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In this work, through a room-temperature template method, Al2O3 was in situ grown on the surface and between the pores of a PVDF–CA composite membrane to increase the electrolyte affinity of the membrane and promote the ionic conductivity and lithium-ion mobility. [ABSTRACT FROM AUTHOR]

The imidazole functionalized poly (phenyl ether) (PPO) is chosen as the organic matrix. UiO-66-NH 2 is prepared by hydrothermal reaction. Then amino modified cationic groups functional Y-UiO-66 as fillers is introduced into the PPO substrates to fabricate composite membranes (called Im-PPO/Y-UiO-66−x%, where x represented Y-UiO-66's weight percentage). The structures, morphologies and properties of UiO-66-NH 2 , Y-UiO-66 and composites are described. The greatest ionic conductivity (103.10 mS cm−1 at 80 °C) is demonstrated by the Im-PPO/Y-UiO-66−1% composite membrane, surpassing that of pure Im-PPO (77.19 mS cm−1 at 80 °C). In addition, the Im-PPO/Y-UiO-66-1% composite membrane shows good alkali stability. After soaking in 2 M NaOH solution for 648 h, the ionic conductivity of Im-PPO/Y-UiO-66-1% decreases from 34.35 to 25.34 mS cm−1. The ionic conductivity of Im-PPO decreases from 29.31 to 20.35 mS cm−1. The above results show that the Im-PPO/Y-UiO-66-1% has good application potential as anion exchange membranes. [Display omitted] • The metal-organic frame Y-UiO-66 filler was synthesized. • An efficient and orderly anion transport channel was constructed. • The introduction of Y-UiO-66 increased the ion transport site. • AEM had good alkali resistance and long-term stability. [ABSTRACT FROM AUTHOR]

In the field of hydrogen storage and transportation, the development of hydrogen barrier coatings with excellent hydrogen permeation resistance is crucial for reducing hydrogen-induced damage caused by hydrogen leakage and hydrogen embrittlement. In recent years, benefiting from its excellent hydrogen barrier performance and wide application range, polymer-based hydrogen barrier composite coatings, membrane and films are expected to become an essential technology in promoting efficient hydrogen storage and transportation in the future. Primarily, starting from the material design of the composite systems, commonly applied gas barrier polymers and two-dimensional nanofillers are explicitly outlined. The detailed data of hydrogen barrier performance as well as advantages and disadvantages of their applications in this field are analysed and highlighted, and strategies are conceived and proposed to optimize their hydrogen barrier performance. Then, the major factors influencing the performance of hydrogen barrier composite system are put forward, providing ideas for strengthening the performance of hydrogen barrier composite from diverse perspectives and exploring failure mechanisms. Finally, a systematic classification overview of the currently researched hydrogen barrier composite system has been provided, and based on their different categories, the development trend of how to achieve large-scale applications of these coatings in the future is discussed. The H 2 barrier composite membrane, coating & film exhibit tremendous application prospects in abundant hydrogen-related fields. [Display omitted] • The H 2 barrier composites for efficient H 2 transportation and storage are discussed. • Major gas barrier polymers are explicitly summarized. • Common two-dimensional gas barrier fillers are outlined and compared. • Future development and optimization of H 2 barrier composites are envisioned. [ABSTRACT FROM AUTHOR]

Radiative cooling is promising in meeting the current global demand for green sustainable development. However, the effective cooling of the existing radiant cooler will be limited due to the serious solar energy absorption and poor thermal insulation performance on the cold side. To addresss these issues, we propose herein a novel composite material of silicon dioxide (SiO 2) aerogel microspheres combined with polyvinylidene fluoride-cohexafluoropropylene (PVDF-HFP) nanofiber membrane, in which SiO 2 aerogel microspheres are firstly synthesized by sol-gel method and then incorporated into PVDF-HFP nanofiber membrane to give radiative cooling performance. As we expected, the molecular vibration characteristics of PVDF-HFP nanofiber membrane and the phonon polarization resonance of Si-O-Si bond in the transparent window can enhance the infrared emissivity of the membrane surface. In addition, the high porosity and the mesoporous structure formed by the interconnection of nano-network skeletons of SiO 2 aerogel microspheres determine its excellent thermal insulation performance. The as-prepared material displays that the average solar reflectance of the composite membrane is 96.07 % and the average infrared emissivity of the atmospheric window is 94.95 %. Notably, when the average solar radiation intensity is 885.56 W•m−2, the passive radiative cooling temperature during the day can reach 11.2 °C. Furthermore, this material has excellent self-cleaning and thermal insulation performance, making it a potential radiant cooling candidate in many fields. [ABSTRACT FROM AUTHOR]

Photothermal antibacterial composite membranes have a broad range of clinical applications such as wound dressing, drug delivery, and physiotherapy. However, existing photothermal antimicrobial films have limitations related to biosafety, stability, and degradability. Herein, we develop an environmentally‐friendly composite membrane with antibacterial properties, photothermal conversion capability, and facile processing. The composite membrane film is comprised of polylactic acid (PLA) with graphene (G) and is synthesized via melt co‐blending and hot pressing. We verify that graphene is uniformly dispersed in the PLA phase, and an antibacterial rate of 99.7% can be achieved by a PLA/G composite membrane with only 3.0 wt.% graphene added. Moreover, the obtained films exhibit efficient photothermal conversion, reaching thermal treatment temperatures (40–60°C) within 10 s and maintaining temperature stability for extended periods. Additionally, the composite fiber film exhibited a tensile strength of 3.5 cN/dtex and good hydrophobicity (>90° contact angle). The combination of antibacterial properties, efficient photothermal conversion, noninfiltration, high strength, hydrophobicity, and mechanical stability, along with the inherent degradability of PLA and the scalability of the synthesis process for mass production, offer broad application prospects for PLA‐based composite materials. [ABSTRACT FROM AUTHOR]

[Display omitted] • A zwitterion-modified fiber substrate was used to fill with SPEEK to prepare PEM. • Zwitterionic interface provided fast channels for proton transport. • High proton conductivity and chemical stability were obtained. • Better DMFC performance than that of commercial Nafion 212 membrane was obtained. Proton exchange membranes with high ionic conductivity and good chemical stability are critical for achieving high power density and long lifespan of direct methanol cells (DMFCs). Herein, a zwitterionic molecule was grafted onto the surface of polyvinylidene fluoride (PVDF) nanofibers to obtain functionalized PVDF porous substrate (SBMA-PDA@PVDF). Then, sulfonated poly(ether ether ketone) (SPEEK) was filled into the pores of SBMA-PDA@PVDF, and further ionic cross-linked via H 2 SO 4 to prepare the composite membrane (SBMA-PDA@PVDF/SPEEK). The basic groups on the zwitterionic interface could not only establish ionic cross-linking with SPEEK to increase chemical stability and reduce swelling, but also serve as the adsorption sites for subsequent H 2 SO 4 cross-linking to significantly enhance proton conductivity. Super-high proton conductivity (165.34 mS cm−1, 80 °C) was achieved for the membrane, which was 2.12 times higher than that of the pure SPEEK. Moreover, the SBMA-PDA@PVDF/SPEEK membrane exhibited remarkably improved oxidative stability of 91.6 % mass retention after soaking in Fenton's agent for 12 h, while pure SPEEK completely decomposed. Satisfactorily, the DMFC assembled with SBMA-PDA@PVDF/SPEEK exhibited a peak power density of 99.01 mW cm−2, which was twice as much as that of commercial Nafion 212 (48.88 mW cm−2). After 235 h durability test, only 11 % voltage loss was observed. [ABSTRACT FROM AUTHOR]

