Articles de revues : « Composite nanofibers »

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Chang, Zhen Jun. « Development of a Polyurethane Nanocomposite Reinforced with Carbon Nanotube Composite Nanofibers ». Materials Science Forum 688 (juin 2011) : 41–44. http://dx.doi.org/10.4028/www.scientific.net/msf.688.41.

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Functionalized carbon nanotubes (CNTs) composite nanofibers with high melting point polyurethane (PUH) as matrix were fabricated by electrospinning method, which were later stacked alternately with low melting point polyurethane (PUL) films into composite nanofiber reinforced composites through a hot press treatment. The tensile modulus (30 wt.% composite nanofibers) reaches 54.3 MPa, 187% higher than that pure PUL film.

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Liu, Ning, et Lilin Jiang. « Effect of microstructural features on the thermal conducting behavior of carbon nanofiber–reinforced styrene-based shape memory polymer composites ». Journal of Intelligent Material Systems and Structures 31, n^o 14 (20 juin 2020) : 1716–30. http://dx.doi.org/10.1177/1045389x20932216.

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This article presents a novel hierarchical micromechanics approach to carefully investigate the thermal conductivities of styrene-based shape memory polymer composites containing carbon nanofibers. The research is mainly focused on the simulation of carbon nanofiber/shape memory polymer interfacial thermal resistance and carbon nanofiber agglomeration as two critical microstructural features of carbon nanofiber–shape memory polymer composite materials. The computed results are compared with the available experimental measurements. It is found that both of those microstructural factors along with carbon nanofiber non-straight shape significantly affecting the thermal conducting behavior must be incorporated in the analysis to have a more realistic prediction. The thermal conductivity of carbon nanofiber–reinforced shape memory polymer composites reduces significantly due to the effects of carbon nanofiber/shape memory polymer interfacial resistance and carbon nanofiber agglomeration and waviness. It is suggested to uniformly disperse carbon nanofibers into the shape memory polymers and reduce interfacial resistance for improving the carbon nanofiber–styrene composite thermal properties. In addition, the present study reveals that the effective thermal conductivities of the shape memory polymer composites reinforced by aligned carbon nanofibers are greatly enhanced over those of the shape memory polymer composites containing randomly dispersed carbon nanofibers. The effects of percentage, waviness parameters, degree of agglomeration, material properties, length and diameter of carbon nanofibers as well as interfacial thermal resistance value on the thermal behavior of carbon nanofiber–reinforced styrene-based shape memory polymer composites are investigated.

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Gao, Dawei, Hui Qiao, Qingqing Wang, Yibing Cai et Qufu Wei. « Structure, Morphology and Thermal Stability of Porous Carbon Nanofibers Loaded with Cobalt Nanoparticles ». Journal of Engineered Fibers and Fabrics 6, n^o 4 (décembre 2011) : 155892501100600. http://dx.doi.org/10.1177/155892501100600402.

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Porous carbon/cobalt (C/Co) composite nanofibers with diameters of 200–300 nm were prepared by electrospinning and subsequent carbonization processes. Two polymer solutions of polyacrylonitrile (PAN), polyvinyl pyrrolidone (PVP), and Co (CH3COOH) 2 (Co (OAc) 2) were used as C/Co composite nanofiber precursors. The study revealed that C/Co composite nanofibers were successfully prepared and cobalt particles with diameters of 20–30 nm were uniformly scattered in the carbon nanofibers. It was also observed that clear fibrous morphology with grainlike particles and good structural integrity were still maintained after calcination. The TGA analysis indicated the improved thermal stability properties of the composite nanofibers. The Brunauer-Emmett-Teller (BET) analysis indicated that C/Co composites nanofibers with meso-pores possessed larger specific surface area than that of carbon nanofibers.

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Toriello, Mariela, Morteza Afsari, Ho Kyong Shon et Leonard D. Tijing. « Progress on the Fabrication and Application of Electrospun Nanofiber Composites ». Membranes 10, n^o 9 (28 août 2020) : 204. http://dx.doi.org/10.3390/membranes10090204.

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Nanofibers are one of the most attractive materials in various applications due to their unique properties and promising characteristics for the next generation of materials in the fields of energy, environment, and health. Among the many fabrication methods, electrospinning is one of the most efficient technologies which has brought about remarkable progress in the fabrication of nanofibers with high surface area, high aspect ratio, and porosity features. However, neat nanofibers generally have low mechanical strength, thermal instability, and limited functionalities. Therefore, composite and modified structures of electrospun nanofibers have been developed to improve the advantages of nanofibers and overcome their drawbacks. The combination of electrospinning technology and high-quality nanomaterials via materials science advances as well as new modification techniques have led to the fabrication of composite and modified nanofibers with desired properties for different applications. In this review, we present the recent progress on the fabrication and applications of electrospun nanofiber composites to sketch a progress line for advancements in various categories. Firstly, the different methods for fabrication of composite and modified nanofibers have been investigated. Then, the current innovations of composite nanofibers in environmental, healthcare, and energy fields have been described, and the improvements in each field are explained in detail. The continued growth of composite and modified nanofiber technology reveals its versatile properties that offer alternatives for many of current industrial and domestic issues and applications.

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Bayat, Masoumeh, Heejae Yang et Frank Ko. « Effect of iron oxide nanoparticle size on electromagnetic properties of composite nanofibers ». Journal of Composite Materials 52, n^o 13 (20 septembre 2017) : 1723–36. http://dx.doi.org/10.1177/0021998317732139.

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Electrically conductive and magnetically permeable carbon nanofiber-based composites were developed using the electrospinning with subsequent heat treatment. The composite nanofiber contains a variable composition of magnetite nanoparticles with two different size regimes, ranging from superparamagnetic (10–20 nm) to ferromagnetic (20–30 nm). The composite nanofibers are then characterized using Scanning/Transmission Electron Microscopy, X-Ray Diffractometry, Raman Spectroscopy, four-point probe, and a Superconducting Quantum Interference Device. Electromagnetic Interference Shielding Effectiveness of pristine carbon nanofibers as well as electromagnetic composite nanofibers are examined in the X-band frequency region. Higher degree of graphitization, electrical conductivity, and magnetic strength are obtained for nanocomposites containing larger magnetite nanoparticles (20–30 nm). A transition from superpartamagnetic to ferromagnetic characteristics is observed during nanocomposite processing. Electromagnetic Interference Shielding Effectiveness of as high as 68 dB (in the working frequency of 10.4 GHz) is observed for composite nanofibers fabricated with larger magnetite nanoparticles carbonized at 900℃.

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Tan, Noel Peter B., Luis K. Cabatingan et Kramer Joseph A. Lim. « Synthesis of TiO₂ Nanofiber by Solution Blow Spinning (SBS) Method ». Key Engineering Materials 858 (août 2020) : 122–28. http://dx.doi.org/10.4028/www.scientific.net/kem.858.122.

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Synthesis of ceramic nanofibers is commonly carried out through electrospinning method. However, with the emergence of solution blow spinning (SBS) technology, spinning of nanofiber and its composites has resulted in a more straightforward and commercially scalable process. In this study, ceramic nanofibers (i.e., TiO2 nanofibers) were synthesized through SBS followed by calcination. Three critical parameters were investigated (i.e., precursor concentration, calcination temperature and time) to produce ready-to-use composite membranes and pure ceramic nanofibers. Characterizations of ceramic membranes and pure nanofibers include scanning electron microscope (SEM) analysis and energy dispersive x-ray (EDX) for elemental component analysis. Insights on the transformation of composite membranes into pure ceramic nanofibers and the role of calcination are also discussed.

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XIANHUA, Z., F. XIANGWEI, Y. BIN, L. FAN, C. LINA et Z. CENGCENG. « STUDY ON PREPARATION AND PROPERTIES OF PVA/AgNPs COMPOSITE NANOFIBER MASK MATERIAL ». Digest Journal of Nanomaterials and Biostructures 15, n^o 2 (avril 2020) : 299–309. http://dx.doi.org/10.15251/djnb.2020.152.299.

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In this paper, the preparation and properties of polyvinyl alcohol (PVA)/silver nanoparticles (AgNPs) composite nanofiber mask material were studied. Firstly, PVA spinning solution was prepared, and PVA nanofibers with different mass fractions (5 wt%, 7 wt%, 8 wt%, 9 wt% and 11 wt%) were prepared by electrospinning technology. The morphology of PVA nanofibers was observed under electron microscope, and the results showed that 8 wt% PVA nanofibers had the best morphology. AgNPs with different mass fractions (0.02 wt%, 0.03 wt%, 0.04 wt%, 0.05 wt% and 0.06 wt%) were dispersed in pure water and blended with 8 wt% PVA solution to prepare PVA/AgNPs composite nanofibers by electrospinning. The effects of different mass fractions of AgNPs on the morphology of PVA/AgNPs composite nanofibers were analyzed. Infrared spectroscopy and X-ray diffraction were used to test the PVA/AgNPs composite nanofibers. PVA/AgNPs composite nanofiber mask fabric was prepared by using activated carbon nonwoven fabric as substrate. The filterability, air permeability and moisture permeability of PVA/AgNPs composite nanofiber mask material were tested and analyzed. The result showed that PVA/AgNPs composite nanofiber mask material has good filtration, moisture permeability and air permeability, and has broad application prospects.

