Modified Polyethersulfone Membranes Research Articles

Removal of Monovalent and Divalent Cations from Brine Water by Electrodialysis Using Modified Polyethersulfone Membranes

In electrodialysis, an ion exchange membrane removes unwanted ions from wastewater and toxic metal ions from effluents. Montmorillonite-based modified "polyethersulfone membranes" have been studied as a potential small-scale electrodialysis approach for removing ions from wastewater. The study featured several steps, including solid polymerization, electrolyte balance, and removal of each component from the water. The study used three distinct “cation-exchange membranes (CEM)" types. The selected water body was diluted 100 times before being added to the electrodialysis cell in amounts of the center, cathodic, and anodic chambers, each containing 55, 30, and 40 mL. The initial pH for the real solutions of the water body was 7.16 at 25°C. Compared to "Sulfonated poly arylene ether sulfone (S-PESOS)" (23.23%) and Nafion® (35.34%), "hexamethylenediamine (HEXCl)" stands out as the only cross-linked material with significantly high-water content. When the membrane water content is too high, the membrane may lose its mechanical strength and cannot provide enough ionic conductivity. The semi-empirical model's parameters were estimated to simulate the elimination of Na+, K+, Ca2+, and Mg2+ by three membranes. HEXCl and S-PESOS were electrodialyzed and used to treat the serial dilution from the water with cationics. The removal rate gradually rose after the electrodialysis started.

Preparation of polyethersulfone ultrafiltration membrane coated natural additives toward antifouling and antimicrobial agents for surface water filtration

Chitosan (CS) and polyphenon 60 from green tea (PGT) as natural additives were used in the preparation of antifouling and antibacterial polyethersulfone (PES) ultrafiltration membranes via the surface coating method. The effect of additive coating on fouling resistance and antibacterial properties were evaluated. The membrane characterizations were carried out using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy, and surface hydrophilicity by contact angle. The results showed that the optimized modified membrane (1 wt% CS/3 wt% PGT-coated PES, denoted as CS1PGT3) demonstrated better hydrophilicity than the pristine PES membrane. In addition, the CS1PGT3 membrane exhibited high BSA rejection (99.99%), relatively high flux recovery (78.78%), and the highest water flux (46.83 L/m2.h) among all modified PES membranes. After the CS1PGT3 membrane was immersed in different soaking solutions (i.e., acid, alkaline, and neutral) for 21 days, the stability of CS and PGT groups on the PES membrane was also confirmed. Moreover, during examination using surface water filtration, the removal rates of chemical oxygen demand, turbidity, and aromatic compounds were increased from 64.30%, 34.23%, and 62.78% to 88.22%, 64.18%, and 84.21%, respectively. The largest inhibition zone diameter (7.83 mm of E. coli) and highest antibacterial efficiency (99% of E. coli) were achieved, suggesting the outstanding antibacterial properties of the optimized modified membrane. Thus, the incorporation of CS/PGT into PES membrane via the surface coating showed promising method to enhance antifouling and antibacterial properties.

Morphology and characteristics of polyethersulfone membrane modified with polyethylene glycol hexadecyl ether and nanocarbon

The development of polyethersulfone (PES) membranes to improve membrane performance can be done in various ways; one is by combining two types of additives (organic and inorganic) in one dope polymer solution. In this study, researchers analyzed the effect of combining polyethylene glycol hexadecyl ether (PEG-HE) as an organic additive and nanocarbon as an inorganic additive on the characteristics and performance of PES membranes. The membrane performance test includes analysis of pure water flux and rejection of synthetic fertilizer factory wastewater (Mg2+) with a concentration of 300 ppm. The membrane characterization was carried out by analyzing the morphology of the membrane structure using Scanning Electron Microscopy (SEM), water contact angle (WCA), porosity, and membrane pore size. Ultrafiltration experiment showed that the modified PES membrane with PEG-HE and Nanocarbon had the highest pure water flux. The most significant rejection coefficient of 96.88% was found in an ultrafiltration experiment using pure PES membranes. The characteristic of other membranes will be described in detail in this article.

