Membrane Structure Research Articles

Influence and mechanism of typical transition metal ions on the denitrification performance of heterotrophic nitrification-aerobic denitrification bacteria

To investigate the inhibitory effects of various transition metal ions on nitrogen removal and their underlying mechanisms, the single and combined effects of Cu2+ Ni2+ and Zn2+ on Heterotrophic nitrification-aerobic denitrification (HN-AD) bacteria Acinetobacter sp. TAC-1 were studied in a batch experiment system. The results revealed that increasing concentrations of Cu2+ and Ni2+ had a detrimental effect on the removal of ammonium nitrogen (NH4+-N) and total nitrogen (TN). Specifically, Cu2+ concentration of 10 mg/L, the TN degradation rate was 55.09%, compared to 77.60% in the control group. Cu2+ exhibited a pronounced inhibitory effect. In contrast, Zn2+ showed no apparent inhibitory effect on NH4+-N removal and even enhanced TN removal at lower concentrations. However, when the mixed ion concentration of Zn2++Ni2+ exceeded 5 mg/L, the removal rates of NH4+-N and TN were significantly reduced. Moreover, transition metal ions did not significantly impact the removal rates of chemical oxygen demand (COD). The inhibition model fitting results indicated that the inhibition sequence was Cu2+ > Zn2+ > Ni2+. Transcriptome analysis demonstrated that metal ions influence TAC-1 activity by modulating the expression of pivotal genes, including zinc ABC transporter substrate binding protein (znuA), ribosomal protein (rpsM), and chromosome replication initiation protein (dnaA) and DNA replication of TAC-1 under metal ion stress, leading to disruptions in transcription, translation, and cell membrane structure. Finally, a conceptual model was proposed by us to summarize the inhibition mechanism and possible response strategies of TAC-1 bacteria under metal ion stress, and to address the lack of understanding regarding the influence mechanism of TAC-1 on nitrogen removal in wastewater co-polluted by metal and ammonia nitrogen. The results provided practical guidance for the management of transition metal and ammonia nitrogen co-polluted water bodies, as well as the removal of high nitrogen.

How to understand the effect of relative humidity on the morphology and performance of polypiperazine-amide NF membrane during heat curing process

Recent studies have shown that the temperature and time of the heat curing process have important effects on the nanofiltration (NF) membrane structure and properties. However, the mechanism of the relative humidity (RH), as one of the important factors in the heat curing of NF membranes, is still unclear. To analyze the specific effect of RH, we compared the heat curing results of the NF polyamide (PA) membranes fabricated with different monomer concentrations at various RH. The nanofiltration performance of the membranes appeared to be non-uniform when the RH was in the range of 40 %–60 %. Within the appropriate RH range, the rejection of Na2SO4 was preserved at about 98.5 % for the manufactured NF membranes. At high concentrations, the increasing RH created a discontinuous condensate layer on the PA layer surface, which affected the morphology and physicochemical properties of the NF membrane causing a doubling of pure water permeability (PWP) to 8.33 L m−2 h−1·bar−1. At low concentrations, the PA layer was not significantly changed with the increase of RH, but the evaporation of water from the smaller capillary pores in its PES substrate was slowed down, which reduced the capillary stress on the substrate and prevented the collapse of the substrate pore size, resulting in a nearly 20 times increase in its PWP to 39.7 L m−2 h−1·bar−1. This work reveals the effect of RH during heat curing and gives significant guidance to the design and synthesis of high-performance NF membranes.

