Enhancement Of Hydrophilicity Research Articles

DHNTs assimilated TPU/PEG membrane a new combination for evaluation of in-vitro blood-coagulation

Thermoplastic polyurethane is known for its elasticity and hydrophobicity, which is significant for a few biomedical applications. The risk of clotting formation in blood-contacting devices is a major concern. Altering the surface of polymer with the addition of suitable nanofillers and additives can improve the blood compatibility of the prepared materials. Thus, aiming for enhanced blood compatibility of TPU (1) addition of PEG as an effective pore creator leads to enhancement in hydrophilicity, (2) modification of halloysite by universal bio-adhesives such as polydopamine, attach to the wall of HNTs by oxidation and self-polymerization, resulting as superior biomedical nanocomposites. The membrane is fabricated via the phase-inversion technique. TPU, TPU/PEG, and DHNTs@TPU/PEG were compared based on major characteristics such as hydrophilicity, pore analysis by SEM (ImageJ), and the blood compatibility test. In-Vitro blood coagulation and degradation study of pure TPU, TPU/PEG and DHNTs@TPU/PEG membrane suggest that the modified DHNTs-TPU/PEG membrane has better blood coagulation time and decreased hemolysis ratio. A degradation study with a variation in pH shows the breakage of a polymeric chain of the membrane. These results can suggest that the modified membrane has a potential application in the biomedical.

Hydrophilic nanoclay-polyaniline decorated membrane with improved permeability for separation of endocrine-disrupting chemical and fitness of fouling using model

Bisphenol A (BPA) is identified endocrine-disrupting compounds (EDCs) that is detected in water resources. The intrinsic properties of nanoclays favor to stimulate the combination of sieving and electrostatic interaction mechanisms during the removal of BPA using membrane separation. Herein, the synthesised hydrophilic bentonite-polyaniline (B-PANI) and cloisite 15A-polyaniline (C-PANI) was loaded individually into polyethersulfone (PES) for fabricating mixed matrix membranes (MMMs). The PANI nanoclays was presented in both surface layer and inside pores of nanocomposite membranes at 0.5, 1 and 1.5 wt% loading. The results showed the enhancement in surface hydrophilicity for all the membranes in loading of PANI nanoclays. The presence of B-PANI influenced the higher water flux of 82.2 Lm-2h−1 at 1.5 wt%, indicating hydrophilic property. YBP2 MMM with 1 wt% B-PAN depicted higher BPA rejection efficiency of 77.2 %. B-PANI bestow the MMM with hydroxyl and amine functional groups which retard the transport of hydrophobic BPA through the hydrophilic MMM. Further, higher BPA rejection was ascribed to the electrostatic repulsion between MMM surface and BPA. The fouling mechanism was identified by Hermia model that represents YBP2 membrane revealed cake filtration fouling model with reversible fouling. This work highlights the feasibility of B-PANI in MMM for BPA removal from water.

Comprehensive Analysis of Spinel-Type Mixed Metal Oxide-Functionalized Polysulfone Membranes toward Fouling Resistance and Dye and Natural Organic Matter Removal.

Nanostructured polymeric membranes are of great importance in enhancing the antifouling properties during water filtration. Nanomaterials with tunable size, morphology and composition, surface modification, and increased functionality provide considerable opportunities for effective wastewater treatment. Thus, in this work, an attempt has been made to use spinel-structured MnCo2O4 as a nanofiller in the fabrication of nanostructured polysulfone (PSF) mixed matrix membranes and is investigated in terms of morphology, hydrophilicity, permeability, protein and natural organic matter separation, dye removal, and, finally, antifouling properties. The MnCo2O4 nanomaterials are synthesized and characterized via X-ray diffraction and field emission scanning electron microscopy and are loaded into a membrane matrix with varied concentrations (0 to 1.5 wt %). PSF nanocomposite membranes are prepared via a nonsolvent-induced phase-separation process. The results show an enhancement in hydrophilicity, porosity, and permeability with respect to the modified nanocomposite membranes because of oxygen-rich species in the membrane matrix, which increases affinity toward water. It was also found that the modified membranes display remarkably greater pure water flux (PWF) (220 L/m2 h), higher Congo red rejection coefficient (99.86%), higher humic acid removal (99.81%), higher fouling resistance, and a significant flux recovery ratio (FRR) (88%) when tested with bovine serum albumin protein when compared to a bare PSF membrane (30 L/m2 h PWF and 35% FRR). This is because the addition of MnCo2O4 nanoparticles into the polymeric casting solution yielded tighter PSF membranes with a denser skin layer and greater selectivity. Thus, the enhanced permeability, greater rejection coefficient, and antifouling properties show the promising potential of the fabricated PSF-spinel nanostructured membrane to be utilized in membrane technology for wastewater treatment.

