Phase Inversion Method Research Articles

Understanding Thermodynamics and Kinetics of PEDOT:PSS Using ATR-FTIR and Density Functional Theory.

This work demonstrates poly(3,4-ethylenedioxythiophene) polystyrenesulfonate (PEDOT:PSS) and divinyl sulfone (DVS) cross-linking to form insoluble and porous PEDOT:PSS-DVS hydrogels. We propose a reaction mechanism and demonstrate the kinetics of a PEDOT:PSS modification that prevents PEDOT:PSS dispersibility. PSS and DVS undergo a second-order reaction between the DVS secondary carbocations and PSS oxygen anion to form a PSS-DVS network. The kinetics, from real-time attenuated total reflectance-Fourier transform infrared spectroscopy and density functional theory, reveal a temperature-dependent rate expression with a 1.458 1/s pre-exponential factor and a 2.429 kcal/mol activation energy. Cryogelation, phase separation, and phase inversion methods induce porosity in the PEDOT:PSS-DVS hydrogels with pore sizes ranging from 12 to 121 μm. Most importantly, the porous PEDOT:PSS-DVS hydrogels do not redisperse in solution. The results provide evidence for the reaction mechanism and kinetics of porous nondispersible PEDOT:PSS-DVS hydrogels.

Shaping Phenolic Resin-Coated ZIF-67 to Millimeter-Scale Co/N Carbon Beads for Efficient Peroxymonosulfate Activation.

Catalytic performance decline is a general issue when shaping fine powder into macroscale catalysts (e.g., beads, fiber, pellets). To address this challenge, a phenolic resin-assisted strategy was proposed to prepare porous Co/N carbon beads (ZACBs) at millimeter scale via the phase inversion method followed by confined pyrolysis. Specially, p-aminophenol-formaldehyde (AF) resin-coated zeolitic imidazolate framework (ZIF-67) nanoparticles were introduced to polyacrylonitrile (PAN) solution before pyrolysis. The thermosetting of the coated AF improved the interface compatibility between the ZIF-67 and PAN matrix, inhibiting the shrinkage of ZIF-67 particles, thus significantly improving the void structure of ZIF-67 and the dispersion of active species. The obtained ZACBs exhibited a 99.9% removal rate of tetracycline (TC) within 120 min, with a rate constant of 0.069 min-1 (2.3 times of ZIF-67/PAN carbon beads). The quenching experiments and electron paramagnetic resonance (EPR) tests showed that radicals dominated the reaction. This work provides new insight into the fabrication of high-performance MOF catalysts with outstanding recycling properties, which may promote the use of MOF powder in more practical applications.

ZIF-67@polyvinylidene fluoride mixed matrix membranes towards improved hydrogen separation performance.

This work is primarily focused on overcoming the limitations of polymeric membranes in achieving the balance between permeability and selectivity of the separation performance. The filler, Zeolitic imidazole framework -67 (ZIF-67) nanoparticles were synthesised in cubical morphology using hexadecyltrimethylammonium bromide (CTAB) as a surfactant via the wet-chemical method. The uniform particles with particle sizes ranging between 120-180nm were incorporated into the polyvinylidene fluoride (PVDF) matrix to fabricate mixed matrix membranes via the phase inversion method. These mixed matrix membranes were systematically characterised to confirm the chemical, structural and morphological properties of the materials and membranes. Furthermore, the membranes showed a 56.5% improvement in their mechanical properties. The results confirm that 5 wt.% ZIF-67/PVDF membrane showed the best separation results compared to its pure counterpart. The permeability of H₂ gas was reported to be 1,094,511 Barrer, with selectivities of 3.03 for H₂/CO₂ and 3.06 for H₂/N₂. This represents a 210.6% increase in the permeability of H₂ gas. These results demonstrate the influence of ZIF-67 loading in the PVDF polymer matrix along with the potential of ZIF-67/PVDF mixed matrix membranes in the field of hydrogen separation and purification.