Impact of cationic surfactants molecular structure on physicochemical structure and properties of polyamide reverse osmosis membrane via tailoring interfacial polymerization

Surfactants assisted interfacial polymerization (IP) has been demonstrated as an effective method to finely tailor the structure and performance of polyamide (PA) reverse osmosis (RO) membranes. However, little is done to illustrate how molecular structure of cationic surfactants affects IP and the amounts of surfactants incorporated into PA. In this study, three types of quaternary ammonium cationic surfactants were employed to assist the IP process and to fabricate RO membranes. Results show that these three cationic surfactants can not only significantly accelerate m-phenylenediamine (MPD) diffusion from aqueous phase into oil phase and promote the PA crosslinking, but also can be incorporated into PA to affect the surface properties (hydrophilicity, charge properties). Benzyl dimethyl phenyl ammonium chloride (BDMPAC) having two benzene rings had been found to be incorporated into PA with the highest amount because of its similar benzene structure as PA. Moreover, benzalkonium chloride (BAC) with the longest aliphatic tail induced a pronounced Marangoni convection during IP, resulting in an enlarged surface area of PA with large leaves and abundant internal/backside voids, and thus the highest water permeance. This study demonstrates a facile and simple way of using cationic surfactants to engineer the high-performance polyamide RO membrane.

Investigating the influence of molybdenum disulfide quantum dots coated with DSPE-PEG-TPP on molecular structures of liver lipids and proteins: An in vivo study

Molybdenum disulfide (MoS2) quantum dots (QDs) based therapeutic approaches hold great promise for biomedical applications, necessitating a thorough evaluation of their potential effects on biological systems. In this study, we systematically investigated the impact of MoS2 QDs coated with 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[amino(polyethyleneglycol)-2000](DPSE-PEG) linked with (3-carboxypropyl)triphenyl-phosphonium-bromide (TPP) on molecular structures of hepatic tissue lipids and proteins through a multifaceted analysis. The DSPE-PEG-TPP-MoS2 QDs were prepared and administered to the mice daily for 7 weeks. Liver tissues were subjected to a comprehensive examination using various techniques, including Fourier-transform infrared (FTIR) spectroscopy, UV–vis spectroscopy, and liver function tests. FTIR revealed subtle changes in the lipid composition of liver tissues, indicating potential modifications in the cell membrane structure. Also, the (CH stretching and amides I and II regions) analysis unveiled tiny alterations in lipid chain length and fluidity without changes in the protein structures, suggesting a minor influence of DSPE-PEG-TPP-MoS2 QDs on the liver’s cellular membrane and no effect on the protein structures. Further scrutiny using UV–vis spectroscopy demonstrated that DSPE-PEG-TPP-MoS2 QDs had no discernible impact on the absorbance intensities of aromatic amino acids and the Soret band. This observation implies that the treatment with SPE-PEG-TPP-MoS2 QDs did not induce significant alterations in helical conformation or the microenvironment surrounding prosthetic groups in liver tissues. The liver function tests, including ALP, ALT, AST, and BIL levels, revealed no statistically significant changes in these key biomarkers despite minor fluctuations in their values, indicating a lack of significant liver dysfunction. This study provides a detailed understanding of the effects of DSPE-PEG-TPP-MoS2 QDs on hepatic lipids and proteins, offering valuable insights into the biocompatibility and limited impact on the molecular and functional aspects of the liver tissue. These findings could be essential for the application of MoS2 QDs-based therapies.

The life cycle assessment of temporary reusable membrane structures: Case study analysis

Membrane structures represent lightweight spatial structures composed of a primary framework combined with tensioned membranes. Their popularity has increased due to their lightweight, flexible, and durable characteristics. However, as all constructions, their production and use come with an environmental impact. This study aims to assess the life cycle assessment of membrane structures with temporary use, specially focusing on the Global Warming Potential, a well-recognised indicator of greenhouse gas emissions.Using Life Cycle Assessment methodology, this research evaluates the environmental impact of membrane structures from raw material extraction to disposal. The investigation concentrates on temporary membrane structures installed multiple times across different locations within a 25-year lifespan. Two case studies, Nomad ADD-ON rental sails and Wolke Marienfeld, are analysed. The LCA of a temporary structure involves three distinct LCAs: one for the initial installation, one for each intermediate installation, and a final assessment for the end installation.Results indicate that temporary reusable membrane structures demonstrate a significant environmental impact, primarily due to the high energy consumption during manufacturing and transportation. It is essential to consider the effects of the ‘End-of-Life’ stages and the ‘benefits and loads beyond the system boundaries’ stage, particularly for temporary structures.This research aims to raise awareness about the environmental impact of temporary membrane structures and offers a framework for sustainable design and construction methods. Additionally, it explores potential strategies to reduce the environmental impact including thoughtful material choices, innovative construction practices and effective End-of-Life management.

