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Membranes
Special Issues
Surface Modification and Performance Enhancement for Membranes
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Surface Modification and Performance Enhancement for Membranes

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

Deadline for manuscript submissions: closed (31 August 2023) | Viewed by 24813

Special Issue Editors

Dr. Joanna Kacprzyńska-Gołacka

E-Mail Website
Guest Editor
Surface Engineering Centre, Łukasiewicz Research Network – Institute for Sustainable Technologies, Radom, Poland
Interests: polymer membranes; plasma activation; magnetron sputtering; antibacterial properties and hydrophilic properties
Prof. Dr. Smolik Jerzy

E-Mail Website
Guest Editor
Surface Engineering Centre, Łukasiewicz Research Network – Institute for Sustainable Technologies, Radom, Poland
Interests: PVD coating; hybrid methods; plasma processes; thin coatings; advanced materials; nanomaterials
Special Issues, Collections and Topics in MDPI journals
Dr. Piotr Wieciński

E-Mail Website
Guest Editor
Faculty of Chemistry, Warsaw University of Technology, Warsaw, Poland
Interests: material characterization; phase composition analysis; microstruture analysis; thin coatings

Special Issue Information

Dear Colleagues,

Polymer membranes play an increasingly important role in various filtration processes. They are widely used in filtration processes in various industries thanks to advantages such as simple application, efficiency, and low cost. The cost associated with the operating process of the membranes is a significant problem for using membrane filtration. Currently, a lot of filtration processes, e.g., in the dairy industry, are concerned with the filtration of complex mixtures containing substances with different natures and activities, which can be deposited on the surface and in the pores of the membrane, thus reducing its filtration properties. One of the most promising ways to enrich the functional properties of polymer membranes is surface modification. Modern technologies of surface modification allow for a significant improvement in the efficiency and lifetime of membranes, which has a positive effect on reducing the costs of the filtration process.

We are pleased to invite you to submit your latest results (research articles and reviews) to the Special Issue on “Surface Modification and Performance Enhancement for Membranes” of the journal Membranes. This Special Issue aims to seek contributions to assess the state of the art and future developments in the field of modification methods used to functionalize the surface of membranes. Topics include (but are not limited to) the following: membranes materials, surface modification techniques, membrane formation mechanisms, and characterization and analysis of membrane structure and function.

We look forward to receiving your contributions.

Dr. Piotr Wieciński
Prof. Dr. Smolik Jerzy
Dr. Joanna Kacprzyńska-Gołacka
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 2200 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

  • surface modification
  • chemical treatment
  • plasma treatment
  • membranes characterization
  • enhancement of membranes
  • functional properties
  • polymer membranes
  • microfiltration
  • ultrafiltration
  • nanofiltration

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Published Papers (11 papers)