Photo responsive single layer MoS2 nanochannel membranes for photocatalytic degradation of contaminants in water

The major polluting aspects of our global fashion industries are the textile wastewater that turns black all our freshwater reservoirs. Nano-filtration through membrane technology is one of the biggest solutions of industrial wastewater treatment but the fouling of membrane is the major limitation of previous work. In this research, novel PVDF/MoS2-TNT (PMT) nanocomposite membranes were fabricated through a modified In-situ polymerisation phase inversion method. X-ray diffraction (XRD) analysis also confirmed the β-phase of PVDF within the developed PVDF/MoS2-TNT membrane. XPS analysis provides evidence about the presence of a specific chemical states of titanium nanotube and molybdenum disulphide which is involved in the photocatalytic degradation of pollutant molecules. Scanning electron microscope (SEM) shows that our membranes are porous in nature. PVDF/MoS2-TNT membranes exhibit excellent filtration efficiency (∼97%) for textile wastewater. The results and outcomes of the research demonstrate that PMT membranes have enormous potential in the commercial application of textile wastewater treatment.

EDAC-modified chitosan/imidazolium-polysulfone composite beads for removal of Cr(VI) from aqueous solution

To enhance the stability and adsorption performance of chitosan in Cr(VI)-contaminated acidic wastewater, a novel EDAC-modified-EDTA-crosslinked chitosan derivative (CSEC) was synthesized via a one-pot method with chitosan, 1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDAC), and Na2EDTA as raw materials. To further improve the mechanical strength and separation performance of CSEC, a novel composite bead (CSEP) of CSEC and imidazolium-functionalized polysulfone (IMPSF) was prepared through a phase inversion method. The chemical composition and microstructure of CSEC and CSEP were characterized by FESEM, FTIR, NMR and XPS techniques. The maximum adsorption capacities of CSEC and CSEP for Cr(VI) were 145.96 and 135.82 mg g−1 at pH 3, respectively, and the equilibrium time for Cr(VI) adsorption by CSEC and CSEP was 5 min and 8 h, respectively. The adsorption process of Cr(VI) by both CSEC and CSEP was exothermic and spontaneous. Compared to CSEC, CSEP has significantly enhanced resistance to interference from coexisting anions. The removal mechanism of Cr(VI) by CSEP might involve redox reaction as well as electrostatic attraction between Cr(VI) oxyanions and various nitrogen cations, including protonated amino groups, guanidinium groups, protonated tertiary amine groups, and imidazolium cations. The CSEP beads have potential application value in the treatment of acidic wastewater containing Cr(VI).

Advanced photocatalytic membrane GO-NiFe@SiO2/PVDF for efficient decontamination of synthetic dyes in batik wastewater with superior antifouling features

A novel composite membrane, GO-NiFe@SiO2/polyvinylidene fluoride (PVDF), was prepared via the sol-gel method for nanocomposite synthesis and phase inversion method for membrane fabrication. The investigation encompassed the structural features and properties of the nanocomposite membranes, including photocatalytic activity under UV type C, antifouling capability, and self-cleaning behavior. The degradation of dyes in real Batik wastewater followed pseudo-first-order kinetics, with the GO-NiFe@SiO2/PVDF 1 wt% nanocomposite membranes exhibiting a highest dyes removal efficiency up to 90.50 % within 8 h, compared to the pristine PVDF membrane (60.95 %). The XRD pattern analysis indicates that the incorporation of GO-NiFe@SiO2 into the PVDF membrane induced a transformation in the semi-crystalline phase of PVDF, shifting from the alpha-phase to the beta-phase, consequently facilitating the development of electrostatic charge on the membrane surface. The pore-size distribution analysis revealed that all prepared membranes fall within the range of nanofiltration and tight ultrafiltration (NF-TUF). Additionally, the photocatalytic membrane demonstrated enhanced permeation flux of 30.46 L.m−2.h−1 and flux recovery rate up to 92.57 % under simulated UV light irradiation, showcasing improved antifouling capability. Moreover, the membrane exhibited outstanding cycle test with 6 consecutive cleaning every 3 h, self-cleaning efficiency, with 61.32 % cleaning efficiency under UV irradiation. The incorporation of GO-NiFe@SiO2 enhanced the physicochemical properties of the photocatalytic membrane, including hydrophilicity, surface topologies, and mechanical strength, thereby improving photocatalytic anti-fouling performance and expanding the potential applications of membrane filtration technology.