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Huang, Yi-Jen, Chien-Lin Huang, Ruo-Yu Lai, Cheng-Han Zhuang, Wei-Hao Chiu et Kun-Mu Lee. « Microstructure and Biological Properties of Electrospun In Situ Polymerization of Polycaprolactone-Graft-Polyacrylic Acid Nanofibers and Its Composite Nanofiber Dressings ». Polymers 13, n^o 23 (3 décembre 2021) : 4246. http://dx.doi.org/10.3390/polym13234246.

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In this study, polycaprolactone (PCL)- and poly(acrylic acid) (PAA)-based electrospun nanofibers were prepared for the carriers of antimicrobials and designed composite nanofiber mats for chronic wound care. The PCL- and PAA-based electrospun nanofibers were prepared through in situ polymerization starting from PCL and acrylic acid (AA). Different amounts of AA were introduced to improve the hydrophilicity of the PCL electrospun nanofibers. A compatibilizer and a photoinitiator were then added to the electrospinning solution to form a grafted structure composed of PCL and PAA (PCL-g-PAA). The grafted PAA was mainly located on the surface of a PCL nanofiber. The optimization of the composition of PCL, AA, compatibilizer, and photoinitiator was studied, and the PCL-g-PAA electrospun nanofibers were characterized through scanning electron microscopy and 1H-NMR spectroscopy. Results showed that the addition of AA to PCL improved the hydrophilicity of the electrospun PCL nanofibers, and a PCL/AA ratio of 80/20 presented the best composition and had smooth nanofiber morphology. Moreover, poly[2 -(tert-butylaminoethyl) methacrylate]-grafted graphene oxide nanosheets (GO-g-PTA) functioned as an antimicrobial agent and was used as filler for PCL-g-PAA nanofibers in the preparation of composite nanofiber mats, which exerted synergistic effects promoted by the antibacterial properties of GO-g-PTA and the hydrophilicity of PCL-g-PAA electrospun nanofibers. Thus, the composite nanofiber mats had antibacterial properties and absorbed body fluids in the wound healing process, thereby promoting cell proliferation. The biodegradation of the PCL-g-PAA electrospun nanofibers also demonstrated an encouraging result of three-fold weight reduction compared to the neat PCL nanofiber. Our findings may serve as guidelines for the fabrication of electrospun nanofiber composites that can be used mats for chronic wound care.

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Gao, Da Wei, Qu Fu Wei, Chun Xia Wang, Guo Liang Liu, Xue Mei He, Li Li Wang, Tian Chi Zhou, Bian Bian Yuan et Xin Zou. « Preparation and Characterization of Porous Carbon/Nickle Nanofibers by Electrospinning ». Advanced Materials Research 853 (décembre 2013) : 101–4. http://dx.doi.org/10.4028/www.scientific.net/amr.853.101.

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By employing the electrospinning technique and subsequent carbonization processes, porous carbon/nickle (C/Ni) composite nanofibers with diameters of 100-200 nm were successfully prepared. Two polymer solutions of polyacrylonitrile (PAN), polyvinyl pyrrolidone (PVP), and Ni (CH3COOH)2(Ni (OAc)2) were used as C/Ni composite nanofiber precursors. The study revealed that C/Ni composite nanofibers were successfully prepared and nickle particles with diameters of 20-70 nm were uniformly scattered in the carbon nanofibers. It was also observed that the fiber with clear fibrous morphology with particles broke into shorter fibers after sinter. X-ray diffraction (XRD) showed that these particles crystallized with the face centered cubic (FCC) structure. The Brunauer-Emmett-Teller (BET) analysis indicated that C/Ni composites nanofibers with meso-pores possessed larger specific surface area than that of carbon nanofibers.

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Wei, Anfang, Juan Wang, Xueqian Wang, Dayin Hou et Qufu Wei. « Morphology and Surface Properties of Poly (L-lactic acid)/Captopril Composite Nanofiber Membranes ». Journal of Engineered Fibers and Fabrics 7, n^o 1 (mars 2012) : 155892501200700. http://dx.doi.org/10.1177/155892501200700115.

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In this study, Poly (L-lactic acid)/Captopril composite nanofiber membranes were electrospun for drug delivery. Different mass fractions of Poly (L-lactic acid), different ratios of Captopril and the influences of PEG4000 added in the spinning solution are discussed. The morphology, chemical components, the surface areas and pore sizes, wettability of the composite nanofiber membranes were investigated. The results showed that the diameters of the composite nanofibers increased with the increase of Poly (L-lactic acid) mass fractions, the diameters decreased with the increase of Captopril content as well as the addition of the surfactant. Fourier Transform Infrared (FT-IR) showed the chemical components of Captopril remained unchanged when it was electrospun into the composite nanofibers. The surface areas pore width and pore volume of the composite nanofibers became a little larger than those of poly (L-lactic acid) nanofibers, and the wettability of the composite nanofiber membranes was better than those of poly (L-lactic acid) nanofiber membranes. Wettability was improved by an increase of the drug load amount.

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Mei, Linyu, Huiyu Chen, Yunpeng Shao, Junyuan Wang et Yaqing Liu. « Highly aligned magnetic composite nanofibers fabricated by magnetic-field-assisted electrospinning PAN/FeCo solution ». High Performance Polymers 31, n^o 2 (4 avril 2018) : 230–37. http://dx.doi.org/10.1177/0954008318760697.

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Composite nanofiber meshes of well-aligned polyacrylonitrile (PAN)/FeCo nanofibers containing nanoparticles (NPs) were successfully fabricated by a magnetic-field-assisted electrospinning technology, which was confirmed to be a favorable method for the preparation of aligned composite nanofibers in this article. Meanwhile, FeCo NPs, with a particle size of approximately 60 nm, were synthesized using a hydrothermal route. The nanocomposite fibers were prepared by an electrospun solution of PAN containing 0, 2, 4, and 6 wt% NPs. The as-spun nanofibers were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and vibrating sample magnetometer. Both the diameters and the degree of alignment of the composite nanofibers decreased with the increase in voltage and increased with the increase in FeCo content. The composite nanofibers exhibited superior ordered performance, with the highest alignment value being 97%. Due to the highly ordered alignment structures, the composite nanofiber meshes showed large anisotropic magnetic property. In particular, the saturation magnetization of the composite nanofiber films in the parallel and perpendicular directions of the fiber axis were 42 emu/g and 19.5 emu/g, respectively. Meanwhile, the remanence also exhibited distinction in different directions (parallel: 2.01 emu/g; perpendicular: 0.86 emu/g).

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Lin, Zhan, Liwen Ji, Ozan Toprakci, Wendy Krause et Xiangwu Zhang. « Electrospun carbon nanofiber-supported Pt–Pd alloy composites for oxygen reduction ». Journal of Materials Research 25, n^o 7 (juillet 2010) : 1329–35. http://dx.doi.org/10.1557/jmr.2010.0163.

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Carbon nanofiber-supported Pt–Pd alloy composites were prepared by co-electrodepositing Pt–Pd alloy nanoparticles directly onto electrospun carbon nanofibers. The morphology and size of Pt–Pd alloy nanoparticles were controlled by the surface treatment of carbon nanofibers and the electrodeposition duration time. Scanning electron microscopy/energy dispersive spectrometer (SEM)/(EDS) and x-ray photoelectron spectroscopy (XPS) were used to study the composition of Pt–Pd alloy on the composites, and the co-electrodeposition mechanism of Pt–Pd alloy was investigated. The resultant Pt–Pd/carbon nanofiber composites were characterized by running cyclic voltammograms in oxygen-saturated 0.1 M HClO4 at 25 °C to study their electrocatalytic ability to reduce oxygen. Results show that Pt–Pd/carbon nanofiber composites possess good performance in the electrocatalytic reduction of oxygen. Among all Pt–Pd/carbon nanofibers prepared, the nanofiber composite with a Pt–Pd loading of 0.90 mg/cm2 has the highest electrocatalytic activity by catalyst mass.

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Trabelsi, Marah, Al Mamun, Michaela Klöcker et Lilia Sabantina. « Investigation of metallic nanoparticle distribution in PAN/magnetic nanocomposites fabricated with needleless electrospinning technique ». Communications in Development and Assembling of Textile Products 2, n^o 1 (26 février 2021) : 8–17. http://dx.doi.org/10.25367/cdatp.2021.2.p8-17.

