M2 Membrane Research Articles

Membrane Percrystallization for Production of Lithium Salt and Basic Compounds

Abstract Membrane percrystallization is an emerging and productive crystallization technology. In this research, experiments using sugar-derived carbon membranes demonstrate the production of lithium hydroxide, carbonate, chloride, sulfate and acetate, from feed solutions with concentrations ranging from 1 to 20 wt.% (weight solute/weight solution). Sugar-derived carbon membranes were coated on a porous alumina substrate via vacuum impregnation and pyrolysis resulting in a tailorable porosity and homogenous membrane which was chemically robust over a wide range of solution chemistries. The highest flux was for 20 wt.% lithium chloride solution, equivalent to an annual salt production rate of 70 t for 1 m2 of membrane. The percrystallizer productivity was 54 times higher than evaporative crystallization, shown by comparing the membrane surface area to the exposed surface area of a stirred solution–vacuum interface of an evaporative crystallizer at equivalent conditions of initial solution composition, temperature, and vacuum. The percrystallized solids were characterized in terms of their microstructures, crystal structure, and chemical compositions via scanning electron microscopy, x-ray diffraction, and thermogravimetric analysis, providing the first information of this type for lithium salts and basic compounds produced using this new technology.

Preparation of Highly Antibacterial MXene Nanofiltration Membranes and Investigation of Their Separation Performance.

In this study, polyethersulfone (PES)/sulfonated polyethersulfone (SPES) composite nanofiltration membranes doped with different contents of monolayer titanium carbide nanosheets (Ti3C2TX) were prepared by the nonsolvent induced phase inversion (NIPS) method. The effects of Ti3C2TX on membrane structure, separation performance and antibacterial activity were investigated systematically. The results demonstrated that the viscosity of the casting solution increased significantly with the increasing content of Ti3C2TX. In addition, the pore size of the membrane surface first decreased and then increased; porosity and hydrophilicity were optimized synchronously; and the density of negative charges on the surface increased. The M2 membrane showed a rejection rate of more than 90% for Metanil yellow (MY) and methylene blue (MEB). The order of salt ion rejection rates was magnesium sulfate (MgSO4) > sodium sulfate (Na2SO4) > sodium chloride (NaCl), and water flux reached the peak (18.5 L/m2·h·bar). The antibacterial activity of the M2 membrane was significantly enhanced, and its antibacterial rate against Bacillus subtilis increased from 15% (M0) to 58%. This phenomenon was attributed to the synergistic mechanism of the Ti3C2TX physical capture effect, reactive oxygen species (ROS) generation and sharp edge damage to bacterial cell membranes. This study provides theoretical support and a technical path for the development of MXene composite membranes with high separation efficiency and excellent antibacterial properties.

Testing Low-Density Polyethylene Membranes for Lithium Isotope Electromigration System.

The growing energy demand has emphasized the importance of developing nuclear technologies and high-purity lithium isotopes (6Li and 7Li) as raw materials. This study investigates how voltage and migration time affect two types of low-density polyethylene membranes-one impregnated with ionic liquids and the other non-impregnated-for lithium isotope separation via electromigration from a lithium-loaded organic phase to an aqueous solution. We developed a laboratory-made setup for high-precision lithium isotope measurements (2RSD = ±0.30‱) of natural carbonate samples (LSVEC) and an optimized protocol for isotope ratio measurements using quadrupole ICP-MS with the sample-standard bracketing method (SSB). The results document that both impregnated and non-impregnated membranes can achieve promising 6Li enrichment under different environmental conditions, including ionic liquids and organic solutions in the cathode chamber. Lithium-ion mobility is influenced by voltage in an environment assisted by 0.1 mol/L tetrabutylammonium perchlorate and increases quasi-linearly from 5 to 15 V. Between 20 and 25 h, the lithium-ion concentration had the maximum value, after which the trend declined. In the BayesGLM model, we incorporated all data and systematically eliminated those with a low enrichment factor, either individually or in groups. Our findings indicated that the model was not significantly affected by the exclusion of measurements with low α. This suggests that voltage and migration time are crucial, and achieving a better enrichment factor depends on applying the optimal ratio of ionic liquids, crown ethers, and organic solvents. Ionic liquids used for impregnation sustain enrichment in the first hours, particularly for 7Li; however, after 25 h, 6Li demonstrated a higher enrichment capacity. The maximum single-stage separation factor for 6Li/7Li was achieved at 24 and 48 h for an impregnated membrane M2 (α = 1.021/1.029) and a non-impregnated membrane M5 (α = 1.031/1.038).