Enhanced antifouling and flux performances of a composite membrane via incorporating TiO2 functionalized with hydrophilic groups of L‐cysteine for nanofiltration

AbstractA new TiO2 nanoparticle modified via L‐cysteine is presented in this study. The L‐cysteine (cys) modified TiO2 nanomaterials impact as membrane modifier was examined in terms of pure water flux, hydrophilicity, morphology, and resistance ability. The mixed matrix membranes morphology investigated by using scanning electron microscope (SEM), atomic force microscopy (AFM), water contact angle measurement, porosity and pore size and Fourier transform infrared spectroscopy analysis. Membrane hydrophilicity and permeation flux were notably improved by introducing TiO2‐cys nanomaterials to the membrane matrix. The SEM image indicated the expanded finger‐like pores for the modified membranes comparing to the bare polyethersulfone (PES). The obtained AFM image exhibited lower surface roughness parameters for the modified membranes. In case of prepared membranes assessment, dye removal capability using the direct red‐16 and real liquorice wastewater were examined. The results confirmed that the modified membranes indicated high‐ranking dye rejection ability (more than 98% for direct red‐16 and 90% for real liquorice wastewater) comparing to the bare membrane (86 ± 2.58%). The antifouling tests were run based on milk powder (1000 mg/L) filtration and the best antifouling performance was obtained for 0.5 wt% of TiO2‐cys membrane (flux recovery ratio = 90.57 ± 2.71%, Rir = 9.43 ± 0.28%). Also, the results showed high potential of TiO2‐cys nanomaterials for membrane hydrophilicity enhancement.

Green synthesis of graphene oxide polysulfone membrane using dimethyl sulfoxide as green solvent

Membrane technology has been widely used in various industries such as medical, food, pharmaceutical, and wastewater treatment industries. It is known as a remarkable green technology owing to its low energy consumption, small footprint and easy to be scale up. However, the usage of conventional solvent has been reported to bring undesirable impacts to the environment and public health. In view of these, green solvent namely dimethyl sulfoxide (DMSO) was used along with polysulfone (PSf) polymer and graphene oxide (GO) nanomaterials to a form a new generation mixed matrix membrane (MMM). A series of membranes were fabricated through the immersion precipitation method by varying the GO concentration from 0.0 wt% to 2.0 wt% at fixed polymer and solvent weight ratio. The fabricated membrane was characterized by contact angle, porosity, and average pore size while the performance of the membrane was evaluated through the pure water flux measurement, rejection study, and flux recovery ratio. The presence of the GO in the membrane has substantially enhanced the membrane performance in terms of hydrophilicity and pure water flux associated with the hydrophilic nature of GO. The optimal membrane performance was found at 0.5 wt% of GO nanomaterials whereby it demonstrated approximately three times increment of water flux from 28.95 L/m2·hr to 76.14 L/m2·hr while maintaining a slightly better humic acid rejection which improved by 9.55% from 48.88% to 53.55% and 13.13% enhancement in membrane hydrophilicity. At the same times, it also demonstrated great antifouling properties with a high flux recovery rate up to 96.25%.

