Polyamide Thin Film Composite Membranes Research Articles

A review on antifouling polyamide reverse osmosis membrane for seawater desalination.

A review on antifouling polyamide reverse osmosis membrane for seawater desalination.

Assessment of permeance and selectivity of thin-film composite polyamide membranes for diverse applications

Assessment of permeance and selectivity of thin-film composite polyamide membranes for diverse applications

Tunable Hydrated Channels in Covalent Organic Framework Membrane for Seawater Desalination.

Nanofiltration and reverse osmosis (RO) are instances of pressure-driven membrane desalination processes (PMDs), which have been extensively employed for seawater desalination due to their great efficiency and environmental friendliness. However, the PMD process is usually limited to thin-film composite polyamide membranes, despite enormous research efforts in recent decades. Here, light-controlled RO COF membranes are developed by using a defect-engineered strategy to chemically rivet spiropyran units into COF channels. The spatial arrangement of spiropyran provides the defect-engineered COF membranes with manageable apertures spanning from 6.9 to 11.1 Å. The COF membrane featuring ordered ultramicropores (6.9 Å, TAPA-TFP-SP-25% COFs) exhibits a preeminent desalinization performance with a NaCl rejection of 91.2%. Furthermore, under light stimulation, the COF channels decorated with spiropyran units are capable of self-regulating the framework structure and hydration conformation by controlling the interconnectivity of confined water clusters, thus achieving hydrated pore size tuning from 11.1 to ∼4.0 Å (from TAPA-TFP-SP-50% to TAPA-TFP-MC-50% COF membrane). Under dark conditions, zwitterionic COF membranes after photoisomerization (TAPA-TFP-MC-50%) exhibit an enhanced KCl rejection (96.2%), representing a 24.1% increase when compared to the COF membrane without interconnected hydrated channels (TAPA-TFP-SP-50%). This membrane channel design concept exploits a viable avenue for developing RO membranes to achieve efficient water purification.

Photothermal-Assisted Interfacial Polymerization toward Microstructure Regulation of a Polyamide Membrane with Enhanced Separation Performance.

A highly permeable thin-film composite (TFC) polyamide membrane with efficient salt rejection is valuable for numerous industrial processes. To achieve this objective, it is essential to innovate the membrane fabrication process to produce an ultrathin polyamide separation layer. In this study, a photothermal-assisted interfacial polymerization (IP) strategy was proposed to fabricate TFC polyamide membranes by incorporating carboxylated carbon nanotubes (CNTs) with exceptional photothermal properties. CNTs absorb solar energy and convert it into heat, significantly elevating the temperature in their microregions, thereby accelerating the reaction between m-phenylenediamine (MPD) and trimesoyl chloride (TMC) during the IP process. Exploiting the self-inhibition characteristics of IP, the preformed polyamide layer suppresses the subsequent diffusion of MPD into the reaction interface, resulting in the formation of an ultrathin polyamide layer. Consequently, the CNTs-modified polyamide membrane with photothermal assistance obtains a thickness of approximately 94 nm, significantly thinner than the control membrane (189 nm). Furthermore, it demonstrates a superior water flux of 54.4 L m-2 h-1, higher than that of the pristine TFC membrane without CNTs and the conventional CNTs-modified membrane, while maintaining a NaCl rejection of ∼96%. The photothermal-assisted IP strategy provides some inspiration for engineering high-performance polyamide membranes available in various advanced separations.

Advanced fabrication and characterization of thin-film composite polyamide membranes for superior performance in reverse osmosis desalination

Thin film composite (TFC) polyamide membranes are crucial for efficient reverse osmosis (RO) desalination, offering high selectivity and permeability. This study investigates the fabrication and optimization of TFC membranes on polysulfone supports, focusing on their structural, morphological, and performance properties for enhanced desalination efficiency using the phase inversion technique, a method that enables precise control over membrane structure. Key fabrication parameters including the concentrations of m-phenylene diamine (MPD) and trimesoyl chloride (TMC), and the immersion times for both monomers were systematically varied to investigate their impact on membrane hydrophilicity, morphology, and structure. Hydrophilicity was assessed via contact angle measurements, Scanning electron microscopy was used to characterize the morphology (SEM), and structural properties were analyzed by Fourier-transform infrared spectroscopy (FTIR). The RO membranes’ desalination performance was evaluated by measuring water flux and salt rejection in a cross-flow setup with saline water (10,000 ppm) under controlled processing conditions. Results indicated that variations in MPD and TMC concentrations, as well as immersion times, significantly influenced membrane hydrophilicity and pore structure, affecting water flux and salt rejection. The maximum salt rejection and water flux for the prepared thin film composite reverse osmosis membrane were 98.6% and 19.1 L/m2 h, respectively obtained at m-phenylenediamine concentration of 2 wt% and tri mesoyl chloride concentration of 0.1 wt/v reacted for 1 min. The study provides insights into optimizing TFC-RO membrane fabrication parameters to enhance desalination efficiency, highlighting the potential of these membranes for high-performance RO desalination applications.