Relationship of Additive Dosages to Polyvinylidene Fluoride (PVDF) Ultrafiltration: Dye Rejection Study

Ultrafiltration membrane is often used in wastewater treatment plants to remove dyes and other contaminations. This study aims to improve the properties and methylene blue rejection efficiency of the polyvinylidene fluoride (PVDF) ultrafiltration (UF) membranes by introducing copper acetate monohydrate/magnesium sulphate (CuMgNTs) at different loading dosages. The flat sheet membranes were successfully fabricated using the phase inversion method. The physicochemical properties of membranes were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) and Fourier transform infrared spectroscopy (FT-IR). The pure water flux tests showed that the M3 membrane with 3wt.% of CuMgNTs loading exhibits the highest pure water flux of 47 L/m2h. For methylene blue rejection efficiency M3 membrane possessed the highest rejection efficiency up to 94%. The M3 membrane performance showed an increase in pure water flux and methylene blue dye rejection up to 224% and 74%, respectively, compared to pristine PVDF membrane. Therefore, it can conclude that 3wt.% of CuMgNTs is the optimum loading for PVDF UF membrane in improving its permeability towards pure water and performance to reject methylene blue dyes.

Hyperbranched polyester amide/polyethersulphone mixed matrix nanofiltration membranes for contaminant rejection.

Nanofiltration (NF) separation technology is a low-pressure filtration process, which is highly efficient and environmentally friendly. As a result, it has found wide application in water treatment. This work describes the preparation of flat sheet membranes via the phase inversion method using blends of hyperbranched polyester amide (PEA) and polyether sulphone (PES) in definite ratios. The obtained mixed matrix membranes were characterized using FTIR, TGA and contact angle analysis, and their morphologies were investigated using SEM. SEM images showed a porous membrane with micro-voids found underneath, confirming the suitability of the membranes for nanofiltration. Adding PEA to PES changed the porosity, which changed the membrane performance. Examining the removal of heavy metals [Pb(NO3) and CuSO4] using the prepared membranes revealed that the NF membranes had a higher salt rejection efficiency than pure PES with a good permeate flux. M3 membrane showed 81% rejection of Pb (NO3)2, while M2, the membrane with a low PEA ratio, rejected 85%, with high water flux for both membranes. Moreover, the presence of PEA in the membrane tissue led to protein rejection up to 99.5%. Thus, these novel blend membranes proved themselves as NF-type membranes with better performance in water treatment.

Fabrication of anti-fouling and self-cleaning PHI modified PVDF membranes for high-flux dye removal.

The large pore size of ultrafiltration membranes presents a challenge in rejecting small molecules and the accumulated contaminants on the membrane surface severely restrict the treatment efficiency and shorten the lifespan of separation membranes. Herein, poly(heptazine imide) (PHI) is utilized as a modifier to fabricate anti-fouling and self-cleaning polyvinylidene fluoride (PVDF) membranes for high-flux dye removal. The introduction of PHI does not affect the rejection performance of bovine serum albumin (>97%), whilst improving the water permeability and mechanical strength of membranes. The anti-fouling ability is also significantly enhanced with a flux recovery ratio of 91.61%. In addition, the rejection performance of PHI modified PVDF (PHI/PVDF) membranes for anionic dyes, especially for those of low molecular weight, is obviously improved. The rejection ratios of Congo red (CR) and orange G are 99.8% and 87.4%, respectively, and rejection performance for methyl orange is increased from 22.0% (pure PVDF membrane) to 62.5% (M3 membrane with 3 g PHI added). Furthermore, in the presence of anionic dye (such as CR), 99.3% of methylene blue, 91.8% of malachite green and 95.9% of basic red 46 can be rejected and approximately 613 L m-2 of 50 mg per L CR solution can be processed after 2 h of operation, with the rejection ratio consistently above 98%. The accumulated CR dyes on PHI/PVDF membranes can be easily self-cleaned within 60 min by the H2O2-assisted photocatalytic reaction, effectively solving the problem of membrane fouling.