Embedded three spinel ferrite nanoparticles in PES-based nano filtration membranes with enhanced separation properties

Abstract In this study, three types of ferrites nanoparticles including CoFe2O4, NiFe2O4, and ZnFe2O4 were synthesized by microwave-assisted hydrothermal method. The X-ray diffraction analysis (XRD), Fourier transform infrared spectroscopy (FTIR), and field emission scanning electron microscopy (FESEM) were employed to analyze synthesized nanoparticles and fabricated membranes. The morphology of membrane surface was investigated by surface images. The ability of ferrite nanoparticles was evaluated to the separation of sodium salt and heavy metals such as Cr2+, Pb2+, and Cu2+ from aqueous solutions. The modified membrane showed the enhancement of membrane surface hydrophilicity, porosity, and mean pore size. The results revealed a significant increase in pure water flux: 152.27, 178, and 172.68 L·m−2·h−1 for PES/0.001 wt% of CoFe2O4, PES/0.001 wt% NiFe2O4, and PES/0.001 wt% ZnFe2O4 NPs, respectively. Moreover, Na2SO4 rejection was reached 78% at 0.1 wt% of CoFe2O4 NPs. The highest Cr (II) rejection obtained 72% for PES/0.001 wt% of NiFe2O4 NPs while it was 46% for the neat PES membrane. The Pb(II) rejection reached above 75% at 0.1 wt% of CoFe2O4 NPs. The Cu(II) rejection was obtained 75% at 0.1 wt% of CoFe2O4 NPs. The ferrite NPs revealed the high potential of heavy metal removal in the filtration membranes.

Plasma surface treatment of polystyrene in a low power low frequency argon glow discharge

A low power low frequency (50 Hz) argon plasma was used to treat the surface of polystyrene (PS) films. Plasma treatment for 3 min produced the best hydrophilic enhancement and it corresponded to doubling of the surface energy. At 45 Pa and flowrate of 44 sccm, a ‘saturation’ region in terms of lowest water contact angle (WCA) attained (WCA = 21°±3°), occurred at low discharge power of 0.15–0.25 W (applied power of 3–8 W). The induced hydrophilicity was attributed mainly to the oxygen-containing functional groups incorporated on the PS surface during the plasma treatment. Oxygen was speculated to be sourced from the dissociation of residual water vapour in the reactor chamber. Upon exposure to the laboratory environment, rapid hydrophobic recovery of the treated samples occurred but WCA stabilized after 72 h and remained at >30° below its value at pristine condition.

Development of MoS2/O-MWCNTs/PES blended membrane for efficient removal of dyes, antibiotic, and protein

In this work, a nanocomposite of MoS2 nanosheets and oxidized multi-walled carbon nanotubes (O-MWCNTs) was prepared using the hydrothermal method. The successful synthesis of the MoS2/O-MWCNTs nanocomposite was further confirmed using a scanning electron microscope (SEM), energy dispersive X-Ray dot mapping, and X-ray diffraction analysis. The synthesized nanocomposite was used as a nanoadditive for the improvement of polyethersulfone (PES) polymeric membrane. The phase inversion route was used to prepare MoS2/O-MWCNTs blended membranes containing different amounts of nanocomposite (0–1 wt%). The morphology of the prepared membranes was studied using SEM and atomic force microscopy techniques. Asymmetric structure with small pores at the top layer and well-developed large finger-like pores and macro voids at the sublayer can be observed in fabricated membranes. The hydrophilicity enhancement of the PES membrane in the existence of nanocomposite was verified by the contact angle test. The modified membrane containing 0.75 wt% of MoS2/O-MWCNTs exhibited improved permeability of 64.1 L/m2 h bar, and high pollutants removal of 93.5% for reactive blue 19, 97.5% for rifampicin, 98.4% for reactive red 195, and 99% for bovine serum albumin, with enhanced flux recovery ratio of 60.8%. Moreover, the stability of the blended membrane in the long-time operation makes it a promising candidate to be applied in the treatment of textile and industrial wastewaters.