Intravenous delivery of furosemide using lipid-based versus polymer-based nanocapsules: in vitro and in vivo studies

Objectives Furosemide (FSM), a potent loop diuretic, is used to treat edema due to hypertension, congestive heart failure, and liver and renal failures. FSM applications are limited by its low bioavailability. Our aim is to use different nanoencapsulation strategies to control the release of FSM and enhance its pharmacokinetic properties. Methods Two types of FSM-loaded nanocapsules, namely FSM-loaded lipid nanocapsules (LNCs) and polymeric nanocapsules (PNCs), were developed, physicochemically characterized, and subjected to pharmacokinetic and pharmacodynamic studies. Lipid nanocapsules were prepared by the simple phase inversion method using LabrafacTM lipid, while the polymeric nanocapsules were prepared by nanoprecipitation method using polycaprolactone polymer. Results Transmission electron microscopy ascertains spherical structures, corroborating the nanometric diameter of both types of nanocapsules. The particle size of the optimized FSM-loaded LNCs and FSM-loaded PNCs was 32.19 ± 0.72 nm and 230.7 ± 5.13 nm, respectively. The percent entrapment efficiency was 63.56 ± 1.40% of FSM for the optimized PNCs. The in vitro release study indicated prolonged drug release compared to drug solutions. The two loaded nanocapsules systems succeeded in enhancing the pharmacokinetic parameters in comparison to the marketed FSM solution with superior diuretic activity (p < 0.05). The results of the stability study and the terminal sterilization by autoclave indicated the superiority of LNCs over PNCs in maintaining the physical parameters under storage conditions and the drastic conditions of sterilization. Conclusions LNCs and PNCs are considered promising nanosysems for improving the diuretic effect of FSM.

Characteristics of Cellulose Acetate Composite Membranes (Ca/Cs, Ca/Pva, Ca/Peg) As Cu(Ii) Metal Ion Filtration Membranes

Industrial development in Indonesia has caused increased pollution, including water pollution by heavy metals, one of which is the metal ion Cu(II). Cellulose acetate composite membranes have been widely used to overcome the problem of Cu(II) metal ion content in water, however, studies on the performance of cellulose acetate membranes with various types of chitosan, polyvinyl alcohol (PVA) and polyethylene glycol (PEG) composites have not been widely reported. This research aims to analyze the characteristics of cellulose acetate composite membranes with chitosan, PEG, and PVA using FTIR and SEM and to determine the performance of these cellulose acetate composite membranes in filtering Cu(II) metal from the resulting rejection values. The membrane was made using the phase inversion method and the composite membrane was made using the dip-coating method. The results of characterization using FTIR showed that there were no new peaks in all cellulose acetate composites, so there were only physical interactions in the composites. SEM analysis shows that the surface of the composite membrane is more irregular and the porosity increases. The performance of the composite membrane in filtering Cu(II) metal is better than the pure cellulose acetate membrane.

Preparation, characterization and applications of polyethersulfone/bentonite clay composite for protein removal

In the current work, asymmetric polyethersulfone/bentonite clay nanocomposite (PES/BNT) membranes with differing clay dosages were successfully prepared by the phase inversion method aimed at protein separation. Means of characterization tools were harnessed to validate the fabrication process. The morphology and structure of membranes were examined by scanning electron microscope (SEM) and Fourier-transform infrared spectroscopy (FTIR) while additional surface properties such as pore size, porosity and hydrophilicity measurements were assessed. The permeability-selectivity trade-off of the membranes were assessed to probe the influence of additive content on the ultimate membrane functionality. The results indicated that best membrane performance was achieved with a BNT content of 0.225 g, resulting in enhanced dispersibility within the polymeric matrix. Besides, the inclusion of clay additive led to an increase in pore size ratio in the skin layer, further improving membrane permeability. The optimal membrane exhibited a permeate flux of 20.5 kg.m−2.h−1, while rejected 93 % of bovine serum albumin (BSA). Meanwhile, porosity, pore size and the contact angle measurements have recorded 71.8 %, 22.6 nm and 40.53°, respectively. These findings suggested that the PES/BNT membrane's permeation and separation characteristics, rendering them a viable option for a wide range of water and wastewater treatment applications.