This study loaded different amounts of UiO‐66‐NH2 onto sulfonated polyphenylene sulfide fibers (SPPS), successfully loading UiO‐66‐NH2 on SPPS fibers confirmed by energy dispersive x‐ray spectroscopy, x‐ray diffraction, and Fourier transform infrared spectroscopy. The UiO‐66‐NH2‐X@SFM were then impregnated in Nafion solution to obtain UiO‐66‐NH2‐X@SFM/Nafion composite membranes. The thermal stability, dimensional stability, mechanical properties, proton conductivity, methanol resistance, and other properties of the UiO‐66‐NH2‐X@SFM/Nafion composite membranes were subsequently comprehensively characterized. The proton conductivity of the UiO‐66‐NH2‐8@SFM/Nafion composite membrane at 80°C and 100% RH was measured to be 0.286 S cm−1, which exhibited a significant enhancement of 1.75 times compared with the original membrane. Simultaneously, the composite membrane demonstrated a remarkable reduction in methanol permeation rate. At 40°C and 100% RH, the UiO‐66‐NH2‐8@SFM/Nafion composite membrane has a selectivity of up to 20.7 × 104 S s cm−3 and a single cell density of 88.3 m W cm−2 at 60°C and 100% RH. [ABSTRACT FROM AUTHOR]

Given the toxicity of wastewater pollutants to both humans and the environment, it is critical to develop a new synthetic membrane with superior permeability and rejection. Herein, a novel asymmetric polyethersulfone (PES) composite filtration membrane was successfully prepared using a simple alternating vacuum‐deposition process with positively charged chitosan and negatively charged cellulose nanofibrils as polycations and polyanions, respectively. As expected, the produced PES composite filtration membranes had a compressed and negatively charged surface, which prevented the anionic dye methyl blue (MB) molecules from infiltrating into the membrane matrix. Consequently, the resulting PES composite filtration membranes exhibited an extremely high MB rejection (99.7%) and a satisfactory flux (37.47 L h−1 m−2 MPa−1). In addition, the composite membrane demonstrated extremely selective removal of anionic dyes in the presence of neutral dyes due to the Donnan effect. Furthermore, the developed PES composite filtration membranes displayed exceptional long‐term stability (99.8% rejection and 36.5 L h−1 m−2 MPa−1 flux after 50 h of filtration) and recycling properties (90.1% flux recovery rate after 3 cycles of running). In conclusion, the PES composite filtration membranes prepared in this study presented great potential in wastewater filtering. [ABSTRACT FROM AUTHOR]

Efficient lithium/magnesium (Li+/Mg2+) separation attainment is fundamental to the extraction of lithium from brine by nanofiltration membrane separation process, which is essential for resource recovery and a circular water economy. However, for poly(piperazine‐amide) nanofilm composite membranes, the higher electronegativity affects the Mg2+ rejection and consequently Li+/Mg2+ separation performance. Manipulating the positive charge density and pore size regulation of the nanofiltration membranes are determinative of the Li+/Mg2+ separation performance improvement. Here, a new monomer 1,1′‐(hexane‐1,6‐diyl)bis(1‐methylpiperazin‐1‐ium) bromide containing bis‐quaternary ammonium cations is employed as a molecular building block to fabricate polyamide nanofilms via interfacial polymerization. The dual quaternary ammoniums and the rod‐shaped conformation of the monomer confer enhanced electropositivity, steric hindrance, loosely packed microporous network structure (pore diameter∼0.8–1.35 nm), and high free volume. The resultant membrane exhibits high water permeance of 28.34 L m−2 h−1 bar−1 with good Li+/Mg2+ selectivity of up to 76.9. In addition, the membrane also exhibits chlorine stability performance owing to the lack of the chlorine sensitive −NH groups in the formed tertiary amide structures. Computational insights on the structural properties, nanofilm formation, and transmembrane water and ion transport behaviors are provided. This study offers insightful theoretical and technological concepts to design and construct membrane materials for energy‐efficient separations. [ABSTRACT FROM AUTHOR]

Graphene oxide (GO) laminate membranes for water purification have surged in popularity due to their hydrophilicity, high throughput and excellent separation abilities. However, concerns about swelling and stability in water persist. Herein, we prepared high stability, composite reduced graphene oxide (rGO)/graphene oxide (GO) membranes. The composite membranes (i.e. rGO/GO composite membranes) displayed excellent rejection performance for methylene blue (MB) of up to 99.0%, together with ultrahigh water permeance (201.7 L m−2 h−1 bar−1) compared to pristine GO membranes (54.8 L m−2 h−1 bar−1). This study broadens the applications of graphene-based membranes and enhances their performance in water treatment. [ABSTRACT FROM AUTHOR]

Mixed matrix materials (MMMs) integrating excellent processability from polymers and distinct separation properties from nanofillers are of interest for membrane gas separations, and they are often made into freestanding films (>100 µm) to demonstrate superior gas separation properties. However, they are difficult to fabricate into thin‐film nanocomposite (TFN) membranes due to interfacial incompatibility between polymers and nanofillers. Here TFN membranes based on MMMs (as thin as 200 nm) are successfully developed comprising amorphous poly(ethylene oxide) (aPEO) and UiO‐66‐NH2 enabling strong hydrogen bonds between the two matrices. Increasing the UiO‐66‐NH2 loading unexpectedly decreases CO2 permeability in freestanding films, but it surprisingly leads to the best CO2/N2 separation properties in the membranes at a loading of 10 mass% (CO2 permeance of 2900 GPU and CO2/N2 selectivity of 48). Nanoconfinement significantly influences the morphological and gas separation properties of the MMM layer. The membrane with 10 mass% UiO‐66‐NH2 demonstrates mixed‐gas CO2 permeance of 1400 GPU and CO2/N2 selectivity of 76 in the presence of 1.2 mol% water vapor at ≈23 °C, surpassing Robeson's upper bound. The membrane also demonstrates stable CO2/N2 separation performance when challenged with real flue gas for 700 h continuously. [ABSTRACT FROM AUTHOR]

To achieve sustainable and energy‐efficient CO2 capture processes, it is imperative to develop membranes that possess both high CO2 permeability and selectivity. One promising approach involves integrating high‐aspect‐ratio nanoscale fillers into polymer matrices. The high‐aspect‐ratio fillers increase surface area and improve interactions between polymer chains and gas molecules passing through the membrane. This study focuses on the integration of cellulose nanocrystals (CNCs) with an impressive aspect ratio of around 12 into rubbery polymers containing polyethylene oxide (PEO), namely PEBAX MH 1657 (poly[ether‐block‐amide] [PEBA]) and polyurethane (PU), to fabricate mixed‐matrix membranes (MMMs). By exploiting the interfacial interactions between the polymer matrix and CNC nanofillers, combined with the surface functionalities of CNC nanofillers, the rapid and selective CO2 transport is facilitated, even at low filler concentrations. This unique feature enables the development of thin‐film composites (TFCs) with a selective layer around 1 μm. Notably, even at a filling ratio as low as 1 weight percent, the resulting membranes exhibit remarkable CO2 permeability (>90 Barrer) and CO2/N2 selectivity (>70). These findings highlight the potential of integrating CNCs into rubbery polymers as a promising strategy for the design and fabrication of highly efficient CO2 capture membranes. [ABSTRACT FROM AUTHOR]

Dye wastewater is becoming one of the most significant sources of water pollution, and its impact on human survival is immeasurable. In this study, we successfully synthesized a nanofiber membrane with environmentally friendly and efficient properties using electrospinning of a mixture of sodium alginate (SA) and copper oxide (CuO) nanoparticles, aimed at effective dye removal. The adsorption performance of the SA/CuO nanofiber membrane was evaluated using the cationic dye methylene blue (MB). The maximum adsorption capacity of the nanofiber membrane was increased significantly with the addition of CuO nanoparticles, reaching a maximum value of 1633.4 mg g−1, almost twice as much as that of pure SA membrane. The adsorption kinetics follows the pseudo‐second‐order model, where chemisorption acts as the rate‐limiting step. The adsorption isotherm data indicate that the adsorption is monolayer. The nanofibrous membranes showed better dye removal under an alkaline environment. After four cycles of adsorption/desorption, the MB removal efficiency remained at 70.1% of the original adsorption capacity. The addition of CuO nanoparticles facilitated the adsorption of MB dyes, while the form of the nanofibrous membrane is easily recoverable and reusable. Therefore, the as‐prepared SA/CuO nanofibrous composite membrane is a potentially favorable adsorbent material for wastewater treatment applications. [ABSTRACT FROM AUTHOR]

