Bovine Serum Albumin Rejection Research Articles

Enhancing compatibility and hydrophilicity of polysulfone/poly (ethylene-co-vinyl alcohol) copolymer blend ultrafiltration membranes using polyethylene glycol as hydrophilic additive and compatibilizer

Hydrophilic poly (ethylene-co-vinyl alcohol) (EVOH) was blended with hydrophobic polysulfone (PSF) in the presence of polyethylene glycol (PEG) (20 kDa), which acted as a hydrophilic additive and compatibilizer, to fabricate ultrafiltration (UF) membranes with high porosity and antifouling properties. The polymer blend containing 10 wt% EVOH was selected for optimization using PEG (0 to 24 wt%). After a detailed study, it was concluded that 20 wt% of PEG content was optimal for mixing with PSF/EVOH to increase miscibility. The membranes were characterized using differential scanning calorimetry (DSC) analysis, contact angle, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The effectiveness of PEG as a compatibilizer was observed via no phase separation occurred when the solution was allowed to stand at room temperature for four weeks. It was further confirmed by the appearance of a single Tm peak in DSC. In addition, molecular dynamic simulations illustrated that the PSF/EVOH 90/10 wt% blend had a radial distribution of g(r) = 3.29 Å, and g(r) = 2.69 Å in the presence of PEG, indicating better miscibility in the presence of PEG. Pure water permeance of blend membrane (85/15 wt%) reached 316 L.m-2h−1 bar−1, 54% greater than the pristine membrane. Simultaneously, bovine serum albumin (BSA) rejection of up to 97% and permeance recovery ratio of 87% were observed for the PSF/EVOH 90/10 wt% blend membrane, showing improved hydrophilicity and antifouling properties. These findings identify a potential modifier for fabricating low fouling UF membranes for wastewater treatment by blending with EVOH and PEG.

Polyvinylidene Difluoride (PVDF) Hollow Fiber Membrane Incorporated with Antibacterial and Anti-Fouling by Zinc Oxide for Water and Wastewater Treatment.

The addition of antibacterial material to hollow fiber membranes improves the membrane anti-biofouling characteristics. Antibacterial membranes were fabricated in this study to improve membrane function while also extending membrane lifetime. Neat polyvinylidene difluoride (PVDF) and PVDF hollow fiber membrane with the incorporation of antibacterial agent zinc oxide (ZnO) nanoparticles with various loading (2.5–7.5 wt.%) were fabricated by using dry/wet spinning method. The membrane structure, particle distribution, functional group, hydrophilicity, and pore size of each membrane were all assessed. The result shows that all ZnO/PVDF hollow fiber membranes have the asymmetric structure with even dispersion of ZnO nanoparticles throughout the membranes. The results showed that increased ZnO loadings considerably improved membrane hydrophilicity, and average pore size, in addition to good performance of pure water flux. Antibacterial testing shows that ZnO incorporated in the membrane matrix and membrane surfaces prevents bacteria that cause biofouling from adhering to the membrane. ZnO/PVDF membrane recorded excellent bovine serum albumin (BSA) rejection at 93.4% ± 0.4 with flux recovery rate at 70.9% ± 2.1. These results suggest that antibacterial ZnO/PVDF hollow fiber membranes are promising in relation to reducing biofouling for various water and wastewater treatment.

Modification and acidification of polysulfone as effective strategies to enhance adsorptive ability of chromium (VI) and separation properties of ultrafiltration membrane

AbstractIn order to improve the hydropilicity, polysulfone was first modified by grafting diethanolamine and further made into the ultrafiltration membranes by a phase inversion process. Ultrafiltration membranes were characterized by nuclear magnetic resonance spectrum, contact angle, thermogravimetric analysis, differential scanning calorimetry, scanning electron microscopy, adsorption, and ultrafiltration experiments. The ultrafiltration membrane containing tertiary amine groups had a 99.2% rejection to bovine serum albumin (BSA), 235.2 L m−2 h−1 pure water flux and 78.6% flux recovery rate. Usually, the ultrafiltration membrane containing tertiary amine groups has a low rejection and a poor adsorptive ability to Cr(VI) in the neutral condition. A novel strategy of acidification in advance was adopted to adjust the separation performance of the polysulfone ultrafiltration membrane containing tertiary amine groups. The pre‐acidification strategy could improve the Cr(VI) rejection from below 10% to 100% in the neutral condition, since ultrafiltration membranes acidified in advance did not lose its H+ in storage. Moreover, the acidification could improve the glass transition temperature and only caused a slight decrease of water flux and BSA rejection.