Design and preparation of woven fabric-reinforced substrate: A new pathway for robust thin film composite membrane

The thin film composite (TFC) membrane possesses the highest commercial application potential among all types of forward osmosis (FO) membranes. The support layer of the membrane plays a crucial role in both bearing mechanical loads and facilitating the active layer formation. Herein, we addressed the issues of low permeability and poor mechanical strength of the conventional TFC FO membrane by selecting suitable fabrics and optimizing membrane design and preparation. Polyester (PS) woven fabric, with its high strength, low thickness, and high porosity, served as an excellent material for reinforcing the strength of the FO membrane. We employed a novel double-blade casting method to address the defect issue associated with the conventional single-blade casting method. The influencing factors and quality control strategies of the fabric-reinforced substrate were systematically investigated. Furthermore, membrane characterization techniques, including scanning electron microscopy (SEM), liquid-liquid displacement porometer, and cross-flow FO system, were used to reveal the influences of different substrates, including polysulfone (PSU), polyacrylonitrile (PAN), and polyetherimide (PEI), on the structure and performance of the fabric-reinforced TFC-FO membrane. Compared to commercial FO membranes, the TFC/PSU membrane exhibited superior FO performance, with a water flux of 24.1 LMH, and outstanding mechanical strength that was more than 10-times higher than that of free-standing membranes. This study demonstrates a new pathway for engineering robust TFC-FO membranes with low structural parameters as well as excellent scalability of the membrane fabrication method.

Oriented Metal-Organic Framework Membranes for Molecular Separations.

Metal-organic framework (MOF) membranes, which are recognized as state-of-the-art platforms applied in various separation processes, have attracted widespread attention. Nonetheless, to overcome the trade-off between permeability and selectivity, which is crucial for achieving efficient separation, it is important to rationally design and manipulate MOF membrane structure. Given remarkable advances in the past decade, a timely summary of recent advancement in this field has become indispensable. This review introduces major strategies for fabricating oriented MOF membranes, including in situ growth, contra-diffusion method, interface-assisted approach, and laminated nanosheet assembly. New insights into their updated progress and potential are elucidated. Of particular note, recent development and emerging applications of oriented MOF membranes, illustrating their potential to address environmental and energy challenges, are highlighted. Finally, remaining challenges facing their bath production and practical applications are discussed.

Role of covalent crosslinking and 2D nanomaterials in the fabrication of advanced organic solvent nanofiltration membranes: A review of fabrication strategies, recent advances, and challenges

Organic solvent nanofiltration (OSN) membranes have gained significant attention owing to their pivotal role in various industrial applications, including pharmaceuticals, fine chemicals, and manufacturing. This review provides a comprehensive overview of the recent advances in OSN membrane technology, focusing on membrane materials, fabrication techniques, and strategies for tuning the chemistry, structure, and performance of OSN membranes. Initially, the fundamental principles underlying OSN are described, highlighting the critical parameters influencing membrane selectivity, permeability, and stability in organic solvents. It also focuses on the importance of covalent crosslinking in the design and fabrication of dense polyamide membranes. Subsequently, the design and synthesis of novel membrane materials are discussed, including polymeric, inorganic, and hybrid membranes. The use of 2D nanomaterials is summarized, with an emphasis on their structural characteristics and tailored properties for solvent separation applications. We further explored the innovative fabrication strategies, such as interfacial polymerization, modification of ultrafiltration supports, and tuning of the active layer chemistry by incorporating the membrane structure with porous nanofillers. This review also discusses the inhomogeneity issues between inorganic nanofillers and organic matrices of membranes as well as the strategies to overcome these limitations through proper functionalization. Finally, we identified emerging trends and prospects in OSN membrane research, encompassing sustainability, scalability, and integration with other membrane processes, to address existing challenges and discover new opportunities for efficient solvent separation in diverse industrial sectors.