This paper reports on the novel composite membrane electrolytes used in Zn/MnO2, Al/MnO2, Al/air, and zinc/air electrochemical devices. The composite membranes were made using poly(vinyl alcohol), poly(acrylic acid), and a sulfonated polypropylene/polyethylene separator to enhance the electrochemical characteristics and dimensional stability of the solid electrolyte membranes. The ionic conductivity was improved significantly by the amount of acrylic acid incorporated into the polymer systems. In general, the ionic conductivity was also enhanced gradually as the testing temperature increased from 20 to 80 °C. Porous zinc gel electrodes and pure aluminum plates were used as the anodes, while porous carbon air electrodes or porous MnO2 electrodes were used as the cathodes. The cyclic voltammetry properties and electrochemical impedance characteristics were investigated to evaluate the cell behavior and electrochemical properties of these prototype cells. The results showed that these prototype cells had a low bulk resistance, a high cell power density, and a unique device stability. The Al/MnO2 cell achieved a density of 110 mW cm−2 at the designated current density for the discharge tests, while the other cells also exhibited good values in the range of 70–100 mW cm−2. Furthermore, the Zn/air cell consisting of the PVA/PAA = 10:5 composite membrane revealed an excellent discharge capacity of 1507 mAh. This represented a very high anode utilization of 95.7% at the C/10 rate. [ABSTRACT FROM AUTHOR]

Thin-film composite (TFC) membranes containing various fillers and additives present an effective alternative to conventional dense polymer membranes, which often suffer from low permeance (flux) and the permeability–selectivity tradeoff. Alongside the development and utilization of numerous new polymers over the past few decades, diverse additives such as metal–organic frameworks (MOFs), graphene oxides (GOs), and ionic liquids (ILs) have been integrated into the polymer matrix to enhance performance. However, achieving desirable interfacial compatibility between these additives and the host polymer matrix, particularly in TFC structures, remains a significant challenge. This review discusses recent advancements in TFC membranes for CO2/N2 separation, focusing on material structure, polymer–additive interaction, interface and separation properties. Specifically, we examine membranes operating under dry conditions to clearly assess the impact of additives on membrane properties and performance. Additionally, we provide a perspective on future research directions for designing high-performance membrane materials. [ABSTRACT FROM AUTHOR]

Functionally graded graphene nanoplatelet reinforced composite (FG-GNPRC) have exhibited significant potential for the development of high-performance and multifunctional structures. In this paper, we present a machine learning (ML) assisted uncertainty analysis of nonlinear vibration of FG-GNPRC membranes under the influence of multi-factor coupling. Effective medium theory (EMT), Mori-Tanaka (MT) model and rule of mixture are utilized to evaluate the effective material properties of the composite membrane. Governing equations are derived via an energy method with the frameworks of the hyperelastic membrane theory, Neo-Hookean constitutive model and the couple dielectric theory. Randomly generated inputs after data pre-processing are fed into governing equations, which are solved by numerical methods for outputs. Three ML models, including artificial neural network (ANN), support vector regression (SVR) and AutoGluon-Tabular (AGT), are adopted to capture the complex relationship between the systematic inputs (i.e., structural dimensions, attributes of GNPs and pores, external electric field, etc.), frequency ratio and dimensionless amplitude of FG-GNPRC membranes. The results demonstrate that all three ML models demonstrate exceptional computational efficiency, and AGT presents higher prediction accuracy compared to the other two models. Based on the Shapley additive explanations (SHAP) approach, the effects of uncertainties of system parameters and multi-factor coupling on the nonlinear vibration of the FG-GNPRC membrane are analyzed. It is found that the uncertainty of structural parameters has the greatest impact on the nonlinear vibration of FG-GNPRC membranes, particularly when the membrane is subjected to a voltage of 10 V and smaller stretching ratio. [ABSTRACT FROM AUTHOR]

Long afterglow nanoparticles, a type of luminescence material, may gradually release stored light energy even after the excitation light has stopped. The modification of polymer membranes by introducing long afterglow nanoparticles via an inorganic particle mixtures, broaden their uses in biomedicine field. In this study, a new membrane modification approach was employed to reduce the loss of physical–mechanical performance, caused by inherent strontium aluminate inorganic particle aggregation. Moreover, eugenol, a cross-linking agent, was used to interact with acrylate monomers to form locally cross-linked compounds using an ex situ approach that improves strontium aluminate particle dispersion. Furthermore, the soap-free emulsion polymerization method used, regulates the degree of cross-linking in the membrane, hence addressing nanoparticles agglomeration. Results showed that the cross-linked structure of the membrane produced improves the heat stability and the hydrophobicity of the material produced while also increasing the nanoparticles dispersion as evidenced by the XRD study. Nevertheless, membranes with cross-linking agents outperformed in water droplet trials by not breaking or whitening the droplets. Furthermore, the generated membranes exhibit high antibacterial activity, making them attractive for paramedical applications such as protective membranes applied on the top of the skin or on the surface areas of sensors, microneedles and metal fasteners. [ABSTRACT FROM AUTHOR]

[Display omitted] • Two kinds of natural and renewable materials are combined to fabricate novel 2D membranes for osmotic energy conversion. • The heterogeneous membranes help to the balance of the trade-off between ion selectivity and ion flux. • A record power density of ∼16.57 W/m2 is achieved with the synergism of space and surface charge. • The ion transport mechanism is theoretically investigated by numerical simulations based on Poisson and Nernst–Planck models. As promising prospects for renewable power harvesting, two-dimensional (2D) nanochannels for osmotic energy capture in a reverse electrodialysis arrangement have garnered significant attention. However, existing 2D nanochannel membranes have shown limited power generation capabilities due to challenges in balancing ion flux and selectivity. Here, we construct montmorillonite (MMT)/TEMPO-mediated oxidation cellulose nanofibers (TOCNFs) nanocomposite membranes for enhanced ion transmembrane transport. The intercalation of TOCNFs not only enlarges the interlayer distance, but also provides abundant space charge inside the nanochannels. Benefiting from the strong ion selectivity and high ion flux, the composite membrane achieves a remarkable power output of ∼16.57 W/m2 in the gradient of artificial seawater and river water, exceeding that of the state-of-the-art heterogeneous membrane-based osmotic energy conversion systems. Both experimental and theoretical findings confirm that the synergism of space and surface charge plays a crucial role in promoting osmotic energy conversion. This research contributes valuable insights into the optimization of 2D membranes for efficient clean energy harvesting purposes. [ABSTRACT FROM AUTHOR]

In this study, polyvinyl alcohol/Nafion nanofibrous composite membranes were produced to investigate their possible application as a polymer electrolyte membrane (PEM) in direct methanol fuel cells. Electrospinning method was used for nanofibrous membrane production, in which the mixture of polyvinyl alcohol (PVA) and Nafion solutions was directly electrospun. Produced nanofibers were subjected to physical stabilization, filler application, and sulfonating to produce composite nanofibrous membranes. PVA and Nafion polymers were used also as filler materials. The properties of resultant composite membranes were compared in terms of water swelling, weight loss in water and methanol solution, thermal stability, morphology, proton conductivity, and methanol permeability. Proton conductivity of the membranes depending on the humidity was also investigated. TGA analysis showed that the membranes had adequate thermal properties regardless of the filler material. The nanofibrous structure was shown to be preserved by scanning electron microscopy (SEM) after treatment with water and methanol solution. It was shown that PVA/Nafion nanofibers displayed proton conductivity after filling process. The use of PVA as a filler material led to higher proton conductivity at 100 RH%. It was reported that proton conductivity could only be obtained at higher relative humidity values (>80% RH). A lower methanol permeability of PVA‐filled membranes was reported. Highlights: PVA/Nafion nanofibrous membranes were produced by electrospinning.PVA and Nafion were also used as pore filling materials.PVA‐filled membranes had higher proton conductivity and lower methanol permeability.Proton conductivity could only be obtained at higher RH% values. [ABSTRACT FROM AUTHOR]