Chemical profile and therapeutic potential of the essential oil and nanoemulsions of Citrus x sp (Tanja Lemon)

The objective of this study was to evaluate the chemical profile and therapeutic potential of the essential oil and nanoemulsions of Citrus x sp (Tanja Lemon). Hydrodistillation was used to extract the essential oil. Gas Chromatography coupled to Mass Spectrometry (GC/MS) was used for the analysis of chemical constituents. The phenolic content (CFT) was analyzed by the Folin-Ciocalteau assay, and flavonoids (CFLT) by complexation with aluminum. The nanoemulsions were formulated by the phase inversion method. The antioxidant activity was evaluated by a hydroxyl radical assay and the anti-inflammatory activity by protein denaturation, and antiarthritic activity by a cyclooxygenase inhibition assay in bovine albumin serum. By means of GC/MS, limonene was identified as the major component (70.25%). The determination of CFT and CFLT quantified 227.645 mg EAT g-1 and 86.57 mg EQ g-1. For antioxidant capacity, nanoemulsions have EC50 values of 9.10-11.28 mg L-1. In anti-inflammatory activity, synergies quantified 4.63-11.03 mg L-1. For the antiarthritic activity, it is noted that among the nine synergies formulated, some manifested excellent antiarthritic activity, with EC50 values of 1.9-1.98 mg L-1. It can be affirmed that the formulations produced from Citrus x sp presented satisfactory results, evidencing the efficacy of their properties.

The anti-fouling and mechanism of Fe3O4@PVDF catalytic membrane in-situ coupling Fenton oxidation for organic pollutants removal

Polyvinylidene fluoride (PVDF) membrane is a promising technique for deep treatment of organic wastewater. However, the unavoidable membrane contamination greatly restrictions its field of application. Herein, we successfully prepared Fe3O4@PVDF membrane with excellent anti-fouling and catalytic ability by non-solvent induced phase inversion method. Meanwhile, Fe3O4@PVDF membrane was characterized by SEM, XRD, FTIR, Water contact Angle and membrane aperture analyzer. The properties of separation and anti-fouling were also evaluated by cross flow filtration of humic acid (HA). Compare with pristine membrane, the pure water flux, rejection rate and FRR respectively increase from 556.81 L m-2 h−1, 65.42 %, 68.26 % to 656.96 L m-2 h−1, 99.64 %, 90.17 % under in-situ Fenton reaction condition. In addition, further mechanistic insights by XDLVO theory, 3D-EEM and EPR verified that high anti-fouling mainly attribute to excellent hydrophilicity of Fe3O4@PVDF and in-situ degradation of HA by OH and 1O2· This work provides insights for improving the separation properties and anti-fouling properties of PVDF membrane in the field of treatment organic wastewater.

Artemisia monosperma essential oil nanoformulations alleviate imiquimod-induced psoriasis-like dermatitis in mice

