Sample records for spray pyrolysis method

  1. Zinc oxide thin films by the spray pyrolysis method

    Microsoft Academic Search

    Malle Krunks; Enn Mellikov

    1995-01-01

    Undoped and In-doped ZnO thin films have been prepared on glass substrates from solutions of Zn(CH3CO2)22H2O in a mixture of deionized water and isopropyl alcohol by spray pyrolysis. Their optical, morphological and structural qualities have been studied and the effect of the preparation conditions discussed. It was shown that the main factors determining the parameters of ZnO films are the

  2. Fabrication of ZnO nanorod using spray-pyrolysis and chemical bath deposition method

    SciTech Connect

    Ramadhani, Muhammad F., E-mail: brian@tf.itb.ac.id; Pasaribu, Maruli A. H., E-mail: brian@tf.itb.ac.id; Yuliarto, Brian, E-mail: brian@tf.itb.ac.id; Nugraha, E-mail: brian@tf.itb.ac.id [Advanced Functional Materials Laboratory, Engineering Physics Department Faculty of Industrial Technology, Institut Teknologi Bandung (Indonesia)

    2014-02-24

    ZnO thin films with nanorod structure were deposited using Ultrasonic Spray Pyrolysis method for seed growth, and Chemical Bath Deposition (CBD) for nanorod growth. High purity Zn-hydrate and Urea are used to control Ph were dissolved in ethanol and aqua bidest in Ultrasonic Spray Pyrolysis process. Glass substrate was placed above the heater plate of reaction chamber, and subsequently sprayed with the range duration of 5, 10 and 20 minutes at the temperatures of 3500 C. As for the Chemical Bath Deposition, the glass substrate with ZnO seed on the surface was immerse to Zn-hydrate, HMTA (Hexa Methylene Tetra Amine) and deionized water solution for duration of 3, 5 and 7 hour and temperatures of 600 C, washed in distilled water, dried, and annealed at 3500 C for an hour. The characterization of samples was carried out to reveal the surface morphology using Scanning Electron Microscopy (SEM). From the data, the combination of 5 minutes of Ultrasonic Spray Pyrolysis process and 3 hour of CBD has showed the best structure of nanorod. Meanwhile the longer Spraying process and CBD yield the bigger nanorod structure that have been made, and it makes the films more dense which make the nanorod collide each other and as a result produce unsymetric nanorod structure.

  3. Flame Spray Pyrolysis

    Microsoft Academic Search

    A. Purwanto; W.-N. Wang; K. Okuyama

    \\u000a Flame spray pyrolysis (FSP) has been applied for the production of powders industrially. FSP allows production of powders\\u000a with controlled characteristics at a high rate. In addition to the process parameters, several other factors are crucial for\\u000a nanoparticle production. Precursor type, as an example, is an important factor determining the particle size. Using metalorganic\\u000a precursors, particles in nano-sized order could

  4. Zinc Oxide Thin Films by Spray Pyrolysis Method

    Microsoft Academic Search

    K. Krunks; O. Bijakina; V. Mikli; T. Varema; E. Mellikov

    1999-01-01

    ZnO thin films were deposited by spraying of zinc acetate solution onto heated glass substrates at 670K. Highly textured in the (002) direction undoped ZnO films, exhibiting exciton emission bands in photoluminescence spectra at 8K, were grown. The initial stages of the thin film growth and effect of doping with In, Ce and Eu were studied. A spraying time of

  5. Properties of cadmium-doped tin oxide thin films prepared by spray pyrolysis method

    Microsoft Academic Search

    M. G. M. Choudhury; M. Mortuza Hossain; M. Mozibur Rahman; M. O. Hakim; M. K. R. Khan

    2003-01-01

    Cadmium doped Tin Oxide Thin Films have been prepared by Spray Pyrolysis Method on glass substrates at 350°C. Structural, electrical and optical properties have been measured. From XRD it is found that films deposited are crystalline in nature with tetragonal structure having lattice constant a=b=3.86 A° and c=5.62A°. Hall effect measurements show that films prepared are of n-type and the

  6. Nonlinear optical characterization of ZnS thin film synthesized by chemical spray pyrolysis method

    SciTech Connect

    G, Sreeja V; Anila, E. I., E-mail: anilaei@gmail.com; R, Reshmi, E-mail: anilaei@gmail.com; John, Manu Punnan, E-mail: anilaei@gmail.com [Optolectronic and Nanomaterials Research Laboratory, Department of Physics, Union Christian College, Aluva-683 102, Kerala (India); V, Sabitha P; Radhakrishnan, P. [International School of Photonics, CUSAT, Cochin-22 (India)

    2014-10-15

    ZnS thin film was prepared by Chemical Spray Pyrolysis (CSP) method. The sample was characterized by X-ray diffraction method and Z scan technique. XRD pattern showed that ZnS thin film has hexagonal structure with an average size of about 5.6nm. The nonlinear optical properties of ZnS thin film was studied by open aperture Z-Scan technique using Q-switched Nd-Yag Laser at 532nm. The Z-scan plot showed that the investigated ZnS thin film has saturable absorption behavior. The nonlinear absorption coefficient and saturation intensity were also estimated.

  7. Nonlinear optical characterization of ZnS thin film synthesized by chemical spray pyrolysis method

    NASA Astrophysics Data System (ADS)

    G, Sreeja V.; V, Sabitha P.; Anila, E. I.; R, Reshmi; John, Manu Punnan; Radhakrishnan, P.

    2014-10-01

    ZnS thin film was prepared by Chemical Spray Pyrolysis (CSP) method. The sample was characterized by X-ray diffraction method and Z scan technique. XRD pattern showed that ZnS thin film has hexagonal structure with an average size of about 5.6nm. The nonlinear optical properties of ZnS thin film was studied by open aperture Z-Scan technique using Q-switched Nd-Yag Laser at 532nm. The Z-scan plot showed that the investigated ZnS thin film has saturable absorption behavior. The nonlinear absorption coefficient and saturation intensity were also estimated.

  8. Preparation and electrochemical behaviour of LiMn 2O 4 thin film by spray pyrolysis method

    Microsoft Academic Search

    A. Subramania; S. N. Karthick; N. Angayarkanni

    2008-01-01

    Spinel lithium manganese oxide thin films were prepared on a stainless steel substrate by a spray pyrolysis method using a precursor solution of lithium acetate and manganese acetate in 1:1 (v\\/v) mixture of methanol and distilled water. Thermal analysis of the precursor solution was carried out for determining the required temperature for the phase formation or complete crystallization of the

  9. Photocatalytic Study of TiO2 Thin Films Deposited by DC Reactive Magnetron Sputtering and Spray Pyrolysis Methods

    Microsoft Academic Search

    A. I. Martínez; D. Acosta; A. López

    2004-01-01

    Amorphous and polycrystalline titanium dioxide thin films were deposited by DC reactive magnetron sputtering and spray pyrolysis methods on glass and glass coated with fluorine tin oxide (FTO). The films were characterized by X-ray diffraction, atomic force microscopy (AFM) and UV-visible spectroscopy. The photocatalytic activity of the samples was tested on the degradation of methylene blue. For films deposited by

  10. AFM and SEM studies of CdS thin films produced by an ultrasonic spray pyrolysis method

    Microsoft Academic Search

    M. C Baykul; A Balcioglu

    2000-01-01

    CdS films have been grown on a glass substrate by a spray pyrolysis method using CdCl2 (0.05 M) and H2NCSNH2 (0.05 M) solutions at a substrate temperature of 310°C. After the production of CdS thin films, one of the thin films was dissolved in the H2SO4 acid and the concentration of the Cd cations in the solution was tested by

  11. Mössbauer studies of nanocrystalline ZnFe2O4 particles prepared by spray pyrolysis method

    NASA Astrophysics Data System (ADS)

    Kurian, Jessyamma; John, Subin P.; M, Jacob Mathew; Reddy, V. R.; E, Abraham K.; Prasad, V. S.

    2015-02-01

    This paper reports the synthesis and characterization of nanoparticles of Zn Fe2O4 by spray pyrolysis method. XRD studies indicates that the particle formed are ultra fine (20 nm) associated with strain. The particle size is confirmed by TEM analysis. The room temperature Mossbauer spectrum shows only a doublet which could be indicative of either paramaganetic or superparamagnetic phase. The value of isomer shift is in the range 0.34±0.01 mm/s while quadruple splitting is in the range 0.48±0.01 mm/s. A series of low temperature studies has been performed and the spectra obtained at 20 K and 5K show the presence of two well resolved sextets, which are attributed to the Fe3+ ion in the tetrahedral and octahedral sites of the spinel structure. The application of external magnetic field yields a better fitting resolution of the sub spectra between A and B sites. The temperature dependant and in-field measurements yielded valuable insights about magnetic phase (superparamagnetic), local cation distribution among A sites and B sites, inversion parameter (? =0.74), canted spin alignment (?A = 29.58, ?B= 48.46) and the blocking temperature (TB= 50 K).

  12. Photocatalytic Study of TiO2 Thin Films Deposited by DC Reactive Magnetron Sputtering and Spray Pyrolysis Methods

    NASA Astrophysics Data System (ADS)

    Martínez, A. I.; Acosta, D.; López, A.

    2004-06-01

    Amorphous and polycrystalline titanium dioxide thin films were deposited by DC reactive magnetron sputtering and spray pyrolysis methods on glass and glass coated with fluorine tin oxide (FTO). The films were characterized by X-ray diffraction, atomic force microscopy (AFM) and UV-visible spectroscopy. The photocatalytic activity of the samples was tested on the degradation of methylene blue. For films deposited by the sputtering technique, we have studied the effect of the total pressure of an Ar-O2 gas mixture on phase composition, crystallinity and the photocatalytic properties. Also TiO2 thin films have been prepared by spray pyrolysis using a low concentration of titanium precursor at different substrates temperatures. The best photocatalytic properties in respect with methylene blue degradation were obtained for TiO2 thin films in anatase phase with an open structure. These films were prepared at high total pressure (16 mTorr) and at moderate substrate temperatures (400 °C) by sputtering and spray pyrolysis respectively.

  13. Electrochromic properties of nano-structured nickel oxide thin film prepared by spray pyrolysis method

    Microsoft Academic Search

    Sheng-Hui Lin; Fu-Rong Chen; Ji-Jung Kai

    2008-01-01

    In this study, we present a simple method to improve the electrochromic properties of a nickel oxide thin film. The method involves a three-step process—(a) conducting indium tin oxide (ITO) nano-particles were first sprayed onto a conducting substrate to form a porous nano-structured ITO layer, (b) nickel oxide film was then deposited onto the nano-structured ITO layer by a spray

  14. Investigation of the properties of nanostructured Li-doped NiO films using the modified spray pyrolysis method

    PubMed Central

    2013-01-01

    The lithium-doped nickel oxide (L-NiO) films were synthetized using the modified spray pyrolysis method with a two-step grown process. By observing the spectra of X-ray photoemission spectroscopy of L-NiO films, the intensity of Ni 2p3/2 peak of Ni3+ bonding state increases with increasing Li concentration that causes the decrease of transparency and resistivity. The L-NiO films with optimum characteristics were obtained at Li = 8 at%, where a p-type resistivity of 4.1 × 10?1 ? cm and optical transparency above 76% in the visible region are achieved. PMID:23331663

  15. Structure and magnetic properties of manganese-zinc-ferrites prepared by spray pyrolysis method

    NASA Astrophysics Data System (ADS)

    Kotsikau, Dzmitry; Ivanovskaya, Maria; Pankov, Vladimir; Fedotova, Yulia

    2015-01-01

    A spray pyrolysis of a water solution of iron, manganese and iron nitrates is applied to prepare Zn0.5Mn0.5Fe2O4 single-phase ferrite with a spinel-type structure. The samples are characterized by means of differential scanning calorimetry, scanning and transmission electron microscopy, X-ray diffraction, infrared and 57Fe Mössbauer spectroscopy. The mass magnetization ? and the magnetic susceptibility 1/? of the ferrites are measured as a function of temperature over the range of 78-728 K. The obtained sample contains nanoparticles with an average diameter d ?7 nm possessing MnxZnyFe3-(x+y)O4 spinel-type structure with a uniform distribution of manganese and zinc atoms over the ferrite lattice. The Curie temperature is determined to be 375 ÷ 380 K.

  16. Doped nanocrystalline ZnO powders for non-linear resistor applications by spray pyrolysis method.

    PubMed

    Hembram, Kaliyan; Vijay, R; Rao, Y S; Rao, T N

    2009-07-01

    Homogeneous and doped nanocrystalline ZnO powders (30-200 nm) were synthesized by spray pyrolysis technique. The spray pyrolysed powders were calcined in the temperature range of 500-750 degrees C. Formation of insulating pyrochlore phase started from 700 degrees C during the calcination itself. The calcined powders were compacted and sintered at different temperatures ranging from 900-1200 degrees C for 0.5-4 h. The densification behavior was found to be dependent on calcination temperature of the nanopowder. The resulting discs were found to have density (5.34-5.62 g/cc) in the range of 96-99% of theoretical density. The breakdown voltage value obtained for the nanopowder based non-linear resistor is 10.3 kV/cm with low leakage current density of 0.7 microA/cm2 and coefficient of nonlinearity as high as 193. The activation energy for grain growth of the doped ZnO nanopowder powders is 449.4 +/- 15 kJ/mol. PMID:19916460

  17. Preparation and characterization of copper(II) oxide thin films grown by a novel spray pyrolysis method

    Microsoft Academic Search

    W. DeSisto; M. Sosnowski; F. Smith; J. Deluca; R. Kershaw; K. Dwight; A. Wold

    1989-01-01

    A novel spray pyrolysis reactor was used to prepare thin films of CuO on silica substrates. The resulting films are characterized by x-ray diffraction, electron microscopy, optical and electrical measurements. The films were single phase, homogeneous, and uniform.

  18. Ultrasonic spray pyrolysis growth of ZnO and ZnO:Al nanostructured films: Application to photocatalysis

    E-print Network

    Ultrasonic spray pyrolysis growth of ZnO and ZnO:Al nanostructured films: Application on glass substrates by ultrasonic spray pyrolysis, a simple, environmental-friendly and inexpensive method deposited using the ultrasonic spray pyrolysis (USP) on Corning glass substrates at 400 C. Furthermore

  19. Producing Quantum Dots by Spray Pyrolysis

    NASA Technical Reports Server (NTRS)

    Banger, Kulbinder; Jin, Michael H.; Hepp, Aloysius

    2006-01-01

    An improved process for making nanocrystallites, commonly denoted quantum dots (QDs), is based on spray pyrolysis. Unlike the process used heretofore, the improved process is amenable to mass production of either passivated or non-passivated QDs, with computer control to ensure near uniformity of size.

  20. Ceramic powder synthesis by spray pyrolysis

    Microsoft Academic Search

    Gary L. Messing; Shi-Chang Zhang; Gopal V. Jayanthi

    1993-01-01

    A variety of spray pyrolysis (SP) techniques have been developed to directly produce ceramic powders from solutions. This paper reviews the current status of these processes in terms of the process parameters that enable the formation of particles with controlled morphology and composition. A model incorporating solute diffusion in the droplet and solvent evaporation from the droplet surface is presented

  1. The effect of substrate temperature on the structure of tin oxide thin films obtained by spray pyrolysis method

    Microsoft Academic Search

    S. M. Rozati

    2006-01-01

    Undoped SnO2 thin films were prepared on glass substrates by spray pyrolysis technique. The variation in the structural properties with a variation in the substrate temperature was investigated by means of X-ray diffraction (XRD). In this paper we employed the XRD technique to achieve the impression of the crystalline planes and also the possible orientation of crystallites in the films

  2. Thin Film Electrode Materials Li4Ti5O12 and LiCoO2 Prepared by Spray Pyrolysis Method

    NASA Astrophysics Data System (ADS)

    Takahashi, M.; Tani, J.; Kido, H.; Hayashi, A.; Tadanaga, K.; Tatsumisago, M.

    2011-05-01

    The Li4Ti5O12 and the LiCoO2 have been considered as promising candidates of electrode materials for all-solid-state lithium secondary batteries. The spray pyrolysis method is a useful economical technique to prepare various thicknesses of oxide films though have not been intensively studied for fabrication of thin film lithium batteries. Thin films of Li4Ti5O12 and LiCoO2 electrode materials about 100-400 nm were prepared on quartz and gold substrates by the spray pyrolysis method by using Liacac and, TiO(acac)4 or Co(acac)3 with DMF solvent as starting materials. Electric properties as electrode materials for lithium batteries were estimated by using 3 probe liquid cells with liquid electrolyte LiPF6 in EC-DMC and Li metal as reference and counter electrodes. Structure and morphology of the films were investigated by XRD and SEM. Crystalline Li4Ti5O12 and LiCoO2 thin films were found to be prepared over 700 °C of substrate temperature. Cyclic voltammograms of the Li4Ti5O12 electrode thin films showed sharp oxidation and reduction peaks around 1.6 and 1.5 V, respectively. Charge-discharge curves for both Li4Ti5O12 and LiCoO2 electrode thin films showed discharge plateaus around 1.4 and 3.8 V with about 80 mAhg-1 of capacity. These results showed that these electrode thin films prepared by the spray pyrolysis method are electrochemically active and spray pyrolysis method is a promising technique to prepare thin film electrode materials.

  3. Spray pyrolysis of CuIn(S,Se)2 solar cells with 5.9% efficiency: a method to prevent Mo oxidation in ambient atmosphere.

    PubMed

    Ho, John C W; Zhang, Tianliang; Lee, Kian Keat; Batabyal, Sudip K; Tok, Alfred I Y; Wong, Lydia H

    2014-05-14

    Direct spray pyrolysis to form CuInS2 (CIS) on molybdenum substrate in ambient environment has been a challenge because of the ease of Mo oxidation at low temperatures. MoO2 formation affects the wettability of precursor solution during spray pyrolysis, which degrades the uniformity of CIS film and acts as a resistive layer for carrier transport. In this paper, Mo oxidation was prevented by using excess sulfur in the precursor solution under a gradual heating and spray process. A thin precursor layer was initially deposited as a barrier layer to prevent oxygen adsorption on Mo surface before the temperature was increased further to form polycrystalline CuInS2. The CuIn(S,Se)2 (CISSe) device fabricated from selenization of the spray-pyrolyzed CIS film exhibited a power conversion efficiency (PCE) of 5.9%. The simple spray method proposed here can be used to deposit a variety of Cu-based chalcopyrite precursor to produce high-quality thin film solar cells. PMID:24697706

  4. Production and characterization of submicron hematite (??Fe{sub 2}O{sub 3}) particles by ultrasonic spray pyrolysis method

    SciTech Connect

    K?rc?, Burak; Ebin, Burçak; Gürmen, Sebahattin [Department of Metallurgical and Materials Engineering, Istanbul Technical University Istanbul (Turkey)

    2013-12-16

    The ultrasonic spray pyrolysis (USP) method has been used to prepare submicron hematite (??Fe{sub 2}O{sub 3}) particles using two different industrial pickling solutions of iron chloride (41 g/L FeCl{sub 2} and 54 g/L FeCl{sub 3}) Particles were obtained by thermal decomposition of generated aerosols from precursor solutions using 1.7 MHz ultrasonic atomizer. Reaction temperature was set up at 800 °C and aerosol droplets were carried into the heated zone by 0.7 L/min air flow rate. X-Ray Diffraction (XRD) studies were used to determine the crystal structure and crystallite size of the particles. Results indicate that patterns correspond to hematite phase with rhombohedral crystal structure (space group: R3c). The crystallite sizes of particles prepared from FeCl{sub 2} and FeCl{sub 3} solutions that were calculated from Scherrer equation are 59 and 33 nm, respectively. Scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS) investigations give detailed information about particle size, morphology and composition. SEM micrographs show that hematite nanoparticles aggregate and formed spherical secondary particles in submicron range.

  5. Improved superconducting properties of MgB2 thin films fabricated by ultrasonic spray pyrolysis method at high temperature

    NASA Astrophysics Data System (ADS)

    Yakinci, M. Eyyuphan; Yakinci, Z. Deniz; Aksan, M. Ali; Balci, Yakup

    2012-12-01

    High quality MgB2 superconducting thin films have been successfully prepared by 2.4 MHz ultrasonic spray pyrolysis (USP) system on single crystal Al2O3 (0 0 1) substrates. The microstructure, electrical and magnetic properties of approximately 500-600 nm thick films were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) in conjunction with the energy dispersive X-ray analysis (EDX), resistance versus temperature (R-T) and magnetization measurements (M-H) under different magnetic fields and transport critical current density (Jc). Films were first heat treated in situ in the spraying chamber with an extra Mg powder during deposition to compensate excess evaporation of Mg from the films and then additionally heat treated in Ar atmosphere at 700 °C for a short time. According to the results obtained, orientation on any particular direction for the crystal growth was not seen. Homogeneous, highly dense and highly smooth surface morphology and low resistance have been achieved under optimum conditions. Optimally treated films exhibited relatively high transport critical current density of 2.37 × 105 A cm-2. These results have been also compared with the Jcmag results calculated from the M-H curves. The electrical resistance property of the best samples was obtained to be 39.5 and 37.4 K for Tc and Tzero, respectively.

  6. Porous carbon powders prepared by ultrasonic spray pyrolysis.

    PubMed

    Skrabalak, Sara E; Suslick, Kenneth S

    2006-10-01

    New, thermally robust meso- and macroporous carbon powders were prepared by ultrasonic spray pyrolysis (USP) of aqueous solutions using an inexpensive high-frequency ultrasound generator from a household humidifier. We choose our molecular precursors rationally, so that the expected decomposition pathways produce only remnant carbon atoms. Specifically, our rational design criterion led to halo-organic carboxylate salts, whose pyrolysis yields well-defined carbon solids with a temporary template being generated in situ, simply an inorganic salt, which is easily dissolved during aqueous workup. The materials have been characterized by SEM, TEM, XRD, 13C NMR MAS, XPS, FTIR spectroscopy, and BET surface area measurements. Changing the alkali metal alters the morphology and pore structure of the final material, which can be explained in terms of the observed differences in the DSC and TGA of the various precursors. This preparatory method provides an extremely facile and versatile method for the generation of meso- and macroporous carbons. PMID:17002346

  7. EFFECT OF ANTIMONY AND FLUORINE DOPING ON ELECTRICAL, OPTICAL AND STRUCTURAL PROPERTIES OF TIN OXIDE FILMS PREPARED BY SPRAY PYROLYSIS METHOD

    Microsoft Academic Search

    K. S. SHAMALA; L. C. S. MURTHY; K. NARASIMHA RAO

    2006-01-01

    Undoped, antimony doped and fluorine doped tin oxide films have been prepared by spray pyrolysis technique. The films were deposited on glass substrates at temperatures ranging between 300°C and 370°C by spraying an alcoholic solution of tin tetra chloride (SnCl4). Dopants used were antimony tri chloride (SbCl3) for antimony doped tin oxide (ATO) films, and ammonium fluoride (NH4F) for fluorine

  8. Band positions and photoelectrochemical properties of Cu2ZnSnS4 thin films by the ultrasonic spray pyrolysis method

    NASA Astrophysics Data System (ADS)

    Huang, Sheng; Luo, Wenjun; Zou, Zhigang

    2013-06-01

    Cu2ZnSnS4 (CZTS) films were prepared by ultrasonic spray pyrolysis on FTO (SnO2?:?F on glass) substrates. The effect of substrate temperatures on the phases, morphologies and photoelectrochemical properties of CZTS films was investigated. X-ray diffraction, Raman spectrum and energy-dispersive spectrometry were used to confirm the phases of the CZTS films. The samples at 400 and 450 °C exhibited a higher photocurrent than the samples at 350 and 500 °C. Moreover, the band positions of CZTS were measured by a facile Mott-Schottky method for the first time. Different from the previous calculation and experimental data, the conduction band position of CZTS was 0.26 eV higher than that of CdS. The results can explain well the low open circuit voltage of a CZTS-based solar cell and offer guidance to improving CZTS solar cells.

  9. Effect of nickel doping on physical properties of zinc oxide thin films prepared by the spray pyrolysis method

    NASA Astrophysics Data System (ADS)

    Jlassi, M.; Sta, I.; Hajji, M.; Ezzaouia, H.

    2014-05-01

    In this study, undoped and nickel-doped zinc oxide thin films (ZnO:Ni) were deposited on glass substrates using a spray pyrolysis technique. The effects of the Zn concentration in the initial solution and the substrate temperature on the physical properties of the thin films are studied. The results show that the optimum Zn concentration and substrate temperature for preparation of basic undoped ZnO films with n-type conductivity and high optical transparency are 0.02 M and 350 °C, respectively. Then, by using these optimized deposition parameters, nickel-doped zinc oxide films are prepared. Surface morphology and crystalline structure of the films are investigated by atomic force microscopy (AFM) and X-ray diffractometer. X-ray diffraction (XRD) patterns show that the films are polycrystalline. The structural analysis shows that all the samples have a hexagonal structure. The crystallite size and the preferred orientation were calculated from the XRD data. From AFM investigations, the surface morphology of the nanostructured films is found to depend on the concentration of Ni. Optical measurements have shown that an increase in the Ni doping results in a reduction in the optical transmission of the layer, but it remains higher than 80% for Ni doping greater than 8 wt%. At the same time, the optical gap increases from 3.4 to 4 eV when the Ni ratio increases. The electrical measurements show that the resistance of the films varies with the duration of pulverization and the nickel content of the film. Low values for the electrical resistivity (around 103 ? cm) were obtained for Ni-doped ZnO thin films.

  10. Photoluminescence of spray pyrolysis deposited ZnO nanorods.

    PubMed

    Kärber, Erki; Raadik, Taavi; Dedova, Tatjana; Krustok, Jüri; Mere, Arvo; Mikli, Valdek; Krunks, Malle

    2011-01-01

    Photoluminescence of highly structured ZnO layers comprising well-shaped hexagonal rods is presented. The ZnO rods (length 500-1,000 nm, diameter 100-300 nm) were grown in air onto a preheated soda-lime glass (SGL) or ITO/SGL substrate by low-cost chemical spray pyrolysis method using zinc chloride precursor solutions and growth temperatures in the range of 450-550°C. We report the effect of the variation in deposition parameters (substrate type, growth temperature, spray rate, solvent type) on the photoluminescence properties of the spray-deposited ZnO nanorods. A dominant near band edge (NBE) emission is observed at 300 K and at 10 K. High-resolution photoluminescence measurements at 10 K reveal fine structure of the NBE band with the dominant peaks related to the bound exciton transitions. It is found that all studied technological parameters affect the excitonic photoluminescence in ZnO nanorods.PACS: 78.55.Et, 81.15.Rs, 61.46.Km. PMID:21711895

  11. Photoluminescence from Cu activated glass prepared by spray pyrolysis

    Microsoft Academic Search

    A. Ortiz; E Andrade; M Garc??a; C Falcony; J. C Pineda; E. P Zavala

    1998-01-01

    Photoluminescent copper activated glass has been prepared by the spray pyrolysis technique at atmospheric pressure using air as carrier gas. The Cu source is an aqueous solution of CuCl2 sprayed at relatively low substrate temperature, (420–510°C). Rutherford backscattering measurements show that the copper diffuses into the glass substrate. The photoluminescence spectra from these samples show a peak at about 500nm.

  12. Flame spray pyrolysis for sensing at the nanoscale.

    PubMed

    Kemmler, J A; Pokhrel, S; Mädler, L; Weimar, U; Barsan, N

    2013-11-01

    Progress in developing novel gas sensors based on semiconducting metal oxides (SMOX) has been hindered by the cumbersome fabrication technologies currently employed. They involve time intensive synthesis procedures for gaining sensitive materials and preparation of the inks employed for realizing sensing layers. In this paper we review the opportunities offered by the relatively young method of flame spray pyrolysis, with which it is possible not only to synthesize a broad selection of SMOX in pure or doped form, but also to simultaneously deposit thick and highly porous gas sensitive films on a variety of substrates. In less than ten years the properties of nine base materials have been evaluated for all most relevant target gases and the obtained results are promising for future development. PMID:24113649

  13. Flame spray pyrolysis for sensing at the nanoscale

    NASA Astrophysics Data System (ADS)

    Kemmler, J. A.; Pokhrel, S.; Mädler, L.; Weimar, U.; Barsan, N.

    2013-11-01

    Progress in developing novel gas sensors based on semiconducting metal oxides (SMOX) has been hindered by the cumbersome fabrication technologies currently employed. They involve time intensive synthesis procedures for gaining sensitive materials and preparation of the inks employed for realizing sensing layers. In this paper we review the opportunities offered by the relatively young method of flame spray pyrolysis, with which it is possible not only to synthesize a broad selection of SMOX in pure or doped form, but also to simultaneously deposit thick and highly porous gas sensitive films on a variety of substrates. In less than ten years the properties of nine base materials have been evaluated for all most relevant target gases and the obtained results are promising for future development.

  14. Effect of fuel rate and annealing process of LiFePO{sub 4} cathode material for Li-ion batteries synthesized by flame spray pyrolysis method

    SciTech Connect

    Halim, Abdul; Setyawan, Heru; Machmudah, Siti; Nurtono, Tantular; Winardi, Sugeng [Chemical Engineering, Sepuluh Nopember Institute of Technology, Kampus Sukolilo Surabaya Indonesia 60111 (Indonesia)

    2014-02-24

    In this study the effect of fuel rate and annealing on particle formation of LiFePO{sub 4} as battery cathode using flame spray pyrolysis method was investigated numerically and experimentally. Numerical study was done using ANSYS FLUENT program. In experimentally, LiFePO{sub 4} was synthesized from inorganic aqueous solution followed by annealing. LPG was used as fuel and air was used as oxidizer and carrier gas. Annealing process attempted in inert atmosphere at 700°C for 240 min. Numerical result showed that the increase of fuel rate caused the increase of flame temperature. Microscopic observation using Scanning Electron Microscopy (SEM) revealed that all particles have sphere and polydisperse. Increasing fuel rate caused decreasing particle size and increasing particles crystallinity. This phenomenon attributed to the flame temperature. However, all produced particles still have more amorphous phase. Therefore, annealing needed to increase particles crystallinity. Fourier Transform Infrared (FTIR) analysis showed that all particles have PO4 function group. Increasing fuel rate led to the increase of infrared spectrum absorption corresponding to the increase of particles crystallinity. This result indicated that phosphate group vibrated easily in crystalline phase. From Electrochemical Impedance Spectroscopy (EIS) analysis, annealing can cause the increase of Li{sup +} diffusivity. The diffusivity coefficient of without and with annealing particles were 6.84399×10{sup ?10} and 8.59888×10{sup ?10} cm{sup 2} s{sup ?1}, respectively.

  15. Effects of ultraviolet light on B-doped CdS thin films prepared by spray pyrolysis method using perfume atomizer

    NASA Astrophysics Data System (ADS)

    Novruzov, V. D.; Keskenler, E. F.; Tomakin, M.; Kahraman, S.; Gorur, O.

    2013-09-01

    Boron doped CdS thin films were deposited by spray pyrolysis method using perfume atomizer. The effects of ultraviolet light on the structural, optical and electrical properties of B-doped CdS thin films were investigated as a function of dopant concentration (B/Cd). X-ray diffraction studies showed that all samples were polycrystalline nature with hexagonal structure. It was determined that the preferred orientation of non-illuminated samples changes from (1 0 1) to (0 0 2) with B concentration. The c lattice constant of films decreases from 6.810 Å to 6.661 Å with boron doping. The XRD peak intensity increased with the illumination for almost all the samples. The lattice parameters of B-doped samples remained nearly constant after illumination. It was found that the optical transmittance, photoluminescence spectra, resistivity and carrier concentration of the B-doped samples are stable after the illumination with UV light. Also the effects of UV light on B-doped CdS/Cu2S solar cell were investigated and it was determined that photoelectrical parameters of B-doped solar cell were more durable against the UV light.

  16. Spray pyrolysis deposition of cadmium–zinc oxide thin films

    Microsoft Academic Search

    O. Vigil; L Vaillant; F Cruz; G Santana; A Morales-Acevedo; G Contreras-Puente

    2000-01-01

    Mixed thin film oxides of cadmium and zinc with different compositions were deposited on glass substrates by spray pyrolysis. The effect of the various parameters on the growth and on the film properties is presented. The sample structure was studied by X-ray diffraction (XRD) having found the presence of a cubic phase resembling that of pure CdO XRD pattern for

  17. Effect of aluminium doping on zinc oxide thin films grown by spray pyrolysis

    Microsoft Academic Search

    A. El Manouni; F. J. Manjón; M. Mollar; B. Marí; R. Gómez; M. C. López; J. R. Ramos-Barrado

    2006-01-01

    We report the structural, optical, and electrical characterization of aluminium-doped zinc oxide thin films grown by the spray pyrolysis method. We report the effect of Al concentration on the resistivity and on the X-ray diffraction, transmittance, photoluminescence and Raman scattering spectra of the films. The minimum resistivity is obtained for the sample with nominal Al concentration of 1%. An increase

  18. Investigations of AlGaN/GaN MOS-HEMT with Al2O3 deposition by ultrasonic spray pyrolysis method

    NASA Astrophysics Data System (ADS)

    Chou, Bo-Yi; Hsu, Wei-Chou; Liu, Han-Yin; Lee, Ching-Sung; Wu, Yu-Sheng; Sun, Wen-Ching; Wei, Sung-Yen; Yu, Sheng-Min; Chiang, Meng-Hsueh

    2015-01-01

    This work investigates Al2O3/AlGaN/GaN metal-oxide-semiconductor high electron mobility transistors (MOS-HEMTs) grown on SiC substrate by using the non-vacuum ultrasonic spray pyrolysis deposition (USPD) method. The Al2O3 was deposited as gate dielectric and surface passivation simultaneously to effectively suppress gate leakage current, enhance output current density, reduce RF drain current collapse, and improve temperature-dependent stabilities performance. The present MOS-HEMT design has shown improved device performances with respect to a Schottky-gate HEMT, including drain-source saturation current density at zero gate bias (IDSS: 337.6 mA mm?1 ? 462.9 mA mm?1), gate-voltage swing (GVS: 1.55 V ? 2.92 V), two-terminal gate-drain breakdown voltage (BVGD: ?103.8 V ? ?183.5 V), unity-gain cut-off frequency (fT: 11.3 GHz ? 17.7 GHz), maximum oscillation frequency (fmax: 14.2 GHz ? 19.1 GHz), and power added effective (P.A.E.: 25.1% ? 43.6%). The bias conditions for measuring fT and fmax of the studied MOS-HEMT (Schottky-gate HEMT) are VGS = ?2.5 (?2) V and VDS = 7 V. The corresponding VGS and VDS biases are ?2.5 (?2) V and 15 V for measuring the P.A.E. characteristic. Moreover, small capacitance-voltage (C–V) hysteresis is obtained in the Al2O3-MOS structure by using USPD. Temperature-dependent characteristics of the present designs at 300–480 K are also studied.

  19. Synthesis and characterization of YSZ by spray pyrolysis technique

    NASA Astrophysics Data System (ADS)

    Jadhav, L. D.; Jamale, A. P.; Bharadwaj, S. R.; Varma, Salil; Bhosale, C. H.

    2012-10-01

    The conventional zirconium based yttria stabilized zirconia (YSZ) electrolyte has been synthesized from aqueous solution by cost effective air atomized spray pyrolysis technique (SPT). The films show well developed dense, nanocrystalline material. The thermal analysis of zirconyl nitrate reveals the possibility of crystalline YSZ film formation only above 400 °C, which is confirmed from the XRD pattern. The activation energy of 1.14 eV clarifies its conductivity behavior, verified from DC and AC conductivity measurements.

  20. Spray pyrolysis deposition and characterization of titanium oxide thin films

    Microsoft Academic Search

    L Castañeda; J. C Alonso; A Ortiz; E Andrade; J. M Saniger; J. G Bañuelos

    2003-01-01

    Titanium oxide films were deposited by the ultrasonic spray pyrolysis process using titanium oxide acetylacetonate (TAAc) as source material dissolved in pure methanol. As-deposited films show the anatase crystalline structure, while annealed samples at 850°C have the rutile phase. Rutherford backscattering measurements indicate that the deposited films are formed by stoichiometric TiO2 material. Root-mean-square (rms) roughness depends on the substrate

  1. Fabrication of functional nanomaterials using flame assisted spray pyrolysis

    SciTech Connect

    Purwanto, Agus, E-mail: aguspur@uns.ac.id [Chemical Engineering Department, Faculty of Engineering, Sebelas Maret University, Surakarta 632112 (Indonesia)

    2014-02-24

    Flame assisted spray pyrolysis (FASP) is a class of synthesis method for nanomaterials fabrication. The ability to control nanomaterials characteristics and easy to be-scaled up are the main features of FASP. The crystallinity and particles size of the prepared nanomaterials can be easily controlled by variation of fuel flow rate. The precursor concentration, carrier gas flow rate, and carrier gas can be also used to control the prepared nanomaterials. Energy related nanomaterials preparation uses as the example case in FASP application. These material are yttrium aluminum garnet (YAG:Ce) and tungsten oxide (WO{sub 3}). It needs strategies to produce these materials into nano-sized order. YAG:Ce nanoparticles only can be synthesized by FASP using the urea addition. The decomposition of urea under high temperature of flame promotes the breakage of YAG:Ce particles into nanoparticles. In the preparation of WO{sub 3}, the high temperature flame can be used to gasify WO{sub 3} solid material. As a result, WO{sub 3} nanoparticles can be prepared easily. Generally, to produce nanoparticles via FASP method, the boiling point of the material is important to determine the strategy which will be used.

  2. Improvement of the redox durability of Ni-gadolinia doped ceria anodes due to the use of the composite particles prepared by spray pyrolysis method

    NASA Astrophysics Data System (ADS)

    Hashigami, Satoshi; Yoshida, Hiroyuki; Ueno, Daisuke; Kawano, Mitsunobu; Inagaki, Toru

    2014-02-01

    The redox behaviors of Ni-gadolinia doped ceria (GDC) anodes with different compositions and microstructures were investigated. When the NiO-GDC composite particles prepared by spray pyrolysis were used for an anode (SP-cells), the decrease of the cell voltage during the redox cycles was smaller than that of the cell with anode using the mixed powder of NiO and GDC (Mix-cells). Current interruption and AC impedance measurements were examined before redox cycle, after 1st redox cycle, and after 10th redox cycles. The ohmic and polarization losses after 10th cycles for SP-cells were smaller than those for Mix cells. The morphology changes of the Ni-GDC anodes between before-redox cycle and after-10th redox cycles were observed by scanning electron microscopy (SEM). These results indicate that the use of NiO-GDC composite particles suppressed the excessive agglomerations of nickel grains during the redox cycles.

  3. Near field behavior of SnO(2) particle-layer deposited on standard optical fiber by electrostatic spray pyrolysis method.

    PubMed

    Cusano, A; Pilla, P; Consales, M; Pisco, M; Cutolo, A; Buosciolo, A; Giordano, M

    2007-04-16

    We report the emergent optical near field profiles from standard single mode optical fibers on the cleaved end of which were deposited particle layers of SnO(2). The layers, composed of micron and sub-micron sized particles, were deposited by means of Electrostatic Spray Pyrolysis (ESP) technique. Powerful analytical tools such as Atomic Force Microscopy (AFM) and Scanning Near-field Optical Microscopy (SNOM) were used to obtain simultaneously the SnO(2) layers topography and the related optical near field intensity distribution, when the fiber-substrate is illuminated by a light radiation in NIR range. We show that isolated microstructures, positioned in correspondence of the fiber core, reveal highly unusual capability of locally enhancing the collected optical near field. The observed phenomenon leads to new concepts of fiber optic chemical sensors and in fiber microsystems as well. PMID:19532764

  4. Microstructure and electrical properties of iron oxide thin films deposited by spray pyrolysis

    Microsoft Academic Search

    Alaa A Akl

    2004-01-01

    Microstructure and electrical properties of iron oxide Fe2O3 thin films prepared by spray pyrolysis method have been experimentally characterized. The effect of substrate temperature as well as deposition time on the structural features (crystallite size and microstrain) and electric resistivity of these films has been investigated. X-ray diffraction (XRD) and scanning electron microscope (SEM) characterized the structure study. The results

  5. Microstructural characterization of annealed cadmium–zinc oxide thin films obtained by spray pyrolysis

    Microsoft Academic Search

    F Cruz-Gandarilla; Arturo Morales-Acevedo; O Vigil; M Hesiquio-Garduño; L Vaillant; G Contreras-Puente

    2003-01-01

    The structural properties of annealed (ZnO)x(CdO)1?x thin films are studied by x-ray diffraction methods. The films were obtained by spray pyrolysis using different values for the nominal composition (x), and then they were annealed at 450°C from 0 to 120min. The structural analysis confirms previous results on the formation of a homogeneously mixed oxide semiconductor, but in which crystalline and

  6. Carbon Powders Prepared by Ultrasonic Spray Pyrolysis of Substituted Alkali Benzoates Sara E. Skrabalak and Kenneth S. Suslick*

    E-print Network

    Suslick, Kenneth S.

    Carbon Powders Prepared by Ultrasonic Spray Pyrolysis of Substituted Alkali Benzoates Sara E Ultrasonic spray pyrolysis (USP) has been used to prepare carbon spheres from aqueous solutions limiting their utility. Ultrasonic spray pyrolysis (USP) is well-suited for the continuous production

  7. Tin oxide thin films deposited by ultrasonic spray pyrolysis

    Microsoft Academic Search

    D. Jadsadapattarakul; C. Euvananont; C. Thanachayanont; J. Nukeaw; T. Sooknoi

    2008-01-01

    This study investigated microstructure of SnO2 thin films deposited by ultrasonic spray pyrolysis technique using 0.2M of SnCl4·5H2O in absolute ethanol as a precursor. The deposition temperature (350–450°C) and time (20–90min) were varied. The influence of film-deposition conditions on grain size and orientation were discussed. The deposited SnO2 films were textured polycrystalline films. The preferred orientation of SnO2 films were

  8. Characterization of Undoped and Cu-Doped ZnO Thin Films Deposited on Glass Substrates by Spray Pyrolysis

    NASA Astrophysics Data System (ADS)

    Metin, Bedir; Mustafa, Öztas; A. Necmeddin, Yazici; E. Vural, Kafadar

    2006-04-01

    Undoped and copper doped zinc oxide (ZnO) thin films have been prepared on glass substrates by spray pyrolysis technique. The films were doped with copper using the direct method by addition of a copper salt (CuCl2) in the spray solution of ZnO. Variation of structural, electrical, optical and thermoluminescence (TL) properties with doping concentrations is investigated in detail.

  9. Generation of size-monodisperse metal nanoparticles by spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Kim, Jung Hyeun

    2003-10-01

    Size-monodisperse pure copper metal particles were formed from metal salt precursors in a spray pyrolysis process that uses ethanol as a co-solvent, thus avoiding the addition of hydrogen or other reducing gases. In addition, the uniform-size particles were classified using a droplet impactor plate, which eliminates larger droplets at the atomizer prior to entering the reactor furnace. To investigate the role of ethanol co-solvent for the formation of phase pure metal particles in the spray pyrolysis process, the generation of phase pure copper and nickel particles from aqueous solutions of copper acetate, copper nitrate, and nickel nitrates over the temperature range of 450°C to 1000°C was demonstrated. Addition of ethanol as a co-solvent played a crucial role in producing phase pure metal powders. Results of a modeling study of ethanol decomposition kinetics suggested that co-solvent decomposition created a strong reducing atmosphere during spray pyrolysis via in-situ production of hydrogen and carbon monoxide. With the size-classified copper spheres as well as monodisperse polystyrene latex (PSL) spheres, the polarization and intensity of light scattered by those spheres, having diameters ranging from 92 nm to 218 nm, deposited on silicon substrates were measured using 442 nm, 532 nm, and 633 nm light. The results showed that accurate calculation of the scattering of light by a metal sphere requires that the near-field interaction between the sphere and its image is included in a complete manner. The normal incidence approximation did not suffice for this interaction, and the existence of any thin oxide layer on the substrate must be included in the calculation. In order to further examine the effects of light scattering by particles on a silicon substrate having an oxide coating, the polarization and intensity of light scattered by 101 nm polystyrene latex (PSL) and 100 nm copper spheres, deposited on silicon substrates containing various thickness of oxide films, were measured using 532 nm light. Substrate film thickness had a strong influence on sizing of surface bound particles. Particle shape had a greater effect on light scattering behavior for very thin substrate oxide films as compared to thick oxide films.

  10. Effect of doping level and spray time on zinc oxide thin films produced by spray pyrolysis for transparent electrodes applications

    Microsoft Academic Search

    Z. Ben Achour; T. Ktari; B. Ouertani; O. Touayar; B. Bessais; J. Ben Brahim

    2007-01-01

    In this paper, we present the results of optical, electrical and structural properties of zinc oxide (ZnO) semiconductors thin layers with various aluminium (Al) doping level and deposited at different spray time using the spray pyrolysis technique in atmospheric pressure. The study of optical properties from reflection and transmission spectra shows a high transmission value a band gap energy of

  11. Structural, electrical, optical, thermoelectrical and photoconductivity properties of the SnO2-Al2O3 binary transparent conducting films deposited by the spray pyrolysis method

    NASA Astrophysics Data System (ADS)

    Moharrami, F.; Bagheri-Mohagheghi, M.-M.; Azimi-Juybari, H.; Shokooh-Saremi, M.

    2012-01-01

    In this paper, the SnO2-Al2O3 binary thin-film system has been deposited on a glass substrate by the spray pyrolysis technique. The effect of aluminum concentration on the structural, electrical, thermoelectrical, optical and photoconductivity properties of films was studied. The [Al]/[Sn] atomic ratio was in the range 0-100 at.% in solution. X-ray diffraction analysis shows that all films with different doping levels have polycrystalline SnO2 cassiterite phase. At doping levels of 40 at.% and above, the Al2O3 phase was observed and the sheet resistance of the films increased with increasing Al doping in the ranges from 5 at.% to less than 40 at.% and more than 60 at.% due to the substitution of Al3+ with Sn4+. Minimum sheet resistance of films was found in the range 40-60 at.%. Using Hall effect measurements, the majority carriers concentration obtained was of the order of 1018 cm-3. Hall effect and thermoelectrical measurements show that at doping levels between 10 and 20% and also higher than 60 at.%, majority carriers change from electrons (n-type conduction) to holes (p-type conduction). Also, a higher Seebeck coefficient value equal to -341 ?V K-1 was obtained for the 30 at.% Al-doping level. The average transmittance of the films at low doping levels was about 75-90%. The photoconductivity properties of SnO2-Al2O3 thin films increased with increasing doping level.

  12. Magnetic and porous nanospheres from ultrasonic spray pyrolysis.

    PubMed

    Suh, Won Hyuk; Suslick, Kenneth S

    2005-08-31

    We have used an inexpensive high-frequency ultrasound generator from a household humidifier to create a useful source for ultrasonic spray pyrolysis and produced submicrometer silica particles that are porous on the nanometer scale. By using two heated zones, we first initiate polymerization of organic monomers in the presence of silica colloid, which creates in situ a composite of silica with an organic polymer, followed by a second heating to pyrolyze and remove the polymer. The morphology and surface area of the final porous silica are controlled by varying the silica-to-organic monomer ratio. In a single flow process, ferromagnetic cobalt nanoparticles can be easily encapsulated in the porous silica, and the resulting nanospheres are extremely resistant to air oxidation. Products were characterized by SEM, (S)TEM, EDS, XPS, and SQUID. PMID:16117540

  13. SnS2 Thin Film Deposition by Spray Pyrolysis

    NASA Astrophysics Data System (ADS)

    Jaber, Abdallah Yahia; Alamri, Saleh Noaiman; Aida, Mohammed Salah

    2012-06-01

    Tin disulfide (SnS2) thin films have been synthesized using a simplified spray pyrolysis technique using a perfume atomizer. The films were deposited using two different solutions prepared by the dilution of SnCl2 and thiourea in distilled water and in methanol. The obtained films have a microcrystalline structure. The film deposited using methanol as the solvent is nearly stochiometric SnS2 with a spinel phase having a (001) preferential orientation. The film prepared with an aqueous solution is Sn-rich. Scanning electronic microscopy (SEM) images reveal that the film deposited with the aqueous solution is rough and is formed with large wires. However, the film deposited with methanol is dense and smooth. Conductivity measurements indicate that the aqueous solution leads to an n-type semiconductor, while methanol leads to a p-type semiconductor.

  14. The thermal stability of porous alumina/stainless steel catalyst support obtained by spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Novakovi?, Tatjana; Radi?, Nenad; Grbi?, Boško; Dondur, Vera; Mitri?, Miodrag; Randjelovi?, Danijela; Stoychev, Dimitar; Stefanov, Plamen

    2008-12-01

    Active porous alumina coatings were obtained by deposition of boehmite sol on stainless steel (SS) substrate by spray pyrolysis method. The temperature and the doping of polyethylene glycol (PEG) and La 3+ in the boehmite sol effects on the textural and structural properties and surface morphology of alumina coatings on stainless steel samples are presented. It was found that the addition of polyethylene glycol combined with La 3+ to the boehmite sol before spraying improves the thermal stability of porous alumina coatings. X-ray diffraction patterns of a doped sample, even after 5 h at 1000 °C, point out to the presence only of ?-Al 2O 3, with a SBET of 74 m 2/g. XPS data and SEM photographs of coated samples show that alumina were well deposited on the metallic supports. The absence of any lanthanum compounds indicates very well homogeneous dispersion of La 3+-ions on the surface of alumina crystallites. AFM images show sphere like alumina grains and agglomerates with surface roughness from 60 to 180 nm, depending on temperature and doping. Surface roughness of doped alumina samples was higher than that of non-doped. It was pointed out that spray pyrolysis method enables preparation of alumina layers with relatively high specific surface area, suitable for applications as catalysts supports.

  15. Synthesis and characterization of iron-impregnated porous carbon spheres prepared by ultrasonic spray pyrolysis

    E-print Network

    Suslick, Kenneth S.

