Nanofibrous Membranes Research Articles

Nanofiber membranes fabricated by coaxial electrospinning with porous channel structure for high-efficiency oil-water separation

The electrospinning nanofiber membranes modified by nanoparticles can effectively improve anti-oil adhesion and separation performance. However, the low stability of nanoparticles on the fiber membrane surface substantially limits the operational lifespan of the membrane. Herein, poly(vinylidene fluoride) (PVDF) nanofiber membranes with multi-scale microporous channel structures are prepared using coaxial electrospinning and a sacrificial template strategy. Subsequently, iron phytate nanoparticles are grown in situ on the fibers to fill the porous structures by utilizing the hollow and porous nanofibers as a framework. The interlocking structure between the nanoparticles and the porous fibers significantly enhances the stability and durability between nanoparticles and the fiber membrane. Even after being subjected to ultrasonic treatment for 7 h, there is no discernible shedding of nanoparticles from the fiber membrane. The prepared nanofiber membrane demonstrates exceptional superhydrophilicity and underwater superoleophobicity, exhibiting remarkable self-cleaning capability and resistance to crude oil contamination. Additionally, the membrane efficiently separates various oil-in-water emulsions, achieving a high separation efficiency of over 99%. Moreover, the membrane also demonstrates excellent adsorption capability towards cationic dyes. Therefore, this interlocking structure composed of nanoparticles and nanofibers presents new ideas and insights for the preparation of high-performance and durable oil–water separation membranes.

Electrochemical degradation of small molecule dyes by TiO2-decorated polyacrylonitrile nanofiber membranes with superior properties

To optimize the uniform dispersion of nanoparticles and enhance their catalytic degradation effect on small molecule dyes in textile wastewater, titanium dioxide (TiO2) was deposited on polyacrylonitrile (PAN) fiber membranes using magnetron sputtering technology, and TiO2/PAN nanofiber membrane (NFM) with low content and high catalytic efficiency was successfully prepared. Through membrane separation coupling electrocatalysis, the composite membranes exhibited outstanding performance in removing Congo red (CR), Sunset yellow (SY), Methyl orange (MO), and Methylene blue (MB) dyes, with removal rates of 99.5%, 98.8%, 98.5%, and 87.2% respectively. Even after continuous catalysis for 10 h, the composite membranes maintained a high dye removal rate, demonstrating their remarkable stability and water treatment capabilities. Furthermore, TiO2/PAN NFMs displayed high pure water permeance, dye permeance, and mechanical strength. Specifically, M20 (magnetron sputtering time of 20 min) showed water permeance and dye (SY) permeance values of 1944 L·m−2·h−1·bar−1 and 816 L·m−2·h−1·bar−1, respectively, and indicate superior mechanical and electrochemical properties. During the electrocatalytic process, TiO2/PAN NFMs generated reactive oxygen species (ROS) on the surface, imparting a self-cleaning property that extended the service life of the membranes and offered an effective solution for textile wastewater treatment.

Developing novel multifunctional protective clothes for disabled individuals using bio-based electrospun nanofibrous membranes

A novel kind of protective apparel for handicapped persons has been created with bio-based electrospun nanofibrous (NFs) membranes. Hydrophobic membranes with fine polylactic acid (PLA) NFs had a smooth, bead-less structure with an average diameter of 950 nm. The hydrophilic layer has a similar pattern but a smaller fiber diameter dispersion and an average diameter of 750 nm. The silica nanoparticle-modified super-hydrophobic top layer (contact angle, ~153°) repels water and keeps the user dry. Super-hydrophilic silver nanoparticles in the fabric's bottom layer react with perspiration to kill microorganisms. The fabric's porosity (avg. 1.2–1.5 μm) allows for breathability, while silica nanoparticles boost infrared radiation reflection, keeping users cool on hot days. The dual-layer textile has 4.9 MPa ultimate tensile strength and 68 % elongation compared to the membrane's super-hydrophobic and super-hydrophilic layers. Wearing protective clothes reduced hand temperature by 25 % in direct sunlight and 13 % in a sun simulator with 1 Sun. This fabric will work well for adult diapers, outdoor clothing, and disability accessories. Overall, the protective textiles may improve the quality of life for disabled and elderly people by providing usable textile items adapted to their needs.