Evaluating of the performance of natural mineral vermiculite modified PVDF membrane for oil/water separation by membrane fouling model and XDLVO theory

A novel vermiculite nanoparticles (Verm NPs) modified poly(vinylidene fluoride) (PVDF) ultrafiltration membrane was firstly fabricated via surface coating at pH 7.2–7.3. The dense but porous modified surface formed by controlling the self-polymerization rate of dopamine at relatively weak alkalinity provided both high water flux and rejection rate of BSA, which broke the trade-off between permeability and rejection rate. The contact angle of optimal modified membrane decreased from 69.6° to 45.0°, showing the effectively enhancement of hydrophilicity. By filtrating two kinds of real oil-in-water emulsions, the stable flux of modified membrane was approximately 2 times higher than that of pristine membrane for both low and high concentration oil-in-water emulsions. In addition, the Verm-PVDF membrane also showed a higher removal efficiency of oil and total organic carbon. According to membrane fouling model analysis, the fouling behavior including adsorption, deposition, blockage of membrane pores and formation of cake layer had obviously alleviated after Verm modification for the two kinds of oil-in-water emulsions due to the formation of water layer by isomorphism substitution and surface hydroxylation of Verm NPs. Assessed by extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) theory, Verm-PVDF membrane exhibited a higher energy barrier and an extremely strong repulsive force for foulants to overcome in low and high concentration emulsions during fouling. Overall, the improved antifouling ability and separation performance of modified membrane indicated that the inartificial Verm NPs was a robust material for pH-control membrane modification with potential application value in oil/water separation.

Interfacial coupling perovskite CeFeO3 on layered graphitic carbon nitride as a multifunctional Z-scheme photocatalyst for boosting nitrogen fixation and organic pollutants demineralization

The application of pristine graphitic carbon nitride (PCN, g-C3N4)/cerium ferrite (CeFeO3, CFO) composites as photocatalysts for energy production and water treatment has not yet been reported despite its great potential. In this study, CFO, an orthorhombic perovskite-type oxide, was covalently coupled to PCN via a facile single-step calcination strategy. Compared to PCN, optimized 1% CFO-doped PCN (PCN@CFO1) exhibited wide ranges of organic-micropollutant removal (sulfamethoxazole (SMX), atrazine, and bisphenol A) and achieved approximately 49.9% of total-organic-carbon (TOC) removal for SMX in 4 h with 5 stable reusable performances. Further, scavenger experiments and the electron paramagnetic resonance (EPR) spin-trap analysis revealed that PCN@CFO1 could produce superoxide (O2−) and hydroxyl radicals (OH) for organic-pollutant degradation. Meanwhile, the intermediate species of organic pollutants were investigated using liquid chromatography-tandem mass spectrometry to identify the degradation pathways. Of note, PCN@CFO1 achieved up to 573.12 µmol l−1 g−1 of ammonia production rate and 2.92% of apparent quantum efficiency of nitrogen photo-fixation at 400 nm, which was 8 times higher than that of PCN. Through coupling CFO and PCN, the flat band potential was found to be upshifted, and a high ratio of the Ce3+ interface associated with oxygen vacancies was generated, resulting in the formation of a Z-scheme system. Remarkably, the formation of the Z-scheme structure on PCN@CFO1 showed enhancement in charge transfer, hydrophilicity, and charge separation, significantly improving the photocatalytic performance for organic-micropollutant demineralization and nitrogen photo-fixation under UVA-LED (400 nm) light irradiation. Our study provided a facile and scalable preparation strategy for multifunctional photocatalysts that could be effectively activated under energy-efficient UVA-LED irradiation for energy production and emerging pollutants degradation.

Effect of alumina nanoparticles on the antifouling properties of polycarbonate‐polyurethane blend ultrafiltration membrane for water treatment

AbstractIn this work, the flexibility of polycarbonate (PC) membrane was improved by using polyurethane (PU) additive. However, due to the hydrophobic nature of the PU polymer, alumina (Al2O3) nanoparticles were incorporated to PC‐PU blend membrane. The prepared membranes have been used in a submerged membrane system to eliminate humic acid molecules from polluted water in both the presence and absence of coagulant (polyaluminum chloride). The obtained results showed that introduction of PU into PC membrane diminished hydrophilicity and enhanced porosity. Moreover, the flexibility of the PC membrane remarkably improved. Introduction of 1.5 wt% Al2O3 to the PC‐PU blend membrane led to enhancement in both porosity and hydrophilicity. Results of morphological studies showed that in the presence of Al2O3 nanostructures, finger‐shaped voids seemed to elongate across the entire thickness of the prepared membrane. Atomic force microscopy images showed that incorporation of PU and Al2O3 to the PC membrane resulted in a smoother surface. The antifouling performance of membranes revealed that the PC‐PU/Al2O3 nanocomposite membrane possessed the most favorable antifouling features owing to its lowest surface roughness as well as highest hydrophilicity. For all membranes utilizing coagulant (PAC), the irreversible fouling ratio and the flux recovery ratio significantly diminished and increased, respectively.