    Synthesis and characterization of iron-impregnated porous carbon spheres prepared by ultrasonic process using ultrasonic spray pyrolysis (USP). Precursor solutions containing a carbon source, an inorganic salt, and an iron salt are ultrasonically aerosolized and pyrolyzed. Solutions containing nitrate

  16. Preparation of oxide particles with ordered macropores by colloidal templating and spray pyrolysis

    SciTech Connect

    Abdullah, Mikrajuddin [Department of Chemical Engineering, Graduate School of Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashi-Hiroshima 739-8527 (Japan); Iskandar, Ferry [Department of Chemical Engineering, Graduate School of Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashi-Hiroshima 739-8527 (Japan); Shibamoto, Shinji [Hiroshima Joint Research Center for Nanotechnology Particle Project, Japan Chemical Innovation Institute, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8530 (Japan); Ogi, Takashi [Department of Chemical Engineering, Graduate School of Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashi-Hiroshima 739-8527 (Japan); Okuyama, Kikuo [Department of Chemical Engineering, Graduate School of Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashi-Hiroshima 739-8527 (Japan)]. E-mail: okuyama@hiroshima-u.ac.jp

    2004-10-04

    Silicon dioxide, titanium dioxide, aluminium dioxide, zirconium dioxide, and yttrium dioxide particles containing macropores with ordered, hexagonal closed packing structures were produced by spray pyrolysis. A mixture of a solution of the oxide source (nitrous metal) and a colloid comprised of polystyrene latex (PSL) particles was used. The process involved initial drying at low temperature to evaporate the solvent, followed by drying at high temperature to permit the pyrolysis reaction to occur and to decompose the PSL beads. This takes place in a vertical reactor and requires around 1-2 s. This method can, in principle, be used to produce various types of oxide particles containing ordered pores. It allows easy control of the particle size, pore size and space, and the porosity of particles. Bragg reflection of the powdered material was observed under ultraviolet irradiation.

  17. Nanosized barium ferrite powders prepared by spray pyrolysis from citric acid solution

    Microsoft Academic Search

    Min Ha Kim; Dae Soo Jung; Yun Chan Kang; Jeong Hoo Choi

    2009-01-01

    Highly crystalline nanosized barium ferrite (BaFe12O19) powders were prepared by spray pyrolysis from a spray solution containing a high concentration of the metal components. The precursor powders obtained from the spray solution containing citric acid were amorphous with a porous and hollow structure. Purely crystalline and fine BaFe12O19 powders were obtained after post-treatment between 700 and 1000°C and subsequent mechanical

  18. Methods and apparatuses for preparing upgraded pyrolysis oil

    DOEpatents

    Brandvold, Timothy A; Baird, Lance Awender; Frey, Stanley Joseph

    2013-10-01

    Methods and apparatuses for preparing upgraded pyrolysis oil are provided herein. In an embodiment, a method of preparing upgraded pyrolysis oil includes providing a biomass-derived pyrolysis oil stream having an original oxygen content. The biomass-derived pyrolysis oil stream is hydrodeoxygenated under catalysis in the presence of hydrogen to form a hydrodeoxygenated pyrolysis oil stream comprising a cyclic paraffin component. At least a portion of the hydrodeoxygenated pyrolysis oil stream is dehydrogenated under catalysis to form the upgraded pyrolysis oil.

  19. Optical, structural and electrical properties of tin doped indium oxide thin films prepared by spray-pyrolysis technique

    Microsoft Academic Search

    Kodigala Subba Ramaiah; V. Sundara Raja; A. K. Bhatnagar; R. D. Tomlinson; R. D. Pilkington; A. E. Hill; S. J. Chang; Y. K. Su; F. S. Juang

    2000-01-01

    Tin doped indium oxide (In2O3:Sn) or indium tin oxide (ITO) thin films have been successfully deposited by the low cost spray-pyrolysis method. Low sheet resistance and high mobility films were obtained when the films were deposited at the substrate temperature of 793 K. The direct optical bandgaps for the films deposited at 793 (a) and 753 K (b) were found

  20. Electrical, optical and structural properties of aluminum doped cadmium oxide thin films prepared by spray pyrolysis technique

    Microsoft Academic Search

    R. Kumaravel; S. Menaka; S. Regina Mary Snega; K. Ramamurthi; K. Jeganathan

    2010-01-01

    Transparent conducting aluminum doped cadmium oxide (CdO:Al) thin films were deposited by spray pyrolysis method on glass substrates for various concentrations of aluminum (1–5wt.%). CdO:Al films were characterized using different techniques such as X-ray diffraction (XRD), atomic force microscopy, optical transmittance and Hall measurement. XRD analysis showed that CdO films exhibit cubic crystal structure with (200) preferred orientation. A minimum

  1. Porous MoS2 Synthesized by Ultrasonic Spray Pyrolysis Sara E. Skrabalak and Kenneth S. Suslick*

    E-print Network

    Suslick, Kenneth S.

    Porous MoS2 Synthesized by Ultrasonic Spray Pyrolysis Sara E. Skrabalak and Kenneth S. Suslick techniques. Here, ultrasonic spray pyrolysis6 (USP) has been used to synthesize porous, nanostructured MoS2 is ultrasonically nebulized into microdroplets,9 which are carried by a gas flow into a furnace where solvent

  2. Synthesis and characterization of ZnO nano and micro structures grown by low temperature spray pyrolysis and vapor transport.

    PubMed

    Agouram, S; Bushiri, M J; Montenegro, D N; Reig, C; Martínez-Tomás, M C; Muñoz-Sanjosé, V

    2012-08-01

    In this work we present a systematic study of ZnO micro and nanostructures grown by spray pyrolysis (SP) and by physical vapour transport (PVT) on glass and c-sapphire substrates at low temperatures. Optimised growth conditions have allowed to obtain homogeneous ZnO nanolayers composed of quasi-spherical nanoparticles in the range 2 to 8 nm by spray pyrolysis, while by PVT the selected growth conditions allow to produce a wide variety of morphologies (tripods, grains, arrows and wires) of nano and microsize dimension. Grazing incidence X-ray diffraction, field emission scanning electron microscopy (FE-SEM), high resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED) and energy dispersive X-ray spectroscopy (EDX) were used as characterization techniques in the investigation of structural, morphological and compositional nature of these nanostructures in relation with the growth method. PMID:22962824

  3. The fabrication of fine and homogenous Bi-2223 precursor powder by a spray pyrolysis process

    NASA Astrophysics Data System (ADS)

    Yoo, Jaimoo; Kim, Sunghwan; Ko, Jae-Woong; Kim, Young-Kuk

    2004-09-01

    Spherical and fine BSCCO precursor powders were prepared by an ultrasonic spray pyrolysis (SP) method from an aqueous solution of metal nitrates. The synthesized precursor powders had a narrow particle size distribution and a low carbon content of less than 80 ppm. The reactivity of the precursor powder made by the SP method is very high; this is attributed to the fine particle size and narrow size distribution of the precursor powders. The precursor powder made by the SP method promoted a very quick formation of the BSCCO 2223 phase for short sintering times, while the secondary phases such as large alkaline earth cuprates and Ca2PbO4 were minimized for SP tapes.

  4. Growth of ZnO rods on FTO electrodes by spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Dedova, Tatjana; Volobujeva, Olga; Krunks, Malle; Mikli, Valdek; Gromyko, Inga; Katerski, Atanas; Mere, Arvo

    2013-12-01

    ZnO layers comprizing rods were deposited by chemical spray pyrolysis (CSP) method at 520 °C on different FTO (SnO2:F)/glass substrates using zinc chloride aqueous solutions. Substrates were purchased from different manufactures and differ by morphology, grain size and roughness of FTO electrode. FTO/glass substrates and ZnO layers grown on them were characterised with the help of XRD, AFM, high resolution SEM, EDX methods. The relationship between nanorod formation and substrate properties was studied. It was found that substrate roughness and grain size influence the ZnO rods formation. Deposition of rods (d=300 nm, L=1.4 ?m) was successful on the FTO layers with grain sizes around 30-50 nm and roughness below 10 nm, whereas large-grained FTO (grain size > 130 nm) resulted in thick, low-aspect ratio crystals with diameter around 400 nm and length of about 400 nm.

  5. Studies on transparent spinel magnesium indium oxide thin films prepared by chemical spray pyrolysis

    Microsoft Academic Search

    A. Moses Ezhil Raj; V. Senthilkumar; V. Swaminathan; Joachim Wollschläger; M. Suendorf; M. Neumann; M. Jayachandran; C. Sanjeeviraja

    2008-01-01

    Ternary semiconducting oxide compound magnesium indium oxide films (MgIn2O4), manifesting high transparency were prepared by metal organic chemical spray pyrolysis technique. Precursors prepared for various cationic ratios of Mg\\/In=0.35, 0.40, 0.45 and 0.50 were thermally sprayed onto quartz substrates, decomposed at 450 °C and the spinel phase evolution was studied. X-ray diffraction, Rutherford backscattering and X-ray photoelectron spectroscopy studies have been

  6. First synthesis of vanadium oxide thin films by spray pyrolysis technique

    Microsoft Academic Search

    A. Bouzidi; N. Benramdane; A. Nakrela; C. Mathieu; B. Khelifa; R. Desfeux; A. Da Costa

    2002-01-01

    Vanadium oxide thin films have been successfully deposited in the first time by spray pyrolysis technique at two substrate temperatures, 200 and 250°C. In view of defining the optimal conditions for elaboration of vanadium oxide films, the as-deposited films were studied as a function of spray solution concentrations, using X-ray diffraction (XRD) and optical measurements. V2O5 and V4O9 polycrystalline films

  7. Properties of mixed molybdenum oxide–iridium oxide thin films synthesized by spray pyrolysis

    Microsoft Academic Search

    P. S. Patil; R. K. Kawar; S. B. Sadale; A. I. Inamdar; H. P. Deshmukh

    2006-01-01

    Molybdenum-doped iridium oxide thin films have been deposited onto corning glass- and fluorine-doped tin oxide coated corning glass substrates at 350°C by using a pneumatic spray pyrolysis technique. An aqueous solution of 0.01M ammonium molybdate was mixed with 0.01M iridium trichloride solution in different volume proportions and the resultant solution was used as a precursor solution for spraying. The as-deposited

  8. Influence of the process parameters on the spray pyrolysis technique, on the synthesis of gadolinium doped-ceria thin film

    SciTech Connect

    Halmenschlager, C.M., E-mail: cibelemh@yahoo.com.br [Laboratory of Materials Ceramic LACER/PPGEM, Federal University of Rio Grande do Sul, Av. Osvaldo Aranha, 99/705C, CEP: 90035-190, Porto Alegre, RS (Brazil); National Research Council, Institute for Fuel Cell Innovation NRC-IFCI, 4250 Wesbrook Mall, V6T 1W5 Vancouver, BC (Canada); Neagu, R. [National Research Council, Institute for Fuel Cell Innovation NRC-IFCI, 4250 Wesbrook Mall, V6T 1W5 Vancouver, BC (Canada)] [National Research Council, Institute for Fuel Cell Innovation NRC-IFCI, 4250 Wesbrook Mall, V6T 1W5 Vancouver, BC (Canada); Rose, L. [National Research Council, Institute for Fuel Cell Innovation NRC-IFCI, 4250 Wesbrook Mall, V6T 1W5 Vancouver, BC (Canada) [National Research Council, Institute for Fuel Cell Innovation NRC-IFCI, 4250 Wesbrook Mall, V6T 1W5 Vancouver, BC (Canada); Department of Materials Engineering, V6T 1Z1 Vancouver, BC (Canada); Malfatti, C.F. [Laboratory of Research in Corrosion LAPEC/PPGEM, Federal University of Rio Grande do Sul, Av. Bento Gonçalves, 9500, Setor 4, Prédio 75/2° Andar, CEP: 91501-970, Campus do Vale, Porto Alegre, RS (Brazil)] [Laboratory of Research in Corrosion LAPEC/PPGEM, Federal University of Rio Grande do Sul, Av. Bento Gonçalves, 9500, Setor 4, Prédio 75/2° Andar, CEP: 91501-970, Campus do Vale, Porto Alegre, RS (Brazil); Bergmann, C.P. [Laboratory of Materials Ceramic LACER/PPGEM, Federal University of Rio Grande do Sul, Av. Osvaldo Aranha, 99/705C, CEP: 90035-190, Porto Alegre, RS (Brazil)] [Laboratory of Materials Ceramic LACER/PPGEM, Federal University of Rio Grande do Sul, Av. Osvaldo Aranha, 99/705C, CEP: 90035-190, Porto Alegre, RS (Brazil)

    2013-02-15

    Graphical abstract: Gas-tight CGO made by spray pyrolysis suitable to be used as SOFC electrolyte. Display Omitted Highlights: ? Dense and crystalline CGO films deposited by spray pyrolysis on various substrates. ? Solvent did not have a strong influence on the film microstructure, defect concentration or thickness. ? The substrate did not have a strong influence on the film microstructure, defect concentration or thickness. ? Films with at least 2.5 ?m of thickness presented high impermeability. ? The films obtained are suitable to use as a SOFC electrolyte. -- Abstract: This work presents the results of a process of optimization applied to gadolinia-doped ceria (Ce{sub 0.8}Gd{sub 0.2}O{sub 1.9?x}, or CGO) thin films, deposited by spray pyrolysis (SP). Spray pyrolysis is a high thermal deposition method that combines material deposition and heat treatment. This combination is advantageous since the post-deposition heat treatment step is not necessary. However, stresses are solidified in the coating during the deposition, which may lead to the initiation of a crack in the coating. The aim of this work was to achieve thin, dense, and continuous CGO coatings, which may be used as gas separation membranes and as a solid state electrochemical interfaces. Dense, flat, low-defect substrates such as silica slides, silicon mono crystal wafers, and porous substrates were used as substrates in this work. Cerium ammonium nitrate and gadolinium acetylacetonate were dissolved in ethanol and butyl carbitol to form a precursor solution that was sprayed on the heated substrates. Process parameters such as solvent composition, deposition rate and different heating regimes were analyzed. The microstructure was analyzed by secondary electron microscopy (SEM) and was found that thin, dense, and defect-free films could be produced on dense and porous substrates. The results obtained show that it is possible to obtain a CGO dense film deposited by spray pyrolysis. X-ray diffraction (XRD) analysis showed that the films were crystalline after the deposition without requiring post-deposition heat treatment. The crystallite size does not vary significantly as a function of the annealing temperature.

  9. In-situ deposition of gold nanoparticles onto different substrates by chemical spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Oja Acik, I.; Oyekoya, N. G.; Mere, A.; Katerski, A.; Mikli, V.; Krunks, M.

    2015-03-01

    Au-nanoparticles were deposited in-situ by chemical spray pyrolysis method onto glass and indium tin oxide (ITO) covered glass substrates in the temperature range of 260 to 400 °C. SEM studies showed that the number of Au-NPs increased and the particle size decreased with increasing the deposition temperature. The surface plasmon resonance effect of Au-NPs on glass substrate shifts from 550 to 520 nm with decreasing the mean crystallite size of Au-NPs from 49 to 24 nm. The surface plasmon resonance effect of Au-NPs on ITO substrate shift from 570 to 540 nm with decreasing the mean crystallite size of Au-NPs from 53 to 16 nm.

  10. Studies on ionic intercalation properties of cobalt oxide thin films prepared by spray pyrolysis technique

    Microsoft Academic Search

    L. D Kadam; S. H Pawar; P. S Patil

    2001-01-01

    Cobalt oxide thin films were prepared by spray pyrolysis technique onto the fluorine doped tin oxide (FTO) coated glass substrates from cobalt chloride solution. They were characterized by cyclic-voltammetry, chronoamperometry and spectrophotometry techniques. The films exhibited anodic electrochromism, changing colour from grey to pale yellow. Colouration efficiency at 633nm was calculated to be 12cm2C?1.

  11. Synthesis and characterization of nanostructured nickel oxide thin films prepared with chemical spray pyrolysis

    Microsoft Academic Search

    R. Romero; F. Martin; J. R. Ramos-Barrado; D. Leinen

    2010-01-01

    Nickel oxide thin films have been deposited in an open atmosphere onto glass substrates by chemical spray pyrolysis using aqueous nickel acetate solutions and air as driving gas. The films show a strong variation in the surface morphology depending on the substrate temperature and the precursor solution flux. At 350°C substrate temperature, a reticular tissue-like film morphology is obtained, becoming

  12. Structural, optical and electrical properties of indium tin oxide thin films prepared by spray pyrolysis

    Microsoft Academic Search

    E. Benamar; M. Rami; C. Messaoudi; D. Sayah; A. Ennaoui

    1999-01-01

    Spray pyrolysis process has been used to deposit highly transparent and conducting films of tin-doped indium oxide onto glass substrates. The electrical, structural and optical properties have been investigated as a function of various deposition parameters namely dopant concentrations, temperature and nature of substrate. The morphology of the surface as a function of the substrate temperature has been studied using

  13. Deposition of Aluminum---Doped Zinc Oxide Thin Films by Spray Pyrolysis

    Microsoft Academic Search

    Devendra Goyal; Parag Solanki; Balkrishna Marathe; Murlidhar Takwale; Vishnu Bhide

    1992-01-01

    Aluminum---doped zinc oxide films were prepared on Corning 7059 by an inexpensive spray pyrolysis technique. Variation in structural, electrical and optical properties with doping concentration is investigated in detail. The films were highly transparent to the visible radiation and electrically conductive. X-ray diffraction results show that all films were polycrystalline in nature with [002] preferred orientation. Texture coefficient and grain

  14. Transient photoconductivity properties of tungsten oxide thin films prepared by spray pyrolysis

    Microsoft Academic Search

    Jianhua Hao; S. A. Studenikin; Michael Cocivera

    2001-01-01

    Tungsten oxide (WO3) thin films were deposited by spray pyrolysis of an ammonium tungsten oxide solution. The effect of postannealing on the structural, transport and optical properties of the films has been studied. Under steady-state illumination, slow photoconductivity growth and relaxation transients were observed at room temperature. The contributions of carrier concentration and mobility to the photoconductivity were determined from

  15. Growth and characterization of iron oxide nanocrystalline thin films via low-cost ultrasonic spray pyrolysis

    Microsoft Academic Search

    Rajendra N. Goyal; Davinder Kaur; Ashish K. Pandey

    2009-01-01

    The preparation and characterization of iron oxide nanocrystalline thin films by ultrasonic spray pyrolysis technique is reported. Iron oxide films were grown on quartz substrate at different deposition temperatures varying from 400°C to 700°C. Both orientation and the size of the crystallites were found to depend on the substrate temperature. The XRD results of nanocrystalline thin films revealed the magnetite

  16. Influence of the doping and annealing atmosphere on zinc oxide thin films deposited by spray pyrolysis

    Microsoft Academic Search

    P Nunes; A Malik; B Fernandes; E Fortunato; P Vilarinho; R Martins

    1999-01-01

    Undoped and doped (indium and aluminium) zinc oxide (ZnO) thin films have been prepared by spray pyrolysis, and the effect of the doping and annealing atmosphere on the electrical, optical and structural properties of the produced films has been investigated. The deposited films have a high resistivity. Annealing the films in an argon atmosphere or under vacuum leads to a

  17. Performances presented by zinc oxide thin films deposited by spray pyrolysis

    Microsoft Academic Search

    P. Nunes; B Fernandes; E Fortunato; P Vilarinho; R Martins

    1999-01-01

    The effect of doping and annealing atmosphere on the performances of zinc oxide thin films prepared by spray pyrolysis have been studied. The results show that the way doping influences the electrical and structural properties depends also on the characteristics of the doping element. Annealing the as-deposited films in an inert atmosphere leads to a substantial reduction in the resistivity

  18. Structural, optical and electrical properties of zinc oxide thin films deposited by a spray pyrolysis technique

    NASA Astrophysics Data System (ADS)

    Aoun, Yacine; Benhaoua, Boubaker; Gasmi, Brahim; Benramache, Said

    2015-01-01

    Zinc oxide (ZnO) thin films were deposited on glass substrates by spray pyrolysis technique decomposition of zinc acetate dihydrate in an ethanol solution with 30 mL of deposition rate, the ZnO thin films were deposited at two different temperatures: 300 and 350 °C. The substrates were heated using the solar cells method. The substrate was R217102 glass, whose size was 30 × 17.5 × 1 mm3. The films exhibit a hexagonal wurtzite structure with a strong (002) preferred orientation. The higher value of crystallite size is attained for sprayed films at 350 °C, which is probably due to an improvement of the crystallinity of the films at this point. The average transmittance of obtain films is about 90%–95%, as measured by a UV—vis analyzer. The band gap energy varies from 3.265 to 3.294 eV for the deposited ZnO thin film at 300 and 350 °C, respectively. The electrical resistivity measured of our films are in the order 0.36 ?·cm.

  19. Structural, electrical and optical characteristics of SnO 2:Sb thin films by ultrasonic spray pyrolysis

    Microsoft Academic Search

    Seung-Yup Lee; Byung-Ok Park

    2006-01-01

    Antimony-doped tin oxide (SnO2:Sb) thin films were fabricated by an ultrasonic spray pyrolysis method. The effect of antimony doping on the structural, electrical and optical properties of tin oxide thin films were investigated. Tin(II) chloride dehydrate (SnCl2·2H2O) and antimony(III) chloride (SbCl3) were used as a host and a dopant precursor. X-ray diffraction analysis showed that the non-doped SnO2 thin film

  20. The negative effects of alcohols on carbon nanotube synthesis in a nebulised spray pyrolysis process

    Microsoft Academic Search

    Leskey M Cele; Neil J Coville

    2009-01-01

    Multi-walled carbon nanotubes were synthesized by the nebulised spray pyrolysis (frequency 1.6MHz) of toluene and toluene–alcohol mixtures with ferrocene as the catalyst precursor. The CNTs produced were characterized by TEM, SEM, Laser-Raman spectroscopy and TGA. The results show that the presence of ethanol, 2-propanol and octanol in the reaction mixture reduces the CNT yield, growth rate and produces CNTs that

  1. Spray Pyrolysis Preparation and Humidity Sensing Characteristics of Spinel Zinc Stannate Thin Films

    Microsoft Academic Search

    I. Stambolova; K. Konstantinov; D. Kovacheva; P. Peshev; T. Donchev

    1997-01-01

    Polycrystalline spinel Zn2SnO4films were successfully deposited on alumina substrates by spray pyrolysis. It was found that the ratio of the two cations in the films obtained differs considerably from the ratio in the initial solutions. By optimizing the solution compositions and the deposition and heat-treatment parameters, it was possible to obtain homogeneous single phase films with good adhesion to the

  2. Synthesis and characterization of spherical magnesium di-boride nano-powders obtained by spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Ko, Jae-Woong; Yoo, Jaimoo; Kim, Young-Kuk; Chung, Soo Jin; Yoo, Sang Im

    2004-10-01

    Nano-sized spherical MgB 2 powders were prepared by spray pyrolysis, starting from an aqueous solution which contains Mg and B ions. The influence of solution concentration, furnace temperature and mass flow of carrier gas on microstructure and average particle size were investigated. The powders were synthesized without further heat treatment. For adequate preparation conditions, it has mostly spherical, solid and narrow particle size distribution. Average particle size ( X50) distribution was between 100 and 400 nm.

  3. Optical constants of CdS thin films prepared by spray pyrolysis

    Microsoft Academic Search

    Sunny Mathew; K. P. Vijayakumar

    1994-01-01

    CdS thin films were prepared by spray pyrolysis techniques. Variable angle spectroscopic ellipsometry was used for optical\\u000a constant calculations. Multiple angle measurements were taken in the most sensitive angle of incidence region. The sensitive\\u000a regions of angle of incidence were obtained theoretically using 3-dimensional graph of?? and??. Real partn and imaginary partk of the complex refractive index of the samples

  4. The effect of process variables on the characteristics of carbon nanotubes obtained by spray pyrolysis

    Microsoft Academic Search

    Mariane C. Schnitzler; Aldo J. G. Zarbin

    2008-01-01

    A simple spray pyrolysis setup is used to grow multi-walled carbon nanotubes (MWCNTs), from a ferrocene solution in benzene\\u000a as precursor. The effects of process variables such as growth temperature, position of the aerosol generator and position\\u000a in the reactor where the sample was formed were investigated. These variables have a strong influence on the graphitization\\u000a degree, homogeneity, diameter and

  5. Supercapacitive cobalt oxide (Co 3O 4) thin films by spray pyrolysis

    Microsoft Academic Search

    V. R. Shinde; S. B. Mahadik; T. P. Gujar; C. D. Lokhande

    2006-01-01

    Uniform and adherent cobalt oxide thin films have been deposited on glass substrates from aqueous cobalt chloride solution, using the solution spray pyrolysis technique. Their structural, optical and electrical properties were investigated by means of X-ray diffraction (XRD), scanning electron micrograph (SEM), optical absorption and electrical resistivity measurements. Along with this, to propose Co3O4 for possible application in energy storage

  6. Characterization of cobalt oxide thin films prepared by a facile spray pyrolysis technique using perfume atomizer

    Microsoft Academic Search

    A. Louardi; A. Rmili; F. Ouachtari; A. Bouaoud; B. Elidrissi; H. Erguig

    2011-01-01

    Cobalt oxide (Co3O4) thin films were prepared by a facile spray pyrolysis technique using perfume atomizer from aqueous solution of hydrated cobalt chloride salt (CoCl2·6H2O) as source of cobalt. The films were deposited onto the amorphous glass substrates kept at different temperatures (300–500°C). The influences of molar concentration of the starting solution and substrate temperature on the structural, morphological and

  7. Supercapacitive cobalt oxide (Co3O4) thin films by spray pyrolysis

    Microsoft Academic Search

    V. R. Shinde; S. B. Mahadik; T. P. Gujar; C. D. Lokhande

    2006-01-01

    Uniform and adherent cobalt oxide thin films have been deposited on glass substrates from aqueous cobalt chloride solution, using the solution spray pyrolysis technique. Their structural, optical and electrical properties were investigated by means of X-ray diffraction (XRD), scanning electron micrograph (SEM), optical absorption and electrical resistivity measurements. Along with this, to propose Co3O4 for possible application in energy storage

  8. High-mobility molybdenum doped indium oxide thin films prepared by spray pyrolysis technique

    Microsoft Academic Search

    S. Parthiban; K. Ramamurthi; E. Elangovan; R. Martins; E. Fortunato; R. Ganesan

    2008-01-01

    Molybdenum doped indium oxide (IMO) thin films were deposited on the glass substrates preheated to 450 °C by spray pyrolysis technique. The Mo doping was varied between 0 and 2.0 at.%. The films were characterized by their structural, electrical and optical properties. The films are confirmed to be cubic bixbyite In2O3 with a strongest orientation along (222) plane, which is shifted to

  9. Physicochemical, optical and electrochemical properties of iron oxide thin films prepared by spray pyrolysis

    Microsoft Academic Search

    L. Dghoughi; B. Elidrissi; C. Bernède; M. Addou; M. Alaoui Lamrani; M. Regragui; H. Erguig

    2006-01-01

    Iron oxide thin films were prepared by spray pyrolysis technique onto glass substrates from iron chloride solution. They were characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and (UV–vis) spectroscopy. The films deposited at Ts?450°C were amorphous; while those produced at Tsub=500°C were polycrystalline ?-Fe2O3 with a preferential orientation along the (104) direction. By observing

  10. Properties of mixed molybdenum oxide iridium oxide thin films synthesized by spray pyrolysis

    Microsoft Academic Search

    P. S. Patil; R. K. Kawar; S. B. Sadale; A. I. Inamdar; H. P. Deshmukh

    2006-01-01

    Molybdenum-doped iridium oxide thin films have been deposited onto corning glass- and fluorine-doped tin oxide coated corning glass substrates at 350 °C by using a pneumatic spray pyrolysis technique. An aqueous solution of 0.01 M ammonium molybdate was mixed with 0.01 M iridium trichloride solution in different volume proportions and the resultant solution was used as a precursor solution for

  11. Superconducting Bi-Ca-Sr-Cu oxide thin films by spray pyrolysis of metal acetates

    Microsoft Academic Search

    Dale F. Vaslow; Gunter H. Dieckmann; David Dawson Elli; Arthur B. Ellis; D. Scott Holmes; Anthony Lefkow; Mark MacGregor; James E. Nordman; Michael F. Petras; Yifeng Yang

    1988-01-01

    Superconducting Bi-Ca-Sr-Cu oxide thin films have been prepared on ZrO2-coated silicon (111) wafers by spray pyrolysis of metal acetate precursors followed by rapid annealing to 850 °C in air. Resistivity measurements indicate a broad superconducting transition with Tc onset near 90 K and zero resistivity below 60 K. The films are highly oriented with the c axis normal to the

  12. Transparent conductive Sn-doped indium oxide thin films deposited by spray pyrolysis technique

    Microsoft Academic Search

    S. M. Rozati; T. Ganj

    2004-01-01

    Films of indium oxide doped with tin (ITO) are prepared using the low cost spray pyrolysis technique. The effect of tin doping on the physical properties of In2O3 are studied. In this study the polycrystalline ITO films with the different Sn concentration of 1 to 100-wt% SnCl2 were prepared on Corning 7059 glass substrate. These films were confirmed to show

  13. Spray pyrolysis deposition and characterization of highly (100) oriented magnesium oxide thin films

    Microsoft Academic Search

    A. Moses; Ezhil Raj; L. C. Nehru; M. Jayachandran

    2007-01-01

    Transparent dielectric thin films of MgO has been deposited on quartz substrates at different temperatures between 400 and 600°C by a pneumatic spray pyrolysis technique using Mg(CH3COO)2.4H2O as a single molecular precursor. The thermal behavior of the precursor magnesium acetate is described in the results of thermogravimetry analysis (TGA) and differential thermal analysis (DTA). The prepared films are reproducible, adherent

  14. Optical properties of crystalline and non-crystalline iron oxide thin films deposited by spray pyrolysis

    Microsoft Academic Search

    Alaa A. Akl

    2004-01-01

    Crystalline and non-crystalline iron oxide (?-Fe2O3) thin films were obtained by spray pyrolysis onto glass substrate at different temperatures. The results of X-ray diffraction showed that with increasing the deposition time, the film structure changed from non-crystalline to crystalline at the same substrate temperature. At different substrate temperatures and low deposition times (5min), iron oxide appears almost in non-crystalline form.

  15. Sensing of LPG with nanostructured zinc oxide thin films grown by spray pyrolysis technique

    Microsoft Academic Search

    C. S. Prajapati; S. N. Pandey; P. P. Sahay

    2011-01-01

    Nanostructured zinc oxide thin films were prepared by spray pyrolysis technique using Zn(NO3)2·6H2O as the precursor solution. The resulting films were investigated by X-ray diffraction and scanning electron microscopy to know crystal structure, size of crystallites and surface morphology. The films have been found to be polycrystalline zinc oxide, possessing hexagonal wurtzite crystal structure and nanocrystallite with grain size of

  16. Studies on electrochromic properties of nickel oxide thin films prepared by spray pyrolysis technique

    Microsoft Academic Search

    L. D. Kadam; P. S. Patil

    2001-01-01

    Electrochromic nickel oxide thin films were prepared by using a simple and inexpensive spray pyrolysis technique (SPT) onto fluorine-doped tin oxide (FTO) coated glass substrates from nickel chloride solution. Transparent NiO-thin films were obtained at a substrate temperature 350°C. The films were cubic NiO with preferred orientation in the (111) direction. Infrared spectroscopy results show presence of free hydroxyl ion

  17. Preparation and characterization of iron oxide thin films by spray pyrolysis using methanolic and ethanolic solutions

    Microsoft Academic Search

    J. D. Desai; H. M. Pathan; Sun-Ki Min; Kwang-Deog Jung; Oh-Shim Joo

    2006-01-01

    Iron oxide thin films have been obtained by spray pyrolysis using 100% methanolic and ethanolic solutions of iron tri-chloride. The films were deposited onto ITO-coated glass substrates. The preparative conditions have been optimized to obtain compact, pin-hole-free and smooth thin films which are adherent to the substrate. The structural, morphological and compositional characterizations have been carried out by X-ray diffraction,

  18. Photoluminescence characteristics of zinc oxide thin films prepared by spray pyrolysis technique

    Microsoft Academic Search

    Ki Hyun Yoon; Joon Yeob Cho

    2000-01-01

    The photoluminescence characteristics of zinc oxide films prepared by spray pyrolysis technique were studied as a function of the substrate temperature, film thickness, and post heat treatment. The ZnO films with the (002) plane oriented wurtzite structure were formed in the temperature range 250–350°C and post heat treatment did not affect the crystal structure of the films. It was observed

  19. Temperature dependence of Fluorine-doped tin oxide films produced by ultrasonic spray pyrolysis

    Microsoft Academic Search

    Chin-Ching Lin; Mei-Ching Chiang; Yu-Wei Chen

    2009-01-01

    Fluorine-doped tin oxide (FTO) films were prepared at different substrate temperatures by ultrasonic spray pyrolysis technique on glass substrates. Among F-doped tin oxide films, the lowest resistivitiy was found to be 6.2×10?4 ?-cm for a doping percentage of 50 mol% of fluorine in 0.5 M solution, deposited at 400 °C. Hall coefficient analyses and secondary ion mass spectrometry (SIMS) measured the electron carrier concentration

  20. Phase transition studies in bismuth ferrite thin films synthesized via spray pyrolysis technique

    NASA Astrophysics Data System (ADS)

    Goyal, Ankit; Lakhotia, Harish

    2013-06-01

    Multiferroic are the materials, which combine two or more "ferroic" properties, ferromagnetism, ferroelectricity or ferroelasticity. BiFeO3 is the only single phase multiferroic material which possesses a high Curie temperature (TC ˜ 1103 K), and a high Neel temperature (TN ˜ 643 K) at room temperature. Normally sophisticated methods are being used to deposit thin films but here we have tried a different method Low cost Spray Pyrolysis Method to deposit BiFeO3 thin film of Glass Substrate with rhombohedral crystal structure and R3c space group. Bismuth Ferrite thin films are synthesized using Bismuth Nitrate and Iron Nitrate as precursor solutions. X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) were used to study structural analysis of prepared thin films. XRD pattern shows phase formation of BiFeO3 and SEM analysis shows formation of nanocrystals of 200 nm. High Temperature Resistivity measurements were done by using Keithley Electrometer (Two Probe system). Abrupt behavior in temperature range (313 K - 400K) has been observed in resistance studies which more likely suggests that in this transition the structure is tetragonal rather than rhombohedral. BiFeO3 is the potential active material in the next generation of ferroelectric memory devices.

  1. A study of the dielectric characteristics of aluminum oxide thin films deposited by spray pyrolysis from Al(acac) 3

    Microsoft Academic Search

    M. Aguilar-Frutis; M Garcia; C Falcony; G Plesch; S Jimenez-Sandoval

    2001-01-01

    The dielectric characteristics of aluminum oxide thin films deposited by the spray pyrolysis technique are reported. The films were deposited with different molarities from a spraying solution of aluminum acetylacetonate and N,N-dimethylformamide. The films were deposited on silicon substrates at temperatures ranging from 450 to 650°C. The addition of water mist during the deposition process led to a remarkable improvement

  2. Characterization and Electrochromic Properties of Vanadium Oxide Thin Films Prepared via Spray Pyrolysis

    NASA Astrophysics Data System (ADS)

    Mousavi, M.; Kompany, A.; Shahtahmasebi, N.; Bagheri-Mohagheghi, M.-M.

    2013-08-01

    Vanadium oxide thin films were grown on glass substrates using spray pyrolysis technique. The effects of substrate temperature, vanadium concentration in the initial solution and the solution spray rate on the nanostructural and the electrochromic properties of deposited films are investigated. Characterization and the electrochromic measurements were carried out using X-ray diffraction, scanning electron microscopy and cyclic voltammogram. XRD patterns showed that the prepared films have polycrystalline structure and are mostly mixed phases of orthorhombic ?-V2O5 along with minor ?-V2O5 and V4O9 tetragonal structures. The preferred orientation of the deposited films was found to be along [101] plane. The cyclic voltammogram results obtained for different samples showed that only the films with 0.2 M solution concentration, 5 ml/min solution spray rate and 450°C substrate temperature exhibit two-step electrochromic properties. The results show a correlation between cycle voltammogram, morphology and resistance of the films.

  3. ZnO based visible-blind UV photodetector by spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Inamdar, S. I.; Ganbavle, V. V.; Rajpure, K. Y.

    2014-12-01

    Zinc oxide (ZnO) metal-semiconductor-metal ultraviolet photodetectors were fabricated by economical spray pyrolysis method. The devices have been characterized to investigate the effect of precursor solution concentration on the photoconductive properties of ZnO. The structural, morphological and optical properties of the ZnO thin films were studied using different techniques. The crystal structure, size and lattice parameters have been estimated by X-ray diffraction (XRD) analysis. The UV photodetector device prepared using 0.1 M solution concentration exhibits low dark current and high UV photocurrent of about 134 ?A at 5 V bias at 365 nm peak wavelength. The surface morphology and the surface roughness have been studied by AFM analysis. UV-Vis measurements have been used to study the effect of solution concentration on absorption spectra and hence on the band gap. The present device shows fast response in UV region of electromagnetic spectrum and shows almost no response to visible light. The characteristic times for rise and fall of the photocurrent device were 12 s and 9 s respectively. This devices are providing a simple and economical way to fabricate high-performance 'visible-blind' UV detectors and promising for use in large-area UV-A photodetector applications.

  4. Emission of ZnO:Ag nanorods obtained by ultrasonic spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Velázquez Lozada, E.; Torchynska, T. V.; Casas Espinola, J. L.; Pérez Millan, B.

    2014-11-01

    Scanning electronic microscopy (SEM), X ray diffraction (XRD), photoluminescence (PL) and its temperature dependence have been studied in ZnO:Ag nanorods (NRs) prepared by the ultrasonic spray pyrolysis (USP) method. The time variation at the growth of ZnO:Ag films permits modifying the ZnO phase from the amorphous to crystalline, to change the size of ZnO:Ag NRs and to vary their emission spectra. PL spectra of ZnO:Ag NRs versus temperature has been investigated. This study reveals that the PL band related to the acceptor AgZn (LO phonon replicas of an acceptor bound exciton, ABE (2.877 eV)), and its second-order diffraction peak (1.44 eV) disappeared in the temperature range of 10-170 K with the formation of free exciton (FX). The PL intensity of defect related PL bands decreases monotonously in the range 10-300 K with the activation energy of 13 meV. The PL band (3.22 eV), related to the LO phonon replica of free exciton (FX-2LO) and its second-order diffraction peak (1.61 eV) increase monotonously in the range 10-300 K. FX related peak dominates in PL spectra at room temperature that testifies on the high quality of ZnO:Ag films prepared by the USP technology.

  5. Growth and characterization of molybdenum doped ZnO thin films by spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Swapna, R.; Santhosh Kumar, M. C.

    2013-03-01

    Undoped and molybdenum doped zinc oxide (MZO) thin films were deposited on the glass substrate at a substrate temperature of 623 K by spray pyrolysis method. The effect of molybdenum (Mo) dopant concentration (0-4 at%) on the structural, morphological, optical and electrical properties of n-type MZO films was studied. The X-ray diffraction (XRD) results confirmed that the MZO thin films were polycrystalline with wurtzite structure. The scanning electron microscopy (SEM) measurements showed that the surface morphology of the films changes with Mo doping. The surface roughness of the films was investigated by atomic force microscopy (AFM). It was observed that the roughness of the films increases with the increase of Mo doping percentage. A blue shift of the optical band gap was observed. Room temperature photoluminescence (PL) measurement of the deposited films indicates the incorporation of Mo in ZnO lattice. The temperature dependence of the electrical conductivity was studied in the range of 300 K-425 K. At 2 at% Mo doping, the films have shown comparatively high electrical conductivity.

  6. Nanosized LiMn2O4 powders prepared by flame spray pyrolysis from aqueous solution

    NASA Astrophysics Data System (ADS)

    Yi, Jang Heui; Kim, Jung Hyun; Koo, Hye Young; Ko, You Na; Kang, Yun Chan; Lee, Jong-Heun

    2011-03-01

    LiMn2O4 powders have been directly prepared by flame spray pyrolysis from an aqueous spray solution of the metal salts. The powders prepared at a low fuel gas flow rate (3 L min-1) comprise particles with a bimodal size distribution, i.e., submicron- and nanometer-sized particles, and have crystal structures of LiMn2O4 and Mn3O4 phases. However, the powders prepared at a high fuel gas flow rate (5 L min-1) comprise nanometer-sized particles and have pure crystal structure of LiMn2O4 phase. The powders comprising nanosized particles are well crystallized, and the particles have a polyhedral structure. The mean particle size of these powders is 27 nm. The powders prepared directly by flame spray pyrolysis comprise nanosized particles and have the pure crystal structure of LiMn2O4, irrespective of the amount of excess lithium in the precursor solution. The initial discharge capacities of these powders increase from 91 to 112 mAh g-1 when the amount of excess lithium is increased from 0% to 30% of the stoichiometric amount. The optimum amount of excess lithium required to prepare LiMn2O4 powders with nanosized particles and the maximum possible initial discharge capacity is 10%.

  7. Yolk-shelled cathode materials with extremely high electrochemical performances prepared by spray pyrolysis.

    PubMed

    Choi, Seung Ho; Hong, Young Jun; Kang, Yun Chan

    2013-09-01

    A facile, continuous preparation process of yolk-shell-structured lithium-metal oxide powders without a template for use as cathode materials in lithium ion batteries is introduced for the first time. Single and double-shelled LiNi0.5Mn1.5O4 yolk-shell powders as the first target materials are prepared directly by spray pyrolysis from a spray solution with sucrose, at a short residence time of 4 s. Fast combustion and contraction of a carbon-mixed oxide composite intermediate, formed from a micro-sized droplet inside a hot wall reactor maintained at 700 °C, produces the yolk-shell powders. The yolk-shell structure of the precursor powders directly prepared by spray pyrolysis is well maintained even at a high post-treatment temperature of 750 °C. The yolk-shell LiNi0.5Mn1.5O4 powders delivered a 1000(th) high discharge capacity of 108 mA h g(-1) at 10 C. The discharge capacities are as high as 103, 95, and 91 mA h g(-1) at extremely high discharge rates of 100, 200, and 300 C and the corresponding specific energy densities are 420, 370, and 328 W h kg(-1). The capacity retention at a constant discharge rate of 200 C is 90% after 500 cycles. PMID:23846530

  8. Structural and morphological transformations during NiO and Ni particles generation from chloride precursor by ultrasonic spray pyrolysis

    Microsoft Academic Search

    S. Stopi?; I. Ili?; D. Uskokovi?

    1995-01-01

    Submicrometer NiO and Ni powders were obtained by ultrasonic spray pyrolysis of aqueous solutions of NiCl2 followed by thermal decomposition of generated aerosols in an oxidation or N2H2 reduction atmosphere, respectively. Particle sizes of the prepared powders can be controlled by the change of reaction temperature and the concentration of initial solutions. Pyrolysis temperatures in the range from 973 to

  9. Simultaneous Formation of Both Single- and Multi-Wall Carbon Nanotubes by Ultrasonic Spray Pyrolysis

    NASA Astrophysics Data System (ADS)

    Khatri, Ishwor; Kishi, Naoki; Zhang, Jianhui; Soga, Tetsuo; Jimbo, Takashi

    2011-02-01

    In this paper, we report the simultaneous formation of both single-walled carbon nanotubes (SWCNTs) and multi-wall carbon nanotubes (MWCNTs) in a reactor by ultrasonic spray pyrolysis. MWCNTs were formed at the center of the tube since catalyst particles accumulated on the substrates at the center agglomerate into a larger size. However, SWCNTs were formed downstream of the tube on desired substrates. Light transmission of the fluorine-doped tin oxide (FTO) substrate is reduced after SWCNT formation but returns to its initial state after ozone treatment.

  10. Photoluminescence characteristics of undoped and terbium chloride doped zinc oxide films deposited by spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Falcony, C.; Ortiz, A.; García, M.; Helman, J. S.

    1988-04-01

    The photoluminescence characteristics of undoped and TbCl3-doped zinc oxide films deposited by the spray pyrolysis technique are reported. Undoped films present the characteristic blue-green emission peak at ˜508 nm observed in single-crystal and powder ZnO. The TbCl3-doped films present a luminescence peak at ˜540 nm. The light emission of the doped films decreases with time of exposure of the sample to the excitation light. The phenomenon is interpreted in terms of a simple model in which a competitive process of hole trapping and phototrapping occurs at a radiative recombination center generated by the TbCl3.

  11. Study of photoconductivity in Ni doped CdS thin films prepared by spray pyrolysis technique

    NASA Astrophysics Data System (ADS)

    Patidar, Manju Mishra; Ajay, Akhil; Wala, Arwa Dewas; Kiran, N.; Panda, Richa; Gangrade, Mohan; Nath, R.; Ganesan, V.

    2014-04-01

    Ni-doped cadmium sulphide [Cd1-xNixS, (x=0, 0.03, 0.05 and 0.20)] thin films were investigated for photoconductive properties. The films were prepared by spray Pyrolysis technique (SPT). AFM and two probe resistivity measurements were carried out to analyze the morphological and electrical properties of the films. AFM shows the note worthy changes in the morphology where the nanorod structures in CdS is changed into nano particles with the Ni doping. The presence of persistence photo current is demonstrated and extensive photoconductivity analysis has been studied on these films.

  12. Semiconducting properties of Tm doped Yb-ZnO films by spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Chaki, Imane; Belayachi, Azzam; El Bahraoui, Toufik; Regragui, Mohamed; Abd-Lefdil, Mohamed

    2014-12-01

    In this work, we have investigated the structural, optical and electrical properties of rare earth co-doped zinc oxide thin films prepared by spray pyrolysis technique. X-ray diffraction has shown that the films are polycrystalline and textured with the c-axis of the wurtzite structure along the growth direction. Scanning electronic microscopy and transmission electronic microscopy were used to study the films composition and morphology. Photoluminescence measurements showed that all the films have a strong emission band at around 380 nm. Layers with electrical resistivity values as low as 5.7 × 10-2 ? cm were obtained.

  13. Room temperature ferromagnetism in Co doped ZnO thin film grown using spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Thakur, Vikas; Verma, Urvashi; Verma, U. P.; Rajaram, P.

    2013-06-01

    Co doped ZnO thin films were prepared using spray pyrolysis. XRD results confirm the absence of metallic Co clusters or any other phase different from wurtzite-type ZnO. UV-VIS studies show that the band edge of ZnO films is red-shifted with Co doping. Room temperature ferromagnetism has been observed in ZnCoO films. The field dependence of magnetization (M-H) curve measured at room temperature using SQUID magnetometer exhibits the clear ferromagnetism (FM).

  14. Zinc Oxide Thin-Film Transistors Fabricated at Low Temperature by Chemical Spray Pyrolysis

    NASA Astrophysics Data System (ADS)

    Jeong, Yesul; Pearson, Christopher; Lee, Yong Uk; Winchester, Lee; Hwang, Jaeeun; Kim, Hongdoo; Do, Lee-Mi; Petty, Michael C.

    2014-11-01

    We report the electrical behavior of undoped zinc oxide thin-film transistors (TFTs) fabricated by low-temperature chemical spray pyrolysis. An aerosol system utilizing aerodynamic focusing was used to deposit the ZnO. Polycrystalline films were subsequently formed by annealing at the relatively low temperature of 140°C. The saturation mobility of the TFTs was 2 cm2/Vs, which is the highest reported for undoped ZnO TFTs manufactured below 150°C. The devices also had an on/off ratio of 104 and a threshold voltage of -3.5 V. These values were found to depend reversibly on measurement conditions.

  15. Thin Film CuInS2 Prepared by Spray Pyrolysis with Single-Source Precursors

    NASA Technical Reports Server (NTRS)

    Jin, Michael H.; Banger, Kulinder K.; Harris, Jerry D.; Cowen, Jonathan E.; Hepp, Aloysius F.; Lyons, Valerie (Technical Monitor)

    2002-01-01

    Both horizontal hot-wall and vertical cold-wall atmospheric chemical spray pyrolysis processes deposited near single-phase stoichiometric CuInS2 thin films. Single-source precursors developed for ternary chalcopyrite materials were used for this study, and a new liquid phase single-source precursor was tested with a vertical cold-wall reactor. The depositions were carried out under an argon atmosphere, and the substrate temperature was kept at 400 C. Columnar grain structure was obtained with vapor deposition, and the granular structure was obtained with (liquid) droplet deposition. Conductive films were deposited with planar electrical resistivities ranging from 1 to 30 Omega x cm.

  16. Transparent conducting lithium-doped nickel oxide thin films by spray pyrolysis technique

    Microsoft Academic Search

    P Puspharajah; S Radhakrishna; A. K Arof

    1997-01-01

    Nickel oxide (NiO) and lithium-doped nickel oxide films were deposited by the spray pyrolysis technique using NiCl2 and LiCl\\u000a as starting materials. All the films were greenish-grey in colour and confirmed by X-ray analysis. The best NiO films were\\u000a obtained when the substrate temperature, Ts=480 C where a conductivity of 2.110-1?-1 cm-1 and transparency above 80% in\\u000a the visible region

  17. Hydroxyapatite forming ability of electrostatic spray pyrolysis derived calcium phosphate nano powder.

    PubMed

    Hwang, Kyu-Seog; Jeon, Kyung-Ok; Jeon, Young-Sun; Kim, Byung-Hoon

    2007-04-01

    A novel fabrication technique, i.e., electrostatic spray pyrolysis (ESP), has been used in this study to prepare calcium phosphate nano powders. Final annealing was done at 400 degrees C for 30 min in air. The hydroxyapatite-forming ability of the annealed powder has been investigated in Eagle's minimum essential medium solution. X-ray diffracton, field emission scanning electron microscope, energy dispersive X-ray spectroscope, and Fourier transform infrared spectroscope were employed to characterize the annealed powders after immersion. The powder with an amorphous structure induced hydroxyapatite formation on their surfaces after immersion for 15 days. PMID:17546422

  18. Growth of ?-In2Se3 Thin Films by Electrostatic Spray Pyrolysis Deposition

    NASA Astrophysics Data System (ADS)

    Kato, Takamasa; Hiramatsu, Toshitaka; Onojima, Norio

    2011-05-01

    ?-In2Se3 thin films were grown by the electrostatic spray pyrolysis deposition growth technique. We investigated the dependence of the crystalline quality and optical properties of the grown films on the growth conditions, such as growth temperatures and the molar ratios of source material Se/In in the precursor solution. The films which were highly aligned to the c-axis were grown at low growth temperature of 250 °C on glass substrates. The optical band gap energy was about 1.94 eV and was independent of the growth temperatures and the molar ratios Se/In in the precursor solution.