The Development and Evaluation of PFSA‐Free Polyacrylonitrile‐co‐Methyl Acrylate (PAN‐MA) Nanofiber Membranes for its Potential Application as a Proton Exchange Membrane in Fuel Cells

AbstractThe 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.

Room Temperature Phosphorescent Nanofiber Membranes by Bio-Fermentation.

Stimuli-responsive materials exhibiting exceptional room temperature phosphorescence (RTP) hold promise for emerging technologies. However, constructing such systems in a sustainable, scalable, and processable manner remains challenging. This work reports a bio-inspired strategy to develop RTP nanofiber materials using bacterial cellulose (BC) via bio-fermentation. The green fabrication process, high biocompatibility, non-toxicity, and abundant hydroxyl groups make BC an ideal biopolymer for constructing durable and stimuli-responsive RTP materials. Remarkable RTP performance is observed with long lifetimes of up to 1636.79ms at room temperature. Moreover, moisture can repeatedly quench and activate phosphorescence in a dynamic and tunable fashion by disrupting cellulose rigidity and permeability. With capabilities for repeatable moisture-sensitive phosphorescence, these materials are highly suitable for applications such as anti-counterfeiting and information encryption. This pioneering bio-derived approach provides a reliable and sustainable blueprint for constructing dynamic, scalable, and processable RTP materials beyond synthetic polymers.

Preparation of ethyl cellulose bimodal nanofibrous membrane by green electrospinning based on molecular weight regulation for high-performance air filtration

Preparing bio-based air filtration membrane through green electrospinning strategy is a vital approach to alleviating environmental and energy crises. However, the development of related biomaterials and method for regulating membrane structure are still lacking. In this study, ethyl cellulose (EC) bimodal nanofibrous membrane was prepared by electrospinning using ethanol and water as solvents to achieve high-performance air filtration. A new strategy for bimodal fiber molding based on molecular weight modulation was proposed. The EC polymer chains with medium molecular weights were subject to the highest degree of inhomogeneity of solvent intrusion, and there were significant differences in viscous forces “microscopically”, leading to the formation of bimodal structure by inhomogeneous stretching of the jet. The well-defined bimodal structure endowed EC membrane with excellent air filtration performance. The filtration efficiency for PM0.3, pressure drop, quality factor were 99.11 %, 42.2 Pa, and 0.112 Pa−1, respectively. Compared to the commonly used zein, EC cost just 12.77 %, and its solution had a 50 % longer shelf life, making it a more desirable biomaterial. This work will facilitate the application of more biomaterials in air filtration, promote the green fabrication of high-performance air filtration membranes, and realize sustainable development.

Surface modification of polyacrylonitrile nanofiber membrane by Bimetallic organic frameworks for enhanced antibacterial properties

With the increasing environmental degradation, bacterial contamination is threatening human health. Thus, it is crucial to develop an efficient and safe antimicrobial strategy. In this work, the polyacrylonitrile (PAN) nanofiber membranes contained Co/Zn-metal organic framework (Co/Zn-MOF@PAN) were fabricated via electrospinning technique and surface modified method. The optimal preparation condition for nanofiber membranes were further regulated by adjusting 2-methylimidazole (2-MIM) concentration and secondary growth time. The antibacterial activity of Co/Zn-MOF@PAN against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were determined by turbidimetry and plate colony-counting methods. As the 2-MIM concentration and secondary growth time increased, the hydrophilicity and surface roughness of Co/Zn-MOF@PAN nanofiber membranes increased. In addition, when the 2-MIM concentration was 0.16 mol/L, the Co/Zn-MOF@PAN nanofiber membranes had an antibacterial rate of over 99% against E. coli and S. aureus., and the minimum inhibitory concentration (MIC) value of Co/Zn-MOF@PAN nanofiber membranes was 0.75 mg/mL. It could be indicated that Co/Zn-MOF@PAN nanofiber membranes exhibited an excellent antibacterial effect. The main antibacterial mechanism of nanofiber membranes was that ROS produced by MOFs could destroy the physiological activities of the bacteria lead to death. The Co/Zn-MOF@PAN nanofiber membranes will have a wide range of applications value in the fields of antibacterial packaging materials and sterilization of water resources.