Highly efficient and selective nitrate and Hg(II) removal from wet oxidation flue gas purification wastewater using bifunctional MXene nanofiltration membrane

The wet oxidation process is a promising method for simultaneously removing SO2, NO, and Hg0 from coal-fired flue gas. However, the resource utilization of the resulting wastewater, which is enriched with complex ions such as Hg2+, NH4+, NO3−, and SO42−, remains a significant challenge. To achieve the simultaneous goals of concentrating NH4+/NO3−/SO42− ions, adsorbing and separating Hg2+ ions, and reusing wastewater, a bifunctional MXene composite nanofiltration membrane with large interlayer spacing and excellent electrostatic repulsion was developed. The membrane was prepared by co-depositing MXene nanosheets, carboxylated multi-walled carbon nanotubes (MWCNTs), and sodium dodecyl sulfate (SDS) onto an NF-90 membrane. The resulting MXene-MWCNTs-SDS (MMS-COOH) composite membrane demonstrated exceptional salt rejection of 84.4 % for NO3−, 89.0 % for NH4+, 99.8 % for SO42−, and 99.7 % for Hg2+. After 30 cycles, the membrane structure remained stable, maintaining good reusability, with NH4+ and SO42− rejection still reaching 90.0 %. Moreover, the maximum adsorption capacity for Hg2+ was 2869.6 mg g−1, while the capacities for Cr6+ and Pb2+ were 577.6 and 316.8 mg g−1, respectively. The MMS-COOH composite membrane introduces an innovative method for the benign treatment of wet oxidation flue gas purification wastewater and facilitates the recovery of (NH4)2SO4 and NH4NO3 as fertilizers, holding a promising application prospect.

Genetically programmable cell membrane-camouflaged nanoparticles for targeted combination therapy of colorectal cancer

Cell membrane-camouflaged nanoparticles possess inherent advantages derived from their membrane structure and surface antigens, including prolonged circulation in the bloodstream, specific cell recognition and targeting capabilities, and potential for immunotherapy. Herein, we introduce a cell membrane biomimetic nanodrug platform termed MPB-3BP@CM NPs. Comprising microporous Prussian blue nanoparticles (MPB NPs) serving as both a photothermal sensitizer and carrier for 3-bromopyruvate (3BP), these nanoparticles are cloaked in a genetically programmable cell membrane displaying variants of signal regulatory protein α (SIRPα) with enhanced affinity to CD47. As a result, MPB-3BP@CM NPs inherit the characteristics of the original cell membrane, exhibiting an extended circulation time in the bloodstream and effectively targeting CD47 on the cytomembrane of colorectal cancer (CRC) cells. Notably, blocking CD47 with MPB-3BP@CM NPs enhances the phagocytosis of CRC cells by macrophages. Additionally, 3BP, an inhibitor of hexokinase II (HK2), suppresses glycolysis, leading to a reduction in adenosine triphosphate (ATP) levels and lactate production. Besides, it promotes the polarization of tumor-associated macrophages (TAMs) towards an anti-tumor M1 phenotype. Furthermore, integration with MPB NPs-mediated photothermal therapy (PTT) enhances the therapeutic efficacy against tumors. These advantages make MPB-3BP@CM NPs an attractive platform for the future development of innovative therapeutic approaches for CRC. Concurrently, it introduces a universal approach for engineering disease-tailored cell membranes for tumor therapy.

Design an in-situ anti-bacterial structure of nanofiltration membrane with a novel bisimidazoline aqueous monomer

