Nanofibrous Membranes Research Articles

Porous covalent organic framework nanofibrous membrane for excellent enrichment and ultra-high sensitivity detection of trace organochlorine pesticides in water

Developing adsorbents with high performance and long service life for effective extracting the trace organochlorine pesticides (OCPs) from real water is attracting numerous attentions. Herein, a self-standing covalent organic framework (COF-TpPa) membrane with fiber morphology was successfully synthesized by using electrospun nanofiber membranes as template and employed as solid-phase microextraction (SPME) coating for ultra-high sensitivity extraction and analysis of trace OCPs in water. The as-synthesized COF-TpPa membrane exhibited a high specific surface area (800.83 m2 g−1), stable nanofibrous structure, and excellent chemical and thermal stability. Based on the COF-TpPa membrane, a new SPME analytical method in conjunction with gas chromatography-mass spectrometry (GC–MS) was established. This proposed method possessed favorable linearity in concentration of 0.05–2000 ng L−1, high sensitivity with enrichment factors ranging from 2175 to 5846, low limits of detection (0.001–0.150 ng L−1), satisfactory precision (RSD < 10 %), and excellent repeatability (>150 cycles), which was better than most of the reported works. Additionally, the density functional theory (DFT) calculations and XPS results demonstrated that the outstanding enrichment performance of the COF-TpPa membrane was owing to synergistic effect of π–π stacking effects, high specific surface area and hydrogen bonding. This work will expect to extend the applications of COF membrane to captures trace organic pollutants in complex environmental water, as well as offer a multiscale interpretation for the design of effective adsorbents.

High performance bimetallic ZIF-CoZn@PVDF-HFP composite nanofiber membrane for membrane distillation based on coaxial electrospinning technology

Membrane Distillation (MD) technology stands out for its cost-effectiveness and sustainability in diverse applications, such as high-salinity wastewater treatment and seawater desalination. However, conventional MD membranes frequently encounter challenges associated with inadequate permeate flux and insufficient anti-wetting performance. In the present study, we fabricated a series of ZIF-CoZn@PVDF-HFP composite nanofiber membranes with a core–shell structure via coaxial electrospinning. Here, PVDF-HFP functions as the core, while a blend of bimetallic Zeolitic imidazolate framework ZIF-CoZn nanoparticles and PVDF-HFP constitutes the shell. Through the utilization of the coaxial technology, functional nanoparticles achieve uniform and stably dispersed on the nanofiber surface, leading to the creation of a secondary rough structure in addition to the inherent roughness of single-nozzle electrospinning. This results in a surface with a 3D-hierarchical structure. The significantly amplifies the evaporation area on the surface of the composite nanofiber membrane, thereby bolstering the permeate flux in the MD process. Additionally, the incorporation of bimetallic ZIF-CoZn nanoparticles, recognized for their superior hydrophobicity and low thermal conductivity, improves the anti-wetting and heat-insulating properties of the composite nanofiber membrane, further advancing permeate flux performance. Using a 35 g L−1 NaCl as the feed solution, the optimal 1 % ZIF-CoZn@PVDF-HFP composite nanofiber membrane demonstrated a permeate flux of 21.8 L m−2 h−1, coupled with a salt rejection rate exceeding 99.9 %. Even during long-term MD testing, it maintained excellent insulation and anti-wetting capabilities. Our research offers a convenient and effective approach for fabricating anti-wetting composite nanofiber membranes.

Eu3+ embedded hybrid fluorescent membrane for Ultrasensitive and efficient sensing of Cu2+ in aqueous media

