Membrane Surface Properties Research Articles

Variations in the Morphology, Mechanics and Adhesion of Persister and Resister E. coli Cells in Response to Ampicillin: AFM Study.

Persister bacterial cells are great at surviving antibiotics. The phenotypic means by which they do that are underexplored. As such, atomic force microscope (AFM) was used to quantify the contributions of the surface properties of the outer membrane of multidrug resistance (MDR)-Escherichia coli Strains (A5 and A9) in the presence of ampicillin at minimum inhibitory concentration (MIC) (resistant cells) and at 20× MIC (persistent cells). The properties quantified were morphology, root mean square (RMS) roughness, adhesion, elasticity, and bacterial surface biopolymers’ thickness and grafting density. Compared to untreated cells, persister cells of E. coli A5 increased their RMS, adhesion, apparent grafting density, and elasticity by 1.2, 3.4, 2.0, and 3.3 folds, respectively, and decreased their surface area and brush thickness by 1.3 and 1.2 folds, respectively. Similarly, compared to untreated cells, persister cells of E. coli A9 increased their RMS, adhesion and elasticity by 1.6, 4.4, and 4.5 folds, respectively; decreased their surface area and brush thickness by 1.4 and 1.6 folds, respectively; and did not change their grafting densities. Our results indicate that resistant and persistent E. coli A5 cells battled ampicillin by decreasing their size and going through dormancy. The resistant E. coli A9 cells resisted ampicillin through elongation, increased surface area, and adhesion. In contrast, the persistent E. coli A9 cells resisted ampicillin through increased roughness, increased surface biopolymers’ grafting densities, increased cellular elasticities, and decreased surface areas. Mechanistic insights into how the resistant and persistent E. coli cells respond to ampicillin’s treatment are instrumental to guide design efforts exploring the development of new antibiotics or renovating the existing antibiotics that may kill persistent bacteria by combining more than one mechanism of action.

Alteration of the morphology of polyvinylidene fluoride membrane by incorporatingMOF‐199 nanomaterials for improving water permeation with antifouling and antibacterial property

AbstractMOF‐199@PVDF composite membranes are prepared by blending with different amounts of ultrasonic synthesized MOF‐199 nanomaterials for improving the pure water flux (PWF) and achieving better antifouling and antibacterial performance. The membrane morphology, elemental composition, and surface properties are analyzed by various means of characterizations, including scanning electron microscopy, energy‐dispersive X‐ray spectroscopy, and water contact angle measurements. The performance of the modified membranes is also determined from the perspective of the PWF, bovine serum albumin rejection, as well as antifouling and antibacterial properties. Due to the variation in the viscosity of dope solution, the composite membranes possess remarkably different morphology, and the M5 membrane, which exhibited a sponge‐like structure, the largest surface pore size, and the highest porosity, shows the highest PWF, reaching up to 185.05 L/m2h. Moreover, with the incorporation of MOF‐199 nanocrystals, the antifouling property, together with the antibacterial property, toward both gram‐negative bacteria and gram‐positive bacteria, based on M5 and M7 membranes, increases dramatically compared with the pristine polyvinylidene fluoride membrane. In addition, the long‐term permeation performance and copper leakage of the membrane are investigated. As a result, the composite membrane, M5, shows great potential in real water treatment.

Current-sensing atomic force microscopy for analyzing conformations and properties of polymer membranes for fuel cells

Abstract The three-dimensional structures of polymer membranes are different at surfaces and inside bulks, and thus, in general, physical/chemical properties are also different. Morphologies and properties of membrane surfaces are now visualized by current-sensing atomic force microscopy. The increase in performances of a single cell is discussed based on the three-dimensional structures of the polymer membrane, anion-exchange membrane as an example, used for fuel cells. Other reports on Nafion®, proton-exchange membrane, are also introduced to show the importance of this microscopic method.