Thin-Film Composite Polyamide Membranes Modified with HKUST-1 for Water Treatment: Characterization and Nanofiltration Performance.

The development of sustainable nanofiltration membranes requires alternatives to petroleum-derived polymer substrates. This study demonstrates the successful use of an eco-friendly cellulose acetate/cellulose nitrate (CA/CN) blend substrate for fabricating high-performance modified thin-film composite (mTFC) membranes. A dense, non-porous polyamide (PA) selective layer was formed via the interfacial polymerization method and modified with 0.05-0.1 wt.% HKUST-1 (Cu3BTC2, MOF-199). Characterization by FTIR, XPS, SEM, AFM, and contact angle measurements confirmed the CA/CN substrate's suitability for TFC membrane fabrication. HKUST-1 incorporation created a distinctive ridge-and-valley morphology while significantly altering PA layer hydrophilicity and roughness. The mTFC membrane performance could be fine-tuned by the controlled incorporation of HKUST-1; incorporation through the aqueous phase slowed down the formation of the PA layer and significantly reduced its thickness, while the addition through the organic phase resulted in the formation of a denser layer due to HKUST-1 agglomeration. Thus, either enhanced permeability (123 LMH bar-1 with 0.05 wt.% aqueous-phase incorporation) or rejection (>89% dye removal with 0.05 wt.% organic-phase incorporation) were achieved. Both mTFC membranes also exhibited improved heavy metal ion rejection (>91.7%), confirming their industrial potential. Higher HKUST-1 loading (0.1 wt.%) caused MOF agglomeration, reducing performance. This approach establishes a sustainable fabrication route for tunable TFC membranes targeting specific separation tasks.

High temperature resistant polyamide thin film composite nanofiltration membrane based on polyethylene substrate

High temperature resistant polyamide thin film composite nanofiltration membrane based on polyethylene substrate

Ionic covalent organic framework engineered super-charged thin-film composite polyamide membrane for desalination

Ionic covalent organic framework engineered super-charged thin-film composite polyamide membrane for desalination

Networked cellulose-integrated highly permeable TFC polyamide membranes with tailored nanofiltration performance.

Networked cellulose-integrated highly permeable TFC polyamide membranes with tailored nanofiltration performance.

Preparation of Crown Ether-Containing Polyamide Membranes via Interfacial Polymerization and Their Desalination Performance.

The large-scale application of aromatic polyamide (PA) thin-film composite (TFC) membranes for reverse osmosis has provided an effective way to address worldwide water scarcity. However, the water permeability and salt rejection capabilities of the PA membrane remain limited. In this work, cyclic micropores based on crown ether were introduced into the PA layer using a layer-by-layer interfacial polymerization (LbL-IP) method. After interfacial polymerization between m-phenylenediamine (MPD) and trimesoyl chloride (TMC), the di(aminobenzo)-18-crown-6 (DAB18C6) solution in methanol was poured on the membrane to react with the residual TMC. The cyclic micropores of DAB18C6 provided the membrane with rapid water transport channels and improved ion rejection due to its hydrophilicity and size sieving effect. The membranes were characterized by FTIR, XPS, SEM, and AFM. Compared to unmodified membranes, the water contact angle decreased from 54.1° to 31.6° indicating better hydrophilicity. Moreover, the crown ether-modified membrane exhibited both higher permeability and enhanced rejection performance. The permeability of the crown ether-modified membrane was more than ten times higher than unmodified membranes with a rejection above 95% for Na2SO4, MgSO4, MgCl2, and NaCl solution. These results highlight the potential of this straightforward surface grafting strategy and the modified membranes for advanced water treatment technologies, particularly in addressing seawater desalination challenges.

Lignin alkali regulated interfacial polymerization towards ultra-selective and highly permeable nanofiltration membrane

Thin-film composite polyamide (TFC PA) membranes hold promise for energy-efficient liquid separation, but achieving high permeance and precise separation membrane via a facile approach that is compatible with present manufacturing line remains a great challenge. Herein, we demonstrate the use of lignin alkali (LA) derived from waste of paper pulp as an aqueous phase additive to regulate interfacial polymerization (IP) process for achieving high performance nanofiltration (NF) membrane. Various characterizations and molecular dynamics simulations revealed that LA can promote the diffusion and partition of aqueous phase monomer piperazine (PIP) molecules into organic phase and their uniform dispersion on substrate, accelerating the IP reaction and promoting greater interfacial instabilities, thus endowing formation of TFC NF membrane with an ultrathin, highly cross-linked, and crumpled PA layer. The optimal membrane exhibited a remarkable water permeance of 26.0 L m-2 h-1 bar-1 and Cl-/SO42- selectivity of 191.0, which is superior to the state-of-the-art PA NF membranes. This study provides a cost-effective scalable strategy for fabricating ultra-selective and highly permeable NF membrane for precise ion-ion separation and small organic compounds removal.

