Nanofiber Webs Research Articles

Electrospun Cerium Oxide Nanoparticle/Aloe Vera Extract-Loaded Nanofibrous Poly(Ethylene Oxide)/Polyurethane Mats As Diabetic Wound Dressings.

Currently the prevalence of diabetic wounds brings a huge encumbrance onto patients, causing high disability and mortality rates and a major medical challenge for society. Therefore, in this study, we are targeting to fabricate aloe vera extract infused biocompatible nanofibrous patches to facilitate the process of diabetic wound healing. Additionally, clindamycin has been adsorbed onto the surface of in-house synthesized ceria nanoparticles and again used separately to design a nanofibrous web, as nanoceria can act as a good drug delivery vehicle and exhibit both antimicrobial and antidiabetic properties. Various physicochemical characteristics such as morphology, porosity, and chemical composition of the produced nanofibrous webs were investigated. Bacterial growth inhibition and antibiofilm studies of the nanofibrous materials confirm its antibacterial and antibiofilm efficacy against Gram-positive and Gram-negative bacteria. An in vitro drug release study confirmed that the nanofibrous mat show a sustained drug release pattern (90% of drug in 96 h). The nanofibrous web containing drug loaded nanoceria not only showed superior in vitro performance but also promoted greater wound contraction (95 ± 2%) in diabetes-induced mice in just 7 days. Consequently, it efficaciously lowers the serum glucose level, inflammatory cytokines, oxidative stress, and hepatotoxicity markers as endorsed by various ex vivo tests. Conclusively, this in-house-fabricated biocompatible nanofibrous patch can act as a potential medicated suppository that can be used for treating diabetic wounds in the proximate future.

Flexible nanofiber web electrode with high surface area and capacitance for electrochemical capacitor

Flexible nanofiber web electrode with high surface area and capacitance for electrochemical capacitor

3D Printed and Electrospun, Transparent, Hierarchical Polylactic Acid Mask Nanoporous Filter.

Face masks are becoming one of the most useful personal protective equipment with the outbreak of the coronavirus (CoV) pandemic. The entire world is experiencing shortage of disposable masks and melt-blown non-woven fabrics, which is the raw material of the mask filter. Recyclability of the discarded mask is also becoming a big challenge for the environment. Here, we introduce a facile method based on electrospinning and three-dimensional printing to make changeable and biodegradable mask filters. We printed polylactic acid (PLA) polymer struts on a PLA nanofiber web to fabricate a nanoporous filter with a hierarchical structure and transparent look. The transparent look overcomes the threatening appearance of the masks that can be a feasible way of reducing the social trauma caused by the current CoV disease-19 pandemic. In this study, we investigated the effects of nozzle temperature on the optical, mechanical, and morphological and filtration properties of the nanoporous filter.

Enrofloxacin Pharmaceutical Formulations through the Polymer-Free Electrospinning of β-Cyclodextrin-oligolactide Derivatives.

Enrofloxacin (ENR), a member of the fluoroquinolone class of antibiotics, is widely used in veterinary medicine to treat bacterial infections. Like many antibiotics, ENR has limited water solubility and low bioavailability. To address these challenges, drug formulations using solid dispersions, nanosuspensions, surfactants, cocrystal/salt formation, and inclusion complexes with cyclodextrins may be employed. The approach described herein proposes the development of ENR formulations by co-electrospinning ENR with custom-prepared cyclodextrin-oligolactide (CDLA) derivatives. This method benefits from the high solubility of these derivatives, enabling polymer-free electrospinning. The electrospinning parameters were optimized to incorporate significant amounts of ENR into the CDLA nanofibrous webs, reaching up to 15.6% by weight. The obtained formulations were characterized by FTIR and NMR spectroscopy methods and evaluated for their antibacterial activity against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. This study indicates that the presence of CDLA derivative does not inhibit the antibacterial activity of ENR, recommending these formulations for further development.

Two-Dimensional Piezoelectric Nanofibrous Webs by Self-Polarized Assembly for High-Performance PM0.3 Filtration.