The purpose of this study was to prepare Pickering emulsions stabilized by waste jujube kernel cellulose nanocrystals (CNC) using composite essential oils (EOs) (i.e., cinnamon essential oil [CIN] combined with clove essential oil [CL]). The Pickering emulsions were blended with chitosan (CS) to generate a composite film (CS/CNC/EOs Pickering emulsions). We evaluated the mechanical properties, barrier properties, and microstructures of CS/CNC/EOs bio-based packaging films containing different concentrations of EOs. In addition, the fresh-keeping effects of the composite membranes on beef sausages were evaluated over a 12-day storage period. Notably, the EOs exhibited good compatibility with CS. With the increase in the EOs concentration, the droplet size increased, the composite films became thicker, the elongation at break decreased, the tensile strength increased, and the water vapor permeability decreased. When the composite films were used for preserving beef sausages, the antioxidant and antibacterial activity of the membranes improved as the concentration of EOs increased, effectively prolonging the shelf life of the sausages. Composite membranes with an EOs concentration of 2% exerted the best fresh-keeping effects. Overall, owing to their antioxidant and antimicrobial properties, the bio-based composite films prepared using CS/CNC/EOs Pickering emulsions demonstrated immense potential for application in the packaging of meat products. [ABSTRACT FROM AUTHOR]

High-performance proton exchange membranes are of great importance for fuel cells. Here, we have synthesized polycarboxylate plasticizer modified MIL-101-Cr-NH2 (PCP-MCN), a kind of hybrid metal-organic framework, which exhibits a superior proton conductivity. PCP-MCN nanoparticles are used as additives to fabricate PCP-MCN/Nafion composite membranes. Microstructures and characteristics of PCP-MCN and these membranes have been extensively investigated. Significant enhancement in proton conduction for PCP-MCN around 55 °C is interestingly found due to the thermal motion of the PCP molecular chains. Robust mechanical properties and higher thermal decomposition temperature of the composite membranes are directly ascribed to strong intermolecular interactions between PCP-MCN and Nafion side chains, i.e., the formation of substantial acid-base pairs (-SO-<3 ···+H-NH-), which further improves compatibility between additive and Nafion matrix. At the same humidity and temperature condition, the water uptake of composite membranes significantly increases due to the incorporation of porous additives with abundant functional groups and thus less crystallinity degree in comparison to pristine Nafion. Proton conductivity (s) over wide ranges of humidities (30 - 100% RH at 25 °C) and temperatures (30 - 98 °C at 100% RH) for prepared membranes is measured. The s in PCPMCN/ Nafion composite membranes is remarkably enhanced, i.e. 0.245 S/cm for PCP-MCN-3wt.%/Nafion is twice that of Nafion membrane at 98 °C and 100% RH, because of the establishment of well-interconnected proton transport ionic water channels and perhaps faster protonation-deprotonation processes. The composite membranes possess weak humidity-dependence of proton transport and higher water uptake due to excellent water retention ability of PCP-MCN. In particular, when 3 wt.% PCP-MCN was added to Nafion, the power density of a single-cell fabricated with this composite membrane reaches impressively 0.480, 1.098 W/cm² under 40% RH, 100% RH at 60 °C, respectively, guaranteeing it to be a promising proton exchange membrane. [ABSTRACT FROM AUTHOR]

This study demonstrates a high‐throughput fabrication of fiber interlayers for proton exchange membranes based on poly(pentafluorostyrene) (PPFSt) and its aminated derivatives. The fibers are produced by electrospinning, where the parameters are carefully screened. The controlled parameters are solvent composition, weight percentage, voltage, flow rate, and temperature, controlled with a self‐designed heating jacket. The parameters are iterated toward optimized fiber structure and maximum output. The yielded fibers are infiltrated with Nafion and sulfonated polymer from bisphenol AF and decafluorobiphenyl (SFS001) by spray‐coating and doctor blading to obtain the fiber‐reinforced proton exchange membranes. Tensile tests reveal a higher Young's modulus and yield stress than pure Nafion. Here, the basicity of the aminated PPFSt fibers correlates with the Young's modulus due to improved acid‐base interactions between amine groups and sulfonic acid. The acid‐base interactions influence the composite membrane's proton conductivity, varying from 23 mS cm−1 for strongly alkaline fibers to 69 mS cm−1 for non‐basic fibers. These findings can be transferred to fabricating fiber reinforcements beyond routinely used poly(benzimidazoles). [ABSTRACT FROM AUTHOR]

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Bacterial cellulose composites hold promise as renewable bioinspired materials for industrial and environmental applications. However, their use as free-standing water filtration membranes is hindered by low compressive strength, fouling, and poor contaminant selectivity. This study investigates the potential of bacterial cellulose-graphene oxide composites membranes for fouling resistance in pressure-driven filtration. Graphene oxide dispersed in poly(ethylene glycol) (PEG-400) is incorporated as a reinforcing filler into 3D network of bacterial cellulose using an in-situ synthesis method. The effect of graphene oxide on in situ fermentation yield and the formation of percolated-network in the composites shows that the optimal membrane properties are reached at a graphene oxide loading of 2 mg/mL. The two-dimensional graphene oxide nanosheets uniformly dispersed into the matrix of bacterial cellulose nanofibers via hydrogen-bonded interactions demonstrated nearly twofold higher water flux (380 L m−2 h−1) with a molecular weight cut-off ranging between 100–200 KDa and a sixfold increase in wet compression strength than pristine BC. When exposed to synthetic organic foulants and bacterial rich feed solutions, the composite membranes showed more than 95% flux recovery. Additionally, the membranes achieved over 95% rejection of synthetic natural organic matter and bacterial rich solutions, showcasing their enhanced fouling resistance and selectivity. [ABSTRACT FROM AUTHOR]

AbstractThe treatment of industrial wastewater is crucial for recovering water of high purity, especially considering its significance in mitigating environmental pollution and ensuring sustainable water resources. This study focuses on the purification of industrial wastewater, emphasizing the separation of tetrahydrofuran (THF) from aqueous solutions using membrane-based techniques. Composite membranes incorporating magnetic nanomaterial (magnetite) within a sodium alginate matrix were synthesized and evaluated for their effectiveness in purifying water from THF mixtures. Both Pervaporation (PV) and Vapor Permeation (VP) processes were employed, with thorough analysis conducted on the impact of magnetite content on permeate purity. The study identified optimal magnetite content for industrial wastewater treatment and developed a new membrane composition based on these findings. The VP process’s performance was evaluated by determining the permeation flux and separation factor. The highest separation factor of 460 was obtained for an 80% wt. THF-water solution in the VP process. Using these findings, the optimal magnetite content for industrial wastewater treatment was identified, and a new membrane composition was developed. The activation energies for the permeation of THF through the NaAlg-Fe20 membrane were found to be 10.50 kcal/mol and 7 kcal/mol for the VP and PV processes, respectively. [ABSTRACT FROM AUTHOR]

This study endeavors to enhance the safety of lithium‐ion batteries (LIBs) by synthesizing a polyamide acid (PAA)/Al2O3 composite spinning solution using 4,4′‐diaminodiphenyl ether (ODA) and pyromellitic anhydride (PMDA) as monomers, and nano‐Al2O3 as a thermal conductivity filler. Subsequently, the PAA/Al2O3 fiber membrane is fabricated via electrostatic spinning, followed by gradient heating imidization to produce a polyimide (PI)/Al2O3 composite membrane. This membrane is then dipped into a boron nitride (BM) slurry to ultimately yield an organic–inorganic PI/Al2O3/BM composite separator with superior flame‐retardant and thermal conductivity properties. The thermal stability, flame retardancy, electrolyte wettability, mechanical integrity, and cycle rate performance of the composite membranes are rigorously evaluated. The results demonstrate that the PI/5% Al2O3/BM composite membrane exhibits the most favorable overall performance, with no shrinkage observed at 200°C and no significant changes after sustained ignition for 10 s. The incorporation of the thermal conductivity Al2O3 filler significantly enhances the heat transfer properties of the composite separator. The room temperature ionic conductivity reaches 2.786 mS cm−1 after electrolyte absorption, and the initial discharge capacity of the assembled battery is 156.28 mAhg−1. Following 100 charge/discharge cycles at 0.2C, the capacity retention rate is 97.7%, and at a discharge rate of 5C, the capacity retention rate is 74.9%. [ABSTRACT FROM AUTHOR]

