Graphene oxide/hydrotalcite modified polyethersulfone nanohybrid membrane for the treatment of lead ion from battery industrial effluent

In the present study, polyethersulfone based nanohybrid membranes were effectively fabricated by incorporating graphene oxide(GO) and hydrotalcite(HT) nanosheets into the membrane structure. HT was prepared to overcome the irreversible agglomeration behavior of GO at a high concentration which affects the performance of the membranes. In particular, the shedding of HT in formamide provides a two-dimensional nanosheet with a higher positive charge density to prevent the restacking of GO nanosheets. Here, exfoliated GO and HT with different combinations(1:1, 1:2 and 1:3) were infused in the membrane matrix to treat lead-acid battery effluent effectively. Finally, the hybrid membranes were characterized for hydrophilicity, mechanical strength and pure water flux. In combination with the superior properties of GO and HT, the prepared hybrid membranes can be used as effectively to improve the separation and permeation performance. The phase inversion process eliminated the leaching of nanoparticles from the membrane matrix. The reusability of the hybrid membrane was achieved using0.1 mol·L^(-1)NaOH solution and reused without significant reduction in lead removal efficiency. The cost analysis of the membrane was also estimated from the lab study. Therefore, the present study suggested the selective and sustainable treatment of lead from a real-life effluent.

Polyethersulfone-polyvinylpyrrolidone composite membranes: Effects of polyvinylpyrrolidone content and polydopamine coating on membrane morphology, structure and performances

Hydrophilic modification is a promising method to inhibit fouling formation on ultrafiltration membrane.In this work,different mass concentrations(1%–16%)of hydrophilic polyvinylpyrrolidone were incorporated into polyethersulfone(PES)membranes fabricated by none-solvent induced phase separation.Then,polydopamine(PDA)coating on the surface of prepared membrane was carried out at pH 8.5.The morphology and structure,surface hydrophilicity,permeation flux,BSA rejection,antifouling and stability performances of PES and PDA/PES modified membranes were investigated in detail.The results indicated that PDA was successfully attached onto the membranes.Membrane hydrophilicity was evaluated by water contact angle measurement.The contact angles of modified membranes reduced remarkably,suggesting that the membrane hydrophilicities were significantly increased.The results of filtration tests,which were done by dead-end filtration of bovine serum albumin solution,showed that the properties of permeability and fouling resistance were obviously improved by PDA modification.When polyvinylpyrrolidone mass content reached 10%,flux recovery ratio of modified membrane was up to91.23%,and its BSA rejection were over 70%.The results of stability tests showed that the modified membranes had good mechanical stability and chemical stability.This facile fabrication procedure and outstanding performances suggested that the modified membranes had a potential in treating fouling.

Purifying chylous plasma by precluding triglyceride via carboxylated polyethersulfone microfiltration membrane

Precluding the excessive lipoproteins from plasma rapidly and effectively is highly needed for biomedical detection and reducing plasma product scrap in blood donation stations.The current centrifugation procedure is high-cost and time-consuming.Herein,we fabricated an anionic microfiltration polyethersulfone(PES)membrane modified by interface swelling and implanting of acrylic acid(AA)for screening out large particle lipoprotein chylomicron(CM)and adsorbing cationic very low-density lipoproteins(VLDL).To improve the separation efficiency,a two-stage filtration through carboxylated polyethersulfone microfiltration membranes with the mean pore size of 0.45 and 0.22μm respectively were conducted.Attenuated total reflection Fourier transform infrared technique(ATR-FTIR),water contact angle(WCA),Zeta potential and scanning electron microscope(SEM)were employed to characterize the modified membrane.To test the effectiveness of this membrane,plasma flux and concentration variation of plasma components were examined to study the purification effectiveness.Furthermore,the hemocompatibility of modified membranes was tested to confirm its practicability on bloodcontacting materials.The carboxylated polyethersulfone microfiltration membrane shows its promising potential application to purify chylous plasma.

