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Sample records for prepared pe-co-gma nanofibers

  1. Controllable Biotinylated Poly(Ethylene-co-Glycidyl Methacrylate) (PE-co-GMA) Nanofibers to Bind Streptavidin-Horseradish Peroxidase (HRP) for Potential Biosensor Applications

    Science.gov (United States)

    Poly(ethylene-co-glycidyl methacrylate) (PE-co-GMA) nanofibers with abundant active epoxy groups on surfaces were fabricated through a novel manufacturing process. The prepared PE-co-GMA nanofibers with different average diameters ranging from 100 to 400 nm were aminated by reacting the epoxy groups...

  2. Chitin nanofibers: preparations, modifications, and applications

    Science.gov (United States)

    Ifuku, Shinsuke; Saimoto, Hiroyuki

    2012-05-01

    Chitin nanofibers are prepared from the exoskeletons of crabs and prawns by a simple mechanical treatment after the removal of proteins and minerals. The obtained nanofibers have fine nanofiber networks with a uniform width of approximately 10-20 nm and a high aspect ratio. The method used for chitin-nanofiber isolation is also successfully applied to the cell walls of mushrooms. They form a complex with glucans on the fiber surface. A grinder, a Star Burst atomization system, and a high speed blender are all used in the mechanical treatment to convert chitin to nanofibers. Mechanical treatment under acidic conditions is the key to facilitate fibrillation. At pH 3-4, the cationization of amino groups on the fiber surface assists nano-fibrillation by electrostatic repulsive force. By applying this finding, we also prepared chitin nanofibers from dry chitin powder. Chitin nanofibers are acetylated to modify their surfaces. The acetyl DS can be controlled from 1 to 3 by changing the reaction time. An acetyl group is introduced heterogeneously from the surface to the core. Nanofiber morphology is maintained even in the case of high acetyl DS. Optically transparent chitin nanofiber composites are prepared with 11 different types of acrylic resins. Due to the nano-sized structure, all of the composites are highly transparent. Chitin nanofibers significantly increase the Young's moduli and the tensile strengths and decrease the thermal expansion of all acrylic resins due to the reinforcement effect of chitin nanofibers. Chitin nanofibers show chiral separation ability. The chitin nanofiber membrane transports the d-isomer of glutamic acid, phenylalanine, and lysine from the corresponding racemic amino acid mixtures faster than the corresponding l-isomer. The chitin nanofibers improve clinical symptoms and suppress ulcerative colitis in a DSS-induced mouse model of acute ulcerative colitis. Moreover, chitin nanofibers suppress myeloperoxidase activation in the colon and

  3. Preparation of chitosan nanofiber tube by electrospinning.

    Science.gov (United States)

    Matsuda, Atsushi; Kagata, Go; Kino, Rikako; Tanaka, Junzo

    2007-03-01

    Water-insoluble chitosan nanofiber sheets and tubes coated with chitosan-cast film were prepared by electrospinning. When as-spun chitosan nanofiber sheets and tubes were immersed in 28% ammonium aqueous solution, they became insoluble in water and showed nanofiber structures confirmed by SEM micrography. Mechanical properties of chitosan nanofiber sheets and tubes were improved by coating with chitosan-cast film, which gave them a compressive strength higher than that of crab-tendon chitosan, demonstrating that chitosan nanofiber tubes coated with chitosan-cast film are usable as nerve-regenerative guide tubes.

  4. Preparation and characterization of crosslinked chitosan-based nanofibers

    Institute of Scientific and Technical Information of China (English)

    Ying Shan Zhou; Dong Zhi Yang; Jun Nie

    2007-01-01

    Crosslinked chitosan-based nanofibers were successfully prepared via electrospinning technique with heat mediated chemical crosslinking followed. The structure, morphology and mechanical property of nanofibers were characterized by attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR), scanning electron microscopy (SEM), Instron machine, respectively. The results showed that, nanofibers exhibited a smooth surface and regular morphology, and tensile strength of nanofibers improved with increasing of triethylene glycol dimethacrylate (TEGDMA) content.

  5. UV-responsive polyvinyl alcohol nanofibers prepared by electrospinning

    Energy Technology Data Exchange (ETDEWEB)

    Khatri, Zeeshan, E-mail: zeeshan.khatri@faculty.muet.edu.pk [Department of Textile Engineering, Mehran University of Engineering and Technology, Jamshoro 76062 (Pakistan); Nano Fusion Technology Research Lab, Division of Frontier Fibers, Institute for Fiber Engineering (IFES), Interdisciplinary Cluster for Cutting Edge Research (ICCER), Shinshu University, 3-15-1, Tokida, Ueda, Nagano 386-8567 (Japan); Ali, Shamshad [Department of Textile Engineering, Mehran University of Engineering and Technology, Jamshoro 76062 (Pakistan); Department of Organic and Nano Engineering, Hanyang University, 17 Haengdang-dong, Seongdong-gu, Seoul 133-791 (Korea, Republic of); Khatri, Imran [Department of Entomology, Sindh Agriculture University, Tandojam (Pakistan); Mayakrishnan, Gopiraman [Nano Fusion Technology Research Lab, Division of Frontier Fibers, Institute for Fiber Engineering (IFES), Interdisciplinary Cluster for Cutting Edge Research (ICCER), Shinshu University, 3-15-1, Tokida, Ueda, Nagano 386-8567 (Japan); Kim, Seong Hun [Department of Organic and Nano Engineering, Hanyang University, 17 Haengdang-dong, Seongdong-gu, Seoul 133-791 (Korea, Republic of); Kim, Ick-Soo, E-mail: kim@shinshu-u.ac.jp [Nano Fusion Technology Research Lab, Division of Frontier Fibers, Institute for Fiber Engineering (IFES), Interdisciplinary Cluster for Cutting Edge Research (ICCER), Shinshu University, 3-15-1, Tokida, Ueda, Nagano 386-8567 (Japan)

    2015-07-01

    Graphical abstract: - Highlights: • UV responsive PVA nanofibers were prepared via electrospinning. • Quick response codes were recorded multiple times on UV responsive nanofibers. • The rate of photo-coloration was found faster than the rate of photo-reversibility. - Abstract: We report UV-responsive polyvinyl alcohol (PVA) nanofibers for potential application for recording and erasing quick response (QR) codes. We incorporate 1′-3′-dihydro-8-methoxy-1′,3′,3′-trimethyl-6-nitrospiro [2H-1-benzopyran-2,2′-(2H)-indole] (indole) and,3-dihydro-1,3,3-trimethylspiro [2H-indole-2,3′-[3H] phenanthr [9,10-b] (1,4) oxazine] (oxazine) into PVA polymer matrix via electrospinning technique. The resultant nanofibers were measured for recording–erasing, photo-coloration and thermal reversibility. The rate of photo-coloration of PVA–indole nanofibers was five times higher than the PVA–oxazine nanofibers, whereas the thermal reversibility found to be more than twice as fast as PVA–oxazine nanofibers. Results showed that the resultant nanofibers have very good capability of recording QR codes multiple times. The FTIR spectroscopy and SEM were employed to characterize the electrospun nanofibers. The UV-responsive PVA nanofibers have great potentials as a light-driven nanomaterials incorporated within sensors, sensitive displays and in optical devices such as erasable and rewritable optical storage.

  6. Preparation of photocrosslinkable polystyrene methylene cinnamate nanofibers via electrospinning.

    Science.gov (United States)

    Yi, Chuan; Nirmala, R; Navamathavan, R; Li, Xiang-Dan; Kim, Hak-Yong

    2011-10-01

    Nanoscaled photocrosslinkable polystyrene methylene cinnamate (PSMC) nanofibers were fabricated by electrospinning. The PSMC was prepared by the modification of polystyrene as a starting material via a two-step reaction process, chloromethylation and esterification. The chemical structure of PSMC was confirmed by 1H NMR and Fourier transform infrared spectroscopy (FT-IR). The photosensitivity of the PSMC was investigated using ultraviolet (UV) spectroscopic methods. Electrospun PSMC nanofiber mat showed excellent solubility in many organic solvents. UV irradiation of the electrospun mats led to photodimerization to resist dissolving in organic solvents. The morphology of the nanofiber was observed by scanning electron microscopy (SEM) and the result indicated that the average diameter of nanofibers is 350 nm and the crosslinked nanofibers were not collapsed after dipping into organic solvent showing good solvent-stability. This photocrosslinked nanofibers has the potential application in filtration, catalyst carrier and protective coating.

  7. Preparation of natural brucite nanofibers by the dispersion method

    Institute of Scientific and Technical Information of China (English)

    Li Xu; Wen Ni; Wenping Li; Xingde Liu; Hailong Yang; Xiaoguang Yang

    2008-01-01

    The preparation of natural brucite nanofibers through dispersion by the wet process is described. The test results indicate that brucite fibers can be well dispersed by using sodium dioctyl sulfosuccinate (OT) as the dispersant at a dispersant/fiber mass ratio of 0.15:1, dispersing for 30 min at a water/solid mass ratio of 20:1. The prepared nanofibers were characterized with X-ray diffraction (XRD), scanning electron microscope (SEM), and transmission electron microscope (TEM). It is shown that the prepared single brucite nanofiber is around 30 run in diameter and the talus of the nonsingle brucite nanofibers is about 50-150 nm in diameter. Natural brucite mineral fibers were treated by the dispersion method to obtain nanomaterials. These fibers have significant advantages over artificial nanofibers both in yield and in cost.

  8. Fabrication of WS2 nanofibers from WO3 nanofibers prepared by an electrospinning method.

    Science.gov (United States)

    Zhu, Yajun; Zhang, Xuebin; Ji, Yi; Feng, Yi; Zhang, Jingcheng

    2013-03-01

    This paper describes a procedure of synthesizing long WS2 nanofibers. WO3 nanofibers were prepared as precursors by electrospinning of ammonium meta-tungstate (AMT), polyvinyl alcohol (PVA) and alcohol solution followed by calcination at 550 degrees C in air. WS2 nanofibers were obtained by sulfurization of the WO3 nanofibres at 800 degrees C in an argon atmosphere, with sulfur powder acting as sulfuration reducer. The nanofibres were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), and transmission electron microscopy (TEM). The results show that the final products are pure WS2 nanofibres, which have high aspect ratio. The WS2 nanofibers with rough surface were formed of nanoparticles, while some nanoflakes appeared on the surface of WS2 nanofibres. The diameters of the WS2 nanofibers were between 200 and 300 nm, which is similar to WO3 nanofibers. In addition, the WS2 nanofibers were polycrystalline.

  9. Polysulfone nanofibers prepared by electrospinning and gas/jet-electrospinning

    Institute of Scientific and Technical Information of China (English)

    Yao Yongyi; Zhu Puxin; Ye Hai; Niu Anjian; Gao Xushan; Wu Dacheng

    2006-01-01

    Polysulfone nanofibers were prepared by electrospinning.The electrospinning equipment was designed in a new way,wherein the spinneret was combined with a gas jet device.The intrinsic viscosity of the used polysulfone was 0.197 dL/g in dimethyl acetamide,which was also the solvent in electrospinning.The gas used in this gas jet/electrostatic spinning was nitrogen.The relationship between the process parameters and the average diameter of polysulfone nanofibers was investigated.The main process parameters studied in this work were the voltage,the flow rate of the spinning fluid,the distance between the spinneret and the nanofiber collector and the temperature in the spinning chamber.The other important factors determining the nanometer diameter were the spinning fluid properties including its viscosity,surface tension and electrical conductivity.The average diameter and the diameter distribution of electrospinning nanofibers were measured experimentally by using scanning electron microscopy.The diameter of polysnlfone nanofibers prepared by the gas jet/electrostatic spinning was in the range 50-500 nm.It was found that the diameter of nanofibers mainly depended on high voltage,the gap between the spinneret and the collector and the concentration of polymer solutions.It is concluded that the gas-jet/electrospinning is a better method than the conventional electrospinning,in that it makes the nanofibers finer and more uniform and exhibits higher efficiency in the process of electrospinning.

  10. Preparation and Electrochemical Properties of Silver Doped Hollow Carbon Nanofibers

    Directory of Open Access Journals (Sweden)

    LI Fu

    2016-11-01

    Full Text Available Silver doped PAN-based hollow carbon nanofibers were prepared combining co-electrospinning with in situ reduction technique subsequently heat treatment to improve the electrochemical performances of carbon based supercapacitor electrodes. The morphology, structure and electrochemical performances of the resulted nanofiber were studied. The results show that the silver nanoparticles can be doped on the surface of hollow carbon nanofibers and the addition of silver favors the improvement of the electrochemical performances, exhibiting the enhanced reversibility of electrode reaction and the capacitance and the reduced charge transfer impedance.

  11. Preparation and Characterization of Organic/Inorganic Hybrid Nanofibers

    Institute of Scientific and Technical Information of China (English)

    WU Ning; WEI Qu-fu; LI Qi; XU Wen-zheng

    2006-01-01

    A new class of nanocomposites based on organic and inorganic species integrated at a nanoscale has obtained more attention these years. Organic-inorganic hybrids have both the advantages of organic materials, such as light weight, flexibility and good moldability, and inorganic materials, such as high strength, heat stability and chemical resistance. In this work, PVAc/TiO2 organicinorganic hybrid was prepared by sol-gel process. Electrospinning technique was used to fabricate PVAc/TiO2hybrid nanofibers. The structures and properties of the hybrid nanofibers were characterized by Scanning Electron Microscopy (SEM), Atomic Force Microscope (AFM),Differential Scanning Calorimeter (DSC) and Fouriertransform infrared (FTIR) spectra. SEM and AFM were employed to study the topography of the hybrid nanofibers.The chemical structure of the hybrid nanofibers were examined by FTIR. The DSC scansrevealed the second order transition temperature of the hybrid materials were higher than PVAc.

  12. Preparation and biomedical applications of chitin and chitosan nanofibers.

    Science.gov (United States)

    Azuma, Kazuo; Ifuku, Shinsuke; Osaki, Tomohiro; Okamoto, Yoshiharu; Minami, Saburo

    2014-10-01

    Chitin (β-(1-4)-poly-N-acetyl-D-glucosamine) is widely distributed in nature and is the second most abundant polysaccharide after cellulose. Chitin occurs in nature as ordered macrofibrils. It is the major structural component in the exoskeleton of crab and shrimp shells and the cell wall of fungi and yeast. As chitin is not readily dissolved in common solvents, it is often converted to its more deacetylated derivative, chitosan. Chitin, chitosan, and its derivatives are widely used in tissue engineering, wound healing, and as functional foods. Recently, easy methods for the preparation of chitin and chitosan nanofibers have been developed, and studies on biomedical applications of chitin and chitosan nanofibers are ongoing. Chitin and chitosan nanofibers are considered to have great potential for various biomedical applications, because they have several useful properties such as high specific surface area and high porosity. This review summarizes methods for the preparation of chitin and chitosan nanofibers. Further, biomedical applications of chitin and chitosan nanofibers in (i) tissue engineering, (ii) wound dressing, (iii) cosmetic and skin health, (iv) stem cell technology, (v) anti-cancer treatments and drug delivery, (vi) anti-inflammatory treatments, and (vii) obesity treatment are summarized. Many studies indicate that chitin and chitosan nanofibers are suitable materials for various biomedical applications.

  13. Preparation of Electrically Conductive Polystyrene/Carbon Nanofiber Nanocomposite Films

    Science.gov (United States)

    Sun, Luyi; O'Reilly, Jonathan Y.; Tien, Chi-Wei; Sue, Hung-Jue

    2008-01-01

    A simple and effective approach to prepare conductive polystyrene/carbon nanofiber (PS/CNF) nanocomposite films via a solution dispersion method is presented. Inexpensive CNF, which has a structure similar to multi-walled carbon nanotubes, is chosen as a nanofiller in this experiment to achieve conductivity in PS films. A good dispersion is…

  14. PREPARATION OF CARBON NANOFIBERS BY POLYMER BLEND TECHNIQUE

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The polymer blend technique is a novel method to produced carbon nanofibers. In this paper, we have prepared fine carbon fibers and porous carbon materials by this technique, and we will discuss the experiment results by means of SEM, TGA, Element Analysis, etc.

  15. Advances in Poly(4-aminodiphenylaniline) Nanofibers Preparation by Electrospinning Technique.

    Science.gov (United States)

    Della Pina, C; Busacca, C; Frontera, P; Antonucci, P L; Scarpino, L A; Sironi, A; Falletta, E

    2016-05-01

    Polyaniline (PANI) nanofibers are drawing a great deal of interest from academia and industry due to their multiple applications, especially in biomedical field. PANI nanofibers were successfully electrospun for the first time by MacDiarmid and co-workers at the beginning of the millennium and since then many efforts have been addressed to improve their quality. However, traditional PANI prepared from aniline monomer shows some drawbacks, such as presence of toxic (i.e., benzidine) and inorganic (salts and metals) co-products, that complicate polymer post-treatment, and low solubility in common organic solvents, making hard its processing by electrospinning technique. Some industrial sectors, such as medical and biomedical, need to employ materials free from toxic and polluting species. In this regard, the oxidative polymerization of N-(4-aminophenyl)aniline, aniline dimer, to produce poly(4-aminodiphenylaniline), P4ADA, a kind of PANI, represents an innovative alternative to the traditional synthesis because the obtained polymer results free from carcinogenic and/or polluting co-products, and, moreover, more soluble than traditional PANI. This latter feature can be exploited to obtain P4ADA nanofibers by electrospinning technique. In this paper we report the advances obtained in the P4ADA nanofibers electrospinnig. A comparison among polyethylene oxide (PEO), polymethyl methacrylate (PMMA) and polystyrene (PS), as the second polymer to facilitate the electrospinning process, is shown. In order to increase the conductivity of P4ADA nanofibers, two strategies were adopted and compared: selective insulating binder removal from electrospun nanofibers by a rinsing tratment, afterwards optimizing the minimum amount of binder necessary for the electrospinning process. Moreover, the effect of PEO/P4ADA weight ratio on the fibers morphology and conductivity was highlighted.

  16. Preparation of Biopolymeric Nanofiber Containing Silica and Antibiotic

    Directory of Open Access Journals (Sweden)

    A. Bagheri Pebdeni

    2016-01-01

    Full Text Available The biocompatible and biodegradable polymer nanofiber with high potential for anti-bacterial coating are used for: multi-functional membranes, tissue engineering, wound dressings, drug delivery, artificial organs, vascular grafts and etc. Electrospinning nanofiber made of scaffolding due to characteristics such as high surface to volume ratio, high porosity and very fine pores are used for a wide range of applications. In this study, polymer composite nanofiber Silica/chitosan/poly (ethylene oxide /cefepime antibiotic synthesis and antibacterial properties will be discussed. The optimum conditions for preparation of electrospun nanofiber were: voltage; 21 kV, feed rate; 0.5 mL/h, nozzle-collector distance; 10 cm, and chitosan/poly(ethylene oxide weight ratio 90:10 and the volume ratio of chitosan/silica is 70:30.  The antibacterial activity of composite scaffolds were tested by agar plate method by two type bacteria including Escherichia coli and Staphylococcus aureus. With the addition of the silica to chitosan, the hybrid was more biodegradable and improves the mechanical properties of biopolymer.

  17. Ethylene tetrafluoroethylene nanofibers prepared by CO2 laser supersonic drawing

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    A. Suzuki

    2013-06-01

    Full Text Available Ethylene tetrafluoroethylene (ETFE nanofibers were prepared by carbon dioxide (CO2 laser irradiation of asspun ETFE fibers with four different melt flow rates (MFRs in a supersonic jet that was generated by blowing air into a vacuum chamber through the fiber injection orifice. The drawability and superstructure of fibers produced by CO2 laser supersonic drawing depend on the laser power, the chamber pressure, the fiber injection speed, and the MFR. Nanofibers obtained using a laser power of 20 W, a chamber pressure of 20 kPa, and an MFR of 308 g•10 min–1 had an average diameter of 0.303 µm and a degree of crystallinity of 54%.

  18. Preparation of poly (Vinyl Alcohol) nanofibers containing silver nanoparticles by gamma-ray irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yun Hye [AMOTECH Co., Ltd., Kimpo (Korea, Republic of); Shin, Jun Wha; An, Sung Jun; Youn, Min Ho; Lim, Youn Mook; Gwon, Hui Jeong; Nho, Young Chang [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of)

    2008-08-15

    PVA nanofibers containing silver nanoparticles were prepared by two methods. The first method was electrospinning of irradiated solution. The prepared PVA/AgNO{sub 3} solution was irradiated by gamma-rays. And then the irradiated solution was electrospun. The second method was irradiation of electrospun nanofibers. Nanofibers prepared by electrospinning of unirradiated PVA/AgNO{sub 3} solution. The morphology of the nanofibers was observed with a SEM, TEM. When the irradiated PVA/AgNO{sub 3} solution were electrospun, the average size of the Ag nanoparticles was increased, but their number was decreased.

  19. Preparation of Ag/HBP/PAN Nanofiber Web and Its Antimicrobial and Filtration Property

    Directory of Open Access Journals (Sweden)

    Li-Rong Yao

    2016-01-01

    Full Text Available To widen the application of nanofibers web in the field of medical health materials, a new Ag/amino-terminated hyperbranched polymer (HBP/polyacrylonitrile (PAN nanofiber web with excellent antimicrobial activity and filtration property was produced with Ag/HBP dispersion solution and PAN nanofiber. Ag/HBP dispersion solution was prepared with HBP as reducer and stabilizer, and Ag/HBP/PAN nanofiber was prepared by modifying electrospun PAN nanofiber with Ag/HBP aqueous solution. The characterization results showed that spherical Ag nanoparticles were prepared and they had a narrow distribution in HBP aqueous solution. The results of Ag/HBP/PAN nanofiber characterized with SEM and EDS showed that the content of silver nanoparticles on the surface of PAN nanofiber was on the increase when the treating temperature rose. The bacterial reduction rates of HBP-treated PAN nanofiber against S. aureus and E. coli were about 89%, while those of the Ag/HBP/PAN nanofiber against S. aureus and E. coli were 99.9% and 99.96%, respectively, due to the cooperative effects from the amino groups in HBP and Ag nanoparticles. Moreover, the small pores and high porosity in Ag/HBP/PAN nanofiber web resulted in high filtration efficiency (99.9% for removing smaller particles (0.1 μm~0.7 μm, which was much higher than that of the gauze mask.

  20. Preparation and characterization of Ag nanoparticle-embedded polymer electrospun nanofibers

    Energy Technology Data Exchange (ETDEWEB)

    Dong Guoping, E-mail: guoping_dong@163.com; Xiao Xiudi; Liu, Xiaofeng; Qian Bin [Chinese Academy of Sciences, Shanghai Institute of Optics and Fine Mechanics (China); Ma Zhijun; Ye Song [Zhejiang University, State Key Laboratory of Silicon Materials (China); Chen Danping [Chinese Academy of Sciences, Shanghai Institute of Optics and Fine Mechanics (China); Qiu Jianrong, E-mail: jrqiu@zju.edu.c [Zhejiang University, State Key Laboratory of Silicon Materials (China)

    2010-05-15

    Poly (vinyl alcohol) (PVA) and poly (vinyl pyrrolidone) (PVP) nanofibers embedding Ag nanoparticles (5-18 nm) have been prepared successfully by electrospinning at room temperature. Scanning electron microscope (SEM), X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), Fourier transform IR spectra (FTIR), and Raman scattering were used to characterize the structure and properties of Ag nanoparticle-embedded PVA and PVP nanofibers before and after heat treatment at different temperature. The antibacterial activity of Ag nanoparticle-embedded PVP nanofibers after heat treatment was also tested, which indicated that the biological activity of yeast cells was effectively inhibited by these Ag nanoparticle-embedded PVP nanofibers.

  1. Titanium carbide/carbon composite nanofibers prepared by a plasma process

    Energy Technology Data Exchange (ETDEWEB)

    El Mel, A A; Gautron, E; Angleraud, B; Granier, A; Tessier, P Y [Universite de Nantes, CNRS, Institut des Materiaux Jean Rouxel, UMR 6502, 2 rue de la Houssiniere BP 32229-44322 Nantes cedex 3 (France); Choi, C H [Department of Mechanical Engineering, Stevens Institute of Technology, Hoboken, NJ 07030 (United States)

    2010-10-29

    The incorporation of metal or metal carbide nanoparticles into carbon nanofibers modifies their properties and enlarges their field of application. The purpose of this work is to report a new non-catalytic and easy method to prepare organized metal carbide-carbon composite nanofibers on nanopatterned silicon substrates prepared by laser interference lithography coupled with deep reactive ion etching. Titanium carbide-carbon composite nanofibers were grown on the top of the silicon lines parallel to the substrate by a hybrid plasma process combining physical vapor deposition and plasma enhanced chemical vapor deposition. The prepared nanofibers were analyzed by scanning electron microscopy, x-ray photoelectron spectroscopy, Raman spectroscopy and transmission electron microscopy. We demonstrate that the shape, microstructure and the chemical composition of the as-grown nanofibers can be tuned by changing the plasma conditions.

  2. Titanium carbide/carbon composite nanofibers prepared by a plasma process.

    Science.gov (United States)

    El Mel, A A; Gautron, E; Choi, C H; Angleraud, B; Granier, A; Tessier, P Y

    2010-10-29

    The incorporation of metal or metal carbide nanoparticles into carbon nanofibers modifies their properties and enlarges their field of application. The purpose of this work is to report a new non-catalytic and easy method to prepare organized metal carbide-carbon composite nanofibers on nanopatterned silicon substrates prepared by laser interference lithography coupled with deep reactive ion etching. Titanium carbide-carbon composite nanofibers were grown on the top of the silicon lines parallel to the substrate by a hybrid plasma process combining physical vapor deposition and plasma enhanced chemical vapor deposition. The prepared nanofibers were analyzed by scanning electron microscopy, x-ray photoelectron spectroscopy, Raman spectroscopy and transmission electron microscopy. We demonstrate that the shape, microstructure and the chemical composition of the as-grown nanofibers can be tuned by changing the plasma conditions.

  3. Electrospinning preparation and electrical and biological properties of ferrocene/poly(vinylpyrrolidone composite nanofibers

    Directory of Open Access Journals (Sweden)

    Ji-Hong Chai

    2013-03-01

    Full Text Available Nanofibers containing ferrocene (Fc have been prepared for the first time by electrospinning. In this paper, Fc was dispersed uniformly throughout the poly(vinypyrrolidone (PVP matrix for the purpose of combining the properties of PVP and Fc. The effects of solvents and Fc concentration on the morphologies and diameters of nanofibers were investigated. In the DMF/ethanol solvent, the morphologies of the obtained nanofibers significantly changed with the increase of Fc concentration. The results demonstrated that the morphologies of the nanofibers could be controlled through adjusting solvents and Fc concentration. Scanning electron microscopy (SEM showed that the diameters of the obtained composite fibers were about 30–200 nm at different Fc concentrations. Thermogravimetric analysis (TGA results confirmed the presence of ferrocene within the PVP nanofibers. X-ray diffraction (XRD results showed that the crystalline structure of Fc in the fibers was amorphous after the electrospinning process. A biological evaluation of the antimicrobial activity of Fc/PVP nanofibers was carried out by using Gram-negative Escherichia coli (E. coli as model organisms. The nanofibers fabricated by this method showed obvious antibacterial activity. Electrochemical properties were characterized based on cyclic voltammetry measurements. The CV results showed redox peaks corresponding to the Fc+/Fc couple, which suggested that Fc molecules encapsulated inside PVP nanofibers retian their electrochemical activity. The properties and facile preparation method make the Fc/PVP nanofibers promising for antibacterial and sensing applications.

  4. Preparation of nanofibers consisting of MnO/Mn3O4 by using the electrospinning technique: the nanofibers have two band-gap energies

    Science.gov (United States)

    Barakat, Nasser A. M.; Woo, Kee-Do; Ansari, S. G.; Ko, Jung-Ahn; Kanjwal, Muzafar A.; Kim, Hak Yong

    2009-06-01

    In the present study, nanofibers consisting of manganese monoxide (MnO), which is hard to prepare because of the chemical activity of the manganese metal, and the popular Mn3O4 have been synthesized via the electrospinning technique. The nanofibers were obtained by electrospinning of an aqueous sol-gel consisting of manganese acetate tetra-hydrate and poly(vinyl alcohol). The obtained nanofiber mats were dried in vacuum at 80°C for 24 h and then calcined in argon atmosphere at 900°C for 5 h. According to X-ray diffraction results, the obtained nanofibers contain 65% MnO. Transmission electron microscope analysis reveals good crystallinity of the produced nanofibers. UV-visible spectroscopic analysis has indicated that the produced nanofibers have two band-gap energies, 2 and 3.7 eV, which enhances utilizing of the nanofibers in different applications.

  5. Preparation of chitosan nanofibers from completely deacetylated chitosan powder by a downsizing process.

    Science.gov (United States)

    Aklog, Yihun Fantahun; Dutta, Ajoy Kumar; Izawa, Hironori; Morimoto, Minoru; Saimoto, Hiroyuki; Ifuku, Shinsuke

    2015-01-01

    Chitosan nanofibers were easily prepared from fully deacetylated chitosan dry powder using a high-pressure waterjet system. From SEM observation, after 10 cycles of treatment, most of the chitosan had been reduced to homogeneous nanofibers measuring tens of nanometers. On the other hand, further mechanical treatment did not show a significant change. Relative crystallinity of chitosan nanofibers gradually decreased as the number of passes increased since high-pressure waterjet treatment damaged the crystalline region of chitosan nanofibers. The transmittance of the chitosan nanofiber slurry increased steeply, as the number of passes increased, indicating that the chitosan fibers were disintegrated effectively. Viscosity of chitosan nanofiber slurry also showed that the chitosan disintegrated well into nanofibers up to 10 passes. Above 10 passes, disintegration efficiency was saturated. The molecular weights of the nanofibers steeply decreased due to the depolymerization of chitosan by mechanical disintegration. The Young's modulus and tensile strength of chitosan nanofiber sheets were improved as the number of treatments increased, but further treatments deteriorated the tensile strength.

  6. Preparation and Grafting Functionalization of Self-Assembled Chitin Nanofiber Film

    Directory of Open Access Journals (Sweden)

    Jun-ichi Kadokawa

    2016-07-01

    Full Text Available Chitin is a representative biomass resource comparable to cellulose. Although considerable efforts have been devoted to extend novel applications to chitin, lack of solubility in water and common organic solvents causes difficulties in improving its processability and functionality. Ionic liquids have paid much attention as solvents for polysaccharides. However, little has been reported regarding the dissolution of chitin with ionic liquids. The author found that an ionic liquid, 1-allyl-3-methylimidazolium bromide (AMIMBr, dissolved chitin in concentrations up to ~4.8 wt % and the higher contents of chitin with AMIMBr gave ion gels. When the ion gel was soaked in methanol for the regeneration of chitin, followed by sonication, a chitin nanofiber dispersion was obtained. Filtration of the dispersion was subsequently carried out to give a chitin nanofiber film. A chitin nanofiber/poly(vinyl alcohol composite film was also obtained by co-regeneration approach. Chitin nanofiber-graft-synthetic polymer composite films were successfully prepared by surface-initiated graft polymerization technique. For example, the preparation of chitin nanofiber-graft-biodegradable polyester composite film was achieved by surface-initiated graft polymerization from the chitin nanofiber film. The similar procedure also gave chitin nanofiber-graft-polypeptide composite film. The surface-initiated graft atom transfer radical polymerization was conducted from a chitin macroinitiator film derived from the chitin nanofiber film.

  7. Preparation of porous carbon nanofibers derived from PBI/PLLA for supercapacitor electrodes

    Science.gov (United States)

    Jung, Kyung-Hye; Ferraris, John P.

    2016-10-01

    Porous carbon nanofibers were prepared by electrospinning blend solutions of polybenzimidazole/poly-L-lactic acid (PBI/PLLA) and carbonization. During thermal treatment, PLLA was decomposed, resulting in the creation of pores in the carbon nanofibers. From SEM images, it is shown that carbon nanofibers had diameters in the range of 100-200 nm. The conversion of PBI to carbon was confirmed by Raman spectroscopy, and the surface area and pore volume of carbon nanofibers were determined using nitrogen adsorption/desorption analyses. To investigate electrochemical performances, coin-type cells were assembled using free-standing carbon nanofiber electrodes and ionic liquid electrolyte. cyclic voltammetry studies show that the PBI/PLLA-derived porous carbon nanofiber electrodes have higher capacitance due to lower electrochemical impedance compared to carbon nanofiber electrode from PBI only. These porous carbon nanofibers were activated using ammonia for further porosity improvement and annealed to remove the surface functional groups to better match the polarity of electrode and electrolyte. Ragone plots, correlating energy density with power density calculated from galvanostatic charge-discharge curves, reveal that activation/annealing further improves energy and power densities.

  8. Preparation of porous carbon nanofibers derived from PBI/PLLA for supercapacitor electrodes.

    Science.gov (United States)

    Jung, Kyung-Hye; Ferraris, John P

    2016-10-21

    Porous carbon nanofibers were prepared by electrospinning blend solutions of polybenzimidazole/poly-L-lactic acid (PBI/PLLA) and carbonization. During thermal treatment, PLLA was decomposed, resulting in the creation of pores in the carbon nanofibers. From SEM images, it is shown that carbon nanofibers had diameters in the range of 100-200 nm. The conversion of PBI to carbon was confirmed by Raman spectroscopy, and the surface area and pore volume of carbon nanofibers were determined using nitrogen adsorption/desorption analyses. To investigate electrochemical performances, coin-type cells were assembled using free-standing carbon nanofiber electrodes and ionic liquid electrolyte. cyclic voltammetry studies show that the PBI/PLLA-derived porous carbon nanofiber electrodes have higher capacitance due to lower electrochemical impedance compared to carbon nanofiber electrode from PBI only. These porous carbon nanofibers were activated using ammonia for further porosity improvement and annealed to remove the surface functional groups to better match the polarity of electrode and electrolyte. Ragone plots, correlating energy density with power density calculated from galvanostatic charge-discharge curves, reveal that activation/annealing further improves energy and power densities.

  9. UV-responsive polyvinyl alcohol nanofibers prepared by electrospinning

    Science.gov (United States)

    Khatri, Zeeshan; Ali, Shamshad; Khatri, Imran; Mayakrishnan, Gopiraman; Kim, Seong Hun; Kim, Ick-Soo

    2015-07-01

    We report UV-responsive polyvinyl alcohol (PVA) nanofibers for potential application for recording and erasing quick response (QR) codes. We incorporate 1‧-3‧-dihydro-8-methoxy-1‧,3‧,3‧-trimethyl-6-nitrospiro [2H-1-benzopyran-2,2‧-(2H)-indole] (indole) and,3-dihydro-1,3,3-trimethylspiro [2H-indole-2,3‧-[3H] phenanthr [9,10-b] (1,4) oxazine] (oxazine) into PVA polymer matrix via electrospinning technique. The resultant nanofibers were measured for recording-erasing, photo-coloration and thermal reversibility. The rate of photo-coloration of PVA-indole nanofibers was five times higher than the PVA-oxazine nanofibers, whereas the thermal reversibility found to be more than twice as fast as PVA-oxazine nanofibers. Results showed that the resultant nanofibers have very good capability of recording QR codes multiple times. The FTIR spectroscopy and SEM were employed to characterize the electrospun nanofibers. The UV-responsive PVA nanofibers have great potentials as a light-driven nanomaterials incorporated within sensors, sensitive displays and in optical devices such as erasable and rewritable optical storage.

  10. White-light emission of polyvinyl alcohol/ZnO hybrid nanofibers prepared by electrospinning

    Science.gov (United States)

    Sui, X. M.; Shao, C. L.; Liu, Y. C.

    2005-09-01

    Polyvinyl alcohol/ZnO (PVA/ZnO) hybrid nanofibers were prepared by the electrospinning technique. The structural and spectral information of the nanofibers was characterized by scanning electron microscopy, x-ray diffraction, Fourier transform infrared spectroscopy, differential scanning calorimetry, resonant Raman, and photoluminescence (PL). The results indicate that ZnO were successfully embedded in the one-dimensional hybrid fibers via chemical interactions between ZnO and PVA. PL results show the PVA/ZnO nanofibers have an intense white-light emission, which originates from the simultaneous emission of three bands covering from the UV to visible range. A possible PL mechanism was proposed accordingly.

  11. Poly(hydroxybutyrate)/cellulose acetate blend nanofiber scaffolds: Preparation, characterization and cytocompatibility

    Energy Technology Data Exchange (ETDEWEB)

    Zhijiang, Cai, E-mail: caizhijiang@hotmail.com [School of Textiles, Tianjin Polytechnic University, Tianjin 300387 (China); State Key Laboratory of Hollow Fiber Membrane Material and Processes, No 399 BingShuiXi Street, XiQing District, Tianjin, China, 300387 (China); Yi, Xu; Haizheng, Yang; Jia, Jianru; Liu, Yuanpei [School of Textiles, Tianjin Polytechnic University, Tianjin 300387 (China)

    2016-01-01

    Poly(hydroxybutyrate) (PHB)/cellulose acetate (CA) blend nanofiber scaffolds were fabricated by electrospinning using the blends of chloroform and DMF as solvent. The blend nanofiber scaffolds were characterized by SEM, FTIR, XRD, DSC, contact angle and tensile test. The blend nanofibers exhibited cylindrical, uniform, bead-free and random orientation with the diameter ranged from 80–680 nm. The scaffolds had very well interconnected porous fibrous network structure and large aspect surface areas. It was found that the presence of CA affected the crystallization of PHB due to formation of intermolecular hydrogen bonds, which restricted the preferential orientation of PHB molecules. The DSC result showed that the PHB and CA were miscible in the blend nanofiber. An increase in the glass transition temperature was observed with increasing CA content. Additionally, the mechanical properties of blend nanofiber scaffolds were largely influenced by the weight ratio of PHB/CA. The tensile strength, yield strength and elongation at break of the blend nanofiber scaffolds increased from 3.3 ± 0.35 MPa, 2.8 ± 0.26 MPa, and 8 ± 0.77% to 5.05 ± 0.52 MPa, 4.6 ± 0.82 MPa, and 17.6 ± 1.24% by increasing PHB content from 60% to 90%, respectively. The water contact angle of blend nanofiber scaffolds decreased about 50% from 112 ± 2.1° to 60 ± 0.75°. The biodegradability was evaluated by in vitro degradation test and the results revealed that the blend nanofiber scaffolds showed much higher degradation rates than the neat PHB. The cytocompatibility of the blend nanofiber scaffolds was preliminarily evaluated by cell adhesion studies. The cells incubated with PHB/CA blend nanofiber scaffold for 48 h were capable of forming cell adhesion and proliferation. It showed much better biocompatibility than pure PHB film. Thus, the prepared PHB/CA blend nanofiber scaffolds are bioactive and may be more suitable for cell proliferation suggesting that these scaffolds can be used for

  12. Preparation, characterization of electrospun meso-hydroxylapatite nanofibers and their sorptions on Co(II)

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Hualin, E-mail: hlwang@hfut.edu.cn [School of Chemical Technology, Hefei University of Technology, Hefei, Anhui 230009 (China); Zhang, Peng; Ma, Xingkong; Jiang, Suwei; Huang, Yan; Zhai, Linfeng [School of Chemical Technology, Hefei University of Technology, Hefei, Anhui 230009 (China); Jiang, Shaotong [School of Biotechnology and Food Engineering, Hefei University of Technology, Hefei, Anhui 230009 (China)

    2014-01-30

    Highlights: • PVA/HA nanofibers could change into meso-HA nanofibers by calcination process. • Sorption of Co(II) on meso-HA was strongly dependent on pH and ionic strength. • Sorption kinetic data were well fitted by the pseudo-second-order rate equation. • Sorption isotherms could be well described by the Langmuir model. • Sorption process of Co(II) on meso-HA nanofibers was spontaneous and endothermic. -- Abstract: In this work, mesoporous hydroxylapatite (meso-HA) nanofibers were prepared via calcination process with polyvinyl alcohol/HA (PVA/HA) hybrid nanofibers fabricated by electrospinning technique as precursors, and the removal efficiency of meso-HA nanofibers toward Co(II) was evaluated via sorption kinetics and sorption isotherms. Furthermore, the sorption behaviors of Co(II) on meso-HA nanofibers were explored as a function of pH, ionic strength, and thermodynamic parameters. There existed hydrogen bonds between HA and PVA matrix in precursor nanofibers which could change into meso-HA nanofibers with main pore diameter at 27 nm and specific surface area at 114.26 m{sup 2}/g by calcination process. The sorption of Co(II) on meso-HA was strongly dependent on pH and ionic strength. Outer-sphere surface complexation or ion exchange was the main mechanisms of Co(II) adsorption on meso-HA at low pH, whereas inner-sphere surface complexation was the main adsorption mechanism at high pH. The sorption kinetic data were well fitted by the pseudo-second-order rate equation. The sorption isotherms could be well described by the Langmuir model. The thermodynamic parameters (ΔH°, ΔS° and ΔG°) calculated from the temperature-dependent sorption isotherms suggested that the sorption process of Co(II) on meso-HA nanofibers was spontaneous and endothermic.

  13. Preparations, properties and applications of chitosan based nanofibers fabricated by electrospinning

    Directory of Open Access Journals (Sweden)

    2011-04-01

    Full Text Available Chitosan is soluble in most acids. The protonation of the amino groups on the chitosan backbone inhibits the electrospinnability of pure chitosan. Recently, electrospinning of nanofibers based on chitosan has been widely researched and numerous nanofibers containing chitosan have been prepared by decreasing the number of the free amino groups of chitosan as the nanofibiers have enormous possibilities for better utilization in various areas. This article reviews the preparations and properties of the nanofibers which were electrospun from pure chitosan, blends of chitosan and synthetic polymers, blends of chitosan and protein, chitosan derivatives, as well as blends of chitosan and inorganic nanoparticles, respectively. The applications of the nanofibers containing chitosan such as enzyme immobilization, filtration, wound dressing, tissue engineering, drug delivery and catalysis are also summarized in detail.

  14. Electrospinning preparation and luminescence properties of Eu(TTA)_3phen/polystyrene composite nanofibers

    Institute of Scientific and Technical Information of China (English)

    张小萍; 温世鹏; 胡水; 张立群; 刘力

    2010-01-01

    Efficient luminescent composite nanofibers,composed of polystyrene(PS,Mw=250000) and europium complex Eu(TTA)3phen(TTA=2-thenoyltrifluoroacetone,phen=1,10-phenanthroline) with diameters ranging from 350 nm to 700 nm,were prepared by electrospinning and characterized by scanning electron microscope(SEM),Fourier transform infrared spectroscopy(FT-IR),fluorescence spectroscopy,and thermogravimetric analysis(TG).The room-temperature fluorescence spectra of the composite nanofibers were composed of the typical E...

  15. Preparation and characterization of UV-cured hybrid polyvinyl alcohol nanofiber membranes by electrospinning

    OpenAIRE

    2014-01-01

    The present study investigated the possibility of preparing polyvinyl alcoholic (PVA) organic-inorganic hybrid nanofiber membranes by electrospinning with UV irradiation. To this end, PVA, PVA/SiO2 organic-inorganic hybrid obtained with Geniosil® XL 33 as a SiO2 source, and imidazole-functionalized mesoporous PVA/SiO2/N=N nanofiber membranes were synthesized. These membranes were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, thermogravimetric-differen...

  16. Preparation of Mn 2O 3 and Mn 3O 4 nanofibers via an electrospinning technique

    Science.gov (United States)

    Shao, Changlu; Guan, Hongyu; Liu, Yichun; Li, Xiliang; Yang, Xinghua

    2004-07-01

    Thin PVA/manganese acetate composite fibers were prepared by using sol-gel processing and electrospinning technique. After calcinations of the above precursor fibers, Mn 2O 3 and Mn 3O 4 nanofibers with a diameter of 50-200 nm could be successfully obtained. The fibers were characterized by TG-DTA, Scanning electron microscopy, FT-IR, WAXD, respectively. The results showed that the crystalline phase and morphology of nanofibers were largely influenced by the calcination temperature.

  17. Preparation and characterization of carbon nanofiber-polymide composites

    Science.gov (United States)

    Li, Xiaobing

    Carbon nanofibers (CNFs) are potentially excellent reinforcements in polymer-based composites due to very good mechanical properties, thermal and electrical conductivity, and low cost to manufacture. The dispersion of fibers and the interfacial interaction with the polymer matrix need to be improved for CNF composites to achieve this potential. Treatment of the nanofiber surface with groups that are compatible with the polymer is key to addressing these issues. Attached functional groups may enhance the adhesion between reinforcement phase and matrix phase and reduce the slip of polymer chains on the surfaces of fibers. As a result, load can be transferred to fibers efficiently. In this investigation, CNFs were used as reinforcements in a polyimide (PI) matrix to produce a composite. To improve dispersion of fibers as well as interfacial adhesion, oxidized carbon nanofibers (OCNFs) were functionalized by covalently attaching 1,4-phenylenediamine (1,4-PDA) or polyimide oligomer to the surfaces. The functionalization with diamine was carried out either through direct reaction with OCNFs in dimethylacetimide (DMAc) solvent or through a two-step approach in which oxidized fibers were reacted with thionyl chloride (SOCl2) to improve surface reactivity followed by reaction with PDA in DMAc. The PDA was successfully bonded to the surfaces of fibers using both strategies. The further attachment of oligomer proceeded as expected in DMAc. The functionalized CNFs were characterized using Raman spectroscopy, thermal gravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS) to confirm the functionalization reaction. Raman spectra and XPS spectra qualitatively indicated target chemical bonds were formed in each reaction step. Quantifications of TGA and XPS consistently supported that desired chemical moieties were present on the surfaces of fibers. In short, the interfaces of fibers were tailored with groups that would mimic the structure of polyimide and can

  18. Preparation and characterization of Ce-doped ZnO nanofibers by an electrospinning method

    Directory of Open Access Journals (Sweden)

    Jong-Pil Kim

    2011-02-01

    Full Text Available ZnO and Ce-doped ZnO Nanofibers on (111 Pt/SiO2/Si substrates were produced using an electrospinning technique. The as-prepared composite fibres were subjected to high-temperature calcination to produce inorganic fibers. After calcining at a temperature of 500 °C, the average diameter of the ZnO and Ce-doped ZnO nanofibers were determined to be 170 nm and 225 nm, respectively. The average grain size of the ZnO and Ce-doped ZnO nanofibers were about 50 nm and 57 nm, respectively. The microstructure, chemical bonding state and photoluminescence of the produced ZnO and Ce-doped ZnO nanofibers were investigated. The Ce-doped ZnO nanofiber can be assigned to the presence of Ce ions on substitutional sites of Zn ions and the Ce3+ state from X-ray photoelectron spectra. Compared with PL spectra of ZnO nanofibers, the peak position of the UV emission of the Ce-doped ZnO nanofibers is sharply suppressed while the green emission band is highly enhanced.

  19. Preparation of Coaxial-Electrospun Poly[bis(p-methylphenoxy]phosphazene Nanofiber Membrane for Enzyme Immobilization

    Directory of Open Access Journals (Sweden)

    Xiao-Jun Huang

    2012-11-01

    Full Text Available A core/sheath nanofiber membrane with poly[bis(p-methylphenoxy]phospha-zene (PMPPh as the sheath and easily spinnable polyacrylonitrile (PAN as the core was prepared via a coaxial electrospinning process. Field-emission scanning electron microscopy and transmission electron microscopy were used to characterize the morphology of the nanofiber membrane. It was found that the concentration of the PAN spinning solution and the ratio of the core/sheath solution flow rates played a decisive role in the coaxial electrospinning process. In addition, the stabilized core/sheath PMPPh nanofiber membrane was investigated as a support for enzyme immobilization because of its excellent biocompatibility, high surface/volume ratio, and large porosity. Lipase from Candida rugosa was immobilized on the nanofiber membrane by adsorption. The properties of the immobilized lipase on the polyphosphazene nanofiber membrane were studied and compared with those of a PAN nanofiber membrane. The results showed that the adsorption capacity (20.4 ± 2.7 mg/g and activity retention (63.7% of the immobilized lipase on the polyphosphazene nanofiber membrane were higher than those on the PAN membrane.

  20. Preparation of Amidoxime Polyacrylonitrile Chelating Nanofibers and Their Application for Adsorption of Metal Ions

    Directory of Open Access Journals (Sweden)

    You-Lo Hsieh

    2013-03-01

    Full Text Available Polyacrylonitrile (PAN nanofibers were prepared by electrospinning and they were modified with hydroxylamine to synthesize amidoxime polyacrylonitrile (AOPAN chelating nanofibers, which were applied to adsorb copper and iron ions. The conversion of the nitrile group in PAN was calculated by the gravimetric method. The structure and surface morphology of the AOPAN nanofiber were characterized by a Fourier transform infrared spectrometer (FT-IR and a scanning electron microscope (SEM, respectively. The adsorption abilities of Cu2+ and Fe3+ ions onto the AOPAN nanofiber mats were evaluated. FT-IR spectra showed nitrile groups in the PAN were partly converted into amidoxime groups. SEM examination demonstrated that there were no serious cracks or sign of degradation on the surface of the PAN nanofibers after chemical modification. The adsorption capacities of both copper and iron ions onto the AOPAN nanofiber mats were higher than those into the raw PAN nanofiber mats. The adsorption data of Cu2+ and Fe3+ ions fitted particularly well with the Langmuir isotherm. The maximal adsorption capacities of Cu2+ and Fe3+ ions were 215.18 and 221.37 mg/g, respectively.

  1. Porous starch/cellulose nanofibers composite prepared by salt leaching technique for tissue engineering.

    Science.gov (United States)

    Nasri-Nasrabadi, Bijan; Mehrasa, Mohammad; Rafienia, Mohammad; Bonakdar, Shahin; Behzad, Tayebeh; Gavanji, Shahin

    2014-08-08

    Starch/cellulose nanofibers composites with proper porosity pore size, mechanical strength, and biodegradability for cartilage tissue engineering have been reported in this study. The porous thermoplastic starch-based composites were prepared by combining film casting, salt leaching, and freeze drying methods. The diameter of 70% nanofibers was in the range of 40-90 nm. All samples had interconnected porous morphology; however an increase in pore interconnectivity was observed when the sodium chloride ratio was increased in the salt leaching. Scaffolds with the total porogen content of 70 wt% exhibited adequate mechanical properties for cartilage tissue engineering applications. The water uptake ratio of nanocomposites was remarkably enhanced by adding 10% cellulose nanofibers. The scaffolds were partially destroyed due to low in vitro degradation rate after more than 20 weeks. Cultivation of isolated rabbit chondrocytes on the fabricated scaffold proved that the incorporation of nanofibers in starch structure improves cell attachment and proliferation.

  2. The Preparation of Chitosan Oligosaccharide/Alginate Sodium/Gelatin Nanofibers by Spiral-Electrospinning.

    Science.gov (United States)

    Lu, Weipeng; Xu, Haitao; Zhang, Bing; Ma, Ming; Guo, Yanchuan

    2016-03-01

    A spiral-electrospinning was used to mass-produce gelatin nanofibers with a content of chitosan oligosaccharide (COS) and alginate sodium (AS). Multiple jets were observed to form on the edges of the helix slice-spinneret simultaneously. Important electrospinning parameters, such as concentration of COS/gelatin aqueous solution, rotational velocity of spinneret and spinning distance, were examined to investigate the electrospinnability of COS/gelatin solution and the morphology of COS/gelatin nanofiber membranes. Due to the poor miscibility between COS and AS, COS/AS/gelatin nanofiber membranes were obtained from COS/gelatin solution and AS/gelatin solution by mixing electrospinning with multi-spinnerets. The novel needleless electrospinning not only avoided the possibility of nozzle-clogging, but also prepared COS/AS/gelatin nanofibers on a large scale for a wide variety of applications.

  3. Modified coaxial electrospinning for the preparation of high-quality ketoprofen-loaded cellulose acetate nanofibers.

    Science.gov (United States)

    Yu, Deng-Guang; Yu, Jia-Hui; Chen, Lan; Williams, Gareth R; Wang, Xia

    2012-10-01

    This study investigates the use of a modified coaxial electrospinning process in the production of drug-loaded cellulose acetate (CA) nanofibers. With CA employed as a filament-forming matrix and ketoprofen (KET) as an active pharmaceutical ingredient, modified coaxial processes using sheath fluids comprising only mixed solvents were undertaken. With a sheath-to-core flow rate ratio of 0.2:1, the nanofibers prepared from the coaxial process had a smaller average diameter, narrower size distribution, more uniform structures, and smoother surface morphologies than those generated from single fluid electrospinning. In addition, the coaxial fibers provided a better zero-order drug release profile. The use of a sheath solvent means that the core jet is subjected to electrical drawing for a longer period, facilitating homogeneous core jet solidification and retarding the formation of wrinkles on the surface of the nanofibers. This modified coaxial electrospinning protocol allows the systematic fabrication of functional polymer nanofibers with improved quality.

  4. A method for top down preparation of chitosan nanoparticles and nanofibers.

    Science.gov (United States)

    Wijesena, Ruchira N; Tissera, Nadeeka; Kannangara, Yasun Y; Lin, Yuan; Amaratunga, Gehan A J; de Silva, K M Nalin

    2015-03-01

    A method of top down preparation of chitosan nanoparticles and nanofibers is proposed. Chitin nanofibrils (chitin NFs) were prepared using ultrasonic assisted method from crab shells with an average diameter of 5 nm and the length less than 3 μm as analyzed by atomic force microscopy and transmission electron microscopy. These chitin nanofibers were used as the precursor material for the preparation of chitosan nanoparticles and nanofibers. The degree of deacetylation of these prepared chitosan nanostructures were found to be approximately 98%. In addition these chitosan nanostructures showed amorphous crystallinity. Transmission electron microscopic studies revealed that chitosan nanoparticles were roughly spherical in nature and had diameters less than 300 nm. These larger particles formed through self-assembly of much smaller 25 nm particles as evidenced by the TEM imaging. The diameter and the length of the chitosan nanofibers were found to be less than 100 nm and 3 μm respectively. It is envisaged that due to the cavitation effect, the deacetylated chitin nanofibers were broken down to small pieces to form seed particles. These seed particles can then be self-assembled to form larger chitosan nanoparticles.

  5. Preparation and characterization of porous TiO2/ZnO composite nanofibers via electrospinning

    Institute of Scientific and Technical Information of China (English)

    Hai Ying Wang; Yang Yang; Xiang Li; Li Juan Li; Ce Wang

    2010-01-01

    Porous TiO2/ZnO composite nanofibers have been successfully prepared by electrospinning technique for the first time.It was generated by calcining TiO2/ZnCl2/PVP[PVP:poly(vinyi pyrrolidone)]nanofibers,which were electrospun from a mixture solution of TiO2,ZnCl2 and PVE Transmission electron microscopy(TEM)and X-ray diffraction(XRD)analyses were used to identify the morphology of the TiO2/ZnO nanofibers and a formation of inorganic TiO2/ZnO fibers.The porous structure of the TiO2/ZnO fbers was characterized by N2 adsoption/desorption isotherm.Surface photovoltage spectroscopy(SPS)and photo-catalytic activity measurements revealed advance properties of the porous TiO2/ZnO composite nanofibers and the results were compared with pure TiO2 nanofibers,pure ZnO nanofibers and TiO2/ZnO nanoparticles.

  6. Preparation of Imprinted PVB/β-CD Nanofiber by Electrospinning Technique and Its Selective Binding Abilities for Naringin%Preparation of Imprinted PVB/β-CD Nanofiber by Electrospinning Technique and Its Selective Binding Abilities for Naringin

    Institute of Scientific and Technical Information of China (English)

    马秀玲; 陈震; 陈晓; 陈日耀; 郑曦

    2011-01-01

    A novel molecularly imprinted composite nanofiber was prepared by a simple electrospinning technique, in which polyvinylbutyral (PVB) was chosen as matrix, fl-cyclodextrin (β-CD) was used as a functional monomer and naringin (NG) as template molecules. After cross-linked by hexamethylene diisocyanate (HMDI), the composite nanofiber exhibited a high specific binding capacity. The morphological structure of the nanofibers was studied by means of infrared spectrum (IR), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The β-CD molecules were mostly homogeneously distributed within the PVB nanofiber without forming phase separated crystalline aggregates. Compared with traditional imprinted β-CD polymer, the binding experiments demonstrated that the molecularly imprinted composite nanofiber shows the specific binding sites and the selective binding ability for NG. The molecularly imprinted nanofiber could be used at least six times without any loss in binding capacity.

  7. Biotemplated preparation of CdS nanoparticles/bacterial cellulose hybrid nanofibers for photocatalysis application.

    Science.gov (United States)

    Yang, Jiazhi; Yu, Junwei; Fan, Jun; Sun, Dongping; Tang, Weihua; Yang, Xuejie

    2011-05-15

    In this work, we describe a novel facile and effective strategy to prepare micrometer-long hybrid nanofibers by deposition of CdS nanoparticles onto the substrate of hydrated bacterial cellulose nanofibers (BCF). Hexagonal phase CdS nanocrystals were achieved via a simple hydrothermal reaction between CdCl(2) and thiourea at relatively low temperature. The prepared pristine BCF and the CdS/BCF hybrid nanofibers were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), UV-vis absorption spectroscopy (UV-vis), and X-ray photoelectron spectroscopy (XPS). The results reveal that the CdS nanoparticles were homogeneously deposited on the BCF surface and stabilized via coordination effect. The CdS/BCF hybrid nanofibers demonstrated high-efficiency photocatalysis with 82% methyl orange (MO) degradation after 90 min irradiation and good recyclability. The results indicate that the CdS/BCF hybrid nanofibers are promising candidate as robust visible light responsive photocatalysts.

  8. Effect of additives on the properties of polyaniline nanofibers prepared by high gravity chemical oxidative polymerization.

    Science.gov (United States)

    Zhao, Yibo; Arowo, Moses; Wu, Wei; Chen, Jianfeng

    2015-05-12

    Polyaniline (PANI) nanofibers with improved properties were prepared by high gravity chemical oxidative polymerization in a rotating packed bed with the assistance of p-aminodiphenylamine (AD) and p-phenylenediamine (AP). The effects of reactor type, additive dosage, reaction temperature, and high-gravity level on the properties of products were investigated in detail. Three conclusions were made: (1) a small amount of additive can significantly improve some properties of the nanofibers such as uniformity, specific surface area, and specific capacitance; (2) in order to obtain high-quality nanofibers, the high-gravity level should coordinate with the reaction rate; (3) the molecular weight and conductivity of PANI decrease with the increase of additive dosage. The products have larger specific surface areas of up to 73.9 and 68.4 m(2)/g and consequently improved specific capacitance of up to 527.5 and 552 F/g for the PANI nanofibers prepared with AD and AP, respectively. However, the specific surface area and specific capacitance of pure PANI are only 49.1 m(2)/g and 333.3 F/g, respectively. This research provides a simple, reliable, and scalable method to produce PANI nanofibers of high performances.

  9. Preparation of Co3O4 Nanofibers via an Electrospinning Technique

    Institute of Scientific and Technical Information of China (English)

    Chang Lu SHAO; Hong Yu GUAN; Shang Bin WEN; Bin CHEN; Xing Hua YANG; Jian GONG; Yi Chun LIU

    2004-01-01

    Thin PVA/cobalt acetate composite fibers were prepared by using sol-gel processing and electrospinning technique.After calcination of the above precursor fibers, Co3O4 nanofibers with a diameter of 50-150 nm could be successfully obtained.The fibers were characterized by SEM, FT-IR,WAXD,respectively.

  10. Preparation of α-Fe2O3 Nanofiber via Electrospinning Process

    Institute of Scientific and Technical Information of China (English)

    SHAO Chang-lu; YANG Xing-hua; GUAN Hong-yu; YU Na; LIU Yi-chun

    2004-01-01

    A thin PVA/FeCl3 composite fiber was prepared by using sol-gel processing and electrospinning tech niques. A nanofiber of α-Fe2O3 with the diameter of 50-150 nm was obtained via high temperature calcina tion of the PVA/FeCl3 composite fiber. The material was characterized by infra-red(IR) spectroscopy, X-ray diffraction(XRD), and scanning electron microscopy(SEM). The results show that the fiber after the calci nation at 700 ℃ was a pure α-Fe2O3 nanofiber.

  11. Preparation and Characterization of Highly Aligned Carbon Nanotubes/Polyacrylonitrile Composite Nanofibers

    Directory of Open Access Journals (Sweden)

    Yanhua Song

    2017-01-01

    Full Text Available In the electrospinning process, a modified parallel electrode method (MPEM, conducted by placing a positively charged ring between the needle and the parallel electrode collector, was used to fabricate highly aligned carbon nanotubes/polyacrylonitrile (CNTs/PAN composite nanofibers. Characterizations of the samples—such as morphology, the degree of alignment, and mechanical and conductive properties—were investigated by a combination of scanning electron microscopy (SEM, transmission electron microscopy (TEM, universal testing machine, high-resistance meter, and other methods. The results showed the MPEM could improve the alignment and uniformity of electrospun CNTs/PAN composite nanofibers, and enhance their mechanical and conductive properties. This meant the successful preparation of highly aligned CNT-reinforced PAN nanofibers with enhanced physical properties, suggesting their potential application in appliances and communication areas.

  12. Room temperature ferromagnetism in undoped ZnO nanofibers prepared by electrospinning

    Energy Technology Data Exchange (ETDEWEB)

    Kumar Das, Arnab, E-mail: arnab.das@iitg.ernet.in [Department of Physics, Indian Institute of Technology Guwahati, Guwahati 781039 (India); Kar, Manoranjan, E-mail: mano@iitp.ac.in [Department of Physics, Indian Institute of Technology Patna, Patna 800013 (India); Srinivasan, Ananthakrishanan, E-mail: asrini@iitg.ernet.in [Department of Physics, Indian Institute of Technology Guwahati, Guwahati 781039 (India)

    2014-09-01

    We report ferromagnetic behavior in undoped ZnO nanofibers prepared by electrospinning a solution of zinc acetate and poly vinyl alcohol followed by annealing at 550 °C for about 90 min. X-ray diffraction patterns of the heat treated as-spun composite fibers reveal the formation of ZnO nanowires in wurtzite structure with no noticeable impurity phases. ZnO nanowires annealed between 500 °C and 600 °C exhibited room temperature ferromagnetism with decreasing magnetization with increasing annealing temperature. Room temperature ferromagnetism was observed in as-spun fibers annealed in air as well as under vacuum. However, vacuum annealed nanofibers show higher magnetization as compared to air annealed fibers, which indicates that oxygen vacancy is a cause for the observed room temperature ferromagnetism in the ZnO nanofibers.

  13. Preparation and characterization of ZnO nanofibers by electrospinning

    Energy Technology Data Exchange (ETDEWEB)

    Siddheswaran, R. [Material Research Centre, Department of Physics, Velammal Engineering College, Chennai-600066 (India); Department of Physics, Pachaiyappa' s College, Chennai- 600 030 (India); Sankar, R.; Ramesh Babu, M.; Jayavel, R. [Crystal Growth Centre, Anna University, Chennai-600 025 (India); Rathnakumari, M.; Sureshkumar, P. [Material Research Centre, Department of Physics, Velammal Engineering College, Chennai-600066 (India); Murugakoothan, P. [Department of Physics, Pachaiyappa' s College, Chennai- 600 030 (India)

    2006-05-15

    Electrospun ZnO nanofibers were obtained by calcinating PVA/Zinc Acetate composite fibers at various temperatures. Atomic Force Microscopy (AFM) revealed that the ZnO fibers have diameters in the range of 100-200 nm. The fibers were characterized by FT- IR, TGA-DTA, and XRD studies. The XRD results showed that the crystal structure and the morphology of the fibers were largely dependent on the calcination temperature (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  14. Preparation of polyvinylidene fluoride nanofiber membrane and its antibacterial characteristics with nanosilver or graphene oxide.

    Science.gov (United States)

    Hong, Byungpyo; Jung, Hyemin; Byun, Hongsik

    2013-09-01

    Polyvinylidene fluoride (PVdF) (Kynar 761) nanofibers were prepared by electrospinning at an external voltage of 6-10 kV, a traveling distance of 7-15 cm and flow rate of 0.4-1 ml/hr. Although the diameter of the fiber was not significantly changed, the electrospinning conditions affected the overall distribution of diameter. This is probably due to the interactions, both attraction and repulsion, of positive charges on polymer solutions and the electrically grounded collector. Especially, the effect of voltage on the distribution of diameter was investigated in this study. The final PVdF nanofiber membrane showed narrow pore-size distribution and high water flux compared with the commercial MF membrane. PVdF nanofiber membranes incorporated nanosilver or graphene oxide were also prepared as nanosilver and graphene have an antibacterial activity. It was found that more than 200 ppm of silver nanoparticles in the PVdF nanofiber had 99.9% of growth inhibition of Staphylococcus aureus and Klebsiella pneumonia. It was also found that 0.2 wt% of graphene oxide in the PVdF electrospinning solution had 99.6% of disinfection property to E-Coli.

  15. Preparation of Pd/Bacterial Cellulose Hybrid Nanofibers for Dopamine Detection

    Directory of Open Access Journals (Sweden)

    Dawei Li

    2016-05-01

    Full Text Available Palladium nanoparticle-bacterial cellulose (PdBC hybrid nanofibers were synthesized by in-situ chemical reduction method. The obtained PdBC nanofibers were characterized by a series of analytical techniques. The results revealed that Pd nanoparticles were evenly dispersed on the surfaces of BC nanofibers. Then, the as-prepared PdBC nanofibers were mixed with laccase (Lac and Nafion to obtain mixture suspension, which was further modified on electrode surface to construct novel biosensing platform. Finally, the prepared electrochemical biosensor was employed to detect dopamine. The analysis result was satisfactory, the sensor showed excellent electrocatalysis towards dopamine with high sensitivity (38.4 µA·mM−1, low detection limit (1.26 µM, and wide linear range (5–167 µM. Moreover, the biosensor also showed good repeatability, reproducibility, selectivity and stability and was successfully used in the detection of dopamine in human urine, thus providing a promising method for dopamine analysis in clinical application.

  16. Preparation and Characterization of Soluble Eggshell Membrane Protein/PLGA Electrospun Nanofibers for Guided Tissue Regeneration Membrane

    Directory of Open Access Journals (Sweden)

    Jun Jia

    2012-01-01

    Full Text Available Guided tissue regeneration (GTR is a widely used method in periodontal therapy, which involves the placement of a barrier membrane to exclude migration of epithelium and ensure repopulation of periodontal ligament cells. The objective of this study is to prepare and evaluate a new type of soluble eggshell membrane protein (SEP/poly (lactic-co-glycolic acid (PLGA nanofibers using electrospinning method for GTR membrane application. SEP/PLGA nanofibers were successfully prepared with various blending ratios. The morphology, chemical composition, surface wettability, and mechanical properties of the nanofibers were characterized using scanning electron microscopy (SEM, contact angle measurement, Fourier transform-infrared spectroscopy (FTIR, and a universal testing machine. L-929 fibroblast cells were used to evaluate the biocompatibility of SEP/PLGA nanofibers and investigate the interaction between cells and nanofibers. Results showed that the SEP/PLGA electrospun membrane was composed of uniform, bead-free nanofibers, which formed an interconnected porous network structure. Mechanical property of SEP has been greatly improved by the addition of PLGA. The biological study results showed that SEP/PLGA nanofibers could enhance cell attachment, spreading, and proliferation. The study indicated the potential of SEP/PLGA nanofibers for GTR application and provided a basis for future optimization.

  17. New Chitosan/Poly(ethylene oxide/Thyme Nanofiber Prepared by Electrospinning Method for Antimicrobial Wound Dressing

    Directory of Open Access Journals (Sweden)

    Minoo Sadri

    2016-10-01

    Full Text Available A new natural and environmental friendly wound dressing was introduced for the first time that was prepared by electrospinning method. This new wound dressing has chitosan base, and poly (ethylene oxide was added as co-spinning agent to improve spinnability of chitosan. Moreover, thyme extract as a natural antibacterial additive was introduced in the as electrospun nanofibers scaffold in order to increase those wound healing properties. Some parameters of electrospinning such as feed rate, nozzle-collector distance, voltage and content of thyme extract in nanofiber structure were studied and optimized. The average diameters of prepared nanofibers was determined by “Clemex vision professional edition” software. Morphology and structure of electrospun nanofibers was studied with use of scaning electorn microscopy and Fourier transform infrared spectroscopy spectroscopy. The results showed that the antibacterial activity of nanofibers increased as the amount of thyme extract was increased, thus a chitosan/PEO containing 3% of thyme extract was selected as the best prepared nanofiber for wound dressing preparation. Chitosan/PEO/thyme nanofiber showed high stability in the buffer and good antibacterial activity against three understudy bacteria including Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus.

  18. Preparation and pharmaceutical evaluation of acetaminophen nano-fiber tablets: Application of a solvent-based electrospinning method for tableting.

    Science.gov (United States)

    Hamori, Mami; Nagano, Kana; Kakimoto, Sayaka; Naruhashi, Kazumasa; Kiriyama, Akiko; Nishimura, Asako; Shibata, Nobuhito

    2016-03-01

    In this study, we developed nano-fiber-based tablets with acetaminophen (AAP; LogPow=0.51) for controlled-release delivery systems and evaluated in vitro drug dissolution and in vivo pharmacokinetics in rats. Nano-fibers made from methacrylic acid copolymer S (MAC; EUDRAGIT S100) and containing AAP were prepared using a solvent-based electrospinning (ES) method. In vitro dissolution rate profiles of AAP showed tableting pressure-dependent decreases and pH-dependent increases. The results of tablet tracking by X-ray irradiation showed tablets based on MAC nano-fibers did not disintegrate in the upper intestinal lumen and had the properties of a long-term-acting tablet. In addition, the in vitro release profiles of AAP from nano-fiber tablets prepared by dissolving MAC with AAP (NFT), nano-fiber tablets prepared by adsorbing AAP to drug-free MAC nano-fibers (NFTadso), and tablets prepared by adsorbing half the amount of AAP to MAC nano-fibers containing the remaining amount of AAP (NFThalf) showed independent controlled-release aspects of AAP compared with physical mixture tablets (PMT). In vivo pharmacokinetic studies in rats after intraduodenal administration of 14 mg/rat AAP in NFT, NFTadso, and NFThalf demonstrated that all these tablets based on MAC nano-fibers showed sustained-release profiles compared with PMT, and showed ultra-sustained release properties for AAP. These new tablets based on MAC nano-fibers did not disintegrate in the intestine in the lower pH region, and the tablets could regulate the release of AAP in a pH-dependent manner. The ES method is a useful technique to prepare nano-fibers and showed promising results as an oral delivery system for sustained-release regulation. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  19. PANI-nanofibers/polyethylene blends: preparation and properties; Blendas de nanofibras de PANI/polietileno: preparacao e propriedades

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, F.; Hubler, R.; Basso, N.R.S., E-mail: nrbass@pucrs.b [Pontificia Universidade Catolica do Rio Grande do Sul (PUC-RS), Porto Alegre, RS (Brazil); Fim, F.C.; Galland, G.B. [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil)

    2010-07-01

    In this work polyaniline nanofibers (PANI-nanofibers) were prepared via interfacial polymerization. The PANI-nanofibers were dispersed in polyethylene (PE) matrix by in situ polymerization of ethylene using Cp{sub 2}ZrCl{sub 2} [bis(cyclopentadienyl) zirconium(IV) dichloride)] and methylaluminoxane as catalytic system. The composites were characterized by infra-red spectroscopy, X-ray diffraction, thermal analysis, transmission electron microscopy and scanning electron microscopy. The results show that nanofibers with average diameters of 200 nm were synthesized and that it was obtained well dispersed PE/PANI nanocomposites. The PANI-nanofibers load did not affect the catalytic activity, but it decreased crystallinity degree of nanocomposites. (author)

  20. Preparation of electrospun Ag/g-C3N4 loaded composite carbon nanofibers for catalytic applications

    Science.gov (United States)

    Yu, Bo; Liu, Yongkun; Jiang, Guohua; Liu, Depeng; Yu, Weijiang; Chen, Hua; Li, Lei; Huang, Qin

    2017-01-01

    In this paper, the electrospun Ag nanoparticles and g-C3N4 (Ag/g-C3N4) loaded composite carbon nanofibers were successfully prepared combing the electrospinning technology and carbonization treatment. The composition and microstructure of the resultant composite nanofibers were characterized by x-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), energy dispersive spectrometer (EDS), transmission electron microscopy (TEM) and x-ray photoelectron spectrometry (XPS). Due to the synergistic effect between catalytic activity of Ag nanoparticles (NPs) and g-C3N4 and excellent adsorption capacity of carbon nanofibers, the resultant electrospun Ag/g-C3N4 loaded composite carbon nanofibers exhibited excellent conversion of 4-nitrophenol to 4-aminophenol and benzylamine to N-benzylbenzaldimine. The resultant hybrid carbon composite nanofibers offer the significant advantages, such as low dosage, high catalytic activity, easy recycling and excellent stability.

  1. Preparation and Characterization of Cellulose Nanofibers from Two Commercial Hardwood and Softwood Pulps

    DEFF Research Database (Denmark)

    Stelte, Wolfgang; Sanadi, Anand R.

    2009-01-01

    The aim of this work was to study the mechanical fibrillation process for the preparation of cellulose nanofibers from two commercial hard- and softwood cellulose pulps. The process consisted of initial refining and subsequent high-pressure homogenization. The progress in fibrillation was studied...... using different microscopy techniques, mechanical testing, and fiber density measurements of cellulose films prepared after different processing stages. The mechanical properties of cellulose films showed an increase in strength and stiffness with decreasing fiber size, and this stabilized after...... a certain number of passes in the homogenizer. Atomic force microscopy studies showed that the obtained cellulose nanofibers had diameters in the 10−25-nm range. The significant difference between the two samples was that the ultimate failure strain for cellulose films made of softwood fibers increased...

  2. Preparation of polysilsesquioxane-urethaneacrylate copolymer film reinforced with chitin nanofibers.

    Science.gov (United States)

    Ifuku, Shinsuke; Ikuta, Akiko; Hosomi, Tetsuya; Kanaya, Shingo; Shervani, Zameer; Morimoto, Minoru; Saimoto, Hiroyuki

    2012-07-01

    Chitin nanofibers (CNFs) reinforced silsesquioxane-urethaneacrylate (SSQ-UA) copolymer films were prepared. CNFs-SSQ-UA nanocomposite films were highly transparent due to the filling of nanometer sized (10-20 nm) CNFs inside the hybrid organic-inorganic SSQ-UA copolymer. CNFs due to their crystalline structure drastically increased Young's moduli and the tensile strengths of the composite and decreased the thermal expansion. High thermal stability of polysilsesquioxane improved heat resistance of CNFs.

  3. Preparation of flexible zinc oxide/carbon nanofiber webs for mid-temperature desulfurization

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Soojung; Bajaj, Bharat [Carbon Convergence Materials Research Center, Institute of Advanced Composite Materials, Korea Institute of Science and Technology, San 101, Eunha-ri, Bongdong-eup, Wanju-gun, Jeollabuk-do 565-905 (Korea, Republic of); Byun, Chang Ki; Kwon, Soon-Jin [Department of Chemical Engineering Education, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon 305-764 (Korea, Republic of); Joh, Han-Ik [Carbon Convergence Materials Research Center, Institute of Advanced Composite Materials, Korea Institute of Science and Technology, San 101, Eunha-ri, Bongdong-eup, Wanju-gun, Jeollabuk-do 565-905 (Korea, Republic of); Yi, Kwang Bok, E-mail: cosy32@cnu.ac.kr [Department of Chemical Engineering Education, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon 305-764 (Korea, Republic of); Lee, Sungho, E-mail: sunghol@kist.re.kr [Carbon Convergence Materials Research Center, Institute of Advanced Composite Materials, Korea Institute of Science and Technology, San 101, Eunha-ri, Bongdong-eup, Wanju-gun, Jeollabuk-do 565-905 (Korea, Republic of); Department of Nano Material Engineering, University of Science and Technology, Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136-791 (Korea, Republic of)

    2014-11-30

    Graphical abstract: - Highlights: • Polyacrylonitrile (PAN) and zinc precursor were electrospun and heat-treated for preparing zinc oxide (ZnO) modified carbon nanofibers (CNF). • A facile synthesis of composite webs resulted in uniformly loaded ZnO on the surface of CNFs. • The composites showed significant hydrogen sulfide adsorption efficiency at 300 °C. • The flexible webs can be applied for mid-temperature desulfurization. - Abstract: Polyacrylonitrile (PAN) derived carbon nanofiber (CNF) webs loaded with zinc oxide (ZnO) were synthesized using electrospinning and heat treatment at 600 °C. Uniformly dispersed ZnO nanoparticles, clarified by X-ray diffraction and scanning electron microscopy, were observed on the surface of the nanofiber composites containing 13.6–29.5 wt% of ZnO. The further addition of ZnO up to 34.2 wt% caused agglomeration with a size of 50–80 nm. Higher ZnO contents led the concentrated ZnO nanoparticles on the surface of the nanofibers rather than uniform dispersion along the cross-section of the fiber. The flexible composite webs were crushed and tested for hydrogen sulfide (H{sub 2}S) adsorption at 300 °C. Breakthrough experiments with the ZnO/CNF composite containing 25.7 wt% of ZnO for H{sub 2}S adsorption showed three times higher ZnO utilization efficiency compared to pure ZnO nano powders, attributed to chemisorption of the larger surface area of well dispersed ZnO particles on nanofibers and physical adsorption of CNF.

  4. Preparation of core-shell PAN nanofibers encapsulated α-tocopherol acetate and ascorbic acid 2-phosphate for photoprotection.

    Science.gov (United States)

    Wu, Xiao-Mei; Branford-White, Christopher J; Yu, Deng-Guang; Chatterton, Nicholas P; Zhu, Li-Min

    2011-01-01

    Magnesium l-ascorbic acid 2-phosphate (MAAP) and α-tocopherol acetate (α-TAc), as the stable vitamin C and vitamin E derivative, respectively, are often applied to skin care products for reducing UV damage. The encapsulation of MAAP (0.5%, g/mL) and α-TAc (5%, g/mL) together within the polyacrylonitrile (PAN) nanofibers was demonstrated using a coaxial electrospinning technique. The structure and morphology characterizations of the core-shell fibers MAAP/α-TAc-PAN were investigated by SEM, FTIR and XRD. As a negative control, the blend nanofibers MAAP/α-TAc/PAN were prepared from a normal electrospinning method. The results from SEM indicated that the morphology and diameter of the nanofibers were influenced by concentration of spinning solution, the polymer component of the shell, the carrying agent of the core and the fabricating methods, and the core-shell nanofibers obtained at the concentration of 8% had finer and uniform structure with the average diameters of 200 ± 15nm. From in vitro release studies it could be seen that both different fiber specimens showed a gradual increase in the amount of α-TAc or MAAP released from the nanofibers. Furthermore, α-TAc and MAAP released from the blend nanofibers showed the burst release at the maximum release of ∼15% and ∼40% during the first 6h, respectively, but their release amount from the core-shell nanofibers was only 10-12% during the initial part of the process. These results showed that core-shell nanofibers alleviated the initial burst release and gave better sustainability compared to that of the blend nanofibers. The present study would provide a basis for further optimization of processing conditions to obtain desired structured core-shell nanofibers and release kinetics for practical applications in dermal tissue.

  5. Protein/CaCO3/Chitin Nanofiber Complex Prepared from Crab Shells by Simple Mechanical Treatment and Its Effect on Plant Growth

    Directory of Open Access Journals (Sweden)

    Yihun Fantahun Aklog

    2016-09-01

    Full Text Available A protein/CaCO3/chitin nanofiber complex was prepared from crab shells by a simple mechanical treatment with a high-pressure water-jet (HPWJ system. The preparation process did not involve chemical treatments, such as removal of protein and calcium carbonate with sodium hydroxide and hydrochloric acid, respectively. Thus, it was economically and environmentally friendly. The nanofibers obtained had uniform width and dispersed homogeneously in water. Nanofibers were characterized in morphology, transparency, and viscosity. Results indicated that the shell was mostly disintegrated into nanofibers at above five cycles of the HPWJ system. The chemical structure of the nanofiber was maintained even after extensive mechanical treatments. Subsequently, the nanofiber complex was found to improve the growth of tomatoes in a hydroponics system, suggesting the mechanical treatments efficiently released minerals into the system. The homogeneous dispersion of the nanofiber complex enabled easier application as a fertilizer compared to the crab shell flakes.