Bead‐free and tough electrospun PCL/gelatin/PGS ternary nanofibrous scaffolds for tissue engineering application

AbstractPoly(glycerol sebacate) (PGS) is a biodegradable and biocompatible polyester that is increasingly used in the biomedical field. Herein, a novel ternary poly(ε‐caprolactone)/gelatin/PGS (PCL/gelatin/PGS) blend nanofibers were designed and fabricated with a wide range of chemical compositions, mechanical properties, and modulated degradability levels. PGS blends with gelatin are commonly used for enhancing electrospinability but their low‐mechanical properties, lack of structural stability in an aqueous medium, and unmodulated degradation behavior limited their application. Blending PGS and gelatin with PCL could improve their properties in a ternary structure. In addition, considering ternary blends of PCL/gelatin/PGS, an enhancement of hydrophilicity due to the presence of gelatin in the system is expected, resulting in better biocompatibility and controlled biodegradation. By increasing the polymer concentration, voltage, and distance of the needle to the collector, the bead‐free electrospun nanofibers were obtained. The ternary blend nanofibers with an equal weight ratio of polymers, T33 (containing 33 wt% PGS, 33 wt% gelatin, and 33 wt% PCL), possess more than a 4‐fold increase in tensile strength (7 MPa) and 89‐fold increase in elongation at break (1760.6%) compared to gelatin/PGS binary nanofibers. In vitro studies on glioma cells showed well attachment and proliferation of C6 glioma cells. The obtained results demonstrated the potential of these scaffolds for nerve tissue engineering applications.

Antifouling enhancement of polyacrylonitrile-based membrane grafted with poly(sulfobetaine methacrylate) layers

Abstract In this work, zwitterionic polyacrylonitrile (PAN)-based membranes were synthesized via surface grafting strategy for improving the antifouling properties. The copolymer membrane consisting of PAN and poly(hydroxyethyl methacrylate) segments, was cast via nonsolvent induced phase separation, and then treated with acryloyl chloride to tether with carbon-carbon double bonds. Zwitterionic poly(sulfobetaine methacrylate) (PSBMA) layers were grafted onto membrane surface via concerted reactions of radical grafting copolymerization and quaternization with 2-(dimethylamino)ethyl methacrylate) and 1, 3-propanesultone (1, 3-PS) as the monomers. The grafting degree (GD) of PSBMA layers increases with the incremental content of monomers, leading to the enhancement in membranes surface hydrophilicity. The permeation experiments show that the flux of the zwitterionic membrane increases and then decreases with the increasing GD value, because of the surface coverage of PSBMA layers. The zwitterionic membrane has excellent separation efficiency for oil-in-water emulsion, with the rejection of a higher value than 99%. The irreversible membrane fouling caused by oil adsorption has been suppressed, as proved by the cycle-filtration tests. These outcomes confirm that oil-fouling resistances of membranes are improved obviously by the surface grafting of zwitterionic PSBMA layers.