Structure design and performance optimization of PVDF-CTFE nanofibrous composite nanofiltration membrane modified by C–Cl active site grafting

The substrate membrane plays a crucial role in determining the performance of composite nanofiltration membranes prepared by interfacial polymerization (IP). In this study, persistent hydrophilic modification of polyvinylidene fluoride-co-chlorotrifluoroethylene (PVDF-CTFE) was achieved by incorporating N-methylglucamine (N-MG) without altering the membrane's morphology or pore size. Moreover, thin-film nanofibrous composite (TFNC) nanofiltration membranes were prepared using the surfactant assembly regulated interfacial polymerization (SARIP) method with the modified PVDF-CTFE@N-MG nanofibrous membrane as the substrate. The effect of N-MG addition on the substrate membrane's hydrophilicity and the structure and performance of the polyamide (PA) separation layer was investigated. The results showed that the addition of N-MG significantly improved the hydrophilicity of the PVDF-CTFE nanofibrous membrane. The TFNC-5 membrane, prepared with the modified PVDF-CTFE@N-MG nanofibrous membrane as the substrate, exhibited permeability exceeding 13.5 L m−2 h−1·bar−1 for various dye solutions at 3 bar pressure, with rejection rates above 98 %. It also demonstrated excellent selective separation performance (separation factor for NaCl/Orange G reaching 97.38) and long-term operational stability. This work provides a method for the preparation of low-pressure, high-flux nanofiltration membranes, which is applicable to seawater desalination and dye wastewater treatment.

The polycaprolactone and silk fibroin nanofibers with Janus-structured sheaths for antibacterial and antioxidant by loading Taxifolin

Electrospinning is a widely recognized method for producing Janus or core-shell nanofibers. In this study, nanofibrous membranes were fabricated through co-axial electrospinning utilizing polycaprolactone (PCL) and silk fibroin (SF) as the Janus shell, and taxifolin (TAX) and SF as the core. The resulting nanofibers had diameters of 816 ± 161 nm and core diameters of 73 ± 5 nm. The morphology and properties of the PCL-SF@SF/TAX nanofibers were subsequently analyzed. The results demonstrated that the nanofibrous membranes achieved physical and chemical characteristics potential for tissue engineering and drug delivery. Specifically, the membranes exhibited a Young's modulus of 9.64 ± 0.29 MPa, a water contact angle of 79.1 ± 1.3°, and a weight loss of 17.3 ± 1.0 % over a period of 28 days. The incorporation of TAX endowed the membranes with antibacterial properties, effectively combating Escherichia coli and Staphylococcus aureus. Furthermore, the membranes demonstrated antioxidant capabilities, with a DPPH radical scavenging efficiency of 38.5 ± 5.6 % and a Trolox-equivalent antioxidant capacity of 0.24 ± 0.01 mM. The release of the antioxidant was sustained over 28 days, following first-order release kinetics. The nanofibrous membranes, referred to as PSST, exhibit promising potential for use as biomaterials, characterized by their antibacterial activity, antioxidant and cytocompatibility.

Tuning a Superhydrophobic Surface on an Electrospun Polyacrylonitrile Nanofiber Membrane by Polysulfone Blending.