Systematic investigation of MAX phase (Ti3AlC2) modified polyethersulfone membrane performance for forward osmosis applications in desalination

The current work presented an in-depth investigation of the design and fabrication of thin film membranes for desalination applications by forward osmosis (FO). This includes manipulating the substrate membrane structure aiming to optimize the final thin film composite membrane characteristics. In this context, the MAX phase (Ti3AlC2) as a 2D material has been harnessed to impart novel desirable traits on the prepared membrane. MAX phase has been impregnated in two disparate concentrations and three different scenarios including the substrate membrane and the polyamide layer in both the aqueous and organic phases during the interfacial polymerization. Membranes were comprehensively characterized by a series of experimental tools and methodologies including Atomic Force Microscopy, Scanning Electron Microscopy, Contact Angle, Fourier-transform infrared spectroscopy, pore size and porosity. Results disclosed that substrate membrane structure has a pivotal impact on final TFC/TFN membrane performance. Besides, the MAX phase (Ti3AlC2) could significantly enhance the morphological characteristics of the membrane and ultimately the performance in terms of water flux and reverse salt flux based on the content and the way impregnated. The permeation properties of the composite membranes were significantly superior to the pure PES membrane and the mean pore size also increased with the addition amount of MAX phase (Ti3AlC2) increased.

Metode Modifikasi Membran Polietersulfon (PES) Untuk Meningkatkan Antifouling−Mini Review Modifikasi Membran

Polyethersulfone (PES) is the most common material in various medical and water treatment applications because of its excellent mechanical and thermal properties. The hydrophobicity of polyethersulfone is considered as one of the main drawbacks because the hydrophobic surface causes a high biofouling effect on the membrane, so it has limitations in using Polietersulfon PES membrane technology. Modification of PES membranes is an important topic to be continuously developed to improve the properties of PES membranes. Membrane modifications focus on increasing the hydrophilicity, selectivity, and stability of membranes that are expected to be used commercially. Modifications were made to change the hydrophobic membrane surface into a hydrophilic membrane with good mechanical properties by introducing hydrophilic properties and functional groups to the polyethersulfone membrane surface. This review includes reviews and discussions on modifying PES membranes by mixing, coating, and grafting methods. In particular, adding functional groups to polyethersulfone is a suitable method for introducing hydrophilic properties. The addition of nanomaterials to the surface of the polyethersulfone membrane by mixing, coating, grafting, and combinations significantly increases the surface of the membrane, and all modifications affect the surface roughness of the membrane.

Antifouling and Water Flux Enhancement in Polyethersulfone Ultrafiltration Membranes by Incorporating Water-Soluble Cationic Polymer of Poly [2-(Dimethyl amino) ethyl Methacrylate].

Novel ultrafiltration (UF) polymer membranes were prepared to enhance the antifouling features and filtration performance. Several ultrafiltration polymer membranes were prepared by incorporating different concentrations of water-soluble cationic poly [2-(dimethyl amino) ethyl methacrylate] (PDMAEMA) into a homogenous casting solution of polyethersulfone (PES). After adding PDMAEMA, the effects on morphology, hydrophilicity, thermal stability, mechanical strength, antifouling characteristics, and filtration performance of these altered blended membranes were investigated. It was observed that increasing the quantity of PDMAEMA in PES membranes in turn enhanced surface energy, hydrophilicity, and porosity of the membranes. These new modified PES membranes, after the addition of PDMAEMA, showed better filtration performance by having increased water flux and a higher flux recovery ratio (FRR%) when compared with neat PES membranes. For the PES/PDMAEMA membrane, pure water flux with 3.0 wt.% PDMAEMA and 0.2 MPa pressure was observed as (330.39 L·m-2·h-1), which is much higher than that of the neat PES membrane with the value of (163.158 L·m-2·h-1) under the same conditions. Furthermore, the inclusion of PDMAEMA enhanced the antifouling capabilities of PES membranes. The total fouling ratio (TFR) of the fabricated PES/PDMAEMA membranes with 3.0 wt.% PDMAEMA at 0.2 MPa applied pressure was 36 percent, compared to 64.9 percent for PES membranes.