Copper (Cu2+) detection is of great significance as it is important constituent of human body and its excessive amount may cause the neurodegenerative diseases. Herein, we developed fluorogenic indicator Eu3+ complex (Eu(TTA)3phen) embedded a novel polyvinylidene fluoride (PVDF)/polyvinylpyrrolidone (PVP) hybrid fibrous membrane (HFM), prepared via electrospinning technique, for the Cu2+ detection in the aqueous media. Compared with conventional pristine PVDF membrane, the current PVDF/PVP hybrid flexible fibrous membrane exhibited improved hydrophilicity (contact angle decreased from 135° to 33°), which was attributed to uniformly dispersed PVP. Scanning electron microscopic study confirmed the bead like nanofibrous morphology of electrospun Eu(TTA)3phen doped PVDF/PVP hybrid membrane. The devised nanofibrous membrane exhibited a fast response and good selectivity and sensitivity towards Cu2+, almost no response was observed for other ions. Efficient fluorescence quenching was observed upon addition of Cu2+ ions onto the membrane owing to the interruption of antenna affect from ligand to Eu3+. The current nanofibrous membrane sensor allowed the Cu2+ detection in the range of 2.5–30 μM, with a detection limit of 4.47 μM in aqueous media, demonstrating its potential for use in the clinical test of neurodegenerative diseases.

Pre-oxidized PAN Nanofibrous Membrane to Efficiently and Continuously Separate Large-Scale Viscous Oil-in-Water Emulsions Under Harsh Conditions with Ultra-Long-Term Oil-Fouling Recovery

Pre-oxidized PAN Nanofibrous Membrane to Efficiently and Continuously Separate Large-Scale Viscous Oil-in-Water Emulsions Under Harsh Conditions with Ultra-Long-Term Oil-Fouling Recovery

Enhancing filter efficiency of polyimide/polyethersulfone nanofiber membranes via novel treatments of high pressure processing, thermocompression, atmospheric plasma, and corona discharge

In this study, novel post-treatments contained of high pressure processing (HPP), thermocompression, atmospheric plasma, and corona discharge were used to progress the filter quality of polyimide/polyethersulfone (PI/PES) nanofiber membranes in the conditions of 50/50 % PI/PES, 0.15 ml/hr flow rate, 22.5 kV, and 20 min. The filter quality of nanofiber membrane did not get progress after HPP and thermocompression treatments, so high temperature and pressure did not improve the filter quality. Otherwise, atmospheric plasma destroyed the morphology of fiber surface, caused loss of filter efficiency and filter quality. However, corona discharge treatment presented different result with the above three treatments, and the filter efficiency and filter quality of the fiber membrane was improved after corona discharge treatment. Furthermore, factor influence order was ranged as operational voltage, discharge time, and discharge distance from result of filter quality on comparison of S/N value and level difference via Taguchi method. The application of corona discharge resulted in fiber acquired surface electric potential of 0.315 ± 0.56 kV at the optimized conditions of operational voltage (25 kV), discharge distance (7 cm), and discharge time (60 min), and filter efficiency of fiber enhanced from 95.66 ± 0.96 % to 98.70 ± 0.36 %. Further, the optimized PI/PES nanofiber membranes with corona discharge not only had a remarkable filter quality (2.214 Pa−1) but also maintained an effective filtration efficiency of ultra-fine particles (98.70 %) and a low pressure loss of 1.961 Pa for creating a promising filter of air purification and N95 Masks of USA NIOSH Standard.

Current Update on Electrospun Nanofiber Mats as a Wound Healing Drug Carrier

Electrospun nanofiber mats are being researched as attractive wound-healing drug carriers owing to their exclusive features, large active surface area, interlinked porosity, and customizable drug release kinetics. These mats may be infused with antibiotics, growth hormones, or stem cells to hasten the process of healing and lessen the likelihood of problems. Controlled and sustained medication delivery is the key payback of electrospun nanofiber mats. Electrospun nanofiber mats promote wound healing in part because of the favorable milieu they provide cell adhesion and proliferation of the affected tissue due to their enhanced active surface area. Mats of many kinds are discussed in the review. Electrospun nanofiber membranes can be created in a diversity of configurations, along with a single layer, a coaxial structure, and many layers. Recent studies have shown the efficacy of using electrospun nanofiber mats to deliver a variety of therapeutic compounds for wound healing. Treatment of wound infections using antibiotic-loaded electrospun nanofiber mats may help slow the spread of antibiotic-resistant bacteria. Electrospun nanofiber mats supplemented with growth hormones are known to hasten wound healing by encouraging the local tissue’s proliferation and differentiation. Delivery of stem cells to the wound site, where they may develop into new skin cells and stimulate tissue regeneration, can be accomplished with the help of electrospun nanofiber mats. In conclusion, electrospun nanofiber mats provide an exciting new platform for the delivery of drugs to promote wound healing. Their enormous surface area, interconnected porosity, and adaptable drug release kinetics all make them excellent vehicles for delivering a wide range of therapeutic medicines to the wound site.