The urgent need to mitigate climate change has spurred research into innovative carbon dioxide (CO2) capture materials. In this study, the design and synthesis of CO2‐responsive diblock copolymers, poly (N‐[3‐(dimethylamino)propyl]‐acrylamide)‐b‐poly(methyl methacrylate) (PDMAPAm‐b‐PMMA) are focused on via a two‐step reversible addition−fragmentation chain‐transfer (RAFT) polymerization as well as the application of the synthesized diblock copolymer as a membrane for CO2 capture. The resulting diblock copolymer possesses distinct blocks with varying properties. The poly (N‐[3‐(dimethylamino)propyl]‐acrylamide) (PDMAPAm) block provides CO2‐responsive behavior, while the poly(methyl methacrylate) (PMMA) block contributes to mechanical stability. The gas transport properties of the fabricated thin‐film composite membrane made of PDMAPAm‐b‐PMMA are measured. It is determined that the copolymer exhibits dual responsiveness towards CO2 and can be tailored for use in fabrication of membranes for direct air capture (DAC). [ABSTRACT FROM AUTHOR]

To improve the properties of quaternized QPAF‐4 copolymers as anion exchange membranes, compositing with hydrophilic Ta–TiO2 particles are investigated. Flexible QPAF‐4/Ta–TiO2 composite membranes are obtained using solution‐casting and die coating methods. Cross‐sectional scanning electron microscopy reveals that the die coating method produces a more homogenous and uniform distribution of Ta–TiO2 particles in the composite membranes than the solution‐casting method. The Ta‐TiO2 particles promotes the suppression of water absorbability and dimensional swelling of the composite membranes which is more pronounced in the die coated membranes. The Ta–TiO2 increase hydroxide ion conductivity to 116.9 mS cm−1 at 80 °C for the die‐coated membrane, surpassing that of the pristine QPAF‐4 membrane (92 mS cm−1). Ta–TiO2 with the composite membranes survive in 4 m KOH at 80 °C for 1000 h, maintaining 96–112 mS cm−1 (88–99% remaining) of initial conductivity. All composite membranes exhibit higher mechanical robustness (elongation of >200%), with the die‐coated composite membranes. The optimized die coated composite membrane is fabricated in an alkaline water electrolysis cell achieving 1.63 V at 1.0 A cm−2 (75.5% efficiency). [ABSTRACT FROM AUTHOR]

This study assesses the gas and water vapor permeance of PIM-derivative thin-film composite (TFC) membranes using pervaporation and "pressure increase" methods, and provides a comparative view of "time lag" measurements of thick films obtained from our previous work. In this study, TFC membranes were prepared using PIM-1 and homopolymers that were modified with different side groups to explore their effects on gas and water vapor transport. Rigid and bulky aliphatic groups were used to increase the polymer's free volume and were evaluated for their impact on both gas and water transport. Aromatic side groups were specifically employed to assess water affinity. The permeance of CO2, H2, CH4 and water vapor through these membranes was analyzed using the 'pressure increase' method to determine the modifications' influence on transport efficiency and interaction with water molecules. Over a 20 h period, the aging and the permeance of the TFC membranes were analyzed using this method. In parallel, pervaporation experiments were conducted on samples taken independently from the same membrane roll to assess water flux, with particular attention paid to the liquid form on the feed side. The significantly higher water vapor transport rates observed in pervaporation experiments compared to those using the "pressure increase" method underline the efficiency of pervaporation. This efficiency suggests that membranes designed for pervaporation can serve as effective alternatives to conventional porous membranes used in distillation applications. Additionally, incorporating "time lag" results from a pioneering study into the comparison revealed that the trends observed in "time lag" and pervaporation results exhibited similar trends, whereas "pressure increase" data showed a different development. This discrepancy is attributed to the state of the polymer, which varies significantly depending on the operating conditions. [ABSTRACT FROM AUTHOR]

[Display omitted] Proton exchange membranes (PEMs) applied in fuel cell technology suffer from the trade-off between fast proton conduction and durable operation involving dimensional stability, mechanical strength, and oxidative resistance. To address this issue, a novel branched polybenzimidazole (brPBI) was synthesized, covalently cross-linked with (3-chloropropyl)triethoxysilane (CTS), and doped with a novel proton conductor FeATMP to prepare brPBI-CTS/FeATMP membranes. The branching degree of brPBI was optimized to achieve high molecular weight while the branching structure offered high free volume, abundant end-groups, and self-cross-linking moiety that enhanced proton conduction and dimensional/mechanical/oxidative stability. Covalent cross-linking with CTS enhanced the dimensional, mechanical, and oxidative stability while improving the water-assisted proton conduction owing to the hydrophilic nature of siloxane structure formed. At 180 ℃, the proton conductivity of the brPBI3-CTS/FeATMP composite membrane reached 0.136, 0.073, and 0.041 S cm−1 at 100 % RH, 50 % RH, and 0 % RH, respectively, while its swelling ratio after immersion in water at 90 ℃ for 24 h was 4.69 %. The performance of the membranes demonstrated that construction of hydrophilic structure by covalent cross-linking was a successful strategy to break the trade-off effect for PEMs. [ABSTRACT FROM AUTHOR]

[Display omitted] The difficulty of recycling and the finite photocatalytic performance of primitive nano-photocatalysts restrict their application in wastewater purification. In this study, a multifunctional membrane with efficient synergistic adsorption and degradation performance was constructed. The nano-photocatalyst layered bimetallic oxide (LDO) was combined with the matrix membrane polyarylether nitrile (PEN) by delayed phase transition technology. The introduced 2-Methylimidazole (2-MeIm) provided a virtual electron transfer pathway between PEN and LDO and enhanced the photocatalytic performance. The results suggested that PEN/LDO/2-MeIm has outstanding removal performance to organic dyes methylene blue (MB). After three consecutive cycles, the reacted membrane can be readily recovered from the system. The MB removal rate remained high at 89.38%, suggesting that the functional membrane is eligible for recycling and reuse. Finally, based on liquid chromatography-mass spectrometry (LC-MS) analysis and density functional theory (DFT) calculations, the mechanism and pathway of MB photodegradation by the PEN/LDO/2-MeIm system were proposed. Therefore, constructing PEN/LDO/2-MeIm membranes in this study may offer a novel perspective on creating eco-friendly and functional PEN-based membranes for practical use in wastewater purification. [ABSTRACT FROM AUTHOR]

[Display omitted] Intelligent shape memory polymer can be potentially used in manufacturing implantable devices that enables a benign variation of implant dimensions with the external stimuli, thus effectively lowering insertion forces and evading associated risks. However, in surgical implantation, biomaterials-associated infection has imposed a huge burden to healthcare system that urgently requires an efficacious replacement of antibiotic usages. Preventing the initial attachment and harvesting a biocidal function upon native surfaces may be deemed as a preferable strategy to tackle the issues of bacterial infection. Herein, a functionalized polylactic acid (PLA) composite membrane assembled with graphene (GE, a widely used photothermal agent) was fabricated through a blending process and then polydimethylsiloxane utilized as binders to pack hydrophobic SiO 2 tightly onto polymer surface (denoted as PLA-GE/SiO 2). Such an active platform exhibited a moderate shape-memory performance upon near-infrared (NIR) light stimulation, which was feasible for programmed deformation and shape recovery. Particularly stirring was that PLA-GE/SiO 2 exerted a pronounced bacteria-killing effect under NIR illumination, 99.9 % of E. coli and 99.8 % of S. aureus were effectively eradicated in a lean period of 5 min. Furthermore, the obtained composite membrane manifested excellent antiadhesive properties, resulting in a bacteria-repelling efficacy of up to 99 % for both E. coli and S. aureus species. These findings demonstrated the potential value of PLA-GE/SiO 2 as a shape-restorable platform in "kill&repel" integration strategy, further expanding its applications for clinical anti-infective treatment. [ABSTRACT FROM AUTHOR]