Preparation and Characterization of Regenerated Cellulose Membrane Blended with ZrO2 Nanoparticles.

It is of great significance to search for efficient, renewable, biodegradable and economical membrane materials. Herein, we developed an organic-inorganic hybrid regenerated cellulose membrane (ZrO2/BCM) with excellent hydrophilic and anti-fouling properties. The membrane was prepared by introducing ZrO2 particles into an N-Methylmorpholine-N-oxide(NMMO)/bamboo cellulose(BC) solution system by the phase inversion method. The physi-chemical structure of the membranes were characterized based on thermal gravimetric analysis (TGA), Fourier transform infrared spectroscopy (ATR-FTIR), field emission scanning electron microscopy (FE-SEM), and X-ray diffraction (XRD). The modified regenerated cellulose membrane has the excellent rejection of bovine serum albumin (BSA) and anti-fouling performance. The membrane flux of ZrO2/BCM is 321.49 (L/m2·h), and the rejection rate of BSA is 91.2%. Moreover, the membrane flux recovery rate after cleaning with deionized water was 90.6%. This new type of separation membrane prepared with green materials holds broad application potential in water purification and wastewater treatment.

Enhancing water flux and antifouling properties of PES hollow fiber membranes via incorporation of surface‐functionalized Fe3O4 nanoparticles

AbstractBACKGROUNDIn this study, polyethersulfone (PES) hollow fiber membranes incorporated with surface‐functionalized iron oxide (Fe3O4) nanoparticles were developed in order to improve water flux and antifouling properties of PES membrane. Commercial Fe3O4 nanoparticles was coated by polydopamine (PDA), followed by functionalization using (3‐aminopropyl)triethoxysilane (APTES) and sulfonic acid to produce Fe3O4/PDA‐Amine and Fe3O4/PDA‐Sulf nanoparticles, respectively. All the nanoparticles‐modified membranes were synthesized using dope solution composed of different nanoparticles, followed by a series of instrumental characterization and filtration assessments.RESULTSIt is found that the membrane incorporated with Fe3O4/PDA‐Amine exhibited the best filtration performance, achieving water flux of 137.23 L m−2 h−1 bar−1 and bovine serum albumin (BSA) rejection of 92.16%. As a comparison, the pristine PES membrane only showed 82.60 L m−2 h−1 bar−1 and 71.92%, respectively. The membrane with Fe3O4/PDA‐Sulf also showed lower performance, recording 129.88 L m−2 h−1 bar−1 and 88.39%, respectively. The improved performance of the Fe3O4/PDA‐Amine‐modified PES membrane could be attributed to its lowest water contact angle (65.10°), highest porosity (68.14%), ideal pore size (65 nm) as well as good structural integrity. More importantly, the improved surface properties also led to outstanding fouling resistance, achieving flux recovery rate of 97%. This membrane also achieved excellent chemical oxygen demand (95.17%) and color (89.86%) reduction when tested using river water sample.CONCLUSIONOur work demonstrated a simple approach to functionalize the surface of Fe3O4 nanoparticles and showed the effectiveness of the surface‐functionalized Fe3O4 nanoparticles in improving not only the surface properties of PES membrane but also its filtration performance in terms of permeability, rejection and antifouling property. © 2021 Society of Chemical Industry (SCI).

Zwitterionic Polysulfone Copolymer/Polysulfone Blended Ultrafiltration Membranes with Excellent Thermostability and Antifouling Properties.

Membrane fouling has been one of the most important challenges in membrane separation operations. In this study, we report a facile strategy to prepare antifouling polysulfone (PSf) UF membranes by blending amphiphilic zwitterion polysulfone-co-sulfobetaine polysulfone (PSf-co-SBPSf) copolymer. The copolymer chemical structure was characterized by 1HNMR spectroscopy. The PSf/PSf-co-SBPSf blend membranes with various zwitterionic SBPSf segment contents exhibited better surface hydrophilicity and excellent antifouling ability compared to PSf and PSf/PEG membranes. The significant increase of both porosity and water permeance indicates that the PSf-co-SBPSf has a pore-forming effect. The pure water flux and flux recovery ratio of the PSf/PSf-co-SBPSf blend membranes were both remarked to improve 286.43 L/m2h and 92.26%, while bovine serum albumin (BSA) rejection remained at a high level (97.66%). More importantly, the water flux and BSA rejection see minimal variance after heat treatment, indicating excellent thermostability. Overall, the PSf/PSf-co-SBPSf blend membranes achieved a comprehensive performance of sustainable hydrophilic, high permeation flux, and remarkable antifouling ability, thus becoming a promising candidate in high-temperature separation application.