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Research

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17 pages, 6006 KiB  
Article
SiO2 Modification of Silicon Carbide Membrane via an Interfacial In Situ Sol–Gel Process for Improved Filtration Performance
by Shuangjie Shi, Kejie Jian, Minfeng Fang, Jian Guo, Pinhua Rao and Guanghui Li
Membranes 2023, 13(9), 756; https://doi.org/10.3390/membranes13090756 - 24 Aug 2023
Cited by 6 | Viewed by 1694
Abstract
Silicon carbide (SiC) membrane has emerged as a promising class of inorganic ceramic membranes with many advantageous attributes and has been used for a variety of industrial microfiltration (MF) processes. The state-of-the-art industrial manufacturing of SiC membranes based on the particle sintering method [...] Read more.
Silicon carbide (SiC) membrane has emerged as a promising class of inorganic ceramic membranes with many advantageous attributes and has been used for a variety of industrial microfiltration (MF) processes. The state-of-the-art industrial manufacturing of SiC membranes based on the particle sintering method can only achieve an average pore size that ranges from 40 nm to a few micrometers, which is still unsatisfactory for ultrafiltration (UF) applications. Thus, the pore size control of SiC membranes remains a focus of continuing study. Herein, we provide an in situ sol–gel modification strategy to tailor the pore size of SiC membranes by a superficial deposition of SiO2 onto the membrane surface and membrane pore channels. Our in situ sol–gel modification method is simple and effective. Furthermore, the physical characteristics and the filtration performance of the membrane can easily be controlled by the in situ reaction time. With an optimal in situ reaction time of 30 min, the average pore size of the membrane can be reduced from macropores (400 nm) to mesopores (below 20 nm), and the retention ability for 20 nm fluorescent PS microspheres can be improved from 5% to 93%; the resultant SiC/SiO2 composite membranes are imparted with water permeance of 77 L·m−2·h−1·bar−1, improved anti-protein-fouling properties, excellent performance, and anti-acid stabilities. Therefore, modified SiC/SiO2 membranes based on the in situ sol–gel process have great potential as UF membranes for a variety of industrial processes. Full article
(This article belongs to the Special Issue Surface Modification and Performance Enhancement for Membranes)
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18 pages, 11869 KiB  
Article
Treatment of Multi-Walled Carbon Nanotubes with Dichromic Acid: Oxidation and Appearance of Intercalation
by Valeriy Golovakhin, Ekaterina Yu. Kim, Oksana N. Novgorodtseva, Evgene A. Maksimovskiy, Arina V. Ukhina, Arcady V. Ishchenko and Alexander G. Bannov
Membranes 2023, 13(8), 729; https://doi.org/10.3390/membranes13080729 - 12 Aug 2023
Cited by 2 | Viewed by 1554
Abstract
This work is dedicated to the study of the treatment of multi-walled carbon nanotubes (MWCNTs) with dichromic acid. The dichromic acid was formed by dissolving different concentrations of CrO3 in water. The effect of the concentration of dichromic acid on the change [...] Read more.
This work is dedicated to the study of the treatment of multi-walled carbon nanotubes (MWCNTs) with dichromic acid. The dichromic acid was formed by dissolving different concentrations of CrO3 in water. The effect of the concentration of dichromic acid on the change in texture characteristics, elemental composition, defectiveness, graphitization degree, and surface chemistry of MWCNTs was investigated using various analytical techniques, such as transmission electron microscopy, energy-dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction, and X-ray photoelectron spectroscopy (XPS). Testing of MWCNTs as electrodes for supercapacitors in 3.5 M H2SO4 solution was carried out using cyclic voltammetry. A decrease in the average diameter of CNTs after treatment was found. The EDX and XPS showed that the oxygen content on the surface of MWCNTs increased after treatment with dichromic acid. The formation of Cr2O3 after treatment with dichromic acid was detected by XPS. High angle annular dark field scanning transmission electron microscopy was used to confirm the intercalation of the chromium-containing compound between graphene layers of MWCNTs after treatment with dichromic acid. It was found that two different types of MWCNTs showed diverse behavior after treatment. The highest specific capacitance of the MWCNTs after treatment was 141 F g−1 (at 2 mV s−1) compared to 0.3 F g−1 for the untreated sample. Full article
(This article belongs to the Special Issue Surface Modification and Performance Enhancement for Membranes)
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24 pages, 6624 KiB  
Article
Effects of the Applied Potential on the Performance of Polysulfone Membranes Functionalized with Sulfonated Polyether Ether Ketone Polymers
by Abelline Fionah, Kate McLarney, Aviana Judd and Isabel C. Escobar
Membranes 2023, 13(7), 675; https://doi.org/10.3390/membranes13070675 - 18 Jul 2023
Cited by 4 | Viewed by 1687
Abstract
The global water crisis growth has led to a tremendous increase in membrane technology research. Membranes are favored over many other technologies for water treatment because, in principle, they require no chemical additives and can be used isothermally at low temperatures. Membranes that [...] Read more.