[Display omitted] • Cu2+-chelated SPEEK membrane with high IEC is prepared. • High mechanical and dimensional stability are observed for SPEEK-Cu membrane. • Proton conductivity of SPEEK-based membranes reaches 0.074 S/cm at −25 °C. • Water states of samples at subzero temperatures are quantified via DSC analysis. • SPEEK-Cu membrane possesses a stronger anti-freezing property. Improving the proton conductivity (σ) of proton exchange membranes at low temperatures is very important for expanding their application areas. Here, sulfonated poly ether ether ketone (SPEEK) membranes were prepared with different sulfonation degrees, and its maximum ion exchange capacity is 3.15 mmol/g for 10 h at 60 °C. Highly sulfonated SPEEK membrane exhibits ultra-high water uptake and excellent proton conductivity of 0.074 S/cm at −25 °C due to its abundant −SO 3 H. Nevertheless, its high swelling ratio and low mechanical strength are not conducive to the practical application of the membrane. Luckily, by employing the chelation of Cu2+ with −SO 3 − on the SPEEK chain, Cu2+-coordinated SPEEK membranes were prepared, and they not only retain high −SO 3 H content but also possess robust mechanical properties and good dimensional stability compared to pristine SPEEK membrane. Meanwhile, the σ of the SPEEK-Cu membrane reaches 0.054 S/cm at −25 °C, and its fuel cell maximum power (W max) reaches 0.42 W/cm2 at −10 °C, demonstrating superior low-temperature performance in comparison to other reported materials. Particularly, water states in the prepared membranes are quantified by low-temperature differential scanning calorimetry. Because much more water bound to the plentiful −SO 3 H and Cu2+ inside the membrane endows it with anti-freezing performance, the decay of the σ and the W max for the SPEEK-Cu membrane is retarded at sub-zero temperatures. It is envisioned that composite membranes comprising metal ions such as Cu2+-SPEEK have a high potential for sub-zero fuel cell applications. [ABSTRACT FROM AUTHOR]

Various electrospun fibrous membranes have been addressed for oil/water separation owing to their advantages of high specific surface ratio, lightweight, and high porosity. However, they are commonly obtained by solution electrospinning of non‐green raw materials, which could cause serious environmental issues. To realize effective oil/water separation, the optimal processing parameters for melt electrospun polylactic acid (PLA) were determined through orthogonal experiments. Subsequently, PLA fibrous films with cellulose nanofiber (CNF) or sodium chloride (NaCl) for oil/water separation were produced via melt electrospinning. The effects of incorporating CNF or NaCl on the physiochemical properties of melt electrospun PLA fibrous membranes were investigated. In contrast to the pure PLA membranes, the obtained PLA/CNF and PLA/NaCl composite membranes exhibit a finer average fiber diameter and an increased porosity. Also, the oil absorption characteristics and oil/water separation abilities of these fibrous membranes were experimentally studied. In contrast to the 84.55% oil/water separation efficiency of melt‐electrospun PLA fibrous membranes, PLA/CNF exhibits the highest oil/water separation efficiency at 93.54%, whereas PLA/NaCl achieves a maximum efficiency of 90.29%. These findings show the applicability of the eco‐friendly PLA‐based melt electrospun fibrous membrane in the treatment of oily wastewater. [ABSTRACT FROM AUTHOR]

This study investigates the enhancement of mechanical and electrical properties of composite electrolyte membranes through the incorporation of polylactic acid (PLA) fibers and nanocrystalline cellulose (NCC) derived from kapok. PLA fibers were prepared using electrospinning, while kapok NCC was synthesized through pulping, bleaching, and hydrolysis. Scanning electron microscopy (SEM) analysis revealed an average PLA fiber diameter of 597 nm and a kapok NCC grain size of 70.2 nm. The composite electrolyte membranes were prepared by combining polyvinyl alcohol (PVA), potassium hydroxide (KOH), glycerol, and varying amounts of PLA/NCC reinforcement. Tensile tests showed that the addition of 0.05 g kapok NCC improved the tensile strength by 87.6% and increased elongation. Impedance analysis demonstrated a decrease in impedance with the incorporation of PLA and kapok NCC fibers, indicating enhanced conductivity. The sample with 0.05 g kapok NCC (FKP5) exhibited the highest conductivity of 0.068 mS/cm. Cyclic voltammetry revealed more pronounced reduction and oxidation reactions in FKP5, while electrical power measurements showed a maximum power of 12.6 mW for FKP5. The improved mechanical and electrical properties of the composite membranes containing PLA and kapok NCC highlight their potential for use in sustainable batteries and other industrial applications. [ABSTRACT FROM AUTHOR]

Nowadays, due to the lack of drinking water and the increase in global demand, desalination by reverse osmosis (RO) has been developed. In this regard, activities have been carried out to increase water flux and salt removal, which are important indicators in this process, including membrane modification by loading nanoparticles (NPs). Process simulation plays an important role in reducing laboratory costs, improving efficiency, and investigating operational parameters in more detail. This is an important factor that leads us to process simulation. The simulation of the RO process by thin‐film composite membranes modified with nanoporous titanate (mNTs) NPs has been conducted using COMSOL software. The performance of this process was checked by loading different amounts of mNTs with the desired membrane. The results revealed that by adding 0.01 w % of mNTs to the membrane composition, the performance of the process was improved in that the initial water flux through the membrane increased by about 95.4 %, while the salt rejection remained nearby 98 % and did not decrease much. Finally, to validate and expand the simulation results, the model outcomes were compared with experimental data, and the mean relative error for water flux and salt removal percentage was 1.15 % and 0.83 %, respectively. [ABSTRACT FROM AUTHOR]

Metal organic framework (MOF) materials have attracted widespread attention due to their tunable structure, high porosity, and large specific surface area. MOF modified with functional groups were introduced into ionic polymers that could provide proton conduction, which could prepare proton exchange membranes with high proton conductivity. In this paper, UiO-66-NH2 were introduced into sulfonated polyphosphazene (SPFPP) to prepare composite proton exchange membranes, the thermal stability, swelling degree, water uptake, and proton conductivity were characterized. Composite membranes exhibits excellent thermal stability, the swelling degree of the composite membranes are lower than that of the pure SPFPP membrane. UiO-66-NH2 could improve the water retention capacity of composite membranes, resulting in higher water uptakes of composite membranes than pure SPFPP membranes. This higher water retention capacity could improve the proton conductivity of the membrane under high humidity conditions. The proton conductivity of composite membranes SP/UiO-66-NH2 -0. 6 reaches up to 0. 179 S/cm under 80 ℃, 100% RH, while the proton conductivity of pure SPFPP membranes is 0. 120 S/cm under the same conditions. [ABSTRACT FROM AUTHOR]

The significance of hydrogen energy has grown considerably due to climate change and the depletion of fossil fuels. PEM fuel cells are the key hydrogen technologies. Commercial membranes based on perfluorosulfonic acid (PFSA) with a polymer structure containing fluorine are currently available. However, it has been determined that certain perfluorosulfonic acids (PFSAs) are hazardous, persistent, and bioaccumulative. Advancements in hydrogen technology rely on effective, inexpensive, and perfluorocarbon‐free membranes, specifically proton exchange membranes (PEMs). In this research, a PFSA‐free polyacrylonitrile‐co‐methyl acrylate (PAN‐MA) membrane doped with phosphoric acid is prepared using the electrospinning method and then characterized by SEM, FE‐SEM, XRD, FTIR, TGA, DMA, and EIS. The DMA analysis reveals that the storage modulus of the doped membrane increases from 0.98 to 5.66 MPa at 80 °C. The nanofiber composite membrane, with a thickness of 181 µm, exhibits the highest proton conductivity of 0.306 S m−1 at 20 °C, 1.76 times higher than that of the Nafion 212 membrane. The Nafion 212 membrane has an ionic conductivity of 0.173 S m−1 under the same conditions. These results indicate that the prepared nanofiber membranes are promising materials for evaluating fuel cell applications. [ABSTRACT FROM AUTHOR]

Natural gas dehydration is a critical process in natural gas extraction and transportation, and the membrane separation method is the most suitable technology for gas dehydration. In this paper, based on molecular dynamics theory, we investigate the performance of a metal–organic composite membrane (ZIF-90 membrane) in natural gas dehydration. The paper elucidates the adsorption, diffusion, permeation, and separation mechanisms of water and methane with the ZIF-90 membrane, and clarifies the influence of temperature on gas separation. The results show that (1) the diffusion energy barrier and pore size are the primary factors in achieving the separation of water and methane. The diffusion energy barriers for the two molecules (CH4 and H2O) are ΔE(CH4) = 155.5 meV and ΔE(H2O) = 50.1 meV, respectively. (2) The ZIF-90 is more selective of H2O, which is mainly due to the strong interaction between the H2O molecule and the polar functional groups (such as aldehyde groups) within the ZIF-90. (3) A higher temperature accelerates the gas separation process. The higher the temperature is, the faster the separation process is. (4) The pore radius is identified as the intrinsic mechanism enabling the separation of water and methane in ZIF-90 membranes. [ABSTRACT FROM AUTHOR]