Psoriasis is an inflammatory immune-mediated skin disease that affects nearly 2–3 % of the global population. The current study aimed to develop safe and efficient anti-psoriatic nanoformulations from Artemisia monosperma essential oil (EO). EO was extracted using hydrodistillation (HD), microwave-assisted hydrodistillation (MAHD), and head-space solid-phase microextraction (HS–SPME), as well as GC/ MS was used for its analysis. EO nanoemulsion (NE) was prepared using the phase inversion method, while the biodegradable polymeric film (BF) was prepared using the solvent casting technique. A.monosperma EO contains a high percentage of non-oxygenated compounds, being 90.45 (HD), 82.62 (MADH), and 95.17 (HS–SPME). Acenaphthene represents the major aromatic hydrocarbon in HD (39.14 %) and MADH (48.60 %), while sabinene as monoterpene hydrocarbon (44.2 %) is the primary compound in the case of HS–SPME. The anti-psoriatic Effect of NE and BF on the successful delivery of A.monosperma EO was studied using the imiquimod (IMQ)-induced psoriatic model in mice. Five groups (n = 6 mice) were classified into control group, IMQ group, IMQ+standard group, IMQ+NE group, and IMQ+BF group. NE and BF significantly alleviated the psoriatic skin lesions and decreased the psoriasis area severity index, Baker’s score, and spleen index. Also, they reduced the expression of Ki67 and attenuated the levels of tumor necrosis factor-alpha, interleukin 6, and interleukin 17. Additionally, NE and NF were able to downregulate the NF-κB and GSK-3β signaling pathways. Despite the healing properties of BF, NE showed a more prominent effect on treating the psoriatic model, which could be referred to as its high skin penetration ability and absorption. These results potentially contribute to documenting experimental and theoretical evidence for the clinical uses of A.monosperma EO nanoformulations for treating psoriasis.

High Stability Hypha-Like Core-Shell Nanostructure by In Situ Induced Phase Inversion for Zinc Metal Batteries.

Nanomaterials are widely used in many fields for their unique physical and chemical properties and especially demonstrate irreplaceability in energy storage systems. In this paper, a novel composite of copper sulfide with hypha-like core-shell nano-structure is synthesized by in situ phase inversion method, which serves as high stability negative electrode materials of zinc-ion batteries (ZIBs). The unique structure facilitates efficient electron and ion transport, enhances the kinetics of electrochemical reactions, and effectively suppresses the undesired expansion and decomposition of transition metal compounds. As a result, the half battery exhibits high specific capacity (250.2 mAh g-1 at 0.1 A g-1), reliable rate performance, and cycle stability (98.3 mAh g-1 at 1 A g-1 after 500 cycles). Additionally, when assembled with ZnxMnO2 positive to form a full battery, it demonstrates good cycling capacity at an intermediate current density of 2 A g-1, while maintaining excellent structural stability over 5,000 cycles (61% retention).

Ultrafiltration membranes for dye wastewater treatment: Utilizing cellulose acetate and microcrystalline cellulose fillers from Ceiba Pentandra

Dye hurts the threat of human health problems and environmental pollution. Microcrystalline cellulose (MCC) based membrane is a good material to be used as an dye separation membrane for having the high hydrophilicity of the membrane. It has been successfully isolated from kapok (ceiba pentandra) with characteristic X-ray diffraction patterns and FTIR absorption peaks, which corresponded to the typical peaks of cellulose. The ultrafiltration membrane was made up of a cellulose acetate matrix created using the phase inversion method. Characterization results indicated that the inclusion of MCC derived from kapok led to a reduction in the contact angle from 65 to 52o, and an increase in membrane porosity from 82 to 85%. In the separation of dye, the composite membrane incorporating MCC filler demonstrated superior performance compared to the membrane lacking MCC, manifesting in an elevated water flux from 43 to 84 L/m².h and methylene blue (MB) rejection from 64 to 99%. The use of MCC as a filler in cellulose acetate membranes can enhance the characteristics and performance of the membrane in MB separation.

Photocatalytic hydrogen evolution on tubular shape cellulose acetate/crystalline nanocellulose/polyvinyl alcohol membranes with embedded nanocrystalline catalysts

In this work, we design an efficient and cost-effective porous membrane composed by polymeric blend that supports different photocatalytic materials. The thin (300 μm) porous photocatalytic membrane has a tubular shape and was flexible for easy handle in the reactor. The membrane is composed of a polymeric blend based on cellulose acetate, crystalline nanocellulose and polyvinyl alcohol, obtained by the phase inversion method, using cold water as non-solvent. Bismuthates (KBiO3, NaBiO3) and aluminates (ZnAl2O4 and Cu0·9Zn0·1Al2O4) powders were synthesized by diverse methodologies and were embedded into polymeric matrix. The hydrogen evolution performance of photocatalyst powders and photocatalytic composite membranes, under UV light irradiation during 180 min, were compared. The best result of hydrogen evolution was obtained by Cu0·9Zn0·1Al2O4 powders reaching 117.74 μmolg−1h−1 and the M−CuZn membrane reaching 90.07 μmolg−1h−1. The obtained results show the high potential of these polymeric membranes as a green alternative support for photocatalysts for hydrogen evolution.

