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Symmetry
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Asymmetric Membranes
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Asymmetric Membranes

A special issue of Symmetry (ISSN 2073-8994). This special issue belongs to the section "Chemistry: Symmetry/Asymmetry".

Deadline for manuscript submissions: closed (30 May 2020) | Viewed by 76902

Special Issue Editor

Prof. Dr. Maria Giovanna Buonomemna

E-Mail Website
Guest Editor
Ordine Regionale dei Chimici e Fisici della Campania, Naples, Italy
Interests: polymeric membranes; mixed matrix membranes; nanostructured membranes; membrane processes; sustainable processes
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Nowadays, membranes are key components in various relevant fields. In fact, their application is gradually increasing from traditional fields, such as water desalination and purification and food processing, to applications in oil and petrochemical, biopharmaceutical, power and energy-related industries.

Asymmetric membranes consist of a number of layers, each with different structures and permeabilities. Asymmetric membranes can be considered hierarchically-structured systems where well and purposefully hierarchical structures are designed to overcome transport limitations. In this context, worthy of mention is the recent special issue on hierarchically-structured porous materials edited by Martin Hartmann and Wilhelm Schwieger [1].

The present Special Issue of Symmetry features articles about membranes of different materials for different applications, with asymmetry as the unifying theme. We are soliciting contributions covering a broad range of topics including: polymers based membranes (polymers of intrinsic microporosity, high free volumes polymers, block copolymers, semi-glassy polymers, amorphous polymers); inorganic membranes (zeolites membranes, carbon molecular sieves membranes, ceramic membranes, silica membranes); mixed matrix membranes and inorganic and organic hybrid materials based membranes such as MOF membranes.

Prof. Dr. Maria Giovanna Buonomenna
Guest Editor

References

[1] Martin Hartmann and Wilhelm Schwieger, Hierarchically-structured porous materials: from basic understanding to applications, Chem. Soc. Rev., 2016, 45, 3311.

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. Symmetry 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 2400 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

  • asymmetric membranes
  • inorganic membranes
  • polymeric membranes
  • porous membranes
  • membrane design

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Published Papers (12 papers)

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Editorial

Jump to: Research, Review, Other

2 pages, 142 KiB  
Editorial
Asymmetric Membranes
by Maria Giovanna Buonomenna
Symmetry 2021, 13(8), 1360; https://doi.org/10.3390/sym13081360 - 27 Jul 2021
Viewed by 1518
Abstract
Nowadays, membranes are key components in various relevant fields [...] Full article
(This article belongs to the Special Issue Asymmetric Membranes)

