Polysulfone Membrane Surface Research Articles

Swelling-assisted surface grafting strategy for multichannel antifouling membranes: Reconstruction of surface pore structure and applications in microalgae harvesting and blood purification

Membrane fouling remains a major challenge in membrane separation. The modification of hydrophilic membrane surfaces can mitigate irreversible fouling deposition, thereby improving antifouling properties. Effective surface modification strategies are essential techniques for developing highly efficient antifouling membranes. In this work, a swelling-assisted surface grafting strategy was proposed for multichannel antifouling membranes, where various lengths of polyvinylpyrrolidone (PVP) brushes were grafted on the surface of polysulfone membrane using reversible addition-fragmentation chain transfer polymerization. The successful grafting of PVP polymer brushes was confirmed using Fourier transform infrared spectrometer and X-ray Photoelectron Spectroscopy. Changes in membrane morphology and pore structure were observed via scanning electron microscope and atomic force microscope. During the grafting process, the amphiphilic macromolecules formed through grafting were selectively swelled by graft solvent, leading to the formation of mesopores in both the surface layer and sublayer of the membrane, which formed additional water transport channels. The introduction of hydrophilic polymer brushes and the change of pore structure significantly boosted the hydrophilicity and permeability of the membranes. As a result, the water contact angle decreased from 85° to 42°, accompanied by an approximate 3.24-fold increase in pure water flux (PWF). Due to superior hydrophilicity, modified membranes demonstrated exemplary performance in microalgae harvesting, boasting a microalgae retention rate nearing 100 % and low fouling resistance (2.12 × 1012 m−1). In algal filtration experiments, a confocal laser scanning microscope was employed to assess the activity of filtered algae on the membrane surface. The prepared membranes effectively maintained the bioactivity of algae while also achieving a high flux recovery rate (90.7 %) following filtration and cleaning. Furthermore, in blood cell compatibility tests, the modified membranes exhibited resistance to blood cell adhesion and sustained a low hemolysis rate (0.06 %). Overall, this strategy offers unique insights into the fabrication of antifouling surfaces and shows considerable promise for large-scale applications in microalgae harvesting and blood purification.

Flexible inner surface of polysulfone membranes prevents platelet adhesive protein adsorption and improves antithrombogenicity in vitro.

We investigated whether the condition of the inner surface of hollow fibers affects the blood compatibility of hemodialyzers. We used scanning probe microscope/atomic force microscopy (SPM/AFM) to investigate the height of the swelling and flexible layers (thickness and softness) on the inner surfaces of the hollow fibers. Next, we tested the blood compatibility between dialyzers comprising a hollow fiber membrane, in which the other dialyzers, except for PVP, were additionally coated using PS membranes coated with other materials. After blood was injected into the dialyzer and plugged, dynamic stimulation was performed by slightly rotating the dialyzer for 4 h, although there was no blood circulation. The vitamin E-coated polysulfone (PS) membrane showed a higher thickness and softness of the flexible layer than the asymmetric cellulose triacetate membrane without polyvinylpyrrolidone (PVP) and the PS membranes with PVP. We found that the dialyzer with vitamin E coating significantly suppressed the decrease in platelets, increase in β-TG, and increase in PF4 compared to those coated with NV polymer. Additionally, as the adsorbed protein on the inner surface, the total protein, fibronectin, and vWF levels were significantly lower in the vitamin E-coated dialyzer. The thickness and softness of the flexible layer of the inner surface of the hollow fiber membrane in vitro affect differences in blood coagulation performance in clinical research. Future clinical trials are required to confirm our results.