Nitrogen-doped carbon nanotube modified ultrafiltration membrane activating peroxymonosulfate for catalytic transformation of phosphonate and mitigation of membrane fouling

The nitrogen-doping carbon nanotube modified polyethersulfone membrane (NCNT@PES) was prepared by vacuum-assisted filtration. The catalytic activity and anti-fouling capacity of NCNT@PES/peroxymonosulfate (PMS) system were both systematically investigated. Selecting ethylenediamine tetra(methylene phosphonic acid) (EDTMP) as a target phosphonate, the NCNT@PES/PMS system degraded almost 100% of EDTMP, and about 60% of the total phosphorus (TP) in EDTMP could be transformed into orthophosphate (PO43−) within 1 min. Scavenger experiments and electron paramagnetic resonance (EPR) technique verified that the surface-bound radicals were mainly contributed the degradation and transformation of EDTMP in the NCNT@PES/PMS system. The presence of HCO3−, SO42− and NOM weakened the catalytic reactions, nevertheless, the NCNT@PES/PMS system still showed considerable effectiveness on the transformation of EDTMP in real sewage effluent. Moreover, the anti-fouling experiment proved that NCNT@PES/PMS system were superior on the removal of fluorescent components in the real sewage effluent, and their removal rates for the dissolved organic matter (DOC) and UV absorbance at 254 nm (UV254) were also improved. During the filtration cycles, the NCNT@PES/PMS system mitigated the membrane fouling significantly, which had been verified by the slower decline of normalized flux, less ultrapure water flux loss rates and higher ultrapure water flux recovery rates. This study provided a novel but simple way for effective EDTMP decontamination, at the same time, confirmed the potential of NCNT@PES membrane coupled with PMS activation on anti-fouling and water purification ability.

CdSe/ZnS QDs embedded polyethersulfone fluorescence composite membrane for sensitive detection of copper ions in various drinks

The copper ion was detected rapidly by a novel sensing membrane in this paper for its damage to health and the environment. CdSe/ZnS QDs modified polyethersulfone membrane (QDs@PESM) was made by phase-inversion method using a membrane separation technique and quantum dots (QDs). When the sample passed through the membrane, the copper ions in the sample caused the membrane’s fluorescence to be quenched. The fluorescence quenching value of the membrane is used to calculate the concentration of copper ions. With R 2= 0.9964, Cu2+could be quantitatively detected over a wide concentration range (10–1000 μg/L). The method’s LOD and LOQ were 4.27 and 14.23 μg/L, respectively. When the CdSe/ZnS QDs@PESM was used to analyze Cu2+ in various real drinks, including well water, baijiu, orange juice, beer, and milk, the recovery ranged from 79.1 to 123.9%, indicating that the CdSe/ZnS QDs@PESM can be used as a rapid, simple and reliable method to determine Cu2+ in various matrices.

Tethering hydrophilic macromolecules onto inorganic nanoparticles via RAFT toward biocompatible polyethersulfone membrane

Polyethersulfone (PES) polymers are useful for a variety of membranes' bio-related applications. However, due to its failure to satisfy certain performance and biocompatibility standards, PES requires further surface modification. Herein, we report a facile and flexible method of PES membrane modification by combining the synthesis of silicon oxide nanoparticles grafted with polyvinylpyrrolidone (PVP) as hydrophilic macromolecules via reversible addition fragmentation chain-transfer polymerization (RAFT) and aminated polyethersulfone. The blending of polyethersulfone-modified membranes with SiO2@PVP and aminated polyethersulfone results in a robust, hydrophilic, and biocompatible surface. This research work uniquely uses this strategy to stabilize the existence of the hydrophilic modifiers (SiO2@PVP and aminated polyethersulfone) within the membrane matrix. Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and scanning electron microscopy (SEM) are used to analyze the prepared polymer brush and the modified membranes. The modified membranes demonstrate high pure water flux at 345 ​L ​m−2 ​h−1 and bovine serum albumin (BSA) rejection at 98 ​%. The prepared membranes also show favorable hydrophilicity with a contact angle of 46.8° compared with pristine polyethersulfone at 79°. Furthermore, the modified membranes demonstrate an acceptable degree of blood biocompatibility according to partial thromboplastin time (APTT), prothrombin time (PT), thrombin time (TT), and fibrinogen (FIB) concentration analysis. Based on inductively coupled plasma optical emission spectroscopy (ICP-OES), the silicon nanoparticle leaching in permeate is in a safe range. Accordingly, the modified polyethersulfone membrane is safe and suitable for hemodialysis and bio-related applications.