  19. Study of photoconductivity in Ni doped CdS thin films prepared by spray pyrolysis technique

    SciTech Connect

    Patidar, Manju Mishra, E-mail: manjumishra.iuc@gmail.com; Gangrade, Mohan; Nath, R.; Ganesan, V. [UGC-DAE Consortium for Scientific Research, Khandawa Road, Indore 452001 (India); Ajay, Akhil [Physics Department, University of Delhi, Delhi-110007 (India); Wala, Arwa Dewas [Holkar Science College, Indore - 452001 (India); N, Kiran [Physics Department, University of Mysore, Mysore-570005 (India); Panda, Richa [AITR, Bhopal-462044 (India)

    2014-04-24

    Ni-doped cadmium sulphide [Cd{sub 1?x}Ni{sub x}S, (x=0, 0.03, 0.05 and 0.20)] thin films were investigated for photoconductive properties. The films were prepared by spray Pyrolysis technique (SPT). AFM and two probe resistivity measurements were carried out to analyze the morphological and electrical properties of the films. AFM shows the note worthy changes in the morphology where the nanorod structures in CdS is changed into nano particles with the Ni doping. The presence of persistence photo current is demonstrated and extensive photoconductivity analysis has been studied on these films.

  20. Preparation of ZnO-doped Al films by spray pyrolysis technique

    NASA Astrophysics Data System (ADS)

    Kaid, M. A.; Ashour, A.

    2007-01-01

    Al-doped zinc oxide (AZO) thin films have been prepared by spray pyrolysis (SP) technique of zinc acetate and aluminium nitrate, and the effect of thickness on structural and optical properties has been investigated. The structural and optical characteristics of the AZO films were examined by X-ray diffraction (XRD) and double-beam spectrophotometry. These films, deposited on glass substrates at an optimal substrate temperature ( TS = 450 °C), have a polycrystalline texture with a hexagonal structure. Transmission measurements showed that for visible wavelengths, the AZO films have an average transmission of over 90%. The optical parameters have been calculated. The dependence of the refractive index, n, and extinction coefficient, k, on the wavelength for the sprayed films is also reported. Optical band gap of AZO is 3.30 and 3.55 eV, respectively, depending on the film thicknesses.

  1. Low-defect CeO2 films synthesis by combined spray pyrolysis using different precursors

    NASA Astrophysics Data System (ADS)

    Silva, T. G.; Ferreira, A. L.; Ribeiro, E.; Silveira, E.; Mattoso, N.

    2015-03-01

    films were fabricated by combining both a modified spray pyrolysis and the vapour transport deposition techniques. Two different precursors, cerium chloride and cerium acetate, were explored. In our approach, the pyrolytic process was not concomitant with the spray deposition and the introduction of the vapour transport condition has showed to improve both the morphological and optical quality of the films. Samples obtained from cerium chloride show a porous morphology, usual for polycrystalline layers, and a homogeneous light emission. When using vapour transport during thermal treatment, we achieved an enhanced luminescence, blue shifted to 3.08 eV and with negligible presence of defect bands. Films obtained from cerium acetate present similar crystalline properties, and a more defined light emission line shape, also peaked at 3.08 eV but with even lower contribution from known green-red defect bands. These results show that the proposed combined technique leads to films with homogeneous, enhanced optical properties.

  2. Synthesis and properties of Ce 1? x Gd x O 2? x\\/2 solid solution prepared by flame spray pyrolysis

    Microsoft Academic Search

    Dae Jong Seo; Kyoung Ok Ryu; Seung Bin Park; Ki Young Kim; Rak-Hyun Song

    2006-01-01

    Flame spray pyrolysis, which produces ultrafine particles, was applied to the synthesis of Ce1?xGdxO2?x\\/2 solid solutions by substituting Gd from a mole fraction of 0–0.40. The solubility limit of Gd in the Ce1?xGdxO2?x\\/2 solid solution produced by flame spray pyrolysis was between 0.25 and 0.30, which is consistent with the reported value. The as-prepared Ce1?xGdxO2?x\\/2 particles had a square morphology

  3. Uniform nanoparticles by flame-assisted spray pyrolysis (FASP) of low cost precursors

    PubMed Central

    Rudin, Thomas; Wegner, Karsten

    2013-01-01

    A new flame-assisted spray pyrolysis (FASP) reactor design is presented, which allows the use of inexpensive precursors and solvents (e.g., ethanol) for synthesis of nanoparticles (10–20 nm) with uniform characteristics. In this reactor design, a gas-assisted atomizer generates the precursor solution spray that is mixed and combusted with externally fed inexpensive fuel gases (acetylene or methane) at a defined height above the atomizing nozzle. The gaseous fuel feed can be varied to control the combustion enthalpy content of the flame and onset of particle formation. This way, the enthalpy density of the flame is decoupled from the precursor solution composition. Low enthalpy content precursor solutions are prone to synthesis of non-uniform particles (e.g., bimodal particle size distribution) by standard flame spray pyrolysis (FSP) processes. For example, metal nitrates in ethanol typically produce nanosized particles by gas-to-particle conversion along with larger particles by droplet-to-particle conversion. The present FASP design facilitates the use of such low enthalpy precursor solutions for synthesis of homogeneous nanopowders by increasing the combustion enthalpy density of the flame with low-cost, gaseous fuels. The effect of flame enthalpy density on product properties in the FASP configuration is explored by the example of Bi2O3 nanoparticles produced from bismuth nitrate in ethanol. Product powders were characterized by nitrogen adsorption, X-ray diffraction, X-ray disk centrifuge, and transmission electron microscopy. Homogeneous Bi2O3 nanopowders were produced both by increasing the gaseous fuel content and, most notably, by cutting the air entrainment prior to ignition of the spray. PMID:23408113

  4. Surfactant-assisted ultrasonic spray pyrolysis of nickel oxide and lithium-doped nickel oxide thin films, toward electrochromic applications

    NASA Astrophysics Data System (ADS)

    Denayer, Jessica; Bister, Geoffroy; Simonis, Priscilla; Colson, Pierre; Maho, Anthony; Aubry, Philippe; Vertruyen, Bénédicte; Henrist, Catherine; Lardot, Véronique; Cambier, Francis; Cloots, Rudi

    2014-12-01

    Lithium-doped nickel oxide and undoped nickel oxide thin films have been deposited on FTO/glass substrates by a surfactant-assisted ultrasonic spray pyrolysis. The addition of polyethylene glycol in the sprayed solution has led to improved uniformity and reduced light scattering compared to films made without surfactant. Furthermore, the presence of lithium ions in NiO films has resulted in improved electrochromic performances (coloration contrast and efficiency), but with a slight decrease of the electrochromic switching kinetics.

  5. Preparation of mixed oxide MoO 3–WO 3 thin films by spray pyrolysis technique and their characterisation

    Microsoft Academic Search

    P. R Patil; P. S Patil

    2001-01-01

    Mixed oxide MoO3–WO3 thin films have been deposited onto the amorphous and fluorine doped tin oxide (FTO) coated glass substrates at 300°C by using a simple and inexpensive spray pyrolysis technique. Equimolar ammonium tungstate and ammonium molybdate solutions were mixed together in volume proportions and used as precursors for spraying. The samples were annealed at 400°C for 1 h. They

  6. Electrochemical properties of tungsten sulfide–carbon composite microspheres prepared by spray pyrolysis

    PubMed Central

    Choi, Seung Ho; Boo, Sung Jin; Lee, Jong-Heun; Kang, Yun Chan

    2014-01-01

    Tungsten sulfide (WS2)–carbon composite powders with superior electrochemical properties are prepared by a two-step process. WO3-carbon composite powders were first prepared by conventional spray pyrolysis, and they were then sulfidated to form WS2-carbon powders. Bare WS2 powders are also prepared by sulfidation of bare WO3 powders obtained by spray pyrolysis. Stacked graphitic layers could not be found in the bare WS2 and WS2–carbon composite powders. The amorphous bare WS2 and WS2–carbon composite powders have Brunauer–Emmett–Teller (BET) surface areas of 2.8 and 4?m2 g?1, respectively. The initial discharge and charge capacities of the WS2–carbon composite powders at a current density of 100?mA g?1 are 1055 and 714?mA h g?1, respectively, and the corresponding initial Coulombic efficiency is 68%. On the other hand, the initial discharge and charge capacities of the bare WS2 powders are 514 and 346?mA h g?1, respectively. The discharge capacities of the WS2–carbon composite powders for the 2nd and 50th cycles are 716 and 555?mA h g?1, respectively, and the corresponding capacity retention measured after first cycle is 78%. PMID:25169439

  7. Electrochemical properties of tungsten sulfide-carbon composite microspheres prepared by spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Choi, Seung Ho; Boo, Sung Jin; Lee, Jong-Heun; Kang, Yun Chan

    2014-08-01

    Tungsten sulfide (WS2)-carbon composite powders with superior electrochemical properties are prepared by a two-step process. WO3-carbon composite powders were first prepared by conventional spray pyrolysis, and they were then sulfidated to form WS2-carbon powders. Bare WS2 powders are also prepared by sulfidation of bare WO3 powders obtained by spray pyrolysis. Stacked graphitic layers could not be found in the bare WS2 and WS2-carbon composite powders. The amorphous bare WS2 and WS2-carbon composite powders have Brunauer-Emmett-Teller (BET) surface areas of 2.8 and 4 m2 g-1, respectively. The initial discharge and charge capacities of the WS2-carbon composite powders at a current density of 100 mA g-1 are 1055 and 714 mA h g-1, respectively, and the corresponding initial Coulombic efficiency is 68%. On the other hand, the initial discharge and charge capacities of the bare WS2 powders are 514 and 346 mA h g-1, respectively. The discharge capacities of the WS2-carbon composite powders for the 2nd and 50th cycles are 716 and 555 mA h g-1, respectively, and the corresponding capacity retention measured after first cycle is 78%.

  8. Energy band diagram of In: ZnO/p-Si structures deposited using chemical spray pyrolysis technique

    NASA Astrophysics Data System (ADS)

    Hassan, Marwa Abdul Muhsien; Saleh, Arwaa Fadil; Mezher, Sabah J.

    2014-08-01

    Near-ideal In: ZnO/p-Si heterojunction band edge lineup has been investigated with aid of I-V and C-V measurements. The heterojunction was manufactured by spray pyrolysis method of (Zn (CH3COO)2·2H2O) at different indium doping concentrations on monocrystalline p-type silicon. The experimental data of the conduction band offset ? Ec and valence band offset ? Ec were compared with theoretical values. The band offset ? Ec = 0.45 eV and ? Ev = 1.65 eV obtained at 300 K. The energy band diagram of In: ZnO/p-Si HJ was constructed. C-V measurements depict that the junction was an abrupt type and the built-in voltage was determined from C-2-V plot.

  9. Nanostructured ZnO films with various morphologies prepared by ultrasonic spray pyrolysis and its growing process

    NASA Astrophysics Data System (ADS)

    Ma, H. L.; Liu, Z. W.; Zeng, D. C.; Zhong, M. L.; Yu, H. Y.; Mikmekova, E.

    2013-10-01

    Nanostructured ZnO films were prepared by the ultrasonic spray pyrolysis method using Zn(CH3COO)2·2H2O as a precursor. The effects of substrate temperature (Ts) on the morphology and properties were systematically studied. As the Ts increased from 430 °C to 610 °C, the morphology of the film transforms from closed packed nanosheets to dense nanocrystalline film and then to hexagonal nanorod array. The dense film formed at a temperature of 550 °C has the lowest electric resistivity and highest carrier concentration. The optical transmittance for all prepared samples was higher than 90%. The photoluminescence (PL) properties varied with the Ts due to the internal defect difference. The growth mechanism of ZnO film involves island growth and diffusion, which was evident by observing the samples prepared at various times.

  10. Effect of aluminium doping on structural and gas sensing properties of zinc oxide thin films deposited by spray pyrolysis

    Microsoft Academic Search

    Satish S. Badadhe; I. S. Mulla

    2011-01-01

    A facile spray pyrolysis route is used to deposit aluminium doped ZnO (AZO) thin films on to the glass substrates. It is observed that on aluminium doping the particle size of ZnO reduces significantly; moreover, uniformity of particle also gets enhanced. Their XRD study reveals that intensity ratio of crystal planes depend on the aluminium doping concentration. The gas response

  11. Opto-structural, electrical and electrochromic properties of crystalline nickel oxide thin films prepared by spray pyrolysis

    Microsoft Academic Search

    S. A. Mahmoud; A. A. Akl; H. Kamal; K. Abdel-Hady

    2002-01-01

    Polycrystalline nickel oxide films with preferential growth along (111) plane were deposited onto glass substrates, maintained at 350°C, by the spray pyrolysis technique using nickel chloride as starting solution. The effect of solution concentration on their structural, electrical, and optical properties was studied. Using X-ray diffraction, the structural characteristics have been studied and due to the high degree of preferred

  12. Synthesis and characterization of nickel oxide thin films deposited on glass substrates using spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Jlassi, M.; Sta, I.; Hajji, M.; Ezzaouia, H.

    2014-07-01

    A simple and inexpensive spray pyrolysis technique was employed to deposit nickel oxide (NiO) thin films from hydrated nickel chloride salt solution onto amorphous glass substrate. The as-deposited films were transparent, uniform and well adherent to the glass substrate. The effect of the substrate temperature, the volume and the concentration of the sprayed solution on the structural, optical and electrical properties was studied using X-ray diffraction, optical transmittance, four point probe, scanning electron microscopy and atomic force microscopy. The structural analyses show that all the samples have a cubic structure. It was found that the increase in the volume of sprayed solution leads to an increment in the crystallite size of NiO and improves the homogeneity of the film. Optical measurements have shown that an increase in the thickness of the layer results in a decrease in the optical transmission, but it remains higher than 70% even if the thickness exceeds 600 nm. At the same time, the optical gap decreases from 3.7 to 3.55 eV when the thickness increases from 133 to 620 nm. Low values of the electrical resistivity (less than 10 ? cm) were obtained for thin films with thicknesses less than about 240 nm, but for higher thicknesses the resistivity increases linearly to reach about 170 ? cm for a thickness of 620 nm.

  13. Low-cost plasmonic solar cells prepared by chemical spray pyrolysis.

    PubMed

    Kärber, Erki; Katerski, Atanas; Oja Acik, Ilona; Mikli, Valdek; Mere, Arvo; Sildos, Ilmo; Krunks, Malle

    2014-01-01

    Solar cells consisting of an extremely thin In2S3/CuInS2 buffer/absorber layer uniformly covering planar ZnO were prepared entirely by chemical spray pyrolysis. Au nanoparticles (Au-NPs) were formed via thermal decomposition of a gold(III) chloride trihydrate (HAuCl4·3H2O) precursor by spraying 2 mmol/L of the aqueous precursor solution onto a substrate held at 260 °C. Current-voltage scans and external quantum efficiency spectra were used to evaluate the solar cell performance. This work investigates the effect of the location of the Au-NP layer deposition (front side vs rear side) in the solar cell and the effect of varying the volume (2.5-10 mL) of the sprayed Au precursor solution. A 63% increase (from 4.6 to 7.5 mA/cm(2)) of the short-circuit current density was observed when 2.5 mL of the precursor solution was deposited onto the rear side of the solar cell. PMID:25551068

  14. Properties of NiO thin films deposited by intermittent spray pyrolysis process

    NASA Astrophysics Data System (ADS)

    Reguig, B. A.; Khelil, A.; Cattin, L.; Morsli, M.; Bernède, J. C.

    2007-02-01

    NiO thin films have been grown on glass substrates by intermittent spray pyrolysis deposition of NiCl 2·6H 2O diluted in distilled water, using a simple "perfume atomizer". The effect of the solution molarity on their properties was studied and compared to those of NiO thin films deposited with a classical spray system. It is shown that NiO thin films crystallized in the NiO structure are achieved after deposition. Whatever the precursor molarity, the grain size is around 25-30 nm. The crystallites are preferentially oriented along the (1 1 1) direction. All the films are p-type. However, the thickness and the conductivity of the NiO films depend on the precursor contraction. By comparison with the properties of films deposited by classical spray technique, it is shown that the critical precursor concentration, which induces strong thin films properties perturbations, is higher when a perfume atomizer is used. This broader stability domain can be attributed to better chlorides decomposition during the rest time used in the perfume atomizer technique.

  15. Low-cost plasmonic solar cells prepared by chemical spray pyrolysis

    PubMed Central

    Katerski, Atanas; Oja Acik, Ilona; Mikli, Valdek; Mere, Arvo; Sildos, Ilmo; Krunks, Malle

    2014-01-01

    Summary Solar cells consisting of an extremely thin In2S3/CuInS2 buffer/absorber layer uniformly covering planar ZnO were prepared entirely by chemical spray pyrolysis. Au nanoparticles (Au-NPs) were formed via thermal decomposition of a gold(III) chloride trihydrate (HAuCl4·3H2O) precursor by spraying 2 mmol/L of the aqueous precursor solution onto a substrate held at 260 °C. Current–voltage scans and external quantum efficiency spectra were used to evaluate the solar cell performance. This work investigates the effect of the location of the Au-NP layer deposition (front side vs rear side) in the solar cell and the effect of varying the volume (2.5–10 mL) of the sprayed Au precursor solution. A 63% increase (from 4.6 to 7.5 mA/cm2) of the short-circuit current density was observed when 2.5 mL of the precursor solution was deposited onto the rear side of the solar cell. PMID:25551068

  16. Improvement on droplet production rate of ultrasonic - nebulizer in spray pyrolysis process

    NASA Astrophysics Data System (ADS)

    Panatarani, Camellia; Demen, Tuti Aryati; Men, Liu Kin; Maulana, Dwindra Wilham; Hidayat, Darmawan; Joni, I. Made

    2013-09-01

    Atomization is an important part in Spray Pyrolysis (SP) process which is applied to synthesize submicron or nano sized particles or to deposit thin film. Ultrasonic Nebulizer (UN) is usually use in SP due to its homogeneous droplets production with size between 1-5 ?m. The drawback of the UN is low droplets production rate. In this research, we successfully developed a Digital Ultrasonic Nebulizer (DUN) with high droplets production rate using two ultrasonic traducers with applied frequency of 2.4 MHz. The result of DUN atomization was improved 4-6 fold compare to the conventional UN. The DUN also has an additional digital features such as pushbutton, LCD and microcontroller which is allow to set duration and applied voltage.

  17. Spray Pyrolysis Preparation and Humidity Sensing Characteristics of Spinel Zinc Stannate Thin Films

    NASA Astrophysics Data System (ADS)

    Stambolova, I.; Konstantinov, K.; Kovacheva, D.; Peshev, P.; Donchev, T.

    1997-02-01

    Polycrystalline spinel Zn 2SnO 4films were successfully deposited on alumina substrates by spray pyrolysis. It was found that the ratio of the two cations in the films obtained differs considerably from the ratio in the initial solutions. By optimizing the solution compositions and the deposition and heat-treatment parameters, it was possible to obtain homogeneous single phase films with good adhesion to the substrate. At room temperaturethe electrical resistance of the films was strongly dependent on humidity, the response and recovery times being very short (1-2 min). The humidity sensing characteristics deteriorated in the presence of a binary oxide (ZnO or SnO 2) impurity in the film.

  18. Emission and Structure Varieties in ZnO:Ag Nanorods Obtained by Ultrasonic Spray Pyrolysis

    NASA Astrophysics Data System (ADS)

    Velázquez Lozada, E.; Torchynska, T. V.; Casas Espinola, J. L.

    2014-04-01

    Scanning electronic microscopy (SEM), X ray diffraction (XRD) and photoluminescence (PL) have been applied to the study of the structural and optical properties of ZnO nanocrystals prepared by the ultrasonic spray pyrolysis (USP) at different temperatures. The variation of temperatures and times at the growth of ZnO films permits modifying the ZnO phase from the amorphous to crystalline, to change the size of ZnO nanocrystals (NCs), as well as to vary their photoluminescence spectra. The study has revealed three types of PL bands in ZnO NCs: defect related emission, the near-band-edge (NBE) PL, related to the LO phonon replica of free exciton (FE) recombination, and FE second-order diffraction peaks. The PL bands related to the LO phonon replica of FE in PL spectra measured at room temperature testify on the high quality of ZnO films prepared by the USP technology.

  19. Optoelectronic characteristics of YAG phosphor-incorporated ZnO films deposited by ultrasonic spray pyrolysis.

    PubMed

    Chen, Lung-Chien; Huang, Chien-Chung

    2012-01-01

    This work presents a novel white light device. An yttrium aluminum garnet (YAG) phosphor-incorporated zinc oxide (ZnO) film is deposited on a slide glass substrate by ultrasonic spray pyrolysis. A nanoflower consisting of a hexagonal nanopetal is formed on the surfaces of the samples, and the sizes of the nanopetal are approximately 200 to 700 nm. Additionally, the nanopetal becomes blunted with an increasing incorporated amount of YAG. As the incorporated amount is 1.5 and 2.5 wt.%, the photoluminescence color of the YAG-incorporated ZnO film is nearly white, possibly contributing to the YAG emission and the band-to-deep level transition in the ZnO film. PMID:23151219

  20. Optoelectronic characteristics of YAG phosphor-incorporated ZnO films deposited by ultrasonic spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Chen, Lung-Chien; Huang, Chien-Chung

    2012-11-01

    This work presents a novel white light device. An yttrium aluminum garnet (YAG) phosphor-incorporated zinc oxide (ZnO) film is deposited on a slide glass substrate by ultrasonic spray pyrolysis. A nanoflower consisting of a hexagonal nanopetal is formed on the surfaces of the samples, and the sizes of the nanopetal are approximately 200 to 700 nm. Additionally, the nanopetal becomes blunted with an increasing incorporated amount of YAG. As the incorporated amount is 1.5 and 2.5 wt.%, the photoluminescence color of the YAG-incorporated ZnO film is nearly white, possibly contributing to the YAG emission and the band-to-deep level transition in the ZnO film.

  1. Electrical Characterization of n-ZnO/p-Si Heterojunction Prepared by Spray Pyrolysis Technique

    NASA Astrophysics Data System (ADS)

    Bedia, F. Z.; Bedia, A.; Benyoucef, B.; Hamzaoui, S.

    The study reports the experimental and the electrical junction properties analysis of current-voltage characteristics of n-ZnO/p-Si heterostructures. Wide band gap semiconducting layer of n-type ZnO thin film was fabricated on p-type Si wafer with spray pyrolysis technique at 550C° to form n-ZnO/ p-Si heterojunctions. The current-voltage characteristic of the n-Zn0/ p-Si heterojunction device has been measured at room temperature in the dark and under illumination (lamp/160 W). The characteristic parameters of the structure such as barrier height, ideality factor and series resistance were determined from the current-voltage measurement.

  2. Optoelectronic characteristics of YAG phosphor-incorporated ZnO films deposited by ultrasonic spray pyrolysis

    PubMed Central

    2012-01-01

    This work presents a novel white light device. An yttrium aluminum garnet (YAG) phosphor-incorporated zinc oxide (ZnO) film is deposited on a slide glass substrate by ultrasonic spray pyrolysis. A nanoflower consisting of a hexagonal nanopetal is formed on the surfaces of the samples, and the sizes of the nanopetal are approximately 200 to 700 nm. Additionally, the nanopetal becomes blunted with an increasing incorporated amount of YAG. As the incorporated amount is 1.5 and 2.5 wt.%, the photoluminescence color of the YAG-incorporated ZnO film is nearly white, possibly contributing to the YAG emission and the band-to-deep level transition in the ZnO film. PMID:23151219

  3. Semiconducting properties of aluminum-doped ZnO thin films grown by spray pyrolysis technique

    NASA Astrophysics Data System (ADS)

    Mahadik, M. A.; Hunge, Y. M.; Shinde, S. S.; Rajpure, K. Y.; Bhosale, C. H.

    2015-03-01

    Highly transparent and preferential c-axis oriented nanocrystalline undoped and Al doped zinc oxide (AZO) thin films have been deposited onto amorphous glass substrate by spray pyrolysis. The XRD studies reveal that AZO with a hexagonal (wurtzite) crystal structure having (002) preferred orientation is formed. The atomic force microscope (AFM) shows uniform surface topography. The optical band gap values of undoped and AZO thin films were changed from 3.34 to 3.35 eV. The band gap energy and photoluminescence are found to depend on the Al doping. Thermoelectric power measurement shows film having n-type in nature. Dielectric constant and loss (tan ?) were found to be frequency dependent. Interparticle interactions in the deposited films are studied by complex impendence spectroscopy.

  4. Room temperature defect related electroluminescence from ZnO homojunctions grown by ultrasonic spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Du, G. T.; Liu, W. F.; Bian, J. M.; Hu, L. Z.; Liang, H. W.; Wang, X. S.; Liu, A. M.; Yang, T. P.

    2006-07-01

    ZnO homojunction light-emitting diode was grown on single-crystal GaAs (100) substrate by ultrasonic spray pyrolysis. This diode was comprised of N-In codoped p-type ZnO and unintentionally doped n-type ZnO film. Ohmic contact on n-type ZnO layer and GaAs substrate was formed by Zn /Au and Au /Ge/Ni alloyed metal electrodes, respectively. An electroluminescence emission associated with defects was observed from the ZnO homojunction under forward current injection at room temperature. The I-V characteristics of the homojunction showed a threshold voltage of ˜4V under forward bias.

  5. Thulium and Ytterbium-Doped Titanium Oxide Thin Films Deposited by Ultrasonic Spray Pyrolysis

    NASA Astrophysics Data System (ADS)

    Forissier, Sébastien; Roussel, Hervé; Chaudouet, Patrick; Pereira, Antonio; Deschanvres, Jean-Luc; Moine, Bernard

    2012-12-01

    Thin films of thulium and ytterbium-doped titanium oxide were grown by metal-organic spray pyrolysis deposition from titanium(IV)oxide bis(acetylacetonate), thulium(III) tris(2,2,6,6-tetramethyl-3,5-heptanedionate) and ytterbium(III) tris(acetylacetonate). Deposition temperatures have been investigated from 300 to 600 °C. Films have been studied regarding their crystallinity and doping quality. Structural and composition characterisations of TiO2:Tm,Yb were performed by electron microprobe, x-ray diffraction, and Fourier transform infrared spectroscopy. The deposition rate can reach 0.8 ?m/h. The anatase phase of TiO2 was obtained after synthesis at 400 °C or higher. Organic contamination at low deposition temperature is eliminated by annealing treatments.

  6. Preparation of indium sulfide thin films by spray pyrolysis using a new precursor indium nitrate

    NASA Astrophysics Data System (ADS)

    John, Teny Theresa; Kartha, C. Sudha; Vijayakumar, K. P.; Abe, T.; Kashiwaba, Y.

    2005-12-01

    Indium nitrate and thiourea were used as the precursor solutions for preparing indium sulfide thin films using Chemical Spray Pyrolysis (CSP) technique. Films having various In/S ratios were characterized using X-Ray Diffraction (XRD), Energy Dispersive X-ray Analysis (EDX), Scanning Electron Microscopy (SEM), X-ray Photoelectron Spectroscopy (XPS), optical absorption, transmission and photosensitivity measurements. Sample having In/S ratio 2/3 showed better crystallinity with band gap 2.66 eV. Depth profile of the sample also indicated the formation of indium sulfide. It was also observed that In/S ratio in the initial precursor solution determined the composition as well as electrical properties of the films. Maximum photosensitivity was observed for the sample prepared using solution having In/S ratio 2/4.

  7. Chemical spray pyrolysis of ?-In2S3 thin films deposited at different temperatures

    NASA Astrophysics Data System (ADS)

    Sall, Thierno; Marí Soucase, Bernabé; Mollar, Miguel; Hartitti, Bouchaib; Fahoume, Mounir

    2015-01-01

    In2S3 thin films were deposited onto indium tin oxide-coated glass substrates by chemical spray pyrolysis while keeping the substrates at different temperatures. The structures of the sprayed In2S3 thin films were characterized by X-ray diffraction (XFD). The quality of the thin films was determined by Raman spectroscopy. Scanning electron microscopy (SEM) and atomic force microscopy were used to explore the surface morphology and topography of the thin films, respectively. The optical band gap was determined based on optical transmission measurements. The indium sulfide phase exhibited a preferential orientation in the (0, 0, 12) crystallographic direction according to the XRD analysis. The phonon vibration modes determined by Raman spectroscopy also confirmed the presence of the In2S3 phase in our samples. According to SEM, the surface morphologies of the films were free of defects. The optical band gap energy varied from 2.82 eV to 2.95 eV.

  8. Supercapacitive cobalt oxide (Co 3O 4) thin films by spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Shinde, V. R.; Mahadik, S. B.; Gujar, T. P.; Lokhande, C. D.

    2006-08-01

    Uniform and adherent cobalt oxide thin films have been deposited on glass substrates from aqueous cobalt chloride solution, using the solution spray pyrolysis technique. Their structural, optical and electrical properties were investigated by means of X-ray diffraction (XRD), scanning electron micrograph (SEM), optical absorption and electrical resistivity measurements. Along with this, to propose Co 3O 4 for possible application in energy storage devices, its electrochemical supercapacitor properties have been studied in aqueous KOH electrolyte. The structural analysis from XRD pattern showed the oriented growth of Co 3O 4 of cubic structure. The surface morphological studies from scanning electron micrographs revealed the nanocrystalline grains alongwith some overgrown clusters of cobalt oxide. The optical studies showed direct and indirect band gaps of 2.10 and 1.60 eV, respectively. The electrical resistivity measurement of cobalt oxide films depicted a semiconducting behavior with the room temperature electrical resistivity of the order of 1.5 × 10 3 ? cm. The supercapacitor properties depicted that spray-deposited Co 3O 4 film is capable of exhibiting specific capacitance of 74 F/g.

  9. Transformation of amorphous iron oxide thin films predeposited by spray pyrolysis into a single FeSe 2-phase by selenisation

    Microsoft Academic Search

    B. Ouertani; J. Ouerfelli; M. Saadoun; B. Bessaïs; H. Ezzaouia; J. C. Bernède

    2005-01-01

    The present paper investigates a simple and non-toxic method to transform amorphous iron oxide pre-deposited by spray pyrolysis of FeCl3·6H2O (0.03M)-based aqueous solution onto glass substrates heated at 350°C into FeSe2 thin films. The amorphous iron oxide films were heat treated under a selenium atmosphere (10?4Pa) at different temperatures for 6h. X-ray diffraction (XRD) was used to investigate the structure

  10. Elaboration by spray pyrolysis and characterization in the VUV range of phosphor particles with spherical shape and micronic size

    Microsoft Academic Search

    Nicolas Joffin; Bruno Caillier; Jeannette Dexpert-Ghys; Marc Verelst; Guy Baret; Alain Garcia; Philippe Guillot; Jacques Galy; Robert Mauricot; Sylvie Schamm

    2005-01-01

    Y2O3 : Eu and Zn2SiO4 : Mn are the red and green phosphors actually used in plasma display panels. These phosphors have been prepared by spray pyrolysis synthesis and thermal post-treatments. Their optical properties in the vacuum ultraviolet (VUV) energy range have been investigated. The absorption coefficients have been extracted from electron energy loss spectroscopy. The luminescence properties of phosphors

  11. Processing and synthesis of multi-metallic nano oxide ceramics via liquid-feed flame spray pyrolysis

    Microsoft Academic Search

    Jose Antonio Azurdia

    2009-01-01

    The liquid-feed flame spray pyrolysis (LF-FSP) process aerosolizes metal-carboxylate precursors dissolved in alcohol with oxygen and combusts them at >1500°C. The products are quenched rapidly (˜10s msec) to < 400°C. By selecting the appropriate precursor mixtures, the compositions of the resulting oxide nanopowders can be tailored easily, which lends itself to combinatorial studies of systems facilitating material property optimization. The

  12. Polycrystalline RbTiOPO 4 and KTiOPO 4 bilayer thin films by spray pyrolysis

    Microsoft Academic Search

    Nickolay Golego; Michael Cocivera

    1998-01-01

    A novel titanium precursor has been used with spray pyrolysis (SP) to deposit polycrystalline rubidium titanyl phosphate, RbTiOPO4 (RTP), thin films on thin film potassium titanyl phosphate, KTiOPO4 (KTP), for possible waveguide applications. The titanium precursor for this process was titanium peroxo–hydroxo complex (TPH) in aqueous diluted HNO3. The morphology of thin films of RTP and KTP depended on the

  13. Comparative study of nano-structured CdS thin films prepared by CBD and spray pyrolysis: Annealing effect

    Microsoft Academic Search

    J. Hiie; T. Dedova; V. Valdna; K. Muska

    2006-01-01

    CdS films were deposited on glass and ITO-covered glass substrates by two techniques: chemical bath deposition (CBD) and spray pyrolysis technique. CdCl2 and thiocarbamide were used as basic precursors in both cases.After deposition, films were isothermally annealed in evacuated (1.3 Pa) quartz ampoules at 450 °C for 5 min and slowly cooled down to room temperature.The morphology of the films

  14. Characterization of ultrafine LaâSr{sub 1-x}MnOâ powder prepared by spray pyrolysis

    Microsoft Academic Search

    B. Zhao; R. Zhang; L. Lu; H. Xie

    1997-01-01

    As a device for generating electricity, solid oxide fuel cell (SOFC) has excellent potential advantages. LaâSr{sub 1-x}MnOâ powders are widely used as air electrode materials in SOFC systems; they are an essential component part and are therefore directly related to the efficiency of the system. The characterization of LaâSr{sub 1-x}MnOâ powders produced by spray pyrolysis using scanning electron microscopy (SEM)

  15. Organic light emitting diodes using fluorine doped tin oxide thin films, deposited by chemical spray pyrolysis, as anode

    Microsoft Academic Search

    J. Ouerfelli; S. Ouro Djobo; J. C. Bernède; L. Cattin; M. Morsli; Y. Berredjem

    2008-01-01

    Thin films of tin oxide doped with fluorine (SnO2:F) have been deposited by chemical spray pyrolysis. The SnO2:F thin films are crystallized in the excepted tetragonal structure, with a preferential orientation of their crystallites along the (200) direction. They exhibit a good transparency in the visible and a small resistivity (?=4.23×10?4?cm). These SnO2:F thin films have been used as anode

  16. Optical, structural, and electrical characteristics of high dielectric constant zirconium oxide thin films deposited by spray pyrolysis

    Microsoft Academic Search

    M. Aguilar-Frutis; G. Reyna-Garcia; M. Garcia-Hipolito; J. Guzman-Mendoza; C. Falcony

    2004-01-01

    The spray pyrolysis technique was used to obtain high dielectric constant zirconium oxide films. These films were deposited on silicon substrates, and quartz slides from two different solution concentrations (0.033 and 0.066 M) of zirconium acetylacetonate dissolved in N,N-dimethylformamide at substrate temperatures in the range of 400-600 °C. The films are transparent with a surface roughness lower than 40 Å

  17. Fabrication and characterization of fluorine-doped thin oxide thin films and nanorod arrays via spray pyrolysis

    Microsoft Academic Search

    B. Russo; G. Z. Cao

    2008-01-01

    This paper reports the synthesis and characterization of fluorine-doped tin oxide (FTO) thin films via intermittent spray\\u000a pyrolysis utilizing a solution mixture of tin chloride pentahydrate and ammonia fluoride. Utilizing the same solution, nanorod\\u000a arrays were fabricated via template-based growth. Uniform and crack-free FTO films over 20×20 mm with a thickness up to 900 nm\\u000a have been routinely achieved; such FTO films

  18. Formation of self-assembled quantum dots of iron oxide thin films by spray pyrolysis from non-aqueous medium

    Microsoft Academic Search

    J. D. Desai; H. M. Pathan; Sun-Ki Min; Kwang-Deog Jung; Oh-Shim Joo

    2006-01-01

    Quantum dots (QDs) of iron oxide have been deposited onto ITO coated glass substrates by spray pyrolysis technique, using ferric chloride (FeCl3·7H2O) in non-aqueous medium as a starting material. The non-aqueous solvents namely methanol, ethanol, propanol, butanol and pentanol were used as solvents. The effect of solvents on the film structure and morphology was studied. The structural, morphological, compositional and

  19. Green photoluminescence efficiency and free-carrier density in ZnO phosphor powders prepared by spray pyrolysis

    Microsoft Academic Search

    K. Vanheusden; C. H. Seager; W. L. Warren; D. R. Tallant; J. Caruso; M. J. Hampden-Smith; T. T. Kodas

    1997-01-01

    Electron paramagnetic resonance, optical absorption, and photoluminescence spectroscopy have been combined to characterize ZnO powders that were prepared by spray pyrolysis. We generally observe a good correlation between the 510 nm green emission intensity and the density of paramagnetic isolated oxygen vacancies. In addition, both quantities increase with free-carrier concentration ne, as long as ne < 1.4 × 1018cm?3. At

  20. Enhancement of surface areas of Co 3O 4 and NiCo 2O 4 electrocatalysts prepared by spray pyrolysis

    Microsoft Academic Search

    P. Nkeng; J.-F. Koenig; J. L. Gautier; P. Chartier; G. Poillerat

    1996-01-01

    Nickel and cobalt cobaltites have been prepared as thin films by spray pyrolysis of solutions containing cobalt and nickel nitrates. An alkali nitrate has been added to the sprayed solution which remained undecomposed during the formation of the oxide film. Then, this alkali nitrate dissolved leading to an enhancement of the roughness of the films which can be controlled. We

  1. Effect of solvent composition on oxide morphology during flame spray pyrolysis of metal nitrates.

    PubMed

    Strobel, Reto; Pratsinis, Sotiris E

    2011-05-28

    The effect of solvent composition on particle formation during flame spray pyrolysis of inexpensive metal-nitrates has been investigated for alumina, iron oxide, cobalt oxide, zinc oxide and magnesium oxide. The as-prepared materials were characterized by electron microscopy, nitrogen adsorption, X-ray diffraction (XRD) and disc centrifugation (XDC). The influence of solvent parameters such as boiling point, combustion enthalpy and chemical reactivity on formation of either homogeneous nanoparticles by evaporation/nucleation/coagulation (gas-to-particle conversion) or large particles through precipitation and conversion within the sprayed droplets (droplet-to-particle conversion) is discussed. For Al(2)O(3), Fe(2)O(3), Co(3)O(4) and partly also MgO, the presence of a carboxylic acid in the FSP solution resulted in homogeneous nanoparticles. This is attributed to formation of volatile metal carboxylates in solution as evidenced by attenuated total reflectance spectroscopy (ATR). For ZnO and MgO rather homogeneous nanoparticles were formed regardless of solvent composition. For ZnO this is attributed to its relatively low dissociation temperature compared to other oxides. While for MgO this is traced to the high decomposition temperature of Mg(NO(3))(2) together with Mg(OH)(2)?MgO transformations. Cobalt oxide (Co(3)O(4)) nanoparticles made by FSP were not aggregated but rather loosely agglomerated as determined by the excellent agreement between XRD- and XDC-derived crystallite and particle sizes, respectively, pointing out the potential of FSP to make non-aggregated particles. PMID:21468418

  2. Properties of NiO thin films deposited by chemical spray pyrolysis using different precursor solutions

    NASA Astrophysics Data System (ADS)

    Cattin, L.; Reguig, B. A.; Khelil, A.; Morsli, M.; Benchouk, K.; Bernède, J. C.

    2008-07-01

    NiO thin films have been deposited by chemical spray pyrolysis using a perfume atomizer to grow the aerosol. The influence of the precursor, nickel chloride hexahydrate (NiCl 2·6H 2O), nickel nitrate hexahydrate (Ni(NO 3) 2·6H 2O), nickel hydroxide hexahydrate (Ni(OH) 2·6H 2O), nickel sulfate tetrahydrate (NiSO 4·4H 2O), on the thin films properties has been studied. In the experimental conditions used (substrate temperature 350 °C, precursor concentration 0.2-0.3 M, etc.), pure NiO thin films crystallized in the cubic phase can be achieved only with NiCl 2 and Ni(NO 3) 2 precursors. These films have been post-annealed at 425 °C for 3 h either in room atmosphere or under vacuum. If all the films are p-type, it is shown that the NiO films conductivity and optical transmittance depend on annealing process. The properties of the NiO thin films annealed under room atmosphere are not significantly modified, which is attributed to the fact that the temperature and the environment of this annealing is not very different from the experimental conditions during spray deposition. The annealing under vacuum is more efficient. This annealing being proceeded in a vacuum no better than 10 -2 Pa, it is supposed that the modifications of the NiO thin film properties, mainly the conductivity and optical transmission, are related to some interaction between residual oxygen and the films.

  3. Structural, optical and electrical properties of undoped and indium doped zinc oxide prepared by spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Addou, M.; Moumin, A.; El Idrissi, B.; Regragui, M.; Bougrine, A.; Kachouane, A.; Monty, C.

    1999-02-01

    Thin films of transparent undoped and indium doped ZnO have been deposited using the spray pyrolysis technique. The structural, optical properties and electrical resistivity of these films are investigated as a function of substrate temperature and indium concentration in the solution. X-ray diffraction showed that the films prepared at substrate temperature greater than 300 °C exhibit the hexagonal wurtzite structure with a preferential orientation along the (002) direction. Indium doping changes the orientation of grains to the (110) direction. This result is confirmed by SEM. The composition of the films is also examined by XPS. High transmittance (80%) in the visible region and low resistivity of about 10-1 ?.cm at room temperature are obtained for thin films prepared under optimum deposition conditions: Ts = 450 ^circC and In/Zn = 2 at.%. Des couches minces transparentes et conductrices d'oxydes de zinc (ZnO) non dopées et dopées indium ont été élaborées par pulvérisation chimique réactive en phase liquide (spray). Les propriétés structurales, optiques et électriques de ces couches ont été étudiées en fonction de certains paramètres expérimentaux tel que la température du dépôt et la concentration d'indium dans la solution. L'étude par diffraction X a montré que les couches préparées à des températures de dépôt supérieures à 300 °C ont une structure hexagonale type wurtzite avec une orientation préférentielle suivant l'axe [002]. Le dopage à l'indium change l'orientation des cristallites suivant la direction [110]. Ce résultat a été confirmé par la microscopie électronique à balayage. La résistivité électrique de l'ordre de 10-1 ?.cm et la transmission optique de 80 % ont été obtenues pour des couches préparées dans les conditions optimales : Ts = 450 ^circC et In/Zn = 2 at.%.

  4. Self-organized macroporous carbon structure derived from phenolic resin via spray pyrolysis for high-performance electrocatalyst.

    PubMed

    Balgis, Ratna; Sago, Sumihito; Anilkumar, Gopinathan M; Ogi, Takashi; Okuyama, Kikuo

    2013-11-27

    The synthesis and evaluation of porous carbon derived from phenolic resin using a fast and facile spray pyrolysis method has been studied for use as a new electrocatalyst support material. By adding polystyrene latex nanoparticles as a template to the phenolic resin precursor, self-organized macroporous carbon structure was first developed. The mass ratio of phenolic resin to PSL at 0.625 gave the optimum porous morphology. Pt nanoparticles (?20 wt %) were grown on the carbon surface using a standard industrial impregnation method. Well-dispersed Pt nanoparticles of average size 3.91 nm were observed on the surface of porous carbon particles. The high catalytic performance of porous Pt/C electrocatalyst was confirmed by the high mass activity and electrochemically active surface area, which were 450.81 mA mg(-1)-Pt and 81.78 m(2) g(-1)-Pt, respectively. The porous Pt/C catalyst obtains two times higher mass activity than that of the commercial Pt/C catalyst and performs excellent durability under acid conditions. PMID:24171401

  5. Effects of N- and N-In doping on ZnO films prepared by using ultrasonic spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Wang, Qun; Park, Se-Jeong; Shin, Dong-Myeong; Kim, Hyung-Kook; Hwang, Yoon-Hwae; Zhang, Yiwen; Li, Xiaomin

    2014-12-01

    The effects of N-doping, and N-In co-doping on ZnO films were studied by analyzing the structural, electrical, and optical properties of the films prepared by using an ultrasonic spray pyrolysis (USP) method. According to scanning electron microscopy (SEM) data, all films had very complex surface structures. Their polycrystallinity were also proven by using an X-ray diffraction method. The Hall-effect measurement showed that both the undoped and the N-doped ZnO films exhibited n-type conductivity and that the N-In co-doped ZnO film showed p-type conductivity. In the extended X-ray absorption fine structure (EXAFS) analysis, the number of oxygen atoms in the N-In codoped ZnO films was found to be larger than that in the N-doped and the undoped ZnO films. The photoluminescence spectra also showed that the N-In co-doping suppressed the concentration of oxygen vacancies in the ZnO films. Through an effective incorporation of indium atoms, more oxygen atoms seem to have been introduced into the lattice of the N-In co-doped ZnO films.

  6. ZnO-based Thin Film Transistors Employing Aluminum Titanate Gate Dielectrics Deposited by Spray Pyrolysis at Ambient Air.

    PubMed

    Afouxenidis, Dimitrios; Mazzocco, Riccardo; Vourlias, Georgios; Livesley, Peter J; Krier, Anthony; Milne, William I; Kolosov, Oleg; Adamopoulos, George

    2015-04-01

    The replacement of SiO2 gate dielectrics with metal oxides of higher dielectric constant has led to the investigation of a wide range of materials with superior properties compared with SiO2. Despite their attractive properties, these high-k dielectrics are usually manufactured using costly vacuum-based techniques. To overcome this bottleneck, research has focused on the development of alternative deposition methods based on solution-processable metal oxides. Here we report the application of spray pyrolysis for the deposition and investigation of Al2x-1·TixOy dielectrics as a function of the [Ti(4+)]/[Ti(4+)+2·Al(3+)] ratio and their implementation in thin film transistors (TFTs) employing spray-coated ZnO as the active semiconducting channels. The films are studied by UV-visible absorption spectroscopy, spectroscopic ellipsometry, impedance spectroscopy, atomic force microscopy, X-ray diffraction and field-effect measurements. Analyses reveal amorphous Al2x-1·TixOy dielectrics that exhibit a wide band gap (?4.5 eV), low roughness (?0.9 nm), high dielectric constant (k ? 13), Schottky pinning factor S of ?0.44 and very low leakage currents (<5 nA/cm(2)). TFTs employing stoichiometric Al2O3·TiO2 gate dielectrics and ZnO semiconducting channels exhibit excellent electron transport characteristics with low operating voltages (?10 V), negligible hysteresis, high on/off current modulation ratio of ?10(6), subthreshold swing (SS) of ?550 mV/dec and electron mobility of ?10 cm(2) V(-1) s(-1). PMID:25774574

  7. Effect of pH on the production of chalcopyrite CuInSe2 prepared by spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Bates, C. W., Jr.; Nelson, K. F.; Abernathy, C. R.; Uekita, M.; Mooney, J. B.

    1983-11-01

    Thin films (about 1 micron) of CuInSe2 were prepared by spray pyrolysis from solutions with various initial Cu:In:Se ratios and in which 75-90 percent of the acid was neutralized. The substrate temperature was varied between 225 and 300 C. The chalcopyrite structure dominated the as-sprayed films with 90 percent of the acid neutralized and 300 C substrate temperature. At 225 C all films were sphalerite independent of the degree of acid neutralization. Unlike previous studies which only produced the sphalerite structure in films prepared from unneutralized solutions, the present study indicates that the chalcopyrite phase can be produced in as-sprayed films with a range of initial ratios.

  8. Nitrogen-doped carbon nanotubes with tunable structure and high yield produced by ultrasonic spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Liu, Jian; Zhang, Yong; Ionescu, Mihnea Ioan; Li, Ruying; Sun, Xueliang

    2011-06-01

    Nitrogen-doped carbon nanotubes (CN x) were prepared by ultrasonic spray pyrolysis from mixtures of imidazole and acetonitrile. Imidazole, as an additive, was used to control the structure and nitrogen doping in CN x by adjusting its concentration in the mixtures. Scanning electron microscopy observation showed that the addition of imidazole increased the nanotube growth rate and yield, while decreased the nanotube diameter. Transmission electron microscopy study indicated that the addition of imidazole promoted the formation of a dense bamboo-like structure in CN x. X-ray photoelectron spectroscopy analysis demonstrated that the nitrogen content varied from 3.2 to 5.2 at.% in CN x obtained with different imidazole concentrations. Raman spectra study showed that the intensity ratio of D to G bands gradually increased, while that of 2D to G bands decreased, due to increasing imidazole concentration. The yield of CN x made from mixtures of imidazole and acetonitrile can reach 192 mg in 24 min, which is 15 times that of CN x prepared from only acetonitrile. The aligned CN x, with controlled nitrogen doping, tunable structure and high yield, may find applications in developing non-noble catalysts and novel catalyst supports for fuel cells.

  9. Superhydrophobic and transparent ZnO thin films synthesized by spray pyrolysis technique

    NASA Astrophysics Data System (ADS)

    Tarwal, N. L.; Patil, P. S.

    2010-10-01

    Superhydrophobic and transparent zinc oxide (ZnO) thin films were deposited by a simple and cost effective spray pyrolysis technique (SPT) onto the glass substrates at 723 K from an aqueous zinc acetate precursor solution. The solution concentration was varied from 0.1 to 0.4 M and its effect on structural, morphological, wetting and optical properties of ZnO thin films was studied. The synthesized films were found to be polycrystalline, with preferential growth along c-axis. A slight improvement in the crystallite size and texture coefficient is observed as the concentration of the solution is increased. SEM micrographs show the uniform distribution of spherical grains of about 60-80 nm grain size. The films were specular and highly transparent with average transmittance of about 85%. The spectrum shows sharp absorption band edge at 381 nm, corresponding to optical gap of 3.25 eV. The samples of texture coefficient less than 90% and roughness less than 75 nm are hydrophobic and above these values they become superhydrophobic in nature. The hydrophobicity coupled with high transmittance is of great importance in commercial application such as transparent self-cleaning surfaces, anti-fog, anti-snow, fluid microchips and microreactors.

  10. Studies on nanocrystalline cadmium sulphide (CdS) thin films deposited by spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Yadav, A. A.; Barote, M. A.; Masumdar, E. U.

