Recent advancements in the application of new monomers and membrane modification techniques for the fabrication of thin film composite membranes: A review

Farahbakhsh, Javad; Vatanpour, Vahid; Khoshnam, Mahsa; Zargar, Masoumeh

doi:10.1016/j.reactfunctpolym.2021.105015

Cited by 54 publications

(16 citation statements)

References 204 publications

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“…IP limits the polymerization reaction to the interface between two monomers (typically, amines and acyl chlorides) in immiscible solvents, resulting in an ultrathin (10–300 nm) barrier layer. − Reacting monomers and solvents in IP must be designed to achieve the desired permeability and selectivity . For higher selectivity, the PA layer of RO membranes is synthesized using m -phenylenediamine (MPD) and trimesoyl chloride (TMC) . MPD allows for a higher degree of cross-linking density when compared to piperazine (PIP), the aqueous monomer typically used for TFC NF membranes .…”

Section: Solution-diffusion In Salt-rejecting Membranesmentioning

confidence: 99%

“…68 For higher selectivity, the PA layer of RO membranes is synthesized using m-phenylenediamine (MPD) and trimesoyl chloride (TMC). 69 MPD allows for a higher degree of cross-linking density when compared to piperazine (PIP), the aqueous monomer typically used for TFC NF membranes. 70 Higher cross-linking density reduces the average void size in the polymer matrix, yielding more saltselective and less water-permeable membranes.…”

Section: ■ Introductionmentioning

confidence: 99%

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Applying Transition-State Theory to Explore Transport and Selectivity in Salt-Rejecting Membranes: A Critical Review

Shefer

Lopez

Straub

et al. 2022

Environ. Sci. Technol.

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Membrane technologies using reverse osmosis (RO) and nanofiltration (NF) have been widely implemented in water purification and desalination processes. Separation between species at the molecular level is achievable in RO and NF membranes due to a complex and poorly understood combination of transport mechanisms that have attracted the attention of researchers within and beyond the membrane community for many years. Minimizing existing knowledge gaps in transport through these membranes can improve the sustainability of current water-treatment processes and expand the use of RO and NF membranes to other applications that require high selectivity between species. Since its establishment in 1949, and with growing popularity in recent years, Eyring’s transition-state theory (TST) for transmembrane permeation has been applied in numerous studies to mechanistically explore molecular transport in membranes including RO and NF. In this review, we critically assess TST applied to transmembrane permeation in salt-rejecting membranes, focusing on mechanistic insights into transport under confinement that can be gained from this framework and the key limitations associated with the method. We first demonstrate and discuss the limited ability of the commonly used solution-diffusion model to mechanistically explain transport and selectivity trends observed in RO and NF membranes. Next, we review important milestones in the development of TST, introduce its underlying principles and equations, and establish the connection to transmembrane permeation with a focus on molecular-level enthalpic and entropic barriers that govern water and solute transport under confinement. We then critically review the application of TST to explore transport in RO and NF membranes, analyzing trends in measured enthalpic and entropic barriers and synthesizing new data to highlight important phenomena associated with the temperature-dependent measurement of the activation parameters. We also discuss major limitations of the experimental application of TST and propose specific solutions to minimize the uncertainties surrounding the current approach. We conclude with identifying future research needs to enhance the implementation and maximize the benefit of TST application to transmembrane permeation.

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Section: Solution-diffusion In Salt-rejecting Membranesmentioning

confidence: 99%

Section: ■ Introductionmentioning

confidence: 99%

Applying Transition-State Theory to Explore Transport and Selectivity in Salt-Rejecting Membranes: A Critical Review

Shefer

Lopez

Straub

et al. 2022

Environ. Sci. Technol.

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“…The fouled SWRO membrane element selected for the autopsy study was used for nearly three years. In general, RO membrane comprises three layers [ 34 ]: (1) active layer made up of polyamide (thickness of ~10–200 nm), (2) porous polysulfone layer (thickness of ~50 µm), and (3) support layer (thickness of ~100–150 µm); this is to reinforce the membrane mechanical durability. In the spiral RO membrane cartridge, two layers of membrane are sandwiched by one layer of fine spacer (called as one pair) and each pair of membranes is separated by a thicker spacer.…”