Development of Ruthenium Oxide Modified Polyethersulfone Membranes for Improvement of Antifouling Performance Including Decomposition Kinetic of Polymer

In this study, RuO2-embedded PES membrane was prepared and it was used for protein separation. The antifouling properties of the fabricated composite membranes were also investigated using bovine serum albumin (BSA) as protein solution. The mean roughness increased proportionally by introducing RuO2 particles. The porosity of the composite membranes was higher than that of the pristine PES membrane. On the other hand, composite membranes has smaller average pore size after addition of RuO2 particles. The blending of RuO2 particles to the PES membrane caused to increase the hydrophilicity. The contact angle was measured 76.67 ± 1.21°, 73.23 ± 0.84°, 70.28 ± 0.77°, and 67.13 ± 0.80° for pristine PES, PES/RuO2 0.50 wt%., PES/RuO2 0.75 wt%., and PES/RuO2 1.00 wt%, respectively. The pure water flux of the membranes decreased from 439.7 to 379.3 L/m2/h for the pristine PES and PES/RuO2 1.00 wt%. The pore size was calculated as 16.47 nm for the pristine PES and pore size decreased up to 6.05 nm when RuO2 particles increased up to 1.00 wt%. BSA fluxes were 84.1 ± 2.1, 86.3 ± 2.5, and 93.9 ± 3.2 L/m2/h for pristine, PES/RuO2 0.50 wt%, and PES/RuO2 0.75 wt% membranes, respectively. PES/RuO2 1.00 wt%. membrane supplied the lowest BSA flux (73.6 ± 3.1 L/m2/h). BSA rejection efficiencies increased from 45.5 ± 1.8% to 92.6 ± 1.5% when blended RuO2 particles increased from 0 to 1.00 wt%. The results depicted that Rir values decreased while Rr values increased after the blending of RuO2. The thermal studies of the PES/RuO2 membranes were also performed by DTA/TG. The Activation Energy (Ea) values of the PES/RuO2 membranes were found to be 57.67-641.34 kJ/mol for Flynn-Wall-Ozawa (FWO) and 55.13–659.10 kJ/mol for Kissenger-Akahira-Sunose (KAS).Graphical Abstract

Modification of Polyethersulfone Ultrafiltration Membrane Using Poly(terephthalic acid-co-glycerol-g-maleic anhydride) as Novel Pore Former.

In this research, poly terephthalic acid-co-glycerol-g-maleic anhydride (PTGM) graft co-polymer was used as novel water-soluble pore formers for polyethersulfone (PES) membrane modification. The modified PES membranes were characterized to monitor the effect of PTGM content on their pure water flux, hydrophilicity, porosity, morphological structure, composition, and performance. PTGM and PES/PTGM membranes were characterized by field emission scanning electron microscopy (FESEM), Fourier-transform infrared spectroscopy (FTIR), and contact angle (CA). The results revealed that the porosity and hydrophilicity of the fabricated membrane formed using a 5 wt.% PTGM ratio exhibited an enhancement of 20% and 18%, respectively. Similarly, upon raising the PTGM ratio in the casting solution, a more porous with longer finger-like structure was observed. However, at optimum PTGM content (i.e., 5%), apparent enhancements in the water flux, bovine serum albumin (BSA), and sodium alginate (SA) retention were noticed by values of 203 L/m2.h (LMH), 94, and 96%, respectively. These results illustrated that the observed separation and permeation trend of the PES/PTGM membrane may be a suitable option for applications of wastewater treatment. The experimental results suggest the promising potential of PTGM as a pore former on the membrane properties and performance.

Fabrication of a Modified Polyethersulfone Membrane with Anti-Fouling and Self-Cleaning Properties from SiO2-g-PHEMA NPs for Application in Oil/Water Separation