    2010-07-01

    Cadmium chalcogenides with appropriate band gap energy have been attracting a great deal of attention because of their potential applications in optoelectronic devices. CdS in the form of thin film is prepared at different substrate temperatures by a simple and inexpensive chemical spray pyrolysis technique. The as-deposited thin films have been characterized by XRD, SEM, EDAX and electrical resistivity measurement techniques. The XRD patterns show that the films are polycrystalline with hexagonal crystal structure irrespective of substrate temperature. SEM studies reveal that the grains are uniform with uneven spherically shaped, distributed over the entire surface of the substrates. Compositional analysis reveals that the material formed is stoichiometric at the optimized substrate temperature. The optical band gap energy is found to be 2.44 eV with direct allowed band-to-band transition for film deposited at 300°C. The electrical resistivity measurement shows that the films are semiconducting with a minimum resistivity for film deposited at 300°C. The thermoelectric power measurement shows that films exhibit n-type of conductivity.

  11. Hierarchical porous carbon by ultrasonic spray pyrolysis yields stable cycling in lithium-sulfur battery.

    PubMed

    Jung, Dae Soo; Hwang, Tae Hoon; Lee, Ji Hoon; Koo, Hye Young; Shakoor, Rana A; Kahraman, Ramazan; Jo, Yong Nam; Park, Min-Sik; Choi, Jang Wook

    2014-08-13

    Utilizing the unparalleled theoretical capacity of sulfur reaching 1675 mAh/g, lithium-sulfur (Li-S) batteries have been counted as promising enablers of future lithium ion battery (LIB) applications requiring high energy densities. Nevertheless, most sulfur electrodes suffer from insufficient cycle lives originating from dissolution of lithium polysulfides. As a fundamental solution to this chronic shortcoming, herein, we introduce a hierarchical porous carbon structure in which meso- and macropores are surrounded by outer micropores. Sulfur was infiltrated mainly into the inner meso- and macropores, while the outer micropores remained empty, thus serving as a "barricade" against outward dissolution of long-chain lithium polysulfides. On the basis of this systematic design, the sulfur electrode delivered 1412 mAh/g sulfur with excellent capacity retention of 77% after 500 cycles. Also, a control study suggests that even when sulfur is loaded into the outer micropores, the robust cycling performance is preserved by engaging small sulfur crystal structures (S2-4). Furthermore, the hierarchical porous carbon was produced in ultrahigh speed by scalable spray pyrolysis. Each porous carbon particle was synthesized through 5 s of carrier gas flow in a reaction tube. PMID:25007002

  12. Flame Spray Pyrolysis for Preparing Red-Light-Emitting, Submicron-Sized Luminescent Strontium Titanate Particles

    NASA Astrophysics Data System (ADS)

    Chang, Hankwon; Lenggoro, I. Wuled; Okuyama, Kikuo; Jang, Hee Dong

    2006-02-01

    SrTiO3:Pr3+,Al3+ red-light-emitting phosphor particles were directly prepared by flame spray pyrolysis without any post-heat treatments. The morphology, crystallinity and photoluminescence (PL) of the as-prepared SrTiO3:Pr3+,Al3+ particles were systematically investigated. The as-prepared particles showed good morphological characteristics and a high crystallinity. The geometric mean diameters of the particles ranged from 0.53 to 0.70 ?m. The particles showed a bright red emission at 615 nm from 1D2-3H4 transition under 365 nm excitation. Optimization to the enhance PL was conducted by systematically controlling gas flow rates, and activator, additive and salt-flux concentrations. The highest PL intensity at 615 nm was obtained at Pr/Ti and Al/Ti molar ratios of 0.001 and 0.03, respectively, and a 40 mol % LiNO3 flux. The photoluminescence intensity of submicron-sized SrTiO3:Pr3+,Al3+ particles prepared under the optimal synthetic conditions was as high as 107% that of micron-sized particles prepared by a solid-state reaction.

  13. Structural and Optical Properties of Nanostructured Zinc Oxide Thin Films by Spray Pyrolysis and Ethanol Sensing

    NASA Astrophysics Data System (ADS)

    Charles, J.; Lawrence, N.; Thiruvenkadam, S.

    Polycrystalline Zinc Oxide thin films were deposited on a glass substrate by Spray Pyrolysis technique using zinc acetate dehydrate precursor at 220?C substrate temperature. The concentration of the solution was 0.05 M, the deposited films are annealed at 300?C temperature in air atmosphere. The X-ray diffraction pattern shows that the films are in the hexagonal Wurtzite phase with preferential orientation (002) along the c-axis. It confirms polycrystalline nature and grain size is 14.666 nm. Scanning Electron Microscope images reveals that the surface of the films are flat and smooth, spherical and wheat in shape and grain size is about 30- 50 nm. Optical spectrum shows that the films are having high transmittance and low absorption in the visible region. Ultra violet-visible spectra shown that the optical energy gaps for ZnO films were estimated in the range 3.25 and 3.31 eV. It confirms zinc oxide thin films are semiconductors with wide band gap energy. The applications of zinc oxide thin films are sensing towards various concentrations of ethanol at an operating temperature of 100 °C. It shows that the resistance increases with increasing the concentration of Ethanol gas.

  14. Spray pyrolysis synthesis of ZnS nanoparticles from a single-source precursor.

    PubMed

    Liu, Sha; Zhang, Hongwang; Swihart, Mark T

    2009-06-10

    ZnS, a II-VI semiconductor with a relatively high direct bandgap (approximately 3.6 eV) in the near-UV region, has potential applications in areas such as solar cells, lasers and displays. In addition, ZnS nanoparticles can be applied as phosphors, probes for bioimaging, emitters in light emitting diodes and photocatalysts. Here, we report synthesis of cubic ZnS nanoparticles from a low-cost single-source precursor in a continuous spray pyrolysis reactor. In this approach, the evaporation and decomposition of precursor and nucleation of particles occur sequentially. Product particles were characterized by HRTEM, XRD, and EDX. Particles with diameters ranging from 2 to 7 nm were produced. HF was used to remove ZnO impurities and other surface contamination. As-synthesized ZnS nanoparticles exhibit blue photoluminescence near 440 nm under UV excitation and have quantum yields up to 15% after HF treatment. This demonstrates a potentially general approach for continuous low-cost synthesis of semiconductor quantum dots for applications where tight control of the size distribution is less important than scalable, economical production. PMID:19451680

  15. Synthesis and characterization of thorium phosphate phases by spray pyrolysis: chemistry of thorium phosphates

    SciTech Connect

    Marchin, L.; Trombe, J.C.; Verelst, M

    2004-10-04

    This paper describes the synthesis of some thorium phosphate compounds with different Th/P ratio (1/2, 2/3 and 3/4) by a spray pyrolysis technique. The so-prepared rough compounds were annealed at different temperatures for 2 h and then analyzed by mainly X-ray diffraction on powder and infrared spectroscopy. Every rough compound is composed by very badly crystallized ThO{sub 2} phase polluted by carbon residue. An annealing treatment at 800 deg. C leads to the thorium diphosphate phase, {alpha}-ThP{sub 2}O{sub 7} in every case. At 900 deg. C, such a phase is decomposed into a thorium phosphate diphosphate phase (Th{sub 4}(PO{sub 4}){sub 4}P{sub 2}O{sub 7}, called TPD). However, a thorium excess in the initial mixture (Th/P = 3/4) leads also to observe the ThO{sub 2} phase. The TPD phase is stable up to 1200 deg. C and does not react with the ThO{sub 2} compound. Beyond 1200 deg. C, the TPD phase is slowly decomposed into a thorium phosphate compound which should be a thorium oxide phosphate; this compound does not contain any diphosphate species.

  16. Characterization of thorium dioxide thin films prepared by the spray pyrolysis technique

    NASA Astrophysics Data System (ADS)

    Mahmoud, Safwat A.

    2002-02-01

    Thorium dioxide (ThO 2) thin films were deposited by the spray pyrolysis technique onto a glass substrate maintained in the temperature range 100-350 °C by using thorium nitrate as a starting solution. Structural, morphological, optical and electrical properties have been investigated. The results of FTIR showed that thorium nitrate is completely decomposed to ThO 2 at 350 °C, via two unstable intermediates. XRD patterns showed that the films deposited at Ts<350 °C were amorphous, whereas those deposited at higher temperatures crystallized in the cubic structure with a preferential orientation along the (1 1 1) direction. The film growth was investigated experimentally by atomic force microscopy (AFM). The dark resistivity was of the order of 10 6 ? cm. The activation energy was found to be 0.81 eV. The optical parameters such as refractive index, absorption coefficient, energy gap width have also been determined. The energy of the effective dispersion oscillator and the dispersion energy which measures the average strength of interband optical transitions were found to be 6.62 and 3.04 eV, respectively, and the dielectric constant, ??, was found to be 3.17. The free-carrier concentration Nopt have also been determined.

  17. Fourier transform infrared and Raman spectroscopic properties of Cd1-xSbxS films deposited by ultrasonic spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Özer, T.; Aksay, S.; Köse, S.

    2010-07-01

    Cd1-xSbxS films (x = 0.0, 0.1 and 0.2) were deposited by the ultrasonic spray pyrolysis method. The films were deposited on glass substrates at temperatures of 300 °C. The effect of antimony doping on the structural and vibrational (FT-IR and Raman) properties of cadmium sulphide films were examined. Structural investigations of the films showed the hexagonal polycrystalline structure and that the incorporation of antimony leads to substantial changes in the structural characteristics of CdS films. The preferential orientation of the Cd1-xSbxS films shifts from (002) to (101) with increasing x values. The Raman spectrum for CdS films is dominated by an intense band at 301.5 cm-1(1LO) assigned to the first-order longitudinal optic phonon and the second-order phonon peak 598.5 cm-1 (2LO). Cd1-xSbxS films have been prepared and their FT-IR (400-4000 cm-1) spectra are reported for the first time. The vibrations at 550-1164 cm-1 are caused by Cd-S and C-O stretching vibrations.

  18. Effect of annealing on the properties of Bi doped ZnO thin films grown by spray pyrolysis technique

    NASA Astrophysics Data System (ADS)

    Sadananda Kumar, N.; Bangera, Kasturi V.; Shivakumar, G. K.

    2014-11-01

    The effect of annealing temperature on the structural, optical and electrical properties of transparent and conducting Bi doped ZnO (BZO) films deposited on glass substrate by spray pyrolysis technique was investigated. The BZO thin films were annealed in the temperature range from 450 °C to 550 °C for 4 h in air atmosphere. The grain size of the BZO films increased with increasing annealing temperature. The annealed BZO films were electrically stable and there was a drastic change in the electrical conductivity after annealing. The films annealed at 500 °C showed better conductivity and optical transmittance.

  19. Effect of Sb doping on the properties of SnO2 thin films grown by spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Gupta, Archana; Rajaram, P.; Bhatnagar, M. C.

    2012-06-01

    Thin film of antimony doped Tin Oxide have been prepared using an economic spray pyrolysis technique. The films were deposited onto glass substrates at 450°C. The mesostructured tin oxide thin films with various Sb concentrations exhibited highly selective response towards CO. The novelty of the present sensor material is its mesostructured nature with high sensitivity and selectivity towards CO at 350°C The correlation of the antimony incorporation in the mesostructure with morphology and structure is discussed based on the results of scanning electron microscopy (SEM), X-ray diffraction (XRD), AFM and gas sensing behavior.

  20. Growth and Characterization of Co-Doped Fluorine and Antimony in Tin Oxide Thin Films Obtained by Ultrasonic Spray Pyrolysis

    Microsoft Academic Search

    Thitinai Gaewdang; Ngamnit Wongcharoen

    2007-01-01

    Fluorine (F)-doped, antimony (Sb)-doped, fluorine and antimony co-doped tin oxide (SnO2) thin films were prepared by ultrasonic spray pyrolysis technique using SnCl2, NH4F and SbCl3 as precursors of Sn, F and Sb elements respectively. F and Sb doping concentrations carried out from 1 to 20 wt% and 1 to 4 wt% in F-doped and Sb-doped SnO2 films respectively. In F

  1. Apparatus and method for spraying liquid materials

    DOEpatents

    Alvarez, J.L.; Watson, L.D.

    1988-01-21

    A method for spraying liquids involving a flow of gas which shears the liquid. A flow of gas is introduced in a converging-diverging nozzle where it meets and shears the liquid into small particles which are of a size and uniformity which can be controlled through adjustment of pressures and gas velocity. 5 figs.

  2. Novel mechanism for high speed growth of transparent and conducting tin oxide thin films by spray pyrolysis

    Microsoft Academic Search

    L. Kameswara Rao; V. Vinni

    1993-01-01

    A novel mechanism is proposed for efficient manipulation of transport forces acting on the droplets during spray pyrolytic deposition of thin films. A ‘‘burst mode’’ technique of spraying is used to adjust the deposition conditions so as to transport the droplets under the new mechanism. Transparent, conducting thin films of undoped tin oxide prepared by this method showed significant improvement

  3. Characterization of thin CuCo 2O 4 films prepared by chemical spray pyrolysis. Study of their electrochemical stability by ex situ spectroscopic analysis

    Microsoft Academic Search

    J. L. Gautier; E. Trollund; E. Ríos; P. Nkeng; G. Poillerat

    1997-01-01

    Pure copper cobalt oxide with spinel structure can be prepared as thin films at 340°C by chemical spray pyrolysis of the metal nitrate aqueous solution over conducting glass. Addition of ammonium nitrate to the sprayed solution increases the crystallization. We report herein the preparation and characterization of such films using X-ray diffraction, FTIR reflectance and transmission spectroscopy, UV-vis spectroscopy, scanning

  4. Leidenfrost temperature related CVD-like growth mechanism in ZnO-TFTs deposited by pulsed spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Ortel, Marlis; Wagner, Veit

    2013-01-01

    Zinc oxide thin films were prepared by pulsed spray pyrolysis (SP) from aqueous zinc acetate precursor solution. The deposition behavior of the solution with regard to the pool boiling curve of the solvent was investigated to gain insights of the deposition mechanism which leads to homogeneous and reproducible ZnO layers. The Leidenfrost effect was found to play an important role since the Leidenfrost temperature has to be exceeded to form high quality layers. It is concluded that 3D nucleation of ZnO nano-crystals takes place out of the gaseous phase by a CVD-like process on ITO as well as on SiO2 substrates. Crystal orientation and surface roughness of the zinc oxide layer are found to depend strongly on the substrate. An increasing grain size with film thickness is observed. These findings were utilized to fabricate and investigate the semiconducting properties of the films in ZnO thin film transistors (TFTs). The mobility exceeded 12 cm2 V-1 s-1, the on-set was at 1 V and the on-off current ratio was found to be higher than 108. Hence the morphology and the electrical parameters of the ZnO films deposited by pulsed spray pyrolysis from non-toxic aqueous zinc acetate solution above the Leidenfrost point show excellent properties for electronic applications.

  5. Comparison of carrier transport mechanism under UV/Vis illumination in an AZO photodetector and an AZO/p-Si heterojunction photodiode produced by spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Shasti, M.; Mortezaali, A.; Dariani, R. S.

    2015-01-01

    In this study, Aluminum doped Zinc Oxide (AZO) layer is deposited on p-type silicon (p-Si) by spray pyrolysis method to fabricate ultraviolet-visible (UV/Vis) photodetector as Al doping process can have positive effect on the photodetector performance. Morphology, crystalline structure, and Al concentration of AZO layer are investigated by SEM, XRD, and EDX. The goal of this study is to analyze the mechanism of carrier transport by means of current-voltage characteristics under UV/Vis illumination in two cases: (a) electrodes connected to the surface of AZO layer and (b) electrodes connected to cross section of heterojunction (AZO/p-Si). Measurements indicate that the AZO/p-Si photodiode exhibits a higher photocurrent and lower photoresponse time under visible illumination with respect to AZO photodetector; while under UV illumination, the above result is inversed. Besides, the internal junction field of AZO/p-Si heterojunction plays an important role on this mechanism.

  6. Modifying Optical Properties of ZnO Films by Forming Zn[subscript 1-x] Co[subscript x]O Solid Solutions via Spray Pyrolysis

    ERIC Educational Resources Information Center

    Bentley, Anne K.; Weaver, Gabriela C.; Russell, Cianan B.; Fornes, William L.; Choi, Kyoung-Shin; Shih, Susan M.

    2007-01-01

    A simple and cost-effective experiment for the development and characterization of semiconductors using Uv-vis spectroscopy is described. The study shows that the optical properties of ZnO films can be easily modified by forming Zn[subscript 1-x] Co[subscript x]O solid solutions via spray pyrolysis.

  7. Ionization potentials of transparent conductive indium tin oxide films covered with a single layer of fluorine-doped tin oxide nanoparticles grown by spray pyrolysis deposition

    Microsoft Academic Search

    Tatsuo Fukano; Tomoyoshi Motohiro; Takashi Ida; Hiroo Hashizume

    2005-01-01

    Indium tin oxide (ITO) films deposited with single layers of monodispersive fluorine-doped tin oxide (FTO) nanoparticles of several nanometers in size were grown on glass substrates by intermittent spray pyrolysis deposition using conventional atomizers. These films have significantly higher ionization potentials than the bare ITO and FTO films grown using the same technique. The ITO films covered with FTO particles

  8. Low oxygen biomass-derived pyrolysis oils and methods for producing the same

    DOEpatents

    Marinangeli, Richard; Brandvold, Timothy A; Kocal, Joseph A

    2013-08-27

    Low oxygen biomass-derived pyrolysis oils and methods for producing them from carbonaceous biomass feedstock are provided. The carbonaceous biomass feedstock is pyrolyzed in the presence of a catalyst comprising base metal-based catalysts, noble metal-based catalysts, treated zeolitic catalysts, or combinations thereof to produce pyrolysis gases. During pyrolysis, the catalyst catalyzes a deoxygenation reaction whereby at least a portion of the oxygenated hydrocarbons in the pyrolysis gases are converted into hydrocarbons. The oxygen is removed as carbon oxides and water. A condensable portion (the vapors) of the pyrolysis gases is condensed to low oxygen biomass-derived pyrolysis oil.

  9. Effect of the substrate temperature on the physical properties of molybdenum tri-oxide thin films obtained through the spray pyrolysis technique

    SciTech Connect

    Martinez, H.M. [Grupo de Materiales con Aplicaciones Tecnologicas, Departamento de Fisica Universidad Nacional de Colombia sede Bogota (Colombia)] [Grupo de Materiales con Aplicaciones Tecnologicas, Departamento de Fisica Universidad Nacional de Colombia sede Bogota (Colombia); Torres, J., E-mail: njtorress@unal.edu.co [Grupo de Materiales con Aplicaciones Tecnologicas, Departamento de Fisica Universidad Nacional de Colombia sede Bogota (Colombia); Lopez Carreno, L.D. [Grupo de Materiales con Aplicaciones Tecnologicas, Departamento de Fisica Universidad Nacional de Colombia sede Bogota (Colombia)] [Grupo de Materiales con Aplicaciones Tecnologicas, Departamento de Fisica Universidad Nacional de Colombia sede Bogota (Colombia); Rodriguez-Garcia, M.E. [Departamento de Nanotecnologia, Centro de Fisica Aplicada y Tecnologia Avanzada, Universidad Nacional Autonoma de Mexico, Campus Juriquilla, Queretaro, Qro., Mexico (Colombia)] [Departamento de Nanotecnologia, Centro de Fisica Aplicada y Tecnologia Avanzada, Universidad Nacional Autonoma de Mexico, Campus Juriquilla, Queretaro, Qro., Mexico (Colombia)

    2013-01-15

    Polycrystalline molybdenum tri-oxide thin films were prepared using the spray pyrolysis technique; a 0.1 M solution of ammonium molybdate tetra-hydrated was used as a precursor. The samples were prepared on Corning glass substrates maintained at temperatures ranging between 423 and 673 K. The samples were characterized through micro Raman, X-ray diffraction, optical transmittance and DC electrical conductivity. The species MoO{sub 3} (H{sub 2}O){sub 2} was found in the sample prepared at a substrate temperature of 423 K. As the substrate temperature rises, the water disappears and the samples crystallize into {alpha}-MoO{sub 3}. The optical gap diminishes as the substrate temperature rises. Two electrical transport mechanisms were found: hopping under 200 K and intrinsic conduction over 200 K. The MoO{sub 3} films' sensitivity was analyzed for CO and H{sub 2}O in the temperature range 160 to 360 K; the results indicate that CO and H{sub 2}O have a reduction character. In all cases, it was found that the sensitivity to CO is lower than that to H{sub 2}O. - Highlights: Black-Right-Pointing-Pointer A low cost technique is used which produces good material. Black-Right-Pointing-Pointer Thin films are prepared using ammonium molybdate tetra hydrated. Black-Right-Pointing-Pointer The control of the physical properties of the samples could be done. Black-Right-Pointing-Pointer A calculation method is proposed to determine the material optical properties. Black-Right-Pointing-Pointer The MoO{sub 3} thin films prepared by spray pyrolysis could be used as gas sensor.

  10. Flow rate and interface roughness of zinc oxide thin films deposited by spray pyrolysis technique

    Microsoft Academic Search

    J. Ebothé; A. El Hichou; P. Vautrot; M. Addou

    2003-01-01

    The interface growth and topology of sprayed ZnO thin films are examined here using the spatial scaling approach to the film surface in relation with the effect of a spraying deposition flow rate, f, ranging between 1 and 8 mil min-1. This thermally activated process is performed at the optimal temperature of the material (T=723 K). Two different growth mechanisms

  11. Photoluminescence of (YGd)2O3:Eu phosphors produced by nanoparticle-seeded flame-assisted spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Kubrin, R.; Huang, J.; Moglia, F.; Petermann, K.; Bauhofer, W.

    2011-05-01

    We report on synthesis of europium-doped (Y1-xGdx)2O3 by flame-assisted spray py-rolysis in premixed propane/air flames. Phosphor powders with an average particle size on the order of 0.5 ?m were obtained from 0.2 M aqueous solutions of the corresponding metal salts. Relative concentration of gadolinium (x) was varied in the range 0 to 1. For excitation at a wavelength of 254 nm, the highest intensity of photoluminescence was achieved for x = 0.2 (110% of brightness of the samples without gadolinia). Doping pure yttria and gadolinia with nanoparticles of Y2O3:Eu (dBET = 24 nm) was tested. Addition of nanoseeds (up to 50 mol.% in the obtained powders) noticeably decreased surface roughness of phosphor particles.

  12. Selective detection of ammonia using spray pyrolysis deposited pure and nickel doped ZnO thin films

    NASA Astrophysics Data System (ADS)

    Mani, Ganesh Kumar; Rayappan, John Bosco Balaguru

    2014-08-01

    This research paper reports the deposition of nanostructured pure and Ni-doped ZnO thin films deposited at the substrate temperature of 523 K using simple and economical spray pyrolysis technique and subsequently post annealed at 673 K in air atmosphere for 3 h. Ni-doping greatly affected the crystallographic orientation, surface morphology, roughness and room temperature sensing response. Noticeable change in the crystallite size, transmittance and electrical properties was observed. The room temperature sensing characteristics like selectivity, response recovery studies, range of detection, stability and reproducibility of the undoped and Ni-doped ZnO thin films were investigated. Especially, the sensing elements exhibited an excellent selectivity towards ammonia. A lower detection limit of 5 and 25 ppm was observed for undoped and Ni-doped ZnO thin films respectively. The upper detection range was widened to 1000 ppm for the Ni-doped film.

  13. Spectroscopic study and optical and electrical properties of Ti-doped ZnO thin films by spray pyrolysis.

    PubMed

    Sridhar, R; Manoharan, C; Ramalingam, S; Dhanapandian, S; Bououdina, M

    2014-01-01

    Zinc oxide films were doped with different concentrations of Ti on glass substrates at 400°C by spray pyrolysis technique. The films exhibited single phase ZnO for low concentrations of Ti. Wurtzite ZnO peaks were observed at higher doping concentration with decreased crystallinity. Crystallite size, strain and dislocation density were evaluated from the X-ray diffraction data. Surface morphology of the films indicated that a remarkable decrease in grain size with increasing of Ti concentration. The band gap of the films was found to be increased from 3.20 eV to 3.32 eV as the concentration of Ti doping increases. The resistivity of the films decreased from 9×10(5) ? cm to 9×10(4) ? cm with the increase of Ti doping concentration. Both Raman spectroscopy and room temperature photoluminescence exhibited characteristic peaks that confirmed the formation of ZnO phase. PMID:24184923

  14. Effect of annealing on the properties of Sb doped ZnO thin films prepared by spray pyrolysis technique

    NASA Astrophysics Data System (ADS)

    Kumar, N. Sadananda; Bangera, Kasturi V.; Shivakumar, G. K.

    2014-01-01

    Sb doped ZnO thin films have been deposited on glass substrate at 450°C using spray pyrolysis technique. The X-ray diffraction studies revealed that the as deposited films are polycrystalline in nature with (100) preferred orientation. Whereas the films annealed at 450° C for 6h show a preferential orientation along (101) direction. Crystallites size varies from 15.7 nm to 34.95 nm with annealing duration. The Scanning electron microscopic analysis shows the plane and smooth surface of the films. The optical properties of annealed films have shown a variation in the band gap between 3.37 eV and 3.19 eV. Transparency of as grown and annealed films decreases from 78 % to 65% respectively in the visible region. The electrical conductivity of the as grown film shows an increase in the electrical conductivity by one order of magnitude with increase in the annealing duration.

  15. Effect of annealing on the properties of zinc oxide nanofiber thin films grown by spray pyrolysis technique

    NASA Astrophysics Data System (ADS)

    Sadananda Kumar, N.; Bangera, Kasturi V.; Shivakumar, G. K.

    2013-01-01

    Zinc oxide nanofiber thin films have been deposited on glass substrate by spray pyrolysis technique. The X-ray diffraction studies revealed that the films are polycrystalline with the hexagonal structure and a preferred orientation along (002) direction for films annealed for 1 h at 450 °C. Further increase in annealing time changes the preferred orientation to (100) direction. The scanning electron microscopic analysis showed the formation of ZnO nanofiber with an average diameter of approximately 800 nm for annealed films. The compositional analysis of nanofiber ZnO thin films were studied by time of flight secondary ion mass spectroscopy, which indicated oxygen deficiency in the films. The optical properties of annealed films have shown a variation in the band gap between 3.29 and 3.20 eV. The electrical conductivity of the as grown and annealed films showed an increase in the conductivity by two orders of magnitude with increase in annealing duration.

  16. Effect of substrate temperature on structure and optical properties of Co3O4 films prepared by spray pyrolysis technique

    NASA Astrophysics Data System (ADS)

    Abbas, S. Z.; Aboud, A. A.; Irfan, M.; Alam, S.

    2014-06-01

    Polycrystalline Co3O4 films of spinel cubic phase were prepared by spray pyrolysis on amorphous substrate. The deposition time was kept constant (30min) with variable ranges of substrate temperature (573-723 K). The structural and optical properties of films were studied. The average crystallite size calculated by Scherrer's equation was found to increase as substrate temperature increased. Very small particle size was achieved. Even at the highest deposition temperature, the size did not exceed 11.6nm. The average crystallite size obtained from AFM photos was ranged in from 182 to 248nm which reveals the presence of agglomerates. Optical data were recorded in the wavelength range 300-2500nm. A considerable difference in transmittance was observed for films prepared at different substrate temperatures. The absorption coefficient was measured and then correlated with the photon energy to estimate the energy gap, which was the value of the spinel phase with a direct transition

  17. Effect of annealing on the properties of Sb doped ZnO thin films prepared by spray pyrolysis technique

    SciTech Connect

    Kumar, N. Sadananda; Bangera, Kasturi V.; Shivakumar, G. K. [Thin Films Laboratory, Department of Physics, National Institute of Technology Karnataka,Surathkal - 575025, Mangalore (India)

    2014-01-28

    Sb doped ZnO thin films have been deposited on glass substrate at 450°C using spray pyrolysis technique. The X-ray diffraction studies revealed that the as deposited films are polycrystalline in nature with (100) preferred orientation. Whereas the films annealed at 450° C for 6h show a preferential orientation along (101) direction. Crystallites size varies from 15.7 nm to 34.95 nm with annealing duration. The Scanning electron microscopic analysis shows the plane and smooth surface of the films. The optical properties of annealed films have shown a variation in the band gap between 3.37 eV and 3.19 eV. Transparency of as grown and annealed films decreases from 78 % to 65% respectively in the visible region. The electrical conductivity of the as grown film shows an increase in the electrical conductivity by one order of magnitude with increase in the annealing duration.

  18. Optical, electrical and surface properties of annealed CdO:Mg thin films prepared by spray pyrolysis

    SciTech Connect

    Karakaya, Seniye, E-mail: seniyek@ogu.edu.tr, E-mail: oozbas@ogu.edu.tr; Ozbas, Omer, E-mail: seniyek@ogu.edu.tr, E-mail: oozbas@ogu.edu.tr [Eskisehir Osmangazi University, Physics Department, Eskisehir (Turkey)

    2013-12-16

    The use of transparent conducting oxides in optoelectronic and photovoltaic devices has encouraged research on this field in recent years. Especially, cadmium oxide is a promising material for solar cell application but also for photodiodes and gas sensors. Mg doped CdO (CdO:Mg) films have been prepared on glass substrates by the ultrasonic spray pyrolysis (USP) technique. After the production, the films have been annealed in air atmosphere at 475°C and half hour. Results on surface, optical and electrical properties of the films as a function of the thermal annealing have been reported. Thicknesses of the films have been determined by the filmetrics thin film measurement system. Transmission and absorbance spectra have been taken by UV-vis spectrophotometer. Atomic Force Microscopy (AFM) analysis indicates that the roughness of the surface decreases upon increasing Mg concentration. The minimum resistivity value of the films was 2×10{sup ?3} ? cm.

  19. Effect of the flame temperature on the characteristics of zirconium oxide fine particle synthesized by flame assisted spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Widiyastuti, W.; Machmudah, Siti; Nurtono, Tantular; Winardi, Sugeng

    2013-09-01

    Zirconium oxide fine particles were synthesized by flame assisted spray pyrolysis using zirconium chloride solution as precursor. Propane gas and air were used as a fuel and an oxidizer, respectively. The ratio of flow rate of oxidizer and fuel was maintained constant at 10:1 to ensure a complete combustion. Increasing fuel flow rate led to the increase of temperature distribution in the flame reactor. The intensity of XRD patterns increased with temperature and precursor concentration. Phase composition of zirconium oxide produced by this process consisted of monoclinic and tetragonal phases. The volume fraction of monoclinic phase of zirconium oxide increased with temperature and precursor concentration. The morphology particles observed by SEM resulted in spherical particles with size in the submicron range depending on the precursor concentration.

  20. Optical, electrical and surface properties of annealed CdO:Mg thin films prepared by spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Karakaya, Seniye; Ozbas, Omer

    2013-12-01

    The use of transparent conducting oxides in optoelectronic and photovoltaic devices has encouraged research on this field in recent years. Especially, cadmium oxide is a promising material for solar cell application but also for photodiodes and gas sensors. Mg doped CdO (CdO:Mg) films have been prepared on glass substrates by the ultrasonic spray pyrolysis (USP) technique. After the production, the films have been annealed in air atmosphere at 475°C and half hour. Results on surface, optical and electrical properties of the films as a function of the thermal annealing have been reported. Thicknesses of the films have been determined by the filmetrics thin film measurement system. Transmission and absorbance spectra have been taken by UV-vis spectrophotometer. Atomic Force Microscopy (AFM) analysis indicates that the roughness of the surface decreases upon increasing Mg concentration. The minimum resistivity value of the films was 2×10-3 ? cm.

  1. Photovoltaic properties of indium tin oxide (ITO)/silicon junctions prepared by spray pyrolysis-dependence on oxidation time

    NASA Astrophysics Data System (ADS)

    Vasu, V.; Subrahmanyam, A.

    1992-03-01

    Indium tin oxide (ITO)/silicon (on both n- and p-type) junctions are prepared at 380 degrees C by spray pyrolysis technique. The ITO/p-Si yielded an ohmic contact. The photovoltaic behaviour of ITO/n-Si junctions as a function of oxidation time tox is reported in the present paper with the view to understanding the role of the interfacial oxide layer in the photovoltaic process. The junctions have been characterized by I-V and C-V measurements. A maximum efficiency of 9.4% is observed (under GE-ELH illumination of 100 mW cm-2) for both small (0.04 cm2) and large (1.0 cm2) areas of ITO/n-Si junctions at an oxidation time of 60 s. The junctions are observed to be quite stable with time.

  2. Observation of Nanospherical n-SnO2/p-Si Heterojunction Fabricated by Ultrasonic Spray Pyrolysis Technique

    NASA Astrophysics Data System (ADS)

    He, Bo; Xu, Jing; Xing, Huaizhong; Wang, Chunrui; Guo, Ying; Lu, Hongwei

    2013-10-01

    Thin film of tin oxide (SnO2) was prepared on p-type polished silicon wafer by ultrasonic spray pyrolysis technique using SnCl4 precursor solution to fabricate nanospherical n-SnO2/p-Si heterojunction photoelectric device. Deposition of film was achieved at 400°C substrate temperature. The self-made ultrasonic spray pyrolysis system is very cheap and convenient. The microstructural, optical and electrical properties of the SnO2 film were characterized by XRD, SEM, XPS, UV-VIS spectrophotometer, four point probe and Hall effect measurement, respectively. The SnO2 film has the nanospherical particles. The electrical properties of heterojunction were investigated by I-V measurement, which reveals that the heterojunction shows strong rectifying behavior under a dark condition. The ideality factor and the saturation current density of this diode are 4.27 and 2.52 × 10-6 A/cm2, respectively. And the values of IF/IR (IF and IR stand for forward and reverse current, respectively) at 5 V is found to be as high as 248. The SnO2/p-Si heterojunction device exhibits obvious photovoltaic effect. Under an AM1.5 illumination condition, the open-circuit voltage (Voc), short-circuit current density (JSC), fill factor (FF) of the device are 150 mV, 3.9 × 10-3 mA/cm2 and 20.58%, respectively. High photocurrent is obtained under a reverse bias when the crystalline quality of SnO2 film is good enough to transmit the light into p-Si. Under 6.3 mW/cm2 illumination, when the reverse bias is -5 V, the photocurrent gain is as high as 86.

  3. CaO-based sorbents for CO2 capture prepared by ultrasonic spray pyrolysis

    E-print Network

    Suslick, Kenneth S.

    pyrolysis (USP) synthesis and charac- terization of composite calcium oxide-based sorbents for carbon of additives in the CaO matrix and the relatively high surface area materials obtained via USP explain of surface area.10 The decline in the performance of CaO materials during cycling are generally attributed

  4. Synthesis of electrochromic tin oxide thin films with faster response by spray pyrolysis

    Microsoft Academic Search

    P. S. Patil; S. B. Sadale; S. H. Mujawar; P. S. Shinde; P. S. Chigare

    2007-01-01

    Tin oxide thin films have been synthesized via pyrolysis of tri-n-butyl tin acetate solution at various substrate temperatures. The effect of substrate temperature on electrochromic properties is studied by electrochemical cyclic voltammetry and chronoamperometry. The films deposited at various substrate temperatures (450, 475 and 500 °C) were polycrystalline and their preferred orientation changes from (1 1 0) to (2 0

  5. Electron microscopy and EXAFS studies on oxide-supported gold silver nanoparticles prepared by flame spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Hannemann, Stefan; Grunwaldt, Jan-Dierk; Krumeich, Frank; Kappen, Peter; Baiker, Alfons

    2006-09-01

    Gold and gold-silver nanoparticles prepared by flame spray pyrolysis (FSP) were characterized by electron microscopy, in situ X-ray absorption spectroscopy (XANES and EXAFS), X-ray diffraction (XRD) and their catalytic activity in CO oxidation. Within this one-step flame-synthesis procedure, precursor solutions of dimethyl gold(III) acetylacetonate and silver(I) benzoate together with the corresponding precursor of the silica, iron oxide or titania support, were sprayed and combusted. In order to prepare small metal particles, a low noble metal loading was required. A loading of 0.1-1 wt.% of Au and Ag resulted in 1-6 nm particles. The size of the noble metal particles increased with higher loadings of gold and particularly silver. Both scanning transmission electron microscopy (STEM) combined with energy dispersive X-ray spectroscopy (EDXS) and X-ray absorption spectroscopy (XAS) studies proved the formation of mixed Au-Ag particles. In case of 1% Au-1% Ag/SiO 2, TEM combined with electron spectroscopic imaging (ESI) using an imaging filter could be used in addition to prove the presence of silver and gold in the same noble metal particle. CO oxidation in the presence of hydrogen was chosen as a test reaction sensitive to small gold particles. Both the influence of the particle size and the alloying of gold and silver were reflected in the CO oxidation activity.

  6. Effect of deposition conditions on the physical properties of SnxSy thin films prepared by the spray pyrolysis technique

    NASA Astrophysics Data System (ADS)

    Fadavieslam, M. R.; Shahtahmasebi, N.; Rezaee-Roknabadi, M.; Bagheri-Mohagheghi, M. M.

    2011-11-01

    Tin sulfide thin films (SnxSy) with an atomic ratio of y/x = 0.5 have been deposited on a glass substrate by spray pyrolysis. The effects of deposition parameters, such as spray solution rate (R), substrate temperature (Ts) and film thickness (t), on the structural, optical, thermo-electrical and photoconductivity related properties of the films have been studied. The precursor solution was prepared by dissolving tin chloride (SnCl4, 5H2O) and thiourea in propanol, and SnxSy thin film was prepared with a mole ratio of y/x = 0.5. The prepared films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-vis spectroscopy. It is indicated that the XRD patterns of SnxSy films have amorphous and polycrystalline structures and the size of the grains has been changed from 7 to 16 nm. The optical gap of SnxSy thin films is determined to be about 2.41 to 3.08 eV by a plot of the variation of (?h?)2 versus h? related to the change of deposition conditions. The thermoelectric and photo-conductivity measurement results for the films show that these properties are depend considerably on the deposition parameters.

  7. Aluminum oxide thin films deposited on silicon substrates from Al(NO3)3 and an organic solvent by spray pyrolysis

    Microsoft Academic Search

    M. Aguilar-Frutis; J. Guzmán-Mendoza; T. Alejos; M. García-Hipólito; C. Falcony

    2003-01-01

    Aluminum oxide thin films were deposited on silicon substrates at temperatures in the range from 500 to 650 °C, from Al(NO3)3 dissolved in N,N-Dimethylformamide and using the spray pyrolysis technique. The films of aluminum oxide resulted stoichiometric, amorphous and optically transparent in the visible spectrum, with a refractive index close to 1.66 when a 0.2 molar solution of Al(NO3)3 was

  8. Temperature Effect on the Synthesis of Multi-Walled Carbon Nanotubes by Spray Pyrolysis of Botanical Carbon Feedstocks: Turpentine, ?-pinene and ?-pinene

    Microsoft Academic Search

    J. Lara-Romero; J. C. Calva-Yañez; J. López-Tinoco; G. Alonso-Nuñez; S. Jiménez-Sandoval

    2011-01-01

    The chemistry of the different components of turpentine and the effect of temperature on the synthesis of multi-walled carbon nanotubes (MWCNTs) by spray pyrolysis using ferrocene as catalyst in a temperature range of 700–1000°C at 100°C intervals was investigated. Turpentine with high ?-pinene concentration (83.4%) and low ?-pinene concentration (8.22%), as well as pure ?-pinene and ?-pinene, were used as

  9. Physicochemical characterization and study of nonlinear optical properties of tin and fluoride doped indium oxide thin films deposed by spray pyrolysis

    Microsoft Academic Search

    F. N. Fellahi; M. Addou; M. A. Lamrani; T. El Habbani; Z. Sofiani; M. El Jouad; K. Bahedi; L. Dghoughi; B. Sahraoui; N. Gaumer; A. Monteil

    2007-01-01

    The thin films of undoped oxide indium and doped oxide indium by fluorine and tin were prepared by SPRAY pyrolysis. These layers were deposited on glass substrates from the Indium chloride (InCl3), tin chloride (SnCl2;2H2O) and ammonium fluoride (NH4F).The microstructure, morphological, optical transmittance and chemical composition of these layers were studied by the X ray diffraction (XRD), the scanning electron

  10. The electrical, optical, structural and thermoelectrical characterization of n- and p-type cobalt-doped SnO 2 transparent semiconducting films prepared by spray pyrolysis technique

    Microsoft Academic Search

    Mohammad-Mehdi Bagheri-Mohagheghi; Mehrdad Shokooh-Saremi

    2010-01-01

    The electrical, optical and structural properties of Cobalt (Co) doped SnO2 transparent semiconducting thin films, deposited by the spray pyrolysis technique, have been studied. The SnO2:Co films, with different Co-content, were deposited on glass substrates using an aqueous–ethanol solution consisting of tin and cobalt chlorides. X-ray diffraction studies showed that the SnO2:Co films were polycrystalline only with tin oxide phases

  11. Effect of doping concentration on the properties of aluminium doped zinc oxide thin films prepared by spray pyrolysis for transparent electrode applications

    Microsoft Academic Search

    C. M. Muiva; T. S. Sathiaraj; K. Maabong

    2011-01-01

    Zinc oxide possesses many interesting properties, such as modifiable conductivity, wide band gap, high excitonic binding energy, piezo-electric polarisation and cathodoluminiscence. In this study transparent conducting aluminium doped zinc oxide (ZnO:Al) thin films were deposited on float glass substrates by tailor made spray pyrolysis with adaptation for measuring the actual temperature of the substrate surface during deposition. The films were

  12. Indium doped zinc oxide thin films deposited by ultrasonic spray pyrolysis technique: Effect of the substrate temperature on the physical properties

    Microsoft Academic Search

    L. Castañeda; A. Maldonado; A. Escobedo-Morales; M. Avendaño-Alejo; H. Gómez; J. Vega-Pérez; M. de la L. Olvera

    2011-01-01

    Indium doped zinc oxide (ZnO:In) thin solid films were deposited on soda-lime glass substrates by the ultrasonic spray pyrolysis technique. The effect of the substrate temperature on the electrical, morphology, and optical characteristics of ZnO:In thin films was studied. It was found that, as the substrate temperature increases, the electrical resistivity decreases, reaching a minimum value in the order of

  13. Comparison of the structural and optical properties of zinc oxide thin films deposited by d.c. and r.f. sputtering and spray pyrolysis

    Microsoft Academic Search

    A. Mosbah; A. Moustaghfir; S. Abed; N. Bouhssira; M. S. Aida; E. Tomasella; M. Jacquet

    2005-01-01

    ZnO thin films were deposited using three processes: d.c. reactive sputtering of Zn, r.f. sputtering of ZnO, and spray pyrolysis. The influence of the temperature (substrate temperature or post-deposition annealing) on composition, structural, and optical properties of these thin films was investigated. All sputtered ZnO thin film exhibit a preferred orientation along the c-axis of the hexagonal structure if they

  14. Photoluminescence of Eu 3 + : Y 2 O 3 as an indication of crystal structure and particle size in nanoparticles synthesized by flame spray pyrolysis

    Microsoft Academic Search

    Dosi Dosev; Bing Guo; Ian M. Kennedy

    2006-01-01

    Nanoparticles of europium-doped yttrium oxide (Eu:Y2O3) were synthesized by flame spray pyrolysis. The nanoparticles were separated by centrifugation into two size groups (5–60nm and 50–200nm), each characterized by laser induced fluorescence spectroscopy, Transmission Electron Microscopy (TEM) and X-ray Diffraction (XRD). The fluorescence spectra, the electron diffraction pattern, and the XRD pattern of the large particles were typical of the stable

  15. Structural characterization of cadmium oxide thin films deposited by spray pyrolysis

    Microsoft Academic Search

    K. Gurumurugan; D. Mangalaraj; Sa. K. Narayandass

    1995-01-01

    A series of CdO thin films have been prepared by spray pyrolytic technique at different substrate temperatures. X-ray diffraction scans confirmed the polycrystalline structure of the films. The films exhibit preferential orientation along the (111) plane. To describe the preferential orientation, the texture coefficient has been calculated and the standard deviation factor has also been evaluated to explain the growth

  16. Chemical composition and temperature dependent performance of ZnO-thin film transistors deposited by pulsed and continuous spray pyrolysis

    SciTech Connect

    Ortel, Marlis; Balster, Torsten; Wagner, Veit [School of Engineering and Science, Jacobs University Bremen, Campus Ring 1, 28759 Bremen (Germany)

    2013-12-21

    Zinc oxide thin film transistors (TFTs) deposited by continuous and pulsed spray pyrolysis were investigated to analyze process kinetics which make reduction of process temperature possible. Thus, fluid mechanics, chemical composition, electrical performance, and deposition and annealing temperature were systematically analyzed. It was found that ZnO layers continuously deposited at 360?°C contained zinc oxynitrides, CO{sub 3}, and hydro carbonate groups from pyrolysis of basic zinc acetate. Statistically, every second wurtzite ZnO unit cell contained an impurity atom. The purity and performance of the ZnO-TFTs increased systematically with increasing deposition temperature due to an improved oxidation processes. At 500?°C the zinc to oxygen ratio exceeded a high value of 0.96. Additionally, the ZnO film was not found to be in a stabilized state after deposition even at high temperatures. Introducing additional subsequent annealing steps stabilizes the film and allows the reduction of the overall thermal stress to the substrate. Further improvement of device characteristics was obtained by pulsed deposition which allowed a more effective transport of the by-products and oxygen. A significant reduction of the deposition temperature by 140?°C was achieved compared to the same performance as in continuous deposition mode. The trap density close to the Fermi energy could be reduced by a factor of two to 4?×?10{sup 17}?eV{sup ?1}?cm{sup ?3} due to the optimized combustion process on the surface. The optimization of the deposition processes made the fabrication of TFTs with excellent performance possible. The mobility was high and exceeded 12 cm{sup 2}/V s, the subthreshold slope was 0.3 V dec{sup ?1}, and an on-set close to the ideal value of 0?V was achieved.

  17. Chemical composition and temperature dependent performance of ZnO-thin film transistors deposited by pulsed and continuous spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Ortel, Marlis; Balster, Torsten; Wagner, Veit

    2013-12-01

    Zinc oxide thin film transistors (TFTs) deposited by continuous and pulsed spray pyrolysis were investigated to analyze process kinetics which make reduction of process temperature possible. Thus, fluid mechanics, chemical composition, electrical performance, and deposition and annealing temperature were systematically analyzed. It was found that ZnO layers continuously deposited at 360 °C contained zinc oxynitrides, CO3, and hydro carbonate groups from pyrolysis of basic zinc acetate. Statistically, every second wurtzite ZnO unit cell contained an impurity atom. The purity and performance of the ZnO-TFTs increased systematically with increasing deposition temperature due to an improved oxidation processes. At 500 °C the zinc to oxygen ratio exceeded a high value of 0.96. Additionally, the ZnO film was not found to be in a stabilized state after deposition even at high temperatures. Introducing additional subsequent annealing steps stabilizes the film and allows the reduction of the overall thermal stress to the substrate. Further improvement of device characteristics was obtained by pulsed deposition which allowed a more effective transport of the by-products and oxygen. A significant reduction of the deposition temperature by 140 °C was achieved compared to the same performance as in continuous deposition mode. The trap density close to the Fermi energy could be reduced by a factor of two to 4 × 1017 eV-1 cm-3 due to the optimized combustion process on the surface. The optimization of the deposition processes made the fabrication of TFTs with excellent performance possible. The mobility was high and exceeded 12 cm2/V s, the subthreshold slope was 0.3 V dec-1, and an on-set close to the ideal value of 0 V was achieved.

  18. Synthesis and characterization of nano-V2O5 by flame spray pyrolysis, and its cathodic performance in Li-ion rechargeable batteries

    NASA Astrophysics Data System (ADS)

    Sel, Sinem; Duygulu, Ozgur; Kadiroglu, Umit; Machin, Nesrin E.

    2014-11-01

    Vanadium pentoxide (V2O5) nano-particles have been synthesized by flame spray pyrolysis method to investigate their cathodic performance in Li-ion rechargeable batteries. They were characterized by surface area (Brunauer-Emmett-Teller, BET method), scanning electron microscopy (SEM), transmission electron microscopy-energy dispersive spectrometry (TEM-EDS), selected area electron diffraction (SAED), high resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD) methods. Spherical, crystalline (orthorhombic) nano-V2O5 particles were produced. The electrochemical tests, including cyclic voltammetry (CV) and ac impedance spectroscopy (IS), were performed to obtain the reversibility and conductivity kinetic parameters. From IS measurements, nano film conductivity was found to be 2.42 × 10-6 S cm-1, which is 10-fold higher than the commercial micro-particle V2O5 counterparts. From spectra, it was also found that the interfacial resistance became stable after 7200 s. The impedance results indicated that the rate of reaction at the interphase was controlled by both charge transfer and diffusion processes. The cyclic voltammogram showed high reversibility rate and low polarization.

  19. Photoluminescence Properties and Morphologies of Submicron-Sized ZnO Crystals Prepared by Ultrasonic Spray Pyrolysis

    NASA Astrophysics Data System (ADS)

    Htay, Myo Than; Itoh, Minoru; Hashimoto, Yoshio; Ito, Kentaro

    2008-01-01

    Spectral features of the near-band-edge photoluminescence (PL) of submicron-sized ZnO crystals such as nanoplatelets, nanowires, and nanorods grown by an ultrasonic spray pyrolysis (USP) technique were investigated. The measurements of time-integrated and time-resolved PL spectra were performed in the temperature range of 8-300 K under various excitation densities by using the fourth harmonics (4.66 eV) of a Nd:YAG laser. Exciton-related emission bands were clearly observed in the ZnO crystals having different morphologies. In nanoplatelets, an emission band originating from radiative recombination of donor-acceptor pairs was also found at around 3.17 eV, indicating the existence of acceptor centers. The binding energies of donor and acceptor were about 53 and 200 meV, respectively. In nanowires, the intensity of an emission band peaking at 3.32 eV obeyed a quadratic dependency on the density of excitation. This fact shows that an inelastic exciton-exciton scattering process is efficient in the nanowires because of high crystal quality.

  20. The role of substrates on the structural, optical, and morphological properties of ZnO nanotubes prepared by spray pyrolysis.