Rates of air flow in and out of closed atmospheric-pressure plasma jet system affected surface properties of treated polysulfone membrane

The cold plasma jet works in an atmospheric-pressure condition, and is used to modify polymer membranes by creating hydrophilic functional groups on the membrane surface. Since it can be used without a pressure-reducing system, treatment time and cost are reduced. However, the plasma jet has a narrow beam which limits the area of the membrane surface that can be activated. In this study, a plasma jet was generated in a closed system with controllable rates of air flow in and out of the system. The plasma discharge was recorded with a camera and analyzed by optical emission spectroscopy (OES). Polysulfone membrane surfaces were treated with various conditions of plasma discharge, and the induced membrane hydrophilicity was assessed from water contact angle (WCA) and surface energy (SE) measurements. Atomic force microscopy (AFM), Fourier Transform Infrared Spectroscopy (FTIR) and WCA contour mapping were respectively employed to study surface roughness, functional groups, and WCA distribution on the treated membrane surfaces. The airflow had distinctly different effects on the plasma characteristics. The inflow rate condition affected the width of the plasma beam, and the outflow rate condition affected the diffusion of the plasma beam. Water flux was changed according to the plasma characteristic, and an air outflow rate of 6 L/min was the optimum condition for this experiment.

Separation Characteristics of Surface Modified Polysulfone Ultrafiltration Membrane using Oxidative Catalytic Polymerization of Aniline

The commercially available Polysulfone (PSF) membrane surface was modified by solution polymerization of aniline using different oxidation catalysts i.e., FeCl3, CuCl2, and APS. Modified membranes were then characterized with respect to physio-chemical properties like surface chemistry, porosity, wettability, surface roughness, morphology, etc. It was observed that the hydrophilicity/ wettability of membranes was increased upon surface modification by polyaniline which again depended on the nature of the oxidation catalyst used. Membranes developed using FeCl3 and CuCl2 as oxidants exhibit improved permeation, protein rejection, and antifouling properties, whereas decrement was observed in modified membrane performance using APS as an oxidant. Among all modified membranes, PSF/PANI-CuCl2 membrane demonstrates the most promising performance in terms of higher pure water flux and protein solution permeation flux i.e., 453.3 L/m2.h and 122.3 L/m2.h respectively. The PSF/PANI-CuCl2 membrane unveils superior resistance towards bio-fouling in comparison to the other modified membranes. Analytical techniques were used for the characterization of the modified membranes such as ATR, XPS, FESEM, and AFM. Contact angle measurement also supports the fact that PSF/PANI-CuCl2 membrane has a better chemical and physiological attachment to the polysulfone membrane surface.

Tailoring confined CdS quantum dots in polysulfone membrane for efficiently durable performance in solar-driven wastewater remediating systems

In this work, CdS quantum dots (QDs) were successfully confined in polysulfone membrane (PSM) to develop a photoactive membrane under solar illumination that was suited in wastewater remediating system. The CdS@PSM membranes were prepared using the nonsolvent induced phase separation (NIPS) approach. Optical measurements show the confinement of CdS quantum dots (QDs) in the PS matrix within the narrowest band gap (2.41 eV) at 5 wt% loading. PS has two strong emission peaks at 411 and 432 nm due to photoelectron-hole recombination on pure PSM's surface. Adding 1 wt% CdS QDs to PSM reduced the earlier peak and blue-shifted the latter, within the appearance of three emission peaks attributed to the near band-edge emission of confined CdS QDs. Overloading CdS reduced all emission peaks. Moreover, fluorimetric monitoring of •OH radicals indicates that PSM produces the least amount of photogenerated •OH radicals while CdS@PSM(5 wt%) achieved the highest productivity. Examining the developed membranes in detoxifying methylene blue (MB) from aqueous solution of natural pH 8.1 showed weak adsorption in dark over 90 min of contact while switching to solar illumination significantly photodegrade MB where the degradation efficiency starts from 49% for pure PSM to 79% for CdS@PSM(5 wt%). Influence of pH was found crucial on photodegradation efficacy. Acidic pH 3 showed the weakest photodegradation efficacy, while the alkaline pH 12 was 18.88 times more effective. The used CdS@PSM (5 wt%) was successfully photo-renovated by soaking in 10 mL of NaOH solution under Solar illumination for 15 min to be used in 4 consecutive photodegradation cycles with insignificant decrease in efficacy. These findings are promising and could lead to a high-efficiency, sustainable photocatalytic suite.