Research

Jump to: Editorial, Review, Other

14 pages, 3606 KiB  
Article
Specific Structure and Properties of Composite Membranes Based on the Torlon® (Polyamide-imide)/Layered Perovskite Oxide
by Alexandra Pulyalina, Valeriia Rostovtseva, Iana Minich, Oleg Silyukov, Maria Toikka, Nataliia Saprykina and Galina Polotskaya
Symmetry 2020, 12(7), 1142; https://doi.org/10.3390/sym12071142 - 8 Jul 2020
Cited by 9 | Viewed by 3298
Abstract
The use of perovskite-type layered oxide K2La2Ti3O10 (Per) as a modifier of the Torlon® polyamide-imide (PAI) membrane has led to the formation of an specific structure of a dense nonsymmetrical film, namely, a thin perovskite-enriched [...] Read more.
The use of perovskite-type layered oxide K2La2Ti3O10 (Per) as a modifier of the Torlon® polyamide-imide (PAI) membrane has led to the formation of an specific structure of a dense nonsymmetrical film, namely, a thin perovskite-enriched layer (3–5 μm) combined with the polymer matrix (~30 μm). The PAI/Per membrane structure was studied by SEM in combination with energy dispersive microanalysis of the elemental composition which illustrated different compositions of top and bottom surfaces of the perovskite-containing membranes. Measurement of water and alcohol contact angles and calculation of surface tension revealed hydrophilization of the membrane surface enriched with perovskite. The transport properties of the nonsymmetrical PAI/Per membranes were studied in the pervaporation of ethanol‒ethyl acetate mixture. The inclusion of 2 wt.% Per in the PAI gives a membrane with a high separation factor and increased total flux. Full article
(This article belongs to the Special Issue Asymmetric Membranes)
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15 pages, 5610 KiB  
Article
Preparation of a Zirconia-Based Ceramic Membrane and Its Application for Drinking Water Treatment
by Mohamed Boussemghoune, Mustapha Chikhi, Fouzia Balaska, Yasin Ozay, Nadir Dizge and Brahim Kebabi
Symmetry 2020, 12(6), 933; https://doi.org/10.3390/sym12060933 - 3 Jun 2020
Cited by 28 | Viewed by 4917
Abstract
This work concerns the preparation of a mineral membrane by the slip casting method based on zirconium oxide (ZrO2) and kaolin. The membrane support is produced from a mixture of clay (kaolin) and calcium carbonate (calcite) powders using heat treatment (sintering). [...] Read more.
This work concerns the preparation of a mineral membrane by the slip casting method based on zirconium oxide (ZrO2) and kaolin. The membrane support is produced from a mixture of clay (kaolin) and calcium carbonate (calcite) powders using heat treatment (sintering). Membrane and support characterization were performed by Scanning Electron Microscopy (SEM), X-ray Fluorescence (XRF), Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), and Raman Spectroscopy. The prepared mineral membrane was tested to treat drinking water obtained from different zones of the El Athmania (Algeria) water station (raw, coagulated, decanted, and bio filtered water). Experimental parameters such as permeate flux, turbidity, and total coliforms were monitored. The results showed that the mineral membrane was mainly composed of SiO2 and Al2O3 and the outer surface, which represented the membrane support, was much more porous than the inner surface where the membrane was deposited. The permeate flux of the raw water decreased with filtration time, due to a rejection of the organic matters contained in the raw water. Moreover, the absence of total coliforms in the filtrate and the increase in concentration in the concentrate indicate that the prepared mineral membrane can be used for drinking water treatment. Full article
(This article belongs to the Special Issue Asymmetric Membranes)
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12 pages, 10644 KiB  
Article
The Investigation of Organic Binder Effect on Morphological Structure of Ceramic Membrane Support
by Mohamed Boussemghoune, Mustapha Chikhi, Yasin Ozay, Pelin Guler, Bahar Ozbey Unal and Nadir Dizge
Symmetry 2020, 12(5), 770; https://doi.org/10.3390/sym12050770 - 6 May 2020
Cited by 17 | Viewed by 5363
Abstract
In this study, we investigated the effect of different organic binders on the morphologic structure of ceramic membrane support. Natural raw clay material (kaolin) was used as the main mineral for ceramic membrane support. The physical and chemical properties of kaolin powder and [...] Read more.
