Articoli di riviste: "Optical nanofibers"

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Matic, Alexandre, Adrien Godet, Jacques Chrétien, Kien Phan-Huy e Jean-Charles Beugnot. "Optical nanofibers for signal delaying". EPJ Web of Conferences 266 (2022): 11008. http://dx.doi.org/10.1051/epjconf/202226611008.

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In this abstract, we purpose an optical delay line based on optical nanofibers. Silica high elasticity and the low pulling force required to stretch a nanofiber allow to get optical delays up to 20 picoseconds with a 10 centimeter-long optical nanofiber at telecommunications wavelength.

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Li, Jinze, Xin Liu, Jiawei Xi, Li Deng, Yanxin Yang, Xiang Li e Hao Sun. "Recent Development of Polymer Nanofibers in the Field of Optical Sensing". Polymers 15, n. 17 (31 agosto 2023): 3616. http://dx.doi.org/10.3390/polym15173616.

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In recent years, owing to the continuous development of polymer nanofiber manufacturing technology, various nanofibers with different structural characteristics have emerged, allowing their application in the field of sensing to continually expand. Integrating polymer nanofibers with optical sensors takes advantage of the high sensitivity, fast response, and strong immunity to electromagnetic interference of optical sensors, enabling widespread use in biomedical science, environmental monitoring, food safety, and other fields. This paper summarizes the research progress of polymer nanofibers in optical sensors, classifies and analyzes polymer nanofiber optical sensors according to different functions (fluorescence, Raman, polarization, surface plasmon resonance, and photoelectrochemistry), and introduces the principles, structures, and properties of each type of sensor and application examples in different fields. This paper also looks forward to the future development directions and challenges of polymer nanofiber optical sensors, and provides a reference for in-depth research of sensors and industrial applications of polymer nanofibers.

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Lebedev N. M., Min'kov K. N., Shitikov A. E., Danilin A. N., Krasivskaya M. I., Lonshakov E. A., Gorelov I. K., Dmitriev N. Y. e Bilenko I. A. "Optimizing the production of single-mode optical microfibers for coherent microoptics". Technical Physics 92, n. 6 (2022): 723. http://dx.doi.org/10.21883/tp.2022.06.54419.30-22.

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Micro- and nanofibers are the universal elements of the optical schemes for solving wide variety of experimental tasks. One usually uses the commercial optical fiber tapering in the burner?s flame to produce such nanofibers. Such tapers are actively used for production of highly sensitive sensors, experiments with the cold atoms and coupling to optical microresonators. The theoretical model of geometrical shape altering during the fiber tapering and heating was adapted in this publication for use in the algorithm with universal adjustment of the tapering modes to get a fiber with the desired set of parameters. One of the innovations was the implementation of the computer vision to control the tapering process. As a result, the nanofibers with the optimal waist diameter of about 700 nm for the radiation wavelength of 1.55 micron were obtained. The optimized methodic of tapering allows the production of the nanofibers with the transmittance of up to 80%. The produced nanofibers were successfully used for coupling to the crystalline whispering gallery mode microresonator. As a result, the optical combs with the spectrum range up to 200 nm were obtained in IR range.. Keywords: Nanofiber, whispering gallery mode microresonator, optical comb, fiber tapering.

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Asriani, Asriani, e Iman Santoso. "Reduced Graphene Oxide/Polyvinyl Alcohol Nanofibers Fabricated by Electrospinning Technique as An Ideal Candidate for Organic Solar Cell Devices". JPSE (Journal of Physical Science and Engineering) 6, n. 1 (19 maggio 2021): 10–18. http://dx.doi.org/10.17977/um024v6i12021p010.

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Functionalization of rGO that previously obtained by chemical reduction using hydrazine hydrate, has been done by changing its morphology into nanofiber with electrospinning technique and using PVA as a polymer matrix. The rGO nanofibers that had been formed were then characterized using Fourier Transformation-Infra Red (FTIR) spectroscopy, Scanning Electron Microscopy (SEM), and UV-Vis Spectrophotometer. FTIR spectroscopy confirmed the presence of C – C group and C = O group in nanofibers. SEM showed the change of nanofibers morphology which is marked by the increasing of fibres diameter and the hollow fibres become brighter. Furthermore, the effect of rGO concentration to nanofiber optical properties was confirmed by UV-Vis spectrophotometer. According to this characterization, the absorbance of rGO/PVA nanofiber is decreased due to increased rGO concentration. The detail of optical properties of rGO is studied through complex refractive index and dielectric constant in which Kramers-Kronig transformation is then employed to calculate complex refractive index and complex dielectric constant. From the data, the optical properties of rGO/PVA nanofibers indicating that rGO/PVA nanofibers can be applied as transparent electrode an organic solar cell devices.

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Morais, Michele Greque de, Christopher Stillings, Roland Dersch, Markus Rudisile, Patrícia Pranke, Jorge Alberto Vieira Costa e Joachim Wendorff. "Biofunctionalized Nanofibers UsingArthrospira(Spirulina) Biomass and Biopolymer". BioMed Research International 2015 (2015): 1–8. http://dx.doi.org/10.1155/2015/967814.

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Electrospun nanofibers composed of polymers have been extensively researched because of their scientific and technical applications. Commercially available polyhydroxybutyrate (PHB) and polyhydroxybutyrate-co-valerate (PHB-HV) copolymers are good choices for such nanofibers. We used a highly integrated method, by adjusting the properties of the spinning solutions, where the cyanophyteArthrospira(formallySpirulina) was the single source for nanofiber biofunctionalization. We investigated nanofibers using PHB extracted fromSpirulinaand the bacteriaCupriavidus necatorand compared the nanofibers to those made from commercially available PHB and PHB-HV. Our study assessed nanofiber formation and their selected thermal, mechanical, and optical properties. We found that nanofibers produced fromSpirulinaPHB and biofunctionalized withSpirulinabiomass exhibited properties which were equal to or better than nanofibers made with commercially available PHB or PHB-HV. Our methodology is highly promising for nanofiber production and biofunctionalization and can be used in many industrial and life science applications.

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Vu, Thi Hong Nhung, Svetlana N. Morozkina, Roman O. Olekhnovich, Aleksandr V. Podshivalov e Mayya V. Uspenskaya. "Study on Fabrication and Properties of Polyvinyl Alcohol/Chitosan Nanofibers Created from Aqueous Solution with Acetic Acid and Ethanol by the Electrospinning Method". Polymers 16, n. 23 (30 novembre 2024): 3393. https://doi.org/10.3390/polym16233393.

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The development of nanofibers with incorporated biologically active molecules with a targeted mode of action is a current research trend. Potential materials for the development of such systems include poly(vinyl alcohol) (PVA) and chitosan (CS) nanofibers, which are traditionally fabricated by the electrospinning of aqueous solutions of these polymers with acetic acid. To improve drug integration, ethanol was added to the binary-solvent system. This results in several important data: noticeable shifts in the solvent system’s solubility parameter, the interaction of the various component forces, and optical and rheological properties of the PVA-CS solution. The use of ethanol in the electrospun solution also contributes to adjusting the solubility parameters of the solution in the Teas graph, maintaining the “fh − fd” in the optimal region for the fabrication of PVA-CS nanofibers. Increasing the efficiency of PVA-CS nanofiber fabrication by electrospinning is quite difficult due to the requirements of solution parameters, technological parameters, and environmental parameters; however, this efficiency was increased in this work by 2 to 3 times with a more optimal PVA-CS nanofiber morphology. These results demonstrate that aqueous solution containing 4% PVA, 3% CS, 15% ethanol, and 45% acetic acid is optimal for increasing the nanofiber fabrication productivity, improving the morphology and diameter of PVA-CS nanofibers without changing in chemical bonds. The XRD spectrum revealed that the alterations in the crystal lattice and diameter of the PVA-CS nanofibers led to the variation in their thermal and tensile properties.