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Needleless electrospinning can be used to produce polyacrylonitrile nanofibres, for example, to which magnetic nanoparticles can additionally be added. Such composite nanofibres can then be stabilised and carbonised to produce carbon composite nanofibres. The magnetic nanoparticles have an influence not only on the structure but also on the mechanical and electrical properties of the finished carbon nanofibres, as does the heat treatment during stabilisation and incipient carbonisationThe present study reports on the fabrication, heat treatment and resulting properties of poly(acrylonitrile) (PAN)/magnetic nanofibre mats prepared by needleless electrospinning from polymer solutions. A variety of microscopic and thermal characterisation methods were used to investigate in detail the chemical and morphological transition during oxidative stabilisation (280 °C) and incipient carbonisation (500 °C). PAN and nanoparticles were analysed during all stages of heat treatment. Compared to pure PAN nanofibres, the PAN/ magnetic nanofibers showed larger fiber diameters and the presence of beads and agglomerations. In this study, magnetic nanofibers were investigated in more detail with the aim of detecting undesired agglomerations. Visual observation, for example with CLSM or SEM, does not provide conclusive evidence of agglomerations in the nanofibers. But based on the capabilities of SEM/EDS many different types of samples can be easily analysed where other analytical techniques simply cannot give the fast answer.

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Hwang, Eunjeong, Yura Hyun et Chang-Seop Lee. « Synthesis and Electrochemical Properties of Ru/PC/SiO2/Carbon Nanofiber Composites as Anode Materials in Lithium Secondary Batteries ». Journal of Nanoscience and Nanotechnology 20, n^o 3 (1 mars 2020) : 1622–30. http://dx.doi.org/10.1166/jnn.2020.16953.

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Carbon nanofibers (CNFs) were grown by chemical vapor deposition method on C-fiber textiles that Ni and Cu catalysts were pre-deposited via electrophoretic deposition. Carbon nanofibers were oxidized by nitric acid to create hydroxyl group and then coated with silica layer via hydrolysis of TEOS (Tetraethyl orthosilicate). Pyrolytic carbon was coated on the SiO2/CNFs composite by flowing ethylene gas at 900 °C, and then Ru was dip-coated to prepare Ru/PC/SiO2/CNFs composite. The morphologies, compositions, and crystal qualities of CNFs and the various carbon nanofiber composites were characterized by SEM, TEM, XPS, and Raman spectroscopy. The electrochemical properties and the capacitance of the carbon nanofibers and its composites as anode materials of Li secondary batteries were investigated by galvanostatic charge-discharge and cyclic voltammetry. The galvanostatic charge/discharge results of the CNFs, SiO2/CNFs composite, (PC)SiO2/CNFs composite, and Ru/(PC)SiO2/CNFs composite exhibited maximum capacities of 809 mAh/g, 1,289 mAh/g, 2,469 mAh/g, and 2,451 mAh/g, respectively.

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Howe, J. Y., G. G. Tibbetts, C. Kwag et M. L. Lake. « Heat treating carbon nanofibers for optimal composite performance ». Journal of Materials Research 21, n^o 10 (octobre 2006) : 2646–52. http://dx.doi.org/10.1557/jmr.2006.0325.

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Partial graphitization of carbon nanofibers by high-temperature heat treatment can give improved composite properties. The intrinsic electrical conductivity of the bulk carbon nanofibers measured under compression is maximized by giving the fibers an initial heat treatment at 1500 °C. Similarly, for carbon nanofiber/polypropylene composites containing up to 12 vol% fiber, initial fiber heat treatments near 1500 °C give tensile modulus and strength superior even to composites made from fibers graphitized at 2900 °C. However, optimum composite conductivity is obtained with a somewhat lower heat-treatment temperature, near 1300 °C. Transmission electron microscopy (TEM) along with x-ray diffraction (XRD) explains these results, showing that heat treating the fibers alters the exterior planes from continuous, coaxial, and poorly crystallized to discontinuous nested conical crystallites inclined at about 25° to the fiber axis.

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Barbak, Zarife, Hale Karakas, Imren Esenturk, M. Sedef Erdal et A. Sezai Sarac. « Silver sulfadiazine Loaded Poly (ε-Caprolactone)/Poly (Ethylene Oxide) Composite Nanofibers for Topical Drug Delivery ». Nano 15, n^o 06 (juin 2020) : 2050073. http://dx.doi.org/10.1142/s1793292020500733.

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In this study, silver sulfadiazine (SSD) loaded Poly ([Formula: see text]-caprolactone)/Poly (ethylene oxide) (PCL/PEO) nanofiber patches were prepared via electrospinning method for topical drug delivery applications. SSD was loaded for the first time into PCL/PEO nanofibers. Nanofiber patches were characterized by Attenuated Total Reflectance Infrared Spectroscopy (FTIR-ATR) to check the presence of chemical bonding between SSD and polymer matrix. The surface morphology of the nanofibers was observed by Scanning Electron Microscopy (SEM). SEM images showed that uniform and smooth composite nanofibers were obtained. The diameter of the nanofibers decreased with the addition of SSD. X-Ray Diffraction (XRD) analysis was carried out to examine the crystallinity of composite nanofiber patches. Energy dispersive spectroscopy (EDS) analysis was performed to confirm Ag and S contents in the SSD loaded composite nanofibers and EDS Mapping was used to show the homogeneous distribution of SSD in the fiber structure. In order to investigate the release and solubility properties of SSD, an unused buffer solution; Water/Propylene Glycol/Phosphoric Acid (82:16:2) was prepared. The release of SSD was performed in this buffer and the release amount of SSD was calculated by UV-Visible Spectrophotometer. Thereby, SSD containing PCL/PEO composite nanofiber carriers were electrospun to achieve the enhancement in solubility, effective drug release and efficient drug loading of SSD. All experimental studies demonstrated that SSD loaded PCL/PEO composite nanofibers have great potential to be used in topical drug delivery applications.

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Meng, Na, Xiangqin Wang, Binjie Xin, Zhuoming Chen et Yan Liu. « Preparation, structure and electrochromic behavior of PANI/PVA composite electrospun nanofiber ». Textile Research Journal 89, n^o 12 (4 septembre 2018) : 2490–99. http://dx.doi.org/10.1177/0040517518797345.

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In this study, the preparation of polyaniline/polyvinyl alcohol (PANI/PVA) emulsion and the fabrication of PANI/PVA nanocomposite and electrochromic device are presented systematically. The surface morphologies, chemical structural and mechanical properties of the PANI/PVA nanofibers were characterized using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and instrumental equipment. Four PANI/PVA composites with different PANI concentrations (i.e. 0 wt%, 0.2 wt%, 0.4 wt%, 0.6 wt%) were prepared to investigate the effects of PANI content on the electrochemical properties of the composites. Electrochromic properties of these PANI/PVA electrospun composite nanofibers are systematically characterized by an electrochemical workstation. Cyclic voltammetry was conducted to measure the electrochemical behavior of the PANI/PVA electrospun composite nanofibers at scanning speeds of 5 mV/s, 20 mV/s, 50 mV/s and 100 mV/s; it could be found that the redox peaks almost disappear. The discoloration of PANI/PVA composite electrospun nanofiber presents the color changing among the three mainstream colors of green, yellow, and blue.

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Celik Bedeloglu, Ayse, et Zeynep Islek Cin. « Functional sol-gel coated electrospun polyamide 6,6/ZnO composite nanofibers ». Journal of Polymer Engineering 39, n^o 8 (27 août 2019) : 752–61. http://dx.doi.org/10.1515/polyeng-2019-0099.

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Abstract Polymer-based nanofibers are good candidates for medical textiles due to their excellent properties including high surface area, breathability and flexibility. Doping polymer nanofibers with different nanoparticles enhances their existing properties. In this study, electrospun polyamide 6,6 (PA6,6) composite nanofibers containing ZnO nanoparticles (<50 nm) in different amounts (1%, 3% and 5%) were first produced by electrospinning technique; then, these nanofibers were coated with sol-gel ZnO solution (0.5 m) via dip coating method at 1000, 3000 and 5000 μm/s speeds. The sol-gel coating process increased the breaking strength of nanofiber mats, while the incorporation of ZnO nanoparticles into the polymer nanofibers reduced. Compared to pure PA6,6 nanofiber mats, the ZnO sol-gel coated samples and doped nanofibers had lower reflectance values. In addition, the reflection values decreased as the additive and coating speed increased.

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Takagi, Hitoshi, Antonio N. Nakagaito, Kazuya Kusaka et Yuya Muneta. « Development of green nanocomposites reinforced by cellulose nanofibers extracted from paper sludge ». Modern Physics Letters B 29, n^o 06n07 (20 mars 2015) : 1540025. http://dx.doi.org/10.1142/s0217984915400254.

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Cellulose nanofibers have been showing much greater potential to enhance the mechanical and physical properties of polymer-based composite materials. The purpose of this study is to extract the cellulose nanofibers from waste bio-resources; such as waste newspaper and paper sludge. The cellulosic raw materials were treated chemically and physically in order to extract individualized cellulose nanofiber. The combination of acid hydrolysis and following mechanical treatment resulted in the extraction of cellulose nanofibers having diameter of about 40 nm. In order to examine the reinforcing effect of the extracted cellulose nanofibers, fully biodegradable green nanocomposites were fabricated by composing polyvinyl alcohol (PVA) resin with the extracted cellulose nanofibers, and then the tensile tests were conducted. The results showed that the enhancement in mechanical properties was successfully obtained in the cellulose nanofiber/PVA green nanocomposites.

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Takagi, Hitoshi. « Strength Properties of Cellulose Nanofiber Green Composites ». Key Engineering Materials 462-463 (janvier 2011) : 576–81. http://dx.doi.org/10.4028/www.scientific.net/kem.462-463.576.