    PubMed

    Vijayalakshmi, K; Karthick, K

    2014-03-01

    ZnO films were deposited onto glass, ITO coated glass, and sapphire substrate by spray pyrolysis, and subsequently annealed at the same temperature of 400°C for 3 h. The role of substrate on the properties of ZnO films was investigated. The structural and optical properties of the films were investigated by X-ray diffractometer (XRD) and photoluminescence (PL) spectrophotometer, respectively. The surface morphology of the nanostructured ZnO film was investigated by scanning electron microscopy (SEM) and atomic force microscopy (AFM). Crystallographic properties revealed that the ZnO films deposited on sapphire and ITO substrates exhibit a strong c-axis orientation of grains with hexagonal wurtzite structure. Extremely high UV emission intensity was determined in the film on ITO. The different luminescence behaviors was discussed, which would be caused by least value of strain in the film. Films grown on different substrates revealed differences in the morphology. ZnO films on ITO and sapphire substrates revealed better morphology than that of the film on glass. AFM images of the films prepared on ITO show uniform distribution of grains with large surface roughness, suitable for application in dye sensitized solar cells. PMID:24375777

  1. Defect-induced magnetism in undoped and Mn-doped wide band gap zinc oxide grown by aerosol spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Motaung, D. E.; Kortidis, I.; Papadaki, D.; Nkosi, S. S.; Mhlongo, G. H.; Wesley-Smith, J.; Malgas, G. F.; Mwakikunga, B. W.; Coetsee, E.; Swart, H. C.; Kiriakidis, G.; Ray, S. S.

    2014-08-01

    We present a systemic study on the structural, optical and magnetic properties of the un-doped and Mn doped ZnO thin films grown by aerosol spray pyrolysis at different deposition times. XRD profiling has shown that the structures of the prepared products are wurtzite without any evidence of second phases. Surface morphology analysis revealed that incorporation of Mn in the ZnO matrix results in the formation of "doughnut-like" structures while the corresponding un-doped ZnO showed permeable structures only at long deposition time. Optical results demonstrated that Mn-doped ZnO nanostructures exhibited both the characteristic orange Mn2+ ion-related emission at 595 nm and a shoulder around 667 nm, denoting that the Mn ions have successfully occupied lattice positions of Zn ions. The chemical composition and charge states of the Mn ions in the doped ZnO nanostructures analysed by the EDX and XPS, also confirmed that Mn2+ ions were successfully incorporated onto zinc sites in the ZnO host crystal. With the combination of defect analysis based on PL and XPS, the effect of defects on the nature and origin of ferromagnetism through EPR was investigated. These findings suggested that zinc and oxygen defects, especially zinc interstitials and singly ionized oxygen vacancies, play a crucial role in mediating ferromagnetism in the undoped ZnO.

  2. The effect of solution concentration on the physical and electrochemical properties of vanadium oxide films deposited by spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Mousavi, M.; Kompany, A.; Shahtahmasebi, N.; Bagheri-Mohagheghi, M. M.

    2013-10-01

    Vanadium oxide thin films were prepared on glass substrates by using the spray pyrolysis technique. The effect of solution concentration (0.1 M, 0.2 M and 0.3 M) on the nanostructural, electrical, optical, and electrochromic properties of deposited films were investigated using X-ray diffraction, scanning electron microscopy, UV—vis spectroscopy, and cyclic volta-metrics. The X-ray diffraction shows that only the sample at 0.1 M has a single ?-V2O5 phase and the others have mixed phases of vanadium oxide. The lowest sheet resistance was obtained for the samples prepared at 0.3 M solution. It was also found that the optical transparency of the samples changes from 70% to 35% and the optical band gap of the samples was in the range of 2.20 to 2.41 eV, depending on the morality of solution. The cycle voltammogram shows that the sample prepared at 0.3 M has one-step electerochoromic but the other samples have two-step electerochoromic. The results show a correlation between the cycle voltammogram and the physical properties of the films.

  3. Ni-SiO2 Catalysts for the Carbon Dioxide Reforming of Methane: Varying Support Properties by Flame Spray Pyrolysis.

    PubMed

    Lovell, Emma C; Scott, Jason; Amal, Rose

    2015-01-01

    Silica particles were prepared by flame spray pyrolysis (FSP) as a support for nickel catalysts. The impact of precursor feed rate (3, 5 and 7 mL/min) during FSP on the silica characteristics and the ensuing effect on catalytic performance for the carbon dioxide, or dry, reforming of methane (DRM) was probed. Increasing the precursor feed rate: (i) progressively lowered the silica surface area from ?340 m2/g to ?240 m2/g; (ii) altered the silanol groups on the silica surface; and (iii) introduced residual carbon-based surface species to the sample at the highest feed rate. The variations in silica properties altered the (5 wt %) nickel deposit characteristics which in turn impacted on the DRM reaction. As the silica surface area increased, the nickel dispersion increased which improved catalyst performance. The residual carbon-based species also appeared to improve nickel dispersion, and in turn catalyst activity, although not to the same extent as the change in silica surface area. The findings illustrate both the importance of silica support characteristics on the catalytic performance of nickel for the DRM reaction and the capacity for using FSP to control these characteristics. PMID:25774491

  4. High-Temperature Jet Spray Reactor for the Preparation of Rare Earth Oxides by Pyrolysis: Computer Simulation

    NASA Astrophysics Data System (ADS)

    Zhao, Qiu-yue; Lv, Chao; Zhang, Zi-mu; Dou, Zhi-he; Zhang, Ting-an; Liu, Yan; Lv, Guo-zhi

    2014-09-01

    A new type of high-temperature jet spray pyrolysis (SP) reactor is investigated in this article as part of studies on the preparation of rare earth oxides at Northeastern University (NEU), Shenyang, China. The jet spray reactor examined here is a horizontal, tubular reactor conveying the hot products of the combustion of methane and oxygen with a converging-diverging jet section in an arrangement that provides for inspiration of LaCl3 solution to pyrolyze to La2O3 with the hot gas. The present article is concerned with a computer simulation using a computational fluid dynamic model to develop the velocity, temperature, and pressure profiles in the jet reactor since direct measurement is difficult. The article includes brief comments on a room-temperature model designed to examine the flow characteristics of the jet SP reactor. It was found that the velocity decreased at first, and then it increased near the jet throat. The highest velocity occurred at the throat of jet SP reactor where the LaCl3 enters the unit. Along the reactor axis, the temperature decreases with distance from the gas inlet. The lowest temperature zone was near the wall before the throat of the reactor due to wall heat losses. The temperature was estimated to be close to 1700 K at the throat of the reactor, and it was about 1300 K toward the exit of the reactor. It was shown that a reaction would take place mainly in the throat and in the vicinity of first contact between gas and induced spray. A negative pressure was produced as gas passes through the converging-diverging throat of the jet SP reactor that causes the LaCl3 solution to enter the throat of the reactor. While the investigations of this type of reactor are at an early stage, the results look promising. NEU continues to investigate this approach for the preparation of La2O3 based on high-temperature testwork and physical modeling techniques.

  5. High-Temperature Jet Spray Reactor for the Preparation of Rare Earth Oxides by Pyrolysis: Computer Simulation

    NASA Astrophysics Data System (ADS)

    Zhao, Qiu-yue; Lv, Chao; Zhang, Zi-mu; Dou, Zhi-he; Zhang, Ting-an; Liu, Yan; Lv, Guo-zhi

    2014-08-01

    A new type of high-temperature jet spray pyrolysis (SP) reactor is investigated in this article as part of studies on the preparation of rare earth oxides at Northeastern University (NEU), Shenyang, China. The jet spray reactor examined here is a horizontal, tubular reactor conveying the hot products of the combustion of methane and oxygen with a converging-diverging jet section in an arrangement that provides for inspiration of LaCl3 solution to pyrolyze to La2O3 with the hot gas. The present article is concerned with a computer simulation using a computational fluid dynamic model to develop the velocity, temperature, and pressure profiles in the jet reactor since direct measurement is difficult. The article includes brief comments on a room-temperature model designed to examine the flow characteristics of the jet SP reactor. It was found that the velocity decreased at first, and then it increased near the jet throat. The highest velocity occurred at the throat of jet SP reactor where the LaCl3 enters the unit. Along the reactor axis, the temperature decreases with distance from the gas inlet. The lowest temperature zone was near the wall before the throat of the reactor due to wall heat losses. The temperature was estimated to be close to 1700 K at the throat of the reactor, and it was about 1300 K toward the exit of the reactor. It was shown that a reaction would take place mainly in the throat and in the vicinity of first contact between gas and induced spray. A negative pressure was produced as gas passes through the converging-diverging throat of the jet SP reactor that causes the LaCl3 solution to enter the throat of the reactor. While the investigations of this type of reactor are at an early stage, the results look promising. NEU continues to investigate this approach for the preparation of La2O3 based on high-temperature testwork and physical modeling techniques.

  6. Polymer and surfactant-templated synthesis of hollow and porous ZnS nano- and microspheres in a spray pyrolysis reactor.

    PubMed

    Sharma, Munish K; Rohani, Parham; Liu, Sha; Kaus, Mark; Swihart, Mark T

    2015-01-13

    Nanostructured zinc sulfide can provide unique photonic, electronic, and catalytic properties that are of interest for applications ranging from bioimaging to photocatalysis. Here we report an easily controllable continuous method to produce porous and hollow ZnS nano- and microspheres. We used poly(ethylene glycol) methyl ether (PEG), polyvinylpyrrolidone (PVP), ethylene oxide/propylene oxide block copolymer (Pluronic F-38), and cetyltrimethylammonium bromide (CTAB) as templates to synthesize ZnS nano- and microspheres with controlled internal morphology in a spray pyrolysis process, starting from an aqueous solution of chemical precursors and templating agents. Spherical particles were produced by droplet-to-particle conversion of droplets. Zinc acetate and thiourea, used here as precursors for ZnS, react in solution to form bis-thiourea zinc acetate (BTZA), which precipitates with the evaporation of solvent. Upon further heating, BTZA decomposes to yield ZnS. During solvent evaporation, PEG and Pluronic precipitate after BTZA, driving formation of a shell of ZnS and a hollow core. In contrast, PVP and CTAB interact strongly with BTZA and ZnS, such that the PVP and ZnS remain intermixed. After evaporation of solvent, the templating agents can be pyrolyzed at high temperature to leave behind porous or hollow ZnS microspheres composed of many much smaller nanocrystals. PMID:25547202

  7. Structural and optical properties of ZnO nanostructures grown by aerosol spray pyrolysis: Candidates for room temperature methane and hydrogen gas sensing

    NASA Astrophysics Data System (ADS)

    Motaung, D. E.; Mhlongo, G. H.; Kortidis, I.; Nkosi, S. S.; Malgas, G. F.; Mwakikunga, B. W.; Ray, S. Sinha; Kiriakidis, G.

    2013-08-01

    We report on the synthesis of ZnO films by aerosol spray pyrolysis method at different deposition times. The surface morphology, crystal structure and the cross-sectional analysis of the prepared ZnO films were characterized by X-ray diffraction (XRD), focused ion beam scanning electron microscopy (FIB-SEM), atomic force microscopy (AFM) and high resolution transmission electron microscopy (HR-TEM). XRD analysis revealed that the ZnO films are polycrystalline in nature. Structural analysis exploiting cross-sectional TEM profile showed that the films composed of nano-particles and columnar structures growing perpendicular to the substrate. AFM revealed that the columnar structures have a higher surface roughness as compared to the nanoparticles. The effect of ZnO crystallite size and crystallinity on the gas sensing performance of hydrogen and methane gases was also evaluated. Sensing film based on ZnO nanoparticles has numerous advantages in terms of its reliability and high sensitivity. These sensing materials revealed an improved response to methane and hydrogen gases at room temperature due to their high surface area, indicating their possible application as a gas sensor.

  8. Effects of synthesis conditions on Curie temperature of La0.75Sr0.25MnO3 fine particles formed by ultrasonic spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Kinoshita, Takuya; Furuyabu, Takamitsu; Adachi, Motoaki

    2014-10-01

    Manganese perovskite La0.75Sr0.25MnO3 (LSM) fine particles were synthesized by an ultrasonic spray pyrolysis method at various synthesis temperatures (Ts), reaction times (tr), and source solution concentrations (Ctotal) to clarify the effects of these synthesis conditions on their Curie temperature Tc and maximum particle temperature attained by magnetic heating at Thmax. At constant Ctotal, the Tc of synthesized LSM particles was increased from 288.6 to 363.5 K (15.6 to 90.5 °C) by increasing Ts from 1073 to 1627 K (800 to 1400 °C), and was increased from 281.8 to 339 K (8.89 to 66 °C) by increasing tr from 2.4 to 19 s. When the AC magnetic field was applied, the particles generated heat, and the particle temperature Th increased with time for t < about 2 min, and then attained constant Thmax near Tc. Thmax increased with increasing Tc. The LSM particles produced at Ts = 1213 K, Ctotal = 0.5 mol L-1, and tr = 9.4 s had Thmax = 316.6 K (43.6 °C), which is within the temperature range of 316-318 K (43-45 °C) for hyperthermia therapy for cancer.

  9. Investigations on structural, vibrational, morphological and optical properties of CdS and CdS/Co films by ultrasonic spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Aksay, S.; Polat, M.; Özer, T.; Köse, S.; Gürbüz, G.

    2011-09-01

    CdS and CdS/Co films have been deposited on glass substrates by an ultrasonic spray pyrolysis method. The effects of Co incorporation on the structural, optical, morphological, elemental and vibrational properties of these films were investigated. XRD analysis confirmed the hexagonal wurtzite structure of all films and had no impurity phase. While CdS film has (0 0 2) as the preferred orientation, CdS/Co films have (1 1 0) as the preferred orientation. The direct optical band gap was found to decrease from 2.42 to 2.39 eV by Co incorporation. The decrease of the direct energy gaps by increasing Co contents is mainly due to the sp-d exchange interaction between the localized d-electrons of Co2+ ions and band electrons of CdS. After the optical investigations, it was seen that the transmittance of CdS films decreased by Co content. The Raman measurements revealed two peaks corresponding to the 1LO and 2LO modes of hexagonal CdS. The vibrational modes of Cd-S were obtained in the wavenumber range (590-715 cm-1) using Fourier transform infrared spectroscopy (FTIR). The elemental analysis of the film was done by energy dispersive X-ray spectrometry.

  10. Structural and magnetic characterization of LiMn{sub 1.825}Cr{sub 0.175}O{sub 4} spinel obtained by ultrasonic spray pyrolysis

    SciTech Connect

    Jugovic, D. [Institute of Technical Sciences of the Serbian Academy of Sciences and Arts, Knez Mihailova 35/IV, 11 000 Belgrade (Serbia); Cvjeticanin, N. [Faculty of Physical Chemistry, University of Belgrade, Studentski trg 12-16, P.O. Box 137, Belgrade (Serbia); Kusigerski, V. [Vinca Institute of Nuclear Sciences, Laboratory for Theoretical and Condensed Matter Physics, P.O. Box 522, 11001 Belgrade (Serbia); Mitric, M. [Vinca Institute of Nuclear Sciences, Laboratory for Theoretical and Condensed Matter Physics, P.O. Box 522, 11001 Belgrade (Serbia); Miljkovic, M. [Faculty of Medicine, University of Nis (Serbia); Makovec, D. [Jozef Stefan Institute, Ljubljana (Slovenia); Uskokovic, D. [Institute of Technical Sciences of the Serbian Academy of Sciences and Arts, Knez Mihailova 35/IV, 11 000 Belgrade (Serbia)

    2007-03-22

    Quaternary spinel oxide LiMn{sub 1.825}Cr{sub 0.175}O{sub 4} powder was synthesized by using an ultrasonic spray pyrolysis method, without additional annealing. The crystal structure of the as-prepared powder was revealed by X-ray powder diffraction and identified as a single spinel phase with Fd3m space group. The powders had a spherical morphology with extremely smooth surface appearance and densely congested interior structure. Transmission electron microscopy confirmed that the particle consisted by the cohesion of the primary particles. Magnetic measurements performed in DC field in both zero-field-cooled and field-cooled regimes, as well as AC susceptibility experiments, show that system undergoes spin-glass transition at the freezing temperature T {sub f} = 20 K. The value of the effective magnetic moment {mu} {sub eff} = 4.34 {mu} {sub B} obtained from the Curie-Weiss fit in the high temperature region confirms the substitution of Mn{sup 3+} ions with Cr{sup 3+} ions.

  11. Effect of variation of tin concentration on the properties of Cu2ZnSnS4 thin films deposited using chemical spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Rajeshmon, V. G.; Kuriakose, Abin; Kartha, C. Sudha; Vijayakumar, K. P.

    2013-02-01

    Cu2ZnSnS4 (CZTS) thin films were prepared using chemical spray pyrolysis technique on soda lime glass (SLG) substrates. The effect of tin concentration on the structural, optical and electrical properties was investigated. We deposited films by varying tin concentration from 0.007 M to 0.013 M in steps of 0.0015 M keeping the concentration of copper, zinc and sulphur at 0.02 M, 0.01 M and 0.12 M respectively. It was found that crystallinity of the film increased up to the tin concentration of 0.01 M and then decreases. Band gap of the films steadily decreased from 1.48 to 1.26 eV with increase in tin concentration. All the samples were observed to be p-type by hot probe method. Resistivity of the films increased with increase in tin concentration. In this work we tuned the optoelectronic properties by varying the tin concentration alone and optimized the concentration of tin which yields samples ideal for photovoltaic applications.

  12. Highly photoconducting O2-doped CdS films deposited by spray pyrolysis

    NASA Technical Reports Server (NTRS)

    Richards, D.; El-Korashy, A. M.; Stirn, R. J.; Karulkar, P. C.

    1984-01-01

    CdS films have been prepared by spraying in air solutions of thiourea with either cadmium chloride or cadmium acetate with varying mole ratio and substrate temperature, and subsequently heat treating in oxygen. Substrates included both bare glass or sapphire and transparent conducting oxide-coated sapphire for electrical measurements lateral and transverse to the CdS plane, respectively. Dark resistances of over 10 to the 14th ohms and light-to-dark conductivities of up to 10 to the 7th were obtained using uncoated substrates. The use of Cd(C2H3O2)2 in place of CdCl2 greatly increased the speed of response although with some sacrifice in photoconductivity. Deposition of CdS on ITO-coated surfaces led to greatly reduced dark resistances for the case of CdCl2, but not Cd(C2H3O2)2, presumably due to HCl reaction with the ITO coating in the course of spraying with the former. Ion microprobe analysis detected indium within the CdS films exhibiting low dark resistance. Measurements of the dark and light conductivities at temperatures down to 77 K are given as are the response times for unetched and HCl-etched surfaces.

  13. CuInS2 films using repeated chemical spray pyrolysis

    NASA Astrophysics Data System (ADS)

    John, Teny Theresa; Wilson, K. C.; Ratheesh Kumar, P. M.; Sudha Kartha, C.; Vijayakumar, K. P.; Kashiwaba, Y.; Abe, T.; Yasuhiro, Y.

    2005-01-01

    CuInS2 films of thickness 1.17 µm were deposited onto glass substrates using repeated spraying technique without any pinholes on the samples. It has been shown that the structure, optical and electrical properties depend on the [Cu]/[In] ratio taken in the solution. Studies using X-ray Diffraction, X-ray Photoelectron Spectroscopy (XPS), Energy Dispersive X-ray Analysis (EDX), optical absorption, photosensitivity and conductivity measurements proved this. Moreover, XPS depth-profiling revealed that there is no oxygen present in the bulk of the film; even though it was prepared using repeated spraying. Oxygen was present only in few atomic layers at the surface of the film and near the substrate-film interface. Use of Cu-rich initial solution resulted in better crystallinity as well as conductivity. EDX measurements showed that [Cu]/[In] ratio in the film is slightly less than that taken in the solution. Photosensitivity of the samples decreased with increase in [Cu]/[In] ratio.

  14. Pyrolysis and catalytic pyrolysis as a recycling method of waste CDs originating from polycarbonate and HIPS.

    PubMed

    Antonakou, E V; Kalogiannis, K G; Stephanidis, S D; Triantafyllidis, K S; Lappas, A A; Achilias, D S

    2014-12-01

    Pyrolysis appears to be a promising recycling process since it could convert the disposed polymers to hydrocarbon based fuels or various useful chemicals. In the current study, two model polymers found in WEEEs, namely polycarbonate (PC) and high impact polystyrene (HIPS) and their counterparts found in waste commercial Compact Discs (CDs) were pyrolysed in a bench scale reactor. Both, thermal pyrolysis and pyrolysis in the presence of two catalytic materials (basic MgO and acidic ZSM-5 zeolite) was performed for all four types of polymers. Results have shown significant recovery of the monomers and valuable chemicals (phenols in the case of PC and aromatic hydrocarbons in the case of HIPS), while catalysts seem to decrease the selectivity towards the monomers and enhance the selectivity towards other desirable compounds. PMID:25246066

  15. Impact of annealing duration on spray pyrolysis deposited nanostructured zinc oxide thin films

    NASA Astrophysics Data System (ADS)

    Mani, Ganesh Kumar; Rayappan, John Bosco Balaguru

    2014-03-01

    The effect of annealing duration on structural, morphological, optical and electrical properties of spray deposited nanostructured ZnO thin films was investigated. Films were deposited on glass substrates at the substrate temperature of 523 K subsequently post annealed at 673 K for 6 h, 12 h and 24 h durations. X-ray diffraction pattern of the films confirmed the polycrystalline nature with hexagonal wurtzite structure. The gradual grain growth along the c axis and increase in crystallite size with reference to annealing duration were confirmed by X-ray diffraction data. Scanning electron micrographs of the films revealed the grain growth as an effect of annealing duration. Optical band gap was found to be decreased from 3.31 to 3.26 eV when the annealing period was increased from 0 to 24 h. Film thickness and electrical conductivity were found to be decreased and increased respectively as the annealing duration was increased.

  16. Flash Pyrolysis -A Powerful Method for Characterization of Polymers Helge Egsgaard

    E-print Network

    by GC/MS at the very low pg-level Very fast heating rates by lasers or ohmic/inductive heating (rates 10.000- 100.000 °C/s) Introduction #12;Analytical flash pyrolysis · Inductive heating (Curie point pyrolysis of temperature and the use of very high heating rates. The method can be used for qualitative, quantitative

  17. Dual acceptor doping and aging effect of p-ZnO:(Na, N) nanorod thin films by spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Swapna, R.; Amiruddin, R.; Santhosh Kumar, M. C.

    2014-01-01

    An attempt has been made to realize p-type ZnO by dual acceptor doping (Na-N) into ZnO thin films. Na and N doped ZnO thin films of different concentrations (0 to 8 at.%) have been grown by spray pyrolysis at 623 K. The grown films on glass substrate have been characterized by X-ray diffraction (XRD), Hall measurement, UV-Vis spectrophotometer, Photoluminescence (PL) and Energy dispersive spectroscopy (EDS) to validate the p-type conduction. The surface morphology and roughness of the ZnO:(Na, N) films are studied by scanning electron microscopy (SEM) and atomic force microscopy (AFM), respectively. Hall measurement shows that all the films exhibit p-type conductivity except for 0 at.% Na-N doped ZnO film. The obtained resistivity (5.60×10-2 ? cm) and hole concentration (3.15×1018 cm-3) for the best dual acceptor doped film is 6 at.%. It has been predicted that (NaZn-NO) acceptor complex is responsible for the p-type conduction. The p-type conductivity of the ZnO:(Na, N) films is stable even after 6 months. The crystallinity of the films has been studied by XRD. Energy dispersive spectroscopy (EDS) confirms the presence of Na and N in 6 at.% ZnO:(Na, N) film. Photoluminescence (PL) spectra of ZnO:(Na, N) films show NBE and deep level emissions in the UV and visible regions, respectively. The ZnO:(Na, N) films exhibit a high transmittance about 90% in the visible region.

  18. Growth and Characterization of Co-Doped Fluorine and Antimony in Tin Oxide Thin Films Obtained by Ultrasonic Spray Pyrolysis

    NASA Astrophysics Data System (ADS)

    Gaewdang, Thitinai; Wongcharoen, Ngamnit

    Fluorine (F)-doped, antimony (Sb)-doped, fluorine and antimony co-doped tin oxide (SnO2) thin films were prepared by ultrasonic spray pyrolysis technique using SnCl2, NH4F and SbCl3 as precursors of Sn, F and Sb elements respectively. F and Sb doping concentrations carried out from 1 to 20 wt% and 1 to 4 wt% in F-doped and Sb-doped SnO2 films respectively. In F and Sb co-doped SnO2 films, the proportions of F and Sb to Sn in starting solution were 15 and 2 wt% respectively. XRD patterns showed that the preferred orientation of SnO2:F, SnO2:Sb and SnO2:F, Sb is dependent on the doping concentration. The variation of doping concentration and preferred orientation of the films was reflected in their morphology as investigated by SEM. The electrical properties of the films were performed by Hall effect measurements in van der Pauw configuration. The minimum resistivity values of SnO2:F and SnO2:Sb were found in the films doped with 15 wt% of F and 2 wt% of Sb. However, The minimum of resistivity value of F and Sb co-doped SnO2 films is not better than neither the one of F-doped nor the one of Sb-doped SnO2 films. The optical transmission of SnO2:F films was found to increase with increasing in F doping concentration. Whereas the optical transmission of SnO2:Sb was found to decrease with increasing in Sb concentration. The F and Sb co-doped SnO2 films annealed in three different conditions at 500°C show the lower transmission values than the value obtained in the as-prepared SnO2:F, Sb films.

  19. Using simple spray pyrolysis to prepare yolk-shell-structured ZnO-Mn3O4 systems with the optimum composition for superior electrochemical properties.

    PubMed

    Choi, Seung Ho; Kang, Yun Chan

    2014-03-10

    A spray-pyrolysis process is introduced as an effective tool for the preparation of yolk-shell-structured materials with electrochemical properties suitable for anode materials in Li-ion batteries (LIBs). Yolk-shell-structured ZnO-Mn3O4 systems with various molar ratios of the Zn and Mn components are prepared. The yolk-shell-structured ZnO-Mn3O4 powders with a molar ratio of 1:1 of the Zn and Mn components are shown to have high capacities and good cycling performances. PMID:24532417

  20. Thin films of Ln 1? x Sr x CoO 3 (Ln=La, Nd and Gd) and SrRuO 3 by nebulized spray pyrolysis

    Microsoft Academic Search

    E. E. Ebenso; Kripasindhu Sardar; M. Chandrasekhar; A. R. Raju; C. N. R. Rao

    2000-01-01

    Thin films of La1?xSrxCoO3, Nd0.5Sr0.5CoO3, Gd0.5Sr0.5CoO3 and SrRuO3 have been deposited on Si(100), LaAlO3(100) and SrTiO3(100) single crystal substrates by nebulized spray pyrolysis. The films deposited on Si are generally polycrystalline, but they are highly oriented on the oxide substrates. The cobaltate films are generally not metallic, but exhibit low resistivity specially when x=0.3 and 0.5, the latter also exhibiting

  1. Influence of optical properties of ZnO thin-films deposited by spray pyrolysis and RF magnetron sputtering on the output performance of silicon solar cell

    NASA Astrophysics Data System (ADS)

    Tripathi, Brijesh; Patel, Malkesh; Ray, Abhijit; Kumar, Manoj

    2013-05-01

    ZnO thin-films were deposited by spray pyrolysis and RF magnetron sputtering techniques. The optical reflection of these thin-films is measured using UV-Vis spectrophotometer. The measured optical reflection data is used in PC-1D simulation software to study the output performance of commercial silicon wafer-based solar cell. As far as optical performance is concerned it could be demonstrated that the sprayed ZnO thin-film under laboratory conditions show equivalent performance compared to sputtered ZnO thin-film. The influence of optical properties of 65 nm thick zinc oxide thin-films deposited by vacuum and non-vacuum techniques on quantum efficiency and IV characteristics of commercial silicon-wafer based solar cell is studied and reported here.

  2. Method and apparatus for spraying molten materials

    DOEpatents

    Glovan, R.J.; Tierney, J.C.; McLean, L.L.; Johnson, L.L.; Nelson, G.L.; Lee, Y.M.

    1996-06-25

    A metal spray apparatus is provided with a supersonic nozzle. Molten metal is injected into a gas stream flowing through the nozzle under pressure. By varying the pressure of the injected metal, the droplet can be made in various selected sizes with each selected size having a high degree of size uniformity. A unique one piece graphite heater provides easily controlled uniformity of temperature in the nozzle and an attached tundish which holds the pressurized molten metal. A unique U-shaped gas heater provides extremely hot inlet gas temperatures to the nozzle. A particularly useful application of the spray apparatus is coating of threads of a fastener with a shape memory alloy. This permits a fastener to be easily inserted and removed but provides for a secure locking of the fastener in high temperature environments. 12 figs.

  3. Method and apparatus for spraying molten materials

    DOEpatents

    Glovan, Ronald J. (Butte, MT); Tierney, John C. (Butte, MT); McLean, Leroy L. (Butte, MT); Johnson, Lawrence L. (Butte, MT); Nelson, Gordon L. (Butte, MT); Lee, Ying-Ming (Butte, MT)

    1996-01-01

    A metal spray apparatus is provided with a supersonic nozzle. Molten metal is injected into a gas stream flowing through the nozzle under pressure. By varying the pressure of the injected metal, the droplet can be made in various selected sizes with each selected size having a high degree of size uniformity. A unique one piece graphite heater provides easily controlled uniformity of temperature in the nozzle and an attached tundish which holds the pressurized molten metal. A unique U-shaped gas heater provides extremely hot inlet gas temperatures to the nozzle. A particularly useful application of the spray apparatus is coating of threads of a fastener with a shape memory alloy. This permits a fastener to be easily inserted and removed but provides for a secure locking of the fastener in high temperature environments.

  4. Effects of precursor types of Fe and Ni components on the properties of NiFe 2O 4 powders prepared by spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Jung, Dae Soo; Kang, Yun Chan

    2009-03-01

    The effects of the precursor types of Ni and Fe components on the morphology, mean size, and magnetic property of NiFe 2O 4 powders prepared by spray pyrolysis from the spray solution, with citric acid were studied. The precursor powders with hollow and thin wall structure turned to the nano-sized NiFe 2O 4 powders after post-treatment at a temperature of 800 °C. The nickel ferrite powders obtained from the spray solution with ferric chloride had nanometer sizes and narrow size distributions irrespective of the types of nickel precursor. The nickel ferrite powders obtained from the spray solution with ferric nitrate and nickel chloride also had nanometer size and narrow size distribution. The saturation magnetizations of the NiFe 2O 4 powders changed from 37 to 42 emu/g according to the types of the Fe and Ni precursors. The saturation magnetizations of the NiFe 2O 4 powders increased with increasing the Brunauer-Emmett-Teller (BET) surface areas of the powders.

  5. A fluorescent tracer method for evaluating spray transport and fate of field and laboratory spray applications

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Field and laboratory testing spray nozzles and application systems use spray collectors to assess where the spray deposits once it leaves the spray system. Tracer materials, such as oil and water soluble fluorescent dyes, can be mixed into spray solutions in small amounts with minimal impact on the...

  6. Flame spray pyrolysis for finding multicomponent nanomaterials with superior electrochemical properties in the CoO(x)-FeO(x) system for use in lithium-ion batteries.

    PubMed

    Kim, Jung Hyun; Lee, Jong-Heun; Kang, Yun Chan

    2014-10-01

    High-temperature flame spray pyrolysis is employed for finding highly efficient nanomaterials for use in lithium-ion batteries. CoO(x)-FeO(x) nanopowders with various compositions are prepared by one-pot high-temperature flame spray pyrolysis. The Co and Fe components are uniformly distributed over the CoO(x)-FeO(x) composite powders, irrespective of the Co/Fe mole ratio. The Co-rich CoO(x)-FeO(x) composite powders with Co/Fe mole ratios of 3:1 and 2:1 have mixed crystal structures with CoFe2O4 and Co3O4 phases. However, Co-substituted magnetite composite powders prepared from spray solutions with Co and Fe components in mole ratios of 1:3, 1:2, and 1:1 have a single phase. Multicomponent CoO(x)-FeO(x) powders with a Co/Fe mole ratio of 2:1 and a mixed crystal structure with Co3O4 and CoFe2O4 phases show high initial capacities and good cycling performance. The stable reversible discharge capacities of the composite powders with a Co/Fe mole ratio of 2:1 decrease from 1165 to 820?mA?h?g(-1) as the current density is increased from 500 to 5000?mA?g(-1); however, the discharge capacity again increases to 1310?mA?h?g(-1) as the current density is restored to 500?mA?g(-1). PMID:25065898

  7. Evaluation of VOC emission measurement methods for paint spray booths.

    PubMed

    Eklund, B M; Nelson, T P

    1995-03-01

    Interest in regulations to control solvent emissions from automotive painting systems is increasing, especially in ozone nonattainment areas. Therefore, an accurate measurement method for VOC emissions from paint spray booths used in the automotive industry is needed to ascertain the efficiency of the spray booth capture and the total emissions. This paper presents the results of a laboratory study evaluating potential VOC sampling and analytical methods used in estimating paint spray booth emissions, and discusses these results relative to other published data. Eight test methods were selected for evaluation. The accuracy of each sampling and analytical method was determined using test atmospheres of known concentration and composition that closely matched the actual exhaust air from paint spray booths. The solvent mixture to generate the test atmospheres contained a large proportion of polar, oxygenated hydrocarbons such as ketones and alcohols. A series of identical tests was performed for each sampling/analytical method with each test atmosphere to assess the precision of the methods. The study identified significant differences among the test methods in terms of accuracy, precision, cost, and complexity. PMID:15658160

  8. A novel gas-droplet numerical method for spray combustion

    NASA Technical Reports Server (NTRS)

    Chen, C. P.; Shang, H. M.; Jiang, Y.

    1991-01-01

    This paper presents a non-iterative numerical technique for computing time-dependent gas-droplet flows. The method is a fully-interacting combination of Eulerian fluid and Lagrangian particle calculation. The interaction calculations between the two phases are formulated on a pressure-velocity coupling procedure based on the operator-splitting technique. This procedure eliminates the global iterations required in the conventional particle-source-in-cell (PSIC) procedure. Turbulent dispersion calculations are treated by a stochastic procedure. Numerical calculations and comparisons with available experimental data, as well as efficiency assessments are given for some sprays typical of spray combustion applications.

  9. Processing and synthesis of multi-metallic nano oxide ceramics via liquid-feed flame spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Azurdia, Jose Antonio

    The liquid-feed flame spray pyrolysis (LF-FSP) process aerosolizes metal-carboxylate precursors dissolved in alcohol with oxygen and combusts them at >1500°C. The products are quenched rapidly (˜10s msec) to < 400°C. By selecting the appropriate precursor mixtures, the compositions of the resulting oxide nanopowders can be tailored easily, which lends itself to combinatorial studies of systems facilitating material property optimization. The resulting nanopowders typically consist of single crystal particles with average particle sizes (APS) < 35 nm, specific surface areas (SSA) of 20-60 m2/g and spherical morphology. LF-FSP provides access to novel single phase nanopowders, known phases at compositions outside their published phase diagrams, intimate mixing at nanometer length scales in multi metallic oxide nanopowders, and control of stoichiometry to ppm levels. The materials produced may exhibit unusual properties including structural, catalytic, and photonic ones and lower sintering temperatures. Prior studies used LF-FSP to produce MgAl2O4 spinel for applications in transparent armor and IR radomes. In these studies, a stable spinel structure with a (MgO)0.1(Al2O3)0.9 composition well outside the known phase field was observed. The work reported here extends this observation to two other spinel systems: Al2O3-NiO, Al2O3-CoOx; followed by three series of transition metal binary oxides, NiO-CoO, NiO-MoO3, NiO-CuO. The impetus to study spinels derives both from the fact that a number of them are known transparent ceramics, but also others offer high SSAs coupled with unusual phases that suggest potentially novel catalytic materials. Because LF-FSP provides access to any composition, comprehensive studies of the entire tie-lines were conducted rather than just compositions of value for catalytic applications. Initial efforts established baseline properties for the nano aluminate spinels, then three binary transition metal oxide sets (Ni-Co, Ni-Mo and Ni-Cu) known for their catalytic properties. These materials then serve as baseline studies for ternary systems, such as Al:(Ni-Co)O, or Al(Ni-Cu)O likely to offer superior catalytic properties because of the relatively high SSA Al2O3. The final chapter returns to photonic materials, in the MgO-Y2O 3 system targeting transparent ceramics through select compositions along the tie-line. The work presented here builds on the MgAl2O 4 spinel material and continues to develop the processing techniques required to achieve transparent nano-grained ceramic materials. Thus the overall goal of this dissertation was to systematically produce novel nano-oxide materials and characterized their material properties. The first chapters focus on solid solutions at low Ni or Co amounts that form phase pure spinels outside the expected composition range, at 21-22 mol % NiO and CoO. Additionally, (NiO)0.22(Al2O3) 0.78 was found to be very stable, as it did not convert to alpha-Al 2O3 plus cubic-NiO on heating to 1200°C for 10 h. The last chapter is a preliminary step toward identifying optimal Y 2O3-MgO powders that can be transparent ceramics. Ball milling led to much higher adsorption of surface species. Preliminary sintering studies of the this system showed that vacuum has the largest effect on lowering the temperature of maximum shrinkage rate by ? 80°C.

  10. Investigation of the structural, optical and electrical properties of Nd-doped ZnO thin films deposited by spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Douayar, A.; Prieto, P.; Schmerber, G.; Nouneh, K.; Diaz, R.; Chaki, I.; Colis, S.; El Fakir, A.; Hassanain, N.; Belayachi, A.; Sekkat, Z.; Slaoui, A.; Dinia, A.; Abd-Lefdil, M.

    2013-01-01

    Neodymium-doped zinc oxide (NZO) thin films were deposited on glass substrates by spray pyrolysis technique. X-ray diffraction patterns have shown that both undoped and Nd-doped ZnO films exhibit the hexagonal wurtzite crystal structure with a preferential orientation along [0 0 2] direction. The effective doping concentration has been determined by Rutherford backscattering measurements showing that the neodymium is not incorporated easily into ZnO host matrix. The surface roughness was shown to increase with Nd doping. NZO films are highly transparent in the visible region. The lowest electrical resistivity value of about 4.0 10-2 ? cm was obtained for 1% Nd effective doping.

  11. Effect of Fe-doping on the structural and optical properties of ZnO thin films prepared by spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Salaken, S. M.; Farzana, E.; Podder, J.

    2013-07-01

    Fe-doped ZnO thin films have been prepared by spray pyrolysis on glass substrates and the influence of Fe-doping concentration on the structural and optical properties of the films has been studied. The X-ray diffraction (XRD) analysis shows that Fe doping has a significant effect on crystalline quality, grain size and strain in the thin films. The best crystalline structure is obtained for 3 at% Fe doping as observed from scanning electron microscopy (SEM) and XRD. However, lower or higher Fe-doping degrades the crystalline quality in turn. Moreover, UV spectroscopy demonstrates the influence of Fe-incorporation on visible range transmittance of ZnO where the best transmittance is obtained for 3 at% doping. The results have been illustrated simultaneously focusing previous results obtained from literature.

  12. High electron mobility thin-film transistors based on Ga{sub 2}O{sub 3} grown by atmospheric ultrasonic spray pyrolysis at low temperatures

    SciTech Connect

    Thomas, Stuart R., E-mail: s.thomas09@imperial.ac.uk, E-mail: thomas.anthopoulos@imperial.ac.uk; Lin, Yen-Hung; Faber, Hendrik; Anthopoulos, Thomas D., E-mail: s.thomas09@imperial.ac.uk, E-mail: thomas.anthopoulos@imperial.ac.uk [Department of Physics, Blackett Laboratory, Imperial College London, London SW7 2BW (United Kingdom); Adamopoulos, George [Department of Engineering, Engineering Building, Lancaster University, Bailrigg, Lancaster LA1 4YR (United Kingdom); Sygellou, Labrini [Institute of Chemical Engineering and High Temperature Processes (ICEHT), Foundation of Research and Technology Hellas (FORTH), Stadiou Strasse Platani, P.O. Box 1414, Patras GR-265 04 (Greece); Stratakis, Emmanuel [Institute of Electronic Structure and Laser (IESL), Foundation for Research and Technology-Hellas (FORTH), Heraklion 71003 (Greece); Materials Science and Technology Department, University, of Crete, Heraklion 71003 (Greece); Pliatsikas, Nikos; Patsalas, Panos A. [Laboratory of Applied Physics, Department of Physics, Aristotle University of Thessaloniki, Thessaloniki GR-54124 (Greece)

    2014-09-01

    We report on thin-film transistors based on Ga{sub 2}O{sub 3} films grown by ultrasonic spray pyrolysis in ambient atmosphere at 400–450?°C. The elemental, electronic, optical, morphological, structural, and electrical properties of the films and devices were investigated using a range of complementary characterisation techniques, whilst the effects of post deposition annealing at higher temperature (700?°C) were also investigated. Both as-grown and post-deposition annealed Ga{sub 2}O{sub 3} films are found to be slightly oxygen deficient, exceptionally smooth and exhibit a wide energy bandgap of ?4.9?eV. Transistors based on as-deposited Ga{sub 2}O{sub 3} films show n-type conductivity with the maximum electron mobility of ?2?cm{sup 2}/V s.

  13. The Effect of Film Composition on the Texture and Grain Size of CuInS2 Prepared by Spray Pyrolysis

    NASA Technical Reports Server (NTRS)

    Jin, Michael H.-C.; Banger, Kulbinder K.; Harris, Jerry D.; Hepp, Aloysius F.

    2003-01-01

    CuInS2 was deposited by spray pyrolysis using single-source precursors synthesized in-house. Films with either (112) or (204/220) preferred orientation always showed Cu-rich and In-rich composition respectively. The In-rich (204/220)-oriented films always contained a secondary phase evaluated as an In-rich compound, and the hindrance of (112)-oriented grain growth was confirmed by glancing angle X-ray diffraction. In conclusion, only the Cu-rich (112)-oriented films with dense columnar grains can be prepared without the secondary In-rich compound. The effect of extra Cu on the grain size and the solar cell results will be also presented.

  14. The Effect of Film Composition on the Texture and Grain Size of CuInS2 Prepared by Spray Pyrolysis

    NASA Technical Reports Server (NTRS)

    Jin, Michael H.; Banger, Kulinder K.; Harris, Jerry D.; Hepp, Aloysius F.

    2003-01-01

    Ternary single-source precursors were used to deposit CuInS2 thin films using chemical spray pyrolysis. We investigated the effect of the film composition on texture, secondary phase formation, and grain size. As-grown films were most often In-rich. They became more (204/220)-oriented as indium concentration increased, and always contained a yet unidentified secondary phase. The (112)-prefened orientation became more pronounced as the film composition became more Cu-rich. The secondary phase was determined to be an In-rich compound based on composition analysis and Raman spectroscopy. In addition, as-grown Cu-rich (112)-oriented films did not exhibit the In-rich compound. Depositing a thin Cu layer prior to the growth of CuInS2 increased the maximum grain size from - 0.5 micron to - 1 micron, and prevented the formation of the In-rich secondary phase.

  15. Crystalline phase reduction of cuprous oxide (Cu2O) nanoparticles accompanied by a morphology change during ethanol-assisted spray pyrolysis.

    PubMed

    Firmansyah, Dudi Adi; Kim, Taeil; Kim, Songkil; Sullivan, Kyle; Zachariah, Michael R; Lee, Donggeun

    2009-06-16

    Metallic copper nanoparticles are produced by spray pyrolysis of copper nitrates with an addition of ethanol as cosolvent at 600 degrees C. Depending on the synthesis temperature, two interesting reaction pathways are found: below 525 degrees C, approximately 10% of hollow Cu(2)O parent particles are oxidized to CuO and then reduced to Cu, but at higher temperature, the remaining Cu(2)O takes a direct path to Cu, accompanied by a morphology change. These interesting reaction regimes are discussed in the aspects of phase-transformation kinetics, gas-phase and solid-phase thermodynamics, force balance, and their possible influences on structural instability. Experimental observations are fairly consistent with the predictions by the present models. PMID:19505165

  16. Study on anomalous high p-type conductivity in ZnO films on silicon substrate prepared by ultrasonic spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Zhao, Jun-Liang; Li, Xiao-Min; Krtschil, André; Krost, Alois; Yu, Wei-Dong; Zhang, Yi-Wen; Gu, Yan-Fei; Gao, Xiang-Dong

    2007-02-01

    N-In codoped ZnO films were prepared by ultrasonic spray pyrolysis. Hall-effect measurements indicate that the films on silicon exhibit anomalous high p-type conductivity, while films on insulating substrates show n-type conductivity. Scanning capacitance microscopy was employed to analyze the microconductivity type of ZnO films. The grains of ZnO film on silicon show n-type conductivity and no significant p-type grains were found. The authors further investigated the microstructure of ZnO film and the band structure of the ZnO /Si interface and propose a model of an interface state induced two-dimensional hole gas as the origin of the anomalous high p-type behavior.

  17. Optical, electrical and structural properties of nano-pyramidal ZnO films grown on glass substrate by spray pyrolysis technique

    NASA Astrophysics Data System (ADS)

    Bedia, A.; Bedia, F. Z.; Aillerie, M.; Maloufi, N.; Ould Saad Hamady, S.; Perroud, O.; Benyoucef, B.

    2014-05-01

    Optical, electrical and structural properties of ZnO nano-pyramidal films, synthesized by chemical spray pyrolysis technique on glass substrates were investigated. A complete set of structural, optical and electrical parameters is proposed in this contribution. ZnO films possess polycrystalline wurtzite structure showing a preferential orientation along the c-axis as confirmed by XRD measurements. The structure has been investigated by using Raman spectroscopy, at 532 nm excitation source and the morphology is characterized by scanning electron microscopy (SEM). Link to the specific growing parameters, the morphology of the so-obtained films is rarely observed in nanostructures family with a diameter of ZnO hexagonal nano-pyramids in the range of 50-150 nm smaller than this usually obtained by spray pyrolysis. The strong peaks of the E2 Raman mode at 99.3 cm-1 (low) and 439.4 cm-1 (high), indicate a good crystal quality of the ZnO nano-pyramids. The existence of a compressive stress in the ZnO structure was pointed out by Raman scattering and estimated by XRD measurements. High optical transmittance value of the film above 90% in the visible region was observed and the optical band gap was found to be 3.273 eV at room temperature. The photoluminescence (PL) spectrum of ZnO hexagonal pyramid shows an intensity ratio of the UV emission to the visible band more than 20. By electrical characterizations of the ZnO films, we obtained the values of the resistivity and Hall mobility equal to 17 ? cm and 8.49 cm2 V-1 s-1, respectively.

  18. Formation of core-shell-structured Zn2SnO4-carbon microspheres with superior electrochemical properties by one-pot spray pyrolysis.

    PubMed

    Hong, Young Jun; Kang, Yun Chan

    2015-01-14

    Core-shell structured Zn2SnO4-carbon microspheres with different carbon contents are prepared by one-pot spray pyrolysis without any further heating process. A Zn2SnO4-carbon composite microsphere is prepared from one droplet containing Zn and Sn salts and polyvinylpyrrolidone (PVP). Melted PVP moves to the outside of the composite microsphere during the drying stage of the droplet. In addition, melting of the phase separated metal salts forms the dense core. Carbonization of the phase separated PVP forms the textured and porous thick carbon shell. The discharge capacities of the core-shell structured Zn2SnO4-carbon microspheres for the 2(nd) and 120(th) cycles at a current density of 1 A g(-1) are 864 and 770 mA h g(-1), respectively. However, the discharge capacities of the bare Zn2SnO4 microspheres prepared by the same process without PVP for the 2(nd) and 120(th) cycles are 1106 and 81 mA h g(-1), respectively. The stable and reversible discharge capacities of the Zn2SnO4-carbon composite microspheres prepared from the spray solution with 15 g PVP decrease from 894 to 528 mA h g(-1) as current density increases from 0.5 to 5 A g(-1). PMID:25429709

  19. Structural, electrical and optical properties of nanostructured Cd1-xFexS thin films deposited by chemical spray pyrolysis technique

    NASA Astrophysics Data System (ADS)

    Ibrahim, S. G.; Ubale, A. U.

    2014-11-01

    Multi-component nanostructured thin films of Cd1-xFexS were successfully deposited onto glass substrates from aqueous solutions of ferric chloride, cadmium chloride and thiourea using chemical spray pyrolysis technique. The structural, compositional and morphological studies were carried out by using X-ray diffractometer (XRD), energy dispersive X-ray analysis (EDAX) and scanning electron microscopy (SEM) and atomic force microscopy (AFM) respectively. The structural study revealed that, CdS, FeS and Cd1-xFexS films are nanocrystalline in nature with hexagonal lattice. The optical characterization shows that the band gap of the spray deposited CdS film is 2.20 eV and it increases with ‘x' and becomes 2.44 eV for FeS. The electrical resistivity of Cd1-xFexS thin films is of the order of 106 ? cm and shows variation depending on ‘x'. The thermo-emf measurement confirms n-type conductivity of Cd1-xFexS thin films.

  20. Effects of Doping Ratio and Thermal Annealing on Structural and Electrical Properties of Boron-Doped ZnO Thin Films by Spray Pyrolysis

    NASA Astrophysics Data System (ADS)

    Yu, Cheng-Chang; Hsu, Yu-Ting; Lee, Shao-Yi; Lan, Wen-How; Kuo, Hsin-Hui; Shih, Ming-Chang; Jui-Yang Feng, David; Huang, Kai-Feng

    2013-06-01

    Boron-doped zinc oxide (BZO) thin films have been fabricated by spray pyrolysis on a glass substrate. The morphology and electrical properties of the thin films were investigated. X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses were performed. It was found that [B]/[Zn] ratio altered both the microstructure and concentration of the BZO thin films. The film grain size was reduced by increasing the [B]/[Zn] ratio. The highest Hall mobility was 3.65 cm2 V-1 s-1 for the undoped ZnO thin film, and the highest carrier concentration of 1.0×1019 cm-3 was achieved for the as-deposited BZO thin film with [B]/[Zn] = 1.5 at. %. Conductivity was determined at different measurement temperatures and shallow donors provided the dominate conduction mechanism for the as-deposited BZO thin films. After 600 °C annealing, shallow level reduction and donors with a high activation energy of 129+/-6 meV in the BZO thin films were characterized, and the shallow donors that dominate the carrier concentration for the as-deposited spray-pyrolized BZO thin film were eliminated.