Bio-fouling is a key issue for the nanofiltration operation. In this study, 1, 2-bis (N-aminoethyl imidazoline) ethane (BAIE) firstly was used as a novel bisimidazoline aqueous monomer to prepare the anti-bacterial nanofiltration (NF) membranes. A novel nanofiltration (BAIE-TMC NF) membrane with in-situ anti-bacterial structure and anti-fouling property was fabricated via interfacial polymerization (IP) with trimesoyl chloride (TMC), basing on a polyethersulfone (PES) substrate. Protonated imidazole endowed the surface of BAIE-TMC NF membrane with weak electronegativity, and its salt rejection sequence was MgSO4 > Na2SO4 > MgCl2 > NaCl > LiCl. Meantime, the BAIE-TMC NF membrane with 0.5 wt% BAIE (M-0.5) exhibited a high rejection for bivalent ions, with a high MgSO4 rejection (94.7 %). Notably, BAIE-TMC NF membrane containing an in-situ anti-bacterial imidazole structure showed significant anti-fouling and anti-bacterial properties. After BSA or HA filtration process, the flux recovery rates of all BAIE-TMC NF membranes were higher than 95 %, and M-0.5 exhibited high inhibition performance against Escherichia coli (98.5 %) and Staphylococcus aureus (98.4 %). Furthermore, M-0.5 exhibited excellent long-term separation stability during the three weeks separation experiment. BAIE can serve as an effective aqueous monomer for fabricating in-situ anti-bacterial and anti-fouling NF membrane to achieve the rejection of organic pollutant and bivalent ions.

Effects of steady-state fluid-structure interactions on air-supported membrane structures subjected to wind actions

With the perspective of static aeroelasticity, steady-state influences of fluid-structure interaction (FSI) on wind loads and responses of rectangular-planed air-supported membrane structure (ASMS) are investigated in this study. Steady-state FSI simulations are performed by coupling Reynolds-averaged computational fluid dynamics solving wind loads and static finite element analysis solving structural deformations. The feasibility of these simulations is validated with wind tunnel tests concerning time-averaged results. In contrast to analysis without static aeroelasticity, significant variations in wind pressure distributions and amplifications on structural wind responses due to steady-state FSI effects are observed. Subsequently, influencing factors and mechanisms of steady-state FSI effects are analyzed. These time-averaged effects are more significant with the increasing magnitude of structural wind actions, lower internal pressures and less membrane tensile stiffness. Though unlikely to induce irreversible effects as shell structures, the buckling of ASMS can make steady-state FSI more pronounced because of the coupling between stronger flow separation and larger membrane deformations. Accompanied with steady-state FSI, such buckling effect usually contributes to varying locations of the structural maximum responses and noticeable increases in response amplification factors, which deserves attentions in practice. Practically, it is realizable to evaluate these steady-state FSI effects above with simulations because of the much lower computational cost and reliable accuracy.

Mechanism, structural and functional insights into nidovirus-induced double-membrane vesicles.

During infection, positive-stranded RNA causes a rearrangement of the host cell membrane, resulting in specialized membrane structure formation aiding viral genome replication. Double-membrane vesicles (DMVs), typical structures produced by virus-induced membrane rearrangements, are platforms for viral replication. Nidoviruses, one of the most complex positive-strand RNA viruses, have the ability to infect not only mammals and a few birds but also invertebrates. Nidoviruses possess a distinctive replication mechanism, wherein their nonstructural proteins (nsps) play a crucial role in DMV biogenesis. With the participation of host factors related to autophagy and lipid synthesis pathways, several viral nsps hijack the membrane rearrangement process of host endoplasmic reticulum (ER), Golgi apparatus, and other organelles to induce DMV formation. An understanding of the mechanisms of DMV formation and its structure and function in the infectious cycle of nidovirus may be essential for the development of new and effective antiviral strategies in the future.

1D Topological Interface States for Improving Optical Sensors

AbstractThe field of compact optical microcavities has received significant research in the past decades, and a broad range of cavity‐based micromechanical sensors has been demonstrated. The present approach replaces the frequently employed, complex etched cantilever and membrane structures with a simple thin‐film system based on a compressible photonic microcavity to achieve pressure‐sensitive wavelength shifting of resonant modes. The effects of a topological dielectric mirror architecture on the light propagation in the system are extensively investigated. Topologically improved light‐matter interaction is experimentally demonstrated for systems where thin‐film devices are mounted on one side of the photonic cavity due to mechanical constraints. Coupled topological states are examined under the aspect of mode splitting and exhibit advantageous splitting tunability compared to non‐topological systems. The findings are complemented by the proposal of a simple spectral evaluation method allowing significant improvement in the precision of integrated Fabry‐Pérot sensors. The readout concept of the presented sensor allows a scalable improvement of the measurement precision by evaluating the resonant‐mode order in the deformable cavity. The experimental results and conceptual advancements provide pathways for significant improvements addressing the efficiency of light‐matter interaction in Fabry‐Pérot cavities and the readout precision of sensors incorporating thin‐film photodiodes in multimode photonic cavities.