Nanofibers made of different materials have been continuously studied and widely used as membranes due to their simple fabrication techniques and tunable surface characteristics. In this work, we developed polyacrylonitrile (PAN) nanofiber membranes by the electrospinning method and blended them with polysulfone (PSU) to obtain superhydrophobic surfaces on the fiber structures. The scanning electron microscopy (SEM) images show that the fabricated nanofibers have smooth and continuous morphology. In addition, to observe the effect of the PSU-based blending material, Fourier-transform infrared (FTIR) spectra of the samples were acquired, providing chemical compositions of the bare and PSU-blended PAN nanofibers. The fabricated PSU/PAN composite nanofibers have a diameter range of 222-392 nm. In terms of the wettability, the measured water contact angle (WCA) value of the PAN nanofibers was improved from (14 ± 1)° to (156 ± 6)°, (160 ± 4)°, (156 ± 6)°, and (158 ± 4)° after being blended with PSU solutions having concentrations of 0.5, 1, 1.5, and 2 wt %, respectively. This result has proven that the PAN nanofiber surfaces can be tuned from hydrophilic to superhydrophobic characteristics simply by introducing PSU into the PAN solution prior to electrospinning, where a small PSU concentration of 0.5% has been sufficient to provide the desired effect. Owing to its low-cost and highly efficient process, this strategy may be further explored for other types of polymer-based nanofibers.

Non-isocyanate polyurethane-co-polyglycolic acid electrospun nanofiber membrane wound dressing with high biocompatibility, hemostasis, and prevention of chronic wound formation

The prevention of chronic wound formation has already been a primary subject in wound management, particularly for deep wounds. The electrospun nanofiber membranes hold tremendous potential in the prevention of chronic wounds due to their micro/nano pore structures. Currently, many natural and synthetic materials have been utilized in the fabrication of nanofiber membranes. However, striking a balance between the structural stability and the biocompatibility remains challenging. It is necessary not only to ensure the long-term durability of nanofiber membranes but also to enhance their biocompatibility for alleviating patients' suffering. In this study, we reported a nanofiber membrane dressing with excellent biocompatibility and mechanical properties, which is potential for the treatment of deep wounds. The basal material chosen for the preparation of the nanofiber membrane was a co-polyester (NI-LPGD5) synthesized by non-isocyanate polyurethane (NIPU) and polyglycolic acid with a dihydroxy structure (LPGD—synthesized from glycolic acid and neopentyl glycol). Moreover, curcumin was also added as a bioactive substance to enhance the pro-healing effect of dressings. The physicochemical properties of the prepared nanofiber membranes were characterized through various physicochemical tools. Our results demonstrated that the NI-LPGD5 co-polymer can be electrospun into smooth fibers. Meanwhile, curcumin-loaded nanofiber membranes (Cur/NI-LPGD5) also exhibited a favorable microscopic morphology. The fabricated membranes exhibited suitable mechanical properties, outstanding hygroscopic-swelling rate and water vapor transmittance. Besides, in vitro cell culturing, the cells on the NI-LPGD5 membrane maintained their maximum viability. The potential of in vivo wound healing was further demonstrated through animal experiments. The experimental results showed that the nanofiber membranes effectively prevented chronic wounds from forming and promoted granulation tissue growth without replacing the dressing throughout the healing process. We also found that these nanofiber membranes could effectively promote the expression of related biomarkers to accelerate wound healing, particularly the Cur/NI-LPGD5 membrane. In conclusion, the fabricated membranes possess suitable physicochemical properties and promising bioactivity. As a result, it effectively prevented the formation of chronic wounds and demonstrated significant potential in reducing the frequency of dressing changes.

Electrospun Silicon Dioxide/poly(vinylidene fluoride) Nanofibrous Membrane Comprising a Skin Multicore-Shell Nanostructure as a New High-Heat-Resistant Separator for Lithium-Ion Polymer Batteries.