In this study, we investigated the effect of different organic binders on the morphologic structure of ceramic membrane support. Natural raw clay material (kaolin) was used as the main mineral for ceramic membrane support. The physical and chemical properties of kaolin powder and the supports were identified by X-ray fluorescence (XRF), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Brunauer–Emmett–Teller (BET), thermo gravimetric analysis (TGA), scanning electron microscopy (SEM), particle size and zeta potential distribution. Based on the XRF test, the main composition of kaolin powder was SiO2 (47.41%) and Al2O3 (38.91%), while the rest were impurities. The FTIR spectra showed the functional groups of Si-O and Al-O. The XRD diffractogram of natural raw clay powder identified kaolinite and nacrite were the main mineral phase whereas muscovite and quartz were detected in small quantities in the sample. After prepared the ceramic membrane supports, XRD diffractogram showed that anorthite and gehlenite were detected as the main mineral phases for ethylene glycol (EG), gelatin, methocel and for polyethylene glycol (PEG), respectively. According to BET analyses, the maximum and the minimum pore width were obtained for PEG and gelatin organic binders. Full article
(This article belongs to the Special Issue Asymmetric Membranes)
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11 pages, 4077 KiB  
Article
Polyimide Asymmetric Membrane vs. Dense Film for Purification of MTBE Oxygenate by Pervaporation
by Alexandra Pulyalina, Maksim Tataurov, Ilya Faykov, Valeriia Rostovtseva and Galina Polotskaya
Symmetry 2020, 12(3), 436; https://doi.org/10.3390/sym12030436 - 9 Mar 2020
Cited by 13 | Viewed by 4049 | Correction
Abstract
Membrane properties are determined by their morphology, which may be symmetric (dense) or asymmetric (dense/porous). Two membrane types based on the poly[(4,4′-oxydiphenylene)pyromelliteimide] (symmetric dense and asymmetric dense/porous) were prepared for a comparative study of morphology, physical properties, and transport characteristics in the pervaporation [...] Read more.
Membrane properties are determined by their morphology, which may be symmetric (dense) or asymmetric (dense/porous). Two membrane types based on the poly[(4,4′-oxydiphenylene)pyromelliteimide] (symmetric dense and asymmetric dense/porous) were prepared for a comparative study of morphology, physical properties, and transport characteristics in the pervaporation of methanol/MTBE mixture over a wide range of concentrations including the azeotropic composition. The asymmetric membrane is a good example of improving the transport properties of the polyimide by creating structure composed of a thin dense top layer on the surface of sponge-like microporous substrate. It was found that the use of the asymmetric membrane allows increasing the total flux in separation of azeotropic mixture by 15 times as compared with the dense membrane. Full article
(This article belongs to the Special Issue Asymmetric Membranes)
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16 pages, 4095 KiB  
Article
Mechanical Vibration for the Control of Membrane Fouling in Direct Contact Membrane Distillation
by Frank Y.C. Huang, Carolyn Medin and Allie Arning
Symmetry 2019, 11(2), 126; https://doi.org/10.3390/sym11020126 - 22 Jan 2019
Cited by 12 | Viewed by 4899
Abstract
One of the biggest challenges for direct contact membrane distillation (DCMD) in treating wastewater from flue gas desulfurization (FGD) is the rapid deterioration of membrane performance resulting from precipitate fouling. Chemical pretreatment, such as lime-soda ash softening, has been used to mitigate the [...] Read more.
One of the biggest challenges for direct contact membrane distillation (DCMD) in treating wastewater from flue gas desulfurization (FGD) is the rapid deterioration of membrane performance resulting from precipitate fouling. Chemical pretreatment, such as lime-soda ash softening, has been used to mitigate the issue, however, with significant operating costs. In this study, mechanical vibration of 42.5 Hz was applied to lab-scale DCMD systems to determine its effectiveness of fouling control for simulated FGD water. Liquid entry pressure and mass transfer limit of the fabricated hollow fiber membranes were determined and used as the operational constraints in the fouling experiments so that the observed membrane performance was influenced solely by precipitate fouling. Minimal improvement of water flux was observed when applying vibration after significant (~16%) water-flux decline. Initiating vibration at the onset of the experiments prior to the exposure of foulants, however, was promising for the reduction of membrane fouling. The water-flux decline rate was reduced by about 50% when compared to the rate observed without vibration. Increasing the module packing density from 16% to 50% resulted in a similar rate of water-flux decline, indicating that the fouling propensity was not increased with packing density in the presence of vibration. Full article
(This article belongs to the Special Issue Asymmetric Membranes)
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Review