Host cellular protein RAB33B facilitates influenza viral replication and modulates M2 trafficking by enhancing autophagy

Influenza A virus (IAV) remains a major global health threat. Its M2 protein plays crucial roles in viral fusion, transportation, assembly, and release. Recent studies have shown that IAV impairs host autophagy flux to enhance viral replication. However, the precise mechanisms by which IAV M2 manipulates host cellular autophagy during virus replication remain unclear. In this study, we analysed cellular transcriptional responses of cells to IAV M2 overexpression and identified RAB GTPase protein RAB33B as a key factor. RAB33B was significantly up-regulated by IAV M2 and promoted IAV replication by enhancing autophagy. We further found that autophagy regulates the interaction of IAV M2, RAB33B, and LC3, facilitating M2 membrane trafficking through autophagic-like vesicles. In addition, ATG16L1 (an effector of RAB33B) and TBC1D25 (a GTPase-activating protein for RAB33B) contributed to IAV M2-induced autophagy, thereby affecting viral replication. Collectively, our findings reveal a novel mechanism in which RAB33B is essential for IAV M2 trafficking to the plasma membrane, facilitating viral replication through enhanced autophagy. These insights shed new light on the autophagy-based cellular transport mechanisms of IAV M2 and highlight potential antiviral targets.

Dynamic simulation of solar-powered desalination with integrated photovoltaic/thermal collectors and membrane distillation

This study describes a computational model that simulates the behaviour of a solar-powered desalination system. The model incorporates photovoltaic/thermal (PVT) collectors and direct contact membrane distillation (DCMD). A novel DCMD unit model was established and verified using existing data from the literature and the model was incorporated into the TRNSYS library. The effect of feed water mass flow rate and temperature on production was investigated through a parametric analysis. The PVT-DCMD system was modeled, analyzed, and dynamically simulated for the month of June in Algeria using TRNSYS software. Results show that the PVT collector's outlet solar fluid temperature ranges from 20 °C to 85 °C, providing 5000 kJ/hr of useful energy for seawater desalination through a heat exchanger. Meanwhile, the auxiliary heater utilizes around 10,000 kJ/hr of solar energy. The simulation demonstrates the feasibility and effectiveness of using PVT collectors with a DCMD system for seawater desalination, achieving a distillate production rate of approximately 12 L/hr.m2 of membrane.

Sustainable Pb(II) Removal and Recovery from Wastewater Using a Bioinspired Metal-Phenolic Hybrid Membrane with Efficient Regeneration.

High-performance adsorbents often require efficient selectivity in wastewater, recoverability, and ease of multiple regeneration cycles, but achieving this remains a significant challenge. We report a new strategy for the efficient removal of lead (Pb(II)) from contaminated water streams using an innovative tannic acid (TA)-Fe(III)-based metal-phenolic network (MPN) hybrid membrane (MPN-PAM). This novel membrane exploits the tunable pH-sensitive coordination structure of the MPN to achieve selective removal and recovery of Pb(II) while enabling efficient membrane regeneration by filtration. This membrane demonstrates superior selectivity for Pb(II) with a removal efficiency of up to 98 % and an adsorption capacity of approximately 117.58 mg/g, even in the presence of high salinity, as well as coexisting heavy metals. The membrane maintains high Pb(II) removal efficiency over 20 consecutive cycles and 95 % efficiency over 10 regeneration cycles. Under continuous operation, it treats approximately 85 L per m2 of membrane, reducing Pb(II) concentrations to trace levels (~40 μg/L), meeting electroplating wastewater standard (GB21900-2008). Additionally, even low concentrations of Pb(II) (<5 mg/L) are efficiently purified to below WHO drinking water standard (10 μg/L). The operational cost for treating Pb(II)-contaminated wastewater is about $0.13 per ton, highlighting the cost-effectiveness and potential for large-scale application in wastewater treatment.