Construction of antifouling zwitterionic membranes by facile multi-step integration method

Membrane fouling during the use of separation membrane has always been the main reason for the degradation of membrane performance. The traditional solution is complicated and inefficient, so we proposed multi-step integration method to prepare antifouling zwitterionic poly(aryl ether sulfone) (PAES-Z-x) ultrafiltration (UF) membrane with higher efficiency. We designed and synthesized a bisphenol precursor containing tertiary amine groups, which could provide reactive sites for grafting zwitterionic group. Afterwards, the zwitterionic modified UF membrane was prepared by graft copolymerization and non-solvent-induced phase separation (NIPS). The morphology, hydrophilicity, water flux and rejection of the PAES-Z-x membrane could be optimized by tuning zwitterion content. The hydration layer formed by zwitterions effectively reduced the adsorption of proteins and endowed the membrane good antifouling properties. The resulting membrane showed the pure water flux increased (up to 311 L m−2h−1 bar−1), high bovine serum albumin (BSA) rejection (97%) and good water flux recovery ratio (FRR) (82.8%). Zwitterionic antifouling PAES UF membrane prepared by a simple and effective method provided a new direction for improving PAES UF membrane’s antifouling performance.

Green Synthesis of Silver Nanoparticles as an Effective Antibiofouling Material for Polyvinylidene Fluoride (PVDF) Ultrafiltration Membrane.

Silver nanoparticles (AgNPs) were successfully synthesized using the aqueous extract of the Paronychia argentea Lam (P. argentea) wild plant. The results showed that the conversion of Ag+ to Ag0 nanoparticles ratio reached 96.5% as determined by Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES), with a negative zeta potential (ζ) of −21.3 ± 7.68 mV of AgNPs expected to improve the stability of synthesized AgNPs. AgNP antibacterial activity has been examined against Streptococcus aureus (S. aureus) and Escherichia coli (E. coli) bacteria. The minimum inhibition concentration (MIC) was 4.9 µL/mL for both E. coli and S. aureus bacteria, while the minimum bactericidal concentrations (MBC) were 19.9 µL/mL and 4.9 µL/mL for S. aureus and E. coli, respectively. The synthesized AgNPs were incorporated in ultrafiltration polyvinylidene Fluoride (PVDF) membranes and showed remarkable antibiofouling behavior against both bacterial strains. The membranes were characterized using Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), and X-ray diffraction (XRD). The contact angle and porosity of the membrane were also determined. The efficiency of the membranes regarding rejection rate was assessed using bovine serum albumin (BSA). It was found in the flux experiments that membranes BSA rejection was 99.4% and 98.7% with and without AgNPs, respectively.

Enhancing the permeation and antifouling performance of PVDF hybrid membranes by incorporating Co–Fe hydroxide nanoparticles in reverse microemulsion

This study attempted to enhance the permeation and antifouling performance of polyvinylidene fluoride (PVDF) ultrafiltration membranes. Reverse microemulsion containing cobalt and iron (Co–Fe) bimetallic hydroxide nanoparticles was blended with the PVDF membranes to construct a novel PVDF hybrid membrane. The permeation performance, antifouling property, and long-term operational stability of the hybrid membranes were evaluated via ultrafiltration process of water flux and bovine serum albumin (BSA) rejection. Structural characterization showed that the protection endowed by reverse microemulsion made the hydroxide nanoparticles to distribute uniformly in the PVDF polymeric matrix. The introduction of well-distributed bimetallic hydroxide nanoparticles substantially improved the pore structures and hydrophilicity of the PVDF hybrid membranes, thereby enhancing their permeation performance and antifouling property. The optimal water flux of the PVDF hybrid membranes (MD-10) reached 328 L·m−2·h−1 and was 5.4-fold higher than that of neat PVDF. Moreover, the MD-10 membrane had a high a high BSA rejection rate (91.04%). After four cycles of successive fouling-cleaning processes, the water flux of the MD-10 membrane still exceeded 160 L·m−2·h−1 and was fourfold higher than that of neat PVDF. However, excessive amounts of the microemulsion could not be uniformly mixed with the PVDF membranes, thereby decreasing the permeation and antifouling performance of the PVDF hybrid membranes.