This review discusses the progress of research on sulfonated poly(ether ether ketone) (SPEEK) and its composite membranes in proton exchange membrane fuel cells (PEMFCs). SPEEK is a promising material for replacing traditional perfluorosulfonic acid membranes due to its excellent thermal stability, mechanical property, and tunable proton conductivity. By adjusting the degree of sulfonation (DS) of SPEEK, the hydrophilicity and proton conductivity of the membrane can be controlled, while also balancing its mechanical, thermal, and chemical stability. Researchers have developed various composite membranes by combining SPEEK with a range of organic and inorganic materials, such as polybenzimidazole (PBI), fluoropolymers, and silica, to enhance the mechanical, chemical, and thermal stability of the membranes, while reducing fuel permeability and improving the overall performance of the fuel cell. Despite the significant potential of SPEEK and its composite membranes in PEMFCs, there are still challenges and room for improvement, including proton conductivity, chemical stability, cost-effectiveness, and environmental impact assessments. [ABSTRACT FROM AUTHOR]

A growing interest in dental practice in intranasal anesthesia using tetracaine and oxymetazoline dictates the need for their simultaneous determination in combination drugs and human saliva. Potentiometric multisensory systems based on perfluorosulfonic acid membranes, including polyaniline‐modified ones, were developed for these purposes. A change in the distribution of the sensor sensitivity to the related analytes was achieved by variation of the conditions for concentration polarization at the membrane interface with a studied solution due to a change in the intrapore volume, nature, and availability of the sorption centers, as well as the hydrophilicity of the membrane surface that were specified by the conditions for their synthesis and subsequent hydrothermal treatment. Reversibility of the analyte sorption using the chosen conditions for regeneration provided long‐term stable work of both the sensors and the calibration equations established by multivariate linear regression. The membrane modification promoted their resistance to fouling. The relative errors of the simultaneous tetracaine and oxymetazoline determination in the combination drug solutions were no greater than 7% and 11%, while in the artificial saliva solutions, they were 15% and 17%, respectively, when an array of the cross‐sensitive sensors based on the composite membranes prepared by different methods was used. The analysis errors were reduced to 3%–6% when analyzing the drug and to 0.2%–6% when analyzing the artificial saliva if an array was organized with the sensors based on the membrane with the dopant and the membrane without it, due to the decreasing correlation between their responses. Potentiometric multisensory systems based on perfluorosulfonic acid membranes, including polyaniline‐modified ones, were developed for the simultaneous determination of tetracaine and oxymetazoline in combination drugs and human saliva. Reversibility of the analyte sorption during regeneration provided long‐term stable work of the sensors and calibration equations established by multivariate linear regression. The analysis errors were 0.2%–6% for the sensor array based on the membrane with polyaniline and the one without it, due to the low correlation between the responses. [ABSTRACT FROM AUTHOR]

Graphene oxide (GO) membranes have garnered significant attention in the field of membrane separation due to their superb hydrophilicity, abundant functional groups, extensive surface area, and chemical stability. In this study, we have established a simple and effective method to enhance GO layered materials using nitrogen-doped carbon dots (N–CDs) molecules as inserts and surface modifiers, aiming to develop highly efficient GO-based membranes. Consequently, the incorporation of N–CDs into the two-dimensional GO membrane augments its hydrophilicity and increases the membrane interlayer distance. Under ultra-low pressure nanofiltration conditions, the optimum GN-12 composite membrane exhibited a remarkable average pure water flux of 6.06 L m−2 h−1 bar−1. This flux was approximately 19.5 times higher than that of the pure GO membrane, which had a flux of 0.31 L m−2 h−1 bar−1. Furthermore, the composite membrane exhibited excellent capability in intercepting several charged dye molecules, with an interception rate exceeding 99.6%. Furthermore, the optimized composite membrane demonstrated robust performance and structural stability even under varying pH conditions. The findings of this fundamental research provide a straightforward and cost-effective strategy for the production of high-performance two-dimensional based nanofiltration membranes. [ABSTRACT FROM AUTHOR]

A wide range of active agents, synthetic and natural agents such as essential oils, chitosan and polyphneols consisting of curcumin, gallic acid, anthocyanins, and catechins have been used in order to develop antimicrobial packaging systems, and among them, natural polyphenolic compounds, specially curcumin (Cur) has great potential due to effective biological activities in developing food packaging material. Quercetin (Quer) is also the mostly studied flavonol as a color‐changing indicator in the food industry and has been already developed as a realistic alternative for smart and active food packaging. The reason for choosing these two polyphenolic compounds is that they simultaneously possess many beneficial properties such as antioxidant, antibacterial, antiviral, antitumoral, and anti‐inflammatory effects. Additionally, the main objective of the study is to combine polypropylene (PP), which is the most preferred and cost‐effective polymer in the packaging industry, with these active ingredients, rather than using more expensive polymer types. In this context, PP‐Quer or PP‐Cur membranes, which are new experiences based on these literatures were chemically characterized by Fourier transform infrared spectroscopy, and the surface morphology of these composite membranes was characterized by scanning electron microscopy. The antibacterial response against gram‐positive (Staphylococcus aureus) and gram‐negative (Escherichia coli) bacteria species was investigated. Furthermore, the reactive oxygen species generation and anticancer activity of these composite membranes using human colorectal adenocarcinoma (HT‐29) were observed. We proposed that PP‐Quer or PP‐Cur composite membranes can be a potential candidate as active packaging material in the food industry. [ABSTRACT FROM AUTHOR]

Desulfurization as a pre-treatment technique, of the transportation fuel is peremptory both for upgrading fuel quality for commercial exploitation and reducing the outflow of poisonous sulfur compounds for environmental remediation. This article encompasses the applications of mixed matrix membranes (MMMs) for the desulfurization of transportation fuels. This composite membrane system synergizes viable processability of the polymers and enhanced selectivity of different incorporated fillers. Hence it offers increased thermal stability, mechanical strength, excellent separation, and purification performance over traditional polymeric and inorganic membranes. These composite materials are widely studied for their potential applications in sensing, catalysis, water purification, gas separation, and adsorption. Herein, different types of MMMs with respect to fillers, chemical compositions and fabrication methods are focused and then systematically compiled and discussed the recent trend for the desulfurization of transportation fuels with profound scientific rationale. Finally, future prospects and room for further advancements in the wider spectrum of MMMs are discussed for better applications and adoptability in the processing of fuel oils. This review will assist the researchers working on the large-scale processing of transportation fuels with a single-point source of knowledge and will save ample amount of time as well as contribute into key future research directions. [ABSTRACT FROM AUTHOR]

3D printed mixed matrix membrane (MMM) thin film, as a novel adsorbent, was introduced for the extraction of two steroid hormones from wastewater and tap water samples before their determination by high-performance liquid chromatography. The designed adsorbent was fabricated as thin film utilizing digital light processing (DLP) 3D printing. The thin film was made of acrylate photo resin, graphitic carbon nitride (g-C3N4), and polyvinylpyrrolidone and its application was investigated for thin film microextraction of 17β-estradiol (E2) and estrone (E1). The morphology of the 3D printed film surface and its chemical changes were studied using field emission scanning electron microscopy and attenuated total reflectance-Fourier transform infrared spectroscopy, respectively. The surface wettability of the proposed MMM films was measured by water contact angle analysis and its porosity was studied by N2 adsorption/desorption analysis. To attain optimal microextraction performance, optimization of both thin film composition and microextraction procedure was conducted, followed by a thorough evaluation of figures of merit under the optimized conditions. The limits of detection and quantitation were determined to be 1.5 and 5 µg L−1 for both E2 and E1. The linear dynamic range for both compounds was from 5 to 150 µg L−1. The method's repeatability was investigated on a single film for 6 extractions, as well as on 3 different films and the relative standard deviation values were 4.43 and 4.91 for E2 and 5.36 and 6.03 for E1, respectively. [ABSTRACT FROM AUTHOR]