Synthesis and Characterization of Antibacterial ZnO - Functionalized Polysulfone Membrane

Membrane technology is an emerging alternative in water treatment. This study aims to synthesize a filtration membrane made of polysulfone polymer with the addition of ZnO in order to enhanced the membrane antibacterial/antibiofouling property. The membrane was manufactured via Non-Induced Phase Separation (NIPS) phase inversion of the polymer casting solution. The composition of ZnO was varied into 0%, 0.5%, 1%, 2%, and 3%. The results of the membrane synthesis were characterized using Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscope (SEM), pure water permeability test, and selectivity test with a turbid meter. The hydrophilic properties of the membrane were analysed by measuring the contact angle, and the antibacterial characteristics were analyzed by the disc diffusion test. Analysis by FTIR showed the presence of a sulfone functional group (S=O) derived from polysulfone polymer and a methyl functional group (C-H) derived from PEG. SEM analysis showed that each variation of the polysulfone membrane had an upper surface structure that was close to the honeycomb structure. The pure air permeability test shows that the membrane is porous and able to pass through pure air. Selectivity test with a turbid meter showed that the membrane is selective to the feed stream that passes through it. Analysis of contact angle measurements showed that the polysulfone membrane surface was hydrophilic. Antibacterial activity analysis showed that polysulfone membrane had antibacterial ability with the largest zone of inhibition with a value 1.8 mm on the membrane with the largest concentration of ZnO.

Preparation of modified polysulfone material decorated by sulfonated citric chitosan for haemodialysis and its haemocompatibility.

Polysulfone (PSF) works potentially in haemodialysis due to its great mechanical and chemical stability, but performs poorly in haemocompatibility. For promoting the unpleasant haemocompatibility, sulfonated citric chitosan (SCACS) with the structure and groups similar to heparin was primarily synthesized by acylation and sulfonation. Furthermore, the chloroacylated PSF was pretreated by electrophilic chloroacetyl chloride to achieve more active sites for further reaction; the following membranes underwent the amination and were named amination polysulfone (AMPSF) membranes. Moreover, SCACS with abundant carboxyl and sulfonic groups was covalently grafted at the surface of pretreated PSF membranes, called PSF-SCACS membranes. The PSF-SCACS membranes were successfully synthesized and characterized by 1H NMR, ATR-FTIR and XPS. In addition, the water contact angle of PSF-SCACS membranes decreased by 47° and the morphologies of the membranes changed little compared with the unmodified PSF membranes. The haemocompatible testing results, including protein adsorption, platelet adhesion, haemolysis rate, plasma recalcification time, activated partial thromboplastin time (APTT), prothrombin time (PT) and thrombin time (TT), demonstrated that the PSF-SCACS membranes possessed excellent haemocompatible performances, and SCACS played an important role in the modification.

Performance enhancement of commercial ultrafiltration polysulfone membrane via in situ polymerization of aniline using copper chloride as a catalyst

AbstractBACKGROUNDPolyaniline is well known for enhancing hydrophilicity and antifouling properties, which could be beneficial for protein separation processes in membranes. The development of polyaniline in the presence of cupric chloride as an oxidant was a target for better distribution.RESULTSBiofouling‐resistant hydrophilic membrane surfaces were developed via in situ polymerization of aniline on a polysulfone membrane surface. Membrane surface modifications were made with various percentages of monomer (0.5, 1 and 2%). All the modified membranes exhibited improved membrane surface properties. The modified membrane (Poly(Sulf‐Ani‐2)) containing 2% aniline as a monomer in polymerization solution showed the best hydrophilicity, exceptional permeability and better protein rejection ability as well as enhanced anti‐biofouling property.CONCLUSIONSIn situ polyaniline attachment might be an easy and beneficial technique for the fabrication of hydrophilic membrane surfaces for large‐scale industrial applications. The attachment of polyaniline on polysulfone membrane surfaces through in situ polymerization in the present study proved to be an advanced approach for crafting better membranes with considerable hydrophilicity and fouling control enhancement.