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Environmentally friendly cellulose nanofiber green composites were newly developed by combining two dispersion-type biodegradable resins: polylactic acid (PLA) and chemically modified starch, and cellulose nanofibers of two kinds. The nanoscale cellulose fibers were prepared by homogenization of wood pulp. The 10–100 nm diameter nanoscale cellulose fibers have a web-like network microstructure. The mixture of dispersion-type biodegradable resin and cellulose nanofibers was dried in an air-circulating oven to make composite preform sheets. Cellulose nanofiber composite samples were fabricated by press-forming of the preform sheets. Their mechanical properties were evaluated using room-temperature tensile tests. The composite composed of PLA-based resin and highly homogenized cellulose nanofibers showed higher mechanical properties than those of starch-based resin and coarse cellulose fibers. It is suggested that coarse cellulose fibers act as a defect, resulting in low mechanical properties. Maximum tensile strength reaches approximately 90 MPa at fiber weight contents of 60% by weight. This mechanical property is comparable to that of conventional glass-fiber-reinforced plastics.

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Lasenko, Inga, Dace Grauda, Dalius Butkauskas, Jaymin Vrajlal Sanchaniya, Arta Viluma-Gudmona et Vitalijs Lusis. « Testing the Physical and Mechanical Properties of Polyacrylonitrile Nanofibers Reinforced with Succinite and Silicon Dioxide Nanoparticles ». Textiles 2, n^o 1 (8 mars 2022) : 162–73. http://dx.doi.org/10.3390/textiles2010009.

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In this research, we focused on testing the physical and mechanical properties of the developed polyacrylonitrile (PAN) composite nanofibers with succinite (Baltic amber) and SiO2 particles using standard methods of nanofiber testing (physical and mechanical properties). Polyacrylonitrile composite nanofibers (based on the electrospinning method) were coated on an aluminum substrate for structural investigation. SEM was used to determine the average fiber diameter and standard deviation. The mechanical properties of the fibers were determined using a universal testing machine (NANO, MTS). We observed that constant or decreased levels of crystallinity in the ultrafine composite nanofibers led to the preservation of high levels of strain at failure and that the strength of nanofibers increased substantially as their diameter reduced. Improvements in PAN composite nanofibers with succinite and SiO2 nanopowder are feasible with continuous decreases in diameter. The drastically decreased strain at failure demonstrated a substantial reduction in viscosity (toughness) of the annealed nanofibers. Large stresses at failure in the as-spun nanofibers were a result of their low crystallinity. As a result, decreasing the diameter of PAN nanofibers from approximately 2 micrometers to 139 nanometers (the smallest nanofiber tested) resulted in instantaneous increases in the elastic modulus from 1 to 26 GPa, true strength from 100 to 1750 MPa, and toughness from 20 to 604 MPa.

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Yu, Jaesang, Thomas E. Lacy, Hossein Toghiani, Charles U. Pittman et Youngkeun Hwang. « Classical micromechanics modeling of nanocomposites with carbon nanofibers and interphase ». Journal of Composite Materials 45, n^o 23 (24 mai 2011) : 2401–13. http://dx.doi.org/10.1177/0021998311401092.

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A micromechanics parametric study was performed to investigate the effect of carbon nanofiber morphology (i.e. hollow vs. solid cross-section), nanofiber waviness, and both nanofiber–resin interphase properties and dimensions on bulk nanocomposite elastic moduli. Mori–Tanaka and self-consistent models were developed for composites containing heterogeneities with multilayered coatings. For a given nanofiber axial force–displacement relationship, the elastic modulus for hollow nanofibers can significantly exceed that for solid nanofibers resulting in notable differences in bulk nanocomposite properties. In addition, the development of a nanofiber–resin interphase had a notable effect on the bulk elastic moduli. Consistent with results from the literature, small degrees of nanofiber waviness resulted in a significant decrease in effective composite properties.

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Kim, Se Wook, Seong Ok Han, I. Na Sim, Ja Young Cheon et Won Ho Park. « Fabrication and Characterization of Cellulose Acetate/Montmorillonite Composite Nanofibers by Electrospinning ». Journal of Nanomaterials 2015 (2015) : 1–8. http://dx.doi.org/10.1155/2015/275230.

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Nanofibers composed of cellulose acetate (CA) and montmorillonite (MMT) were prepared by electrospinning method. MMT was first dispersed in water and mixed with an acetic acid solution of CA. The viscosity and conductivity of the CA/MMT solutions with different MMT contents were measured to compare with those of the CA solution. The CA/MMT solutions were electrospun to fabricate the CA/MMT composite nanofibers. The morphology, thermal stability, and crystalline and mechanical properties of the composite nanofibers were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), thermogravimetric analysis (TGA), X-ray diffraction (XRD), and tensile test. The average diameters of the CA/MMT composite nanofibers obtained by electrospinning 18 wt% CA/MMT solutions in a mixed acetic acid/water (75/25, w/w) solvent ranged from 150~350 nm. The nanofiber diameter decreased with increasing MMT content. TEM indicated the coexistence of CA nanofibers. The CA/MMT composite nanofibers showed improved tensile strength compared to the CA nanofiber due to the physical protective barriers of the silicate clay layers. MMT could be incorporated into the CA nanofibers resulting in about 400% improvement in tensile strength for the CA sample containing 5 wt% MMT.

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Wang, Xin, Xue Jia Li, Qing Qing Wang et Qu Fu Wei. « Preparation and Characterization of PVP/Fe₃O₄ Composite Nanofibers ». Advanced Materials Research 332-334 (septembre 2011) : 783–86. http://dx.doi.org/10.4028/www.scientific.net/amr.332-334.783.

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The PVP/Fe3O4 composite nanofibers with different Fe3O4 nanoparticle loading were obtained by electrospinning. The characterization and performance analysis of the composite nanofibers were studied by scanning electron microscopy (SEM), X-Ray diffraction (XRD), transmission electron microscopy (TEM), thermogravimetric analysis (TGA) and antistatic fabric instrument. The results showed that the average diameter of PVP/Fe3O4 composite nanofibers is smaller than that of pure PVP. At 5wt% Fe3O4 nanoparticle loading, the coefficient of variation CV value was low, while the composite nanofiber diameter distribution was good. Fe3O4 nanoparticles were spherical and had no obvious agglomeration. With increasing Fe3O4 nanoparticle loading, the thermal and antistatic properties of PVP/Fe3O4 composite nanofibers were significantly improved.

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Gao, Dawei, Lili Wang, Xin Xia, Hui Qiao, Yibing Cai, Fenglin Huang, Kishor Gupta, Qufu Wei et Satish Kumar. « Preparation and Characterization of porous Carbon/Nickel Nanofibers for Supercapacitor ». Journal of Engineered Fibers and Fabrics 8, n^o 4 (décembre 2013) : 155892501300800. http://dx.doi.org/10.1177/155892501300800405.

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Two polymer solutions of polyacrylonitrile, polyvinyl pyrrolidone, and Ni(CH3COOH)2 in dimethylformamide were electrospun into ternary composite nanofibers, followed by stabilization and carbonization processes to obtain porous carbon/nickel composite nanofibers with diameters of 100–200 nm. The study revealed that carbon/nickel composite nanofibers were successfully prepared, which allowed nickel particles with diameters of 20–70 nm to be uniformly distributed in the carbon nanofibers. It was also observed that the fibrous structures with particles embedded formed and the fibers broke into shorter fibers after sintering. X-ray diffraction indicated that embedded particles crystallized with the face centered cubic structure. The Brunauer-Emmett-Teller analysis revealed that carbon/nickel composite nanofibers with meso-pores possessed larger specific surface area than that of carbon nanofibers. The specific capacitance of the composite nanofiber electrode was as high as 103.8 F/g and showed stable cyclicity (73.8%).

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Hong, Sheng-Zhe, Qing-Yi Huang et Tzong-Ming Wu. « Facile Synthesis of Polyaniline/Carbon-Coated Hollow Indium Oxide Nanofiber Composite with Highly Sensitive Ammonia Gas Sensor at the Room Temperature ». Sensors 22, n^o 4 (17 février 2022) : 1570. http://dx.doi.org/10.3390/s22041570.

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Hollow carbon-coated In2O3 (C#In2O3) nanofibers were prepared using an efficiently combined approach of electrospinning, high-temperature calcination, and hydrothermal process. The polyaniline (PANI)/hollow C#In2O3 nanofiber composites were synthesized used hollow C#In2O3 nanofibers worked as a core through the in situ chemical oxidative polymerization. The morphology and crystalline structure of the PANI/hollow C#In2O3 nanofiber composite were identified using wide-angle X-ray diffraction and transmission electron microscopy. The gas-sensing performances of the fabricated PANI/hollow C#In2O3 nanofiber composite sensor were estimated at room temperature, and the response value of the composite sensor with an exposure of 1 ppm NH3 was 18.2, which was about 5.74 times larger than that of the pure PANI sensor. The PANI/hollow C#In2O3 nanofiber composite sensor was demonstrated to be highly sensitive to the detection of NH3 in the concentration range of 0.6~2.0 ppm, which is critical for kidney or hepatic disease detection from the human breath. This composite sensor also displayed superior repeatability and selectivity at room temperature with exposures of 1.0 and 2.0 ppm NH3. Because of the outstanding repeatability and selectivity to the detection of NH3 at 1.0 and 2.0 ppm confirmed in this investigation, the PANI/hollow C#In2O3 nanofiber composite sensor will be considered as a favorable gas-sensing material for kidney or hepatic disease detection from human breath.