  6. Preparation of animal polysaccharides nanofibers by electrospinning and their potential biomedical applications.

    Science.gov (United States)

    Zhao, Wen; Liu, Wenlong; Li, Jiaojiao; Lin, Xiao; Wang, Ying

    2015-02-01

    Animal polysaccharides belong to a class of biological macromolecules. They are natural biopolymers with numerous advantages for biomedical applications, such as biocompatibility, biodegradability, non-antigenicity and non-toxicity. Electrospinning is a versatile and facile technique which can produce continuous fibers with nanoscale from a wide range of natural and synthetic polymers. The review aims to provide an up-to-date overview of the preparation of animal polysaccharides nanofibers by electrospinning and their potential biomedical applications such as tissue engineering, wound healing, and drug delivery. Various animal polysaccharides including chitin and chitosan (CS), hyaluronic acid (HA), heparin and heparan sulfate (HS), and chondroitin sulfate (ChS), are discussed. The challenges and some useful strategies in electrospinning of animal polysaccharides also are summarized. In addition, future study of animal polysaccharides nanofibers by electrospinning is proposed.

  7. Polymer nanofibers prepared by low-voltage near-field electrospinning

    Institute of Scientific and Technical Information of China (English)

    Zheng Jie; Long Yun-Ze; Sun Bin; Zhang Zhi-Hua; Shao Feng; Zhang Hong-Di; Zhang Zhi-Ming; Huang Jia-Yin

    2012-01-01

    Electrospinning is a straightforward method to produce micro/nanoscale fibers from polymer solutions typically using an operating voltage of 10 kV-30 kV and spinning distance of 10 cm-20 cm.In this paper,polyvinyl pyrrolidone (PVP) non-woven nanofibers with diameters of 200 nm-900 nm were prepared by low-voltage near-field electrospinning with a working voltage of less than 2.8 kV and a spinning distance of less than 10 mm.Besides the uniform fibers,beaded-fibers were also fabricated and the formation mechanism was discussed.Particularly,a series of experiments were carried out to explore the influence of processing variables on the formation of near-field electrospun PVP nanofibers,including concentration,humidity,collecting position,and spinning distance.

  8. Adsorption behavior of Cu(II) onto titanate nanofibers prepared by alkali treatment.

    Science.gov (United States)

    Li, Nian; Zhang, Lide; Chen, Yongzhou; Tian, Yue; Wang, Huimin

    2011-05-15

    Novel low-cost adsorbents of titanate nanofibers with formula Na(x)H(2-x)Ti(3)O(7) · nH(2)O have been prepared by alkali treatment for Cu(II) removal from aqueous solutions. The nanofibers have structures in which three edge-shared TiO(6) octahedras join at the corners to form stepped, zigzag Ti(3)O(7)(2-) layers. The sodium cations located between the layers are exchangeable. The results of batch adsorption experiments suggest that the nanofibers with high sodium content can be effective adsorbents for Cu(II) removal. Effects of several important factors such as Na amount in adsorbents, pH, temperature, contact time and initial concentration are systematically studied. Results show that the adsorption is highly pH-dependent and the removal is almost complete (99.8%) for initial concentration under 100mg/l at pH 4. Equilibrium adsorption follows Langmuir isotherms well and the maximum Cu(II) uptake calculated is 167.224 mg/g. The adsorption kinetics can be explained by pseudo-second-order model well and the time needed for equilibrium is 180 min. Thermodynamic study indicates that the adsorption is spontaneous and endothermic. Desorption of Cu(II) from adsorbents using EDTA-2Na solutions exhibits a high efficiency and the adsorbents can be used repeatedly. These results demonstrate that the titanate nanofibers are readily prepared, enabling promising applications for the removal of Cu(II) from aqueous solutions.

  9. Adsorption behavior of Cu(II) onto titanate nanofibers prepared by alkali treatment

    Energy Technology Data Exchange (ETDEWEB)

    Li, Nian [Key Laboratory of Materials Physics, Anhui Key laboratory of Nanomaterials and Nanostructure, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031 (China); Zhang, Lide, E-mail: ldzhang@issp.ac.cn [Key Laboratory of Materials Physics, Anhui Key laboratory of Nanomaterials and Nanostructure, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031 (China); Chen, Yongzhou; Tian, Yue; Wang, Huimin [Key Laboratory of Materials Physics, Anhui Key laboratory of Nanomaterials and Nanostructure, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031 (China)

    2011-05-15

    Novel low-cost adsorbents of titanate nanofibers with formula Na{sub x}H{sub 2-x}Ti{sub 3}O{sub 7}.nH{sub 2}O have been prepared by alkali treatment for Cu(II) removal from aqueous solutions. The nanofibers have structures in which three edge-shared TiO{sub 6} octahedras join at the corners to form stepped, zigzag Ti{sub 3}O{sub 7}{sup 2-} layers. The sodium cations located between the layers are exchangeable. The results of batch adsorption experiments suggest that the nanofibers with high sodium content can be effective adsorbents for Cu(II) removal. Effects of several important factors such as Na amount in adsorbents, pH, temperature, contact time and initial concentration are systematically studied. Results show that the adsorption is highly pH-dependent and the removal is almost complete (99.8%) for initial concentration under 100 mg/l at pH 4. Equilibrium adsorption follows Langmuir isotherms well and the maximum Cu(II) uptake calculated is 167.224 mg/g. The adsorption kinetics can be explained by pseudo-second-order model well and the time needed for equilibrium is 180 min. Thermodynamic study indicates that the adsorption is spontaneous and endothermic. Desorption of Cu(II) from adsorbents using EDTA-2Na solutions exhibits a high efficiency and the adsorbents can be used repeatedly. These results demonstrate that the titanate nanofibers are readily prepared, enabling promising applications for the removal of Cu(II) from aqueous solutions.

  10. Preparation of LiCoO2 nanofibers by electrospinning technique

    Science.gov (United States)

    Shao, Changlu; Yu, Na; Liu, Yichun; Mu, Rixiang

    2006-07-01

    Using a sol gel processing and electrospinning technique, extrathin fibers of PVA (polyvinyl alcohol)/lithium chloride/cobalt acetate composite were prepared. After calcinations of the above precursor fibers at 600°C, LiCoO2 nanofibers with a diameter of 100 150 nm, were successfully obtained. Measurements of TG/DTA, IR, XRD, Raman, SEM, EDS, respectively, were performed to characterize the properties of the as-prepared materials. We observed a strong correlation between crystalline phase and morphology of the fibers and calcinations temperature.

  11. Preparation of Polyacrylonitrile/Ferrous Chloride Composite Nanofibers by Electrospinning for Efficient Reduction of Cr(VI).

    Science.gov (United States)

    Zhou, Shilin; Liu, Fang; Zhang, Qian; Chen, Bor-Yann; Lin, Chin-Jung; Chang, Chang-Tang

    2015-08-01

    In this study, A novel adsorbent material of polyacrylonitrile (PAN)/ferrous chloride (FeCl2) composite nanofibers is prepared by electrospinning, a simple and effective method. The obtained composite nanofibers have a non-uniform morphology and structure and a large specific surface area of 13.8 m2 g-1. Fourier transform infrared spectroscopy (FTIR) revealed that Fe2+ was successful introduced into the composite nanofibers. Furthermore, the PAN/FeC12 composite nanofibers exhibited excellent performance in Cr removal, especially when reacted with reduction from a Cr(VI) standard containing solution, which has much faster removal efficiency than the previous report of Lin et al. (2011). The results of the adsorption isotherm show that the data fitted well to the Langmuir isotherm model. The maximum adsorption of chromium ions composite nanofibers is 108 mgCr/gFeCl2. An attempted model prediction of the transient dynamics of adsorption-desorption elucidated the feasible kinetic analysis of Cr6+ from the PAN/FeCl2 composite nanofibers. This kinetic modeling can be used both for adsorption of heavy metals wastewater and for organic-adsorption and biosorption of diverse wastewaters. The PAN/FeCl2 composite nanofibers producted in this study exhibit high efficiency in Cr(VI) removal from wastewater, and may be used as a reference for future investigation.

  12. Preparation and electrochemical properties of carbon-coated LiFePO4 hollow nanofibers

    Science.gov (United States)

    Wei, Bin-bin; Wu, Yan-bo; Yu, Fang-yuan; Zhou, Ya-nan

    2016-04-01

    Carbon-coated LiFePO4 hollow nanofibers as cathode materials for Li-ion batteries were obtained by coaxial electrospinning. X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Brunauer-Emmett-Teller specific surface area analysis, galvanostatic charge-discharge, and electrochemical impedance spectroscopy (EIS) were employed to investigate the crystalline structure, morphology, and electrochemical performance of the as-prepared hollow nanofibers. The results indicate that the carbon-coated LiFePO4 hollow nanofibers have good long-term cycling performance and good rate capability: at a current density of 0.2C (1.0C = 170 mA·g-1) in the voltage range of 2.5-4.2 V, the cathode materials achieve an initial discharge specific capacity of 153.16 mAh·g-1 with a first charge-discharge coulombic efficiency of more than 97%, as well as a high capacity retention of 99% after 10 cycles; moreover, the materials can retain a specific capacity of 135.68 mAh·g-1, even at 2C.

  13. Preparation and electrochemical properties of carbon-coated LiFePO4 hollow nanofibers

    Institute of Scientific and Technical Information of China (English)

    Bin-bin Wei; Yan-bo Wu; Fang-yuan Yu; Ya-nan Zhou

    2016-01-01

    Carbon-coated LiFePO4 hollow nanofibers as cathode materials for Li-ion batteries were obtained by coaxial electrospinning. X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Brunauer–Emmett–Teller specific surface area analysis, galvanostatic charge–discharge, and electrochemical impedance spectroscopy (EIS) were employed to investigate the crystalline structure, morphology, and electrochemical performance of the as-prepared hollow nanofibers. The results indicate that the carbon-coated LiFePO4 hollow nanofibers have good long-term cycling performance and good rate capability:at a current density of 0.2C (1.0C=170 mA·g−1) in the voltage range of 2.5–4.2 V, the cathode materials achieve an initial discharge specific capacity of 153.16 mAh·g−1 with a first charge–discharge coulombic efficiency of more than 97%, as well as a high capacity retention of 99%after 10 cycles;moreover, the materi-als can retain a specific capacity of 135.68 mAh·g−1, even at 2C.

  14. Preparation of asiaticoside-loaded coaxially electrospinning nanofibers and their effect on deep partial-thickness burn injury.

    Science.gov (United States)

    Zhu, Lifei; Liu, Xiaoyan; Du, Lina; Jin, Yiguang

    2016-10-01

    Sodium alginate and chitosan were in favor of wound healing. However, the two polymers were not compatible in one formulation due to the electrostatic interaction. Coaxially electrospinning technology could make two or more noneletrospun polymers to be electrospun in independent core and shell layer. Asiaticoside-loaded coaxially electrospinning nanofibers of alginate, polyvinyl alcohol (PVA) and chitosan (alginate/PVA/chitosan) were prepared and evaluated. Morphologies and microstructure of nanofibers were observed with scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Drug release in vitro of coaxial nanofibers was also evaluated. Deep partial-thickness burn injury were established and used to evaluate the improved healing effect of asiaticoside-loaded coaxial nanofibers. Drug-loaded coaxial nanofibers prepared with the optimized formulations and technologies had the obvious core-shell structure. Coaxial nanofibers showed faster drug release profiles in vitro and this facilitated wound healing. Its healing effect on rats with deep partial-thickness burn injury was also significant based on morphology, wound healing ratio, and pathological sections. Positive expression of vascular endothelial growth factor (VEGF), cluster of differentiation 31 (CD31), and proliferating cell nuclear antigen (PCNA), and down regulation of tumor necrosis factor (TNF) and interleukin-6 (IL-6) also validated the improved effect of wound healing. In general, the asiaticoside-loaded coaxial nanofibers had obvious core-shell structure with smooth surface and uniform diameter. Its healing effect on deep partial-thickness burn injury of rats was obvious. Asiaticoside-loaded coaxial nanofibers provide a novel promising option for treatment of deep partial-thickness burn injury.

  15. High Yield Preparation Method of Thermally Stable Cellulose Nanofibers

    Directory of Open Access Journals (Sweden)

    Hongli Zhu

    2014-02-01

    Full Text Available The preparation of nanocellulose fibers (NFs is achieved through pretreating cellulose in a NaOH/urea/thiourea solution, and then defibrillating the fibers through ultrasonication, resulting in a high yield of 85.4%. Extensive work has been done to optimize the preparation parameters. The obtained NFs are about 30 nm in diameter with cellulose II crystal structure. They possess high thermal stability with an onset of thermal degradation at 270 °C and a maximum degradation temperature of 370 °C. Such NFs have potential applications in transistors and batteries with high thermal stability. NFs-H were obtained by homogenizing undefibrillated fibers separated from the preparation of NFs. NFs-H were also in cellulose II crystal form but with lower thermal stability due to low crystallinity. They can be applied to make highly transparent paper.

  16. Preparation and evaluation of electrospun nanofibers containing pectin and time-dependent polymers aimed for colonic drug delivery of celecoxib

    Directory of Open Access Journals (Sweden)

    A. Akhgari

    2016-01-01

    Full Text Available Objective(s:The aim of this study was to prepare electrospun nanofibers of celecoxib using combination of time-dependent polymers with pectin to achieve a colon-specific drug delivery system for celecoxib. Materials and Methods:Formulations were produced based on two multilevel 22 full factorial designs. The independent variables were the ratio of drug:time-dependent polymer (X1 and the amount of pec­tin in formulations (X2. Electrospinning process was used for preparation of nanofibers. The spinning solutions were loaded in 5 mL syringes. The feeding rate was fixed by a syringe pump at 2.0 mL/h and a high voltage supply at range 10-18 kV was applied for electrospinning. Electrospun nanofibers were collected and evaluated by scanning electron microscopy and drug release in the acid and buffer with pH 6.8 with and without pectinase. Results:Electrospun nanofibers of celecoxib with appropriate morphological properties were produced via electrospinning process. Drug release from electrospun nanofibers was very low in the acidic media; while, drug release in the simulated colonic media was the highest from formulations containing pectin. Conclusion: Formulation F2 (containing drug:ERS with the ratio of 1:2 and 10% pectin exhibited acceptable morphological characteristics and protection of drug in the upper GI tract and could be a good candidate as a colonic drug delivery system for celecoxib.

  17. Durable antibacterial Ag/polyacrylonitrile (Ag/PAN) hybrid nanofibers prepared by atmospheric plasma treatment and electrospinning

    Science.gov (United States)

    Durable antibacterial Ag/polyacrylonitrile (Ag/PAN) hybrid nanofibers were prepared by atmospheric plasma treatment and electrospinning. Atmospheric helium plasma treatment was first used to reduce the silver nitrate precursor in pre-electrospinning solutions into metallic silver nanoparticles, foll...

  18. Synthesis of organic-inorganic hybrid azobenzene materials for the preparation of nanofibers by electrospinning

    Science.gov (United States)

    Bućko, Aleksandra; Zielińska, Sonia; Ortyl, Ewelina; Larkowska, Maria; Barille, Regis

    2014-12-01

    The new photochromic hybrid materials containing different mole fractions of highly photoactive 4-[(E)-[4-[ethyl(2-hydroxyethyl)amino]phenyl]azo]-N-(4-methylpyrimidin-2-yl)benzenesulfonamide (SMERe) were prepared by a low temperature sol-gel process. The guest-host systems with triethoxyphenylsilane matrix were obtained. These materials were used to form thin transparent films by a spin-coating technique. Then the ability of thin hybrid films to reversible trans-cis photoisomerization under illumination was investigated using ellipsometry and UV-Vis spectroscopy. The reversible changes of refractive index of the films under illumination were in the range of 0.005-0.056. The maximum absorption of these materials was located at 462-486 nm. Moreover, the organic-inorganic azobenzene materials were used to form nanofibers by electrospinning using various parameters of the process. The microstructure of electrospun fibers depended on sols properties (e.g. concentration and viscosity of the sols) and process conditions (e.g. the applied voltage, temperature or type of the collector) at ambient conditions. The morphology of obtained nanofibers was analyzed by an optical microscopy and scanning electron microscopy. In most instances, the beadless fibers were obtained. The wettability of the surface of electrospun fibers deposited on glass substrates was investigated.

  19. Fabrication and optical properties of Y2O3: Eu3+ nanofibers prepared by electrospinning.

    Science.gov (United States)

    Dong, Guoping; Chi, Yingzhi; Xiao, Xiudi; Liu, Xiaofeng; Qian, Bin; Ma, Zhijun; Wu, E; Zeng, Heping; Chen, Danping; Qiu, Jianrong

    2009-12-07

    Y(2)O(3): Eu(3+) nanofibers with the average diameter of ~300 nm were in situ fabricated by electrospinning. X-ray diffraction (XRD) pattern confirmed that the Y(2)O(3): Eu(3+) nanofibers were composed of pure body-centered cubic (bcc) Y(2)O(3) phase. High-resolution transmission electron microscopy (HRTEM) results indicated that Y(2)O(3): Eu(3+) nanofibers were constituted of nonspherical crystalline grains, and these crystalline grains were orderly arranged along the axial direction of single nanofiber. These Y(2)O(3): Eu(3+) nanofibers showed a partially polarized photoluminescence (PL). The arrangement of crystalline grains and the mismatch of dielectric constant between Y(2)O(3): Eu(3+) nanofiber and its environment probably contributed together to the polarized PL from Y(2)O(3): Eu(3+) nanofiber.

  20. Preparation of Electrospun Nanocomposite Nanofibers of Polyaniline/Poly(methyl methacrylate with Amino-Functionalized Graphene

    Directory of Open Access Journals (Sweden)

    Hanan Abdali

    2017-09-01

    Full Text Available In this paper we report upon the preparation and characterization of electrospun nanofibers of doped polyaniline (PANI/poly(methyl methacrylate (PMMA/amino-functionalized graphene (Am-rGO by electrospinning technique. The successful functionalization of rGO with amino groups is examined by Fourier transforms infrared (FTIR, X-ray photoelectron spectroscopy (XPS and Raman microspectrometer. The strong electric field enables the liquid jet to be ejected faster and also contributes to the improved thermal and morphological homogeneity of PANI/PMMA/Am-rGO. This results in a decrease in the average diameter of the produced fibers and shows that these fibers can find promising uses in many applications such as sensors, flexible electronics, etc.

  1. Preparation and photoluminescence characteristics of Tb-, Sm- and Dy-doped Y{sub 2}O{sub 3} nanofibers by electrospinning

    Energy Technology Data Exchange (ETDEWEB)

    Li Xiaoyan; Chen Yuming [College of Chemistry and Materials Science, College of Environmental Science and Engineering, Fujian Normal University, Fuzhou 350007 (China); Fujian Modified Plastic Institute of Research and Technology Development, Fuzhou 350007 (China); Fujian Engineering Research Center of Environment-friendly Polymer Material, Fuzhou 350007 (China); Qian Qingrong, E-mail: qrqian@fjnu.edu.cn [College of Chemistry and Materials Science, College of Environmental Science and Engineering, Fujian Normal University, Fuzhou 350007 (China); Fujian Modified Plastic Institute of Research and Technology Development, Fuzhou 350007 (China); Fujian Engineering Research Center of Environment-friendly Polymer Material, Fuzhou 350007 (China); Liu Xinping; Xiao Liren [College of Chemistry and Materials Science, College of Environmental Science and Engineering, Fujian Normal University, Fuzhou 350007 (China); Fujian Modified Plastic Institute of Research and Technology Development, Fuzhou 350007 (China); Fujian Engineering Research Center of Environment-friendly Polymer Material, Fuzhou 350007 (China); Chen Qinghua, E-mail: cqhuar@pub5.fz.fj.cn [College of Chemistry and Materials Science, College of Environmental Science and Engineering, Fujian Normal University, Fuzhou 350007 (China); Fujian Modified Plastic Institute of Research and Technology Development, Fuzhou 350007 (China); Fujian Engineering Research Center of Environment-friendly Polymer Material, Fuzhou 350007 (China)

    2012-01-15

    An electrospinning-calcination strategy was established to fabricate Y{sub 2}O{sub 3} nanofibers doped with rare earth ions (Tb, Sm and Dy) using electrospun PVA/RE(NO{sub 3}){sub x}/Y(NO{sub 3}){sub 3} composite nanofibers as precursors (x=3.4). The prepared nanofibers were characterized by XRD, FESEM, EDS, (HR)TEM and PL analyses. Based on the experimental results, a solid-solid growth mechanism (SS) was proposed to describe the formation of inorganic crystalline fibers from organic/inorganic composite nanofibers by calcination. It was determined that carbonaceous nanoparticles that were formed in the process of pre-carbonization adsorbed Y{sub 2}O{sub 3}:RE nanoparticles to grow Y{sub 2}O{sub 3}:RE crystal, and the resultant nanofibers exhibited a typical crystalline domain with grain boundary. The obtained Y{sub 2}O{sub 3}:RE nanofibers possessed excellent luminescent characteristics and could be used as an appreciable luminescent material. - Highlights: > Fabricate Y{sub 2}O{sub 3}:RE fibers by the calcination of electrospun PVA/Y(NO{sub 3}){sub 3}/RE(NO{sub 3}){sub 3} composite nanofibers. > Prepared Y{sub 2}O{sub 3}:RE nanofibers display more intensive photoluminescence performance than the bulk materials. > Propose a solid-solid growth mechanism for the formation of inorganic crystalline fibers via calciation.

  2. Preparation and Photocatalysis of Mesoporous TiO2 Nanofibers via an Electrospinning Technique

    Institute of Scientific and Technical Information of China (English)

    WANG Wei; YUAN Qing; CHI Yue; SHAO Chang-lu; LI Nan; LI Xiao-tian

    2012-01-01

    Mesoporous TiO2 nanofibers have been synthesized by a new method that combines sol-gel chemistry and electrospinning technique.The obtained mesoporous TiO2 nanofibers were characterized with scanning electron microscopy(SEM),X-ray diffraction(XRD),transmission electron microscopy(TEM) and nitrogen adsorptiondesorption isotherms.The photocatalytic performance was evaluated by the photocatalytic degradation of Rhodamine B undcr UV light irradiation.The results show that mesoporous TiO2 nanofibers exhibit higher photocatalytic activity compared with nonporous TiO2 nanofibers.

  3. Preparation and Application as the Filler for Elastomers of Flake-Shaped Cellulose Particles and Nanofibers

    Science.gov (United States)

    Nagatani, Asahiro; Lee, Seung-Hwan; Endo, Takashi; Tanaka, Tatsuya

    Fibrous cellulose made from wood pulp was mechanically milled into flake-shaped cellulose particles(FS-CPs) using a planetary ball mill with additives under several conditions. The average particle diameter of the FS-CPs was ca. 15μm, and the particles were available in a variety of thicknesses by changing the kind of the additives used in the milling process. FS-CPs-reinforced olefinic thermoplastic elastomer composites were prepared under melt mixing and passed through an open roll to orient the particles. The tensile modulus of the composites with a compatibilizer increased with increasing the particle content. The damping properties of the composites improved, compared to the neat elastomer. On the other hand, the fibrous cellulose was suspended in water, followed by wet disk-milled to prepare cellulose nanofibers(CNFs). The wet ground products showed nanoscopic fine morphology. CNFs-reinforced natural rubber(NR) composites were prepared by mixing the water suspension of CNFs with NR latex using a homogenizer. Then, it was dried in an oven and mixed again with vulcanizing ingredients of rubber using an open roll. The tensile properties of the composites improved remarkably by the addition of small amount of CNFs.

  4. Coaxial Electrospinning Method for the Preparation of TiO2 @CdS/PVA Composite Nanofiber Mat and Investigation on its Photodegradation Catalysis.

    Science.gov (United States)

    Luo, Yanmei; Jia, Yiru; Zhang, Dexian; Cheng, Xinjian

    2016-07-01

    TiO2 /PVA composite nanofiber mat was prepared via an electrospinning technology. SH-TiO2 -SiO2 hybrid particles and PVA solution were injected through a coaxial syringe, yielding a composite nanofiber mat. The as-prepared SH-TiO2 -SiO2 /PVA composite nanofiber mat was immersed in Cd(2+) cation solution and S(2-) anion solution in turn. Thus, yellow TiO2 @CdS/PVA composite nanofiber mats were prepared. By adjusting the number of times a mat was immersed in the Cd(2+) and S(2-) solutions, different amounts of CdS particles attaching to the mats were obtained. Both SH-TiO2 -SiO2 /PVA and TiO2 @CdS/PVA composite nanofiber mats were employed to catalyze the photodegradation of a model dye, methylene blue. The photodegradation performance could be greatly enhanced by the introduction of CdS particles anchoring onto TiO2 particles. The photodegradation efficiency reached 99.2% within 180 min. Also, the nanofiber mat could be recycled and reused at least 10 times. The photodegradation efficiency of TiO2 @CdS/PVA composite nanofiber mats remained 68.8% for 10 cycles.

  5. Characterization and application of zeolitic imidazolate framework-8@polyvinyl alcohol nanofibers mats prepared by electrospinning

    Science.gov (United States)

    Fan, Xiaoxiao; Yu, Linling; Li, Lianghao; Yang, Cao; Wen, Junjie; Ye, Xiaokun; Cheng, Jianhua; Hu, Yongyou

    2017-02-01

    In this study, Zeolitic imidazolate framework-8@polyvinyl alcohol (ZIF-8@PVA) nanofibers were creatively fabricated by electrospinning technique, and the nanofibers membranes were characterized by SEM, TEM, XRD, FTIR, TG, DSC, DTA, BET. Its thermal stability, mechanical property, water stability and adsorption nature were also performed. The optimized fabrication parameter of the ZIF-8@PVA was 10 wt% and the uniform diameters of the nanofibers has been obtained. In addition, the ZIF-8@PVA nanofibers displayed unique properties such as a water stable and flexible structure. The adsorption test for Congo red treatment revealed that the nanofibers had a great adsorption performance. The results indicated that the nonwoven fiber mats had a great potential as a new type of membrane adsorbents in wastewater purification. The possible mechanism of CR adsorption onto ZIF-8@PVA was researched.

  6. Release of Bacteriocins from Nanofibers Prepared with Combinations of Poly(D,L-lactide (PDLLA and Poly(Ethylene Oxide (PEO

    Directory of Open Access Journals (Sweden)

    Leon Dicks

    2011-03-01

    Full Text Available Plantaricin 423, produced by Lactobacillus plantarum, and bacteriocin ST4SA produced by Enterococcus mundtii, were electrospun into nanofibers prepared from different combinations of poly(D,L-lactide (PDLLA and poly(ethylene oxide (PEO dissolved in N,N-dimethylformamide (DMF. Both peptides were released from the nanofibers with a high initial burst and retained 88% of their original antimicrobial activity at 37 °C. Nanofibers have the potential to serve as carrier matrix for bacteriocins and open a new field in developing controlled antimicrobial delivery systems for various applications.

  7. Release of bacteriocins from nanofibers prepared with combinations of poly(d,l-lactide) (PDLLA) and poly(ethylene oxide) (PEO).

    Science.gov (United States)

    Heunis, Tiaan; Bshena, Osama; Klumperman, Bert; Dicks, Leon

    2011-01-01

    Plantaricin 423, produced by Lactobacillus plantarum, and bacteriocin ST4SA produced by Enterococcus mundtii, were electrospun into nanofibers prepared from different combinations of poly(d,l-lactide) (PDLLA) and poly(ethylene oxide) (PEO) dissolved in N,N-dimethylformamide (DMF). Both peptides were released from the nanofibers with a high initial burst and retained 88% of their original antimicrobial activity at 37 °C. Nanofibers have the potential to serve as carrier matrix for bacteriocins and open a new field in developing controlled antimicrobial delivery systems for various applications.

  8. Characterization of Pullulan/Chitosan Oligosaccharide/Montmorillonite Nanofibers Prepared by Electrospinning Technique.

    Science.gov (United States)

    Rabbani, Mohammad Mahbub; Yang, Seong Baek; Park, Soo-Jin; Oh, Weontae; Yeum, Jeong Hyun

    2016-06-01

    Pullulan/Chitosan oligosaccharide (COS)/Montmorillonite (MMT) hybrid nanofibers were electrospun from their aqueous solution using different Pullulan/COS mass ratios and variable amounts of MMT. The effects of Pullulan/COS mass ratios and MMT contents on the morphologies and properties of PulluIan/COS/MMT hybrid nanofibers were investigated. The obtained nanofibers were characterized with field emission-scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), thermo gravimetric analysis (TGA), and tensile strength measurement. The Pullulan/COS mass ratio and MMT contents significantly influence the morphologies and properties of the Pullulan/COS/MMT hybrid nanofibers. Higher Pullulan contents than COS contents forms uniform and bead free nanofibers. The addition of COS to Pullulan improves the thermal stability of Pullulan/COS blend nanofibers. The incorporation of MMT to the Pullulan/COS/MMT hybrid nanofibers increase their fiber diameter, improves their thermal stability and tensile strength. These morphological changes and property enhancement depend on the amount of MMT added. The XRD and TEM results suggest the coexistence of Pullulan, COS and MMT within polymer matrix through intercalation of polymer chain between silicate layers forming well-ordered multiplayer morphology with alternating polymeric and silicate layers.

  9. Preparation of Pt/TiO2 hollow nanofibers with highly visible light photocatalytic activity

    Science.gov (United States)

    Yang, Ziling; Lu, Jing; Ye, Weichun; Yu, Chushu; Chang, Yanlong

    2017-01-01

    The Pt/TiO2 hollow nanofibers (HNFs) as a photocatalyst have been successfully prepared by a uniaxial electrospinning method combined with photo-deposition. The as-synthesized photocatalysts were characterized by TEM, XRD, SAED, EDX, XPS, N2 adsorption-desorption, and UV-vis DRS. The TiO2 HNFs were composed of an anatase-rutile mixed phase, with the ratio of ∼70:30. The band gap of TiO2 HNFs decreased from 3.09 down to 2.77 eV with 2 wt.% Pt loading, this led to an enhanced photocatalytic performance under visible light. By evaluating the degradation of azo dye Orange II, the pseudo-first-rate constant (k) of Pt/350-TiO2 HNFs system was 0.0069 min-1, which was 11.5 and 3.63 times higher than for TiO2 HNFs and Pt/P25, respectively. The main factors affecting the photocatalytic activity were further investigated, these included the loading amount of Pt, the calcination temperature of TiO2 HNFs, the pH of initial solution and the light source. The results of repeated use of the Pt/TiO2 HNFs demonstrated that the photocatalysts exhibited an excellent stability even after ten cycles. The possible degradation mechanism was also studied. It was shown that rad O2- radicals were the main reactive oxygen species for the degradation of Orange II.

  10. Zwitterionic phosphorylcholine grafted chitosan nanofiber: Preparation, characterization and in-vitro cell adhesion behavior.

    Science.gov (United States)

    Oktay, Burcu; Kayaman-Apohan, Nilhan; Süleymanoğlu, Mediha; Erdem-Kuruca, Serap

    2017-04-01

    In this study, zwitterionic phosphorylcholine grafted electrospun chitosan fiber was accomplished in three steps: (1) Azide groups on the chitosan were regioselectively replaced with hydroxyl side group and then the product was electrospun. (2) Chitosan based macroinitiator was prepared using an azide-alkyne click reaction from azide-functionalized electrospun chitosan fiber. (3) Poly(2-methacryloyloxyethyl phosphorylcholine) (MPC) was grafted onto the electrospun chitosan fiber by atom transfer radical polymerization (ATRP) in order to enhance cellular viability and proliferation of 3T3, ECV and Saos. The structure of surface modified chitosan was characterized by Fourier transform infrared spectrometer (FT-IR) and (1)H nuclear magnetic resonance ((1)H NMR). The surface morphology of the nanofibers was investigated by scanning electron microscope (SEM). In-vitro cellular attachment and spreading experiments of 3T3, ECV304 and Saos were performed on electrospun chitosan fibers in the presence and the absence of MPC grafting. Poly(MPC) grafted electrospun fiber showed an excellent performance due to phosphorylcholine groups mimicking the natural phospholipid. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Preparation of antibacterial PVA and PEO nanofibers containing Lawsonia Inermis (henna) leaf extracts.

    Science.gov (United States)

    Avci, H; Monticello, R; Kotek, R

    2013-01-01

    Concerns about health issues and environmental pollution stimulate research to find new health and hygiene related products with healing properties and minimum negative effect on the environment. Development of new, natural antibacterial agents has become one of the most important research areas to combat some pathogens such as Gram- positive and Gram-negative bacteria, fungi, algae, yeast, and some microorganisms which cause serious human infections. Lawsonia Inermis (henna) leaf extracts for preparation of antibacterial poly(ethylene oxide) (PEO) and poly(vinyl alcohol) (PVA) nanofibers via electrospinning technique were investigated. PEO and PVA based electrospun fibers containing henna extract were verified by the appearance of FTIR peaks corresponding to the pure extract. Our study demonstrates that 2.793 wt.% Li in PVA and PEO based solutions showed bactericidal effects against Staphylococcus aureus and bacteriostatic action to Escherichia coli. Concentrations of henna leaf extract strongly impacted antibacterial activities against both bacteria. Henna leaves have a great potential to be used as a source of a potent eco-friendly antimicrobial agent.

  12. Preparation and Characterization of Amphiphilic Triblock Terpolymer-Based Nanofibers as Antifouling Biomaterials

    KAUST Repository

    Cho, Youngjin

    2012-05-14

    Antifouling surfaces are critical for the good performance of functional materials in various applications including water filtration, medical implants, and biosensors. In this study, we synthesized amphiphilic triblock terpolymers (tri-BCPs, coded as KB) and fabricated amphiphilic nanofibers by electrospinning of solutions prepared by mixing the KB with poly(lactic acid) (PLA) polymer. The resulting fibers with amphiphilic polymer groups exhibited superior antifouling performance to the fibers without such groups. The adsorption of bovine serum albumin (BSA) on the amphiphilic fibers was about 10-fold less than that on the control surfaces from PLA and PET fibers. With the increase of the KB content in the amphiphilic fibers, the resistance to adsorption of BSA was increased. BSA was released more easily from the surface of the amphiphilic fibers than from the surface of hydrophobic PLA or PET fibers. We have also investigated the structural conformation of KB in fibers before and after annealing by contact angle measurements, transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), and coarse-grained molecular dynamics (CGMD) simulation to probe the effect of amphiphilic chain conformation on antifouling. The results reveal that the amphiphilic KB was evenly distributed within as-spun hybrid fibers, while migrated toward the core from the fiber surface during thermal treatment, leading to the reduction in antifouling. This suggests that the antifouling effect of the amphiphilic fibers is greatly influenced by the arrangement of amphiphilic groups in the fibers. © 2012 American Chemical Society.

  13. Preparation and characterization of naproxen-loaded electrospun thermoplastic polyurethane nanofibers as a drug delivery system.

    Science.gov (United States)

    Akduman, Cigdem; Özgüney, Işık; Kumbasar, E Perrin Akcakoca

    2016-07-01

    The design and production of drug-loaded nanofiber based materials produced by electrospinning is of interest for use in innovative drug delivery systems. In the present study, ultra-fine fiber mats of thermoplastic polyurethane (TPU) containing naproxen (NAP) were successfully prepared by electrospinning from 8 and 10% (w/w) TPU solutions. The amount of NAP in the solutions was 10 and 20% based on the weight of TPU. The collection period of the drug-loaded electrospun TPU fibers was 5, 10 and 20h, and they were characterized by FTIR, DSC and TGA analysis. The morphology of the NAP-loaded electrospun TPU fiber mats was smooth, and the average diameters of these fibers varied between 523.66 and 723.50nm. The release characteristics of these fiber mats were determined by the total immersion method in the phosphate buffer solution at 37°C. It was observed that the collection period in terms of the mat thickness played a major role in the release rate of NAP from the electrospun TPU mats.

  14. Preparation and Performance of Inorganic Heat Insulation Panel Based on Sepiolite Nanofibers

    Directory of Open Access Journals (Sweden)

    Fei Wang

    2014-01-01

    Full Text Available High efficiency and low cost thermal insulation energy saving panel materials containing sepiolite nanofibers were developed by means of the synergistic action of inorganic adhesive, curing agent, and hydrogen peroxide. The water soluble sodium silicate was used as inorganic adhesive, and the sodium fluorosilicate was chosen as curing agent. Moreover, appropriate amount of hydrogen peroxide was added in order to decrease the bulk density and improve the heat insulation performance of panel materials. The results showed that the synergistic action of inorganic adhesive, curing agent, and hydrogen peroxide could make thermal insulation energy saving panel materials have low bulk density and high mechanical performance, and the optimal process was as follows: 120°C of drying temperature, 1.6% of sodium silicate as inorganic adhesive, 12% of sodium fluorosilicate as curing agent in sodium silicate, and 2.5% of hydrogen peroxide. The thermal insulation energy saving panel materials as prepared could arrest heat transmission and resist external force effectively.

  15. In-vitro anticancer and antimicrobial activities of PLGA/silver nanofiber composites prepared by electrospinning.

    Science.gov (United States)

    Almajhdi, Fahad N; Fouad, H; Khalil, Khalil Abdelrazek; Awad, Hanem M; Mohamed, Sahar H S; Elsarnagawy, T; Albarrag, Ahmed M; Al-Jassir, Fawzi F; Abdo, Hany S

    2014-04-01

    In the present work, a series of 0, 1 and 7 wt% silver nano-particles (Ag NPs) incorporated poly lactic-co-glycolic acid (PLGA) nano-fibers were synthesized by the electrospinning process. The PLGA/Ag nano-fibers sheets were characterized using SEM, TEM and DSC analyses. The three synthesized PLGA/silver nano-fiber composites were screened for anticancer activity against liver cancer cell line using MTT and LDH assays. The anticancer activity of PLGA nano-fibers showed a remarkable improvement due to increasing the concentration of the Ag NPs. In addition to the given result, PLGA nano-fibers did not show any cytotoxic effect. However, PLGA nano-fibers that contain 1 % nano silver showed anticancer activity of 8.8 %, through increasing the concentration of the nano silver to 7 % onto PLGA nano-fibers, the anticancer activity was enhanced to a 67.6 %. Furthermore, the antibacterial activities of these three nano-fibers, against the five bacteria strains namely; E.coli o157:H7 ATCC 51659, Staphylococcus aureus ATCC 13565, Bacillus cereus EMCC 1080, Listeria monocytogenes EMCC 1875 and Salmonella typhimurium ATCC25566 using the disc diffusion method, were evaluated. Sample with an enhanced inhibitory effect was PLGA/Ag NPs (7 %) which inhibited all strains (inhibition zone diameter 10 mm); PLGA/Ag NPs (1 %) sample inhibited only one strain (B. cereus) with zone diameter 8 mm. The PLGA nano-fiber sample has not shown any antimicrobial activity. Based on the anticancer as well as the antimicrobial results in this study, it can be postulated that: PLGA nanofibers containing 7 % nano silver are suitable as anticancer- and antibiotic-drug delivery systems, as they will increase the anticancer as well as the antibiotic drug potency without cytotoxicity effect on the normal cells. These findings also suggest that Ag NPs, of the size (5-10 nm) evaluated in the present study, are appropriate for therapeutic application from a safety standpoint.

  16. Preparation of Surface Adsorbed and Impregnated Multi-walled Carbon Nanotube/Nylon-6 Nanofiber Composites and Investigation of their Gas Sensing Ability.

    Science.gov (United States)

    Lala, Neeta L; Thavasi, Velmurugan; Ramakrishna, Seeram

    2009-01-01

    We have prepared electrospun Nylon-6 nanofibers via electrospinning, and adsorbed multi-walled carbon nanotubes (MWCNTs) onto the surface of Nylon-6 fibers using Triton(®) X-100 to form a MWCNTs/Nylon-6 nanofiber composite. The dispersed MWCNTs have been found to be stable in hexafluoroisopropanol for several months without precipitation. A MWCNTs/Nylon-6 nanofiber composite based chemical sensor has demonstrated its responsiveness towards a wide range of solvent vapours at room temperature and only mg quantities of MWCNTs were expended. The large surface area and porous nature of the electrospun Nylon-6/MWCNT nanofibers facilitates greater analyte permeability. The experimental analysis has indicated that the dipole moment, functional group and vapour pressure of the analytes determine the magnitude of the responsiveness.

  17. Preparation of Surface Adsorbed and Impregnated Multi-walled Carbon Nanotube/Nylon-6 Nanofiber Composites and Investigation of their Gas Sensing Ability

    Directory of Open Access Journals (Sweden)

    Velmurugan Thavasi

    2009-01-01

    Full Text Available We have prepared electrospun Nylon-6 nanofibers via electrospinning, and adsorbed multi-walled carbon nanotubes (MWCNTs onto the surface of Nylon-6 fibers using Triton® X-100 to form a MWCNTs/Nylon-6 nanofiber composite. The dispersed MWCNTs have been found to be stable in hexafluoroisopropanol for several months without precipitation. A MWCNTs/Nylon-6 nanofiber composite based chemical sensor has demonstrated its responsiveness towards a wide range of solvent vapours at room temperature and only mg quantities of MWCNTs were expended. The large surface area and porous nature of the electrospun Nylon-6/MWCNT nanofibers facilitates greater analyte permeability. The experimental analysis has indicated that the dipole moment, functional group and vapour pressure of the analytes determine the magnitude of the responsiveness.

  18. Preparation and Characterization of Polyaniline Nanofibers by Template-free Method

    Institute of Scientific and Technical Information of China (English)

    Xuemei GUO; Kun LUO; Nanlin SHI

    2005-01-01

    In the presence of p-toluene sulfonic acid (TSA) as a dopant, polyaniline (PAni) nanofibers, (about 80~165 nm in diameter) were successfully synthesized with a chemical template-free method. It was found that the formation probability, morphology, and diameter of the resulting PAni-TSA nanofibers were sensitive to the synthetic conditions,such as reaction temperature, the molar ratio of TSA to aniline, and the concentration of TSA in the polymerization media. The molecular structure was characterized by using the FT-IR, Raman spectra and X-ray diffraction, which shows that the main chain structure of PAni-TSA nanofibers was in agreement with that of granular PAni.

  19. A Novel Route for the Preparation of Gold Nanoparticles in Polycaprolactone Nanofibers

    Directory of Open Access Journals (Sweden)

    Simón Yobanny Reyes-López

    2015-01-01

    Full Text Available A facile strategy for the fabrication of polycaprolactone (PCL nanofibers containing gold nanoparticles (AuNPs is proposed. The method is based on electrospinning nanosuspensions loaded with passivated Au nanoparticles. The optical property of gold nanoparticles synthesized was observed by UV-visible absorption spectra. Morphology and structure of the Au-PCL hybrid nanofibers were characterized by scanning electron microscopy, scanning transmission electron microscopy, and Fourier transformed infrared spectroscopy. The results of investigations by UV-visible and dynamic light scattering confirmed the presence of gold nanoparticles with diameters less than 10 nm. The STEM images show the presence of gold nanoparticles and gold agglomerates with diameter around 30 to 180 nm distributed over the surface of nanofibers, which is likely due to the increased incidence of agglomerations of AuNPs, due to drying process used.

  20. Preparation of NiO-CuO-MgO fine powders by ultrasonic spray pyrolysis for carbon nanofibers synthesis

    Science.gov (United States)

    Krasnikova, Irina V.; Mishakov, Ilya V.; Bauman, Yury I.; Karnaukhov, Timofey M.; Vedyagin, Aleksey A.

    2017-09-01

    Carbon nanofibers with uniform diameter distribution are of great importance to be applied in composite materials production. Characteristics of the final carbon product obtained via catalytic chemical vapour deposition are known to be determined by the catalyst characteristics and the process conditions. In this work, ultrasonic spray pyrolysis was used for the preparation of uniform-sized NiO-CuO-MgO fine powders. Spherical particles of 170-340 nm in diameter were obtained in a temperature range of 400-600 °C. Synthesized powders exhibited high catalytic activity in CCVD of ethylene with the formation of CNF with relatively narrow diameter distribution (60 ± 20 nm).

  1. Preparation and characterization of poly(vinyl alcohol)/graphene nanofibers synthesized by electrospinning

    Science.gov (United States)

    Barzegar, Farshad; Bello, Abdulhakeem; Fabiane, Mopeli; Khamlich, Saleh; Momodu, Damilola; Taghizadeh, Fatemeh; Dangbegnon, Julien; Manyala, Ncholu

    2015-02-01

    We report on the synthesis and characterization of electrospun polyvinyl alcohol (PVA)/graphene nanofibers. The samples produced were characterized by Raman spectroscopy for structural and defect density analysis, scanning electron microscopy (SEM) for morphological analysis, and thermogravimetric (TGA) for thermal analysis. SEM measurements show uniform hollow PVA fibers formation and excellent graphene dispersion within the fibers, while TGA measurements show the improved thermal stability of PVA in the presence of graphene. The synthesized polymer reinforced nanofibers have potential to serve in many different applications such as thermal management, supercapacitor electrodes and biomedical materials for drug delivery.

  2. Preparation of paclitaxel/chitosan co-assembled core-shell nanofibers for drug-eluting stent

    Science.gov (United States)

    Tang, Jing; Liu, Yongjia; Zhu, Bangshang; Su, Yue; Zhu, Xinyuan

    2017-01-01

    The paclitaxel/chitosan (PTX/CS) core-shell nanofibers (NFs) are easily prepared by co-assembly of PTX and CS and used in drug-eluting stent. The mixture solution of PTX (dissolved in ethanol) and CS (dissolved in 1% acetic acid water solution) under sonication will make the formation of NFs, in which small molecule PTX co-assembles with biomacromolecular CS through non-covalent interactions. The obtained NFs are tens to hundreds nanometers in diameter and millimeter level in length. Furthermore, the structure of PTX/CS NFs was characterized by confocal laser scanning microscopy (CLSM), zeta potential, X-ray photoelectron spectroscopy (XPS) and nanoscale infra-red (nanoIR), which provided evidences demonstrated that PTX/CS NFs are core-shell structures. The 'shell' of CS wrapped outside of the NFs, while PTX is located in the core. Thus it resulted in high drug loading content (>40 wt.%). The well-controlled drug release, low cytotoxicity and good haemocompatibility were also found in drug carrier system of PTX/CS NFs. In addition, the hydrophilic and flexible properties of NFs make them easily coating and filming on stent to prepare drug-eluting stent (DES). Therefore, this study provides a convenient method to prepare high PTX loaded NFs, which is a promising nano-drug carrier used for DES and other biomedical applications. The possible molecular mechanism of PTX and CS co-assembly and core-shell nanofiber formation is also explored.

  3. Electrospinning preparation, characterization and magnetic properties of cobalt-nickel ferrite (Co(1-x)Ni(x)Fe2)O4) nanofibers.

    Science.gov (United States)

    Xiang, Jun; Chu, Yanqiu; Shen, Xiangqian; Zhou, Guangzhen; Guo, Yintao

    2012-06-15

    Uniform Co(1-)(x)Ni(x)Fe(2)O(4) (x=0.0, 0.2, 0.4, 0.6, 0.8 and 1.0) nanofibers with average diameter of 110 nm and length up to several millimeters were prepared by calcination of electrospun precursor nanofibers containing polymer and inorganic salts. The as-spun and calcined nanofibers were characterized in detail by TG-DTA, XRD, FE-SEM, TEM, SAED and VSM, respectively. The effect of composition of the nanofibers on the structure and magnetic properties were investigated. The nanofibers are formed through assembling magnetic nanoparticles with poly(vinyl pyrrolidone) as the structure-directing template. The structural characteristics and magnetic properties of the resultant nanofibers vary with chemical composition and can be tuned by adjusting the Co/Ni ratio. Both lattice parameter and particle size decrease gradually with increasing nickel concentration. The saturation magnetization and coercivity lie in the range 29.3-56.4 emu/g and 210-1255 Oe, respectively, and both show a monotonously decreasing behavior with the increase in nickel concentration. Such changes in magnetic properties can mainly be attributed to the lower magnetocrystalline anisotropy and the smaller magnetic moment of Ni(2+) ions compared to Co(2+) ions. Furthermore, the coercivity of Co-Ni ferrite nanofibers is found to be superior to that of the corresponding nanoparticle counterparts, presumably due to their large shape anisotropy. These novel one-dimensional Co-Ni ferrite magnetic nanofibers can potentially be used in micro-/nanoelectronic devices, microwave absorbers and sensing devices. Copyright © 2012 Elsevier Inc. All rights reserved.

  4. Electrospun chitosan nanofibers with controlled levels of silver nanoparticles. Preparation, characterization and antibacterial activity.

    Science.gov (United States)

    Lee, Sang Jin; Heo, Dong Nyoung; Moon, Ji-Hoi; Ko, Wan-Kyu; Lee, Jung Bok; Bae, Min Soo; Park, Se Woong; Kim, Ji Eun; Lee, Dong Hyun; Kim, Eun-Cheol; Lee, Chang Hoon; Kwon, Il Keun

    2014-10-13

    The ideal wound dressing would have properties that allow for absorption of exudates, and inhibition of microorganism for wound protection. In this study, we utilized an electrospinning (ELSP) technique to design a novel wound dressing. Chitosan (CTS) nanofibers containing various ratios of silver nanoparticles (AgNPs) were obtained. AgNPs were generated directly in the CTS solution by using a chemical reduction method. The formation and presence of AgNPs in the CTS/AgNPs composite was confirmed by x-ray diffraction (XRD), ultraviolet-visible spectroscopy (UV) and thermogravimetric analysis (TGA). The electrospun CTS/AgNPs nanofibers were characterized morphologically by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). These nanofibers were subsequently tested to evaluate their antibacterial activity against gram-negative Pseudomonas aeruginosa (P. aeruginosa) and gram-positive Methicillin-resistant Staphylococcus aureus (MRSA). Results of this antibacterial testing suggest that CTS/AgNPs nanofibers may be effective in topical antibacterial treatment in wound care.

  5. Processing and Structure of Carbon Nanofiber Paper

    Directory of Open Access Journals (Sweden)

    Zhongfu Zhao

    2009-01-01

    Full Text Available A unique concept of making nanocomposites from carbon nanofiber paper was explored in this study. The essential element of this method was to design and manufacture carbon nanofiber paper with well-controlled and optimized network structure of carbon nanofibers. In this study, carbon nanofiber paper was prepared under various processing conditions, including different types of carbon nanofibers, solvents, dispersants, and acid treatment. The morphologies of carbon nanofibers within the nanofiber paper were characterized with scanning electron microscopy (SEM. In addition, the bulk densities of carbon nanofiber papers were measured. It was found that the densities and network structures of carbon nanofiber paper correlated to the dispersion quality of carbon nanofibers within the paper, which was significantly affected by papermaking process conditions.

  6. Preparation and luminescence properties of La6MoO12:Eu3+/PVA nanofibers by Pechini/electrospinning process.

    Science.gov (United States)

    Qin, Chuanxiang; Gu, Mingbo; Huang, Yanlin; Dai, Lixing; Chen, Guoqiang; Shi, Liang; Qiao, Xuebin; Seo, Hyo Jin

    2011-11-01

    The 20% concentration Eu3+-based red-emitting phosphor, nano-sized La6MoO12:Eu3+ was prepared by the Pechini method. X-ray diffraction (XRD), thermogravimetric and differential thermal analysis (TG-DTA), scanning electron microscopy (SEM), photoluminescence (PL), and decay curves were used to characterize the resulting samples. The phosphor can be efficiently excited by near UV light and exhibits an intense red luminescence corresponding to the electric dipole transition 5D0 --> 7F2 at 615 nm. When the phosphor was mixed into poly(vinyl alcohol) aqueous solution, the fluorescent nanofibers could be prepared by electrospinning process. It was suggested that the La6MoO12:Eu3+ phosphor would be a promising red component for solid-state lighting devices based on InGaN or GaN light-emitting diodes.

  7. Preparation and characterization of chitosan/Aloe Vera composite nanofibers generated by electrostatic spinning

    Science.gov (United States)

    Ibrahim, Illani; Sekak, Khairunnadim Ahmad; Hasbullah, Norazurean

    2015-08-01

    Researches on the fabrication of nanostructured based membrane have attracted great attention amongst scientists due to their wide potential applications on medical application. In this work, Chitosan and Aloe Vera sol-gel solution were electrospun using 20 kV DC supply at room temperature. Morphological structure and functional group of nanofibers were characterized using field emission scanning electron microscopy (FESEM) and Fourier-transform infrared spectroscopy (FT-IR) respectively. The optimum parameter obtained at 90% concentration of acetic acid, 0.3 ml/h of solution flow rate and 10 cm distance of nozzle to collector. The fiber diameters were analyzed using the ImageJ software. Average diameters of the Chitosan/Aloe Vera composite nanofibers is 183nm in ranges of 140-260nm.

  8. Preparation and characterization of chitosan/Aloe Vera composite nanofibers generated by electrostatic spinning

    Energy Technology Data Exchange (ETDEWEB)

    Ibrahim, Illani; Sekak, Khairunnadim Ahmad; Hasbullah, Norazurean [Center of Physics and Material Studies, Faculty of Applied Sciences, Universiti Teknologi Mara (UiTM) 40450 Shah Alam, Selangor (Malaysia)

    2015-08-28

    Researches on the fabrication of nanostructured based membrane have attracted great attention amongst scientists due to their wide potential applications on medical application. In this work, Chitosan and Aloe Vera sol-gel solution were electrospun using 20 kV DC supply at room temperature. Morphological structure and functional group of nanofibers were characterized using field emission scanning electron microscopy (FESEM) and Fourier-transform infrared spectroscopy (FT-IR) respectively. The optimum parameter obtained at 90% concentration of acetic acid, 0.3 ml/h of solution flow rate and 10 cm distance of nozzle to collector. The fiber diameters were analyzed using the ImageJ software. Average diameters of the Chitosan/Aloe Vera composite nanofibers is 183nm in ranges of 140–260nm.

  9. Preparation of methacrylic acid copolymer S nano-fibers using a solvent-based electrospinning method and their application in pharmaceutical formulations.

    Science.gov (United States)

    Hamori, Mami; Shimizu, Yuki; Yoshida, Kaori; Fukushima, Keizo; Sugioka, Nobuyuki; Nishimura, Asako; Naruhashi, Kazumasa; Shibata, Nobuhito

    2015-01-01

    In this study, we applied an electrospinning (ES) method, which is mainly employed in the textile industry, to the field of pharmaceuticals. We developed and modified an ES instrument and then utilized it to produce methacrylic acid copolymer S (MAC) nano-fibers to prepare tablets. By attaching a conductor rod made from stainless steel to the central part of the nano-fiber-collection plate of the ES apparatus, a MAC nano-fiber sheet could be produced effectively. In addition, we studied various operating conditions for this new ES method, including needle gauge, voltage between the electrodes, distance between the needle and nano-fiber-collection plate and the flow rate of MAC polymer solution, but these had no significant effect on the diameter of MAC nano-fibers. On the other hand, the viscosity (concentration) of MAC polymer solution and permittivity of solvent used to dilute MAC were closely related to the mean diameter of the nano-fibers. Tableting of MAC nano-fibers was performed using a tableting machine without lubricants, and addition of Tween 20 to the tablets enabled regulation of the release profile of a water-soluble drug. The modified ES method reported here is a useful technique for the controlled-release of drugs and has wide-ranging potential for pharmaceutical applications.

  10. Preparation of Aligned Ultra-long and Diameter-controlled Silicon Oxide Nanotubes by Plasma Enhanced Chemical Vapor Deposition Using Electrospun PVP Nanofiber Template

    Directory of Open Access Journals (Sweden)

    Zhou Ming

    2009-01-01

    Full Text Available Abstract Well-aligned and suspended polyvinyl pyrrolidone (PVP nanofibers with 8 mm in length were obtained by electrospinning. Using the aligned suspended PVP nanofibers array as template, aligned ultra-long silicon oxide (SiOx nanotubes with very high aspect ratios have been prepared by plasma-enhanced chemical vapor deposition (PECVD process. The inner diameter (20–200 nm and wall thickness (12–90 nm of tubes were controlled, respectively, by baking the electrospun nanofibers and by coating time without sacrificing the orientation degree and the length of arrays. The micro-PL spectrum of SiOx nanotubes shows a strong blue–green emission with a peak at about 514 nm accompanied by two shoulders around 415 and 624 nm. The blue–green emission is caused by the defects in the nanotubes.

  11. Polymer structure and antimicrobial activity of polyvinylpyrrolidone-based iodine nanofibers prepared with high-speed rotary spinning technique.

    Science.gov (United States)

    Sebe, István; Szabó, Barnabás; Nagy, Zsombor K; Szabó, Dóra; Zsidai, László; Kocsis, Béla; Zelkó, Romána

    2013-12-15

    Poly(vinylpyrrolidone)/poly(vinylpyrrolidone-vinylacetate)/iodine nanofibers of different polymer ratios were successfully prepared by a high-speed rotary spinning technique. The obtained fiber mats were subjected to detailed morphological analysis using an optical and scanning electron microscope (SEM), while the supramolecular structure of the samples was analyzed by positron annihilation lifetime spectroscopy (PALS). The maximum dissolved iodine of the fiber samples was determined, and microbiological assay was carried out to test their effect on the bacterial growth. SEM images showed that the polymer fibers were linear, homogenous, and contained no beads. The PALS results, both the o-positronium (o-Ps) lifetime values and distributions, revealed the changes of the free volume holes of fibers as a function of their composition and the presence of iodine. The micro- and macrostructural characterisation of polymer fiber mats enabled the selection of the required composition from the point of their applicability as a wound dressing.

  12. Preparation of polyacrylnitrile (PAN)/ Manganese oxide based activated carbon nanofibers (ACNFs) for adsorption of Cadmium (II) from aqueous solution

    Science.gov (United States)

    Abdullah, N.; Yusof, N.; Jaafar, J.; Ismail, AF; Che Othman, F. E.; Hasbullah, H.; Salleh, W. N. W.; Misdan, N.

    2016-06-01

    In this work, activated carbon nanofibers (ACNFs) from precursor polyacrylnitrile (PAN) and manganese oxide (MnO2) were prepared via electrospinning process. The electrospun PAN/MnO2-based ACNFs were characterised in term of its morphological structure and specific surface area using SEM and BET analysis respectively. The comparative adsorption study of cadmium (II) ions from aqueous solution between the neat ACNFs, composite ACNFs and commercial granular activated carbon was also conducted. SEM analysis illustrated that composite ACNFs have more compact fibers with presence of MnO2 beads with smaller fiber diameter of 437.2 nm as compared to the neat ACNFs which is 575.5 nm. BET analysis elucidated specific surface area of ACNFs/MnO2 to be 67 m2/g. Under adsorption study, it was found out that Cd (II) removal by ACNFs/MnO2 was the highest (97%) followed by neat ACNFs (96%) and GAC (74%).

  13. Preparation and characterization of a Lithium-ion battery separator from cellulose nanofibers

    Directory of Open Access Journals (Sweden)

    Hongfeng Zhang

    2015-10-01

    Full Text Available Optimizing the desired properties for stretch monolayer separators used in Lithium-ion batteries has been a challenge. In the present study a cellulose nanofiber/PET nonwoven composite separator is successfully fabricated, using a wet-laid nonwoven (papermaking process, which can attain optimal properties in wettability, mechanical strength, thermal resistance, and electrochemical performance simultaneously. The PET nonwoven material, which is fabricated from ultrafine PET fibers by a wet-laid process, is a mechanical support layer. The porous structure of the composite separator was created by cellulose nanofibers coating the PET in a papermaking process. Cellulose nanofibers (CNFs, which are an eco-friendly sustainable resource, have been drawing considerable attention due to their astounding properties, such as: incredible specific surface area, thermal and chemical stability, high mechanical strength and hydrophilicity. The results show that the CNF separator exhibits higher porosity (70% than a PP (polypropylene separator (40%. The CNF separator can also be wetted by electrolyte in a few seconds while a PP separator cannot be entirely wetted after 1 min. The CNF separator has an electrolyte uptake of 250%, while a PP separator has only 65%. Another notable finding is that the CNF separator has almost no shrinkage when exposed to 180 °C for 1 h, whereas a PP separator shrinks by more than 50%. Differential Scanning Calorimetry (DSC shows that the CNF separator has a higher melting point than a PP separator. These findings all indicate that the CNF 29 separator will be more favorable than stretch film for use in Lithium-ion batteries.

  14. Preparation and characterization of doped TiO{sub 2} nanofibers by coaxial electrospining combined with sol–gel process

    Energy Technology Data Exchange (ETDEWEB)

    Tong, Haixia, E-mail: tonghaixia@126.com; Tao, Xican; Wu, Daoxin; Zhang, Xiongfei; Li, Dan; Zhang, Ling

    2014-02-15

    Graphical abstract: The surface of the precursor of Fe/TiO{sub 2} nanofibers are smoother than that of Fe /TiO{sub 2} nanofibers. After calcined at 500 °C, the tubers on the surface of the nanofibers become more obvious, and which also provides a direct proof for the dopant of Fe element. -- Highlights: • N, Fe, and W doped TiO{sub 2} nanofibers have been fabricated by coaxial electrospining. • The dopant has obvious influences on the surface topographies and crystal structures. • Fe doping can make remarkable topography changes and easy formation of rutile TiO{sub 2}. • The maximum doping amount of W in TiO{sub 2} nanofibers is less than 10% under 500 °C. -- Abstract: N, Fe, and W doped TiO{sub 2} nanofibers were fabricated by coaxial electrospining and directly annealing polyvinylpyrrolidone (PVP)/Tetrabutyl titanate (TBT) composite nanofibers. The crystal structure, morphology, and surface composition of the doped TiO{sub 2} nanofibers were investigated by the X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) respectively. The results show that the dopants have different influence on the surface topographies, the crystal structures and the transformation of anatase to rutile of TiO{sub 2} nanofibers. Fe dopant promotes bigger influence on topographies, phase transformation and crystallite growth of TiO{sub 2} nanofibers than that of either N or W dopant.

  15. Novel polyamide-based nanofibers prepared by electrospinning technique for headspace solid-phase microextraction of phenol and chlorophenols from environmental samples.

    Science.gov (United States)

    Bagheri, Habib; Aghakhani, Ali; Baghernejad, Masoud; Akbarinejad, Alireza

    2012-02-24

    A novel solid phase microextraction (SPME) fiber was fabricated by electrospinning method in which a polymeric solution was converted to nanofibers using high voltages. A thin stainless steel wire was coated by the network of polymeric nanofibers. The polymeric nanofiber coating on the wire was mechanically stable due to the fine and continuous nanofibers formation around the wire with a three dimensional structure. Polyamide (nylon 6), due to its suitable characteristics was used to prepare the unbreakable SPME nanofiber. The scanning electron microscopy (SEM) images of this new coating showed a diameter range of 100-200 nm for polyamide nanofibers with a homogeneous and porous surface structure. The extraction efficiency of new coating was investigated for headspace solid-phase microextraction (HS-SPME) of some environmentally important chlorophenols from aqueous samples followed by gas chromatography-mass spectrometry (GC-MS) analysis. Effect of different parameters influencing the extraction efficiency including extraction temperature, extraction time, ionic strength and polyamide amount were investigated and optimized. In order to improve the chromatographic behavior of phenolic compounds, all the analytes were derivatized prior to the extraction process using basic acetic anhydride. The detection limits of the method under optimized conditions were in the range of 2-10 ng L(-1). The relative standard deviations (RSD) (n=3) at the concentration level of 1.7-6.7 ng mL(-1) were obtained between 1 and 7.4%. The calibration curves of chlorophenols showed linearity in the range of 27-1330 ng L(-1) for phenol and monochlorophenols and 7-1000 ng L(-1) for dichloro and trichlorophenols. Also, the proposed method was successfully applied to the extraction of phenol and chlorophenols from real water samples and relative recoveries were between 84 and 98% for all the selected analytes except for 2,4,6 tricholophenol which was between 72 and 74%. Copyright © 2011

  16. Novel polyamide-based nanofibers prepared by electrospinning technique for headspace solid-phase microextraction of phenol and chlorophenols from environmental samples

    Energy Technology Data Exchange (ETDEWEB)

    Bagheri, Habib, E-mail: bagheri@sharif.edu [Environmental and Bio-Analytical Laboratories, Department of Chemistry, Sharif University of Technology, Azadi Av., P.O. Box 11365-9516, Tehran (Iran, Islamic Republic of); Aghakhani, Ali; Baghernejad, Masoud; Akbarinejad, Alireza [Environmental and Bio-Analytical Laboratories, Department of Chemistry, Sharif University of Technology, Azadi Av., P.O. Box 11365-9516, Tehran (Iran, Islamic Republic of)

    2012-02-24

    A novel solid phase microextraction (SPME) fiber was fabricated by electrospinning method in which a polymeric solution was converted to nanofibers using high voltages. A thin stainless steel wire was coated by the network of polymeric nanofibers. The polymeric nanofiber coating on the wire was mechanically stable due to the fine and continuous nanofibers formation around the wire with a three dimensional structure. Polyamide (nylon 6), due to its suitable characteristics was used to prepare the unbreakable SPME nanofiber. The scanning electron microscopy (SEM) images of this new coating showed a diameter range of 100-200 nm for polyamide nanofibers with a homogeneous and porous surface structure. The extraction efficiency of new coating was investigated for headspace solid-phase microextraction (HS-SPME) of some environmentally important chlorophenols from aqueous samples followed by gas chromatography-mass spectrometry (GC-MS) analysis. Effect of different parameters influencing the extraction efficiency including extraction temperature, extraction time, ionic strength and polyamide amount were investigated and optimized. In order to improve the chromatographic behavior of phenolic compounds, all the analytes were derivatized prior to the extraction process using basic acetic anhydride. The detection limits of the method under optimized conditions were in the range of 2-10 ng L{sup -1}. The relative standard deviations (RSD) (n = 3) at the concentration level of 1.7-6.7 ng mL{sup -1} were obtained between 1 and 7.4%. The calibration curves of chlorophenols showed linearity in the range of 27-1330 ng L{sup -1} for phenol and monochlorophenols and 7-1000 ng L{sup -1} for dichloro and trichlorophenols. Also, the proposed method was successfully applied to the extraction of phenol and chlorophenols from real water samples and relative recoveries were between 84 and 98% for all the selected analytes except for 2,4,6 tricholophenol which was between 72 and 74%.

  17. Preparation of graphene oxide/poly (3,4-ethylenedioxytriophene): Poly (styrene sulfonate) (PEDOT:PSS) electrospun nanofibers

    Science.gov (United States)

    Widianto, Eri; Efelina, Vita; Rusdiana, Dadi; Nugroho, A. A.; Kusumaatmaja, Ahmad; Triyana, Kuwat; Santoso, Iman

    2016-04-01

    Graphene oxide (GO)/Poly (3,4-Ethylenedioxytriophene):Poly (styrene Sulfonate) (PEDOT:PSS)nanofibers have been successfully fabricated by a simple electrospinning technique to develop conductive nanofibers with polyvinyl alcohol (PVA) act as a carrier solution. Graphene oxide hasbeen synthesized by Hummer's method and has been confirmed by Raman Spectroscopy, FTIR, and UV-Vis Spectroscopy. The structural and morphological properties of GO/PEDOT:PSS composite nanofiberswere characterized by Scanning Electron Microscopy (SEM). The result of SEM showed that GO/PEDOT:PSS nanofibers have a relatively uniform morphology nanofiber with adiameterof 180 nm - 340 nm with smooth nanofiber surface. The produced nanofibers from this study can be utilized for various applicationssuch as aflexible, conductive and transparent electrode.

  18. Encapsulation of amoxicillin within laponite-doped poly(lactic-co-glycolic acid) nanofibers: preparation, characterization, and antibacterial activity.

    Science.gov (United States)

    Wang, Shige; Zheng, Fuyin; Huang, Yunpeng; Fang, Yuting; Shen, Mingwu; Zhu, Meifang; Shi, Xiangyang

    2012-11-01

    We report a facile approach to encapsulating amoxicillin (AMX) within laponite (LAP)-doped poly(lactic-co-glycolic acid) (PLGA) nanofibers for biomedical applications. In this study, a synthetic clay material, LAP nanodisks, was first used to encapsulate AMX. Then, the AMX-loaded LAP nanodisks with an optimized AMX loading efficiency of 9.76 ± 0.57% were incorporated within PLGA nanofibers through electrospinning to form hybrid PLGA/LAP/AMX nanofibers. The loading of AMX within LAP nanodisks and the loading of LAP/AMX within PLGA nanofibers were characterized via different techniques. In vitro drug release profile, antimicrobial activity, and cytocompatibility of the formed hybrid PLGA/LAP/AMX nanofibers were also investigated. We show that the loading of AMX within LAP nanodisks does not lead to the change of LAP morphology and crystalline structure and the incorporation of LAP/AMX nanodisks does not significantly change the morphology of the PLGA nanofibers. Importantly, the loading of AMX within LAP-doped PLGA nanofibers enables a sustained release of AMX, much slower than that within a single carrier of LAP nanodisks or PLGA nanofibers. Further antimicrobial activity and cytocompatibility assays demonstrate that the antimicrobial activity of AMX toward the growth inhibition of a model bacterium of Staphylococcus aureus is not compromised after being loaded into the hybrid nanofibers, and the PLGA/LAP/AMX nanofibers display good cytocompatibility, similar to pure PLGA nanofibers. With the sustained release profile and the reserved drug activity, the organic/inorganic hybrid nanofiber-based drug delivery system may find various applications in tissue engineering and pharmaceutical science.

  19. Bubbfil electrospinning of PA66/Cu nanofibers

    Directory of Open Access Journals (Sweden)

    Li Ya

    2016-01-01

    Full Text Available Different PA66/Cu nanofibers were prepared under various electrospinning parameters through bubbfil electrospinning. The process parameters were determined. Cuprum particles with different size were added to PA66 solution to produce PA6/66-Cu composite nanofibers. The influence of cuprum nanoparticle size on the PA66 nanofibers was analyzed.

  20. Preparation of mesohollow and microporous carbon nanofiber and its application in cathode material for lithium–sulfur batteries

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Yuanhe; Gao, Mingxia, E-mail: gaomx@zju.edu.cn; Li, Xiang; Liu, Yongfeng; Pan, Hongge, E-mail: hgpan@zju.edu.cn

    2014-09-01

    Highlights: • Mesohollow and microporous carbon fibers were prepared via electrospinning and carbonization. • Sulfur (S) incorporated into the porous fibers by thermal heating in 60 wt.%, forming composite. • S fills fully in the micropores and partially in the mesohollows of the carbon fibers. • The composite shows high capacity and capacity retention as cathode material for Li–S batteries. • Mesohollow and microporous structure is effective in improving the property of S cathode. - Abstract: Mesohollow and microporous carbon nanofibers (MhMpCFs) were prepared by a coaxial electrospinning with polyacrylonitrile (PAN) and polymethylmethacrylate (PMMA) as outer and inner spinning solutions followed by a carbonization. The carbon fibers were thermal treated with sublimed sulfur to form S/MhMpCFs composite, which was used as cathode material for lithium–sulfur batteries. Electrochemical study shows that the S/MhMpCFs cathode material provides a maximum capacity of 815 mA h/g after several cycles of activation, and the capacity retains 715 mA h/g after 70 cycles, corresponding to a retention of 88%. The electrochemical property of the S/MhMpCFs composite is much superior than the S-incorporated solid carbon fibers prepared from electrospinning of single PAN. The mechanism of the enhanced electrochemical property of the S/MhMpCFs composite is discussed.

  1. Novel preparation and characterization of human hair-based nanofibers using electrospinning process.

    Science.gov (United States)

    Park, Mira; Shin, Hye Kyoung; Panthi, Gopal; Rabbani, Mohammad Mahbub; Alam, Al-Mahmnur; Choi, Jawun; Chung, Hea-Jong; Hong, Seong-Tshool; Kim, Hak-Yong

    2015-05-01

    Human hair-based biocomposite nanofibers (NFs) have been fabricated by an electrospinning technique. Aqueous keratin extracted from human hair was successfully blended with poly(vinyl alcohol) (PVA). The focus here is on transforming into keratin/PVA nanofibrous membranes and insoluble property of electrospun NFs. The resulting hair-based NFs were characterized using Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), differential scanning colorimetry (DSC), and thermogravimetric analysis (TGA). Toward the potential use of these NFs after cross-linking with various weight fractions of glyoxal, its physicochemical properties, such as morphology, mechanical strength, crystallinity, and chemical structure were investigated. Keratin/PVA ratio of 2/1 NFs with 6 wt%-glyoxal showed good uniformity in fiber morphology and suitable mechanical properties, and excellent antibacterial activity providing a potential application of hair-based NFs in biomedical field.

  2. Templates for integrated nanofiber growth

    DEFF Research Database (Denmark)

    Oliveira Hansen, Roana Melina de

    Para-hexaphenylene (p6P) molecules have the ability to self-assemble into organic nanofibers. These nanofibers hold unique optoelectronic properties, which make them interesting candidates as elements in electronic and optoelectronic devices. Typically these nanofibers are grown on specific single......, high-volume integration. Besides such single-crystalline templates, the nanofibers can also be grown on non-crystalline gold surfaces, on which the orientation of the nanofibers can be manipulated by structuring the gold surface prior to p6P deposition. In this work, a novel method for in-situ growth...... of p6P nanofibers on nano-structured gold surfaces is presented. The substrates are prepared by conventional nanofabrication techniques such as e-beam lithography and metal deposition, which increase their potential as device platforms. Some of the results presented here demonstrate, that both...

  3. Ultrasonic dyeing of cellulose nanofibers.

    Science.gov (United States)

    Khatri, Muzamil; Ahmed, Farooq; Jatoi, Abdul Wahab; Mahar, Rasool Bux; Khatri, Zeeshan; Kim, Ick Soo

    2016-07-01

    Textile dyeing assisted by ultrasonic energy has attained a greater interest in recent years. We report ultrasonic dyeing of nanofibers for the very first time. We chose cellulose nanofibers and dyed with two reactive dyes, CI reactive black 5 and CI reactive red 195. The cellulose nanofibers were prepared by electrospinning of cellulose acetate (CA) followed by deacetylation. The FTIR results confirmed complete conversion of CA into cellulose nanofibers. Dyeing parameters optimized were dyeing temperature, dyeing time and dye concentrations for each class of the dye used. Results revealed that the ultrasonic dyeing produced higher color yield (K/S values) than the conventional dyeing. The color fastness test results depicted good dye fixation. SEM analysis evidenced that ultrasonic energy during dyeing do not affect surface morphology of nanofibers. The results conclude successful dyeing of cellulose nanofibers using ultrasonic energy with better color yield and color fastness results than conventional dyeing.

  4. Preparation and up-conversion luminescence properties of LaOBr:Yb3+/Er3+ nanofibers via electrospinning.

    Science.gov (United States)

    Ma, Wenwen; Yu, Wensheng; Dong, Xiangting; Wang, Jinxian; Liu, Guixia

    2014-11-01

    LaOBr:Yb(3+)/Er(3+) nanofibers were synthesized for the first time by calcinating electrospun PVP/[La(NO3)3 + Er(NO3)3 + Yb(NO3)3 + NH4 Br] composites. The morphology and properties of the final products were investigated in detail using scanning electron microscopy (SEM), energy dispersion spectroscopy (EDS), X-ray diffractometry (XRD) and fluorescence spectroscopy. The results indicate that LaOBr:Yb(3+)/Er(3+) nanofibers are tetragonal in structure with a space group of P4/nmm. The diameter of LaOBr:Yb(3+)/Er(3+) nanofibers is ~ 147 nm. Under the excitation of a 980-nm diode laser, LaOBr:Yb(3+)/Er(3+) nanofibers emit strong green and red up-conversion emission centering at 519, 541 and 667 nm, ascribed to the (2)H11/2, (4)S3/2 → (4) I(15/2) and (4)F9/2 → (4)I(15/2) energy-level transitions of Er(3+) ions, respectively. The up-conversion luminescent mechanism of LaOBr:Yb(3+)/Er(3+) nanofibers is advanced. Moreover, near-infrared emission of LaOBr:Yb(3+)/Er(3+) nanofibers is obtained under the excitation of a 532-nm laser. The formation mechanism of LaOBr:Yb(3+)/Er(3+) nanofibers is proposed. LaOBr:Yb(3+)/Er(3+) nanofibers could be important up-conversion luminescent materials.

  5. Preparation of a novel composite nanofiber gel-encapsulated human placental extract through layer-by-layer self-assembly.

    Science.gov (United States)

    Liu, Guohui; Chen, X I; Zhou, W U; Yang, Shuhua; Ye, Shunan; Cao, Faqi; Liu, Y I; Xiong, Yuan

    2016-04-01

    Aqueous human placenta extract (HPE) has been previously used to treat chronic soft tissue ulcer; however, the optimal dosage of HPE has yet to be elucidated. The present study investigated a novel nanofiber gel composed through layer-by-layer (LbL) self-assembly, in which HPE was encapsulated. IKVAV, RGD, RAD16 and FGL-PA were screened and combined to produce an optimal vehicle nanofiber gel through LbL assembly. Subsequently, the aqueous HPE was encapsulated into this nanofiber at the appropriate concentration, and the morphology, particle size, drug loading efficacy, encapsulation rate, release efficiency and structure validation were detected. The encapsulation efficiency of all three HPE samples was >90%, the nanofiber gel exhibited a slow releasing profile, and the structure of HPE encapsulated in the nanofiber gel was unvaried. In conclusion, this type of novel composite nanocapsules may offer a promising delivery system for HPE.

  6. Biodegradable conductive composites of poly(3-hydroxybutyrate and polyaniline nanofibers: Preparation, characterization and radiolytic effects

    Directory of Open Access Journals (Sweden)

    2011-01-01

    Full Text Available Poly(3-hydroxybutyrate is a biodegradable polyester produced by microorganisms under nutrient limitation conditions. We obtained a biodegradable poly(3-hydroxybutyrate composite having 8 to 55% of chemically in situ polymerized hydrochloric acid-doped polyaniline nanofibers (70-100 nm in diameter. Fourier transform infrared spectroscopy and X-rays diffractometry data did not show evidence of significant interaction between the two components of the nanocomposite, and polyaniline semiconductivity was preserved in all studied compositions. Gamma-irradiation at 25 kGy absorbed dose on the semiconductive composite presenting 28% of doped polyaniline increased its conductivity from 4.6*10-2 to 1.1 S/m, while slightly decreasing its biodegradability. PANI-HCl biodegradation is negligible when compared to PHB biodegradability in an 80 day timeframe. Thus, this unprecedented all-polymer nanocomposite presents, at the same time, semiconductivity and biodegradability and was proven to maintain these properties after gamma irradiation. This new material has many potential applications in biological science, engineering, and medicine.

  7. Preparation and Characterization of Vancomycin-Loaded Electrospun Rana chensinensis Skin Collagen/Poly(L-lactide Nanofibers for Drug Delivery

    Directory of Open Access Journals (Sweden)

    Mei Zhang

    2016-01-01

    Full Text Available Collagen was extracted from abandoned Rana chensinensis skin in northeastern China via an acid enzymatic extraction method for the use of drug carriers. In this paper we demonstrated two different nanofiber-vancomycin (VCM systems, that is, VCM blended nanofibers and core-shell nanofibers with VCM in the core. Rana chensinensis skin collagen (RCSC and poly(L-lactide (PLLA (3 : 7 were blended in 1,1,1,3,3,3-hexafluoroisopropanol (HFIP at a concentration of 10% (g/mL to fabricate coaxial and blend nanofibers, respectively. Coaxial and blend electrospun RCSC/PLLA nanofibers containing VCM (5 wt% were evaluated for the local and temporal delivery of VCM. The nanofiber scaffolds were characterized by environmental scanning electron microscope (ESEM, transmission electron microscopy (TEM, Fourier transform infrared spectra (FTIR, differential scanning calorimeter (DSC, water contact angle (WCA, and mechanical tests. The drug release of VCM in these two systems was compared by using UV spectrophotometer. The empirical result indicated that both the blend and coaxial RCSC/PLLA scaffolds followed sustained control release for a period of 80 hours, but the coaxial nanofiber might be a potential drug delivery material for its better mechanical properties and sustained release effect.

  8. Preparation and electrochemical performance of hyper-networked Li4Ti5O12/carbon hybrid nanofiber sheets for a battery-supercapacitor hybrid system.