The global water crisis growth has led to a tremendous increase in membrane technology research. Membranes are favored over many other technologies for water treatment because, in principle, they require no chemical additives and can be used isothermally at low temperatures. Membranes that can reject contaminants and salts, produce adequate permeate flux values, and require minimal cleaning are highly demanded. However, most synthesized membranes on the market have associated problems, such as membrane fouling; inverse relationships between flux and solute rejection; and the high cost of synthesis, operation, and maintenance. Therefore, there is a continuied need to produce membranes with properties that make them able to sustain flux and selectivity over time. This research study focused on increasing the surface charge and hydrophilicity of polysulfone (PSf) membranes by incorporating sulfonate-functionalized poly-ether-ether-ketone (SPEEK) into PSf/N-Methyl-2-pyrrolidone (PSf/NMP) membranes. The sulfonation of the PEEK provided a net increase in negative charge on the surface of the membranes that enabled charge repulsion to take place, thus increasing the rejection of ions. In this project, the effect of the applied potential on the performance of SPEEK: PSf/NMP membranes was evaluated. The characterization of the as-synthesized membranes was carried out using the surface’s structure and morphology, contact angle, and zeta potential. Furthermore, a voltage of 1.5 V was applied to the membranes in the presence of various salts (sodium chloride, calcium chloride, and potassium chloride salts) to evaluate the effects of the applied potential on solute rejection. It was found that both the permeability and the selectivity of the membranes increased when the voltage was applied. The obtained results indicate that incorporating SPEEK into PSf/NMP membranes increased the hydrophilicity of the membranes, and under the applied voltage, the incorporation allowed it to function as an electrodialysis process that is capable of removing ions from water bodies by utilizing the charge repulsion of ions. Full article
(This article belongs to the Special Issue Surface Modification and Performance Enhancement for Membranes)
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21 pages, 46083 KiB  
Article
The Development of Alginate/Ag NPs/Caffeic Acid Composite Membranes as Adsorbents for Water Purification
by Angela Spoială, Cornelia-Ioana Ilie, Georgiana Dolete, Gabriela Petrișor, Roxana-Doina Trușcă, Ludmila Motelica, Denisa Ficai, Anton Ficai, Ovidiu-Cristian Oprea and Mara-Lia Dițu
Membranes 2023, 13(6), 591; https://doi.org/10.3390/membranes13060591 - 9 Jun 2023
Cited by 9 | Viewed by 1910
Abstract
Since the water pollution problem still affects the environmental system and human health, the need to develop innovative membranes has become imperious. Lately, researchers have focused on developing novel materials to help diminish the contamination problem. The aim of present research was to [...] Read more.
Since the water pollution problem still affects the environmental system and human health, the need to develop innovative membranes has become imperious. Lately, researchers have focused on developing novel materials to help diminish the contamination problem. The aim of present research was to obtain innovative adsorbent composite membranes based on a biodegradable polymer, alginate, to remove toxic pollutants. Of all pollutants, lead was chosen due to its high toxicity. The composite membranes were successfully obtained through a direct casting method. The silver nanoparticles (Ag NPs) and caffeic acid (CA) from the composite membranes were kept at low concentrations, which proved enough to bestow antimicrobial activity to the alginate membrane. The obtained composite membranes were characterised by Fourier transform infrared spectroscopy and microscopy (FTIR), scanning electron microscopy (SEM), and thermogravimetric analysis (TG-DSC). Swelling behaviour, lead ion (Pb2+) removal capacity, regeneration and reusability were also determined. Further, the antimicrobial activity was tested against selected pathogenic strains (S. aureus, E. faecalis sp., P. aeruginosa, E. coli and C. albicans). The presence of Ag NPs and CA improves the antimicrobial activity of the newly developed membranes. Overall, the composite membranes are suitable for complex water treatment (removal of heavy metal ions and antimicrobial treatment). Full article
(This article belongs to the Special Issue Surface Modification and Performance Enhancement for Membranes)
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19 pages, 5147 KiB  
Article
Modification Approaches of Polyphenylene Oxide Membranes to Enhance Nanofiltration Performance
by Mariia Dmitrenko, Xeniya Sushkova, Anastasia Chepeleva, Vladislav Liamin, Olga Mikhailovskaya, Anna Kuzminova, Konstantin Semenov, Sergey Ermakov and Anastasia Penkova
Membranes 2023, 13(5), 534; https://doi.org/10.3390/membranes13050534 - 21 May 2023
Cited by 1 | Viewed by 1859
Abstract
Presently, water pollution poses a serious threat to the environment; the removal of organic pollutants from resources, especially dyes, is very important. Nanofiltration (NF) is a promising membrane method to carry out this task. In the present work, advanced supported poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) [...] Read more.