Particulate matter (PM) pollution has posed a serious threat to public health, especially the global spread of infectious diseases. Most existing air filtration materials are still subjected to a compromise between removal efficiency and air permeability on account of their stacking bulk structures. Here, we proposed a self-polarized assembly technique to create two-dimensional piezoelectric nanofibrous webs (PNWs) directly from polymer solutions. The strategy involves droplets deforming into ultrathin liquid films by inertial flow, liquid films evolving into web-like architectures by instantaneous phase inversion, and enhanced dipole alignment by cluster electrostatics. The assembled continuous webs exhibit integrated structural superiorities of nanoscale diameters (∼20 nm) of the internal fibers and through pores (∼100 nm). Combined with the wind-driven electrostatic property derived from the enhanced piezoelectricity, the PNW filter shows high efficiency (99.48%) and low air resistance (34 Pa) against PM0.3 as well as high transparency (84%), superlight weight (0.7 g m-2), and long-term stable service life. This creation of such versatile nanomaterials may offer insight into the design and upgrading of high-performance filters.

Piezoelectric Outputs of Electrospun PVDF Web as Full-Textile Sensor at Different Mechanical Excitation Frequencies.

With the increasing application of electrospun PVDF webs in piezoelectric sensors and energy-harvesting devices, it is crucial to understand their responses under complex mechanical excitations. However, the dependence of the piezoelectric effect on mechanical excitation properties is not fully comprehended. This study aims to investigate the piezoelectric output of randomly oriented electrospun PVDF nanofiber webs fabricated through different electrospinning processes at various mechanical excitation frequencies. The electrospun PVDF web was sandwiched between two textile electrodes, and its piezoelectric output as a full-textile sensor was measured across a frequency range from 0.1 Hz to 10 Hz. The experimental results revealed that the piezoelectric output of the electrospun PVDF web exhibited a nearly linear increase at excitation frequencies below 1.0 Hz and then reached an almost constant value thereafter up to 10 Hz, which is different from the hybrid PVDF or its copolymer web. Furthermore, the dependency of the piezoelectric output on the excitation frequency was found to be influenced by the specific electrospinning process employed, which determined the crystalline structure of electrospun PVDF nanofibers. These findings suggest that determining an appropriate working frequency for randomly oriented electrospun PVDF nanofiber webs is essential before practical implementation, and the piezoelectric response mode in different mechanical activation frequency ranges can be used to detect different human physiological behaviors.

Optimization and investigation of Physical, chemical, and biological properties of nanofibers produced from (poly glycerol Sebacate-co-caprolactone)/gelatin/peptide and scaffold’s cellular behavior

Recently, peptide and Poly(Glycerol Sebacat) PGS-based materials have garnered significant attention in tissue engineering. In this study, we synthesized two novel nanofibrous webs, namely Poly (glycerol sebacate)/gelatin/peptide (PGS/Gel/PT) and Poly (glycerol sebacate co caprolactone)/gelatin/peptide (P(GScoCL)/Gel/PT), utilizing the electrospinning technique with acetic acid as a cost-effective and eco-friendly solvent. To optimize the diameter of the electrospun nanofibrous samples, we employed response surface methodology and artificial neural network, investigating the impact of various electrospinning parameters. Nanofibrous webs with a diameter of 232 nm under the optimized conditions. Nanofibers were characterized using FTIR, DSC, contact angle measurement, and mechanical testing. The biological properties including biodegradability, cell adhesion, MTT assay, and antibacterial efficacy were performed. Nanofibrous samples antibacterial activity, displaying 99% effectiveness against both Gram-positive and Gramnegative bacteria. Moreover, in-vitro studies on the cellular proliferation of human Mesenchymal Stem Cells (hMSCs) nanofiber scaffold demonstrated normal cell morphology and significantly enhanced cell growth after 4 days.