A novel dual-layer, gas-assisted electrospun, nanofibrous SAN4-HIPS membrane for industrial textile wastewater treatment by direct contact membrane distillation (DCMD)

In this work, a dual-layer nanfibrous SAN4-HIPS membrane has been fabricated via the gas-assisted electrospinning, and employed for industrial textile wastewater treatment by direct contact membrane distillation (DCMD). The obtained results showed that the new membrane is robust and able to remove the contaminants, remarkably, with almost 99.28 %, 97.93 %, and 100 % reductions for COD, BOD and color, respectively. However, a flux decline of up to 42.58 % was observed after 48 h DCMD process. Concerning the rejection results, it can be concluded that the flux decline is mainly caused by the membrane fouling rather than the partial pore wetting as the membrane remained hydrophobic after the 48-h experiment. The surface contact angle reduced from 143.2° to 121.5°. Foulants accumulation on the membrane surface can increase the mass transfer resistance of vapor molecules. This can considerably reduce the productivity. The obtained results were also compared with the literature on the other MD processes, as well as the conventional pressure-driven membrane processes. Further studies on enhancing the membrane surface properties are required to control and reduce the fouling tendency caused by the contaminants in the industrial textile wastewater. This is of crucial for the long-term DCMD performance.

A green approach to modify surface properties of polyamide thin film composite membrane for improved antifouling resistance

A green approach based on plasma enhanced chemical vapour deposition (PECVD) method was adopted in this work to modify surface properties of thin film composite (TFC) membranes for improved antifouling resistance during desalination process. Two types of hydrophilic monomers, i.e., acrylic acid (AA) and 2-hydroxyethyl methacrylate (HEMA) was respectively deposited onto the surface of commercial TFC membranes (XLE and NF270) and the effect of plasma deposition time (15 s, 1 min and 5 min) on the membrane physiochemical properties was investigated using different analytical instruments. The deposition of AA and HEMA was able to improve the membrane hydrophilicity owing to the presence of hydroxyl and carboxyl functional groups. However, prolonged plasma polymerization period was not encouraged as it led to the formation of thicker skin layer that significantly reduced water permeability. With 15-s plasma deposition time, AA and HEMA-modified XLE and NF270 membranes could achieve higher NaCl and Na2SO4 rejections as well as demonstrate 100% flux recovery rate. The improved antifouling resistance of modified TFC membranes is mainly due to the improved surface hydrophilicity coupled with greater surface charge properties. This work demonstrated a rapid solvent-free surface modification method that can be employed to enhance TFC membrane properties for desalination process.

Hybrid Cell Membrane-Camouflaged Nanoparticle: A Novel Multifunctional Biomimetic Drug Delivery Carrier for Cancer Therapy

Biomimetic nanotechnology through camouflaging synthetic nanoparticles with natural cell membranes, which bestows with immune evasion and superior targeting capacity, has been extensively applied in drug delivery systems (DDS) over the last decades. Theses biomimetic nanoparticles (NPs) not only reserve the physicochemical features of the synthetic vehicles but also inherit the cell membranes' intrinsic functionalities. Combined with these benefits, optimized nano-biomimetic DDS allow maximum delivery efficacy. Compared to erythrocyte/cancer single cell membrane, the hybrid cell membranes expressing CD47 membrane protein and self-recognition molecules, from erythrocytes and cancer cells, provides incredible features to the synthetic vehicles, such as immune evasion, long-term circulation, and homotypic targeting. In this review, we described the preparation strategies, the camouflaging mechanism, and the antitumor applications of hybrid cell membrane-camouflaged nanoparticles. Moreover, we discussed further modification of the hybrid cell membranes and the surface properties of fusion cellular membranes. Finally, we summarized the primary challenges and opportunities associated with these nanoparticles.

Initial Deposition and Pioneering Colonization on Polymeric Membranes of Anaerobes Isolated from an Anaerobic Membrane Bioreactor (AnMBR).

Membrane biofouling constitutes a great challenge in anaerobic membrane bioreactor (AnMBR). Here, we studied the initial deposition of anaerobes, the first step in biofilm formation, with a consortium isolated from an AnMBR on membranes with different surface properties and under two shear rate conditions without filtration. We found that the cell transfer coefficient, calculated from the initial deposition experiments, was similar under the two shear rates for the hydrophobic membranes, but much higher under low shear rate and much lower under high shear rate, for the hydrophilic membrane. The cell transfer coefficient measured under filtration mode and at a higher shear rate showed a similar trend. The pioneer bacteria and archaea (without filtration) were identified by next-generation sequencing. The results showed that the selective force for the dissimilarity of the pioneer bacterial and archaeal diversity was the shear rate and the membrane surface properties, respectively. However, statistical analyses revealed minor changes in the pioneer bacteria (class level) and archaea (order level) populations under the various conditions. These results shed light on the first step of biofilm formation on the membranes in AnMBRs and emphasize the importance of hydrodynamic shear and membrane surface properties on the initially deposited anaerobes.