Influence of GO-Ag nano-filler on the antibacterial, antifouling and hydrophilic characteristics of polyvinyl chloride membrane

The integral hydrophobic characteristic of polymers hinders their implementations towards water treatment. In the present work, highly hydrophilic and antifouling polyvinyl chloride membranes were fabricated based on graphene oxide-silver (GO-Ag) nanolayers. The distinctive infiltration approach of polyvinyl chloride resin through the stacked GO-Ag layers results in surface availability of highly hydrophilic graphene oxide nanosheets. Incorporation of different weight percent of GO-Ag to the polyvinyl chloride resin increases the permeability, rejection and antifouling properties of polyvinyl chloride membranes. Water contact angle of pure polyvinyl chloride was found to decrease from 92.5° to 61.4° for GO-Ag based membrane. Water flux and bovine serum albumin rejection of pure polyvinyl chloride membrane were improved from 192 Lm−2 h−1 to 613 Lm−2 h−1 and 81.5% to 92.1% respectively. Besides this, graphene oxide silver based membrane depicts least irreversible fouling 14.3% and highest flux recovery ratio 85.6%. Maintenance of high flux recovery ratio of P/GO-Ag 0.5 wt% membrane after three consecutive cycles of water and bovine serum albumin filtration justify the high durability of membrane. The synthesized GO-Ag nanoadditive showed appreciable antibacterial activity against Escherichia coli. Thermo gravimetric analysis and Differential scanning calorimetry analysis of GO-Ag based membranes proves their high thermal stability as well.

Fabrication and Characterization of Sulfonated Graphene Oxide (SGO) Doped PVDF Nanocomposite Membranes with Improved Anti-Biofouling Performance.

Emergence of membrane technology for effective performance is qualified due to its low energy consumption, no use of chemicals, high removal capacity and easy accessibility of membrane material. The hydrophobic nature of polymeric membranes limits their applications due to biofouling (assemblage of microorganisms on surface of membrane). Polymeric nanocomposite membranes emerge to alleviate this issue. The current research work was concerned with the fabrication of sulfonated graphene oxide doped polyvinylidene fluoride (PVDF) membrane and investigation of its anti-biofouling and anti-bacterial behavior. The membrane was fabricated through phase inversion method, and its structure and morphology were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-rays diffraction (XRD) and thermo gravimetric analysis (TGA) techniques. Performance of the membrane was evaluated via pure water flux; anti-biofouling behavior was determined through Bovine Serum albumin (BSA) rejection. Our results revealed that the highest water flux was shown by M7 membrane about 308.7 Lm−2h−1/bar having (0.5%) concentration of SGO with improved BSA rejection. Furthermore, these fabricated membranes showed high antibacterial activity, more hydrophilicity and mechanical strength as compared to pristine PVDF membranes. It was concluded that SGO addition within PVDF polymer matrix enhanced the properties and performance of membranes. Therefore, SGO was found to be a promising material for the fabrication of nanocomposite membranes.

Fabrication and dialysis performance of functionalized multiwall carbon nanotubes integrated cellulose acetate/poly(vinylpyrrolidone) membranes

Mixed matrix membranes (MMMs) of cellulose acetate/poly(vinylpyrrolidone) (CA/PVP) infused with acid functionalized multiwall carbon nanotubes (f-MWCNTs) were fabricated by an immersion phase separation technique for hemodialysis application. Membranes were characterized using FTIR, water uptake, contact angle, TGA, DMA and SEM analysis. The FTIR was used to confirm the bonding interaction between CA/PVP membrane matrix and f-MWCNTs. Upon addition of f-MWCNTs, TGA thermograms and glass transition temperature indicated improved thermal stability of MMMs. The surface morphological analysis demonstrated revealed uniform distribution of f-MWCNTs and asymmetric membrane structure. The water uptake and contact angle confirmed that hydrophilicity was increased after incorporation of f-MWCNTs. The membranes demonstrated enhancement in water permeate flux, bovine serum albumin (BSA) rejection with the infusion of f-MWCNTs; whereas BSA based anti-fouling analysis using flux recovery ratio test shown up to 8.4% improvement. The urea and creatinine clearance performance of MMMs were evaluated by dialysis experiment. It has been found that f-MWCNTs integrated membranes demonstrated the higher urea and creatinine clearance with increase of 12.6% and 10.5% in comparison to the neat CA/PVP membrane. Thus, the prepared CA/PVP membranes embedded with f-MWCNTs can be employed for wide range of dialysis applications.