Tailoring of Gelatin-Chitosan Nanofibers Functionalized with Eucalyptus Essential Oil via Electroblowing for Potential Food Packaging and Wound Dressing Applications

In recent years, new approaches to fabricating nanofiber networks for potential applications in wound dressing and food packaging have been in the spotlight. This study aimed to produce functional webs based on gelatin, chitosan, and eucalyptus essential oil using the electro-blowing method instead of traditional spinning methods such as electrospinning. The resultant nanofiber webs exhibit promising morphological characteristics, including reduced fiber diameters, enhanced air permeability, and improved thermal stability. The integration of chitosan and eucalyptus essential oil overcomes limitations associated with gelatin, offering enhanced mechanical properties, antibacterial efficacy, and potential attributes for wound healing and food packaging. The combination of gelatin and chitosan contributes to biodegradability and biocompatibility, crucial for developing materials compatible with the natural environment. The addition of eucalyptus essential oil provides an additional layer of antimicrobial protection, aligning with sustainability goals in wound care and active food packaging. A comprehensive analysis encompassing SEM morphologies, fiber diameters, air permeability, FTIR spectra, TGA thermograms, and contact angle measurements establishes a thorough understanding of the fabricated nanofiber webs’ characteristics. Despite the favorable properties exhibited by the developed nanofiber webs for wound healing and food packaging applications, the incorporation of eucalyptus essential oil resulted in a reduction in tensile strength and elongation ratios. This observation highlights the necessity for further optimization and fine-tuning of the formulation to strike a balance between antimicrobial benefits and mechanical properties. Distinguished by its unique combination of gelatin, chitosan, and eucalyptus essential oil, this research contributes to the advancement of nanofiber technology, expanding knowledge in the field and paving the way for the development of advanced materials with enhanced therapeutic properties for wound healing and food packaging.Graphical

Assessing the Sound and Heat Insulation Characteristics of Layered Nonwoven Composite Structures Composed of Meltblown and Recycled Thermo-Bonded Layers.

Sound and heat insulation are among the most important concerns in modern life and nonwoven composite structures are highly effective in noise reduction and heat insulation. In this study, three layered nonwoven composite structures composed of a recycled polyester (r-Pet)-based thermo-bonded nonwoven outer layer and meltblown nonwovens from Polypropylene (PP) and Polybutylene terephthalate (PBT) as inner layers were formed to provide heat and sound insulation. Fiber fineness and cross-section of the thermo-bonded outer layer, fiber type (PP/PBT), areal weight (100/200 g/m2) and process conditions (calendared/non-calendared) of the meltblown inner layer were changed systematically and the influence of these independent variables on thickness, bulk density, air permeability, sound absorption coefficient and thermal resistance of composite structures were analyzed statistically by using Design Expert 13 software. Additionally, the results were compared with composite structures including an electrospun nanofiber web inner layer and with structures without an inner layer. It was concluded that comparable or even better sound absorption values were achieved with the developed nonwoven composites containing meltblown layers compared to nanofiber-included composites and the materials in previous studies.

Preparation of binder-free MoP/SnO2 carbon fiber composites with Cu-mediated surface modification for high-rate sodium ion storage

Nanofiber webs stacking with circular cross-section generally suffer from insufficient inter-fiber connection and thus poor electrical contact. Beyond regular 1D nanofibers, electrospinning is able to fabricate nanobelt webs with reinforced electron transfer for energy storage and conversion. Previously, we prepared quasi-2D belt-like fiber through electrospinning of PMo12-PPy-SnCl2-PVP-based solution (phosphomolybdic acid /polypyrrole /SnCl2 /polyvinylpyrrolidone) with freestanding property. Here, to boost the electrochemical performance, we proposed Cu-mediated surface engineering for construction of accessible active sites with balanced material components of MoP/SnO2 and carbon. As a result, thinner and porous belt-like fibers were obtained with high specific surface area (above 100 m2 g−1). The interfacial charge transfer was improved by superficial phosphides, as binder-free electrode the Cu-mediated MoP/SnO2 carbon fiber composite can deliver capacity above 200 mAh g−1 at 0.2 A g−1 under low mass loading (1.5–2.5 mg cm−2) and sustain capacity above 1.0 mAh cm−2 with loading around 5 mg cm−2 at 2 mA cm−2. Combined with ex-situ characterization, the sodiation process was probed.