[Display omitted] • 3D hierarchically-microstructure evaporator with enhanced light utilization and water transport is constructed by a simple two-step method. • Surface functionalization synergizes substrate engineering. • APTES grafting enables MXene with large interlayer spacing and high hydrophilicity. • NWF substrate guarantees low cost, durability, and high performance. • A considerable cost-effectiveness of 89.4 gh−1/$ and outstanding long-term stabilities in harsh conditions are achieved. Recently, the solar-driven interfacial evaporation desalination has attracted more and more attentions due to the advantages of low cost, zero energy consumption, and high water purification rate, etc. One of the bottlenecks of this emerging technique lies in a lack of simple and low-cost ways to construct three-dimensional (3D) hierarchical microstructures for photothermal membranes. To this end, a two-step strategy is carried out by combining surface functionalization with substrate engineering. Firstly, a silane coupling agent 3-aminopropyltriethoxysilane (APTES) is grafted onto an ideal photothermal material of Ti 3 C 2 T x MXene, to improve the nanochannel sizes and hydrophilicity, which are attributed to enlarged interspaces of MXene and introduced hydrophilic group e.g., –NH 2 and –OH, respectively. Secondly, a low-cost and robust nonwoven fiber (NWF) substrate, which has a 3D micron-sized mesh structure with interlaced fiber stacks, is employed as the skeleton to load enough APTES-grafted MXene by a simple soaking method. Benefited from above design, the Ti 3 C 2 T x -APTES/NWF composite membrane with a 3D hierarchical structure shows enhanced light scattering and utilization, water transport and vapor escape. A remarkable evaporation rate of 1.457 kg m−2 h−1 and an evaporation efficiency of 91.48 % are attained for a large-area (5 × 5 cm2) evaporator, and the evaporation rate is further increased to 1.672 kg m−2 h−1 for a small-area (2 × 2 cm2) device. The rejection rates of salt ions and heavy metal ions are higher than 99 % and 99.99 %, respectively, and the removal rates of organic dye molecules are nearly to 100 %. Besides, the composite photothermal membrane exhibits great stabilities in harsh conditions such as high salinities, long cycling, large light intensities, strong acid/alkali environments, and mechanical bending. Most importantly, the photothermal membrane shows a considerable cost-effectiveness of 89.4 g h−1/$. Hence, this study might promote the commercialization of solar-driven interfacial evaporation desalination by collaboratively considering surface modification and substrate engineering for MXene. [ABSTRACT FROM AUTHOR]

BACKGROUND AND OBJECTIVES: Nanoparticles are presently employed in a multitude of applications due to their advantageous features, which encompass simplicity, non-toxicity, affordability, lack of pollutants, and environmentally friendly process. Utilization of Sargassum sp extract for producing nano-copper oxide is environmentally friendly. The study demonstrates the synthesis of nano-copper oxide facilitated by the macroalgae Sargassum sp. and its application in functionalizing cellulose acetate membrane to enhance dye adsorption capacity. The objective of the current study is to assess the properties of the green synthesis product of nano-copper oxide by employing Sargassum sp. macroalgae and its functionalized cellulose acetate membrane for the purpose of dye adsorption. METHODS: The preparation of Sargassum sp. extract involved utilizing quantities of 2.5, 5.0, and 10.0 grams, which were subsequently combined with a copper sulphate solution to yield nano-copper oxide. Nano-copper oxide was characterized using ultra violet-visual spectroscopy, scanning electron microscope - energy dispersive spectroscopy, x-ray diffraction, and fourier transform infrared techniques. Nano-copper oxide was introduced to bacterial acetate produced from pineapple peel waste to make a composite membrane and observed the antibacterial activity against E.coli and S.aureus, and dye adsorption to Methylene Blue, Malachite Green, Metanil Yellow, and Congo Red for 60 minutes contact time. FINDINGS: Nano-copper oxide is successfully synthesized using macroalgae Sargassum sp. proved by wavelength of ultra violet-visual spectroscopy results at 300 nanometer and energy dispersive spectroscopy analysis that denotes the presence of copper at 0.93 and 8.04 kilo electron volt. It has been verified that the inclusion of Sargassum sp. has effectively facilitated the production of nano-copper oxide. The findings from X-ray diffraction analysis reveal that the crystallite size of the nano-copper oxide measures approximately 19.5 nanometers. Adding nano-copper oxide as much as 2.0 weight percent into cellulose acetate membrane reduces membrane crystalline index from 88.6 percent to 85.7 percent but gives benefit in increasing the anti-bacterial activity against Escherichia coli and Staphylococcus aureus. The adsorption capacity is enhanced for Methylene Blue and Malachite Green dyes, whereas it is diminished for Metanil Yellow and Congo Red dyes. CONCLUSION: Sargassum sp. was effectively employed as a reducing agent to synthesize nano-copper oxide, with an optimal concentration of 5.0 grams for achieving green synthesis. The copper metal obtained through green synthesis exhibits a spherical morphology and possesses an average crystallite size of approximately 19.5 nanometers. It has a percentage atomic weight of 60.6 percent. Introducing nano-copper oxide by 2.0 weight percent into bacterial cellulose acetate membrane reduces the crystalline index from 88.6 percent to 85.7 percent. The rise in nano-copper oxide content within the cellulose acetate membrane leads to a proportional increase in the membrane's antibacterial properties. Additionally, the adsorption of cationic dye in cellulose acetate composite is enhanced, while the adsorption of anionic dye is diminished. [ABSTRACT FROM AUTHOR]

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The rapid development of piezoelectric sensors has been studied extensively, owing to their good flexibility, wearability, high sensitivity and low cost. However, some inorganic materials with good piezoelectricity cannot make sensors flexible, and the organic materials with good flexibility have a weak output electrical signal and low strength. In order to explore and optimize the preparation technology of piezoelectric sensors, a BaTiO3@polyacrylonitrile (PAN)/poly(vinylidene fluoride) (PVDF) nanofibrous composite membrane (NCM) was prepared by cross-electrospinning technology and the central combination design (CCD) method. The morphology, structure, hydrophobicity, mechanical properties and piezoelectricity of the BaTiO3@PAN/PVDF NCMs were investigated. The BaTiO3@PAN/PVDF NCMs had the better hydrophobicity and mechanical properties compared with the pure PAN/PVDF NCM. The 5BaTiO3@PAN/PVDF NCM designed by CCD had a more uniform fiber diameter, and a more stable output voltage with a 46% improvement. With the help of cross-electrospinning technology and the CCD method, the NCM will be outstanding for the development of fabricating flexible wearable piezoelectric sensors. [ABSTRACT FROM AUTHOR]

In order to improve the functionality of cellulosic materials research and development of high performance soluble materials. Therefore, the Fe3O4/CMS composite membrane was prepared by using carboxymethyl salix powder (CMS) and Fe3O4 as raw materials, 1-propenyl-3-methylimidazolium chloride and dimethyl sulfoxide as dissolution system. The effects of swelling time, swelling temperature, pH and ionic strength on the swelling performance of Fe3O4/CMS composite membranes and the swelling kinetics of the composite membranes were studied. The structure of the composite membrane was characterized by SEM, FT-IR, XRD and TG. The results showed that the swelling degree reached 5.54 g·g−1, when the swelling time was 45 min, the swelling temperature was 65°C, the pH was 5 and the ionic strength was 0.08 mol·L−1. The initial phase of dissolution of the composite membrane fits well with the Fickian diffusion model, and the whole dissolution process belongs to the Schott model, indicating that the main role of the dissolution process is the diffusion of water molecules, while the composite membrane can be preserved for a long time at high temperature, which provides sustainability for the composite membrane. The characterization results showed that the surface of Fe3O4/CMS composite film was rough with small grooves. The O-H effect was enhanced and the Fe-O absorption peak appeared at 600 cm−1, indicating that Fe3O4 had been successfully loaded onto the cellulose membrane. The Fe3O4/CMS composite membrane belonged to cellulose type II structure, meanwhile, the composite membrane had good thermal stability. [ABSTRACT FROM AUTHOR]