded Pullulan Nanofibers for Sulfathiazole Removal from Wastewater Streams

by Muhammad Omer Aijaz, Munir Ahmad, Mohammad I. Al-Wabel, Mohammad Rezaul Karim, Adel R. A. Usman and Abdulaziz K. Assaifan

Membranes 2022, 12(2), 228; https://0-doi-org.brum.beds.ac.uk/10.3390/membranes12020228 - 16 Feb 2022

Cited by 6 | Viewed by 2183

Abstract

Carbon nanodots (CNDs)-embedded pullulan (PUL) nanofibers were developed and successfully applied for sulfathiazole (STZ) removal from wastewater streams for the first time. The CNDs were incorporated into PUL at 0.0%, 1.0%, 2.0%, and 3.0% (w/w) to produce M1, M2, M3, and M4 nanofibers (PUL-NFs), respectively. The produced PUL-NFs were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction analysis (XRD), thermal gravimetric analysis (TGA) and Differential scanning calorimetry (DSC) and applied for STZ removal from aqueous solutions through pH, kinetics, and equilibrium batch sorption trials. A pH range of 4.0–6.0 was observed to be optimal for maximum STZ removal. Pseudo-second order, intraparticle diffusion, and Elovich models were suitably fitted to kinetics adsorption data (R² = 0.82–0.99), whereas Dubinin–Radushkevich, Freundlich, and Langmuir isotherms were fitted to equilibrium adsorption data (R²= 0.88–0.99). STZ adsorption capacity of PUL-NFs improved as the amount of embedded CNDs increased. Maximum STZ adsorption capacities of the synthesized PUL-NFs were in the order of: M4 > M3 > M2 > M1 (133.68, 124.27, 93.09, and 35.04 mg g⁻¹, respectively). Lewis acid–base reaction and π-π electron donor–acceptor interactions were the key STZ removal mechanisms under an acidic environment, whereas H-bonding and diffusion were key under a basic environment. Therefore, CNDs-embedded PUL-NFs could be employed as an environmentally friendly, efficient, and non-toxic adsorbent to remove STZ from wastewater streams. Full article

(This article belongs to the Special Issue Composite Conducting Membranes: Preparation, Properties, and Applications)

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18 pages, 9442 KiB

Open AccessArticle

Efficient Photocatalytic Degradation of Organic Pollutant in Wastewater by Electrospun Functionally Modified Polyacrylonitrile Nanofibers Membrane Anchoring TiO₂ Nanostructured

by Fahad A. AlAbduljabbar, Sajjad Haider, Fekri Abdulraqeb Ahmed Ali, Abdulaziz A. Alghyamah, Waheed A. Almasry, Raj Patel and Iqbal M. Mujtaba

Membranes 2021, 11(10), 785; https://0-doi-org.brum.beds.ac.uk/10.3390/membranes11100785 - 14 Oct 2021