Bioactive baicalin rhamno-nanocapsules as phytotherapeutic platform for treatment of acute myeloid leukemia

Leukemia, particularly acute myeloid leukemia (AML) is considered a serious health condition with high prevalence among adults. Accordingly, finding new therapeutic modalities for AML is urgently needed. This study aimed to develop a biocompatible nanoformulation for effective oral delivery of the phytomedicine; baicalin (BAC) for AML treatment. Lipid nanocapsules (LNCs) based on bioactive natural components; rhamnolipids (RL) as a biosurfactant and the essential oil linalool (LIN), were prepared using a simple phase-inversion method. The elaborated BAC-LNCs displayed 61.1 nm diameter and 0.2 PDI. Entrapment efficiency exceeded 98 % with slow drug release and high storage-stability over 3 months. Moreover, BAC-LNCs enhanced BAC oral bioavailability by 2.3-fold compared to BAC suspension in rats with higher half-life and mean residence-time. In vitro anticancer studies confirmed the prominent cytotoxicity of BAC-LNCs on the human leukemia monocytes (THP-1). BAC-LNCs exerted higher cellular association, apoptotic capability and antiproliferative activity with DNA synthesis-phase arrest. Finally, a mechanistic study performed through evaluation of various tumor biomarkers revealed that BAC-LNCs downregulated the angiogenic marker, vascular endothelial growth-factor (VEGF) and the anti-apoptotic marker (BCl-2) and upregulated the apoptotic markers (Caspase-3 and BAX). The improved efficacy of BAC bioactive-LNCs substantially recommends their pharmacotherapeutic potential as a promising nanoplatform for AML treatment.

Forward osmosis membrane substrates with low structure parameter: Modification with PSf‐g‐PMMA graft copolymer

AbstractIn this work, using the combination of atom transfer radical polymerization and click chemistry, the graft copolymer polysulfone‐graft‐poly (methyl methacrylate) (PSf‐g‐PMMA) was synthesized as a modifying agent. The copolymer was embedded in the PSf substrate using a nonsolvent phase inversion method. Then, the modified substrate was used to make thin film composite forward osmosis (TFC‐FO) membranes using the interfacial polymerization method. Also, the effect of PSf‐g‐PMMA copolymer content on the surface properties of the membrane, as well as the filtration performance, was investigated. The increase in hydrophilicity, porosity, and average pore diameter indicated the favorable effect of PSf‐g‐PMMA copolymer on the characteristics of modified substrates. In addition, the improvement in the membrane morphology (an increase in the length and number of finger‐like pores) provided a substrate with low tortuosity and structure parameters. Therefore, the pure water permeability increased from 79.9 LMH/bar for the control membrane to 372.1 LMH/bar for the membrane containing 20 wt.% of PSf‐g‐PMMA copolymer. Investigating the FO separation properties of TFC‐FO membranes showed an increase in water flux and selectivity due to an improvement in the morphology of the modified substrate with low structural parameters. The new TFC‐FO membranes have been optimized, and water flux has significantly improved. Compared with the control membrane, which did not have copolymer blending, the new membranes have a triply enhanced water flux of 17.1 LMH. In addition, the selectivity of these optimized membranes has improved when 1 M NaCl is used as the draw, and DI water is used as the feed in the FO mode.

