Polysulfone Substrate Research Articles

Immobilization of sulfonated polysulfone via 2D LDH nanosheets during phase-inversion: A novel strategy towards greener membrane synthesis and enhanced desalination performance

Sulfonated polysulfone (sPSf) is a commonly used hydrophilic additive to polysulfone (PSf) substrates for preparing polyamide membranes with enhancement desalination performance. However, severe leaching of water-soluble sPSf into the coagulation water bath during substrate formation can lead to weakened mechanical strength of the substrate, loss of the expensive sPSf polymer, and potential environmental pollution. In this study, we report a novel and efficient strategy to “anchor” sPSf in the PSf matrix by using 2D layered double hydroxide (LDH) nanosheets. LDH nanosheets effectively immobilized sPSf due to their electrostatic interaction, resulting in greener membrane synthesis. Substrates modified with LDH anchored sPSf (PSf/sPSf5-LDHx) exhibited enhanced mechanical strength and water permeability compared to the pristine PSf substrate as well as the sPSf-blended substrates (sPSf/sPSf5). Interfacial polymerization on the PSf/sPSf5-LDHx substrate resulted in a polyamide rejection film containing more extensive nanovoids and thus greater effective filtration area, which enhanced water permeability without major loss of salt rejection. In forward osmosis tests, this novel membrane enjoyed an additional advantage of less severe internal concentration polarization, as reflected by its significantly reduced structural parameter.

Effects of polyethylene glycol and glutaraldehyde cross-linker on TFC-FO membrane performance

Polymers containing polyethylene glycols (PEGs) and Glutaraldehyde (GLA) cross-linker in the casting solution can improve the membrane performance such as porosity and swelling properties in the fabrication process. The highly hydrophilic polyethylene glycols (PEGs) including PEG 20000, PEG 6000, and PEG 1000 were utilized as the additives to modify the membrane structure. GLA was also added into the PEGs combined with a polysulfone (PSf) substrate to create a cross-linked polymer in the PSf membrane structure. This cross-linker significantly improved the water flux by increasing the porosity and decreasing the swelling within the PSf membrane structure. The hydroxyl hydrophilic functional group in GLA enhanced the water permeability by grafting the polymer chains. The newly developed cross-linker not only reduced the swelling in the membrane structure but also created tightly linked between the monomers to reduce the solute diffusion through the membrane. The presence of the PEG can enhance the TFC-FO membrane hydrophilicity by changing the PSf polymer nature, and PEG 6000 showed a better performance with macrovoid-free sponge-like structure and lower surface roughness. The combination of PEG 6000 (wt.% = 17%) and cross-linker exhibited an excellent performance with water flux of 6.22 L/m2h and reverse salt flux of 1.79 g/m2h when using 2 M NaCl as the draw solution and deionized water as the feed solution.

A composite membrane of cross-linked GO network semi-interpenetrating in polysulfone substrate for dye removal from water

There has been an increasing focus on the application of graphene oxide (GO) composite membrane in water treatment. For long-term operation in aqueous solutions, the diamine cross-linkers are widely used to stabilize the GO laminates on the supporting substrate. Polysulfone (PSf) is a superior candidate to support the GO laminates due to its highly chemical, mechanical and thermal stability, but its lack of active sites for cross-linking reaction leads to the easy exfoliation of the GO laminates from the PSf surface within a few hours. In this work, we report a novel fabrication approach to obtain a composite membrane with semi-interpenetrating network of cross-linked GO film in the PSf substrate coupled with a high hydration stability in the application of water treatment. The hydration swelling has little effect on the water permeability and dye rejection. The GO composite membrane exhibits excellent structure stability in water, acid, and alkaline solutions for several days or even longer. Such membranes show comparable water flux with the pristine GO composite membranes, and nearly complete rejection to dyes (i.e. methyl orange, methylene blue, congo red and reactive green). This work provides a novel and facile strategy for the fabrication of structure-enhanced GO composite membrane highly promising for practical applications.