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Bojarus, Ratchaneekorn, Tienthong Yuangkaew, Thawach Thammabut, Mati Horprathum, Papot Jaroenapibal e Napat Triroj. "Optical Absorption and Photoconversion Characteristics of WO₃ Nanofiber Photoanodes Prepared by Electrospinning with Different Calcination Temperatures". Solid State Phenomena 324 (20 settembre 2021): 103–8. http://dx.doi.org/10.4028/www.scientific.net/ssp.324.103.

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This study aims to synthesize and examine the optical and photoelectrochemical properties of tungsten oxide (WO3) nanofibers prepared by electrospinning and calcination using different temperatures (500, 700, and 900 °C). The electrospinning solution contained a mixture of polyvinyl alcohol (PVA, 7.5% w/v) and ammonium metatungstate hydrate (AMH, 16.7% w/v). The morphology of WO3 nanofibers was observed via scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The absorbance of calcined WO3 nanofibers was measured, and the data was used to calculate the optical band gap energy (Eg) through Tauc’s relation. The of calcined WO3 nanofibers were found to be from 2.85 to 3.08 eV. The minimum value of was obtained from the sample calcined at 900 °C. Linear sweep voltammetry (LSV) was employed in the photocurrent measurements under simulated AM 1.5G at 100 mW/cm2 irradiance. The WO3 nanofiber photoanode calcined at 900 °C exhibited the maximum photoconversion efficiency (PCE) of 1.53%, a twice enhancement in PCE compared with those obtained from WO3 nanofibers calcined at lower temperatures. This study suggests the potential pathway for the optimal synthesis of high performance nanostructured metal oxide electrodes for photoelectrochemical water splitting.

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Sumetsky, Michael. "Optical micro/nanofibers: achievements and future directions". Photonics Insights 3, n. 2 (2024): C03. http://dx.doi.org/10.3788/pi.2024.c03.

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Ihn, Yong Sup, Zaeill Kim e Su-Yong Lee. "Optical Wave Guiding and Spectral Properties of Micro/Nanofibers Used for Quantum Sensing and Quantum Light Generation". Applied Sciences 10, n. 2 (20 gennaio 2020): 715. http://dx.doi.org/10.3390/app10020715.

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Subwavelength optical micro/nanofibers have been widely used as basic building blocks in the field of quantum sensing and quantum light source by virtue of their properties which include pronounced evanescent field, large surface area, and small optical mode area. This paper presents theoretical studies on the propagation properties of the guided optical wave and the spectral properties of entangled photons from spontaneous four-wave mixing in micro/nanofibers. We first analyze numerically single-mode propagation, field distribution, fraction of power, and group-velocity-dispersions by solving Maxwell’s equations with boundary conditions in cylindrical coordinates. Then, optical wave guiding properties of micro/nanofibers are applied to estimate the spectral properties such as central wavelengths and bandwidths of the created photons via spontaneous four-wave mixing that can be tailored by controlling diameter and length of micro/nanofibers. This theoretical work provides useful guidelines to design micro/nanofiber-based quantum sensing and quantum light sources for quantum technologies.

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Olvera Bernal, Rigel Antonio, Roman Olegovich Olekhnovich e Mayya Valerievna Uspenskaya. "Chitosan/PVA Nanofibers as Potential Material for the Development of Soft Actuators". Polymers 15, n. 9 (25 aprile 2023): 2037. http://dx.doi.org/10.3390/polym15092037.

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Chitosan/PVA nanofibrous electroresponsive soft actuators were successfully obtained using an electrospinning process, which showed fast speed displacement under an acidic environment. Chitosan/PVA nanofibers were prepared and characterized, and their electroactive response was tested. Chitosan/PVA nanofibers were electrospun from a chitosan/PVA solution at different chitosan contents (2.5, 3, 3.5, and 4 wt.%). Nanofibers samples were characterized using Fourier transform infrared analyses, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), optical microscopy, and tensile test. The electroactive behavior of the nanofiber hydrogels was tested under different HCl pH (2–6) under a constant voltage (10 V). The electroactive response test showed a dependence between the nanofiber’s chitosan content and pH with the bending speed displacement, reaching a maximum speed displacement of 1.86 mm−1 in a pH 3 sample with a chitosan content of 4 wt.%. The results of the electroactive response were further supported by the determination of the proportion of free amine groups, though deconvoluting the FTIR spectra in the range of 3000–3700 cm−1. Deconvolution results showed that the proportion of free amine increased as the chitosan content was higher, being 3.6% and 4.59% for nanofibers with chitosan content of 2.5 and 4 wt.%, respectively.

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Fanjoux, Gil, Jacques Chrétien, Adrien Godet, Kien Phan-Huy, Jean-Charles Beugnot e Thibaut Sylvestre. "Evanescent Kerr effect using an optical nanofiber in acetone". EPJ Web of Conferences 238 (2020): 08008. http://dx.doi.org/10.1051/epjconf/202023808008.

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We report on a theoretical and experimental investigation of the optical Kerr effect in the evanescent field of silica nanofibers immersed in several highly nonlinear liquids such as ethanol, acetone and water and we further compare them with air cladding. We provide formula of the effective nonlinear coefficients including the contribution of the nanofiber silica core and of the evanescent field for varying nanofiber diameter and for different surrounding media.

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Xia, Hongyan, Tingkuo Chen, Chang Hu e Kang Xie. "Recent Advances of the Polymer Micro/Nanofiber Fluorescence Waveguide". Polymers 10, n. 10 (30 settembre 2018): 1086. http://dx.doi.org/10.3390/polym10101086.

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Subwavelength optical micro/nanofibers have several advantages, such as compact optical wave field and large specific surface area, which make them widely used as basic building blocks in the field of micro-nano optical waveguide and photonic devices. Among them, polymer micro/nanofibers are among the first choices for constructing micro-nano photonic components and miniaturized integrated optical paths, as they have good mechanical properties and tunable photonic properties. At the same time, the structures of polymer chains, aggregated structures, and artificial microstructures all have unique effects on photons. These waveguided micro/nanofibers can be made up of not only luminescent conjugated polymers, but also nonluminous matrix polymers doped with luminescent dyes (organic and inorganic luminescent particles, etc.) due to the outstanding compatibility of polymers. This paper summarizes the recent progress of the light-propagated mechanism, novel design, controllable fabrication, optical modulation, high performance, and wide applications of the polymer micro/nanofiber fluorescence waveguide. The focus is on the methods for simplifying the preparation process and modulating the waveguided photon parameters. In addition, developing new polymer materials for optical transmission and improving transmission efficiency is discussed in detail. It is proposed that the multifunctional heterojunctions based on the arrangement and combination of polymer-waveguided micro/nanofibers would be an important trend toward the construction of more novel and complex photonic devices. It is of great significance to study and optimize the optical waveguide and photonic components of polymer micro/nanofibers for the development of intelligent optical chips and miniaturized integrated optical circuits.

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Blachowicz, Tomasz, e Andrea Ehrmann. "Optical Properties of Electrospun Nanofiber Mats". Membranes 13, n. 4 (18 aprile 2023): 441. http://dx.doi.org/10.3390/membranes13040441.

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Electrospun nanofiber mats are usually applied in fields where their high specific surface area and small pore sizes are important, such as biotechnology or filtration. Optically, they are mostly white due to scattering from the irregularly distributed, thin nanofibers. Nevertheless, their optical properties can be modified and become highly important for different applications, e.g., in sensing devices or solar cells, and sometimes for investigating their electronic or mechanical properties. This review gives an overview of typical optical properties of electrospun nanofiber mats, such as absorption and transmission, fluorescence and phosphorescence, scattering, polarized emission, dyeing and bathochromic shift as well as the correlation with dielectric constants and the extinction coefficient, showing which effects may occur and can be measured by which instruments or used for different applications.