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12 pages, 2001 KiB  
Review
Asymmetric Cellulosic Membranes: Current and Future Aspects
by Tuerxun Duolikun, Nadiah Ghazali, Bey Fen Leo, Hwei Voon Lee, Chin Wei Lai and Mohd Rafie Bin Johan
Symmetry 2020, 12(7), 1160; https://doi.org/10.3390/sym12071160 - 13 Jul 2020
Cited by 13 | Viewed by 6432
Abstract
In this paper, we report our attempt to elaborate on cellulose-based materials and their potential application in membrane science, especially in separation applications. Furthermore, the cellulosic membrane has received attention for potential use as biomaterials such as novel wound-dressings and hemodialysis materials. In [...] Read more.
In this paper, we report our attempt to elaborate on cellulose-based materials and their potential application in membrane science, especially in separation applications. Furthermore, the cellulosic membrane has received attention for potential use as biomaterials such as novel wound-dressings and hemodialysis materials. In this mini-review, we mainly focus on the separation and antimicrobial properties of cellulosic membranes and the advanced synthesis/processing methods for superior functional quality for various potential applications. Finally, we conclude with the market and the impact of developments of future expectations. Full article
(This article belongs to the Special Issue Asymmetric Membranes)
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33 pages, 2840 KiB  
Review
Surface Modifications of Nanofillers for Carbon Dioxide Separation Nanocomposite Membrane
by Pei Sean Goh, Kar Chun Wong, Lukka Thuyavan Yogarathinam, Ahmad Fauzi Ismail, Mohd Sohaimi Abdullah and Be Cheer Ng
Symmetry 2020, 12(7), 1102; https://doi.org/10.3390/sym12071102 - 2 Jul 2020
Cited by 21 | Viewed by 4556
Abstract
CO2 separation is an important process for a wide spectrum of industries including petrochemical, refinery and coal-fired power plant industries. The membrane-based process is a promising operation for CO2 separation owing to its fundamental engineering and economic benefits over the conventionally [...] Read more.
CO2 separation is an important process for a wide spectrum of industries including petrochemical, refinery and coal-fired power plant industries. The membrane-based process is a promising operation for CO2 separation owing to its fundamental engineering and economic benefits over the conventionally used separation processes. Asymmetric polymer–inorganic nanocomposite membranes are endowed with interesting properties for gas separation processes. The presence of nanosized inorganic nanofiller has offered unprecedented opportunities to address the issues of conventionally used polymeric membranes. Surface modification of nanofillers has become an important strategy to address the shortcomings of nanocomposite membranes in terms of nanofiller agglomeration and poor dispersion and polymer–nanofiller incompatibility. In the context of CO2 gas separation, surface modification of nanofiller is also accomplished to render additional CO2 sorption capacity and facilitated transport properties. This article focuses on the current strategies employed for the surface modification of nanofillers used in the development of CO2 separation nanocomposite membranes. A review based on the recent progresses made in physical and chemical modifications of nanofiller using various techniques and modifying agents is presented. The effectiveness of each strategy and the correlation between the surface modified nanofiller and the CO2 separation performance of the resultant nanocomposite membranes are thoroughly discussed. Full article
(This article belongs to the Special Issue Asymmetric Membranes)
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18 pages, 3638 KiB  
Review
Asymmetric Membranes: A Potential Scaffold for Wound Healing Applications
by Seyyed Mojtaba Mousavi, Maryam Zarei, Seyyed Alireza Hashemi, Seeram Ramakrishna, Wei-Hung Chiang, Chin Wei Lai, Ahmad Gholami, Navid Omidifar and Mansoureh Shokripour
Symmetry 2020, 12(7), 1100; https://doi.org/10.3390/sym12071100 - 2 Jul 2020
Cited by 54 | Viewed by 5912
Abstract
Currently, due to uprising concerns about wound infections, healing agents have been regarded as one of the major solutions in the treatment of different skin lesions. The usage of temporary barriers can be an effective way to protect wounds or ulcers from dangerous [...] Read more.
Currently, due to uprising concerns about wound infections, healing agents have been regarded as one of the major solutions in the treatment of different skin lesions. The usage of temporary barriers can be an effective way to protect wounds or ulcers from dangerous agents and, using these carriers can not only improve the healing process but also they can minimize the scarring and the pain suffered by the human. To cope with this demand, researchers struggled to develop wound dressing agents that could mimic the structural and properties of native skin with the capability to inhibit bacterial growth. Hence, asymmetric membranes that can impair bacterial penetration and avoid exudate accumulation as well as wound dehydration have been introduced. In general, synthetic implants and tissue grafts are expensive, hard to handle (due to their fragile nature and poor mechanical properties) and their production process is very time consuming, while the asymmetric membranes are affordable and their production process is easier than previous epidermal substitutes. Motivated by this, here we will cover different topics, first, the comprehensive research developments of asymmetric membranes are reviewed and second, general properties and different preparation methods of asymmetric membranes are summarized. In the two last parts, the role of chitosan based-asymmetric membranes and electrospun asymmetric membranes in hastening the healing process are mentioned respectively. The aforementioned membranes are inexpensive and possess high antibacterial and satisfactory mechanical properties. It is concluded that, despite the promising current investigations, much effort is still required to be done in asymmetric membranes. Full article