Macrophage membrane-encapsulated miRNA nanodelivery system for the treatment of hemophilic arthritis

Macrophage membrane-encapsulated miRNA nanodelivery system for the treatment of hemophilic arthritis

Refinery oily wastewater treatment using PVC/SiO2 ultrafiltration membranes

Abstract Polyvinyl chloride (PVC)/SiO2 membranes were prepared and characterized for ultrafiltration of oily wastewater from Tabriz Oil Refinery. The results showed that the addition of SiO2 into the membranes increased the density of surface pores. The contact angle decreased from 78.89° for the PVC membrane to 63.16° for the 0.75% PVC/SiO2 membrane, indicating that the presence of SiO2 resulted in enhancement of hydrophilicity. In addition, the pure water flux of the membranes witnessed an increasing trend with increasing SiO2 content. The mechanical tensile strength of the membranes was enhanced as a result of the reinforcement effect of nanoparticles. The results of filtration revealed that the antifouling properties and rejection of the composite membranes were higher than those of the PVC membrane because of the presence of SiO2. Membrane M3 containing 0.75 wt.% SiO2 nanoparticles exhibited a rejection of 84.19%, a total fouling ratio (TFR) value of 31.7% and an irreversible fouling ratio (IFR) value of 6.4%. In general, PVC/SiO2 membranes exhibited acceptable performance and can be tested for separation applications.

Innovation of poly(ionic liquid)-stabilized TiO2 for membrane-based dye waste remediation

Innovation of poly(ionic liquid)-stabilized TiO2 for membrane-based dye waste remediation

Bioinspired black phosphorus delivers histone deacetylase inhibitor-induced synergistic therapy for lung cancer

Bioinspired black phosphorus delivers histone deacetylase inhibitor-induced synergistic therapy for lung cancer

Investigating novel thin-film nanocomposite membranes for sustainable water recovery using fertilizer-driven forward osmosis – Experimental and machine learning approaches

Investigating novel thin-film nanocomposite membranes for sustainable water recovery using fertilizer-driven forward osmosis – Experimental and machine learning approaches

Preparation of TA-O-MoS2/PES mixed matrix ultrafiltration membrane for rare earth wastewater treatment

Preparation of TA-O-MoS2/PES mixed matrix ultrafiltration membrane for rare earth wastewater treatment

Desalination Performance Evaluation of hBN@UiO‐66 MOF Incorporated Hollow Fiber Membrane using Membrane Distillation

Abstract In the present study, the polyvinylidene fluoride (PVDF) modified hollow fiber (HF) membranes have been synthesized by dry‐jet wet phase inversion technique for desalination via direct contact membrane distillation (DCMD). UiO‐66 metal‐Organic framework (MOF) and surface‐modified UiO‐66 with h‐BN nanomaterial have been incorporated with PVDF‐HF membrane. The various analytical methods like FE‐SEM, FTIR, PXRD, TGA, tensile strength, were used to characterize prepared MOF and HF membranes. It was observed from DCMD results that the h‐BN@UiO‐66/PVDF (M3) HF membrane gives higher flux than UiO‐66/PVDF (M2) and pure PVDF (M1) membrane. In the present investigation, response surface methodology (RSM) by box‐behnken design (BBD) was used to optimize the DCMD system and evaluate the behavior of operating parameters such as feed temperature, feed concentration, and feed flow rate. The optimum operating values of feed temperature, feed flow rate, and feed concentration were found as 65 °C, 1 LPM, and 1.5 wt.%, respectively. Under optimum conditions, the M3 HF membrane gives the highest flux of 26.78 L/m2 ⋅ h compared to M2 and M1 membranes. During DCMD, salt rejection is almost greater than 99.8 % for all prepared membranes. Other salts like potassium chloride (KCl), Magnisium Sulphate (MgSO4), and calcium sulphate (CaSO4) are also used to check salt rejection of all membranes at optimum operating conditions. Moreover, the M3 membrane exhibits stable permeate flux and high salt rejection (&gt;99.9 %) at optimized process parameters over 80 h running. Overall, the present study provides the positive effects of h‐BN nanoparticles and UiO‐66 MOF on HF membrane to improve performance in DCMD.

Exercise Intolerance in McArdle Disease: A Role for Cardiac Impairment? A Preliminary Study in Humans and Mice.