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Azzoune, Abderrahim, Laurent Divay, Christian Larat e Sylvie Lebrun. "Improving photon pair generation in silica nanofibers through PMMA/DR1 nonlinear coating optimization". EPJ Web of Conferences 287 (2023): 06012. http://dx.doi.org/10.1051/epjconf/202328706012.

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We report on the use of PMMA/DR1 coating to enhance the efficiency of photon pair generation in silica nanofibers. The coating improves the second-order nonlinear susceptibility of the nanofibers, leading to improved photon pair generation efficiency. We investigate the effect of varying the nonlinear optical properties of the composite material, and we characterize the photon pair generation efficiency of the coated silica nanofibers. Our modelling results show a significant enhancement in photon pair generation efficiency by a factor of 1000 compared to a bare silica nanofiber.

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Zhang, Y., H. Yu e Z. Li. "Optical forces in optical nanofibers". Journal of Physics: Conference Series 1077 (agosto 2018): 012007. http://dx.doi.org/10.1088/1742-6596/1077/1/012007.

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Martínez-Pérez, Paula, Salvador Ponce-Alcántara, Nieves Murillo, Ana Pérez-Márquez, Jon Maudes, Inés Peraile, Laura González-López, Matilde Gil-García, Paloma Lorenzo-Lozano e Jaime García-Rupérez. "Label-Free Optical Biosensing Using Low-Cost Electrospun Polymeric Nanofibers". Chemosensors 8, n. 4 (26 novembre 2020): 119. http://dx.doi.org/10.3390/chemosensors8040119.

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Polymeric nanofiber matrices are promising structures to develop biosensing devices due to their easy and affordable large-scale fabrication and their high surface-to-volume ratio. In this work, the suitability of a polyamide 6 nanofiber matrix for the development of a label-free and real-time Fabry–Pérot cavity-based optical biosensor was studied. For such aim, in-flow biofunctionalization of nanofibers with antibodies, bound through a protein A/G layer, and specific biodetection of 10 µg/mL bovine serum albumin (BSA) were carried out. Both processes were successfully monitored via reflectivity measurements in real-time without labels and their reproducibility was demonstrated when different polymeric nanofiber matrices from the same electrospinning batch were employed as transducers. These results demonstrate not only the suitability of correctly biofunctionalized polyamide 6 nanofiber matrices to be employed for real-time and label-free specific biodetection purposes, but also the potential of electrospinning technique to create affordable and easy-to-fabricate at large scale optical transducers with a reproducible performance.

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Mohammed Aldawsari, Haya, e Smail Bougouffa. "Exploring Optical Nanofibers for Atom-Photon Hybrid Quantum Systems: Chirality Effects and Optical Forces". Journal of Nanoelectronics and Optoelectronics 18, n. 8 (1 agosto 2023): 946–58. http://dx.doi.org/10.1166/jno.2023.3463.

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Recent advancements have revealed the growing effectiveness of optical nanofibers in enabling the implementation of atom-photon hybrid quantum systems. These nanofibers serve as non-intrusive tools for probing cold atoms, offering a unique approach to circumvent the limitations imposed by the Rayleigh domain, thereby achieving increased intensities in a beam of light over long distances. This study investigates the interaction between the atom and light, focusing on the dipole transition in sodium atoms near a nanofiber. Notably, we uncover the influence of the direction of light propagation, known as the optical chirality effect, on the spatial distribution of the steady-state density matrix elements. Furthermore, we examine the optical forces acting on a two-level atom during the 32S1/2 →32P3/2 transition in sodium. Our findings demonstrate that optical chirality’s effect significantly impacts the magnitude of these optical forces. The concept of optical chirality holds great promise for advancing technology and enhancing our understanding of atomic behavior. The numerical results presented in this work are based on experimental parameters within a realistic range.

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Tański, Tomasz, Wiktor Matysiak, Weronika Smok e Zaborowska Marta. "Study of the Optical Properties of Electrospun PAN/GO Nanocomposites". Solid State Phenomena 326 (2 novembre 2021): 17–31. http://dx.doi.org/10.4028/www.scientific.net/ssp.326.17.

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Polymer nanocomposites with unique optical properties are currently one of the materials most desired by the industry. An effective method of producing this type of materials is the method of electrospinning from a solution or melted polymers, which allows to obtain a nanocomposite in the form of a mat composed of nanofibers. This paper describes the process of producing nanofibers from polyacrylonitrile (PAN) and composite thin nanofiber mats from PAN with the addition of graphene oxide (GO) particles using the electrospinning method. In addition, the aim of the work was to investigate the influence of process parameters and filler on the morphology and optical properties of the nanomaterial. By changing the configuration of the distance between the nozzle and the collector (10 and 20 cm) and keeping the remaining parameters of the electrospinning process constant, two PAN polymer samples and two PAN/GO composite samples were manufactured. The analysis of the chemical composition and morphology of the obtained materials was performed using X-ray microanalysis (EDX) and scanning electron microscopy (SEM), respectively. In order to examine the chemical structure of the polymer and composite nanofibers, Fourier-Transform Infrared Spectroscopy (FTIR) was used. The analysis of the optical properties and the energy band gap of the prepared nanofibers was determined by spectral analysis using a UV–Vis spectrophotometer. The research showed a significant influence of the filler on the morphology.

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Kim, Yeong-Ung, e Won-Ju Cho. "Transparent and High-Performance Extended Gate Ion-Sensitive Field-Effect Transistors Using Electrospun Indium Tin Oxide Nanofibers". Chemosensors 11, n. 6 (25 maggio 2023): 319. http://dx.doi.org/10.3390/chemosensors11060319.

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Herein, we propose a transparent high-performance extended-gate ion-sensitive field-effect transistor (EG-ISFET) using an electrospun indium-tin-oxide (ITO) nanofiber sensing membrane with a high specific surface area. Electrospinning is a simple and effective technique for forming nanofibers. Nevertheless, one-step calcination, such as conventional thermal annealing or microwave annealing, cannot sufficiently eliminate the inherent defects of nanofibers. In this study, we efficiently removed residual polymers and internal impurities from nanofibers via a two-step calcination process involving combustion and microwave annealing. Moreover, Ar plasma treatment was performed to improve the electrical characteristics of ITO nanofibers. Conformally coated thin-film sensing membranes were prepared as a comparative group and subjected to the same calcination conditions to verify the effect of the nanofiber sensing membrane. The characteristics of the ITO nanofiber and ITO thin-film sensing membranes were evaluated using scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), optical transmittance, and conductivity. Moreover, the sensor operation of the EG-ISFETs is evaluated in terms of sensitivity and non-ideal behaviors. The optimized process improves the sensor characteristics and sensing membrane quality. Therefore, the ITO nanofiber sensing membrane improves the sensitivity and stability of the EG-ISFET, suggesting its applicability as a high-performance biochemical sensor.

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Kusumawati, D. H., K. V. N. Istiqomah, I. Husnia e N. Fathurin. "Synthesis of Nanofiber Polyvinyl Alcohol (PVA) with Electrospinning Method". Journal of Physics: Conference Series 2110, n. 1 (1 novembre 2021): 012010. http://dx.doi.org/10.1088/1742-6596/2110/1/012010.

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Abstract PVA nanofibers are PVA solution-based nanofibers. PVA solution is a synthetic polymer that is non-toxic, soluble in air, and has excellent thermal, gas permeability, and chemical resistance qualities. Nanofibers were synthesized using PVA (Polyvinyl alcohol) solutions at concentrations of 8%, 10%, and 12%. The electrospinning method is used in this investigation, with input voltages of 17 kV and 20 kV, needle distances of 7 cm, 10 cm, and 15 cm from the collector, and a flow rate of 5 ml/hour for each concentration. An optical microscope was used to examine the nanofiber synthesis results in order to assess the morphology and diameter of the fiber. PVA nanofiber with the best fiber from electrospinning has a diameter of 1.06 μm and homogeneous fiber without beads is a synthesized nanofiber with a variation of 10% PVA solution concentration, 15 cm distance from the syringe needle to drum collector, and 20 kV voltage.