  1. Nanoscale Texture Control of Polyelectrolyte Multilayer Using Spray Layer-by-Layer Method

    NASA Astrophysics Data System (ADS)

    Kyung, Kyu-Hong; Shiratori, Seimei

    2011-02-01

    Weak polyelectrolyte multilayer thin films deposited by sequential spraying of poly(allylamine hydrochloride) (PAH) and poly(acrylic acid) (PAA) solutions are described. Using the spray layer-by-layer (spray-LBL) method, nanoscale texture structures were fabricated considering several factors such as the concentration of spray solution, spray quantity, and the flow rate of spray solution. It was also found that the formation of nanoscale texture structures was dependent on all three factors. Then, their surface morphologies were characterized. The surface morphologies of the fabricated films were observed by field-emission scanning electron microscopy (FE-SEM) and atomic force microscopy (AFM). The FE-SEM and AFM images showed that using the spray-LBL method, the surface morphology can be controlled with nanometer-order accuracy. As a result, the speed of fabricating thin films by the spray-LBL method was markedly increased compared with that by the dipping LBL method.

  2. Preparation and characterization of microparticles of piroxicam by spray drying and spray chilling methods

    PubMed Central

    Dixit, M.; Kini, A.G.; Kulkarni, P.K.

    2010-01-01

    Piroxicam, an anti-inflammatory drug, exhibits poor water solubility and flow properties, poor dissolution and poor wetting. Consequently, the aim of this study was to improve the dissolution of piroxicam. Microparticles containing piroxicam were produced by spray drying, using isopropyl alcohol and water in the ratio of 40:60 v/v as solvent system, and spray chilling technology by melting the drug and chilling it with a pneumatic nozzle to enhance dissolution rate. The prepared formulations were evaluated for in vitro dissolution and solubility. The prepared drug particles were characterized by scanning electron microscopy (SEM), differential scanning calorimeter, X-ray diffraction and Fourier transform infrared spectroscopy. Dissolution profile of the spray dried microparticles was compared with spray-chilled microparticles, pure and recrystallized samples. Spray dried microparticles and spray chilled microparticles exhibited decreased crystallinity and improved micromeritic properties. The dissolution of the spray dried microparticle and spray chilled particles were improved compared with recrystallized and pure sample of piroxicam. Consequently, it was believed that spray drying of piroxicam is a useful tool to improve dissolution but not in case of spray chilling. This may be due to the degradation of drug or variations in the resonance structure or could be due to minor distortion of bond angles. Hence, this spray drying technique can be used for formulation of tablets of piroxicam by direct compression with directly compressible tablet excipients. PMID:21589797

  3. Characterisation of iron oxide thin films prepared from spray pyrolysis of iron trichloride-based aqueous solution

    Microsoft Academic Search

    B. Ouertani; J. Ouerfelli; M. Saadoun; H. Ezzaouia; B. Bessais

    2008-01-01

    This work concerns growth and characterization of iron oxide (mainly ?-Fe2O3) thin films with a non-toxic and easy to manipulate technique. The latter consists of spraying FeCl3·6H2O (0.03 M)-based aqueous solution during 30 min onto glass substrates heated at 350 °C with a spray flow of 5 ml\\/min. These conditions led to the formation of rust red amorphous films. Well crystallized Fe2O3 films were

  4. Oxygen evolution electrocatalysis in alkaline medium at thin Mn x Co 3- x O4 (0 ? x ? 1) spinel films on glass \\/ SnO 2: F prepared by spray pyrolysis

    Microsoft Academic Search

    E. Rios; P. Chartier; J.-L. Gautier

    1999-01-01

    Films of a series of manganese-cobalt mixed valency spinel oxides of theoretical formula MnxCo3-xO4, (x = 0; 0.25; 0.5; 0.75 and 1), have been prepared by spray pyrolysis at 150 °C on conductive glass in order to relate solid state and surface chemistry to electrocatalytical activity towards the oxygen evolution reaction (OER). X-ray diffraction (XRD) and IR spectroscopy characterized their

  5. Pyrolysis of Organomercury Compounds: Investigation by the Method of Matrix Isolation

    PubMed Central

    Maltsev, A. K.; Mikaelian, R. G.; Nefedov, O. M.; Hauge, R. H.; Margrave, J. L.

    1971-01-01

    The method of matrix isolation has been used to investigate mechanisms of gas-phase chemical reactions, in particular the pyrolysis of some organomercury compounds. A molecular beam of pyrolysis products was condensed simultaneously with a large excess of rare gas at temperatures from 5 to 15°K to form a matrix that was subsequently studied by infrared spectroscopy. In the case of C6H5HgCCl3, we found that pyrolysis in the temperature range 220-400°C produced mainly dichlorocarbene. In addition, some trichloromethyl radical was observed and increased in relative importance at increased temperatures. Another identified product of pyrolysis was C6H5HgCl. In general, the same reactive intermediates, CCl2 and CCl3, were found from pyrolysis of Hg(CCl3)2 in the temperature range 250-500°C, along with CCl3HgCl and HgCl2. The identity of CCl2 and CCl2 was demonstrated by measurement of the relative intensities and isotopic splittings of stretching vibrations due to the chlorine isotopes. Isotopic patterns found for CCl2 are: v3 (745.8, 744.0, 741.8 cm-1), v1 (719.5, 717.0, 714.9 cm-1) and for CCl3 are: v3 (897.8, 896.4, 895.2, 893.9 cm-1). Less dilution with the rare gas or warming of the matrix produced a decrease of CCl2 and CCl3 spectral bands and an increase of bands due to C2Cl4, C2Cl6, and other products. These results show the usefulness of matrix isolation in the study of such reactive species as CCl2 produced by pyrolysis in the gas phase. PMID:16591960

  6. Formation of core-shell-structured Zn2SnO4-carbon microspheres with superior electrochemical properties by one-pot spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Hong, Young Jun; Kang, Yun Chan

    2014-12-01

    Core-shell structured Zn2SnO4-carbon microspheres with different carbon contents are prepared by one-pot spray pyrolysis without any further heating process. A Zn2SnO4-carbon composite microsphere is prepared from one droplet containing Zn and Sn salts and polyvinylpyrrolidone (PVP). Melted PVP moves to the outside of the composite microsphere during the drying stage of the droplet. In addition, melting of the phase separated metal salts forms the dense core. Carbonization of the phase separated PVP forms the textured and porous thick carbon shell. The discharge capacities of the core-shell structured Zn2SnO4-carbon microspheres for the 2nd and 120th cycles at a current density of 1 A g-1 are 864 and 770 mA h g-1, respectively. However, the discharge capacities of the bare Zn2SnO4 microspheres prepared by the same process without PVP for the 2nd and 120th cycles are 1106 and 81 mA h g-1, respectively. The stable and reversible discharge capacities of the Zn2SnO4-carbon composite microspheres prepared from the spray solution with 15 g PVP decrease from 894 to 528 mA h g-1 as current density increases from 0.5 to 5 A g-1.Core-shell structured Zn2SnO4-carbon microspheres with different carbon contents are prepared by one-pot spray pyrolysis without any further heating process. A Zn2SnO4-carbon composite microsphere is prepared from one droplet containing Zn and Sn salts and polyvinylpyrrolidone (PVP). Melted PVP moves to the outside of the composite microsphere during the drying stage of the droplet. In addition, melting of the phase separated metal salts forms the dense core. Carbonization of the phase separated PVP forms the textured and porous thick carbon shell. The discharge capacities of the core-shell structured Zn2SnO4-carbon microspheres for the 2nd and 120th cycles at a current density of 1 A g-1 are 864 and 770 mA h g-1, respectively. However, the discharge capacities of the bare Zn2SnO4 microspheres prepared by the same process without PVP for the 2nd and 120th cycles are 1106 and 81 mA h g-1, respectively. The stable and reversible discharge capacities of the Zn2SnO4-carbon composite microspheres prepared from the spray solution with 15 g PVP decrease from 894 to 528 mA h g-1 as current density increases from 0.5 to 5 A g-1. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr05373g

  7. Physical properties of Zn doped TiO2 thin films with spray pyrolysis technique and its effects in antibacterial activity

    NASA Astrophysics Data System (ADS)

    Arunachalam, A.; Dhanapandian, S.; Manoharan, C.; Sivakumar, G.

    2015-03-01

    Zinc doped Titanium dioxide (TiO2: Zn) thin films were deposited onto glass substrates by the spray pyrolysis technique with the substrate temperature 450 °C. The structural, optical, photoluminescence (PL) properties and morphological studies were investigated for the films deposited with various doping concentration (0, 2, 4, 6 and 8 at.%) of zinc. The results of X-ray diffraction (XRD) had shown the presence of anatase peak with a strong orientation along (1 0 1) plane at 8 at.% of Zn-doped TiO2 film. Scanning electron microscopy (SEM) study showed the uniform distribution of grains with porous nature. Atomic force microscopy (AFM) observations indicated the tetragonal shape at 8 at.% of Zn-doped TiO2 with the particle size and decrease in surface roughness. The emission at 398 nm was observed at the 8 at.% of Zn-doped TiO2 thin film. The carrier concentration and Hall mobility was increased with doping. The antibacterial activity was highly yielded for the Zn-doped TiO2 thin films.

  8. Effect of Sb dopant on the structural, optical and electrical properties of SnS thin films by spray pyrolysis technique.

    PubMed

    Santhosh Kumar, K; Manoharan, C; Dhanapandian, S; Gowri Manohari, A

    2013-11-01

    Thin films of antimony doped tin sulphide (SnS:Sb) with different antimony concentrations have been prepared by the spray pyrolysis technique at the substrate temperature of 350°C. The physical properties of the films were studied as a function of increase in antimony dopant concentration (up to 10at.%). The films were characterized by different techniques to study their structural, optical and electrical properties. The X-ray diffraction analysis revealed that the films were polycrystalline in nature and having orthorhombic crystal structure with a preferred orientation in (111) direction. Due to Sb doping, the crystalline quality and the preferential orientation of SnS films were improved up to 6at.% of doping concentration. However, when doping concentration was increased above 6at.%, the crystalline quality and the preferential orientation of SnS films was deteriorated. Atomic force microscopy images revealed that the surface roughness of the films increased due to Sb doping. Optical measurements showed that the band gap values decreased from 1.60eV to 1.15eV with increase in Sb concentration. The photoluminescence spectra displayed that all the samples have an emission peak centered at 760nm. At 6at.% of Sb doping, the film has the lowest resistivity of 2.598×10(-2)?cm while the carrier concentration was high. PMID:23892347

  9. Electrochemical properties of Li2O-2B2O3 glass-modified LiMn2O4 powders prepared by spray pyrolysis process

    NASA Astrophysics Data System (ADS)

    Choi, Seung Ho; Kim, Jung Hyun; Ko, You Na; Hong, Young Jun; Kang, Yun Chan

    2012-07-01

    Li2O-2B2O3 glass-modified LiMn2O4 cathode powders are prepared using spray pyrolysis. The powders with 1 and 5 wt% glass material have a spherical shape, dense structure, and large grain size. The BET surface areas of LiMn2O4 powders with 0 and 1 wt% glass material are 15.0 and 5.9 m2 g-1, and their mean crystallite sizes are 29 and 49 nm. The lithium boron oxide (LBO) glass material improves the cycle properties as well as the initial discharge capacities of the LiMn2O4 powders at a constant current density of 1 C. The discharge capacity of LiMn2O4 powders without any glass material decreases from 116.3 to 92.6 mAh g-1 after 100 cycles, the reduced capacity being 80% of the initial capacity. However, the discharge capacity of the LiMn2O4 powders with 1 wt% glass material decreases from 131.0 to 113.2 mAh g-1 after 100 cycles; thus, the capacity retention is 86% of the initial capacity.

  10. Tin-Incorporation Induced Changes in the Microstructural, Optical, and Electrical Behavior of Tungsten Oxide Nanocrystalline Thin Films Grown Via Spray Pyrolysis

    NASA Astrophysics Data System (ADS)

    Mukherjee, Ramnayan; Prajapati, C. S.; Sahay, P. P.

    2014-12-01

    Undoped and Sn-doped WO3 thin films were grown on cleaned glass substrates by chemical spray pyrolysis, using ammonium tungstate (NH4)2WO4 as the host precursor and tin chloride (SnCl4·5H2O) as the source of dopant. The XRD spectra confirm the monoclinic structure with a sharp narrow peak along (200) direction along with other peaks of low relative intensities for all the samples. On Sn doping, the films exhibit reduced crystallinity relative to the undoped film. The standard deviation for relative peak intensity with dopant concentration shows enhancement in heterogeneous nucleation growth. As evident from SEM images, on Sn doping, appearance of island-like structure (i.e., cluster of primary crystallites at few places) takes place. The transmittance has been found to decrease in all the Sn-doped films. The optical band gap has been calculated for both direct and indirect transitions. On Sn doping, the direct band gap shows a red shift and becomes 2.89 eV at 2 at.% doping. Two distinct peaks, one blue emission at 408 nm and other green emission at 533 nm, have been found in the PL spectra. Electrical conductivity has been found to increase with Sn doping.

  11. Preparation and characterization of nanostructures of in-doped ZnO films deposited by chemically spray pyrolysis: Effect of substrate temperatures

    NASA Astrophysics Data System (ADS)

    Benhaliliba, M.; Benouis, C. E.; Mouffak, Z.; Ocak, Y. S.; Tiburcio-Silver, A.; Aida, M. S.; Garcia, A. A.; Tavira, A.; Sanchez Juarez, A.

    2013-11-01

    We deposited undoped (ZnO) and indium-doped ZnO (IZO) films onto glass substrate via ultrasonic spray pyrolysis technique. The variation in structural, surface morphology, electrical, optical and photoluminescent properties as a function of substrate temperature is investigated. X-rays pattern confirms that as-synthesized IZO phase is grown along a (002) preferential plane. Nanosized grains (<50 nm) are determined by X-ray analysis. Morphology of as-grown films shows broadened nanostructures which have grown along c-axis and nanostructures are found to be smooth (RMS˜60 nm). Study by spectrophotometer reveals that the as-grown films are highly transparent in the visible and IR spectra (T ˜ 88%), and that the bandgap is slightly narrowed (3.17 eV). Electrical measurements confirm the enhancement of conductivity, ? < 1 ? cm, due to indium incorporation into the starting solution. An electron concentration of 1017 cm-3 and a mobility of 3 cm2/Vs are found for IZO films grown at 400 °C. The photoluminescence analysis demonstrates strong yellow (2.1 eV) and blue (2.8 eV) light and weak green (2.3 eV) emissions.

  12. Improving electrical performance of ultrasonic spray pyrolysis grown textured ZnO films by introducing In2O3:W interface layer

    NASA Astrophysics Data System (ADS)

    Jiao, Bao-chen; Zhang, Xiao-dan; Wei, Chang-chun; Huang, Qian; Chen, Xin-liang; Zhao, Ying

    2013-08-01

    The main focus of this paper was the improvement in the Hall mobility of ZnO films prepared by ultrasonic spray pyrolysis. In order to achieve low resistivity and high transparency simultaneously, we used the tungsten doped In2O3 (IWO) deposited by electron beam evaporation as interface layer to prepare IWO/ZnO films. Hall mobility can be improved to close to 50 cm2 V-1 s-1, and the resistivity kept as low as 1.48 × 10-3 ? cm, while the transparency of the IWO/ZnO was about 80% in the range of 400-2000 nm (including glass) at the same time. X-ray diffraction and scanning electron microscope measurements were used to investigate the structure properties and surface morphologies of the ZnO and IWO/ZnO films. Secondary ion mass spectrometry measurement revealed that the indium and tungsten can diffuse from the IWO layer into the following deposited ZnO layer. The oxygen interstitial of the ZnO layer can be decreased by the tungsten diffusing from the IWO layer, and this was the main reason of the higher Hall mobility. Atom force microscopy measurement indicated the IWO/ZnO films with high value texture.

  13. Influence of Sn doping level on antibacterial activity and certain physical properties of ZnO films deposited using a simplified spray pyrolysis technique

    NASA Astrophysics Data System (ADS)

    Vasanthi, M.; Ravichandran, K.; Jabena Begum, N.; Muruganantham, G.; Snega, S.; Panneerselvam, A.; Kavitha, P.

    2013-03-01

    Nanocrystalline tin-doped zinc oxide (ZnO:Sn) films with different Sn doping levels (0, 2, 4, … , 10 at.%) were fabricated using a simplified spray pyrolysis technique. All the deposited films were characterized in order to explore the influence of Sn doping level on antibacterial and certain physical properties. The XRD studies revealed that all the films exhibited preferential orientation along the (0 0 2) plane irrespective of the Sn doping level. The electrical sheet resistance (Rsh) sharply decreases with the increase in the Sn doping level and attain a minimum value (3.88 × 102 ?/?) at 6 at.% and then increases for further doping. The reason for this observed variation in the Rsh value is discussed in detail. The optical studies showed that all the films exhibited good transparency (?85%) in the visible region. The obtained photoluminescence (PL) spectra endorsed the good crystalline quality of the films and enhancement of the optical band gap (Eg) caused by Sn doping. From the SEM images, it is inferred that the incorporation of Sn has the tendency of repairing the porous structure of ZnO films. The antibacterial activity of ZnO:Sn films was found to be enhanced with the increase in Sn incorporation into the ZnO lattice.

  14. Third harmonic generation in undoped and X doped ZnO films (X: Ce, F, Er, Al, Sn) deposited by spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Sofiani, Zouhair; Sahraoui, Bouchta; Addou, Mohammed; Adhiri, Rahma; Lamrani, Mehdi Alaoui; Dghoughi, Leila; Fellahi, Nabil; Derkowska, Beata; Bala, Waclaw

    2007-03-01

    There is a current interest in research of wide band gap semiconductor materials for the purposes of third order nonlinear optical properties in view of optoelectronics applications. Materials for nonlinear optics should present important changes of nonlinear intensity, dependence on changes of nonlinear refractive index, short response time, and weak absorption losses. We report the results of the third order nonlinear optical susceptibilities of undoped and doped (cerium, fluorine, erbium, aluminum, and tin) zinc oxide films using the third harmonic generation technique at 1064 nm wavelength region in picoseconds regime. Thin films were grown on glass substrate by the spray pyrolysis technique at different temperatures of substrates and characterized by using the x-ray diffraction, scanning electron microscope, transmission, and photoluminescence. A strong third harmonic signal was obtained from the studied films with a good crystallinity and roughness. We have found that at high conductivity, there is a big conversion of the third harmonic signal at different dopants and at an appropriate concentration. We might say that the morphology and the crystalline quality of the films are the main factors for this high conversion.

  15. Photoelectrochemical performances of n-CdS{sub 1-x}Se{sub x} thin films prepared by spray pyrolysis technique

    SciTech Connect

    Yadav, A.A.; Masumdar, E.U. [Thin Film Physics Laboratory, Department of Physics, Electronics and Photonics, Rajarshi Shahu Mahavidyalaya, Latur-413 512, Maharashtra (India)

    2010-08-15

    The CdS{sub 1-x}Se{sub x} (0.0 {<=} x {<=} 1.0) thin films of various compositions have been deposited onto the amorphous and FTO coated glass substrates using a spray pyrolysis technique. An electrode/electrolyte interface has been formed between an n-type CdS{sub 1-x}Se{sub x} (0.0 {<=} x {<=} 1.0) alloyed/mixed type semiconductor and a sulphide/polysulphide redox electrolyte and investigated through the current-voltage, capacitance-voltage and photovoltaic power output characteristics. The dependence of the dark current through the junction and the junction capacitance on the voltage across the junction have been examined and analysed. Upon illumination of the interface with a light of 20 mW/cm{sup 2}, an open-circuit voltage of the order of 335 mV and a short-circuit current of 1.02 mA/cm{sup 2} have been developed (for x = 0.8), which results in energy conversion efficiency and fill factor 0.79% and 0.46% respectively. The magnitudes of the barrier heights at the interfaces have been determined. The significant electrochemical properties have been observed for a cell with electrode composition x = 0.8. (author)

  16. Preparation and characterization of indium doped CdS{sub 0.2}Se{sub 0.8} thin films by spray pyrolysis

    SciTech Connect

    Yadav, A.A., E-mail: aay_physics@yahoo.co.in [Thin Film Physics Laboratory, Department of Physics, Electronics and Photonics, Rajarshi Shahu Mahavidyalaya, Latur 413512, Maharashtra (India); Masumdar, E.U. [Thin Film Physics Laboratory, Department of Physics, Electronics and Photonics, Rajarshi Shahu Mahavidyalaya, Latur 413512, Maharashtra (India)] [Thin Film Physics Laboratory, Department of Physics, Electronics and Photonics, Rajarshi Shahu Mahavidyalaya, Latur 413512, Maharashtra (India)

    2010-10-15

    The CdS{sub 0.2}Se{sub 0.8} and indium doped CdS{sub 0.2}Se{sub 0.8} thin films have been deposited onto the amorphous glass and fluorine doped tin oxide coated glass substrates by spray pyrolysis. The doping concentration of indium has been optimized by photoelectrochemical characterization technique. The structural, surface morphological, optical and electrical properties of CdS{sub 0.2}Se{sub 0.8} and indium doped CdS{sub 0.2}Se{sub 0.8} thin films have been studied. X-ray diffraction studies reveal that the films are polycrystalline in nature with hexagonal crystal structure. Scanning electron microscopy studies reveal that the grains are uniform with uneven spherically shaped, distributed over the entire substrate surface. The complete surface morphology has been changed after doping. In optical studies, the transition of the deposited films is found to be direct allowed with optical energy gaps decreasing from 1.91 to 1.67 eV with indium doping. Semiconducting behavior has been observed from resistivity measurements. The thermoelectric power measurements reveal that the films exhibit n-type conductivity.

  17. Physical properties of Zn doped TiO2 thin films with spray pyrolysis technique and its effects in antibacterial activity.

    PubMed

    Arunachalam, A; Dhanapandian, S; Manoharan, C; Sivakumar, G

    2015-03-01

    Zinc doped Titanium dioxide (TiO2: Zn) thin films were deposited onto glass substrates by the spray pyrolysis technique with the substrate temperature 450°C. The structural, optical, photoluminescence (PL) properties and morphological studies were investigated for the films deposited with various doping concentration (0, 2, 4, 6 and 8at.%) of zinc. The results of X-ray diffraction (XRD) had shown the presence of anatase peak with a strong orientation along (101) plane at 8at.% of Zn-doped TiO2 film. Scanning electron microscopy (SEM) study showed the uniform distribution of grains with porous nature. Atomic force microscopy (AFM) observations indicated the tetragonal shape at 8at.% of Zn-doped TiO2 with the particle size and decrease in surface roughness. The emission at 398nm was observed at the 8at.% of Zn-doped TiO2 thin film. The carrier concentration and Hall mobility was increased with doping. The antibacterial activity was highly yielded for the Zn-doped TiO2 thin films. PMID:25479105

  18. Spray pyrolysis of tin selenide thin-film semiconductors: the effect of selenium concentration on the properties of the thin films

    NASA Astrophysics Data System (ADS)

    Fadavieslam, M. R.; Bagheri-Mohagheghi, M. M.

    2013-08-01

    Thin films of tin selenide (SnxSey) with an atomic ratio of , 1 and 1.5 were prepared on a glass substrate at T = 470°C using a spray pyrolysis technique. The initial materials for the preparation of the thin films were an alcoholic solution consisting of tin chloride (SnCl4· 5H2O) and selenide acide (H2SeO3). The prepared thin films were characterized by X-ray diffraction (XRD), scanning electron microscopy, scanning tunneling microscopy, scanning helium ion microscopy, and UV-vis spectroscopy. The photoconductivity and thermoelectric effects of the SnxSey thin films were then studied. The SnxSey thin films had a polycrystalline structure with an almost uniform surface and cluster type growth. The increasing atomic ratio of r in the films, the optical gap, photosensitivity and Seebeck coefficient were changed from 1.6 to 1.37 eV, 0.01 to 0.31 and -26.2 to -42.7 mV/K (at T = 350 K), respectively. In addition, the XRD patterns indicated intensity peaks in r = 1 that corresponded to the increase in the SnSe and SnSe2 phases.

  19. Effect of substrate temperature on optical, structural and electrical properties of FeSe thin films deposited by spray pyrolysis technique

    NASA Astrophysics Data System (ADS)

    Ubale, A. U.; Sakhare, Y. S.

    2013-10-01

    The versatile spray pyrolysis technique was employed to prepare thin films of iron selenide on glass substrates at different substrate temperatures. The deposition temperature was varied between 473 and 673 K. The as-deposited films were characterized by X-ray diffraction (XRD), SEM, optical and electrical characterization techniques. The X-ray studies reveal that the films are nanocrystalline with tetragonal structure and exhibit (101) preferred orientation. The SEM and AFM studies indicate that the film surface is homogenous with no cracks or pinholes and well covers the glass substrate. The film thickness was found to vary from 110 to 230 nm with substrate temperature. The optical band gap was found to decrease from 2.92 to 2.68 eV depending on deposition temperature. The resistivity of p-type FeSe film is of the order of 8×104 ? cm and it decreases to 1.5×104 ? cm as substrate temperature is increased from 473 K to 673 K.

  20. Colloidal spray method for low cost thin coating deposition

    DOEpatents

    Pham, Ai-Quoc; Glass, Robert S.; Lee, Tae H.

    2005-01-25

    A dense or porous coating of material is deposited onto a substrate by forcing a colloidal suspension through an ultrasonic nebulizer and spraying a fine mist of particles in a carrier medium onto a sufficiently heated substrate. The spraying rate is essentially matched to the evaporation rate of the carrier liquid from the substrate to produce a coating that is uniformly distributed over the surface of the substrate. Following deposition to a sufficient coating thickness, a single sintering step may be used to produce a dense ceramic coating. Using this method, coatings ranging in thickness from about one to several hundred microns can be obtained. By using a plurality of compounds in the colloidal suspension, coatings of mixed composition can be obtained. By using a plurality of solutions and separate pumps and a single or multiple ultrasonic nebulizer(s), and varying the individual pumping rates and/or the concentrations of the solutions, a coating of mixed and discontinuously graded (e.g., stepped) or continuously graded layers may be obtained. This method is particularly useful for depositing ceramic coatings. Dense ceramic coating materials on porous substrates are useful in providing improved electrode performance in devices such as high power density solid oxide fuel cells. Dense ceramic coatings obtained by the invention are also useful for gas turbine blade coatings, sensors, steam electrolyzers, etc. The invention has general use in preparation of systems requiring durable and chemically resistant coatings, or coatings having other specific chemical or physical properties.

  1. Colloidal spray method for low cost thin coating deposition

    DOEpatents

    Pham, Ai-Quoc (San Jose, CA); Glass, Robert S. (Livermore, CA); Lee, Tae H. (Naperville, IL)

    2002-01-01

    A dense or porous coating of material is deposited onto a substrate by forcing a colloidal suspension through an ultrasonic nebulizer and spraying a fine mist of particles in a carrier medium onto a sufficiently heated substrate. The spraying rate is essentially matched to the evaporation rate of the carrier liquid from the substrate to produce a coating that is uniformly distributed over the surface of the substrate. Following deposition to a sufficient coating thickness, a single sintering step may be used to produce a dense ceramic coating. Using this method, coatings ranging in thickness from about one to several hundred microns can be obtained. By using a plurality of compounds in the colloidal suspension, coatings of mixed composition can be obtained. By using a plurality of solutions and separate pumps and a single or multiple ultrasonic nebulizer(s), and varying the individual pumping rates and/or the concentrations of the solutions, a coating of mixed and discontinuously graded (e.g., stepped) or continuously graded layers may be obtained. This method is particularly useful for depositing ceramic coatings. Dense ceramic coating materials on porous substrates are useful in providing improved electrode performance in devices such as high power density solid oxide fuel cells. Dense ceramic coatings obtained by the invention are also useful for gas turbine blade coatings, sensors, steam electrolyzers, etc. The invention has general use in preparation of systems requiring durable and chemically resistant coatings, or coatings having other specific chemical or physical properties.

  2. Fabrication of antimony doped tin oxide (ATO) films by an inexpensive, simplified spray technique using perfume atomizer

    Microsoft Academic Search

    K. Ravichandran; P. Philominathan

    2008-01-01

    By employing a simplified version of spray technique using perfume atomizer, antimony doped tin oxide (ATO) films were fabricated. The structural, electrical and optical properties of the ATO films prepared by this technique were studied and compared with that of the films grown by the conventional spray pyrolysis method using carrier gas. The preferred orientation of the ATO films was

  3. Spray automated balancing of rotors: Methods and materials

    NASA Technical Reports Server (NTRS)

    Smalley, Anthony J.; Baldwin, Richard M.; Schick, Wilbur R.

    1988-01-01

    The work described consists of two parts. In the first part, a survey is performed to assess the state of the art in rotor balancing technology as it applies to Army gas turbine engines and associated power transmission hardware. The second part evaluates thermal spray processes for balancing weight addition in an automated balancing procedure. The industry survey reveals that: (1) computerized balancing equipment is valuable to reduce errors, improve balance quality, and provide documentation; (2) slow-speed balancing is used exclusively, with no forseeable need for production high-speed balancing; (3) automated procedures are desired; and (4) thermal spray balancing is viewed with cautious optimism whereas laser balancing is viewed with concern for flight propulsion hardware. The FARE method (Fuel/Air Repetitive Explosion) was selected for experimental evaluation of bond strength and fatigue strength. Material combinations tested were tungsten carbide on stainless steel (17-4), Inconel 718 on Inconel 718, and Triballoy 800 on Inconel 718. Bond strengths were entirely adequate for use in balancing. Material combinations have been identified for use in hot and cold sections of an engine, with fatigue strengths equivalent to those for hand-ground materials.

  4. ZnO and Al-doped ZnO thin films prepared by spray pyrolysis for ethanol gas sensing

    NASA Astrophysics Data System (ADS)

    Bakha, Y.; Bendimerad, K. M.; Hamzaoui, S.

    2011-09-01

    Chemically sprayed aluminum-doped ZnO (1% Al) and undoped ZnO thin films were deposited on glass substrates at T = 420 °C. The thin films are characterized by X-ray diffraction and scanning electron microscopy. The characterization results show that all the compounds are wurtzite with hexagonal structure (0 0 2). They are well crystallized and the grain size is (e = 0.1 ?m) for undoped ZnO and (e = 0.13 ?m) for Al-doped ZnO. The prepared Al-doped ZnO showed good gas responses to ethanol for two concentrations 200 ppm and 400 ppm. Short response time is given by Al-doped ZnO comparing with undoped ZnO films, its estimate at (~10 s) and recovery time (~15 s) to 200 ppm at T = 220 °C.

  5. Numerical modeling of spray combustion with an advanced VOF method

    NASA Technical Reports Server (NTRS)

    Chen, Yen-Sen; Shang, Huan-Min; Shih, Ming-Hsin; Liaw, Paul

    1995-01-01

    This paper summarizes the technical development and validation of a multiphase computational fluid dynamics (CFD) numerical method using the volume-of-fluid (VOF) model and a Lagrangian tracking model which can be employed to analyze general multiphase flow problems with free surface mechanism. The gas-liquid interface mass, momentum and energy conservation relationships are modeled by continuum surface mechanisms. A new solution method is developed such that the present VOF model can be applied for all-speed flow regimes. The objectives of the present study are to develop and verify the fractional volume-of-fluid cell partitioning approach into a predictor-corrector algorithm and to demonstrate the effectiveness of the present approach by simulating benchmark problems including laminar impinging jets, shear coaxial jet atomization and shear coaxial spray combustion flows.

  6. Facile synthesis of antimony-doped tin oxide nanoparticles by a polymer-pyrolysis method

    SciTech Connect

    Li, Yuan-Qing, E-mail: yqli@mail.ipc.ac.cn [School of Materials Science and Engineering, Shijiazhuang Railway Institute, Shijiazhuang 050043 (China)] [School of Materials Science and Engineering, Shijiazhuang Railway Institute, Shijiazhuang 050043 (China); Wang, Jian-Lei [School of Materials Science and Engineering, Shijiazhuang Railway Institute, Shijiazhuang 050043 (China)] [School of Materials Science and Engineering, Shijiazhuang Railway Institute, Shijiazhuang 050043 (China); Fu, Shao-Yun, E-mail: syfu@mail.ipc.ac.cn [Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190 (China)] [Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Mei, Shi-Gang; Zhang, Jian-Min; Yong, Kang [School of Materials Science and Engineering, Shijiazhuang Railway Institute, Shijiazhuang 050043 (China)] [School of Materials Science and Engineering, Shijiazhuang Railway Institute, Shijiazhuang 050043 (China)

    2010-06-15

    In this article, antimony-doped tin oxide (ATO) nanoparticles was synthesized by a facile polymer-pyrolysis method. The pyrolysis behaviors of the polymer precursors prepared via in situ polymerization of metal salts and acrylic acid were analyzed by simultaneous thermogravimetric and differential scanning calorimetry (TG-DSC). The structural and morphological characteristics of the products were studied by powder X-ray diffraction (XRD) and transmission electron microscope (TEM). The results reveal that the ATO nanoparticles calcined at 600 {sup o}C show good crystallinity with the cassiterite structure and cubic-spherical like morphology. The average particle size of ATO decreases from 200 to 15 nm as the Sb doping content increases from 5 mol% to 15 mol%. Electrical resistivity measurement shows that the resistivity for the 10-13 mol% Sb-doped SnO{sub 2} nanoparticles is reduced by more than three orders compared with the pure SnO{sub 2} nanoparticles. In addition, due to its versatility this polymer-pyrolysis method can be extended to facile synthesis of other doped n-type semiconductor, such as In, Ga, Al doped ZnO, Sn doped In{sub 2}O{sub 3}.

  7. Molecular characterization and comparison of shale oils generated by different pyrolysis methods

    USGS Publications Warehouse

    Birdwell, Justin E.; Jin, Jang Mi; Kim, Sunghwan

    2012-01-01

    Shale oils generated using different laboratory pyrolysis methods have been studied using standard oil characterization methods as well as Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) with electrospray ionization (ESI) and atmospheric photoionization (APPI) to assess differences in molecular composition. The pyrolysis oils were generated from samples of the Mahogany zone oil shale of the Eocene Green River Formation collected from outcrops in the Piceance Basin, Colorado, using three pyrolysis systems under conditions relevant to surface and in situ retorting approaches. Significant variations were observed in the shale oils, particularly the degree of conjugation of the constituent molecules and the distribution of nitrogen-containing compound classes. Comparison of FT-ICR MS results to other oil characteristics, such as specific gravity; saturate, aromatic, resin, asphaltene (SARA) distribution; and carbon number distribution determined by gas chromatography, indicated correspondence between higher average double bond equivalence (DBE) values and increasing asphaltene content. The results show that, based on the shale oil DBE distributions, highly conjugated species are enriched in samples produced under low pressure, high temperature conditions, and under high pressure, moderate temperature conditions in the presence of water. We also report, for the first time in any petroleum-like substance, the presence of N4 class compounds based on FT-ICR MS data. Using double bond equivalence and carbon number distributions, structures for the N4 class and other nitrogen-containing compounds are proposed.

  8. Cu doping: An effective method for improving optoelectronic properties of sprayed SnS thin films

    NASA Astrophysics Data System (ADS)

    Ninan, Gisa Grace; Rajeshmon, V. G.; Kartha, C. Sudha; Vijayakumar, K. P.

    2014-04-01

    SnS thin films were deposited using Chemical Spray Pyrolysis (CSP) technique at a substrate temperature of 415 °C. Resistivity of pristine SnS thin film was 120 ?.cm. In order to decrease resistivity, in-situ copper doping was done and its effects on the structural, optical and electrical properties were studied. Percentage of Cu was varied as 2%, 4%, 6%, 8% and 10% of tin in the precursor solution. Resistivity decreased with minimum resistivity of 1.6 ?.cm for the sample doped with 6% copper. Beyond 6 % doping, resistivity increased. All the films were n type irrespective of doping.

  9. Spray-spinning: a novel method for making alginate\\/chitosan fibrous scaffold

    Microsoft Academic Search

    Jian-Zheng Wang; Xiao-Bo Huang; Jing Xiao; Nan Li; Wei-Ting Yu; Wei Wang; Wei-Yang Xie; Xiao-Jun Ma; Ying-Li Teng

    2010-01-01

    The subject of our investigations was the process of obtaining alginate\\/chitosan polyelectrolyte complex (PEC) fibers. In\\u000a this study, a novel method named “spray-spinning” was developed for the making of these hybrid fibers. In spray-spinning,\\u000a a chitosan solution was sprayed into a flowing sodium alginate solution and sheared into streamlines. The elongated streamlines\\u000a subsequently transformed into alginate\\/chitosan PEC fibers. Average diameter

  10. Effect of substrate temperature and precursor ratio on properties of thin ZnS films sprayed by improved method

    NASA Astrophysics Data System (ADS)

    Zaware, Rangnath V.; Wagh, Bhiva G.

    2014-09-01

    Zinc sulphide (ZnS) thin films were prepared by improved spray pyrolysis (ISP) method. The ISP parameters, such as carrier gas flow rate, solution flow rate and substrate temperature, were controlled with an accuracy of ±0.25 lpm, ±1 ml/h and ±1 °C, respectively. The solution was sprayed in a pulsed mode. The substrate temperature was optimized by analyzing substrate temperature dependent properties of thin films. The thin film deposited at a temperature of 450 °C was dense and fairly smooth with satisfactory crystallinity and very small impurity content. The effect of precursor ratio in the solution on structural, compositional and optical properties of thin ZnS films, deposited at a temperature of 450 °C, was studied. A gradual increase in band gap energy from 3.524 eV to 3.634 eV, refractive index from 2.5 to 2.9 and dielectric constant from 6.6 to 8.7 were observed with the variation of solution precursor (Zn:S) ratio from (1:2) to (1:6). The structural and compositional studies support this kind of enhancement in optical properties. The results show that the thin ZnS film prepared by ISP at the substrate temperature of 450 °C from a solution with specific precursor ratio can be used for optoelectronic and photovoltaic applications.

  11. Preparation and electrical properties of Ga-doped ZnO nanoparticles by a polymer pyrolysis method

    Microsoft Academic Search

    Yuan-Qing Li; Kang Yong; Hong-Mei Xiao; Wang-Jing Ma; Guang-Lei Zhang; Shao-Yun Fu

    2010-01-01

    In this article, preparation of Ga-doped zinc oxide (GZO) nanoparticles by a polymer pyrolysis method is reported. The pyrolysis behaviors of the polymer precursors prepared via the in situ polymerization of metal salts and acrylic acid are analyzed using thermalgravity-differential scanning calorimetry (TG-DSC) techniques. Then, the structural characteristics of the products are studied by X-ray diffraction (XRD) and transmission electron

  12. Characterization of a Heterostructure TiO2/SnO2:F/SUBSTRATE with Two Different Geometries, Prepared by Spray Pyrolysis to BE Used as Photocatalyst

    NASA Astrophysics Data System (ADS)

    Velázquez-Cruz, E. I.; Anaya-Castillejos, K. M.; Martínez-Martínez, R.; Soto-Guzmán, A. B.; Falcony, C.

    2013-08-01

    Two TiO2/SnO2:F/substrate hetero-structures (HS) with different geometry were deposited by spray pyrolysis. The thickness for the TiO2 and SnO2:F films was 3.8 ?m and 2.3 ?m, and the band gap energy 3.3 eV and 3.6 eV, respectively. Both films have a transmittance greater than 70% in most of the visible spectrum. The electrical resistivity of the SnO2:F film was ? = (1.7)×10-4? ? cm. The surface morphology of the TiO2 film shows hemispheric agglomerates formed by nano-metric needle/platy shaped particles that give them a porous texture much like a "ball of wool," the length of the needles is from 100 nm and its thickness close to 20 nm. The geometry of HS has an important influence on its efficiency as photocatalyst under low-powered UV radiation. One of the geometry for this HS, in which the TiO2/SnO2:F interface is exposed, showed greater efficiency than the TiO2 and SnO2:F films separately, or than the common "sandwich" type HS geometry. Specifically, a decrease by 62% of the initial concentration of a watery solution of methylene blue (mb) of 20 ppm in approximately 5 h of UV radiation is observed for the exposed interface HS compared with less than 30% reduction observed for the common sandwich type HS.

  13. High-capacity cathodes for lithium-ion batteries from nanostructured LiFePO4 synthesized by highly-flexible and scalable flame spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Hamid, N. A.; Wennig, S.; Hardt, S.; Heinzel, A.; Schulz, C.; Wiggers, H.

    2012-10-01

    Olivine, LiFePO4 is a promising cathode material for lithium-ion batteries due to its low cost, environmental acceptability and high stability. Its low electric conductivity prevented it for a long time from being used in large-scale applications. Decreasing its particle size along with carbon coating significantly improves electronic conductivity and lithium diffusion. With respect to the controlled formation of very small particles with large specific surface, gas-phase synthesis opens an economic and flexible route towards high-quality battery materials. Amorphous FePO4 was synthesized as precursor material for LiFePO4 by flame spray pyrolysis of a solution of iron acetylacetonate and tributyl phosphate in toluene. The pristine FePO4 with a specific surface from 126-218 m2 g-1 was post-processed to LiFePO4/C composite material via a solid-state reaction using Li2CO3 and glucose. The final olivine LiFePO4/C particles still showed a large specific surface of 24 m2 g-1 and were characterized using X-ray diffraction (XRD), electron microscopy, X-ray photoelectron spectrocopy (XPS) and elemental analysis. Electrochemical investigations of the final LiFePO4/C composites show reversible capacities of more than 145 mAh g-1 (about 115 mAh g-1 with respect to the total coating mass). The material supports high drain rates at 16 C while delivering 40 mAh g-1 and causes excellent cycle stability.

  14. A study of the photoconductivity and thermoelectric properties of SnxSy optical semiconductor thin films deposited by the spray pyrolysis technique

    NASA Astrophysics Data System (ADS)

    Fadavieslam, M. R.; Shahtahmasebi, N.; Rezaee-Roknabadi, M.; Bagheri-Mohagheghi, M. M.

    2011-09-01

    In this paper, thin films of tin sulfide (SnxSy) with atomic ratios of y/x=0.25, 0.50, 0.75, 1.00, 1.25 and 1.50 have been prepared on a glass substrate at T=420 °C using the spray pyrolysis technique. The initial materials for the preparation of thin films were an alcoholic solution consisting of tin chloride (SnCl4.5H2O) and thiourea (CS(NH3)2). The prepared thin films were characterized by x-ray diffraction, scanning electron microscopy, energy dispersive x-ray analysis, scanning helium ion microscopy and UV-vis spectroscopy. The photoconductivity and thermoelectric effects of SnxSy thin films have been studied. The SnxSy thin films had a polycrystalline structure with a nearly uniform surface and cluster-type growth. With increasing the atomic ratio of (y/x) in films, the optical gap, photosensitivity, thermal activation energy and Seebeck coefficient changed from 2.72 to 2.37 eV, from 0.05 to 0.78, from 0.07 to 0.48 eV (in the high temperature range) and from +0.17 to -0.22 mV K-1 (at T=350 K), respectively. In addition, the structure of tin sulfide thin films tends to a nearly single-crystal state in (001) preferred orientation corresponding to SnS2 phase with increasing (y/x) ratio. These structure situations considerably influence the photosensitivity and thermoelectric properties of thin films.

  15. The electrical, optical, structural and thermoelectrical characterization of n- and p-type cobalt-doped SnO 2 transparent semiconducting films prepared by spray pyrolysis technique

    NASA Astrophysics Data System (ADS)

    Bagheri-Mohagheghi, Mohammad-Mehdi; Shokooh-Saremi, Mehrdad

    2010-10-01

    The electrical, optical and structural properties of Cobalt (Co) doped SnO 2 transparent semiconducting thin films, deposited by the spray pyrolysis technique, have been studied. The SnO 2:Co films, with different Co-content, were deposited on glass substrates using an aqueous-ethanol solution consisting of tin and cobalt chlorides. X-ray diffraction studies showed that the SnO 2:Co films were polycrystalline only with tin oxide phases and preferential orientations along (1 1 0) and (2 1 1) planes and grain sizes in the range 19-82 nm. Optical transmittance spectra of the films showed high transparency ?75-90% in the visible region, decreasing with increase in Co-doping. The optical absorption edge for undoped SnO 2 films was found to be 3.76 eV, while for higher Co-doped films shifted toward higher energies (shorter wavelengths) in the range 3.76-4.04 eV and then slowly decreased again to 4.03 eV. A change in sign of the Hall voltage and Seebeck coefficient was observed for a specific acceptor dopant level ?11.4 at% in film and interpreted as a conversion from n-type to p-type conductivity. The thermoelectric electro-motive force (e.m.f.) of the films was measured in the temperature range 300-500 K and Seebeck coefficients were found in the range from -62 to +499 ?VK -1 for various Co-doped SnO 2 films.

  16. Highly durable superhydrophobic coatings with gradient density by movable spray method

    NASA Astrophysics Data System (ADS)

    Tenjimbayashi, Mizuki; Shiratori, Seimei

    2014-09-01

    Superhydrophobic surface is expected to be applied in anti-fouling, anti-icing, and anti-bacterial. However, practical use is interrupted by low mechanical strength, time-consuming process, and limited coating substrate. Here highly durable superhydrophobic coatings were prepared by simple and novel spraying method, which sprays with changing the "spray distance between substrate and spray" (SD), named "movable spray method." We prepared the solution that changes wettability and durability with spraying distance by mixing SiO2 nanoparticles and ethyl alpha cyanoacrylate polymer (EAC). Then, we evaluated the chemical components and surface morphologies of each spraying distance coatings (0 ˜ 50 cm) by XPS, SEM, and laser scanning microscope. It revealed that surface roughness and SiO2/EAC ratio increased as the SD increases. Thus, durable superhydrophobic coatings were designed by spraying with increasing SD gradually. Glow discharge-optical emission spectrometry analysis revealed that designed coatings showed the gradual increase of SiO2/EAC ratio. As a result, coatings prepared on glass, wood, or aluminum substrates maintained their superhydrophobicity up to the abrasion at 40 kPa. This movable spray method is simple coating by the wet process and prepares robust hydrophobic coating on complex shape and large area substrates. The gradient functional surface was found to have mechanical durability and superhydrophobicity, and wide area applications will be expected.

  17. Systems and methods for coating conduit interior surfaces utilizing a thermal spray gun with extension arm

    DOEpatents

    Moore, Karen A.; Zatorski, Raymond A.

    2005-07-12

    Systems and methods for applying a coating to an interior surface of a conduit. In one embodiment, a spray gun configured to apply a coating is attached to an extension arm which may be inserted into the bore of a pipe. The spray gun may be a thermal spray gun adapted to apply a powder coating. An evacuation system may be used to provide a volume area of reduced air pressure for drawing overspray out of the pipe interior during coating. The extension arm as well as the spray gun may be cooled to maintain a consistent temperature in the system, allowing for more consistent coating.

  18. Methods for coating conduit interior surfaces utilizing a thermal spray gun with extension arm

    DOEpatents

    Moore, Karen A. (Idaho Falls, ID); Zatorski, Raymond A. (East Hampton, CT)

    2007-10-02

    Systems and methods for applying a coating to an interior surface of a conduit. In one embodiment, a spray gun configured to apply a coating is attached to an extension arm which may be inserted into the bore of a pipe. The spray gun may be a thermal spray gun adapted to apply a powder coating. An evacuation system may be used to provide a volume area of reduced air pressure for drawing overspray out of the pipe interior during coating. The extension arm as well as the spray gun may be cooled to maintain a consistent temperature in the system, allowing for more consistent coating.

  19. Method and apparatus for pyrolysis of atactic polypropylene

    DOEpatents

    Staffin, H. Kenneth (New Brunswick, NJ); Roaper, R. B. (Martinsville, NJ)

    1986-09-23

    This invention relates to an apparatus and a method for pyrolytic decomposition of polymeric materials into lower molecular weight products involving the heat treatment of raw polymeric material within reactive conduits submerged in a fluidized bed furnace operated at pyrolizing temperatures.

  20. Preparation and characterization of spray pyrolysed cobalt oxide thin films

    Microsoft Academic Search

    P. S. Patil; L. D. Kadam; C. D. Lokhande

    1996-01-01

    Cobalt oxide thin films were prepared by the spray pyrolysis method on amorphous glass substrates kept at 300 °C. The films formed were uniform, pin-hole free, and strongly adherent to the substrates. The X-ray diffraction studies revealed that the films consist of Co3O4 oxide phase. The optical and the electrical properties of the film were also studied.

  1. Method and apparatus for heat extraction by controlled spray cooling

    DOEpatents

    Edwards, Christopher Francis (5492 Lenore Ave., Livermore, Alameda County, CA 94550); Meeks, Ellen (304 Daisyfield Dr., Livermore, Alameda County, CA 94550); Kee, Robert (864 Lucille St., Livermore, Alameda County, CA 94550); McCarty, Kevin (304 Daisyfield Dr., Livermore, Alameda County, CA 94550)

    1999-01-01

    Two solutions to the problem of cooling a high temperature, high heat flux surface using controlled spray cooling are presented for use on a mandrel. In the first embodiment, spray cooling is used to provide a varying isothermal boundary layer on the side portions of a mandrel by providing that the spray can be moved axially along the mandrel. In the second embodiment, a spray of coolant is directed to the lower temperature surface of the mandrel. By taking advantage of super-Leidenfrost cooling, the temperature of the high temperature surface of the mandrel can be controlled by varying the mass flux rate of coolant droplets. The invention has particular applicability to the field of diamond synthesis using chemical vapor deposition techniques.

  2. Synthesis of Nanoporous Metal Oxide Particles by a New Inorganic Matrix Spray Pyrolysis Method

    E-print Network

    Zachariah, Michael R.

    for the formation of nanoporous particles in which a thermally stable, water-soluble, and therefore easily leached of relative humidity, temperature, and salt fractions. Specific surface area of the product particles for the remaining Al2O3 particles following aqueous leaching to remove the NaCl filler. Nanoporous particles could

  3. Physical Fundamentals of the Novel Method of Nanoparticles Production by Low Pressure Spray Pyrolysis

    NASA Astrophysics Data System (ADS)

    Fisenko, S. P.; Khodyko, J. A.; Penyazkov, O. G.; Saverchenko, V. I.

    2013-05-01

    Contributions of relevant heat and mass transfer processes and characteristic times in nanoparticles production during evaporation of droplet solution are discussed. Low-temperature transformation of aqueous solution of NiCl2 into nickel oxide nanoparticles is obtained. Classification of morphologies of obtained ensembles of nanoparticles is developed. Details of electrostatic deposition of droplets on metallic substrate are reported.