Preparation, characterization and scaling propensity study of a dopamine incorporated RO/FO TFC membrane for pesticide removal

The poor permeability of prevalent thin film composite (TFC) membranes impedes their application in forward osmosis (FO). In this study, a high-flux TFC membrane was prepared by incorporating dopamine (DA) into an aqueous solution with various concentrations of m-phenylendiamine (MPD) in interfacial polymerization with trimesoyl chloride (TMC) on a fabricated polysulfone (PSF) substrate. SEM, AFM, XPS, ATR-FTIR, and water contact angle measurement (WCA) and Zeta potential were exploited to characterize synthesized membranes. The optimized TFC membrane (TFC-2; MPD: 2 wt%, DA: 0.1 wt%) attained a nearly five-fold water flux improvement (33.3 LMH (L.m−2.h−1) versus 7.1 LMH for control membrane), an acceptable reverse salt flux of 4.1 g/m2h and a reduced structural parameter (125 μm) in FO with 1 M NaCl draw solution. Membranes were then employed for pesticide removal from water in both reverse osmosis (RO) and FO resulting in high rejection values of >92% in RO and >91% in FO by the optimal membrane for all studied pesticides. Furthermore, the optimized DA-incorporated sample exhibited a better performance compared to the control membrane in terms of anti-scaling behavior and the scaling propensity of RO and FO processes was studied through flux decline measurement in supersaturated solutions with different concentrations of gypsum as model scalant. This study suggests that the FO process, regardless of the membrane material, is per se more resistant against scaling with a threshold gypsum concentration of 25–30 mM compared to RO starting to scale within 20–25 mM of gypsum solution within 24 h.

Enhancing the permeability of reverse osmosis membrane by embedding the star‐like rigid supports in the substrate

AbstractThin film composite (TFC) reverse osmosis (RO) membranes with high permeability have been prepared by interfacial polymerization based on tailoring the polysulfone (PSf) substrate structure by in situ embedded poly(p‐phenylene terephthamide) (PPTA) star‐like rigid supports. The star‐like rigid supports were observed by the polarizing optical microscopy (POM) and transmission electron microscope (TEM). The surface properties of the substrates were investigated by FTIR, the water contact angle (WCA), FESEM and AFM. The WCA was decreased from 88.5° to 72.3° with the PPTA increasing from 0% to 8%, and the surface roughness increased from 24.2, 25.1, 33.5 and 58.6 nm, respectively. Furthermore, numerous interconnect micro‐structures were constructed in the substrate when the PPTA content was up to 8%. The pure water flux of 8% PPTA/92%PSf substrate was up to 377.0 L m−2 h−1 and the flux decline rate was lowest (64%) after compacted at 5.5 MPa for 30 min. Otherwise, increasing the PPTA contents in the substrate enhanced the roughness, encouraged nanosheet formation and improved the permeability of TFC RO membranes. The pure water flux of the TFC RO membranes increased from 36.32 to 58.42 L m−2 h−1, where the NaCl rejection was about 99.5% at 5.5 MPa.

Enhancing the desalination performance of forward osmosis membrane through the incorporation of green nanocrystalline cellulose and halloysite dual nanofillers

AbstractBACKGROUNDMembrane fouling remains an unmet challenge for all membrane processes, including osmotically driven forward osmosis (FO). Membrane modification is a straightforward and feasible approach to enhancing fouling resistance. In this study, thin film nanocomposite (TFN) membranes incorporated with dual nanofiller were prepared. Halloysite nanotube (HNT) was incorporated into the polysulfone substrate while functionalized nanocrystalline cellulose (NCC) was embedded within the polyamide (PA) thin layer of the TFN.RESULTSThe formation of crystalline needle‐like NCC was observed through X‐ray diffraction (XRD) patterns and transmission electron microscopy (TEM) images. TFNs embedded with functionalized NCC at different loadings were characterized in terms of morphology, surface roughness and hydrophilicity, separation performance and antifouling propensity. The incorporation of hydrophilic NCC has significantly reduced the water contact angle from 69° for the TFN0.0 to 45° for TFN incorporated with 0.1 wt/v% of NCC. The water flux of TFN0.05, as the best performing membrane, was recorded as 21.34 L/m2 h. This was about 140% greater than that of TFN0.0 at the same operating conditions. The embedment of NCC also reduced the extent of concentration polarization (CP) in TFN0.05, which resulted in better protein fouling resistance and lower water flux decline in comparison to neat membranes.CONCLUSIONSOverall, the enhancement of both the water flux and antifouling properties of the membrane, without compromising the salt rejection when a low amount of NCC (<0.1 wt/v%) was incorporated into the thin PA layer, demonstrated the potential of dual nanofillers TFN for effective forward osmosis desalination application. © 2020 Society of Chemical Industry

Dissecting the Role of Substrate on the Morphology and Separation Properties of Thin Film Composite Polyamide Membranes: Seeing Is Believing.