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Mamun, Al, Michaela Klöcker, Tomasz Blachowicz e Lilia Sabantina. "Investigation of the Morphological Structure of Needle-Free Electrospun Magnetic Nanofiber Mats". Magnetochemistry 8, n. 2 (8 febbraio 2022): 25. http://dx.doi.org/10.3390/magnetochemistry8020025.

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Electrospun magnetic nanofibers are promising for a variety of applications in biomedicine, energy storage, filtration or spintronics. The surface morphology of nanofiber mats plays an important role for defined application areas. In addition, the distribution of magnetic particles in nanofibers exerts an influence on the final properties of nanofiber mats. A simple method for the production of magnetic nanofiber mats by the addition of magnetic nanoparticles in an electrospinning polymer solution was used in this study. In this work, magnetic nanofibers (MNFs) were prepared by needle-free electrospinning technique from poly(acrylonitrile) (PAN) in the low-toxic solvent dimethy lsulfoxide (DMSO) and 20 wt% Fe3O4 at different parameter conditions such as PAN concentration, voltage and ultrasonic bath. The distribution of nanoparticles in the fiber matrix was investigated as well as the chemical and morphological properties of the resulting magnetic nanofibers. In addition, the surface morphology of magnetic nanofiber mats was studied by confocal laser scanning microscope (CLSM), scanning electron microscope (SEM), Fourier transform infrared microscope (FTIR) and ImageJ software, and distribution of Fe3O4 particles in the matrix was investigated by energy dispersive X-ray spectroscopy (EDX).

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Hyeon, Jae Young, Sung-Hoon Choa, Kyoung Wan Park e Jung Hyun Sok. "Graphene Oxide Coated Silver Nanofiber Transparent Conducting Electrode". Korean Journal of Metals and Materials 58, n. 9 (5 settembre 2020): 626–32. http://dx.doi.org/10.3365/kjmm.2020.58.9.626.

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We fabricated a transparent conducting electrode composed of graphene oxide (GO) and silver (Ag) nanofibers. The graphene oxide was spray-coated on the Ag nanofiber film, which was fabricated by electrospinning process. Ag/poly(vinyl alcohol) ink was fabricated in a polymer matrix solution using the solgel method. The sprayed film was sintered at 200 <sup>o</sup>C for 100 min under H<sub>2</sub>/Ar atmosphere. The optical transmittance of the transparent electrodes was measured by UV/VIS spectroscopy, and sheet resistance was measured using I-V measurement system. As the amount of GO sprayed on the nanofibers increased, the diameters of the nanofibers increased, therefore, the transmittance of the electrode linearly decreased. However, the conductivity of the electrode increased. This is because the sprayed GO filled the gap between the nanofibers, and GO deposited on the surface of the nanofibers will form more effective electron pathways, resulting in increased conductivity. The GO-Ag nanofiber electrode also exhibited excellent environmental stability, and the sheet resistance of the electrode remained very stable during 30 days testing. The lowest sheet resistance of the transparent electrode was 250 ohm/sq with approximately 83% transparency at a wavelength of 550 nm. This excellent electrical properties and environmental stability might facilitate applications of the GO-Ag nanofiber electrode in optoelectronic devices.

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Dulgerbaki, Cigdem, Aliihsan Komur e Aysegul Uygun Oksuz. "Tungsten Oxide Nanofibers for Electrochromic Device Application". Academic Perspective Procedia 1, n. 1 (9 novembre 2018): 902–10. http://dx.doi.org/10.33793/acperpro.01.01.152.

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The tungsten oxide (WO3) nanofibers were grown directly onto an ITO-coated glass via an electrospinning method for electrochromic applications. The electrochromic properties of WO3 nanofibers were investigated in the presence of different electrolytes including a series of ionic liquids and classic LiClO4-PC system. A significant optical modulation of 20.82% at 760 nm, reversible coloration with efficiency of 64.58 cm2/C and excellent cycling stability were achieved for the nanofiber electrochromic device (ECD) with ionic liquid based gel electrolyte.

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Radee, Farah M. "Electrospinning and Optical Properties of Polyacrylonitrile/Titanium Dioxide Nanocomposite Fibers". BASRA JOURNAL OF SCIENCE 41, n. 2 (1 luglio 2023): 337–54. http://dx.doi.org/10.29072/basjs.20230209.

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In situ polymerization was used in this work to prepare polyacrylonitrile (PAN) and titanium dioxide (TiO2) nanocomposite at various ratios (5, 10, 15, and 20 weight percent of TiO2). PAN/TiO2 nanofibers were created using the electrospinning process from a homogenized solution. X-ray diffraction data demonstrated that a structural change to an amorphous state had taken place. Using scanning electron microscopy (SEM), the morphology of the high-aligned fibers with PAN diameters of roughly 33 nm and 51 nm of PAN/(10wt%)TiO2 was examined. A spectrophotometer was used to examine the optical characteristics of the nanofiber films at wavelengths between 200 and 900 nm. The energy gap (Eg) of the nanofiber films was computed, and it decreased as the weight ratio of the TiO2 nanoparticle increased. With 5, 10, and 15% weight percentage of TiO2, respectively, the energy gap (Eg) of PAN nanofibers changes from 3.92 eV to 3.72, 3.39, 3.19 eV. Several other parameters have also been calculated, including the excitation coefficient (k), refractive index (n), Urbach tail (Et), dielectric constant (e1), dielectric loss (e2), and volume and surface energy loss functions (VELF) and (SELF).

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Vylegzhanin, Alexey, Dylan J. Brown, Aswathy Raj, Danil F. Kornovan, Jesse L. Everett, Etienne Brion, Jacques Robert e Síle Nic Chormaic. "Excitation of ⁸⁷Rb Rydberg atoms to nS and nD states (n≤68) via an optical nanofiber". Optica Quantum 1, n. 1 (28 settembre 2023): 6. http://dx.doi.org/10.1364/opticaq.1.000006.

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Abstract (sommario):

Cold Rydberg atoms are a promising platform for quantum technologies, and combining them with optical waveguides has the potential to create robust quantum information devices. Here, we experimentally observe the excitation of cold rubidium atoms to a large range of Rydberg S and D states through interaction with the evanescent field of an optical nanofiber. We develop a theoretical model to account for experimental phenomena present such as the AC Stark shifts and the Casimir–Polder interaction. This work strengthens the knowledge of Rydberg atom interactions with optical nanofibers and is a critical step toward the implementation of all-fiber quantum networks and waveguide quantum electrodynamics (QED) systems using highly excited atoms.

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Vylegzhanin, Alexey, Dylan J. Brown, Aswathy Raj, Danil F. Kornovan, Jesse L. Everett, Etienne Brion, Jacques Robert e Síle Nic Chormaic. "Excitation of ⁸⁷Rb Rydberg atoms to nS and nD states (n≤68) via an optical nanofiber". Optica Quantum 1, n. 1 (28 settembre 2023): 6. http://dx.doi.org/10.1364/opticaq.498414.

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Abstract (sommario):

Cold Rydberg atoms are a promising platform for quantum technologies, and combining them with optical waveguides has the potential to create robust quantum information devices. Here, we experimentally observe the excitation of cold rubidium atoms to a large range of Rydberg S and D states through interaction with the evanescent field of an optical nanofiber. We develop a theoretical model to account for experimental phenomena present such as the AC Stark shifts and the Casimir–Polder interaction. This work strengthens the knowledge of Rydberg atom interactions with optical nanofibers and is a critical step toward the implementation of all-fiber quantum networks and waveguide quantum electrodynamics (QED) systems using highly excited atoms.