High-throughput production of silk fibroin-based electrospun fibers as biomaterial for skin tissue engineering applications.

In this work, a nozzle-free electrospinning device was built to obtain high-throughput production of silk fibroin-based biocompatible composite fibers with tunable wettability. Synthetic biomaterials tend to present suboptimal cell growth and proliferation, with many studies linking this phenomenon to the hydrophobicity of such surfaces. In this study, electrospun mats consisting of Poly(caprolactone) blended with variant forms of Poly(glycerol sebacate) (PGS) and regenerated silk fibroin were fabricated. The main aim of this work was the development of fiber mats with tunable hydrophobicity/hydrophilicity properties depending on the esterification degree and concentration of PGS. A variation of the conventional protocol used for the extraction of silk fibroin from Bombyx mori cocoons was employed, achieving significantly increased yields of the protein, in a third of the time required via the conventional extraction protocol. By altering the surface properties of the electrospun membranes, the trinary composite biomaterial presented good in vitro fibroblast attachment behavior and optimal growth, indicating the potential of such constructs towards the development of an artificial skin-like platform that can aid wound healing and skin regeneration.

Facile dual-functionalization of polyamide reverse osmosis membrane by a natural polypeptide to improve the antifouling and chlorine-resistant properties

Long-term durability is of significant importance for the polyamide thin film composite (PA-TFC) reverse osmosis (RO) membranes under the complicated operation conditions of the water treatment. Herein, dual-functional RO membranes with improved antifouling and chlorine-resistant properties were facilely fabricated. A natural polypeptide, ε-poly-l-lysine (PL), was employed as the surface modifier for RO membrane, and covalently immobilized on the PA-TFC membrane surface through one-step chemical coupling under ambient conditions, without sacrificing the permselectivity. Surface properties of the PL-modified membranes were systematically characterized, and the modification method was also optimized. The greatly enhanced surface hydrophilicity derived from PL layer resulted in less propensity to the deposition of organic foulants. Moreover, the topmost PL sacrificial layer effectively improved the membrane chlorine-resistance, with the normalized salt rejection higher than 99.5% after accelerating chlorination. The readily available modifier and straightforward modification process make PL modification on PA layer a potential strategy for the fabrication of antifouling and chlorine-resistant RO membrane.

Formulation and characterization of crosslinked polyvinyl alcohol (PVA) membranes: effects of the crosslinking agents

The article addresses the formulation and characterization of the polyvinyl alcohol membrane (PVA) with citric acid, succinic acid and their mixing as crosslinking agents. PVA is highly hydrophilic and has excellent film (membrane) properties. Chemical crosslinking is the most common approach to stabilize and produce PVA membranes with enhanced mechanical resistance. Thus, we prepared membranes with variable PVA and crosslinking agents. The thermal properties of the membranes were analyzed using thermogravimetric method (TGA), while the functional groups formed in the membrane were determined using Fourier-transform infrared spectroscopy. The water absorption of the membranes was determined by the degree of swelling. The oxidative stability was obtained using the Fenton test. The ion exchange capacity was also evaluated. Membrane structure, morphology and surface properties were analyzed by topography and adhesion force using atomic force microscopy. The scanning electron microscopy was used to elucidate the fractures. The results indicated that the membranes exhibited roughness uniformly distributed, indicating homogeneous films and excellent crosslinking features allied to enhanced adhesion and strength properties with good stability.

Performance of tannic acid/tetraethylenepentamine coated polymeric membrane for the separation of different surfactant-stabilized oil in water emulsions

The present research reported on the surface coating of PVDF membrane with polyphenolic-amine, which improves the hydrophilicity and underwater oleophobic properties. The separation efficiency and antifouling property of emulsion oil by pristine PVDF and polyphenolic-amine coated PVDF microfiltration membranes were evaluated. The performance of pristine and coated membrane was compared using three different types of surfactant-stabilized oil droplets (T80/Diesel/H2O, SDS/Diesel/H2O and CTAB/Diesel/H2O) in terms of flux recovery ratio (FRR) and removal efficiency. The continuous cycle using cross-flow filtration mode was also investigated. The filtration experiments indicated that modifying the surface properties of the PVDF polymer membrane by polyphenolic-amine coating method can significantly improve the antifouling properties compared to unmodified polymeric membranes.