Enhancing the hydrophilicity and biofoulant removal ability of a PVDF ultrafiltration membrane via π-π interactions as measured by AFM

Antibiotics are commonly used as inhibitors to terminate protein formation in the biotechnology and pharmaceutical industries; however, due to the large difference in molecular weight between antibiotics and proteins, it is hard to remove them simultaneously through ultrafiltration or nanofiltration. In this work, a novel membrane with nanoscale pores and anti-protein adsorption was developed to reject antibiotics and reduce protein adhesion. Amphiphiles consisting of hydrophobic and hydrophilic moieties were synthesized from a poly(styrene-alt-maleic anhydride) (SMA) copolymer with a 2-hydroxyethyl acrylate (HEA) monomer to enhance the hydrophilicity of polyvinylidene difluoride (PVDF) membranes. A series of SMAs with different polystyrene molar ratios (maleic acid/styrene (m/s) = 1:1, 1:2 and 1:3) was synthesized in this study, and the bonding force between the amphiphiles and PVDF, namely, π-π interactions between styrene molecules and the C–F bonds of PVDF, was evaluated. The π-π interaction between the amphiphiles and the PVDF membrane was determined via atomic force microscopy (AFM) repulsive force measurements for the first time in this work. The repulsive force increased significantly from -5.9 ± 1.0 nN to −18.3 ± 0.8 nN as the m/s ratio increased to 1:3, indicating that the π-π interaction was enhanced as the proportion of polystyrene in the SMA-HEA copolymer increased, resulting in tight attachment. Furthermore, the amphiphile-modified membrane demonstrated better hydrophilicity than the pristine PVDF membrane, and the water contact angle (WCA) decreased considerably from 104° (PVDF) to 55° (m/s = 1:2, P2000-600). The pure water flux recovery rate of P2000-600 improved by approximately 10%, and antibiotic rejections of 92.8%, 99.9% and 97.1% for tetracycline (TC), chloramphenicol (CL) and erythromycin (EM), respectively, were observed during the 7-h filtration process, indicating that P2000-600 can effectively remove antibiotics from water. In addition, P2000-600 also displayed good restriction of bovine serum albumin (BSA) adsorption at 28.4 ± 8.1 μg/cm2 under static adsorption processes and BSA rejection of nearly 90% during the three-cycle filtration.

Designing of a novel polyvinylidene fluoride/TiO2/UiO-66-NH2 membrane with photocatalytic antifouling properties using modified zirconium-based metal-organic framework.

Novel polyvinylidene fluoride/TiO2/UiO-66-NH2 (PVDF/TiUN) membranes were produced by the delay phase separation method via introducing the TiO2/UiO-66-NH2 (TiUN) nanocomposite into PVDF casting solution. Interconnection of TiO2 and UiO-66-NH2 improved photocatalysis capacity and endowed PVDF/TiUN membranes with self-cleaning capability. Quantitative measurements showed that, firstly, PVDF/TiUN membranes exhibited improved photodegradation kinetics and efficiency (up to 88.1%) to Rhodamine B (RhB). Secondly, the performances of bovine serum albumin (BSA) rejection and permeation of PVDF/TiUN membranes outperformed those of other check samples, indicating enhanced hydrophilicity. Thirdly, rejection rate of BSA reached a breathtaking 98.14% and flux recovery ratio (FRR) of BSA reached a breathtaking 95.37%. Thus, given their excellent anti-contamination property and separation performance, the PVDF/TiUN membrane is very likely to be a novel water treatment membrane.