Permeation properties of CO2 and CH4 in asymmetric polyethersulfone/ polyesterurethane and polyethersulfone/polyetherurethane blend membranes

The transport performances of carbon dioxide and methane were studied in polyethersulfone, polyethersulfone/polyeterurethane(PES–ETPU) and polyethersulfone/polyestherurethane(PES–ESPU) blend membranes separately with different compositions. The variations in the structural characteristics of PES membrane after incorporation of ESPU and ETPU were investigated by different techniques. Additionally, the effect of pressure and composition on the permeance of CO_2, CH_4 and ideal selectivity of CO_2/CH_4 were checked on the membranes.The results revealed that the morphology of the blend membranes was affected by two opposite factors: thermodynamic enhancement and kinetic hindrance. The membranes with denser sponge layers were formed at lower ratio of PU/PES, while more porous structure with enlarged macrovoids membranes were observed at higher PU content. The results indicated that adding PU to PES membrane, caused permeance improvement of the gases with nearly no change and/or reduction in ideal selectivity of CO_2/CH_4. Moreover, PES–ETPU membranes showed higher permeability and less CO_2/CH_4 selectivity in comparison with PES–ESPU samples. For PES–ESPU membrane containing 1.5% ESPU, CO_2 permeance at 10 bar was improved up to 20% with almost no change in CO_2/CH_4 selectivity with respect to PES. Finally, response surface methodology was used to evaluate the effects of the operating parameters on the permeance and ideal selectivity.

PREPARATION OF POLYETHERSULFONE ULTRAFILTRATION MEMBRANES FOR MILK CONCENTRATION AND EFFECTS OF ADDITIVES ON THEIR MORPHOLOGY AND PERFORMANCE

Polyethersulfone membranes were prepared from quaternary systems containing N,N-dimethylacetamide （DMAc） as solvent, polyvinylpyrrolidone （PVP） as constant additive and acetic acid, acetone and water as variable additives. Phase inversion via immersion precipitation was employed for manufacturing of membranes. The prepared films were immersed in the mixture of pure water and 2-propanol （30/70 vol%） as the non-solvent. Acetic acid caused an increment in the flux at high polymer concentration （16 wt%） and a decline in the flux at low polymer concentrations （10 wt% and 13 wt%）. Acetone and water as the solvent in the casting solution declined the flux at any polymer concentration tested. The morphology and performance of the prepared membranes were investigated by scanning electron microscopy and separation experiments using milk as the feed.

Morphology and Compatibility of Compatibilized Polyethersulfone and Polycarbonate Blends

A PES-PC （polyethersulfone-polycarbonate） multi block random copolymer was synthesized with two oligomers, polyethersulfone and polycarbonate. The effects of the copolymer, as a compatibilizer, on the morphology and compatibility of the PES-PC blends were investigated. It was found that the addition of this copolymer to the PES-PC blends could improve their compatibility.

Harvesting Microalgae Biomass Using Sulfonated Polyethersulfone(SPES)/PES Porous Membranes in Forward Osmosis Processes

This study was performed to investigate the availability of forward osmosis(FO)for microalgae harvesting using sulfonated polyethersulfone(SPES)/PES porous membranes.In FO process,porous membranes(<25.0 L m^−2 h^−1)exhibited more superior water flux than TFC FO membranes(<2.6 L m^−2 h^−1).Furthermore,the incorporation of SPES has been demonstrated to enhance membrane performance.The effects of SPES content on pore structure and separation performance were investigated.Compared with pure PES porous membranes,porous membranes with 40%SPES yielded an improved hydrophilicity and greater porosity.It exhibited two times higher water fluxes than the pure PES porous membrane.For microalgae harvesting,AL-FS mode(active layer facing the feed solution)was more favourable than AL-DS mode(active layer facing the draw solution)because less deposited microalgae on the active layer mitigate the membrane biofouling.FO operation combined with SPES/PES porous membranes is conducive to preserving microalgae cell integrity under the mild condition.In addition,FO membrane can be cleaned by a simple water rinse.Potential implications were highlighted as a sustainable method for microalgae harvesting because of no pressure input and less chemical cleaning demand.

Preparation of Hemodialyzer Made from Polyethersulfone Membrane by Dual-bath Coagulation Method

The dual-bath coagulation method was used for the preparation of PES membrane in this experiment. The main intent of this stndy was to assess the efforts of gelation conditions on the structures and properties. The dense top layer as well as porous supporting layer can be made by duel-bath coagulation method simultaneous- ly. Different internal quench medium obtained different membrane with different structures. With the increase in time in the first coagulation bath, pure water flux decreased and the clearance rates of urea and creatinine both first increased then decreased and increased slightly in the end. With the temperature of the second coagtdation bath increasing, pure water flux increases and the clearance rates of urea and creatinine first increases then de- creases and increases a little at last. Higher DMSO concentration （wt/wt） in the second coagulation bath results in the increase of pure water flux and the decrease of urea ＆ creatinine clearance rates.