The hemocompatibility of the modified polysulfone membrane with 4-(chloromethyl)benzoic acid and sulfonated hydroxypropyl chitosan

Polysulfone (PSf) membrane is widely employed in blood purification fields, but the blood compatibility of PSf membrane is not adequate. To improve the hemocompatibility of PSf membrane, 4-(chloromethyl)benzoic acid (CMBA) and sulfonated hydroxypropyl chitosan (SHPCS) were grafted onto PSf membrane surface. In our strategy, CMBA was firstly grafted on the PSf membrane surface through the Friedel-Crafts alkylation reaction, and the product was named BAPSf membrane. Then, SHPCS was grafted onto the BAPSf membrane surface by esterification, and the product was named SHPCS-BAPSf membrane. The effects of temperature and reaction time on the productivity of BAPSf and the grafting density of carboxyl and the effects of reaction time on the grafting density of SHPCS grafted onto the BAPSf membrane surface were studied. The SHPCS-BAPSf membranes are investigated by ATR-FTIR, XPS, contact angle measurements and evaluated by blood compatibility in vitro. The results reveal that the hydrophilicity of SHPCS-BAPSf membranes were grealy improved and the evaluation of protein adsorption, hemolysis test, platelet adhesion plasma recalcification time(PRT), activated partial thromboplastin time(APTT), prothrombin time(PT) and thrombin time(TT) confirmed that the SHPCS-BAPSf membranes have remarkable blood compatibility.

Application of UV irradiation enhanced by CuS photosensitive nanoparticles to mitigate polysulfone membrane fouling

In this research, enhanced ultraviolet (UV) irradiation was used to offer antifouling properties to the surface of polysulfone (PSf) membranes. For this purpose, a thin layer of polyacrylic acid (PAA) was grafted to the membrane surface through UV irradiation in order to synthesize PAA/PSf membrane. Aiming to enhance the performance of UV irradiation, copper sulfide (CuS) and acrylic acid coated copper sulfide (AA©CuS) nanoparticles were embedded in the acrylic acid thin layer where CuS/PAA/PSf and AA©CuS/PAA/PSf membranes were fabricated. Presence of CuS and AA©CuS enhanced the wavelength of excitability of polysulfone from 254 to 322 and 354 nm, respectively. Thus, UV irradiation for 165 min on the surface of PSf membrane caused heightened degree of grafting from 16 % for PAA/PSf to 19 and 46 % for CuS/PAA/PSf and AA©CuS/PAA/PSf membranes, respectively. UV Irradiation for 240 min in the presence of nanoparticles also caused the CuS/PAA/PSf and AA©CuS/PAA/PSf membranes to be 28 and 42 % more hydrophilic and 26 and 37 % less rough respectively compared to PAA/PSf membrane. The mentioned factors eventually contributed to 40 %, 23 %, and 20 % irreversible fouling for PAA/PSf, CuS/PAA/PSf, and AA©CuS/PAA/PSf membranes, respectively.

Cyclonic plasma surface hydrophilization of polysulfone membrane material

Atmospheric-pressure plasma cyclone with argon as the carrier gas was employed to modify the polysulfone membrane to increase its surface hydrophilicity. The variation of the polysulfone surface hydrophilicity was evaluated by static contact angle measurement and it became highly hydrophilic when exposed to cyclonic plasma. The substantial rise in the surface energy of the treated polysulfone membranes as a result of surface etching and bond cleavage effect in the plasma surface modification was also observed. The chemical composition and surface morphological alteration of cyclonic plasma-treated polysulfone membranes were characterized by field-emission scanning electron microscopy and X-ray photoelectron spectroscopy. The major findings in this study showed considerably higher surface concentrations of polar functional groups for cyclonic plasma-activated polysulfone membrane surfaces. This was more than for original pristine polysulfone membrane surfaces.