Synthesis of PVDF‐B4C mixed matrix membrane for ultrafiltration of protein and photocatalytic dye removal

AbstractIn this work, polyvinylidene fluoride‐boron carbide mixed matrix membranes were synthesized via phase inversion method. The synthesized membranes were characterized using field emission scanning electron microscopy, X‐ray diffraction spectroscopy, energy dispersive spectroscopy, porosity, and contact angle. The mixed matrix membranes (0–5 wt.% of boron carbide) were tested for ultrafiltration of bovine serum albumin solution and photodegradation property using rhodamine B and methylene blue dyes. The morphological images reveal the existence of boron carbide particles on the surface of the membranes. Upon introduction of B4C particles, the performance of the membranes was improved: permeate flux increases from 163.13 to 351.15 L/m2 h; bovine serum albumin rejection increased from 77.1% to 99.1%; relative flux reduction decreased from 45.58% to 16.06%; flux recovery ratio increased from 61.71% to 98.42%. Furthermore, maximum photodegradation yield was observed for membranes with 4 wt.% boron carbide particles with degradation efficiency of 96.7% and 96% for rhodamine B and methylene blue dyes, respectively. Furthermore, the rate constant of the optimum membrane was higher than the pristine membrane (about 2.05 and 2.26 times higher for rhodamine B and methylene blue dyes, respectively). Indeed, the mixed matrix membranes present a great prospect for the photodegradation of organic dyes.

Facile synthesis of 2D TiO2@MXene composite membrane with enhanced separation and antifouling performance

While composite membranes with two-dimensional (2D) lamellar materials (e.g., graphene and MXene) have recently attracted increasing attention, fabrication of high-performance 2D membrane still faces a serious challenge. In this study, 2D TiO2@MXene nanomaterial was prepared and introduced to fabricate polyethersulfone (PES)-TiO2@MXene composite membrane. The composite membrane displayed superior separation and antifouling performance. When filtrating 1.0 g L−1 bovine serum albumin (BSA) solution, the flux of the optimal membrane (BSA rejection 95%) reached to 756.8 L m−2 h−1·bar−1, which is 185% higher than that of the original membrane (BSA rejection 70%). Moreover, the PES-TiO2@MXene composite membrane possessed excellent self-cleaning function under UV irradiation, which was verified by the flux recovery rate (FRR) values of 80.2%, 100%, 100% and 99.56% for BSA, sodium alginate (SA), humic acid (HA) and yeast (YE) solution, respectively. The excellent self-cleaning ability can be put down to the special 2D TiO2@MXene structure where there exists a synergy between MXene and TiO2 for self-cleaning. The composite membrane demonstrated a significant superiority in filtration performance over those in the literature. According to extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) approach, the PES-TiO2@MXene composite membrane displayed an optimal interface condition, significantly reducing the attractive interactions with foulants. The facile fabrication method, together with the efficient membrane performance, indicated good application prospects of the PES-TiO2@MXene composite membrane proposed in this study.

Multifunctional hybrid UF membrane from poly(ether sulfone) and quaternized polydopamine anchored reduced graphene oxide nanohybrid for water treatment

In this study, a new quaternized polydopamine anchored reduced graphene oxide (QSiPD-rGO) nanohybrid was prepared through a one-step mussel-inspired tailoring of GO using a quaternized silica precursor and dopamine. The QSiPD-rGO was applied for the first time as a nanofiller, at a significant loading rate of up to 8 wt%, to manufacture positively charged, high flux, fouling resistant and antibacterial hybrid poly(ether sulfone) (PES) ultrafiltration (UF) membranes, via non-solvent induced phase separation. A suite of tools was utilized to thoroughly characterize the nanohybrid and the membranes, including SEM-EDX, Raman, ATR-FTIR, TGA, AFM, zeta potential and contact angle measurements. The surface morphology, charge and hydrophilicity of the membranes were tuned upon integrating the nanohybrid. Consequently, pure water flux significantly increased, reaching ~ 270 L m−2 h−1 (at 1 bar) for PMQ4 with 6 wt% QSiPD-rGO loading. This was 94% higher than the corresponding flux of pristine membrane (139 L m−2 h−1, at 1 bar). The hybrid membranes also showed superior fouling resistance during the UF of 500 ppm bovine serum albumin (BSA) solution. The BSA rejection rate of the hybrid membranes was very high and uncompromised by their high flux, exceeding 98% for PMQ4. Additionally, a remarkable antibacterial activity (against E. Coli.) of the membranes was induced by the nanohybrid, with a strong correlation between this activity and QSiPD-rGO loading.