Cited by 15 | Viewed by 2583

Abstract

In this study, polyacrylonitrile (PAN_P) nanofibers (NFs) were fabricated by electrospinning. The PAN_P NFs membrane was functionalized with diethylenetriamine to prepare a functionalized polyacrylonitrile (PAN_F) NFs membrane. TiO₂ nanoparticles (NPs) synthesized in the laboratory were anchored to the surface of the PAN_F NFs membrane by electrospray to prepare a TiO₂ NPs coated NFs membrane (PAN_Coa). A second TiO₂/PAN_P composite membrane (PAN_Co) was prepared by embedding TiO₂ NPs into the PAN_P NFs by electrospinning. The membranes were characterized by microscopic, spectroscopic and X-ray techniques. Scanning electron micrographs (SEM) revealed smooth morphologies for PAN_P and PAN_F NFs membranes and a dense cloud of TiO₂ NPs on the surface of PAN_Coa NFs membrane. The attenuated total reflectance in the infrared (ATR-IR) proved the addition of the new amine functionality to the chemical structure of PAN. Transmission electron microscope images (TEM) revealed spherical TiO₂ NPs with sizes between 18 and 32 nm. X-ray powder diffraction (XRD) patterns and energy dispersive X-ray spectroscopy (EDX) confirmed the existence of the anatase phase of TiO₂. Surface profilometry da-ta showed increased surface roughness for the PAN_F and PAN_Coa NFs membranes. The adsorption-desorption isotherms and hysteresis loops for all NFs membranes followed the IV -isotherm and the H3 -hysteresis loop, corresponding to mesoporous and slit pores, respectively. The photocatalytic activities of PAN_Coa and PAN_Co NFs membranes against methyl orange dye degradation were evaluated and compared with those of bare TiO₂ NPs.The higher photocatalytic activity of PAN_Coa membrane (92%, 20 ppm) compared to (PAN_Co) NFs membrane (41.64%, 20 ppm) and bare TiO₂ (49.60%, 20 ppm) was attributed to the synergy between adsorption, lower band gap, high surface roughness and surface area. Full article

(This article belongs to the Special Issue Composite Conducting Membranes: Preparation, Properties, and Applications)

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25 pages, 33480 KiB

Open AccessArticle

Experimental Study on a Ceramic Membrane Condenser with Air Medium for Water and Waste Heat Recovery from Flue Gas

by Da Teng, Liansuo An, Guoqing Shen, Shiping Zhang and Heng Zhang

Membranes 2021, 11(9), 701; https://0-doi-org.brum.beds.ac.uk/10.3390/membranes11090701 - 13 Sep 2021

Cited by 12 | Viewed by 2450

Abstract

Ceramic membrane condensers that are used for water and waste heat recovery from flue gas have the dual effects of saving water resources and improving energy efficiency. However, most ceramic membrane condensers use water as the cooling medium, which can obtain a higher water recovery flux, but the waste heat temperature is lower, which is difficult to use. This paper proposes to use the secondary boiler air as the cooling medium, build a ceramic membrane condenser with negative pressure air to recover water and waste heat from the flue gas, and analyze the transfer characteristics of flue gas water and waste heat in the membrane condenser. Based on the experimental results, it is technically feasible for the ceramic membrane condenser to use negative pressure air as the cooling medium. The flue gas temperature has the most obvious influence on the water and heat transfer characteristics. The waste heat recovery is dominated by latent heat of water vapor, accounting for 80% or above. The negative pressure air outlet temperature of the ceramic membrane condenser can reach 50.5 °C, and it is in a supersaturated state. The research content of this article provides a new idea for the water and waste heat recovery from flue gas. Full article

(This article belongs to the Special Issue Composite Conducting Membranes: Preparation, Properties, and Applications)

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16 pages, 6301 KiB

Open AccessArticle

Linking the Tuneability and Defouling of Electrically Conductive Polyaniline/Exfoliated Graphite Composite Membranes

by Lili Xu, Kunpeng Wang, Jun Wang and Darrell Alec Patterson

Membranes 2021, 11(8), 631; https://0-doi-org.brum.beds.ac.uk/10.3390/membranes11080631 - 17 Aug 2021

Cited by 2 | Viewed by 2181

Abstract

Stimuli responsive membranes, which are able to respond to environmental stimuli, are attracting ever-increasing interests. In this study, we blended exfoliated graphite (EG) into the polyaniline (PANI) and developed PANI/EG composite membranes. The properties of the new generated membranes, especially the stimuli response properties (e.g., electrical tuneability, deformation), were studied. The fouling removal ability of the membrane under applied electrical potential was also investigated by using bovine serum albumin (BSA) as a model foulant. A flat membrane with defect-free surface and good adhesion to the support layer was formed by non-solvent induced phase separation method. The electrical conductivity of the formed PANI/EG composite membrane was (5.10 ± 0.27) ×10⁻⁴ S cm⁻¹. The dynamic droplet penetration rate through the membranes showed an increase under applied electrical potential, which gives a preliminary quantitative indication of the electrical tuneability of the membranes. The membrane deformation appeared at a fast response under applied potential and recovered to its original position immediately when removing the applied potential. The application of electrical potential led to the removal of BSA foulant from the membrane surface as indicated by the increase in permeance of the fouled membrane on cleaning with 46.2% flux recovery ratio and increased BSA concentration in the wash solution. The electrically conductive PANI/EG composite membranes are able to respond to electrical stimuli, enabling a new range of potential applications including externally tuneability and in situ removal and control of fouling. Full article