To prepare anti-fouling and self-cleaning membrane material, a physical blending modification combined with surface grafting modification has been carried out; first, poly (2-hydroxyethyl methacrylate) grafted silica nanoparticles (SiO2-g-PHEMA NPs) were synthesized using surface-initiated activators regenerated by electron transfer atom transfer radical polymerization (ARGET ATRP) and used as a blending modifier to fabricate a polyethersulfone (PES)/SiO2-g-PHEMA organic–inorganic membrane by the phase-inversion method. During the membrane formation process, hydrophobic PES segments coagulated immediately to form a membrane matrix, and the hydrophilic SiO2-g-PHEMA NPs migrated spontaneously to the membrane surface in order to reduce interfacial energy, which enhanced the hydrophilicity and anti-fouling properties of the PES/SiO2-g-PHEMA membrane. Importantly, the membrane surface contained abundant PHEMA segments, which provided active sites for further surface functionalization. Subsequently, the carboxyl-terminated fluorocarbon surfactant (fPEG-COOH) composed of hydrophilic polyethyleneglycol segments and low-surface-energy perfluorinated alkyl segments was synthesized via the esterification of fPEG with succinic anhydride. Lastly, the PES/SiO2-g-PHEMA/fPEG membrane was prepared by grafting fPEG-COOH onto surface of the PES/SiO2-g-PHEMA. Thus, a versatile membrane surface with both fouling-resistant and fouling-release properties was acquired. The PES/SiO2-g-PHEMA/fPEG membrane has a large oil–water flux (239.93 L·m−2·h−1), almost 21 times that of PES blank membrane and 2.8 times of the PES/SiO2-g-PHEMA membrane. Compared with the unmodified PES membrane, the flux recovery ratio increased from 45.75% to 90.52%, while the total flux decline ratio decreased drastically from 82.70% to 13.79%, exhibiting outstanding anti-fouling and self-cleaning properties. Moreover, the grafted fPEG segments on the membrane surface show excellent stability due to the presence of stable chemical bonds. The grafted segments remain at the surface of the membrane even after a long shaking treatment. This suggests that this PES/SiO2-g-PHEMA/fPEG membrane material has potential for application in oil/water separation.

Comparative analysis of performance of fabricated nitrogen-doped carbon-nanotubes, silicon/germanium dioxide embedded polyethersulfone membranes for removal of emerging micropollutants from water

The occurrence of emerging micropollutants (EMPs) in water is a new challenge to scientific community and ecosystems health worldwide. There remains widespread data gaps regarding effective removal of EMPs from water. In this study, nitrogen-doped carbon nanotubes/polyethersulfone (N-CNT/PES), silicon dioxide (silica) (SiO2) and germanium dioxide (GeO2) embedded polyethersulfone (PES) membranes were fabricated using phase inversion method. A comparative multivariate statistical analysis was done to comprehend major underlying factors behind the performance of the membranes in the removal of EMPs from water using the cross flow filtration system. The EMPs were detected and quantified using GC xGc-HRTOFMS Strong statistically significant positive correlations were observed between removal efficiency of all analytes, namely carbamazepine (CBZ), tonalide (AHTN), galaxolide (HHCB), caffeine (CAF), technical 4-nonylphenol (NP) and bisphenol A (BPA) and various membrane characteristics such as pore density number, ultimate tensile strength, Young's modulus, flux recovery ratio (p-value < 0.05, 95% confidence level). Statistically significant negative corrections were observed between the removal efficiency of the EMPs with pore size, contact angle and surface roughness. The EMPs were observed to be removed from real water samples in the following order: HHCB > NP > AHTN > BPA > CBZ > CAF. The removal of the EMPs followed the order of the decrease in hydrophobicity. It was also observed that modification of PES membranes with N-CNTs, SiO2 and GeO2 nanoparticles enhanced the fouling resistance of the membranes. Generally, the performance of the fabricated membranes in the removal of all analytes followed the following order: SiO2/PES > GeO2/PES > N-CNT/PES > pristine PES. The order of increase in water flux (L/m2/h) was observed to be PES (200.60 ± 0), N-CNT/PES (265.01 ± 0), GeO2/PES (300.01 ± 0) and SiO2/PES (305.88 ± 0). However, lower nanoparticle loadings were required to bring statistically significant improvements in performance and characteristics of the N-CNT/PES membranes than that in the SiO2/PES and GeO2/PES membranes. The results showed that the capability fabricated membranes in removing EMPs from water was superior to the majority of methods reported in the literature.

A novel asymmetric structured nanocomposite PEO-Cloisite based membrane for salt and dye separation

In this study a novel approach was adopted to couple cloisite functionalised with PEO nanoparticles to modify the polyether sulfone (PES) at low pressure nanofiltration membrane for the removal of salts and dyes from waste water. PES/f-(PEO-Cloisite) nanocomposite membranes were fabricated by phase inversion process in presence of DMF as solvent. The functionalised PEO-Cloisite mixture was characterised by SEM-EDX and the membranes were characterised by hydrophilicity and morphology. The highest water flux of 152.77 Lm−2h−1 was observed for 4.5 wt% of PEO-Cloisite in PES membrane. Contact angle values reduced from 74.3° to 60.9° with the increase in the concentration of PEO-Cloisite and confirmed the increase of hydrophilicity. The membrane performance was tested using model saline and dye solutions by low pressure nanofiltration under longer run mode. This study infers that modification of PES membranes using functionalised PEO-Cloisite increase the membrane stability can be used to alleviate the fouling in the treatment of industrial waste water.