Enhanced adsorption and biocompatibility of polysulfone hollow fibre membrane via the addition of silica/alpha-mangostin hybrid nanoparticle for uremic toxins removal

In this study, a highly biocompatible adsorptive membrane is developed for haemodialysis application. Silica/α-mangostin hybrid nanoparticle was incorporated into polysulfone (PSf) based membrane to enhance the biocompatibility and the adsorption capacity of the membrane. The PSf based membranes were fabricated via dry-wet phase inversion technique and characterised based on scanning electron microscopy and contact angle measurement. The effects of silica/α-mangostin nanoparticle incorporation into PSf membrane were evaluated in terms of permeability, p-cresol adsorption capacity, urea, and creatinine removal capabilities, bovine serum albumin rejection and p-cresol dynamic adsorption. The biocompatibility assessment was done based on platelet adhesion, antioxidant properties, and complement activation of the membrane. The incorporation of the nanoparticle into PSf based membrane helped to smoothen the surface of the membrane and enhanced its hydrophilicity of the membrane by 12.54%. The presence of silica/α-mangostin in the membrane enhanced the adsorption capacity of the membrane by 20.92% with adsorption capacity of 55.64 mg/g at 500 mg/L initial concentration. The modified PSf membrane had also successfully improved the biocompatibility of the membrane by enhancing the scavenging activity of hydrogen peroxide and nitrogen oxide by 61.8% and 36%, respectively and inhibited the formation of C5a by 27.27%. The developed biocompatible PSf based adsorptive membrane has a good potential to be used for haemodialysis application.

Enhanced antifouling property of poly(aryl ether nitrile) ultrafiltration membranes via copolymerization with phenolphthalin

In this work, phenolphthalin was successfully introduced into the molecule chain of poly(aryl ether nitrile) (PEN) by nucleophilic substitution method in order to get carboxylated PEN (PEN-COOH) copolymers with a controlled carboxylation degree. Then, a series of PEN-COOH ultrafiltration membranes were prepared by immersion precipitation phase inversion method. The influence of the carboxylation degree of PEN-COOH on the structure and performance of the prepared polymeric membrane was studied by scanning electron microscope, atomic force microscope, porosity, contact angle, ultrafiltration and antifouling experiments, etc. The results showed that with the increase of carboxylation degree of polymeric membrane, the surface of PEN-COOH membrane gradually became dense and smooth, and its hydrophilicity increased. Meanwhile, both the pure water flux and permeation flux of the membrane decreased obviously, and the corresponding rejection ratio of bovine serum albumin (BSA) was slightly enhanced. Also, the membrane showed improvement in antifouling property. As the membrane with the best comprehensive performance, PEN-COOH-60% membrane had a BSA rejection ratio as high as 99.3%, while maintaining water flux of 351.7 (L m−2 h−1) and permeation flux of 160.1 (L m−2 h−1). With a water contact angle of 59.7°, the flux recovery rate of PEN-COOH-60% membrane significantly increased 37.1% compared with PEN and basically stable in the three cycles of antifouling experiments. These results proved that the introduction of carboxyl group into PEN molecular chain could effectively improve the antifouling performance of PEN-COOH membrane.

Fabrication of Zwitterion TiO2 Nanomaterial-Based Nanocomposite Membranes for Improved Antifouling and Antibacterial Properties and Hemocompatibility and Reduced Cytotoxicity.

Although zwitterion nanomaterials exhibit outstanding antifouling property, hemocompatibility, and antibacterial activity, their poor solubility in organic solvents limits their practical applications. In the present study, natural lysine (amino acids) was surface-grafted onto one-dimensional (1D) TiO2 nanofibers (NFs) through an epoxy ring opening in which the 3-glycidyloxypropyl (dimethoxy) methyl silane was used as a coupling agent. Chemical binding and morphological studies, such as Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and transmission electron microscopy, were conducted to confirm the successful grafting of lysine onto the TiO2 NFs. The lysine-grafted TiO2 NF-polyethersulfone (PES) membrane induced electrostatic interactions and increased the surface charges from −28 to 16 mV in ζ-potential analysis. The lysine exhibited zwitterion characteristics owing to the presence of amino (cations) and carboxyl (anions) functional groups. Moreover, the modified TiO2-PES zwitterion membranes exhibited good water flux performances compared to the pristine membrane. ZT-4 membrane displayed the highest water fluxand bovine serum albumin (BSA) rejection of 137 ± 1.8 L m–2 h–1 and 94 ± 1%, respectively. The cell viability results revealed that the zwitterion PES membrane had excellent biocompatibility with peripheral blood mononuclear cells. The present work offers a convenient strategy to improve the hydrophilicity, antifouling property, and hemocompatibility of modified TiO2-PES zwitterion membranes for their biomedical and blood-contacting applications such as hemodialysis.