Thermal Mechanical Stretching to Imprint Pores Morphology of Nitrocellulose Membrane for Immuno-sensing Application

Performance of membrane such as the lateral flow wicking time and protein binding ability are important to generate consistent results for diagnostics purposes. Different diagnostic kit need different surface properties of membrane, structures and dimension. This work evaluates the feasibility of controlling membrane pores morphology through thermal-mechanical stretching. Results shows that membrane fabricated using longer nitrocellulose (NC) polymer chain length produced smaller pores with lower porosity (56%). Thus, it took longer time of 32s to migrate the testing liquid along the membrane strip. By having higher membrane’s porosity (72.3%), the membrane synthesized using shorter NC chain length exhibited faster wicking time, which is 3 times faster (wicking time of 8s) than that of the membrane produced with longer NC chain length. In terms of the thermal-mechanical stretching effects, the stretched membranes (both uniaxial and biaxial directions) had demonstrated improved immunoassay performances compared to the unstretched membrane. Specifically, uniaxial stretching is preferable than biaxial stretching configuration, due to the great improvement of lateral wicking time (22% faster) without jeopardize the membrane protein binding capacity (only 1.7% decrement), in relative to the unstretched membrane. This study provides some interesting insight on the physical membrane modification to provide better performance in immunoassay applications.

Membrane fouling in microfiltration of alkali/surfactant/polymer flooding oilfield wastewater: Effect of interactions of key foulants

HypothesisMembrane filtration is a promising technology for the treatment of alkali/surfactant/polymer (ASP) flooding oilfield wastewater, which contains high concentration of salt, surfactant, polymer and crude oil. The interactions of key foulants may influence the degree of membrane fouling. By comparing flux decline and interfacial free energies, it should be possible to derive the foulants governing the interactions with the membrane. ExperimentsPolytetrafluoroethylene microfiltration membrane was employed to treat eleven types of model solutions to understand the effect of the interactions of key foulants on membrane fouling. The extended Derjaguin–Landau–Verwey–Overbeek theory was used to quantify the foulant-membrane and foulant-foulant interaction energies. The cake models were implemented to analyze the fouling form. Fourier transform infrared spectroscopy, atomic force microscopy, and contact angle were used to study the surface properties of various membranes. FindingsMicrofiltration experiments and thermodynamic analysis revealed that both ions and sodium dodecylbenzenesulfonate could mitigate membrane fouling caused by anionic polyacrylamide (APAM) and crude oil. Moreover, APAM would produce a “shielding effect” on crude oil fouling. In addition, complete pore blocking, which primarily occurred on the membrane surface and formed a fouling layer, was the dominant form of membrane fouling.

Studies on surface properties of polyethersulfone membrane by remote argon plasma

Using double suspension probe and electron spin resonance method, we studied the concentration distribution of electrons, ions and free radicals in remote argon plasma and the optimal surface modification region was to be predicted. To be specific, PES membranes were placed in this region and modified by remote argon plasma. In addition, water contact angle measurement, bovine serum albumin separation experiment, X-ray photoelectron spectroscopy and scanning electron microscope were used to characterize the surface structure and properties of PES membranes. It is found that the relative concentration of electrons and ions in remote region were gradually decreased along the axial. But free radicals still maintain above 90% at the position of 40 cm, which was the best possible surface modification region. The modified PES membranes by remote plasma obtained a higher hydrophilicity and did not showed significant etch on PES membranes surface. And the remote argon plasma contributed more effectively to the oxygen-containing groups (O/C = 0.43) from PES membranes than untreated PES membranes (O/C = 0.18). Moreover, the membrane fouling rate after modification reduced from 70.3% to 64.7% and contact angle decreased from 67° to 18°. The above results indicated that the possibility of free radicals reaction can be enhanced by remote argon plasma.

Modification of structural and magnetic properties of Co[formula omitted]Ni[formula omitted]Fe2O4 nanoparticles embedded Polyvinylidene Fluoride nanofiber membrane via electrospinning method