    Science.gov (United States)

    Choi, Hong Soo; Kim, TaeHoon; Im, Ji Hyuk; Park, Chong Rae

    2011-10-07

    Hyper-networked Li(4)Ti(5)O(12)/carbon hybrid nanofiber sheets that contain both a faradaically rechargeable battery-type component, namely Li(4)Ti(5)O(12), and a non-faradaically rechargeable supercapacitor-type component, namely N-enriched carbon, are prepared by electrospinning and their dual function as a negative electrode of lithium-ion batteries (LIBs) and a capacitor is tested for a new class of hybrid energy storage (denoted BatCap). An aqueous solution composed of polyvinylpyrrolidone, lithium hydroxide, titanium(IV) bis(ammonium-lactato)dihydroxide and ammonium persulfate is electrospun to obtain hyper-networked nanofiber sheets. Next, the sheets are exposed to pyrrole monomer vapor to prepare the polypyrrole-coated nanofiber sheets (PPy-HNS). The hyper-networked Li(4)Ti(5)O(12)/N-enriched carbon hybrid nanofiber sheets (LTO/C-HNS) are then obtained by a stepwise heat treatment of the PPy-HNS. The LTO/C-HNS deliver a specific capacity of 135 mAh g(-1) at 4000 mA g(-1) as a negative electrode for LIBs. In addition, potentiodynamic experiments are performed using a full cell with activated carbon (AC) as the positive electrode and LTO/C-HNS as the negative electrode to estimate the capacitance properties. This new asymmetric electrode system exhibits a high energy density of 91 W kg(-1) and 22 W kg(-1) at power densities of 50 W kg(-1) and 4000 W kg(-1), respectively, which are superior to the values observed for the AC [symbol: see text] AC symmetric electrode system.

  9. Preparation and electrochemical performance of hyper-networked Li4Ti5O12/carbon hybrid nanofiber sheets for a battery-supercapacitor hybrid system

    Science.gov (United States)

    Choi, Hong Soo; Kim, TaeHoon; Im, Ji Hyuk; Park, Chong Rae

    2011-10-01

    Hyper-networked Li4Ti5O12/carbon hybrid nanofiber sheets that contain both a faradaically rechargeable battery-type component, namely Li4Ti5O12, and a non-faradaically rechargeable supercapacitor-type component, namely N-enriched carbon, are prepared by electrospinning and their dual function as a negative electrode of lithium-ion batteries (LIBs) and a capacitor is tested for a new class of hybrid energy storage (denoted BatCap). An aqueous solution composed of polyvinylpyrrolidone, lithium hydroxide, titanium(IV) bis(ammonium-lactato)dihydroxide and ammonium persulfate is electrospun to obtain hyper-networked nanofiber sheets. Next, the sheets are exposed to pyrrole monomer vapor to prepare the polypyrrole-coated nanofiber sheets (PPy-HNS). The hyper-networked Li4Ti5O12/N-enriched carbon hybrid nanofiber sheets (LTO/C-HNS) are then obtained by a stepwise heat treatment of the PPy-HNS. The LTO/C-HNS deliver a specific capacity of 135 mAh g - 1 at 4000 mA g - 1 as a negative electrode for LIBs. In addition, potentiodynamic experiments are performed using a full cell with activated carbon (AC) as the positive electrode and LTO/C-HNS as the negative electrode to estimate the capacitance properties. This new asymmetric electrode system exhibits a high energy density of 91 W kg - 1 and 22 W kg - 1 at power densities of 50 W kg - 1 and 4000 W kg - 1, respectively, which are superior to the values observed for the {AC} \\parallel {AC} symmetric electrode system.

  10. Electrospinning of Nanofibers for Energy Applications.

    Science.gov (United States)

    Sun, Guiru; Sun, Liqun; Xie, Haiming; Liu, Jia

    2016-07-02

    With global concerns about the shortage of fossil fuels and environmental issues, the development of efficient and clean energy storage devices has been drastically accelerated. Nanofibers are used widely for energy storage devices due to their high surface areas and porosities. Electrospinning is a versatile and efficient fabrication method for nanofibers. In this review, we mainly focus on the application of electrospun nanofibers on energy storage, such as lithium batteries, fuel cells, dye-sensitized solar cells and supercapacitors. The structure and properties of nanofibers are also summarized systematically. The special morphology of nanofibers prepared by electrospinning is significant to the functional materials for energy storage.

  11. Electrospinning of Nanofibers for Energy Applications

    Directory of Open Access Journals (Sweden)

    Guiru Sun

    2016-07-01

    Full Text Available With global concerns about the shortage of fossil fuels and environmental issues, the development of efficient and clean energy storage devices has been drastically accelerated. Nanofibers are used widely for energy storage devices due to their high surface areas and porosities. Electrospinning is a versatile and efficient fabrication method for nanofibers. In this review, we mainly focus on the application of electrospun nanofibers on energy storage, such as lithium batteries, fuel cells, dye-sensitized solar cells and supercapacitors. The structure and properties of nanofibers are also summarized systematically. The special morphology of nanofibers prepared by electrospinning is significant to the functional materials for energy storage.

  12. A novel method for preparing Co{sub 3}O{sub 4} nanofibers by using electrospun PVA/cobalt acetate composite fibers as precursor

    Energy Technology Data Exchange (ETDEWEB)

    Guan Hongyu; Shao Changlu; Wen Shangbin; Chen Bin; Gong Jian; Yang Xinghua

    2003-12-20

    Thin PVA/cobalt acetate composite fibers were prepared by using sol-gel processing and electrospinning technique. After calcination of the above precursor fibers, Co{sub 3}O{sub 4} nanofibers with a diameter of 50-200 nm were successfully obtained. The fibers were characterized by scanning electron microscopy, FT-IR, wide-angle X-ray diffraction, respectively. The results showed that the crystalline phase and morphology of the as-prepared fibers were largely influenced by the calcination temperature.

  13. Preparation of Pure and Stable Chitosan Nanofibers by Electrospinning in the Presence of Poly(ethylene oxide).

    Science.gov (United States)

    Mengistu Lemma, Solomon; Bossard, Frédéric; Rinaudo, Marguerite

    2016-10-26

    Electrospinning was employed to obtain chitosan nanofibers from blends of chitosans (CS) and poly(ethylene oxide) (PEO). Blends of chitosan (MW (weight-average molecular weight) = 102 kg/mol) and PEO (M (molecular weight) = 1000 kg/mol) were selected to optimize the electrospinning process parameters. The PEO powder was solubilized into chitosan solution at different weight ratios in 0.5 M acetic acid. The physicochemical changes of the nanofibers were determined by scanning electron microscopy (SEM), swelling capacity, and nuclear magnetic resonance (NMR) spectroscopy. For stabilization, the produced nanofibers were neutralized with K₂CO₃ in water or 70% ethanol/30% water as solvent. Subsequently, repeated washings with pure water were performed to extract PEO, potassium acetate and carbonate salts formed in the course of chitosan nanofiber purification. The increase of PEO content in the blend from 20 to 40 w% exhibited bead-free fibers with average diameters 85 ± 19 and 147 ± 28 nm, respectively. Their NMR analysis proved that PEO and the salts were nearly completely removed from the nanostructure of chitosan, demonstrating that the adopted strategy is successful for producing pure chitosan nanofibers. In addition, the nanofibers obtained after neutralization in ethanol-aqueous solution has better structural stability, at least for six months in aqueous solutions (phosphate buffer (PBS) or water).

  14. Preparation and characterization of PVA/Au composite nanofiber%PVA/Au纳米复合纤维的制备及表征

    Institute of Scientific and Technical Information of China (English)

    吴涛; 钱琛

    2011-01-01

    以聚乙烯醇(PVA)为还原剂和保护剂,采用PVA还原氯金酸(HAuCl4)制备纳米金(Au),一步法制备PVA/Au溶液,通过静电纺丝制备了PVA/Au纳米复合纤维.利用紫外可见光谱仪、透明电镜和扫描电镜对PVA/Au纳米复合纤维进行了表征.结果表明:随着HAuCl4浓度的增加,Au纳米粒子的粒径逐渐增大;HAuCl4的浓度对纳米复合纤维的形貌影响较大,在HAuCl4浓度较低或较高时,均可以获得直径较为均一的PVA/Au纳米复合纤维;低电导率和高粘度的PVA/Au溶液可得到纤维直径均一的纳米复合纤维.%Using polyvinyl alcohol (PVA) as a reductant and a protectant, gold (Au) mmoparticles were produced from gold chloric acid ( HauCl4 ), from which PVA/Au solution was prepared by one-step process and was spun into PVA/Au composite nanofiber via electrospinning process. PVA/Au composite nanofiber was characterized with ultraviolet-visible spectroscope, transparent electron microscope and scanning electron microscope. The results showed that the Au runoparticle size gradually increased with the increase of HAuCl4 concentration. The HAuCl4 concentration had a great effect on the morphology of the composite nanofiber. PVA/Au composite nanofiber with uniform diameter can be obtained from PVA/Au solution with low conductivity and high viscosity at relatively high or low HAuCl4 concentration.

  15. Preparation of Aluminum Nanoparticles/Nitrocellulose Nanofibers%含纳米铝粉的纳米NC纤维的制备

    Institute of Scientific and Technical Information of China (English)

    谢龙; 邵自强; 王文俊; 王飞俊; 王慧庆

    2011-01-01

    In order to overcome the agglomeration of aluminum nanoparticles(AlNPs) in the propellant processing,the smooth and uniform nanofibers of AlNPs/nitrocellulose(NC) have been successfully fabricated by simple adding AlNPs to NC solution before electrospinning.The effect of electrospinning technique on the morphology and diameter of the nitrocellulose nanofibers were investigated by SEM.The suitable electrospinning conditions were as follows: water content, 10 % - 15 %, nitrocellulose solution concentration, 5 % - 10 %, voltage, 25 - 30 kV and extrusion rate,0.5~4 mL/h.The AlNPs/NC nanofibers prepared in the above-mentioned feasible condition reveal that AlNPs distribute uniformly in nanofibers matrix.%为了克服纳米铝粉在推进剂使用过程中分散不均匀的问题,采用静电纺丝技术制备了材料表面光滑、直径均匀、且纳米铝粉分散均匀的纳米NC纤维.用扫描电镜研究了含水率、溶液浓度、电压和挤出速率对纤维形态和直径的影响,得到静电纺丝最佳工艺条件:含水率为10%~15%,NC纺丝液质量分数5%~10%,电压25~30kV,挤出速率0.5~4mL/h.在此工艺条件下,制备出含纳米铝粉的纳米硝化棉纤维,显示纳米铝粉均匀地分散在硝化棉纤维中.

  16. Preparation and characterization of multi-layer biodegradable nanofibers by coaxial electrospinning and their potential for tissue engineering

    Science.gov (United States)

    Liu, Wenwen

    As an evolution of conventional electrospinning, coaxial electrospinning became popular soon after its debut as a novel way to develop nanofibers with special structures, such as core-shell and hollow interior. In recent years, there has been an increasing interest in a modified coaxial electrospinning, tri-layer coaxial electrospinning, to develop more complex structures, such as multi-layer and nanowire-in-microtube. Previous studies have primarily concentrated on the fabrication of tri-layered inorganic fibers while studies on tri-layered coaxial polymeric fibers has not been reported until very recently. Our research focuses on the fabrication of core-shell and tri-layer structured biodegradable polymeric nanofibers with coaxial electrospinning. Different characterization methods have been applied to observe the internal structure in single nanofibers and the potential application of tri-layer coaxial electrospinning has been discussed. The material system consists of biodegradable natural polymer gelatin, synthetic polymers poly (epsilon-caprolactone) (PCL) and poly (lactic-co-glycolic acid) (PLGA). A uniquely designed three-needle concentric spinneret is developed to perform tri-layer coaxial electrospinning. Different kinds of core-shell structured nanofibers, including gelatin/PCL, PCL/gelatin, gelatin/PLGA and PCL/PLGA, have been fabricated with a customized coaxial electrospinning apparatus. Two kinds of tri-layer coaxial nanofibers, two-component ABA structured gelatin/PCL/gelatin biodegradable nanofibers and tri-component ABC structured gelatin/PCL/PLGA biodegradable nanofibers, have been developed with the customized three needle coaxial electrospinning setup. The core-shell and tri-layered structures of electrospun nanofibers have been characterized by several commonly used techniques, such as laser scanning confocal microscopy (LSCM) and transmission electron microscopy (TEM). Besides the conventional methods, other newer techniques, including

  17. Insights to Advanced Inorganic Nanoparticles,Nanorods,Nanofibers and Nanotubes:Preparation and Applications

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    1 Results Quasi one-dimensional nanostructured materials have received considerable attention due to their unique optical and electrical properties and potential applications in nanodevices.Much effort has been directed toward exploring novel synthetic methods and understanding the chemical and physical properties of these nanostructures.The chemical vapor deposition and thermal evaporation,are proved to be efficient for the preparation of wirelike nanomaterials,however these methods are quite energy co...

  18. Magnetic and electrical properties of oxygen stabilized nickel nanofibers prepared by the borohydride reduction method

    Energy Technology Data Exchange (ETDEWEB)

    Srinivas, V. [Department of Physics and Meteorology, Indian Institute of Technology, Kharagpur West Bengal 721 302 India (India)], E-mail: veeturi@phy.iitkgp.ernet.in; Barik, S.K.; Bodo, Bhaskarjyoti [Department of Physics and Meteorology, Indian Institute of Technology, Kharagpur West Bengal 721 302 India (India); Karmakar, Debjani; Chandrasekhar Rao, T.V. [Technical Physics and Prototype Engineering Division, Bhabha Atomic Research Centre, Bombay 400085 India (India)

    2008-03-15

    Fine nickel fibers have been synthesized by chemical reduction of nickel ions in aqueous medium with sodium borohydride. The thermal stability and relevant properties of these fibers, as-prepared as well as air-annealed, have been investigated by structural, magnetic and electrical measurements. As-prepared samples appear to have a novel crystal structure due to the presence of interstitial oxygen. Upon annealing in air, the fcc-Ni phase emerges out initially and develops into a nanocomposite subsequently by retaining its fiber-like structure in nano phase. The as-prepared sample is observed to be weakly magnetic at room temperature, but attains surprisingly high magnetization values at low temperatures. This is attributed to the modified spin structure, presumably due to the presence of interstitial oxygen in the lattice. Development of a weakly ferromagnetic and electrically conducting phase upon annealing in air is attributed to the formation of the fcc-Ni phase. The structural phase transformations corroborate well with magnetic and electrical measurements.

  19. A simple and effective route for the preparation of poly(vinylalcohol) (PVA) nanofibers containing gold nanoparticles by electrospinning method

    Science.gov (United States)

    Bai, Jie; Li, Yaoxian; Yang, Songtao; Du, Jianshi; Wang, Shugang; Zheng, Jifu; Wang, Yongzhi; Yang, Qingbiao; Chen, Xuesi; Jing, Xiabin

    2007-02-01

    Poly(vinylalcohol) (PVA) nanofibers containing gold nanoparticles have been simply obtained by electrospinning a solution containing gold nanoparticles without the additional step of introducing other stabilizing agents. The optical property of gold nanoparticles in PVA aqueous solution was observed by UV-visible absorption spectra. Morphology of the Au/PVA nanofibers and distribution of the gold nanoparticles were characterized by transmission electron microscopy (TEM). The structure transformation was characterized from PVA to PVA/Au composite by Fourier transform infrared spectroscopy (FTIR).

  20. Effect of airflow on nanofiber yarn spinning

    Directory of Open Access Journals (Sweden)

    He Jian-Xin

    2015-01-01

    Full Text Available The paper proposes a new air-jet spinning method for the preparation of continuous twisted nanofiber yarns. The nozzle-twisting device is designed to create the 3-D rotating airflow to twist nanofiber bundles. The airflow characteristics inside the twisting chamber are studied numerically. The airflow field distribution and its effect on nanofiber yarn spinning at different pressures are also discussed.

  1. Preparation, in vitro mineralization and osteoblast cell response of electrospun 13-93 bioactive glass nanofibers.

    Science.gov (United States)

    Deliormanlı, Aylin M

    2015-08-01

    In this study, silicate based 13-93 bioactive glass fibers were prepared through sol-gel processing and electrospinning technique. A precursor solution containing poly (vinyl alcohol) and bioactive glass sol was used to produce fibers. The mixture was electrospun at a voltage of 20 kV by maintaining tip to a collector distance of 10 cm. The amorphous glass fibers with an average diameter of 464±95 nm were successfully obtained after calcination at 625 °C. Hydroxyapatite formation on calcined 13-93 fibers was investigated in simulated body fluid (SBF) using two different fiber concentrations (0.5 and 1 mg/ml) at 37 °C. When immersed in SBF, conversion to a calcium phosphate material showed a strong dependence on the fiber concentration. At 1mg/ml, the surface of the fibers converted to the hydroxyapatite-like material in SBF only after 30 days. At lower solid concentrations (0.5 mg/ml), an amorphous calcium phosphate layer formation was observed followed by the conversion to hydroxyapatite phase after 7 days of immersion. The XTT (2,3-Bis-(2-Methoxy-4-Nitro-5-Sulfophenyl)-2H-Tetrazolium-5-Carboxanilide) assay was conducted to evaluate the osteoblast cell response to the bioactive glass fibers. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Preparation and Study of Electromagnetic Interference Shielding Materials Comprised of Ni-Co Coated on Web-Like Biocarbon Nanofibers via Electroless Deposition

    Directory of Open Access Journals (Sweden)

    Xiaohu Huang

    2015-01-01

    Full Text Available Electromagnetic interference (EMI shielding materials made of Ni-Co coated on web-like biocarbon nanofibers were successfully prepared by electroless plating. Biocarbon nanofibers (CF with a novel web-like structure comprised of entangled and interconnected carbon nanoribbons were obtained using bacterial cellulose pyrolyzed at 1200°C. Paraffin wax matrix composites filled with different loadings (10, 20, and 30 wt%, resp. of CF and Ni-Co coated CF (NCCF were prepared. The electrical conductivities and electromagnetic parameters of the composites were investigated by the four-probe method and vector network analysis. From these results, the EMI shielding efficiencies (SE of NCCF composites were shown to be significantly higher than that of CF at the same mass fraction. The paraffin wax composites containing 30 wt% NCCF showed the highest EMI SE of 41.2 dB (99.99% attenuation, which are attributed to the higher electrical conductivity and permittivity of the NCCF composites than the CF composites. Additionally, EMI SE increased with an increase in CF and NCCF loading and the absorption was determined to be the primary factor governing EMI shielding. This study conclusively reveals that NCCF composites have potential applications as EMI shielding materials.

  3. Nickel nanofibers synthesized by the electrospinning method

    Energy Technology Data Exchange (ETDEWEB)

    Ji, Yi [School of Materials Science and Engineering, Hefei University of Technology, Anhui 230000 (China); Zhang, Xuebin, E-mail: zzhhxxbb@126.com [School of Materials Science and Engineering, Hefei University of Technology, Anhui 230000 (China); Zhu, Yajun; Li, Bin; Wang, Yang; Zhang, Jingcheng; Feng, Yi [School of Materials Science and Engineering, Hefei University of Technology, Anhui 230000 (China)

    2013-07-15

    Highlights: ► The nickel nanofibers have been obtained by electrospinning method. ► The nickel nanofibers had rough surface which was consisted of mass nanoparticles. ► The average diameter of nickel nanofibers is about 135 nm and high degree of crystallization. ► The Hc, Ms, and Mr were estimated to be 185 Oe, 51.9 and 16.9 emu/g respectively. - Abstract: In this paper, nickel nanofibers were prepared by electrospinning polyvinyl alcohol/nickel nitrate precursor solution followed by high temperature calcination in air and deoxidation in hydrogen atmosphere. The thermal stability of the as-electrospun PVA/Ni(NO{sub 3}){sub 2} composite nanofibers were characterized by TG–DSC. The morphologies and structures of the as-prepared samples were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), field-emission scanning electronmicroscope (FE-SEM) and field-emission transmission electron microscopy (FE-TEM). The hysteresis loops (M–H loops) were measured by Physical Property Measurement System (PPMS). The results indicate that: the PVA and the nickel nitrate were almost completely decomposed at 460 °C and the products were pure nickel nanofibers with face-centered cubic (fcc) structure. Furthermore, the as-prepared nickel nanofibers had a continuous structure with rough surface and high degree of crystallization. The average diameter of nickel nanofibers was about 135 nm. The nanofibers showed a stronger coercivity of 185 Oe than value of bulk nickel.

  4. Tailoring Supramolecular Nanofibers for Air Filtration Applications.

    Science.gov (United States)

    Weiss, Daniel; Skrybeck, Dominik; Misslitz, Holger; Nardini, David; Kern, Alexander; Kreger, Klaus; Schmidt, Hans-Werner

    2016-06-15

    The demand of new materials and processes for nanofiber fabrication to enhance the performance of air filters is steadily increasing. Typical approaches to obtain nanofibers are based on top-down processes such as melt blowing, centrifugal spinning, and electrospinning of polymer materials. However, fabrication of polymer nanofibers is limited with respect to either a sufficiently high throughput or the smallest achievable fiber diameter. This study reports comprehensively on a fast and simple bottom-up process to prepare supramolecular nanofibers in situ inside viscose/polyester microfiber nonwovens. Here, selected small molecules of the materials class of 1,3,5-benzenetrisamides are employed. The microfiber-nanofiber composites exhibit a homogeneous nanofiber distribution and morphology throughout the entire nonwoven scaffold. Small changes in molecular structure and processing solvent have a strong influence on the final nanofiber diameter and diameter distribution and, consequently, on the filtration performance. Choosing proper processing conditions, microfiber-nanofiber composites with surprisingly high filtration efficiencies of particulate matter are obtained. In addition, the microfiber-nanofiber composite integrity at elevated temperatures was determined and revealed that the morphology of supramolecular nanofibers is maintained compared to that of the utilized polymer nonwoven.

  5. Preparation and Characterization of Cyclic N-halamine Modified Chitosan/PVA Nanofibers%环状卤胺化合物改性壳聚糖/PVA纳米纤维的制备与表征

    Institute of Scientific and Technical Information of China (English)

    李蓉; 刘喆; 任学宏

    2013-01-01

    Antibacterial nanofibers were prepared by electrospinning the mixtures of 3-glycidyl-5,5-dimethylhydantoin modified chitosan (CTS-GH) and poly(vinyl alcohol) (PVA).The structures and thermo properties of electro-spun nanofibers were measured by SEM,FT-IR,and TGA.The effect of the spinning flow rates on the diameters and chlorine loadings of nanofibers were investigated.The results show that the diameter of nanofibers decreased with the increase of the flow rate.The high chlorine contents of the nanofibers indicate that the nanofibers have excellent antibacterial property after chlorination.These nanofibers may serve as potential materials for filtration and biomedical applications.%以易于纺丝的聚乙烯醇(PVA)为纤维基材,添加3-环氧丙基-5,5-二甲基海因改性壳聚糖(CTS-GH),利用静电纺丝法制备出具有高效抗茵效果的纳米纤维.采用扫描电镜、红外光谱、热重分析仪表征和分析了纳米纤维的结构和热性能,考察了纺丝液流量对纳米纤维结构和氯含量的影响.结果表明,纳米纤维的直径随着纺丝速度的加快而减小.利用碘量法测定了纳米纤维的氯含量,说明该纳米纤维经过氯化处理后具有很好的抗茵效果.该纳米纤维可用于抗茵过滤材料、生物医药等方面.

  6. Preparation and characterization of electrospun PLCL/Poloxamer nanofibers and dextran/gelatin hydrogels for skin tissue engineering.

    Directory of Open Access Journals (Sweden)

    Jian-feng Pan

    Full Text Available In this study, two different biomaterials were fabricated and their potential use as a bilayer scaffold for skin tissue engineering applications was assessed. The upper layer biomaterial was a Poly(ε-caprolactone-co-lactide/Poloxamer (PLCL/Poloxamer nanofiber membrane fabricated using electrospinning technology. The PLCL/Poloxamer nanofibers (PLCL/Poloxamer, 9/1 exhibited strong mechanical properties (stress/strain values of 9.37 ± 0.38 MPa/187.43 ± 10.66% and good biocompatibility to support adipose-derived stem cells proliferation. The lower layer biomaterial was a hydrogel composed of 10% dextran and 20% gelatin without the addition of a chemical crosslinking agent. The 5/5 dextran/gelatin hydrogel displayed high swelling property, good compressive strength, capacity to present more than 3 weeks and was able to support cells proliferation. A bilayer scaffold was fabricated using these two materials by underlaying the nanofibers and casting hydrogel to mimic the structure and biological function of native skin tissue. The upper layer membrane provided mechanical support in the scaffold and the lower layer hydrogel provided adequate space to allow cells to proliferate and generate extracellular matrix. The biocompatibility of bilayer scaffold was preliminarily investigated to assess the potential cytotoxicity. The results show that cell viability had not been affected when cocultured with bilayer scaffold. As a consequence, the bilayer scaffold composed of PLCL/Poloxamer nanofibers and dextran/gelatin hydrogels is biocompatible and possesses its potentially high application prospect in the field of skin tissue engineering.

  7. Heterojunctions of p-BiOI Nanosheets/n-TiO2 Nanofibers: Preparation and Enhanced Visible-Light Photocatalytic Activity

    Directory of Open Access Journals (Sweden)

    Kexin Wang

    2016-01-01

    Full Text Available p-BiOI nanosheets/n-TiO2 nanofibers (p-BiOI/n-TiO2 NFs have been facilely prepared via the electrospinning technique combining successive ionic layer adsorption and reaction (SILAR. Dense BiOI nanosheets with good crystalline and width about 500 nm were uniformly assembled on TiO2 nanofibers at room temperature. The amount of the heterojunctions and the specific surface area were well controlled by adjusting the SILAR cycles. Due to the synergistic effect of p-n heterojunctions and high specific surface area, the obtained p-BiOI/n-TiO2 NFs exhibited enhanced visible-light photocatalytic activity. Moreover, the p-BiOI/n-TiO2 NFs heterojunctions could be easily recycled without decreasing the photocatalytic activity owing to their one-dimensional nanofibrous structure. Based on the above, the heterojunctions of p-BiOI/n-TiO2 NFs may be promising visible-light-driven photocatalysts for converting solar energy to chemical energy in environment remediation.

  8. Influence of graphene oxide doping on the morphology and the magnetic properties of Ni0.8Gd0.2Fe2O4 nanofibers prepared by electrospinning

    Science.gov (United States)

    Mansour, Michel; Bechelany, Mikhael; Habchi, Roland; Eid, Cynthia

    2017-02-01

    Nickel-gadolinium ferrite nanofibers doped with graphene oxide (GO) were prepared for the first time by the electrospinning technique. The structure and morphology of the as-obtained composites were characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy, X-ray diffractometer, Fourier transform infrared spectra, and Raman spectroscopy. The magnetic properties were analyzed by Quantum design MPMS-XL magnetometer. A transition from a 'fiber' morphology to a 'ribbon' morphology was detected for the samples doped with GO. Also, an increase in the magnetic saturation was found when the GO amount increases. Therefore, doping with GO influences both the morphology and the magnetic properties of the electrospun nickel-gadolinium ferrite nanofibers. These results provide a promising lead for the future synthesis of a variety of GO doped ferrites nanofiber morphologies with controllable magnetic properties.

  9. Biologically Active Polycaprolactone/Titanium Hybrid Electrospun Nanofibers for Hard Tissue Engineering

    DEFF Research Database (Denmark)

    Barakat, Nasser A. M.; Sheikh, Faheem A.; Al-Deyab, Salem S.

    2011-01-01

    In this study, a novel strategy to improve the bioactivity of polycaprolactone nanofibers is proposed. Incorporation of pure titanium nanoparticles into polycaprolactone nanofibers strongly enhances the precipitation of bone-like apatite materials when the doped nanofibers are soaked in a simulat...... nanofiber mats and the successful incorporation of the titanium nanoparticles make the prepared polycaprolactone nanofiber mat a proper candidate for the hard-tissue engineering applications....

  10. Preparation of Magnesium Hydroxide and Nanofiber Polymer Composites to Reduce the Flammability and Melt Dripping Behaviour of Polymers

    Directory of Open Access Journals (Sweden)

    S. S. Raza

    2014-12-01

    Full Text Available Nanoscale alumina fibers reduce the flammability and melt dripping behaviour of polymers. Magnesium hydroxide breaks the agglomerates by generating shear and iterative forces. Mixing was done with Brabender Plasticoder. The temperature and time of mixing greatly affects the mixing behaviour. At higher temperatures blow holes were observed. By increasing the mixing time agglomerates were broken to a greater extent. Different concentrations of nanofibers, Magnesium hydroxide and surface treatments are used to investigate the properties of polymer. Thermogravimetric analysis (TGA, optical microscopy and flame test was done to see the effect of different parameters on mixing and flame retardancy behaviour.

  11. Photocatalytic Performance Investigation of TiO2/PVA Nanofibers Prepared by Electrospinning%静电纺制备TiO2/PVA复合纳米纤维及其光催化性能研究

    Institute of Scientific and Technical Information of China (English)

    丁源维; 王騊; 姚菊明; 王晟

    2013-01-01

    通过静电纺丝的方法制备一种以二氧化钛(TiO2)为催化剂,聚乙烯醇(PVA)为载体的TiO2/PVA复合纳米纤维光催化材料.使用FE-SEM,XRD,Tg,FTIR对制备的TiO2/PVA复合纳米纤维膜进行了表征,并考察了其紫外光照射下光催化降解罗丹明B(Rh B)的能力.结果表明:制备的TiO2/PVA复合纳米纤维具有较高的光催化活性.%This paper prepares TiO2/PVA nanofibers via electrospinning and by using TiO2 as photo-catalysts and PVA as carriers. The as-prepared TiO2/PVA nanofibers are characterized by FE-SEM, XRD, TG and FT-IR. Furthermore, under UV light irradiation, the authors investigate the photodecom-position of Rhodamine B solution by applying TiO2/PVA nanofibers as photocatalysts. The results indicate that TiCWPVA nanofibers are efficient photocatalysts.

  12. Preparation and application of amino functionalized mesoporous nanofiber membrane via electrospinning for adsorption of Cr3+ from aqueous solution

    Institute of Scientific and Technical Information of China (English)

    Ahmed A.Taha; Junlian Qiao; Fengting Li; Bingru Zhang

    2012-01-01

    Novel amino (-NH2) functionalized mesoporous polyvinyl pyrrolidone (PVP)/SiO2 composite nanofiber membranes were fabricated by a one-step electrospinning method using poly (vinyl alcohol) and tetraethyl orthosilicate (TEOS) mixed with cationic surfactant,cetyltrimethyl ammonium bromide (CTAB) as the structure directing agent.Ureidopropyltriethoxysilane was used for functionalization of the internal pore surfaces.The membranes were characterized by scanning electron microscopy (SEM),high-resolution transmission electron microscopy (HRTEM) images,X-ray diffraction (XRD),Fourier-transform infrared spectroscopy (FT-IR),element analyzer and N2 adsorption-desorption isotherms.The nanofiber diameters,average pore diameters and surface areas were 100-700 nm,2.86 nm and 873.62 m2/g,respectively.These mesoporous membranes functionalized with -NH2 groups exhibited very high adsorptions properties based on the adsorption of Cr3+ from an aqueous solution.Equilibrium adsorption was achieved after approximately 20 min and more than 97% of chromium ions in the solution were removed.The membrane could be regenerated through acidification.

  13. Alkylated graphene nanosheet composites with polyaniline nanofibers.

    Science.gov (United States)

    Grinou, Ali; Yun, Young Soo; Cho, Se Youn; Jin, Hyoung-Joon

    2011-07-01

    We demonstrate a simple method to prepare alkylated graphene/polyaniline composites (a-GR/PANI) using solution mixing of exfoliated alkyl Iodododecane treated graphene oxide sheets with polyaniline nanofiber; polyaniline nanofibers (PANI) prepared by using rapid mixing polymerization significantly improve the processibility of polyaniline and its performance in many conventional applications. Also, polyaniline nanofibers exhibit excellent water dispersibility due to their uniform nanofiber morphology. Morphological study using SEM and TEM analysis showed that the fibrous PANI in the composites a-GR/PANI mainly adsorbed onto the surface or intercalated between the graphene sheets, due especially to the good interfacial interaction between the alkylated gaphene and the polyaniline nanofibers. The existence of polyaniline nanofibers on the surface of the garphene and the alkylated graphene sheets was confirmed by using FT-IR, FT-Raman and X-ray diffraction analysis. Due to the good interfacial interaction between the alkylated graphene and the polyanilines nanofibers, the composite (a-GR/PANI) exhibited excellent dispersion stability in DMF compared to the same composite (GR/PANI) without alkylation. The electrical conductivity of the (GR/PANI) composite was 9% higher than that of pure PANI and the same weight percent for the composite after alkylation was 13% higher than that of pure PANI nanofibers.

  14. 二氧化硅@聚合物同轴纳米纤维%Silica@Polymers Coaxial Nanofibers

    Institute of Scientific and Technical Information of China (English)

    洪友良; 商铁存; 靳玉伟; 杨帆; 王策

    2005-01-01

    The preparation and formation mechamsm ot silica/polyvinylpyrrolidone(PAN) coaxial nanofibers were presented in this paper. The PVP-PAN composite nanofibers were obtained via an electrospinning technique, while SiO2 nanoparticles were prepared according to a Stoeher method. The measurements of water contact angle(WCA), the compared results of silica coating PVPPAN composite nanofibers with PAN nanofibers indicate that much PVP resided on the composite nanofiber surface, which resuks in the occurrence of SiO2@polymer coaxial nanofibers due to the formation of hydrogen bonding between silica and composite nanofibers and subsequent adsorption of silica on the fiber surface.

  15. Synthesis and electrochemical properties of polyaniline nanofibers by interfacial polymerization.

    Science.gov (United States)

    Manuel, James; Ahn, Jou-Hyeon; Kim, Dul-Sun; Ahn, Hyo-Jun; Kim, Ki-Won; Kim, Jae-Kwang; Jacobsson, Per

    2012-04-01

    Polyaniline nanofibers were prepared by interfacial polymerization with different organic solvents such as chloroform and carbon tetrachloride. Field emission scanning electron microscopy and transmission electron microscopy were used to study the morphological properties of polyaniline nanofibers. Chemical characterization was carried out using Fourier transform infrared spectroscopy, UV-Vis spectroscopy, and X-ray diffraction spectroscopy and surface area was measured using BET isotherm. Polyaniline nanofibers doped with lithium hexafluorophosphate were prepared and their electrochemical properties were evaluated.

  16. Preparation and characterization of bioactive composite scaffolds from polycaprolactone nanofibers-chitosan-oxidized starch for bone regeneration.

    Science.gov (United States)

    Nourmohammadi, Jhamak; Ghaee, Azadeh; Liavali, Samira Hosseini

    2016-03-15

    The objective of this study was to fabricate and investigate the characteristics of a suitable scaffold for bone regeneration. Therefore, chitosan was combined with various amounts of oxidized starch through reductive alkylation process. Afterwards, chopped CaP-coated PCL nanofibers were added into the chitosan-starch composite scaffolds in order to obtain bioactivity and mimic bone extracellular matrix structure. Scanning electron microscopy confirmed that all scaffolds had well-interconnected porous structure. The mean pore size, porosity, and water uptake of the composite scaffolds increased by incorporation of higher amounts of starch, while this trend was opposite for compressive modulus and strength. Osteoblast-like cells (MG63) culturing on the scaffolds demonstrated that higher starch content could improve cell viability. Moreover, the cells spread and anchored well on the scaffolds, on which the surface was covered with a monolayer of cells. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Influence of graphene oxide doping on the morphology and the magnetic properties of Ni{sub 0.8}Gd{sub 0.2}Fe{sub 2}O{sub 4} nanofibers prepared by electrospinning

    Energy Technology Data Exchange (ETDEWEB)

    Mansour, Michel [EC2M, Faculty of Sciences 2, and Research Platform for Nanoscience and Nanotechnologies, Campus Pierre Gemayel, Fanar, Lebanese University, 90656 (Lebanon); Institut Européen des Membranes, UMR 5635 ENSCM UM CNRS, Université du Montpellier, Place Eugène Bataillon, 34095 Montpellier (France); Bechelany, Mikhael [Institut Européen des Membranes, UMR 5635 ENSCM UM CNRS, Université du Montpellier, Place Eugène Bataillon, 34095 Montpellier (France); Habchi, Roland [EC2M, Faculty of Sciences 2, and Research Platform for Nanoscience and Nanotechnologies, Campus Pierre Gemayel, Fanar, Lebanese University, 90656 (Lebanon); Eid, Cynthia, E-mail: cynthia.eid@ul.edu.lb [EC2M, Faculty of Sciences 2, and Research Platform for Nanoscience and Nanotechnologies, Campus Pierre Gemayel, Fanar, Lebanese University, 90656 (Lebanon)

    2017-02-12

    Nickel–gadolinium ferrite nanofibers doped with graphene oxide (GO) were prepared for the first time by the electrospinning technique. The structure and morphology of the as-obtained composites were characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy, X-ray diffractometer, Fourier transform infrared spectra, and Raman spectroscopy. The magnetic properties were analyzed by Quantum design MPMS-XL magnetometer. A transition from a ‘fiber’ morphology to a ‘ribbon’ morphology was detected for the samples doped with GO. Also, an increase in the magnetic saturation was found when the GO amount increases. Therefore, doping with GO influences both the morphology and the magnetic properties of the electrospun nickel–gadolinium ferrite nanofibers. These results provide a promising lead for the future synthesis of a variety of GO doped ferrites nanofiber morphologies with controllable magnetic properties. - Highlights: • Graphene oxide doped nickel–gadolinium nanofibers are obtained by the low cost method of electrospinning. • With higher GO amounts, higher magnetic saturation was obtained. • Total conversion from the fiber morphology to ribbon morphology was observed starting from a doping rate of 12%.

  18. Preparation of Bacterial Cellulose Nanofiber Through Electrospinning%静电纺丝法制备细菌纤维素纳米纤维

    Institute of Scientific and Technical Information of China (English)

    关晓辉; 于磊; 鲁敏; 张月明

    2013-01-01

    Using bacterial cellulose (BC) as raw material,room temperature ionic liquid AMIMCL as a solution system,the bacterial cellulose nanofibers were prepared through electrospinning technology.Co-solvent N,N-dimethyl formamide (DMF) was added to reduce the viscosity of spinning fluid,and a rotating drum collector was designed and applied.The influences of BC mass fraction,DMF amount,voltage,and curing distance on the spinning process were investigated.The electrospun nanofibers were analyzed by optical microscope,SEM and XRD.The experimental results showed that,when BC mass fraction,ratio of AMIMCL to DMF,voltage,curing distance,and environmental humidity were 5%,1:2.5,23 kV,12 cm,and 60%-80%,respectively,the electrospun B(nanofibers were continuous and the diameter was 500-800 nm.The crystal structure of BC was cellulose of type-Ⅰ,but after BC was dissolved by ionic liquid and electrospun into nanofibers,its crystal structure conversed into cellulose type-Ⅱ.%利用静电纺丝技术,以实验室自制的细菌纤维素(BC)为原材料,选择室温离子液体1-烯丙基-3-甲基咪唑氯化物(AMIMCL)为溶解体系,制备出细菌纤维素纳米纤维.实验中通过添加助溶剂N,N-二甲基甲酰胺(DMF)降低纺丝液的粘度,并设计了转动的滚筒收集器,考察了BC质量分数、DMF的添加量、电压、固化距离等因素对静电纺丝的影响,利用光学显微镜、扫描电子显微镜(SEM)以及X射线衍射(XRD)对纺丝进行分析.研究表明,在BC质量分数为5%、AMIMCL与DMF的质量比为1:2.5、电压为23 kV、固化距离为12 cm、环境湿度为60%~80%的条件下能够制备出连续的、直径为500~800nm的细菌纤维素纳米纤维;BC的晶体结构为纤维素Ⅰ型,而BC经离子液体溶解并静电纺丝后其结构转化为纤维素Ⅱ型.

  19. Fabrication of nanofiber mats from electrospinning of functionalized polymers

    Science.gov (United States)

    Oktay, Burcu; Kayaman-Apohan, Nilhan; Erdem-Kuruca, Serap

    2014-08-01

    Electrospinning technique enabled us to prepare nanofibers from synthetic and natural polymers. In this study, it was aimed to fabricate electrospun poly(vinyl alcohol) (PVA) based nanofibers by reactive electrospinning process. To improve endurance of fiber toward to many solvents, PVA was functionalized with photo-crosslinkable groups before spinning. Afterward PVA was crosslinked by UV radiation during electrospinning process. The nanofiber mats were characterized by scanning electron microscopy (SEM). The results showed that homogenous, uniform and crosslinked PVA nanofibers in diameters of about 200 nm were obtained. Thermal stability of the nanofiber mat was investigated with thermal gravimetric analysis (TGA). Also the potential use of this nanofiber mats for tissue engineering was examined. Osteosarcoma (Saos) cells were cultured on the nanofiber mats.

  20. Novel continuous carbon and ceramic nanofibers and nanocomposites

    Science.gov (United States)

    Wen, Yongkui

    2004-12-01

    studied. In Chapter 6, ZrO2 nanofibers were prepared using commercial and novel polymer-containing sol-gel precursors. The ZrO2 nanofibers were continuous, circular in cross section, and had diameters as small as 80 mn. Aligned ZrO2 nanofibers were prepared using newly developed polymer containing composite precursor for the first time. The possibility of nanomanufacturing of nanocrystalline continuous nanofibers was demonstrated. The results of this dissertation will have an impact in the field of high performance fibers and nanocomposites. This study is expected to catalyze research on advanced continuous nanofibers and may pave way for consideration of continuous advanced electrospun nanofibers as reinforcement in the next generation nanocomposites. (Abstract shortened by UMI.)

  1. Chemistry on electrospun polymeric nanofibers: merely routine chemistry or a real challenge?

    Science.gov (United States)

    Agarwal, Seema; Wendorff, Joachim H; Greiner, Andreas

    2010-08-03

    Nanofiber-based non-wovens can be prepared by electrospinning. The chemical modification of such nanofibers or chemistry using nanofibers opens a multitude of application areas and challenges. A wealth of chemistry has been elaborated in recent years on and with electrospun nanofibers. Known methods as well as new methods have been applied to modify the electrospun nanofibers and thereby generate new materials and new functionalities. This Review summarizes and sorts the chemistry that has been reported in conjunction with electrospun nanofibers. The major focus is on catalysis and nanofibers, enzymes and nanofibers, surface modification for biomedical and specialty applications, coatings of fibers, crosslinking, and bulk modifications. A critical focus is on the question: what could make chemistry on or with nanofibers different from bulk chemistry?

  2. Preparation of amide-t-butylcalix[8] arene/polyacrylonitrile nanofibers by electrospinning%对叔丁基酰胺化杯[8]芳烃/聚丙烯腈纳米纤维的制备

    Institute of Scientific and Technical Information of China (English)

    高春; 房伟; 陈铭; 刁国旺

    2012-01-01

    Amide-t-butylcalix[8] arene/polyacrylonitrile (Amide-Cal[8]/PAN) nanofibers were prepared by electrospinning. The nanofibers were characterized by fourier transform infrared spectros-copy (FTIR), field emission scanning electron microscope (FE-SEM), conductivity meter, torque rheometer. The results showed that Amide-Cal[8]/PAN was successfully prepared by electrospinning. The diameter of nanofibers was smaller than that of the blank PAN nanofibers. Moreover, the surface of nanofibers was smooth and uniform, but with the Amide-Cal[8] content increased, diameter of nanofibers and the surface roughness were increased. Rheometer results indicated that the viscosities of Amide-Cal[8]/PAN spinning solutions were increased with the increase of Amide-Cal[8] content. Conductivity results showed that the electrical conductivities of Amide-Cal[8]/ PAN spinning solution were higher than that of pure PAN solution and it was conducive to electrospinning.%采用静电纺丝技术制备了对叔丁基酰胺化杯[8]芳烃/聚丙烯腈(Amide-Cal[8]/PAN)复合纳米纤维,并通过傅里叶变换红外光谱(FTIR)仪、场发射扫描电镜(FE-SEM)、电导率仪、转矩流变仪对其结构与性质进行表征.实验结果表明:①Amide-Cal[8]/PAN纳米纤维的直径较空白的PAN纳米纤维小;②随着Amide-Cal[8]含量的增加,纳米纤维的直径先减小后增大,且纤维表面的粗糙程度逐渐增加,粗细不均;Amide-Cal[8]/PAN电纺溶液的黏度随着Amide-Cal[8]含量的增加而线性增大;③Amide-Cal[8]/PAN电纺溶液比PAN溶液的电导率大,有利于静电纺丝.

  3. Fabrication of Conductive Polypyrrole Nanofibers by Electrospinning

    Directory of Open Access Journals (Sweden)

    Yiqun Cong

    2013-01-01

    Full Text Available Electrospinning is employed to prepare conductive polypyrrole nanofibers with uniform morphology and good mechanical strength. Soluble PPy was synthesized with NaDEHS as dopant and then applied to electrospinning with or without PEO as carrier. The PEO contents had great influence on the morphology and conductivity of the electrospun material. The results of these experiments will allow us to have a better understanding of PPy electrospun nanofibers and will permit the design of effective electrodes in the BMIs fields.

  4. Doubly curved nanofiber-reinforced optically transparent composites

    Science.gov (United States)

    Shams, Md. Iftekhar; Yano, Hiroyuki

    2015-11-01

    Doubly curved nanofiber-reinforced optically transparent composites with low thermal expansion of 15 ppm/k are prepared by hot pressing vacuum-filtered Pickering emulsions of hydrophobic acrylic resin monomer, hydrophilic chitin nanofibers and water. The coalescence of acrylic monomer droplets in the emulsion is prevented by the chitin nanofibers network. This transparent composite has 3D shape moldability, making it attractive for optical precision parts.

  5. Adsorption of Th4+, U6+, Cd2+, and Ni2+ from aqueous solution by a novel modified polyacrylonitrile composite nanofiber adsorbent prepared by electrospinning

    Science.gov (United States)

    Dastbaz, Abolfazl.; Keshtkar, Ali Reza.

    2014-02-01

    In this study, SiO2 nanoparticles were modified by 3-aminopropyltriethoxysilane (APTES) and then applied to prepare a novel polyacrylonitrile (PAN) composite nanofiber adsorbent by the electrospinning method. In addition, the adsorbent was characterized by SEM, BET, and FTIR analyses. Then the effects of pH, SiO2 and APTES content, adsorbent dosage, contact time and temperature were investigated. Moreover, adsorption experiments were carried out with initial concentrations in the range of 30-500 mg L-1 and the adsorbent affinity for metal ions was in order of Th4+ > U6+ > Cd2+ > Ni2+. Furthermore, it was observed that the optimum pH for adsorption was different for each metal. Some isotherm and kinetic models were applied to analyze the experimental data, among which the Langmuir and pseudo-second order models were better than the others. The regeneration study showed that the adsorbent could be used for industrial processes repeatedly without any significant reduction in its adsorption capacity. Based on the Langmuir model, the maximum adsorption capacity of Th4+, U6+, Cd2+, and Ni2+ at 45 °C was 249.4, 193.1, 69.5 and 138.7 mg g-1, respectively. Besides, the calculated thermodynamic parameters showed an endothermic as well as chemical nature through the adsorption process.

  6. Microwave-assisted preparation of carbon nanofiber-functionalized graphite felts as electrodes for polymer-based redox-flow batteries

    Science.gov (United States)

    Schwenke, A. M.; Janoschka, T.; Stolze, C.; Martin, N.; Hoeppener, S.; Schubert, U. S.

    2016-12-01

    A simple and fast microwave-assisted protocol to functionalize commercially available graphite felts (GFs) with carbon nanofibers (CNFs) for the application as electrode materials in redox-flow batteries (RFB) is demonstrated. As catalyst for the CNF synthesis nickel acetate is applied and ethanol serves as the carbon source. By the in-situ growth of CNFs, the active surface of the electrodes is increased by a factor of 50, which is determined by the electrochemical double layer capacities of the obtained materials. Furthermore, the morphology of the CNF-coating is investigated by scanning electron microscopy. Subsequently, the functionalized electrodes are applied in a polymer-based redox-flow battery (pRFB) using a TEMPO- and a viologen polymer as active materials. Due to the increased surface area as compared to an untreated graphite felt electrode, the current rating is improved by about 45% at 80 mA cm-2 and, furthermore, a decrease in overpotentials is observed. Thus, using this microwave-assisted synthesis approach, CNF-functionalized composite electrodes are prepared with a very simple protocol suitable for real life applications and an improvement of the overall performance of the polymer-based redox-flow battery is demonstrated.

  7. Fast preparation of PtRu catalysts supported on carbon nanofibers by the microwave-polyol method and their application to fuel cells.

    Science.gov (United States)

    Tsuji, Masaharu; Kubokawa, Masatoshi; Yano, Ryuto; Miyamae, Nobuhiro; Tsuji, Takeshi; Jun, Mun-Suk; Hong, Seonghwa; Lim, Seongyop; Yoon, Seong-Ho; Mochida, Isao

    2007-01-16

    PtRu alloy nanoparticles (24 +/- 1 wt %, Ru/Pt atomic ratios = 0.91-0.97) supported on carbon nanofibers (CNFs) were prepared within a few minutes by using a microwave-polyol method. Three types of CNFs with very different surface structures, such as platelet, herringbone, and tubular ones, were used as new carbon supports. The dependence of particles sizes and electrochemical properties on the structures of CNFs was examined. It was found that the methanol fuel cell activities of PtRu/CNF catalysts were in the order of platelet > tubular > herringbone. The methanol fuel cell activities of PtRu/CNFs measured at 60 degrees C were 1.7-3.0 times higher than that of a standard PtRu (29 wt %, Ru/Pt atomic ratio = 0.92) catalyst loaded on carbon black (Vulcan XC72R) support. The best electrocatalytic activity was obtained for the platelet CNF, which is characterized by its edge surface and high graphitization degree.

  8. Graphitized carbon nanofiber-Pt nanoparticle hybrids as sensitive tool for preparation of screen printing biosensors. Detection of lactate in wines and ciders.

    Science.gov (United States)

    Loaiza, Oscar A; Lamas-Ardisana, Pedro J; Añorga, Larraitz; Jubete, Elena; Ruiz, Virginia; Borghei, Maryam; Cabañero, Germán; Grande, Hans J

    2015-02-01

    This work describes the fabrication of a new lactate biosensor. The strategy is based on the use of a novel hybrid nanomaterial for amperometric biosensors i.e. platinum nanoparticles (PtNps) supported on graphitized carbon nanofibers (PtNps/GCNF) prepared by chemical reduction of the Pt precursor at GCNF surfaces. The biosensors were constructed by covalent immobilization of lactate oxidase (LOx) onto screen printed carbon electrodes (SPCEs) modified with PtNps (PtNps/GCNF-SPCEs) using polyethyleneimine (PEI) and glutaraldehyde (GA). Experimental variables concerning both the biosensor design and the detection process were investigated for an optimal analytical performance. Lactate biosensors show good reproducibility (RSD 4.9%, n=10) and sensitivity (41,302±546) μA/Mcm(2), with a good limit of detection (6.9μM). Covalent immobilization of the enzyme allows the reuse of the biosensor for several measurements, converting them in a cheap alternative to the solid electrodes. The long-term stability of the biosensors was also evaluated. 90% of the signal was kept after 3months of storage at room temperature (RT), while 95% was retained after 18months at -20°C. These results demonstrate that the method provides sensitive electrochemical lactate biosensors where the stability of the enzymatic activity can be preserved for a long period of time in adequate storage conditions.

  9. 锐钛矿相TiO2纳米纤维制备与摩擦学性能%Preparation of Anatase TiO2 Nanofiber and Its Tribological Properties as Additive in Liquid Paraffin

    Institute of Scientific and Technical Information of China (English)

    刘琳; 阴翔宇; 张月; 钱建华

    2013-01-01

    Anatase TiO2 nanofiber was prepared via an available alkaline hydrothermal method and surface modified. The obtained products were characterized by using X-ray diffraction (XRD), scanning electron microscope (SEM) measurements and Fourier transform infrared spectroscopy (FT-IR). The as-prepared TiO2 nanofiber could be well dispersed in liquid paraffin, and its tribological properties as additive were evaluated with a four-ball tester. The results showed that the as-prepared TiO2 nanofiber exhibited good performance in anti-wear and friction-reduction, load-carrying capacity, and extreme pressure properties. When addition amount of the as-prepared TiO2 nanofiber was 1.5% of mass fraction in liquid paraffin, the best anti-friction wear reducing and bearing capacity enhancing were obtained, which made the TiO2 nanofiber promising for green lubricating oil additives.%采用简便且可重复性较好的碱熔法制备锐钛矿相TiO2,采用简便的表面修饰技术对其进行表面改性,得到TiO2纳米纤维,并采用XRD、SEM和FT-IR方法对其进行表征.利用四球摩擦试验机考察其作为油品润滑添加剂的摩擦学性能.结果表明,所合成的TiO2纳米纤维为锐钛矿相结构,结晶度和纯度较高,而且在油品中具有良好的分散性;TiO2纳米纤维具有良好的抗磨减摩性能,并能够很好地提高油品承载能力,当其加入量为1.5%(质量分数)时,抗磨减摩以及提高承载能力的效果最好.这些特性使得锐钛矿相TiO2纳米纤维有望在未来成为绿色润滑油添加剂.

  10. Preparation and electrochemical performance of hyper-networked Li{sub 4}Ti{sub 5}O{sub 12}/carbon hybrid nanofiber sheets for a battery-supercapacitor hybrid system

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Hong Soo; Kim, TaeHoon; Im, Ji Hyuk; Park, Chong Rae, E-mail: crpark@snu.ac.kr [Carbon Nanomaterials Design Laboratory, Global Research Laboratory, Research Institute of Advanced Materials, and Department of Materials Science and Engineering, Seoul National University, 599 Gwanak-ro, Gwanak-gu, Seoul 151-744 (Korea, Republic of)

    2011-10-07

    Hyper-networked Li{sub 4}Ti{sub 5}O{sub 12}/carbon hybrid nanofiber sheets that contain both a faradaically rechargeable battery-type component, namely Li{sub 4}Ti{sub 5}O{sub 12}, and a non-faradaically rechargeable supercapacitor-type component, namely N-enriched carbon, are prepared by electrospinning and their dual function as a negative electrode of lithium-ion batteries (LIBs) and a capacitor is tested for a new class of hybrid energy storage (denoted BatCap). An aqueous solution composed of polyvinylpyrrolidone, lithium hydroxide, titanium(IV) bis(ammonium-lactato)dihydroxide and ammonium persulfate is electrospun to obtain hyper-networked nanofiber sheets. Next, the sheets are exposed to pyrrole monomer vapor to prepare the polypyrrole-coated nanofiber sheets (PPy-HNS). The hyper-networked Li{sub 4}Ti{sub 5}O{sub 12}/N-enriched carbon hybrid nanofiber sheets (LTO/C-HNS) are then obtained by a stepwise heat treatment of the PPy-HNS. The LTO/C-HNS deliver a specific capacity of 135 mAh g{sup -1} at 4000 mA g{sup -1} as a negative electrode for LIBs. In addition, potentiodynamic experiments are performed using a full cell with activated carbon (AC) as the positive electrode and LTO/C-HNS as the negative electrode to estimate the capacitance properties. This new asymmetric electrode system exhibits a high energy density of 91 W kg{sup -1} and 22 W kg{sup -1} at power densities of 50 W kg{sup -1} and 4000 W kg{sup -1}, respectively, which are superior to the values observed for the AC||AC symmetric electrode system.

  11. Preparation and Characterization of Wheat Protein/PVA Blend Composite Nanofiber%小麦蛋白/聚乙烯醇复合纳米纤维的制备及其表征

    Institute of Scientific and Technical Information of China (English)

    潘丽军; 张黎黎; 姜绍通; 王华

    2012-01-01

    Wheat protein/PVA composite nanofiber was prepared via electrospining technique. The effects of total concentration of the solution, voltages, tip to collector distance and structure of the nanofibers were investigated by scanning electron microscopy (SEM), fourier transform infratred (FT-IR) and X-ray diffraction (XRD). The results indicated that the uniform and smooth wheat protein/PVA composite nanofiber with average diameter of 280 nm could be prepared with following optimal process parameters: total concentration of the solution 10 %, weight ratio of wheat protein to PVA 8:2, applied voltage 12 kV, and the tip-to-collector distance 10 cm. There were hydrogen bonds between wheat protein and PVA in the composite nanofibers.%以小麦蛋白、聚乙烯醇(PVA)为原料,采用静电纺丝法制备小麦蛋白/PVA共混复合纳米纤维,重点研究纺丝液质量分数、电压、接收距离对纤维形态的影响,利用扫描电镜、傅里叶变换红外光谱、X-射线衍射光谱对纤维的形态与结构进行表征.结果表明:在纺丝液质量分数10%、小麦蛋白与PVA质量比8∶2、电压12 kV、接收距离10 cm的条件下,可以制备平均直径为280 nm左右的均一、表面光滑的纳米纤维.小麦蛋白与PVA复合后,分子间以氢键结合.

  12. 电纺CoFe2O4纳米纤维及其磁性研究%Electrospinning preparation and magnetic properties of CoFe2O4 nanofibers

    Institute of Scientific and Technical Information of China (English)

    韩丽艳; 于娜; 邵长路

    2012-01-01

    PVA/FeCl3/Co (CH3COO)2 composite nanofibers were synthesized by using sol-gel processing combination with electrospinning technology,where polyacrylonitrile and manganese acetate were used as precursors. After high temperature calcination, CoFe2O4 nanofibers were successful prepared. The samples were characterized by scanning electron microscopy (SEM) ,fourier transform infrared ( FT-IR) spectroscopy, thermogravimetry-differential thermal ( TG-DTA) and X-ray diffraction (XRD) analysis, respectively. The results showed that CoPe2O4 nanofibers with one-dimensional structure had been prepared uniformly. And,magnetic property measurements suggested that the CoFe2O4 nanofibers exhibited ferromagnetic paramagnetic.%采用溶胶-凝胶过程和静电纺丝技术,以三氯化铁(FeCl3·6H2O)、醋酸钴(Co(CH3COO)2·4H2O)和聚乙烯醇(PVA)为前驱物,制得PVA/FeCl3/Co(CH3COO)2复合纳米纤维.经高温煅烧,制备了CoFe2O4纳米纤维.利用扫描电镜(SEM)、红外光谱(FT-IR)、差热-热重(TG-DTA)和X射线衍射(XRD)等分析测试手段对样品进行了表征,并研究了其磁性质.结果表明:静电纺丝技术制备的CoFe2O4纳米纤维为规则的一维结构,直径分布均匀,具有良好的铁磁性.

  13. DC Electrical Conductivity Retention, Optical Properties and Ammonia Sensing Analysis of Naturally Degraded CSA-Doped Graphene/polyaniline Composite Nanofibers Prepared with CTAB

    Science.gov (United States)

    Ghazali, Sayyed; Hossain, Muhammad M.; Khan, Abuzar; Khan, Mohd Y.; Hasan, Mudassir

    2016-09-01

    In this paper, we report surfactant-mediated synthesis of camphor sulfonic acid (CSA)-doped polyaniline/graphene (PANI/GN) composite nanofibers as an electrical conductor and excellent ammonia sensor. The synthesis was mediated by cetyltrimethylammonium bromide as surfactant. The as-synthesized composite nanofibers were characterized by Raman spectroscopy, scanning electron microscopy, tunneling electron microscopy, x-ray diffraction, diffused reflectance spectroscopy and differential scanning calorimetry. The electrical conductivity of the CSA-doped PANI/GN composite nanofibers was found to be remarkably enhanced as compared to the CSA-doped PANI. The boost in electronic conductivity could be attributed to an improved electronic interaction between CSA-doped PANI backbone and GN present in the composite system. The naturally degraded CSA-doped PANI/GN composite nanofibers showed a decrease in electrical conductivity but worked as a good ammonia sensor in open atmospheric conditions.

  14. DC Electrical Conductivity Retention, Optical Properties and Ammonia Sensing Analysis of Naturally Degraded CSA-Doped Graphene/polyaniline Composite Nanofibers Prepared with CTAB

    Science.gov (United States)

    Ghazali, Sayyed; Hossain, Muhammad M.; Khan, Abuzar; Khan, Mohd Y.; Hasan, Mudassir

    2017-01-01

    In this paper, we report surfactant-mediated synthesis of camphor sulfonic acid (CSA)-doped polyaniline/graphene (PANI/GN) composite nanofibers as an electrical conductor and excellent ammonia sensor. The synthesis was mediated by cetyltrimethylammonium bromide as surfactant. The as-synthesized composite nanofibers were characterized by Raman spectroscopy, scanning electron microscopy, tunneling electron microscopy, x-ray diffraction, diffused reflectance spectroscopy and differential scanning calorimetry. The electrical conductivity of the CSA-doped PANI/GN composite nanofibers was found to be remarkably enhanced as compared to the CSA-doped PANI. The boost in electronic conductivity could be attributed to an improved electronic interaction between CSA-doped PANI backbone and GN present in the composite system. The naturally degraded CSA-doped PANI/GN composite nanofibers showed a decrease in electrical conductivity but worked as a good ammonia sensor in open atmospheric conditions.

  15. Fabrication of Poly(4-vinylpyridine) Nanofiber and Fluorescent Poly(4-vinylpyridine)/Porphyrin Nanofiber by Electrospinning

    Institute of Scientific and Technical Information of China (English)

    SONG Yan; ZHAN Nai-qian; YU Miao; YANG Qing-biao; ZHANG Chao-qun; WANG Heng-guo; LI Yao-xian

    2008-01-01

    Poly(4-vinylpyridine)(P4-VP) nanofiber and fluoresent poly(4-vinylpyridine)/porphyrin(P4-VP/TPPA) nanofiber were respectively prepared by electrospinning.The effect of the concentration of P4-VP/dimethylformamide (DMF) electrospinning solutions on the morphology of P4-VP nanofiber was investigated and it was found that the average diameter of the nanofiber of P4-VP/DMF increased with the increase of the concentration of the spinning solution.After the addition of TPPA to the P4-VP/DMF spinning solution,the diameter of P4-VP/TPPA nanofiber became even due to the increase of the conductivity of the P4-VP/DMF-TPPA solution.The photoluminescent(PL) spectral analysis indicates that the emission peak position of P4-VP/TPPA nanofiber is almost the same as that of pure TPPA at about 650 nm without peak shift,and when it was stored for 20 days,the emission peak of P4-VP/TPPA nanofiber is also at 650 rim,indicating that the fuorescent property of P4-VP/TPPA nanofiber is stable.Fourier-transform infrared(FTIR) spectrum confirms the chemical composition of the resulting P4-VP/TPPA composite nanoflber.

  16. Fabrication of Cellulose Nanofiber/AlOOH Aerogel for Flame Retardant and Thermal Insulation

    OpenAIRE

    Bitao Fan; Shujun Chen; Qiufang Yao; Qingfeng Sun; Chunde Jin

    2017-01-01

    Cellulose nanofiber/AlOOH aerogel for flame retardant and thermal insulation was successfully prepared through a hydrothermal method. Their flame retardant and thermal insulation properties were investigated. The morphology image of the cellulose nanofiber/AlOOH exhibited spherical AlOOH with an average diameter of 0.5 μm that was wrapped by cellulose nanofiber or adhered to them. Cellulose nanofiber/AlOOH composite aerogels exhibited excellent flame retardant and thermal insulation propertie...

  17. Polyurethane nanofibers containing copper nanoparticles as future materials

    DEFF Research Database (Denmark)

    Sheikh, Faheem A.; Kanjwal, Muzafar Ahmed; Saran, Saurabh

    2011-01-01

    In the present study, we aimed to represent a novel approach to fabricate polyurethane nanofibers containing copper nanoparticles (NPs) by simple electrospinning process. A simple method, not depending on additional foreign chemicals, has been employed to utilize prepared copper NPs in polyurethane...... nanofibers. Typically, a colloidal gel consisting of copper NPs and polyurethane has been electrospun. SEM-EDX and TEM results confirmed well oriented nanofibers and good dispersion of pure copper NPs. Copper NPs have diameter in the range of 5–10nm. The thermal stability of the synthesized nanofibers...

  18. Synthesis of Uniform Polyaniline Nanofibers through Interfacial Polymerization

    Directory of Open Access Journals (Sweden)

    Shahrir Hashim

    2012-08-01

    Full Text Available The present paper aims to study the preparation of polyaniline nanofibers through simple interfacial polymerization. Ammonium persulfate, hydrochloric acid and chloroform were used as oxidant, dopant and organic solvent respectively. Field Emission Scanning Electron Microscopy (FESEM, X-ray diffraction and Fourier Transform Infrared Spectroscopy (FTIR techniques were used to analyze the product. FESEM results show that polyaniline has nano-fiber morphology. XRD results show the crystalline properties of polyaniline nanofiber, and FTIR results confirmed the formation of polyaniline in different monomer/oxidant molar ratios. This study provides a better understanding on the synthesis of uniform polyaniline nanofibers through interfacial polymerization.

  19. Multifunctional ZnO/Nylon 6 nanofiber mats by an electrospinning– electrospraying hybrid process for use in protective applications

    Science.gov (United States)

    ZnO/Nylon 6 nanofiber mats were prepared by an electrospinning–electrospraying hybrid process in which ZnO nanoparticles were dispersed on the surface of Nylon 6 nanofibers without becoming completely embedded. The prepared ZnO/Nylon 6 nanofiber mats were evaluated for their abilities to kill bacter...

  20. NiB/PVDF-PVA纳米纤维催化剂的制备及其应用%Preparation and application of NiB/PVDF-PVA nanofiber catalyst

    Institute of Scientific and Technical Information of China (English)

    李芳; 郑权; 李其明; 付琛; 郭瑞东

    2015-01-01

    NiCl2/PVDF-PVA composite nanofibers were prepared via electrospinning technique, and then NiB/PVDF-PVA nanofiber catalyst can be prepared by in-situ reduction. This catalyst was applied in hydro-gen production from hydrolysis of NaBH4 . SEM characterization showed that the well-defined nanoscaled mi-crostructure can be obtained for NiB/PVDF-PVA composite nanofiber,which possesses uniform nanofiber diameter (50~200 nm) . TG analysis revealed that NiB/PVDF-PVA nanofiber catalyst can be stable up to approximately 390 ℃ which is suitable to be used in hydrolysis of NaBH4 . The measurement of water con-tact angle indicated that the wettability of PVDF-PVA nanofiber is better than that of pure PVDF nanofiber due to hydrophilic PVA doping. The results showed that the catalytic activity of NiB/PVDF-PVA composite catalyst can be remarkably improved through the doping of hydrophilic PVA compared with NiB/PVDF cat-alysts. Hence,NiB/PVDF-PVA nanofiber catalyst has an extensive application prospect.%通过静电纺丝技术首先制备了NiCl2/PVDF-PVA复合高分子纳米纤维,通过原位还原法得到了PVDF-PVA复合纳米纤维负载NiB的非晶态合金催化剂,并把该催化剂用于 NaBH4水解制氢反应。 SEM 表征表明, NiCl2/PVDF-PVA复合纳米纤维具有纤细微观纳米形貌,纤维直径均匀,介于50~200 nm。 TG分析表明, NiCl2/PVDF-PVA纳米纤维可以稳定到大约390℃,超过该温度纳米纤维开始发生热解,说明该纳米纤维催化剂载体具有适于硼氢化钠水解反应的热稳定性。接触角测试表明,PVA共纺显著提高了PVDF纳米纤维的亲水性,有利于NaBH4和水分子在催化剂表面上的接触反应。水解制氢实验表明,PVA共混静电纺丝法得到的NiB /PVDF-PVA较NiB/PVDF催化剂催化活性显著提高,该催化剂具有较好的应用前景。

  1. The synthesis of titanium carbide-reinforced carbon nanofibers.

    Science.gov (United States)

    Zhu, Pinwen; Hong, Youliang; Liu, Bingbing; Zou, Guangtian

    2009-06-24

    Tailoring hard materials into nanoscale building blocks can greatly extend the applications of hard materials and, at the same time, also represents a significant challenge in the field of nanoscale science. This work reports a novel process for the preparation of carbon-based one-dimensional hard nanomaterials. The titanium carbide-carbon composite nanofibers with an average diameter of 90 nm are prepared by an electrospinning technique and a high temperature pyrolysis process. A composite solution containing polyacrylonitrile and titanium sources is first electrospun into the composite nanofibers, which are subsequently pyrolyzed to produce the desired products. The x-ray diffraction pattern and transmission electron microscopy results show that the main phase of the as-synthesized nanofibers is titanium carbide. The Raman analyses show that the composite nanofibers have low graphite clusters in comparison with the pure carbon nanofibers originating from the electrospun polyacrylonitrile nanofibers. The mechanical property tests demonstrate that the titanium carbide-carbon nanofiber membranes have four times higher tensile strength than the carbon nanofiber membranes, and the Young's modulus of the titanium carbide-carbon nanofiber membranes increases in direct proportion to the titanium quantity.

  2. Wet-Laid Meets Electrospinning: Nonwovens for Filtration Applications from Short Electrospun Polymer Nanofiber Dispersions.

    Science.gov (United States)

    Langner, Markus; Greiner, Andreas

    2016-02-01

    Dispersions of short electrospun fibers are utilized for the preparation of nanofiber nonwovens with different weight area on filter substrates. The aerosol filtration efficiencies of suspension-borne nanofiber nonwovens are compared to nanofiber nonwovens prepared directly by electrospinning with similar weight area. The filtration efficiencies are found to be similar for both types of nonwovens. With this, a large potential opens for processing, design, and application of new nanofiber nonwovens obtained by wet-laying of short electrospun nanofiber suspensions. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Preparation of CuO/NiO composite nanofibers by electrospinning and their application for electro-catalytic oxidation of hydrazine

    Science.gov (United States)

    Hosseini, Sayed Reza; Ghasemi, Shahram; Kamali-Rousta, Mina

    2017-03-01

    In present work, polyvinyl alcohol/copper acetate-nickel acetate composite nanofibers (PVA/Cu(OAc)2-Ni(OAc)2 NFs) with various weight percentages of Cu(OAc)2:Ni(OAc)2 such as 25:75, 50:50 and 75:25 are fabricated by electrospinning method. After this, the CuO/NiO composite NFs are produced after thermal treatment. A calcination temperature at about 600 °C is determined by thermal gravimetric analysis. Field-emission scanning electron microscopy (FE-SEM) for morphology characterization indicates that large quantities of the prepared PVA/Cu(OAc)2-Ni(OAc)2 composite fibers have smooth and bead-free surfaces. Fourier transform infrared spectroscopy, FE-SEM and energy dispersive X-ray spectroscopy are used to characterize the CuO/NiO composites. According to FE-SEM results, with increasing of Cu(OAc)2 content in polymeric solution, the fibers don't remain as continuous structures after calcination and accumulate in the form of nanoparticles. Also, a carbon paste electrode (CPE) bulky modified with CuO/NiO composites is used for investigation of the electro-catalytic oxidation of hydrazine hydrate in NaOH solution. The catalytic activities of the synthesized catalysts are studied through cyclic voltammetry, chronoamperometry and electrochemical impedance spectroscopy. The obtained results demonstrate that the most appropriate proportion of Cu(OAc)2:Ni(OAc)2 in electrospinning solution to enhance the electro-catalytic ability is 25:75.

  4. Preparing photochromic nanofibers and animal cells using a photochromic compound of 1',3',3'-trimethyl-6-nitrospiro (2H-1-benzopyran-2,2'-indoline).

    Science.gov (United States)

    Li, Xiaoqiang; Lin, Lin; Kanjwal, Muzafar A; Chronakis, Ioannis S; Liu, Shuiping; Chen, Yanmo

    2012-01-01

    In this work, the photochromic compound 1',3',3'-trimethyl-6-nitrospiro (2H-1-benzopyran-2,2'-indoline) (NOSP) was synthesized by a two step process. The photochromic properties of NOSP were investigated by ultraviolet-visible (UV-Vis) spectrophotometry. The results showed that NOSP was very sensitive to UV irradiation with absorption peaks at about 336 nm and 567 nm. Our hypothesis was that both photochromic nanofibers and photochromic living animal cells could be obtained by combining them with NOSP. To test the hypothesis, photochromic nanofibers were fabricated by electrospinning from various mixed solutions of NOSP and polymers (including a synthetic polymer of poly(methyl methacrylate) and a natural polymer of gelatin); NOSP/ethanol solution was dissolved in culture medium to stain pig iliac endothelial cells (PIEC) and endow them with photochromic capability. Polymer nanofibers from electrospinning were characterized by water contact angle measurements, ultraviolet-visible (UV-Vis) spectrophotometry and fluorescence microscopy. Morphology of photochromic PIEC was observed by fluorescence microscopy after being irradiated. It was shown that nanofibers from electrospun polymers and NOSP-treated PIEC had photochromic properties. The bio-toxicity of the photochromic compound was also evaluated and it was shown that ~50% of PIEC remained viable for at least 20 min. The photochromic compound NOSP could be a potentially powerful tool for development of multi-functional nanofibers and biological applications.

  5. Preparation of Coaxial-Line and Hollow Mn2O3 Nanofibers by Single-Nozzle Electrospinning and Their Catalytic Performances for Thermal Decomposition of Ammonium Perchlorate.

    Science.gov (United States)

    Liang, Jiyuan; Yang, Jie; Cao, Weiguo; Guo, Xiangke; Guo, Xuefeng; Ding, Weiping

    2015-09-01

    Coaxial-line and hollow Mn2O3 nanofibers have been synthesized by a simple single-nozzle electrospinning method without using a complicated coaxial jet head, combined with final calcination. The crystal structure and morphology of the Mn2O3 nanofibers were investigated by using the X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The results indicate that the electrospinning distance has important influence on the morphology and structure of the obtained Mn2O3 nanofibers, which changes from hollow fibers for short electrospinning distance to coaxial-line structure for long electrospinning distance after calcination in the air. The formation mechanisms of different structured Mn2O3 fibers are discussed in detail. This facile and effective method is easy to scale up and may be versatile for constructing coaxial-line and hollow fibers of other metal oxides. The catalytic activity of the obtained Mn2O3 nanofibers on thermal decomposition of ammonium perchlorate (AP) was studied by differential scanning calorimetry (DSC). The results show that the hollow Mn2O3 nanofibers have good catalytic activity to promote the thermal decomposition of AP.

  6. Ammonia Sensing Behaviors of TiO2-PANI/PA6 Composite Nanofibers

    Science.gov (United States)

    Wang, Qingqing; Dong, Xianjun; Pang, Zengyuan; Du, Yuanzhi; Xia, Xin; Wei, Qufu; Huang, Fenglin

    2012-01-01

    Titanium dioxide-polyaniline/polyamide 6 (TiO2-PANI/PA6) composite nanofibers were prepared by in situ polymerization of aniline in the presence of PA6 nanofibers and a sputtering-deposition process with a high purity titanium sputtering target. TiO2-PANI/PA6 composite nanofibers and PANI/PA6 composite nanofibers were fabricated for ammonia gas sensing. The ammonia sensing behaviors of the sensors were examined at room temperature. All the results indicated that the ammonia sensing property of TiO2-PANI/PA6 composite nanofibers was superior to that of PANI/PA6 composite nanofibers. TiO2-PANI/PA6 composite nanofibers had good selectivity to ammonia. It was also found that the content of TiO2 had a great influence on both the morphology and the sensing property of TiO2-PANI/PA6 composite nanofibers. PMID:23235446

  7. Ammonia Sensing Behaviors of TiO2-PANI/PA6 Composite Nanofibers

    Directory of Open Access Journals (Sweden)

    Fenglin Huang

    2012-12-01

    Full Text Available Titanium dioxide-polyaniline/polyamide 6 (TiO2-PANI/PA6 composite nanofibers were prepared by in situ polymerization of aniline in the presence of PA6 nanofibers and a sputtering-deposition process with a high purity titanium sputtering target. TiO2-PANI/PA6 composite nanofibers and PANI/PA6 composite nanofibers were fabricated for ammonia gas sensing. The ammonia sensing behaviors of the sensors were examined at room temperature. All the results indicated that the ammonia sensing property of TiO2-PANI/PA6 composite nanofibers was superior to that of PANI/PA6 composite nanofibers. TiO2-PANI/PA6 composite nanofibers had good selectivity to ammonia. It was also found that the content of TiO2 had a great influence on both the morphology and the sensing property of TiO2-PANI/PA6 composite nanofibers.

  8. Transparent Conductive Films Fabricated from Polythiophene Nanofibers Composited with Conventional Polymers

    Directory of Open Access Journals (Sweden)

    Borjigin Aronggaowa

    2013-11-01

    Full Text Available Transparent, conductive films were prepared by compositing poly(3-hexylthiophene (P3HT nanofibers with poly(methyl methacrylate (PMMA. The transparency, conductivity, atmospheric stability, and mechanical strength of the resulting nanofiber composite films when doped with AuCl3 were evaluated and compared with those of P3HT nanofiber mats. The conductivity of the nanofiber composite films was 4.1 S∙cm−1, which is about seven times less than that which was previously reported for a nanofiber mat with the same optical transmittance (~80% reported by Aronggaowa et al. The time dependence of the transmittance, however, showed that the doping state of the nanofiber composite films in air was more stable than that of the nanofiber mats. The fracture stress of the nanofiber composite film was determined to be 12.3 MPa at 3.8% strain.

  9. Novel Cu@SiO{sub 2}/bacterial cellulose nanofibers: Preparation and excellent performance in antibacterial activity

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Bo [Chemicobiology and Functional Materials Institute of Nanjing University of Science and Technology, Xiao Ling Wei 200, Nanjing 210094 (China); Department of Life Sciences of Lianyungang Teacher' s College, Sheng Hu Lu 28, Lianyungang 222006 (China); Huang, Yang; Zhu, Chunlin; Chen, Chuntao; Chen, Xiao; Fan, Mengmeng [Chemicobiology and Functional Materials Institute of Nanjing University of Science and Technology, Xiao Ling Wei 200, Nanjing 210094 (China); Sun, Dongping, E-mail: sundpe301@163.com [Chemicobiology and Functional Materials Institute of Nanjing University of Science and Technology, Xiao Ling Wei 200, Nanjing 210094 (China)

    2016-05-01

    The antibacterial composite based on bacterial cellulose (BC) was successfully prepared by in-situ synthesis of SiO{sub 2} coated Cu nanoparticles (Cu@SiO{sub 2}/BC) and its properties were characterized. Its chemical structures and morphologies were evaluated by Fourier transformation infrared spectrum (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The results demonstrated that the SiO{sub 2} coated Cu particles were well homogeneously precipitated on the surface of BC. The Cu@SiO{sub 2}/BC was more resistant to oxidation than the Cu nanoparticles impregnated into BC (Cu/BC) and then Cu@SiO{sub 2}/BC could prolong the antimicrobial activity against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). - Graphical abstract: Schematic illustration of the preparation of Cu@SiO{sub 2}/BC. Due to its unique structure, the Cu@SiO{sub 2}/BC membrane shows excellent antibacterial effects and can be used for a long time. - Highlights: • This work paves the novel way to fabricate antibacterial nanomaterial with good efficiency. • We prepare the antibacterial membrane based on bacterial cellulose by in-situ synthesis of SiO{sub 2}-coated Cu nanoparticles. • The antibacterial membrane is more resistant to oxidation and can prolong the antimicrobial activity.