Porous silicon dioxide (SiO2)/poly(vinylidene fluoride) (PVdF), SiO2/PVdF, and fibrous composite membranes were prepared by electrospinning a blend solution of a SiO2 sol-gel/PVdF. The nanofibers of the SiO2/PVdF (3/7 wt. ratio) blend comprised skin and nanofibrillar structures which were obtained from the SiO2 component. The thickness of the SiO2 skin layer comprising a thin skin layer could be readily tuned depending on the weight proportions of SiO2 and PVdF. The composite membrane exhibited a low thermal shrinkage of ~3% for 2 h at 200 °C. In the prototype cell comprising the composite membrane, the alternating current impedance increased rapidly at ~225 °C, and the open-circuit voltage steeply decreased at ~170 °C, almost becoming 0 V at ~180 °C. After being exposed at temperatures of >270 °C, its three-dimensional network structure was maintained without the closure of the pore structure by a melt-down of the membrane.

A novel tiny triboelectric acoustic sensor design based on nanocomposite enhancement for highly-sensitive, broadband, and self-powered multi-functional applications

This work proposes a novel acoustic nanocomposite fibrous membrane-based triboelectric nanogenerator (NFM-TENG) with excellent acoustical-to-electrical conversion performance. The optimal combination for the triboelectric pairs of NFM-TENG is identified: a polyvinylidene fluoride-multiwalled carbon nanotubes (PVDF-MWCNTs (1 wt%)) nanofibrous membrane as the tribo-positive layer, and a corona-charged fluorinated ethylene-propylene (FEP) solid membrane as the tribo-negative layer, resulting in higher electric output than single-friction-layered NFM-TENG (32 times). Under the acoustic excitation of 116 dB at 200 Hz, the acoustic NFM-TENG can generate a maximum areal power density of 3.78 W/m2. The NFM-TENG can be used not only as a acoustic energy harvester, but also as a self-powered triboelectric acoustic sensor (TAS) for real-time voice recording and control. For convenience, for the first time, an advanced tiny TAS (TTAS, diameter: only 9.7 mm) based on the NFM-TENG is developed and its sensitivity is calibrated as -50 dB according to the International standard IEC61094. Experimental results also verified that the TTAS with broadband response ability (20–20,000 Hz) is fully competent for commercial applications such as real-time voice control, HMI, and other multi-scenarios. The TTAS is smart, reliable and customizable, potentially leading to a new revolution in intelligent interaction.

Multifunctional nanofibrous membranes for highly efficient harsh environmental air filtration and oil–water separation

With the acceleration of the global industrialization process, the treatment of corrosive waste gas and oily wastewater in pharmaceutical, petrochemical and smelting fields still remains tremendous challenges. Herein, a robust polysulfonamide/polyacrylonitril@silica (PSA/PAN@SiO2) nanofibrous membrane with a hierarchical structure was successfully developed to deal with air filtration and oil–water separation under practical complex environments. In the process of air purification, the synergistic effect of multiple components could effectively surmount the conflict between pollution particle removal efficiency and pressure resistance. The air cleaning efficiency (PM0.3) of the PSA/PAN@SiO2 composite membranes could reach 99.05 ± 0.13 % at a low pressure drop of 30 ± 2 Pa. Due to the outstanding stability of PSA and SiO2, the composite membranes still possessed stable filtration performance in complex environments (strong acid, strong alkali and high temperature). Furthermore, PSA/PAN@SiO2 composite membranes with unique wettability (under oil superhydrophobicity and underwater superoleophobicity) could efficiently separate oil–water mixtures and emulsions. This multifunctional filtration membrane provides enormous application potential for the field of individual protection and environmental governance, even in complex environments.