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27

Fadhil, Wasan Adeeb, Hanaa K. Essa, Hiba S. Rasheed e Tariq J. Alwan. "Optical parameters of PANI.CSA/PMMA nanofibers". Journal of Physics: Conference Series 2857, n. 1 (1 ottobre 2024): 012002. http://dx.doi.org/10.1088/1742-6596/2857/1/012002.

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Abstract (sommario):

Abstract Polyaniline doped with camphor sulphonic/Poly(methyl methacrylate) PANI.CSA/PMMA nanofibers were manufactured by electrospinning technology, where all parameters of the electrospinning system are fixed and the effect of the needle gauge on the properties of the prepared nanofibers is studied at different needle gauge (18, 20, 23 G). The polyaniline was manufactured by aniline-chemical oxidation polymerization. The nanofibers were diagnosed by an FE-SEM scanner to identify the surface morphology of the samples and the diameters of the nanofibers, it shows that nanofibers become more regular and their diameters become smaller as the diameter of the needle decreases. The samples were measured by the analysis of UV-visible spectroscopy, identifying the optical properties of the nanofibers and calculating the energy gap, which was valued ranging from 2.8 eV to 3.2 eV, increased due to the phenomenon of the quantitative restriction. Absorption coefficient and optical constants were also studied as a function of needle gauge.

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28

Stourm, Erwan, Maxence Lepers, Jacques Robert, Sile Nic Chormaic, Klaus Mølmer e Étienne Brion. "Rydberg atoms in the vicinity of an optical nanofiber". EPJ Web of Conferences 266 (2022): 11013. http://dx.doi.org/10.1051/epjconf/202226611013.

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Abstract (sommario):

Highly excited (so-called Rydberg) atoms are the key ingredient of many quantum information schemes. In this presentation, we shall theoretically investigate how spontaneous emission properties and van der Waals interactions of such atoms are modified in the neighbourhood of an optical nanofiber with respect to the free-space (vacuum) case. This work constitutes a very preliminary step towards the realization of a quantum network based on atomic ensembles linked via optical nanofibers.

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Hoffman, J. E., S. Ravets, J. A. Grover, P. Solano, P. R. Kordell, J. D. Wong-Campos, L. A. Orozco e S. L. Rolston. "Ultrahigh transmission optical nanofibers". AIP Advances 4, n. 6 (giugno 2014): 067124. http://dx.doi.org/10.1063/1.4879799.

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Wu, Xiaoqin, e Limin Tong. "Optical microfibers and nanofibers". Nanophotonics 2, n. 5-6 (16 dicembre 2013): 407–28. http://dx.doi.org/10.1515/nanoph-2013-0033.

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Abstract (sommario):

AbstractAs a combination of fiber optics and nanotechnology, optical microfibers and nanofibers (MNFs) have been emerging as a novel platform for exploring fiber-optic technology on the micro/nanoscale. Typically, MNFs taper drawn from glass optical fibers or bulk glasses show excellent surface smoothness, high homogeneity in diameter and integrity, which bestows these tiny optical fibers with low waveguiding losses and outstanding mechanical properties. Benefitting from their wavelength- or sub-wavelength-scale transverse dimensions, waveguiding MNFs exhibit a number of interesting properties, including tight optical confinement, strong evanescent fields, evident surface field enhancement and large and abnormal waveguide dispersion, which makes them ideal nanowaveguides for coherently manipulating light, and connecting fiber optics with near-field optics, nonlinear optics, plasmonics, quantum optics and optomechanics on the wavelength- or sub-wavelength scale. Based on optical MNFs, a variety of technological applications, ranging from passive micro-couplers and resonators, to active devices such as lasers and optical sensors, have been reported in recent years. This review is intended to provide an up-to-date introduction to the fabrication, characterization and applications of optical MNFs, with emphasis on recent progress in our research group. Starting from a brief introduction of fabrication techniques for physical drawing glass MNFs in Section 2, we summarize MNF optics including waveguiding modes, evanescent coupling, and bending loss of MNFs in Section 3. In Section 4, starting from a “MNF tree” that summarizes the applications of MNFs into 5 categories (waveguide & near field optics, nonlinear optics, plasmonics, quantum & atom optics, optomechanics), we go to details of typical technological applications of MNFs, including optical couplers, interferometers, gratings, resonators, lasers and sensors. Finally in Section 5 we present a brief summary of optical MNFs regarding their current challenges and future opportunities.

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Garcia-Fernandez, R., W. Alt, F. Bruse, C. Dan, K. Karapetyan, O. Rehband, A. Stiebeiner, U. Wiedemann, D. Meschede e A. Rauschenbeutel. "Optical nanofibers and spectroscopy". Applied Physics B 105, n. 1 (22 settembre 2011): 3–15. http://dx.doi.org/10.1007/s00340-011-4730-x.

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32

Yoo, Tae Hee, Heejoong Ryou, In Gyu Lee, Byung Jin Cho e Wan Sik Hwang. "Enhanced Photocatalytic Activity of Electrospun β-Ga2O3 Nanofibers via In-Situ Si Doping Using Tetraethyl Orthosilicate". Catalysts 9, n. 12 (30 novembre 2019): 1005. http://dx.doi.org/10.3390/catal9121005.

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Abstract (sommario):

β-Ga2O3 has attracted considerable attention as an alternative photocatalyst to replace conventional TiO2 under ultraviolet-C irradiation due to its high reduction and oxidation potential. In this study, to enhance the photocatalytic activity of β-Ga2O3, nanofibers are formed via the electrospinning method, and Si atoms are subsequently doped. As the Si concentration in the β-Ga2O3 nanofiber increases, the optical bandgap of the β-Ga2O3 nanofibers continuously decreases from 4.5 eV (intrinsic) to 4.0 eV for the Si-doped (2.4 at. %) β-Ga2O3 nanofibers, and accordingly, the photocatalytic activity of the β-Ga2O3 nanofibers is enhanced. This higher photocatalytic performance with Si doping is attributed to the increased doping-induced carriers in the conduction band edges. This differs from the traditional mechanism in which the doping-induced defect sites in the bandgap enhance separation and inhibit the recombination of photon-generated carriers.

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Лебедев, Н. М., К. Н. Миньков, А. Е. Шитиков, А. Н. Данилин, М. И. Красивская, Е. А. Лоншаков, И. К. Горелов, Н. Ю. Дмитриев e И. А. Биленко. "Оптимизация изготовления одномодовых растянутых оптических волокон для когерентной микрооптики". Журнал технической физики 92, n. 6 (2022): 852. http://dx.doi.org/10.21883/jtf.2022.06.52515.30-22.

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Abstract (sommario):

Micro- and nanofibers are the universal elements of the optical schemes for solving wide variety of experimental tasks. One usually uses the commercial optical fiber tapering in the burner’s flame to produce such nanofibers. Such tapers are actively used for production of highly sensitive sensors, experiments with the cold atoms and coupling to optical microresonators. The theoretical model of geometrical shape altering during the fiber tapering and heating was adapted in this publication for use in the algorithm with universal adjustment of the tapering modes to get a fiber with the desired set of parameters. One of the innovations was the implementation of the computer vision to control the tapering process. As a result, the nanofibers with the optimal waist diameter of about 700 nm for the radiation wavelength of 1.55 micron were obtained. The optimized methodic of tapering allows the production of the nanofibers with the transmittance of up to 80%. The produced nanofibers were successfully used for coupling to the crystalline whispering gallery mode microresonator. As a result, the optical combs with the spectrum range up to 200 nm were obtained in IR range.

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Lifka, Sebastian, Kristóf Harsányi, Erich Baumgartner, Lukas Pichler, Dariya Baiko, Karsten Wasmuth, Johannes Heitz et al. "Laser-processed antiadhesive bionic combs for handling nanofibers inspired by nanostructures on the legs of cribellate spiders". Beilstein Journal of Nanotechnology 13 (7 novembre 2022): 1268–83. http://dx.doi.org/10.3762/bjnano.13.105.