Ferrite nanoparticles have garnered significant attention due to their remarkable ferromagnetic properties. However, the functionality of the ferrite nanoparticles can be enhanced with the development of nanofiber membranes. This helps to control the surface, structural and magnetic properties of the composite nanofiber membrane. Herein, we report the fabrication of novel nanofiber membrane containing Co0.5Ni0.5Fe2O4-Polyvinylidene Fluoride (PVDF) via electrospinning method. The Co0.5Ni0.5Fe2O4 nanoparticles were synthesized with the help of sol–gel combustion method. Investigations on the effect of Co0.5Ni0.5Fe2O4 nanoparticles embedded within PVDF polymer nanofiber membrane on structural, morphological and magnetic properties are discussed. XRD line profile analysis revealed cubic spinel structure of the Co0.5Ni0.5Fe2O4 nanoparticles To determine the crystallite size of the samples; Scherrer, Williamson–Hall (W–H), and Size-Strain plot (SSP) were carried out with the help of XRD spectra. The crystallite size of the nanoparticles reduced as they were embedded within PVDF polymer. FTIR studies confirmed that the presence of Co0.5Ni0.5Fe2O4 pristine nanoparticles within the polymeric nanofiber membrane was accountable for the enhanced β-phase bands which makes a significant effect on the ferroelectric properties of the nanofiber membrane. In addition, the VSM technique was used to study the ferromagnetic properties. The enhanced remnant magnetization and saturation magnetization of the nanoparticles was responsible for magnetic nature of the non-magnetic polymer PVDF.

Improved performance of thin-film nanofiltration membranes fabricated with the intervention of surfactants having different structures for water treatment

We fabricated thin-film composite nanofiltration polyamide membranes through the interfacial polymerization of two monomers: polyethyleneimine (PEI) and trimesoyl chloride (TMC). Three different types of surfactants with varied chemical structures were added to aqueous PEI solutions: sodium dodecyl sulfate (SDS), sodium octyl sulfate, and sodium dodecylbenzenesulfonate; the aim was to improve the rejection of divalent ions. Adding the surfactants led to increased isoelectric point, and, in turn, enhanced the membrane hydrophilic properties, heightened the membrane surface charge, and augmented the rejection of MgCl2. Among the three surfactants, SDS effected the most favorable conditions: the resultant composite membrane delivered the highest pure water flux (44.87 ± 3.22 L∙m−2∙h−1), and exhibited high rejections of divalent salts (RNa2SO4 = 92.26 ± 3.30%; RMgSO4 = 93.83 ± 3.22%; RMgCl2 = 94.15 ± 2.52%). SDS had long alkane chains and highly polar heads, which were conducive to bringing about an effective interaction between PEI and the polysulfone (PSf) support, thereby increasing the sorption of PEI in PSf. Accordingly, the reaction of PEI with TMC produced more amide and amine functional groups that were instrumental in raising the rejections of divalent salts and enhancing the membrane surface properties.

Synergistic mode of action of catechin, vanillic and protocatechuic acids to inhibit the adhesion of uropathogenic Escherichia coli on silicone surfaces.

To study the individual and combined contribution of catechin, protocatechuic and vanillic acids to inhibit the adhesion of uropathogenic Escherichia coli (UPEC) on the surface of silicone catheters. The adhesion of UPEC to silicone catheters during the exposure to nonlethal concentrations of phenolic compounds was measured, as well as changes in motility, presence of fimbriae, extra-cellular polymeric substances, surface charge, hydrophobicity and membrane fluidity. The phenolic combination reduced 26-51% of motility, 1 log CFU per cm2 of adhered bacteria and 20-40% the carbohydrate and protein content in the biofilm matrix. Curli fimbriae, surface charge and cell hydrophobicity were affected to a greater extent by the phenolic combination. In the mixture, vanillic acid was the most effective for reducing bacterial adhesion, extra-polymeric substance production, motility, curli fimbriae and biofilm structure. Notwithstanding, protocatechuic acid caused major changes in the bacterial cell surface properties, whereas catechin affected the cell membrane functionality. Catechin, protocatechuic and vanillic acids have different bacterial cell targets, explaining the synergistic effect of their combination against uropathogenic E. coli. This study shows the contribution of catechin, protocatechuic and vanillic acids in producing a synergistic mixture against the adhesion of uropathogenic E. coli on silicone catheters. The action of catechin, vanillic and protocatechuic acids included specific contributions of each compound against the E. coli membrane's integrity, motility, surface properties and production of extracellular polymeric substances. Therefore, the studied mixture of phenolic compounds could be used as an antibiotic alternative to reduce urinary tract infections associated with silicone catheters.