Promoting renal I/R injury repair by in-situ electric stimulation using biodegradable piezoelectric polylactide/vitamin B2 composite nanofibrous membrane

Ischemia/reperfusion (I/R) injury during renal transplantation remains a prevalent challenge. Recent studies proposed protective effects against renal I/R injury using electric fields during organ preservation stage. However, I/R process extends to the post reperfusion stage and traditional electrical stimulation methods face limitations, requiring power sources and electrodes. Hence, there is a need for implantable, biodegradable materials capable of continuously generating electrical stimulation to treat kidney I/R injury over an extended period. In this work, a polylactide/Vitamin B2 (PLLA/VB2) composite nanofibrous membrane was designed. The incorporation of VB2 into PLLA, coupled with electrospinning, significantly enhanced its piezoelectric performance and flexibility, thereby enabling optimal adherence and efficient in-situ electrical stimulation. Experimental results underscored that PLLA/VB2 nanofibrous membrane could mitigate tubular injury, facilitate cell regeneration, and alleviate interstitial fibrosis possibly by preserving mitochondrial structure and function. This innovative approach not only pioneers new strategies for addressing I/R related conditions but also offers potential treatments for a range of diseases linked to oxidative stress.

A visual ratio PVA/curcumin/indigo nanofibre membrane based on natural pigments for detecting mutton freshness

SummaryIn the storage process, meat is susceptible to external factors that produce corruption and deterioration, affecting consumers' health. Therefore, preparing an indicator membrane that can detect freshness in real time, non‐destructively, and visually is significant. Herein, an indicator membrane was prepared by electrostatic spinning technology using polyvinyl alcohol (PVA) as the substrate and curcumin (CUR) and indigo (IND) as the mixed indicator for freshness detection. When curcumin and indigo were mixed at 3:1 (w/w), CUR was transformed from ketone type to enol type with the gradual increase of pH, and IND underwent electron leaps, which resulted in green, brown, and reddish‐brown colour changes in the solution, and the colour development effect was effectively improved. The characterisation results showed that the average fibre diameter of the PVA/0.8 indicator membrane was 252 nm, the hybrid indicator was successfully loaded in the nanofibres, and the water contact angle was 103.6°, which was hydrophobic. In addition, the indicator membrane was sensitive to trimethylamine (limit of detection 17.38 ppm) and triethylamine (limit of detection 27.77 ppm) but insensitive to saline, ethanol, ethyl acetate, and other contaminants with detection specificity. Finally, the colour of the indicating membrane changes from green to brown during the storage of mutton in the mutton was rotten, indicating that the naked eye can judge the freshness of the mutton. Therefore, the PVA/CUR/IND indicator membrane has excellent potential for application in real‐time and non‐destructive detection of mutton freshness.

CeO2-loaded PVA/GelMA core-shell nanofiber membrane to promote wound healing

Chronic wounds are a significant health issue due to various pathogenic abnormalities that hinder the healing process. Nanofiber membranes, with their favorable conductivity for cell growth, proliferation, and adhesion, offer immense potential for effective chronic wound healing. In this study, we utilized the coaxial electrospinning method to synthesize core-shell structured nanofiber membranes for chronic wound healing. To obtain superior nanofiber membranes, we modified the shell part of the electrospun nanofiber by combining gelatin methacrylate (GelMA) with cerium oxide (CeO2). The results show that these nanofibers exhibit promising wound healing properties, including ideal hydrophilicity, swelling ratio, porosity, mechanical properties, antibacterial activity, and fibroblast cell viability. With the addition of 3 % w/v CeO2 nanoparticles (PGCe-3 CL sample), the nanofiber membrane had a 53.7° water contact angle, 384.47 % swelling ratio, 83.91 % porosity, and 8.49 MPa tensile strength, which are optimal for the wound healing process. The PGCe-3 CL sample also demonstrated increased antibacterial activity, reducing bacterial colonies by up to 88.46 % for S. aureus and 93.14 % for E. coli compared to PG-CL and PGCe-1.5 CL. Furthermore, the cell viability test showed that the nanofiber membranes are non-toxic to human dermal fibroblast cells and significantly enhance cell proliferation compared to other samples. Accordingly, the synthesized nanofiber membranes loaded with nano CeO2 in this study show promising performance as suitable dressings for chronic wounds. Moreover, the findings of this study provide valuable insights for developing more effective and innovative materials for chronic wound healing.