(This article belongs to the Special Issue Composite Conducting Membranes: Preparation, Properties, and Applications)

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16 pages, 8132 KiB

Open AccessArticle

Comparison of Different Methods for Spongin-like Collagen Extraction from Marine Sponges (Chondrilla caribensis and Aplysina fulva): Physicochemical Properties and In Vitro Biological Analysis

by Tiago A. T. Araújo, Amanda de Souza, Alan F. Santana, Anna Rafaela C. Braga, Márcio R. Custódio, Fábio R. Simões, Gabriela M. Araújo, Antônio Miranda, Flávio Alves, Renata N. Granito, Na Yu and Ana Claudia M. Renno

Membranes 2021, 11(7), 522; https://0-doi-org.brum.beds.ac.uk/10.3390/membranes11070522 - 12 Jul 2021

Cited by 6 | Viewed by 2834

Abstract

This study aimed to compare different protocols (Protocol 1: P1; Protocol 2: P2; Protocol 3: P3; Protocol 4: P4) for the extraction of spongin-like collagen (SC) from marine sponges. The SEM micrographs demonstrated a fibrillar structure for the extracts from Chondrilla caribensis and the nodular/particulate aggregates for Aplysina fulva. FTIR showed for all samples peaks similar to collagen for both species. For C. caribensis, the extracts obtained using P2, P3, and P4 protocols presented higher values of extraction yield, TPQ, and GAGs. P2 and P4 showed higher values of SC concentration and for antioxidant analysis. For A. fulva, P2, P3, and P4 provided a higher extraction yield besides an increase in the antioxidant assay. For both species, no difference was observed for Col quantification and TPQ analysis; also, higher values of GAGs were found using P2 and P4. Fibroblast proliferation observed for C. caribensis was lower for P1 on day 1 and for P2 and P3 on day 3 (for 50%) compared to the control group. There was a significant reduction in fibroblast cell proliferation for all A. fulva extracts evaluated. It can be concluded that protocols P2 and P4 were more efficient for extracting SC from C. caribensis. Full article

(This article belongs to the Special Issue Composite Conducting Membranes: Preparation, Properties, and Applications)

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16 pages, 5468 KiB

Open AccessArticle

Amorphous NdIZO Thin Film Transistors with Contact-Resistance-Adjustable Cu S/D Electrodes

by Xinyi Zhang, Kuankuan Lu, Zhuohui Xu, Honglong Ning, Zimian Lin, Tian Qiu, Zhao Yang, Xuan Zeng, Rihui Yao and Junbiao Peng

Membranes 2021, 11(5), 337; https://0-doi-org.brum.beds.ac.uk/10.3390/membranes11050337 - 30 Apr 2021