Preparation of β-cyclodextrin derivatives/metamizole inclusion complex nanofibers: Characterization, drug release, and wound scratch assay

Nanofibrous wound dressings fabricated by electrospinning have attracted significant research interest as they enable the controlled release of active substances at the wound site. The development of electrospun nanofibers with anti-inflammatory drugs, which demonstrate great potential for wound healing applications, is one of the main focuses of present research efforts. In this study, nanofibrous webs of 2-hydroxypropyl-β-cyclodextrin (HPβCD) and methyl-β-cyclodextrin (MβCD) loaded with metamizole (MMS) were fabricated by electrospinning. The prepared nanofibers were characterized by field-emission scanning electron microscopy, X-ray diffraction, Fourier-transform infrared spectroscopy, thermogravimetric/differential thermal analysis, 1H nuclear magnetic resonance spectroscopy, ultraviolet diffuse reflectance spectroscopy, and photoluminescence analysis. The interactions of HPβCD and MβCD with MMS in aqueous solutions were studied using absorption and fluorescence spectroscopy, and the 1:1 MMS/CD inclusion complexes were theoretically analyzed at the PM3 level of theory. Furthermore, the drug release, biocompatibility, and wound scratch assay of the nanofibers were evaluated. In vitro drug release analysis revealed controllable release of MMS from the nanofibers. The CD nanofibers loaded with MMS showed good biocompatibility with skin fibroblasts. An in vitro wound scratch assay indicated that the nanofibers promoted fast wound closure with a rate of 98.66 ± 3.9%. In summary, the prepared nanofibrous webs are promising candidates for wound-dressing applications.

Characterization of polyvinyl alcohol and vitex negundo blended bio nanofilm for wound healing scaffold

Polyvinyl alcohol blended nanofilms have shown great promise as a material for wound healing applications because of their biocompatibility, biodegradability, and antibacterial characteristics. This article has typically utilized electrospinning to create a scaffold for wound healing meanwhile investigating the characteristics of the polyvinyl alcohol (PVA) and vitex negundo (VN) blend nanofilm. The PVA concentrations were kept at 10% Weight/Volume (W/V), which was then mixed with VN solution at various volumetric ratios and electrospun into nanofilms. Field Emission Scanning Electron Microscopy (FESEM) was used to determine and analyze the nanofiber diameter. The plant extract concentration and the viscosity of the electrospinning solution influenced the fiber diameter to grow from 120.32 nanometers (nm) to 171.11 nanometers (nm). Fourier Transform Infrared Spectroscopy (FTIR) verifies the interaction between plant extract and PVA and records a new peak between 1731 and 1750 cm−1, which represents the production of the ester group. The swellability of the developed sample was studied which is negligibly reduced when the plant extract was added. In comparison to both Gram-positive and Gram-negative bacteria, the pure plant extract and composite nanofibrous web demonstrated greater antibacterial activity. PVA-blended nanofilms can promote cell migration, proliferation, and differentiation, hence promoting wound healing by creating a moist environment.

Designing PVdF-HFP/BTO Piezoelectric Sensor based Sensing System for Detecting Volume Expansion of Battery Cell

Piezoelectric sensor can be used to inform the battery safety by detecting the battery swelling induced pressure. In this study, a piezoelectric sensing material, sensor unit, and sensing system were developed using piezoelectric polymer polyvinylidene fluoride-co-hexafluoropropylene(PVdF-HFP) and piezoelectric ceramic BaTiO<sub>3</sub>(BTO). Free-standing PVdF-HFP/BTO composite nanofiber web was retrieved as the sensing material due to the nanofiber web-based flexibility and the molecular arrangement driven piezoelectric performances. The PVdF-HFP/BTO composite nanofiber web-based sensor was employed in the automatic pressure sensing system, which provides the visual and audible signals once the pressure exceeds a certain limit. Our work demonstrates that the design of new piezoelectric sensing system is a fruitful pathway to sensing the battery malfunctions.