The Preparation and Performance Study of Polyamide Film Based on PDA@MWCNTs/PVDF Porous Support Layer.

It is urgent to develop a polyamide (PA) thin-film composite (TFC) membrane with a new method in this study by designing and constructing a new nanomaterial support layer instead of the conventional support layer. Polydopamine-wrapped single-walled carbon nanotubes (PDA@MWCNTs) as the place of the polymerization reaction can optimize the PA film structure and performance. The resulting composite membrane presents a higher water flux of 15.8 L·m-2·h-1·bar-1 and a rejection rate of 97% to Na2SO4, simultaneously maintaining this high separation performance in 300 min. It is a new ideal to construct novel support layer by using inorganic nanoparticles and organic polymer nanofiber membranes.

Ultra-flexible TiO2/SiO2 nanofiber membranes with layered structure for thermal insulation

High-performance thermally insulating ceramic materials with excellent mechanical and thermal insulation properties are essential for thermal management in extreme environments. In this work, SiO2 was introduced into the crystalline lattice and grain boundary of TiO2 to inhibit its phase transition and grain growth. Meanwhile, layered TiO2/SiO2 nanofiber membranes (TS NFMs) were designed and prepared. The TS NFMs had lightweight (44 mg/cm3), high tensile strength (4.55 MPa), ultra-flexibility, and low thermal conductivity (31.5 mW∙m−1·K−1). The prepared TS-1100 NFMs had excellent buckling fatigue resistance, which could undergo 100 buckling-recovery cycles at up to 80% strain. Low density and high diffuse reflectance endow the TS NFMs with excellent thermal insulation effects. A single-layer nanofiber membrane was composed of multiple layers of nanofibers. According to the principle of multi-level reflection, the multilayer structure had a better near-infrared reflection effect. Through the stacking effect of layers, a 10 mm thick sample composed of about 300 layers of nanofiber membranes could reduce the hot surface temperature from 1,200 °C to about 220 °C, demonstrating an excellent comprehensive thermal insulation effect. The layered TS NFMs with ultra-flexibility, high tensile strength and high-temperature resistance (1,100 °C) provide a dominant pathway in producing materials in extremely high-temperature environments.

Fabrication of Poly(Lactic Acid)@TiO2 Electrospun Membrane Decorated with Metal-Organic Frameworks for Efficient Air Filtration and Bacteriostasis.

The development of high-performance filtration materials is essential for the effective removal of airborne particles, and metal-organic frameworks (MOFs) anchored to organic polymer matrices are considered to be one of the most promising porous adsorbents for air pollutants. Nowadays, most air filters are generally based on synthetic fiber polymers derived from petroleum residues and have limited functionality, so the use of MOFs in combination with nanofiber air filters has received a lot of attention. Here, a conjugated electrostatic spinning method is demonstrated for the one-step preparation of poly(lactic acid) (PLA) nanofibrous membranes with a bimodal diameter distribution and the anchoring of Zeolitic Imidazolate Framework-8 (ZIF-8) by the introduction of TiO2 and in situ generation to construct favorable multiscale fibers and rough structures. The prepared PLA/TZ maintained a good PM2.5 capture efficiency of 99.97%, a filtration efficiency of 96.43% for PM0.3, and a pressure drop of 96.0 Pa, with the highest quality factor being 0.08449 Pa-1. Additionally, ZIF-8 was uniformly generated on the surface of PLA and TiO2 nanofibers, obtaining a roughened structure and a larger specific surface area. An enhanced filtration retention effect and electrostatic interactions, as well as active free radicals, can be generated for the deep inactivation of bacteria. Compared with the unmodified membrane, PLA/TZ prepared antibacterial characteristics induced by photocatalysis and Zn2+ release, with excellent bactericidal effects against S. aureus and E. coli. Overall, this work may provide a promising approach for the development of efficient biomass-based filtration materials with antimicrobial properties.