Enhanced activity of Rhizomucor miehei lipase by directed saturation mutation of the propeptide

The propeptide is a short sequence that facilitates protein folding. In this study, four highly active Rhizomucor miehei lipase (RML) mutants were obtained through saturation mutagenesis at three propeptide positions: Ser8, Pro35, and Pro47. The enzyme activities of mutants P35 N, P47 G, P47 N, and S8E/P35S/P47A observed at 40 °C, and pH 8.0 were 10.19, 7.53, 6.15, and 8.24 times of that wild-type RML, respectively. The S8E/P35S/P47A mutant showed good thermostability. After incubation at 40 °C for 1 h, 98.98 % of its initial activity remained, whereas wild-type RML retained only 78.76 %. This result indicated that the enhancement of hydrophilicity of 35- and 47- amino-acid residues could promote the interaction between the propeptide and the mature peptide and the enzyme activity and expression level. Highly conserved sites had a more significant impact on enzyme performance than did other sites, similar to the Pro35 and Pro47 mutants showed in this study. This study provides a new idea for protein modification: enzyme performance can be improved through propeptide regulation.

Highly selective custom‐made chitosan based membranes with reduced fuel permeability for direct methanol fuel cells

AbstractCustom‐made nanocomposite proton exchange membranes (PEMs) are fabricated using the blends of sulfonated chitosan (S‐Chitosan) and sulfonated graphene oxide (SGO) nanosheets for direct methanol fuel cells (DMFCs). Sulfonation of chitosan and GO are carried out by 1,3‐propane sultone and sulfanilic acid, respectively. Scanning electron microscope (SEM) with energy dispersive X‐ray investigation revealed that the thick, folded and wrinkled sheet‐like morphology of SGO and the existence of elemental sulfur. SEM and atomic force microscopy images showed the uniform dispersion of hydrophilic SGO nanosheets. Besides the S‐Chitosan/SGO membranes showed higher water uptake, swelling ratio and ion exchange capacity due to the enhancement in hydrophilicity. The modified PEMs displayed improvement in proton conductivity since the ion‐exchangeable sulfonic acid groups facilitate the proton conduction and effectively resist the methanol permeability by forming a strong hydrogen bond network with chitosan and thus diminish the void volume. Particularly, S‐Chiotsan‐1 membrane showed superior proton conductivity of 4.86 × 10−3 Scm−1 at (25°C), selectivity of 1.89 × 105 Scm−3 s and lesser methanol permeability of 2.57 × 10−8 cm2s−1. Overall results suggest that the S‐Chitosan/SGO membranes found to be a suitable alternate for Nafion® in DMFCs.

Hydrolytic degradation of PLA/Posidonia Oceanica green composites: A simple model based on starting morpho-chemical properties

In this work, we studied the degradability of PLA-based biocomposites containing Posidonia Oceanica flour at different loading levels and aspect ratios. Hydrolytic tests were carried out in neutral (pH = 7.4) and alkaline (pH = 10) environment. Time-dependent evolution of some key features, including residual mass and solution uptake, was monitored, and correlated with the changes observed in both morphology and chemical structure of the matrix. The results pointed out that biocomposites degraded much faster than neat PLA in both conditions, up to lose 70% of their initial weight after 1000 h immersion. A complex mechanism was unveiled, evidencing the crucial role of the fillers, capable of both imparting degradation to PLA during processing with enhancement of hydrophilicity and offering preferential gateways for solution penetration through filler-matrix interface by capillarity and swelling-aided polymer cracking. Based on data collected, we propose a new model allowing to predict the triggering and final extent of degradation pathways by considering starting morphological and chemical features of composites via the use of a novel yet simple indicator of chemical stability, which we called morphochemical parameter.

High flux polysulfone braided hollow fiber membrane for wastewater treatment role of zinc oxide as hydrophilic enhancer