  4. On the physical properties of indium oxide thin films deposited by pyrosol in comparison with films deposited by pneumatic spray pyrolysis

    Microsoft Academic Search

    Mihaela Girtan; H Cachet; G. I Rusu

    2003-01-01

    This paper presents the structural, electrical and optical properties of indium oxide thin films deposited by (1) pyrosol technique in comparison with the results that were obtained by spraying the same solution using (2) a pneumatic spray system. Films were deposited at temperatures ranged between 623 and 863 K onto glass substrates and investigated by scanning electron microscopy and X-ray

  5. Production Characteristics of Liquid Ice by Solution Spraying Method

    NASA Astrophysics Data System (ADS)

    Horibe, Akihiko; Fukusako, Shoichiro; Yamada, Masahiko

    An experimental study has been performed to investigate the production characteristics of liquid ice as a new phase change material along horizontal cylinders immersed in a cold air stream with spraying droplets of propylene-glycol aqueous solution. The experiments were carried out under a variety of experimental parameters such as wind velocity, air temperature, and droplet mass flow rate. Both single lucite tube and three tubes, on which stainless steel foil of 50µm in thickness was wound, were utilized as icing cylinders. The formation of the ice layer along the cylinders were extensively observed. The weight of the liquid ice produced in the wind tunnel were measured. For the present experiments, it was found that the most suitable condition for producing the liquid ice might be in wind velocity Ua=6 m/s and air temperature =-120°C. In this condition, more than 90% of the sprayed aqueous solution could be collected as the liquid ice in the wind tunnel.

  6. Facile water-based spray pyrolysis of earth-abundant Cu2FeSnS4 thin films as an efficient counter electrode in dye-sensitized solar cells.

    PubMed

    Prabhakar, Rajiv Ramanujam; Huu Loc, Nguyen; Kumar, Mulmudi Hemant; Boix, Pablo P; Juan, Sun; John, Rohit Abraham; Batabyal, Sudip K; Wong, Lydia Helena

    2014-10-22

    A novel approach to produce earth-abundant Cu2FeSnS4 (CFTS) thin film using spray pyrolysis of nontoxic aqueous precursors followed by sulfurization is reported. The CFTS phase formation was confirmed by both Raman spectroscopy and X-ray diffraction techniques. Hall measurements of these films reveal p-type conductivity with good charge carrier density and mobilities appropriate for solar harvesting devices. To the best of our knowledge, this is the first report on the electrical properties of solution-processed Cu2FeSnS4 thin films estimated using Hall measurements. Dye-sensitized solar cells (DSSC) fabricated with CFTS thin film as a photocathode in iodine/iodide electrolyte exhibit good power conversion efficiency, 8.03%, indicating that CFTS would be a promising cheaper alternative to replace Pt as a counter electrode in DSSCs. PMID:25255739

  7. Nano spray drying: a novel method for preparing protein nanoparticles for protein therapy.

    PubMed

    Lee, Sie Huey; Heng, Desmond; Ng, Wai Kiong; Chan, Hak-Kim; Tan, Reginald B H

    2011-01-17

    There has been an increasing interest in the development of protein nanotherapeutics for diseases such as cancer, diabetes and asthma. Spray drying with prior micro mixing is commonly used to obtain these powders. However, the separation and collection of protein nanoparticles with conventional spray dryer setups has been known to be extremely challenging due to its typical low collection efficiency for fine particles less than 2?m. To date, there has been no feasible approach to produce these protein nanoparticles in a single step and with high yield (>70%). In this study, we explored the feasibility of the novel Nano Spray Dryer B-90 (equipped with a vibrating mesh spray technology and an electrostatic particle collector) for the production of bovine serum albumin (BSA) nanoparticles. A statistical experimental design method (Taguchi method based on three levels, five variables L(18) orthogonal array robust design) was implemented to study the effect of and optimize the experimental conditions of: (1) spray mesh size, (2) BSA solution concentration, (3) surfactant concentration, (4) drying air flow rate and (5) inlet temperature on: (1) size and (2) morphology (axial ratio). Particle size and morphology were predominantly influenced by the spray mesh size and surfactant concentration, respectively. The drying air flow rate and inlet temperature had minimal impact. Optimized production of smooth spherical nanoparticles (median size: 460±10nm, axial ratio: 1.03±0.00, span 1.03±0.03, yield: 72±4%) was achieved using the 4?m spray mesh at BSA concentration of 0.1% (w/v), surfactant concentration of 0.05% (w/v), drying flow rate of 150L/min and inlet temperature of 120°C. The Nano Spray Dryer B-90 thus offers a new, simple and alternative approach for the production of protein nanoparticles suited for a variety of drug delivery applications. PMID:20951781

  8. Antibody immobilization using pneumatic spray: comparison with the avidin-biotin bridge immobilization method.

    PubMed

    Figueroa, Jhon; Magaña, Sonia; Lim, Daniel V; Schlaf, Rudy

    2012-12-14

    The formation of a thin antibody film on a glass surface using pneumatic spray was investigated as a potential immobilization technique for capturing pathogenic targets. Goat-Escherichia coli O157:H7 IgG films were made by pneumatic spray and compared against the avidin-biotin bridge immobilized films by assaying with green fluorescent protein (GFP) transformed E. coli O157:H7 cells and fluorescent reporter antibodies. Functionality, stability, and immobilization of the films were tested. The pneumatic spray films had lower fluorescence intensity values than the avidin-biotin bridge films but resulted in similar detection for E. coli O157:H7 at 10(5)-10(7)cells/ml sample concentrations with no detection of non-E. coli O157:H7 strains. Both methods also resulted in similar percent capture efficiencies. The results demonstrated that immobilization of antibody via pneumatic spray did not render the antibody non-functional and produced stable antibody films. The amount of time necessary for immobilization of the antibody was reduced significantly from 24h for the avidin-biotin bridge to 7 min using the pneumatic spray technique, with additional benefits of greatly reduced use of materials and chemicals. The pneumatic spray technique promises to be an alternative for the immobilization of antibodies on glass slides for capturing pathogenic targets and use in biosensor type devices. PMID:22955211

  9. Investigation of two-fluid methods for Large Eddy Simulation of spray combustion in Gas Turbines

    E-print Network

    Investigation of two-fluid methods for Large Eddy Simulation of spray combustion in Gas Turbines of real combustion chamber: (1) a one-dimensional lam- inar JP10/air flame and (2) a non-reacting swirled the EL method well suited for gas turbine computations, but RANS with the EE approach may also be found

  10. DEVELOPMENT OF PROPOSED STANDARD TEST METHOD FOR SPRAY PAINTING TRANSFER EFFICIENCY. VOLUME 2. VERIFICATION PROGRAM

    EPA Science Inventory

    The two-volume report gives results of a program to develop and verify a standardized spray-painting transfer-efficiency test method. Both review of the literature and laboratory research were conducted. Transfer efficiency measurement methods presently used by industry were eval...

  11. DEVELOPMENT OF PROPOSED STANDARD TEST METHOD FOR SPRAY PAINTING TRANSFER EFFICIENCY. VOLUME 1. LABORATORY DEVELOPMENT

    EPA Science Inventory

    The two-volume report gives results of a program to develop and verify a standardized spray-painting transfer-efficiency test method. Both review of the literature and laboratory research were conducted. Transfer efficiency measurement methods presently used by industry were eval...

  12. Nanometer Sized Silver Particles Embedded Silica Particles-Spray Method.

    PubMed

    Gnana Kumar, G; Karunagaran, B; Nahm, Kee Suk; Nimma Elizabeth, R

    2009-01-01

    Spherical shaped, nanometer to micro meter sized silica particles were prepared in a homogeneous nature by spray technique. Silver nanoparticles were produced over the surface of the silica grains in a harmonized manner. The size of silver and silica particles was effectively controlled by the precursors and catalysts. The electrostatic repulsion among the silica spheres and the electro static attraction between silica spheres and silver particles make the synchronized structure of the synthesized particles and the morphological images are revealed by transmission electron microscope. The silver ions are reduced by sodium borohydride. Infra red spectroscopy and X-ray photoelectron spectroscopy analysis confirm the formation of silver-silica composite particles. Thermal stability of the prepared particles obtained from thermal analysis ensures its higher temperature applications. The resultant silver embedded silica particles can be easily suspended in diverse solvents and would be useful for variety of applications. PMID:20596511

  13. Method and system including a double rotary kiln pyrolysis or gasification of waste material

    DOEpatents

    McIntosh, M.J.; Arzoumanidis, G.G.

    1997-09-02

    A method is described for destructively distilling an organic material in particulate form wherein the particulates are introduced through an inlet into one end of an inner rotating kiln ganged to and coaxial with an outer rotating kiln. The inner and outer kilns define a cylindrical annular space with the inlet being positioned in registry with the axis of rotation of the ganged kilns. During operation, the temperature of the wall of the inner rotary kiln at the inlet is not less than about 500 C to heat the particulate material to a temperature in the range of from about 200 C to about 900 C in a pyrolyzing atmosphere to reduce the particulate material as it moves from the one end toward the other end. The reduced particulates including char are transferred to the annular space between the inner and the outer rotating kilns near the other end of the inner rotating kiln and moved longitudinally in the annular space from near the other end toward the one end in the presence of oxygen to combust the char at an elevated temperature to produce a waste material including ash. Also, heat is provided which is transferred to the inner kiln. The waste material including ash leaves the outer rotating kiln near the one end and the pyrolysis vapor leaves through the particulate material inlet. 5 figs.

  14. Method and system including a double rotary kiln pyrolysis or gasification of waste material

    DOEpatents

    McIntosh, Michael J. (Bolingbrook, IL); Arzoumanidis, Gregory G. (Naperville, IL)

    1997-01-01

    A method of destructively distilling an organic material in particulate form wherein the particulates are introduced through an inlet into one end of an inner rotating kiln ganged to and coaxial with an outer rotating kiln. The inner and outer kilns define a cylindrical annular space with the inlet being positioned in registry with the axis of rotation of the ganged kilns. During operation, the temperature of the wall of the inner rotary kiln at the inlet is not less than about 500.degree. C. to heat the particulate material to a temperature in the range of from about 200.degree. C. to about 900.degree. C. in a pyrolyzing atmosphere to reduce the particulate material as it moves from the one end toward the other end. The reduced particulates including char are transferred to the annular space between the inner and the outer rotating kilns near the other end of the inner rotating kiln and moved longitudinally in the annular space from near the other end toward the one end in the presence of oxygen to combust the char at an elevated temperature to produce a waste material including ash. Also, heat is provided which is transferred to the inner kiln. The waste material including ash leaves the outer rotating kiln near the one end and the pyrolysis vapor leaves through the particulate material inlet.

  15. Numerical simulation of spray coalescence in an Eulerian framework: Direct quadrature method of moments and multi-fluid method

    SciTech Connect

    Fox, R.O. [Department of Chemical and Biological Engineering, 2114 Sweeney Hall, Iowa State University, Ames, IA 50011-2230 (United States); Laurent, F. [Laboratoire d'Energetique Moleculaire et Macroscopique, Combustion, UPR CNRS 288 - Ecole Centrale Paris, Grande Voie des Vignes, 92295 Chatenay-Malabry (France)], E-mail: frederique.laurent@em2c.ecp.fr; Massot, M. [Laboratoire d'Energetique Moleculaire et Macroscopique, Combustion, UPR CNRS 288 - Ecole Centrale Paris, Grande Voie des Vignes, 92295 Chatenay-Malabry (France)

    2008-03-01

    The scope of the present study is Eulerian modeling and simulation of polydisperse liquid sprays undergoing droplet coalescence and evaporation. The fundamental mathematical description is the Williams spray equation governing the joint number density function f(v,u;x,t) of droplet volume and velocity. Eulerian multi-fluid models have already been rigorously derived from this equation in Laurent et al. [F. Laurent, M. Massot, P. Villedieu, Eulerian multi-fluid modeling for the numerical simulation of coalescence in polydisperse dense liquid sprays, J. Comput. Phys. 194 (2004) 505-543]. The first key feature of the paper is the application of direct quadrature method of moments (DQMOM) introduced by Marchisio and Fox [D.L. Marchisio, R.O. Fox, Solution of population balance equations using the direct quadrature method of moments, J. Aerosol Sci. 36 (2005) 43-73] to the Williams spray equation. Both the multi-fluid method and DQMOM yield systems of Eulerian conservation equations with complicated interaction terms representing coalescence. In order to focus on the difficulties associated with treating size-dependent coalescence and to avoid numerical uncertainty issues associated with two-way coupling, only one-way coupling between the droplets and a given gas velocity field is considered. In order to validate and compare these approaches, the chosen configuration is a self-similar 2D axisymmetrical decelerating nozzle with sprays having various size distributions, ranging from smooth ones up to Dirac delta functions. The second key feature of the paper is a thorough comparison of the two approaches for various test-cases to a reference solution obtained through a classical stochastic Lagrangian solver. Both Eulerian models prove to describe adequately spray coalescence and yield a very interesting alternative to the Lagrangian solver. The third key point of the study is a detailed description of the limitations associated with each method, thus giving criteria for their use as well as for their respective efficiency.

  16. Influence of Al, In, Cu, Fe and Sn dopants in the microstructure of zinc oxide thin films obtained by spray pyrolysis

    Microsoft Academic Search

    J. Morales; W. Estrada L; E. Andrade; M. Miki-Yoshida

    2000-01-01

    A spray pyrolytic system was used to obtain ZnO:X films doped with different elements, X=Al, In, Cu, Fe and Sn. A 0.1 M solution of zinc acetate in a mixture of ethanol and deionised water, in a volume proportion of 3:1, was employed. Dopant sources were aluminium chloride, indium acetate, copper acetate, iron chloride and tin tetrachloride. The atomic percentage

  17. Methods for detecting the mobility of trace elements during medium-temperature pyrolysis

    USGS Publications Warehouse

    Shiley, R.H.; Konopka, K.L.; Cahill, R.A.; Hinckley, C.C.; Smith, G.V.; Twardowska, H.; Saporoschenko, M.

    1983-01-01

    The mobility (volatility) of trace elements in coal during pyrolysis has been studied for distances of up to 40 cm between the coal and the trace element collector, which was graphite or a baffled solvent trap. Nineteen elements not previously recorded as mobile were detected. ?? 1983.

  18. Confined-Pyrolysis as an Experimental Method for Hydrothermal Organic Synthesis

    NASA Technical Reports Server (NTRS)

    Leif, Roald N.; Simoneit, Bernd R. T.

    1995-01-01

    A closed pyrolysis system has been developed as a tool for studying the reactions of organic compounds under extreme hydrothermal conditions. Small high pressure stainless steel vessels in which the ratio of sediment or sample to water has been adjusted to eliminate the headspace at peak experimental conditions confines the organic components to the bulk solid matrix and eliminates the partitioning of the organic compounds away from the inorganic components during the experiment. Confined pyrolysis experiments were performed to simulate thermally driven catagenetic changes in sedimentary organic matter using a solids to water ratio of 3.4 to 1. The extent of alteration was measured by monitoring the steroid and triterpenoid biomarkers and polycyclic aromatic hydrocarbon distributions. These pyrolysis experiments duplicated the hydrothermal transformations observed in nature. Molecular probe experiments using alkadienes, alkenes and alkanes in H2O and D2O elucidated the isomerization and hydrogenation reactions of aliphatic and the competing oxidative reactions occurring under hydrothermal conditions. This confined pyrolysis technique is being applied to test experiments on organic synthesis of relevance to chemical evolution for the origin of life.

  19. High temperature fatigue deformation behaviors of thermally sprayed steel measured with electronic speckle pattern interferometry method

    SciTech Connect

    Wang, Rongguang; Kido, Mitsuo

    2003-07-14

    High temperature fatigue (R=0) damage and deformation behaviors of SUS304 steel thermally sprayed with Al{sub 2}O{sub 3}/NiCr coating were investigated using an electronic speckle pattern interferometry (ESPI) method. Surface cracks and delamination occurred after 1x10{sup 5} cycles test when {sigma}{sub max} was 202 MPa at 873 K. The lengths and number of cracks and delamination largely decreased when {sigma}{sub max} or temperature decreased to 115 MPa or 573 K, respectively. Strain values along cracks measured with the ESPI method were much larger than other areas due to crack opening under the tensile load. The positions of strain concentration zones on strain distribution figures by ESPI method were well corresponded to those of cracks on sprayed coatings. Strain values decreased largely where local delamination occurred.

  20. Oxygen evolution electrocatalysis in alkaline medium at thin Mn xCo 3- xO4 (0 ? x ? 1) spinel films on glass / SnO 2: F prepared by spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Rios, E.; Chartier, P.; Gautier, J.-L.

    1999-07-01

    Films of a series of manganese-cobalt mixed valency spinel oxides of theoretical formula Mn xCo 3-xO 4, (x = 0; 0.25; 0.5; 0.75 and 1), have been prepared by spray pyrolysis at 150 °C on conductive glass in order to relate solid state and surface chemistry to electrocatalytical activity towards the oxygen evolution reaction (OER). X-ray diffraction (XRD) and IR spectroscopy characterized their bulk crystalline properties. Both techniques have confirmed that all oxides belong to the spinel family. Their surface properties were characterized by XPS yielding the Co 3+ / Co 2+ surface ratio. The kinetics of the OER was investigated in 1 M KOH by means of steady state current-potential curves, obtained in the potentiostatic mode and by reaction order determination. The order of reaction ranging from 1.0 to 1.2, and the Tafel slopes ranging from 67 to 69 mV dec -1 can be tentatively interpreted by a mechanism involving a Temkin type of electrosorption of OH intermediates associated with an electrochemical rate-determining step. Replacing progressively Co by Mn, the electrodes were increasingly electrocatalytically less active, surface Co 3+ ions being the active sites, and making Co 3O 4 the most active in the series.

  1. Study on Porosity of Plasma-Sprayed Coatings by Digital Image Analysis Method

    NASA Astrophysics Data System (ADS)

    Du, Hao; Lee, Soo Wohn; Shin, Jae Heyg

    2005-12-01

    The porosities of plasma-sprayed Al2O3, ZrO2, and TiO2 coatings deposited on 304 stainless steel plates were evaluated by the digital image analysis method. As the accuracy of this method depends significantly on metallographic preparation and metallography procedure for coating specimens, the effects of cross-surface roughness, magnification, and number of fields of view on the porosity were studied. The results indicate that the porosity value from polished specimen with cross-surface roughness no more than 0.1 µm is acceptable. The porosity value obtained at higher magnification is a little bit higher, especially when the real porosity is higher; more fields of view have to be considered in this case. Both experimental results and statistic analysis suggest that 15 fields of view at 1000× magnification can be implemented to evaluate porosity of plasma-sprayed coating considering both the domain size and the resolution at the same time.

  2. Effect of Al-doped on physical properties of ZnO Thin films grown by spray pyrolysis on SnO2: F/glass

    NASA Astrophysics Data System (ADS)

    Ajili, M.; Jebbari, N.; Kamoun Turki, N.; Castagné, M.

    2012-06-01

    Transparent conducting thin films of aluminum-doped zinc oxide (ZnO:Al) have been deposited on SnO2:F/glass by the chemical spray technique, starting from zinc acetate (CH3CO2)2Zn.2H2O and aluminum chloride AlCl3. The effect of changing the aluminum-to-zinc ratio y from 0 to 3 at.%, has been thoroughly investigated. It was found that the optical and electrical properties of Al doped ZnO films improved with the addition of aluminum in the spray solution until y=2%. At this Al doping percentage, the thin layers have a resistivity equal to 4.1 × 10-4 ?.cm and a transmittance of about 90 % in the region [600-1000] nm. XRD patterns confirm that the films have polycristalline nature and a wurtzite (hexagonal) structure which characterized with (100), (002) and (101) principal orientations. The undoped films have (002) as the preferred orientation but Al doped ones have (101) as the preferred orientation. Beyond y= 1%, peak intensities decrease considerably.

  3. Real-time evolved gas analysis by FTIR method: an experimental study of cellulose pyrolysis

    Microsoft Academic Search

    S Li; J Lyons-Hart; J Banyasz; K Shafer

    2001-01-01

    A two heating zone pyrolysis system capable of a heating rate of 40°C\\/s and a flow rate of 70ml\\/s was coupled to a rapid scanning Fourier transform infrared (FTIR) spectrometer. This fast evolved gas analysis system was applied to the study of the simultaneous evolution of low molecular weight gas phase products, such as CO, CO2, H2O, CH4, C2H4, and

  4. Method for the assessment of airborne off-target pesticide spray concentrations due to aircraft wing-tip vortex

    E-print Network

    Oliva, Sergio Eduardo

    2003-01-01

    The purpose of this thesis is to develop a method for assessing airborne concentrations caused by off-target pesticide drift. Concentrations are bounded by the worst credible circumstances within a normal aircraft pesticide spraying. It is assumed...

  5. NDE Methods for the External Tank Spray on Foam Insulation

    NASA Technical Reports Server (NTRS)

    Walker, James L.; Johnson, Kenneth L.; Santos, Fernando E.; Ussery, W. Warren

    2007-01-01

    The foam thermal protection system (TPS) of the space shuttle External Tank (ET) has provided some unique challenges to the nondestructive testing community. Three nondestructive evaluation methods have been developed to identify defects in the foam TPS of the ET. Terahertz imaging and backscatter radiography have been developed to identify voids in thick foam regions while shearography has been developed to identify shallow delaminations, shallow voids and crush damage in the foam. The basic theory of operation along with factors, determined from a series of designed experiments, affecting the results of these methods will be described. Results from both test panels and flight tank inspections will be provided, along with predicted probability of detection estimates to show the range in defect sizes and types that can be readily detected.

  6. Effect of solvent volume on the physical properties of aluminium doped nanocrystalline zinc oxide thin films deposited using a simplified spray pyrolysis technique

    NASA Astrophysics Data System (ADS)

    Jabena Begum, N.; Mohan, R.; Ravichandran, K.

    2013-01-01

    Aluminium doped zinc oxide (AZO) thin films were deposited by employing a low cost and simplified spray technique using a perfume atomizer from starting solutions having different volumes (10, 20, … , 50 mL) of solvent. The effect of solvent volume on the structural, electrical, optical, photoluminescence (PL) and surface morphological properties was studied. The electrical resistivity of the AZO films is remarkably influenced by the variation in the solvent volume. The X-ray diffraction profiles clearly showed that all the films have preferential orientation along the (0 0 2) plane irrespective of the solvent volume. The crystallite size was found to be in the nano range of 35-46 nm. The optical transmittance in the visible region is desirably high (>85%). The AFM images show columnar morphology with varying grain size. The PL studies revealed that the AZO film deposited from 50 mL of solvent volume has good quality with lesser defect density.

  7. Method and Process Development of Advanced Atmospheric Plasma Spraying for Thermal Barrier Coatings

    NASA Astrophysics Data System (ADS)

    Mihm, Sebastian; Duda, Thomas; Gruner, Heiko; Thomas, Georg; Dzur, Birger

    2012-06-01

    Over the last few years, global economic growth has triggered a dramatic increase in the demand for resources, resulting in steady rise in prices for energy and raw materials. In the gas turbine manufacturing sector, process optimizations of cost-intensive production steps involve a heightened potential of savings and form the basis for securing future competitive advantages in the market. In this context, the atmospheric plasma spraying (APS) process for thermal barrier coatings (TBC) has been optimized. A constraint for the optimization of the APS coating process is the use of the existing coating equipment. Furthermore, the current coating quality and characteristics must not change so as to avoid new qualification and testing. Using experience in APS and empirically gained data, the process optimization plan included the variation of e.g. the plasma gas composition and flow-rate, the electrical power, the arrangement and angle of the powder injectors in relation to the plasma jet, the grain size distribution of the spray powder and the plasma torch movement procedures such as spray distance, offset and iteration. In particular, plasma properties (enthalpy, velocity and temperature), powder injection conditions (injection point, injection speed, grain size and distribution) and the coating lamination (coating pattern and spraying distance) are examined. The optimized process and resulting coating were compared to the current situation using several diagnostic methods. The improved process significantly reduces costs and achieves the requirement of comparable coating quality. Furthermore, a contribution was made towards better comprehension of the APS of ceramics and the definition of a better method for future process developments.

  8. Pyrolysis process

    SciTech Connect

    Durai-swamy, K.

    1982-04-13

    In a process for recovery of values contained in solid carbonaceous material, a solid carbonaceous material is comminuted and then treated at an elevated temperature in a pretreatment zone with a first capping agent which is at treating conditions either a liquid or a gas. The treating conditions are such that the first capping agent is sorbed by the solid particulate carbonaceous material. The solid particulate carbonaceous material containing the sorbed first capping agent is then subjected to pyrolysis in the presence of a second capping agent, and preferably in the presence of a solid particulate source of heat and a transport gas in a transport flash pyrolysis reactor, to form a pyrolysis product stream. The solid particulate carbonaceous feed material is pyrolyzed and newly formed volatilized hydrocarbon free radicals are substantially simultaneously terminated by the sorbed first capping agent, or the second capping agent as such radicals are formed, to form a pyrolysis product stream. The pyrolysis product stream contains a gaseous mixture and particulate solids which are separated from the gaseous mixture to form a substantially particulate solids-free gaseous mixture stream which contains capping agent terminated volatilized hydrocarbon free radicals, hydrogen depleted capping agents, pyrolysis product vapors and a transport gas. Hydrocarbons of four or more carbon atoms in the gaseous mixture stream are condensed. A liquid stream containing the stabilized liquid product is then treated or separated into various fractions. A liquid containing the hydrogen depleted capping agents is hydrogenated to form regenerated capping agents, at least a portion of which is recycled to the pretreatment zone and at least another portion is recycled to the pyrolysis zone. In another embodiment the capping agents are produced by the process , separated from the liquid product mixture, and recycled.

  9. Effect of boric acid on the properties of Li{sub 2}MnO{sub 3}·LiNi{sub 0.5}Mn{sub 0.5}O{sub 2} composite cathode powders prepared by large-scale spray pyrolysis with droplet classifier

    SciTech Connect

    Hong, Young Jun; Choi, Seung Ho; Sim, Chul Min; Lee, Jung-Kul [Department of Chemical Engineering, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul 143-701 (Korea, Republic of)] [Department of Chemical Engineering, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul 143-701 (Korea, Republic of); Kang, Yun Chan, E-mail: yckang@konkuk.ac.kr [Department of Chemical Engineering, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul 143-701 (Korea, Republic of)

    2012-12-15

    Graphical abstract: Display Omitted Highlights: ? Spherical shape Li{sub 2}MnO{sub 3}·LiNi{sub 0.5}Mn{sub 0.5}O{sub 2} composite cathode powders are prepared by large-scale spray pyrolysis with droplet classifier. ? Boric acid improves the morphological and electrochemical properties of the composite cathode powders. ? The discharge capacity of the composite cathode powders decreases from 217 to 196 mAh g{sup ?1} by the 30th cycle. -- Abstract: Spherically shaped 0.3Li{sub 2}MnO{sub 3}·0.7LiNi{sub 0.5}Mn{sub 0.5}O{sub 2} composite cathode powders with filled morphology and narrow size distribution are prepared by large-scale spray pyrolysis. A droplet classification reduces the standard deviation of the size distribution of the composite cathode powders. Addition of boric acid improves the morphological properties of the product powders by forming a lithium borate glass material with low melting temperature. The optimum amount of boric acid dissolved in the spray solution is 0.8 wt% of the composite powders. The powders prepared from the spray solution with 0.8 wt% boric acid have a mixed layered crystal structure comprising Li{sub 2}MnO{sub 3} and LiNi{sub 0.5}Mn{sub 0.5}O{sub 2} phases, thus forming a composite compound. The initial charge and discharge capacities of the composite cathode powders prepared from the 0.8 wt% boric acid spray solution are 297 and 217 mAh g{sup ?1}, respectively. The discharge capacity of the powders decreases from 217 to 196 mAh g{sup ?1} by the 30th cycle, in which the capacity retention is 90%.

  10. Spray-spinning: a novel method for making alginate/chitosan fibrous scaffold.

    PubMed

    Wang, Jian-Zheng; Huang, Xiao-Bo; Xiao, Jing; Li, Nan; Yu, Wei-Ting; Wang, Wei; Xie, Wei-Yang; Ma, Xiao-Jun; Teng, Ying-Li

    2010-02-01

    The subject of our investigations was the process of obtaining alginate/chitosan polyelectrolyte complex (PEC) fibers. In this study, a novel method named "spray-spinning" was developed for the making of these hybrid fibers. In spray-spinning, a chitosan solution was sprayed into a flowing sodium alginate solution and sheared into streamlines. The elongated streamlines subsequently transformed into alginate/chitosan PEC fibers. Average diameter of the fibers increased with the increasing of chitosan concentration used in spinning. The fibers showed a high water-absorbability of about 45 folds of water to their dry weight and retained their integrity after incubation in Minimum Essential Medium (MEM) for up to 30 days. In vitro co-culture experiments indicated that the fibers could support the three-dimensional growth of HepG2 cells and did not display any cyto-toxicity. Moreover, in vivo implanting experiments indicated that the connective tissue cells infiltrated into the implanted fibrous scaffolds in 3 weeks after surgery. These results demonstrated the potential applications of the as-spun fibers in regenerative medicine and tissue engineering. PMID:19756966

  11. Pyrolysis process

    SciTech Connect

    Durai-swamy, K.

    1983-03-01

    In a process for recovery of values contained in solid carbonaceous material, the solid carbonaceous material is comminuted and then subjected to pyrolysis, in the presence of a solid particulate source of heat in a pyrolysis zone, to form a pyrolysis product stream. The pyrolysis product stream contains a gaseous mixture and particulate solids. The solids are separated from the gaseous mixture to form a substantially solids-free gaseous stream which comprises volatilized hydrocarbon free radicals newly formed by pyrolysis. The solid particulate source of heat is formed by oxidizing part of the separated particulate solids. Condensed stabilized hydrocarbons are obtained by quenching the gaseous mixture stream with a quench fluid which contains a capping agent for stabilizing and terminating newly formed volatilized hydrocarbon free radicals. The capping agent is partially depleted of hydrogen by the stabilization and termination reaction. Hydrocarbons of four or more carbon atoms in the gaseous mixture stream are condensed. A liquid stream containing the stabilized liquid product is then treated or separated into various fractions. A liquid containing the hydrogen depleted capping agent is hydrogenated to form a regenerated capping agent. At least a portion of the regenerated capping agent is recycled to the quench zone as the quench fluid. In another embodiment capping agent is produced by the process, separated from the liquid product mixture, and recycled.

  12. Preparation and Characterization of Celecoxib Dispersions in Soluplus®: Comparison of Spray Drying and Conventional Methods

    PubMed Central

    Homayouni, Alireza; Sadeghi, Fatemeh; Nokhodchi, Ali; Varshosaz, Jaleh; Afrasiabi Garekani, Hadi

    2015-01-01

    The present study deals with characterization of dispersions of a poorly water-soluble drug, celecoxib (CLX) in polyvinyl caprolactame–polyvinyl acetate–polyethylene glycol graft copolymer (Soluplus® (SOL)) prepared by different techniques. Dispersions of CLX in SOL at different ratios (2:1, 1:1, 1:2, 1:4 and 1:6) were prepared by spray drying, conventional solvent evaporation and melting methods. The solid states of samples were characterized using particle size measurements, optical and scanning electron microscopy, XRPD, DSC and FT-IR. The Gordon-Taylor equation was used to predict the Tg of samples and the possibility of interaction between CLX and SOL. The solubility and dissolution rate of all samples were determined. Stability of samples was studied at ambient conditions for a period of 12 months. DSC and XRPD analyses confirmed amorphous state of drug in samples. Surprisingly dispersions of CLX:SOL with the ratio of 2:1 and 1:1 showed slower dissolution rate than CLX while other samples showed higher dissolution rate. At 1:2 ratio the spray dried samples exhibited higher dissolution rate than corresponding samples prepared by other methods. However at higher SOL content (1:4 and 1:6), samples prepared by different methods showed similar dissolution profiles. The stability studies showed that there were no remarkable changes in the dissolution profiles and solid state of the drug after 12 months storage at ambient conditions. It was concluded that SOL was a proper carrier to enhance the dissolution rate of CLX. At high SOL ratios the method of preparation of dispersed samples had no effect on dissolution rate, whilst at low SOL content spray drying was more efficient method. PMID:25561910

  13. Chemical spray pyrolysis of Tl-Ba-Ca-Cu-O high-T(sub c) superconductors for high-field bitter magnets

    NASA Technical Reports Server (NTRS)

    Derochemont, L. Pierre; Zhang, John G.; Squillante, Michael R.; Hermann, A. M.; Duan, H. M.; Andrews, Robert J.; Kelliher, Warren C.

    1991-01-01

    The deposition of Tl-Ba-Ca-Cu-O thick films by spray pyrolyzing a Ba-Ca-Cu-O precursor film and diffusing thallium into the film to form the superconducting phase is examined. This approach was taken to reduce exposure to thallium and its health and safety hazards. The Tl-Ba-Ca-Cu-O system was selected because it has very attractive features which make it appealing to device and manufacturing engineering. Tl-Ba-Ca-Cu-O will accommodate a number of superconducting phases. This attribute makes it very forgiving to stoichiometric fluctuations in the bulk and film. It has excellent thermal and chemical stability, and appears to be relatively insensitive to chemical impurities. Oxygen is tightly bound into the systems, consequently there is no orthorhombic (conductor) to tetragonal (insulator) transition which would affect a component's lifetime. More significantly, the thallium based superconductors appear to have harder magnetic properties than the other high-Tc oxide ceramics. Estimates using magnetoresistance measurements indicate that at 77 K Tl2Ba2CaCu2O10 will have an upper critical field, H(sub c2) fo 26 Tesla for applied fields parallel to the c-axis and approximately 1000 Tesla for fields oriented in the a-b plane. Results to date have shown that superconducting films can be reproducibly deposited on 100 oriented MgO substrates. One film had a zero resistance temperature of 111.5 K. Furthermore, x ray diffraction analysis of the films showed preferential c-axis orientation parallel to the plane of the substrate. These results have now made it possible to consider the manufacture of a superconducting tape wire which can be configured into a topology useful for high-field magnet designs. The research which leads to the preparation of these films and plans for further development are reviewed.

  14. A novel preparation method for drug nanocrystals and characterization by ultrasonic spray-assisted electrostatic adsorption

    PubMed Central

    Gao, Bing; Wang, Jun; Wang, Dunju; Zhu, Ziqiang; Qiao, Zhiqiang; Yang, Guangcheng; Nie, Fude

    2013-01-01

    Purpose The purpose of this study was to develop a novel and continuous method for preparing a nanosized particle of drug crystals and to characterize its properties. Materials and methods A new apparatus was introduced to crystallize nanosized drug crystals of amitriptyline hydrochloride as a model drug. The samples were prepared in the pure state by ultrasonic spray, and elaborated deposition was completed via electrostatic adsorption. Scanning electron microscopy, X-ray powder diffraction, and atomic force microscopy were used to characterize the size of the particles; this was subsequently followed by differential scanning calorimetry. Results and discussion Nanoparticles of drug crystals were successfully prepared. The size of the drug crystals ranged from 20 nm to 400 nm; the particle size of amitriptyline hydrochloride was approximately 71 nm. The particles were spherical and rectangular in shape. Moreover, the melting point of the nanoparticles decreased from 198.2°C to 196.3°C when compared to raw particle crystals. Furthermore, the agglomeration effect was also attenuated as a result of electrostatic repulsion among each particle when absorbed, and depositing on the inner wall of the gathering unit occurred under the electrostatic effect. Conclusion Ultrasonic spray-assisted electrostatic adsorption is a very effective and continuous method to produce drug nanocrystals. This method can be applied to poorly water-soluble drugs, and it can also be a very effective alternative for industrial production. Once the working parameters are given, drug nanocrystals will be produced continuously. PMID:24143097

  15. Method and Apparatus for Thermal Spraying of Metal Coatings Using Pulsejet Resonant Pulsed Combustion

    NASA Technical Reports Server (NTRS)

    Paxson, Daniel E. (Inventor)

    2014-01-01

    An apparatus and method for thermal spraying a metal coating on a substrate is accomplished with a modified pulsejet and optionally an ejector to assist in preventing oxidation. Metal such as Aluminum or Magnesium may be used. A pulsejet is first initiated by applying fuel, air, and a spark. Metal is inserted continuously in a high volume of metal into a combustion chamber of the pulsejet. The combustion is thereafter controlled resonantly at high frequency and the metal is heated to a molten state. The metal is then transported from the combustion chamber into a tailpipe of said pulsejet and is expelled therefrom at high velocity and deposited on a target substrate.

  16. Study of surface cleaning methods and pyrolysis temperatures on nanostructured carbon films using x-ray photoelectron spectroscopy

    SciTech Connect

    Kerber, Pranita; Porter, Lisa M.; McCullough, Lynne A.; Kowalewski, Tomasz; Engelhard, Mark; Baer, Donald [Department of Materials Science and Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, Pennsylvania 15213 (United States); Chemistry Department, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, Pennsylvania 15213 (United States); Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99352 (United States)

    2012-11-15

    Nanostructured carbon (ns-C) films fabricated by stabilization and pyrolysis of diblock copolymers are of interest for a variety of electrical/electronic applications due to their chemical inertness, high-temperature insensitivity, very high surface area, and tunable electrical resistivity over a wide range [Kulkarni et al., Synth. Met. 159, 177 (2009)]. Because of their high porosity and associated high specific surface area, controlled surface cleaning studies are important for fabricating electronic devices from these films. In this study, quantification of surface composition and surface cleaning studies on ns-C films synthesized by carbonization of diblock copolymers of polyacrylonitrile-b-poly(n-butyl acrylate) at two different temperatures were carried out. X-ray photoelectron spectroscopy was used for elemental analysis and to determine the efficacy of various surface cleaning methods for ns-C films and to examine the polymer residues in the films. The in-situ surface cleaning methods included HF vapor treatment, vacuum annealing, and exposure to UV-ozone. Quantitative analysis of high-resolution XPS scans showed 11 at. % nitrogen was present in the films pyrolyzed at 600 Degree-Sign C, suggesting incomplete denitrogenation of the copolymer films. The nitrogen atomic concentration decreased significantly for films pyrolyzed at 900 Degree-Sign C confirming extensive denitrogenation at that temperature. Furthermore, quantitative analysis of nitrogen subpeaks indicated higher loss of nitrogen atoms residing at the edge of graphitic clusters relative to that of nitrogen atoms within the graphitic clusters, suggesting higher graphitization with increasing pyrolysis temperature. Of the surface cleaning methods investigated, in-situ annealing of the films at 300 Degree-Sign C for 40 min was found to be the most efficacious in removing adventitious carbon and oxygen impurities from the surface.

  17. Study of Surface Cleaning Methods and Pyrolysis Temperature on Nano-Structured Carbon Films using X-ray Photoelectron Spectroscopy

    SciTech Connect

    Kerber, Pranita B.; Porter, Lisa M.; McCullough, L. A.; Kowalewski, Tomasz; Engelhard, Mark H.; Baer, Donald R.

    2012-10-12

    Nanostructured carbon (ns-C) films fabricated by stabilization and pyrolysis of di-block copolymers are of interest for a variety of electrical/electronic applications due to their chemical inertness, high-temperature insensitivity, very high surface area, and tunable electrical resistivity over a wide range [Kulkarni et al., Synth. Met. 159, (2009) 177]. Because of their high porosity and associated high specific surface area, controlled surface cleaning studies are important for fabricating electronic devices from these films. In this study, quantification of surface composition and surface cleaning studies on ns-C films synthesized by carbonization of di-block copolymers of polyacrylonitrile-b-poly(n-butyl acrylate) (PAN-b-PBA) at two different temperatures were carried out. X-ray photoelectron spectroscopy was used for elemental analysis and to determine the efficacy of various surface cleaning methods for ns-C films and to examine the polymer residues in the films. The in-situ surface cleaning methods included: HF vapor treatment, vacuum annealing, and exposure to UV-ozone. Quantitative analysis of high-resolution XPS scans showed 11 at. % of nitrogen present in the films pyrolyzed at 600 °C, suggesting incomplete denitrogenation of the copolymer films. The nitrogen atomic concentration reduced significantly for films pyrolyzed at 900 °C confirming extensive denitrogenation at that temperature. Furthermore, quantitative analysis of nitrogen sub-peaks indicated higher loss of nitrogen atoms residing at the edge of graphitic clusters relative to that of nitrogen atoms within the graphitic cluster, suggesting higher graphitization with increasing pyrolysis temperature. Of the surface cleaning methods investigated, in-situ annealing of the films at 300 °C for 40 min was found to be the most efficacious in removing adventitious carbon and oxygen impurities from the surface.

  18. Molecular characterization and comparison of shale oils generated by different pyrolysis methods using FT-ICR mass spectrometry

    USGS Publications Warehouse

    Jin, J.M.; Kim, S.; Birdwell, J.E.

    2011-01-01

    Fourier transform ion cyclotron resonance mass spectrometry (FT ICR-MS) was applied in the analysis of shale oils generated using two different pyrolysis systems under laboratory conditions meant to simulate surface and in situ oil shale retorting. Significant variations were observed in the shale oils, particularly the degree of conjugation of the constituent molecules. Comparison of FT ICR-MS results to standard oil characterization methods (API gravity, SARA fractionation, gas chromatography-flame ionization detection) indicated correspondence between the average Double Bond Equivalence (DBE) and asphaltene content. The results show that, based on the average DBE values and DBE distributions of the shale oils examined, highly conjugated species are enriched in samples produced under low pressure, high temperature conditions and in the presence of water.

  19. Deposition of titanium nitride layers by electric arc - Reactive plasma spraying method

    NASA Astrophysics Data System (ADS)

    ?erban, Viorel-Aurel; Ro?u, Radu Alexandru; Bucur, Alexandra Ioana; Pascu, Doru Romulus

    2013-01-01

    Titanium nitride (TiN) is a ceramic material which possesses high mechanical properties, being often used in order to cover cutting tools, thus increasing their lifetime, and also for covering components which are working in corrosive environments. The paper presents the experimental results on deposition of titanium nitride coatings by a new combined method (reactive plasma spraying and electric arc thermal spraying). In this way the advantages of each method in part are combined, obtaining improved quality coatings in the same time achieving high productivity. Commercially pure titanium wire and C45 steel as substrate were used for experiments. X-ray diffraction analysis shows that the deposited coatings are composed of titanium nitride (TiN, Ti2N) and small amounts of Ti3O. The microstructure of the deposited layers, investigated both by optical and scanning electron microscopy, shows that the coatings are dense, compact, without cracks and with low porosity. Vickers microhardness of the coatings presents maximum values of 912 HV0.1. The corrosion tests in 3%NaCl solution show that the deposited layers have a high corrosion resistance compared to unalloyed steel substrate.

  20. A novel method for preparing proton exchange membrane fuel cell electrodes by the ultrasonic-spray technique

    NASA Astrophysics Data System (ADS)

    Millington, Ben; Whipple, Vincent; Pollet, Bruno G.

    2011-10-01

    A novel ultrasonic-spray method for preparing gas diffusion electrodes (GDEs) for proton exchange membrane fuel cell (PEMFC) is described. Platinum (Pt) loaded on Nafion®-bonded GDEs were prepared by the ultrasonic-spray method on various commercial woven and non-woven gas diffusion layers (GDLs) at several Pt loadings in the range of 0.40-0.05 mg cm-2. The ultrasonic-sprayed GDEs were tested and compared to commercial and hand-painted GDEs. It was found that the GDEs prepared by the ultrasonic-spray method exhibited better performances compared to those prepared by the hand-painting technique, especially at low Pt loadings. GDEs fabricated by the ultrasonic-spray method with a platinum loading of 0.05 mg cm-2 exhibited a peak power rating of 10.9 W mg-1 compared to 9.8 W mg-1 for hand-painted GDEs. For all experiments using various GDLs, Sigracet SGL 10BC exhibited the best performance with a peak power of 0.695 W cm-2.

  1. A composition joint PDF method for the modeling of spray flames

    NASA Technical Reports Server (NTRS)

    Raju, M. S.

    1995-01-01

    This viewgraph presentation discusses an extension of the probability density function (PDF) method to the modeling of spray flames to evaluate the limitations and capabilities of this method in the modeling of gas-turbine combustor flows. The comparisons show that the general features of the flowfield are correctly predicted by the present solution procedure. The present solution appears to provide a better representation of the temperature field, particularly, in the reverse-velocity zone. The overpredictions in the centerline velocity could be attributed to the following reasons: (1) the use of k-epsilon turbulence model is known to be less precise in highly swirling flows and (2) the swirl number used here is reported to be estimated rather than measured.

  2. Constrained Response Surface Optimisation and Taguchi Methods for Precisely Atomising Spraying Process

    NASA Astrophysics Data System (ADS)

    Luangpaiboon, P.; Suwankham, Y.; Homrossukon, S.

    2010-10-01

    This research presents a development of a design of experiment technique for quality improvement in automotive manufacturing industrial. The quality of interest is the colour shade, one of the key feature and exterior appearance for the vehicles. With low percentage of first time quality, the manufacturer has spent a lot of cost for repaired works as well as the longer production time. To permanently dissolve such problem, the precisely spraying condition should be optimized. Therefore, this work will apply the full factorial design, the multiple regression, the constrained response surface optimization methods or CRSOM, and Taguchi's method to investigate the significant factors and to determine the optimum factor level in order to improve the quality of paint shop. Firstly, 2? full factorial was employed to study the effect of five factors including the paint flow rate at robot setting, the paint levelling agent, the paint pigment, the additive slow solvent, and non volatile solid at spraying of atomizing spraying machine. The response values of colour shade at 15 and 45 degrees were measured using spectrophotometer. Then the regression models of colour shade at both degrees were developed from the significant factors affecting each response. Consequently, both regression models were placed into the form of linear programming to maximize the colour shade subjected to 3 main factors including the pigment, the additive solvent and the flow rate. Finally, Taguchi's method was applied to determine the proper level of key variable factors to achieve the mean value target of colour shade. The factor of non volatile solid was found to be one more additional factor at this stage. Consequently, the proper level of all factors from both experiment design methods were used to set a confirmation experiment. It was found that the colour shades, both visual at 15 and 45 angel of measurement degrees of spectrophotometer, were nearly closed to the target and the defective at quality gate was also reduced from 0.35 WDPV to 0.10 WDPV. This reveals that the objective of this research is met and this procedure can be used as quality improvement guidance for paint shop of automotive vehicle.

  3. An approximate method for analyzing transient condensation on spray in HYLIFE-II

    SciTech Connect

    Bai, R.Y.; Schrock, V.E. (California Univ., Berkeley, CA (USA). Dept. of Nuclear Engineering)

    1990-01-01

    The HYLIFE-II conceptual design calls for analysis of highly transient condensation on droplets to achieve a rapidly decaying pressure field. Drops exposed to the required transient vapor pressure field are first heated by condensation but later begin to reevaporate after the vapor temperature falls below the drop surface temperature. An approximate method of analysis has been developed based on the assumption that the thermal resistance is concentrated in the liquid. The time dependent boundary condition is treated via the Duhamel integral for the pure conduction model. The resulting Nusselt number is enhanced to account for convection within the drop and then used to predict the drop mean temperature history. Many histories are considered to determine the spray rate necessary to achieve the required complete condensation.

  4. Method and Apparatus for Thermal Spraying of Metal Coatings Using Pulsejet Resonant Pulsed Combustion

    NASA Technical Reports Server (NTRS)

    Paxson, Daniel E. (Inventor)

    2010-01-01

    An apparatus and method [or thermal spraying a metal coating on a substrate is accomplished with a modified pulsejet and optionally an ejector to assist in preventing oxidation. Metal such a Aluminum or Magnesium may be used. A pulsejet is first initiated by applying fuel, air. and a spark. Metal is inserted continuously in a high volume of meta1 into a combustion chamber of the pulsejet. The combustion is thereafter. controlled resonantly at high frequency and the metal is heated to a molten state. The metal is then transported from the combustion chamber into a tail pipe of said pulsejet and is expelled therefrom at high velocity and deposited on a target substrate.

  5. Processing and in vitro behavior of hydroxyapatite coatings prepared by electrostatic spray assisted vapor deposition method.

    PubMed

    Hou, Xianghui; Choy, Kwang-Leong; Leach, Sian Ellen

    2007-12-01

    Hydroxyapatite (HA) bioactive coatings are often used to improve bone attachment and reduce corrosion of metal prosthesis implants. This paper reports the preparation of HA coatings onto titanium substrates using a novel electrostatic spray assisted vapor deposition (ESAVD)-based method. The deposited coatings are characterized using a combination of Fourier transform infrared spectrometer, X-ray diffraction, Raman spectroscopy, scanning electron microscopy, and scratch test. The results confirm that well-crystallized HA coatings can be produced directly via the single-step ESAVD process, without further heat-treatment. The in vitro behavior of the as-deposited HA coating in simulated body fluid (SBF) is also presented. After 14-day immersion in SBF, the adhesion of the HA coating to the substrate increases significantly. PMID:17530629

  6. Laser processing of high-chromium nickel-chromium coatings deposited by various thermal spraying methods

    SciTech Connect

    Longa, Y.; Takemoto, M. (Aoyama Gakuin Univ., Tokyo (Japan). Coll. of Science and Engineering)

    1994-11-01

    High-chromium Ni-Cr coatings were deposited by thermal spraying in air and in an argon gas atmosphere. Coatings sprayed in Ar gas were free of pores and defects and of the same chemical composition as the spraying material. Following thermal spraying for each coating, laser glazing or laser gas alloying was applied to provide a protective chromium oxide film, produced by the intermediate oxidation process on top of the coatings. Five types of coatings were treated: (1) arc and (2) flame spraying in Ar, (3) arc and (4) flame spraying in air, and (5) low-pressure plasma spraying (LPPS). Oxide formation mechanisms during laser processing were studied, and the oxidation and hot-corrosion resistance of the coatings in the presence of a sulfate-vanadate fused salt at 900 C in air were examined. High-chromium Ni-Cr coatings deposited by thermal spraying, and they are used mostly to prevent ash attack of boilers and furnace tubes in power plants and oil refineries.