Research on the screening and inhibition mechanism of angiotensin I-converting enzyme (ACE) inhibitory peptides from tuna dark muscle

The rapid screening of angiotensin I-converting enzyme (ACE) inhibitory peptides (ACEIPs) from protein hydrolysates remains a challenge in current researches. The current study presents the development of an efficient affinity medium (AOPAN–ACE) consisting of ACE immobilized on the surface of electrostatically spun polyacrylonitrile nanofibrous membranes for the efficient screening of ACEIPs. The application of this affinity medium followed by liquid chromatography–tandem mass spectrometry analysis resulted in the successful screening and identification of 60 potential ACEIPs from protein hydrolysates of tuna dark muscle. Notably, the application of PeptideRanker, pLM4ACE, and molecular docking approaches resulted in the screening and identification of a novel ACEIP FPPDVA. Furthermore, the peptide FPPDVA was synthesized using the solid-phase method, and its IC50 value on ACE was determined to be 87.11 ± 1.02 μM. Molecular docking analysis suggested that the ACEIP of the peptide FPPDVA is attributable to the formation of hydrogen bonds with the S1 active site (Ala354 and Tyr523) of ACE and metal–ligand bonds with Zn2+. In addition, molecular dynamics simulations revealed that the peptide FPPDVA formed a stable complex with ACE and was consistently localized within the active pocket of ACE over a simulation duration of 100 ns without being displaced from the active site. Lineweaver–Burk analysis further confirmed that the peptide FPPDVA exhibited mixed mode of inhibition against ACE. Overall, the affinity medium developed in the current study is potentially useful for highly efficient screening of ACEIPs, and the novel ACEIP FPPDVA identified herein is a promising functional food ingredient for antihypertensive application.

A flexible nanofiber membrane containing dendritic oxygen probe for visual monitoring pressure distribution

Pressure-sensitive paints (PSP) enable non-intrusive visualization of surface pressure distribution on model surface which is important for aerodynamic studies. However, conventional PSP materials suffer from photobleaching and inadequate sensitivity. In this work, we rationally designed and synthesized novel dendritic oxygen probes (PT1 and PT2) by covalently grafting fluorinated dendrons onto platinum tetrakis(pentafluorophenyl)porphyrin (PT0) (a common oxygen probe). Subsequently, PT2 loaded nanofibers membranes from polycaprolactone (PCL) were fabricated by electrospinning. Fabricated membranes showed high oxygen sensitivity (I0/I100 = 35.3) with excellent flexibility, good reversibility, and outstanding photostability (merely 2.0% intensity loss after prolonged irradiation). The pressure sensitivity was found around 0.73 % per kilopascal. Furthermore, significant variation in emission intensity with respect to the variation in air pressure (1.3–101.32 kPa), facilitates the naked eye visualization of the pressure distribution on the membrane surface. Such excellent oxygen and pressure sensitivity and photostability might be due to high fluorine contents of complex dendritic structure of PT2. This flexible fluorine-functionalized dendritic oxygen probe puts forward a facile and effective strategy to develop advanced PSP materials enabling accurate pressure mapping for aerodynamic studies.

Thermostable, water-repellent, moisture-permeable Nomex nanofibrous membranes with a connected PTFE network for personal protective fabrics

Water-repellent and moisture-permeable membranes are highly desirable for improving wearing comfort and protection; however, constructing thermostable fabrics with excellent moisture permeability and high resistance to water penetration in high-temperature personal protection remains a great challenge. Therefore, we fabricate Nomex nanofibrous membranes via electrospinning, and further perform dip-coating with polytetrafluoroethylene (PTFE) emulsion and hot-pressing for constructing connected PTFE network. The Nomex membranes possess hydrophobic PTFE networks and retain porous structures, improving their water repellent without influencing water vapor transmission. Furthermore, the membranes demonstrate prominent thermostability due to the synergistic effect of the high-temperature-resistant Nomex substrate and PTFE hydrophobic agent. Consequently, the Nomex/PTFE membranes exhibit prominent water-repellent and moisture-permeability with high hydrostatic pressure of 58 kPa and satisfactory water vapor transmission rate of 6008 g m−2 d−1, as well as remarkable thermostability to maintain structural stability under 300 °C, suggesting great promise as exceptional candidates for high-temperature personal protection and comfort management.