  10. Functionalized electrospun nanofibers as bioseparators in microfluidic systems.

    Science.gov (United States)

    Matlock-Colangelo, Lauren; Cho, Daehwan; Pitner, Christine L; Frey, Margaret W; Baeumner, Antje J

    2012-05-01

    Functionalized electrospun nanofibers were integrated into microfluidic channels to serve as on-chip bioseparators. Specifically, poly(vinyl alcohol) (PVA) nanofiber mats were shown to successfully serve as bioseparators for negatively charged nanoparticles. Nanofibers were electrospun onto gold microelectrodes, which were incorporated into poly(methyl methacrylate) (PMMA) microfluidic devices using UV-assisted thermal bonding. PVA nanofibers functionalized with poly(hexadimethrine bromide) (polybrene) were positively charged and successfully filtered negatively charged liposomes out of a buffer solution, while negatively charged nanofibers functionalized with Poly(methyl vinyl ether-alt-maleic anhydride) (POLY(MVE/MA)) were shown to repel the liposomes. The effect of fiber mat thickness was studied using confocal fluorescence microscopy, determining a quite broad optimal range of thicknesses for specific liposome retention, which simplifies fiber mat production with respect to retention reliability. Finally, it was demonstrated that liposomes bound to positively charged nanofibers could be selectively released using a 4-(2-Hydroxyethyl)piperazine-1-ethanesulfonic acid (HEPES)-sucrose-saline (HSS) solution of pH 9, which dramatically changes the nanofiber zeta potential and renders the positively charged nanofibers negatively charged. This is the first demonstration of functional electrospun nanofibers used to enable sample preparation procedures of isolation and concentration in lab-on-a-chip devices. This has far reaching impact on the ability to integrate functional surfaces and materials into microfluidic devices and to significantly expand their ability toward simple lab-on-a-chip devices.

  11. Surface modification of polyvinyl alcohol/malonic acid nanofibers by gaseous dielectric barrier discharge plasma for glucose oxidase immobilization

    Science.gov (United States)

    Afshari, Esmail; Mazinani, Saeedeh; Ranaei-Siadat, Seyed-Omid; Ghomi, Hamid

    2016-11-01

    Polymeric nanofiber prepares a suitable situation for enzyme immobilization for variety of applications. In this research, we have fabricated polyvinyl alcohol (PVA)/malonic acid nanofibers using electrospinning. After fabrication of nanofibers, the effect of air, nitrogen, CO2, and argon DBD (dielectric barrier discharge) plasmas on PVA/malonic acid nanofibers were analysed. Among them, air plasma had the most significant effect on glucose oxidase (GOx) immobilization. Attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectrum analysis and X-ray photoelectron spectroscopy (XPS) results revealed that in case of air plasma modified nanofibers, the carboxyl groups on the surface are increased. The scanning electron microscopy (SEM) images showed that, after GOx immobilization, the modified nanofibers with plasma has retained its nanofiber structure. Finally, we analysed reusability and storage stability of GOx immobilized on plasma modified and unmodified nanofibers. The results were more satisfactory for modified nanofibers with respect to unmodified ones.

  12. Evaluation of the genotoxicity of cellulose nanofibers

    Directory of Open Access Journals (Sweden)

    de Lima R

    2012-07-01

    Full Text Available Renata de Lima,1 Leandro Oliveira Feitosa,1 Cintia Rodrigues Maruyama,1 Mariana Abreu Barga,1 Patrícia Cristina Yamawaki,1 Isolda Jesus Vieira,1 Eliangela M Teixeira,2 Ana Carolina Corrêa,2 Luiz Henrique Caparelli Mattoso,2 Leonardo Fernandes Fraceto31Department of Biotechnology, University of Sorocaba, Sorocaba, 2Embrapa Instrumentation (CNPDIA, National Nanotechnology Laboratory for Agriculture (LNNA, São Carlos, 3Department of Environmental Engineering, State University of São Paulo (UNESP, Sorocaba, SP, BrazilBackground: Agricultural products and by products provide the primary materials for a variety of technological applications in diverse industrial sectors. Agro-industrial wastes, such as cotton and curaua fibers, are used to prepare nanofibers for use in thermoplastic films, where they are combined with polymeric matrices, and in biomedical applications such as tissue engineering, amongst other applications. The development of products containing nanofibers offers a promising alternative for the use of agricultural products, adding value to the chains of production. However, the emergence of new nanotechnological products demands that their risks to human health and the environment be evaluated. This has resulted in the creation of the new area of nanotoxicology, which addresses the toxicological aspects of these materials.Purpose and methods: Contributing to these developments, the present work involved a genotoxicological study of different nanofibers, employing chromosomal aberration and comet assays, as well as cytogenetic and molecular analyses, to obtain preliminary information concerning nanofiber safety. The methodology consisted of exposure of Allium cepa roots, and animal cell cultures (lymphocytes and fibroblasts, to different types of nanofibers. Negative controls, without nanofibers present in the medium, were used for comparison.Results: The nanofibers induced different responses according to the cell type used. In

  13. Polyurethane nanofibers containing copper nanoparticles as future materials

    Science.gov (United States)

    Sheikh, Faheem A.; Kanjwal, Muzafar A.; Saran, Saurabh; Chung, Wook-Jin; Kim, Hern

    2011-01-01

    In the present study, we aimed to represent a novel approach to fabricate polyurethane nanofibers containing copper nanoparticles (NPs) by simple electrospinning process. A simple method, not depending on additional foreign chemicals, has been employed to utilize prepared copper NPs in polyurethane nanofibers. Typically, a colloidal gel consisting of copper NPs and polyurethane has been electrospun. SEM-EDX and TEM results confirmed well oriented nanofibers and good dispersion of pure copper NPs. Copper NPs have diameter in the range of 5-10 nm. The thermal stability of the synthesized nanofibers was examined for identifying the proper settlement of copper NPs among the nanofibers, according to the concentrations used in original solutions. Furthermore, XRD results well demonstrated crystalline feature of copper NPs. Model microorganisms Escherichia coli and Bacillus subtillus had been used to check the antimicrobial efficacy of these nanofiber mats. Subsequently, antimicrobial tests have indicated that the prepared nanofibers do posses good bactericidal effect. Accordingly, it is noted that the obtained nanofiber mats can be used as future filter membranes with good antimicrobial activities.

  14. Influences of Silver-Doping on the Crystal Structure, Morphology and Photocatalytic Activity of TiO2 Nanofibers

    DEFF Research Database (Denmark)

    Barakat, Nasser A. M.; Kanjwal, Muzafar Ahmed; Al-Deyab, Salem S.

    2011-01-01

    activity of titanium oxide nanofibers has been studied. Sil-ver-doped TiO2 nanofibers having different silver contents were prepared by calcination of electrospun nanofiber mats consisting of silver nitrate, titanium isopropoxide and poly(vinyl acetate) at 600°C. The results affirmed formation of silver...

  15. Electrospun Perovskite Nanofibers

    Science.gov (United States)

    Chen, Dongsheng; Zhu, Yanyan

    2017-02-01

    CH3NH3PbI3 perovskite nanofibers were synthesized by versatile electrospinning techniques. The synthetic CH3NH3PbI3 nanofibers were characterized by X-ray diffraction, scanning electron microscopy, thermogravimetric analysis, and photoluminescence. As counter electrodes, the synthesized nanofibers increased the performance of the dye-sensitized solar cells from 1.58 to 2.09%. This improvement was attributed to the enhanced smoothness and efficiency of the electron transport path. Thus, CH3NH3PbI3 perovskites nanofibers are potential alternative to platinum counter electrodes in dye-sensitized solar cells.

  16. PEG/PVA相变复合纳米纤维的制备及其性能研究%Prepare PVA/PEG phase change composite nanofibers and study its characteristics

    Institute of Scientific and Technical Information of China (English)

    张梅; 刘永佳; 栾加双; 徐天宇; 孙大辉

    2012-01-01

    在室温下制得了PEG/PVA相变复合纳米纤维。探讨了PVA/PEG和PEG2000/PEG4000各自不同质量分数、外加电压、接收距离、外加盐离子等参数对纤维直径和纤维网形态的影响。结果表明PEG/PVA为60/40,电压为15kV,接受距离为10cm时,成纤较好。运用DSC测试复合纳米纤维的可逆相转变特性,Tm和TC值与PEG2000/PEG4000的比例有关。%In this work,PVA /PEG phase change composite nanofibers were prepared by electrospinning at room temperature.The diameter and morphology of PVA / PEG nanofibers were studied by scanning electron microscopy(SEM) to research the relationship with different weight content,applied voltage,collect distance and added ionic salt on fiber diameter and fiber network morphology.Experimental results showed that PVA/PEG blend solution of 4∶6 weight content,a fixed electric field of 15kV/10cm was the best process parameters.Using DSC method,the phase change characteristics of PVA/PEG composite nanofibers has been tested.Tm and TC values are affected by different ratios of PEG component(Mw = 2000,4000).

  17. High Sensitive Sensor Fabricated by Reduced Graphene Oxide/Polyvinyl Butyral Nanofibers for Detecting Cu (II) in Water

    OpenAIRE

    2015-01-01

    Graphene oxide (GO)/polyvinyl butyral (PVB) nanofibers were prepared by a simple electrospinning technique with PVB as matrix and GO as a functional nanomaterial. GO/PVB nanofibers on glassy carbon electrode (GCE) were reduced through electrochemical method to form reduced graphene oxide (RGO)/PVB nanofibers. The morphology and structure of GO/PVB nanofiber were studied by scanning election microscopy (SEM), transmission electron microscopy (TEM), and Fourier transform infrared (FTIR). RGO/PV...

  18. Antifouling Electrospun Nanofiber Mats Functionalized with Polymer Zwitterions.

    Science.gov (United States)

    Kolewe, Kristopher W; Dobosz, Kerianne M; Rieger, Katrina A; Chang, Chia-Chih; Emrick, Todd; Schiffman, Jessica D

    2016-10-06

    In this study, we exploit the excellent fouling resistance of polymer zwitterions and present electrospun nanofiber mats surface functionalized with poly(2-methacryloyloxyethyl phosphorylcholine) (polyMPC). This zwitterionic polymer coating maximizes the accessibility of the zwitterion to effectively limit biofouling on nanofiber membranes. Two facile, scalable methods yielded a coating on cellulose nanofibers: (i) a two-step sequential deposition featuring dopamine polymerization followed by the physioadsorption of polyMPC, and (ii) a one-step codeposition of polydopamine (PDA) with polyMPC. While the sequential and codeposited nanofiber mat assemblies have an equivalent average fiber diameter, hydrophilic contact angle, surface chemistry, and stability, the topography of nanofibers prepared by codeposition were smoother. Protein and microbial antifouling performance of the zwitterion modified nanofiber mats along with two controls, cellulose (unmodified) and PDA coated nanofiber mats were evaluated by dynamic protein fouling and prolonged bacterial exposure. Following 21 days of exposure to bovine serum albumin, the sequential nanofiber mats significantly resisted protein fouling, as indicated by their 95% flux recovery ratio in a water flux experiment, a 300% improvement over the cellulose nanofiber mats. When challenged with two model microbes Escherichia coli and Staphylococcus aureus for 24 h, both zwitterion modifications demonstrated superior fouling resistance by statistically reducing microbial attachment over the two controls. This study demonstrates that, by decorating the surfaces of chemically and mechanically robust cellulose nanofiber mats with polyMPC, we can generate high performance, free-standing nanofiber mats that hold potential in applications where antifouling materials are imperative, such as tissue engineering scaffolds and water purification technologies.

  19. Nanofiber of ultra-structured aluminum and zirconium oxide hybrid.

    Science.gov (United States)

    Kim, Hae-Won; Kim, Hyoun-Ee

    2006-02-01

    An internally ultrastructured Al- and Zr-oxide hybrid was developed into a nanofiber. As a precursor for the generation of nanofiber, a hybridized sol was prepared using the Pechini-type sol-gel process, whereby the Al- and Zr-metallic ions were to be efficiently distributed and stabilized within the polymeric network. The hybridized sol was subsequently electrospun and heat treated to a nanofiber with diameters of tens to hundreds of nanometers. The internal structure of the nanofiber was organized at the molecular level, with the Al- and Zr-oxide regions being interspaced at distances of less than ten nanometers. This ultrastructured Al- and Zr-oxide hybrid nanofiber is considered to be potentially applicable in numerous fields.

  20. Layered Perovskite Nanofibers via Electrospinning for Overall Water Splitting.

    Science.gov (United States)

    Hildebrandt, Nils C; Soldat, Julia; Marschall, Roland

    2015-05-06

    The (111)-layered perovskite materials Ba5 Ta4 O15 , Ba5 Ta2 Nb2 O15 and Ba5 Nb4 O15 are prepared with nanofiber morphology via electrospinning for the first time. The nanofibers are built up from small single crystals, with up to several micrometers length even after calcination. The formation mechanism is investigated in detail, revealing an intermediate formation of amorphous barium carbonate strengthening the nanofiber morphology for high temperature treatment. All nanofiber compounds are able to generate hydrogen without any co-catalyst in photocatalytic reformation of methanol. After photodeposition of Rh-Cr2 O3 co-catalysts, the nanofibers show better activity in overall water splitting compared to sol-gel-derived powders.

  1. Study on the Electrospun CNTs/Polyacrylonitrile-Based Nanofiber Composites

    Directory of Open Access Journals (Sweden)

    Bo Qiao

    2011-01-01

    Full Text Available CNTs/PAN nanofibers were electrospun from PAN-based solution for the preparation of carbon nanofiber composites. The as-spun polyacrylonitrile-based nanofibers were hot-stretched by weighing metal in a temperature controlled oven. Scanning electron microscopy (SEM and transmission electron microscopy (TEM were used to characterize the morphology of the nanofibers, which indicated that carbon nanotubes were dispersed well in the composites and were completely wrapped by PAN matrix. Because of the strong interfacial interaction between CNTs and PAN, the CNTs/PAN application performance will be enhanced correspondingly, such as the mechanical properties and the electrical conductivity. It was concluded that the hot-stretched CNTs/PAN nanofibers can be used as a potential precursor to produce high-performance carbon composites.

  2. Imaging, spectroscopy, mechanical, alignment and biocompatibility studies of electrospun medical grade polyurethane (Carbothane™ 3575A) nanofibers and composite nanofibers containing multiwalled carbon nanotubes.

    Science.gov (United States)

    Sheikh, Faheem A; Macossay, Javier; Cantu, Travis; Zhang, Xujun; Shamshi Hassan, M; Esther Salinas, M; Farhangi, Chakavak S; Ahmad, Hassan; Kim, Hern; Bowlin, Gary L

    2015-01-01

    In the present study, we discuss the electrospinning of medical grade polyurethane (Carbothane™ 3575A) nanofibers containing multi-walled-carbon-nanotubes (MWCNTs). A simple method that does not depend on additional foreign chemicals has been employed to disperse MWCNTs through high intensity sonication. Typically, a polymer solution consisting of polymer/MWCNTs has been electrospun to form nanofibers. Physiochemical aspects of prepared nanofibers were evaluated by SEM, TEM, FT-IR and Raman spectroscopy, confirming nanofibers containing MWCNTs. The biocompatibility and cell attachment of the produced nanofiber mats were investigated while culturing them in the presence of NIH 3T3 fibroblasts. The results from these tests indicated non-toxic behavior of the prepared nanofiber mats and had a significant attachment of cells towards nanofibers. The incorporation of MWCNTs into polymeric nanofibers led to an improvement in tensile stress from 11.40 ± 0.9 to 51.25 ± 5.5 MPa. Furthermore, complete alignment of the nanofibers resulted in an enhancement on tensile stress to 72.78 ± 5.5 MPa. Displaying these attributes of high mechanical properties and non-toxic nature of nanofibers are recommended for an ideal candidate for future tendon and ligament grafts. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. NANOFIBER PRODUCTION [REVIEW

    Directory of Open Access Journals (Sweden)

    KESKIN Reyhan

    2016-05-01

    Full Text Available Nanofibers are very thin fibers having diameters lower than 100 nm and their lengths might be as long as possible within production limits. The large surface area of nanofibers gives opportunity to functionalize them. Nanofibers have several applications including both applications for industrial production in many sectors and for research studies. Nanofibers find applications in energy devices such as solar cells, fuel cells and nanogenarators; in filtration applications (such as water/oil filtration, fine particle filtration, aerosol filtration, air filtration, nanoparticle filtration and in several medical applications including antibacterial efficacy, wound healing, drug delivery and scaffolds for tissue engineering. There are several methods to produce nanofibers: Electrospinning, self assembly, phase separation, bacterial cellulose, templating, drawing, extraction, vapor-phase polymerization, kinetically controlled solution synthesis, conventional chemical polymerization for anyline. Electrospinning is the most widely used method to produce nanofibers.In electrospinning, a high electric field, which is in kilovolts, is applied to a polymer solution. The polymer solution is drawn from a syringe to a collector surface.Electrospinning requires usage of appropriate solvent, removal of evaporating solvent, an adequate power supply to overcome the viscosity and surface tension of the polymer solution; while, jet instability and jet control remain as challenges in electrospinning. Nanofiber production methods possess some disadvantages as: higher cost compared to conventional fiber production methods, health hazards such as inhale risk of nanofibers during production and keeping the environment safe from evaporating solvents used during nanofiber production. Up to date, many researches have been conducted on nanofibers and electrospinning; still, more controllable, more cost effective, more environmentally friendly and safer methods are of

  4. Preparation of novel carbon microfiber/carbon nanofiber-dispersed polyvinyl alcohol-based nanocomposite material for lithium-ion electrolyte battery separator.

    Science.gov (United States)

    Sharma, Ajit K; Khare, Prateek; Singh, Jayant K; Verma, Nishith

    2013-04-01

    A novel nanocomposite polyvinyl alcohol precursor-based material dispersed with the web of carbon microfibers and carbon nanofibers is developed as lithium (Li)-ion electrolyte battery separator. The primary synthesis steps of the separator material consist of esterification of polyvinyl acetate to produce polyvinyl alcohol gel, ball-milling of the surfactant dispersed carbon micro-nanofibers, mixing of the milled micron size (~500 nm) fibers to the reactant mixture at the incipience of the polyvinyl alcohol gel formation, and the mixing of hydrophobic reagents along with polyethylene glycol as a plasticizer, to produce a thin film of ~25 μm. The produced film, uniformly dispersed with carbon micro-nanofibers, has dramatically improved performance as a battery separator, with the ion conductivity of the electrolytes (LiPF6) saturated film measured as 0.119 S-cm(-1), approximately two orders of magnitude higher than that of polyvinyl alcohol. The other primary characteristics of the produced film, such as tensile strength, contact angle, and thermal stability, are also found to be superior to the materials made of other precursors, including polypropylene and polyethylene, discussed in the literature. The method of producing the films in this study is novel, simple, environmentally benign, and economically viable.

  5. Highly Aligned Poly(vinylidene fluoride-co-hexafluoro propylene) Nanofibers via Electrospinning Technique.

    Science.gov (United States)

    Han, Tae-Hwan; Nirmala, R; Kim, Tae Woo; Navamathavan, R; Kim, Hak Yong; Park, Soo Jin

    2016-01-01

    We report on the simple way of obtaining aligned poly(vinylidiene fluoride-co-hexafluoropropylene) (PVDF-HFP) nanofibers by electrospinning process. The collector drum rotation speed was adjusted to prepare well aligned PVDF-HFP nanofibers. The degree of alignment and the orientation of PVDF-HFP nanofibers can be significantly altered by varying the speed of collector drum rotation. The resultant PVDF-HFP nanofibers were systematically characterized. From the scanning electron microscopy data, it was found that the electrospun PVDF-HFP nanofibers were formed with well-aligned nature. The X-ray diffraction results revealed that the electrospun PVDF-HFP nanofibers with β-phase can be formed by the increased collector drum rotation speed. Overall, the collector rotation speed during the electrospinning process plays an important role in obtaining well-aligned and improved characteristics of PVDF-HFP nanofibers.

  6. Biofunctionalizing nanofibers with carbohydrate blood group antigens.

    Science.gov (United States)

    Barr, Katie; Kannan, Bhuvaneswari; Korchagina, Elena; Popova, Inna; Ryzhov, Ivan; Henry, Stephen; Bovin, Nicolai

    2016-11-01

    A rapid and simple method of biofunctionalising nylon, cellulose acetate, and polyvinyl butyral electrospun nanofibers with blood group glycans was achieved by preparing function-spacer-lipid constructs and simply contacting them to fibers with a piezo inkjet printer. A series of water dispersible amphipathic glycan-spacer constructs were synthesized representing a range ABO and related blood group antigens. After immediate contact of the amphipathic glycan-spacer constructs with nanofiber surfaces they self-assembled and were detectable by enzyme immunoassays with high sensitivity and specificity.

  7. Preparation of water stable methyl-modified metal-organic framework-5/polyacrylonitrile composite nanofibers via electrospinning and their application for solid-phase extraction of two estrogenic drugs in urine samples.

    Science.gov (United States)

    Asiabi, Mina; Mehdinia, Ali; Jabbari, Ali

    2015-12-24

    The nanofibers of methyl-modified metal-organic framework-5/polyacrylonitrile composite (CH3MOF-5/PAN) were successfully synthesized and used as a solid-phase extraction (SPE) sorbent for pre-concentration of two estrogenic drugs, levonorgestrel and megestrol acetate, in urine samples. A simple, cheap and accessible electrospinning method was employed to prepare a water stable CH3MOF-5/PAN composite. The nanofibers were packed into the mini-disc cartridges to be used as SPE devices. They were also characterized by scanning electron microscopy, thermogravimetric analysis, Fourier transform infrared spectroscopy, X-ray diffraction and N2 adsorption-desorption experiments. The effects of different parameters influencing the extraction efficiency including the type of eluent and its volume, the amount of the sorbent, pH, the ionic strength, the sample volume and the reusability of the sorbent were investigated and optimized. Under the optimized conditions, the linearity varied in range of 0.05-100μgL(-1) with R(2) values higher than 0.999. The limit of detection for both of the analytes was 0.02μgL(-1). The applicability of the method was examined by analyzing the analytes in the urine samples. The recovery of the analytes varied in the range of 82.8-94.8% which shows capability of the method for the determination of the drugs in the urine samples.

  8. Preparation of polyvinyl alcohol/chitosan hybrid nanofibers and study on their properties%聚乙烯醇/壳聚糖复合纳米纤维的制备和性能研究

    Institute of Scientific and Technical Information of China (English)

    闫尔云; 范英梅; 郝小原; 樊姗; 张德庆

    2013-01-01

    Polyvinyl alcohol/chitosan(PVA/CS)hybrid nanofibers were prepared by electrospinning method. The morphology change of the pure PVA fibers and PVA/CS hybrid fibers was investigated via scanning electron microscopy. Studies have shown that with the increase of the concentration of electrospinning solution, the diameter of fibers became bigger, and the morphology of fibers became more regular. The PVA/CS composite nanofibers with good biocompatibility were expected to used in the field of biomedicine.%采用高压静电纺丝技术制备了聚乙烯醇/壳聚糖(PVA/CS)的复合纳米纤维。通过扫描电子显微镜考察了纯聚乙烯醇PVA纤维和PVA/CS复合纳米纤维的形貌变化。研究表明,随着纺丝溶液浓度的不断增大,所得的纤维形貌越来越规则,纤维直径也逐渐变大。这种具有良好生物相容性的PVA/CS复合纳米纤维有望在生物医学方面得到应用。

  9. Biodegradable poly (ɛ-caprolactone)/gelatin nanofibers: Effect of tubular halloysite on structure and properties

    Science.gov (United States)

    Švachová, Veronika; Khunová, Viera; Vojtová, Lucy; PavliÅák, David

    2016-05-01

    The work explores preparation of new advanced nanofibers based on biodegradable polymers and biocompatible tubular halloysite (HNT). Electrospun nanofibers comprising 8 wt% gelatin (Gel) and 8 wt% poly (͛-caprolactone) (PCL) have been prepared by using eco-friendly solvent - acetic acid. The content of HNT in PCL/Gel nanofibers was 0.5, 1.0, 3.0, 6.0 and 9.0 wt%. It was found that the addition of HNT significantly affected the polymer mixture spinnability and the fiber diameter. SEM observations revealed that the structure of nanofibers depends on nanofiber composition. Whilst in nanofibers with lower HNT content uniform morphology with HNTs located merely inside the individual nanofibers has been observed, in nanofibers with 6 and 9 wt% HNT individual particles as well as the agglomerates of HNT have been detected in both, the inner part as well as outside part of nanofiber. Important reinforcing effect has been achieved in whole HNT content. The highest improvement has been reached when the HNT content was 0.5 wt%. In this case, multiple enhancements of strength (2x), elongation (4x) and modulus (2x) have been confirmed. ATR-FTIR revealed that improvement of mechanical properties is also due to the increase of interface interaction in between PCL/Gel and HNT. The prepared PCL/Gel/HNT nanofibers can be used for tissue engineering and/or as drug carriers or signal molecules in whole spectrum of medical applications.

  10. Antioxidant activity of polyaniline nanofibers

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Well-confined uniform polyaniline (PANT) nanofibers were synthesized by using photo-assisted chemical oxidative polymerization of aniline in the presence of different dopant acids, and the radical scavenging ability of the produced PANI nanofibers was determined by the DPPH assay. It was found that the antioxidant activity of PANI nanofibers was higher than conventional PANI,and increased with decreasing of averaged diameter of the nanofibers. The enhanced antioxidant activity was concerned with increased surface area of PANI nanofibers.

  11. Surface modification of polyvinyl alcohol/malonic acid nanofibers by gaseous dielectric barrier discharge plasma for glucose oxidase immobilization

    Energy Technology Data Exchange (ETDEWEB)

    Afshari, Esmail, E-mail: e.afshari@mail.sbu.ac.ir [Laser and Plasma Research Institute, Shahid Beheshti University, Evin, 1983963113 Tehran (Iran, Islamic Republic of); Mazinani, Saeedeh [Amirkabir Nanotechnology Research Institute (ANTRI), Amirkabir University of Technology, 15875-4413, Tehran (Iran, Islamic Republic of); Ranaei-Siadat, Seyed-Omid [Protein Research Center, Shahid Beheshti University, Evin, 1983963113 Tehran (Iran, Islamic Republic of); Ghomi, Hamid [Laser and Plasma Research Institute, Shahid Beheshti University, Evin, 1983963113 Tehran (Iran, Islamic Republic of)

    2016-11-01

    Highlights: • We fabricated polyvinyl alcohol/malonic acid nanofibers using electrospinning. • The surface nanofibers were modified by gaseous (air, nitrogen, CO{sub 2} and argon) dielectric barrier discharge. • Among them, air plasma had the most significant effect on glucose oxidase immobilization. • Chemical analysis showed that after modification of nanofibers by air plasma, the carboxyl group increased. • After air plasma treatment, reusability and storage stability of glucose oxidase immobilized on nanofibers improved. - Abstract: Polymeric nanofiber prepares a suitable situation for enzyme immobilization for variety of applications. In this research, we have fabricated polyvinyl alcohol (PVA)/malonic acid nanofibers using electrospinning. After fabrication of nanofibers, the effect of air, nitrogen, CO{sub 2}, and argon DBD (dielectric barrier discharge) plasmas on PVA/malonic acid nanofibers were analysed. Among them, air plasma had the most significant effect on glucose oxidase (GOx) immobilization. Attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectrum analysis and X-ray photoelectron spectroscopy (XPS) results revealed that in case of air plasma modified nanofibers, the carboxyl groups on the surface are increased. The scanning electron microscopy (SEM) images showed that, after GOx immobilization, the modified nanofibers with plasma has retained its nanofiber structure. Finally, we analysed reusability and storage stability of GOx immobilized on plasma modified and unmodified nanofibers. The results were more satisfactory for modified nanofibers with respect to unmodified ones.

  12. Surface functionalization of carbon nanofibers by sol-gel coating of zinc oxide

    Energy Technology Data Exchange (ETDEWEB)

    Shao Dongfeng [Key Laboratory of Eco-textiles, Ministry of Education, Jiangnan University, Wuxi 214122 (China); Changzhou Textile Garment Institute, Changzhou 213164 (China); Wei Qufu [Key Laboratory of Eco-textiles, Ministry of Education, Jiangnan University, Wuxi 214122 (China)], E-mail: qfwei@jiangnan.edu.cn; Zhang Liwei; Cai Yibing; Jiang Shudong [Key Laboratory of Eco-textiles, Ministry of Education, Jiangnan University, Wuxi 214122 (China)

    2008-08-15

    In this paper the functional carbon nanofibers were prepared by the carbonization of ZnO coated PAN nanofibers to expand the potential applications of carbon nanofibers. Polyacrylonitrile (PAN) nanofibers were obtained by electrospinning. The electrospun PAN nanofibers were then used as substrates for depositing the functional layer of zinc oxide (ZnO) on the PAN nanofiber surfaces by sol-gel technique. The effects of coating, pre-oxidation and carbonization on the surface morphology and structures of the nanofibers were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) and Scanning electron microscopy (SEM), respectively. The results of SEM showed a significant increase of the size of ZnO nanograins on the surface of nanofibers after the treatments of coating, pre-oxidation and carbonization. The observations by SEM also revealed that ZnO nanoclusters were firmly and clearly distributed on the surface of the carbon nanofibers. FTIR examination also confirmed the deposition of ZnO on the surface of carbon nanofibers. The XRD analysis indicated that the crystal structure of ZnO nanograins on the surface of carbon nanofibers.

  13. Cyclodextrin-grafted electrospun cellulose acetate nanofibers via “Click” reaction for removal of phenanthrene

    Science.gov (United States)

    Celebioglu, Asli; Demirci, Serkan; Uyar, Tamer

    2014-06-01

    Beta-cyclodextrin (β-CD) functionalized cellulose acetate (CA) nanofibers have been successfully prepared by combining electrospinning and “click” reaction. Initially, β-CD and electrospun CA nanofibers were modified so as to be azide-β-CD and propargyl-terminated CA nanofibers, respectively. Then, “click” reaction was performed between modified CD molecules and CA nanofibers to obtain permanent grafting of CDs onto nanofibers surface. It was observed from the SEM image that, while CA nanofibers have smooth surface, there were some irregularities and roughness at nanofibers morphology after the modification. Yet, the fibrous structure was still protected. ATR-FTIR and XPS revealed that, CD molecules were successfully grafted onto surface of CA nanofibers. The adsorption capacity of β-CD-functionalized CA (CA-CD) nanofibers was also determined by removing phenanthrene (polycyclic aromatic hydrocarbons, PAH) from its aqueous solution. Our results indicate that CA-CD nanofibers have potential to be used as molecular filters for the purpose of water purification and waste water treatment by integrating the high surface area of nanofibers with inclusion complexation property of CD molecules.

  14. Facile aqueous-phase synthesis of copper sulfide nanofibers

    Science.gov (United States)

    Tang, Zengmin; Im, Sang Hyuk; Kim, Woo-Sik; Yu, Taekyung

    2017-07-01

    We report a facile aqueous-phase synthetic route to vine-like copper sulfide (CuS) nanofibers prepared by reacting elemental sulfur with Cu+-branched polyethyleneimine (BPEI) complex obtained by the reaction of Cu2+ with ascorbic acid in the presence of BPEI. By controlling the concentration of BPEI, we could easily control the morphology of CuS from nanofibers to hollow nanoparticles. We also found that concentration of BPEI and the presence of halide anion would play important roles in the formation of vine-like CuS nanofibers.

  15. Bioactive thermoresponsive polyblend nanofiber formulations for wound healing

    Energy Technology Data Exchange (ETDEWEB)

    Pawar, Mahesh D. [Polymer Science and Engineering, National Chemical Laboratory, Homi Bhabha Road, Pashan, Pune 411008 (India); MAEER' s Maharashtra Institute of Pharmacy S. No. 124, MIT Campus Paud Road, Kothrud, Pune 411 038 (India); Rathna, G.V.N., E-mail: rv.gundloori@ncl.res.in [Polymer Science and Engineering, National Chemical Laboratory, Homi Bhabha Road, Pashan, Pune 411008 (India); Agrawal, Shubhang [Polymer Science and Engineering, National Chemical Laboratory, Homi Bhabha Road, Pashan, Pune 411008 (India); Kuchekar, Bhanudas S. [MAEER' s Maharashtra Institute of Pharmacy S. No. 124, MIT Campus Paud Road, Kothrud, Pune 411 038 (India)

    2015-03-01

    The rationale of this work is to develop new bioactive thermoresponsive polyblend nanofiber formulations for wound healing (topical). Various polymer compositions of thermoresponsive, poly(N-isopropylacrylamide), egg albumen and poly(ε-caprolactone) blend solutions with and without a drug [gatifloxacin hydrochloride, Gati] were prepared. Non-woven nanofibers of various compositions were fabricated using an electrospinning technique. The morphology of the nanofibers was analyzed by an environmental scanning electron microscope. The morphology was influenced by the concentration of polymer, drug, and polymer blend composition. Fourier transform infrared spectroscopy analysis showed the shift in bands due to hydrogen ion interactions between polymers and drug. Thermogram of PNIPAM/PCL/EA with Gati recorded a shift in lower critical solution temperature (LCST) and glass transition temperature (T{sub g}) of PNIPAM. Similarly T{sub g} and melting temperature (T{sub m}) of PCL were shifted. X-ray diffraction patterns recorded a decrease in the crystalline state of PCL nanofibers and transformed crystalline drug to an amorphous state. In vitro release study of nanofibers with Gati showed initial rapid release up to 10 h, followed by slow and controlled release for 696 h (29 days). Nanofiber mats with Gati exhibited antibacterial properties to Staphylococcus aureus, supported suitable controlled drug release with in vitro cell viability and in vivo wound healing. - Highlights: • Thermoresponsive and bioactive nanofiber blends of PNIPAM/EA/PCL were fabricated. • Nanofiber blends favored initial rapid release, followed by controlled release. • In vitro cell viability of pure polymers and nanofiber blends was least toxic. • In vivo studies of drug loaded nanofiber mats recorded faster tissue regeneration.

  16. Electrochemical Preparation of Chiral Polyaniline Nanofibers%手性聚苯胺纳米纤维的电化学制备

    Institute of Scientific and Technical Information of China (English)

    翁少煌; 周剑章; 林仲华; 林新华

    2012-01-01

    Chiral polyaniline ( PANI) nanofibers were synthesized via facilely potentiostatic electropolymeriza-tion method without template in the presence of ( IS) -( +) -camphor-10-sulfonic acid(D-CSA) or ( IR) -( -)-camphor-10-sulfonic acid(L-CSA) as the dopant. The morphology and optical property of chiral PANI nanofibers were characterized with scanning electron microscopy ( SEM ) , transmission electron microscopy ( TEM ) , UV-Vis spectrum(UV-Vis) and circular dichroism(CD) . Combined with the average diameter of micelles and zeta-potential of different deposition solutions, the formation mechanism and the enhanced optical activity of the optical PANI nanofibers were studied. The morphology of PANI nanofibers without the helical structure was consistent with the change of the concentration of aniline in the deposition solution when the concerntion of CSA was 1 mol/L. Furthermore, the chiral PANI nanofibers induced by different chiral CSA exhibited mirror-imaged circular dichroism spectra with high ellipticity, indicating the stereochemical selectivity of the molecular structure of PANI chain in the electrodeposited process. The colors and optical activities of the chiral PANI nanofibers not only can be kept with the chemical dedoping/redoping treatment, but also can reversibly varied with the different oxidized forms which were controlled via electrochemical route.%采用恒电位电聚合法制备了樟脑磺酸(CSA)掺杂的旋光异构性聚苯胺(PANI)纳米纤维.用扫描电子显微镜(SEM)、透射电子显微镜(TEM)、紫外-可见吸收光谱(UV-Vis)和圆二色光谱(CD)对PANI纳米纤维的形貌和光学性质进行表征,结合电聚合溶液胶束平均粒径和ξ电位的测定,研究了具有旋光异构性PANI纳米纤维的形成机理和具有增强旋光异构性的原因.所制备的PANI纳米纤维具有无双螺旋结构,其形貌不随着苯胺浓度的改变而变化.不同手性樟脑磺酸掺杂制备的PANI纳米纤维具有镜像对称

  17. Fabrication and durable antibacterial properties of electrospun chitosan nanofibers with silver nanoparticles.

    Science.gov (United States)

    Liu, Yanan; Liu, Yang; Liao, Nina; Cui, Fuhai; Park, Mira; Kim, Hak-Yong

    2015-08-01

    Non-precipitation chitosan/silver nanoparticles (AgNPs) in 1% acetic acid aqueous solution was prepared from chitosan colloidal gel with various contents of silver nitrate via electron beam irradiation (EBI). Electrospun chitosan-based nanofibers decorated with AgNPs were successfully performed by blending poly(vinyl alcohol). The morphology of as-prepared nanofibers and the size of AgNPs in the nanofibers were investigated by field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). The presence of AgNPs in as-obtained nanofibers was also confirmed by ultraviolet-visible spectroscopy (UV), Fourier transform infrared (FT-IR) spectroscopy, EDX spectrum and metal mapping. Silver ion release behavior indicated that these hybrid nanofibers continually release adequate silver to exhibit antibacterial activity over 16 days. These biocomposite nanofibers showed pronounced antibacterial activity against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli).

  18. Collection of Electrospun Polymer Nanofibers

    Science.gov (United States)

    Kataphinan, Woraphon; Reneker, Darrell H.

    2000-03-01

    The dry nanofibers produced in a typical electrospinning process are electrically charged. The nanofibers were directed by an electrical field, a tensile force along the axis of the fiber, and by the viscous drag force of moving air. The looping and spiraling path of the nanofibers, which resulted from bending and other kinds of instabilities that occurred as the fiber was formed, also complicated the collection process. Non-woven sheets of nanofibers were made by attracting the nanofibers to a conducting sheet or screen. The sheet or screen was flat and stationary, or wrapped around a rotating drum. Nanofibers were also collected in a liquid. The liquid removed charge or solvent. Nanofibers were collected on the surface of a non-wetting liquid, so that the patterns formed by the arriving nanofibers were observed directly. Streams of air, and air vortices were also used. These methods are being combined with robotic manipulators to collect nanofibers in many useful forms.

  19. Preparation of poly(3,4-ethylenedioxythiophene) nanofibers modified pencil graphite electrode and investigation of over-oxidation conditions for the selective and sensitive determination of uric acid in body fluids

    Energy Technology Data Exchange (ETDEWEB)

    Özcan, Ali, E-mail: aozcan3@anadolu.edu.tr; İlkbaş, Salih

    2015-09-03

    In this study, we have performed the preparation of over-oxidized poly(3,4-ethylenedioxythiophene) nanofibers modified pencil graphite electrode (Ox-PEDOT-nf/PGE) to develop a selective and sensitive voltammetric uric acid (UA) sensor. It was noted that the over-oxidation potential and time had a prominent effect on the UA response of the Ox-PEDOT-nf/PGE. Characterizations of PEDOT-nf/PGE and Ox-PEDOT-nf/PGE have been performed by cyclic voltammetry, electrochemical impedance spectroscopy, scanning electron microscopy, Fourier transform infrared spectroscopy and Raman spectroscopy. The highest voltammetric response of UA was obtained at pH 2.0. A linear relationship between the concentration of UA and oxidation peak currents was observed in the concentration range of 0.01–20.0 μM. The detection limit (1.3 nM according to S/N = 3) and reproducibility (RSD: 4.6 % for N:10) have also been determined. The effects of different substances on the determination of UA have been investigated. A very high peak separation value of 423 mV was obtained between UA and ascorbic acid which is the major interfering substance for UA. The use of Ox-PEDOT-nf/PGE has been successfully tested in the determination of UA in human blood serum and urine samples for the first time in the literature. - Highlights: • Modification of pencil graphite with over-oxidized PEDOT nanofibers was performed. • The prepared electrodes were used in the voltammetric determination of uric acid. • The over-oxidation potential and time has a prominent effect on the responses. • A very high peak separation (463 mV) was obtained between ascorbic and uric acids. • Analytical application of the electrodes was successfully tested in real samples.

  20. ACF-Ag-TiO2纳米纤维的制备及其光催化性能%Preparation of ACF-Ag-TiO2 Nanofibers and Their Photocatalytic Properties

    Institute of Scientific and Technical Information of China (English)

    万郁楠; 李巧玲; 李洪刚; 刘晓霞; 武润平; 续丽丽

    2013-01-01

    Activated carbon fiber(ACF)-Ag-TiO2 nanofiber composite materials were prepared using hydrothermal method combining with sol-gel method. The samples were analyzed by SEM, TEM and EDS. Taking methylene orange degradation as a model reaction, the photocatalytic property of the material was investigated. The results indicate that the length of nanofibers is between 4 and 8 μm, and the diameter is between S and 50 nm. As the mass fraction of element Ag doping in the prepared materials is 0.5%, the photocatalysis efficiency was at the maximum. The photocatalysis efficiency on the methylene orange is up to 95 % after lighting for 30 min.%将溶胶-凝胶法与水热法相结合制备活性碳纤维(ACF)-Ag-TiO2纳米纤维复合材料,利用扫描电镜、透射电镜、能量色散型X射线光谱仪对ACF-Ag-TiO2纳米纤维复合物的表面形貌及晶型进行表征,并以甲基橙的脱色降解为模式反应,考察样品的光催化性能.结果表明,ACF-Ag-TiO2纳米纤维长度为4~8 μm,直径约为5~50 nm;制备的材料中Ag元素的质量分数为0.5%时,ACF-Ag-TiO2的催化效果最优,光照30 min后时甲基橙的降解率为95%.

  1. Smart nanofibers with a photoresponsive surface for controlled release.

    Science.gov (United States)

    Fu, Guo-Dong; Xu, Li-Qun; Yao, Fang; Li, Guo-Liang; Kang, En-Tang

    2009-11-01

    A novel photocontrolled "ON-OFF" release system for the alpha-cyclodextrin-5-fluorouracial (alpha-CD-5FU) prodrug, based on host-guest interaction on the photoresponsive and cross-linked nanofiber surface, was demonstrated. The nanofibers with a stimuli-responsive surface were electrospun from the block copolymer prepared via controlled radical polymerization, followed by surface modification via "Click Chemistry", and loading of the prodrug via host-guest interaction.

  2. Control of mechanical properties of chitin nanofiber film using glycerol without losing its characteristics.

    Science.gov (United States)

    Ifuku, Shinsuke; Ikuta, Akiko; Izawa, Hironori; Morimoto, Minoru; Saimoto, Hiroyuki

    2014-01-30

    Surface-deacetylated chitin nanofiber films plasticized with glycerol were prepared to control mechanical properties. Nanofiber networks were able to retain excessive glycerol content up to 70% to obtain self-standing film. All films were flexible and highly transparent independent of glycerol content. Glycerol significantly decreased the Young's moduli and tensile strengths, and increased the fracture strain due to its plasticizing effect. At the same time, glycerol did not change the high transparency or the low thermal expansion of the nanofiber film.

  3. Electrospun nanofibers of poly(vinyl pyrrolidone)/Eu3+ and its photoluminescence properties

    Institute of Scientific and Technical Information of China (English)

    Shan Shan Tang; Chang Lu Shao; Shou Zhu Li

    2007-01-01

    Nanofibers of poly(vinyl pyrrolidone) (PVP)/Eu3+ with diameters of 300-900 nm were prepared by using sol-gel processing and electrospinning technique. The products were characterized by scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FT-IR), and photoluminescence (PL). The results indicated that, Eu3+ was successfully embedded in the onedimensional hybrid nanofibers, and the PVP/Eu3+ hybrid nanofibers had favorable photoluminescence properties.

  4. Carbon-coated Li3 N nanofibers for advanced hydrogen storage.

    Science.gov (United States)

    Xia, Guanglin; Li, Dan; Chen, Xiaowei; Tan, Yingbin; Tang, Ziwei; Guo, Zaiping; Liu, Huakun; Liu, Zongwen; Yu, Xuebin

    2013-11-20

    3D porous carbon-coated Li3 N nanofibers are successfully fabricated via the electrospinning technique. The as-prepared nanofibers exhibit a highly improved hydrogen-sorption performance in terms of both thermodynamics and kinetics. More interestingly, a stable regeneration can be achieved due to the unique structure of the nanofibers, over 10 cycles of H2 sorption at a temperature as low as 250 °C.

  5. Preparation and Characterization of Self-assembly Vesicle of Icariin Nanofiber%淫羊藿苷纳米纤维膜自组装囊泡的制备及表征

    Institute of Scientific and Technical Information of China (English)

    江永南; 莫红缨

    2012-01-01

    OBJECTIVE To improve the compatibility and absorption properties of icariin in vivo by preparing electrospun icariin nanofiber and forming self-assembly nano-vesicles. METHODS Solubility test in solvent was performed to screen suitable solvent system. Icariin nanofibers was prepared by electrospinning. SEM and TEM were used to observe fiber membrane surface and self-assembly vehicle morphology respectively. XRD, DSC and IR were applied to characterize the drug-loaded nanofilber. RESULTS Methanol and dimethylacetamide were selected as the solvent mixture for providing good solubility and formation of drug-loaded fiber. The electron scan microscope showed that diameter of fiber was (400-600 nm) and the fiber surface was smooth without drug absorption. The polymers were well compatible with drug. Hydrogen bonds played a key interaction between drug and polymers. Nano-vehicle was self-assembled by dispersing the drug-loaded nanofiler into water. CONCLUSION Preparation of icariin nanofiber membrane by electrospinning was simple and icariin was highly dispersed in nanofiberse in amorphous form. Nanofibers can be self-assembled in water to form nano-vehicles.%目的 采用静电纺丝制备淫羊藿苷纳米纤维膜,并通过自组装技术形成纳采囊泡,改善淫羊藿苷在体内的相容性及吸收性能.方法 通过溶解度实验筛选合适溶剂,以静电纺丝技术制备淫羊藿苷纳米纤维膜,采用扫描电镜对纤维膜表面形态进行观察,采用X射线晶体衍射(XRD)和差示扫描量热分析(DSC)检测纤维膜中药物的存在状态,通过红外光谱分析药物与纤维材料之间的相互作用.并通过透射电镜观察纳米纤维膜自组装纳采囊泡的性能.结果 甲醇与二甲基乙酰胺混合溶剂的溶解性及纤维成型性较好;载药纤维直径分布均匀(400~600 nm)、表面光滑无药物颗粒,药物与聚合物之间通过氢键作用,具有良好的相容性,水中溶解试验发现纳米纤维膜能

  6. PLGA新型纳米支架的制备及其生物相容性7%Preparation of a novel PLGA nano-fiber scaffold and its biocompatibility

    Institute of Scientific and Technical Information of China (English)

    任谞挺; 刘轶洋; 刘宏伟

    2012-01-01

    目的 探讨和比较应用不同参数静电纺丝技术制备复合型聚乳酸-羟基乙酸[ poly( lactic-co-glycolic acid),PLGA]纳米纤维缓释膜片的可行性,检测其表面特性以及生物相容性.方法 使用不同参数制备纳米纤维膜,扫描电镜观察膜片表面形态;人牙周膜细胞(human periodontal ligament cells,hPLDCs)培养及鉴定后接种于空白膜上,扫描电镜观察细胞与膜的附着情况,以MTT[3-(4,5-dimethylthiaozol-2-yl)-2,5-dip henyltetrazolium bromide]实验检测不同浓度材料浸提液对细胞增殖变化情况的影响.结果 随着PLGA流量增加,纳米纤维直径增加;细胞与PLGA膜复合后粘附良好且增殖状态无明显变化;不同浓度材料浸提液对牙周膜细胞增殖的影响无明显差异.结论 通过不同参数静电纺丝制备的新型纳米纤维膜具有良好的生物相容性,可进一步作为多种药物及细胞因子载体构建缓释型支架,从而用于引导性牙周组织再生(guided tissue regeneration,GTR)或者牙周组织工程.%Objective To prepare a novel poly(lactic-co-glycolic acid) (PLGA) electrospinning nano-fiber membrane and to test its biocompatibility in vitro. Methods Blank nano-fiber membrane was prepared. The morphology and characteristics of membrane surface were observed with electron microscopy. Human periodontal ligament cells ( HPDLCs) were cultured and identified, then inoculated onto the blank membrane. Proliferation of HPDLCs were determined by MTT method and cell adhesion to the membrane was observed by electron microscopy. Results The diameter of nano-fiber was increased with the increasing flow of PLGA. hPDLCs adhered well to PLGA, and the membrane had no effect on cell proliferation. Conclusion The novel PLGA nano-fiber membrane prepared with electrospinning has good biocompatibility in vitro, which may be used as a drug of cytokine carrier for guided tissue regeneration or periodontal tissue engineering.

  7. Influence of Solution Properties and Process Parameters on the Formation and Morphology of YSZ and NiO Ceramic Nanofibers by Electrospinning

    NARCIS (Netherlands)

    Cadafalch Gazquez, G.; Smulders, V.; Veldhuis, S.A.; Wieringa, P.; Moroni, L.; Boukamp, B.A.; Elshof, ten J.E.

    2017-01-01

    The fabrication process of ceramic yttria-stabilized zirconia (YSZ) and nickel oxide nanofibers by electrospinning is reported. The preparation of hollow YSZ nanofibers and aligned nanofiber arrays is also demonstrated. The influence of the process parameters of the electrospinning process, the phys

  8. A Composite of Electrospun Nylon-6 Nanofibers and in-situ Polymerized Polypyrrole as an NH3 Gas Sensor

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    1 Results Electrospinning provides a simple and versatile method for preparing nanofibers with different morphology, such as porous fibers and nanotubes. It has been widely used for preparing nanomaterials with unique properties and potential applications in medicine, catalyst, photonics and sensors[1, 2]. In this study, uniform Nylon-6 nanofibers with diameter of ≈300 nm by electrospun from formic acid solution containing 15%wt Nylon-6. Polypyrrole (PPy) was then deposited on the nanofibers by in-situ ...

  9. Fabrication of electrospun nanofibers bundles

    Science.gov (United States)

    Ye, Junjun; Sun, Daoheng

    2007-12-01

    Aligned nanofibers, filament bundle composed of large number of nanofibers have potential applications such as bio-material, composite material etc. A series of electrospinning experiments have been conducted to investigate the electrospinning process,in which some parameters such as polymer solution concentration, bias voltage, distance between spinneret and collector, solution flow rate etc have been setup to do the experiment of nanofibers bundles construction. This work firstly reports electrospun nanofiber bundle through non-uniform electrical field, and nanofibers distributed in different density on electrodes from that between them. Thinner nanofibers bundle with a few numbers of nanofiber is collected for 3 seconds; therefore it's also possible that the addressable single nanofiber could be collected to bridge two electrodes.

  10. Environmental remediation and superhydrophilicity of ultrafine antibacterial tungsten oxide-based nanofibers under visible light source

    Energy Technology Data Exchange (ETDEWEB)

    Srisitthiratkul, Chutima; Yaipimai, Wittaya [Nano Functional Textile Laboratory, National Nanotechnology Center (NANOTEC), National Science and Technology Development Agency (NSTDA), 111 Thailand Science Park, Phahonyothin Rd., Klong 1, Klong Luang, Pathumthani 12120 (Thailand); Intasanta, Varol, E-mail: varol@nanotec.or.th [Nano Functional Textile Laboratory, National Nanotechnology Center (NANOTEC), National Science and Technology Development Agency (NSTDA), 111 Thailand Science Park, Phahonyothin Rd., Klong 1, Klong Luang, Pathumthani 12120 (Thailand)

    2012-10-15

    Graphical abstract: Nanosilver-decorated WO{sub 3} photocatalytic nanofibers are antibacterial and superhydrophilic under a visible light source. Highlights: Black-Right-Pointing-Pointer Deposition of nanosilver onto electrospun WO{sub 3} nanofibers' surface was done exploiting visible or UV light driven photoreduction of silver ion. Black-Right-Pointing-Pointer Nanofibers showed antibacterial characteristics. Black-Right-Pointing-Pointer Nanofibers degraded a model toxin effectively. Black-Right-Pointing-Pointer Nanofibers showed superhydrophilicity under a visible light source. - Abstract: Fabrication of nanosilver-decorated WO{sub 3} nanofibers was successfully performed. First, deposition of nanosilver onto electrospun WO{sub 3} nanofibers' surface was done via photoreduction of silver ion under visible or UV light. The resulting hybrid nanofibers not only revealed antibacterial characteristics but also maintained their photocatalytic performance towards methylene blue decomposition. Unexpectedly, the nanofibrous layers prepared from these nanofibers showed superhydrophilicity under a visible light source. The nanofibers might be advantageous in environmental and hygienic nanofiltration under natural light sources, where the self-cleaning characteristics could be valuable in maintenance processes.

  11. Preparation of asymmetrically distributed bimetal ceria (CeO₂) and copper (Cu) nanoparticles in nitrogen-doped activated carbon micro/nanofibers for the removal of nitric oxide (NO) by reduction.

    Science.gov (United States)

    Bhaduri, Bhaskar; Verma, Nishith

    2014-12-15

    A novel multi-scale web of carbon micro/nanofibers (ACF/CNF) was prepared by the catalytic chemical vapor deposition (CCVD), in which CeO2 and Cu nanoparticles (NPs) were in-situ incorporated during a synthesis step. The CVD temperature was adjusted such that the prepared material had asymmetric distribution of the bimetals, with the Cu NPs located at the tips of the CNFs and the CeO2 particles adhered to the surface of the ACF substrate. The prepared bimetals-dispersed web of ACF/CNF was treated with pyridine and the surface functionalized material was applied for the removal of NO by reduction. The complete reduction of NO was achieved at 500°C and for 400ppm NO concentration. Whereas the Cu NPs acted as the catalyst for the reduction, CeO2 facilitated the incorporation of nitrogen from the pyridine source into the ACF/CNF surface. The produced nitrogen containing surface functional groups enhanced the reactivity of the material toward the NO. The bimetals CeO2 and Cu nanoparticles (NPs)-dispersed ACF/CNF produced in this study is a potential candidate for effectively removing NO by reduction, without requiring urea or ammonia used in conventional abatement methods. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. Novel dental composites reinforced with zirconia-silica ceramic nanofibers.

    Science.gov (United States)

    Guo, Guangqing; Fan, Yuwei; Zhang, Jian-Feng; Hagan, Joseph L; Xu, Xiaoming

    2012-04-01

    To fabricate and characterize dental composites reinforced with various amounts of zirconia-silica (ZS) or zirconia-yttria-silica (ZYS) ceramic nanofibers. Control composites (70 wt% glass particle filler, no nanofibers) and experimental composites (2.5, 5.0, and 7.5 wt% ZS or ZYS nanofibers replacing glass particle filler) were prepared by blending 29 wt% dental resin monomers, 70 wt% filler, and 1.0 wt% initiator, and polymerized by either heat or dental curing light. Flexural strength (FS), flexural modulus (FM), energy at break (EAB), and fracture toughness (FT) were tested after the specimens were stored in 37°C deionized water for 24h, 3 months, or 6 months. Degree of conversion (DC) of monomers in composites was measured using Fourier transformed near-infrared (FT-NIR) spectroscopy. Fractured surfaces were observed by field-emission scanning electron microscope (FE-SEM). The data were analyzed using ANOVA with Tukey's Honestly Significant Differences test used for post hoc analysis. Reinforcement of dental composites with ZS or ZYS nanofibers (2.5% or 5.0%) can significantly increase the FS, FM and EAB of dental composites over the control. Further increase the content of ZS nanofiber (7.5%), however, decreases these properties (although they are still higher than those of the control). Addition of nanofibers did not decrease the long-term mechanical properties of these composites. All ZS reinforced composites (containing 2.5%, 5.0% and 7.5% ZS nanofibers) exhibit significantly higher fracture toughness than the control. The DC of the composites decreases with ZS nanofiber content. Incorporation of ceramic nanofibers in dental composites can significantly improve their mechanical properties and fracture toughness and thus may extend their service life. Copyright © 2011 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  13. Porous block nanofiber composite filters

    Energy Technology Data Exchange (ETDEWEB)

    Ginley, David S.; Curtis, Calvin J.; Miedaner, Alexander; Weiss, Alan J.; Paddock, Arnold

    2016-08-09

    Porous block nano-fiber composite (110), a filtration system (10) and methods of using the same are disclosed. An exemplary porous block nano-fiber composite (110) includes a porous block (100) having one or more pores (200). The porous block nano-fiber composite (110) also includes a plurality of inorganic nano-fibers (211) formed within at least one of the pores (200).

  14. Influence of TiO2 nanofiber additives for high efficient dye-sensitized solar cells.

    Science.gov (United States)

    Hwang, Kyung-Jun; Lee, Jae-Wook; Park, Ju-Young; Kim, Sun-Il

    2011-02-01

    TiO2 nanofibers were prepared from a mixture of titanium-tetra-isopropoxide and poly vinyl pyrrolidone by applying the electrospinning method. The samples were characterized by XRD, FE-SEM, TEM and BET analyses. The diameter of electrospun TiO2 nanofibers is in the range of 70 approximately 160 nm. To improve the short-circuit photocurrent, we added the TiO2 nanofibers in the TiO2 electrode of dye-sensitized solar cells (DSSCs). TiO2 nanofibers added in DSSCs can make up to 20% more conversion energy than the conventional DSSC with only TiO2 films only.

  15. Highly Sensitive Local Surface Plasmon Resonance in Anisotropic Au Nanoparticles Deposited on Nanofibers

    Directory of Open Access Journals (Sweden)

    Masanari Saigusa

    2015-01-01

    Full Text Available This paper reports the facile and high-throughput fabrication method of anisotropic Au nanoparticles with a highly sensitive local surface plasmon resonance (LPR using cylindrical nanofibers as substrates. The substrates consisting of nanofibers were prepared by the electrospinning of poly(vinylidene fluoride (PVDF. The Au nanoparticles were deposited on the surface of electrospun nanofibers by vacuum evaporation. Scanning electron microscopy revealed the formation of a curved Au island structure on the surface of cylindrical nanofibers. Polarized UV-visible extinction spectroscopy showed anisotropy in their LPR arising from the high surface curvature of the nanofiber. The LPR of the Au nanoparticles on the thinnest nanofiber with a diameter of ~100 nm showed maximum refractive index (RI sensitivity over 500 nm/RI unit (RIU. The close correlation between the fiber diameter dependence of the RI sensitivity and polarization dependence of the LPR suggests that anisotropic Au nanoparticles improve RI sensitivity.

  16. Electrospun nanofibers composed of poly({epsilon}-caprolactone) and polyethylenimine for tissue engineering applications

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jang Ho [Department of Biosystems and Biomaterials Science and Engineering, Seoul National University, Seoul 151-921 (Korea, Republic of); Choung, Pill-Hoon [Department of Oral and Maxillofacial Surgery, Tooth Bioengineering National Research Lab, School of Dentistry, Seoul National University, Seoul 110-744 (Korea, Republic of); Kim, In Yong [Department of Agricultural Biotechnology, Seoul National University, Seoul 151-921 (Korea, Republic of); Lim, Ki Taek; Son, Hyun Mok [Department of Biosystems and Biomaterials Science and Engineering, Seoul National University, Seoul 151-921 (Korea, Republic of); Choung, Yun-Hoon [Department of Otolaryngology, Ajou University School of Medicine, Suwon, 443-721 (Korea, Republic of); Cho, Chong-Su, E-mail: chocs@plaza.snu.ac.kr [Department of Agricultural Biotechnology, Seoul National University, Seoul 151-921 (Korea, Republic of); Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul 151-921 (Korea, Republic of); Chung, Jong Hoon, E-mail: jchung@snu.ac.kr [Department of Biosystems and Biomaterials Science and Engineering, Seoul National University, Seoul 151-921 (Korea, Republic of); Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul 151-921 (Korea, Republic of)

    2009-06-01

    Poly({epsilon}-caprolactone) (PCL) electrospun nanofibers have been reported as a scaffold for tissue engineering application. However, high hydrophobicity of PCL limits use of functional scaffold. In this study, PCL/polyethylenimine (PEI) blend electrospun nanofibers were prepared to overcome the limitation of PCL ones because the PEI as a cationic polymer can increase cell adhesion and can improve the electrospinnability of PCL. The structure, mechanical properties and biological activity of the PCL/PEI electrospun nanofibers were studied. The diameters of the PCL/PEI nanofibers ranged from 150.4 {+-} 33 to 220.4 {+-} 32 nm. The PCL/PEI nanofibers showed suitable mechanical properties with adequate porosity and increased hydrophilic behavior. The cell adhesion and cell proliferation of PCL nanofibers were increased by blending with PEI due to the hydrophilic properties of PEI.

  17. Antibacterial polylactic acid/chitosan nanofibers decorated with bioactive glass

    Energy Technology Data Exchange (ETDEWEB)

    Goh, Yi-fan; Akram, Muhammad; Alshemary, Ammarz [Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, 81310 Johor Bahru, Johor (Malaysia); Hussain, Rafaqat, E-mail: rafaqat@comsats.edu.pk [Department of Physics, COMSATS Institute of Information Technology, Islamabad (Pakistan)

    2016-11-30

    Highlights: • PLA/Chitosan nanofibers were coated with functional bioglass. • Polymer/ceramic composite fibers exhibited good in-vitro bioactivity. • Nanofibers coated with Ag doped bioglass exhibited good antibacterial activity. - Abstract: In this study, we have presented the structural and in vitro characterization of electrospun polylactic acid (PLA)/Chitosan nanofibers coated with cerium, copper or silver doped bioactive glasses (CeBG/CuBG/AgBG). Bead-free, smooth surfaced nanofibers were successfully prepared by using electrospinning technique. The nanocomposite fibers were obtained using a facile dip-coating method, their antibacterial activities against E. coliE. coli (ATCC 25922 strains) were measured by the disk diffusion method after 24 h of incubation at 37 °C. CeBG and CuBG decorated PLA/Chitosan nanofibers did not develop an inhibition zone against the bacteria. On the other hand, nanofibers coated with AgBG developed an inhibition zone against the bacteria. The as-prepared nanocomposite fibers were immersed in SBF for 1, 3 and 7 days in Simulated Body Fluid (SBF) for evaluation of in vitro bioactivity. All samples induced the formation of crystallites with roughly ruffled morphology and the pores of fibers were covered with the extensive growth of crystallites. Energy Dispersive X-ray (EDX) composition analysis showed that the crystallites possessed Ca/P ratio close to 1.67, confirming the good in-vitro bioactivity of the fibers.

  18. Fabrication of Poly(vinylidene fluoride) (PVDF) Nanofibers Containing Nickel Nanoparticles as Future Energy Server Materials.

    Science.gov (United States)

    Sheikh, Faheem A; Cantu, Travis; Macossay, Javier; Kim, Hern

    2011-04-01

    In the present study, we introduce Poly(vinylidene fluoride) (PVDF) nanofibers containing nickel (Ni) nanoparticles (NPs) as a result of an electrospinning. Typically, a colloidal solution consisting of PVDF/Ni NPs was prepared to produce nanofibers embedded with solid NPs by electrospinning process. The resultant nanostructures were studied by SEM analyses, which confirmed well oriented nanofibers and good dispersion of Ni NPs over them. The XRD results demonstrated well crystalline feature of PVDF and Ni in the obtained nanostructures. Physiochemical aspects of prepared nano-structures were characterized for TEM which confirmed nanofibers were well-oriented and had good dispersion of Ni NPs. Furthermore, the prepared nano-structures were studied for hydrogen production applications. Due to high surface to volume ratio of nanofibers form than the thin film ones, there was tremendous increase in the rate of hydrogen production. Overall, results satisfactorily confirmed the use of these materials in hydrogen production.

  19. Development and characterization of the cisplatin loaded nanofibers for the treatment of cervical cancer.

    Science.gov (United States)

    Aggarwal, Urvashi; Goyal, Amit Kumar; Rath, Goutam

    2017-06-01

    A small scale study was carried out to investigate the therapeutic efficacy cisplatin loaded poly-caprolactone/chitosan composite electrospun nanofibers for local chemotherapy of cervical cancers in mice. The prepared nanofibers had shown the sustained release pattern up to one month. Prepared nanofibers were found to have greater mucoadhesive strength. An orthotopic cervical cancer model was established by inducing the EAC cell lines in the vaginal mucosa at cervix region of the mice. Intravaginal administration of the cisplatin loaded nanofibers showed lesser % cell viability as compared to the plain drug. In vivo studies showed a better anti-tumour efficacy of prepared nanofibers in animals at 14th and 21st after the beginning of treatment. Therefore the technique of electrospinning provides a favourable approach for the targeted delivery of the anti-cancer drug via vaginal route against cervical cancer. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Controlled Morphology of Porous Polyvinyl Butyral Nanofibers

    Directory of Open Access Journals (Sweden)

    Daniela Lubasova

    2011-01-01

    Full Text Available A simple and effective method for the fabrication of porous nanofibers based on the solvent evaporation methods in one-step electrospinning process from the commercial polyvinyl butyral (PVB is presented. The obtained nanofibers are prevalently amorphous with diameters ranging from 150 to 4350 nm and specific surface area of approximately 2–20 m2/g. Pore size with irregular shape of the porous PVB fibers ranged approximately from 50 to 200 nm. The effects of polymer solution concentration, composition of the solvents mixture, and applied voltage on fiber diameter and morphology were investigated. The theoretical approach for the choice of poor and good solvents for PVB was explained by the application Hansen solubility parameter (HSP and two-dimensional graph. Three basic conditions for the production of porous PVB nanofibers were defined: (i application of good/poor solvent mixture for spinning solution, (ii differences of the evaporation rate between good/poor solvent, and (iii correct ratios of good/poor solvent (v/v. The diameter of prepared porous PVB fibers decreased as the polymer concentration was lowered and with higher applied voltage. These nanofiber sheets with porous PVB fibers could be a good candidate for high-efficiency filter materials in comparison to smooth fibers without pores.

  1. Novel electrospun gelatin/oxycellulose nanofibers as a suitable platform for lung disease modeling

    Energy Technology Data Exchange (ETDEWEB)

    Švachová, Veronika, E-mail: xcsvachova@fch.vutbr.cz [Institute of Materials Chemistry, Brno University of Technology (Czech Republic); Vojtová, Lucy [CEITEC – Central European Institute of Technology, Brno University of Technology (Czech Republic); SCITEG, a.s., Brno (Czech Republic); Pavliňák, David [Department of Physical Electronics, Masaryk University (Czech Republic); Vojtek, Libor [Institute of Experimental Biology, Masaryk University (Czech Republic); Sedláková, Veronika [Department of Histology and Embryology, Masaryk University (Czech Republic); International Clinical Research, St. Anne' s University Hospital, Brno (Czech Republic); Hyršl, Pavel [Institute of Experimental Biology, Masaryk University (Czech Republic); Alberti, Milan [Department of Physical Electronics, Masaryk University (Czech Republic); Jaroš, Josef; Hampl, Aleš [Department of Histology and Embryology, Masaryk University (Czech Republic); International Clinical Research, St. Anne' s University Hospital, Brno (Czech Republic); Jančář, Josef [Institute of Materials Chemistry, Brno University of Technology (Czech Republic); CEITEC – Central European Institute of Technology, Brno University of Technology (Czech Republic); SCITEG, a.s., Brno (Czech Republic)

    2016-10-01

    Novel hydrolytically stable gelatin nanofibers modified with sodium or calcium salt of oxycellulose were prepared by electrospinning method. The unique inhibitory effect of these nanofibers against Escherichia coli bacteria was examined by luminometric method. Biocompatibility of these gelatin/oxycellulose nanofibers with eukaryotic cells was tested using human lung adenocarcinoma cell line NCI-H441. Cells firmly adhered to nanofiber surface, as determined by scanning electron microscopy, and no signs of cell dying were detected by fluorescent live/dead assay. We propose that the newly developed gelatin/oxycellulose nanofibers could be used as promising scaffold for lung disease modeling and anti-cancer drug testing. - Highlights: • Novel hydrolytically stable gelatin nanofibers modified with oxycellulose were prepared by electrospinning. • ATR–FTIR spectroscopy and EDX confirmed the presence of oxycellulose in the nanofibers. • Nanofibers modified with calcium salt of oxycellulose exhibited significant antibacterial properties. • Nanofibers modified with sodium salt of oxycellulose revealed excellent biocompatibility with cell line NCI-H441.

  2. Photovoltaic and thermal properties of electrolytes based on electrospun poly(vinylidene fluoride-hexafluoro propylene)/poly(methyl methacrylate) nanofibers for dye-sensitized solar cells.

    Science.gov (United States)

    Jang, Young-Wook; Won, Du-Hyun; Kim, Young-Keun; Hwang, Won-Pill; Jang, Sung-Il; Jeong, Sung-Hoon; Kim, Mi-Ra; Lee, Jin-Kook

    2014-08-01

    We prepared electrospun polymer nanofibers by electrospnning method and investigated about their applications to dye-sensitized solar cells (DSSCs). Electrospun polymer nanofibers applied to the polymer matrix in electrolyte for DSSCs. To improve the stiffness of polymer nanofiber, poly(vinylidene fluoride-hexafluoro propylene)/Poly(methyl methacrylate) (PVDF-HFP/PMMA) blend nanofibers were prepared and examined. In the electrospun PVDF-HFP/PMMA (1:1) blend nanofibers, the best results of VOC, JSC, FF, and efficiency of the DSSC devices showed 0.71 V, 12.8 mA/cm2, 0.61, and 5.56% under AM 1.5 illumination.

  3. Effects of Electrode Reversal on the Distribution of Naproxen in the Electrospun Cellulose Acetate Nanofibers

    Directory of Open Access Journals (Sweden)

    Zhuang Li

    2014-01-01

    Full Text Available Naproxen (NAP/cellulose acetate hybrid nanofibers were prepared by positive and reversed emitting electrodes electrospinning setups. The morphology and structure of the resultant nanofibers were characterized, and the NAP release behaviors were investigated. It was found that NAP dispersed in the CA matrix in molecular level, and no aggregation and dimers of NAP were found in the resultant NAP/CA hybrid nanofibers due to the formation of hydrogen bonds between NAP and CA. The nanofibers obtained by reversed emitting electrode electrospinning setup have a thicker diameter and a faster NAP release rate compared with those obtained by positive emitting electrode electrospinning setup. The faster drug release of NAP from nanofibers prepared by reversed emitting electrode electrospinning is due to the fact that the concentration of NAP molecules near the surface of the nanofibers is relatively higher than that of the nanofibers prepared by positive emitting electrode electrospinning setup. The effects of the electrode polarity on the distribution of drugs in nanofibers can be used to prepare hybrid electrospun fibers of different drug release rates, which may found applications in biomedical materials.

  4. Soft Graphene Nanofibers Designed for the Acceleration of Nerve Growth and Development.

    Science.gov (United States)

    Feng, Zhang-Qi; Wang, Ting; Zhao, Bin; Li, Jiacheng; Jin, Lin

    2015-11-01

    Soft graphene nanofibers with recoverable electrical conductivity and excellent physicochemical stability are prepared by a controlled assembly technique. By using the soft graphene nanofibers for cellular electrical stimulation, the common inhibitory effect of long-term electrical stimulation on nerve growth and development is avoided, which usually happens with traditional 2D conductive materials.

  5. Preparation and Properties of Composite Filtration Membranes Containing Energy-storage Nanofibers%纳米储能纤维复合过滤膜的制备及性能

    Institute of Scientific and Technical Information of China (English)

    王海霞; 刘明巧; 崔建平; 石海峰; 齐鲁; 王笃金

    2014-01-01

    以静电纺丝技术制备的同轴聚甲基丙烯酸十八烷基酯( PSMA)/聚对苯二甲酸乙二酯( PET)纳米储能纤维为支撑层,经聚偏氟乙烯( PVDF)涂覆成膜和溶剂化处理,制备了一种低压高水通量的纳米储能纤维复合过滤膜( NFCM),其中以水或乙醇为凝固溶液的复合过滤膜分别记为NFCM@H2 O或NFCM@EtOH.分析并讨论了不同溶剂处理方式对NFCM力学性能和表面形貌的影响,表征了膜的纯水通量和抗污性能,用扫描电子显微镜( SEM)观察了膜的横断面形貌.结果表明, PSMA/PET纳米储能纤维具有明显的吸放热行为,熔融温度和热焓值分别为36.5℃和10.7 J/g, NFCM的熔融温度和热焓值分别为36℃和2.7 J/g. NFCM的形貌结构、纯水通量和截留率与溶剂处理方式相关, NFCM@EtOH膜的水通量介于100~1400 L/( m2·h)之间,而NFCM@H2 O膜的水通量仅在40~220 L/( m2·h)之间. NFCM的拉伸强度由初始0.925 MPa( PVDF)提高到4.28 MPa以上. NFCM中的相变材料对膜过滤性能有重要影响,并在过滤温度低于50℃时具有减缓作用.%Two type of composite membranes ( NFCM ) containing poly ( stearyl methacrylate ) ( PSMA )/poly( ethylene terephthalate) ( PET) nanofiber supporting layer, prepared by coaxial electrospinning technolo-gy, and poly( vinylidene fluoride) ( PVDF) substrate, were prepared using water or ethanol as the coagulation solution. NFCM has the low pressure and high water flux against the bulk PVDF membrane at the same condition. The morphological structure, the pure water flux and the rejection of NFCM show the strong dependence upon the solvent-treated process. The water flux of NFCM@EtOH is in the range from 100 to 1400 L/( m2 ·h);while for NFCM@H2 O, its water flux only is between 40 and 220 L/( m2 ·h) , indicating that EtOH shows the greatly influence on the surface porosity of membrane. The tensile strength of membrane changes from 0. 925 MPa of the original PVDF to 4. 28 MPa of NFCM

  6. PA6/PVA复合纳米纤维的制备及性能研究%Research of preparation and property of PA6/PVA composite nanofibers

    Institute of Scientific and Technical Information of China (English)

    丁玲; 侯大寅; 凤权

    2011-01-01

    Electrospinning method was used to fabricate PA6 and PVA composite nanofibers.The viscosity,conductivity and surface tension of PA6/PVA blended electrospun solutions with different concentration ratio were analyzed,and their influences on the electrospinning was investigated.The morphology of the nanofiber mats,the compatibility and hydrophilic of composition were characteristiced by scanning electron microscopy,Infrared Spectroscopy and the determination of surface tension.The results show that well-shaped fibers were obtained when the concentration ratio of PA6/PVA was 12%∶4%,the spinning voltage was 19 KV,the collecting distance was 16 cm and the extruding speed was 0.2 mL/h.PA6/PVA prossessed perfect nanofibrous morphology and eliminated the excess swelling in aqueous solution effectively.%采用静电纺丝法制备了PA6/PVA复合纳米纤维.分析了不同质量比的PA6/PVA共混纺丝溶液的粘度、电导率、表面张力,并探讨其静电纺丝效果.采用扫描电镜、红外光谱、表面张力仪等对纳米纤维膜的形貌结构、成分相容性及亲水性能进行表征.结果表明,在纺丝电压为19kV、纺丝距离为20cm、丝液流量为0.2mL/h的条件下,共混溶液质量比为12%∶4%时的静电纺丝所得纤维具有良好的形貌,复合纳米纤维中PA6与PVA具有良好的相容性,并有效地克服了纯纺PVA纳米纤维在水溶液中出现的过度溶胀问题.

  7. Preparation and Characterization of Poly(L-lactic acid)/Rapeseed Protein Blend Nanofiber%聚L-乳酸/菜籽蛋白共混纳米纤维毡的制备与表征

    Institute of Scientific and Technical Information of China (English)

    姜绍通; 刘涛涛; 姜苏薇; 江勤; 王华林

    2011-01-01

    以聚L-乳酸、菜籽蛋白为原料,高压静电纺丝制备聚L-乳酸(PLLA)/菜籽蛋白共混复合纳米纤维毡,考察了不同电压、极距和三氟乙酸添加量对纳米纤维形态及直径的影响,采用傅里叶变换红外光谱(FT-IR)、扫描电镜(SEM)和X-射线衍射(XRD)对相关产物进行结构表征.结果表明:复合纤维中PLLA与菜籽蛋白之间以氢键结合,PLLA的结晶性能降低;PLLA纺丝溶液中,菜籽蛋白的三氟乙酸溶液的适量引入可显著提高纺丝速率.在PLLA质量浓度为24%的氯仿溶液中,6.5%菜籽蛋白的三氟乙酸溶液加入量为0.25 mL,电压16 kV,极距10 cm的条件下,可快速制备平均直径622 am的PLLA/菜籽蛋白复合纳米纤维毡,纺丝速率达到5.2 mg/min.%The rapeseed protein/PLLA composite nanofiber felt was prepared via electrospinning. The effects of voltages, tip to collector distance and trifluoroaeetic acid on the morphology and structure of the nanofibers were investigated by scanning electron microscopy (SEM), Fourier transform infrared (FT-IR),X-ray diffraction(XRD). Results indicated that there were hydrogen bonds between rapeseed protein and PLLA in the composite fibers, and the crystal structure of PLLA was destroyed seriously. The addition of rapeseed protein/trifluoroaeetie acid solution results in a higher spinning speed, and the finer fibers would be also obtained. The rapeseed protein/PLLA composite fiber felt (about 5.2 mg/min) with average diameter of 622 nm could be prepared quickly at the following optimal process parameters: the concentration of PLLA was 24 %(contained 1 g PLLA), the volume of rapeseed protein/trifluoroacetic acid solution was 0.25 mL, the applied voltage was 16 kV, and the tip-to-collector distance was 10 cm.

  8. 静电纺丝法制备金纳米粒子/PVP复合纳米纤维%The Preparation of Gold Nanoparticles/PVP Composites Nanofibers by Electrospinning Technique

    Institute of Scientific and Technical Information of China (English)

    白杰

    2011-01-01

    The paper dealing with the preparation of gold nanoparticles by chemical reducing from relativety with a solution of HAuCl4 with N2H4· H2O as reduction reagent and polyvinylpyrrolidone (PVP) as dispersion and stabilizer,the smaller gold nanoparticles were obtained, the optical property of gold nanoparticles in PVP aqueous solution was observed by UV-visible absorption spectra. Gold nanoparticles/PVP composite fibers were prepared by electrospinning technique. The composite nanofibers were characterized by scanning electron microscope (SEM) and X-ray diffraction (XRD). Field-emission scanning electron microscopy (FESEM) showed the morphology of fibers,and the diameters of composite nanofibers obviously decreased with the increasing concentration of gold nanoparticles in the solution. The existence of the gold nanoparticles was approved by XRD patterns.%采用水合肼还原一定浓度氯金酸溶液的方法,在聚乙烯吡咯烷酮(PVP)作保护剂的乙醇/水溶液中,成功制备出粒度较小,且高度分散的金溶胶,紫外吸收光谱证实了溶液中金纳米粒子的存在.采用静电纺丝技术制备了AuNs/PVP复合纳米纤维.采用扫描电镜(SEM)和X射线衍射(XRD)等分析手段对纤维的表面形貌等进行了表征.由扫描电镜照片可以看出所制得的纤维的尺寸较为均匀,随着纺前溶液内金纳米粒子含量的增加,获得的复合纤维的直径随之减小;XRD测试显示出样品内含有立方面心结构的金纳米粒子.

  9. High-Temperature Stable Anatase Titanium Oxide Nanofibers for Lithium-Ion Battery Anodes.

    Science.gov (United States)

    Lee, Sangkyu; Eom, Wonsik; Park, Hun; Han, Tae Hee

    2017-08-02

    Control of the crystal structure of electrochemically active materials is an important approach to fabricating high-performance electrodes for lithium-ion batteries (LIBs). Here, we report a methodology for controlling the crystal structure of TiO2 nanofibers by adding aluminum isopropoxide to a common sol-gel precursor solution utilized to create TiO2 nanofibers. The introduction of aluminum cations impedes the phase transformation of electrospun TiO2 nanofibers from the anatase to the rutile phase, which inevitably occurs in the typical annealing process utilized for the formation of TiO2 crystals. As a result, high-temperature stable anatase TiO2 nanofibers were created in which the crystal structure was well-maintained even at high annealing temperatures of up to 700 °C. Finally, the resulting anatase TiO2 nanofibers were utilized to prepare LIB anodes, and their electrochemical performance was compared to pristine TiO2 nanofibers that contain both anatase and rutile phases. Compared to the electrode prepared with pristine TiO2 nanofibers, the electrode prepared with anatase TiO2 nanofibers exhibited excellent electrochemical performances such as an initial Coulombic efficiency of 83.9%, a capacity retention of 89.5% after 100 cycles, and a rate capability of 48.5% at a current density of 10 C (1 C = 200 mA g(-1)).

  10. Optics of Nanofibers

    DEFF Research Database (Denmark)

    Bordo, Vladimir

    During the last decade, fabrication and investigation of submicron-sized optical fibers have been received growing attention. Such nanofibers or nanowires can be grown from both inorganic and organic semiconductor materials being arranged in mutually parallel nanoaggregates. Also, selected...... nanofibers can be placed on a substrate or immersed in a liquid that allows one to study them individually. It has been demonstated that such structures possess promising waveguiding and photoluminescence properties. Under pumping conditions, they operate as a nanolaser. This remarkable progress dictates...