Cell-Impermeable Buffering Fluorogenic Probes for Live-Cell Super-Resolution Imaging of Plasma Membrane Morphology Dynamics.

Super-resolution fluorescence imaging has emerged as a potent tool for investigating the nanoscale structure and function of the plasma membrane (PM). Nevertheless, the challenge persists in achieving super-resolution imaging of PM dynamics due to limitations in probe photostability and issues with cell internalization staining. Herein, we report assembly-mediated buffering fluorogenic probes BMP-14 and BMP-16 exhibiting fast PM labeling and extended retention time (over 2 h) on PM. The incorporation of alkyl chains proves effective in promoting the aggregation of BMP-14 and BMP-16 into nonfluorescent nanoparticles to realize fluorogenicity and regulate the buffering capacity to rapidly replace photobleached probes ensuring stable long-term super-resolution imaging of PM. Utilizing these PM-buffering probes, we observed dynamic movements of PM filopodia and continuous shrinkage, leading to the formation of extracellular vesicles (EVs) using structured illumination microscopy (SIM). Furthermore, we discovered two distinct modes of EV fusion: one involving fusion through adjacent lipids and the other through filamentous lipid traction. The entire process of EV fusion outside the PM was dynamically tracked. Additionally, BMP-16 exhibited a unique capability of inducing single-molecule fluorescence blinking when used for cell membrane staining. This property makes BMP-16 suitable for the PAINT imaging of cell membranes.

Photosynthesis and stress response of coal fly ash on stem elongation in wheat.

Coal is one of the primary energy sources in China and is widely used for electricity generation. Crops growing in overlapped areas of farmland and coal resources (OAFCR) suffer from coal fly ash stress, especially during stem elongation, which is a key stage that impacts wheat yield and is sensitive to environmental stress. As a primary food crop of China, wheat is essential for food security. However, the characteristics of wheat under the combined stress of fly ash and various heavy metals have not been sufficiently investigated. In this study, we explored the response of stem elongation in wheat to different levels of coal fly ash stress and determined the content of heavy metals (HMs) in wheat leaves. We found that with an increase in fly ash content, the Cu content in the shoots increased, while that in the roots decreased. Coal fly ash exposure reduced the proportions of Pb and Zn in the cytoderm, and the proportion of Cu in the soluble constituents decreased from 58.3% to 45.7%. Total chlorophyll, chlorophyll a, and chlorophyll b levels decreased significantly, whereas peroxidase (POD) and catalase (CAT) activities generally increased with increasing fly ash dose. Meanwhile, chloroplasts, mitochondria, and their internal structures were damaged, and the cell structures of leaves, such as the internal membrane structure, were damaged.

Surface re-modification based on poly-(triazine-amine) from commercial nanofiltration membrane to reverse osmosis membranes with improved antifouling property

Reverse osmosis (RO) has been limited by membrane fouling, which reduces membrane performance, shortens membrane service life, and increases operating costs. This study designed a new poly-(triazine-amine) reverse osmosis (PTA1-RO) membrane that uses a commercial membrane as the substrate for remodification with better anti-fouling performance based on the interfacial polymerization (IP) reaction between piperazine (PIP) and cyanuric chloride (CC). The PTA1-RO membrane has a rejection of 97.8 % for NaCl and a water permeance of 1.56 L m−2·h−1 bar−1. The PTA coating filled the “ridge-valley” structure of the polyamide membranes, reducing surface roughness and enhancing antifouling property. As much as 90 % and 100 % flux recovery of BSA and HA were achieved by PTA1-RO membrane, significantly higher than the current state-of-the-art commercial RO membranes SW30 and BW30.