Large-scale fabrication of nanofibers by tiny-needle-spaced electrostatic-induction-assisted solution blowing spinning

In this paper, a technology and device for large-scale fabrication of nanofibers called tiny-needle-spaced electrostatic-induction-assisted solution blowing spinning (TESBS) was developed. The airflow stretching force is used as the initial driving force for jet formation in TESBS, which avoids the electric field interference existing in the jet formation stage of multi-needle electrospinning(MES). The addition of an induced electric field in TESBS solves the problem of mutual merging of jets in multi-needle solution blowing spinning (MSBS). The needle spacing of TESBS can be as small as 1 mm, which is much smaller than MES (100 mm) and MSBS (3 mm). The substantial reduction in needle spacing can increase the arrangement density of blunt needles, thereby increasing the output of nanofibers. Compared with MSBS, the average diameter and diameter standard deviation of TESBS nanofibers can be reduced by 52.6% and 78.7%, respectively. Compared with MES, the uniformity of the TESBS nanofiber web has been significantly improved. The formula for the critical needle spacing to ensure that the TESBS jets do not merge with each other was derived. The output of 15-needle TESBS can reach as high as 3 ml/min. The average diameter of TESBS nanofibers decreases with the decrease in injection speed or the increase in voltage. The distance between the needle and the receiver has little effect on the average fiber diameter. TESBS nanofibers with good quality and high yield have broad and bright application prospects in many fields.

Nanofiber applications in microbial fuel cells for enhanced energy generation: a mini review.

Microbial fuel cells (MFCs) represent simple devices that harness the metabolic activities of microorganisms to produce electrical energy from diverse sources such as organic waste and sustainable biomass. Because of their unique advantage to generate sustainable energy, through the employment of biodegradable and repurposed waste materials, the development of MFCs has garnered considerable interest. Critical elements are typically the electrodes and separator. This mini-review article presents a critical assessment of nanofiber technology used as electrodes and separators in MFCs to enhance energy generation. In particular, the review highlights the application of nanofiber webs in each part of MFCs including anodes, cathodes, and membranes and their influence on energy generation. The role of nanofiber technology in this regard is then analysed in detail, focusing on improved electron transfer rate, enhanced biofilm formation, and enhanced durability and stability. In addition, the challenges and opportunities associated with integrating nanofibers into MFCs are discussed, along with suggestions for future research in this field. Significant developments in MFCs over the past decade have led to a several-fold increase in achievable power density, yet further improvements in performance and the exploration of cost-effective materials remain promising areas for further advancement. This review demonstrates the great promise of nanofiber-based electrodes and separators in future applications of MFCs.

Thermal and acoustic characterization of nanofibrous polymeric structures for insulation applications

Nanofibrous structures are engineered materials for high-end applications. The impact of electrospinning settings on the thermal and acoustic properties of polyurethane (PU) nanofibrous structures is examined in this research. The excellent sound-absorbing properties of PU make it a versatile material that may be used in a variety of acoustic applications. The study focuses on how PU nanofiber morphology, such as fiber diameter and volume fraction, is affected by varying ambient conditions. Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) are used to examine the stability and thermal behavior of PU nanofibers. The findings show that raising the fiber volume fraction improves thermal stability and changes the way PU nanofibers behave thermally. PU nanofiber webs provide efficient sound absorption in low and intermediate frequency ranges according to the study's analysis of the sound absorption coefficients. According to the results, PU nanofiber webs may offer novel approaches to noise control, especially in situations where acoustic panel insulation is needed with no weight penalty.

Fabrication of porous carbon nanofiber webs from polyacrylonitrile and cellulose acetate for NaCl removal from water using capacitive deionization

Abstract Capacitive deionization (CDI) has shown potential in addressing freshwater scarcity. CDI's electrode design is a key to better performance as it determines the extent of water purification. For carbon electrodes, the pore structure is an important factor influencing removal kinetics and ion storage. Herein, porous carbon nanofibers with diameters ranging from 277 to 348 nm were fabricated from blends of polyacrylonitrile (PAN) and cellulose acetate (CA) through electrospinning and carbonization. Surface area and pore properties were adjusted by varying the proportions of the precursors while ensuring no adverse alteration to the products' tangible properties. Enhanced pore structure and specific surface area were evident in the blend-based carbon nanofibers. The blend ratio of 2:8 (CA:PAN) had a high specific surface area of 925.47 m2/g and a pore volume of 0.7884 cm3/g. Correspondingly, a high specific capacitance of 177.5 F/g was attained. Desalination performance was determined in batch mode using 500 mg/L NaCl solution. A salt adsorption capacity of 6.57 mg/g and charge efficiency of 0.46 was obtained for the blend that had 20% CA. The carbon nanofibers demonstrated good desalination stability when used repetitively indicating their excellent potential for practical application.