  11. Enhanced photocatalytic activity in electrospun bismuth vanadate nanofibers with phase junction.

    Science.gov (United States)

    Cheng, Jing; Feng, Jing; Pan, Wei

    2015-05-13

    BiVO4 nanofibers were successfully prepared by electrospinning and precisely controlled heat treatment. The obtained BiVO4 nanofibers showed an enhanced photocatalytic activity in the degradation of rhodamine-B under visible light irradiation. The as-prepared nanofibers were characterized by means of numerous techniques. The enhanced photocatalyst activity is attributed to the formation of a phase junction of tetragonal sheelite (s-t) and monoclinic sheelite (s-m) phases in the electrospun BiVO4 nanofibers. We have also investigated the band structure of BiVO4 using first principle calculation. The main photon transition mechanism of the photocatalyst should be from the O 2p to V 3d state of s-m/t BiVO4 nanofibers.

  12. Titanium Carbide Nanofibers-Reinforced Aluminum Compacts, a New Strategy to Enhance Mechanical Properties

    Directory of Open Access Journals (Sweden)

    Khalil Abdelrazek Khalil

    2016-05-01

    Full Text Available TiC nanofibers reinforced Al matrix composites were produced by High Frequency Induction Heat Sintering (HFIHS.The titanium carbide nanofibers with an average diameter of 90 nm are first prepared by electrospinning technique and high temperature calcination process. A composite solution containing polyacrylonitrile and titanium isopropoxide is first electrospun into the nanofibers, which are subsequently stabilized and then calcined to produce the desired TiC nanofibers. The X-ray diffraction pattern and transmission electron microscopy results show that the main phase of the as-synthesized nanofibers is titanium carbide. The TiC nanofibers is then mixed with the aluminum powders and introduced into high frequency induction heat sintering (HFIHS to produce composites of TiC nanofibers reinforced aluminum matrix. The potential application of the TiC nanofibers reinforced aluminum matrix composites was systematically investigated. 99.5% relative density and around 85 HV (833 MPa Vickers hardness of the Al reinforced with 5 wt % TiC nanofiber has been obtained. Furthermore, the sample of Al contains 5 wt % TiC, has the highest value of compression and yield strength of about 415 and 350 MPa, respectively. The ductility of the Al/5 wt % TiC showed increasing with increasing the TiC contents.

  13. CONFORMATION AND MICROSTRUCTURE OF CARBON NANOFIBERS DEPOSITED ON FOAM Ni

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Bundles of pure carbon nanofibers were prepared by catalytic decomposition of acetylene on foam Ni. The morphological and structural characteristics of the carbon nanostructures, in the as-prepared state, were analyzed by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and high resolution transmission electron microscopy (HTEM). A special conformation of carbon nanofibers composed of segmented structures was found among the products by both SEM and TEM observations. Further HTEM ex amination indicated that the segments were stacked with well ordered graphite platelets arranged perpendicular to the axis of the filaments.

  14. Dispersion of cellulose nanofibers in biopolymer based nanocomposites

    Science.gov (United States)

    Wang, Bei

    The focus of this work was to understand the fundamental dispersion mechanism of cellulose based nanofibers in bionanocomposites. The cellulose nanofibers were extracted from soybean pod and hemp fibers by chemo-mechanical treatments. These are bundles of cellulose nanofibers with a diameter ranging between 50 to 100 nm and lengths of thousands of nanometers which results in very high aspect ratio. In combination with a suitable matrix polymer, cellulose nanofiber networks show considerable potential as an effective reinforcement for high quality specialty applications of bio-based nanocomposites. Cellulose fibrils have a high density of --OH groups on the surface, which have a tendency to form hydrogen bonds with adjacent fibrils, reducing interaction with the surrounding matrix. The use of nanofibers has been mostly restricted to water soluble polymers. This thesis is focused on synthesizing the nanocomposite using a solid phase matrix polypropylene (PP) or polyethylene (PE) by hot compression and poly (vinyl alcohol) (PVA) in an aqueous phase by film casting. The mechanical properties of nanofiber reinforced PVA film demonstrated a 4-5 fold increase in tensile strength, as compared to the untreated fiber-blend-PVA film. It is necessary to reduce the entanglement of the fibrils and improve their dispersion in the matrix by surface modification of fibers without deteriorating their reinforcing capability. Inverse gas chromatography (IGC) was used to explore how various surface treatments would change the dispersion component of surface energy and acid-base character of cellulose nanofibers and the effect of the incorporation of these modified nanofibers into a biopolymer matrix on the properties of their nano-composites. Poly (lactic acid) (PLA) and polyhydroxybutyrate (PHB) based nanocomposites using cellulose nanofibers were prepared by extrusion, injection molding and hot compression. The IGC results indicated that styrene maleic anhydride coated and ethylene

  15. Nanomembranes and Nanofibers from Biodegradable Conducting Polymers

    Directory of Open Access Journals (Sweden)

    Jordi Puiggalí

    2013-09-01

    Full Text Available This review provides a current status report of the field concerning preparation of fibrous mats based on biodegradable (e.g., aliphatic polyesters such as polylactide or polycaprolactone and conducting polymers (e.g., polyaniline, polypirrole or polythiophenes. These materials have potential biomedical applications (e.g., tissue engineering or drug delivery systems and can be combined to get free-standing nanomembranes and nanofibers that retain the better properties of their corresponding individual components. Systems based on biodegradable and conducting polymers constitute nowadays one of the most promising solutions to develop advanced materials enable to cover aspects like local stimulation of desired tissue, time controlled drug release and stimulation of either the proliferation or differentiation of various cell types. The first sections of the review are focused on a general overview of conducting and biodegradable polymers most usually employed and the explanation of the most suitable techniques for preparing nanofibers and nanomembranes (i.e., electrospinning and spin coating. Following sections are organized according to the base conducting polymer (e.g., Sections 4–6 describe hybrid systems having aniline, pyrrole and thiophene units, respectively. Each one of these sections includes specific subsections dealing with applications in a nanofiber or nanomembrane form. Finally, miscellaneous systems and concluding remarks are given in the two last sections.

  16. Synthesis of NiO Nanofibers Composed of Hollow Nanospheres with Controlled Sizes by the Nanoscale Kirkendall Diffusion Process and Their Electrochemical Properties.

    Science.gov (United States)

    Cho, Jung Sang; Lee, Seung Yeon; Ju, Hyeon Seok; Kang, Yun Chan

    2015-11-25

    NiO nanofibers composed of hollow NiO nanospheres with different sizes were prepared by electrospinning method. The mean size of the hollow NiO nanospheres was determined by the mean size of the Ni nanocrystals of the Ni-C composite nanofibers formed as an intermediate product. Porous-structured NiO nanofibers were also prepared as a comparison sample by direct oxidation of the electrospun nanofibers. The discharge capacities of the nanofibers composed of hollow nanospheres reduced at 300, 500, and 700 °C for the 250th cycle were 707, 655, and 261 mA h g(-1), respectively. However, the discharge capacity of the porous-structured NiO nanofibers for the 250th cycle was low as 206 mA h g(-1). The nanofibers composed of hollow nanospheres had good structural stability during cycling.

  17. Adsorption of Th{sup 4+}, U{sup 6+}, Cd{sup 2+}, and Ni{sup 2+} from aqueous solution by a novel modified polyacrylonitrile composite nanofiber adsorbent prepared by electrospinning

    Energy Technology Data Exchange (ETDEWEB)

    Dastbaz, Abolfazl [Department of Chemical engineering, University of Tehran, Tehran (Iran, Islamic Republic of); Keshtkar, Ali Reza, E-mail: akeshtkar@aeoi.org.ir [Nuclear Fuel Cycle Research School, Nuclear Science and Technology Research Institute, Tehran (Iran, Islamic Republic of)

    2014-02-28

    In this study, SiO{sub 2} nanoparticles were modified by 3-aminopropyltriethoxysilane (APTES) and then applied to prepare a novel polyacrylonitrile (PAN) composite nanofiber adsorbent by the electrospinning method. In addition, the adsorbent was characterized by SEM, BET, and FTIR analyses. Then the effects of pH, SiO{sub 2} and APTES content, adsorbent dosage, contact time and temperature were investigated. Moreover, adsorption experiments were carried out with initial concentrations in the range of 30–500 mg L{sup −1} and the adsorbent affinity for metal ions was in order of Th{sup 4+} > U{sup 6+} > Cd{sup 2+} > Ni{sup 2+}. Furthermore, it was observed that the optimum pH for adsorption was different for each metal. Some isotherm and kinetic models were applied to analyze the experimental data, among which the Langmuir and pseudo-second order models were better than the others. The regeneration study showed that the adsorbent could be used for industrial processes repeatedly without any significant reduction in its adsorption capacity. Based on the Langmuir model, the maximum adsorption capacity of Th{sup 4+}, U{sup 6+}, Cd{sup 2+}, and Ni{sup 2+} at 45 °C was 249.4, 193.1, 69.5 and 138.7 mg g{sup −1}, respectively. Besides, the calculated thermodynamic parameters showed an endothermic as well as chemical nature through the adsorption process.

  18. Temperature responsive hydrogel nanofibers and nanoparticles

    Science.gov (United States)

    Ruokolainen, Janne

    2011-03-01

    Poly(N-isopropylacrylamide) (PNIPAM) is one of the most extensively investigated synthetic temperature-responsive polymers. In this work temperature-responsive PNIPAM based triblock copolymer hydrogels, their self-assembly and phase behavior in bulk, are described. Additionally, recent results from responsive hydrogel nanofibers and hydrogel nanoparticles are shown. It is known that block copolymers form well-organized nano structures in bulk or thin films when annealed thermally or in solvent vapours. However, in the case of nanofibers or nanoparticles, the annealing leads in most cases to aggregation and particle sintering. This work utilizes aerosol-based gas phase method where the preparation and annealing of hydrogel nanoparticles with well-organized, hierarchical inner structures are performed without any particle coagulation or sintering. In the method, the block copolymers assemble within aerosol nanoparticles to form, for instance, lamellar onion-like or gyroid inner structures.

  19. Process Dependence of Cellulose Nanofiber Fabrication

    Science.gov (United States)

    Henderson, Doug; Zhang, Xin; Mao, Yimin; Jang, Soo-Hwan; Hu, Liangbing; Briber, Robert; Wang, Howard

    Cellulose nanofibers (CNF) are the most abundant natural nanomaterial on earth with potential applications in renewable energy, polymer nanocomposites and flexible electronics. CNF can be produced through TEMPO oxidation which separates the hierarchical structure of cellulose fibers into smaller micro- and nanofibers by altering their surface chemistry, inducing a repulsive electrostatic charge on the fibers. This work will examine the structural evolution of CNF during production. Samples were prepared by removing and quenching aliquots during the TEMPO reaction. The fibers were washed, filtered and re-dispersed into D2O for small angle neutron scattering (SANS) measurements. The SANS data was analyzed to track the changes in the CNF structure as a function of reaction time.

  20. General strategy for fabricating thoroughly mesoporous nanofibers

    KAUST Repository

    Hou, Huilin

    2014-12-03

    Recently, preparation of mesoporous fibers has attracted extensive attentions because of their unique and broad applications in photocatalysis, optoelectronics, and biomaterials. However, it remains a great challenge to fabricate thoroughly mesoporous nanofibers with high purity and uniformity. Here, we report a general, simple and cost-effective strategy, namely, foaming-assisted electrospinning, for producing mesoporous nanofibers with high purity and enhanced specific surface areas. As a proof of concept, the as-fabricated mesoporous TiO2 fibers exhibit much higher photocatalytic activity and stability than both the conventional solid counterparts and the commercially available P25. The abundant vapors released from the introduced foaming agents are responsible for the creation of pores with uniform spatial distribution in the spun precursor fibers. The present work represents a critically important step in advancing the electrospinning technique for generating mesoporous fibers in a facile and universal manner.

  1. Study on preparation of hollow α-Fe2 O3 magnetic nanofibers%α-Fe2O3中空磁性纳米纤维的制备研究

    Institute of Scientific and Technical Information of China (English)

    王新月; 高强; 高春霞; 葛明桥; 冯古雨

    2015-01-01

    磁性铁氧化物纳米材料是近几十年发展起来的一种具有磁靶向性的纳米材料。其中磁性纳米纤维由于具有独特的形状各向异性和磁晶各向异性,可以突破各向同性的磁性粉体材料对电磁性能的限制而引起研究者的广泛关注。通过静电纺丝、水热合成以及高温煅烧相结合的方法成功制备了新型 Fe2 O 3中空磁性纳米纤维。采用扫描电子显微镜(SEM)、红外光谱分析仪(FT-IR)、差热扫描量热仪(DSC)、热重分析仪(TG)及 X 射线衍射仪(XRD)对煅烧产物进行测试表征,结果表明煅烧产生的磁性纳米纤维非织造布具有新颖的中空结构,对甲基橙有快速吸附。%In recent decades,magnetic iron oxide material has developed into a kind of nanomaterial with the property of magnetic targeting.Magnetic nanoscale fibers have aroused extensive concern of researchers because of the unique shape anisotropy and magnetocrystalline anisotropy which can break through the isotropic magnet-ic powder materials on the properties of electromagnetic limit.Electrospinning,hydrothermal synthesis and high-temperature calcination were combined successfully to prepare novel magnetic nanofibers.Scanning elec-tron microscopy (SEM),fourier transform infrared spectroscopy (FT-IR),thermal gravimetric analysis (TG) and X-ray diffraction (XRD)were employed to test and represent the calcination.The results indicated that the magnetic nanofiber after calcination has a novel structure of the hollow porous microstructure which shows quick and effective adsorption of methyl orange.

  2. Daidzein-loaded nanostructured lipid carriers-PLGA nanofibers for transdermal delivery.

    Science.gov (United States)

    Song, Jia; Fan, Xiucong; Shen, Qi

    2016-03-30

    Daidzein is one of the most effective candidates for treating cardiovascular and cerebrovascular disease. However, considering its poor oral absorption and limited bioavailability, daidzein-loaded nanostructured lipid carriers-PLGA nanofibers were designed to handle the drawbacks. Daidzein-NLCs were successfully prepared by an emulsification and low-temperature solidification method. The physicochemical characteristics of NLCs were evaluated afterwards. Based on the preparation of daidzein-loaded NLCs, Daidzein-NLCs-nanofibers were optimized by electrospinning and were observed under Scanning Electron Microscope to capture the appearance. The sustained release profile of daidzein from Daidzein-NLCs-nanofibers in vivo was best fitted to the Kormeyer-Peppas equation. The in vitro skin permeable behavior showed the cumulative amount of daidzein from Daidzein-NLCs-nanofibers reached 21.71 μg cm(-2) at 60 h, which was 3.78 times higher than pure daidzein solution. It demonstrated that the Daidzein-NLCs-nanofibers could significantly enhance the transported amount of drug. Confocal Laser Scanning Microscopy resulting images revealed a more effective content accumulation of Daidzein-NLCs-nanofibers than Daidzein-NLCs in epidermis. In vivo study indicated that Daidzein-NLCs-nanofibers had better skin retention than Daidzein-NLCs in the long term. The skin irritation experiment showed a positive result with no obvious stimulus observed. These results suggested that Daidzein-NLCs-nanofibers could be a potential candidate for transdermal delivery. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Stable and Continuous Long-term Enzymatic Reaction using an Enzyme-Nanofiber Composite

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jin Hyung; Hwang, Ee Taek; Kim, Byoung Chan; Lee, Sun Mi; Sang, Byoung-In; Choi, Yong Su; Kim, Jungbae; Gu, Man Bock

    2007-07-01

    This study shows the preparation and application of enzyme-nanofiber composites for long-term stable operation. The enzyme-nanofiber composite was prepared by coating an enzyme-aggregate, the esterase from Rhizopus oryzae, on the surface of the nanofibers. The activity and stability of the esterase-nanofiber composite was evaluated by measuring the production of p-nitrophenol from the hydrolysis of p-nitrophenyl butyrate. It was found that enzyme-nanofiber was very stable, even when the fibers were shaken in glasses, preserving 80 % of the initial activity for 100 days. In addition, the enzyme nanofiber composite was repeatedly used in 30 cycles of substrate hydrolysis and still remained active. Consequently, the esterase-nanofiber composite was finally employed to find its feasibility of long-term and stable continuous substrate hydrolysis reaction. In the sample reactor, the production of p-nitrophenol was consistent for 400 hr. Additionally, it was found that the production of p-nitrophenol proportionally decreased as the dilution rate was increased, showing the relationship between the efficiency of hydrolysis and the retention time within the reactor. This study demonstrates that the enzyme-nanofiber composite can be used in both repeated-batch and continuous modes for long-term stable operation.

  4. Properties of Electrospun TiO2 Nanofibers

    Directory of Open Access Journals (Sweden)

    Bianca Caratão

    2014-01-01

    Full Text Available Titanium oxide filled polyvinylpyrrolidone (PVP composite nanofibers have been prepared via a simple electrospinning technique. The combination of good TiO2 properties with its high surface area leads these nanofibers into having a vast applicability such as cosmetics, scaffolds for tissue engineering, catalytic devices, sensors, solar cells, and optoelectronic devices. The structural and chemical properties of the prepared samples have been studied. The presence of the TiO2 phase on the nanofibers was confirmed. An anatase to rutile transformation was observed at 600°C. Regarding the thermogravimetric and differential thermal analysis (TGA/DTA, the TIP decomposition and the PVP evaporation at 225°C were verified.

  5. Preparing of TiO2 Nanofibers Using Electrospinning and Its Application to Photo-degradation of Organic Compound%静电纺丝法制备纳米二氧化钛纤维及其光降解有机物的性能研究

    Institute of Scientific and Technical Information of China (English)

    李美杰; 陆军建

    2015-01-01

    The titania precursor solution is prepared through sol-gel process, and the PVP/TiO2 composite nanofibers are prepared using electrospinning technique. The titanium dioxide precursor fibers are calcinated at 450 ° C for TiO2 nanofibers. Good-shaped, equal-sized TiO2 nanofibers of 300-500 nm can be generated when a voltage of 18 kv, a collecting distance of 20 cm, and a needle speed of 0. 002 mm/s is applied. Fluorescence spectrum analysis shows that TiO2 nanofibers have remarkable catalytic effect on the photo-degradation of the organic light yellow compound.%采用溶胶-凝胶法制备二氧化钛前驱体溶液,借助静电纺丝技术纺丝出PVP/TiO2前驱体复合纤维,将前驱体复合纤维在450 o C煅烧后得到TiO2纳米纤维。当纺丝电压为18 kv,接受距离为20 cm,注射器推进速度为0.002 mm/s时,所制备的TiO2纤维尺寸均一且表面形貌佳,纤维的尺寸在300-500 nm。借助荧光光谱分析法,初步证明了TiO2纳米纤维对有机染料耐晒黄的光降解具有显著的催化作用。

  6. Nanobiotechnology approach to fabricate polycaprolactone nanofibers containing solid titanium nanoparticles as future implant materials

    DEFF Research Database (Denmark)

    Sheikh, Faheem A.; Kanjwal, Muzafar Ahmed; Cha, Jaegwan

    2011-01-01

    are exploited to form nanofibers by the simple electrospinning process. The prepared colloidal solutions were characterized using dynamic light scattering and electrophoratic light scattering which indicated unimodal size distribution and negative zeta potential. To investigate the bioactivity of the resultant...

  7. Chemical isolation and characterization of different cellulose nanofibers from cotton stalks

    Science.gov (United States)

    Recently, cellulose nanofibers (CNFs) have received wide attention in green nanomaterial technologies. Production of CNFs from agricultural residues has many economic and environmental advantages. In this study, four different CNFs were prepared from cotton stalks by different chemical treatments fo...

  8. Nanofibers and nanoplatelets of MoO3 via an electrospinning technique

    Science.gov (United States)

    Li, Shouzhu; Shao, Changlu; Liu, Yichun; Tang, Shanshan; Mu, Rixiang

    2006-08-01

    Polyvinyl alcohol (PVA)/ammonium molybdate composite fibers were prepared by using sol gel processing and electrospinning technique. After calcinations of the above precursor fibers at 500 °C, MoO3 nanofibers with a diameter of 100 150 nm were successfully obtained. MoO3 nanoplatelets and submicron platelets were prepared by further calcinations of the MoO3 nanofibers at 600 and 700 °C. The products were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT IR) and scanning electron microscopy (SEM). A possible growth mechanism for the MoO3 nanofibers and nanoplatelets was suggested.

  9. A facile method for electrospinning of Ag nanoparticles/poly (vinyl alcohol)/carboxymethyl-chitosan nanofibers

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Yinghui; Zhou, Ying [Beijing Key Laboratory for Solid Waste Utilization and Management, College of Engineering, Peking University, Beijing 100871 (China); Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Wu, Xiaomian [Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Department of Orthodontics College of Stomatology, Chongqing Medical University, Chongqing 401147 (China); Wang, Lu [Beijing Key Laboratory for Solid Waste Utilization and Management, College of Engineering, Peking University, Beijing 100871 (China); Xu, Ling, E-mail: lingxu@pku.edu.cn [Beijing Key Laboratory for Solid Waste Utilization and Management, College of Engineering, Peking University, Beijing 100871 (China); Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); PKU-HKUST ShenZhen-HongKong Institution, Shenzhen 518057 (China); Wei, Shicheng, E-mail: sc-wei@pku.edu.cn [Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Department of Oral and Maxillofacial Surgery, School and Hospital of Stomatology, Peking University, Beijing 100081 (China)

    2012-09-01

    Highlights: Black-Right-Pointing-Pointer AgNPs/PVA/CM-chitosan nanofibers were prepared via electrospinning method. Black-Right-Pointing-Pointer AgNPs were in situ synthesized in electrospinning solution via a facile method. Black-Right-Pointing-Pointer AgNPs distributed homogeneously on the surface of nanofibers. Black-Right-Pointing-Pointer The prepared nanofibers possessed certain antibacterial ability against Escherichia coli. Black-Right-Pointing-Pointer The AgNPs containing nanofibers had potential as antibacterial biomaterial. - Abstract: A facile method to prepare silver nanoparticles (AgNPs) containing nanofibers via electrospinning has been demonstrated. AgNPs were in situ synthesized in poly (vinyl alcohol) (PVA)/carboxymethyl-chitosan (CM-chitosan) blend aqueous solution before electrospinning. UV-vis spectra, viscosity and conductivity of the electrospinning solution were measured to investigate their effects on the electrospinning procedure. The morphology of AgNPs/PVA/CM-chitosan nanofibers was observed by Field Emission Scanning Electron Microscopy. The formation and morphology of AgNPs were investigated by Transmission Electron Microscopy and X-ray Photoelectron Spectroscopy. The resulted nanofibers have smooth surface and uniform diameters ranging from 295 to 343 nm. The diameters of AgNPs mainly distributed in the range of 4-14 nm, and the electrostatic interaction between AgNPs and fibers was observed. Finally, in vitro Ag release from the nanofibers was measured and the antibacterial behavior of the nanofibers against Escherichia coli was studied by bacterial growth inhibition halos and bactericidal kinetic testing. The AgNPs/PVA/CM-chitosan nanofibers possessed certain antibacterial ability, which makes them capable for antibacterial biomaterials.

  10. A novel fixed-bed reactor design incorporating an electrospun PVA/chitosan nanofiber membrane

    Energy Technology Data Exchange (ETDEWEB)

    Esmaeili, Akbar, E-mail: akbaresmaeili@yahoo.com; Beni, Ali Aghababai

    2014-09-15

    Graphical abstract: PVA/Cs nanofiber membrane was prepared by the electrospinning technique. The membrane was installed in a new fixed-bed reactor. The test results showed heavy metals absorbed by the PVA/Cs nanofiber membrane. - Highlights: • PVA/Cs nano-fiber membrane was produced using electrospinning technique. • The prepared nanofiber membrane was mesoporous. • Thermal crosslinking was successful to improve the stability of PVA/Cs nano-fiber membrane. • Experimental data were studied by adsorption isotherm models and thermodynamic relationships. - Abstract: In this research, a novel fixed-bed reactor was designed with a nanofiber membrane composed of a polyvinyl alcohol (PVA)/chitosan nanofiber blend prepared using an electrospinning technique. The applied voltage, tip-collector distance, and solution flow rate of the electrospinning process were 18 kV, 14.5 cm, and 0.5 mL h{sup −1}, respectively. Brunauer–Emmett–Teller (BET) theory, scanning electron microscope (SEM), and Fourier transform infrared spectroscopy (FT-IR) were employed to characterize and analyze the nanofiber membranes. Homogeneous electrospun nanofibers with an average diameter of 99.47 nm and surface area of 214.12 m{sup 2} g{sup −1} were obtained. Adsorption experiments were carried out in a batch system to investigate the effect of different adsorption parameters such as pH, adsorbent dose, biomass dose, contact time, and temperature. The kinetic data, obtained at the optimal pH of 6, were analyzed by pseudo first-order and pseudo second-order kinetic models. Three isotherm models and thermodynamic parameters (ΔG°, ΔH°, and ΔS°) were applied to describe the equilibrium data of the metal ions adsorbed onto the PVA/chitosan nanofiber membrane.

  11. Syringeless Electrospinning toward Versatile Fabrication of Nanofiber Web

    Science.gov (United States)

    Moon, Seongjun; Gil, Manjae; Lee, Kyung Jin

    2017-01-01

    Although electrospinning is considered a powerful and generic tool for the preparation of nanofiber webs, several issues still need to be overcome for real-world applications. Most of these issues stem from the use of a syringe-based system, where the key factor influencing successful electrospinning is the maintenance of several subtle balances such as those of between the mass and the electrical state. It is extremely difficult to maintain these balances throughout the spinning process until all the polymeric solution in the syringe has been consumed. To overcome these limitations, we have developed a syringeless electrospinning technique as an alternative and efficient means of preparing a nanofiber web. This new technique uses a helically probed rotating cylinder. This technique can not only cover conventional methods, but also provides several advantages over syringe-based and needless electrospinning in terms of productivity (6 times higher) and processibility. For example, we can produce nanofibers with highly crystalline polymers and nanofiber-webs comprising networks of several different polymers, which is sometimes difficult in conventional electrospinning. In addition, this method provides several benefits for colloidal electrospinning as well. This method should help expand the range of applications for electrospun nanofiber webs in the near future.

  12. Syringeless Electrospinning toward Versatile Fabrication of Nanofiber Web

    Science.gov (United States)

    Moon, Seongjun; Gil, Manjae; Lee, Kyung Jin

    2017-01-01

    Although electrospinning is considered a powerful and generic tool for the preparation of nanofiber webs, several issues still need to be overcome for real-world applications. Most of these issues stem from the use of a syringe-based system, where the key factor influencing successful electrospinning is the maintenance of several subtle balances such as those of between the mass and the electrical state. It is extremely difficult to maintain these balances throughout the spinning process until all the polymeric solution in the syringe has been consumed. To overcome these limitations, we have developed a syringeless electrospinning technique as an alternative and efficient means of preparing a nanofiber web. This new technique uses a helically probed rotating cylinder. This technique can not only cover conventional methods, but also provides several advantages over syringe-based and needless electrospinning in terms of productivity (6 times higher) and processibility. For example, we can produce nanofibers with highly crystalline polymers and nanofiber-webs comprising networks of several different polymers, which is sometimes difficult in conventional electrospinning. In addition, this method provides several benefits for colloidal electrospinning as well. This method should help expand the range of applications for electrospun nanofiber webs in the near future. PMID:28120916

  13. Antibacterial Properties of Novel Bacterial Cellulose Nanofiber Containing Silver Nanoparticles

    Institute of Scientific and Technical Information of China (English)

    杨加志; 刘晓丽; 黄立勇; 孙东平

    2013-01-01

    In this work, we describe a novel facile method to prepare long one-dimensional hybrid nanofibers by using hydrated bacterial cellulose nanofibers (BCF) as a template. Silver (Ag) nanoparticles with an average di-ameter of 1.5 nm were well dispersed on BCF via a simple in situ chemical-reduction between AgNO3 and NaBH4 at a relatively low temperature. A growth mechanism is proposed that Ag nanoparticles are uniformly anchored onto BCF by coordination with BC-containing hydroxyl groups. The bare BCF and as-prepared Ag/BCF hybrid nanofibers were characterized by several techniques including transmission electron microscopy, X-ray diffraction, thermogra-vimetric analyses, and ultraviolet-visible (UV-Vis) absorption spectra. The antibacterial properties of Ag/BCF hybrid nanofibers against Escherichia coli (E. coli, Gram-negative) and Staphylococcu saureus (S. saureus, Gram-positive) bacteria were evaluated by using modified Kirby Bauer method and colony forming count method. The results show that Ag nanoparticles are well dispersed on BCF surface via in situ chemical-reduction. The Ag/BCF hybrid nanofiber presents strong antibacterial property and thus offers its candidature for use as functional antimicrobial agents.

  14. Fabrication of NiCo 2O 4 nanofibers by electrospinning

    Science.gov (United States)

    Guan, Hongyu; Shao, Changlu; Liu, Yichun; Yu, Na; Yang, Xinghua

    2004-07-01

    The spinel NiCo 2O 4 nanofibers with diameters of 50-100 nm were prepared by high temperature calcinations of a simple inorganic-polymer composite fibers, which were obtained by electrospinning of the PVA/cobalt acetate/nickel acetate composite precursor. The crystallinity, purity, and surface morphology of the as-prepared NiCo 2O 4 nanofibers were investigated by XRD, FT-IR, SEM, respectively.

  15. Preparation,performance and comparison of co-electrospun and coaxial-electrospun drug-loaded PVA-SbQ/Zein composite nanofibers%共混与同轴静电纺载药纳米纤维的制备、表征及比较

    Institute of Scientific and Technical Information of China (English)

    崔静; 邱玉宇; 卢杭诣; 聂清欣; 魏取福

    2016-01-01

    采用共混和同轴静电纺制备了负载盐酸四环素药物的聚乙烯醇-苯乙烯吡啶盐(PVA-SbQ)/玉米醇溶蛋白(Zein)复合纳米纤维,在紫外光照射下得到光交联载药 PVA-SbQ/Zein 复合纳米纤维。利用扫描电镜(SEM)对不同纤维的形貌和直径分布进行了分析;采用透射电镜(TEM)对不同静电纺丝法制备的纳米纤维结构进行了观察和比较;强力测试表明同轴静电纺丝制备的纳米纤维力学性能更强;傅里叶变换红外光谱(FT-IR)曲线表明载药PVA-SbQ/Zein复合纳米纤维保持了原有的化学功能基团;最后比较了两种方法制备的载药纳米纤维膜的药物释放行为。%Drug tetracycline hydrochloride (TCH)-loaded PVA-SbQ/Zein composite nanofibers were fabricated by co-electrospinning and coaxial-electrospinning,respectively.Then the nanofibers were irradiated under UV light to get the cross-linked ones.The morphologies and diameter distributions of drug-loaded PVA-SbQ/Zein composite nanofibers were observed by SEM.TEM was used to compare the structure of the two kind of nanofi-bers.The strength test showed that the tensile strength of coaxial-electrospun nanofibers was better than the co-electrospun ones.The spectra of FT-IR indicated that composite nanofibers maintained their own original functional groups.Finally,the drug release behavior of drug-loaded nanofibers prepared with two methods was compared.

  16. Antimicrobial filtration with electrospun poly(vinyl alcohol) nanofibers containing benzyl triethylammonium chloride: Immersion, leaching, toxicity, and filtration tests.

    Science.gov (United States)

    Park, Jeong-Ann; Kim, Song-Bae

    2017-01-01

    Antimicrobial electrospun poly(vinyl alcohol) (PVA) nanofibers were synthesized by impregnating benzyl triethylammonium chloride (BTEAC) as an antimicrobial agent into PVA nanofibers. The BTEAC-PVA nanofibers were heat-methanol treated during the preparation for various tests. The BTEAC-PVA nanofibers became more hydrophilic than the PVA nanofibers due to incorporation of BTEAC. Through heat-methanol treatment, thermal property, crystallinity, and water stability of BTEAC-PVA nanofibers were improved considerably. The immersion test shows that heat-methanol treatment has an advantage over heat treatment to maintain BTEAC content in BTEAC-PVA nanofibers. The acute toxicity test demonstrates that the 24-h EC50 and 48-h EC50 values (EC50 = median effective concentration) of BTEAC to Daphnia magna were 113 and 90 mg/L, respectively. The leaching test indicates that the BTEAC concentration leached from BTEAC-PVA nanofibers was far below the concentration affecting the immobilization of D. magna. For antimicrobial filtration tests, the BTEAC-PVA nanofibers were deposited onto glass fiber filter. The antimicrobial filtration test was conducted against bacteria (Escherichia coli, Staphylococcus aureus) and bacteriophages (MS2, PhiX174), demonstrating that the BTEAC-PVA nanofibers could enhance the removal of E. coli and S. aureus considerably but not the removal of MS2 and PhiX174 under dynamic flow conditions.

  17. AC-driven light emission from in situ grown organic nanofibers

    Science.gov (United States)

    Liu, Xuhai; Kjelstrup-Hansen, Jakob; de Oliveira Hansen, Roana Melina; Madsen, Morten; Rubahn, Horst-Günter

    2012-06-01

    In-situ grown organic nanofibers have been prepared on metal electrodes patterned by electron beam lithography. A systematic investigation shows that the light emission from these nanofibers driven by an AC gate voltage depends nonlinearly on the amplitude of the AC gate voltage and linearly on the frequency of the gate voltage, which indicates that a model involving thermally assisted charge-carrier tunneling can be applied. The photoluminescence spectra of parahexaphenylene (p6P) and α-sexithiophene (6T) nanofibers illustrate that the emission color of the in-situ grown nanofibers can be tuned by depositing two types of discontinuous organic layers on the same platform. Electroluminescence from two nanofiber thin films suggests that the relative light emission contribution from the two organic molecules can be varied by changing, e.g., the nominal thickness of the two materials.

  18. Influence of carbon nanofiber properties as electrocatalyst support on the electrochemical performance for PEM fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Sebastian, D.; Suelves, I.; Moliner, R.; Lazaro, M.J. [Instituto de Carboquimica (CSIC), Energy and Environment, C/Miguel Luesma Castan 4, 50018 Zaragoza (Spain); Calderon, J.C.; Gonzalez-Exposito, J.A.; Pastor, E. [Universidad de La Laguna, Dpto de Quimica-Fisica, Avda. Astrofisico Francisco Sanchez s/n, 38071 La Laguna, Tenerife (Spain); Martinez-Huerta, M.V. [Instituto de Catalisis y Petroleoquimica (CSIC), C/Marie Curie 2, 28049 Madrid (Spain)

    2010-09-15

    Novel carbonaceous supports for electrocatalysts are being investigated to improve the performance of polymer electrolyte fuel cells. Within several supports, carbon nanofibers blend two properties that rarely coexist in a material: a high mesoporosity and a high electrical conductivity, due to their particular structure. Carbon nanofibers have been obtained by catalytic decomposition of methane, optimizing growth conditions to obtain carbon supports with different properties. Subsequently, the surface chemistry has been modified by an oxidation treatment, in order to create oxygen surface groups of different nature that have been observed to be necessary to obtain a higher performance of the electrocatalyst. Platinum has then been supported on the as-prepared carbon nanofibers by different deposition methods and the obtained catalysts have been studied by different electrochemical techniques. The influence of carbon nanofibers properties and functionalization on the electrochemical behavior of the electrocatalysts has been studied and discussed, obtaining higher performances than commercial electrocatalysts with the highest electrical conductive carbon nanofibers as support. (author)

  19. Structural characteristics and biological performance of silk fibroin nanofiber containing microalgae Spirulina extract.

    Science.gov (United States)

    Cha, Bum-Gyu; Kwak, Hyo Won; Park, A Reum; Kim, Shin Hwan; Park, Sook-Young; Kim, Hyun-Jeong; Kim, Ick-Soo; Lee, Ki Hoon; Park, Young Hwan

    2014-04-01

    Silk fibroin (SF) nanofiber scaffold containing microalgae Spirulina extract were prepared by electrospinning and the performance and functionality of the scaffold were evaluated. The viscosity and conductivity of the dope solution of Spirulina containing SF were examined for electrospinability and we found that the morphological structure of SF nanofiber is affected by the concentration of Spirulina extract added. The platelet adhesion and coagulation time test confirmed that the Spirulina containing SF nanofiber scaffold had excellent ability to prevent blood clotting or antithrombogenicity that is comparable to heparin. Low cytotoxicity and excellent cell adhesion and proliferation were also observed for Sprulina containing SF nanofiber scaffold by methylthiazolyldiphenyl-tetrazolium bromide assay and confocal fluorescence microscope using fibroblast and human umbilical vein endothelial cells. Based on these results, we believe SF nanofiber scaffold containing Spirulina extract has the potential to be used as tissue engineering scaffold that requires high hemocompatibility. Copyright © 2013 Wiley Periodicals, Inc.

  20. Development, optimization and evaluation of polymeric electrospun nanofiber: A tool for local delivery of fluconazole for management of vaginal candidiasis.

    Science.gov (United States)

    Sharma, Rahul; Garg, Tarun; Goyal, Amit K; Rath, Goutam

    2016-01-01

    The present study is designed to explore the localized delivery of fluconazole using mucoadhesive polymeric nanofibers. Drug-loaded polymeric nanofibers were fabricated by the electrospinning method using polyvinyl alcohol (PVA) as the polymeric constituent. The prepared nanofibers were found to be uniform, non-beaded and non-woven, with the diameter of the fibers ranging from 150 to 180 nm. Further drug release studies indicate a sustained release of fluconazole over a period of 6 h. The results of studies on anti-microbial activity indicated that drug-loaded polymeric nanofibers exhibit superior anti-microbial activity against Candida albicans, when compared to the plain drug.

  1. Influences of Silver-Doping on the Crystal Structure, Morphology and Photocatalytic Activity of TiO2 Nanofibers

    DEFF Research Database (Denmark)

    Barakat, Nasser A. M.; Kanjwal, Muzafar Ahmed; Al-Deyab, Salem S.

    2011-01-01

    activity of titanium oxide nanofibers has been studied. Sil-ver-doped TiO2 nanofibers having different silver contents were prepared by calcination of electrospun nanofiber mats consisting of silver nitrate, titanium isopropoxide and poly(vinyl acetate) at 600°C. The results affirmed formation of silver......-doped TiO2 nanofibers composed of anatase and rutile when the silver nitrate content in the original electrospun solution was more than 3 wt%. The rutile phase content was directly proportional with the AgNO3 concentration in the electrospun solution. Negative impact of the silver-doping on the nanofibrous...

  2. Nanofibers for drug delivery - incorporation and release of model molecules, influence of molecular weight and polymer structure.

    Science.gov (United States)

    Hrib, Jakub; Sirc, Jakub; Hobzova, Radka; Hampejsova, Zuzana; Bosakova, Zuzana; Munzarova, Marcela; Michalek, Jiri

    2015-01-01

    Nanofibers were prepared from polycaprolactone, polylactide and polyvinyl alcohol using Nanospider(TM) technology. Polyethylene glycols with molecular weights of 2 000, 6 000, 10 000 and 20 000 g/mol, which can be used to moderate the release profile of incorporated pharmacologically active compounds, served as model molecules. They were terminated by aromatic isocyanate and incorporated into the nanofibers. The release of these molecules into an aqueous environment was investigated. The influences of the molecular length and chemical composition of the nanofibers on the release rate and the amount of released polyethylene glycols were evaluated. Longer molecules released faster, as evidenced by a significantly higher amount of released molecules after 72 hours. However, the influence of the chemical composition of nanofibers was even more distinct - the highest amount of polyethylene glycol molecules released from polyvinyl alcohol nanofibers, the lowest amount from polylactide nanofibers.

  3. Nanofibers for drug delivery – incorporation and release of model molecules, influence of molecular weight and polymer structure

    Directory of Open Access Journals (Sweden)

    Jakub Hrib

    2015-09-01

    Full Text Available Nanofibers were prepared from polycaprolactone, polylactide and polyvinyl alcohol using NanospiderTM technology. Polyethylene glycols with molecular weights of 2 000, 6 000, 10 000 and 20 000 g/mol, which can be used to moderate the release profile of incorporated pharmacologically active compounds, served as model molecules. They were terminated by aromatic isocyanate and incorporated into the nanofibers. The release of these molecules into an aqueous environment was investigated. The influences of the molecular length and chemical composition of the nanofibers on the release rate and the amount of released polyethylene glycols were evaluated. Longer molecules released faster, as evidenced by a significantly higher amount of released molecules after 72 hours. However, the influence of the chemical composition of nanofibers was even more distinct – the highest amount of polyethylene glycol molecules released from polyvinyl alcohol nanofibers, the lowest amount from polylactide nanofibers.

  4. Capture of toxic radioactive and heavy metal ions from water by using titanate nanofibers

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Jiasheng, E-mail: jiashengxu@bhu.edu.cn [Liaoning Province Key Laboratory for Synthesis and Application of Functional Compounds, College of Chemistry, Chemical Engineering and Food Safety, Center of Science and Technology Experiment, Bohai University, 19 Sci-tech Road, Jinzhou 121013 (China); Zhang, He; Zhang, Jie [Liaoning Province Key Laboratory for Synthesis and Application of Functional Compounds, College of Chemistry, Chemical Engineering and Food Safety, Center of Science and Technology Experiment, Bohai University, 19 Sci-tech Road, Jinzhou 121013 (China); Kim, Eui Jung [School of Chemical Engineering and Bioengineering, University of Ulsan, Ulsan 680-749 (Korea, Republic of)

    2014-11-25

    Highlights: • Three types of titanate nanofibers were prepared via a hydrothermal porcess. • These nanofibers show availability for removal of the toxic ions from water. • The equilibrium data were fitted well with the Langmuir model. - Abstract: Three types of titanate nanofibers (sodium titanate nanofibers (TNF-A), potassium/sodium titanate nanofibers (TNF-B), potassium titanate nanofibers (TNF-C)) were prepared via a hydrothermal treatment of anatase powders in different alkali solutions at 170 °C for 96 h, respectively. The as-prepared nanofibers have large specific surface area and show availability for the removal of radioactive and heavy metal ions from water system, such as Ba{sup 2+} (as substitute of {sup 226}Ra{sup 2+}) and Pb{sup 2+} ions. The TNF-A shows a better capacity in the removal of Ba{sup 2+} and Pb{sup 2+} than TNF-B and TNF-C. Structural characterization of the materials was performed with powder X-ray diffraction (XRD), scanning electron microscopy (SEM) equipped with energy dispersive spectrometer (EDS) and with inductively coupled plasma optical emission spectrometry (ICP-OES). It is found that the equilibrium data fit well with the Langmuir model. This study highlights that nanoparticles of inorganic ion exchangers with layered structure are potential materials for efficient removal of the toxic ions from contaminated water.

  5. Investigation of electrochemical actuation by polyaniline nanofibers

    Science.gov (United States)

    Mehraeen, Shayan; Alkan Gürsel, Selmiye; Papila, Melih; Çakmak Cebeci, Fevzi

    2017-09-01

    Polyaniline nanofibers have shown promising electrical and electrochemical properties which make them prominent candidates in the development of smart systems employing sensors and actuators. Their electrochemical actuation potential is demonstrated in this study. A trilayer composite actuator based on polyaniline nanofibers was designed and fabricated. Cross-linked polyvinyl alcohol was sandwiched between two polyaniline nanofibrous electrodes as ion-containing electrolyte gel. First, electrochemical behavior of a single electrode was studied, showing reversible redox peak pairs in 1 M HCl using a cyclic voltammetry technique. High aspect ratio polyaniline nanofibers create a porous network which facilitates ion diffusion and thus accelerates redox reactions. Bending displacement of the prepared trilayer actuator was then tested and reported under an AC potential stimulation as low as 0.5 V in a variety of frequencies from 50 to 1000 mHz, both inside 1 M HCl solution and in air. Decay of performance of the composite actuator in air is investigated and it is reported that tip displacement in a solution was stable and repeatable for 1000 s in all selected frequencies.

  6. Silver-functionalized carbon nanofiber composite electrodes for ibuprofen detection

    NARCIS (Netherlands)

    Manea, F.; Motoc, S.; Pop, A.; Remes, A.; Schoonman, J.

    2012-01-01

    The aim of this study is to prepare and characterize two types of silver-functionalized carbon nanofiber (CNF) composite electrodes, i.e., silver-decorated CNF-epoxy and silver-modified natural zeolite-CNF-epoxy composite electrodes suitable for ibuprofen detection in aqueous solution. Ag carbon nan

  7. Dexamethasone loaded core-shell SF/PEO nanofibers via green electrospinning reduced endothelial cells inflammatory damage.

    Science.gov (United States)

    Chen, Weiming; Li, Dawei; Ei-Shanshory, Ahmed; El-Newehy, Mohamed; Ei-Hamshary, Hany A; Al-Deyab, Salem S; He, Chuanglong; Mo, Xiumei

    2015-02-01

    Silk fibroin (SF)/PEO nanofibers prepared by green electrospinning is safe, non-toxic and environment friendly, it is a potential drug delivery carrier for tissue engineering. In this study, a core-shell nanofibers named as Dex@SF/PEO were obtained by green electrospinning with SF/PEO as the shell and dexamethasone (Dex) in the core. The nanofiber morphology and core-shell structure were studied by Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM). The Dex release behavior from the nanofibers was tested by High Performance liquid (HPLC) method. The protective effect of drug loaded nanofibers mats on Porcine hip artery endothelial cells (PIECs) against LPS-induced inflammatory damage were determined by MTT assay. TEM result showed the distinct core-shell structure of nanofibers. In vitro drug release studies demonstrated that dexamethasone can sustain release over 192 h and core-shell nanofibers showed more slow release of Dex compared with the blending electrospinning nanofibers. Anti-inflammatory activity in vitro showed that released Dex can reduce the PIECs inflammatory damage and apoptosis which induced by lipopolysaccharide (LPS). Dex@SF/PEO nanofibers are safe and non-toxic because of no harmful organic solvents used in the preparation, it is a promising environment friendly drug carrier for tissue engineering.

  8. Function of NaOH hydrolysis in electrospinning ZnO nanofibers via using polylactide as templates

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Mengzhu, E-mail: liumengzhu125@163.com [College of Chemistry, Jilin University, Changchun, Jilin Province 130012 (China); Wang, Yongpeng, E-mail: wyp4889@gmail.com [College of Chemistry, Jilin University, Changchun, Jilin Province 130012 (China); Cheng, Zhiqiang, E-mail: czq5974@163.com [College of Chemistry, Jilin University, Changchun, Jilin Province 130012 (China); College of Resources and Environment, Jilin Agriculture University, Changchun, Jilin Province 130118 (China); Song, Lihua, E-mail: 120836684@qq.com [College of Chemistry, Jilin University, Changchun, Jilin Province 130012 (China); Shenyang Institute of Geology and Mineral Resources, CGS, Shenyang, Liaoning Province 110034 (China); Zhang, Mingyue, E-mail: zhangmingyue8803@163.com [College of Chemistry, Jilin University, Changchun, Jilin Province 130012 (China); Hu, Meijuan, E-mail: 442675083@qq.com [College of Chemistry, Jilin University, Changchun, Jilin Province 130012 (China); Li, Junfeng, E-mail: jfli@jlu.edu.cn [College of Chemistry, Jilin University, Changchun, Jilin Province 130012 (China)

    2014-09-15

    Graphical abstract: - Highlights: • PLA was used as templates to electrospin ZnO nanofibers for the first time. • Without NaOH hydrolysis, only ZnO film was prepared. • Under function of NaOH, ZnO nanofibers were obtained. • The function of NaOH was discussed. • ZnO nanofibers showed much higher photocatalytical efficiency than ZnO film. - Abstract: Mixture of polylactide (8 wt%), zinc acetate (6 wt%) and hexafluoroisopropanol was first used as electrospinning solution to fabricate ZnO nanofibers. Unfortunately, after direct calcination of the precursor polylactide/zinc acetate nanofibers, only ZnO film was prepared. Surprisingly, when the precursor fibers were pre-hydrolyzed with NaOH, ZnO nanofibers with diameter of 678 nm were obtained. The mechanism analysis showed that the preserve of fiber structure was attributed to the formation of zinc polylactic acid in the process of hydrolyzation. After characterized by scanning electron microscope and transmission electron microscope, the ZnO film was found to be an aggregation of irregular nanoparticles and the ZnO nanofiber was a necklace-like arrangement of cylindrical grains. X-ray diffraction and photoluminescence measurements indicated that the crystalline quality of the ZnO nanofibers was higher than the film. Furthermore, photocatalytic performance of the ZnO samples was investigated. Comparing with ZnO film, ZnO nanofibers exhibited much higher activity.

  9. Fluorescent carbon nanowires made by pyrolysis of DNA nanofibers and plasmon-assisted emission enhancement of their fluorescence.

    Science.gov (United States)

    Nakao, Hidenobu; Tokonami, Shiho; Yamamoto, Yojiro; Shiigi, Hiroshi; Takeda, Yoshihiko

    2014-10-14

    We report on a facile method for preparing fluorescent carbon nanowires (CNWs) with pyrolysis of highly aligned DNA nanofibers as carbon sources. Silver nanoparticle (AgNP)-doped CNWs were also produced using pyrolysis of DNA nanofibers with well-attached AgNPs, indicating emission enhancement assisted by localized plasmon resonances.

  10. Lecithin blended polyamide-6 high aspect ratio nanofiber scaffolds via electrospinning for human osteoblast cell culture

    Energy Technology Data Exchange (ETDEWEB)

    Nirmala, R. [Bio-nano System Engineering, College of Engineering, Chonbuk National University, Jeonju, 561 756 (Korea, Republic of); Park, Hye-Min [Department of Pharmacology and Toxicology, College of Veterinary Medicine, Chonbuk National University, Jeonju 561 756 (Korea, Republic of); Navamathavan, R. [School of Advanced Materials Engineering, Chonbuk National University, Jeonju 561 756 (Korea, Republic of); Kang, Hyung-Sub [Department of Pharmacology and Toxicology, College of Veterinary Medicine, Chonbuk National University, Jeonju 561 756 (Korea, Republic of); El-Newehy, Mohamed H. [Petrochemical Research Chair, Department of Chemistry, College of Science, King Saud University, Riyadh 11451 (Saudi Arabia); Kim, Hak Yong, E-mail: khy@jbnu.ac.kr [Petrochemical Research Chair, Department of Chemistry, College of Science, King Saud University, Riyadh 11451 (Saudi Arabia); Center for Healthcare Technology and Development, Chonbuk National University, Jeonju, 561 756 (Korea, Republic of)

    2011-03-12

    In this study, we focused on the preparation and characterization of lecithin blended polyamide-6 nanofibers via an electrospinning process for human osteoblastic (HOB) cell culture applications. The morphological, structural characterizations and thermal properties of polyamide-6/lecithin nanofibers were determined by using scanning electron microscopy (SEM), field-emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, differential scanning calorimetry (DSC) and thermogravimetry (TGA). SEM images revealed that the nanofibers were well-oriented with good incorporation of lecithin. FT-IR results indicated the presence of amino groups of lecithin in the blended nanofibers. TGA analysis revealed that the onset degradation temperature decreased with increasing lecithin content in the blended nanofibers. The morphological features of cells attached on polyamide-6/lecithin nanofibers were confirmed by SEM. The adhesion, viability and proliferation properties of osteoblast cells on the polyamide-6/lecithin blended nanofibers were analyzed by in vitro cell compatibility test. This study demonstrated the non-cytotoxic behavior of electrospun polyamide-6/lecithin nanofibers for the osteoblast cell culture.

  11. Synthesis and Characterization of Electrospun Nanocomposite TiO Nanofibers with Ag Nanoparticles for Photocatalysis Applications

    Directory of Open Access Journals (Sweden)

    Srujan Mishra

    2012-01-01

    Full Text Available Polycrystalline mixed-phase TiO2 nanofibers embedded with 2.0% w/v Ag nanoparticles was prepared by the electrospinning technique. Calcination of dry Ag nanoparticles-titanium (IV isopropoxide/PVP electrospun nanofiber mats in air at 510∘C for 24 h yielded polycrystalline TiO2/Ag nanofibers. The morphology and distribution of silver nanoparticles were observed by transmission electron microscopy (TEM, scanning TEM (STEM, and high-angle annular dark-field (HAADF imaging. Mixed-phase anatase and rutile TiO2 nanofibers were produced with Ag nanoparticles. High-resolution TEM lattice-fringe measurements showed good agreement with Ag (111, anatase (101, and rutile (110 phases. The photocatalytic activity of TiO2/Ag nanofibers was compared to the photocatalytic activity of pure TiO2 nanofibers by studying the photodegradation of methyl red dye under UV light irradiation, in a photoreactor. UV-visible absorbance spectra showed that the rate of decay of the dye in case of photodegradation by TiO2/Ag nanofibers was 10.3 times higher than that by pure TiO2 nanofibers. The retaining of the fiber morphology along with the increased surface area due to the addition of Ag nanoparticles can be believed to enhance the photocatalytic oxidation of methyl red dye.

  12. Electrospun polyacrylonitrile nanofibers loaded with silver nanoparticles by silver mirror reaction

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Yongzheng; Li, Yajing; Zhang, Jianfeng; Yu, Zhongzhen; Yang, Dongzhi, E-mail: yangdz@mail.buct.edu.cn

    2015-06-01

    The silver mirror reaction (SMR) method was selected in this paper to modify electrospun polyacrylonitrile (PAN) nanofibers, and these nanofibers loaded with silver nanoparticles showed excellent antibacterial properties. PAN nanofibers were first pretreated in AgNO{sub 3} aqueous solution before the SMR process so that the silver nanoparticles were distributed evenly on the outer surface of the nanofibers. The final PAN nanofibers were characterized by scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), transmission electron microscopy (TEM), TEM-selected area electron diffraction (SAED), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). SEM, TEM micrographs and SAED patterns confirmed homogeneous dispersion of the silver nanoparticles which were composed of monocrystals with diameters 20–30 nm. EDS and XRD results showed that these monocrystals tended to form face-centered cubic single silver. TGA test indicated that the nanoparticles loaded on the nanofibers reached above 50 wt.%. This material was also evaluated by the viable cell-counting method. The results indicated that PAN nanofibers loaded with silver nanoparticles exhibited excellent antimicrobial activities against gram-negative Escherichia coli (E. coli), gram-positive Staphylococcus aureus (S. aureus) and the fungus Monilia albicans. Thus, this material had many potential applications in biomedical fields. - Highlights: • Silver mirror reaction was used to prepare nanofibers loaded with silver nanoparticles. • The SAED patterns demonstrated the monocrystallinity of silver nanocrystals. • The XRD results showed nanoparticles tended to be face-centered cubic single silver. • The material showed excellent antimicrobial activities against bacteria and fungi.

  13. Enhancement of photoresponse and UV-assisted gas sensing with Au decorated ZnO nanofibers

    Energy Technology Data Exchange (ETDEWEB)

    Li Yinhua [School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0620 (United States); State Key Laboratory of Fine Chemicals, R and D Center of Membrane Science and Technology, School of Chemical Engineering, Dalian University of Technology, Dalian 116024 (China); Gong Jian [School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0620 (United States); He Gaohong [State Key Laboratory of Fine Chemicals, R and D Center of Membrane Science and Technology, School of Chemical Engineering, Dalian University of Technology, Dalian 116024 (China); Deng Yulin, E-mail: yulin.deng@chbe.gatech.edu [School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0620 (United States)

    2012-06-15

    To increase the photoresponsive and gas sensing properties of ZnO nanofibers under UV illumination, Au nanoparticles were introduced to the ZnO nanofibers (Au/ZnO) using electrospinning technique. It is found that adding Au nanoparticles into the ZnO nanofibers enhances significantly the photoresponse and makes the nanofibers also respond to visible light. The gas sensing performance with the assist of UV irradiation at room temperature was also improved greatly, e.g., the sensor response (SR) for 5 ppm ethanol increases from 0.12 to 0.31 by introducing 0.20 mol% of Au in ZnO nanofibers. The improvement of gas sensing performance is attributed to the enhanced photocatalytic reactions of organic gases on the Au/ZnO nanofibers surface. In addition, the sensitive behaviors of the nanofibers to ethanol, benzene, toluene and acetone under UV irradiation with different wavelengths were investigated and compared as well. Highlights: Black-Right-Pointing-Pointer Au/ZnO nanofiber sensors were successfully prepared using electrospinning. Black-Right-Pointing-Pointer The Au/ZnO sensors respond not only to UV light but also to visible light. Black-Right-Pointing-Pointer The response to organic analyte at room temperature is also greatly improved. Black-Right-Pointing-Pointer Schottky junction between Au and ZnO is one key for the improvement of sensing.

  14. Nanofibers Offer Alternative Ways to the Treatment of Skin Infections

    Directory of Open Access Journals (Sweden)

    T. D. J. Heunis

    2010-01-01

    Full Text Available Injury to the skin causes a breach in the protective layer surrounding the body. Many pathogens are resistant to antibiotics, rendering conventional treatment less effective. This led to the use of alternative antimicrobial compounds, such as silver ions, in skin treatment. In this review nanofibers, and the incorporation of natural antimicrobial compounds in these scaffolds, are discussed as an alternative way to control skin infections. Electrospinning as a technique to prepare nanofibers is discussed. The possibility of using these structures as drug delivery systems is investigated.

  15. Electrospun anatase-phase TiO2 nanofibers with different morphological structures and specific surface areas.

    Science.gov (United States)

    He, Guangfei; Cai, Yibing; Zhao, Yong; Wang, Xiaoxu; Lai, Chuilin; Xi, Min; Zhu, Zhengtao; Fong, Hao

    2013-05-15

    Electrospun anatase-phase TiO2 nanofibers with desired morphological structure and relatively high specific surface area are expected to outperform other nanostructures (e.g., powder and film) of TiO2 for various applications (particularly dye-sensitized solar cell and photo-catalysis). In this study, systematic investigations were carried out to prepare and characterize electrospun anatase-phase TiO2 nanofibers with different morphological structures (e.g., solid, hollow/tubular, and porous) and specific surface areas. The TiO2 nanofibers were generally prepared via electrospinning of precursor nanofibers followed by pyrolysis at 500°C. For making hollow/tubular TiO2 nanofibers, the technique of co-axial electrospinning was utilized; while for making porous TiO2 nanofibers, the etching treatment in NaOH aqueous solution was adopted. The results indicated that the hollow/tubular TiO2 nanofibers (with diameters of ~300-500 nm and wall-thickness in the range from tens of nanometers to ~200 nm) had the BET specific surface area of ~27.3 m(2)/g, which was approximately twice as that of the solid TiO2 nanofibers (~15.2 m(2)/g) with diameters of ~200-300 nm and lengths of at least tens of microns. Porous TiO2 nanofibers made from the precursor of Al2O3/TiO2 composite nanofibers had the BET specific surface area of ~106.5 m(2)/g, whereas porous TiO2 nanofibers made from the precursor of ZnO/TiO2 composite nanofibers had the highest BET specific surface area of ~148.6 m(2)/g.

  16. Preparation of Polyvinyl Alcohol Nanofiber Membrane Functionalized by Beta-cyclodextrins for Molecular Filtration%β-环糊精修饰聚乙烯醇纳米纤维的制备及其吸附性质研究

    Institute of Scientific and Technical Information of China (English)

    李伟; 杨丰宇; 吴思雨; 赵君霞; 贺君钰; 石军; 尉震(通信作者)

    2013-01-01

    Polyvinyl alcohol (PVA) and glutaraldehyde were used as the materials to prepare PVA nanofiber membrane by electro-spinning technique. Under acidic condition, the membrane was crosslinked into water-stable nanofibrous mats, then in alkaline condition, the epoxy chloropropane reacted with the membrane and the epoxypropyl was bonded to the membrane surface. Consequently, the Beta-cyclodextrin (β-CD) reacted with epoxy group modification on the surface membrane to prepare the nanofiber material with absorption selectivity and recyclability. Fourier transform infrared spectrometer and scanning electron microscopy characterization were used to demonstrate that the membrane surface had been successfully bonded with beta-cyclodextrin (β-CD) and there was no obvious change of membrane surface morphology after the bonding. In the essay, phenolphthalein was used as the probe to detect the c-PVA-β-CD-NF membrane adsorption effect of its solution and the UV spectrophotometry was used to detect the absorption efficiency of the c-PVA-β-CD-NF membrane to phenolphthalein. The experiments show that the adsorption capacity on phenolphthalein of the c-PVA-β-CD-NF membrane was stronger than that of the PVA membrane significantly, it was at 30 min that the adsorption reached the state of equilibrium and the maximum adsorption capacity was 88 mg/g.%通过静电纺丝技术,以聚乙烯醇(PVA)与戊二醛为原料制得聚乙烯醇纳米纤维薄膜(PVA-NF膜)。先在酸性条件下,使该薄膜交联成非水溶性的纳米纤维薄膜(c-PVA-NF膜),而后在碱性条件下,先将环氧氯丙烷与膜反应,将环氧丙基键合到膜上,继而将β-环糊精与环氧基反应修饰到膜表面,制备出具有选择吸附性能并可重复利用的纳米纤维材料(c-PVA-β-CD-NF膜)。通过傅里叶变换红外光谱仪、扫描电子显微镜表征,确定所制得膜表面已成功键合上β-环糊精,且键合前后膜表面形态无明显变化。本

  17. 聚乙烯醇纳米纤维的制备与静电纺丝工艺研究%Preparation of Poly(Vinyl Alcohol) Nanofibers and Research of Electrospinning

    Institute of Scientific and Technical Information of China (English)

    杜江; 李罡; 蓝彩娟

    2014-01-01

    近年来,利用高压静电纺丝技术开发生物医用材料制品已成为研究的热点。本实验利用高压电纺丝技术制备了聚乙烯醇(PVA)纳米纤维,研究了PVA溶液静电纺丝过程中PVA浓度,纺丝电压和收集板距离等电纺工艺参数对PVA纤维形成及其微观形貌的影响。实验结果表明,PVA纤维直径随着电纺溶液浓度的增加而增加;当电压从15 kV增加至25 kV时,纤维直径逐渐下降;电压从25 kV增加至30 kV时纤维直径反而开始增加;收集板间距离增加纤维直径也相对的减小。PVA纤维在浓度20%,电压25 kV,收集板距离15 cm,流速0.2 ml/h的工艺条件下形貌和直径最佳,静电纺丝过程也最稳定。%In recent years,using electrospinning technology preparaed biomedical materials products has become a hot research.In this study,poly (vinyl alcohol) nanofibers were prepared by electrospinning PVA solution with 20%concentration.The electrostatic field strength was fixed at 25 kV/15 cm.The feed rate of the solutions was controlled to about 0.2 ml/h.The structure and morphology of fibers the was observed by scanning electron microscope(SEM).

  18. Conductive Behaviors of Carbon Nanofibers Reinforced Epoxy Composites

    Institute of Scientific and Technical Information of China (English)

    MEI Qilin; WANG Jihui; WANG Fuling; HUANG Zhixiong; YANG Xiaolin; WEI Tao

    2008-01-01

    By means of ultrasonic dispersion,carbon nanofibers reinforced epoxy resin composite was prepared in the lab,the electrical conductivity of composite with different carbon nanofibers loadings were studied,also the voltage-current relationship,resistance-temperature properties and mechano-electric effect were investigated.Results show that the resistivity of composite decreases in geometric progression with the increasing of carbon nanofibers,and the threshold ranges between 0.1 wt%-0.2 wt%.The voltage-current relationship is in good conformity with the Ohm's law,both positive temperature coefficient and negative temperature coefficient can be found at elevated temperature.In the course of stretching,the electrical resistance of the composites increases with the stress steadily and changes sharply near the breaking point,which is of importance for the safety monitor and structure health diagnosis.

  19. Uniaxially aligned ceramic nanofibers obtained by chemical mechanical processing

    Energy Technology Data Exchange (ETDEWEB)

    Tararam, R. [Univ Estadual Paulista – UNESP – Instituto de Química, Rua Prof. Francisco Degni n° 55, CEP 14800-900 Araraquara, SP (Brazil); Foschini, C.R. [Univ Estadual Paulista – UNESP – Faculdade de Engenharia de Bauru, Dept. de Eng. Mecanica, Av. Eng. Luiz Edmundo C. Coube 14-01, CEP 17033-360 Bauru, SP (Brazil); Destro, F.B. [Univ Estadual Paulista – UNESP – Faculdade de Engenharia de Guaratinguetá, Guaratinguetá 12516-410, SP (Brazil); Simões, A.Z., E-mail: alezipo@yahoo.com [Univ Estadual Paulista – UNESP – Faculdade de Engenharia de Guaratinguetá, Guaratinguetá 12516-410, SP (Brazil); Longo, E.; Varela, J.A. [Univ Estadual Paulista – UNESP – Instituto de Química, Rua Prof. Francisco Degni n° 55, CEP 14800-900 Araraquara, SP (Brazil)

    2014-08-01

    For this study, we investigated a simple method to generate well aligned nanofibers over large areas using an organic polymer stretched over the substrate surface With this method, ZnO and CuO 3D parallel nanowire arrays were successfully prepared by calcinations of the polymer fibers. X-ray diffraction (XRD) analysis revealed that the copper oxide has a monoclinic structure while the zinc oxide has a hexagonal structure. Scanning electron microscopy (SEM) analysis showed ceramic nanofibers with an average diameter of 120 nm which were composed of small nanoparticles which are 10 nm in diameter. The ability to obtain uniaxially aligned nanofibers reveals a range of interesting properties with potential applications for sensors, catalysts and energy technologies.

  20. A novel nano-nonwoven fabric with three-dimensionally dispersed nanofibers: entrapment of carbon nanofibers within nonwovens using the wet-lay process

    Science.gov (United States)

    Karwa, Amogh N.; Barron, Troy J.; Davis, Virginia A.; Tatarchuk, Bruce J.

    2012-05-01

    This study demonstrates, for the first time, the manufacturing of novel nano-nonwovens that are comprised of three-dimensionally distributed carbon nanofibers within the matrices of traditional wet-laid nonwovens. The preparation of these nano-nonwovens involves dispersing and flocking carbon nanofibers, and optimizing colloidal chemistry during wet-lay formation. The distribution of nanofibers within the nano-nonwoven was verified using polydispersed aerosol filtration testing, air permeability, low surface tension liquid capillary porometry, SEM and cyclic voltammetry. All these characterization techniques indicated that nanofiber flocks did not behave as large solid clumps, but retained the ‘nanoporous’ structure expected from nanofibers. These nano-nonwovens showed significant enhancements in aerosol filtration performance. The reduction-oxidation reactions of the functional groups on nanofibers and the linear variation of electric double-layer capacitance with nanofiber loading were measured using cyclic voltammetry. More than 65 m2 (700 ft2) of the composite were made during the demonstration of process scalability using a Fourdrinier-type continuous pilot papermaking machine. The scalability of the process with the control over pore size distribution makes these composites very promising for filtration and other nonwoven applications.

  1. Morphological Characterization of Nanofibers: Methods and Application in Practice

    Directory of Open Access Journals (Sweden)

    Jakub Širc

    2012-01-01

    Full Text Available Biomedical applications such as wound dressing for skin regeneration, stem cell transplantation, or drug delivery require special demands on the three-dimensional porous scaffolds. Besides the biocompatibility and mechanical properties, the morphology is the most important attribute of the scaffold. Specific surface area, volume, and size of the pores have considerable effect on cell adhesion, growth, and proliferation. In the case of incorporated biologically active substances, their release is also influenced by the internal structure of nanofibers. Although many scientific papers are focused on the preparation of nanofibers and evaluation of biological tests, the morphological characterization was described just briefly as service methods. The aim of this paper is to summarize the methods applicable for morphological characterization of nanofibers and supplement it by the results of our research. Needleless electrospinning technique was used to prepare nanofibers from polylactide, poly(ε-caprolactone, gelatin, and polyamide. Scanning electron microscopy was used to evaluate the fiber diameters and to reveal eventual artifacts in the nanofibrous structure. Nitrogen adsorption/desorption measurements were employed to measure the specific surface areas. Mercury porosimetry was used to determine total porosities and compare pore size distributions of the prepared samples.

  2. A simple approach for synthesis, characterization and bioactivity of bovine bones to fabricate the polyurethane nanofiber containing hydroxyapatite nanoparticles

    Directory of Open Access Journals (Sweden)

    F. A. Sheikh

    2012-01-01

    Full Text Available In the present study, we had introduced polyurethane (PU nanofibers that contain hydroxyapatite (HAp nanoparticles (NPs as a result of an electrospinning process. A simple method that does not depend on additional foreign chemicals had been employed to synthesize HAp NPs through the calcination of bovine bones. Typically, a colloidal gel consisting of HAp/PU had been electrospun to form nanofibers. In this communication, physiochemical aspects of prepared nanofibers were characterized by FE-SEM, TEM and TEM-EDS, which confirmed that nanofibers were well-oriented and good dispersion of HAp NPs, over the prepared nanofibers. Parameters, affecting the utilization of the prepared nanofibers in various nano-biotechnological fields have been studied; for instance, the bioactivity of the produced nanofiber mats was investigated while incubating in simulated body fluid (SBF. The results from incubation of nanofibers, indicated that incorporation of HAp strongly activates the precipitation of the apatite-like particles, because of the HAp NPs act as seed, that accelerate crystallization of the biological HAp from the utilized SBF.

  3. A simple approach for synthesis, characterization and bioactivity of bovine bones to fabricate the polyurethane nanofiber containing hydroxyapatite nanoparticles.

    Science.gov (United States)

    Sheikh, F A; Kanjwal, M A; Macossay, J; Barakat, N A M; Kim, H Y

    2012-01-01

    In the present study, we had introduced polyurethane (PU) nanofibers that contain hydroxyapatite (HAp) nanoparticles (NPs) as a result of an electrospinning process. A simple method that does not depend on additional foreign chemicals had been employed to synthesize HAp NPs through the calcination of bovine bones. Typically, a colloidal gel consisting of HAp/PU had been electrospun to form nanofibers. In this communication, physiochemical aspects of prepared nanofibers were characterized by FE-SEM, TEM and TEM-EDS, which confirmed that nanofibers were well-oriented and good dispersion of HAp NPs, over the prepared nanofibers. Parameters, affecting the utilization of the prepared nanofibers in various nano-biotechnological fields have been studied; for instance, the bioactivity of the produced nanofiber mats was investigated while incubating in simulated body fluid (SBF). The results from incubation of nanofibers, indicated that incorporation of HAp strongly activates the precipitation of the apatite-like particles, because of the HAp NPs act as seed, that accelerate crystallization of the biological HAp from the utilized SBF.

  4. Preparation and performance study of cross-linked Zein/PVA-SbQ composite nanofibers spun by electrospinning%光交联Zein/PVA-SbQ复合纳米纤维的制备及表征∗

    Institute of Scientific and Technical Information of China (English)

    崔静; 董建成; 赵明明; 王清清; 陈晓东; 魏取福

    2015-01-01

    采用静电纺制备了不同质量比的玉米醇溶蛋白(Zein)/聚乙烯醇-苯乙烯吡啶盐(PVA-SbQ)复合纳米纤维,在紫外光照射下得到光交联 Zein/PVA-SbQ复合纳米纤维。利用扫描电镜(SEM)对复合纳米纤维的形貌和直径分布进行了分析;傅里叶变换红外光谱(FT-IR)曲线表明,Zein/PVA-SbQ 复合纳米纤维保持了两组分原有的化学功能基团;通过差示扫描量热仪(DSC)研究了复合纳米纤维的热学性能,结果表明其具有较高的热稳定性;静态接触角(CA)测试说明,随着 PVA-SbQ 比例增大复合纳米纤维疏水性降低;强力测试表明,PVA-SbQ的加入增大了 Zein 纳米纤维的强度。%Zein/PVA-SbQ composite nanofibers blend with different mass ratios were fabricated by electrospin-ning.Then the nanofibers were irradiated under UV light to get the cross-linked ones.The morphologies and di-ameter distributions of Zein/PVA-SbQ composite nanofibers were observed by SEM.The spectra of FT-IR indi-cated that two compositions of composite nanofibers maintained their own original functional groups.The ther-mal properties of composite nanofibers were studied by DSC,the results from characterizations revealed that the composite nanofibers still maintained superior thermal stability with the addition of PVA-SbQ.The results of CA elucidated the hydrophobicity decreased for composite nanofibers with increasing PVA-SbQ composition. The strength test showed that the addition of PVA-SbQ increased the tensile strength of composite nanofibers.

  5. Preparing photochromic nanofibers and animal cells using a photochromic compound of 1′,3′,3′-trimethyl-6-nitrospiro (2H-1-benzopyran-2,2′-indoline)

    DEFF Research Database (Denmark)

    Li, Xiaoqiang; Lin, Lin; Kanjwal, Muzafar Ahmed

    2012-01-01

    mixed solutions of NOSP and polymers (including a synthetic polymer of poly(methyl methacrylate) and a natural polymer of gelatin); NOSP/ethanol solution was dissolved in culture medium to stain pig iliac endothelial cells (PIEC) and endow them with photochromic capability. Polymer nanofibers from...... electrospinning were characterized by water contact angle measurements, ultraviolet–visible (UV–Vis) spectrophotometry and fluorescence microscopy. Morphology of photochromic PIEC was observed by fluorescence microscopy after being irradiated. It was shown that nanofibers from electrospun polymers and NOSP...

  6. Synthesis and Characterization of Electrospun Nanocomposite T i O Nanofibers with Ag Nanoparticles for Photocatalysis Applications

    OpenAIRE

    Mishra, Srujan; Ahrenkiel, S. Phillip

    2012-01-01

    Polycrystalline mixed-phase TiO2 nanofibers embedded with 2.0% w/v Ag nanoparticles was prepared by the electrospinning technique. Calcination of dry Ag nanoparticles-titanium (IV) isopropoxide/PVP electrospun nanofiber mats in air at 5 1 0 ∘ C for 24 h yielded polycrystalline TiO2/Ag nanofibers. The morphology and distribution of silver nanoparticles were observed by transmission electron microscopy (TEM), scanning TEM (STEM), and high-angle annular dark-field (HAADF) imaging. Mixed-phase an...

  7. Synthesis and Characterization of Electrospun Nanocomposite TiO Nanofibers with Ag Nanoparticles for Photocatalysis Applications

    OpenAIRE

    Srujan Mishra; S. Phillip Ahrenkiel

    2012-01-01

    Polycrystalline mixed-phase TiO2 nanofibers embedded with 2.0% w/v Ag nanoparticles was prepared by the electrospinning technique. Calcination of dry Ag nanoparticles-titanium (IV) isopropoxide/PVP electrospun nanofiber mats in air at 510∘C for 24 h yielded polycrystalline TiO2/Ag nanofibers. The morphology and distribution of silver nanoparticles were observed by transmission electron microscopy (TEM), scanning TEM (STEM), and high-angle annular dark-field (HAADF) imaging. Mixed-phase anatas...

  8. Modulation of a fluorescence switch of nanofiber mats containing photochromic spironaphthoxazine and D-{pi}-A charge transfer dye

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Eun-Mi [BK21 FTIT Department of Advanced Organic Materials and Textile System Engineering, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Gwon, Seon-Young [Department of Advanced Organic Materials Science and Engineering, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Son, Young-A. [BK21 FTIT Department of Advanced Organic Materials and Textile System Engineering, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Kim, Sung-Hoon, E-mail: shokim@knu.ac.kr [Department of Advanced Organic Materials Science and Engineering, Kyungpook National University, Daegu 702-701 (Korea, Republic of); School of Chemistry Science and Technology, Zhanjiang Normal University, Zhanjiang 524048 (China)

    2012-06-15

    Photoswitchable poly(methyl methacrylate) (PMMA) nanofiber mats containing spironaphthoxazine (SPO)/electron donor-{pi}-acceptor (D-{pi}-A) type fluorescent dye (TCF) were prepared by electrospinning. The photoregulated fluorescence switching behaviors of SPO/TCF blended solution and PMMA nanofiber mats containing SPO/TCF were also studied. Not only SPO/TCF blended solution but also PMMA nanofiber mats containing SPO/TCF showed reversible modulation of fluorescence intensity using alternating irradiation with UV and visible light. Highlights: Black-Right-Pointing-Triangle We have designed PMMA nanofiber mats containing a photochromic SPO and fluorescent TCF. Black-Right-Pointing-Triangle Photoswitchable PMMA nanofiber mats containing SPO/TCF were prepared by electrospinning. Black-Right-Pointing-Triangle Reversible modulation of fluorescence intensity was achieved by irradiation with UV/vis.

  9. Highly sensitive and ultrafast response surface acoustic wave humidity sensor based on electrospun polyaniline/poly(vinyl butyral) nanofibers

    Energy Technology Data Exchange (ETDEWEB)

    Lin Qianqian [Department of Polymer Science and Engineering, Cyrus Tang Center for Sensor Materials and Applications, Zhejiang University, MOE Key Laboratory of Macromolecule Synthesis and Functionalization, Hangzhou 310027 (China); Li Yang, E-mail: liyang@zju.edu.cn [Department of Polymer Science and Engineering, Cyrus Tang Center for Sensor Materials and Applications, Zhejiang University, MOE Key Laboratory of Macromolecule Synthesis and Functionalization, Hangzhou 310027 (China); Yang Mujie [Department of Polymer Science and Engineering, Cyrus Tang Center for Sensor Materials and Applications, Zhejiang University, MOE Key Laboratory of Macromolecule Synthesis and Functionalization, Hangzhou 310027 (China)

    2012-10-20

    Highlights: Black-Right-Pointing-Pointer Polyanline/poly(vinyl butyral) nanofibers are prepared by electrospinning. Black-Right-Pointing-Pointer Nanofiber-based SAW humidity sensor show high sensitivity and ultrafast response. Black-Right-Pointing-Pointer The SAW sensor can detect very low humidity. - Abstract: Polyaniline (PANi) composite nanofibers were deposited on surface acoustic wave (SAW) resonator with a central frequency of 433 MHz to construct humidity sensors. Electrospun nanofibers of poly(methyl methacrylate), poly(vinyl pyrrolidone), poly(ethylene oxide), poly(vinylidene fluoride), poly(vinyl butyral) (PVB) were characterized by scanning electron microscopy, and humidity response of corresponding SAW humidity sensors were investigated. The results indicated that PVB was suitable as a matrix to form nanofibers with PANi by electrospinning (ES). Electrospun PANi/PVB nanofibers exhibited a core-sheath structure as revealed by transmittance electron microscopy. Effects of ES collection time on humidity response of SAW sensor based on PANi/PVB nanofibers were examined at room temperature. The composite nanofiber sensor exhibited very high sensitivity of {approx}75 kHz/%RH from 20 to 90%RH, ultrafast response (1 s and 2 s for humidification and desiccation, respectively) and good sensing linearity. Furthermore, the sensor could detect humidity as low as 0.5%RH, suggesting its potentials for low humidity detection. Attempts were done to explain the attractive humidity sensing performance of the sensor by considering conductivity, hydrophilicity, viscoelasticity and morphology of the polymer composite nanofibers.

  10. Characterization of Chitosan Nanofiber Sheets for Antifungal Application

    OpenAIRE

    Mayumi Egusa; Ryo Iwamoto; Hironori Izawa; Minoru Morimoto; Hiroyuki Saimoto; Hironori Kaminaka; Shinsuke Ifuku

    2015-01-01

    Chitosan produced by the deacetylation of chitin is a cationic polymer with antimicrobial properties. In this study, we demonstrate the improvement of chitosan properties by nanofibrillation. Nanofiber sheets were prepared from nanofibrillated chitosan under neutral conditions. The Young’s modulus and tensile strength of the chitosan NF sheets were higher than those of the chitosan sheets prepared from dissolving chitosan in acetic acid. The chitosan NF sheets showed strong mycelial growth in...