Presently, water pollution poses a serious threat to the environment; the removal of organic pollutants from resources, especially dyes, is very important. Nanofiltration (NF) is a promising membrane method to carry out this task. In the present work, advanced supported poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) membranes were developed for NF of anionic dyes using bulk (the introduction of graphene oxide (GO) into the polymer matrix) and surface (the deposition of polyelectrolyte (PEL) layers by layer-by-layer (LbL) technique) modifications. The effect of PEL combinations (polydiallyldimethylammonium chloride/polyacrylic acid (PAA), polyethyleneimine (PEI)/PAA, and polyallylamine hydrochloride/PAA) and the number of PEL bilayers deposited by LbL method on properties of PPO-based membranes were studied by scanning electron microscopy (SEM), atomic force microscopy (AFM), and contact angle measurements. Membranes were evaluated in NF of food dye solutions in ethanol (Sunset yellow (SY), Congo red (CR), and Alphazurine (AZ)). The supported PPO membrane, modified with 0.7 wt.% GO and three PEI/PAA bilayers, exhibited optimal transport characteristics: ethanol, SY, CR, and AZ solutions permeability of 0.58, 0.57, 0.50, and 0.44 kg/(m2h atm), respectively, with a high level of rejection coefficients—58% for SY, 63% for CR, and 58% for AZ. It was shown that the combined use of bulk and surface modifications significantly improved the characteristics of the PPO membrane in NF of dyes. Full article
(This article belongs to the Special Issue Surface Modification and Performance Enhancement for Membranes)
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14 pages, 6245 KiB  
Article
Application of Turbiscan Stability Index for the Preparation of Alumina Photocatalytic Membranes for Dye Removal
by Marida Blasi, Catia Algieri, Sudip Chakraborty and Vincenza Calabrò
Membranes 2023, 13(4), 400; https://doi.org/10.3390/membranes13040400 - 31 Mar 2023
Cited by 7 | Viewed by 2323
Abstract
In this work, for the first time, the stability of the TiO2 suspensions used for the photocatalytic membrane preparation was studied by considering the Turbiscan Stability Index (TSI). The use of a stable suspension during the membrane preparation (by the dip-coating method) [...] Read more.
In this work, for the first time, the stability of the TiO2 suspensions used for the photocatalytic membrane preparation was studied by considering the Turbiscan Stability Index (TSI). The use of a stable suspension during the membrane preparation (by the dip-coating method) permitted a better dispersion of the TiO2 nanoparticles into the membrane structure due to a reduction of agglomerates formation. The dip-coating was performed on the macroporous structure (external surface) of the Al2O3 membrane to avoid large reduction of the permeability. In addition, the reduction of the suspension infiltration along the membrane’s cross-section allowed us to preserve the separative layer of the modified membrane. The water flux was reduced by about 11% after the dip-coating. The photocatalytic performance of the prepared membranes was evaluated using the methyl orange as a model pollutant. The reusability of the photocatalytic membranes was also demonstrated. Full article
(This article belongs to the Special Issue Surface Modification and Performance Enhancement for Membranes)
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18 pages, 4853 KiB  
Article
Performance Enhancement of Kaolin/Chitosan Composite-Based Membranes by Cross-Linking with Sodium Tripolyphosphate: Preparation and Characterization
by S. Bouzid Rekik, S. Gassara, J. Bouaziz, S. Baklouti and A. Deratani
Membranes 2023, 13(2), 229; https://doi.org/10.3390/membranes13020229 - 14 Feb 2023
Cited by 5 | Viewed by 2194
Abstract
A new family of environmentally friendly and low-cost membranes based on readily available mineral and polymeric materials has been developed from cast suspensions of kaolin and chitosan using aqueous phase separation and polyethylene glycol as a pore-forming agent. The as-fabricated membranes were further [...] Read more.
A new family of environmentally friendly and low-cost membranes based on readily available mineral and polymeric materials has been developed from cast suspensions of kaolin and chitosan using aqueous phase separation and polyethylene glycol as a pore-forming agent. The as-fabricated membranes were further cross-linked with sodium tripolyphosphate (STPP) in order to strengthen the properties of the obtained samples. The functional groups determined by FTIR and EDX confirmed that the reaction occurred. A detailed study of the effects of cross-linking time on the physicochemical, surface and permeation properties showed that a 30-minute reaction enabled the composite membrane to be stable in acidic media (up to pH 2) and increased the mechanical strength twofold compared to the non-cross-linked membrane. A similar morphology to that generally observed in polymeric membranes was obtained, with a sponge-like surface overlaying a finger-like through structure. The top layer and cross-section thicknesses of the membranes increased during STPP post-treatment, while the pore size decreased from 160 to 15 nm. At the same time, the molecular weight cut-off and permeance decreased due to the increase in cross-linking density. These results observed in a series of kaolin/chitosan composite membranes showed that STPP reaction can provide control over the separation capability range, from microfiltration to ultrafiltration. Full article
(This article belongs to the Special Issue Surface Modification and Performance Enhancement for Membranes)
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Review