PEDOT:PSS based electrospun nanofibres used as trigger for fibroblasts differentiation

Electrospun nanofibres based on poly(styrene sulfonate) doped poly(3,4-ethylenedioxythiophene) (PEDOT:PSS) were fabricated using a straightforward procedure which combines electrospinning, sputtering deposition and electrochemical synthesis. In general, electrospun fibre meshes based on conducting polymers are prepared by mixing the conducting polymer with a carrier polymer or chemically coverage of the fibres. In contrast, freestanding nylon 6/6 nanofibre webs were prepared through electrospinning and were coated by sputtering with gold in order to make them conductive. Further, a PEDOT:PSS layer was electrochemically deposited onto the metalized nanofibre meshes and the synthesis parameters were chosen in such a way to preserve the high active area of the fibres. The prepared material was morphologically characterized and the formation of PEDOT:PSS was also demonstrated. The PEDOT:PSS coated nanofibres revealed remarkable electrical properties (sheet resistance of about 3.5 Ω cm−2), similar to those of metalized nanofibres (sheet resistance around 3 Ω cm2). The in vitro studies using L929 fibroblast mouse cells showed that the bioactive material has no cytotoxic effect and allows proliferation. Moreover, after 72 h of incubation, the fibroblasts shrunk their nuclei and spread suggesting that a differentiation in myofibroblast occurs without application of any kind of external stimuli. These results will be helpful for developing efficient materials for wound healing applications that work without energy consumption.

WS2 fullerene/plate nanofibers: The tunable crossroad between dimensionalities

Our work describes the nanofibrous materials of tungsten disulfide, which can be tuned by the precursor's crystallinity degree. The carefully formulated nanofibers create the morphological crossroad between fullerenes (0D), nanotubes (1D), plates (2D), and a nonwoven web of nanofibers (3D), containing all the advantageous properties of the presented material categories. Our synthetic methodology (electrospinning, reductive sulfidation) allows scale-up to industrial production. In addition, we studied the optical properties of the WS2 nanofibers using extinction and absolute absorption measurements. The results of the optical analysis further indicate the higher crystallinity of the closed stacked fullerene-based structure. By comparing the extinction with the absorbance, we find that all the examined nanostructures display typical polaritonic spectra. However, the open plate structure exhibits a stronger scattering and thus better pronounced polaritonic features. Moreover, the ability to control the morphology allows for variating polaritonic features of the final nanofibrous material, which can directly impact the potential optoelectronic and photocatalytic applications.

Conductive Nanofiber Web Film with Polydimethylsiloxane Sidewalls Selectively Coated through a Plasma Process for High Performance Flexible Transparent Electrodes.

Transparent electrodes are commonly used in various applications, such as solar cells, touch screens, smart windows, wearable electronic devices, and rollable flexible displays. Currently, indium tin oxide (ITO) is widely used as a transparent electrode material. However, ITO is not suitable for next-generation transparent electrodes that require flexibility; therefore, alternative nanomaterials, such as carbon nanotubes, conductive polymers, and metal nanowires, are being studied. However, these nanomaterials have poor mechanical strength and limited substrate availability. In this study, we developed a high-performance transparent electrode web film fabrication process based on conductive nanofibers, in which metal nanofibers are semiembedded in polydimethylsiloxane (PDMS). The mechanical strength of the conductive nanofibers was improved through the PDMS coating on the entire surface of the film, and the semiembedded structure of the nanofibers was realized using the reactive ion etching (RIE) process. In this study, we confirmed through transparency/conductivity analysis and bending, cycle, and taping tests that the transparent electrode fabricated using our approach has excellent mechanical strength and conductivity. Finally, the transparent electrode fabricated using our method can be widely applied as a next-generation transparent electrode because the process is easy and simple and requires inexpensive equipment and materials.