Structure Change of Polyethersulfone Hollow Fiber Membrane Modified with Pluronic F127, Polyvinylpyrrolidone, and Tetronic 1307

Hydrophilic polyethersulfone (PES) hollow fiber membranes were prepared via non-solvent induced phase separation (NIPS) by addition of polymeric additives as a membrane modifying agent. The effect of the addition of hydrophilic surfactant Pluronic F127, Polyivinylpyrrolidone (PVP), and Tetronic 1307 on the performance of the final PES hollow-fiber membrane was investigated. The morphology of fabricated hollow fiber membrane observed by scanning electron microscopy (SEM) indicated that all of membrane had a skin layer on the surface and finger like macrovoid structure inside the hollow fiber. The addition of 5 wt% polymeric surfactant on the polymer solution results in membrane with improved length and number of macrovoid structure. Sponge formation both near inner surface and near outer surface of hollow fiber membrane was another impact of addition of polymeric additives, which is led to decrease of water permeability of these membrane. Water contact angle measurement was performed to investigate the hydrophilicity property of resulted membrane. It is confirmed that the modified PES hollow fiber membranes had lower water contact angle than that of the original membrane, which indicate that the modified PES membrane with additives has high hydrophilic.

Fabrication and Properties of Graphene Oxide/Sulfonated Polyethersulfone Layer-by-layer Assembled Polyester Fiber Composite Proton Exchange Membranes

Using the hydrogen-bonding interaction between graphene oxide（GO） and sulfonated polyethersulfone （SPES）, we constructed the multilayer structure of GO and SPES on the polyester tiber mats via layer-by-layer self-assembly. In each self-assembled layer, sulfonic acid groups are arranged along the a^s of fiber, which provides the long-range proton transmission channels, promoting the rapidly proton conduction. The performances of the composite membranes based on SPES and multilayer assembled polyester fiber mats were studied. The results show that the proton conductivity of composite membranes increases with the increasing assembly layers. At the same time, the mechanical properties and methanol-resistance of the composite membranes were obviously improved.

Synthesis of amphiphilic tri-block copolymerpoly(vinylpyrrolidone)-b-poly(methyl methacrylate)-b-poly(vinylpyrrolidone) for the modification of polyethersulfone membrane

Well-defined amphiphilic tri-block copolymer PVP-b-PMMA-b-PVP was prepared for the first time via successive reversible addition fragmentation chain transfer（RAFT） polymerization using carboxyl-terminated trithiocarbonate as the RAFT agent.The structure of the copolymer was characterized using FTIR,GPC and ~1H NMR.The block copolymer could be directly blended with polyethersulfone（PES） as a macromolecule additive using N-methyl-2-pyrrolidone（NMP） as the solvent to prepare membranes. The water contact angles for the modified membranes decreased obviously,and therefore,the protein adsorption amount on the membrane surface decreased.

Structure Controlling and Adsorption Application of Polyethersulfone Porous Microspheres Prepared via Electrospraying

The focus of this work is to control the structure of electrosprayed polymer microspheres and then study the effect of different structures on the microspheres＇ adsorption properties. Scanning electron microscopy （SEM） coupled with image analysis software was employed to evaluate the size distributions and the structure of microspheres. According to the observation and analysis results, two types of polyethersulfone （PES） porous microspheres （perfect sphere-shaped and collapsed） were prepared via electrospraying technology by adjusting the solvent and polymer molecular weight. The porous PES microspheres can remove bisphenol A （BPA） from its aqueous solution effectively. Compared with collapsed microspheres, the rough microspheres had much higher specific surface area and better mobility in the BPA aqueous solution, so it showed a better adsorption capacity than that of collapsed microspheres. The solvent evaporation rate and the occurrence rate of phase separation significantly affect the structure and morphology of microspheres.

Modification of PES/PU membrane by supercritical CO2 to enhance CO2/CH4 selectivity:Fabrication and correlation approach using RSM

Integrally skinned asymmetric gas separation membranes of polyethersulfone(PES)/polyurethane(PU) blend were prepared using supercritical CO_2(SC-CO_2) as a nonsolvent for the polymer solution. The membrane consisted of a dense and a porous layer, which were conjoined to separate CO_2 from CH_4. The FTIR, DSC, tensile and SEM tests were performed to study and characterize the membranes. The results revealed that an increase in SC-CO_2 temperature causes an increment in permeance and a decrease in membrane selectivity. Furthermore,by raising the pressure, both permeance and selectivity increased. The modified membrane with SC-CO_2 had much higher selectivity, about 5.5 times superior to the non-modified membrane. This higher selectivity performance compared to previous works was obtained by taking the advantages of both using partial miscible blend polymer due to the strong polar–polar interaction between PU PES and SC-CO_2 to fabricate the membrane. The response surface methodology(RSM) was applied to find the relationships between several explanatory variables and CO_2 and CH_4 permeance and CO_2/CH_4 selectivity as responses. Finally, the results were validated with the experimental data, which the model results were in good agreement with the available experimental data.