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23 pages, 7448 KiB  
Review
Modified Membranes for Redox Flow Batteries—A Review
by Misgina Tilahun Tsehaye, Ramato Ashu Tufa, Roviel Berhane, Francesco Deboli, Kibrom Alebel Gebru and Svetlozar Velizarov
Membranes 2023, 13(9), 777; https://doi.org/10.3390/membranes13090777 - 1 Sep 2023
Cited by 4 | Viewed by 2935
Abstract
In this review, the state of the art of modified membranes developed and applied for the improved performance of redox flow batteries (RFBs) is presented and critically discussed. The review begins with an introduction to the energy-storing chemical principles and the potential of [...] Read more.
In this review, the state of the art of modified membranes developed and applied for the improved performance of redox flow batteries (RFBs) is presented and critically discussed. The review begins with an introduction to the energy-storing chemical principles and the potential of using RFBs in the energy transition in industrial and transport-related sectors. Commonly used membrane modification techniques are briefly presented and compared next. The recent progress in applying modified membranes in different RFB chemistries is then critically discussed. The relationship between a given membrane modification strategy, corresponding ex situ properties and their impact on battery performance are outlined. It has been demonstrated that further dedicated studies are necessary in order to develop an optimal modification technique, since a modification generally reduces the crossover of redox-active species but, at the same time, leads to an increase in membrane electrical resistance. The feasibility of using alternative advanced modification methods, similar to those employed in water purification applications, needs yet to be evaluated. Additionally, the long-term stability and durability of the modified membranes during cycling in RFBs still must be investigated. The remaining challenges and potential solutions, as well as promising future perspectives, are finally highlighted. Full article
(This article belongs to the Special Issue Surface Modification and Performance Enhancement for Membranes)
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11 pages, 551 KiB  
Review
Surface Treatment of Polymer Membranes for Effective Biofouling Control
by Vinita Vishwakarma, Jaya Kandasamy and Saravanamuthu Vigneswaran
Membranes 2023, 13(8), 736; https://doi.org/10.3390/membranes13080736 - 17 Aug 2023
Viewed by 1893
Abstract
Membrane biofouling is the consequence of the deposition of microorganisms on polymer membrane surfaces. Polymeric membranes have garnered more attention for filtering and purifying water because of their ease of handling, low cost, effortless surface modification, and mechanical, chemical, and thermal properties. The [...] Read more.
Membrane biofouling is the consequence of the deposition of microorganisms on polymer membrane surfaces. Polymeric membranes have garnered more attention for filtering and purifying water because of their ease of handling, low cost, effortless surface modification, and mechanical, chemical, and thermal properties. The sizes of the pores in the membranes enable micro- and nanofiltration, ultrafiltration, and reverse osmosis. Commonly used polymers for water filter membranes are polyvinyl chloride (PVA), polyvinylidene fluoride (PVDF), polyamide (PA), polyethylene glycol (PEG), polyethersulfone (PES), polyimide (PI), polyacrylonitrile (PAN), polyvinyl alcohol (PA), poly (methacrylic acid) (PMAA), polyaniline nanoparticles (PANI), poly (arylene ether ketone) (PAEK), polyvinylidene fluoride polysulfone (PSF), poly (ether imide) (PEI), etc. However, these polymer membranes are often susceptible to biofouling because of inorganic, organic, and microbial fouling, which deteriorates the membranes and minimizes their lives, and increases operating costs. Biofouling infection on polymer membranes is responsible for many chronic diseases in humans. This contamination cannot be eliminated by periodic pre- or post-treatment processes using biocides and other chemicals. For this reason, it is imperative to modify polymer membranes by surface treatments to enhance their efficiency and longevity. The main objective of this manuscript is to discuss application-oriented approaches to control biofouling on polymer membranes using various surface treatment methods, including nanomaterials and fouling characterizations utilizing advanced microscopy and spectroscopy techniques. Full article