Cited by 2 | Viewed by 2898

Abstract

High-performance amorphous oxide semiconductor thin film transistors (AOS-TFT) with copper (Cu) electrodes are of great significance for next-generation large-size, high-refresh rate and high-resolution panel display technology. In this work, using rare earth dopant, neodymium-doped indium-zinc-oxide (NdIZO) film was optimized as the active layer of TFT with Cu source and drain (S/D) electrodes. Under the guidance of the Taguchi orthogonal design method from Minitab software, the semiconductor characteristics were evaluated by microwave photoconductivity decay (μ-PCD) measurement. The results show that moderate oxygen concentration (~5%), low sputtering pressure (≤5 mTorr) and annealing temperature (≤300 °C) are conducive to reducing the shallow localized states of NdIZO film. The optimized annealing temperature of this device configuration is as low as 250 °C, and the contact resistance (R_C) is modulated by gate voltage (V_G) instead of a constant value when annealed at 300 °C. It is believed that the adjustable R_C with V_G is the key to keeping both high mobility and compensation of the threshold voltage (V_th). The optimal device performance was obtained at 250 °C with an I_on/I_off ratio of 2.89 × 10⁷, a saturation mobility (μ_sat) of 24.48 cm²/(V·s) and V_th of 2.32 V. Full article

(This article belongs to the Special Issue Composite Conducting Membranes: Preparation, Properties, and Applications)

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20 pages, 5392 KiB

Open AccessEditor’s ChoiceArticle

Batch Reverse Osmosis Desalination Modeling under a Time-Dependent Pressure Profile

by Abdeljalil Chougradi, François Zaviska, Ahmed Abed, Jérôme Harmand, Jamal-Eddine Jellal and Marc Heran

Membranes 2021, 11(3), 173; https://0-doi-org.brum.beds.ac.uk/10.3390/membranes11030173 - 28 Feb 2021

Cited by 9 | Viewed by 3190

Abstract

As world demand for clean water increases, reverse osmosis (RO) desalination has emerged as an attractive solution. Continuous RO is the most used desalination technology today. However, a new generation of configurations, working in unsteady-state feed concentration and pressure, have gained more attention recently, including the batch RO process. Our work presents a mathematical modeling for batch RO that offers the possibility of monitoring all variables of the process, including specific energy consumption, as a function of time and the recovery ratio. Validation is achieved by comparison with data from the experimental set-up and an existing model in the literature. Energetic comparison with continuous RO processes confirms that batch RO can be more energy efficient than can continuous RO, especially at a higher recovery ratio. It used, at recovery, 31% less energy for seawater and 19% less energy for brackish water. Modeling also proves that the batch RO process does not have to function under constant flux to deliver good energetic performance. In fact, under a linear pressure profile, batch RO can still deliver better energetic performance than can a continuous configuration. The parameters analysis shows that salinity, pump and energy recovery devices efficiencies are directly linked to the energy demand. While increasing feed volume has a limited effect after a certain volume due to dilution, it also shows, interestingly, a recovery ratio interval in which feed volume does not affect specific energy consumption. Full article

(This article belongs to the Special Issue Composite Conducting Membranes: Preparation, Properties, and Applications)

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25 pages, 2478 KiB

Open AccessArticle

Optimization of Wind Driven RO Plant for Brackish Water Desalination during Wind Speed Fluctuation with and without Battery

by Emad Ali, Mourad Bumazza, Ali Eltamaly, Sarwono Mulyono and Muath Yasin

Membranes 2021, 11(2), 77; https://0-doi-org.brum.beds.ac.uk/10.3390/membranes11020077 - 20 Jan 2021

Cited by 6 | Viewed by 1843

Abstract

This work aimed to carry out an optimal investigation of the design and operation of a large capacity reverse osmosis (RO) desalination plant powered by wind energy. Different scenarios involving two design options, such as using storage tanks or batteries, and operation options, such as using variable or fixed feed pressure, were analyzed and optimized. In addition, another operation option, of using a fixed number of RO vessels or a varying number of active RO vessels, was also considered. It was found that an optimized plant using storage tanks can provide a less expensive water cost and a less complicated plant structure. Moreover, the use of a variable feed pressure can help in attenuating the disturbances incurred in the form of wind intermittency. Conversely, the use of fixed feed pressure and constantly supplied power per vessel can run the RO units smoothly, leading to a predictable production rate. However, this requires operating the plant on different active sets of vessels each hour, which mandates additional automatic control systems. The water cost when storage tanks are utilized can be as low as 7.42 $/m³, while it is around 19.7 $/m³ when a battery is used. Full article