BSA Hybrid Synthesized Polymer

Bovine serum albumin （BSA）, a naturally occurring biopolymer, was regarded as a polymeric material to graft to an acrylic acid （AA）-N-vinyl pyrrolidone （NVP） copolymer to form a biomacromolecular hybrid polymer. The hybrid polymer can be blended with polyethersulfone （PES） to increase the hydrophilicity of the PES membrane, which suggested that the hybrid polymer might have a wide application in the modification of biomaterials.

Effects of Functionalized Silica Nanoparticles on Characteristics of Nanocomposites PES Cation Exchange Membranes

Nanocomposite cation exchange membranes（CEMs） were prepared by adding various loadings of functionalized silica nanoparticles to the sulfonated polyethersulfone（s PES） polymeric matrix. The silica nanoparticles were functionalized by mercaptopropyl（F1, IEC=0）, propylsulfonic acid（F2, IEC= 2.71）, and sulfonic acid（F3, IEC=2.84）. The properties of prepared membranes were investigated by varying the loadings of functionalized silica nanoparticles. Applying functionalized nanoparticles provides additional ion exchange groups and enhances water contents as well as conductivities and permselectivities of the membranes. The maximum IEC of 1.9 meq.g^-1 was obtained for the membrane having 3 wt% F3 nanoparticles and the maximum conductivity of 0.237 S·cm^-1 was achieved for the membrane having 2 wt% F3 nanoparticles, which were 19.6% and 64% higher than the corresponding values for s PES membrane, respectively. The excellent properties of the nanocomposite cation-exchange membranes make them appropriate candidates for electrodialysis and desalination processes.

Release characteristics of different diameter ultrafine fibers as antibacterial materials

Although the electrospinning technique has been devoted to promoting therapeutic purposes as a drug carrier,however,there are still many fundamental problems in this area.This work focuses on a comparison of various diameter polyethersulfone(PES)electrospun ultrafine fibers as an-timicrobial materials.The fibrous morphology,antimicrobial agent distribution,thermally property,and biocompatibility evaluation of PES-based ultrafine fibers were systematically in-vestigated.The results demonstrated that the PES-based ultrafine fibers were suitable as anti-microbial material.Furthermore,the drug release behavior and mechanism were studied through total immersion.The release mechanism was confirmed to Fickian diffusion.It was revealed that the drug max release amount(71.5%)and release rate(7.71)are the highest for the smallest diameter ultrafine fibers.Meanwhile,the antimicrobial activity of PES ultrafine fibers is also inversely correlated with the diameter of fiber.The electrospun PES fibers would control their release behavior through the diameter and have a potential application in the wound dressings,such as chronic osteomyelitis and exposure injury.

Metal Nanoparticle Modified Polysulfone Membranes for Use in Wastewater Treatment: A Critical Review

Membrane separation processes have been widely applied in the treatment of wastewater. Polysulphone (PSF) membranes are the most common membranes used in ultrafiltration of wastewater due to its mechanical robustness and structural and chemical stability. Unfortunately these membranes are mostly hydrophobic by nature and therefore highly susceptible to fouling. Many studies have been conducted to increase the hydrophilic properties of the polysul-phone/ polyethersulfone membrane surface, more recently metal nanoparticles have been added to the polymer matrix in order to reduce fouling potential and increase membrane performance. TiO2 nanoparticles have proven successful in mitigating fouling of organic matter onto PES. Embedded Ag nanoparticles have improved virus removal from wastewater due to the bactericidal properties of silver. Al2O3 and most recently ZrO2 nanoparticles reduced the fouling rate of polyethersulfone membranes in wastewater, while the latter also showed lower flux decline of the composite membrane. These metal nanoparticles all impart specific properties onto the membrane surface. Scanning electron microscopy, steady state fouling rate and contact angle measurements are membrane characterisation techniques discussed in this review that reveal specific changes to membrane properties brought about by metal nanoparticles. This paper reviews the most recent developments and shortcomings of metal nanocomposite polysulfone and polyethersulfone (PES) membranes and strives to identify specific focus areas to consider in future research.