Mitigating biofouling of polyamide thin-film composite RO membrane modified with AgNPs and pSBMA: an evaluation close to the actual SWRO desalination application scenario

ABSTRACT The long-term sustainability of beneficial effects resulting from the modification of polyamide thin-film composite (PATFC) membranes with zwitterionic poly(sulfobetaine methacrylate) (pSBMA) and silver nanoparticles (AgNPs) in real-world application scenarios remains uncertain. This study used response surface methodology and innovative anti-biofouling evaluation method to optimize the conditions for AgNP- and pSBMA-co-modified PATFC membranes, with reverse osmosis seawater desalination as the test application scenario. A 180-day continuous seawater treatment test was conducted to evaluate the long-term sustainability of anti-biofouling resistance. Results indicated that loading AgNPs before grafting pSBMA enhanced their stability during use and cleaning. Co-modification under optimal conditions led to a 6.3% improvement in membrane flux reduction over long-term operation. The effect of AgNPs was significant for 30 days, while pSBMA remained effective until the end of the test. Water contact angle measurements, confocal laser scanning microscopy, and quorum sensing signal molecule analysis revealed anti-bioflouling improvements due to the hydration layer and electrostatic barrier from pSBMA, as well as quorum sensing inhibition and disinfection from AgNPs. These findings confirm the discount effectiveness and feasibility of the pSBMA and AgNPs co-modification technique during long working time, offering valuable insights into modification operations and anti-biofouling mechanisms.

Post-docking hydrophilic Ag-MOF-303 filled in TFC for nanofiltration of charged PhACs in water

Post-docking hydrophilic Ag-MOF-303 filled in TFC for nanofiltration of charged PhACs in water

High rejection seawater reverse osmosis TFC membranes with a polyamide-polysulfonamide interpenetrated functional layer

High rejection seawater reverse osmosis TFC membranes with a polyamide-polysulfonamide interpenetrated functional layer

High-flux polyamide thin-film composite membranes consisting of Tröger's base motif with enhanced microporosity for nanofiltration

High-flux polyamide thin-film composite membranes consisting of Tröger's base motif with enhanced microporosity for nanofiltration

Nanofoamed Polyamide Membranes: Mechanisms, Developments, and Environmental Implications.

Thin film composite (TFC) polyamide membranes have been widely applied for environmental applications, such as desalination and water reuse. The separation performance of TFC polyamide membranes strongly depends on their nanovoid-containing roughness morphology. These nanovoids not only influence the effective filtration area of the polyamide film but also regulate the water transport pathways through the film. Although there have been ongoing debates on the formation mechanisms of nanovoids, a nanofoaming theory─stipulating the shaping of polyamide roughness morphology by nanobubbles of degassed CO2 and the vapor of volatile solvents─has gained much attention in recent years. In this review, we provide a comprehensive summary of the nanofoaming mechanism, including related fundamental principles and strategies to tailor nanovoid formation for improved membrane separation performance. The effects of nanovoids on the fouling behaviors of TFC membranes are also discussed. In addition, numerical models on the role of nanovoids in regulating the water transport pathways toward improved water permeance and antifouling ability are highlighted. The comprehensive summary on the nanofoaming mechanism in this review provides insightful guidelines for the future design and optimization of TFC polyamide membranes toward various environmental applications.

Carbon nanotube intermediate layer intercalation and its influence on surface charge of thin film composite membrane

Carbon nanotube intermediate layer intercalation and its influence on surface charge of thin film composite membrane

Ultra-Thin Cation Exchange Membranes: Sulfonated Polyamide Thin-Film Composite Membranes with High Charge Density

Ultra-Thin Cation Exchange Membranes: Sulfonated Polyamide Thin-Film Composite Membranes with High Charge Density

Fabrication and optimization of parameters of high-performance polyamide thin film composite membranes for desalination

Abstract Herein, we report the synthesis of polyamide thin film composite (PA-TFC) membranes through interfacial polymerization (IP) using an aqueous solution of diaminodiphenylmethane (DDM) and terephthaloyl chloride (TPC) in n-hexane, onto polysulfone (PSF) surface. The synthesized membranes were characterized by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), scanning electron microscope (SEM) and contact angle measurement. To optimize the conditions for achieving a better membrane function, desalination (%) and permeate flow rate (L/m2.h.bar) were evaluated as a function of synthesis conditions. The membrane efficiency for salt rejection was evaluated against NaCl using a bench-top cross-flow filtration assembly where the membrane showed up to 73.13% salt rejections of NaCl. While, the salt rejection of Na2SO4 and MgSO4 were showed up to 84.92% and 82.94%. The promising synthesized membranes exhibited a permeate flux of 41.7 L/m2.hr.bar. The contact angle analysis revealed that the synthesized PA-TFC membranes are hydrophilic as the value of contact angle measured as 109°-100°. The synthesized membrane offered facile and effective access for the synthesis of high-performance PA-TFC membranes.

Screening of the biphenyl polyamides nanofilms appropriate for molecular separation in organic solution feed

Screening of the biphenyl polyamides nanofilms appropriate for molecular separation in organic solution feed