Novel dual-layer ZIF-71/PH-PSF electrospun nanofiber for robust membrane distillation

Membrane distillation (MD) is a promising technology for the treatment of hypersaline dyeing wastewater. However, commercial membranes still have limitations such as low permeate flux, membrane fouling, and membrane wetting issue in MD process. Herein, a dual-layer MD membrane was fabricated with a polysulfone (PSF) bottom layer and a poly(vinylidene fluoride-co-hexafluoropropylene) (PH) hydrophobic surface layer incorporated with ZIF-71 nanoparticles. The addition of ZIF-71 was optimized based on the results of surface morphology, contact angle, and MD performance. The incorporation of ZIF-71 nanoparticles into PH nanofiber membranes, along with their dual-layer structure, has led to notable improvements in both permeate flux and rejection performance. The fouling resistance of membrane was further evaluated with model dyeing wastewater as feed solution, which contained four types of dyes and heavy metal antimony. The MD performance of the optimized membranes was also measured with real dyeing wastewater as feed solution. The dual-layer membrane decorated with ZIF-71 nanoparticles significantly outperformed the pristine membrane in treating real dyeing wastewater, exhibiting potential for practical applications. Finally, the underlying mechanism on the improved permeate flux and rejection was elucidated systematically.

Polycaprolactone/chitosan electrospun nanofibrous membranes loaded Chinese yam polysaccharide for active food packaging

In this study, the electrospun nanofibrous membranes were prepared by blending electrospinning technology with Polycaprolactone/Chitosan (PCL/CS) as a spinning carrier and Chinese Yam Polysaccharide (CYP) as active material. The membranes were characterized and antimicrobial tested to determine whether they have potential value as food packaging. The results of SEM showed that the nanofiber membranes with different concentrations had good fiber morphology, the average fiber diameter was 313 ± 178 nm–426 ± 237 nm, and the PDI value indicated that the nanofiber was polydisperse. The addition of CYP enhanced the hydrophilicity and water solubility of the nanofiber membranes, but the mechanical strength of the membranes decreased. The spectra of FTIR and DSC indicated that the PCL/CS nanofiber membrane successfully loaded CYP, and the 4 % CYP nanofiber membrane had the best thermal stability. In vitro release tests also showed that most fibrous membranes still released CYP (56.4–81.7 %) after 240 h. In addition, the antibacterial zone diameter of PCL/CS/10 % CYP nanofiber membrane against Escherichia coli and Staphylococcus aureus was 22.01 ± 1.23 mm and 18.40 ± 0.84 mm, respectively, showing obvious antibacterial effect. In the tomato antibacterial experiment, PCL/CS/10 % CYP nanofiber membrane effectively delayed the water-loss rot of cherry tomato and kept the weight loss rate of fruit at 17.6 ± 0.14 %. The results showed that PCL/CS/10% CYP nanofiber membrane had the best effect as active food packaging.

Contact-electro-catalysis for degradation of trace antibiotics in wastewater

Antibiotic contamination of water bodies is a major concern in environmental management. Despite their superior efficacy in antibiotic removal, advanced oxidation processes (AOPs) have yet to be widely adopted owing to their substantial cost associated with the large amounts of chemicals required. In this study, a novel contact-electro-catalysis (CEC) process with reusable polytetrafluoroethylene (PTFE) particles as a trigger catalyst was applied to replace traditional AOPs, and it was able to degrade three typical antibiotics (sulfamethoxazole [SMX], ciprofloxacin [CIP], and tetracycline [TET]) in the secondary effluent of a wastewater treatment plant for the first time. The PTFE particles at a concentration of 0.8 g/L were introduced into antibiotic solutions with an antibiotic concentration of 1 mg/L, and the removal rates of SMX, CIP, and TET after a 90-min operation time reached 50 %, 80 %, and 90 %, respectively. Our findings revealed that the CEC reaction generated ●OH and 1O2, contributing substantially to antibiotic degradation. Thus, new reactive oxygen species generation mechanisms during the CEC process were proposed. Furthermore, we fabricated polyvinylidene fluoride nanofiber membranes using electrospinning to recycle PTFE particles, where a nearly 100 % recovery rate through dead-end filtration was realized with a high water flux of 7.5 m3/(m2∙h). The results of this study provide a promising approach for antibiotic removal from wastewater.