  11. 静电纺丝法制备聚丙烯腈/银纳米粒子复合纳米纤维及其SERS特性%Preparation Polyacrylonitrile/Ag Nanoparticle Composite Nanofibers Via an Elelctrospinning Technique and Their Surface Enhanced Raman Scattering Study

    Institute of Scientific and Technical Information of China (English)

    宋薇; 李婷婷; 王旭; 赵冰

    2015-01-01

    In this paper ,we have prepared polyacrylonitrile (PAN)/Ag nanoparticle composite nanofibers as a surface enhanced Raman scattering (SERS) substrate via an elelctrospinning technique .First ,the PAN and AgNO3 were dissolved in N ,N’‐dim‐ethylformamide solvent to get PAN/Ag seed solution ;then the PAN/Ag seed solution was electrospun for the preparation of PAN/Ag seed composite nanofibers ;Finally ,the PAN/Ag seed composite nanofibers were treated by hydrazine hydrate to syn‐thesize PAN/Ag nanoparticle composite nanofibers .The as‐prepared PAN/Ag nanoparticle composite nanofibers were mixed with the probes for the SERS detection to get the SERS spectrum of the probes .The PAN/Ag nanoparticle composite nanofibers substate showed a good SERS signal when the concentration of PATP is as low as 10-6 mol・L -1 .Furthermore ,this kind of SERS substrate could be large‐scale prepared ,which showed a high commercial value .%利用静电纺丝技术制备了一种聚丙烯腈/银纳米粒子复合纳米纤维的表面增强拉曼光谱基底。通过调节聚丙烯腈溶液的浓度可得到不同直径、不同厚度的纤维薄膜,将聚丙烯腈的N,N‐二甲基甲酰胺溶液与硝酸银溶液混合得到聚丙烯腈/Ag种子溶液,然后利用静电纺丝技术制备聚丙烯腈/Ag种子/AgNO3复合纳米纤维;加入AgNO3并利用水合肼二次还原后可制备适合拉曼检测的聚丙烯腈/Ag纳米粒子复合纤维膜,聚合物纤维表面和内部的金属纳米粒子的密度可调节。通过调节不同的纳米粒子的密集程度,可构筑出具有较高的电磁场增强效果的特殊的“热”结构(高局域强电磁场的亚波长区域)。而聚合物纤维内部的银纳米粒子可通过溶胀作用吸附更多的探针分子,提高拉曼检测的灵敏度。该基底有很好的SERS信号,并且可大规模制备。

  12. Fabrication of Cellulose Nanofiber/AlOOH Aerogel for Flame Retardant and Thermal Insulation

    Directory of Open Access Journals (Sweden)

    Bitao Fan

    2017-03-01

    Full Text Available Cellulose nanofiber/AlOOH aerogel for flame retardant and thermal insulation was successfully prepared through a hydrothermal method. Their flame retardant and thermal insulation properties were investigated. The morphology image of the cellulose nanofiber/AlOOH exhibited spherical AlOOH with an average diameter of 0.5 μm that was wrapped by cellulose nanofiber or adhered to them. Cellulose nanofiber/AlOOH composite aerogels exhibited excellent flame retardant and thermal insulation properties through the flammability test, which indicated that the as-prepared composite aerogels would have a promising future in the application of some important areas such as protection of lightweight construction materials.

  13. Facile synthesis of polypyrrole nanofiber and its enhanced electrochemical performances in different electrolytes

    Directory of Open Access Journals (Sweden)

    C. K. Das

    2012-12-01

    Full Text Available A porous nanocomposite based on polypyrrole (PPy and sodium alginate (SA has been synthesized by easy, inexpensive, eco-friendly method. As prepared nanocomposite showed fibrillar morphology in transmission electron microscopic (TEM analysis. The average diameter of ~100 nm for the nanofibers was observed from scanning electron microscopic (SEM analysis. As prepared nanofiber, was investigated as an electrode material for supercapacitor application in different aqueous electrolyte solutions. PPy nanofiber showed enhanced electrochemical performances in 1M KCl solution as compared to 1M Na2SO4 solution. Maximum specific capacitance of 284 F/g was found for this composite in 1 M KCl electrolyte. It showed 76% specific capacitance retention after 600 cycles in 1 M KCl solution. Electrochemical Impedance Spectra showed moderate capacitive behavior of the composite in both the electrolytes. Further PPy nanofiber demonstrated higher thermal stability as compared to pure PPy.

  14. 聚合物/TiO_2杂化纳米纤维微孔膜的制备及其在染料敏化太阳能电池中的应用%Preparation of Polymer/TiO2 Hybrid Nanofibers Microporous Membranes and Its Application in Dye-Sensitized Solar Cells

    Institute of Scientific and Technical Information of China (English)

    黄先威; 邓继勇; 许律; 沈平; 赵斌; 谭松庭

    2012-01-01

    The electrospinning technique provides a simple,cost-effective approach for producing polymeric and inorganic nanofibers with structures that vary with the processing parameters.In this paper,the polymer/TiO2 hybrid nanofibers microporous membranes were prepared from a polymer solution containing titanium(IV) butoxide(TBT) by electrospinning technique.The as-spun nanofibers microporous membranes were placed in air for 5 h to allow complete hydrolysis.The morphology of the microporous membranes was observed using electron scanning microscopy(SEM) under vacuum condition.The uptake and porosity of microporous membranes were investigated by weighting method before and after soaking electrolyte.The ionic conductivity of the microporous membranes was measured using the complex impedance technique.The blocking cell of stainless steel/microporous membranes/stainless steel was used at 1—105 Hz frequency range at 25 ℃.The AC amplitude was 5 mV.The TiO2 electrode was obtained by spreading titania paste(P25) on the conducting glass substrate using a doctor blade technique.The dye-sensitized solar cells(DSSCs) devices were fabricated based on the microporous membrane electrolyte by sandwiching a slice of the polymer/TiO2 hybrid nanofibers microporous membrane between a dye-sensitized TiO2 electrode and a Pt counter electrode.The edges of the cell were sealed with narrow strips of Surlyn hot melt.The morphology and three-dimensional structure of polymer/TiO2 hybrid nanofibers microporous membranes did not markedly change after absorbing liquid electrolyte,which indicated that the introduction of TiO2 into polymer nanofibers could improve the mechanical properties of the nanofibers.These also made the polymer/TiO2hybrid nanofibers microporous membranes possess high uptake and porosity.The TiO2 content in hybrid nanofibers was about 50 wt% according to the TG results.The wetting and diffusion properties of hybrid nanofibers microporous membranes to liquid

  15. Mechanism of nanofiber crimp

    Directory of Open Access Journals (Sweden)

    Chen Rou-Xi

    2013-01-01

    Full Text Available Fabrication of crimped fibers has been caught much attention recently due to remarkable improvement surface-to-volume ratio. The precise mechanism of the fiber crimp is, however, rare and preliminary. This paper finds that pulsation of fibers is the key factor for fiber crimp, and its configuration (wave formation corresponds to its nature frequency after solidification. Crimping performance can be improved by temperature control of the uncrimped fibers. In the paper, polylactide/ dimethylfomamide solution is fabricated into crimped nanofibers by the bubble electrospinning, an approximate period- amplitude relationship of the wave formation is obtained.

  16. Electrospinning Synthesis and Photocatalytic Activity of Mesoporous TiO2 Nanofibers

    OpenAIRE

    Jing Li; Hui Qiao; Yuanzhi Du; Chen Chen; Xiaolin Li; Jing Cui; Dnt Kumar; Qufu Wei

    2012-01-01

    Titanium dioxide (TiO2) nanofibers in the anatase structure were successfully prepared via electrospinning technique followed by calcination process. The morphologies, crystal structure, surface area, and the photocatalytic activity of resulting TiO2 nanofibers were characterized by field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), nitrogen sorption, and UV-vis spectroscopy. The results revealed that calcination temperature ...

  17. Fabrication and characterization of dense zirconia and zirconia-silica ceramic nanofibers.

    Science.gov (United States)

    Xu, Xiaoming; Guo, Guangqing; Fan, Yuwei

    2010-09-01

    The objective of this study was to prepare dense zirconia-yttria (ZY), zirconia-silica (ZS) and zirconia-yttria-silica (ZYS) nanofibers as reinforcing elements for dental composites. Zirconium (IV) propoxide, yttrium nitrate hexahydrate, and tetraethyl orthosilicate (TEOS) were used as precursors for the preparation of zirconia, yttria, and silica sols. A small amount (1-1.5 wt%) of polyethylene oxide (PEO) was used as a carry polymer. The sols were preheated at 70 degrees C before electrospinning and their viscosity was measured with a viscometer at different heating time. The gel point was determined by viscosity-time (eta-t) curve. The ZY, ZS and ZYS gel nanofibers were prepared using a special reactive electrospinning device under the conditions near the gel point. The as-prepared gel nanofibers had diameters between 200 and 400 nm. Dense (nonporous) ceramic nanofibers of zirconia-yttria (96/4), zirconia-silica (80/20) and zirconia-yttria-silica (76.8/3.2/20) with diameter of 100-300 nm were obtained by subsequent calcinations at different temperatures. The gel and ceramic nanofibers obtained were characterized by scanning electron microscope (SEM), high-resolution field-emission scanning electron microscope (FE-SEM), thermogravimetric analyzer (TGA), differential scanning calorimeter (DSC), Fourier transform infrared spectrometer (FT-IR), and X-ray diffraction (XRD). SEM micrograph revealed that ceramic ZY nanofibers had grained structure, while ceramic ZS and ZYS nanofibers had smooth surfaces, both showing no visible porosity under FE-SEM. Complete removal of the polymer PEO was confirmed by TGA/DSC and FT-IR. The formation of tetragonal phase of zirconia and amorphous silica was proved by XRD. In conclusion, dense zirconia-based ceramic nanofibers can be fabricated using the new reactive sol-gel electrospinning technology with minimum organic polymer additives.

  18. Electrospun gelatin/polyurethane blended nanofibers for wound healing

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sung Eun; Heo, Dong Nyoung; Lee, Jung Bok; Kwon, Il Keun [Department of Oral Biology, School of Dentistry, Kyung Hee University, Seoul 130-701 (Korea, Republic of); Kim, Jong Ryul; Park, Sang Hyuk [Conservative Dentistry and Institute of Oral Biology, School of Dentistry, Kyung Hee University, Seoul 130-701 (Korea, Republic of); Jeon, Seong Ho, E-mail: kwoni@khu.ac.k [College of Pharmacy, Kangwon National University, Chuncheon 200-701 (Korea, Republic of)

    2009-08-15

    In this study, we prepared a blended nanofiber scaffold using synthetic and natural polymers, polyurethane (PU) and gelatin respectively, using the electrospinning method to prepare a material for wound dressing. In order to confirm the properties of this gelatin/PU blended nanofiber scaffold, we performed scanning electron microscopy, atomic force microscopy, attenuated total reflectance Fourier-transform infrared spectroscopy, thermal gravimetric analysis, contact angle, water uptake, mechanical property, recovery, and degradation tests, and cellular response. The results obtained indicate that the mean diameter of these nanofibers was uniformly electrospun and ranged from 0.4 to 2.1{mu}m. According to the results, when the amount of gelatin in the blended solution decreased, the contact angle increased and water uptake of the scaffold decreased concurrently. In the mechanical tests, the blended nanofibrous scaffolds were elastic, and elasticity increased as the total amount of PU increased. Moreover, as the total amount of gelatin increased, the cell proliferation increased with the same amount of culture time. Therefore, this gelatin/PU blended nanofiber scaffold has potential application for use as a wound dressing.

  19. Polysaccharide-coated PCL nanofibers for wound dressing applications.

    Science.gov (United States)

    Croisier, Florence; Atanasova, Ganka; Poumay, Yves; Jérôme, Christine

    2014-12-01

    Polysaccharide-based nanofibers with a multilayered structure are prepared by combining electrospinning (ESP) and layer-by-layer (LBL) deposition techniques. Charged nanofibers are firstly prepared by electrospinning poly(ε-caprolactone) (PCL) with a block-copolymer bearing carboxylic acid functions. After deprotonation of the acid groups, the layer-by-layer deposition of polyelectrolyte polysaccharides, notably chitosan and hyaluronic acid, is used to coat the electrospun fibers. A multilayered structure is achieved by alternating the deposition of the positively charged chitosan with the deposition of a negatively charged polyelectrolyte. The construction of this multilayered structure is followed by Zeta potential measurements, and confirmed by observation of hollow nanofibers resulting from the dissolution of the PCL core in a selective solvent. These novel polysaccharide-coated PCL fiber mats remarkably combine the mechanical resistance typical of the core material (PCL)-particularly in the hydrated state-with the surface properties of chitosan. The control of the nanofiber structure offered by the electrospinning technology, makes the developed process very promising to precisely design biomaterials for tissue engineering. Preliminary cell culture tests corroborate the potential use of such system in wound healing applications.

  20. Antibacterial polylactic acid/chitosan nanofibers decorated with bioactive glass

    Science.gov (United States)

    Goh, Yi-fan; Akram, Muhammad; Alshemary, Ammarz; Hussain, Rafaqat

    2016-11-01

    In this study, we have presented the structural and in vitro characterization of electrospun polylactic acid (PLA)/Chitosan nanofibers coated with cerium, copper or silver doped bioactive glasses (CeBG/CuBG/AgBG). Bead-free, smooth surfaced nanofibers were successfully prepared by using electrospinning technique. The nanocomposite fibers were obtained using a facile dip-coating method, their antibacterial activities against E. coliE. coli (ATCC 25922 strains) were measured by the disk diffusion method after 24 h of incubation at 37 °C. CeBG and CuBG decorated PLA/Chitosan nanofibers did not develop an inhibition zone against the bacteria. On the other hand, nanofibers coated with AgBG developed an inhibition zone against the bacteria. The as-prepared nanocomposite fibers were immersed in SBF for 1, 3 and 7 days in Simulated Body Fluid (SBF) for evaluation of in vitro bioactivity. All samples induced the formation of crystallites with roughly ruffled morphology and the pores of fibers were covered with the extensive growth of crystallites. Energy Dispersive X-ray (EDX) composition analysis showed that the crystallites possessed Ca/P ratio close to 1.67, confirming the good in-vitro bioactivity of the fibers.

  1. Needleless Electrospinning of Uniform Nanofibers Using Spiral Coil Spinnerets

    Directory of Open Access Journals (Sweden)

    Xin Wang

    2012-01-01

    Full Text Available Polyvinyl alcohol nanofibers were prepared by a needleless electrospinning technique using a rotating spiral wire coil as spinneret. The influences of coil dimension (e.g., coil length, coil diameter, spiral distance, and wire diameter and operating parameters (e.g., applied voltage and spinning distance on electrospinning process, nanofiber diameter, and fiber productivity were examined. It was found that the coil dimension had a considerable influence on the nanofiber production rate, but minor effect on the fiber diameter. The fiber production rate increased with the increased coil length or coil diameter, or the reduced spiral distance or wire diameter. Higher applied voltage or shorter collecting distance also improved the fiber production rate but had little influence on the fiber diameter. Compared with the conventional needle electrospinning, the coil electrospinning produced finer fibers with a narrower diameter distribution. A finite element method was used to analyze the electric field on the coil surface and in electrospinning zone. It was revealed that the high electric field intensity was concentrated on the coil surface, and the intensity was highly dependent on the coil dimension, which can be used to explain the electrospinning performances of coils. In addition, PAN nanofibers were prepared using the same needleless electrospinning technique to verify the improvement in productivity.

  2. Reinforcement of polymeric nanofibers by ferritin nanoparticles

    Science.gov (United States)

    Shin, Min Kyoon; Kim, Sun I.; Kim, Seon Jeong; Kim, Sung-Kyoung; Lee, Haiwon

    2006-05-01

    Poly(vinyl alcohol) (PVA) nanofibers containing bimolecular ferritin nanoparticles exhibited the enhancement of elastic modulus as compared to pure PVA nanofibers due to chemical interactions between the ferritin and the PVA matrix. The elastic modulus of the nanofibers was measured using a three-point bending test employing an atomic force microscope (AFM). To improve the reliability of the AFM measurements, uniform nanofibers were oriented linearly on an AFM calibration grating by introducing parallel subelectrodes in an electrospinning system. The length to diameter ratio of the measured nanofibers was >16. The PVA nanofibers reinforced by ferritin are applicable as artificial muscles and actuators.

  3. Morphology and internal structure of polymeric and carbon nanofibers

    Science.gov (United States)

    Zhong, Zhenxin

    Evaporation and the associated solidification are important factors that affect the diameter of electrospun nanofibers. The evaporation and solidification of a charged jet were controlled by varying the partial pressure of water vapor during electrospinning of poly(ethylene oxide) from aqueous solution. As the partial pressure of water vapor increases, the solidification process of the charged jet becomes slower, allowing elongation of the charged jet to continue longer and thereby to form thinner fibers. The morphology and internal structure of electrospun poly(vinylidene fluorides) nanofibers were investigated. Low voltage high resolution scanning electron microscopy was used to study the surface of electrospun nanofibers. Control of electrospinning process produced fibers with various morphological forms. Fibers that were beaded, branched, or split were obtained when different instabilities dominated in the electrospinning process. The high ratio of stretching during electrospinning aligns the polymer molecules along the fiber axis. A rapid evaporation of solvent during electrospinning gives fibers with small and imperfect crystallites. These can be perfected by thermal annealing. Fibers annealed at elevated temperature form plate-like lamellar crystals tightly linked by tie molecules. Electrospinning can provide ultrafine nanofibers with cross-sections that contain only a few polymer molecules. Ultrafine polymer nanofibers are extremely stable in transmission electron microscope. Electrospun nanofibers suspended on a holey carbon film showed features of individual polymer molecules. Carbon fibers with diameters ranging from 100 nm to several microns were produced from mesophase pitch by a low cost gas jet process. The structure of mesophase pitch-based carbon fibers was investigated as a function of heat treatment temperatures. Submicron-sized graphene oxide flakes were prepared by a combination of oxidative treatment and ultrasonic radiation. Because pitch is

  4. Ultrahigh Transmission Optical Nanofibers

    CERN Document Server

    Hoffman, J E; Grover, J A; Solano, P; Kordell, P R; Wong-Campos, J D; Orozco, L A; Rolston, S L

    2014-01-01

    We present a procedure for reproducibly fabricating ultrahigh transmission optical nanofibers (530 nm diameter and 84 mm stretch) with single-mode transmissions of 99.95 $ \\pm$ 0.02%, which represents a loss from tapering of 2.6 $\\,\\times \\,$ 10$^{-5}$ dB/mm when normalized to the entire stretch. When controllably launching the next family of higher-order modes on a fiber with 195 mm stretch, we achieve a transmission of 97.8 $\\pm$ 2.8%, which has a loss from tapering of 5.0 $\\,\\times \\,$ 10$^{-4}$ dB/mm when normalized to the entire stretch. Our pulling and transfer procedures allow us to fabricate optical nanofibers that transmit more than 400 mW in high vacuum conditions. These results, published as parameters in our previous work, present an improvement of two orders of magnitude less loss for the fundamental mode and an increase in transmission of more than 300% for higher-order modes, when following the protocols detailed in this paper. We extract from the transmission during the pull, the only reported...

  5. Preparation of Carbon Nano-fiber Washcoat on Porous Silica Foam as Structured Catalyst Support%大孔二氧化硅膜上纳米碳纤维层结构化催化剂载体的制备

    Institute of Scientific and Technical Information of China (English)

    刘平乐; L.Lefferts

    2006-01-01

    This paper reports how a hairy layer of carbon nano-fibers can be prepared on the macro-porous silica foam produced by the sphere templating method. Firstly, three-dimensional close-packed crystals of polystyrene spheres are assembled on porous disk substrate by vacuum filtration or evaporation. The polystyrene template isannealed slightly above the glass transition temperature in order to strengthen the colloidal crystal and ensure interconnection of the spheres so as to obtain porous materials with open structure. Following the treatment of hexdecyltrimethylammonium bromide, the polystyrene template is filled with silica colloidal solution, which solidifies in the cavities. Then the polystyrene particles are removed by calcination at 843K, leaving behind porous silica foam.Scanning electron microscopy images demonstrate that silica foam has uniform and open structured pores. Nickel particles were deposited on porous silica foam layer by the dipping method and porous carbon nano-fiber washcoat was prepared by catalytic decomposition of ethene over small nickel particles.

  6. Controlled growth of organic nanofibers on nano- and micro-structured gold surfaces

    Science.gov (United States)

    Madsen, Morten; de Oliveira Hansen, Roana M.; Kjelstrup-Hansen, Jakob; Rubahn, Horst-Günter

    2009-08-01

    Nanofibers made from para-hexaphenylene (p6P) molecules hold unique optoelectronic properties, which make them interesting candidates as elements in electronic and optoelectronic devices. Typically these nanofibers are grown on specific single-crystalline substrates, on which long, mutually parallel nanofibers are formed. However, the lack of ability to further process these substrates restrains their use in devices. In this work, a novel method for in-situ growth of p6P nanofibers on nano- and micro-structured gold surfaces is presented. The substrates are prepared by conventional microfabrication techniques such as lithography, etching and metal deposition, which increase their potential as device platforms. The results presented here demonstrate, that both the growth direction and the nanofiber length can be controlled by placement of nano- and micro-structured lines on the substrate. It is shown that the preferred growth direction of the nanofibers is perpendicular to these structures whereas their length scales are limited by the size and placement of the structures. This work therefore demonstrates a new technique, which can be useful within future organic nanofiber based applications.

  7. Photocatalytic properties of silver nanoparticles decorated nanobranched TiO2 nanofibers.

    Science.gov (United States)

    Yi, Chuan; Nirmala, R; Barakat, Nasser A M; Navamathavan, R; Kim, Hak-Yong

    2011-08-01

    In this study, nanobranched TiO2 nanofibers and silver loaded nanobranched TiO2 nanofibers were prepared by electrospinning technique followed by TiCl4 aqueous solution treatment and silver photodeposition method. Field-emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM) were employed to investigate the morphology of the products. X-ray diffractometer (XRD) and X-ray photoelectron spectroscopy (XPS) were conducted on the samples to study their chemical composition as well as crystallographic structure. The photocatalytic activities of these produced nanofibers were examined with two organic dyes, methylene blue and methyl orange, under ultraviolet (UV) light irradiation. The effect of nanobranches and silver modification on TiO2 nanofibers was revealed in the photocatalysis process. The photocatalytic degradation rates of silver loaded on nanobranched TiO2 nanofibers were 1.6 and 1.7 times as that of pure TiO2 nanofibers in the presence of methylene blue and methyl orange, respectively, which indicated silver nanoparticles combined nanobranches modified on the surface of TiO2 nanofibers could enhance the photocatalytic ability.

  8. Electrospinning Synthesis and Photocatalytic Activity of Mesoporous TiO2 Nanofibers

    Directory of Open Access Journals (Sweden)

    Jing Li

    2012-01-01

    Full Text Available Titanium dioxide (TiO2 nanofibers in the anatase structure were successfully prepared via electrospinning technique followed by calcination process. The morphologies, crystal structure, surface area, and the photocatalytic activity of resulting TiO2 nanofibers were characterized by field emission scanning electron microscopy (FE-SEM, transmission electron microscopy (TEM, X-ray diffraction (XRD, nitrogen sorption, and UV-vis spectroscopy. The results revealed that calcination temperature had greatly influenced the morphologies of TiO2 nanofibers, but no obvious effect was noticed on the crystal structure of TiO2 nanofibers. The photocatalytic properties of TiO2 nanofibers were evaluated by photocatalytic degradation of rhodamine B (RhB in water under visible light irradiation. It was observed that TiO2 nanofibers obtained by calcination at 500°C for 3 hours exhibited the most excellent photocatalytic activity. We present a novel and simple method to fabricate TiO2 nanofibers with high-photocatalytic activity.

  9. Nanofibers as carrier systems for antimicrobial microemulsions. Part I: fabrication and characterization.

    Science.gov (United States)

    Kriegel, C; Kit, K M; McClements, D J; Weiss, J

    2009-01-20

    Antimicrobial nanofibers were prepared by solubilizing an antimicrobial essential oil (eugenol; 0.75-1.5 wt %) in surfactant micelles (Surfynol 465; 5-10 wt %) to form eugenol-containing microemulsions. Microemulsions were mixed with a nonionic synthetic polymer (poly(vinyl alcohol), PVA; M(w) = 130 kDa, degree of hydrolysis approximately 87%) and solutions subjected to electrospinning to induce nanofiber formation. Solution properties, fiber morphology, and composition of nanofibers were determined. The surface conductivity and viscosity of the polymer solutions increased, while surface tension decreased as both surfactant and eugenol concentration increased. Material deposited on the collector plate consisted primarily of nanofibers with a circular cross section with some surface roughness, although some bead defects were observed. The mean fiber diameters ranged from 57 to 126 nm with fibers having a broad diameter distribution (10-280 nm). The mean diameter of the nanofibers decreased with increasing surfactant concentration and decreasing eugenol concentration. Transmission electron microscopy indicated that microemulsion droplets were homogenously dispersed throughout the nanofibers. Results suggest that electrospun nanofibers may serve as carrier vehicles for microemulsions containing solubilized lipophilic functional compounds such as bioactives, antimicrobials, antioxidants, flavors, and pharmaceuticals.

  10. Electrospun tilapia collagen nanofibers accelerating wound healing via inducing keratinocytes proliferation and differentiation.

    Science.gov (United States)

    Zhou, Tian; Wang, Nanping; Xue, Yang; Ding, Tingting; Liu, Xin; Mo, Xiumei; Sun, Jiao

    2016-07-01

    The development of biomaterials with the ability to induce skin wound healing is a great challenge in biomedicine. In this study, tilapia skin collagen sponge and electrospun nanofibers were developed for wound dressing. The collagen sponge was composed of at least two α-peptides. It did not change the number of spleen-derived lymphocytes in BALB/c mice, the ratio of CD4(+)/CD8(+) lymphocytes, and the level of IgG or IgM in Sprague-Dawley rats. The tensile strength and contact angle of collagen nanofibers were 6.72±0.44MPa and 26.71±4.88°, respectively. They also had good thermal stability and swelling property. Furthermore, the nanofibers could significantly promote the proliferation of human keratinocytes (HaCaTs) and stimulate epidermal differentiation through the up-regulated gene expression of involucrin, filaggrin, and type I transglutaminase in HaCaTs. The collagen nanofibers could also facilitate rat skin regeneration. In the present study, electrospun biomimetic tilapia skin collagen nanofibers were succesfully prepared, were proved to have good bioactivity and could accelerate rat wound healing rapidly and effectively. These biological effects might be attributed to the biomimic extracellular matrix structure and the multiple amino acids of the collagen nanofibers. Therefore, the cost-efficient tilapia collagen nanofibers could be used as novel wound dressing, meanwhile effectively avoiding the risk of transmitting animal disease in the future clinical apllication.

  11. 聚苯胺纳米纤维修饰石墨箔电极的制备及电化学性能%Preparation and Electrochemical Properties of Polyaniline Nanofiber Modified Graphite Foil

    Institute of Scientific and Technical Information of China (English)

    桑晓光; 曾繁武; 刘晓霞

    2012-01-01

    以石墨箔(GF)为工作电极,采用循环伏安法(CV),通过电化学聚合,制备了聚苯胺(PANI)纳米纤维修饰GF电极(Nano-PANI/GF).利用红外光谱(FTIR)研究了Nano-PANI/GF修饰电极上聚合物的组成,利用扫描电镜(SEM)观测了Nano-PANI/GF修饰电极的表面形貌.利用循环伏安法研究了Nano-PANI/GF修饰电极在0.1 mol/L磷酸盐缓冲溶液(pH=6.9)中的电化学活性,发现Nano-PANI/GF修饰电极在中性溶液中有良好的电化学活性.Nano-PANI/GF修饰电极对抗坏血酸(AA)电化学氧化的催化作用结果表明,在0.2 V(vs.SCE)电位下,在浓度范围1.7 ~2.0×103 μmol/L内,抗坏血酸的氧化电流与浓度呈良好线性关系,线性方程式为y=0.00013x+0.0031.修饰电极对抗坏血酸的最低检测限为1.7 μmol/L( S/N=3).%Polyaniline nanofiber( Nano-PANI) modified graphite foil(GF) (Nano-PANI/GF) was prepared by electrochemical polymerization of aniline on GF electrode. The polymer on the modified electrode Nano-PANI/ GF was characterized by FTIR. The morphologies of the modified electrode were investigated by SEM. The Nano-PANI/GF electrode made through cyclic voltammetric scans in a solution of 0. 1 mol/L aniline and 1.0 mol/L HC1 showed good electroactivites in 0. 1 mol/L phosphate buffer solution(pH = 6.9). The electrocata-lytic properties of the modified electrode toward ascorbic acid oxidation were studied through cyclic voltamme-try and potentiometry. The current for ascorbic acid oxidation on the modified electrode at 0. 2 V showed linear response to the concentration of ascorbic acid in the range of 1. 7-2.0×103μmol/L. The detection limit of ascorbic acid on the modified electrode is 1. 7μmol/L( S/N = 3).

  12. 同轴静电纺丝技术制备 PVA@ Ti O2纳米纤维及光催化性能研究%Preparation of PVA@ TiO2 Nanofiber by Coaxial Electrospinning Technique and Study of Its Photocatalytic Performance

    Institute of Scientific and Technical Information of China (English)

    刘波; 王路峰; 吴亚舟; 王晟; 王騊

    2014-01-01

    The PVA@ TiO2 nanofiber photocatalytic materials are successfully prepared by coaxial elec-trospinning technique with TiO2 aqueous solution as the shell layer ,and polyvinyl alcohol (PVA) solution as the core layer .The as-prepared PVA@ TiO2 nanofibers are characterized by thermogravimetry-differen-tial thermal analysis (TG-DTA) ,X-ray diffraction and scanning electron microscope .The results show the capacity of TiO2 nanofibers is as high as 91% ,more than twice of the similar methods .Meanwhile ,TiO2 nanofibers could well on load on PVA firmly .Furthermore ,under UV light irradiation ,the photodecom-position of Rhodamine B was investigated .The results show 20 mL 1 × 10-5 mol/L Rhodamine B solution is completely degraded within 10 min .%采用同轴静电纺丝技术,以二氧化钛(T iO2)水溶液为壳层、聚乙烯醇(PV A )水溶液为芯层进行同轴静电纺丝,成功制备出了PVA@ TiO2纳米纤维光催化材料。通过热重-差热分析(TG-DTA)、X射线衍射、扫描电镜对样品进行了表征。结果显示:T iO2纳米粒子的负载量高达91%,是同类方法的2倍之多,同时具有良好的负载牢固的性能;研究了其在紫外光照射下光催化降解罗丹明B的能力,实验表明,20 mL的1×10-5 mol/L罗丹明B溶液在10 min内完全降解。

  13. The effect of calcination temperatures on the morphology and structure of ZnO nanofibers prepared by electrospinning%煅烧温度对电纺ZnO 纳米纤维形貌及结构的影响∗

    Institute of Scientific and Technical Information of China (English)

    徐明涛; 常岩岩; 彭博; 路秀真

    2014-01-01

    The morphology and structure of ZnO fibers calcined at different temperatures were studied in this pa-per.The precursor of ZnO nanofibers was prepared by electrospinning technology using PVA and zinc acetate. The ZnO nanofibers were obtained after calcination at 400,500,600,800 ℃.Thermal gravimetric analysis (TGA),energy dispersive spectrometer (EDS),scanning electron microscope (SEM),X-ray diffraction (XRD),transmission electron microscope (TEM)and Raman were introduced to analyze the morphology and structure of the ZnO nanofibers.The diameters were reduced firstly and then increased with the rising of the calcination temperature from 400 to 800 ℃.The grain sizes of ZnO prepared at 400,500,600,800℃ were 24.25,33.52,35.37 nm,respectively,which was increased with the rising of the calcination temperature.The re-sults indicated the optimum calcinations temperature of the ZnO nanofibers was 600 ℃.%对不同温度煅烧下得到的电纺 ZnO 纳米纤维的形貌及结构进行了分析.以醋酸锌和聚乙烯醇(PVA)制备前驱体,采用电纺丝技术制备复合纤维,然后以400,500,600和800℃高温煅烧2 h 得到氧化锌纳米纤维.采用热重分析(TGA)、元素分析(EDS)、扫描电子显微镜(SEM)、X 射线衍射(XRD)、拉曼光谱分析(Raman)、透射电镜(TEM)等方法对得到的纤维的形貌、结构进行测试分析.未处理以及以400,600和800℃煅烧后纤维的直径分别为207,135,158和200 nm,呈先减小后增大的趋势.400,500和600℃煅烧后得到的 ZnO 晶粒尺寸分别为24.25,33.52和35.37 nm,随着温度的升高,晶粒尺寸逐渐增大.对比不同温度煅烧后得到的氧化锌纳米纤维,确定最佳煅烧温度为600℃.

  14. Magnetic composite nanofibers fabricated by electrospinning of Fe{sub 3}O{sub 4}/gelatin aqueous solutions

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Shuhong, E-mail: openair@163.com [Key Laboratory of Functional Inorganic Material Chemistry (School of Chemical Engineering and Material, Heilongjiang University), Ministry of Education, Harbin 150080 (China); Sun, Zhiyao [Key Laboratory of Functional Inorganic Material Chemistry (School of Chemical Engineering and Material, Heilongjiang University), Ministry of Education, Harbin 150080 (China); Yan, Eryun [College of Materials Science and Engineering, Qiqihar University, Qiqihar 161006 (China); Yuan, Jihong; Gao, Yang; Bai, Yuhao; Chen, Yu [Key Laboratory of Functional Inorganic Material Chemistry (School of Chemical Engineering and Material, Heilongjiang University), Ministry of Education, Harbin 150080 (China); Wang, Cheng, E-mail: wangc_93@163.com [Key Laboratory of Functional Inorganic Material Chemistry (School of Chemical Engineering and Material, Heilongjiang University), Ministry of Education, Harbin 150080 (China); Zheng, Yongjie; Jing, Tao [College of Materials Science and Engineering, Qiqihar University, Qiqihar 161006 (China)

    2014-12-15

    Graphical abstract: Superparamagnetic Fe{sub 3}O{sub 4}/GE composite nanofibers with saturation magnetization of 12.87 emμ g{sup −1} were prepared from gelatin aqueous solution at an elevated temperature by electrospinning. - Highlights: • Electrospinning GE aqueous solution at higher temperature. • Presenting a simple and effective technique, combining wet blending with high temperature electrospinning to prepare magnetic composite nanofibers. • Developing composite nanofibers with higher superparamagnetic properties is expected to be useful in application for the biomedical field. - Abstract: We have fabricated magnetic composite nanofibers containing superparamagnetic Fe{sub 3}O{sub 4} nanoparticles by the electrospinning method. Highly dispersed Fe{sub 3}O{sub 4} magnetic nanoparticles were synthesized by one-step co-precipitation of Fe{sup 2+}/Fe{sup 3+} under an alkaline condition with 4 wt% poly(vinyl alcohol) (PVA) aqueous solution as the stabilizer. Gelatin (GE) was used as a polymeric matrix for fabricating the nanocomposites. The prepared Fe{sub 3}O{sub 4}/GE composite nanofibers were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD), respectively. These composite nanofibers show uniform and continuous morphology with the Fe{sub 3}O{sub 4} nanoparticles embedded in the nanofibers. By studying the magnetic properties of the Fe{sub 3}O{sub 4}/GE composite nanofibers, we confirm that the composite nanofibers possess superparamagnetic properties with a high saturated magnetization (M{sub s} = 12.87 emμ g{sup −1}) at room temperature. The features of this approach for getting one-dimensional magnetic nanostructure are its simplicity, effectiveness and safety. The Fe{sub 3}O{sub 4}/GE nanofibers with superparamagnetic properties would be potentially applied in biomedical field.

  15. Mechanical properties of organic nanofibers

    DEFF Research Database (Denmark)

    Kjelstrup-Hansen, Jakob; Hansen, Ole; Rubahn, H.R.

    2006-01-01

    Intrinsic elastic and inelastic mechanical Properties of individual, self-assembled, quasi-single-crystalline para-hexaphenylene nanofibers supported on substrates with different hydrophobicities are investigated as well as the interplay between the fibers and the underlying substrates. We find f...... on a silicon substrate with a low-adhesion coating, whereas such motion on a noncoated substrate is limited to very short (sub-micrometer) nanofiber pieces due to strong adhesive forces....

  16. Preparation and Characterization of Atactic Poly(vinyl alcohol)/Platinum Nanocomposites by Electrospinning

    Science.gov (United States)

    Seok Lyoo, Won; Jae Lee, Young; Wook Cha, Jin; Jae Kim, Min; Woo Joo, Sang; Soon Gal, Yeong; Hwan Oh, Tae; Soo Han, Sung

    2010-06-01

    Poly(vinyl alcohol) (PVA)/platinum composite nanofibers were successfully prepared by the electrospinning method. Water-based colloidal platinum in a PVA solution was directly mixed without any chemical or structural modifications into PVA polymer fibers to form organic-inorganic composite nanofibers. The PVA/platinum composite nanofibers were characterized by field emission scanning electron microscopy (SEM).

  17. Touch- and Brush-Spinning of Nanofibers.

    Science.gov (United States)

    Tokarev, Alexander; Asheghali, Darya; Griffiths, Ian M; Trotsenko, Oleksandr; Gruzd, Alexey; Lin, Xin; Stone, Howard A; Minko, Sergiy

    2015-11-01

    Robust, simple, and scalable touch- and brush-spinning methods for the drawing of nanofibers, core-shell nanofibers, and their aligned 2D and 3D meshes using polymer solutions and melts are discussed.

  18. Characterization and Biocompatibility of Biopolyester Nanofibers

    OpenAIRE

    Tang Hui Ying; Tetsuji Yamaoka; Tadahisa Iwata; Daisuke Ishii

    2009-01-01

    Biodegradable nanofibers are expected to be promising scaffold materials for biomedical engineering, however, biomedical applications require control of the degradation behavior and tissue response of nanofiber scaffolds in vivo. For this purpose, electrospun nanofibers of poly(hydroxyalkanoate)s (PHAs) and poly(lactide)s (PLAs) were subjected to degradation tests in vitro and in vivo. In this review, characterization and biocompatibility of nanofibers derived from PHAs and PLAs are described...

  19. Poly(vinyl alcohol) nanofibers by electrospinning as a protein delivery system and the retardation of enzyme release by additional polymer coatings.

    Science.gov (United States)

    Zeng, Jun; Aigner, Achim; Czubayko, Frank; Kissel, Thomas; Wendorff, Joachim H; Greiner, Andreas

    2005-01-01

    Protein-loaded (bovine serum albumin (BSA) or luciferase) poly(vinyl alcohol) (PVA) nanofibers were obtained by electrospinning. Poly(p-xylylene) (PPX, also coined as parylene) coated PVA/BSA nanofibers were prepared by chemical vapor deposition (CVD). The release of BSA from PVA nanofibers under physiological conditions was monitored by absorption spectroscopy. Burst release of BSA was noted with uncoated PVA nanofibers. In contrast, PPX-coated nanofibers exhibited a significantly retarded release of BSA depending on the coating thickness of PPX (ranging from 40 to 300 nm). Luciferase was used here as model enzyme, which after electrospinning retained its enzyme activity. This preservation of enzyme activity and the continuous release of the intact enzyme from the immersed fibers meets a fundamental prerequisite for the application of enzymes or other sensitive agents released from electrospun nanofibers under physiological conditions.

  20. Enhanced photoluminescence of Si nanocrystals-doped cellulose nanofibers by plasmonic light scattering

    Energy Technology Data Exchange (ETDEWEB)

    Sugimoto, Hiroshi [Department of Electrical and Computer Engineering and Photonics Center, Boston University, 8 Saint Mary Street, Boston, Massachusetts 02215 (United States); Department of Electrical and Electronic Engineering, Graduate School of Engineering, Kobe University, Rokkodai, Nada, Kobe 657-8501 (Japan); Zhang, Ran [Division of Materials Science and Engineering, Boston University, 15 Saint Mary' s Street, Brookline, Massachusetts 02446 (United States); Reinhard, Björn M. [Department of Chemistry and Photonics Center, Boston University, Boston, Massachusetts 02215 (United States); Fujii, Minoru [Department of Electrical and Electronic Engineering, Graduate School of Engineering, Kobe University, Rokkodai, Nada, Kobe 657-8501 (Japan); Perotto, Giovanni; Marelli, Benedetto; Omenetto, Fiorenzo G. [Department of Biomedical Engineering and Department of Physics, Tufts University, 4 Colby Street, Medford, Massachusetts 02155 (United States); Dal Negro, Luca, E-mail: dalnegro@bu.edu [Department of Electrical and Computer Engineering and Photonics Center, Boston University, 8 Saint Mary Street, Boston, Massachusetts 02215 (United States); Division of Materials Science and Engineering, Boston University, 15 Saint Mary' s Street, Brookline, Massachusetts 02446 (United States)

    2015-07-27

    We report the development of bio-compatible cellulose nanofibers doped with light emitting silicon nanocrystals and Au nanoparticles via facile electrospinning. By performing photoluminescence (PL) spectroscopy as a function of excitation wavelength, we demonstrate plasmon-enhanced PL by a factor of 2.2 with negligible non-radiative quenching due to plasmon-enhanced scattering of excitation light from Au nanoparticles to silicon nanocrystals inside the nanofibers. These findings provide an alternative approach for the development of plasmon-enhanced active systems integrated within the compact nanofiber geometry. Furthermore, bio-compatible light-emitting nanofibers prepared by a cost-effective solution-based processing are very promising platforms for biophotonic applications such as fluorescence sensing and imaging.

  1. Adsorption Profile of Basic Dye onto Novel Fabricated Carboxylated Functionalized Co-Polymer Nanofibers

    Directory of Open Access Journals (Sweden)

    Marwa F. Elkady

    2016-04-01

    Full Text Available Acrylonitrile-Styrene co-polymer was prepared by solution polymerization and fabricated into nanofibers using the electrospinning technique. The nanofiber polarization was enhanced through its surface functionalization with carboxylic acid groups by simple chemical modification. The carboxylic groups’ presence was dedicated using the FT-IR technique. SEM showed that the nanofiber attains a uniform and porous structure. The equilibrium and kinetic behaviors of basic violet 14 dye sorption onto the nanofibers were examined. Both Langmuir and Temkin models are capable of expressing the dye sorption process at equilibrium. The intraparticle diffusion and Boyd kinetic models specified that the intraparticle diffusion step was the main decolorization rate controlling the process.

  2. Physicochemical investigations of carbon nanofiber supported Cu/ZrO{sub 2} catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Din, Israf Ud, E-mail: drisraf@yahoo.com, E-mail: maizats@petronas.com.my; Shaharun, Maizatul S., E-mail: drisraf@yahoo.com, E-mail: maizats@petronas.com.my [Department of Fundamental and Applied Sciences, Universiti Teknologi PETRONAS (Malaysia); Subbarao, Duvvuri, E-mail: duvvuri-subbarao@petronas.com.my [Department of Chemical Engineering, Universiti Teknologi PETRONAS (Malaysia); Naeem, A., E-mail: naeeem64@yahoo.com [National Centre of Excellence in Physical Chemistry, University of Peshawar (Pakistan)

    2014-10-24

    Zirconia-promoted copper/carbon nanofiber catalysts (Cu‐ZrO{sub 2}/CNF) were prepared by the sequential deposition precipitation method. The Herringbone type of carbon nanofiber GNF-100 (Graphite nanofiber) was used as a catalyst support. Carbon nanofiber was oxidized to (CNF-O) with 5% and 65 % concentration of nitric acid (HNO{sub 3}). The CNF activated with 5% HNO{sub 3} produced higher surface area which is 155 m{sup 2}/g. The catalyst was characterized by X-ray Diffraction (XRD), Fourier Transform Infra-Red (FTIR) and N{sub 2} adsorption-desorption. The results showed that increase of HNO{sub 3} concentration reduced the surface area and porosity of the catalyst.

  3. Electrospun MgO/Nylon 6 Hybrid Nanofib ers for Protective Clothing

    Institute of Scientific and Technical Information of China (English)

    Nattanmai Raman Dhineshbabu; Gopalu Karunakaran; Rangaraj Suriyaprabha; Palanisamy Manivasakan; Venkatachalam Rajendran

    2014-01-01

    Magnesia (MgO) nanoparticles were produced from magnesite ore (MgCO3) using ball mill. The crystalline size, morphology and specific SSA were characterized by X-ray diffraction analysis, transmission electron microscopy and Brunauer-Emmett-Teller method, respectively. MgO nanoparticle-incorporated nylon 6 solutions were electrospun to produce nanofiber mats. Surface morphology and internal structure of the pre-pared hybrid nanofiber mats were examined by scanning electron microscopy and high-resolution transmission electron microscopy, respectively. The fire retardancy and antibacterial activity (Staphylococcus aureus and Escherichia coli) of coated fabrics made from MgO/nylon 6 hybrid nanofiber are better than those from nylon 6 nanofiber.

  4. Novel hollow α-Fe2O3 nanofibers via electrospinning for dye adsorption

    Science.gov (United States)

    Gao, Qiang; Luo, Jun; Wang, Xingyue; Gao, Chunxia; Ge, Mingqiao

    2015-04-01

    Nanomaterials such as iron oxides and ferrites have been intensively investigated for water treatment and environmental remediation applications. In this work, hollow α-Fe2O3 nanofibers made of rice-like nanorods were successfully synthesized via a simple hydrothermal reaction on polyvinyl alcohol (PVA) nanofiber template followed by calcination. The crystallographic structure and the morphology of the as-prepared α-Fe2O3 nanofibers were characterized by X-ray diffraction, energy dispersive X-ray spectrometer, and scanning electron microscope. Batch adsorption experiments were conducted, and ultraviolet-visible spectra were recorded before and after the adsorption to investigate the dye adsorption performance. The results showed that hollow α-Fe2O3 fiber assembles exhibited good magnetic responsive performance, as well as efficient adsorption for methyl orange in water. This work provided a versatile strategy for further design and development of functional nanofiber-nanoparticle composites towards various applications.

  5. 静电纺PVA/PEO共混纳米纤维膜的制备与性能表征%Preparation and characterization of PVA/PEO blended nanofiber films prepared by electrospinning

    Institute of Scientific and Technical Information of China (English)

    王春红; 刘胜凯; 贺文婷; 王莹

    2015-01-01

    The poly vinyl alcohol (PVA)-poly ethylene oxide (PEO) blend nanofiber films was produced with electrospin-ning technology. The mechanical properties of blend films were tested, fiber microstructure was investigated by SEM, and thermal properties of films were investigated with TGA and DSC. The effects of mass ratio of PVA to PEO on the properties of blend films were analyzed. The results indicate that too much or too little PEO have no obvious improvement on the ability of forming wires of blend films, and when the mass ratio of PVA to PEO is 5∶5, the blend film has good ability of forming wires, the fiber is fine and uniform. Compared with pure films, the mechanical properties of blend films are improved in different degrees, when the mass ratio of PVA to PEO is 7∶3, the elongation and strength of blend films increase by 1 545.71%!and 66%, respectively. The thermal stability of PVA/PEO blend films are better than those of pure films, but the amount of PEO has little effect on the thermal properties of blend films.%采用静电纺丝技术制备聚乙烯醇(PVA)/聚氧化乙烯(PEO)共混纳米纤维膜,测试共混纤维膜的拉伸力学性能,采用SEM观察其微观形貌和结构,利用TGA和DSC分析共混纤维膜的热学性能,考察PEO与PVA共混比例对纤维膜性能的影响.结果表明:PEO加入过多或过少对共混纤维膜结构均无明显改善,当PVA∶PEO质量比为5∶5时,所得纤维膜成丝性和成膜性最佳,膜中纤维线密度最小且粗细均匀;与纯纺纤维膜相比,不同共混比例PVA/PEO纤维膜的力学性能均有不同程度提升,当PVA与PEO质量比为7∶3时其断裂强度和断裂伸长率较纯PVA分别提高了66%和1545.71%;PVA/PEO共混纤维膜的热稳定性优于纯PVA纤维膜,但PEO加入量的变化对共混纤维膜热学性能的影响较小.

  6. Facile Fabrication of Multifunctional Aramid Nanofiber Films by Spin Coating

    Science.gov (United States)

    Lyu, Jing; Liu, Lehao; Zhao, Xing; Shang, Yudong; Zhao, Tingkai; Li, Tiehu

    2016-11-01

    Polymer matrices with excellent mechanical properties, thermal stability and other features are highly demanded for the effective utilization within nanocomposites. Here, we fabricate free-standing aramid nanofiber films via spin coating of an aramid nanofiber/dimethyl sulfoxide solution. Compared with traditional film fabrication methods, this process is time-saving and also able to easily tune the thickness of the films. The resultant films show greatly improved stretchability than that of Kevlar threads and relatively high mechanical strength. Typically, these films with a thickness of 5.5 µm show an ultimate strength of 182 MPa with an ultimate tensile strain of 10.5%. We also apply a finite element modeling to simulate the strain and strength distributions of the films under uniaxial tension, and the results of the simulation are in accordance with the experimental data. Furthermore, the aramid nanofiber films exhibit outstanding thermostability (decomposition at 550 °C under N2 atmosphere and 500 °C in air) and chemical inertness, which would endure acid and alkali. The simple method demonstrated here provides an important way to prepare high-performance aramid nanofiber films for designing new composite systems.

  7. Electrospun propolis/polyurethane composite nanofibers for biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jeong In [Department of Bio-nano System Engineering, Chonbuk National University, Jeonju 561–756 (Korea, Republic of); Pant, Hem Raj, E-mail: hempant@jbnu.ac.kr [Department of Bio-nano System Engineering, Chonbuk National University, Jeonju 561–756 (Korea, Republic of); Department of Engineering Science and Humanities, Pulchowk Campus, Tribhuvan University, Kathmandu (Nepal); Research Institute for Next Generation, Kalanki, Kathmandu (Nepal); Sim, Hyun-Jaung [Department of Bioactive Material Science, Research Center of Bioactive Material, Chonbuk National University, Jeonju, Chonbuk (Korea, Republic of); Lee, Kang Min [Department of Molecular Biology, College of Natural Science, Chonbuk National University, Jeonju, 561–756 (Korea, Republic of); Kim, Cheol Sang, E-mail: chskim@jbnu.ac.kr [Department of Bio-nano System Engineering, Chonbuk National University, Jeonju 561–756 (Korea, Republic of)

    2014-11-01

    Tissue engineering requires functional polymeric membrane for adequate space for cell migration and attachment within the nanostructure. Therefore, biocompatible propolis loaded polyurethane (propolis/PU) nanofibers were successfully prepared using electrospinning of propolis/PU blend solution. Here, composite nanofibers were subjected to detailed analysis using electron microscopy, FT-IR spectroscopy, thermal gravimetric analysis (TGA), and mechanical properties and water contact angle measurement. FE-SEM images revealed that the composite nanofibers became point-bonded with increasing amounts of propolis in the blend due to its adhesive properties. Incorporation of small amount of propolis through PU matrix could improve the hydrophilicity and mechanical strength of the fibrous membrane. In order to assay the cytocompatibility and cell behavior on the composite scaffolds, fibroblast cells were seeded on the matrix. Results suggest that the incorporation of propolis into PU fibers could increase its cell compatibility. Moreover, composite nanofibers have effective antibacterial activity. Therefore, as-synthesized nanocomposite fibrous mat has great potentiality in wound dressing and skin tissue engineering. - Highlights: • Sufficient amount of propolis is simply loaded through PU fibers. • Propolis increases the hydrophilicity and mechanical properties of PU fibers. • Composite mat shows excellent antibacterial activity. • Small amount of propolis can enhance the cell compatibility of PU fibers.

  8. Photocatalytic performance of electrospun CNT/TiO2 nanofibers in a simulated air purifier under visible light irradiation.

    Science.gov (United States)

    Wongaree, Mathana; Chiarakorn, Siriluk; Chuangchote, Surawut; Sagawa, Takashi

    2016-11-01

    The photocatalytic treatment of gaseous benzene under visible light irradiation was developed using electrospun carbon nanotube/titanium dioxide (CNT/TiO2) nanofibers as visible light active photocatalysts. The CNT/TiO2 nanofibers were fabricated by electrospinning CNT/poly(vinyl pyrrolidone) (PVP) solution followed by the removal of PVP by calcination at 450 °C. The molar ratio of CNT/TiO2 was fixed at 0.05:1 by weight, and the quantity of CNT/TiO2 loaded in PVP solution varied between 30 and 60 % wt. CNT/TiO2 nanofibers have high specific surface area (116 m(2)/g), significantly higher than that of TiO2 nanofibers (44 m(2)/g). The photocatalytic performance of the CNT/TiO2 nanofibers was investigated by decolorization of 1 × 10(-5) M methylene blue (MB) dye (in water solution) and degradation of 100 ppm gaseous benzene under visible light irradiation. The 50-CNT/TiO2 nanofibers (calcined CNT/TiO2 nanofibers fabricated from a spinning solution of 50 % wt CNT/TiO2 based on PVP) had higher MB degradation efficiency (58 %) than did other CNT/TiO2 nanofibers and pristine TiO2 nanofibers (15 %) under visible light irradiation. The photocatalytic degradation of gaseous benzene under visible light irradiation on filters made of 50-CNT/TiO2 nanofibers was carried out in a simulated air purifier system. Similar to MB results, the degradation efficiency of gaseous benzene by 50-CNT/TiO2 nanofibers (52 %) was higher than by other CNT/TiO2 nanofibers and pristine TiO2 nanofibers (18 %). The synergistic effects of the larger surface area and lower band gap energy of CNT/TiO2 nanofibers were presented as strong adsorption ability and greater visible light adsorption. The CNT/TiO2 nanofiber prepared in this study has potential for use in air purifiers to improve air treatment efficiency with less energy.

  9. Fabrication and upconversion luminescence properties of YF3:Er3+ hollow nanofibers via monoaxial electrospinning combined with fluorination method.

    Science.gov (United States)

    Li, Dan; Dong, Xiangting; Yu, Wensheng; Wang, Jinxian; Liu, Guixia

    2014-06-01

    YF3:Er3+ hollow nanofibers were successfully fabricated via fluorination of the relevant Y2O3:Er3+ hollow nanofibers which were obtained by calcining the electrospun PVP/[Y(NO3)3 + Er(NO3)3] composite nanofibers. The morphology and properties of the products were investigated in detail by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), and fluorescence spectrometer. YF3:Er3+ hollow nanofibers were pure orthorhombic phase with space group Pnma and were hollow-centered structure with the mean diameter of 172 +/- 23 nm, and YF3:Er3+ hollow nanofibers were composed of nanoparticles with the diameter ranging from 30 nm to 50 nm. Upconversion emission spectrum analysis manifested that YF3:Er3+ hollow nanofibers emitted strong green and weak red upconversion emission centering at 524 nm, 543 nm and 653 nm, respectively. The green emissions and the red emission were respectively originated from 2H11/2/4S3/2 --> 4I15/2 and 4F9/2 --> 4I15/2 energy levels transitions of the Er3+ ions. Moreover, the emitting colors of YF3:Er3+ hollow nanofibers were located in the green region in CIE chromaticity coordinates diagram. The luminescent intensity of YF3:Er3+ hollow nanofibers was increased remarkably with the increasing doping concentration of Er3+ ions. The possible formation mechanism of YF3:Er3+ upconversion luminescence hollow nanofibers was also discussed. This preparation technique could be applied to prepare other rare earth fluoride upconversion luminescence hollow nanofibers.

  10. Ag掺杂SnO2纳米纤维的制备及其气敏特性研究%Preparation and Gas Sensing Properies of Ag-Doped SnO2 Nanofibers by Electrospinning*

    Institute of Scientific and Technical Information of China (English)

    宁玲玲; 贾建峰; 赵明岗; 王新昌; 李新建

    2011-01-01

    以聚乙烯醇(PVA)和SnCl2·2H2O为原料采用静电纺丝技术制备纯sno2及Ag掺杂sno2纳米纤维.经700℃退火烧结后制得了连续多孔的snO2纳米纤维.研究了Ag的掺杂对SnO2纳米纤维的C2H2气体敏感性能的影响,结果表明Ag的掺杂对SnO2纳米纤维的C2H2气体敏感性能具有明显的影响,在Ag掺杂量为8at%时SnO2纳米纤维对C2H2气体具有最佳的气敏特性,在C2H2气体的体积分数为5000ppm温度为200℃时下的灵敏度为166.27.%Pure and Ag doped SnO2 nanofibers have been successfully synthesized by electrospinning of the poly (vinyl alcohol)( PVA)/SnC12 ·2H20 composite precursor. After annlealing at 700 ℃, porous Sn02 nanofibers are obtained. The effects of Ag doping on C2H2 sensing properties were investigated. The results show that the C2H2 sensing properties of SnO2 nanofibers are effectively improved by Ag doping and the optimal doping concentration is 8 at %. The sensitivity is up to 166.27 for the sensors based on 8 at % Ag-doped SnO2 nanofibers when the sensor is exposed to 5000 ppm C2H2 at 200 ℃.

  11. PVA/NiO复合纳米纤维的制备及光催化性能%Preparation and Photocatalytic Properties of PVA/NiO Composite Nanofibers

    Institute of Scientific and Technical Information of China (English)

    李跃军; 曹铁平

    2012-01-01

    Polyacrylic nitrile (PVA)/nickel nitrate (Ni(NO3)2) composite nanofibers were firstly fabricated through electrospinning a precursor solution of PVA and Ni(Noj)2- After further urea assisted hydrothermal treatment,PVA/NiO composite nanofibers were obtained. The morphology and structure of the product were characterized by XRD,FT-IR,SEM and TEM.The results showed that NiO nanoparticles could be evenly grown on the surface of PVA nanofibers. By employing degradation of rodamine B as model reaction,it was found that as-fabricated PVA/NiO composite nanofibers possessed good photocatalytic activity.%采用静电纺丝法,以聚乙烯醇(PVA)和硝酸镍(Ni(NO3)2)为前驱物,制得PVA/Ni(NO3)2纤维;再以尿素(CO(NH)2)为碱源,通过水热合成法制备了PVA/NiO复合纳米纤维.利用X射线衍射(XRD)、红外光谱(FT-(R)、扫描电镜(SEM)和透射电子显微镜(TEM)等分析测试手段对样品的形貌和结构进行了表征,以罗丹明B为目标降解物,考察了PVA/NiO复合纳米纤维的光催化活性.结果表明:NiO纳米粒子均匀地负载于PVA纳米纤维上,形成了具有良好光催化活性的PVA/NiO复合纳米纤维光催化材料.

  12. Performance of electrodes synthesized with polyacrylonitrile-based carbon nanofibers for application in electrochemical sensors and biosensors

    Energy Technology Data Exchange (ETDEWEB)

    Adabi, Mahdi [Department of Medical Nanotechnology, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Saber, Reza [Department of Medical Nanotechnology, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran, Tehran (Iran, Islamic Republic of); Faridi-Majidi, Reza, E-mail: refaridi@sina.tums.ac.ir [Department of Medical Nanotechnology, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran, Tehran (Iran, Islamic Republic of); Faridbod, Farnoush [Science and Technology in Medicine (RCSTIM), Tehran University of Medical Sciences, Tehran, Iran. (Iran, Islamic Republic of)

    2015-03-01

    The purpose of this work was to investigate the performance of electrodes synthesized with Polyacrylonitrile-based carbon nanofibers (PAN-based CNFs). The homogenous PAN solutions with different concentrations were prepared and electrospun to acquire PAN nanofibers and then CNFs were fabricated by heat treatment. The effective parameters for the production of electrospun CNF electrode were investigated. Scanning electron microscopy (SEM) was used to characterize electrospun nanofibers. Cyclic voltammetry was applied to investigate the changes of behavior of electrospun CNF electrodes with different diameters. The structure of CNFs was also evaluated via X-ray diffraction (XRD) and Raman spectroscopy. The results exhibited that diameter of nanofibers reduced with decreasing polymer concentration and applied voltage and increasing tip-to-collector distance, while feeding rate did not have significant effect on nanofiber diameter. The investigations of electrochemical behavior also demonstrated that cyclic voltammetric response improved as diameter of CNFs electrode decreased. - Highlights: • Electrospun CNFs can be directly used as working electrode. • Cyclic voltammetric response improved as diameter of CNFs electrode decreased. • The diameter of nanofibers reduced with decreasing polymer concentration. • The diameter of nanofibers reduced with decreasing applied voltage. • The diameter of nanofibers reduced with increasing tip-to-collector distance.

  13. Osteogenic differentiation of stem cells from human exfoliated deciduous teeth on poly(ε-caprolactone) nanofibers containing strontium phosphate

    Energy Technology Data Exchange (ETDEWEB)

    Su, Wen-Ta, E-mail: f10549@ntut.edu.tw [Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, Taipei, Taiwan (China); Wu, Pai-Shuen [Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, Taipei, Taiwan (China); Huang, Te-Yang [Department of Orthopedic Surgery, Mackay Memorial Hospital, Taipei, Taiwan (China)

    2015-01-01

    Mimicking the architecture of the extracellular matrix is an effective strategy for tissue engineering. Composite nanofibers similar to natural bone structure can be prepared via an electrospinning technique and used in biomedical applications. Stem cells from human exfoliated deciduous teeth (SHEDs) can differentiate into multiple cell lineages, such as cells that are alternative sources of stem cells for tissue engineering. Strontium has important functions in bone remodeling; for example, this element can simulate bone formation and decrease bone resorption. Incorporating strontium phosphate into nanofibers provides a potential material for bone tissue engineering. This study investigated the potential of poly(ε-caprolactone) (PCL) nanofibers coated or blended with strontium phosphate for the osteogenic differentiation of SHEDs. Cellular morphology and MTT assay revealed that nanofibers effectively support cellular attachment, spreading, and proliferation. Strontium-loaded PCL nanofibers exhibited higher expressions of collagen type I, alkaline phosphatase, biomineralization, and bone-related genes than pure PCL nanofibers during the osteogenic differentiation of SHEDs. This study demonstrated that strontium can be an effective inducer of osteogenesis for SHEDs. Understanding the function of bioceramics (such as strontium) is useful in designing and developing strategies for bone tissue engineering. - Highlights: • SHEDs have been considered as alternative sources of adult stem cells in tissue engineering. • Strontium phosphate into nanofibers provides a potential material for bone tissue engineering. • Nanofibers coated or blended with strontium phosphate for the osteogenic differentiation of SHEDs.

  14. Electrospun DOXY-h loaded-poly(acrylic acid) nanofiber mats: in vitro drug release and antibacterial properties investigation.

    Science.gov (United States)

    Khampieng, Thitikan; Wnek, Gary E; Supaphol, Pitt

    2014-01-01

    Electrospun DOXY-h loaded-poly(acrylic acid) (PAA) nanofiber mats (PAA/DOXY-h nanofiber mats) were prepared by the electrospinning technique and post-spinning sorption method at various doses: PAA/DOXY-h125, PAA/DOXY-h250, PAA/DOXY-h500, and PAA/DOXY-h1000. The morphology, drug content, release characteristics, and antibacterial activities of the PAA/DOXY-h nanofiber mats were investigated with scanning electron microscopy, UV-vis spectrophotometry, and disc diffusion methodology. The PAA/DOXY-h nanofiber mats had a diameter range of 285-340 nm, and a smooth surface without beads. Adsorption isotherms of DOXY-h could be described well with the Freundlich model. The amounts of DOXY-h, after the post-spinning sorption process, in the PAA/DOXY-h nanofiber mats ranged between 27.57 and 101.71 mg/g. All of the PAA/DOXY-h nanofiber mats exhibited an initial burst release characteristic with cumulative releasing percentages between 37.14 and 45.97%, which followed the Fickian diffusion mechanism. Based on the antibacterial investigation, the tested gram-positive bacteria, Staphylococcus aureus and Streptococcus agalactiae, seemed to be more sensitive to PAA/DOXY-h nanofiber mats than the tested gram-negative bacteria, Pseudomonas aeruginosa. These PAA/DOXY-h nanofiber mats could be used as an antibacterial wound dressing.

  15. Preparation and modification of PET/PVA composite nanofiber membranes via electrospinning%静电纺丝PET/PVA复合纳米纤维膜的制备及性能

    Institute of Scientific and Technical Information of China (English)

    吕梦青; 曹鼎; 石艳; 付志峰

    2012-01-01

    使用聚乙烯醇(PVA)对聚对苯二甲酸乙二醇酯(PET)进行改性,静电纺丝法制备了PET/PVA纳米纤维复合膜,并采用戊二醛蒸气对其交联处理,通过扫描电子显微镜(SEM)观察了纤维形貌,通过热分析(DSC)、水接触角测试及拉伸测试,考察了制品的性能。结果表明,成功制备了力学性能良好、亲水性优异的纳米纤维复合膜。%PET/PVA composite nanofiber was fabricated by electrospinning,and crosslinked with glutaraldehyde vapor.The morphology of the nanofiber was characterized by SEM,and the properties of the product were measured by thermal analysis(DSC),water contact angle and tensile test.The results showed that the PET/PVA composite nanofiber membrane had good mechanical properties and excellent hydrophilicity.

  16. Biological adhesive based on carboxymethyl chitin derivatives and chitin nanofibers.

    Science.gov (United States)

    Azuma, Kazuo; Nishihara, Masahiro; Shimizu, Haruki; Itoh, Yoshiki; Takashima, Osamu; Osaki, Tomohiro; Itoh, Norihiko; Imagawa, Tomohiro; Murahata, Yusuke; Tsuka, Takeshi; Izawa, Hironori; Ifuku, Shinsuke; Minami, Saburo; Saimoto, Hiroyuki; Okamoto, Yoshiharu; Morimoto, Minoru

    2015-02-01

    Novel biological adhesives made from chitin derivatives were prepared and evaluated for their adhesive properties and biocompatibility. Chitin derivatives with acrylic groups, such as 2-hydroxy-3-methacryloyloxypropylated carboxymethyl chitin (HMA-CM-chitin), were synthesized and cured by the addition of an aqueous hydrogen peroxide solution as a radical initiator. The adhesive strength of HMA-CM-chitin increased when it was blended with chitin nanofibers (CNFs) or surface-deacetylated chitin nanofibers (S-DACNFs). HMA-CM-chitin/CNFs or HMA-CM-chitin/S-DACNFs have almost equal adhesive strength compared to that of a commercial cyanoacrylate adhesive. Moreover, quick adhesion and induction of inflammatory cells migration were observed in HMA-CM-chitin/CNF and HMA-CM-chitin/S-DACNF. These findings indicate that the composites prepared in this study are promising materials as new biological adhesives.

  17. Preparação e Caracterização de Nanofibras de Nanocompósitos de Poliamida 6,6 e Argila Montmorilonita Preparation and Characterization of Nanofibers of Polyamide 66 and Montmorillonite Clay Nanocomposites

    Directory of Open Access Journals (Sweden)

    Camila R. dos Santos

    2011-01-01

    the great objective of researchers and industry, since these fibers have many applications. They can be produced by an electrospinning process from a polymeric solution. In this work, nanocomposites´ fibers of polyamide 66 and montmorillonite clay were obtained by melt mixing, following by electrospinning of the solution. Nanocomposites with three different clay concentrations, 2, 3 and 4 wt.%, were obtained by melt mixing, and solutions of these nanocomposites in formic acid were prepared at different concentrations. The influence of the clay addition, nanocomposites´ solution concentration, variation of the applied electric field on the mixture and solutions properties and on the average diameter of the nanofibers was studied. Wide-angle X-ray (WAXD and transmission electron microscopy (TEM measurements showed that the process of electrospinning was efficient in the maintenance of the clay exfoliation in the fibers. Results of scanning electron microscopy (SEM and differential scanning calorimetry (DSC showed that the fibers had average diameters of the order of nanometers, were cylindrical and not porous, having low degree of crystallinity and residual solvent. The addition of clay increased slightly the viscosity of the polymeric solution, which increased the nanofibers average diameter. It was also observed that the increase in the fiber diameters was proportional to the increase of the polymer concentration in the solution. Regarding the applied electric field, it was observed a tendency to reduction in the average diameter of the fibers with the reduction of this parameter.

  18. Aligned Layers of Silver Nano-Fibers

    Directory of Open Access Journals (Sweden)

    Andrii B. Golovin

    2012-02-01

    Full Text Available We describe a new dichroic polarizers made by ordering silver nano-fibers to aligned layers. The aligned layers consist of nano-fibers and self-assembled molecular aggregates of lyotropic liquid crystals. Unidirectional alignment of the layers is achieved by means of mechanical shearing. Aligned layers of silver nano-fibers are partially transparent to a linearly polarized electromagnetic radiation. The unidirectional alignment and density of the silver nano-fibers determine degree of polarization of transmitted light. The aligned layers of silver nano-fibers might be used in optics, microwave applications, and organic electronics.

  19. Oriented nanofibers embedded in a polymer matrix

    Science.gov (United States)

    Barrera, Enrique V. (Inventor); Rodriguez-Macias, Fernando J. (Inventor); Lozano, Karen (Inventor); Chibante, Luis Paulo Felipe (Inventor); Stewart, David Harris (Inventor)

    2011-01-01

    A method of forming a composite of embedded nanofibers in a polymer matrix is disclosed. The method includes incorporating nanofibers in a plastic matrix forming agglomerates, and uniformly distributing the nanofibers by exposing the agglomerates to hydrodynamic stresses. The hydrodynamic said stresses force the agglomerates to break apart. In combination or additionally elongational flow is used to achieve small diameters and alignment. A nanofiber reinforced polymer composite system is disclosed. The system includes a plurality of nanofibers that are embedded in polymer matrices in micron size fibers. A method for producing nanotube continuous fibers is disclosed. Nanofibers are fibrils with diameters of 100 nm, multiwall nanotubes, single wall nanotubes and their various functionalized and derivatized forms. The method includes mixing a nanofiber in a polymer; and inducing an orientation of the nanofibers that enables the nanofibers to be used to enhance mechanical, thermal and electrical properties. Orientation is induced by high shear mixing and elongational flow, singly or in combination. The polymer may be removed from said nanofibers, leaving micron size fibers of aligned nanofibers.

  20. Antitumor Activity of Doxorubicin-Loaded Carbon Nanotubes Incorporated Poly(Lactic-Co-Glycolic Acid) Electrospun Composite Nanofibers

    Science.gov (United States)

    Yu, Yuan; Kong, Lijun; Li, Lan; Li, Naie; Yan, Peng

    2015-08-01

    The drug-loaded composite electrospun nanofiber has attracted more attention in biomedical field, especially in cancer therapy. In this study, a composite nanofiber was fabricated by electrospinning for cancer treatment. Firstly, the carbon nanotubes (CNTs) were selected as carriers to load the anticancer drug—doxorubicin (DOX) hydrochloride. Secondly, the DOX-loaded CNTs (DOX@CNTs) were incorporated into the poly(lactic-co-glycolic acid) (PLGA) nanofibers via electrospinning. Finally, a new drug-loaded nanofibrous scaffold (PLGA/DOX@CNTs) was formed. The properties of the prepared composite nanofibrous mats were characterized by various techniques. The release profiles of the different DOX-loaded nanofibers were measured, and the in vitro antitumor efficacy against HeLa cells was also evaluated. The results showed that DOX-loaded CNTs can be readily incorporated into the nanofibers with relatively uniform distribution within the nanofibers. More importantly, the drug from the composite nanofibers can be released in a sustained and prolonged manner, and thereby, a significant antitumor efficacy in vitro is obtained. Thus, the prepared composite nanofibrous mats are a promising alternative for cancer treatment.

  1. A comparative study for lipase immobilization onto alginate based composite electrospun nanofibers with effective and enhanced stability.

    Science.gov (United States)

    İspirli Doğaç, Yasemin; Deveci, İlyas; Mercimek, Bedrettin; Teke, Mustafa

    2017-03-01

    In this study, lipase was successfully immobilized on polyvinyl alcohol/alginate and polyethylene oxide/alginate nanofibers that were prepared by electrospinning. Results showed that nanofibers (especially polyvinyl alcohol/alginate) enhanced the stability properties of lipase. When the free lipase lost its all activity after 40-60min at high temperatures, both lipase immobilized nanofibers kept almost 65-70% activity at the same time. The lipase immobilized poly vinyl alcohol/alginate and polyethylene oxide/alginate nanofibers protected approximately all of their activities until pH 9. Lipase immobilized polyvinyl alcohol/alginate and polyethylene oxide/alginate nanofibers maintained 60% of their activities after 14 and 7 reuses, respectively. The morphology of nanofibers was characterized by Scanning Electron Microscope, Fourier Transform Infrared Spectroscopy and Thermal Gravimetric Analyzer. As a result, this nanofiber production method, electrospinning, is simple, versatile and economical for preparing appropriate carrier to immobilize the enzymes. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Biomimetic synthesis of interlaced mesh structures TiO{sub 2} nanofibers with enhanced photocatalytic activity

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Guanghui [Tianjin Key Laboratory of Applied Catalysis Science and Technology, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 China (China); Collaborative Innovation Center of Chemical Science and Engineering(Tianjin), Tianjin 300072 China (China); Zhang, Tianyong, E-mail: tyzhang@tju.edu.cn [Tianjin Key Laboratory of Applied Catalysis Science and Technology, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 China (China); Collaborative Innovation Center of Chemical Science and Engineering(Tianjin), Tianjin 300072 China (China); Li, Bin, E-mail: libin@tju.edu.cn [Tianjin Key Laboratory of Applied Catalysis Science and Technology, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 China (China); Collaborative Innovation Center of Chemical Science and Engineering(Tianjin), Tianjin 300072 China (China); Zhang, Xia; Chen, Xingwei [Tianjin Key Laboratory of Applied Catalysis Science and Technology, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 China (China)

    2016-05-25

    A facile and economical method assisted by PPs (the spongy white peels of pomelo peel) was applied for preparing interlaced mesh structures TiO{sub 2} nanofibers by a liquid impregnation method followed by a calcination process in this study. And the as-prepared materials were comprehensively investigated by X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectra, UV-vis diffuse reflectance spectroscopy, photoluminescence spectra and N{sub 2} adsorption-desorption. The resultant TiO{sub 2} materials exhibit unique morphology, in which the curly nanofibers with the diameter about 90 nm interweave each other for assembling hierarchical mesh structures and there are abundant grooves on the surface of the nanofibers. During the bio-inspired synthetic process, the PPs play important roles as template and induction for forming the hierarchical mesh structures of TiO{sub 2} nanofibers. Furthermore, some of the as-prepared TiO{sub 2} samples exhibit 99% degradation rate for methyl orange in 30 min under UV light irradiation, which can be ascribed to the larger surface area and the unique hierarchical mesh structures. In addition, the stability tests of 5 cycling runs of the photocatalysts indicate that the as-prepared TiO{sub 2} nanofibers can be applied as a practical photocatalyst for degrading organic dyes under UV light irradiation. Therefore, hopefully, the strategy for preparing the TiO{sub 2} nanofibers can be extended to design many more powerful photocatalysts for the environmental remediation in the near future. - Graphical abstract: The TiO{sub 2} nanofibers with interlaced mesh structures were prepared with PPs (the spongy white peels of pomelo peel) as the reactive substrate and directing template, and titanium tetrachloride (TiCl{sub 4}) as titanium resource. And the as-prepared TiO{sub 2} samples exhibit highly photocatalytic activity and good stability for degrading methyl orange under UV light irradiation. - Highlights: • A

  3. Influence of nano-fiber membranes on the silver ions released from hollow fibers containing silver particles

    Directory of Open Access Journals (Sweden)

    Li Huigai

    2016-01-01

    Full Text Available Polyether sulfone was dissolved into dimethylacetamide with the concentration of 20% to prepare a uniform solution for fabrication of nanofiber membranes by bubble electrospinning technique. Morphologies of the nanofiber film were carried out with a scanning electron microscope. The influence on the silver ions escaped from hollow fiber loaded with silver particles was exerted by using different release liquid. The water molecular clusters obtained from the nanofiber membranes filter can slow down the release of silver ions. However, the effect of slowing was weakened with the time increasing. In the end, the trend of change is gradually consistent with the trend of release of silver ions in the deionized water.

  4. Growth of TiO2 nanofibers on FTO substrates and their application in dye-sensitized solar cells

    Science.gov (United States)

    Suryana, R.; Rahmawati, L. R.; Triyana, K.

    2016-11-01

    Growth of TiO2 nanofibers on fluorine-doped tin oxide (FTO) substrates have been performed using electrospinning method. Homogenous TiO2 solution as nanofibers material was prepared with titanium tetraisopropoxide (TTIP), ethanol, acetic acid and polyvinyl pyrrolidone (PVP) which was stirred for 24 h. TiO2 solution was loaded into the syringe pump. Electrospun voltage was operated under 15 kV with optimum distance between syringe tip and collector was 15 cm. FTO substrates were attached on the collector surface. Electrospinning coating time was varied at 15 min, 30 min, 45 min, and 60 min. Then TiO2 nanofibers layer was annealed at temperature of 450° C for 3 h. X-ray diffraction spectrum of TiO2 nanofibers showed major anatase peaks at 25.3°, 48.0° and 37.8° correlating crystal orientation of (101), (200), and (004), respectively while only one rutile peak at 27.5°(110). TiO2 nanofibers diameter was measured using atomic force microscopy (AFM). TiO2 nanofibers have diameter in range of 100-1000 nm. The obtained-TiO2 nanofibers were applied in dye-sensitized solar cell (DSSC) with beta-carotene as dye, carbon as catalyst, and I-/I3- redox couple as electrolyte. DSSC performance was analyzed from I-V characterization. Growth of TiO2 nanofibers at electrospinning time for 45 min has highest efficiency that is 0.016%. It is considered that TiO2 nanofibers at electrospinning time for 45 min can produce optimum thickness so that it is speculated many dyes adsorb on the nanofiber surfaces and many electrons diffuse toward the electrodes.

  5. Electrospinning of Biocompatible Nanofibers

    Science.gov (United States)

    Coughlin, Andrew J.; Queen, Hailey A.; McCullen, Seth D.; Krause, Wendy E.

    2006-03-01

    Artificial scaffolds for growing cells can have a wide range of applications including wound coverings, supports in tissue cultures, drug delivery, and organ and tissue transplantation. Tissue engineering is a promising field which may resolve current problems with transplantation, such as rejection by the immune system and scarcity of donors. One approach to tissue engineering utilizes a biodegradable scaffold onto which cells are seeded and cultured, and ideally develop into functional tissue. The scaffold acts as an artificial extracellular matrix (ECM). Because a typical ECM contains collagen fibers with diameters of 50-500 nm, electrostatic spinning (electrospinning) was used to mimic the size and structure of these fibers. Electrospinning is a novel way of spinning a nonwoven web of fibers on the order of 100 nm, much like the web of collagen in an ECM. We are investigating the ability of several biocompatible polymers (e.g., chitosan and polyvinyl alcohol) to form defect-free nanofiber webs and are studying the influence of the zero shear rate viscosity, molecular weight, entanglement concentration, relaxation time, and solvent on the resulting fiber size and morphology.

  6. Control of physical properties of carbon nanofibers obtained from coaxial electrospinning of PMMA and PAN with adjustable inner/outer nozzle-ends.

    Science.gov (United States)

    Kaerkitcha, Navaporn; Chuangchote, Surawut; Sagawa, Takashi

    2016-12-01

    Hollow carbon nanofibers (HCNFs) were prepared by electrospinning method with several coaxial nozzles, in which the level of the inner nozzle-end is adjustable. Core/shell nanofibers were prepared from poly(methyl methacrylate) (PMMA) as a pyrolytic core and polyacrylonitrile (PAN) as a carbon shell with three types of normal (viz. inner and outer nozzle-ends are balanced in the same level), inward, and outward coaxial nozzles. The influence of the applied voltage on these three types of coaxial nozzles was studied. Specific surface area, pore size diameter, crystallinity, and degree of graphitization of the hollow and mesoporous structures of carbon nanofibers obtained after carbonization of the as spun PMMA/PAN nanofibers were characterized by BET analyses, X-ray diffraction, and Raman spectroscopy in addition to the conductivity measurements. It was found that specific surface area, crystallinity, and graphitization degree of the HCNFs affect the electrical conductivity of the carbon nanofibers.

  7. Hydroxyapatite Mineralization on the Calcium Chloride Blended Polyurethane Nanofiber via Biomimetic Method

    Science.gov (United States)

    Nirmala, R.; Nam, Ki Taek; Navamathavan, R.; Park, Soo-Jin; Kim, Hak Yong

    2011-12-01

    Polyurethane nanofibers containing calcium chloride (CaCl2) were prepared via an electrospinning technique for the biomedical applications. Polyurethane nanofibers with different concentration of CaCl2 were electrospun, and their bioactivity evaluation was conducted by incubating in biomimetic simulated body fluid (SBF) solution. The morphology, structure and thermal properties of the polyurethane/CaCl2 composite nanofibers were characterized by means of scanning electron microscopy (SEM), field-emission scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy and thermogravimetry. SEM images revealed that the CaCl2 salt incorporated homogeneously to form well-oriented nanofibers with smooth surface and uniform diameters along their lengths. The SBF incubation test confirmed the formation of apatite-like materials, exhibiting enhanced bioactive behavior of the polyurethane/CaCl2 composite nanofibers. This study demonstrated that the electrospun polyurethane containing CaCl2 composite nanofibers enhanced the in vitro bioactivity and supports the growth of apatite-like materials.