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Abstract (sommario):

Nanofibers are drawing the attention of engineers and scientists because their large surface-to-volume ratio is favorable for applications in medicine, filter technology, textile industry, lithium-air batteries, and optical sensors. However, when transferring nanofibers to a technical product in the form of a random network of fibers, referred to as nonwoven fabric, the stickiness of the freshly produced and thus fragile nanofiber nonwoven remains a problem. This is mainly because nanofibers strongly adhere to any surface because of van der Waals forces. In nature, there are animals that are actually able to efficiently produce, process, and handle nanofibers, namely cribellate spiders. For that, the spiders use the calamistrum, a comb-like structure of modified setae on the metatarsus of the hindmost (fourth) legs, to which the 10–30 nm thick silk nanofibers do not stick due to a special fingerprint-like surface nanostructure. In this work, we present a theoretical model of the interaction of linear nanofibers with a sinusoidally corrugated surface. This model allows for a prediction of the adhesive interaction and, thus, the design of a suitable surface structure to prevent sticking of an artificially nonwoven of nanofibers. According to the theoretical prediction, a technical analogon of the nanoripples was produced by ultrashort pulse laser processing on different technically relevant metal surfaces in the form of so-called laser-induced periodic surface structures (LIPSS). Subsequently, by means of a newly established peel-off test, the adhesion of an electrospun polyamide fiber-based nonwoven was quantified on such LIPSS-covered aluminium alloy, steel, and titanium alloy samples, as well as on polished (flat) control samples as reference and, additionally, on samples with randomly rough surfaces. The latter revealed that the adhesion of electrospun nanofiber nonwoven is significantly lowered on the nanostructured surfaces compared with the polished surfaces.

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Ehrmann, Andrea, e Tomasz Blachowicz. "Magnetic Force Microscopy on Nanofibers—Limits and Possible Approaches for Randomly Oriented Nanofiber Mats". Magnetochemistry 7, n. 11 (27 ottobre 2021): 143. http://dx.doi.org/10.3390/magnetochemistry7110143.

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Abstract (sommario):

Magnetic force microscopy (MFM) belongs to the methods that enable spatially resolved magnetization measurements on common thin-film samples or magnetic nanostructures. The lateral resolution can be much higher than in Kerr microscopy, another spatially resolved magnetization imaging technique, but since MFM commonly necessitates positioning a cantilever tip typically within a few nanometers from the surface, it is often more complicated than other techniques. Here, we investigate the progresses in MFM on magnetic nanofibers that can be found in the literature during the last years. While MFM measurements on magnetic nanodots or thin-film samples can often be found in the scientific literature, reports on magnetic force microscopy on single nanofibers or chaotic nanofiber mats are scarce. The aim of this review is to show which MFM investigations can be conducted on magnetic nanofibers, where the recent borders are, and which ideas can be transferred from MFM on other rough surfaces towards nanofiber mats.

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Tohluebaji, Nikruesong, Ratchanewan Siri, Nantakan Muensit, Chatchai Putson, Phongpichit Channuie, Paweena Porrawatkul e Jureeporn Yuennan. "Hydrophobic and Optical Properties of P(VDF-HFP) Nanofiber Filled with Nickel (II) Chloride Hexahydrate for Dye-Sensitized Solar Cells Application". Trends in Sciences 21, n. 9 (20 agosto 2024): 8762. http://dx.doi.org/10.48048/tis.2024.8762.

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Abstract (sommario):

This study explores the enhancement of dye-sensitized solar cells (DSSCs) by incorporating nickel chloride hexahydrate (NiCl2ꞏ6H2O) into poly(vinylidene fluoride hexafluoropropylene) (P(VDF-HFP)) nanofiber mats. The addition of NiCl2ꞏ6H2O significantly improves the nanofiber morphology, leading to smoother, bead-free fibers with reduced diameters. Enhanced hydrophobicity is achieved through increased water contact angles and lower surface energy. Crystallinity and mechanical properties, including tensile stress and Young’s modulus, are also improved, though ductility is reduced. Optical properties benefit from additional absorbance features due to Ni2+ ions, while electrical conductivity increases, forming conductive pathways that facilitate electron transport. These modifications collectively suggest that NiCl2ꞏ6H2O/P(VDF-HFP) composite nanofibers can substantially improve DSSC performance by offering superior mechanical strength, hydrophobicity, and electrical conductivity. HIGHLIGHTS The study investigates the impact of incorporating nickel chloride hexahydrate (NiCl₂·6H₂O) into poly(vinylidene fluoride hexafluoropropylene) (P(VDF-HFP)) nanofiber mats to enhance dye-sensitized solar cells (DSSCs). Key findings include: Improved Nanofiber Morphology: NiCl₂·6H₂O leads to smoother, bead-free nanofibers with smaller diameters. Enhanced Hydrophobicity: The composite fibers exhibit higher water contact angles and lower surface energy. Better Mechanical Properties: Increased crystallinity, tensile stress, and Young's modulus, although with reduced ductility. Enhanced Optical and Electrical Properties: Ni²⁺ ions add absorbance features, and electrical conductivity improves, aiding electron transport. GRAPHICAL ABSTRACT

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Sun, Jing, Tao Huang e Zhongyang Wang. "Multiple Scattering-Enhanced Fluorescence Within Randomly Oriented Low-Index Polymer Nanofiber Sensors". Biosensors 15, n. 2 (8 febbraio 2025): 97. https://doi.org/10.3390/bios15020097.

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Abstract (sommario):

Fluorescence enhancement technologies play a crucial role in biological and chemical sensors. Currently, effective fluorescence sensors primarily rely on noble metals and high-index dielectric nanostructures. While effective, they are plagued by optical losses and complex fabrication processes. In contrast, low-index material nanostructures offer significant advantages, including the absence of optical losses, ease of fabrication, and cost-effectiveness, but they face the challenge of weaker electric field enhancement. Here, we designed a low-index, randomly oriented polyvinyl acetate (PVAc) nanofiber sensor via scalable electrospinning, enabling multiple scattering within the disordered nanofibers and resulting in an impressive surface-enhanced fluorescence factor of 1170. This sensor achieves a detection limit for rhodamine 6G as low as 7.24 fM, outperforming the reported fluorescence biosensors. Further results of photoluminescence decay dynamics and random lasing validate the effectiveness of multiple scattering in enhancing fluorescence within the polymer nanofiber sensor. With its excellent performance and scalable production process, this randomly oriented, low-index polymer nanofiber sensor offers a promising new pathway for efficient surface-enhanced fluorescence based on multiple scattering. Furthermore, PVAc nanofibers can be extended to other low-index materials capable of forming randomly oriented nanostructures, offering significant potential for cost-effective, high-performance fluorescence sensor applications.

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Laidmäe, Ivo, Andres Meos, Irja Alainezhad Kjærvik, Sveinung G. Ingebrigtsen, Nataša Škalko-Basnet, Kalle Kirsimäe, Tavo Romann, Urmas Joost, Vambola Kisand e Karin Kogermann. "Electrospun Amphiphilic Nanofibers as Templates for In Situ Preparation of Chloramphenicol-Loaded Liposomes". Pharmaceutics 13, n. 11 (20 ottobre 2021): 1742. http://dx.doi.org/10.3390/pharmaceutics13111742.