Dual functional composite solid electrolyte constructed by double-layer sulfonated polyethersulfone (SPES)/poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) nanofiber membrane in high-performance all-solid-state lithium metal batteries

The successful implementation of polymer electrolytes in next-generation all-solid-state lithium metal batteries (ASSLMBs) is impeded by their low ion conductivity and weak resistance to lithium dendrites. Herein, a composite solid electrolyte (D-SPES-PH-PEO) with dual reinforcement effects is obtained by combining PEO matrix with a double-layer sulfonated polyethersulfone (SPES)-poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) nanofiber membrane. The SPES nanofiber membrane acts as a hopping site for ion transport by utilizing the electronegativity and Coulombic force of its own –SO3H groups, reducing the energy barrier of the D-SPES-PH-PEO electrolyte. Profiting from the existence of C-F bond, PVDF-HFP nanofiber membrane specializes in generating a protective SEI layer on the lithium anode. Moreover, such a functional membrane not only effectually constructs a three-dimensional ion transport channel by fabricating ion conductive substructures, but also enhances the mechanical strength of the electrolyte. Consequently, the D-SPES-PH-PEO electrolyte is equipped with a high ion conductivity of 7.41 × 10−5 S cm−1 at 30 °C and high tensile strength of 8 MPa. Furthermore, Li/Li symmetric battery incorporating D-SPES-PH-PEO electrolyte enables a stable cycle for 2500 h at 0.2 mAh cm−2. The D-SPES-PH-PEO electrolyte represents outstanding compatibility with LiFePO4 and high-voltage LiNi0.8Mn0.1Co0.1O2 (NMC811) electrodes. Especially, the LiFePO4/D-SPES-PH-PEO/Li pouch cell indicates an initial specific capacity of 146.7 mAh g−1 and the NMC811/D-SPES-PH-PEO/Li pouch cell reaches a maximum capacity of 178.5 mAh g−1. This study emphasizes the importance of double reinforcement of ion conduction and anode protection on solid electrolytes.

Flexible and Mechanically Robust Nanofiber Membrane with Candle Soot-Induced Rough Surface for Organic Liquid Separation

Flexible and Mechanically Robust Nanofiber Membrane with Candle Soot-Induced Rough Surface for Organic Liquid Separation

Graphene-decorated polyurethane nanofiber membrane flexible sensor with different fiber orientation

Electrospun polyurethane (PU) nanofiber membranes offer desirable properties such as large strain, good resilience, light weight, good air permeability, and good adhesion to the skin; as a result, they have a unique advantage in the development of flexible sensors. To explore the application of conductive graphene (Gr)/PU nanofiber membranes in the field of strain sensing and to study the influence of the nanofiber orientation structure on the sensing performance of nanofiber sensors, electrospinning technology was adopted to prepare PU nanofiber membranes with different fiber orientations by adjusting the rotating speed of the receiving drum. Gr/PU nanofiber membranes were prepared as strain-resistance sensors, their strain-resistance sensing performance was analyzed, and the membranes were used to monitor human motion and air vibrations. The results showed that the orientation of the nanofibers in the PU nanofiber membranes could be improved by increasing the rotation speed of the receiving drum. Gr/PU nanofiber sensors have good sensing linearity, sensitivity, and stability; an increase in fiber orientation also increases sensor sensitivity, and the sensitivity factor can reach more than 200 at 50 % strain. Sensors with a low detection threshold and high detection sensitivity, which can be used for large-scale motion monitoring of human joints and small-range motion monitoring of air vibrations, have potential applications in wearable human motion health monitoring and other fields.