Incorporation of zinc oxide (ZnO) nanoparticles has played an important role on the improvement of unique membrane characterization and performance, most notably the hydrophilic modification of the membrane for higher pure water permeability. Additionally, the permeability of the membrane can be improved via introduction of braid support by reducing the thickness of the membrane separation layer. Moreover, the braided hollow fiber membrane (BHFM) is able to perform under higher pressure conditions compared to hollow fiber membranes. In this paper, hybrid polysulfone (PSf)/ZnO BHFMs were fabricated via phase inversion method. Hydrophilic 10 ± 1.8 nm polycrystalline ZnO nanoparticles synthesized via sol-gel method were incorporated on BHFM to improve the hydrophilicity and increase flux with constant rejection under high pressure and the effect of the ZnO loading on the membrane properties and performance were thoroughly studied. The fabricated BHFMs with 0.0, 0.5, 1.0 and 1.5 wt% of ZnO nanoparticles concentration were defined as BHFM1, BHFM2, BHFM3 and BHFM4 respectively. Scanning electron microscopy (SEM), contact angle, mechanical strength, flux performance, rejection with bovine serum albumin (BSA) and fouling of best performed membrane were conducted to achieve the target of this paper. The performance of these hybrid ZnO/PSf BHFMs were compared with neat PSf hollow fiber membrane (HFM) and previous studies. The findings from this research work shows that BHFM4 has the most desired properties for wastewater treatment application. The ZnO nanoparticles in BHFM4 have improved hydrophilicity from 108.79° to 71.02°, and thus BHFM4 has increased flux performance from 36.20 to 919.12 L/m2 h at 1.0 bar pressure and 193.48 to 1909.11 L/m2h at 4.0 bar pressure when compared with BHFM1. Constant BSA rejection rates (> 90%) were observed in all BHFMs. The improved hydrophilicity and pure flux performance with constant rejection rate in high pressure conditions illustrates the suitability of fabricated ZnO/PSf BHFMs in wastewater treatment applications.

Investigations of the characteristics and performance of modified polyethersulfones (PES) as membrane oxygenator

AbstractThe modification of membrane oxygenators to minimize protein adsorption onto the surface is often accompanied by the loss of membrane performance. This study aims to explore polyethersulfone (PES) as a new material for membrane oxygenator applications and to assess its potentials. Accordingly, different modification techniques are applied to improve surface properties of PES membranes. To achieve this goal, two separate modification methods including incorporation of TiO2into the membrane matrix as well as grafting polyethylene glycol (PEG) through oxygen plasma treatment are developed and the effects are examined. The results reveal that protein adsorption to the nanocomposite membrane containing 0.50 wt. % TiO2and the grafted membrane decreased by 47 and 31%, respectively. In terms of performance, permeability and oxygen transfer rate of all modified membranes exceeded 808 GPU and 2.7 × 10−4 mol·m−2·s−1, respectively. Contact angle analysis revealed signs of hydrophilicity enhancement of membranes after modifications. The findings suggest that upon proper modifications, membranes based on PES could be considered as promising candidates for membrane oxygenator applications and deserves further investigations.

Hydrophilicity enhancement of low-temperature lignocellulosic biochar modified by physical–chemical techniques

Hydrophilicity enhancement of low-temperature lignocellulosic biochar modified by physical–chemical techniques

Pyrochlores: oxygen-rich moieties as ceramic fillers in uplifting the antifouling property and dye removal capacity of polymeric membranes

Application of nanostructured polymeric membranes for wastewater treatment is growing exceptionally because of their tunable functionalities, size, composition and morphology which offer immense opportunities for wastewater treatment. Here, for the first time, pyrochlore-type ternary metal oxides are explored as ceramic fillers to prepare mixed matrix membranes (MMMs)/polymeric nanocomposite membranes because of its affinity to water and oxygen. The effect of yttrium titanate (Y2Ti2O7) for the fabrication of polysulfone (PSF) MMMs is examined in terms of hydrophilicity, permeability, protein separation, dye removal and antifouling property. The synthesized pyrochlore oxides and the prepared MMMs are characterized using various techniques. The results show that the PSF MMMs manifest an enhancement in hydrophilicity, permeability and dye removal capacity upon addition of oxygen rich Y2Ti2O7 ceramic species into PSF membrane matrix. The PSF MMM with 1 wt% ceramic loading exhibited remarkable PWF (104 L/m2h), higher fouling resistance ratio and larger permeate flux recovery ratio (96%) compared to 27 L/m2h PWF and 40.57% FRR obtained for the pristine PSF membrane, respectively. Furthermore, significantly higher rejection of Congo red dye (100%), Pb2+ (98%) and Cd2+ (99%) heavy metal ions was achieved for mixed matrix membrane. Thus, Y2Ti2O7 ceramic species can open up new possibilities in enhancing the overall performance of the MMM for separation applications.