Modification of polyethersulfone membranes by Polyethyleneimine (PEI) grafted Silica nanoparticles and their application for textile wastewater treatment

ABSTRACT In the current work, a novel nanocomposite membrane for wastewater treatment applications has been synthesized. A hydrophilic nature nanoadditive comprised grafting polyethylenimine (PEI) molecules onto the surfaces of silica nanoparticles (SiO2 NPs) was synthesized then entrapped within a polyethersulfone polymeric matrix at disparate ratios via the classical phase inversion technique. A series of experimental tools were employed to probe the influence of SiO2-PEI on the surface topography and morphological changes, hydrophilicity, porosity, surface chemistry as well as permeation and dyes retention characteristics of the new nanocomposite. Upon increasing the nanoadditives content (up to 0.7 wt. % SiO2- PEI), clear cross-sectional changes were depicted along with a noticeable decline in the water contact angle by 29.7%. Performance evaluation measurements against synthetic dye solutions were disclosed explicit enhancement in both; retention and permeation characteristics of the nanocomposite membranes. Besides, prolonged permeation test has maintained high flux stability against real textile wastewater; implying better resistance and self-cleaning characteristics have been achieved.

Construction of novel antiplatelet modified polyethersulfone membrane and study into its blood compatibility

Blood purification therapy is widely used in patients with renal insufficiency and severe infections, where membrane-associated thrombosis is a side effect. How to improve the hemocompatibility of dialysis membranes and reduce thrombosis is a focus of current research, in which platelets play a key role. However, few dialysis membranes that directly inhibit platelets have been developed to date. In this study, a polyethersulfone (PES) membrane was modified with ticagrelor, a platelet P2Y12 receptor inhibitor, and detailed characterization was performed. The ticagrelor modified PES membrane (TMPES) showed good hydrophilicity and anti-protein adsorption and significantly inhibited platelet adhesion, aggregation, and activation, which demonstrated good antithrombotic properties. In addition, the membrane had excellent red blood cell (RBC) compatibility, anticoagulant, and antiinflammatory effects, which demonstrated superior biosafety in cell and animal experiments. Therefore, the TMPES dialysis membrane could have potential in clinical applications.

Study on the advantageous effect of nano-clay and polyurethane on structure and CO2 separation performance of polyethersulfone based ternary mixed matrix membranes

In recent years, many efforts have been made to develop new membrane materials for natural gas sweetening (CO2/CH4) and post-combustion CO2 capture from flue gas (CO2/N2), especially in coal-fired and natural gas-fired power plants. This study focused on the effect of polyurethane and nano-clay on structure and CO2 separating properties of polyethersulfone (PES) based three-component mixed matrix membranes (MMMs). The different weight fractions polyurethane (PU) (5−30 wt.%) together with clay nano-sheets (Cloisite® 15A) (0.5−10 wt.%) were blended to fabricate a novel PES-based ternary MMMs. The principal purpose was to investigate the effect of loading PU polymer and layered clay particles with 2D channels on the gas separation performance of the PES membranes. Pure gas permeability for N2, CH4, and CO2, and ideal gas separation for CO2/N2 and CO2/CH4 mixtures were examined through neat PES and modified PES membranes. By incorporating 20 wt.% of PU into PES, the permeability of CO2 and selectivities of CO2/N2 and CO2/CH4 were improved by 4, 1.4, and 1.7 times higher than the neat PES membrane, while by loading 20 wt.% of PU and 2 wt.% of nano-clay, the CO2 permeability, and CO2/N2, and CO2/CH4 selectivities were improved by 7.8, 1.8, and 2.2 times higher than the neat membrane, respectively. In general, PU and clay nano-sheets together as a filler into the PES matrix exhibited a meaningful improvement in the gas permeation and separation properties of PES and can be admitted as a worthy membrane for CO2 separation from the flue gas and natural gas.