Section: Materials and Methodologymentioning

confidence: 99%

Autopsy of Used Reverse Osmosis Membranes from the Largest Seawater Desalination Plant in Oman

et al. 2022

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The Barka desalination plant, commissioned in 2018, is the largest desalination plant in Oman. It has a capacity of 281 MLD with a reverse osmosis (RO) first-pass recovery rate of 46%. As part of the standard operator practice, a membrane autopsy was conducted to determine the cause of reductions in membrane performance. This study investigated fouled membranes (model No. SW30HRLE-440) from two different locations in the membrane rack. Various analytical methods were used to conduct the membrane autopsy. Field-emission scanning electron microscopy/energy-dispersive X-ray (FESEM/EDS) analyses of membrane samples showed major components of inorganic foulants. Moreover, black and salt-like crystals deposited on the membrane surface revealed significant carbon (C) components and oxygen (O), with a small amount of magnesium (mg), chloride (Cl), sodium (Na), aluminium (Al), and calcium (Ca), respectively. A Fourier transform infrared (FTIR) analysis revealed the presence of long-chain hydrocarbons, carboxylic acids/esters, carbohydrates/polysaccharides, and inorganic foulants. Thermogravimetric analyses (TGA) of the membranes showed a high initial weight loss due to organic and inorganic fouling. X-ray photoelectron (XPS) analyses further confirmed the presence of inorganic and organic foulants on the membrane surfaces. Bacteria identification results showed the presence of Bacillus cereus and Bacillus marisflavi. This paper offers a detailed analysis of the foulants present on the reverse osmosis membrane surface and sub-surface before and after a cleaning process.

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“…It should be noticed that although several review papers have been published on TFC/TFN membranes, none of the existing articles have specifically studied Pebax-based TFC/TFN membranes for gas separation, and only a cursory glance at this polymer has been made in some cases. In addition, most researchers have focused on the use of TFC/TFN membranes for water and organic solvent purification, and desalination. − More importantly, as the most studied selective layer material, an updated review article should provide valuable insights to researchers for the fabrication of novel types of TFC/TFN gas separation membranes with improved performance. To clarify more and to justify why this review article fills a critical gap in the gas separation field, Table S1 has been provided.…”

Section: Introductionmentioning

confidence: 99%

Recent Progress on Pebax-Based Thin Film Nanocomposite Membranes for CO₂ Capture: The State of the Art and Future Outlooks

et al. 2022

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Over the past three decades, membrane technology has gained increasing relevance owing to its green and energy-efficient process. Among the existing membranes, thin-film composite/nanocomposite (TFC/TFN) membranes are the subject of an increasing number of studies due to their high gas flux, high selectivity, cost reduction, and the possibility to independently control and optimize the materials of each layer. This review examines the advancement in TFC/TFN membranes for CO2 sequestration. The structure of the multilayer composite membranes and the characteristics of each layer are initially presented. Various top-down and bottom-up approaches for the preparation of composite membranes are discussed in detail. The factors influencing TFC membranes are highlighted. The focus of this research is on the separation properties of the Pebax polymer. The impacts of nanofillers on the separation performance of Pebax-based TFN membranes are meticulously inspected. Finally, the most important challenges and future outlooks to improve the membrane performance are presented.

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Recent advancements in the application of new monomers and membrane modification techniques for the fabrication of thin film composite membranes: A review

Cited by 54 publications

References 204 publications

Applying Transition-State Theory to Explore Transport and Selectivity in Salt-Rejecting Membranes: A Critical Review

Applying Transition-State Theory to Explore Transport and Selectivity in Salt-Rejecting Membranes: A Critical Review

Autopsy of Used Reverse Osmosis Membranes from the Largest Seawater Desalination Plant in Oman

Recent Progress on Pebax-Based Thin Film Nanocomposite Membranes for CO₂ Capture: The State of the Art and Future Outlooks

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Recent advancements in the application of new monomers and membrane modification techniques for the fabrication of thin film composite membranes: A review

Cited by 54 publications

References 204 publications

Applying Transition-State Theory to Explore Transport and Selectivity in Salt-Rejecting Membranes: A Critical Review

Applying Transition-State Theory to Explore Transport and Selectivity in Salt-Rejecting Membranes: A Critical Review

Autopsy of Used Reverse Osmosis Membranes from the Largest Seawater Desalination Plant in Oman

Recent Progress on Pebax-Based Thin Film Nanocomposite Membranes for CO2 Capture: The State of the Art and Future Outlooks

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Product

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Recent Progress on Pebax-Based Thin Film Nanocomposite Membranes for CO₂ Capture: The State of the Art and Future Outlooks