Enzyme Immobilization on Polymer Membranes: A Quantum and Molecular Mechanics Study

Adsorption of the phosphotriesterase on a polysulfone membrane surface was investigated in this paper through a double-scale computational approach. Surface charges of the enzyme, as well as membrane, were calculated at sub and nanoscale while protein adsorption was simulated at larger scale. Adsorption energies were calculated as a function of the enzyme–surface distance, and for each distance, several protein rotations were tested to find the most stable orientations of the macromolecule. The results of this model were useful in obtaining information about the adhesion of the enzyme and to give indications on the orientations of its binding site. Adsorption energies agreed with the literature data. Furthermore, the binding site of the immobilized phosphotriesterase was less accessible with respect to native enzymes due to the steric hindrance of the polymer surface; thus, a reduction of its efficiency is expected. The proposed methodology made use of fundamental quantities, calculated without resorting to adjustable or empirical parameters, providing basic outputs useful for ascertaining enzymatic catalysis rate.

Preparation of Antimicrobial Nanofiltration Membrane via Self-polymerization of Dopamine and Surface Grafting of PHGH

A novel antimicrobial nanofiltration membrane was fabricated by the self-polymerization of dopamine on polysulfone membrane surface and following surface grafting of polyhexamethylene guanidine hydrochloride ( PHGH) in aqueous conditions. The membrane structures, morphologies and hydrophilicity were characterized by attenuated total reflectance-Fourier transform infrared spectroscopy ( ATR-FTIR), scanning electron microscopy ( SEM) and water contact angle measurement. The concentration of PHGH on grafting degree and filtration performance were investigated. Furthermore, the antibacterial performance of composite membranes was evaluated. The results showed that an active layer with nanofiltration performance was formed on polysulfone membrane surface and the hydrophilicity of membranes was significantly improved by the introduction of dopamine and PHGH. The fluxes decreased while the rejections of inorganic salts and dyes increased with the increasing concentration of PHGH. The composite membranes after grafting exhibited excellent antibacterial performance, when mass fraction of PHGH was 3%, the antibacterial rate reached up to 98.5%.

Alleviating membrane fouling of modified polysulfone membrane via coagulation pretreatment/ultrafiltration hybrid process

In this study, ultrafiltration membrane fouling was alleviated by hydrophilic modification and coagulation pretreatment. A polydopamine (PDA) layer was used as a bridge to introduce the nano titanium dioxide (TiO2) onto the polysulfone (PSf) membranes, forming a hydrophilic modified layer. A relationship model was established between the coagulation efficiencies and floc properties and membrane fouling of the modified PSf membranes during the coagulation/ultrafiltration (C-UF) process. The combination styles of flocculants, poly dimethyldiallylammonium chloride (PDMDAAC) and polyaluminum chloride (PAC) were used in C-UF hybrid process. The characterization results indicated that the hydrophilicity was significantly enhanced in the modified PSf membranes. Scanning electron microscopy (SEM) tests proved that the PDA layer could be tightly bound to TiO2 by coordination bond onto PSf membrane surface. In the acidic conditions, more TiO2 nano-particles were adhered on the PDA particles surface as the pH of (NH4)2TiF6 solution was increased, which resulted in higher hydrophilicity of membranes. In addition, the C-UF tests exhibited that the coagulation efficiency was greatly improved in the PAC/PDMDAAC system, and the PSf membrane modified by PDA/TiO2 in UF tests significantly reduced the membrane fouling, this was partially due to the formation of TiO2 modified coating with higher hydrophilicity.