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Jalalah, Mohammed, Adnan Ahmad, Asad Saleem, Muhammad Bilal Qadir, Zubair Khaliq, Muhammad Qamar Khan, Ahsan Nazir et al. « Electrospun Nanofiber/Textile Supported Composite Membranes with Improved Mechanical Performance for Biomedical Applications ». Membranes 12, n^o 11 (17 novembre 2022) : 1158. http://dx.doi.org/10.3390/membranes12111158.

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Textile-supported nanocomposite as a scaffold has been extensively used in the medical field, mainly to give support to weak or harmed tissues. However, there are some challenges in fabricating the nanofiber/textile composite, i.e., suitable porous structure with defined pore size, less skin contact area, biocompatibility, and availability of degradable materials. Herein, polyamide-6 (PA) nanofibers were synthesized using needleless electrospinning with the toothed wheel as a spinneret. The electrospinning process was optimized using different process and solution parameters. In the next phase, optimized PA nanofiber membranes of optimum fiber diameter with uniform distribution and thickness were used in making nanofiber membrane–textile composite. Different textile fabrics (woven, non-woven, knitted) were developed. The optimized nanofiber membranes were combined with non-woven, woven, and knitted fabrics to make fabric-supported nanocomposite. The nanofiber/fabric composites were compared with available market woven and knitted meshes for mechanical properties, morphology, structure, and chemical interaction analysis. It was found that the tear strength of the nanofiber/woven composite was three times higher than market woven mesh, and the nanofiber/knitted composite was 2.5 times higher than market knitted mesh. The developed composite structures with woven and knitted fabric exhibited improved bursting strength (613.1 and 751.1 Kpa), tensile strength (195.76 and 227.85 N), and puncture resistance (68.76 and 57.47 N), respectively, than market available meshes. All these properties showed that PA nanofibers/textile structures could be utilized as a composite with multifunctional properties.

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Thammabut, Thawach, Tienthong Yuangkaew, Chanchanok Chumpanya, Thitipong Tamsenanupap, Papot Jaroenapibal et Napat Triroj. « Electrospun Ag/WO₃ Composite Nanofiber Photoanodes Prepared by DС Electrophoretic Deposition for Photoelectrochemical Water Splitting ». Materials Science Forum 947 (mars 2019) : 61–65. http://dx.doi.org/10.4028/www.scientific.net/msf.947.61.

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In this work, tungsten oxide (WO3) nanofibers were synthesized using electrospinning technique. Direct current electrophoretic deposition (DC-EPD) was conducted to deposit the nanofibers onto fluorine-doped tin oxide (FTO) electrodes. The photoelectrochemical performance of WO3 nanostructured electrodes was investigated and compared between the samples containing pristine WO3 and Ag/WO3 composite nanofibers. An up-to-6-fold enhancement in photoconversion efficiency (PCE) was obtained from Ag/WO3 composite nanofiber photoanode.

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Park, Ji Sang, Byung Sun Kim, Jin Bong Kim et Tae Wook Kim. « Effect of VGCF Addition to Carbon Fabric/Ep ». Key Engineering Materials 334-335 (mars 2007) : 741–44. http://dx.doi.org/10.4028/www.scientific.net/kem.334-335.741.

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Despite of the excellent properties of carbon nanofiber, the properties of carbon nanofiber filled polymer composite were not improved as much as expected. The usual reason may be not sufficient dispersion of the nanofibers within the composites. For the improvement in the mechanical properties of composites, the carbon nanofiber reinforced hybrid composites was investigated. For the dispersion of the carbon nanofiber, the solution blending method using ultrasonic was used. The hybrid composite was manufactured by the Solution-Dip-Type prepreg manufacturing machine. This machine is consisted of resin bath, curing tower that evaporates solvent and process controller for manufacturing speed. The prepregs were cured in an Autoclave. 3 wt% of carbon nanofiber containing hybrid composite, Carbon Fabric/Ep, was tested by Universal Testing Machine. The tensile strength and modulus were improved by 25% and 35%, respectively. In-plane shear strength and modulus were improved by 45% and 78%, respectively.

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Giaconia, Michele Amendoeira, Sergiana dos Passos Ramos, Bruna Vitoria Neves, Larissa Almeida, Letícia Costa-Lotufo, Veridiana Vera de Rosso et Anna Rafaela Cavalcante Braga. « Nanofibers of Jussara Pulp : A Tool to Prevent the Loss of Thermal Stability and the Antioxidant Activity of Anthocyanins after Simulated Digestion ». Processes 10, n^o 11 (10 novembre 2022) : 2343. http://dx.doi.org/10.3390/pr10112343.

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Electrospinning can produce a new composite for coating sensitive bioactive compounds, such as anthocyanins, and the product obtained from this process presents characteristics that potentialize the application of natural pigments in foodstuffs. The present work aimed to develop a new nanofiber composite with incorporated anthocyanins from jussara pulp using polyethylene oxide through electrospinning. A decay in the percentage of anthocyanins during digestion was observed. However, the polymeric solution and composites produced maintained the antioxidant activity, showing their protective effect on bioactive compounds; furthermore, both nanofibers and polymer solution improved the thermal stability of the anthocyanins. Thus, the results obtained potentiate electrospinning composites in processed food products since the nanofibers presented superior thermal stability and antioxidant activity, even after the digestion process in vitro.

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Lasenko, Inga, Jaymin Vrajlal Sanchaniya, Sai Pavan Kanukuntla, Yagnik Ladani, Arta Viluma-Gudmona, Olga Kononova, Vitalijs Lusis, Igors Tipans et Turs Selga. « The Mechanical Properties of Nanocomposites Reinforced with PA6 Electrospun Nanofibers ». Polymers 15, n^o 3 (28 janvier 2023) : 673. http://dx.doi.org/10.3390/polym15030673.

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Electrospun nanofibers are very popular in polymer nanocomposites because they have a high aspect ratio, a large surface area, and good mechanical properties, which gives them a broad range of uses. The application of nonwoven structures of electrospun nanofiber mats has historically been limited to enhancing the interlaminar responses of fiber-reinforced composites. However, the potential of oriented nanofibers to improve the characteristics of bulk matrices cannot be overstated. In this research, a multilayered laminate composite was created by introducing polyamide (PA6)-oriented nanofibers into an epoxy matrix in order to examine the effect of the nanofibers on the tensile and thermal characteristics of the nanocomposite. The specimens’ fracture surfaces were examined using scanning electron microscopy (SEM). Using differential scanning calorimetry (DSC) analysis, the thermal characteristics of the nanofiber-layered composites were investigated. The results demonstrated a 10.58% peak in the nanocomposites’ elastic modulus, which was compared to the numerical simulation and the analytical model. This work proposes a technique for the development of lightweight high-performance nanocomposites.

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Chang, Qiqi, Jun Xu, Yijun Han, Andrea Ehrmann, Tianhong He et Ruiping Zheng. « Photoelectric Performance Optimization of Dye-Sensitized Solar Cells Based on ZnO-TiO2 Composite Nanofibers ». Journal of Nanomaterials 2022 (30 avril 2022) : 1–10. http://dx.doi.org/10.1155/2022/7356943.

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As the electron transport layer of dye-sensitized solar cells (DSSCs), the photoanode is an important component that affects photoelectric conversion efficiency (PCE). The commonly used material titanium dioxide (TiO2) is difficult to prepare as nanostructures with large specific surface area, which affects dye loading and electrolyte diffusion. Herein, TiO2 nanofibers and ZnO-TiO2 composite nanofibers with different molar ratios are synthesized by electrospinning technology. The above nanofibers are coated on photoanodes by the doctor blade method to assemble DSSCs. The influence of the composite ratio of ZnO-TiO2 composite nanofibers on the photoelectric performance of the assembled DSSCs is explored. The ZnO-TiO2 composite nanofibers with a molar ratio of 1 : 2 have large specific surface area and porosity and have the smallest charge transfer resistance at the photoanode-electrolyte interface. The PCE of the nanofiber-modified DSSCs reaches a maximum of 3.66%, which is 56% higher than that of the TiO2 nanofiber-modified DSSCs. The photovoltaic parameters such as open circuit voltage (VOC), current density (JSC), and fill factor (FF) are 0.58 V, 10.36 mA/cm2, and 0.61, respectively. Proper compounding of zinc oxide (ZnO) can not only make the nanofibers absorb more dyes and enhance the light-harvesting ability but also improve the diffusion of the electrolyte and enhance the electron transport, thus successfully improving the power conversion efficiency of DSSCs.