Recent studies show that the surface morphology of a thin film composite (TFC) polyamide membrane depends strongly on its porous substrate. Nevertheless, the underlining mechanisms and the effects on membrane separation performance remain controversial. To dissect the exact role of pore properties, we synthesized TFC polyamide membranes on polycarbonate substrates with cylindrical track-etched pores (PCTE) of well-defined pore size ranging from 10 to 800 nm. Leaf-like roughness features were most prominent for polyamide films formed on substrates of intermediate pore sizes (80 and 100 nm). Smaller pores inhibited leaf-like features as a result of insufficient storage of m-phenylenediamine (MPD) monomers for the interfacial reaction, whereas larger pores resulted in diminished surface roughness due to the lack of confinement to the interfacially degassed nanobubbles. Substrate porosity plays a critical role on membrane water permeability, while smaller pores with greater pore density are favored to improve membrane rejection. TFC polyamide membranes prepared on sponge-like poly(ether sulfone) and polysulfone substrates exhibit better water permeability and salt rejection compared to the PCTE-TFC membranes thanks to the simultaneously enhanced confinement and MPD storage effects. The mechanistic insights gained in this study reveal the huge potential of substrate design toward high-performance TFC RO membranes.

Emerging sandwich-like reverse osmosis membrane with interfacial assembled covalent organic frameworks interlayer for highly-efficient desalination

Covalent organic frameworks (COFs) have emerged as promising candidate for the construction of advanced separation membranes due to their well-defined pore structure and highly ordered porous channels. Nevertheless, the implementation of high-efficient COFs-incorporated membranes still suffers from harsh synthetic conditions and possible agglomeration of COFs. Herein, a kind of sandwich-like thin film composite reverse osmosis (RO) membranes was fabricated to overcome such challenges via interfacial assembly of a COFs interlayer on polysulfone substrate, then followed by the formation of a polyamide skin layer via traditional interfacial polymerization (IP) process. The COFs interlayer not only tailored the pore structure and interfacial properties of the substrate, but also manipulated the uptake and release of the amine monomer during the IP process, which would contribute to forming a more ordered polyamide separation layer. The resultant COFs-interlayered RO membrane exhibited a nearly 33.8% higher water permeance (16.78 L m−2 h−1 MPa−1) along with a slightly increased NaCl rejection (99.2%) compared with the pristine RO membrane. More importantly, the emerging RO membrane presented a superior chemical (critic acid and NaOH) resistance and desirable long-term filtration stability, which paved a new pathway to construct high-performance RO membranes for desalination.

Electrospun Weak Anion-Exchange Fibrous Membranes for Protein Purification

Membrane based ion-exchange (IEX) and hydrophobic interaction chromatography (HIC) for protein purification is often used to remove impurities and aggregates operated under the flow-through mode. IEX and HIC are also limited by capacity and recovery when operated under bind-and-elute mode for the fractionation of proteins. Electrospun nanofibrous membrane is characterized by its high surface area to volume ratio and high permeability. Here tertiary amine ligands are grafted onto the electrospun polysulfone (PSf) and polyacrylonitrile (PAN) membrane substrates using UV-initiated polymerization. Static and dynamic binding capacities for model protein bovine serum albumin (BSA) were determined under appropriate bind and elute buffer conditions. Static and dynamic binding capacities in the order of ~100 mg/mL were obtained for the functionalized electrospun PAN membranes whereas these values reached ~200 mg/mL for the functionalized electrospun PSf membranes. Protein recovery of over 96% was obtained for PAN-based membranes. However, it is only 56% for PSf-based membranes. Our work indicates that surface modification of electrospun membranes by grafting polymeric ligands can enhance protein adsorption due to increased surface area-to-volume ratio.

Effect of Organoclay on the Performance of Reverse Osmosis Membrane

This study investigated the effect of Cloisite15A (C15A) organoclay in the substrate layer on the performance of reverse osmosis (RO) membranes. The substrate of the RO membranes was modified using different loading of C15A (ranging from 0.3 - 0.7 wt%) within polysulfone (PSf) substrate and the polyamide (PA) selective layer was formed on the top. Effect of the modified substrate layer on the water flux and salt rejection of the nanocomposite membrane was investigated. The chemical property, morphology, and topography of the membrane surface were characterized by ATR-FTIR, SEM, AFM and contact angle analyzer. The modified membranes showed significantly enhanced pure water flux and salt solution permeability by 60.5 % and 44.3 %, respectively, without sacrificing the salt rejection.