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Abstract (sommario):

The hydration of phospholipids, electrospun into polymeric nanofibers and used as templates for liposome formation, offers pharmaceutical advantages as it avoids the storage of liposomes as aqueous dispersions. The objective of the present study was to electrospin and characterize amphiphilic nanofibers as templates for the preparation of antibiotic-loaded liposomes and compare this method with the conventional film-hydration method followed by extrusion. The comparison was based on particle size, encapsulation efficiency and drug-release behavior. Chloramphenicol (CAM) was used at different concentrations as a model antibacterial drug. Phosphatidylcoline (PC) with polyvinylpyrrolidone (PVP), using ethanol as a solvent, was found to be successful in fabricating the amphiphilic composite drug-loaded nanofibers as well as liposomes with both methods. The characterization of the nanofiber templates revealed that fiber diameter did not affect the liposome size. According to the optical microscopy results, the immediate hydration of phospholipids deposited on the amphiphilic nanofibers occurred within a few seconds, resulting in the formation of liposomes in water dispersions. The liposomes appeared to aggregate more readily in the concentrated than in the diluted solutions. The drug encapsulation efficiency for the fiber-hydrated liposomes varied between 14.9 and 28.1% and, for film-hydrated liposomes, between 22.0 and 77.1%, depending on the CAM concentrations and additional extrusion steps. The nanofiber hydration method was faster, as less steps were required for the in-situ liposome preparation than in the film-hydration method. The liposomes obtained using nanofiber hydration were smaller and more homogeneous than the conventional liposomes, but less drug was encapsulated.

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Putri, Nugrahani Primary, Evi Suaebah, Diva Nuri Islami, Lydia Rohmawati, Diah Hari Kusumawati, Fitriana Fitriana e Zainul Arifin Imam Supardi. "Synthesis and Characterization of PVA/PANI Nanofiber as Active Material for Humidity Sensors". Trends in Sciences 21, n. 6 (30 aprile 2024): 7551. http://dx.doi.org/10.48048/tis.2024.7551.

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Abstract (sommario):

PANI is a nanostructure conductive polymer that has been widely researched by making nanofibers using electrospinning, by adding PVA as a non-conductive material. In this research, we have successfully synthesized PVA/PANI nanofiber using the electrospinning method and applied it as a humidity sensor. The oxidation polymerization method was conducted to produce polyaniline (PANI) powder. PVA was used as a non-conductive polymer to carry PANI. PANI is blended with 10 % PVA to produce nanofiber PVA/PANI. The results of the synthesis of PVA/PANI nanofibers using the electrospinning method have been characterized by FTIR and EDX to identify the functional groups and elements of PVA/PANI. The FTIR results confirmed that for the PVA nanofiber samples, the type of polyvinyl alcohol bond has been identified according to the reference. The EDX results show the elements C, O and N. The element nitrogen (N) is the characteristic element of polyaniline (C6H5(NH)2)n. The optical Microscope and Scanning Electron Microscope show that the electrospinning method has succeeded in synthesizing PVA/PANI nanofibers with a fiber size of around 0.313 mm. The porosity of PVA/PANI is around 55 %, which is related to the ability of PVA/PANI sensitivity to detect humidity. These results are demonstrated by measurements using a Four-Point Probe (FPP), with the humidity value varying from 64 - 80 %. The results show that variations of PANI powder content improve the sensitivity performance of PVA/PANI nanofibers. This method can optimize PVA/PANI nanofiber as a humidity sensor, increase conductivity flexibility, make it easier and enhance the PANI to use as an active sensor. HIGHLIGHTS The active material for the sensor is polyaniline-based. Polyaniline oxidation polymerization using a method with solid acid doping, which can increase the conductivity of polyaniline (PANI). The formation of PANI nanofibers increases the sensing activities’ effectiveness. Polyvinyl alcohol (PVA) is used as a carrier to facilitate the synthesis process by electrospinning. GRAPHICAL ABSTRACT

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Chen, Wu-Jhang, Kuo-Chin Hsu, Te-Hua Fang, Chun-I. Lee, Tao-Hsing Chen e Tung-Han Hsieh. "Structural, optical characterization and photocatalytic behavior of Ag/TiO2 nanofibers". Digest Journal of Nanomaterials and Biostructures 16, n. 4 (ottobre 2021): 1227–34. http://dx.doi.org/10.15251/djnb.2021.164.1227.

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Abstract (sommario):

In this study, Ag doped TiO2 nanofibers were successfully prepared by electrospinning technology for photocatalytic degradation. The structure, morphology and optical properties of the as-prepared nanofibers were analyzed through X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), transmission electron microscope (TEM), and ultraviolet-visible spectroscopy (UV-Vis). Photocatalytic degradation results show that Ag doped TiO2 nanofibers have higher photocatalytic activity than pure TiO2 nanofibers under both visible light and ultraviolet light irradiation, which can effectively improve the degradation efficiency. The best degradation sample in this experiment is 5% Ag doped TiO2 nanofibers, which can complete methylene blue (MB) degradation in 90 minutes under UV light and 70% MB degradation in 240 minutes under visible light.

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Godet, Adrien, Abdoulaye Ndao, Thibaut Sylvestre, Vincent Pecheur, Sylvie Lebrun, Gilles Pauliat, Jean-Charles Beugnot e Kien Phan Huy. "Brillouin spectroscopy of optical microfibers and nanofibers". Optica 4, n. 10 (10 ottobre 2017): 1232. http://dx.doi.org/10.1364/optica.4.001232.

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42

Madsen, Lars S., Christopher Baker, Halina Rubinsztein-Dunlop e Warwick P. Bowen. "Nondestructive Profilometry of Optical Nanofibers". Nano Letters 16, n. 12 (21 novembre 2016): 7333–37. http://dx.doi.org/10.1021/acs.nanolett.6b02460.

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Younas, Bushra, Muhammad Younis, Muhammad Ozair Ahmed e Syed Tahir Raza Rizvi. "Chirped optical solitons in nanofibers". Modern Physics Letters B 32, n. 26 (20 settembre 2018): 1850320. http://dx.doi.org/10.1142/s0217984918503207.

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Abstract (sommario):

The nonlinear chirp solitons are for the first time derived in optical nanofibers, thus illustrating the set of confined structure with nontrivial phase for the model of Schrödinger–Hirota equation. The model is studied with the dispersion of self-phase and self-steeping coefficients. The results show that bright, dark and singular solitons are dependent on the pulse intensity. Additionally, the constraint settings for the existence of solitons are also fall out during the derivation.

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Schoolaert, Ella, Richard Hoogenboom e Karen De Clerck. "Colorimetric Nanofibers as Optical Sensors". Advanced Functional Materials 27, n. 38 (16 agosto 2017): 1702646. http://dx.doi.org/10.1002/adfm.201702646.

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Dubey, Neha, e Sudeshna Chandra. "Miniaturized Biosensors Based on Lanthanide-Doped Upconversion Polymeric Nanofibers". Biosensors 14, n. 3 (21 febbraio 2024): 116. http://dx.doi.org/10.3390/bios14030116.

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Abstract (sommario):

Electrospun nanofibers possess a large surface area and a three-dimensional porous network that makes them a perfect material for embedding functional nanoparticles for diverse applications. Herein, we report the trends in embedding upconversion nanoparticles (UCNPs) in polymeric nanofibers for making an advanced miniaturized (bio)analytical device. UCNPs have the benefits of several optical properties, like near-infrared excitation, anti-Stokes emission over a wide range from UV to NIR, narrow emission bands, an extended lifespan, and photostability. The luminescence of UCNPs can be regulated using different lanthanide elements and can be used for sensing and tracking physical processes in biological systems. We foresee that a UCNP-based nanofiber sensing platform will open opportunities in developing cost-effective, miniaturized, portable and user-friendly point-of-care sensing device for monitoring (bio)analytical processes. Major challenges in developing microfluidic (bio)analytical systems based on UCNPs@nanofibers have been reviewed and presented.

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Mamun, Al, Marah Trabelsi, Michaela Klöcker, Jan Lukas Storck, Robin Böttjer e Lilia Sabantina. "Needleless electrospun polyacrylonitrile/konjac glucomannan nanofiber mats". Journal of Engineered Fibers and Fabrics 15 (gennaio 2020): 155892502096480. http://dx.doi.org/10.1177/1558925020964806.