Surface modification of polysulfone ultrafiltration membrane by in-situ ferric chloride based redox polymerization of aniline-surface characteristics and flux analyses

On the basis of the water-loving nature of Polyaniline (PANI), super hydrophilic polysulfone (PS) ultrafiltration membranes were prepared via in-situ polymerization of aniline on the surface of the membrane. Growing polyaniline in-situ leads to permeability enhancement of the ultrafiltration membrane. Surface-attenuated total reflection Fourier transform infrared spectroscopy, Atomic force microscopy, Scanning electron microscopy and energy dispersive X-spectroscopy and water contact angle demonstrated the successful attachment of PANI on PS membrane surface. Modified membranes containing increased amount of PANI were compared to the unmodified PS membrane to estimate the change in membrane performance, hydrophilicity and anti-fouling properties. PANI modified membranes showed higher water fluxes in comparison to unmodified membranes, while protein rejection was almost similar in both PANI modified and unmodified PS membranes. Atomic force microscopy and contact angle measurements confirmed increased membrane surface hydrophilicity with increasing PANI content. Fouling study and flux recovery experiments revealed that modified membranes exhibit higher flux recovery ratio (65%) and more stability to strong cleaning agents.

Aged PVDF and PSF ultrafiltration membranes restored by functional polydopamine for adjustable pore sizes and fouling control

Hydrophilic polyvinylidene difluoride (PVDF) and polysulfone (PSF) membranes modified by hydrophilic additives such as polyvinylpyrrolidone (PVP) are widely used in various industrial fields. However, the degradation and removal of hydrophilic additives caused by chemical cleaning agents can occur in a short-term aging, which impair the integrity and performances of the membranes. A restoration method is essential for improving the performances of initial aged membranes. In this study, the effects of polydopamine (PDA) coatings on the structural/surface characteristics, the filtration performance and fouling behaviors of aged PVDF and PSF membranes were investigated. Results indicate that the surface properties of aged membranes could be improved by PDA modification. However, the PDA coating structures for PSF and PVDF membranes are different, which are regulated by the different aperture ranges of aged membranes. A mechanism of external and internal PDA restoration for aged membranes with different aperture ranges was introduced. PDA deposited on/in aged PVDF membrane that had large aperture could achieve the synchronous repair of membrane external and pore surface, which not only enhance their surface hydrophilicity (contact angle goes from 80.2° to 58.7°) and zeta potential (from − 23.7 mV to − 30.5 mV at pH 7.5) but also these properties of the pore channel surface and narrow the enlarged pore size simultaneously (the average pore size changes from 220 nm to 170 nm), in turn improved the anti-fouling and rejection performances. By contrast, the PDA was formed as an individual layer on the surface of aged PSF membrane with smaller pore sizes and blocked some pores that showed reduced adsorption and accumulation of foulants on membrane surface, but less reduction of fouling was observed during fouling experiments.

Modification of Asymmetric Polysulfone Membrane Surfaces using Mixed Ar/O2 Plasma Technique

Asymmetric polysulfone (PSF) membranes for gas separation were prepared via dry-wet phase inversion technique at different conditions such as coagulation bath temperature (CBT) and evaporation time (ET). The thickness of the dense layer that plays an important role on gas selectivity has been investigated by adjusting CBT and ET. Additionally, membranes were treated with mixed Ar/O2 DC glow discharge plasma in order to modify membrane wettability, surface roughness, and functional groups on the membrane surface. Scanning electron microscopy (SEM) was used to illustrate a cross sectional structure of PSF membranes. Hydrophilic properties of the membrane surfaces were analyzed via water contact angle (WCA) and surface energy measurements. Morphological structures of membrane surfaces, roughness and creation of functional groups were analyzed both before and after plasma treatment by atomic force microscopy and Fourier transform infrared spectroscopy, respectively. Experimental results show that CBT and ET can change porous voids size of the supporting layer and the dense layer thickness underneath of the membrane surface, while a mixed Ar/O2 gas plasma treatment can enhance hydrophilic properties of the asymmetric PSF membrane surfaces.