(This article belongs to the Special Issue Surface Modification and Performance Enhancement for Membranes)
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17 pages, 2949 KiB  
Review
Mitigation of Physical Aging of Polymeric Membrane Materials for Gas Separation: A Review
by Danila S. Bakhtin, Stepan E. Sokolov, Ilya L. Borisov, Vladimir V. Volkov, Alexey V. Volkov and Vadim O. Samoilov
Membranes 2023, 13(5), 519; https://doi.org/10.3390/membranes13050519 - 17 May 2023
Cited by 6 | Viewed by 3142
Abstract
The first commercial hollow fiber and flat sheet gas separation membranes were produced in the late 1970s from the glassy polymers polysulfone and poly(vinyltrimethyl silane), respectively, and the first industrial application was hydrogen recovery from ammonia purge gas in the ammonia synthesis loop. [...] Read more.
The first commercial hollow fiber and flat sheet gas separation membranes were produced in the late 1970s from the glassy polymers polysulfone and poly(vinyltrimethyl silane), respectively, and the first industrial application was hydrogen recovery from ammonia purge gas in the ammonia synthesis loop. Membranes based on glassy polymers (polysulfone, cellulose acetate, polyimides, substituted polycarbonate, and poly(phenylene oxide)) are currently used in various industrial processes, such as hydrogen purification, nitrogen production, and natural gas treatment. However, the glassy polymers are in a non-equilibrium state; therefore, these polymers undergo a process of physical aging, which is accompanied by the spontaneous reduction of free volume and gas permeability over time. The high free volume glassy polymers, such as poly(1-trimethylgermyl-1-propyne), polymers of intrinsic microporosity PIMs, and fluoropolymers Teflon® AF and Hyflon® AD, undergo significant physical aging. Herein, we outline the latest progress in the field of increasing durability and mitigating the physical aging of glassy polymer membrane materials and thin-film composite membranes for gas separation. Special attention is paid to such approaches as the addition of porous nanoparticles (via mixed matrix membranes), polymer crosslinking, and a combination of crosslinking and addition of nanoparticles. Full article
(This article belongs to the Special Issue Surface Modification and Performance Enhancement for Membranes)
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24 pages, 4437 KiB  
Review
Separation Performance of Membranes Containing Ultrathin Surface Coating of Metal-Polyphenol Network
by Hluf Hailu Kinfu and Md. Mushfequr Rahman
Membranes 2023, 13(5), 481; https://doi.org/10.3390/membranes13050481 - 29 Apr 2023
Cited by 7 | Viewed by 2562
Abstract
Metal–polyphenol networks (MPNs) are being used as versatile coatings for regulating membrane surface chemistry and for the formation of thin separation layers. The intrinsic nature of plant polyphenols and their coordination with transition metal ions provide a green synthesis procedure of thin films, [...] Read more.
Metal–polyphenol networks (MPNs) are being used as versatile coatings for regulating membrane surface chemistry and for the formation of thin separation layers. The intrinsic nature of plant polyphenols and their coordination with transition metal ions provide a green synthesis procedure of thin films, which enhance membrane hydrophilicity and fouling resistance. MPNs have been used to fabricate tailorable coating layers for high-performance membranes desirable for a wide range of applications. Here, we present the recent progress of the use of MPNs in membrane materials and processes with a special focus on the important roles of tannic acid–metal ion (TA-Mn+) coordination for thin film formation. This review introduces the most recent advances in the fabrication techniques and the application areas of TA-Mn+ containing membranes. In addition, this paper outlines the latest research progress of the TA–metal ion containing membranes and summarizes the role of MPNs in membrane performance. The impact of fabrication parameters, as well as the stability of the synthesized films, is discussed. Finally, the remaining challenges that the field still faces and potential future opportunities are illustrated. Full article
(This article belongs to the Special Issue Surface Modification and Performance Enhancement for Membranes)
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