Effect of lithium chloride additive on forward osmosis membranes performance

The research efforts on the development of ideal forward osmosis membranes with high water flux and low reverse salt flux have been devoted in the recent years. In this study, thin film composite polyamide forward osmosis membranes were prepared. The porous polysulfone (PSU), polyphenylsulfone (PPSU), and polyethersulfone (PESU) substrates used in this study were prepared by the phase inversion process, and the active rejection layer was prepared by interfacial polymerization. All the membranes showed highly asymmetric porous structures with a top dense upper layers and finger-like porous substrates with macro voids in the bottom layer. The addition of 3 % lithium chloride (LiCl) to the membrane substrates resulted in an increase in both the water flux and reverse salt flux. PSU and PESU showed the highest water flux when the active layer faced the feed solution (AL-FS), while the largest water flux was obtained when the active layer faced the draw solution (AL-DS). For all the membranes, the water flux under the AL-DS orientation was higher than that under the AL-FS orientation.

Tailoring the surface properties of carbon nitride incorporated thin film nanocomposite membrane for forward osmosis desalination

Thin film nanocomposite (TFN) membranes incorporated with carbon nitride (CN) or protonated CN (pCN) were fabricated for forward osmosis (FO) desalination. The CN and pCN were incorporated within the polyamide (PA) layer which was supported by pCN incorporated polysulfone (PSf) substrate to form the TFN membrane. It was found that the presence of pCN in the substrate has favourably altered the intrinsic properties and affected the formation of PA layer. The physico-chemical characterizations indicated that the presence of both CN and pCN enhanced the surface hydrophilicity but reduced the surface negativity of the PA layer. These features have resulted in the improved water transport and salt rejective ability. As a result, CN-pCN-TFN membranes exhibited improved water permeability by about 70% (0.67 L/m2 h bar) compared to TFC membrane while maintaining salt rejection of 94.5%. CN-pCN-TFN also exhibited better anti-fouling property compared to TFC in which the flux decline was only half of that of TFC membrane during the 9 -h antifouling test. This work demonstrates the feasibility of using functional CN and pCN to independently tailor the substrate and PA layer properties of the TFN membrane, hence improving the desalination performances of the membrane.

Titanium dioxide incorporated thin film composite membrane for bisphenol a removal

The objective of this study was to evaluate the capability of Polyamide (PA) thin film composite (TFC) membrane immobilized with Titanium Dioxide (TiO 2 ) particles on the removal of Endocrine Disruptive Compounds (EDC). Since 1990`s, an increasing environmental pollution by EDC had been noticed, for instance in surface waters, agricultural areas, and atmosphere, especially since the analytical methods for EDC detection have been continuously improved. The estrogenic properties of bisphenol A (BPA), a ubiquitous synthetic monomer which categorized as an EDC that can leach into the food and water supply, have prompted considerable research into exposure-associated health risks in humans. In this study, PA/TiO 2 TFC membrane was fabricated via interfacial polymerization (IP), using Polysulfone (PSf) flat sheet as substrate membrane. Trimesoyl chloride (TMC) and m-phenylenediamine (MPD) have been used as monomer and aqueous solution, respectively. The performance of PA/TiO 2 TFC membrane and PSf substrate membrane on the removal of BPA has been compared and analysed. The membrane was analyzed for several characterizations using Field Emission Scanning Electron Microscopy (FESEM) and water contact angle analysis. Synthetic wastewater using 100ppm of BPA solution has been prepared for membranes performance. The existence of PA/TiO 2 TFC on top of PSf membrane has been confirmed by FESEM and EDX image. Meanwhile, the hydrophilicity of PSF membranes has been improved with the existence of TFC which is good for water treatment system since it improves membrane’s pure water flux. The rejection of BPA has been done using ultrafiltration system and it was found that PA/TiO 2 TFC membrane could reject almost 99% of BPA from feed solution. From the data obtained in this study, the TFC membrane is found to be convincing for wastewater treatment that contains EDC.