Reverse osmosis membrane with simultaneous fouling- and scaling-resistance based on multilayered metal-phytic acid assembly

Mineral scaling and organic fouling are challenging and co-existing issues that compromise membrane performance in reverse osmosis (RO), but membrane materials possessing both scaling and fouling resistance have not been achieved so far. In this study, thin-film composite (TFC) polyamide membranes were modified with multilayered Ferric-phytic acid (PhA) complexes using layer-by-layer (LbL) assembly, which achieves simultaneous resistance against both silica scaling and BSA fouling. The Ferric-PhA complexes enhanced both hydrophilicity and negative charge, while decreasing the surface roughness of the TFC membrane. The Ferric-PhA assembled membranes exhibited excellent resistance against both individual silica scaling and bovine serum albumin (BSA) fouling in RO desalination, with an increase of layer number resulting in improved membrane performance. The Ferric-PhA assembled membranes further showed remarkably less flux decline compared to the pristine TFC membrane when silica scaling and BSA fouling co-existed. The favorable membrane surface properties imparted by Ferric-PhA complexes reduced the membrane interactions with both silica scalants and BSA foulants effectively, resulting in the exceptional and simultaneous scaling and fouling resistance. Our work demonstrates that it is feasible to achieve dual functions of scaling and fouling resistance of RO membranes by smart surface modification.

Elevated nanofiltration performance via mussel-inspired co-deposition for sustainable resource extraction from landfill leachate concentrate

During the disposal of highly saline wastewaters, i.e., landfill leachate concentrate, a conceptual and paradigmatic transformation from contaminant elimination to sustainable resource extraction urges for novel selective membranes. Mussel-inspired modification through dopamine self-polymerization can be a competitive alternative to tailor the membrane surface properties for enhanced permselectivity to target compounds. Herein, co-deposition of polydopamine-polyethylenimine (PEI) complex onto loose nanofiltration (NF) membranes was conducted using persulfate as trigger, which resulted in a significant alteration in membrane surface properties. Particularly, the pore size of bio-inspired NF membranes decreased, along with a reduction in molecular weight cut-off (MWCO) from 640 to 298 Da after 120-min bio-inspired coating, which yielded an enhancement in rejection of humic substances from 95.1% to 98.9% in filtration of landfill leachate concentrate. Furthermore, the charge of membrane surface was tailored to be more positive due to incorporation of positively-charged PEI, which markedly undermined the electrostatic repulsion force for enhanced salt permeation. These bio-inspired NF membranes showed a superior selectivity between humic substances and salts for their potential fractionation from the landfill leachate concentrate. Through an integrated NF-based diafiltration procedure, the concentration of humic substances was remarkably enriched from 1779.4 to 17247.1 mg·L−1 with 96.0% recovery. Additionally, 99.5% desalination efficiency was achieved, resulting in a high purity (i.e., 98.3%) for humic substances as potential organic fertilizer application. These findings suggest that the bio-inspired co-deposition is an effective strategy to tailor the surface properties of NF membranes for efficient fractionation of humic substances and salts, in view of sustainable resource recovery from the landfill leachate concentrate.

Improving the perm-selectivity and anti-fouling property of UF membrane through the micro-phase separation of PSf-b-PEG block copolymers

PSf-b-PEG block copolymers with different PEG contents were synthesized to fabricate the highly perm-selective and anti-fouling ultrafiltration (UF) membranes. PEG homopolymer was also blended into the polysulfone casting solutions to fabricate the control (PSf/PEG blend) membranes. The membrane pore structure, surface properties and separation performances of PSf-b-PEG block copolymer membranes and PSf/PEG blend membranes were investigated to identify the role of PEG block for the pore formation. Our results find that the higher PEG content in the PSf-b-PEG block copolymer and in the PSf/PEG blend system was favorable to form more pores and thinner top skin layer with the slightly larger pore size and the higher MWCO of the fabricated membranes. But under the same content, PEG in the block copolymer could help to generate more pores but with similar pore size than PEG in the blend system during the phase-inversion process, which is because of the micro-phase separation of PSf block and PEG block. The fabricated PSf-b-PEG21 (PSf-b-PEG having 21 wt% PEG) membrane had a high water permeation coefficient of 980.0 ± 33.0 LMH/bar and a high BSA rejection above 98%, succeeding the current perm-selectivity upper-bound of the reported polymeric UF membranes. Antifouling experiments confirmed that the PSf-b-PEG21 membrane exhibited a slow and less flux decline during the fouling stage, but a fast and high flux recovery after the backwash cleaning. Our work provides some insights on the relationship of PSf-b-PEG block copolymer composition and membrane structure-separation properties.