Whether cardiac impairment can be fully discarded in McArdle disease-the paradigm of "exercise intolerance," caused by inherited deficiency of the skeletal muscle-specific glycogen phosphorylase isoform ("myophosphorylase")-remains to be determined. Eight patients with McArdle disease and seven age/sex-matched controls performed a 15-min moderate, constant-load cycle-ergometer exercise bout followed by a maximal ramp test. Electrocardiographic and two-dimensional transthoracic (for cardiac dimension's assessment) and speckle tracking (for left ventricular global longitudinal strain (GLS) assessments) echocardiographic evaluations were performed at baseline. Electrocardiographic and GLS assessments were also performed during constant-load exercise and immediately upon maximal exertion. Four human heart biopsies were obtained in individuals without McArdle disease, and in-depth histological/molecular analyses were performed in McArdle and wild-type mouse hearts. Exercise intolerance was confirmed in patients ("second wind" during constant-load exercise, -55% peak power output vs controls). As opposed to controls, patients showed a decrease in GLS during constant-load exercise, especially upon second wind occurrence, but with no other between-group difference in cardiac structure/function. Human cardiac biopsies showed that all three glycogen phosphorylase-myophosphorylase, but also liver and especially brain-isoforms are expressed in the normal adult heart, thereby theoretically compensating for eventual myophosphorylase deficiency. No overall histological (including glycogen depots), cytoskeleton, metabolic, or mitochondrial (morphology/network/distribution) differences were found between McArdle and wild-type mouse hearts, except for lower levels of pyruvate kinase M2 and translocase of outer-membrane 20-kDa subunit in the former. This study provides preliminary evidence that cardiac structure and function seem to be preserved in patients with McArdle disease. However, the role for an impaired cardiac contractility associated with the second wind phenomenon should be further explored.

Effect of surfactants on the permeation rate and selectivity of polyamide composite membranes for organic solvent nanofiltration

Effect of surfactants on the permeation rate and selectivity of polyamide composite membranes for organic solvent nanofiltration

Surface functionalization of polytetrafluoroethylene membrane by polydopamine and quaternary ammonium compound for fouling mitigation in membrane distillation of secondary effluent

Surface functionalization of polytetrafluoroethylene membrane by polydopamine and quaternary ammonium compound for fouling mitigation in membrane distillation of secondary effluent

Green polycaprolactone/sulfonated kraft lignin phase inversion membrane for dye/salt separation

Exploring environmentally friendly, renewable, and cost-effective raw materials is essential in sustainable membrane fabrication. This study presents a facile and scalable method for fabricating a green and biodegradable tight ultrafiltration membrane for dye/salt separation. This involves simply blending biodegradable polycaprolactone (PCL) with the low-cost biobased sulfonated kraft lignin (SKL) additive. Additionally, we employed acetic acid as a green alternative solvent to enhance the sustainability of the membrane fabrication process. The incorporation of hydrophilic SKL into the PCL matrix resulted in increased hydrophilicity (water contact angle changed from 72° to 56°), surface roughness (increased from 29 nm to 43.5 nm), and enhanced negative electrostatic charge of the membrane (−40 mV to −45 mV). The optimized PCL/SKL membrane (M3) exhibited excellent water flux (∼45 LMH) under 40 psi hydraulic pressure coupled with ∼98 % and ∼10 % rejection rates for reactive red (RR) dye and NaCl, respectively. Moreover, the M3 membrane maintained its exceptional dye/salt fractionation performance while separating the mixtures at low salt concentrations. However, with increasing salt concentration (1–50 g/L), the membrane's RR dye rejection declined from ∼90 % to ∼50 %, with a significant reduction in NaCl and Na2SO4 salts rejection (from ∼14 % to ∼1 % and ∼22 % to –∼1 %, respectively). The M3 membrane exhibited remarkable antifouling properties during dye and humic acid filtration with a high flux recovery ratio (>98 %) and low flux decline rate (<7 %). The PCL/SKL membrane also showed excellent stability and maintained consistent separation performance over a long period. Overall, the novel biodegradable PCL/SKL membrane prepared in this study presents a promising avenue toward sustainable membrane fabrication for wastewater treatment applications.