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Jang, Wongi, Jaehan Yun, Younggee Seo, Hongsik Byun, Jian Hou et Jun-Hyun Kim. « Mixed Dye Removal Efficiency of Electrospun Polyacrylonitrile–Graphene Oxide Composite Membranes ». Polymers 12, n^o 9 (3 septembre 2020) : 2009. http://dx.doi.org/10.3390/polym12092009.

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Exfoliated graphene oxide (GO) was reliably modified with a cetyltrimethylammonium chloride (CTAC) surfactant to greatly improve the dispersity of the GO in a polyacrylonitrile (PAN) polymer precursor solution. Subsequent electrospinning of the mixture readily resulted in the formation of GO–PAN composite nanofibers containing up to 30 wt % of GO as a filler without notable defects. The absence of common electrospinning problems associated with clogging and phase separation indicated the systematic and uniform integration of the GO within the PAN nanofibers beyond the typical limits. After thoroughly examining the formation and maximum loading efficiency of the modified GO in the PAN nanofibers, the resulting composite nanofibers were thermally treated to form membrane-type sheets. The wettability and pore properties of the composite membranes were notably improved with respect to the pristine PAN nanofiber membrane, possibly due to the reinforcing filler effect. In addition, the more GO loaded into the PAN nanofiber membranes, the higher the removal ability of the methylene blue (MB) and methyl red (MR) dyes in the aqueous system. The adsorption kinetics of a mixed dye solution were also monitored to understand how these MB and MR dyes interact differently with the composite nanofiber membranes. The simple surface modification of the fillers greatly facilitated the integration efficiency and improved the ability to control the overall physical properties of the nanofiber-based membranes, which highly impacted the removal performance of various dyes from water.

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Garcia, Cristobal, Irina Trendafilova et Andrea Zucchelli. « Effect of polycaprolactone nanofibers on the vibratory behaviour and the damage resistance of composite laminates ». MATEC Web of Conferences 211 (2018) : 19003. http://dx.doi.org/10.1051/matecconf/201821119003.

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Aircrafts, bridges, wind turbines and other civil structures made of composite materials are frequently subjected to vibrations, which are responsible for a considerable number of accidents. One of the methods to reduce the vibrations is the incorporation of nanofibers in the composite structures. The main purpose of this study is to investigate the effect of the inclusion of polycaprolactone nanofibers on the vibratory behaviour of composite laminates. For this purpose, the vibratory behaviour of nano composites (with nanofibers) and standard composites (without nanofibers) is investigated with the purpose of acquiring their natural frequencies and the damping ratio. The results indicated that the inclusion of polycaprolactone nanofibers in composites increased the damping ratio, however it did not change significantly the natural frequencies. Furthermore, the paper investigates the effect of polycaprolactone nanofibers on the damage resistance of glass fibre composites. For this purpose, a finite element model is used to simulate the damage caused by mechanical impact in standard and nano composites. The numerical simulations show that the interleaving with nanofibers increased the damage resistance considerably. This study contributes to the knowledge about the vibration behaviour and the damage resistance of composites interleaved with polycaprolactone nanofibers. It is demonstrated that the interleaving with polycaprolactone fibres can play an important role for reducing the vibrations and increasing their impact damage resistance in composite structures as aircrafts.

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Pant, Bishweshwar, Mira Park et Soo-Jin Park. « TiO2 NPs Assembled into a Carbon Nanofiber Composite Electrode by a One-Step Electrospinning Process for Supercapacitor Applications ». Polymers 11, n^o 5 (17 mai 2019) : 899. http://dx.doi.org/10.3390/polym11050899.

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In this study, we have synthesized titanium dioxide nanoparticles (TiO2 NPs) into carbon nanofiber (NFs) composites by a simple electrospinning method followed by subsequent thermal treatment. The resulting composite was characterized by state-of-the-art techniques and exploited as the electrode material for supercapacitor applications. The electrochemical behavior of the as-synthesized TiO2 NPs assembled into carbon nanofibers (TiO2-carbon NFs) was investigated and compared with pristine TiO2 NFs. The cyclic voltammetry and charge–discharge analysis of the composite revealed an enhancement in the performance of the composite compared to the bare TiO2 NFs. The as-obtained TiO2-carbon NF composite exhibited a specific capacitance of 106.57 F/g at a current density of 1 A/g and capacitance retention of about 84% after 2000 cycles. The results obtained from this study demonstrate that the prepared nanocomposite could be used as electrode material in a supercapacitor. Furthermore, this work provides an easy scale-up strategy to prepare highly efficient TiO2-carbon composite nanofibers.

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Razavi, Seyed Mohammad Javad, Rasoul Esmaeely Neisiany, Moe Razavi, Afsaneh Fakhar, Vigneshwaran Shanmugam, Vasudevan Alagumalai, Michael Försth, Gabriel Sas et Oisik Das. « Efficient Improvement in Fracture Toughness of Laminated Composite by Interleaving Functionalized Nanofibers ». Polymers 13, n^o 15 (29 juillet 2021) : 2509. http://dx.doi.org/10.3390/polym13152509.

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Functionalized polyacrylonitrile (PAN) nanofibers were used in the present investigation to enhance the fracture behavior of carbon epoxy composite in order to prevent delamination if any crack propagates in the resin rich area. The main intent of this investigation was to analyze the efficiency of PAN nanofiber as a reinforcing agent for the carbon fiber-based epoxy structural composite. The composites were fabricated with stacked unidirectional carbon fibers and the PAN powder was functionalized with glycidyl methacrylate (GMA) and then used as reinforcement. The fabricated composites’ fracture behavior was analyzed through a double cantilever beam test and the energy release rate of the composites was investigated. The neat PAN and functionalized PAN-reinforced samples had an 18% and a 50% increase in fracture energy, respectively, compared to the control composite. In addition, the samples reinforced with functionalized PAN nanofibers had 27% higher interlaminar strength compared to neat PAN-reinforced composite, implying more efficient stress transformation as well as stress distribution from the matrix phase (resin-rich area) to the reinforcement phase (carbon/phase) of the composites. The enhancement of fracture toughness provides an opportunity to alleviate the prevalent issues in laminated composites for structural operations and facilitate their adoption in industries for critical applications.

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Ma, Hui, Huanxia Zhang, Dongsheng Wang, Xiangyu Zeng, Jie Yi, Jianda Cao et Wen Wu. « Structure and performance analysis of flatter ribbon-like electrospun poly(L-lactic acid)/graphene oxide nanofiber webs ». Journal of Engineered Fibers and Fabrics 15 (janvier 2020) : 155892502095292. http://dx.doi.org/10.1177/1558925020952924.

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Polylactic acid matrix composites are widely used in packagings and biomaterials. The specific surface area, flexibility and degradation efficiency of the material are the key factors to determine its application in these fields. In this study, a series of poly(L-lactic acid) (PLLA)/graphene oxide (GO) composite nanofiber webs were prepared using electrospinning technique. The scanning electron microscope (SEM) image of PLLA/GO nanofibers showed a rougher surface and a smaller average diameter compared with that of pure PLLA nanofibers, and the nanofibers with 6 wt% GO in PLLA matrix looked like flatter ribbon. Accordingly, the tensile stress test of the electrospun webs with different GO contents showed high performance, 400% increment in the tensile stress at presence of 6 wt% GO. The hydrolytic degradation behavior of composite the nanofiber webs exhibited that the presence of GOs greatly improved the degradation rate, after 9 days, the degradation ratio of PLLA/GO can reach 16.83%. of the PLLA matrix, resulting from the better hydrophilic property and absorbability. Using GO to improve the preparation of new biocompatible materials from PLLA can provide a reference for problems in the field of packaging materials.

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Takagi, Hitoshi, Antonio Norio Nakagaito et Yuya Sakaguchi. « Fiber Orientation Control by Stretching in Cellulose Nanofiber Green Composites ». Key Engineering Materials 754 (septembre 2017) : 135–38. http://dx.doi.org/10.4028/www.scientific.net/kem.754.135.

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The presence of nanoscale cellulosic fiber; namely cellulose nanofiber, increases year by year because the mechanical and physical properties are believed to be comparable to those of common glass fibers. On the other hand, most of the reported strength data for the cellulose nanofiber-reinforced polymeric composite materials was not as high as expected. In order to obtain high-strength cellulose nanofiber-reinforced polymer composites, we tried to optimize the fiber orientation of cellulose nanofibers in poly (vinyl alcohol)-based polymer matrix by using a repeated mechanical stretching treatment. The fiber orientation of cellulose nanofibers in the poly (vinyl alcohol) matrix can be modified by changing the total amount of stretching strain applied during the multiple stretching treatments. The degree of fiber alignment was directly evaluated by observing the cellulose nanofibers on the sample surface with a digital microscope. The efficacy of proposed nanofiber alignment control has been explored experimentally and theoretically. The tensile strength and modulus of the cellulosic nanocomposites after applying the multiple stretching treatments increased by approximately 80% and 40% respectively, as compared with those of the untreated nanocomposites.

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Xu, Bingjie, Langfei Yang, Wei Pan, Ying Li, Zili Wang, Guoqiang Cai, Jindan Wu et Dongming Qi. « Anchoring silver nanoparticles on nanofibers by thermal bonding to construct functional surface ». Biointerphases 17, n^o 6 (novembre 2022) : 061005. http://dx.doi.org/10.1116/6.0002206.