One-pot assembly tannic acid-titanium dual network coating for low-pressure nanofiltration membranes

Tannic acid (TA)-titanium (Ti) dual network coating was facilely formed via a bio-inspired one-pot assembly on the polysulfone (PSf) substrate as a selective layer for low-pressure nanofiltration. The abundant galloyl and catechol groups of TA could help to a robust affinity for membrane surface, and also serve as chelating sites for metal ions. Herein, TiO2 and TA-TiIV complex were simultaneously introduced as cross-linkers into the network coating, because hydrolysis and chelation reaction could occur spontaneously when titanium tetrachloride (TiCl4) was added into aqueous solution. The effect of TA/TiIV feed ratio and deposition time on the membrane morphologies and properties was systematically investigated. The optimized TA-Ti/PSf membrane exhibited a comparative pure water flux (19.0 L/m2 h) at a low operation pressure of 0.2 MPa, while dye rejection to methyl blue and Congo red achieved as high as 96.8% and 97.2%, respectively. Moreover, TA-Ti/PSf membrane also presented high hydrophilicity, excellent antifouling ability, powerful antimicrobial capability and good long-term stability. These results indicated a great application potential of TA-Ti/PSf membrane for water remediation especially textile wastewater treatment.

Sulfonated graphene oxide incorporated thin film nanocomposite nanofiltration membrane to enhance permeation and antifouling properties

Thin film nanocomposite (TFN) membranes embedded with sulfonated graphene oxide (SGO) were fabricated to improve the hydrophilicity, salt rejection and antifouling of nanofiltration (NF) membrane. In this study, the surface properties and structure of polyamide (PA) layer were improved by incorporating SGO into the PA layer. It was prepared by interfacial polymerization of piperazine (PIP) and trimesoyl chloride (TMC) on the polysulfone substrate surface. The PA layer thickness of TFN membranes decreased and the hydrophilicity and zeta potential of them were improved after incorporating the SGO. According to NF filtration tests, TFN membrane including 0.3 wt% of SGO (TFN 0.3) gave the highest water flux, which was 87.3% higher than that of TFC membrane. Interestingly, despite the significant increase in water permeability, the salt rejection of both membranes was similar due to the improved cross-linking and low molecular weight cut-off (MWCO) of the TFN 0.3 membrane. Furthermore, it showed high antifouling property in long-term NF test, compared to the pristine TFC membrane. The current study may lead to a facile strategy by using SGO nanosheets to improve the hydrophilicity and antifouling properties of NF membrane.

Controllable Interfacial Polymerization for Nanofiltration Membrane Performance Improvement by the Polyphenol Interlayer.

It is a huge challenge to have a controllable interfacial polymerization in the fabrication process of nanofiltration (NF) membranes. In this work, a polyphenol interlayer consisting of polyethyleneimine (PEI)/tannic acid (TA) was simply assembled on the polysulfone (PSf) substrate to fine-tune the interfacial polymerization process, without additional changes to the typical NF membrane fabrication procedures. In addition, three decisive factors in the interfacial polymerization process were examined, including the diffusion kinetics of fluorescence-labeled piperazine (FITC-PIP), the spreading behavior of the hexane solution containing acyl chloride, and the polyamide layer formation on the porous substrate by in situ Fourier transform infrared (FT-IR) spectroscopy. The experimental results demonstrate that the diffusion kinetics of FITC-PIP is greatly reduced, and the spreading behavior of the hexane solution is also impeded to some extent. Furthermore, in situ FT-IR spectroscopy demonstrates that by the mitigation of this PEI/TA interlayer, the interfacial polymerization process is greatly controlled. Moreover, the as-prepared NF membrane exhibits an increased water permeation flux of 65 L m–2 h–1 (at the operation pressure of 0.6 MPa), high Na2SO4 rejection of >99%, and excellent long-term structural stability.

Protonated Carbon Nitride Incorporated Polyamide Thin Film Nanocomposite for Reverse Osmosis Desalination

Protonated carbon nitride (pCN) prepared from acid treatment of carbon nitride (CN) was incorporated in the polysulfone (PSf) substrate and polyamide (PA) layer to produce thin film nanocomposite (TFN) membrane. The hydrophilicity of CN is expected to improve the surface hydrophilicity of the membrane and acid treatment of nanoparticle is aimed to further enhance the surface structure and prevent the agglomeration of nanomaterial from taking place. pCN loading used in the PSf substrate was 0.5% while in the PA layer was varied as 0.05%, 0.1% and 0.15%. All the membrane prepared were characterized in terms of morphology, structural properties, and surface chemistry. Reverse osmosis dead-end filtration system was used to determine the water permeability and the salt rejection. It was observed that, all the membrane prepared could maintain the salt rejection with improvement of water permeability. However, the salt rejection was sacrificed when higher loading of 0.15% pCN was tested, although the water permeability of the membrane has reached approximately 0.5 LMHbar. This work demonstrates that the use of pCN in RO membrane can improve the water permeability without sacrificing the salt rejection.