(This article belongs to the Special Issue Composite Conducting Membranes: Preparation, Properties, and Applications)

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17 pages, 9463 KiB

Open AccessArticle

Magnetic/Polyetherimide-Acrylonitrile Composite Nanofibers for Nickel Ion Removal from Aqueous Solution

by Muhammad Omer Aijaz, Mohammad Rezaul Karim, Hamad F. Alharbi, Nabeel H. Alharthi, Fahad S. Al-Mubaddel and Hany S. Abdo

Membranes 2021, 11(1), 50; https://0-doi-org.brum.beds.ac.uk/10.3390/membranes11010050 - 12 Jan 2021

Cited by 14 | Viewed by 2234

Abstract

In this study, a magnetic/polyetherimide-acrylonitrile composite nanofiber membrane with effective adsorption of nickel ions in an aqueous solution was created using a simple electrospinning method. Iron oxide nanoparticles (NPs) were stirred and ultrasonically dispersed into a polyetherimide-acrylonitrile solution to create a homogenous NPs suspension, which was placed in an electrospinning machine to produce a uniform and smooth nanofiber composite membrane. Nanoparticle incorporation into this membrane was confirmed using scanning electron microscope, energy dispersive X-ray spectroscopy (EDX), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and NPs aqueous stability from a leaching test. The high adsorption capability of the membrane on nickel ions was attributed to the combination of magnetic NPs, polyetherimide-acrylonitrile matrix, and the nanostructure of the membrane. A membrane containing magnetic NPs demonstrated the maximum adsorption capabilities (102 mg/g) of nickel ions in an aqueous solution. Various kinetic and isotherm models were applied to understand the adsorption behavior, such as pseudo-second-order kinetic and Langmuir isotherm models. A polyetherimide-acrylonitrile composite nanofiber membrane containing magnetic NPs could be used as an environmentally friendly and nontoxic adsorbent for the removal of nickel ions in an aqueous medium due to its ease of preparation and use and stability in aqueous mediums. Full article

(This article belongs to the Special Issue Composite Conducting Membranes: Preparation, Properties, and Applications)

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16 pages, 2548 KiB

Open AccessArticle

Comparative Removal of Lead and Nickel Ions onto Nanofibrous Sheet of Activated Polyacrylonitrile in Batch Adsorption and Application of Conventional Kinetic and Isotherm Models

by Muhammad Tahir Amin, Abdulrahman Ali Alazba and Muhammad Shafiq

Membranes 2021, 11(1), 10; https://0-doi-org.brum.beds.ac.uk/10.3390/membranes11010010 - 23 Dec 2020

Cited by 17 | Viewed by 2173

Abstract

We investigated the adsorption of lead (Pb²⁺) and nickel (Ni²⁺) ions by electrospun membranes of polyacrylonitrile (PAN) nanofiber activated with NaHCO₃ (PANmod). Analysis by Fourier-transform infrared spectrometry (FTIR), field emission scanning electron microscopy (FE-SEM), and energy dispersive X-ray spectroscopy (EDX) validated the functionalization of PAN nanofibers with NaHCO₃, and the successful agglomeration of Pb²⁺ and Ni²⁺ onto PANmod. After a rapid uptake of the heavy metal ions (15 min), the equilibrium contact time was attained (60 min) following a linear increase of both adsorption capacity and removal efficiency. PANmod showed a better affinity for Ni²⁺ than Pb²⁺. The adsorption on PANmod was best described by the pseudo-second-order kinetic model for both studied models, supporting chemisorption. By varying the solution pH from 2.0 to 9.0, we found that the adsorption capacity followed an increasing trend, reaching a maximum at the pH of 7.0. Despite increasing adsorption capacities, the removal efficiency of both heavy metal ions exhibited a decreasing trend with increase in initial concentrations. The amount of PANmod directly affects the removal efficiency, with 0.7 and 0.2 g being the optimum dose for maximum uptake of Pb²⁺ and Ni²⁺, respectively. The Langmuir model fitted well the Pb²⁺ adsorption data suggesting monolayer adsorption, and the Freundlich model perfectly fitted the Ni²⁺ adsorption data, indicating heterogeneous adsorption. The estimated values of the mean free energy of adsorption in the D–R isotherm indicated a physical adsorption of both heavy metal ions into the surface of the PANmod. Full article