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Abstract (sommario):

In this study we report for the first time about the preparation of polyacrilontrile (PAN)/konjac glucomannan (KGM) nanofiber mats, needleless electrospinning from the low-toxic solvent dimethyl sulfoxide (DMSO) and the formation of carbon nanocomposites. Konjac glucomannan is a biopolymer and renewable, environmentally friendly raw material and a well-known polysaccharide, which is non-toxic and biocompatible material and is extracted from the Amorphophallus konjac plant. The addition of poloxamer in electrospinning PAN/KGM solution resulted in the reduction of membrane areas and decrease of beads in nanofibers. The concentration of 1.5% or 0.5% of konjac glucomannan in PAN/KGM nanofiber mats was not detected to affect the morphology of the nanofiber mats. The PAN/KGM nanofiber mats received oxidative stabilization and subsequent carbonization. It could be observed that after the oxidative stabilization process the average diameter of PAN/KGM nanofibers increased and after carbonization decreased compared to stabilized nanofibers. Alternative renewable raw materials such as KGM electrospun with synthetic polymers offer the possibility to reduce the environmental impact and are the alternative to new technical materials and lowers the cost of carbon materials. The combination of PAN with konjac glucomannan and the properties of both polymers open up a wide range of applications for the PAN/KGM nanofiber mats and carbon nanocomposites produced in this study, for example, for pharmaceutical and biomedical applications, as absorbents for the removal of pollutants in wastewater and as filter media for air purification, as well as for optical and chemical sensors.

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Zulfikri, Nurul Izzati Zafirah, Abdel-Baset M. A. Ibrahim, Nur Amalina Mustaffa, Rozan Mohamad Mohamad Yunus e Suraya Ahmad Kamil. "Enhancing Photoluminescence Intensity and Spectral Bandwidth of Hybrid Nanofiber/Thin-Film Multilayer Tm3+-Doped SiO2–HfO2". Nanomaterials 12, n. 21 (25 ottobre 2022): 3739. http://dx.doi.org/10.3390/nano12213739.

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Abstract (sommario):

Multilayering of optical thin films is widely used for a range of purposes in photonic technology, but the development of nanofiber structures that can outperform thin films and nanoparticles in optical applications cannot simply be disregarded. Hybrid structures composed of Tm3+-doped SiO2–HfO2 in the form of nanofibers (NFs) and thin films (TFs) are deposited on a single substrate using the electrospinning and dip-coating methods, respectively. Ultrafine nanofiber strands with a diameter of 10–60 nm were fabricated in both single and multilayer samples. Enhanced photoluminescence emission intensity of about 10 times was attained at wavelengths of around 457, 512 and 634 nm under an excitation of 350 nm for NF-TF-NF* hybrid structures when compared with single-layered NF and TF structures. The arrangement of nanofibers and thin films in a multilayer structure influenced the luminescence intensity and spectral bandwidth. High transparency in the range of 75–95% transparency across the wavelength of 200–2000 nm was achieved, making it ideal for photonic application. Theoretical findings obtained through IMD software were compared with experimental results, and they were found to be in good agreement.

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Homaeigohar, Shahin, Danial Kordbacheh, Sourav Banerjee, Jiacheng Gu, Yilong Zhang e Zhihong Huang. "Zinc Oxide Nanoparticle Loaded L-Carnosine Biofunctionalized Polyacrylonitrile Nanofibrous Wound Dressing for Post-Surgical Treatment of Melanoma". Polymers 17, n. 2 (12 gennaio 2025): 173. https://doi.org/10.3390/polym17020173.

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Nanofibrous dressing materials with an antitumor function can potentially inhibit recurrence of melanoma following the surgical excision of skin tumors. In this study, hydrolyzed polyacrylonitrile (hPAN) nanofibers biofunctionalized with L-carnosine (CAR) and loaded with bio (CAR)-synthesized zinc oxide (ZnO) nanoparticles, ZnO/CAR-hPAN (hereafter called ZCPAN), were employed to develop an antimelanoma wound dressing. Inspired by the formulation of the commercial wound healing Zn-CAR complex, i.e., polaprezinc (PLZ), for the first time, we benefitted from the synergy of zinc and CAR to create an antimelanoma nanofibrous wound dressing. According to scanning electron microscopy (SEM) images, ultrafine ZnO nanoparticles were homogenously distributed throughout the nanofibrous dressing. The ZCPAN nanofiber mat showed a significantly higher toughness (18.7 MJ.m−3 vs. 1.4 MJ.m−3) and an enhanced elongation at break (stretchability) compared to the neat PAN nanofiber mat (12% vs. 9.5%). Additionally, optical coherence elastography (OCE) measurements indicated that the ZCPAN nanofibrous dressing was as stiff as 50.57 ± 8.17 kPa which is notably larger than that of the PAN nanofibrous dressing, i.e., 24.49 ± 6.83 kPa. The optimum mechanical performance of the ZCPAN nanofibers originates from physicochemical interaction of CAR ligands, hPAN nanofibers, and ZnO nanoparticles through hydrogen bonding, electrostatic bonding, and esterification, as verified using ATR-FTIR. An in vitro cell viability assay using human skin melanoma cells implied that the cells are notably killed in the presence of the ZCPAN nanofibers compared to the PAN nanofibers. Thanks to ROS generating ZnO nanoparticles, this behavior originates from the high reactive oxygen species (ROS)-induced oxidative damage of melanoma cells, as verified through a CellROX assay. In this regard, an apoptotic cell response to the ZCPAN nanofibers was recorded through an apoptosis assay. Taken together, the ZCPAN nanofibers induce an antimelanoma effect through oxidative stress and thus are a high potential wound dressing material to suppress melanoma regrowth after surgical excision of skin tumors.

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Prasansaeng, Chotiros, Tienthong Yuangkaew, Napat Triroj e Papot Jaroenapibal. "Tuning Optical Properties of Electrospun Titanium Dioxide Nanofibers by Controlling Particle Sizes". Advanced Materials Research 931-932 (maggio 2014): 360–64. http://dx.doi.org/10.4028/www.scientific.net/amr.931-932.360.

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Titanium dioxide (TiO2) nanofibers with different particle sizes were fabricated using an electrospinning technique. The nanofibers were prepared from a mixture of titanium tetraisopropoxide and polyvinyl pyrrolidone (PVP). The scanning electron microscope (SEM) and the transmission electron microscope (TEM) were used to analyze the morphology and sizes of TiO2 nanoparticles within the nanofibers. The particle sizes of TiO2 were measured to be 17 nm, 28 nm and 35 nm for nanofibers calcined at 500 °C, 600 °C and 700 °C, respectively. Ultraviolet-visible absorption spectroscopy analysis and the application of the KubelkaMunk function reveal the size-dependent band gap energy of TiO2 nanofibers. The band gap energies are measured to be 2.9 eV, 2.6 eV and 2.5 eV for TiO2 nanofibers with average particle sizes of 17 nm, 28 nm and 35 nm, respectively.

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50

Risdian, Chandra, Muhamad Nasir, Annisa Rahma e Heni Rachmawati. "The Influence of Formula and Process on Physical Properties and the Release Profile of PVA/BSA Nanofibers Formed by Electrospinning Technique". Journal of Nano Research 31 (aprile 2015): 103–16. http://dx.doi.org/10.4028/www.scientific.net/jnanor.31.103.

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Electrospinning is a simple versatile process to produce nanofibers. However, it requires careful approach to form appropriates fibers for different purposes. This report describes aspects influencing successful development of nanofiber containing BSA using electrospinning method. Optical and scanning electron microscopy, energy dispersive X-Ray and Fourier transformed infrared spectroscopy, differential scanning calorimetric, and X-Ray diffraction analysis of nanofiber were performed. Modification of PVA/BSA nanofiber with Eudragit L-100 was conducted by dip coating method. The presence of BSA increased the diameter of the fibers. Modification of PVA/BSA nanofiber with Eudragit L-100 delayed the release of BSA in acidic medium but promoting its release in intestinal mimicking medium.

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