(This article belongs to the Special Issue Asymmetric Membranes)
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24 pages, 7593 KiB  
Review
Porous Polyvinyl Alcohol Membranes: Preparation Methods and Applications
by Andreas A. Sapalidis
Symmetry 2020, 12(6), 960; https://doi.org/10.3390/sym12060960 - 5 Jun 2020
Cited by 114 | Viewed by 22442
Abstract
Polymeric membrane technology is a constantly developing field in both the research and industrial sector, with many applications considered nowadays as mature such as desalination, wastewater treatment, and hemodialysis. A variety of polymers have been used for the development of porous membranes by [...] Read more.
Polymeric membrane technology is a constantly developing field in both the research and industrial sector, with many applications considered nowadays as mature such as desalination, wastewater treatment, and hemodialysis. A variety of polymers have been used for the development of porous membranes by implementing numerous approaches such as phase inversion, electrospinning, sintering, melt-spinning and cold-stretching, 3D printing, and others. Depending on the application, certain polymer characteristics such as solubility to non-toxic solvents, mechanical and thermal stability, non-toxicity, resistance to solvents, and separation capabilities are highly desired. Poly (vinyl alcohol) (PVA) is a polymer that combines the above-mentioned properties with great film forming capabilities, good chemical and mechanical stability, and tuned hydrophilicity, rendering it a prominent candidate for membrane preparation since the 1970s. Since then, great progress has been made both in preparation methods and possible unique applications. In this review, the main preparation methods and applications of porous PVA based membranes, along with introductory material are presented. Full article
(This article belongs to the Special Issue Asymmetric Membranes)
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38 pages, 4652 KiB  
Review
The Recent Progress in Modification of Polymeric Membranes Using Organic Macromolecules for Water Treatment
by Saraswathi Nagandran, Pei Sean Goh, Ahmad Fauzi Ismail, Tuck-Whye Wong and Wan Rosmiza Zana Binti Wan Dagang
Symmetry 2020, 12(2), 239; https://doi.org/10.3390/sym12020239 - 4 Feb 2020
Cited by 47 | Viewed by 8327
Abstract
For decades, the water deficit has been a severe global issue. A reliable supply of water is needed to ensure sustainable economic development in population growth, industrialization and urbanization. To solve this major challenge, membrane-based water treatment technology has attracted a great deal [...] Read more.
For decades, the water deficit has been a severe global issue. A reliable supply of water is needed to ensure sustainable economic development in population growth, industrialization and urbanization. To solve this major challenge, membrane-based water treatment technology has attracted a great deal of attention to produce clean drinking water from groundwater, seawater and brackish water. The emergence of nanotechnology in membrane science has opened new frontiers in the development of advanced polymeric membranes to enhance filtration performance. Nevertheless, some obstacles such as fouling and trade-off of membrane selectivity and permeability of water have hindered the development of traditional polymeric membranes for real applications. To overcome these issues, the modification of membranes has been pursued. The use of macromolecules for membrane modification has attracted wide interests in recent years owing to their interesting chemical and structural properties. Membranes modified with macromolecules have exhibited improved anti-fouling properties due to the alteration of their physiochemical properties in terms of the membrane morphology, porosity, surface charge, wettability, and durability. This review provides a comprehensive review of the progress made in the development of macromolecule modified polymeric membranes. The role of macromolecules in polymeric membranes and the advancement of these membrane materials for water solution are presented. The challenges and future directions for this subject are highlighted. Full article
(This article belongs to the Special Issue Asymmetric Membranes)
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Other

4 pages, 437 KiB  
Commentary
Design Next Generation Membranes or Rethink the “Old” Asymmetric Membranes?
by Maria Giovanna Buonomenna
Symmetry 2020, 12(2), 270; https://doi.org/10.3390/sym12020270 - 10 Feb 2020
Cited by 14 | Viewed by 3454
Abstract
The first integrally-skinned asymmetric cellulose acetate (CA) membrane for water desalination were developed by Loeb and Sourirajan in the early 1960s at UCLA [...] Full article
(This article belongs to the Special Issue Asymmetric Membranes)
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