Clinical Application of PES Membrane Dialyzer

Objective The dialysate membrane can be classified into acetate membrane and synthetic membrane,while the latter can be further divided into polysulfone,polyacrylonitrile,etc.Polyethersulfone membrane is high molecular membrane material with excellent biocompatibility,stable mechanical properties,high temperature and pressure resistance,and good cleaning performance,which has been applied for more than 10 years.This trial is to assess the safety and efficacy of hollow polysulfone membrane fiber dialyzer with pattern number Enttex^(TM)-16LF(E60)for hemodialysis in patients with acute or chronic renal failure due to multiple factors.Methods Totally 76 patients receiving maintenance hemodialysis were included in a two-site,random,open label,two-stage,positive crossover and non inferiority validation study.The clinical efficacy and safety of the test device were observed,which was a hollow fiber dialyzer produced by Guangzhou Enttex Medical Products Co.,Ltd.,with polyethersulfone membrane imported from Germany.It was a low flux dialyzer with the pattern number of EnttexTM-16LF(E60).Inclusion criteria:①patients with acute or chronic renal failure due to various reasons who needed hemodialysis;②18 to 80 years old,gender unlimited;③patients who received stable dialysis for more than 3 months,regular hemodialysis 3 times a week,4 h at each time,blood flow rate of 200~350ml/min;④using bicarbonate dialysate at a flow rate of 500ml/min;⑤patients with arteriovenous fistula or who received artificial blood vessel puncture dialysis;received anticoagulation by heparin or low molecular weight heparin.Exclusion criteria:①patients needing heparin free dialysis for severe anemia,tumor and active bleeding;②patients with severe cardiac(gradeⅢcardiac function),hepatic(severe hepatitis and cirrhosis)and pulmonary diseases(severe respiratory failure).Results Comparison of parameters,including the changes of Kt/V,general creatinine and urea clearance rates and URR(urea reduction rate)shows no statistical significance in differences between the two devices,indicating that the test and control devices can equally and effectively eliminate toxins including creatinine and urea,etc.PPP and MITTP results are consistent.Comparison of ultrafiltration rates between two groups of patients shows no statistical difference.PPP and MITTP results are consistent,indicating that both the test device and control device can effectively eliminate water.In MITTP,electrolytes including K^+,Na^+,Cl^-,Ca^2+,HCO3^-,etc.show no statistical significance in difference between the test and control devices before and after dialysis(P>0.05).After treating by using test and control devices,body weight,serum potassium and phos-phorus all significantly decrease(P<0.001);serum Ca^2+,PO2,PCO2and HCO3^-all significantly increase(P<0.001).These results indicate that both the test and control devices can effectively eliminate serum potassium and phosphorus,and eliminate excess water in body,maintain the balance between liquid and electrolytes in patients.PPP and MITTP results are consistent.Conclusion This clinical trial confirms that hollow polyethersulfone membrane fiber dialyzer can be safely and effectively used in hemodialysis therapy.

Synergetic Improvement of Interlaminar Fracture Toughness in Carbon Fiber/Epoxy Composites Interleaved with PES/PEK‑C Hybrid Nanofiber Veils

In this study,two types of soluble thermoplastic resins were added to epoxy resin at a fixed weight ratio to prepare a three-phase cast body.The cast was then manufactured into hybrid nanofiber as interleaves for interlaminar toughening of carbon fiber/epoxy resin(CF/EP)composites using a co-solvent method.The results revealed that when the hybrid components reached 15 wt%,Polyethersulfone(PES)and polyaryletherketone cardo(PEK-C)exhibited the best synergistic toughening effect,and the fracture toughness increased by 99.8%and 39.8%,respectively,compared with the reference or the same proportion of the single PES toughened sample.We used PES/PEK-C hybrid nanofibers with an areal density of 19.2 g per square meter(gsm)as composite toughening layers.Apart from the lack of significant influence of PES nanofiber on CF/EP composites,the interlaminar fracture toughness of mode I and mode II layers increased by 88.3%and 46.9%,respectively,compared to the reference sample.Scanning Electron Microscopy of the fracture surface and cross-section micromorphology of the laminate displayed that the thermoplastic microspheres of different sizes contribute differently to crack resistance:PEK-C consumes more energy due to the debonding and extraction of microspheres and resin,whereas the presence of the PES phase can induce more plastic deformation and crack deflection.