(This article belongs to the Special Issue Composite Conducting Membranes: Preparation, Properties, and Applications)

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9 pages, 3515 KiB

Open AccessArticle

Ultralight, Strong and Renewable Hybrid Carbon Nanotubes Film for Oil-Water Emulsions Separation

by Yamei Lu, Yingze Cao, Yi Jia, Chunai Dai and Pengfei Wang

Membranes 2021, 11(1), 1; https://0-doi-org.brum.beds.ac.uk/10.3390/membranes11010001 - 22 Dec 2020

Cited by 10 | Viewed by 1965

Abstract

A novel ultralight superhydrophobic-superoleophilic hybrid Carbon Nanotubes (CNTs) film with double-layer structures is fabricated by using vacuum filtration method. The CNTs film can separate various surfactant-stabilized water-in-oil emulsions with a separation efficiency higher than 99.3%. Moreover, the hybrid films can be regenerated through a simple and rapid combustion process within 2 s. In addition, the CNTs film still retains good hydrophobic properties under the conditions of physical abrasion, and strong acidic and alkaline solutions, which shows the excellent durability. The hybrid CNTs film is ultralight, stable, and easily stored and reused. The outstanding features of the obtained CNTs films we present here may find many important applications in various fields like oil purification and wastewater treatment. Full article

(This article belongs to the Special Issue Composite Conducting Membranes: Preparation, Properties, and Applications)

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Review

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30 pages, 8609 KiB

Open AccessReview

Ionic Liquid in Phosphoric Acid-Doped Polybenzimidazole (PA-PBI) as Electrolyte Membranes for PEM Fuel Cells: A Review

by Leong Kok Seng, Mohd Shahbudin Masdar and Loh Kee Shyuan

Membranes 2021, 11(10), 728; https://0-doi-org.brum.beds.ac.uk/10.3390/membranes11100728 - 24 Sep 2021

Cited by 19 | Viewed by 4858

Abstract

Increasing world energy demand and the rapid depletion of fossil fuels has initiated explorations for sustainable and green energy sources. High-temperature polymer electrolyte membrane fuel cells (HT-PEMFCs) are viewed as promising materials in fuel cell technology due to several advantages, namely improved kinetic of both electrodes, higher tolerance for carbon monoxide (CO) and low crossover and wastage. Recent technology developments showed phosphoric acid-doped polybenzimidazole (PA-PBI) membranes most suitable for the production of polymer electrolyte membrane fuel cells (PEMFCs). However, drawbacks caused by leaching and condensation on the phosphate groups hindered the application of the PA-PBI membranes. By phosphate anion adsorption on Pt catalyst layers, a higher volume of liquid phosphoric acid on the electrolyte–electrode interface and within the electrodes inhibits or even stops gas movement and impedes electron reactions as the phosphoric acid level grows. Therefore, doping techniques have been extensively explored, and recently ionic liquids (ILs) were introduced as new doping materials to prepare the PA-PBI membranes. Hence, this paper provides a review on the use of ionic liquid material in PA-PBI membranes for HT-PEMFC applications. The effect of the ionic liquid preparation technique on PA-PBI membranes will be highlighted and discussed on the basis of its characterization and performance in HT-PEMFC applications. Full article

(This article belongs to the Special Issue Composite Conducting Membranes: Preparation, Properties, and Applications)

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