A facile method for continuous production of temperature-adaptive hyperthermal management core-sheath polyurethane nanofiber yarns based on vanadium dioxide toward commercialization

As a facile method for producing nanofiber materials, electrospinning is widely used in various fields. However, it is generally adopted for fabricating nonwoven nanofiber membranes, which limited its applications. In this study, we propose a new facile mechanism for continuous production of high-strength electrospinning nanofiber-covered yarns, which can be directly used for fabric weaving toward commercialization. After doping of vanadium dioxide(VO2), a solid–solid phase change material (PCM) with a phase change temperature close to room temperature, a smart nanofiber-covered yarn with hyperthermal management capability is obtained. Benefiting from the delicate core-sheath structure and rigorous adjustment of spinning solution composition as well as spinning parameters (including spinning voltage, solution flow rate, and spinning distance), it achieved optimal nanofiber diameter at 510 nm, and patterns sewn on polyester fabric can be lowered by up to 19 °C compared to polyester fabric. The nanofiber-covered yarn can be used for textiles such as garments and curtains, which helps reduce the tremendous energy consumed for thermal regulation.

Biomass-based renewable, eco-friendly nanofiber membrane: Large-scale fabrication and application in PM0.3 capture and oily wastewater purification

Biomass-based poly (trimethylene 2,5-furandicarboxylate) (PTF) was synthesized by the simple and low-cost direct esterification method. The high number-average molecular weight (Mn) of about 39.6 kDa was achieved for PTF with a polydispersity index (PDI) of 2.0, which was suitable for spinning. The electrospun PTF nanofiber membranes were fabricated firstly and displayed adjustable diameters, excellent mechanical properties (lifting 550 g weight, foldability) and large-scale preparation potential (area of 100 cm × 50 cm). More impressively, high initial surface potential (13.5 kV) was found for the electrospun in-suit electret membranes, which facilitated the capture of ultrafine PM particles. Subsequently, the PTF membrane showed exceptional particle capture capability with a filtration performance of 99.96 %, low pressure drops of 78 Pa, and a satisfactory quality factor of 0.1 Pa−1. PTF filters also demonstrated long-term service capability for purifying high PM2.5 concentration smoke (15 cycles, 55 min), and could be flexibly introduced into various practical scenarios. Additionally, based on the selective oil/water wettability of PTF membranes, which showed outstanding separation effects of oily wastewater(＞99.88 %, 15 cycles). Therefore, the development and application of the PTF nanofibers provided a sustainable alternative for separation/purification and various fields in the future.

Electroactive nanofibrous membrane with antibacterial and deodorizing properties for air filtration

Water vapor from respiration can severely accelerate the charge dissipation of the face mask, reducing filtration efficiency. Moreover, the foul odor from prolonged mask wear tends to make people remove their masks, leading to the risk of infection. In this study, an electro-blown spinning electroactive nanofibrous membrane (Zn/CB@PAN) with antibacterial and deodorization properties was prepared by adding zinc (Zn) and carbon black (CB) nanoparticles to the polyacrylonitrile (PAN) nanofibers, respectively. The filtration efficiency of Zn/CB@PAN for PM0.3 was > 99% and could still maintain excellent durability within 4 h in a high-humidity environment (25 ℃ and RH = 95%). Moreover, the bacterial interception rate of the Zn/CB@PAN could reach 99.99%, and it can kill intercepted bacteria. In addition, the deodorization rate of Zn/CB@PAN in the moist state for acetic acid was 93.75% and ammonia was 95.23%, respectively. The excellent filtering, antibacterial, and deodorizing performance of Zn/CB@PAN can be attributed to the synergistic effect of breath-induced Zn/CB galvanic couples’ electroactivity, released metal ions, and generated reactive oxygen species. The developed Zn/CB@PAN could capture and kill airborne environmental pathogens under humid environments and deodorize odors from prolonged wear, holding promise for broad applications as personal protective masks.