Free radical graft polymerization of 2-hydroxyethyl methacrylate and acrylic acid on the polysulfone membrane surface through circulation of reaction media to improve its performance and hemocompatibility properties

In this study, a new facile and cost effective method is used to modify polysulfone membrane surface in order to improve the hydrophilicity, antifouling, and blood compatibility. This modification was performed by adding two functional monomers on the dialysis membrane. Polysulfone (PSF) membranes containing polyvinylpyrrolidone were prepared via phase inversion technique. In the next step, free radical polymerization combined with surface polymerization was used to introduce acrylic acid (AA) and 2-hydroxyethyl methacrylate (HEMA) onto the polysulfone membrane surface via circulation of initiator and monomer solutions across the membrane surface, respectively. Various monomer concentrations were selected to obtain an optimum condition. Field emission scanning electron microscope (FE-SEM), attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), and atomic force microscopy (AFM) confirmed that monomers were successfully grafted on the membrane surface. Water contact angle (WCA) results represented the enhancement of membrane hydrophilicity, which effectively improved water flux and alleviated protein fouling resistance. WCA decreased from 71 °C to 45 °C which corresponds to the negative charge of the membrane surfaces. When the AA concentration was 1 M, the flux recovery ratio reached up to 66% and total protein fouling resistance noticeably decreased to 38%. Nevertheless, urea, creatinine, and vitamin B12 clearance experienced a slight increase. Biocompatibility of membranes was evaluated via activated partial thromboplastin time (APTT), prothrombin time (PT), and cytotoxicity experiments. The presented results indicated that APTT was enhanced by 35% for the best blood compatible sample.

2-methoxyethylacrylate modified polysulfone membrane and its blood compatibility

Hydrophilic material 2-methoxyethylacrylate (MEA) was grafted onto polysulfone (PSF) membrane via Michael addition reaction. The 1H nuclear magnetic resonance (1H NMR), Attenuated total reflectance-Fourier transform infrared spectroscope (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS) characterization of the modified membrane proved that MEA had been successfully grafted onto PSF membrane surface. The water contact angle of the membrane surface was tested. The results showed that the water contact angle changed from 76° to 59.5°, which means that the hydrophilicity of the modified membrane was improved. A series of blood compatibility tests including bovine serum protein adsorption, platelet adhesion, prothrombin time (PT), partial thromboplastin time (APTT) and thrombin time (TT) were carried out on PSF membrane and the modified PSF membrane with highest grafted density of MEA. All of the results indicate that MEA plays an important role in improving the blood compatibility of PSF membrane.

Effects of amphiphilic pluronic F127 on the performance of PS/SPEEK blend ultrafiltration membrane: Characterization and antifouling study

The effect of amphiphilic Pluronic F127 additive on the ultrafiltration performance of polysulfone (PSf)/sulfonated poly (ether ether ketone) (SPEEK) blend flat sheet membranes was investigated in the present work. Fixed amount of SPEEK was used throughout the experiments to improve the PSf membrane surface performance and permeability properties. The addition of various proportions of Pluronic F127 was used to improve the hydrophilic characteristics of blend PSf/SPEEK membranes. It was found that membranes surface hydrophilicity, surface roughness, equilibrium water content and pores size increased with increasing Pluronic F127 concentration in the blend. The increase of Pluronic F127 additive in the blend changed the membrane morphology from finger-like to sponge-like structure. performance of the membranes were evaluated in terms of pure water, humic acid (HA) and bovine serum albumin (BSA) permeation fluxes which were found to increase with increased Pluronic F127 concentration. The BSA was used as a model foulant to investigate flux rejection and flux recovery ratio (FRR%). The PLU-5.5 membrane achieved the highest BSA rejection (97.55%) with FRR (78.18%) values.