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Generally, the anchoring of inorganic nanoparticles onto the surface of fibers faces the problem of poor stability, which limits the wide application of nanoparticle functionalized fibers. Herein, nanofibers with shell-core structures were constructed by coaxial electrospinning of two polymers with different melting points (Tm). Polyglycolic acid (PGA, Tm = 225 °C) was employed as the core layer, while polycaprolactone (PCL, Tm = 60 °C) was used as the shell layer. Silver nanoparticles (AgNPs) were electrosprayed on the nanofibers and the shell layer (PCL) was heated and melted to bond the AgNPs, thus realizing a stable AgNP-composited nanofiber for the construction of antibacterial functional surface. By regulating the shell-core flow ratio and the condition for heat treatment, the appropriate thickness of the shell layer was obtained with a flow ratio of 3:1 (PCL:PGA). The optimal composite structure was constructed when the thermal bonding was taken under 80 °C for 5 min. Furthermore, it was found that the composite nanofibers prepared by thermal bonding had better hydrophilicity, mechanical property, and AgNPs bonding stability, and their antibacterial rate against Staphylococcus aureus ( S. aureus) reached over 97%. Overall, a facile and universal method for the preparation of nanoparticle-anchored nanofibers was established in this study. The robust nanoparticle-composited nanofibers are promising for applications in optoelectronic devices, electrode materials, and so on.

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Habr, Jiří, Jiří Bobek, Luboš Bĕhálek et Martin Seidl. « Adhesion Additive Influence on Polyamide Nanopolymer Composite Properties ». Defect and Diffusion Forum 368 (juillet 2016) : 142–45. http://dx.doi.org/10.4028/www.scientific.net/ddf.368.142.

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In recent years there are efforts to use polymer nanofibers and their properties in polymer composites. The aim of such efforts is to develop composites with nanofibers fillers which would be able into a great extend to take advantage of any unique properties of polymer nanofibers. Such area of research belongs into the research project whose part is also to incorporate nanofibers and nanoparticles into composite with thermoplastic matrix. The important part of research represents also finding the suitable additives to ensure sufficient adhesion between filler and polymer matrix which is crucial for the final composite properties.

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Gou, Jihua, Scott O'Braint, Haichang Gu et Gangbing Song. « Damping Augmentation of Nanocomposites Using Carbon Nanofiber Paper ». Journal of Nanomaterials 2006 (2006) : 1–7. http://dx.doi.org/10.1155/jnm/2006/32803.

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Vacuum-assisted resin transfer molding (VARTM) process was used to fabricate the nanocomposites through integrating carbon nanofiber paper into traditional glass fiber reinforced composites. The carbon nanofiber paper had a porous structure with highly entangled carbon nanofibers and short glass fibers. In this study, the carbon nanofiber paper was employed as an interlayer and surface layer of composite laminates to enhance the damping properties. Experiments conducted using the nanocomposite beam indicated up to 200–700% increase of the damping ratios at higher frequencies. The scanning electron microscopy (SEM) characterization of the carbon nanofiber paper and the nanocomposites was also conducted to investigate the impregnation of carbon nanofiber paper by the resin during the VARTM process and the mechanics of damping augmentation. The study showed a complete penetration of the resin through the carbon nanofiber paper. The connectivities between carbon nanofibers and short glass fibers within the carbon nanofiber paper were responsible for the significant energy dissipation in the nanocomposites during the damping tests.

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Bodnarova, Lenka, Rudolf Hela et Daniel Sedlacek. « Effect of Inorganic SiO2 Nanofibers in High Strength Cementitious Composites ». MATEC Web of Conferences 278 (2019) : 01009. http://dx.doi.org/10.1051/matecconf/201927801009.

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The paper deals with the verification of the effect of the addition of inorganic SiO2 nanofibers to cement composites. In the first stage, a stable suspension of SiO2 nanofibers was prepared in an aqueous medium. It is important to distribute nanofibers so that the nanofibers do not appear in the form of clumps and at the same time do not get damaged during the dispersion process. The ultrasonification process was used for dispersion. The dispersed suspension of SiO2 nanofibers and water was dosed together with the superplasticizing admixtures into the dry components of the cement composite and the components were homogenized. The properties of the cement composite with SiO2 nanofibers have been tested – compressive strength, flexural strength, density. Composites with the addition of SiO2 nanofibers at a dose of 0.008 % by weight of cement exhibited an increased compressive strength of up to 33 % and a 19 % greater flexural strength at doses of 0.016 and 0.032 % of cement weight than the reference sample without nanofibers. The presence of SiO2 nanofibers in the composite was monitored by scanning electron microscopy (SEM).

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Tipu, Javed A. K., Usman Rafiq, Muhammad Arif, Tariq Feroze, Hafiz Waqar, Umer Masood Chaudry, Tea-Sung Jun et Adnan Aslam Noon. « Development of Multiscale Composite with Hybrid Natural Nanofibers ». Materials 15, n^o 13 (30 juin 2022) : 4622. http://dx.doi.org/10.3390/ma15134622.

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Natural nanofibers are widely used in the field of medicine, but the low strength of these nanofibers is one of the major concerns. A number of factors, importantly the composition, affect the strength of natural nanofibers. The purpose of the current study is to ascertain the effect of the composition of natural nanofibers on the strength of hybrid composites formed using these nanofibers. Hybrid composites formed using 32% volume fraction of glass fiber, 0.5% volume fraction of pure cellulose acetate (CA), and 0.5% volume fraction of CA + hemp seed (HS) were developed for this study to carry out the analysis. Hybrid composites were produced with vacuum-assisted resin transfer molding (VARTM) by collecting natural nanofibers, produced using the electrospinning process, over glass fiber mats. The electrospinning process was carried out with 12 kV, 10 cm tip to the collector gap, and 12% concentration of the solution. The tensile strength of the hybrid composites was measured using the universal testing machine (UTM). The results showed that the diameter of the electrospun nanofiber varied between 50 and 1400 nm and was affected by solution concentration, voltage, tip-to-collector distance, flow rate, and inclusion of HS in CA. The inclusion of HS in CA, for all compositions, decreased the fiber diameter and caused the formation of beads prominently at higher concentrations. Hybrid composites formed from nanofibers produced using CA and HS showed higher elastic modulus (232 MPa) and tensile strength (20.4 GPa) as compared with nanofibers produced using CA only (elastic modulus = 110 MPa and 13.7 GPa).

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Feng, Shiyi, Feng Zhang, Saeed Ahmed et Yaowen Liu. « Physico-Mechanical and Antibacterial Properties of PLA/TiO2 Composite Materials Synthesized via Electrospinning and Solution Casting Processes ». Coatings 9, n^o 8 (19 août 2019) : 525. http://dx.doi.org/10.3390/coatings9080525.

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In this study, PLA/TiO2 composites materials were prepared via electrospinning and solution casting processes. By testing the mechanical properties, water contact angle, water vapor permeability, and solubility of the composite nanofibers and films, the comprehensive performances of the two types of nanocomposites were analyzed. The results show that maximum tensile strengths of 2.71 ± 0.11 MPa and 14.49 ± 0.13 MPa were achieved for the nanofibers and films at a TiO2 content of 0.75 wt.%. Moreover, the addition of TiO2 significantly cut down the water vapor transmittance rate of the nanofibers and films while significantly improving the water solubility. Further, the antibacterial activity increased under UV-A irradiation for a TiO2 nanoparticle content of 0.75 wt.%, and the nanofiber and films exhibited inhibition zones of 4.86 ± 0.50 and 3.69 ± 0.40 mm for E. coli, and 5.98 ± 0.77 and 4.63 ± 0.45 mm for S. aureus, respectively. Overall, the performance of the nanofiber was better than that of the film. Nevertheless, both the nanocomposite membranes satisfied the requirements of food packaging materials.

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I. Waisi, Basma. « Carbonized Copolymers Nonwoven Nanofibers Composite : Surface Morphology and Fibers Orientation ». Iraqi Journal of Chemical and Petroleum Engineering 20, n^o 2 (30 juin 2019) : 11–15. http://dx.doi.org/10.31699/ijcpe.2019.2.2.

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Carbonized nonwoven nanofibers composite were fabricated using the electrospinning method of a polymeric solution composite followed by heat treatment including stabilization and calcination steps. The spun polymeric solution was a binary polymer mixture/organic solvent. In this study, two types of polymers (Polymethylmethacrylate (PMMA) and Polyethylene glycol (PEG)) were used separately as a copolymer with the base polymer (Polyacrylonitrile (PAN)) to prepare a binary polymer mixture in a mixing ratio of 50:50. The prepared precursor solutions were used to prepare the precursor nanofibers composite (PAN: PMMA) and (PAN: PEG). The fabricated precursors nonwoven fibers composite were stabilized and carbonized to produce carbon nonwoven nanofibers composite. The effect of the combined polymer type on the fiber size, fiber size distribution, and surface morphology of the prepared nonwoven nanofibers was studied. The nonwoven fibers orientation and surface morphology were characterized using field emission scanning electron microscope (FESEM). In addition, ImageJ software has been used to calculate the fiber size and fiber size distribution. Here, the obvious effect of the copolymer type on the surface morphology, fiber size, and fiber orientation has been demonstrated. Using a copolymer with PAN polymer led to increasing the fiber size. The carbonized nanofibers composite prepared using PEG polymer as a copolymer was more ordered fibers in comparison with the fiber orientation of carbon nanofibers based on pure PAN. In contrast of that, using PMMA as a copolymer resulted curly carbonized nonwoven nanofiber composite.