Novel activated biochar-enhanced superhydrophilic nanofibrous membrane for superior oil-in-water emulsion separation

In this research, a high-performance Polyamide 6/Polyvinyl Alcohol/Activated biochar (PA6/PVA/AB) composite nanofibrous membrane was developed for effective separation of oil-in-water emulsions. The membrane was produced by blend electrospinning of Polyamide 6 (PA6), Polyvinyl Alcohol (PVA), and Activated biochar (AB) derived from peanut shell biomass. Glutaraldehyde (GA) cross-linking was applied to enhance stability in aqueous environments to prevent PVA swelling. The resulting nanofibrous membrane exhibited a cost-effective design with a superhydrophilic/underwater superoleophobic surface (WCA of 0° and UWOCA of 164°), a porous structure (93% porosity), and robust mechanical properties (Tensile strength: 7.73 MPa, Young modulus: 45 MPa). Optimization of the membrane composition, with 5%wt. PVA and 2%wt. AB relative to the total polymer weight in the electrospinning solution, yielded a superhydrophilic membrane capable of withstanding 2 bar pressure. Pure water flux measurements in the pressure range of 0.5–2 bar demonstrated a high permeability of 1727.5 LMH/bar and a pure water flux of 3455 LMH. The PA6/PVA/AB composite membrane exhibited exceptional performance in separating non-surfactant (NS) and surfactant-stabilized (SS) toluene-in-water emulsions (separation flux: 2006 LMH, oil rejection: 99.52%). Furthermore, it demonstrated high efficiency in the separation of SS oil-in-water emulsions of different types of oil (separation flux >1800 LMH, oil rejection >98%). The membrane's durability and chemical stability were confirmed through 15 cycles of oil-in-water emulsion separation, showcasing anti-fouling properties and reusability (separation flux >833, Oil rejection >97%). Considering its superior performance in oil-in-water emulsion separation and robust reusability, the developed nanofibrous membrane holds significant promise for practical applications.

Wound Dressing Based on Silver Nanoparticle Embedded Wool Keratin Electrospun Nanofibers Deposited on Cotton Fabric: Preparation, Characterization, Antimicrobial Activity, and Cytocompatibility.

Wool keratin (WK) protein is attractive for wound dressing and biomedical applications due to its excellent biodegradability, cytocompatibility, and wound-healing properties. In this work, WK-based wound dressings were prepared by depositing WK/poly(vinyl alcohol) (PVA) and silver nanoparticle (Ag NP)-embedded WK/PVA composite nanofibrous membranes on cotton fabrics by electrospinning. Ag NPs were biosynthesized by reduction and stabilization with sodium alginate. The formed Ag NPs were characterized by ultraviolet-visible and Fourier transform infrared (FTIR) spectroscopy, and their size was determined by transmission electron microscopy and image analysis. The formed Ag NPs were spherical and had an average diameter of 9.95 nm. The produced Ag NP-embedded WK/PVA composite nanofiber-deposited cotton fabric surface was characterized by FTIR and dynamic contact angle measurements, and the nanofiber morphologies were characterized by scanning electron microscopy. The average diameter of the nanofibers formed by 0.1% Ag NP-embedded WK/PVA solution was 146.7 nm. The antibacterial activity of the surface of cotton fabrics coated with electrospun composite nanofibers was evaluated against the two most common wound-causing pathogens, Staphylococcus aureus and Pseudomonas aeruginosa. The cotton fabric coated with 0.1% Ag NP-embedded WK/PVA nanofibers showed very good antibacterial activity against both pathogens, and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay results showed good cytocompatibility against L-929 mouse fibroblast cells. However, the increase in Ag NP content in the nanofibers to 0.2% negatively affected the cell viability due to the high release rate of Ag ions. The results achieved show that the developed wound dressing has good potential for wound healing applications.