Surface-attached brush-type CO2-philic poly(PEGMA)/PSf composite membranes by UV/ozone-induced graft polymerization: Fabrication, characterization, and gas separation properties

CO2-philic brush-type poly(poly(ethylene glycol) methyl ether methacrylate)(poly(PEGMA)) was fabricated onto microporous polysulfone (PSf) substrates by ultraviolet (UV)/ozone induced graft polymerization. The PSf substrates were first exposed under UV/ozone to form peroxide groups, which were thermally decomposed to form peroxide radical groups. The substrates were then soaked in aqueous PEGMA solutions to form thin brush-type poly(PEGMA)/PSf composite membranes. The concentration of peroxide was measured by ATR-FTIR and 1,1-diphenyl-2-picrylhydrazyl (DPPH) methods and increased up to 113.75 nM/cm2 at 6min. ATR-FTIR, XPS, and FE-SEM confirmed poly(PEGMA) selective layers without defects were attached well onto the substrate surface and had a thickness of about 750 nm. The optimized composite membranes exhibited noteworthy separation performance; high selectivities of αCO2/H2=13.36, αCO2/CO=43.4, and αCO2/N2=59.41, respectively, and CO2 permeance of 85.47 GPU at 35 oC. This study suggests a facile and effective way to develop composite membranes suitable for CO2 separation and has remarkable potential for other membrane applications.

CuBTC metal organic framework incorporation for enhancing separation and antifouling properties of nanofiltration membrane

Novel thin film nanocomposite (TFN) nanofiltration membrane with tunable physico-chemical properties and separation performances was fabricated by incorporating the copper benzene-1,3,5-tricarboxylate (CuBTC) nanoparticles with different concentrations (ranging from 0 to 0.75wt.%) in the polysulfone (PSf) substrates, followed by the interfacial polymerization process of trimesoyl chloride (TMC) and piperazine (PIP) to establish top selective layer. Charaterization results show that both chemical and physical properties of poly(piperazineamide) selective layer was altered when PSf substrate was modified by CuBTC. The introduction of CuBTC nanoparticles improved the hydrophilicity of the TFN membranes (from 70.25° to 59.02°) and promoted formation of more linear structure of poly(piperazineamide) entangled with −COOH pendant groups. By incorporating 0.25wt.% of CuBTC into the PSf substrate, the resultant membrane flux was enhanced by 22% with MgSO4 rejection remained at 97.31%. Furthermore, a notable increment of rejection against NaCl could be attained by increasing the CuBTC content in the substrate. This could be explained by the Donnan potential effect occurred on the more linear structures of poly(piperazineamide) surfaces, which results in an increase in the selectivity of monovalent salts. Moreover, the incorporation of CuBTC rendered the TFN membranes to exhibit good anti-fouling property against bovine serum albumin.

Ultrathin Support-Free Membrane with High Water Flux for Forward Osmosis Desalination

In this work, an ultrathin polyamide (PA) membrane was fabricated via in situ removing polysulfone (PSF) substrate from the PSF-PA forward osmosis membrane for the first time. The physicochemical properties of the PA membranes were confirmed by means of surface morphology, chemistry analysis, and surface charge characterization. The performance of PA, PSF-PA, and physically combined PSF+PA membrane was compared in terms of water flux, reverse salt flux, and selectivity. The flux performance of these three membranes followed the order of PA>PSF-PA>PSF+PA membranes, and the possible mechanism for their performance was proposed. Compared with home-made PSF-PA and PSF+PA membranes, the ultrathin PA membrane had high water flux (i.e., 80.54 LMH) due to its low membrane resistance and minimized internal concentration polarization under same operation conditions (i.e., DI water feed solution, 1.0 M NaCl draw solution, and AL-FS orientation). This study would provide insights on the preparation and application of ultrathin PA membranes with high permeability in the context of global water/energy-related crisis.