Study of novel Zn-MOF-II modified polymeric membrane in wastewater treatment containing oily waste and humic acid (NOM)

ABSTRACT The prime objective of the present work was to synthesise the polymeric membrane with Zn-MOF-II nanoparticles using the phase inversion method to purify oily wastewater and NOM. The dead-end filtration system was utilised to analyse the performance of fabricated membranes (without and with Zn-MOF-II), various feeds of 100 ppm concentration used, such as organic pollutants and oil effluent at 250 kPa and atmospheric temperature conditions. The following study involves the compaction factor, pure water flux, all mixed matrix membrane permeability, humic acid rejection, and oil–water emulsion rejection, contact angle, and liquid–liquid displacement porosimetry (LLDP). Scanning electron microscopy (SEM) and Fourier transforms infrared spectroscopy-attenuated total reflection (FTIR-ATR) goniometer were used to characterise the polymeric membranes. The FTIR-ATR spectra of the modified membrane exhibit a characteristic peak between 2,900 and 3,000 cm−1 associated with the presence of the –COOH group. The nanoparticles and polymer matrix were well compatible, as evidenced by SEM images of the polymeric membrane containing Zn-MOF-II nanoparticles. The maximum value of percentage rejection of oily wastewater (above 88.89%) and humic acid (above 86.88%) was obtained for the polymeric membrane containing Zn-MOF-II nanoparticles.

Fabrication, characterization, and performance evaluation of polysulfone nanocomposite membranes containing different sizes of ZIF-8 to desalination and heavy metals removal from wastewater

Due to nanotechnology’s emergence and the development of nanocomposite membranes, membrane technologies have gained significant attention in recent years. This research aims to develop a nanocomposite membrane containing ZIF-8 based on polysulfone (PSU) to remove pollutants present in wastewater. This study used a phase inversion method to prepare the desired membrane, and ZIF-8 with different sizes of 14, 23, 65, 144, and 262 nm were added to the PSU. The successful preparation of these nanocomposites was confirmed using techniques such as Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). The morphology of the prepared nanocomposites was examined using field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray analysis (EDAX), atomic force microscopy (AFM), and contact angle (CA). According to the results from performance evaluation tests, the membrane containing ZIF-8 with a size of 14 nm had the best performance. It could remove sodium and magnesium cations from water at a pressure of 7 bar with an efficiency of 57.35 % and 59.50 %, respectively. The investigations related to the removal of heavy metals also demonstrated that this membrane could remove lead by 96.25 % at a pressure of 7 bar. The removal efficiency of the membranes containing ZIF-8 in the size of 14 nm for copper, nickel, and chromium is 90.56 %, 78.81 %, and 67.10 %, respectively. Therefore, it can be claimed that the membranes, including lower sizes of ZIF-8 exhibit high efficiency in practical cases of heavy metal removal.

Simultaneous alleviating oxidative stress and scavenging uric acid via Janus polyethersulfone hemodialysis membrane loaded with urate oxidase-like nanoenzyme

The decline of renal function for the patients with end-stage kidney disease (ESKD) leads to the loss of uric acid excretion, which may reduce the prognosis of patients and increase mortality. Although hemodialysis could remove most uric acid, the long-term hemodialysis patients commonly face the problems of exacerbating oxidative stress and subsequent complications such as inflammation effects. In this work, urate oxidase-like (UOD-like) nanoenzyme is added to the blood side of polyethersulfone (PES) hemodialysis membrane by a simple double-casting phase inversion method, aiming to simultaneously achieve antioxidation and scavenge uric acid. The results demonstrate that the Janus PES/UOD membrane exhibits the ability to scavenge RNS (ABTS+, 59.75 %) and ROS (H2O2, 97.76 %; OH, 74.45 %), while efficiently clears 54.62% uric acid. In addition, the membrane has good blood compatibility and does not cause hemolysis, complement activation, or coagulation. Furthermore, the membrane exhibits the water flux of 56.83 mL/m2·h·mmHg, the urea clearance ratio of 95.33 %, and the BSA retention ratio of 99 %. Overall, we develop a promising hemodialysis membrane with antioxidant, and it opens a new route to fabricate multifunctional hemodialysis membranes.