  8. Pore-Structure-Optimized CNT-Carbon Nanofibers from Starch for Rechargeable Lithium Batteries

    Directory of Open Access Journals (Sweden)

    Yongjin Jeong

    2016-12-01

    Full Text Available Porous carbon materials are used for many electrochemical applications due to their outstanding properties. However, research on controlling the pore structure and analyzing the carbon structures is still necessary to achieve enhanced electrochemical properties. In this study, mesoporous carbon nanotube (CNT-carbon nanofiber electrodes were developed by heat-treatment of electrospun starch with carbon nanotubes, and then applied as a binder-free electrochemical electrode for a lithium-ion battery. Using the unique lamellar structure of starch, mesoporous CNT-carbon nanofibers were prepared and their pore structures were controlled by manipulating the heat-treatment conditions. The activation process greatly increased the volume of micropores and mesopores of carbon nanofibers by etching carbons with CO2 gas, and the Brunauer-Emmett-Teller (BET specific area increased to about 982.4 m2·g−1. The activated CNT-carbon nanofibers exhibited a high specific capacity (743 mAh·g−1 and good cycle performance (510 mAh·g−1 after 30 cycles due to their larger specific surface area. This condition presents many adsorption sites of lithium ions, and higher electrical conductivity, compared with carbon nanofibers without CNT. The research suggests that by controlling the heat-treatment conditions and activation process, the pore structure of the carbon nanofibers made from starch could be tuned to provide the conditions needed for various applications.

  9. Polyethylene oxide (PEO)-hyaluronic acid (HA) nanofibers with kanamycin inhibits the growth of Listeria monocytogenes.

    Science.gov (United States)

    Ahire, J J; Robertson, D D; van Reenen, A J; Dicks, L M T

    2017-02-01

    Listeria monocytogenes is well known to cause prosthetic joint infections in immunocompromised patients. In this study, polyethylene oxide (PEO) nanofibers, containing kanamycin and hyaluronic acid (HA), were prepared by electrospinning at a constant electric field of 10kV. PEO nanofibers spun with 0.2% (w/v) HA and 1% (w/v) kanamycin had a smooth, bead-free structure at 30-35% relative humidity. The average diameter of the nanofibers was 83±20nm. Attenuated total reflectance (ATR)-Fourier transform infrared (FTIR) spectroscopy indicated that kanamycin was successfully incorporated into PEO/HA matrix. The presence of kanamycin affects the thermal properties of PEO/HA nanofibers, as shown by differential scanning calorimetry (DSC) and thermogravimetric analyses (TGA). The kanamycin-PEO-HA nanofibers (1mg; 47±3μg kanamycin) inhibited the growth of L. monocytogenes EDGe by 62%, as compared with PEO-HA nanofibers, suggesting that it may be used to coat prosthetic implants to prevent secondary infections.

  10. Cobalt/copper-decorated carbon nanofibers as novel non-precious electrocatalyst for methanol electrooxidation

    Science.gov (United States)

    Barakat, Nasser A. M.; El-Newehy, Mohamed; Al-Deyab, Salem S.; Kim, Hak Yong

    2014-01-01

    In this study, Co/Cu-decorated carbon nanofibers are introduced as novel electrocatalyst for methanol oxidation. The introduced nanofibers have been prepared based on graphitization of poly(vinyl alcohol) which has high carbon content compared to many polymer precursors for carbon nanofiber synthesis. Typically, calcination in argon atmosphere of electrospun nanofibers composed of cobalt acetate tetrahydrate, copper acetate monohydrate, and poly(vinyl alcohol) leads to form carbon nanofibers decorated by CoCu nanoparticles. The graphitization of the poly(vinyl alcohol) has been enhanced due to presence of cobalt which acts as effective catalyst. The physicochemical characterization affirmed that the metallic nanoparticles are sheathed by thin crystalline graphite layer. Investigation of the electrocatalytic activity of the introduced nanofibers toward methanol oxidation indicates good performance, as the corresponding onset potential was small compared to many reported materials; 310 mV (vs. Ag/AgCl electrode) and a current density of 12 mA/cm2 was obtained. Moreover, due to the graphite shield, good stability was observed. Overall, the introduced study opens new avenue for cheap and stable transition metals-based nanostructures as non-precious catalysts for fuel cell applications.

  11. Fabrication of Progesterone-Loaded Nanofibers for the Drug Delivery Applications in Bovine

    Science.gov (United States)

    Karuppannan, Chitra; Sivaraj, Mehnath; Kumar, J. Ganesh; Seerangan, Rangasamy; Balasubramanian, S.; Gopal, Dhinakar Raj

    2017-02-01

    Progesterone is a potent drug for synchronization of the estrus and ovulation cycles in bovine. At present, the estrus cycle of bovine is controlled by the insertion of progesterone-embedded silicone bands. The disadvantage of nondegradable polymer inserts is to require for disposal of these bands after their use. The study currently focuses on preparation of biodegradable progesterone-incorporated nanofiber for estrus synchronization. Three different concentrations (1.2, 1.9, and 2.5 g) of progesterone-impregnated nanofibers were fabricated using electrospinning. The spun membrane were characterized by scanning electron microscopy, X-ray diffraction, differential scanning calorimetry, thermogravimetric analysis, and Fourier transform infrared spectroscopy. Uniform surface morphology, narrow size distribution, and interaction between progesterone and zein were confirmed by SEM. FTIR spectroscopy indicated miscibility and interaction between zein and progesterone. X-ray analysis indicated that the size of zein crystallites increased with progesterone content in nanofibers. Significant differences in thermal behavior of progesterone-impregnated nanofiber were observed by DSC. Cell viability studies of progesterone-loaded nanofiber were examined using MTT assay. In vitro release experiment is to identify the suitable progesterone concentration for estrus synchronization. This study confirms that progesterone-impregnated nanofibers are an ideal vehicle for progesterone delivery for estrus synchronization of bovines.

  12. Heterogeneous WSx/WO₃ Thorn-Bush Nanofiber Electrodes for Sodium-Ion Batteries.

    Science.gov (United States)

    Ryu, Won-Hee; Wilson, Hope; Sohn, Sungwoo; Li, Jinyang; Tong, Xiao; Shaulsky, Evyatar; Schroers, Jan; Elimelech, Menachem; Taylor, André D

    2016-03-22

    Heterogeneous electrode materials with hierarchical architectures promise to enable considerable improvement in future energy storage devices. In this study, we report on a tailored synthetic strategy used to create heterogeneous tungsten sulfide/oxide core-shell nanofiber materials with vertically and randomly aligned thorn-bush features, and we evaluate them as potential anode materials for high-performance Na-ion batteries. The WSx (2 ≤ x ≤ 3, amorphous WS3 and crystalline WS2) nanofiber is successfully prepared by electrospinning and subsequent calcination in a reducing atmosphere. To prevent capacity degradation of the WSx anodes originating from sulfur dissolution, a facile post-thermal treatment in air is applied to form an oxide passivation surface. Interestingly, WO3 thorn bundles are randomly grown on the nanofiber stem, resulting from the surface conversion. We elucidate the evolving morphological and structural features of the nanofibers during post-thermal treatment. The heterogeneous thorn-bush nanofiber electrodes deliver a high second discharge capacity of 791 mAh g(-1) and improved cycle performance for 100 cycles compared to the pristine WSx nanofiber. We show that this hierarchical design is effective in reducing sulfur dissolution, as shown by cycling analysis with counter Na electrodes.

  13. Effects of O2 plasma treatment of PDMS on the deposition of electrospun PVA nanofibers

    Science.gov (United States)

    Kobayashi, Natsumi; Miki, Norihisa; Hishida, Koichi; Hotta, Atsushi

    2014-03-01

    A new polymeric nanofiber-alignment technique with the selective deposition of the nanofibers using oxygen (O2) plasma treatment on a base material for the electrospinning was introduced. Generally, without any pretreatments, electrospun fibers are deposited randomly on the collector. In this work, we focused on the O2 plasma treatment of the surface of the base material to modify the surface morphology and to add polar groups to the surface. O2 plasma-treated and untreated surface of poly (dimethylsiloxane) (PDMS) was prepared by masking a part of PDMS film by another PDMS film. The polyvinyl alcohol (PVA) fibers were then deposited onto the PDMS film. The surface structure of the PDMS film with PVA nanofibers was analyzed by scanning electron microscopy, water contact angle measurements, and X-ray photon spectroscopy. Only a few PVA nanofibers were deposited randomly on the untreated area of the PDMS film, while a number of PVA nanofibers were selectively deposited onto the O2 plasma-treated area. Intriguingly, PVA nanofibers were neatly aligned along the border of the untreated and the treated areas. The contact angle of the plasma-treated surface of PDMS decreased from 105 to 22 degree and the atomic ratio of O/Si was 1.7 times higher than that of the untreated PDMS.

  14. A facile method for electrospinning of Ag nanoparticles/poly (vinyl alcohol)/carboxymethyl-chitosan nanofibers

    Science.gov (United States)

    Zhao, Yinghui; Zhou, Ying; Wu, Xiaomian; Wang, Lu; Xu, Ling; Wei, Shicheng

    2012-09-01

    A facile method to prepare silver nanoparticles (AgNPs) containing nanofibers via electrospinning has been demonstrated. AgNPs were in situ synthesized in poly (vinyl alcohol) (PVA)/carboxymethyl-chitosan (CM-chitosan) blend aqueous solution before electrospinning. UV-vis spectra, viscosity and conductivity of the electrospinning solution were measured to investigate their effects on the electrospinning procedure. The morphology of AgNPs/PVA/CM-chitosan nanofibers was observed by Field Emission Scanning Electron Microscopy. The formation and morphology of AgNPs were investigated by Transmission Electron Microscopy and X-ray Photoelectron Spectroscopy. The resulted nanofibers have smooth surface and uniform diameters ranging from 295 to 343 nm. The diameters of AgNPs mainly distributed in the range of 4-14 nm, and the electrostatic interaction between AgNPs and fibers was observed. Finally, in vitro Ag release from the nanofibers was measured and the antibacterial behavior of the nanofibers against Escherichia coli was studied by bacterial growth inhibition halos and bactericidal kinetic testing. The AgNPs/PVA/CM-chitosan nanofibers possessed certain antibacterial ability, which makes them capable for antibacterial biomaterials.

  15. Preparation and characterization of graphite/PVA composite nanofibers%石墨/聚乙烯醇复合纳米纤维的制备及性能表征

    Institute of Scientific and Technical Information of China (English)

    王春红; 贺文婷; 王莹; 李康

    2015-01-01

    应用静电纺丝技术制备石墨/聚乙烯醇(PVA)纳米纤维,并将该复合纤维收集成无纺布薄膜;采用扫描电子显微镜(SEM)观察了复合纤维的微观形貌和结构,利用宽频质谱仪测试了纤维的导电性,利用万能强力机测试了不同纳米石墨含量纤维薄膜的拉伸力学性能,并利用X射线衍射仪(XRD)和热重分析仪(TG)测试了复合纤维的物相及热力学行为.结果表明:在聚乙烯醇质量分数为8%、石墨质量分数为4%时,所制备的纳米纤维膜导电性最高,且力学性能最好,与纯PVA相比,电导率和断裂强度分别提高1个数量级和127.33%;XRD测试结果表明,纳米石墨成功附着在PVA中;TG结果表明,石墨/PVA复合纤维初始分解温度相对于纯PVA变化不大,当样品质量保持率为40%时,4%石墨/PVA复合纤维较纯PVA相比,其分解温度提高了35℃.%The electrospinning technology was used to produce graphite/poly (vinyl alcohol) (PVA) composite nanofibers. SEM was used to investigate fiber microstructure, broadband dielectric spectrometer was used to investigate the conductivity, all purpose strength tester was used to test the tensile strength of nanofiber membrane with different graphite contents; and XRD and TGA were used to investigate the phase and thermal properties. The results revealed that the conductivity and tensile strength of the nanofiber membrane reached the highest with 8%!PVA and 4%!graphite, increased by one order of magnitude and 127.33%!respectively. The inclusion of nanographite in the nanocomposite fibers is confirmed by XRD. The TG results showed that compared with PVA nanofibers, the initial heat decomposition temperature of graphite/PVA composite nanofibers had little change, but when the weight percentage was 40%, the heat decomposition temperature of composite nanofibers with 4%! graphite increased by 35℃.

  16. First Introduction of NiSe2 to Anode Material for Sodium-Ion Batteries: A Hybrid of Graphene-Wrapped NiSe2/C Porous Nanofiber

    Science.gov (United States)

    Cho, Jung Sang; Lee, Seung Yeon; Kang, Yun Chan

    2016-03-01

    The first-ever study of nickel selenide materials as efficient anode materials for Na-ion rechargeable batteries is conducted using the electrospinning process. NiSe2-reduced graphene oxide (rGO)-C composite nanofibers are successfully prepared via electrospinning and a subsequent selenization process. The electrospun nanofibers giving rise to these porous-structured composite nanofibers with optimum amount of amorphous C are obtained from the polystyrene to polyacrylonitrile ratio of 1/4. These composite nanofibers also consist of uniformly distributed single-crystalline NiSe2 nanocrystals that have a mean size of 27 nm. In contrast, the densely structured bare NiSe2 nanofibers formed via selenization of the pure NiO nanofibers consist of large crystallites. The initial discharge capacities of the NiSe2-rGO-C composite and bare NiSe2 nanofibers at a current density of 200 mA g-1 are 717 and 755 mA h g-1, respectively. However, the respective 100th-cycle discharge capacities of the former and latter are 468 and 35 mA h g-1. Electrochemical impedance spectroscopy measurements reveal the structural stability of the composite nanofibers during repeated Na-ion insertion and extraction processes. The excellent Na-ion storage properties of these nanofibers are attributed to this structural stability.

  17. Tailored surface structure of LiFePO4/C nanofibers by phosphidation and their electrochemical superiority for lithium rechargeable batteries.

    Science.gov (United States)

    Lee, Yoon Cheol; Han, Dong-Wook; Park, Mihui; Jo, Mi Ru; Kang, Seung Ho; Lee, Ju Kyung; Kang, Yong-Mook

    2014-06-25

    We offer a brand new strategy for enhancing Li ion transport at the surface of LiFePO4/C nanofibers through noble Li ion conducting pathways built along reduced carbon webs by phosphorus. Pristine LiFePO4/C nanofibers composed of 1-dimensional (1D) LiFePO4 nanofibers with thick carbon coating layers on the surfaces of the nanofibers were prepared by the electrospinning technique. These dense and thick carbon layers prevented not only electrolyte penetration into the inner LiFePO4 nanofibers but also facile Li ion transport at the electrode/electrolyte interface. In contrast, the existing strong interactions between the carbon and oxygen atoms on the surface of the pristine LiFePO4/C nanofibers were weakened or partly broken by the adhesion of phosphorus, thereby improving Li ion migration through the thick carbon layers on the surfaces of the LiFePO4 nanofibers. As a result, the phosphidated LiFePO4/C nanofibers have a higher initial discharge capacity and a greatly improved rate capability when compared with pristine LiFePO4/C nanofibers. Our findings of high Li ion transport induced by phosphidation can be widely applied to other carbon-coated electrode materials.

  18. High-performance supercapacitor electrode from cellulose-derived, inter-bonded carbon nanofibers

    Science.gov (United States)

    Cai, Jie; Niu, Haitao; Wang, Hongxia; Shao, Hao; Fang, Jian; He, Jingren; Xiong, Hanguo; Ma, Chengjie; Lin, Tong

    2016-08-01

    Carbon nanofibers with inter-bonded fibrous structure show high supercapacitor performance when being used as electrode materials. Their preparation is highly desirable from cellulose through a pyrolysis technique, because cellulose is an abundant, low cost natural material and its carbonization does not emit toxic substance. However, interconnected carbon nanofibers prepared from electrospun cellulose nanofibers and their capacitive behaviors have not been reported in the research literature. Here we report a facile one-step strategy to prepare inter-bonded carbon nanofibers from partially hydrolyzed cellulose acetate nanofibers, for making high-performance supercapacitors as electrode materials. The inter-fiber connection shows considerable improvement in electrode electrochemical performances. The supercapacitor electrode has a specific capacitance of ∼241.4 F g-1 at 1 A g-1 current density. It maintains high cycling stability (negligible 0.1% capacitance reduction after 10,000 cycles) with a maximum power density of ∼84.1 kW kg-1. They may find applications in the development of efficient supercapacitor electrodes for energy storage applications.

  19. Synthesis and morphology of electrospun PVA/PLZT composite and single phase PLZT nanofibers

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Sarabjit, E-mail: sarabjit@dmrl.drdo.in [Defence Metallurgical Research Laboratory, P.O. Kanchanbagh, Hyderabad 500058 (India); Roy, Subir; Singh, Vajinder; Vijayakumar, M. [Defence Metallurgical Research Laboratory, P.O. Kanchanbagh, Hyderabad 500058 (India)

    2011-08-25

    Highlights: > The composite (PVA/PLZT) nanofibrous mats are prepared by electrospinning process. > Morphological changes of nanofibers after calcination are represented by a schematic. > PLZT nanofibers were obtained by calcining PVA/PLZT nanofibrous mat at 650 deg. C/2 h. - Abstract: Polyvinyl alcohol/lead lanthanum zirconate titanate (PVA/PLZT) composite nanofibers were prepared by the electrospinning method. The PLZT sol was prepared by using lead acetate trihydrate, titanium isopropoxide and zirconium propoxide molecular precursors based on sol-gel procedure. The influence of applied voltage, flow rate and needle-to-collector distance on the composite fiber morphology and diameters has been studied. The nanofibers were characterized by X-ray diffraction, TGA-DSC, FTIR spectroscopy and scanning electron microscopy (SEM). Single phase with perovskite structures PLZT nanofibers were also obtained by calcining the PVA/PLZT nanofibrous mat at 650 deg. C for 2 h. A linear correlation was observed between the single perovskite phase evolution and the calcination temperature.

  20. Superhydrophobic behavior of fluorinated carbon nanofiber arrays

    Science.gov (United States)

    Hsieh, Chien-Te; Fan, Wen-Syuan

    2006-06-01

    Superhydrophobic behavior of fluorinated carbon nanofiber (CNF) arrays, prepared by a template-assisted synthesis, has been investigated. A thermal chemical vapor method, using perfluorohexane as the precursor, was used to coat fluorocarbon on the surface of the CNFs, thus lowering their surface tension. The F-coated CNFs exhibited a good water-repellent behavior, i.e., the highest value of contact angle ˜166°. The superhydrophobicity of water droplets on the arrays can be well predicted by a modified Cassie-Baxter model, incorporating the pore size distributions determined from the density functional theory method. This satisfactory result would shed one light on how the variation of opened sizes would induce the superhydrophobicity of nanostructured surfaces.

  1. Effect of electrolyte in electrospun poly(vinylidene fluoride-co-hexafluoropropylene) nanofibers on dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ji-Un; Park, Sung-Hae; Choi, Hyong-Ju; Lee, Jin-Kook; Kim, Mi-Ra [Department of Polymer Science and Engineering, Pusan National University, Busan 609-735 (Korea); Lee, Won-Ki [Division of Chemical Engineering, Pukyong National University, Busan 608-739 (Korea)

    2009-06-15

    We prepared poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) nanofibers by the electrospinning method and applied to the polymer matrix in polymer electrolytes for dye-sensitized solar cells (DSSCs). The uptake, ionic conductivity, and porosity of the electrospun PVDF-HFP nanofiber films showed 653{+-}50%, 4.53{+-}1.3 x 10{sup -3} S/cm, and 70{+-}2.3%, respectively, regardless of the diameter and morphology of nanofibers. In addition, several DSSC devices using the electrospun PVDF-HFP nanofiber films as the polymer matrix were prepared to investigate the photovoltaic effect of iodine (I{sub 2}) concentrations on DSSC devices. With an increase of I{sub 2} concentration in electrolyte solutions, the ionic conductivity increased, while the photocurrent density of DSSC devices decreased. (author)

  2. 功能性PVA/PA6复合纳米纤维的制备及固定化酶研究%Study on the preparation of functional PVA/PA6 composite nanofibers for enzyme immobilization

    Institute of Scientific and Technical Information of China (English)

    凤权; 马坤强; 李双

    2012-01-01

    利用静电纺丝制得PVA/PA6复合纳米纤维,再通过环氧化反应制备功能性PVA/PA6复合纳米纤维并以之为载体固定过氧化氢酶.实验结果表明,PVA/PA6复合纳米纤维在合理的反应时间内形态稳定;固定后的过氧化氢酶体现出更好的存贮稳定性;经过对酶催化反应进行动力学分析,分别得到自由酶和固定化酶的Vmax值和Km值,动力学参数体现了载体与固定化酶之间良好的生物亲和性.%PVA/PA6 composite nanofibers were formed by electrospinning. The functional PVA/PA6 composite nanofibers were generated by epoxidation reaction, which were used as the support for catalases immobilization. The result of experiments showed that PVA/PA6 composite nanofibers have excellent structural stability during the reaction process. The storage stability of immobilized cata- lases was significantly improved. Kinetic parameters V max and Km were analyzed for both immobilized and free catalases, the results indicated that the immobilized catalases had a high affinity with the support.

  3. 双钙钛矿La2CoNiO6无机纳米纤维的制备及超级电容器性能%Preparation and Supercapacitor Properties of Double-Perovskite La2CoNiO6 Inorganic Nanofibers

    Institute of Scientific and Technical Information of China (English)

    吴艳波; 毕军; 魏斌斌

    2015-01-01

    A La2CoNiO6 inorganic nanofiber supercapacitor electrode material was successful y prepared from a polyvinylpyrrolidone/lanthanum nitrate-cobalt acetate-nickel acetate (PVP/LCN) precursor by electrostatic spinning. Its surface morphology and structure were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). We found that the fibers were connected through rhombohedral La2CoNiO6 nanoparticles resulting in a linear spatial network structure. The electrochemical performance of the as-prepared inorganic nanofibers was characterized by cyclic voltammetry (CV), chronopotentiograms (CP), and cycle life tests. The results show that the La2CoNiO6 nanofiber electrode material has good capacitor performance. For the three-electrode system the electrode achieved a respectable specific capacitance of 335.0 F∙g-1 at 0.25 A∙g-1. For the symmetrical two-electrode system the electrode achieved a specific capacitance of 129.1 F∙g-1 at the same current density.%以聚乙烯吡咯烷酮/硝酸镧-乙酸钴-乙酸镍(PVP/LCN)为前驱体,采用静电纺丝法,经预氧化、碳化,制得双钙钛矿La2CoNiO6无机纳米纤维超级电容器电极材料.利用X射线衍射(XRD)、扫描电镜(SEM)和透射电镜(TEM)对其形貌和结构进行表征.结果表明,纤维由菱形结构的La2CoNiO6纳米颗粒相互连接而成,呈链状空间网状结构.循环伏安(CV)、恒流充放电(CP)和循环寿命测试表明, La2CoNiO6纳米纤维电极材料在三电极体系中,电流密度为0.25 A∙g-1时,比电容值达335.0 F∙g-1;在对称型双电极体系中,电流密度为0.25 A∙g-1时,比电容值可达到129.1 F∙g-1,表现出良好的电容性能.

  4. Carbon-coated SnSb nanoparticles dispersed in reticular structured nanofibers for lithium-ion battery anodes

    Energy Technology Data Exchange (ETDEWEB)

    Niu, Xiao [College of Textiles and Clothing, Xin Jiang University, Xinjiang, Urumqi 830046 (China); Key Laboratory of Textile Science and Technology, Donghua University, Ministry of Education, Shanghai 201620 (China); Zhou, Huimin; Li, Zhiyong; Shan, Xiaohong [College of Textiles and Clothing, Xin Jiang University, Xinjiang, Urumqi 830046 (China); Xia, Xin, E-mail: xjxiaxin@163.com [College of Textiles and Clothing, Xin Jiang University, Xinjiang, Urumqi 830046 (China); Key Laboratory of Textile Science and Technology, Donghua University, Ministry of Education, Shanghai 201620 (China)

    2015-01-25

    Highlights: • Sn{sub 0.92}Sb{sub 0.08}O{sub 2.04} nanoparticles as SnSb alloy precursor. • Carbon-coated SnSb nanoparticles were prepared and then embedded in carbon nanofibers. • The synergic effect of carbon coating and special structure improved cycling stability. - Abstract: Carbon coating and carbon nanofiber processes were used to enhance the cycling performance of SnSb alloys. Carbon-coated SnSb alloys were firstly prepared by a simple hydrothermal method to build the first protection, and then carbon-coated SnSb nanoparticles were embedded in carbon nanofibers via single-spinneret electrospinning followed by carbonization. The crystal structure of carbon-coated SnSb/C hybrid nanofibers was characterized by X-ray diffraction (XRD). The morphologies of carbon-coated SnSb alloys and hybrid nanofibers were characterized by transmission electron microscopy (TEM) and scanning electron microscopy (SEM), respectively. The thermal stability of hybrid nanofibers were determined by thermogravimetric analysis (TGA). The electrochemical properties were investigated as a potential high-capacity anode material for lithium-ion batteries. The results showed that the hybrid nanofibers exhibited excellent electrochemical performance due to the special structure. The carbon shell can effectively hinder the agglomeration of SnSb alloys, while maintaining electronic conduction as well as accommodating drastic volume changes during lithium insertion and extraction and carbon nanofibers formed a further protection. The resultant carbon-coated SnSb nanoparticles dispersed in carbon nanofibers deliver a high capacity of 674 mA h g{sup −1} and a good capacity retention of 68.7% after 50 cycles.

  5. Electrospun PLLA nanofiber scaffolds for bladder smooth muscle reconstruction.

    Science.gov (United States)

    Derakhshan, Mohammad Ali; Pourmand, Gholamreza; Ai, Jafar; Ghanbari, Hossein; Dinarvand, Rassoul; Naji, Mohammad; Faridi-Majidi, Reza

    2016-07-01

    Urinary bladder may encounter several pathologic conditions that could lead to loss of its function. Tissue engineering using electrospun PLLA scaffolds is a promising approach to reconstructing or replacing the problematic bladder. PLLA nanofibrous scaffolds were prepared utilizing single-nozzle electrospinning. The morphology and distribution of fiber diameters were investigated by scanning electron microscopy (SEM). Human bladder smooth muscle cells (hBSMCs) were isolated from biopsies and characterized by immunocytochemistry (ICC). Then, the cells were seeded on the PLLA nanofibers and Alamar Blue assay proved the biocompatibility of prepared scaffolds. Cell attachment on the nanofibers and also cell morphology over fibrous scaffolds were observed by SEM. The results indicated that electrospun PLLA scaffold provides proper conditions for hBSMCs to interact and attach efficiently to the fibers. Alamar Blue assay showed the compatibility of the obtained electrospun scaffolds with hBSMCs. Also, it was observed that the cells could achieve highly elongated morphology and their native aligned direction besides each other on the random electrospun scaffolds and in the absence of supporting aligned nanofibers. Electrospun PLLA scaffold efficiently supports the hBSMCs growth and alignment and also has proper cell compatibility. This scaffold would be promising in urinary bladder tissue engineering.

  6. Nanofibers for drug delivery – incorporation and release of model molecules, influence of molecular weight and polymer structure

    OpenAIRE

    2015-01-01

    Nanofibers were prepared from polycaprolactone, polylactide and polyvinyl alcohol using NanospiderTM technology. Polyethylene glycols with molecular weights of 2 000, 6 000, 10 000 and 20 000 g/mol, which can be used to moderate the release profile of incorporated pharmacologically active compounds, served as model molecules. They were terminated by aromatic isocyanate and incorporated into the nanofibers. The release of these molecules into an aqueous environment was investigated. The influe...

  7. Chitosan nanofibers fabricated by combined ultrasonic atomization and freeze casting.

    Science.gov (United States)

    Wang, Yihan; Wakisaka, Minato

    2015-05-20

    Aligned chitosan nanofibers exhibiting diameters smaller than 100 nm were easily prepared by combining ultrasonic atomization with freeze casting. A major advantage of this approach is the use of distilled water as main solvent. Scanning electron microscopy demonstrated that fiber diameter and morphology mainly depended on the atomizing tools, freezing temperature, and chitosan solution viscosity. Minimum diameter and uniform orientation were achieved using an electric flosser as an atomizing tool, liquid nitrogen as a coolant, 0.4 wt% aqueous chitosan solution (molecular weight = 22 kDa), and a small amount of lactic acid as solvent at 0 °C. The resulting chitosan nanofibers may find application in biomedical and food engineering. Moreover, this new technology may be applicable to other natural and synthetic water-soluble polymers.

  8. Structural characterization and impedance studies of PbO nanofibers synthesized by electrospinning technique

    Energy Technology Data Exchange (ETDEWEB)

    Hari Prasad, Kamatam [Department of Physics, Pondicherry University, Puducherry, 605 014 (India); Vinoth, S. [Department of Physics, Pondicherry University, Puducherry, 605 014 (India); Centre for Nanoscience, Pondicherry University, Puducherry, 605014 (India); Jena, Paramananda [Department of Physics, Pondicherry University, Puducherry, 605 014 (India); School of Materials Science and Technology, Indian Institute of Technology(BHU), Varanasi, 221 005 (India); Venkateswarlu, M. [R & D, Amara Raja Batteries Ltd, Karakambadi, 517 520, A.P (India); Satyanarayana, N., E-mail: nallanis2011@gmail.com [Department of Physics, Pondicherry University, Puducherry, 605 014 (India)

    2017-06-15

    One-dimensional electrospun lead oxide nanofibers synthesized by a simple electrospinning technique. The prepared lead oxide nanofibers investigated by using TG/DTA, FTIR, Raman, X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) surface area analyzer, scanning electron microscopy–energy dispersive X-ray spectroscopy (SEM-EDX), atomic force microscopy (AFM), Transmission electron microscopy (TEM), and impedance spectroscopy techniques. TG/DTA results confirmed the thermal behavior of the as-spun nanofibers. XRD, FTIR, and Raman spectra results, respectively, confirm the formation of pure orthorhombic crystalline phase and structural coordination of the lead oxide (β-PbO) nanofibers. The BET specific surface area of β-PbO nanofibers sample is found to be 51.23 m{sup 2} g{sup -1}. SEM and AFM micrographs showed the formation of β-PbO nanofibers with a diameter of 85–300 nm. The impedance measurements of lead oxide nanofibers as a function of temperature, 25–150 °C, was evaluated by analyzing the measured impedance data using the winfit software. The electrical conductivity of the lead oxide (β-PbO) nanofibers evaluated by analyzing the measured impedance data using the winfit software is found to be 5.68 × 10{sup -6} S cm{sup -1} at 150 °C. Also, an activation energy (E{sub a}) for the migration of the charge carrier evaluated from the temperature dependence of conductivity plot is found to be 0.27 eV. The temperature dependence AC conductivity of β-PbO nanofibers was evaluated using the measured impedance data and sample dimension. The observed variation of high-frequency AC conductivity attributed to the hopping electrons between the adjacent sites. - Highlights: • First time, β-PbO nanofibers were successfully prepared by electrospinning technique. • Structural, morphological, roughness and electrical properties are studied. • TG/DTA, XRD, FTIR, Raman, SEM/AFM, TEM-EDX, and impedance measurements were made.

  9. Superior Electrochemical Properties of Nanofibers Composed of Hollow CoFe2 O4 Nanospheres Covered with Onion-Like Graphitic Carbon.

    Science.gov (United States)

    Hong, Young Jun; Cho, Jung Sang; Kang, Yun Chan

    2015-12-07

    Nanofibers composed of hollow CoFe2 O4 nanospheres covered with onion-like carbon are prepared by applying nanoscale Kirkendall diffusion to the electrospinning process. Amorphous carbon nanofibers embedded with CoFe2 @onion-like carbon nanospheres are prepared by reduction of the electrospun nanofibers. Oxidation of the CoFe2 -C nanofibers at 300 °C under a normal atmosphere produces porous nanofibers composed of hollow CoFe2 O4 nanospheres covered with onion-like carbon. CoFe2 nanocrystals are transformed into the hollow CoFe2 O4 nanospheres during oxidation through a well-known nanoscale Kirkendall diffusion process. The discharge capacities of the carbon-free CoFe2 O4 nanofibers composed of hollow nanospheres and the nanofibers composed of hollow CoFe2 O4 nanospheres covered with onion-like carbon are 340 and 930 mA h g(-1) , respectively, for the 1000th cycle at a current density of 1 A g(-1) . The nanofibers composed of hollow CoFe2 O4 nanospheres covered with onion-like carbon exhibit an excellent rate performance even in the absence of conductive materials.

  10. Evaluation of the Morphology and Osteogenic Potential of Titania-Based Electrospun Nanofibers

    Directory of Open Access Journals (Sweden)

    Xiaokun Wang

    2012-01-01

    Full Text Available Submicron-scale titania-based ceramic fibers with various compositions have been prepared by electrospinning. The as-prepared nanofibers were heat-treated at 700°C for 3 h to obtain pure inorganic fiber meshes. The results show that the diameter and morphology of the nanofibers are affected by starting polymer concentration and sol-gel composition. The titania and titania-silica nanofibers had the average diameter about 100–300 nm. The crystal phase varied from high-crystallized rutile-anatase mixed crystal to low-crystallized anatase with adding the silica addition. The morphology and crystal phase were evaluated by SEM and XRD. Bone-marrow-derived mesenchymal stem cells were seeded on titania-silica 50/50 fiber meshes. Cell number and early differentiation marker expressions were analyzed, and the results indicated osteogenic potential of the titania-silica 50/50 fiber meshes.

  11. Simple green approach to reinforce natural rubber with bacterial cellulose nanofibers.

    Science.gov (United States)

    Trovatti, Eliane; Carvalho, Antonio J F; Ribeiro, Sidney J L; Gandini, Alessandro

    2013-08-12

    Natural rubber (NR) is a renewable polymer with a wide range of applications, which is constantly tailored, further increasing its utilizations. The tensile strength is one of its most important properties susceptible of being enhanced by the simple incorporation of nanofibers. The preparation and characterization of natural-rubber based nanocomposites reinforced with bacterial cellulose (BC) and bacterial cellulose coated with polystyrene (BCPS), yielded high performance materials. The nanocomposites were prepared by a simple and green process, and characterized by tensile tests, dynamical mechanical analysis (DMA), scanning electron microscopy (SEM), and swelling experiments. The effect of the nanofiber content on morphology, static, and dynamic mechanical properties was also investigated. The results showed an increase in the mechanical properties, such as Young's modulus and tensile strength, even with modest nanofiber loadings.

  12. Modification of Nafion membrane with biofunctional SiO2 nanofiber for proton exchange membrane fuel cells

    Science.gov (United States)

    Wang, Hang; Li, Xiaojie; Zhuang, Xupin; Cheng, Bowen; Wang, Wei; Kang, Weimin; Shi, Lei; Li, Hongjun

    2017-02-01

    Proton currents are an integral part of the most important energy-converting structures in biology. We prepared a new type of bioinspired Nafion (Bio-Nafion) membrane composited of biofunctional SiO2 (Bio-SiO2) nanofiber and Nafion matrix. SiO2 nanofibers were prepared by electrospinning silica sol prepared from tetraethyl orthosilicate. Meanwhile, Bio-SiO2 nanofibers were synthesized by immobilizing amino acids (cysteine, serine, lysine, and glycine) on SiO2 nanofibers, which acted as efficient proton-conducting pathways that involved numerous H+ transport sites. In our study, the SiO2 nanofibers biofunctionalized with cysteine were further oxidized, and the composite membranes were designated as Nafion-Cys, Nafion-Lys, Nafion-Ser, and Nafion-Gly, respectively. We then investigated the different polar groups (sbnd SO3H, sbnd OH, and sbnd NH2) of the amino acids that contributed to membrane properties of thermal stability, water uptake (WU), dimensional stability, proton conductivity, and methanol permeability. Nafion-Cys exhibited the highest proton conductivity of 0.2424 S/cm (80 °C). Nafion-Gly showed the lowest proton conductivity and WU because glycine contains the least number of hydrophilic groups among the amino acids. Overall, the introduction of Bio-SiO2 nanofiber to composite membranes significantly improved proton conductivity, dimensional stability, and methanol permeability.

  13. Multifunctional Nanofibers towards Active Biomedical Therapeutics

    Directory of Open Access Journals (Sweden)

    Jaishri Sharma

    2015-02-01

    Full Text Available One-dimensional (1-D nanostructures have attracted enormous research interest due to their unique physicochemical properties and wide application potential. These 1-D nanofibers are being increasingly applied to biomedical fields owing to their high surface area-to-volume ratio, high porosity, and the ease of tuning their structures, functionalities, and properties. Many biomedical nanofiber reviews have focused on tissue engineering and drug delivery applications but have very rarely discussed their use as wound dressings. However, nanofibers have enormous potential as wound dressings and other clinical applications that could have wide impacts on the treatment of wounds. Herein, the authors review the main fabrication methods of nanofibers as well as requirements, strategies, and recent applications of nanofibers, and provide perspectives of the challenges and opportunities that face multifunctional nanofibers for active therapeutic applications.

  14. Ammonia gas sensors based on In2O3/PANI hetero-nanofibers operating at room temperature.

    Science.gov (United States)

    Nie, Qingxin; Pang, Zengyuan; Lu, Hangyi; Cai, Yibing; Wei, Qufu

    2016-01-01

    Indium nitrate/polyvinyl pyrrolidone (In(NO3)3/PVP) composite nanofibers were synthesized via electrospinning, and then hollow structure indium oxide (In2O3) nanofibers were obtained through calcination with PVP as template material. In situ polymerization was used to prepare indium oxide/polyaniline (In2O3/PANI) composite nanofibers with different mass ratios of In2O3 to aniline. The structure and morphology of In(NO3)3/PVP, In2O3/PANI composite nanofibers and pure PANI were investigated by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM) and current-voltage (I-V) measurements. The gas sensing properties of these materials towards NH3 vapor (100 to 1000 ppm) were measured at room temperature. The results revealed that the gas sensing abilities of In2O3/PANI composite nanofibers were better than pure PANI. In addition, the mass ratio of In2O3 to aniline and the p-n heterostructure between In2O3 and PANI influences the sensing performance of the In2O3/PANI composite nanofibers. In this paper, In2O3/PANI composite nanofibers with a mass ratio of 1:2 exhibited the highest response values, excellent selectivity, good repeatability and reversibility.

  15. Ammonia gas sensors based on In2O3/PANI hetero-nanofibers operating at room temperature

    Directory of Open Access Journals (Sweden)

    Qingxin Nie

    2016-09-01

    Full Text Available Indium nitrate/polyvinyl pyrrolidone (In(NO33/PVP composite nanofibers were synthesized via electrospinning, and then hollow structure indium oxide (In2O3 nanofibers were obtained through calcination with PVP as template material. In situ polymerization was used to prepare indium oxide/polyaniline (In2O3/PANI composite nanofibers with different mass ratios of In2O3 to aniline. The structure and morphology of In(NO33/PVP, In2O3/PANI composite nanofibers and pure PANI were investigated by scanning electron microscopy (SEM, Fourier transform infrared spectroscopy (FTIR, X-ray diffraction (XRD, transmission electron microscopy (TEM and current–voltage (I–V measurements. The gas sensing properties of these materials towards NH3 vapor (100 to 1000 ppm were measured at room temperature. The results revealed that the gas sensing abilities of In2O3/PANI composite nanofibers were better than pure PANI. In addition, the mass ratio of In2O3 to aniline and the p–n heterostructure between In2O3 and PANI influences the sensing performance of the In2O3/PANI composite nanofibers. In this paper, In2O3/PANI composite nanofibers with a mass ratio of 1:2 exhibited the highest response values, excellent selectivity, good repeatability and reversibility.

  16. Effect of CSA Concentration on the Ammonia Sensing Properties of CSA-Doped PA6/PANI Composite Nanofibers

    Directory of Open Access Journals (Sweden)

    Zengyuan Pang

    2014-11-01

    Full Text Available Camphor sulfonic acid (CSA-doped polyamide 6/polyaniline (PA6/PANI composite nanofibers were fabricated using in situ polymerization of aniline under different CSA concentrations (0.02, 0.04, 0.06, 0.08 and 0.10 M with electrospun PA6 nanofibers as templates. The structural, morphological and ammonia sensing properties of the prepared composite nanofibers were studied using scanning electron microscopy (SEM, Fourier transform infrared spectroscopy (FT-IR, four-point probe techniques, X-ray diffraction (XRD and a home-made gas sensing test system. All the results indicated that the CSA concentration had a great influence on the sensing properties of CSA-doped PA6/PANI composite nanofibers. The composite nanofibers doped with 0.02 M CSA showed the best ammonia sensing properties, with a significant sensitivity toward ammonia (NH3 at room temperature, superior to that of the composite nanofibers doped with 0.04–0.10 mol/L CSA. It was found that for high concentrations of CSA, the number of PANI–H+ reacted with NH3 would not make up a high proportion of all PANI–H+ within certain limits. As a result, within a certain range even though higher CSA-doped PA6/PANI nanofibers had better conductivity, their ammonia sensing performance would degrade.

  17. Electrospun core-shell nanofibers derived Fe-S/N doped carbon material for oxygen reduction reaction

    Science.gov (United States)

    Guo, Junxia; Niu, Qijian; Yuan, Yichun; Maitlo, Inamullh; Nie, Jun; Ma, Guiping

    2017-09-01

    One-dimensional (1D) nanomaterials have gained attention in energy conversion, storage, and catalyst due to the unique physical and chemical properties. Electrospinning is a kind of simple, versatile, and cost-effective technology to fabricate 1D functional nanofibers. Herein, electrospun polyacrylonitrile (PAN), melamine, and ferric chloride hexahydrate (FeCl3·6H2O) composite nanofibers are used as template, and polythiophene (PT) are prepared by photopolymerization technology on the surface of electrospun nanofibers as shell part of fibers. Then, the core-shell nanofibers are pyrolyzed and converted into Fe-S/N-C nanofibers, which can be used as catalysts for ORR due to the metal and S-/N-codoped structure and unique 1D structure which provided facile pathways for efficient mass transport and charge transfer. The ORR electrocatalytic ability of Fe-S/N-C nanofibers is tested and present excellent property, especially in stability and methanol crossover. The electrocatalytic ability of sample is comparable to that of 20 wt% Pt/C benchmarks. These results offer an easy pathway for exploring metal-heteroatom-codoped carbon nanofibers applicable for ORR catalyst.

  18. In vitro feasibility study of the use of a magnetic electrospun chitosan nanofiber composite for hyperthermia treatment of tumor cells.

    Science.gov (United States)

    Lin, Ta-Chun; Lin, Feng-Huei; Lin, Jui-Che

    2012-07-01

    Hyperthermia has been reported to be an effective cancer treatment modality, as tumor cells are more temperature-sensitive than their normal counterparts. Since the ambient temperature can be increased by placing magnetic nanoparticles in an alternating magnetic field it has become of interest to incorporate these magnetic nanoparticles into biodegradable nanofibers for possible endoscopic hyperthermia treatment of malignant tumors. In this preliminary investigation we have explored various characteristics of biodegradable electrospun chitosan nanofibers containing magnetic nanoparticles prepared by different methods. These methods included: (1) E-CHS-Fe(3)O(4), with electrospun chitosan nanofibers directly immersed in a magnetic nanoparticle solution; (2) E-CHS-Fe(2+), with the electrospun chitosan nanofibers initially immersed in Fe(+2)/Fe(+3) solution, followed by chemical co-precipitation of the magnetic nanoparticles. The morphology and crystalline phase of the magnetic electrospun nanofiber matrices were determined by scanning electron microscopy, transmission electron microscopy, selected area electron diffraction, and X-ray diffraction spectroscopy. The magnetic characteristics were measured using a superconducting quantum interference device. The heating properties of these magnetic electrospun nanofiber matrices in an alternating magnetic field were investigated at a frequency of 750 kHz and magnetic intensity of 6.4 kW. In vitro cell incubation experiments indicated that these magnetic electrospun nanofiber matrices are non-cytotoxic and can effectively reduce tumor cell proliferation upon application of a magnetic field.

  19. Hollow shaped nanofibers with (Ti, Sn)O{sub 2} solid-solutions: Synthesis, characterization, and photocatalytic application

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Jin-Young; Cho, Seho; Lee, Young-Seak, E-mail: youngslee@cnu.ac.kr

    2014-11-25

    Highlights: • Novel hollow shaped nanofibers with (Ti, Sn)O{sub 2} solid-solutions were synthesized. • Uniformly distributed hollow shaped nanofibers were formed in the optimum weight ratio of the TTIP. • The highest degradation ratio of photocatalysts exhibited more than 3.5 times that of TiO{sub 2}. - Abstract: Novel hollow shaped nanofibers with (Ti, Sn)O{sub 2} solid-solutions have been synthesized for photocatalysts by the impregnation method using tin chloride (SnCl{sub 2}) and titanium tetraisopropoxide (TTIP), and further characterized by SEM, EDS, TGA, and XRD. The results showed that uniformly distributed hollow shaped nanofibers with (Ti, Sn)O{sub 2} solid-solutions was successfully formed in the case of the optimum weight ratio of the Ti precursor. These hollow shaped nanofibers exhibited the higher photocatalytic reactivity by the conversion of methylene blue in aqueous solution under UV irradiation than not only prepared SnO{sub 2} but also TiO{sub 2} hollow shaped nanofibers. The highest degradation ratio was about 85% at 70 min using hollow shaped nanofibers with (Ti, Sn)O{sub 2} solid-solutions photocatalysts, which exhibited more than 3.5 times that of TiO{sub 2}. It has been found that enhanced MB degradation efficiency is not only due to the charge separation of electron–hole pairs but also increasing the photocatalytic reactive site.

  20. Preparation

    Directory of Open Access Journals (Sweden)

    M.M. Dardir

    2014-03-01

    Full Text Available Some hexanamide-mono and di-linoleniate esters were prepared by the reaction of linolenic acid and hexanamide (derived from the reaction of hexanoic acid and diethanolamine. The chemical structure for the newly prepared hexanamide-mono and di-linoleniate esters were elucidated using elemental analysis, (FTIR, H 1NMR and chemical ionization mass spectra (CI/Ms spectroscopic techniques. The results of the spectroscopic analysis indicated that they were prepared through the right method and they have high purity. The new prepared esters have high biodegradability and lower toxicity (environmentally friendly so they were evaluated as a synthetic-based mud (ester-based mud for oil-well drilling fluids. The evaluation included study of the rheological properties, filtration and thermal properties of the ester based-muds formulated with the newly prepared esters compared to the reference commercial synthetic-based mud.

  1. Smart Polyacrylonitrile (PAN) Nanofibers with Thermal Energy Storage and Retrieval Functionality

    Science.gov (United States)

    Cherry, De'Andre James

    Phase change materials (PCMs) are generally substances with a high heat of fusion in the process of solid to liquid phase change. The nature of PCMs make them efficient materials to store and retrieve large amounts of thermal energy. Presently, high efficiency thermal energy storage/retrieval in applications where flexibility and space saving are required, such as smart textiles, still remains as a challenge. In this study, lauric acid (LA) and myristic acid (MA) were combined to prepare a specific binary fatty acid eutectic (LA-MA) with a melting point near the operating body temperature of a human being and then encapsulated in polyacrylonitrile (PAN) nanofibers through the electrospinning technique. Functionalized PCM-enhanced PAN nanofibers containing LA-MA at 30%, 50%, 70% and 100% of the weight of the PAN were successfully synthesized. The morphological structures and thermal energy storage capacity of the PCM-enhanced PAN nanofibers were characterized by electron microscopy (EM) and differential scanning calorimetry (DSC). The novel PCM-enhanced PAN nanofibers maintained their cylindrical fiber morphology after multiple heating-cooling cycles and retained their latent heat storage functionality. Thus, it is envisioned that the prepared PCM-enhanced PAN nanofibers will find use in applications such as smart textiles where temperature regulation functionality is required.

  2. The application of electrospun titania nanofibers in dye-sensitized solar cells.

    Science.gov (United States)

    Krysova, Hana; Zukal, Arnost; Trckova-Barakova, Jana; Chandiran, Aravind Kumar; Nazeeruddin, Mohammad Khaja; Grätzel, Michael; Kavan, Ladislav

    2013-01-01

    Titania nanofibers were fabricated using the industrial Nanospider(TM) technology. The preparative protocol was optimized by screening various precursor materials to get pure anatase nanofibers. Composite films were prepared by mixing a commercial paste of nanocrystalline anatase particles with the electrospun nanofibers, which were shortened by milling. The composite films were sensitized by Ru-bipyridine dye (coded C106) and the solar conversion efficiency was tested in a dye-sensitized solar cell filled with iodide-based electrolyte solution (coded Z960). The solar conversion efficiency of a solar cell with the optimized composite electrode (η = 7.53% at AM 1.5 irradiation) outperforms that of a solar cell with pure nanoparticle film (η = 5.44%). Still larger improvement was found for lower light intensities. At 10% sun illumination, the best composite electrode showed η = 7.04%, referenced to that of pure nanoparticle film (η = 4.69%). There are non-monotonic relations between the film's surface area, dye sorption capacity and solar performance of nanofiber-containing composite films, but the beneficial effect of the nanofiber morphology for enhancement of the solar efficiency has been demonstrated.

  3. Influence of acetone on nanostructure and electrochemical properties of interfacial synthesized polyaniline nanofibers

    Directory of Open Access Journals (Sweden)

    Jianyun Zhao

    2015-08-01

    Full Text Available The growth of polyaniline (PANI nanofibers through interfacial polymerization can be well controlled by adding a small amount of acetone in the water/chloroform system. It was found that the polymerization rate became slower in the presence of acetone, yielding PANI nanofibers with larger aspect ratios. The influences of the acetone addition on the morphology, microstructure and properties of as-prepared PANI nanofibers were studied by scanning electron microscope (FE-SEM, ultraviolet–visible spectra (UV–vis, Fourier transform infrared (FT-IR and Raman spectroscopy, X-ray diffraction (XRD, thermogravity analysis (TGA, and electrical and electrochemical measurements. The experimental results showed that PANI nanofibers prepared by using ammonium persulfate (APS as an oxidant with acetone exhibited slower growth, the larger ratio of length to diameter, and higher crystallinity (2θ=6°, 19°, 26° than that without acetone, meanwhile remained larger yield of 11.23% and higher conductivity 1.8×10−2 S/cm compared with that obtained by replacing APS with FeCl3. More importantly, these PANI nanofibers exhibited better electrochemical behaviors, which benefitted from their high crystallinity and good conductivity.

  4. Bio-Photovoltaic Conversion Device Made from Chitosan Nanofibers and Varieties of Natural Pigments

    Directory of Open Access Journals (Sweden)

    Siriwat BOONCHAISRI

    2014-05-01

    Full Text Available In this study, the natural pigments anthocyanin, beta carotene, chlorophyll, and curcumin, extracted from red cabbage, carrot, water hyacinth and turmeric, respectively, were used as sensitized dyes in a Bio-photovoltaic Conversion Device (BPV, and the energy conversion efficiencies (h were compared. The photoelectrodes were designed to use various photoactive layers made of porous TiO2 or a new TiO2:nanofiber interface. The nanofibers were prepared by an electrospinning chitosan solution, a PVA solution (poly(vinylalcohol, and their mixture at different conditions. Analysis from a scanning electron microscope (SEM showed that the formation and the density of nanofibers increase with increasing amount of PVA. The highest h was observed in solar cells which used anthocyanin extracted from red cabbage. When considering the photoactive layers made of TiO2:nanofibers prepared from the mixture between 1.2 % chitosan in acetic acid and 8 % PVA in aqueous solution at the ratio of 1:1. w/w ([1.2Chitosan]+[8PVA], it raised the h up to 5.3 times higher than by the TiO2 alone. Therefore, the utilization of chitosan nanofibers together with the application of natural dyes has the potential to increase h of BPVs.doi:10.14456/WJST.2014.23

  5. Influence of acetone on nanostructure and electrochemical properties of interfacial synthesized polyaniline nanofibers

    Institute of Scientific and Technical Information of China (English)

    Jianyun Zhao; Zongyi Qin; Tao Li; Zhuozhan Li; Zhe Zhou; Meifang Zhu

    2015-01-01

    The growth of polyaniline (PANI) nanofibers through interfacial polymerization can be well controlled by adding a small amount of acetone in the water/chloroform system. It was found that the polymerization rate became slower in the presence of acetone, yielding PANI nanofibers with larger aspect ratios. The influences of the acetone addition on the morphology, microstructure and properties of as-prepared PANI nanofibers were studied by scanning electron microscope (FE-SEM), ultraviolet–visible spectra (UV–vis), Fourier transform infrared (FT-IR) and Raman spectroscopy, X-ray diffraction (XRD), thermogravity analysis (TGA), and electrical and electrochemical measurements. The experimental results showed that PANI nanofibers prepared by using ammonium persulfate (APS) as an oxidant with acetone exhibited slower growth, the larger ratio of length to diameter, and higher crystallinity (2θ¼ 61, 191, 261) than that without acetone, meanwhile remained larger yield of 11.23% and higher conductivity 1.8 ? 10 ? 2 S/cm compared with that obtained by replacing APS with FeCl3. More importantly, these PANI nanofibers exhibited better electrochemical behaviors, which benefitted from their high crystallinity and good conductivity.

  6. Structure, morphology and electrochemical properties of La{sub x}Sr{sub 1−x}Co{sub 0.1}Mn{sub 0.9}O{sub 3−δ} perovskite nanofibers prepared by electrospinning method

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Yi; Lin, Baoping, E-mail: lbp@seu.edu.cn; Sun, Ying; Yang, Hong; Zhang, Xueqin

    2015-03-05

    Highlights: • La{sub x}Sr{sub 1−x}Co{sub 0.1}Mn{sub 0.9}O{sub 3−δ} (0.3 ⩽ x ⩽ 1) (LNF x) electrospinning nanofibers were firstly synthesized. • The LNF x was used as the supercapacitor electrodes. • The LNF x annealed at 700 °C always maintained the fibrous structure. • The electrochemical performance of LNF x was explored in different aqueous electrolyte. • The LNF0.7 possessed superior capacitive performance (485 F g{sup −1}) at KOH electrolyte. - Abstract: La{sub x}Sr{sub 1−x}Co{sub 0.1}Mn{sub 0.9}O{sub 3−δ} (0.3 ⩽ x ⩽ 1) perovskite nanofibers (LNF-x) are firstly prepared by a simple electrospinning method. The microstructure, morphology and electrochemical properties of La{sub x}Sr{sub 1−x}Co{sub 0.1}Mn{sub 0.9}O{sub 3−δ} (0.3 ⩽ x ⩽ 1) are systematically studied through scanning electron microscopy (SEM), X-ray powder diffraction (XRD), transmission electron microscopy (TEM), Brunauer–Emmett–Teller (BET) surface area measurements and electrochemical analyzer etc. The results show that the nanofibers maintain the fibrous structure with perovskite phase after annealed at 700 °C. And with the increase of Sr content in La{sub x}Sr{sub 1−x}Co{sub 0.1}Mn{sub 0.9}O{sub 3−δ} (0.3 ⩽ x ⩽ 1), the diameter range of the samples tend to decrease and the roughness of surface enlarge as well. Furthermore, when 1 M KOH electrolyte is employed, a maximum capacitance of 485 F g{sup −1} at a current density of 1 A g{sup −1} is achieved for the LNF-0.7 as electrode material.

  7. Preparation of Cd2+-PVA/PA6 metal chelated nanofibers and analysis of reaction kinetics%Cd2+-PVA/PA6金属配合纳米纤维的制备及反应动力学分析

    Institute of Scientific and Technical Information of China (English)

    凤权; 王清清; 魏取福; 汪学骞; 侯大寅

    2012-01-01

    PVA/PA6 composite nanofibers were formed by electrospinning and then reacted with Cd2+ solution to prepare Cd2+ -PVA/PA6 metal chelated nanofibers. The metal ions ( Cd2+ ) concentration was determined by atomic absorption spectrophotometry ( AAS ) ; the morphologies were characterized by scanning electronic microscopy ( SEM) ; and the major absorption peaks were assigned by means of Fourier transform infrared (FT-IR) spectrography. The result shows that PVA/PA6 composite nanofibers have excellent adsorption capacity for metals ions such as Cd2+ and good shape stability. The absorption process and kinetics parameters of metal ions were also studied in this work. The saturated amount of coordinated Cd2+ ( Qm ) was 4. 464 3 mmol/g ( dry fiber ) , the adsorption constant ( K1 ) was 0. 025 7 L/mmol, and the correlation coefficient R2 = 0. 997. The process of reaction was corresponding with Langmuir model.%利用静电纺丝技术得到PVA/PA6复合纳米纤维,并将其与镉离子(Cd2+)溶液反应,制备Cd2+ -PVA/PA6金属配合纳米纤维.采用原子吸收光谱( AAS)测定金属离子浓度,用傅里叶红外光谱(FT-IR)对PVA/PA6复合纳米纤维和Cd2+-PVA/PA6金属配合纳米纤维的相应吸收峰进行分析,用扫描电子显微镜(SEM)对其形貌进行表征.结果表明,PVA/PA6纳米纤维具有优异的金属离子配合性能和良好的形态稳定性.同时研究了金属离子吸附过程及动力学参数,得出吸附常数Kl=0.025 7 L/mmol、饱和离子配合量Qm=4.464 3 mmol/g、相关系数R2=0.997,该反应过程符合兰格缪尔吸附模型.

  8. Structural and Thermophysical Studies of Composite Na-Cobaltite Electrospun Nanofibers

    Directory of Open Access Journals (Sweden)

    Fatima-tuz-Zahra

    2015-01-01

    Full Text Available Polymeric nanofibers have been produced in the last few years by electrospinning of polymer solutions. Polyvinyl alcohol (PVA was the selected polymer for the preparation of nanofibers. Processing parameters like flow rate, needle gauge, needle to collector distance, and molarity of the solution have been optimized during electrospinning process. Sol-gel method has been used for the preparation of thermoelectric cobaltite nanoparticles having composition NaCoO2. Sol-gel combined electrospinning technique was used to prepare the composites of the NaCoO2 with PVA nanofibers. X-ray diffraction (XRD, thermogravimetric analysis (TGA, and differential scanning calorimetry (DSC have been used for the structural analysis of the prepared samples. Scanning electron microscopy (SEM was used to observe the morphology of the prepared fibers. SEM micrographs showed that, by increasing the flow rate, diameter of the fibers increased from 185 nm to 200 nm. Two-probe method and Advantageous Transient Plane Source (ATPS were used to study the electrical and thermal transport properties, respectively. Thermal conductivity and electrical conductivity showed a direct dependence on temperature. It was observed that particles, sample has lower thermal conductivity (0.610 W/m-K as compared to that of composite nanofibers (1.129 W/m-K. The measurements reported are novel and are useful for energy applications.

  9. Nanofiber filter media for air filtration

    Science.gov (United States)

    Raghavan, Bharath Kumar

    Nanofibers have higher capture efficiencies in comparison to microfibers in the submicron particle size range of 100-500 nm because of small fiber diameter and increased surface area of the fibers. Pressure drop across the filter increases tremendously with decrease in fiber diameter in the continuum flow regime. Nanofibers with fiber diameter less than 300 nm are in the slip flow regime as a consequence of which steep increase in pressure drop is considerably reduced due to slip effect. The outlet or inlet gases have broad range of particle size distribution varying from few micrometers to nanometers. The economic benefits include capture of a wide range of particle sizes in the gas streams using compact filters composed of nanofibers and microfibers. Electrospinning technique was used to successfully fabricate polymeric and ceramic nanofibers. The nanofibers were long, continuous, and flexible with diameters in the range of 200--300 nm. Nanofibers were added to the filter medium either by mixing microfibers and nanofibers or by directly electrospinning nanofibers as thin layer on the surface of the microfiber filter medium. Experimental results showed that either by mixing Nylon 6 nanofibers with B glass fibers or by electrospinning Nylon 6 nanofibers as a thin layer on the surface of the microfiber medium in the surface area ratio of 1 which is 0.06 g of nanofibers for 2 g of microfibers performed better than microfiber filter media in air filtration tests. This improved performance is consistent with numerical modeling. The particle loading on a microfibrous filter were studied for air filtration tests. The experimental and modeling results showed that both pressure drop and capture efficiency increased with loading time. Nanofiber filter media has potential applications in many filtration applications and one of them being hot gas filtration. Ceramic nanofibers made of alumina and titania nanofibers can withstand in the range of 1000°C. Ceramic nanofibers

  10. Electrospun nanofiber scaffolds: engineering soft tissues

    Energy Technology Data Exchange (ETDEWEB)

    Kumbar, S G; Nukavarapu, S P; Laurencin, C T [Department of Orthopaedic Surgery, University of Virginia, VA 22908 (United States); James, R [Department of Biomedical Engineering, University of Virginia, VA 22908 (United States)], E-mail: laurencin@virginia.edu

    2008-09-01

    Electrospinning has emerged to be a simple, elegant and scalable technique to fabricate polymeric nanofibers. Pure polymers as well as blends and composites of both natural and synthetics have been successfully electrospun into nanofiber matrices. Physiochemical properties of nanofiber matrices can be controlled by manipulating electrospinning parameters to meet the requirements of a specific application. Such efforts include the fabrication of fiber matrices containing nanofibers, microfibers, combination of nano-microfibers and also different fiber orientation/alignments. Polymeric nanofiber matrices have been extensively investigated for diversified uses such as filtration, barrier fabrics, wipes, personal care, biomedical and pharmaceutical applications. Recently electrospun nanofiber matrices have gained a lot of attention, and are being explored as scaffolds in tissue engineering due to their properties that can modulate cellular behavior. Electrospun nanofiber matrices show morphological similarities to the natural extra-cellular matrix (ECM), characterized by ultrafine continuous fibers, high surface-to-volume ratio, high porosity and variable pore-size distribution. Efforts have been made to modify nanofiber surfaces with several bioactive molecules to provide cells with the necessary chemical cues and a more in vivo like environment. The current paper provides an overlook on such efforts in designing nanofiber matrices as scaffolds in the regeneration of various soft tissues including skin, blood vessel, tendon/ligament, cardiac patch, nerve and skeletal muscle.

  11. Fabrication of a novel scaffold of clotrimazole-microemulsion-containing nanofibers using an electrospinning process for oral candidiasis applications.

    Science.gov (United States)

    Tonglairoum, Prasopchai; Ngawhirunpat, Tanasait; Rojanarata, Theerasak; Kaomongkolgit, Ruchadaporn; Opanasopit, Praneet

    2015-02-01

    Clotrimazole (CZ)-loaded microemulsion-containing nanofiber mats were developed as an alternative for oral candidiasis applications. The microemulsion was composed of oleic acid (O), Tween 80 (T80), and a co-surfactant such as benzyl alcohol (BzOH), ethyl alcohol (EtOH) or isopropyl alcohol (IPA). The nanofiber mats were obtained by electrospinning a blended solution of a CZ-loaded microemulsion and a mixed polymer solution of 2% (w/v) chitosan (CS) and 10% (w/v) polyvinyl alcohol (PVA) at a weight ratio of 30:70. The nanofiber mats were characterized using various analytical techniques. The entrapment efficiency, drug release, antifungal activity and cytotoxicity were investigated. The average diameter of the nanofiber mats was in the range of 105.91-125.56 nm. The differential scanning calorimetry (DSC) and powder X-ray diffractometry (PXRD) results revealed the amorphous state of the CZ-loaded microemulsions incorporated into the nanofiber mats. The entrapment efficiency of CZ in the mats was approximately 72.58-98.10%, depended on the microemulsion formulation. The release experiment demonstrated different CZ release characteristics from nanofiber mats prepared using different CZ-loaded microemulsions. The extent of drug release from the fiber mats at 4h was approximately 64.81-74.15%. The release kinetics appeared to follow Higuchi's model. In comparison with CZ lozenges (10mg), the nanofiber mats exhibited more rapid killing activity. Moreover, the nanofiber mats demonstrated desirable mucoadhesive properties and were safe for 2h. Therefore, the nanofiber mats have the potential to be promising candidates for oral candidiasis applications.

  12. High Sensitive Sensor Fabricated by Reduced Graphene Oxide/Polyvinyl Butyral Nanofibers for Detecting Cu (II) in Water.

    Science.gov (United States)

    Ding, Rui; Luo, Zhimin; Ma, Xiuling; Fan, Xiaoping; Xue, Liqun; Lin, Xiuzhu; Chen, Sheng

    2015-01-01

    Graphene oxide (GO)/polyvinyl butyral (PVB) nanofibers were prepared by a simple electrospinning technique with PVB as matrix and GO as a functional nanomaterial. GO/PVB nanofibers on glassy carbon electrode (GCE) were reduced through electrochemical method to form reduced graphene oxide (RGO)/PVB nanofibers. The morphology and structure of GO/PVB nanofiber were studied by scanning election microscopy (SEM), transmission electron microscopy (TEM), and Fourier transform infrared (FTIR). RGO/PVB modified GCE was used for fabricating an electrochemical sensor for detecting Cu (II) in water. The analysis results showed that RGO/PVB modified GCE had good analytical results with the linear range of 0.06-2.2 μM, detection limit of 4.10 nM (S/N = 3), and the sensitivity of 103.51 μA·μM(-1)·cm(-2).

  13. High Sensitive Sensor Fabricated by Reduced Graphene Oxide/Polyvinyl Butyral Nanofibers for Detecting Cu (II in Water

    Directory of Open Access Journals (Sweden)

    Rui Ding

    2015-01-01

    Full Text Available Graphene oxide (GO/polyvinyl butyral (PVB nanofibers were prepared by a simple electrospinning technique with PVB as matrix and GO as a functional nanomaterial. GO/PVB nanofibers on glassy carbon electrode (GCE were reduced through electrochemical method to form reduced graphene oxide (RGO/PVB nanofibers. The morphology and structure of GO/PVB nanofiber were studied by scanning election microscopy (SEM, transmission electron microscopy (TEM, and Fourier transform infrared (FTIR. RGO/PVB modified GCE was used for fabricating an electrochemical sensor for detecting Cu (II in water. The analysis results showed that RGO/PVB modified GCE had good analytical results with the linear range of 0.06–2.2 μM, detection limit of 4.10 nM (S/N=3, and the sensitivity of 103.51 μA·μM−1·cm−2.

  14. Improved fullerene nanofiber electrodes used in direct methanol fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Q [Nano Craft Technologies Co., Ltd., Tsukuba (Japan); Zhang, Y [Nationals Institute of Advanced Industrial Science and Technology, Tsukuba (Japan); Miyazawa, K; Kato, R; Hotta, K; Wakahara, T [National Institute for Materials Science, Tsukuba (Japan)], E-mail: yi.zhang@aist.go.jp, E-mail: q.wang@aist.go.jp

    2009-04-01

    Platinum supported on fullerene nanofibers as possible electrodes for direct methanol fuel cells (DMFC) were studied. Fullerene nanofiber with 20 wt% Pt loading was mixed with 5 wt% Nafion solution. The mixture paste was coated on Nafion 117 membrane and sandwiched with silicon plates. To increase the surface reaction area of catalyst, nanoimprint was used to fabricate micro-patterns in the Nafion proton exchange membrane. Nanoimprint pattern consisted of dots of 500 nm-in-diameter, 140 nm-in-depth and 1 {mu}m-in-spacing. The nanoimprint of the treated proton exchange membrane (PEM) was carried out in a desktop thermal nanoimprint system (NI273, Nano Craft Tech. Corp., Japan) at the optimized conditions of 130 {sup 0}C and pressure of 3 MPa for 6 min. Then the Pt-coated PEM was sandwiched with micro-channelled silicon plates to form a micro-DMFC. With passively feeding of 1 M methanol solution and air at room temperature, the as-prepared cell had the open circuit voltage of 0.34 V and the maximum power density of 0.30 mW/cm{sup 2}. Compared with a fresh cell, the results shows that nanofibers used in nanoimprinted PEM have an improvement on the performance of micro fuel cells.

  15. Dispersions of Aramid Nanofibers: A New Nanoscale Building Block

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Ming; Cao, Keqin; Sui, Lang; Qi, Ying; Zhu, Jian; Waas, Anthony; Arruda, Ellen; Kieffer, John; Thouless, M. D.; Kotov, Nicholas A.

    2011-09-27

    Stable dispersions of nanofibers are virtually unknown for synthetic polymers. They can complement analogous dispersions of inorganic components, such as nanoparticles, nanowires, nanosheets, etc. as a fundamental component of a toolset for design of nanostructures and metamaterials via numerous solvent-based processing methods. As such, strong flexible polymeric nanofibers are very desirable for the effective utilization within composites of nanoscale inorganic components such as nanowires, carbon nanotubes, graphene, and others. Here stable dispersions of uniform high-aspect-ratio aramid nanofibers (ANFs) with diameters between 3 and 30 nm and up to 10 μm in length were successfully obtained. Unlike the traditional approaches based on polymerization of monomers, they are made by controlled dissolution of standard macroscale form of the aramid polymer, that is, well-known Kevlar threads, and revealed distinct morphological features similar to carbon nanotubes. ANFs are successfully processed into films using layer-by-layer (LBL) assembly as one of the potential methods of preparation of composites from ANFs. The resultant films are transparent and highly temperature resilient. They also display enhanced mechanical characteristics making ANF films highly desirable as protective coatings, ultrastrong membranes, as well as building blocks of other high performance materials in place of or in combination with carbon nanotubes.

  16. Light-activated polymethylmethacrylate nanofibers with antibacterial activity

    Energy Technology Data Exchange (ETDEWEB)

    Elashnikov, Roman [Department of Solid State Engineering, University of Chemistry and Technology, 16628 Prague (Czech Republic); Lyutakov, Oleksiy, E-mail: lyutakoo@vscht.cz [Department of Solid State Engineering, University of Chemistry and Technology, 16628 Prague (Czech Republic); Ulbrich, Pavel [Department of Biochemistry and Microbiology, University of Chemistry and Technology, 16628 Prague (Czech Republic); Svorcik, Vaclav [Department of Solid State Engineering, University of Chemistry and Technology, 16628 Prague (Czech Republic)

    2016-07-01

    The creation of an antibacterial material with triggerable properties enables us to avoid the overuse or misuse of antibacterial substances and, thus, prevent the emergence of resistant bacterial strains. As a potential light-activated antibacterial material, polymethylmethacrylate (PMMA) nanofibers doped with silver nanoparticles (AgNPs) and meso-tetraphenylporphyrin (TPP) were prepared by electrospinning. TPP was chosen as an effectively reactive oxygen species (ROS) producer. Antibacterial tests on Staphylococcus epidermidis (S. epidermidis) and Enterococcus faecalis (E. faecalis) showed the excellent light-triggerable antibacterial activity of the doped materials. Upon light irradiation at the wavelength corresponding to the TPP absorption peak (405 nm), antibacterial activity dramatically increased, mostly due to the release of AgNPs from the polymer matrix. Furthermore, under prolonged light irradiation, the AgNPs/TPP/PMMA nanofibers, displayed enhanced longevity and photothermal stability. Thus, our results suggest that the proposed material is a promising option for the photodynamic inactivation of bacteria. - Highlights: • The novelty of proposed work can be summared as follow: • Silver nanoparticles/meso-tetraphenylporphyrin embedded polymethylmethacrylate nanofibers were obtained for the first time. • Light triggering of PMMA fibers leads to sufficient release of AgNPs or their agglomeration, depending on the light source. • Release of AgNPs leads to appearance of pronounced antimicrobial activity, which can be switched on/off by the illumination.

  17. Fabrication of zinc titanate nanofibers by electrospinning technique

    Energy Technology Data Exchange (ETDEWEB)

    Cai Zongying, E-mail: czy1106@sina.co [Institute of Advanced Materials, Mechanical Engineering College, Shijiazhuang, Hebei 050003 (China); Li Junshou; Wang Yigang [Institute of Advanced Materials, Mechanical Engineering College, Shijiazhuang, Hebei 050003 (China)

    2010-01-07

    The zinc titanate composite nanofibers were prepared using electrospinning method combining sol-gel process followed by calcining the precursor PVP/Zn(CH{sub 3}COO){sub 2}-Ti(OC{sub 4}H{sub 9}){sub 4} fibers under air in the temperature range of 400-700 {sup o}C. The nanofibers were characterized by thermal field emission scanning electron microscope (FE-SEM), X-ray diffraction (XRD), thermal gravimetric and differential thermal analysis (TG-DTA). FE-SEM micrographs indicated that the surfaces of the nanofibers are uniform and smooth and the diameter of the fiber decreasing as the calcination temperature increasing. It is also found that ZnO-TiO{sub 2} ceramic fibers including ZnTiO{sub 3}, Zn{sub 2}TiO{sub 4} and rutile phase were synthesized by calcining the precursor PVP/Zn(CH{sub 3}COO){sub 2}-Ti(OC{sub 4}H{sub 9}){sub 4} composite fibers at 700 {sup o}C.

  18. Electrospun Polymer Nanofibers Reinforced by Tannic Acid/Fe+++ Complexes

    Directory of Open Access Journals (Sweden)

    Weiqiao Yang

    2016-09-01

    Full Text Available We report the successful preparation of reinforced electrospun nanofibers and fibrous mats of polyvinyl alcohol (PVA via a simple and inexpensive method using stable tannic acid (TA and ferric ion (Fe+++ assemblies formed by solution mixing and pH adjustment. Changes in solution pH change the number of TA galloyl groups attached to the Fe+++ from one (pH < 2 to two (3 < pH < 6 to three (pH < 7.4 and affect the interactions between PVA and TA. At pH ~ 5.5, the morphology and fiber diameter size (FDS examined by SEM are determinant for the mechanical properties of the fibrous mats and depend on the PVA content. At an optimal 8 wt % concentration, PVA becomes fully entangled and forms uniform nanofibers with smaller FDS (p < 0.05 and improved mechanical properties when compared to mats of PVA alone and of PVA with TA (p < 0.05. Changes in solution pH lead to beads formation, more irregular FDS and poorer mechanical properties (p < 0.05. The Fe+++ inclusion does not alter the oxidation activity of TA (p > 0.05 suggesting the potential of TA-Fe+++ assemblies to reinforce polymer nanofibers with high functionality for use in diverse applications including food, biomedical and pharmaceutical.

  19. Electrospun Nb-doped TiO2 nanofiber support for Pt nanoparticles with high electrocatalytic activity and durability.

    Science.gov (United States)

    Kim, MinJoong; Kwon, ChoRong; Eom, KwangSup; Kim, JiHyun; Cho, EunAe

    2017-03-14

    This study explores a facile method to prepare an efficient and durable support for Pt catalyst of polymer electrolyte membrane fuel cell (PEMFC). As a candidate, Nb-doped TiO2 (Nb-TiO2) nanofibers are simply fabricated using an electrospinning technique, followed by a heat treatment. Doping Nb into the TiO2 nanofibers leads to a drastic increase in electrical conductivity with doping level of up to 25 at. % (Nb0.25Ti0.75O2). Pt nanoparticles are synthesized on the prepared 25 at. % Nb-doped TiO2-nanofibers (Pt/Nb-TiO2) as well as on a commercial powdered carbon black (Pt/C). The Pt/Nb-TiO2 nanofiber catalyst exhibits similar oxygen reaction reduction (ORR) activity to that of the Pt/C catalyst. However, during an accelerated stress test (AST), the Pt/Nb-TiO2 nanofiber catalyst retained more than 60% of the initial ORR activity while the Pt/C catalyst lost 65% of the initial activity. The excellent durability of the Pt/Nb-TiO2 nanofiber catalyst can be attributed to high corrosion resistance of TiO2 and strong interaction between Pt and TiO2.

  20. Electrospun Nb-doped TiO2 nanofiber support for Pt nanoparticles with high electrocatalytic activity and durability

    Science.gov (United States)

    Kim, Minjoong; Kwon, Chorong; Eom, Kwangsup; Kim, Jihyun; Cho, Eunae

    2017-03-01

    This study explores a facile method to prepare an efficient and durable support for Pt catalyst of polymer electrolyte membrane fuel cell (PEMFC). As a candidate, Nb-doped TiO2 (Nb-TiO2) nanofibers are simply fabricated using an electrospinning technique, followed by a heat treatment. Doping Nb into the TiO2 nanofibers leads to a drastic increase in electrical conductivity with doping level of up to 25 at. % (Nb0.25Ti0.75O2). Pt nanoparticles are synthesized on the prepared 25 at. % Nb-doped TiO2-nanofibers (Pt/Nb-TiO2) as well as on a commercial powdered carbon black (Pt/C). The Pt/Nb-TiO2 nanofiber catalyst exhibits similar oxygen reaction reduction (ORR) activity to that of the Pt/C catalyst. However, during an accelerated stress test (AST), the Pt/Nb-TiO2 nanofiber catalyst retained more than 60% of the initial ORR activity while the Pt/C catalyst lost 65% of the initial activity. The excellent durability of the Pt/Nb-TiO2 nanofiber catalyst can be attributed to high corrosion resistance of TiO2 and strong interaction between Pt and TiO2.

  1. Electrospun Nb-doped TiO2 nanofiber support for Pt nanoparticles with high electrocatalytic activity and durability

    Science.gov (United States)

    Kim, MinJoong; Kwon, ChoRong; Eom, KwangSup; Kim, JiHyun; Cho, EunAe

    2017-01-01

    This study explores a facile method to prepare an efficient and durable support for Pt catalyst of polymer electrolyte membrane fuel cell (PEMFC). As a candidate, Nb-doped TiO2 (Nb-TiO2) nanofibers are simply fabricated using an electrospinning technique, followed by a heat treatment. Doping Nb into the TiO2 nanofibers leads to a drastic increase in electrical conductivity with doping level of up to 25 at. % (Nb0.25Ti0.75O2). Pt nanoparticles are synthesized on the prepared 25 at. % Nb-doped TiO2-nanofibers (Pt/Nb-TiO2) as well as on a commercial powdered carbon black (Pt/C). The Pt/Nb-TiO2 nanofiber catalyst exhibits similar oxygen reaction reduction (ORR) activity to that of the Pt/C catalyst. However, during an accelerated stress test (AST), the Pt/Nb-TiO2 nanofiber catalyst retained more than 60% of the initial ORR activity while the Pt/C catalyst lost 65% of the initial activity. The excellent durability of the Pt/Nb-TiO2 nanofiber catalyst can be attributed to high corrosion resistance of TiO2 and strong interaction between Pt and TiO2. PMID:28290503

  2. Antifungal effect of electrospun nanofibers containing cetylpyridinium chloride against Candida albicans

    Directory of Open Access Journals (Sweden)

    Valdirene Alves dos SANTOS

    2014-01-01

    Full Text Available It is known that cetylpyridinium chloride (CPC has in vitro and in vivo antifungal action against Candida albicans, with advantages over other common antiseptics. A CPC delivery-controlled system, transported in polymer nanofibers (PVP/PMMA, was developed to increase the bioavailability of the drug in contact with the oral mucosa. The objectives of this study were to determine if CPC in nanofiber has antifungal action against C. albicans, and in what concentration it must be incorporated, so that the fraction released can yield an inhibitory concentration. The nanofiber was prepared by electrospinning, and sterilized with gamma irradiation. Nanofiber disks with 0.05%, 1.25%, 2.5% and 5% CPC, with 5% miconazole (MCZ and with no drug, as well as filter paper disks with 5% CPC, with 5% MCZ and with no drug were used in this study. A Candida albicans suspension (ATCC 90028 was inoculated in Mueller-Hinton Agar plates. The disks were placed on the plates and the inhibition zone diameters were measured 48h later. The nanopolymeric disks contracted in contact with the agar. All the concentrations of CPC incorporated in the nanofiber presented inhibitory action against C. albicans. Concentrations of 2.5% and 5% CPC presented a significant advantage over the nanofiber with no drug, proving the antifungal action of CPC. Under these experimental conditions, 5% CPC has greater inhibitory action against C. albicans than 5% MCZ, both in nanofiber and in filter paper. A modification made in the polymer to decrease the contraction rate may allow a larger inhibition zone to be maintained, thereby increasing the clinical usefulness of the polymer.