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Jang, Wongi, Jaehan Yun, Yejun Park, In Kee Park, Hongsik Byun et Chang Hyun Lee. « Polyacrylonitrile Nanofiber Membrane Modified with Ag/GO Composite for Water Purification System ». Polymers 12, n^o 11 (22 octobre 2020) : 2441. http://dx.doi.org/10.3390/polym12112441.

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Silver nanoparticle-modified graphene oxide (Ag/GO) was reliably prepared by using sodium borohydride (NaBH4) in the presence of citric acid capping agent via a simple wet chemistry method. This rapidly formed Ag/GO composite exhibited good dispersity in a solution containing hydrophilic polyacrylonitrile (PAN). Subsequent electrospinning of this precursor solution resulted in the successful formation of nanofibers without any notable defects. The Ag/GO-incorporated PAN nanofibers showed thinner fiber strands (544 ± 82 nm) compared to those of GO-PAN (688 ± 177 nm) and bare-PAN (656 ± 59 nm). Subsequent thermal treatment of nanofibers resulted in the preparation of thin membranes to possess the desired pore property and outstanding wettability. The Ag/GO-PAN nanofiber membrane also showed 30% higher water flux value (390 LMH) than that of bare-PAN (300 LMH) for possible microfiltration (MF) application. In addition, the resulting Ag/GO-PAN nanofiber membrane exhibited antibacterial activity against Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive). Furthermore, this composite membrane exhibited outstanding anti-fouling property compared to the GO-PAN nanofiber membrane in the wastewater treatment. Therefore, the simple modification strategy allows for the effective formation of Ag/GO composite as a filler that can be reliably incorporated into polymer nanofiber membranes to possess improved overall properties for wastewater treatment applications.

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Wakiya, Takeru, Manabu Tanaka et Hiroyoshi Kawakami. « Fabrication and Electrolyte Characterizations of Nanofiber Framework-Based Polymer Composite Membranes with Continuous Proton Conductive Pathways ». Membranes 11, n^o 2 (27 janvier 2021) : 90. http://dx.doi.org/10.3390/membranes11020090.

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For future fuel cell operations under high temperature and low- or non-humidified conditions, high-performance polymer electrolyte membranes possessing high proton conductivity at low relative humidity as well as suitable gas barrier property and sufficient membrane stability are strongly desired. In this study, novel nanofiber framework (NfF)-based composite membranes composed of phytic acid (Phy)-doped polybenzimidazole nanofibers (PBINf) and Nafion matrix electrolyte were fabricated through the compression process of the nanofibers. The NfF composite membrane prepared from the pressed Phy-PBINf showed higher proton conductivity and lower activation energy than the conventional NfF composite and recast-Nafion membranes, especially at low relative humidity. It is considered that the compression process increased the nanofiber contents in the composite membrane, resulting in the construction of the continuously formed effective proton conductive pathway consisting of the densely accumulated phosphoric acid and sulfonic acid groups at the interface of the nanofibers and the Nafion matrix. Since the NfF also improved the mechanical strength and gas barrier property through the compression process, the NfF composite polymer electrolyte membranes have the potential to be applied to future fuel cells operated under low- or non-humidified conditions.

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Zhu, Zhu, Ye Zhang, Yibo Zhang, Yanli Shang, Xueji Zhang et Yongqiang Wen. « Preparation of PAN@TiO2 Nanofibers for Fruit Packaging Materials with Efficient Photocatalytic Degradation of Ethylene ». Materials 12, n^o 6 (18 mars 2019) : 896. http://dx.doi.org/10.3390/ma12060896.

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Ethylene causes faster deterioration of perishable crops during postharvest transportation and storage. The present study aimed to develop TiO2-coated nanofibers with efficient photocatalytic activities to enhance the degradation of fruit-emitted ethylene. The consecutive electrospinning of polyacrylonitrile (PAN) and TiO2 deposition was successfully performed to produce PAN@TiO2 nanofibers. The scanning electron microscopy results indicate the uniform distribution of TiO2 nanoparticles on the surface of the PAN nanofiber. The PAN@TiO2 composite nanofibers exhibited enhanced photocatalytic activity for ethylene degradation under low-intensity UV light irradiation. Furthermore, a tomato fruit-ripening test confirmed the effectiveness of the PAN@TiO2 nanofibers. The PAN@TiO2 nanofibers exhibited effective ethylene degradation and slowed the color shift and softening of the tomatoes during storage. The results suggest great potential for use of the PAN@TiO2 composite nanofibers as ethylene scavenging packaging material for fresh fruits and vegetables.

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Gonzales, Ralph, Myoung Park, Leonard Tijing, Dong Han, Sherub Phuntsho et Ho Shon. « Modification of Nanofiber Support Layer for Thin Film Composite forward Osmosis Membranes via Layer-by-Layer Polyelectrolyte Deposition ». Membranes 8, n^o 3 (25 août 2018) : 70. http://dx.doi.org/10.3390/membranes8030070.

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Electrospun nanofiber-supported thin film composite membranes are among the most promising membranes for seawater desalination via forward osmosis. In this study, a high-performance electrospun polyvinylidenefluoride (PVDF) nanofiber-supported thin film composite (TFC) membrane was successfully fabricated after molecular layer-by-layer polyelectrolyte deposition. Negatively-charged electrospun polyacrylic acid (PAA) nanofibers were deposited on electrospun PVDF nanofibers to form a support layer consisted of PVDF and PAA nanofibers. This resulted to a more hydrophilic support compared to the plain PVDF nanofiber support. The PVDF-PAA nanofiber support then underwent a layer-by-layer deposition of polyethylenimine (PEI) and PAA to form a polyelectrolyte layer on the nanofiber surface prior to interfacial polymerization, which forms the selective polyamide layer of TFC membranes. The resultant PVDF-LbL TFC membrane exhibited enhanced hydrophilicity and porosity, without sacrificing mechanical strength. As a result, it showed high pure water permeability and low structural parameter values of 4.12 L m−2 h−1 bar−1 and 221 µm, respectively, significantly better compared to commercial FO membrane. Layer-by-layer deposition of polyelectrolyte is therefore a useful and practical modification method for fabrication of high performance nanofiber-supported TFC membrane.

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Wang, Shangshang, Jun Huang, Xing Zhang et Jianbo Zhang. « Integrated Thermo-Electric Measurement of Electrospun Nanofiber for Polymer Electrolyte Fuel Cell ». ECS Meeting Abstracts MA2022-01, n^o 38 (7 juillet 2022) : 1713. http://dx.doi.org/10.1149/ma2022-01381713mtgabs.

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Polymer electrolyte fuel cell (PEFC), as an efficient hydrogen energy conversion device, has been developed for decades. Catalyst layer (CL), where the oxygen reduction reaction occurs, predominantly determines the performance of PEFC. Since 1889, the mass activity of catalyst layer has been improved for more than three orders of magnitudes, thanks to the invention of PFSA ionomer and highly dispersed catalyst on nano-sized carbon support. In recent years, introducing order into CL is bringing the CL performance to a higher level. The CLs with state-of-the-art performance feature nanofiber structures. One type of is ionomer nanofibers deposited with Pt/C catalyst on the surface, and another type is composite nanofiber containing ionomer, Pt/C catalyst, and binding polymer. Their superior performance may come from the ordered mass transport network and the size effect of nanofiber conductivity. To further improve the CL performance, the structure-property-performance relationship of ionomer nanofibers or composite nanofibers needs to be clarified. In this work, we designed a setup to measure the proton, electron and thermal conductivity as well as the performance of a single ionomer or composite nanofiber. We developed a self-bonding method to fix the nanofiber on the micro-electrode. For proton and electron conductivity measurement, four-probe method was adopted to eliminate the electrical contact resistance and interfacial effect. For thermal conductivity measurement, Raman assisted steady state method was used to directly measure the temperature profile along the nanofiber. So, the measurement error resulting from the thermal contact resistance between the sample and the temperature sensor/heat sink can be eliminated. For performance measurement, three-electrode system was adopted using the Ag/AgCl electrode as the reference electrode and the Zn/ZnCl2 electrode as the counter electrode. We prepared nanofibers with different size, polymer content, and cross-sectional component distribution by controlling the ink recipe and electrospinning parameters. The integrated thermo-electric measurement found that the proton and thermal conductivity of nanofiber are one order of magnitude higher than bulk properties and increases with decreasing fiber radius. This is attributed to the oriented ionic morphology along the nanofiber. Furthermore, a nanofiber model was developed to extract the catalytic activity and gas diffusion coefficient of nanofiber. These characterization and modelling work can provide guidance to the design and optimization of catalyst layer with electrospun ionomer or composite nanofibers.

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