Construction and performance of photo-thermal dual-responsive drug release patches with sandwich-structure based on electrospun

Designing and preparing smart drug release systems suitable for application are important in medicine. In the present work, sandwich-structured drug patches with photo-thermal dual-responsive properties were designed and fabricated based on electrospinning technology and post-assembly. The target sandwich-structured patch comprised of a UV-responsive electrospun membrane and a skin-contacting electrospun gel membrane. The porous structure of the electrospun membrane and electrospun gel endowed the patch’s excellent moisture retention and gas permeability which could ensure the breathe of the skin and prevent from hurting of permeating water at the same time. Moreover, the viscosity properties of the skin contacting layer caused the patches’ good adhesion properties, resulting in improved the long term adheres to the skin. Then drugs and temperature-sensitive substances were clamped in the interlayers of the sandwich-structured patch which was sealed by polyvinylpyrrolidone-silica (PVP-SiO2) electrospinning solution. Thus, the sandwich-structured patches not only exhibited photo-thermal responsive properties but also presented heightened drug carrying capacity and versatile applicability across various drugs.

Fabrication of PVDF membranes via γ-ray irradiation and investigation into their membrane formation mechanisms and water treatment properties

Polyvinylidene fluoride (PVDF) membrane is a cheap and commonly used separation material, but its inherent hydrophobicity results in significant membrane contamination, which limits its engineering application and further development. The hydrophilic PVDF-g/co-NVP membrane was prepared through low-dose γ-ray irradiation and using N-vinyl-2-pyrrolidinone (NVP) as a modifier in this study. The effects of γ-ray dose and incorporating NVP additive on the microstructure, hydrophilicity, anti-fouling capability, and mechanical capacity of membranes were discussed. Molecular dynamics (MD) simulation method was used to comprehensively investigate the impact of the NVP on the physicochemical characteristics of membrane structure. Under a specific NVP load, the water contact angle of the membrane decreases from 87.92° to 52.66°. The pure water permeance reaches 362.1 L/m2 h, and the porosity increases to 55.21 %±1.29 %, which indicates that γ-ray irradiation with NVP addition can effectively adjust the pore structure and hydrophilicity of the membrane. During anti-fouling test against bovine serum albumin (BSA), the modified membrane exhibits remarkable anti-fouling characteristics, including reduced BSA accumulation, enhanced flux recovery, lower irreversible contamination level, and extended cleaning cycle compared with the original pure PVDF membrane because of its higher hydrophilicity and positive zeta-potential value. This study elucidates the mechanism underlying γ-ray graft modification of PVDF membranes, thereby providing valuable insights into the development of efficient functional membrane materials.

Nanoconfined Strategy Optimizing Hard Carbon for Robust Sodium Storage

AbstractDeveloping non‐graphitic carbons with unique microstructure is a popular strategy to enhance the significant potential in practical applications of sodium‐ion batteries (SIB), while the electrochemical performance imbalances arising from their intricate active surface and porous structure pose significant challenges to its commercialization. Inspired by the structure of biological cell membranes, N/P co‐doped hard carbon nanospheres (NPCS) anodes with abundant ultramicropores (≈0.6 nm) are proposed and synthesized as robust sodium anodes. Based on density functional theory calculations, optimizing ultramicropores can enable small Na+ to be well confined within the pores and hinder large solvent molecules from invading and reacting, introducing N/P species contributes to the rapid adsorption/diffusion of Na+. In situ XRD and Raman analysis suggest that the nanoconfinement strategy induced by abundant ultramicropores and N/P co‐doping enables highly reversible electrochemical reactions. Electrochemical test confirms that the nanoconfinement strategy endows the NPCS anode with high reversible capacity (376.3 mAh g−1 at 0.1 A g−1), superior initial coulombic efficiency (87.3% at 1.0 A g−1), remarkable rate capability (155.6 mAh g−1 at 50.0 A g−1) and excellent cycling stability (with capacity retention of ≈94.6% after 10 000 cycles), lightening a promising avenue for developing SIB with robust durability.