  3. Fabrication and characterization of anisotropic nanofiber scaffolds for advanced drug delivery systems

    Directory of Open Access Journals (Sweden)

    Jalani G

    2014-05-01

    Full Text Available Ghulam Jalani,* Chan Woo Jung,* Jae Sang Lee, Dong Woo Lim Department of Bionano Engineering, College of Engineering Sciences, Hanyang University, Education Research Industry Cluster at Ansan Campus, Ansan, South Korea*These authors contributed equally to this workAbstract: Stimuli-responsive, polymer-based nanostructures with anisotropic compartments are of great interest as advanced materials because they are capable of switching their shape via environmentally-triggered conformational changes, while maintaining discrete compartments. In this study, a new class of stimuli-responsive, anisotropic nanofiber scaffolds with physically and chemically distinct compartments was prepared via electrohydrodynamic cojetting with side-by-side needle geometry. These nanofibers have a thermally responsive, physically-crosslinked compartment, and a chemically-crosslinked compartment at the nanoscale. The thermally responsive compartment is composed of physically crosslinkable poly(N-isopropylacrylamide poly(NIPAM copolymers, and poly(NIPAM-co-stearyl acrylate poly(NIPAM-co-SA, while the thermally-unresponsive compartment is composed of polyethylene glycol dimethacrylates. The two distinct compartments were physically crosslinked by the hydrophobic interaction of the stearyl chains of poly(NIPAM-co-SA or chemically stabilized via ultraviolet irradiation, and were swollen in physiologically relevant buffers due to their hydrophilic polymer networks. Bicompartmental nanofibers with the physically-crosslinked network of the poly(NIPAM-co-SA compartment showed a thermally-triggered shape change due to thermally-induced aggregation of poly(NIPAM-co-SA. Furthermore, when bovine serum albumin and dexamethasone phosphate were separately loaded into each compartment, the bicompartmental nanofibers with anisotropic actuation exhibited decoupled, controlled release profiles of both drugs in response to a temperature. A new class of multicompartmental nanofibers could be

  4. Triclosan loaded electrospun nanofibers based on a cyclodextrin polymer and chitosan polyelectrolyte complex.

    Science.gov (United States)

    Ouerghemmi, Safa; Degoutin, Stéphanie; Tabary, Nicolas; Cazaux, Frédéric; Maton, Mickaël; Gaucher, Valérie; Janus, Ludovic; Neut, Christel; Chai, Feng; Blanchemain, Nicolas; Martel, Bernard

    2016-11-20

    This work focuses on the relevance of antibacterial nanofibers based on a polyelectrolyte complex formed between positively charged chitosan (CHT) and an anionic hydroxypropyl betacyclodextrin (CD)-citric acid polymer (PCD) complexing triclosan (TCL). The study of PCD/TCL inclusion complex and its release in dynamic conditions, a cytocompatibility study, and finally the antibacterial activity assessment were studied. The fibers were obtained by electrospinning a solution containing chitosan mixed with PCD/TCL inclusion complex. CHT/TCL and CHT-CD/TCL were also prepared as control samples. The TCL loaded nanofibers were analyzed by Scanning Electron Microscopy (SEM), Fourier Transformed Infrared spectroscopy (FTIR) and X-Ray Diffraction (XRD). Nanofibers stability and swelling behavior in aqueous medium were pH and CHT:PCD weight ratio dependent. Such results confirmed that CHT and PCD interacted through ionic interactions, forming a polyelectrolyte complex. A high PCD content in addition to a thermal post treatment at 90°C were necessary to reach a nanofibers stability during 15days in soft acidic conditions, at pH=5.5. In dynamic conditions (USP IV system), a prolonged release of TCL with a reduced burst effect was observed on CHT-PCD polyelectrolyte complex based fibers compared to CHT-CD nanofibers. These results were confirmed by a microbiology study showing prolonged antibacterial activity of the nanofibers against Escherichia coli and Staphylococcus aureus. Such results could be explained by the fact that the stability of the polyelectrolyte CHT-PCD complex in the nanofibers matrix prevented the diffusion of the PCD/triclosan inclusion complex in the supernatant, on the contrary of the similar system including cyclodextrin in its monomeric form.

  5. Electrospun carbon-tin oxide composite nanofibers for use as lithium ion battery anodes.

    Science.gov (United States)

    Bonino, Christopher A; Ji, Liwen; Lin, Zhan; Toprakci, Ozan; Zhang, Xiangwu; Khan, Saad A

    2011-07-01

    Composite carbon-tin oxide (C-SnO(2)) nanofibers are prepared by two methods and evaluated as anodes in lithium-ion battery half cells. Such an approach complements the long cycle life of carbon with the high lithium storage capacity of tin oxide. In addition, the high surface-to-volume ratio of the nanofibers improves the accessibility for lithium intercalation as compared to graphite-based anodes, while eliminating the need for binders or conductive additives. The composite nanofibrous anodes have first discharge capacities of 788 mAh g(-1) at 50 mA g(-1) current density, which are greater than pure carbon nanofiber anodes, as well as the theoretical capacity of graphite (372 mAh g(-1)), the traditional anode material. In the first protocol to fabricate the C-SnO(2) composites, tin sulfate is directly incorporated within polyacrylonitrile (PAN) nanofibers by electrospinning. During a thermal treatment the tin salt is converted to tin oxide and the polymer is carbonized, yielding carbon-SnO(2) nanofibers. In the second approach, we soak the nanofiber mats in tin sulfate solutions prior to the final thermal treatment, thereby loading the outer surfaces with SnO(2) nanoparticles and raising the tin content from 1.9 to 8.6 wt %. Energy-dispersive spectroscopy and X-ray diffraction analyses confirm the formation of conversion of tin sulfate to tin oxide. Furthermore, analysis with Raman spectroscopy reveals that the additional salt soak treatment from the second fabrication approach increases in the disorder of the carbon structure, as compared to the first approach. We also discuss the performance of our C-SnO(2) compared with its theoretical capacity and other nanofiber electrode composites previously reported in the literature.

  6. Chitosan/siRNA nanoparticles encapsulated in PLGA nanofibers for siRNA delivery

    DEFF Research Database (Denmark)

    Chen, Menglin; Gao, Shan; Dong, Mingdong

    2012-01-01

    Composite nanofibers of biodegradable poly(d,l-lactic-co-glycolic acid) (PLGA) encapsulating chitosan/siRNA nanoparticles (NPs) were prepared by electrospinning. Acidic/alkaline hydrolysis and a bulk/surface degradation mechanism were investigated in order to achieve an optimized release profile...

  7. Magnetic nanofiber composite materials and devices using same

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Xing; Zhou, Ziyao

    2017-04-11

    A nonreciprocal device is described. It includes a housing, a waveguide layer and at least one layer of magnetic nanofiber composite. The magnetic nanofiber composite layer is made up of a polymer base layer, a dielectric matrix comprising magnetic nanofibers. The nanofibers have a high aspect ratio and wherein said dielectric matrix is embedded in the polymer base layer.

  8. Cellulose nanowhiskers and nanofibers from biomass for composite applications

    Science.gov (United States)

    Wang, Tao

    2011-12-01

    Biological nanocomposites such as plant cell wall exhibit high mechanical properties at a light weight. The secret of the rigidity and strength of the cell wall lies in its main structural component -- cellulose. Native cellulose exists as highly-ordered microfibrils, which are just a few nanometers wide and have been found to be stiffer than many synthetic fibers. In the quest for sustainable development around the world, using cellulose microfibrils from plant materials as renewable alternatives to conventional reinforcement materials such as glass fibers and carbon fibers is generating particular interest. In this research, by mechanical disintegration and by controlled chemical hydrolysis, both cellulose nanofibers and nanowhiskers were extracted from the cell wall of an agricultural waste, wheat straw. The reinforcement performances of the two nanofillers were then studied and compared using the water-soluble polyvinyl alcohol (PVOH) as a matrix material. It was found that while both of these nanofillers could impart higher stiffness to the polymer, the nanofibers from biomass were more effective in composite reinforcement than the cellulose crystals thanks to their large aspect ratio and their ability to form interconnected network structures through hydrogen bonding. One of the biggest challenges in the development of cellulose nanocomposites is achieving good dispersion. Because of the high density of hydroxyl groups on the surface of cellulose, it remains a difficult task to disperse cellulose nanofibers in many commonly used polymer matrices. The present work addresses this issue by developing a water-based route taking advantage of polymer colloidal suspensions. Combining cellulose nanofibers with one of the most important biopolymers, poly(lactic acid) (PLA), we have prepared nanocomposites with excellent fiber dispersion and improved modulus and strength. The bio-based nanocomposites have a great potential to serve as light-weight structural materials

  9. Multifunctional and biomimetic fish collagen/bioactive glass nanofibers: fabrication, antibacterial activity and inducing skin regeneration in vitro and in vivo.

    Science.gov (United States)

    Zhou, Tian; Sui, Baiyan; Mo, Xiumei; Sun, Jiao

    2017-01-01

    The development of skin wound dressings with excellent properties has always been an important challenge in the field of biomedicine. In this study, biomimetic electrospun fish collagen/bioactive glass (Col/BG) nanofibers were prepared. Their structure, tensile strength, antibacterial activity and biological effects on human keratinocytes, human dermal fibroblasts and human vascular endothelial cells were investigated. Furthermore, the Sprague Dawley rat skin defect model was used to validate their effect on wound healing. The results showed that compared with pure fish collagen nanofibers, the tensile strength of the Col/BG nanofibers increased to 21.87±0.21 Mpa, with a certain degree of antibacterial activity against Staphylococcus aureus. It was also found that the Col/BG nanofibers promoted the adhesion, proliferation and migration of human keratinocytes. Col/BG nanofibers induced the secretion of type one collagen and vascular endothelial growth factor by human dermal fibroblasts, which further stimulated the proliferation of human vascular endothelial cells. Animal experimentation indicated that the Col/BG nanofibers could accelerate rat skin wound healing. This study developed a type of multifunctional and biomimetic fish Col/BG nanofibers, which had the ability to induce skin regeneration with adequate tensile strength and antibacterial activity. The Col/BG nanofibers are also easily available and inexpensive, providing the possibility for using as a functional skin wound dressing.

  10. Polyacrylonitrile nanofibers coated with silver nanoparticles using a modified coaxial electrospinning process

    Directory of Open Access Journals (Sweden)

    Yu DG

    2012-11-01

    Full Text Available Deng-Guang Yu,1 Jie Zhou,2 Nicholas P Chatterton,3 Ying Li,1 Jing Huang,2 Xia Wang11School of Materials Science and Engineering, University of Shanghai for Science and Technology, Shanghai, People's Republic of China; 2School of Life Sciences, East China Normal University, Shanghai, People's Republic of China; 3Faculty of Life Sciences, London Metropolitan University, London, United KingdomBackground: The objective of this investigation was to develop a new class of antibacterial material in the form of nanofibers coated with silver nanoparticles (AgNPs using a modified coaxial electrospinning approach. Through manipulation of the distribution on the surface of nanofibers, the antibacterial effect of Ag can be improved substantially.Methods: Using polyacrylonitrile (PAN as the filament-forming polymer matrix, an electrospinnable PAN solution was prepared as the core fluid. A silver nitrate (AgNO3 solution was exploited as sheath fluid to carry out the modified coaxial electrospinning process under varied sheath-to-core flow rate ratios.Results: Scanning electron microscopy and transmission electron microscopy demonstrated that the sheath AgNO3 solution can take a role in reducing the nanofibers' diameters significantly, a sheath-to-core flow rate ratio of 0.1 and 0.2 resulting in PAN nanofibers with diameters of 380 ± 110 nm and 230 ± 70 nm respectively. AgNPs are well distributed on the surface of PAN nanofibers. The antibacterial experiments demonstrated that these nanofibers show strong antimicrobial activities against Bacillus subtilis Wb800, and Escherichia coli dh5α.Conclusion: Coaxial electrospinning with AgNO3 solution as sheath fluid not only facilitates the electrospinning process, providing nanofibers with reduced diameters, but also allows functionalization of the nanofibers through coating with functional ingredients, effectively ensuring that the active antibacterial component is on the surface of the material, which leads to

  11. 改性PAN纳米纤维铁配合物的制备及其催化降解染料性能的比较研究%Comparative study of preparation and catalytic performance for dye degradation of modified PAN nanofiber Fe complexes

    Institute of Scientific and Technical Information of China (English)

    赵雪婷; 董永春; 程博闻; 康卫民; 孔迦庆; 于彩虹

    2014-01-01

    分别以聚丙烯腈(PAN)纳米纤维和普通PAN纤维为原料,经偕胺肟改性和 Fe3+配位反应制备了两种改性PAN 纤维铁配合物.考察和比较了偕胺肟改性和 Fe3+配位反应中两种纤维的腈基转化率及其配合物中铁含量的变化.然后在表征的基础上分别将两种改性PAN纤维铁配合物作为非均相 Fenton反应催化剂应用于偶氮染料活性红195的氧化降解反应中,研究了两者在暗态和可见光辐射条件下的催化降解性能.结果表明,PAN 纳米纤维比普通 PAN 纤维更容易发生偕胺肟改性和 Fe3+配位反应.PAN 纳米纤维铁配合物对可见光吸收性能略低于普通 PAN纤维铁配合物.在染料的氧化降解反应中,PAN 纳米纤维铁配合物具有更好的催化活性和稳定性,尤其在暗态时表现得更为突出.%Two kinds of polyacrylonitrile (PAN)fiber Fe complexes were prepared by amidoximation and coordi-nation of ferric ions with PAN nanofibers and conventional PAN fibers as raw materials,respectively.The ni-trile group conversion of two kinds of fibers and the variation of Fe content in their complexes were investigated and compared during amidoxime modification and coordination with ferric ions.Based on the characterization, two kinds of modified PAN fiber Fe complexes were used as the heterogeneous Fenton catalysts for the oxida-tive degradation of azo dye,reactive red 1 95.Their catalytic performance was studied in the dark or under visi-ble irradiation.The results indicated that PAN nanofiber could amidoximate and coordinate with ferric ions more easily than conventional PAN fiber at the same conditions.However,the visible light adsorption of PAN nanofiber Fe complex was slightly lower than conventional PAN fiber.For the oxidative degradation of the dye, PAN nanofiber Fe complex has a much better catalytic activity and stability,especially in the dark.

  12. Towards scalable binderless electrodes: carbon coated silicon nanofiber paper via Mg reduction of electrospun SiO2 nanofibers.

    Science.gov (United States)

    Favors, Zachary; Bay, Hamed Hosseini; Mutlu, Zafer; Ahmed, Kazi; Ionescu, Robert; Ye, Rachel; Ozkan, Mihrimah; Ozkan, Cengiz S

    2015-02-06

    The need for more energy dense and scalable Li-ion battery electrodes has become increasingly pressing with the ushering in of more powerful portable electronics and electric vehicles (EVs) requiring substantially longer range capabilities. Herein, we report on the first synthesis of nano-silicon paper electrodes synthesized via magnesiothermic reduction of electrospun SiO2 nanofiber paper produced by an in situ acid catalyzed polymerization of tetraethyl orthosilicate (TEOS) in-flight. Free-standing carbon-coated Si nanofiber binderless electrodes produce a capacity of 802 mAh g(-1) after 659 cycles with a Coulombic efficiency of 99.9%, which outperforms conventionally used slurry-prepared graphite anodes by over two times on an active material basis. Silicon nanofiber paper anodes offer a completely binder-free and Cu current collector-free approach to electrode fabrication with a silicon weight percent in excess of 80%. The absence of conductive powder additives, metallic current collectors, and polymer binders in addition to the high weight percent silicon all contribute to significantly increasing capacity at the cell level.

  13. Towards Scalable Binderless Electrodes: Carbon Coated Silicon Nanofiber Paper via Mg Reduction of Electrospun SiO2 Nanofibers

    Science.gov (United States)

    Favors, Zachary; Bay, Hamed Hosseini; Mutlu, Zafer; Ahmed, Kazi; Ionescu, Robert; Ye, Rachel; Ozkan, Mihrimah; Ozkan, Cengiz S.

    2015-02-01

    The need for more energy dense and scalable Li-ion battery electrodes has become increasingly pressing with the ushering in of more powerful portable electronics and electric vehicles (EVs) requiring substantially longer range capabilities. Herein, we report on the first synthesis of nano-silicon paper electrodes synthesized via magnesiothermic reduction of electrospun SiO2 nanofiber paper produced by an in situ acid catalyzed polymerization of tetraethyl orthosilicate (TEOS) in-flight. Free-standing carbon-coated Si nanofiber binderless electrodes produce a capacity of 802 mAh g-1 after 659 cycles with a Coulombic efficiency of 99.9%, which outperforms conventionally used slurry-prepared graphite anodes by over two times on an active material basis. Silicon nanofiber paper anodes offer a completely binder-free and Cu current collector-free approach to electrode fabrication with a silicon weight percent in excess of 80%. The absence of conductive powder additives, metallic current collectors, and polymer binders in addition to the high weight percent silicon all contribute to significantly increasing capacity at the cell level.

  14. Optical properties of planar nematic liquid crystals samples which are parallel oriented by nanofibers

    Science.gov (United States)

    Yusuf, Yusril; Kusumasari, Ervanggis Minggar; Ula, Nur Mufidatul; Jahidah, Khannah; Triyana, Kuwat; Sosiati, Harini; Harsojo

    2016-04-01

    Optical properties of two nematic liquid crystals, i.e., 4-methoxybenzylidene-4-butylaniline (MBBA) and 4-cyano-4'-pentylbiphenyl (5 CB) which are parallel oriented by nanofibers has been successfully performed. Planar samples of liquid crystals were made using polyvinyl alcohol (PVA) nanofiber from electrospinning process. Electrospinning method was modified using copper (Cu) as gap collector. These planar samples area are 15 mm x 25 mm. Optical characteristic of these samples were studied by using optical polarizing microscope. The optical intensity changes by a rotationof crossed polarizers is observed. The sinusoidal intensity change was observedin these samples as such as in the planar sample prepared by the rubbing method.

  15. Method of manufacturing tin-doped indium oxide nanofibers

    Energy Technology Data Exchange (ETDEWEB)

    Ozcan, Soydan; Naskar, Amit K

    2017-06-06

    A method of making indium tin oxide nanofibers includes the step of mixing indium and tin precursor compounds with a binder polymer to form a nanofiber precursor composition. The nanofiber precursor composition is co-formed with a supporting polymer to form a composite nanofiber having a precursor composition nanofiber completely surrounded by the supporting polymer composition. The supporting polymer composition is removed from the composite nanofiber to expose the precursor composition nanofiber. The precursor composition nanofiber is then heated in the presence of oxygen such as O.sub.2 to form indium tin oxide and to remove the binder polymer to form an indium tin oxide nanofiber. A method of making metal oxide nanofibers is also disclosed.

  16. Fabrication of unsmooth bamboo-like nanofibers

    Directory of Open Access Journals (Sweden)

    Liu Zhi

    2015-01-01

    Full Text Available Effect of post drawing on morphology of bubbfil-spun polyvinyl alcohol nanofibers was firstly investigated. Bamboo-like nanofibers were observed after drawing. The increase of surface area of the unsmooth fibers has many potential applications in various fields.

  17. Antibacterial properties of laser spinning glass nanofibers.

    Science.gov (United States)

    Echezarreta-López, M M; De Miguel, T; Quintero, F; Pou, J; Landin, M

    2014-12-30

    A laser-spinning technique has been used to produce amorphous, dense and flexible glass nanofibers of two different compositions with potential utility as reinforcement materials in composites, fillers in bone defects or scaffolds (3D structures) for tissue engineering. Morphological and microstructural analyses have been carried out using SEM-EDX, ATR-FTIR and TEM. Bioactivity studies allow the nanofibers with high proportion in SiO2 (S18/12) to be classified as a bioinert glass and the nanofibers with high proportion of calcium (ICIE16) as a bioactive glass. The cell viability tests (MTT) show high biocompatibility of the laser spinning glass nanofibers. Results from the antibacterial activity study carried out using dynamic conditions revealed that the bioactive glass nanofibers show a dose-dependent bactericidal effect on Sthaphylococcus aureus (S. aureus) while the bioinert glass nanofibers show a bacteriostatic effect also dose-dependent. The antibacterial activity has been related to the release of alkaline ions, the increase of pH of the medium and also the formation of needle-like aggregates of calcium phosphate at the surface of the bioactive glass nanofibers which act as a physical mechanism against bacteria. The antibacterial properties give an additional value to the laser-spinning glass nanofibers for different biomedical applications, such as treating or preventing surgery-associated infections. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Novel Synthesis of Aluminium Oxide Nanofibers

    Science.gov (United States)

    2001-11-01

    UNCLASSIFIED Defense Technical Information Center Compilation Part Notice ADP012177 TITLE: Novel Synthesis of Aluminium Oxide Nanofibers DISTRIBUTION...ADP012174 thru ADP012259 UNCLASSIFIED Mat. Res. Soc. Symp. Proc. Vol. 703 © 2002 Materials Research Society V1.8 Novel Synthesis of Aluminium Oxide Nanofibers

  19. Electrospun MOF nanofibers as hydrogen storage media

    CSIR Research Space (South Africa)

    Ren, Jianwei

    2015-06-01

    Full Text Available In this study, Zr-MOF and Cr-MOF were chosen as representatives of the developed MOFs in our laboratory and were incorporated into electrospun nanofibers. The obtained MOF nanofibers composites were evaluated as hydrogen storage media. The results...

  20. Gold nanorods contained polyvinyl alcohol/chitosan nanofiber matrix for cell imaging and drug delivery

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Eryun, E-mail: yaney359@126.com [College of Materials Science and Engineering, Qiqihar University, Qiqihar 161006 (China); Cao, Minglu [College of Materials Science and Engineering, Qiqihar University, Qiqihar 161006 (China); College of Chemistry and Chemical Engineering, Qiqihar University, Qiqihar 161006 (China); Wang, Yuwei; Hao, Xiaoyuan [College of Materials Science and Engineering, Qiqihar University, Qiqihar 161006 (China); Pei, Shichun; Gao, Jianwei; Wang, Yan [College of Food and Biological Engineering, Qiqihar University, Qiqihar 161006 (China); Zhang, Zhuanfang [College of Chemistry and Chemical Engineering, Qiqihar University, Qiqihar 161006 (China); Zhang, Deqing, E-mail: zhdqing@163.com [College of Materials Science and Engineering, Qiqihar University, Qiqihar 161006 (China)

    2016-01-01

    Gold nanorods (AuNRs) that contained polyvinyl alcohol/chitosan (PVA/CS) hybrid nanofibers with dual functions are successfully fabricated by a simple electrospinning method. The results of transmission electron microscopy (TEM), X-ray diffraction (XRD) and energy dispersive X-ray (EDX) spectroscopy indicate that AuNRs are indeed encapsulated into the PVA/CS hybrid nanofibers. FTIR spectra results demonstrate that the chemical structures of PVA and CS are not affected when the AuNRs are introduced into the fibers. In vitro cytotoxicity test reveals that the hybrid fibers involving AuNRs are completely biocompatible. The as-prepared fibers can be used as a carrier for anticancer agent doxorubicin (DOX), and the drug is delivered into the cell nucleus. The AuNRs and DOX incorporated fibers are effective for inhibiting the growth and proliferation of ovary cancer cells and they can also be used as the cell imaging agent due to the unique optical properties of AuNRs. The nanofiber matrix combining two functions of cell imaging and drug delivery may be of great application potential in biomedical-related areas. - Highlights: • The AuNRs contained PVA/CS nanofibers are fabricated by electrospinning. • The hybrid fibers involving AuNRs are completely biocompatible. • The DOX loaded fibers are effective for inhibiting the proliferation of cancer cells. • The nanofibers combined two functions of cell imaging and drug delivery.

  1. Synergistic tungsten oxide/organic framework hybrid nanofibers for electrochromic device application

    Science.gov (United States)

    Dulgerbaki, Cigdem; Komur, Ali Ihsan; Nohut Maslakci, Neslihan; Kuralay, Filiz; Uygun Oksuz, Aysegul

    2017-08-01

    We report the first successful applications of tungsten oxide/conducting polymer hybrid nanofiber assemblies in electrochromic devices. Poly(3,4-ethylenedioxythiophene)/tungsten oxide (PEDOT/WO3) and polypyrrole/tungsten oxide (PPy/WO3) composites were prepared by an in situ chemical oxidative polymerization of monomers in different ionic liquids; 1-butyl-3-methylimidazolium tetrafluoroborate (BMIMBF4), 1-butyl-3-methylimidazolium hexafluorophosphate (BMIMPF6), 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide (BMIMTFSI) and 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl) imide (BMPTFSI). Electrospinning process was used to form hybrid nanofibers from chemically synthesized nanostructures. The electrospun hybrid samples were compared from both morphological and electrochemical perspectives. Importantly, deposition of nanofibers from chemically synthesized hybrids can be achieved homogenously, on nanoscale dimensions. The morphologies of these assemblies were evaluated by SEM, whereas their electroactivity was characterized by cyclic voltammetry. Electrochromic devices made from hybrid nanofiber electrodes exhibited highest chromatic contrast of 37.66% for PEDOT/WO3/BMIMPF6, 40.42% for PPy/WO3/BMIMBF4 and show a strong electrochromic color change from transparent to light brown. Furthermore, the nanofiber devices exhibit outstanding stability when color switching proceeds, which may ensure a versatile platform for color displays, rear-view mirrors and smart windows.

  2. Controlled synthesis of metallic iron nanoparticles and their magnetic hyperthermia performance in polyaniline composite nanofibers

    Science.gov (United States)

    Yang, Ta-I.; Chang, Su-Hua

    2017-02-01

    Electrospun magnetic iron/polyaniline nanofibers with applicable heating performance in an AC magnetic field were developed. A new and low-cost method was introduced to synthesize metallic iron (Fe0) nanoparticles with uniform size distribution. The Fe0 nanoparticles were synthesized in an aqueous environment at room temperature with the assistance of polyvinylpyrrolidone and sodium citrate to tailor their particle sizes ranging from 10 to 20 nm. The experimental results showed that regulating the free iron ions present in the solution is critical for obtaining Fe0 nanoparticles with narrow size distribution. The Fe0 nanoparticles were subsequently incorporated with conductive polyaniline (PANI) to fabricate Fe0/PANI/polycaprolactone nanofibers using an electrospinning technique. The resultant composite nanofibers have controlled fiber diameters and also show electrochemical redox properties originating from the PANI polymer. The heating performance test concluded that both eddy current loss from PANI and Neel relaxation loss of magnetic Fe0 nanoparticles can contribute to the power dissipation of the prepared composite nanofibers. The optimal heating performance can be obtained by adjusting the composition of Fe0 nanoparticles and PANI in nanofibers.

  3. Mechanism study of selective heavy metal ion removal with polypyrrole-functionalized polyacrylonitrile nanofiber mats

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jianqiang; Luo, Chao [Key Laboratory of Carbon Fiber and Functional Polymers, Ministry of Education, Beijing University of Chemical Technology, Beijing 100029 (China); Qi, Genggeng [Department of Materials Science and Engineering, Cornell University, Ithaca, NY (United States); Pan, Kai, E-mail: pankai@mail.buct.edu.cn [Key Laboratory of Carbon Fiber and Functional Polymers, Ministry of Education, Beijing University of Chemical Technology, Beijing 100029 (China); Department of Materials Science and Engineering, Cornell University, Ithaca, NY (United States); Cao, Bing, E-mail: bcao@mail.buct.edu.cn [Key Laboratory of Carbon Fiber and Functional Polymers, Ministry of Education, Beijing University of Chemical Technology, Beijing 100029 (China)

    2014-10-15

    Graphical abstract: - Highlights: • PAN/PPy core/shell nanofiber used for Cr(VI) removal. • Adsorption mechanisms were investigated. • Selective adsorption performances were investigated. - Abstract: Polyacrylonitrile/polypyrrole (PAN/PPy) core/shell nanofiber mat was prepared through electrospinning followed by a simple chemical oxidation method. The polypyrrole-functionalized nanofiber mats showed selective adsorption performance for anions. The interaction between heavy metal anions and polypyrrole (especially the interaction between Cr{sub 2}O{sub 7}{sup 2−} and polypyrrole) during the adsorption process was studied. The results showed that the adsorption process included two steps: one was the anion exchange process between the Cl{sup −} and Cr(VI), and the other was the redox process for the Cr(VI) ions. The adsorption amount was related to the protonation time of the PAN/PPy nanofiber mat and increased as protonation time increased. Meanwhile, the Cr(VI) ions were reduced to Cr(III) through the reaction with amino groups of polypyrrole (from secondary amines to tertiary amines). PAN/PPy nanofiber mat showed high selectivity for Cr(VI), and the adsorption performance was nearly unaffected by other co-existing anions (Cl{sup −}, NO{sub 3}{sup −}, and SO{sub 4}{sup 2−}) except for PO{sub 4}{sup 3−} for the pH change.

  4. Nanofiber of Mn{sub 3}O{sub 4}: Fabrication and application as supercapacitor electrode

    Energy Technology Data Exchange (ETDEWEB)

    Bhagwan, Jai; Sharma, Yogesh, E-mail: yksptfpt@iitr.ac.in [Energy storage laboratory, Department of Applied Science & Engineering, IIT Roorkee Saharanpur Campus Saharanpur-247001 (India); Centre of Nanotechnology, IIT Roorkee, Roorkee-247667 (India); Yadav, K. L. [Centre of Nanotechnology, IIT Roorkee, Roorkee-247667 (India)

    2015-06-24

    Mn{sub 3}O{sub 4}–nanofiber with high aspect ratio is prepared by a simple electrospinning process. The thermal, structural and morphological characterizations are carried out by TGA, XRD and FESEM, respectively. To assess the property of nanofiber for the use in supercapacitors, cyclic voltammetry (CV) and galvanostatic charging-discharging (GCD) are performed in 2M KOH electrolyte with the potential window ranging from +0.42V to −0.45V. Effect of polymer concentration and electric field intensity on the diameter of as-spun nanofiber was studied. Further, appropriate heating rate was used for sintering to obtain aligned nanofiber. High specific capacitance of 150(±5) F g{sup −1} is obtained by Mn{sub 3}O{sub 4} nanofibers. The rate performance is also found to be good. This improved performance in terms of high specific capacitance and rate capability is ascribed to the nanofabric morphology which provides more active sites and easy access path for ions/electrons.

  5. A novel fixed-bed reactor design incorporating an electrospun PVA/chitosan nanofiber membrane.

    Science.gov (United States)

    Esmaeili, Akbar; Beni, Ali Aghababai

    2014-09-15

    In this research, a novel fixed-bed reactor was designed with a nanofiber membrane composed of a polyvinyl alcohol (PVA)/chitosan nanofiber blend prepared using an electrospinning technique. The applied voltage, tip-collector distance, and solution flow rate of the electrospinning process were 18 kV, 14.5 cm, and 0.5 mL h(-1), respectively. Brunauer-Emmett-Teller (BET) theory, scanning electron microscope (SEM), and Fourier transform infrared spectroscopy (FT-IR) were employed to characterize and analyze the nanofiber membranes. Homogeneous electrospun nanofibers with an average diameter of 99.47 nm and surface area of 214.12 m(2)g(-1) were obtained. Adsorption experiments were carried out in a batch system to investigate the effect of different adsorption parameters such as pH, adsorbent dose, biomass dose, contact time, and temperature. The kinetic data, obtained at the optimal pH of 6, were analyzed by pseudo first-order and pseudo second-order kinetic models. Three isotherm models and thermodynamic parameters (ΔG°, ΔH°, and ΔS°) were applied to describe the equilibrium data of the metal ions adsorbed onto the PVA/chitosan nanofiber membrane. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Impact of post-treatment on the characteristics of electrospun poly (vinyl alcohol)/chitosan nanofibers

    Energy Technology Data Exchange (ETDEWEB)

    Susanto, H., E-mail: heru.susanto@undip.ac.id [Department of Chemical Engineering, Faculty of Engineering, Diponegoro University Jl. Prof. Soedarto-Tembalang, Semarang (Indonesia); Samsudin, A. M.; Faz, M. W.; Rani, M. P. H.

    2016-04-19

    Electrospun nanofibers have many advantages such as high porosity, easy to be fabricated in various size and high ratio of surface area to volume. This paper presents the preparation of electrospun PVA/Chitosan nanofibers and more specifically focuses on the effect of post-treatment on the permeability and morphology of electrospun PVA/chitosan nanofibers. The mixtures of various concentrations of PVA (6,7,8 wt%)and 2 wt%.chitosan solution (with the ratio of 3:1)were used in electrospun with a constant rate of 0.7 ml/hour. The post-treatment was conducted by immersing in a ethanol or glutaraldehyde solution to performed crosslink structure. The electrospun PVA/Chitosan nanofiber was characterized by scanning electron microscopy (SEM) and fourier transform infrared (FTIR) spectroscopy. The results revealed that the viscosity of the mixture solution is directly proportional to its concentration. Increasing the viscosity increased the diameter of fiber but also made the larger beads formation. FTIR measurement exhibited the existence of relevant functional groups of both PVA and chitosan in the composites.The crosslinked structure was found for the electrospun PVA/Chitosan nanofibers treated with glutaraldehyde solution.

  7. Porous Carbon Nanofibers from Electrospun Biomass Tar/Polyacrylonitrile/Silver Hybrids as Antimicrobial Materials.

    Science.gov (United States)

    Song, Kunlin; Wu, Qinglin; Zhang, Zhen; Ren, Suxia; Lei, Tingzhou; Negulescu, Ioan I; Zhang, Quanguo

    2015-07-15

    A novel route to fabricate low-cost porous carbon nanofibers (CNFs) using biomass tar, polyacrylonitrile (PAN), and silver nanoparticles has been demonstrated through electrospinning and subsequent stabilization and carbonization processes. The continuous electrospun nanofibers had average diameters ranging from 392 to 903 nm. The addition of biomass tar resulted in increased fiber diameters, reduced thermal stabilities, and slowed cyclization reactions of PAN in the as-spun nanofibers. After stabilization and carbonization, the resultant CNFs showed more uniformly sized and reduced average diameters (226-507 nm) compared to as-spun nanofibers. The CNFs exhibited high specific surface area (>400 m(2)/g) and microporosity, attributed to the combined effects of phase separations of the tar and PAN and thermal decompositions of tar components. These pore characteristics increased the exposures and contacts of silver nanoparticles to the bacteria including Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli, leading to excellent antimicrobial performances of as-spun nanofibers and CNFs. A new strategy is thus provided for utilizing biomass tar as a low-cost precursor to prepare functional CNFs and reduce environmental pollutions associated with direct disposal of tar as an industrial waste.

  8. Carbon nanofiber-based luminol-biotin probe for sensitive chemiluminescence detection of protein.

    Science.gov (United States)

    Baj, Stefan; Krawczyk, Tomasz; Pradel, Natalia; Azam, Md Golam; Shibata, Takayuki; Dragusha, Shpend; Skutil, Krzysztof; Pawlyta, Miroslawa; Kai, Masaaki

    2014-01-01

    A carbon nanofiber-based luminol-biotin probe was synthesized for the sensitive chemiluminescence (CL) detection of a target protein by grafting luminol and biotin onto an oxidized carbon nanofiber. This carbon nanofiber was prepared by chemical vapor-deposition with methane in the presence of the Ni-Cu-MgO catalyst, which was followed by oxidization with HNO3-H2SO4 to produce a carboxyl group on the surface of the nanofiber. The material was grafted with luminol and biotin by means of a standard carbodiimide activation of COOH groups to produce corresponding amides. The substance was water-soluble and thus could be utilized as a sensitive CL probe for a protein assay. The probe showed highly specific affinity towards the biotin-labeled antibody via a streptavidin-biotin interaction. The detection limit for this model assay was approximately 0.2 pmol of the biotinized IgG spotted on a polyvinylidene fluoride (PVDF) membrane. Nonspecific binding to other proteins was not observed. Therefore, the synthesized carbon nanofiber-based CL probe may be useful for a sensitive and specific analysis of the target protein.

  9. Antibacterial wound dressing from chitosan/polyethylene oxide nanofibers mats embedded with silver nanoparticles.

    Science.gov (United States)

    Wang, Xiaoli; Cheng, Feng; Gao, Jing; Wang, Lu

    2015-03-01

    Novel antibacterial nanomaterials have been developed for biomedical applications. The present study involves the preparation and properties of antibacterial nanofibers from chitosan/polyethylene oxide electrospun nanofibers incorporated with silver nanoparticles. Silver nanoparticles were efficiently synthesized in situ after ultra violet (UV) with AgNO3 as precursor and chitosan/polyethylene oxide as reducing agent and protecting agent, respectively. Then the resultant solutions were electrospun into nanofibers. The formation of silver nanoparticles was confirmed with ultraviolet visible (UV-vis) and transmission electron microscopy (TEM), and the electrospun nanofibers were characterized by scanning electron microscopy and energy dispersive X-ray. The resultant fibers exhibited uniform morphology with silver nanoparticles distributed throughout the fiber. Also, the fibers showed certain tensile strength and excellent antibacterial activity against Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria. Sustained release of silver nanoparticles from fibers could last for over 72 h. The silver-containing chitosan/polyethylene oxide nanofibers showed excellent cytocompatibility.

  10. Ferroelectric KNbO3 nanofibers: synthesis, characterization and their application as a humidity nanosensor

    Science.gov (United States)

    Ganeshkumar, Rajasekaran; Sopiha, Kostiantyn V.; Wu, Ping; Cheah, Chin Wei; Zhao, Rong

    2016-09-01

    By virtue of its non-toxicity, high T c, and non-linear optical and ferroelectric properties, one-dimensional (1D) potassium niobate (KNbO3) may enable the development of numerous nanoscale devices. Despite the progress in 1D perovskite materials, preparing high aspect ratio KNbO3 nanostructures is still a concern. This report presents the successful synthesis of ultra-long KNbO3 nanofibers using a simple sol-gel assisted far-field electrospinning process. At optimized conditions, centimeters long, orthorhombic KNbO3 nanofibers with an average diameter of 100 nm have been obtained. The nanofibers are composed of uniform grains densely stacked along the direction of the nanofiber axis. Due to large surface-volume ratio, a high sensitive humidity nanosensor based on KNbO3 nanofibers displaying a logarithmic-linear dependence behavior of the conductance with the relative humidity (RH) was demonstrated. The conductance increases dramatically from 10-10 ℧ to 10-6 ℧ while RH varies from 15% to 95% at room temperature. In addition, the nanosensor exhibits excellent sensing performance, including ultrafast response (≤2 s) and recovery times (≤10 s), good linearity and reproducibility. Furthermore, the change in ferroelectric coercivity with respect to the RH and its effect in the sensing behavior were unveiled. This work could enable broad applications in the fields of environmental sensing and nano-electrical-mechanical systems.

  11. A nanofiber based artificial electronic skin with high pressure sensitivity and 3D conformability.

    Science.gov (United States)

    Zhong, Weibin; Liu, Qiongzhen; Wu, Yongzhi; Wang, Yuedan; Qing, Xing; Li, Mufang; Liu, Ke; Wang, Wenwen; Wang, Dong

    2016-06-16

    Pressure sensors with 3D conformability are highly desirable components for artificial electronic skin or e-textiles that can mimic natural skin, especially for application in real-time monitoring of human physiological signals. Here, a nanofiber based electronic skin with ultra-high pressure sensitivity and 3D conformability is designed and built by interlocking two elastic patterned nanofibrous membranes. The patterned membrane is facilely prepared by casting conductive nanofiber ink into a silicon mould to form an array of semi-spheroid-like protuberances. The protuberances composed of intertwined elastic POE nanofibers and PPy@PVA-co-PE nanofibers afford a tunable effective elastic modulus that is capable of capturing varied strains and stresses, thereby contributing to a high sensitivity for pressure sensing. This electronic skin-like sensor demonstrates an ultra-high sensitivity (1.24 kPa(-1)) below 150 Pa with a detection limit as low as about 1.3 Pa. The pixelated sensor array and a RGB-LED light are then assembled into a circuit and show a feasibility for visual detection of spatial pressure. Furthermore, a nanofiber based proof-of-concept wireless pressure sensor with a bluetooth module as a signal transmitter is proposed and has demonstrated great promise for wireless monitoring of human physiological signals, indicating a potential for large scale wearable electronic devices or e-skin.

  12. Core-shell structured PEO-chitosan nanofibers by coaxial electrospinning.

    Science.gov (United States)

    Pakravan, Mehdi; Heuzey, Marie-Claude; Ajji, Abdellah

    2012-02-13

    Core-shell structured PEO-chitosan nanofibers have been produced using a coaxial electrospinning setup. PEO and chitosan solutions, both in an aqueous acetic acid solvent, were used as the inner (core) and outer (shell) layer, respectively. Uniform-sized defect-free nanofibers of 150-190 nm diameter were produced. In addition, hollow nanofibers could be obtained subsequent to PEO washing of the membranes. The core-shell nanostructure and existence of chitosan on the shell layer were confirmed by TEM images obtained before and after washing the PEO content with water. The presence of chitosan on the surface of the composite nanofibers was further supported by XPS studies. The chitosan and PEO compositions in the nanofibrous mats were determined by TGA analysis, which were similar to their ratio in the feed solutions. The local compositional homogeneity of the membranes and the efficiency of the washing step to remove PEO were also verified by FTIR. In addition, DSC and XRD were used to characterize the crystalline structure and morphology of the co-electrospun nonwoven mats. The prepared coaxial nanofibers (hollow and solid) have several potential applications due to the presence of chitosan on their outer surfaces.

  13. Growth of Y-shaped Carbon Nanofibers from Ethanol Flames

    Directory of Open Access Journals (Sweden)

    Cheng Jin

    2008-01-01

    Full Text Available Abstract Y-shaped carbon nanofibers as a multi-branched carbon nanostructure have potential applications in electronic devices. In this article, we report that several types of Y-shaped carbon nanofibers are obtained from ethanol flames. These Y-shaped carbon nanofibers have different morphologies. According to our experimental results, the growth mechanism of Y-shaped carbon nanofibers has been discussed and a possible growth model of Y-shaped carbon nanofibers has been proposed.

  14. A novel method for fabrication of fascinated nanofiber yarns

    Directory of Open Access Journals (Sweden)

    Liu Hong-Yan

    2015-01-01

    Full Text Available Potential applications of nanofibers as a new-generation of material will be realized if suitable nanofiber yarns become available. Electrospinning has been widely accepted as a feasible technique for the fabrication of continuous nanofiber yarns. However its low output limited its industrial applications. This paper presents a new processing approach to fabrication of fascinated nanofiber yarns which possess excellent properties of nanofibers while enhancing its mechanical strength by the core yarn.

  15. Polyaniline nanofiber/large mesoporous carbon composites as electrode materials for supercapacitors

    Science.gov (United States)

    Liu, Huan; Xu, Bin; Jia, Mengqiu; Zhang, Mei; Cao, Bin; Zhao, Xiaonan; Wang, Yu

    2015-03-01

    A composite of polyaniline nanofiber/large mesoporous carbon (PANI-F/LMC) hybrid was prepared by an in situ chemical oxidative polymerization of aniline monomer with nano-CaCO3 templated LMC as host matrix for supercapacitors. The morphology, composition and electronic structure of the composites (PANI-F/LMC) together with pure PANI nanofibers and the LMC were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), FT-IR, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). It is found that the PANI nanofibers were incorporated into the large mesochannels of LMC with interpenetrating framework formed. Such unique structure endows the PANI-F/LMC composite with a high capacitance of 473 F g-1 at a current load of 0.1 A g-1 with good rate performance and cycling stability, suggesting its potential application in the electrode material for supercapacitors.

  16. All-cellulose nanocomposite film made from bagasse cellulose nanofibers for food packaging application.

    Science.gov (United States)

    Ghaderi, Moein; Mousavi, Mohammad; Yousefi, Hossein; Labbafi, Mohsen

    2014-04-15

    All-cellulose nanocomposite (ACNC) film was produced from sugarcane bagasse nanofibers using N,N-dimethylacetamide/lithium chloride solvent. The average diameter of bagasse fibers (14 μm) was downsized to 39 nm after disk grinding process. X-ray diffraction showed that apparent crystallinity and crystallite size decreased relatively to an increased duration of dissolution time. Thermogravimetric analysis confirmed that thermal stability of the ACNC was slightly less than that of the pure cellulose nanofiber sheet. Tensile strength of the fiber sheet, nanofiber sheet and ACNC prepared with 10 min dissolution time were 8, 101 and 140 MPa, respectively. Water vapor permeability (WVP) of the ACNC film increased relatively to an increased duration of dissolution time. ACNC can be considered as a multi-performance material with potential for application in cellulose-based food packaging owing to its promising properties (tough, bio-based, biodegradable and acceptable levels of WVP).

  17. Effect of Pt Nanoparticles on the Photocatalytic Activity of ZnO Nanofibers

    Science.gov (United States)

    Di Mauro, Alessandro; Zimbone, Massimo; Scuderi, Mario; Nicotra, Giuseppe; Fragalà, Maria Elena; Impellizzeri, Giuliana

    2015-12-01

    For this study, we originally realized ZnO nanofibers (˜50 nm in mean radius) mixed with Pt nanoparticles (˜30 nm in mean radius), prepared by pulsed laser ablation in liquid, and investigated their photocatalytic performance. The material was synthesized by the simple electrospinning method coupled with subsequent thermal treatments. Methylene blue was employed as a representative dye pollutant to evaluate the photocatalytic activity of the nanofibers. It was found that the Pt-ZnO fibers exhibit a photodegradation reaction rate that is ˜40 % higher than the one obtained for reference ZnO fibers. These encouraging results demonstrate that Pt-ZnO nanofibers can be fruitfully applied for environmental applications.

  18. Load bearing enhancement of pin joined composite laminates using electrospun polyacrylonitrile nanofiber mats

    Directory of Open Access Journals (Sweden)

    J. Herwan

    2016-03-01

    Full Text Available Polyacrylonitrile (PAN nanofibers were produced by an electrospinning technique and directly deposited onto carbon fabric to improve the load bearing strength of pin joined composite laminates. Two types of specimens, virgin laminates and nano-modified laminates, were prepared. A modified carbon fiber reinforced polymer (CFRP laminate was fabricated by interleaving electrospun nanofibers at all of the interlayers of an eight-ply woven carbon fiber fabric. The load bearing test results of the pin joined laminates indicated the electrospun PAN nanofibers increased the load bearing strength by 18.9%. In addition, three point bending tests were also conducted to investigate the flexural modulus and flexural strength of both types of laminates. The flexural modulus and flexural strength also increased by 20.9% and 55.91%, respectively.

  19. Study of parallel oriented electrospun polyvinyl alcohol (PVA) nanofibers using modified electrospinning method

    Science.gov (United States)

    Yusuf, Yusril; Ula, Nur Mufidatul; Jahidah, Khannah; Kusumasari, Ervanggis Minggar; Triyana, Kuwat; Sosiati, Harini; Harsojo

    2016-04-01

    Parallel orientedpolyvinyl alcohol (PVA) nanofibershasbeen successfully prepared by using modified electrospinning method. This method uses two pairs of copper (Cu) electrodes which are set apart at a certain distance and applied voltage of 15 kV. The concentrations of PVA were varied from 11%, 13%, 15%, 17%, and 19%. The width of gap collector were varied from 5 mm, 10 mm, 15 mm, and 20 mm. The diameter of nanofibers increase as increasing concentration of PVA. As the width of gap collector increase, first diameter of nanofibers decrease and reach a minimum value at 355 ± 7nm in 15 mm of gap, then the diameters increase again. We also calculated the alignment parameter (S) for given aligned nanofiber. The result showed that alignment parameters (S) were on values around 0,9-1.

  20. Printed second harmonic active organic nanofiber arrays

    DEFF Research Database (Denmark)

    Balzer, Frank; Brewer, Jonathan R.; Kjelstrup-Hansen, Jakob

    2007-01-01

    Organic nanofibers from semiconducting conjugated molecules are well suited to meet refined demands for advanced applications in future optoelectronics and nanophotonics. In contrast to their inorganic counterparts, the properties of organic nanowires can be tailored at the molecular level...... investigated nanofibers as grown via organic epitaxy. In the present work we show how chemically changing the functionalizing end groups leads to a huge increase of second order susceptibility, making the nanofibers technologically very interesting as efficient frequency doublers. For that the nanofibers have...... to be transferred either as individual entities or as ordered arrays onto specific target substrates. Here, we study the applicability of contact printing as a possible route to non-destructive nanofiber transfer....

  1. Characterization and Biocompatibility of Biopolyester Nanofibers

    Directory of Open Access Journals (Sweden)

    Tang Hui Ying

    2009-10-01

    Full Text Available Biodegradable nanofibers are expected to be promising scaffold materials for biomedical engineering, however, biomedical applications require control of the degradation behavior and tissue response of nanofiber scaffolds in vivo. For this purpose, electrospun nanofibers of poly(hydroxyalkanoates (PHAs and poly(lactides (PLAs were subjected to degradation tests in vitro and in vivo. In this review, characterization and biocompatibility of nanofibers derived from PHAs and PLAs are described. In particular, the effects of the crystalline structure of poly[(R-3-hydroxybutyrate], stereocomplex structure of PLA, and monomer composition of PHA on the degradation behaviors are described in detail. These studies show the potential of biodegradable polyester nanofibers as scaffold material, for which suitable degradation rate and regulated interaction with surrounding tissues are required.

  2. Electrospun Nanofibers for Neural and Tissue Engineering

    Science.gov (United States)

    Xia, Younan

    2009-03-01

    Electrospinning has been exploited for almost one century to process polymers and other materials into nanofibers with controllable compositions, diameters, porosities, and porous structures for a variety of applications. Owing to its small size, high porosity, and large surface area, a nonwoven mat of electrospun nanofibers can serve as an ideal scaffold to mimic the extra cellular matrix for cell attachment and nutrient transportation. The nanofiber itself can also be functionalized through encapsulation or attachment of bioactive species such as extracellular matrix proteins, enzymes, and growth factors. In addition, the nanofibers can be further assembled into a variety of arrays or architectures by manipulating their alignment, stacking, or folding. All these attributes make electrospinning a powerful tool for generating nanostructured materials for a range of biomedical applications that include controlled release, drug delivery, and tissue engineering. This talk will focus on the use of electrospun nanofibers as scaffolds for neural and bone tissue engineering.

  3. Growing a carbon nano-fiber layer on a monolith support; effect of nickel loading and growth conditions

    NARCIS (Netherlands)

    Jarrah, Nabeel A.; Ommen, van Jan G.; Lefferts, Leon

    2004-01-01

    This work describes how a new, extremely porous, hairy layer of carbon nano-fibers (CNFs) can be prepared on the surface of porous inorganic bodies, e.g. wash-coated monoliths. CNFs were prepared catalytically by methane and ethene decomposition over a Ni catalyst. The influence of the Ni particle s

  4. Self-floating graphitic carbon nitride/zinc phthalocyanine nanofibers for photocatalytic degradation of contaminants

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Tiefeng; Ni, Dongjing; Chen, Xia; Wu, Fei; Ge, Pengfei; Lu, Wangyang, E-mail: luwy@zstu.edu.cn; Hu, Hongguang; Zhu, ZheXin; Chen, Wenxing, E-mail: wxchen@zstu.edu.cn

    2016-11-05

    Highlights: • A facile synthetic strategy to prepare visible-light responsive electrospun nanofibers. • Self-floating nanofiber photocatalyts for the effective utilization of solar. • Possible degradation pathway of RhB and CBZ under visible light and solar irradiation. • Present a method for removing highly hazardous contaminants. - Abstract: The effective elimination of micropollutants by an environmentally friendly method has received extensive attention recently. In this study, a photocatalyst based on polyacrylonitrile (PAN)-supported graphitic carbon nitride coupled with zinc phthalocyanine nanofibers (g-C{sub 3}N{sub 4}/ZnTcPc/PAN nanofibers) was successfully prepared, where g-C{sub 3}N{sub 4}/ZnTcPc was introduced as the catalytic entity and the PAN nanofibers were employed as support to overcome the defects of easy aggregation and difficult recycling. Herein, rhodamine B (RhB), 4-chlorophenol and carbamazepine (CBZ) were selected as the model pollutants. Compared with the typical hydroxyl radical-dominated catalytic system, g-C{sub 3}N{sub 4}/ZnTcPc/PAN nanofibers displayed the targeted adsorption and degradation of contaminants under visible light or solar irradiation in the presence of high additive concentrations. According to the results of the radical scavenging techniques and the electron paramagnetic resonance technology, the degradation of target substrates was achieved by the attack of active species, including photogenerated hole, singlet oxygen, superoxide radicals and hydroxyl radicals. Based on the results of ultra-performance liquid chromatography and mass spectrometry, the role of free radicals on the photocatalytic degradation intermediates was identified and the final photocatalytic degradation products of both RhB and CBZ were some biodegradable small molecules.

  5. Polyaniline nanofiber/large mesoporous carbon composites as electrode materials for supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Huan; Xu, Bin; Jia, Mengqiu, E-mail: jiamq@mail.buct.edu.cn; Zhang, Mei; Cao, Bin; Zhao, Xiaonan; Wang, Yu

    2015-03-30

    Highlights: • The composites of polyaniline nanofiber and large mesoporous carbon were prepared for supercapacitors. • The large mesoporous carbons were simply prepared by nano-CaCO{sub 3} template method. • The composites exhibit high capacitance and good rate capability and cycle stability. - Abstract: A composite of polyaniline nanofiber/large mesoporous carbon (PANI-F/LMC) hybrid was prepared by an in situ chemical oxidative polymerization of aniline monomer with nano-CaCO{sub 3} templated LMC as host matrix for supercapacitors. The morphology, composition and electronic structure of the composites (PANI-F/LMC) together with pure PANI nanofibers and the LMC were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), FT-IR, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). It is found that the PANI nanofibers were incorporated into the large mesochannels of LMC with interpenetrating framework formed. Such unique structure endows the PANI-F/LMC composite with a high capacitance of 473 F g{sup −1} at a current load of 0.1 A g{sup −1} with good rate performance and cycling stability, suggesting its potential application in the electrode material for supercapacitors.

  6. Electrospun zirconia nanofibers and corresponding formation mechanism study

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Guo-Xun [Key Laboratory for Liquid-Solid Structure Evolution and Processing of Materials, Ministry of Education, Shandong University, Jinan 250061 (China); Engineering Ceramics Key Laboratory of Shandong Province, Shandong University, Jinan 250061 (China); Liu, Fu-Tian [School of Material Science and Engineering, University of Jinan, Jinan 250022 (China); Bi, Jian-Qiang, E-mail: bjq1969@163.com [Key Laboratory for Liquid-Solid Structure Evolution and Processing of Materials, Ministry of Education, Shandong University, Jinan 250061 (China); Engineering Ceramics Key Laboratory of Shandong Province, Shandong University, Jinan 250061 (China); Wang, Chang-An [State Key Laboratory of New Ceramic and Fine Processing, Tsinghua University, Beijing 100084 (China)

    2015-11-15

    Zirconia nanofibers were fabricated by the sol–gel combined with an electrospinning process. The spinnable sol was prepared with zirconium carbonate and acetic acid as raw materials, yttrium nitrate as phase stabilizer, and polyvinyl pyrrolidone as spinning aid. Formation mechanism of spinnable sol was studied. The possible structure of Poly zirconium acetate (PZA) and idealized formation process of PZA were researched in this mechanism. Electrospinning process and heat-treatment process were also researched. Being heat-treated to 1200 °C, the fibers with diameters of 400–600 nm are composed of 20–40 nm tetragonal zirconia grains, which is crack free with smooth surface.

  7. Creation of surface defects on carbon nanofibers by steam treatment

    Institute of Scientific and Technical Information of China (English)

    Zhengfeng; Shao; Min; Pang; Wei; Xia; Martin; Muhler; Changhai; Liang

    2013-01-01

    A direct strategy for the creation of defects on carbon nanofibers (CNFs) has been developed by steam treatment.Nitrogen physisorption,XRD,Raman spectra,SEM and TEM analyses proved the existence of the new defects on CNFs.BET surface area of CNFs after steam treatment was enhanced from 20 to 378 m2/g.Pd catalysts supported on CNFs were also prepared by colloidal deposition method.The different activity of Pd/CNFs catalysts in the partial hydrogenation of phenylacetylene further demonstrated the diverse surfaces of CNFs could be formed by steam treatment.

  8. Effects of La-Zn substitution on microstructure and magnetic properties of strontium ferrite nanofibers

    Science.gov (United States)

    Shen, Xiangqian; Liu, Mingquan; Song, Fuzhan; Zhu, Yongwei

    2011-07-01

    Sr1- x La x Zn x Fe12- x O19/poly(vinylpyrrolidone) (PVP) (0.0≤ x≤0.5) precursor nanofibers were prepared by the sol-gel assisted electrospinning method from starting reagents of metal salts and PVP. Subsequently, the Sr1- x La x Zn x Fe12- x O19 nanofibers with diameters of around 100 nm were obtained by calcination of the precursor at 800 to 1000°C for 2 h. The precursor and resultant Sr1- x La x Zn x Fe12- x O19 nanofibers were characterized by X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectrometer and vibrating sample magnetometer. The grain sizes of Sr0.8La0.2Zn0.2Fe11.8O19 nanofibers are in a nanoscale from 40 to 48 nm corresponding to the calcination temperature from 800 to 1000°C. With La-Zn substitution content increase from 0 to 0.5, the grain size and lattice constants for the Sr1- x La x Zn x Fe12- x O19 nanofibers obtained at 900°C show a steady reduction trend. With variations of the ferrite particle size arising from the La-Zn substitution, the nanofiber morphology changes from the necklace-like structure linking by single elongated plate-like particles to the structure building of multi-particles on the nanofiber cross-section. The specific saturation magnetization of Sr1- x La x Zn x Fe12- x O19 nanofibers initially increases with the La-Zn content, reaching a maximum value 72 A m2 kg-1 at x=0.2, and then decreases with a further La-Zn content increase up to x=0.5, while the coercivity exhibits a continuous reduction from 413 ( x=0) to 219 kA m-1 ( x=0.5). The mechanism for the La-Zn substitution and the nanofiber magnetic property are analyzed.

  9. Novel hollow mesoporous 1D TiO2 nanofibers as photovoltaic and photocatalytic materials.

    Science.gov (United States)

    Zhang, Xiang; Thavasi, Velmurugan; Mhaisalkar, S G; Ramakrishna, Seeram

    2012-03-07

    Hollow mesoporous one dimensional (1D) TiO(2) nanofibers are successfully prepared by co-axial electrospinning of a titanium tetraisopropoxide (TTIP) solution with two immiscible polymers; polyethylene oxide (PEO) and polyvinylpyrrolidone (PVP) using a core-shell spinneret, followed by annealing at 450 °C. The annealed mesoporous TiO(2) nanofibers are found to having a hollow structure with an average diameter of 130 nm. Measurements using the Brunauer-Emmett-Teller (BET) method reveal that hollow mesoporous TiO(2) nanofibers possess a high surface area of 118 m(2) g(-1) with two types of mesopores; 3.2 nm and 5.4 nm that resulted from gaseous removal of PEO and PVP respectively during annealing. With hollow mesoporous TiO(2) nanofibers as the photoelectrode in dye sensitized solar cells (DSSC), the solar-to-current conversion efficiency (η) and short circuit current (J(sc)) are measured as 5.6% and 10.38 mA cm(-2) respectively, which are higher than those of DSSC made using regular TiO(2) nanofibers under identical conditions (η = 4.2%, J(sc) = 8.99 mA cm(-2)). The improvement in the conversion efficiency is mainly attributed to the higher surface area and mesoporous TiO(2) nanostructure. It facilitates the adsorption of more dye molecules and also promotes the incident photon to electron conversion. Hollow mesoporous TiO(2) nanofibers with close packing of grains and crystals intergrown with each other demonstrate faster electron diffusion, and longer electron recombination time than regular TiO(2) nanofibers as well as P25 nanoparticles. The surface effect of hollow mesoporous TiO(2) nanofibers as a photocatalyst for the degradation of rhodamine dye was also investigated. The kinetic study shows that the hollow mesoporous surface of the TiO(2) nanofibers influenced its interactions with the dye, and resulted in an increased catalytic activity over P25 TiO(2) nanocatalysts.

  10. Significant enhancement in energy density of polymer composites induced by dopamine-modified Ba0.6Sr0.4TiO3 nanofibers

    Science.gov (United States)

    Song, Yu; Shen, Yang; Hu, Penghao; Lin, Yuanhua; Li, Ming; Nan, C. W.

    2012-10-01

    Ba0.6Sr0.4TiO3 (BST) nanofibers prepared via electrospinning and modified by dopamine are used as dielectric fillers in polyvinylidene fluoride (PVDF)-based composites. With 4.4 vol. % of BST nanofibers, the extractable energy density of the BST/PVDF composites is more than doubled as compared with pure PVDF matrix. Such significant enhancement is attributed to the combined effect of both surface modification by dopamine and large aspect ratio of the BST nanofibers. Paraelectric or anti-ferroelectric fillers of large aspect ratio may serve as a general strategy for enhanced electric energy density in polymer composites.

  11. Influence of temperature on the photodegradation process using Ag-doped TiO2 nanostructures: Negative impact with the nanofibers

    DEFF Research Database (Denmark)

    Barakata, Nasser A.M.; Kanjwal, Muzafar Ahmed; Chronakis, Ioannis S.

    2013-01-01

    In this study, the influence of the temperature on the photodegradation process using Ag-doped TiO2 nanostructures was investigated. Two morphologies were used; nanoparticles and nanofibers. The nanofibers were synthesized by electrospinning of a sol–gel consisting of titanium isopropoxide, silver......-doped TiO2 nanofibers for all formulations. The nanoparticles were prepared from the same sol–gels, however, instead of spinning the gels were dried, grinded and sintered at 700 °C. Photodegradation under UV irradiation for the rhodamine B at 5, 15, 25, 45 and 55 °C were performed. For the nanoparticles...

  12. Influence of CdO-doping on the photoluminescence properties of ZnO nanofibers: Effective visible light photocatalyst for waste water treatment

    Energy Technology Data Exchange (ETDEWEB)

    Yousef, Ayman [Center for Healthcare Technology Development, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Bionanosystem Engineering Department, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Barakat, Nasser A.M., E-mail: nasser@jbnu.ac.kr [Organic Materials and Fiber Engineering Department, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Chemical Engineering Department, Faculty of Engineering, El-Minia University, El-Minia (Egypt); Amna, Touseef [Center for Healthcare Technology Development, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Unnithan, Afeesh R. [Center for Healthcare Technology Development, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Bionanosystem Engineering Department, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Al-Deyab, Salem S. [Petrochemical Research Chair, Department of Chemistry, College of Science, King Saud University, Riyadh 11451 (Saudi Arabia); Kim, Hak Yong, E-mail: khy@jbnu.ac.kr [Center for Healthcare Technology Development, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Organic Materials and Fiber Engineering Department, Chonbuk National University, Jeonju 561-756 (Korea, Republic of)

    2012-07-15

    Among the various nanostructural morphologies, nanofibers have a distinct interest due to the long axial ratio which strongly modifies the photocatalytic activity. In this work, study of the effect of CdO-doping on the photoluminescence properties of ZnO nanofibers was carried out. Nanofibers composed of the two oxides (ZnO and CdO) were prepared using facile, effective, simple and high yield technique; electrospinning. Typically, a sol-gel consisting of poly(vinyl alcohol), cadmium acetate and zinc acetate was electrospun. Calcination of the produced nanofibers in air did not affect the nanofibrous morphology and led to produce ZnO/CdO alloy nanofibers. Interestingly, variation of Zn to Cd ratio in the original electrospun solution did not influence the morphology, so nanofibers having CdO of 39.4, 56.5 and 72.2 wt% could be prepared. Optical properties study indicated that addition of CdO to ZnO decreases the band gap and consequently the introduced nanofibers can be utilized as photocatalyst under a visible light radiation. Moreover, the results indicated that increasing the CdO content causes to increase the solid solubility. Accordingly, the low content CdO nanofibers (39.4 wt%) reveal two band gaps in the PL spectra. Consequently, these nanofibers have the best photocatalytic activity among the prepared samples; the methylene blue dye was completely eliminated within 4.5 h. However, full dye degradation was obtained at relatively longer times when the other formulations were utilized. Beside the simplicity and low cost aspects in the proposed preparation strategy, utilizing the solar radiation as activation energy to initiate the photoreactions might recommend the introduced nanofibers to be exploited as photocatalyts in the field of waste water treatment. - Highlights: Black-Right-Pointing-Pointer Novel CdO/ZnO nanofibers are introduced as photocatalysts under sun lights. Black-Right-Pointing-Pointer Scientifically, the study affirms that low CdO content is

  13. Influence of temperature on the photodegradation process using Ag-doped TiO2 nanostructures: Negative impact with the nanofibers

    DEFF Research Database (Denmark)

    Barakata, Nasser A.M.; Kanjwal, Muzafar Ahmed; Chronakis, Ioannis S.

    2013-01-01

    In this study, the influence of the temperature on the photodegradation process using Ag-doped TiO2 nanostructures was investigated. Two morphologies were used; nanoparticles and nanofibers. The nanofibers were synthesized by electrospinning of a sol–gel consisting of titanium isopropoxide, silver......-doped TiO2 nanofibers for all formulations. The nanoparticles were prepared from the same sol–gels, however, instead of spinning the gels were dried, grinded and sintered at 700 °C. Photodegradation under UV irradiation for the rhodamine B at 5, 15, 25, 45 and 55 °C were performed. For the nanoparticles...

  14. Encapsulation of plai oil/2-hydroxypropyl-β-cyclodextrin inclusion complexes in polyvinylpyrrolidone (PVP) electrospun nanofibers for topical application.

    Science.gov (United States)

    Tonglairoum, Prasopchai; Chuchote, Tudduo; Ngawhirunpat, Tanasait; Rojanarata, Theerasak; Opanasopit, Praneet

    2014-06-01

    The aim of this study was to prepare electrospun polyvinylpyrrolidone (PVP)/2-hydroxypropyl-β-cyclodextrin (HPβCD) nanofiber mats and to incorporate plai oil (Zingiber Cassumunar Roxb.). The plai oil with 10, 20 and 30% wt to polymer were incorporated in the PVP/HPβCD solution and electrospun to obtain nanofibers. The morphology and structure of the PVP and PVP/HPβCD nanofiber mats with and without the plai oil were analyzed using scanning electron microscopy (SEM). The thermal behaviors of the nanofiber mats were characterized using differential scanning calorimeter (DSC). Terpinen-4-ol was used as a marker of the plai oil. The amount of plai oil remaining in the PVP/HPβCD nanofiber mats was determined using gas chromatography-mass spectoscopy (GC-MS). The SEM images revealed that all of the fibers were smooth. The average diameter of fibers was 212-450 nm, and decreased with the increasing of plai oil content. The release characteristics of plai oil from the fiber showed the fast release followed by a sustained release over the experimental time of 24 h. The release rate ranged was in the order of 10% > 20% ∼ 30% plai oil within 24 h. Electrospun fibers with 20% plai oil loading provided the controlled release and also showed the highest plai oil content. Hence, this electrospun nanofiber has a potential for use as an alternative topical application.

  15. Effects of quaternization on the morphological stability and antibacterial activity of electrospun poly(DMAEMA-co-AMA) nanofibers.

    Science.gov (United States)

    Xu, Jing-Wei; Wang, Yao; Yang, Yun-Feng; Ye, Xiang-Yu; Yao, Ke; Ji, Jian; Xu, Zhi-Kang

    2015-09-01

    Electrospun nanofibers with antibacterial activity are greatly promising for medical treatment and water purification. Herein we report antibacterial nanofibers electrospun from a series of poly(dimethylamino ethyl methacrylate-co-alkyl methacrylates) (poly(DMAEMA-co-AMA)) and to distinguish the effects of free and cross-linked cations derived from quanternization on the antibacterial activity. Poly(DMAEMA-co-AMA)s are simply synthesized by free radical polymerization from commercial monomers. DSC analysis indicates that they have Tg lower than room temperature and thus the electrospun nanofibers adhere to each other and evenly tend to form films, instead of keeping cylinderic shape. Benzyl chloride (BC) and p-xylylene dichloride (XDC) can quaternize DMAEMA units and to generate cations on the nanofiber surface. XPS analysis and colorimetric assay determine the quaternization degree and the surface accessible quaternary amines (N(+)), respectively. It is very promising that this quaternization endows the electrospun nanofibers with both stable morphology and antibacterial activity. The BC-quaternized fibers show better antibacterial behavior against Escherichia coli and Staphylococcus aureus than those of the XDC-quaternized/cross-linked ones, because cross-linking suppresses the chain mobility of cations. Our results confirm that antibacterial nanofibers can be facilely prepared and chain mobility of the formed cations is the necessary prerequisite for their antibacterial activity.

  16. Polydopamine-Templated Hydroxyapatite Reinforced Polycaprolactone Composite Nanofibers with Enhanced Cytocompatibility and Osteogenesis for Bone Tissue Engineering.

    Science.gov (United States)

    Gao, Xiang; Song, Jinlin; Ji, Ping; Zhang, Xiaohong; Li, Xiaoman; Xu, Xiao; Wang, Mengke; Zhang, Siqi; Deng, Yi; Deng, Feng; Wei, Shicheng

    2016-02-10

    Nanohydroxyapatite (HA) synthesized by biomimetic strategy is a promising nanomaterial as bone substitute due to its physicochemical features similar to those of natural nanocrystal in bone tissue. Inspired by mussel adhesive chemistry, a novel nano-HA was synthesized in our work by employing polydopamine (pDA) as template under weak alkaline condition. Subsequently, the as-prepared pDA-templated HA (tHA) was introduced into polycaprolactone (PCL) matrix via coelectrospinning, and a bioactive tHA/PCL composite nanofiber scaffold was developed targeted at bone regeneration application. Our research showed that tHA reinforced PCL composite nanofibers exhibited favorable cytocompatibility at given concentration of tHA (0-10 w.t%). Compared to pure PCL and traditional nano-HA enriched PCL (HA/PCL) composite nanofibers, enhanced cell adhesion, spreading and proliferation of human mesenchymal stem cells (hMSCs) were observed on tHA/PCL composite nanofibers on account of the contribution of pDA present in tHA. More importantly, tHA nanoparticles exposed on the surface of composite nanofibers could further promote osteogenesis of hMSCs in vitro even in the absence of osteogenesis soluble inducing factors when compared to traditional HA/PCL scaffolds, which was supported by in vivo test as well according to the histological analysis. Overall, our study demonstrated that the developed tHA/PCL composite nanofibers with enhanced cytocompatibility and osteogenic capacity hold great potential as scaffolds for bone tissue engineering.

  17. Cell-adhesive RGD peptide-displaying M13 bacteriophage/PLGA nanofiber matrices for growth of fibroblasts.

    Science.gov (United States)

    Shin, Yong Cheol; Lee, Jong Ho; Jin, Linhua; Kim, Min Jeong; Oh, Jin-Woo; Kim, Tai Wan; Han, Dong-Wook

    2014-01-01

    M13 bacteriophages can be readily fabricated as nanofibers due to non-toxic bacterial virus with a nanofiber-like shape. In the present study, we prepared hybrid nanofiber matrices composed of poly(lactic-co-glycolic acid, PLGA) and M13 bacteriophages which were genetically modified to display the RGD peptide on their surface (RGD-M13 phage). The surface morphology and chemical composition of hybrid nanofiber matrices were characterized by scanning electron microscopy (SEM) and Raman spectroscopy, respectively. Immunofluorescence staining was conducted to investigate the existence of M13 bacteriophages in RGD-M13 phage/PLGA hybrid nanofibers. In addition, the attachment and proliferation of three different types of fibroblasts on RGD-M13 phage/PLGA nanofiber matrices were evaluated to explore how fibroblasts interact with these matrices. SEM images showed that RGD-M13 phage/PLGA hybrid matrices had the non-woven porous structure, quite similar to that of natural extracellular matrices, having an average fiber diameter of about 190 nm. Immunofluorescence images and Raman spectra revealed that RGD-M13 phages were homogeneously distributed in entire matrices. Moreover, the attachment and proliferation of fibroblasts cultured on RGD-M13 phage/PLGA matrices were significantly enhanced due to enriched RGD moieties on hybrid matrices. These results suggest that RGD-M13 phage/PLGA matrices can be efficiently used as biomimetic scaffolds for tissue engineering applications.

  18. Effect of polymer concentration on the morphology and mechanical characteristics of electrospun cellulose acetate and poly (vinyl chloride nanofiber mats

    Directory of Open Access Journals (Sweden)

    Bethwel Tarus

    2016-09-01

    Full Text Available Cellulose Acetate (CA and Poly (Vinyl Chloride (PVC nanofiber mats were electrospun into nanofibers. The morphology and mechanical properties of nanofiber mats were evaluated versus different solution concentrations. Solutions were prepared in mixed solvent systems of 2:1 (w/w Acetone/N,N-Dimethylacetamide (DMAc and 3:2 (w/w Acetone/N,N-Dimethylformamide (DMF for CA and 1:1 (w/w Tetrahydrofuran/DMF for PVC. Scanning electron microscopy (SEM images revealed that a beaded fibrous structure could be electrospun beginning at 10% CA in both Acetone/DMAc and Acetone/DMF solvent systems. The experimental results showed that smooth fibers were achievable at 14% CA in Acetone/DMAc and at 16% CA in Acetone/DMF solvent systems. For PVC, beaded fibers were formed at 12% PVC and smooth fibers were formed beginning at 14% PVC. Tensile strength tests showed that mechanical properties of the nonaligned nanofiber mats were influenced by solution concentration. With increasing solution concentration, the tensile strengths, break strains and initial moduli of the CA nanofiber mats increased. The effect of solution concentration on the tensile strengths of nanofiber mats was quite significant while it did not have any considerable effect on the tensile properties of the cast films.

  19. Synthesis of Poly(N-vinylpyrrolidone) Nanofibers Containing Gold Nanoparticles via Electrospinning Technique

    Institute of Scientific and Technical Information of China (English)

    DU Jian-shi; YANG Qing-biao; BAI Jie; WANG Shu-gang; ZHANG Chao-qun; LI Yao-xian

    2007-01-01

    Poly(N-vinylpyrrolidone) (PVP) nanofibers containing gold nanoparticles were prepared by electrospinning method. This simple route was used to prepare composites on a large scale, and the syntheses are simple. The optical property of gold nanoparticles in PVP aqueous solution was investigated by UV-Visible absorption spectra. The morphology of the fibers and the distribution of particles were characterized by transmission electron microscopy. The structure of the composite was characterized by Fourier transform infrared spectroscopy.

  20. Modification of electrospun polyacrylonitrile nanofibers with EDTA for the removal of Cd and Cr ions from water effluents

    Energy Technology Data Exchange (ETDEWEB)

    Chaúque, Eutilério F.C., E-mail: efchauque@gmail.com [Department of Applied Chemistry, University of Johannesburg, Doornfontein 2028, Johannesburg (South Africa); Dlamini, Langelihle N., E-mail: lndlamini@uj.ac.za [Department of Applied Chemistry, University of Johannesburg, Doornfontein 2028, Johannesburg (South Africa); Adelodun, Adedeji A., E-mail: aadelodun@uj.ac.za [Department of Applied Chemistry, University of Johannesburg, Doornfontein 2028, Johannesburg (South Africa); Greyling, Corinne J., E-mail: GreylingC@cput.ac.za [Technology Station in Clothing and Textiles, Cape Peninsula University of Technology, Symphony Way, Bellville, 7535 (South Africa); Catherine Ngila, J., E-mail: jcngila2002@yahoo.com [Department of Applied Chemistry, University of Johannesburg, Doornfontein 2028, Johannesburg (South Africa)

    2016-04-30

    Graphical abstract: - Highlights: • Polyscrylonitrile (PAN) nanofibers prepared through electrospinning and chemically modified with ethylenediaminetetraacetic acid using ethylenediamine crosslinker. • Fabricated nanofibers have enhanced surface chemistry with insignificant impact on the nanofibrous structure. • Excellent maximum adsorption capacities of 66.24 and 32.68 mg g{sup −1} toward Cr and Cd ions, respectively. • A pre-concentration factor of 19 achieved for removal of Cd and Cr in environmental water samples. - Abstract: Polyacrylonitrile (PAN) nanofibers were obtained by electrospinning technique prior to surface modification with polyethylenediaminetetraacetic acid (EDTA) using ethylenediamine (EDA) as the cross-linker. The modified nanofibers (EDTA-EDA-PAN) were subsequently applied in the wastewater treatment for the removal of Cd(II) and Cr(VI). Textural and chemical characterizations of the nanofibers were carried out by analysis of the specific surface area (Brauner Emmet and Teller (BET)) and thermogravimetric analyses, scanning electron microscopy and Fourier transform infrared spectroscopy. From the adsorption equilibrium studies with Langmuir, Freundlich and Temkin isotherm models, Freundlich was found most suitable for describing the removal mechanism of the target metals as they collect on a heterogeneously functionalized polymer surface. The EDTA-EDA-PAN nanofibers showed effective sorption affinity for both Cd(II) and Cr(VI), achieving maximum adsorption capacities of 32.68 and 66.24 mg g{sup -1}, respectively, at 298 K. In furtherance, the nanofibers were regenerated by simple washing with 2 M HCl solution. Conclusively, the EDTA-EDA-PAN nanofibers were found to be efficient for the removal of Cd(II) and Cr(VI) in water effluents.

  1. Optical Properties of GaSb Nanofibers

    Directory of Open Access Journals (Sweden)

    Perez-Bergquist Alejandro

    2011-01-01

    Full Text Available Abstract Amorphous GaSb nanofibers were obtained by ion beam irradiation of bulk GaSb single-crystal wafers, resulting in fibers with diameters of ~20 nm. The Raman spectra and photoluminescence (PL of the ion irradiation-induced nanofibers before and after annealing were studied. Results show that the Raman intensity of the GaSb LO phonon mode decreased after ion beam irradiation as a result of the formation of the amorphous nanofibers. A new mode is observed at ~155 cm-1 both from the unannealed and annealed GaSb nanofiber samples related to the A1g mode of Sb–Sb bond vibration. Room temperature PL measurements of the annealed nanofibers present a wide feature band at ~1.4–1.6 eV. The room temperature PL properties of the irradiated samples presents a large blue shift compared to bulk GaSb. Annealed nanofibers and annealed nanofibers with Au nanodots present two different PL peaks (400 and 540 nm, both of which may originate from Ga or O vacancies in GaO. The enhanced PL and new band characteristics in nanostructured GaSb suggest that the nanostructured fibers may have unique applications in optoelectronic devices.

  2. Functional Self-Assembled Nanofibers by Electrospinning

    Science.gov (United States)

    Greiner, A.; Wendorff, J. H.

    Electrospinning constitutes a unique technique for the production of nanofibers with diameters down to the range of a few nanometers. In strong contrast to conventional fiber producing techniques, it relies on self-assembly processes driven by the Coulomb interactions between charged elements of the fluids to be spun to nanofibers. The transition from a macroscopic fluid object such as a droplet emerging from a die to solid nanofibers is controlled by a set of complex physical instability processes. They give rise to extremely high extensional deformations and strain rates during fiber formation causing among others a high orientational order in the nanofibers as well as enhanced mechanical properties. Electrospinning is predominantly applied to polymer based materials including natural and synthetic polymers, but, more recently, its use has been extended towards the production of metal, ceramic and glass nanofibers exploiting precursor routes. The nanofibers can be functionalized during electrospinning by introducing pores, fractal surfaces, by incorporating functional elements such as catalysts, quantum dots, drugs, enzymes or even bacteria. The production of individual fibers, random nonwovens, or orientationally highly ordered nonwovens is achieved by an appropriate selection of electrode configurations. Broad areas of application exist in Material and Life Sciences for such nanofibers, including not only optoelectronics, sensorics, catalysis, textiles, high efficiency filters, fiber reinforcement but also tissue engineering, drug delivery, and wound healing. The basic electrospinning process has more recently been extended towards compound co-electrospinning and precision deposition electrospinning to further broaden accessible fiber architectures and potential areas of application.

  3. Biofunctionalized Nanofibers Using Arthrospira (Spirulina Biomass and Biopolymer

    Directory of Open Access Journals (Sweden)

    Michele Greque de Morais

    2015-01-01

    Full Text Available Electrospun nanofibers composed of polymers have been extensively researched because of their scientific and technical applications. Commercially available polyhydroxybutyrate (PHB and polyhydroxybutyrate-