Bimetallic polyphenol networks structure modified polyethersulfone membrane with hydrophilic and anti-fouling properties based on reverse thermally induced phase separation method

In order to improve the hydrophobicity of traditional polyethersulfone (PES) membranes, this study combined the reverse thermally induced phase separation (RTIPS) method with the constructed bimetallic polyphenol networks (BMPNs) to prepare hydrophilic anti-fouling membranes. As for BMPNs, tannic acid (TA) was served as an intermediate to construct both the inner and surface hydrophilic layers of the PES membranes. On the one hand, etching Zeolitic imidazolate framework-8 (EZIF-8) with synergistic etching and surface functionalization via TA not only retained the high pore structure of MOFs, but also had good hydrophilicity. On the other hand, the MPN hydrophilic layer was formed on the membrane surface by the combination of TA from the surface of EZIF-8 and iron ions in the coagulation bath. Therefore, BMPNs structure penetrated the interior and surface of PES membrane, which greatly improved the hydrophilic properties. In addition, the membrane with porous surfaces and spongy cross sections by RTIPS method improved the permeability and mechanical properties of the membrane by several times compared with the membrane via NIPS method. The obtained membranes in this experiment showed excellent permeability, just like pure water flux reached 1662.16 L/m2 h, while BSA rejection rate remained at 92.78%. Compared with pure membrane, it showed a better flux recovery rate (FRR = 83.33%) after cleaning, and the reduction of irreversible (Rir = 16.67%) fouling indexes indicated that the adsorption of protein was inhibited. These results suggested that the hydrophilic anti-fouling PES membranes prepared by this method possessed great application potential in membrane separation technology.

Hydrophilic modification of poly(ether)sulfone membrane by atmospheric pressure argon jet plasma: pH dependence of ultrafiltration performance and cleaning efficiency

AbstractThe studies focused on plasma surface modification of poly(ether)sulfone (PES) ultrafiltration (UF) membrane show its potent effect on antifouling propensity but there are few data on the pH dependence of superior surface character achieved. This study examined UF performance and cleaning efficiency of atmospheric pressure argon jet plasma (AP‐AJP) modified PES membrane in whey concentration at various operation pH compared to the plain membrane (UP020). The highest initial permeate flux for the UP020 at pH of 6.4 increased the cake layer formation and the irreversible fouling resistance. The plasma action led to greater intrinsic membrane resistance causing low water permeability compared with the UP020. This effect reduced cake layer resistance despite the fact that the irreversible fouling was more severe at all operation pH. The increase in pH caused to decrease in contribution of fouling to total resistance. For the UP020, the shift in operation pH from acidic point to neutral reduced the recovery in hydraulic permeability after chemical cleaning. The plasma action induced greater cleaning efficiency, which is the most obvious at pH of 6.4. The overall results showed that the AP‐AJP may have the potential to maintain profit‐making UF process in whey concentration at broad range of pH.Practical ApplicationsIn the industrial point of view, cost friendly, and sustainable operation in valorization of whey can be achieved by fouling resistant membranes. Atmospheric pressure argon jet plasma provides extremely hydrophilic character to poly(ether)sulfone membrane. The plasma action decreases fouling resistance and especially cake layer formation. This effect broadens the operating pH of whey without any pre‐adjustment and results in easy to clean membrane surfaces.

Improvement of dye and protein filtration efficiency using modified PES membrane with 2-mercaptoethanol capped zinc sulfide quantum dots

In this work, novel 2-mercaptoethanol capped zinc sulfide (ZnS) quantum dots (QDs) embedded polyethersulfone (PES) nanocomposite membranes were fabricated which revealed wh improved antifouling properties and dye separation performance. A simple water-based precipitation approach was used to obtain 2-mercaptoethanol capped ZnS QDs at ambient temperature. The resulting membranes were fully identified with SEM, AFM, ATR-FTIR analyses, and also underwent porosity and contact angle tests. The developed nanostructure membranes exhibited a remarkable fouling reduction in bovine serum albumin (BSA) protein filtration, as featured by a declined average surface roughness. The flux recovery ratio (FRR) was improved considerably from 52.6% for the neat PES to 87.9% for nanocomposite membrane by inserting 2 wt.% ZnS QDs. The contact angle of membrane decreased, while porosity size was enlarged by increase of the QDs loading. The prepared nanocomposite membranes showed an increased Reactive Red 195 rejection (from 91.3% to 96.1%) and an enhanced water and dye solution flux (from 121 to 163 L m−2 h−1) with respect to the bare PES membrane. Thus, the results proved the potential of the novel QDs/PES membrane for the dye separation applications.