  7. Fabrication and analysis of PMMA, ABS, PS, and PC superhydrophobic surfaces using the spray method

    NASA Astrophysics Data System (ADS)

    Cho, Young-Sam; Ahn, Sang Hyun; Lee, Se-Hwan

    2013-07-01

    In this study, superhydrophobic surfaces were fabricated using a facile spraying technique with poly(methyl methacrylate) (PMMA), acrylonitrile butadiene styrene (ABS), polystyrene (PS) and polycarbonate (PC). Also, the surface energy was qualitatively analyzed via the water contact angle with respect to the spraying time and the sprayed position. Firstly, PMMA, ABS, PS and PC were dissolved by using solvents such as methyl chloride, methanol, THF (tetrahydrofuran), and methanol, respectively. After that, the dissolved polymer was sprayed onto a thin film of the same polymer for various spraying times. Nozzle size, pressure and spraying distance were fixed as 0.2 mm, 0.1 bar, and 100 mm, respectively, after several feasibility experiments. For the sprayed surfaces, the topology was analyzed with scanning electron microscopy (SEM) and confocal microscopy, and the surface energy was qualitatively analyzed using the water-contactangle measurement. According to a quantitative analysis using the roughness factor and he Wenzel equation, all specimens could be assumed to be in a Wenzel state. To convert the Wenzel state into a Cassie-Baxster state by decreasing the surface energy of polymer-sprayed specimen, we treated the polymer-sprayed surfaces by using trichloro (1H, 1H, 2H, 2H-perfluorooctyl) silane. Consequently, non-sticky superhydrophobic surfaces having water contact angles greater than 155° and water sliding angles lower than 8° were fabricated. The water contact angle and the water sliding angle were measured by using a contact-angle-measuring device. In addition, a brief qualitative analysis of the effect of surface topology on the water sliding angle was conducted for the polymer-sprayed specimens.

  8. Thermal Diffusivity Measurement for Thermal Spray Coating Attached to Substrate Using Laser Flash Method

    NASA Astrophysics Data System (ADS)

    Akoshima, Megumi; Tanaka, Takashi; Endo, Satoshi; Baba, Tetsuya; Harada, Yoshio; Kojima, Yoshitaka; Kawasaki, Akira; Ono, Fumio

    2011-11-01

    Ceramic-based thermal barrier coatings are used as heat and wear shields of gas turbine blades. There is a strong need to evaluate the thermal conductivity of coating for thermal design and use. The thermal conductivity of a bulk material is obtained as the product of thermal diffusivity, specific heat capacity, and density above room temperature in many cases. Thermal diffusivity and thermal conductivity are unique for a given material because they are sensitive to the structure of the material. Therefore, it is important to measure them in each sample. However it is difficult to measure the thermal diffusivity and thermal conductivity of coatings because coatings are attached to substrates. In order to evaluate the thermal diffusivity of a coating attached to the substrate, we have examined the laser flash method with the multilayer model on the basis of the response function method. We carried out laser flash measurements in layered samples composed of a CoNiCrAlY bond coating and a 8YSZ top coating by thermal spraying on a Ni-based superalloy substrate. It was found that the procedure using laser flash method with the multilayer model is useful for the thermal diffusivity evaluation of a coating attached to a substrate.

  9. Analysis of polycyclic aromatic hydrocarbons in contaminated soil by Curie point pyrolysis coupled to gas chromatography-mass spectrometry, an alternative to conventional methods.

    PubMed

    Buco, S; Moragues, M; Doumenq, P; Noor, A; Mille, G

    2004-02-13

    Curie point pyrolysis gas chromatography-mass spectrometry (Py-GC-MS) has been compared with classical extraction procedures (Soxhlet, sonication, KOH digestion, microwave-assisted) followed by GC-MS analysis for the determination of polycyclic aromatic hydrocarbons (PAHs) in contaminated soil. In each case, the efficiency of the technique was examined for 16 PAHs included in the US Environmental Protection Agency Priority Pollutant List. The results indicate that the recovery of PAHs is dependent on the extraction technique. The highest recoveries of PAHs were obtained with Curie point pyrolysis and KOH digestion. Py-GC-MS appeared to be interesting alternative method for the determination of PAHs in contaminated soil. The results were validated by certified soil (CRM 104) analysis. PMID:14763749

  10. Miniature spray-painting booth

    NASA Technical Reports Server (NTRS)

    Fee, K. W.

    1970-01-01

    Transparent spray booth provides method for quality painting and repair of surfaces in clean room or other specialized environments. Overspray and virtually all contaminating vapor and odor can be eliminated. Touch-up painting is achieved with spray gun.

  11. Production and analysis of fast pyrolysis oils from proteinaceous biomass

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fast pyrolysis of lignocellulosic biomass is a facile method for producing high yields of liquid fuel intermediates. However, because most fast pyrolysis oils are highly oxygenated, acidic and unstable identification of feedstocks that produce higher quality pyrolysis liquids is desirable. Therefor...

  12. Toxicity of pyrolysis gases from polyether sulfone

    NASA Technical Reports Server (NTRS)

    Hilado, C. J.; Olcomendy, E. M.

    1979-01-01

    A sample of polyether sulfone was evaluated for toxicity of pyrolysis gases, using the toxicity screening test method developed at the University of San Francisco. Animal response times were relatively short at pyrolysis temperatures of 600 to 800 C, with death occurring within 6 min. The principal toxicant appeared to be a compound other than carbon monoxide.

  13. Toxicity of pyrolysis gases from polyoxymethylene

    NASA Technical Reports Server (NTRS)

    Hilado, C. J.; Schneider, J. E.; Brauer, D. P.

    1979-01-01

    A sample of polyoxymethylene was evaluated for toxicity of pyrolysis gases, using the toxicity screening test method developed at the University of San Francisco. Under several test conditions, this material gave shorter times to death than many other synthetic polymers. Carbon monoxide appeared to be the principal toxicant in the pyrolysis gases.

  14. Through-thickness residual stress evaluations for several industrial thermal spray coatings using a modified layer-removal method

    NASA Astrophysics Data System (ADS)

    Greving, D. J.; Rybicki, E. F.; Shadley, J. R.

    1994-12-01

    Residual stresses are inherent in thermal spray coatings because the application process involves large temperature gradients in materials with different mechanical properties. In many cases, failure analysis of thermal spray coatings has indicated that residual stresses contribute to reduced service life. An estab-lished method for experimentally evaluating residual stresses involves monitoring deformations in a part as layers of material are removed. Although the method offers several advantages, applications are lim-ited to a single isotropic material and do not include coated materials. This paper describes a modified layer-removal method for evaluating through-thickness residual stress distributions in coated materials. The modification is validated by comparisons with three-dimensional finite-element analysis results. The modified layer-removal method was applied to determine through-thickness residual stress distributions for six industrial thermal spray coatings: stainless steel, aluminum, Ni-5A1, two tungsten carbides, and a ceramic thermal barrier coating. The modified method requires only ordinary resistance strain-gage measuring equipment and can be relatively insensitive to uncertainties in the mechanical properties of the coating material.

  15. A pyrolysis/gas chromatographic method for the determination of hydrogen in solid samples

    NASA Technical Reports Server (NTRS)

    Carr, R. H.; Bustin, R.; Gibson, E. K.

    1987-01-01

    A method is described for the determination of hydrogen in solid samples. The sample is heated under vacuum after which the evolved gases are separated by gas chromatography with a helium ionization detector. The system is calibrated by injecting known amounts of hydrogen, as determined manometrically. The method, which is rapid and reliable, was checked for a variety of lunar soils; the limit of detection is about 10 ng of hydrogen.

  16. Evaluation of methods to reduce bacteria concentrations in spray-dried animal plasma and its effects on nursery pig performance.

    PubMed

    DeRouchey, J M; Tokach, M D; Nelssen, J L; Goodband, R D; Dritz, S S; Woodworth, J C; James, B W; Webster, M J; Hastad, C W

    2004-01-01

    Four experiments with 1,040 weanling pigs (17 +/- 2 d of age at weaning) were conducted to evaluate the effects of spray-dried animal plasma source, drying technique, and methods of bacterial reduction on nursery pig performance. In Exp. 1, 180 barrows and gilts (initial BW 5.9 +/- 1.8 kg) were used to compare effects of animal plasma, animal plasma source, drying technique (spray-dried or freeze-dried), and plasma irradiation in nursery pig diets. From d 0 to 10, pigs fed diets containing irradiated spray-dried animal plasma had increased ADG and ADFI (P < 0.05) compared with pigs fed diets containing nonirradiated spray-dried animal plasma. Pigs fed irradiated animal plasma Sources 1 and 2 were similar in ADG and ADFI, but pigs fed animal plasma Source 1 had greater ADG (P < 0.05) than pigs fed animal plasma Source 2 and pigs not fed plasma. Pigs fed freeze-dried animal plasma had growth performance similar (P > 0.36) to pigs fed spray-dried animal plasma. Overall (d 0 to 24), pigs fed irradiated spray-dried animal plasma were heavier (P < 0.05) than pigs fed no animal plasma, whereas pigs fed nonirradiated spray-dried plasma were intermediate. In Exp. 2, 325 barrows and gilts (initial BW 5.8 +/- 1.7 kg) were used to compare the effects of irradiation or formaldehyde treatment of animal plasma and formaldehyde treatment of the whole diet. Pigs fed diets containing irradiated animal plasma had greater ADG (P < 0.05) than pigs fed nonirradiated plasma. Pigs fed formaldehyde-treated plasma had greater ADG and ADFI (P < 0.05) than pigs fed diets with either nonirradiated plasma or whole diet treated with formaldehyde. In Exp. 3 (360 barrows and gilts; initial BW 6.3 +/- 2.7 kg) and Exp. 4 (175 barrows and gilts; initial BW 6.1 +/- 1.7 kg), the irradiation of feed (high bacteria) and food-grade (low bacteria) animal plasma in nursery pig diets was examined. Pigs fed irradiated feed-grade plasma Product 2 had increased ADG (P < 0.05) compared with pigs fed nonirradiated plasma Product 2 and pigs fed the control diet without plasma. In Exp. 3 and 4, pigs fed irradiated food-grade plasma had growth performance similar to pigs fed nonirradiated food-grade plasma (P > 0.12). These studies indicate that bacterial reduction of feed-grade, but not food-grade animal plasma, improves nursery pig performance. PMID:14753369

  17. Fluorine doped-tin oxide prepared using spray method for dye sensitized solar cell application

    NASA Astrophysics Data System (ADS)

    Widiyandari, Hendri; Purwanto, Agus; Diharjo, Kuncoro; Suyitno, Hidayanto, Eko

    2013-09-01

    Fluorine-doped Tin Oxide (FTO) film was fabricated by spray deposition method. FTO films were prepared in different sheet resistance 6.7, 12.1, 19.3, and 23.5 ?/sq. X-ray diffractograms showed that the as-grown FTO film was tetragonal SnO2. The prepared FTO film have an average transmittance of 80% in the visible region (?=400-800 nm). These FTO films were then used to fabricate Dye Sensitized Solar Cell (DSSC). The working electrode was made from TiO2 paste using doctor blade technique. DSSC samples were characterized using solar simulator under AM 1.5 (100 mW/cm2). It is found that the efficiency of DSSC was much affected by sheet resistance of FTO film. The efficiency of DCCS was 2.32, 2.4, 1.1 and 0.97 (%) for the FTO sheet resistance 6.7, 12.1, 19.3, and 23.5 ?/sq, respectively. It is shown that the optimum DSSC efficiency was made from FTO with sheet resistance 12.1 ?/sq.

  18. Method for minimizing decarburization and other high temperature oxygen reactions in a plasma sprayed material

    DOEpatents

    Lenling, William J. (Madison, WI); Henfling, Joseph A. (Bosque Farms, NM); Smith, Mark F. (Albuquerque, NM)

    1993-06-08

    A method is disclosed for spray coating material which employs a plasma gun that has a cathode, an anode, an arc gas inlet, a first powder injection port, and a second powder injection port. A suitable arc gas is introduced through the arc gas inlet, and ionization of the arc gas between the cathode and the anode forms a plasma. The plasma is directed to emenate from an open-ended chamber defined by the boundary of the anode. A coating is deposited upon a base metal part by suspending a binder powder within a carrier gas that is fed into the plasma through the first powder injection port; a material subject to degradation by high temperature oxygen reactions is suspended within a carrier gas that is fed into the plasma through the second injection port. The material fed through the second injection port experiences a cooler portion of the plasma and has a shorter dwell time within the plasma to minimize high temperature oxygen reactions. The material of the first port and the material of the second port intermingle within the plasma to form a uniform coating having constituent percentages related to the powder-feed rates of the materials through the respective ports.

  19. Fabrication of electrodes for proton exchange membrane fuel cells using a spraying method and their performance evaluation

    SciTech Connect

    Mosdale, R.; Wakizoe, Masanobu; Srinivasan, S. [Texas A and M Univ., College Station, TX (United States)

    1994-12-31

    A spraying method was developed for the fabrication of electrodes for proton exchange membrane fuel cells (PEMFC). This method could have the advantages of localizing the platinum near the front surface and lowering the manufacturing costs for the electrodes. The performances of the electrodes with low (0.35 mg/cm{sup 2}) and ultra-low (0.1 mg/cm{sup 2}) platinum loading were evaluated in PEMFCs. The PEMFCs with 0.1 to .35 mg Pt/cm{sup 2} in the electrodes showed a higher level of performance than those with E-TEK electrodes, with a lower platinum loading when H{sub 2}/O{sub 2} were used as reactants. With H{sub 2}/air as reactants, the performances of both types of electrodes in PEMFCs were practically identical. Even with the ultra-low platinum loading, the sprayed electrodes exhibited good performances and a high utilization of platinum.

  20. Selection of methods for the supply and mixing of powder materials in the plasma spray deposition of composite coatings

    Microsoft Academic Search

    F. F. Vashkevich; G. F. Degtev

    1972-01-01

    1.Mechanical mixing of copper and alumina powders fails to ensure a uniform feed of the components of composite coatings into the plasma jet, brings about separation of the mixture, and leads to an uneven distribution of components on the surface.2.By employing the method of formation of copper-alumina composite coating material during the actual plasma spraying process, it is possible to

  1. Development and validation of HPLC method for determination of clotrimazole and its two degradation products in spray formulation

    Microsoft Academic Search

    Renata Hájková; Hana Sklená?ová; Ludmila Matysová; Petra Švecová; Petr Solich

    2007-01-01

    A novel simple isocratic HPLC method with UV detection for the determination of three compounds in spray solution (active component clotrimazole and two degradation products imidazole and (2-chlorophenyl)diphenylmethanol) using ibuprofen as an internal standard was developed and validated. The complications with different acido-basic properties of the analysed compounds in HPLC separation – while clotrimazole has pKa 4.7, imidazole has pKa

  2. Microstructure and properties of the CdS thin films prepared by electrostatic spray assisted vapour deposition (ESAVD) method

    Microsoft Academic Search

    B. Su; K. L Choy

    2000-01-01

    CdS thin films were fabricated using an electrostatic spray assisted vapour deposition (ESAVD) method from water\\/ethanol solutions of cadmium chloride and thiourea with different Cd:S ratios. The microstructure and crystallisation of the films were studied by means of XRD, XPS, AFM and SEM techniques. The effect of deposition conditions and precursor composition on the morphology and phase development of the

  3. The effects of Nafion ® ionomer content in PEMFC MEAs prepared by a catalyst-coated membrane (CCM) spraying method

    Microsoft Academic Search

    Kun-Ho Kim; Kwan-Young Lee; Hyoung-Juhn Kim; EunAe Cho; Sang-Yeop Lee; Tae-Hoon Lim; Sung Pil Yoon; In Chul Hwang; Jong Hyun Jang

    2010-01-01

    We analyzed the effects of ionomer content on the proton exchange membrane fuel cell (PEMFC) performance of membrane electrode assemblies (MEAs) fabricated by a catalyst-coated membrane (CCM) spraying method in partially humidified atmospheric air and hydrogen. When high loading Pt\\/C catalysts (45.5 wt.%) were used, we observed that catalytic activity was not directly proportional to electrochemical active surface area (EAS). This

  4. Method and closing pores in a thermally sprayed doped lanthanum chromite interconnection layer

    DOEpatents

    Singh, P.; Ruka, R.J.

    1995-02-14

    A dense, substantially gas-tight electrically conductive interconnection layer is formed on an air electrode structure of an electrochemical cell by (A) providing an air electrode surface; (B) forming on a selected portion of the electrode surface, a layer of doped LaCrO{sub 3} particles doped with an element or elements selected from Ca, Sr, Ba, Mg, Co, Ni, Al and mixtures thereof by thermal spraying doped LaCrO{sub 3} particles, either by plasma arc spraying or flame spraying; (C) depositing a mixture of CaO and Cr{sub 2}O{sub 3} on the surface of the thermally sprayed layer; and (D) heating the doped LaCrO{sub 3} layer coated with CaO and Cr{sub 2}O{sub 3} surface deposit at from about 1,000 C to 1,200 C to substantially close the pores, at least at a surface, of the thermally sprayed doped LaCrO{sub 3} layer. The result is a dense, substantially gas-tight, highly doped, electrically conductive interconnection material bonded to the electrode surface. A solid electrolyte layer can be applied to the nonselected portion of the air electrode. A fuel electrode can be applied to the solid electrolyte, to form an electrochemical cell, for example for generation of electrical power. 5 figs.

  5. Method and closing pores in a thermally sprayed doped lanthanum chromite interconnection layer

    DOEpatents

    Singh, Prabhakar (Export, PA); Ruka, Roswell J. (Pittsburgh, PA)

    1995-01-01

    A dense, substantially gas-tight electrically conductive interconnection layer is formed on an air electrode structure of an electrochemical cell by (A) providing an air electrode surface; (B) forming on a selected portion of the electrode surface, a layer of doped LaCrO.sub.3 particles doped with an element or elements selected from Ca, Sr, Ba, Mg, Co, Ni, Al and mixtures thereof by thermal spraying doped LaCrO.sub.3 particles, either by plasma arc spraying or flame spraying; (C) depositing a mixture of CaO and Cr.sub.2 O.sub.3 on the surface of the thermally sprayed layer; and (D) heating the doped LaCrO.sub.3 layer coated with CaO and Cr.sub.2 O.sub.3 surface deposit at from about 1000.degree. C. to 1200.degree. C. to substantially close the pores, at least at a surface, of the thermally sprayed doped LaCrO.sub.3 layer. The result is a dense, substantially gas-tight, highly doped, electrically conductive interconnection material bonded to the electrode surface. A solid electrolyte layer can be applied to the nonselected portion of the air electrode. A fuel electrode can be applied to the solid electrolyte, to form an electrochemical cell, for example for generation of electrical power.

  6. Method for Thermal Spraying of Coatings Using Resonant-Pulsed Combustion

    NASA Technical Reports Server (NTRS)

    Paxson, Daniel E.

    2008-01-01

    A method has been devised for high-volume, high-velocity surface deposition of protective metallic coatings on otherwise vulnerable surfaces. Thermal spraying is used whereby the material to be deposited is heated to the melting point by passing through a flame. Rather than the usual method of deposition from the jet formed from the combustion products, this innovation uses non-steady combustion (i.e. high-frequency, periodic, confined bursts), which generates not only higher temperatures and heat transfer rates, but exceedingly high impingement velocities an order of magnitude higher than conventional thermal systems. Higher impingement rates make for better adhesion. The high heat transfer rates developed here allow the deposition material to be introduced, not as an expensive powder with high surface-area-to-volume, but in convenient rod form, which is also easier and simpler to feed into the system. The nonsteady, resonant combustion process is self-aspirating and requires no external actuation or control and no high-pressure supply of fuel or air. The innovation has been demonstrated using a commercially available resonant combustor shown in the figure. Fuel is naturally aspirated from the tank through the lower Tygon tube and into the pulsejet. Air for starting is ported through the upper Tygon tube line. Once operation commences, this air is no longer needed as additional air is naturally aspirated through the inlet. A spark plug on the device is needed for starting, but the process carries on automatically as the operational device is resonant and reignites itself with each 220-Hz pulse.

  7. Superhydrophilic multilayer silica nanoparticle networks on a polymer microchannel using a spray layer-by-layer nanoassembly method.

    PubMed

    Lee, Kang Kug; Ahn, Chong H

    2013-09-11

    Nanoporous and superhydrophilic multilayer silica nanoparticle networks have been developed on a hydrophobic cyclic olefin copolymer (COC) microchannel using a spray layer-by-layer (LbL) electrostatic nanoassembly method. This powerful and promising LbL method provides a simple, cost-effective, and high-throughput nanoporous silica multilayer selectively onto the hydrophobic polymer surfaces. These newly developed multilayer networks have also been successfully characterized by contact angle measurement, environmental scanning electron microscopy (ESEM), energy-dispersive X-ray spectroscopy (EDS), and atomic force microscopy (AFM). The superhydrophilic effect, which was confirmed by the contact angle measurements, of the silica networks ensured the hydrophilic nature of the selectively constructed nanoporous silica nanoparticles onto the patterned hydrophobic COC microchannel. The capillary effect of the developed surface was characterized by measuring the length of a test liquid driven by the induced capillary forces in an on-chip capillary pumping platform with horizontal microchannels. The pumping capability achieved from the sprayed nanoporous surface for the on-chip micropump was mainly due to the strong capillary imbibition driven by the multicoated bilayers of hydrophilic silica nanoparticles. The developed networks with spray-assembled nanoparticles were also applied for an on-chip blood plasma separation platform with closed microchannels. The spray LbL method developed in this work can be a highly practical approach for the modification of various polymer microchannels because of several advantages such as an extremely simple process for the multilayer formation and flexibly controlled surface functionality at room temperature. PMID:23915270

  8. Kinetic investigation of wood pyrolysis

    SciTech Connect

    Thurner, F.; Mann, U.; Beck, S. R.

    1980-06-01

    The objective of this investigation was to determine the kinetics of the primary reactions of wood pyrolysis. A new experimental method was developed which enabled us to measure the rate of gas, tar, and char production while taking into account the temperature variations during the wood heating up. The experimental method developed did not require any sophisticated instruments. It facilitated the collection of gas, tar and residue (unreacted wood and char) as well as accurate measurement of the temperature inside the wood sample. Expressions relating the kinetic parameters to the measured variables were derived. The pyrolysis kinetics was investigated in the range of 300 to 400/sup 0/C at atmospheric pressure and under nitrogen atmosphere. Reaction temperature and mass fractions of gas, tar, and residue were measured as a function of time. Assuming first-order reactions, the kinetic parameters were determined using differential method. The measured activation energies of wood pyrolysis to gas, tar, and char were 88.6, 112.7, and 106.5 kJ/mole, respectively. These kinetic data were then used to predict the yield of the various pyrolysis products. It was found that the best prediction was obtained when an integral-mean temperature obtained from the temperature-time curve was used as reaction temperature. The pyrolysis products were analyzed to investigate the influence of the pyrolysis conditions on the composition. The gas consisted mainly of carbon dioxide, carbon monoxide, oxygen, and C/sub 3//sup +/-compounds. The gas composition depended on reaction time as well as reactor temperature. The tar analysis indicated that the tar consisted of about seven compounds. Its major compound was believed to be levoglucosan. Elemental analysis for the char showed that the carbon content increased with increasing temperature.

  9. Antistatic sprays

    NASA Technical Reports Server (NTRS)

    Ming, James E.

    1989-01-01

    Antistatic sprays from several different manufacturers are examined. The sprays are examined for contamination potential (i.e., outgassing and nonvolatile residue), corrosiveness on an aluminum mirror surface, and electrostatic effectiveness. In addition, the chemical composition of the antistatic sprays is determined by infrared spectrophotometry, mass spectrometry, and ultraviolet spectrophotometry. The results show that 12 of the 17 antistatic sprays examined have a low contamination potential. Of these sprays, 7 are also noncorrosive to an aluminum surface. And of these, only 2 demonstrate good electrostatic properties with respect to reducing voltage accumulation; these sprays did not show a fast voltage dissipation rate however. The results indicate that antistatic sprays can be used on a limited basis where contamination potential, corrosiveness, and electrostatic effectiveness is not critical. Each application is different and proper evaluation of the situation is necessary. Information on some of the properties of some antistatic sprays is presented in this document to aid in the evaluation process.

  10. Iranian non-responding contact method German cockroach permethrin resistance strains resulting from field pressure pyrethroid spraying.

    PubMed

    Nasirian, H; Ladonni, H; Shayeghi, M; Ahmadi, M Soleimani

    2009-04-15

    The present study investigated the probable responsible reasons for non-response the B. germanica to permethrin only in World Health Organization glass jar method after insecticide spraying control failure with pyrethroid insecticide groups in Islamic Republic of Iran. Eleven German cockroach strains were collected from field populations of nine infested kitchen student dormitories and two infested hospitals after insecticide spraying control failure with pyrethroid insecticide groups in Iran. The current study, in World Health Organization glass jar and knock down methods conducted on newly emerged adult males. All feral strains, with various levels of resistance to pyrethroids, in World Health Organization glass jar method at 400 min (6 h) time exposures, was not observed mortality, while the susceptible strain was observed 100% mortality in 25 min time exposures. Susceptible strain at LT50 after assessing on mortality data from the replicates by probit analysis in World Health Organization glass jar method was 15.3 min. In this study, all feral strains in World Health Organization glass jar method after 400 min (6 h) time exposures, was not observed mortality, that showed these strains very high-level resistance to permethrin. In the knock down method, the resistance ratios were 3.6 to 26.1-folds compare with the susceptible reference strain. In a comparison, among this study and previous studies resistance ratios of 8.6 to 17.7-folds for permethrin in topical application, indicated that German cockroach have had under pressure spraying. German cockroach have had in vicinity to pyrethroid insecticides especially permethrin in these locations in long period for non-responding to permethrin insecticide only in World Health Organization glass jar method, and the field evident confirm this subject. PMID:19634490

  11. APPLICATION OF A SPRAY DEPOSITION METHOD FOR REVERSED PHASE LIQUID CHROMATOGRAPHY-MASS SPECTROMETRY

    EPA Science Inventory

    Four coal gasification wastewater samples were analyzed for nonvolatile and polar organics by liquid chromatography-mass spectrometry (LC/MS). Samples were separated on a reverse phase liquid chromatographic column using an aqueous solvent as the eluant. A special spray depositio...

  12. Methods and application of residual stress analysis on thermally sprayed coatings and layer composites

    Microsoft Academic Search

    Martin Wenzelburger; Daniel López; Rainer Gadow

    2006-01-01

    Coating and layer composite manufacturing most commonly involves high temperature gradients and intensive heat transfer between the different composite materials. This can be noticed not only for thermal spraying, but also for other coating techniques. The combination of temperature gradients and materials with different thermophysical properties leads to the formation of thermal stresses in the composite, which are superimposed by

  13. Kinetics study on conventional and microwave pyrolysis of moso bamboo.

    PubMed

    Dong, Qing; Xiong, Yuanquan

    2014-11-01

    A comparative study on the pyrolysis kinetics of moso bamboo has been conducted in a conventional thermogravimetric analyzer and a microwave thermogravimetric analyzer respectively. The effect of heating rate on the pyrolysis process was also discussed. The results showed that both the maximum and average reaction rates increased with the heating rate increasing. The values of activation energy increased from 58.30 to 84.22 kJ/mol with the heating rate decreasing from 135 to 60 °C/min during conventional pyrolysis. The value of activation energy was 24.5 kJ/mol for microwave pyrolysis, much lower than that for conventional pyrolysis at a similar heating rate of 160 °C/min. The pyrolysis of moso bamboo exhibited a kinetic compensation effect. The low activation energy obtained under microwave irradiation suggests that microwaves heating would be a promising method for biomass pyrolysis. PMID:25194260

  14. Carbon nanoscrolls by pyrolysis of a polymer

    NASA Astrophysics Data System (ADS)

    Yadav, Prasad; Warule, Sambhaji; Jog, Jyoti; Ogale, Satishchandra

    2012-12-01

    3D network of carbon nanoscrolls was synthesized starting from pyrolysis of poly(acrylic acid-co-maleic acid) sodium salt. It is a catalyst-free process where pyrolysis of polymer leads to formation of carbon form and sodium carbonate. Upon water soaking of pyrolysis product, the carbon form undergoes self-assembly to form carbon nanoscrolls. The interlayer distance between the walls of carbon nanoscroll was found to be 0.34 nm and the carbon nanoscrolls exhibited a surface area of 188 m2/g as measured by the BET method.

  15. Thermal Arc Spray Overview

    NASA Astrophysics Data System (ADS)

    Hafiz Abd Malek, Muhamad; Hayati Saad, Nor; Kiyai Abas, Sunhaji; Mohd Shah, Noriyati

    2013-06-01

    Usage of protective coating for corrosion protection was on highly demand during the past decade; and thermal spray coating played a major part during that time. In recent years, the thermal arc spray coating becomes a popular coating. Many big players in oil and gas such as PETRONAS, EXXON MOBIL and SHELL in Malaysia tend to use the coating on steel structure as a corrosion protection. Further developments in coating processes, the devices, and raw materials have led to expansion of functional coatings and applications scope from conventional coating to specialized industries. It is widely used because of its ability to withstand high process temperature, offer advantages in efficiency, lower cost and acts as a corrosion protection. Previous research also indicated that the thermal arc spray offers better coating properties compared to other methods of spray. This paper reviews some critical area of thermal spray coating by discussing the process/parameter of thermal arc spray technology and quality control of coating. Coating performance against corrosion, wear and special characteristic of coating are also described. The field application of arc spray technology are demonstrated and reviewed.

  16. Zone heating for fluidized bed silane pyrolysis

    NASA Technical Reports Server (NTRS)

    Iya, Sridhar K. (Inventor)

    1987-01-01

    An improved heated fluidized bed reactor and method for the production of high purity polycrystalline silicon by silane pyrolysis wherein silicon seed particles are heated in an upper heating zone of the reactor and admixed with particles in a lower reaction zone, in which zone a silane-containing gas stream, having passed through a lower cooled gas distribution zone not conducive to silane pyrolysis, contacts the heated seed particles whereon the silane is heterogeneously reduced to silicon.

  17. Method of forming a plasma sprayed interconnection layer on an electrode of an electrochemical cell

    DOEpatents

    Spengler, C.J.; Folser, G.R.; Vora, S.D.; Kuo, L.; Richards, V.L.

    1995-06-20

    A dense, substantially gas-tight, electrically conductive interconnection layer is formed on an air electrode structure of an electrochemical cell by (A) providing an electrode surface; (B) forming on a selected portion of the electrode surface, a layer of doped LaCrO{sub 3} particles doped with an element selected from Ca, Sr, Ba, Mg, Co, Ni, Al and mixtures thereof by plasma spraying doped LaCrO{sub 3} powder, preferably compensated with chromium as Cr{sub 2}O{sub 3} and/or dopant element, preferably by plasma arc spraying; and, (C) heating the doped and compensated LaCrO{sub 3} layer to about 1100 C to 1300 C to provide a dense, substantially gas-tight, substantially hydration-free, electrically conductive interconnection material bonded to the electrode surface. A solid electrolyte layer can be applied to the unselected portion of the air electrode, and a fuel electrode can be applied to the solid electrolyte, to provide an electrochemical cell. 6 figs.

  18. Derivation of hydrous pyrolysis kinetic parameters from open-system pyrolysis

    NASA Astrophysics Data System (ADS)

    Tseng, Yu-Hsin; Huang, Wuu-Liang

    2010-05-01

    Kinetic information is essential to predict the temperature, timing or depth of hydrocarbon generation within a hydrocarbon system. The most common experiments for deriving kinetic parameters are mainly by open-system pyrolysis. However, it has been shown that the conditions of open-system pyrolysis are deviant from nature by its low near-ambient pressure and high temperatures. Also, the extrapolation of heating rates in open-system pyrolysis to geological conditions may be questionable. Recent study of Lewan and Ruble shows hydrous-pyrolysis conditions can simulate the natural conditions better and its applications are supported by two case studies with natural thermal-burial histories. Nevertheless, performing hydrous pyrolysis experiment is really tedious and requires large amount of sample, while open-system pyrolysis is rather convenient and efficient. Therefore, the present study aims at the derivation of convincing distributed hydrous pyrolysis Ea with only routine open-system Rock-Eval data. Our results unveil that there is a good correlation between open-system Rock-Eval parameter Tmax and the activation energy (Ea) derived from hydrous pyrolysis. The hydrous pyrolysis single Ea can be predicted from Tmax based on the correlation, while the frequency factor (A0) is estimated based on the linear relationship between single Ea and log A0. Because the Ea distribution is more rational than single Ea, we modify the predicted single hydrous pyrolysis Ea into distributed Ea by shifting the pattern of Ea distribution from open-system pyrolysis until the weight mean Ea distribution equals to the single hydrous pyrolysis Ea. Moreover, it has been shown that the shape of the Ea distribution is very much alike the shape of Tmax curve. Thus, in case of the absence of open-system Ea distribution, we may use the shape of Tmax curve to get the distributed hydrous pyrolysis Ea. The study offers a new approach as a simple method for obtaining distributed hydrous pyrolysis Ea with only routine open-system Rock-Eval data, which will allow for better estimating hydrocarbon generation.

  19. Corrosivity Of Pyrolysis Oils

    Microsoft Academic Search

    James R Keiser; Michael A Bestor; Samuel Arthur Lewis Sr; John Morse Storey

    2011-01-01

    Pyrolysis oils from several sources have been analyzed and used in corrosion studies which have consisted of exposing corrosion coupons and stress corrosion cracking U-bend samples. The chemical analyses have identified the carboxylic acid compounds as well as the other organic components which are primarily aromatic hydrocarbons. The corrosion studies have shown that raw pyrolysis oil is very corrosive to

  20. Ion internal energy distributions validate the charge residue model for small molecule ion formation by spray methods.

    PubMed

    Touboul, David; Jecklin, Matthias Conradin; Zenobi, Renato

    2008-04-01

    This paper reports a detailed study of the internal energy distribution of ions formed by four electrospray ionization (ESI)-related ionization methods, with particular emphasis on electrosonic spray ionization (ESSI). Substituted benzylpyridinium ions were used as thermometer ions to probe the internal energy distribution. The influence of different instrumental parameters was studied. Cone and skimmer voltages as well as the collision energy were found to strongly affect the ion internal energy distribution, whereas the distance between the emitter and the inlet of the mass spectrometer, the nebulizing gas pressure or the flow rate showed no influence. The internal energy distribution obtained with an ESSI source was compared with those obtained for electrospray (ESI), nanoelectrospray (nanoESI) and sonic spray ionization (SSI) on the same mass spectrometer with the same instrumental parameters. No clear differences were observed. As the charge residue model is the only ion formation mechanism possible for SSI, we conclude that benzylpyridinium ions are formed by the pathway suggested by this model. PMID:18327854

  1. Pyrolysis system evaluation study

    NASA Technical Reports Server (NTRS)

    1974-01-01

    An evaluation of two different pyrolysis concepts which recover energy from solid waste was conducted in order to determine the merits of each concept for integration into a Integrated Utility System (IUS). The two concepts evaluated were a Lead Bath Furnace Pyrolysis System and a Slagging Vertical Shaft, Partial Air Oxidation Pyrolysis System. Both concepts will produce a fuel gas from the IUS waste and sewage sludge which can be used to offset primary fuel consumption in addition to the sanitary disposal of the waste. The study evaluated the thermal integration of each concept as well as the economic impact on the IUS resulting from integrating each pyrolysis concepts. For reference, the pyrolysis concepts were also compared to incineration which was considered the baseline IUS solid waste disposal system.

  2. Application of ultrasound to microencapsulation of coconut milk fat by spray drying method.

    PubMed

    Le, Hoang Du; Le, Van Viet Man

    2015-04-01

    Mixtures of coconut milk and gelatin solution were treated by ultrasound, mixed with maltodextrin and subsequently spray-dried to yield powder. The effects of ultrasonic power and sonication time on the microencapsulation efficiency (ME) and microencapsulation yield (MY) of coconut fat were investigated. The results indicated that increase in ultrasonic power from 0 to 5.68 W/g and in sonication time from 0 to 2.5 min augmented ME and MY of coconut fat. However, treatment with sonication power higher than 5.68 W/g led to a drop in fat ME and MY, mainly due to aggregation of fat particles and that blocked the adsorption of gelatin molecules on the particle surface. PMID:25829636

  3. A Generalized Critical Velocity Window Based on Material Property for Cold Spraying by Eulerian Method

    NASA Astrophysics Data System (ADS)

    Li, W. Y.; Yu, M.; Wang, F. F.; Yin, S.; Liao, H. L.

    2014-02-01

    In this paper, the previously developed Eulerian model (Yu et al., J Therm Spray Technol 21(3):745-752, 2012), which could well predict the critical velocity and erosion velocity, was extended to other commonly used materials such as aluminum, iron, nickel, stainless steel 316, and Inconel718 for studying the influence of material property and establishing a generalized window of critical velocity. Results show that the deformation behavior of the used materials could be classified as coordinated deformation (copper, iron, nickel) and uncoordinated deformation patterns (aluminum, stainless steel, and Inconel718). However, it was found that the steady maximum equivalent plastic strain values at the critical velocity for each material concentrate in the extent of 2.6-3.0 regardless of deformation pattern. Dimensionless analysis shows that, the calculated critical velocity increases with the increase of material characteristic velocity, and this relationship can be primarily used to predict the critical velocity.

  4. Catalytic pyrolysis-GC/MS of lignin from several sources

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lignin from four different sources extracted by various methods were pyrolyzed at 650 degree C using analytical pyrolysis methods, py-GC/MS. Pyrolysis was carried out in the absence and presence of two heterogeneous catalysts , an acidic zeolite (HZSM-5) catalyst and a mixed metal oxide catalyst (Co...

  5. Triboelectric spray ionization.

    PubMed

    Özdemir, Abdil; Lin, Jung-Lee; Gillig, Kent J; Chen, Chung-Hsuan

    2013-02-01

    Triboelectric spray ionization (TESI) is a variation of electrospray ionization (ESI) using common instrumental components, including gas flow, solvent flow rate and heat, the only difference being the use of a high-voltage power supply for ESI or a static charge for TESI. The ionization of solvent or analyte is due to the electrostatic potential difference formed between the spray electrode and counter electrode. The ion source contains a pneumatic spray operated over a range of flow rates (0.15-1.5 µl/min) and gas pressures (0-100). This new design contains a standalone spray assembly and an optional metal mesh in front of the spray. There are several parameters that affect the performance during ionization of molecules including the flow rate of solvent, gas pressure, temperature, solvent acidity, distance and potential difference between emitter and counter electrode. A variable electrostatic potential can be applied for higher ionization efficiency. The new ionization method was successfully applied to solutions of various proteins under different conditions. The same charge-state distributions compared to other ESI techniques are observed for all the protein samples. The unique feature of TESI is very efficient spraying by using a natural electrostatic potential even at the potential that a human body can produce. This provides very gentle ionization efficiency of peptides and proteins in different solvents. PMID:23378087

  6. Vacuum Plasma Spraying Replaces Electrodeposition

    NASA Technical Reports Server (NTRS)

    Holmes, Richard R.; Power, Chris; Burns, David H.; Daniel, Ron; Mckechnie, Timothy N.

    1992-01-01

    Vacuum plasma spraying used to fabricate large parts with complicated contours and inner structures, without uninspectable welds. Reduces time, and expense of fabrication. Wall of combustion chamber built up inside of outer nickel-alloy jacket by plasma spraying. Particles of metal sprayed partially melted in plasma gun and thrown at supersonic speed toward deposition surface. Vacuum plasma-spray produces stronger bond between the grooves and covering layer completing channels and wall of combustion chamber. In tests, bond withstood pressure of 20 kpsi, three times allowable limit by old method.

  7. Ocean Spray

    NASA Astrophysics Data System (ADS)

    Veron, Fabrice

    2015-01-01

    Ocean spray consists of small water droplets ejected from the ocean surface following surface breaking wave events. These drops get transported in the marine atmospheric boundary layer, in which they exchange momentum and heat with the atmosphere. Small spray droplets are transported over large distances and can remain in the atmosphere for several days, where they will scatter radiation; evaporate entirely, leaving behind sea salt; participate in the aerosol chemical cycle; and act as cloud condensation nuclei. Large droplets remain close to the ocean surface and affect the air-sea fluxes of momentum and enthalpy, thereby enhancing the intensity of tropical cyclones. This review summarizes recent progress and the emerging consensus about the number flux and implications of small sea spray droplets. I also summarize shortcomings in our understanding of the impact of large spray droplets on the meteorology of storm systems.

  8. Nitroglycerin Spray

    MedlinePLUS

    Nitroglycerin spray is used to treat episodes of angina (chest pain) in people who have coronary artery ... in order to prevent the angina from occurring. Nitroglycerin is in a class of medications called vasodilators. ...

  9. Method of making supercritical fluid molecular spray films, powder and fibers

    DOEpatents

    Smith, Richard D. (Richland, WA)

    1988-01-01

    Solid films are deposited, or fine powders formed, by dissolving a solid material into a supercritical fluid solution at an elevated pressure and then rapidly expanding the solution through a heated nozzle having a short orifice into a region of relatively low pressure. This produces a molecular spray which is directed against a substrate to deposit a solid thin film thereon, or discharged into a collection chamber to collect a fine powder. In another embodiment, the temperature of the solution and nozzle is elevated above the melting point of the solute, which is preferably a polymer, and the solution is maintained at a pressure such that, during expansion, the solute precipitates out of solution within the nozzle in a liquid state. Alternatively, a secondary solvent mutually soluble with the solute and primary solvent and having a higher critical temperature than that of primary solvent is used in a low concentration (<20%) to maintain the solute in a transient liquid state. The solute is discharged in the form of long, thin fibers. The fibers are collected at sufficient distance from the orifice to allow them to solidify in the low pressure/temperature region.

  10. Characterization of pyrolytic carbon blacks from commercial tire pyrolysis plants

    Microsoft Academic Search

    Hans Darmstadt; Christian Roy; Serge Kaliaguine

    1995-01-01

    Pyrolysis of used tires yields oil and pyrolytic carbon black (CBP). The tire pyrolysis process can be performed either in vacuo or at atmospheric pressure. The CBP recovered in both processes are different from the commercial carbon blacks used in the tire fabrication. Different spectroscopic methods such as ESCA, SIMS, Auger-spectroscopy and XRD were used to characterize CBP obtained in

  11. Stabilization of Fast Pyrolysis Oil: Post Processing Final Report

    SciTech Connect

    Elliott, Douglas C.; Lee, Suh-Jane; Hart, Todd R.

    2012-03-01

    UOP LLC, a Honeywell Company, assembled a comprehensive team for a two-year project to demonstrate innovative methods for the stabilization of pyrolysis oil in accordance with DOE Funding Opportunity Announcement (FOA) DE-PS36-08GO98018, Biomass Fast Pyrolysis Oil (Bio-oil) Stabilization. In collaboration with NREL, PNNL, the USDA Agricultural Research Service (ARS), Pall Fuels and Chemicals, and Ensyn Corporation, UOP developed solutions to the key technical challenges outlined in the FOA. The UOP team proposed a multi-track technical approach for pyrolysis oil stabilization. Conceptually, methods for pyrolysis oil stabilization can be employed during one or both of two stages: (1) during the pyrolysis process (In Process); or (2) after condensation of the resulting vapor (Post-Process). Stabilization methods fall into two distinct classes: those that modify the chemical composition of the pyrolysis oil, making it less reactive; and those that remove destabilizing components from the pyrolysis oil. During the project, the team investigated methods from both classes that were suitable for application in each stage of the pyrolysis process. The post processing stabilization effort performed at PNNL is described in this report. The effort reported here was performed under a CRADA between PNNL and UOP, which was effective on March 13, 2009, for 2 years and was subsequently modified March 8, 2011, to extend the term to December 31, 2011.

  12. Thickness-dependent properties of sprayed iridium oxide thin films

    Microsoft Academic Search

    P. S Patil; P. S Chigare; S. B Sadale; T Seth; D. P Amalnerkar; R. K Kawar

    2003-01-01

    Iridium oxide thin films with variable thickness were deposited by spray pyrolysis technique (SPT), onto the amorphous glass substrates kept at 350°C. The volume of iridium chloride solution was varied to obtain iridium oxide thin films with thickness ranging from 700 to 2250Å. The effect of film thickness on structural and electrical properties was studied. The X-ray diffraction (XRD) studies

  13. Studies on electrochromism of spray pyrolyzed cobalt oxide thin films

    Microsoft Academic Search

    P. S Patil; L. D Kadam; C. D Lokhande

    1998-01-01

    Cobalt oxide thin films were prepared by spray pyrolysis technique on to fluorine doped tin oxide (F.T.O.) coated glass substrates. The electrochromic cell was formed by using these films as working electrodes and the electrochromic characteristics were determined by using cyclic voltammetry and chronoamperometry. The films exhibited anodic electrochromism; changing colour from grey to pale yellow.

  14. Simulations of Spray Reacting Flows in a Single Element LDI Injector With and Without Invoking an Eulerian Scalar PDF Method

    NASA Technical Reports Server (NTRS)

    Shih, Tsan-Hsing; Liu, Nan-Suey

    2012-01-01

    This paper presents the numerical simulations of the Jet-A spray reacting flow in a single element lean direct injection (LDI) injector by using the National Combustion Code (NCC) with and without invoking the Eulerian scalar probability density function (PDF) method. The flow field is calculated by using the Reynolds averaged Navier-Stokes equations (RANS and URANS) with nonlinear turbulence models, and when the scalar PDF method is invoked, the energy and compositions or species mass fractions are calculated by solving the equation of an ensemble averaged density-weighted fine-grained probability density function that is referred to here as the averaged probability density function (APDF). A nonlinear model for closing the convection term of the scalar APDF equation is used in the presented simulations and will be briefly described. Detailed comparisons between the results and available experimental data are carried out. Some positive findings of invoking the Eulerian scalar PDF method in both improving the simulation quality and reducing the computing cost are observed.

  15. Characterization of the pyrolysis products of methiopropamine.

    PubMed

    Bouso, Emily D; Gardner, Elizabeth A; O'Brien, John E; Talbot, Brian; Kavanagh, Pierce V

    2014-01-01

    1-(Thien-2-yl)-2-methylaminopropane (methiopropamine, MPA), appeared as a 'legal high' in late 2010. It is structurally similar to methamphetamine, with a thiophene ring replacing the benzene moiety. Methiopropamine reportedly retains the pharmacological properties of amphetamine stimulants, but it does not fall under existing drug laws in the USA and Ireland. The objective of this research was to identify the pyrolysis products formed under conditions that mimic those used by recreational drugs users. Thirteen pyrolysis products were identified and ten were confirmed by comparison to synthesized standards. Methods for synthesizing the standards as well as an alternative method for the synthesis of methiopropamine were developed. The MPA pyrolysis products are formed through N-dealkylation, N-alkylation, N-formylation, ?-carbon oxidation, ?-carbon oxidation/N-alkylation, amine elimination and carbon-carbon bond cleavage. Two pyrazine isomers also formed. Some of these products have the potential to be psychoactive while others are potentially toxic. PMID:24166818

  16. Spray Calendar.

    E-print Network

    Sanborn, C. E. (Charles Emerson)

    1908-01-01

    . XII. G-AS TAR. A ". entive of peach tree borer. I'.iint trcc trrlnk to half an inch below surface of oil. XIII. GASOLINE (A CHEAP GRADE). Spray undiluted on blister beetles or similar insects when they are in droves or colonies. Use a very fine... with fleas, it will give satisfaction. It is a good article to spray on barnyards, cow lots, pig pens, and in poultry houses. XV. HYDRATED LIME. Used largely as a repellant on cucumber and young melon vines to eliminate ravages of cucumber beetles, etc...

  17. [A case of thrombosed popliteal artery by method of endovascular pulse spray thrombolysis in the process of multiple fractures of tibia].

    PubMed

    Maciejczak, P; Kosim, A; Wilamska, E; Lejk, M; Cza?bowska, I; Kwarecki, J; Stryga, W

    1999-01-01

    A case of team-treated thrombosed popliteal artery caused by blunt limb trauma with open tibia fracture is presented. Thrombosed artery was treated by endovascular pulse-spray method using Angiomed catheter. Implementation of this method allowed us to dissolve thrombus and to retrieve arterial circulation in the limb. In our opinion this procedure was an alternative for traditional surgery. After revascularisation of the limb orthopedic operation on fractured bones was performed using Zespol technique. PMID:10367533

  18. Generation of functional structures by laser pyrolysis of polysilazane

    NASA Astrophysics Data System (ADS)

    Krauss, Hans-Joachim; Otto, Andreas

    2002-06-01

    The pyrolysis of polysilazanes by laser power represents an innovative technique for the generation of ceramic-like coatings and structures. The dissolved polysilazanes can be easily applied by painting techniques such as dipping or spraying. In the following pyrolysis the polysilazane layer transforms into an amorphous ceramic-like coating. The laser power is absorbed in the precursor layer, which leads to the latter's ceramization without damaging the substrate by thermal load. While plane laser pyrolysis creates a protective coating, selective pyrolysis creates a raised and adherent ceramic-like structure that remains after the unexposed polymer layer has been removed. The flexibility of a writing laser system in conjunction with a suitable handling system makes it possible to inscribe any kind of 2D structure on nearly any complexly shaped part. Some of the chemical, magnetic, and electrical structure properties can be adjusted by the pyrolysis parameters and special types of filler particles. Especially the possibility to control electric conductivity should make it possible to create structure dielectric films or planar resistors, inductors or capacitors, which are basically written on the surface of the part. Because of their ceramic nature of the structures are resistant against high temperatures and corrosive media. Thus, this new additive structuring technique could finally strike a new path in creating corrosion resistant high- temperature sensors and control systems.

  19. The effect of mixing methods and polymer infiltration and pyrolysis (PIP) cycles on the densification of silicon carbide inert matrix fuel through a polymer precursor route

    NASA Astrophysics Data System (ADS)

    Shih, Chunghao; Tulenko, J. S.; Baney, R. H.

    2011-12-01

    The effect of mixing methods on the fabrication of silicon carbide (SiC) inert matrix fuel through a polymer precursor route was investigated in order to break up the agglomerates of the SiC particles observed in earlier studies. It was found that a high energy shaker mill could effectively break up the agglomerates and thereby achieve a higher pellet density. Moreover, it was found that the pellet density depended less on the pressing pressure, when the particles are well mixed. SEM images showed cracks caused by the springback effect on pellets with a high cold pressing pressure of 600 MPa, but no signs of springback effect were observed for the 200 MPa pressed pellets. The polymer infiltration and pyrolysis (PIP) cycles were used to further increase the pellet density and close the open pores. The first PIP cycle was found to increase the theoretical density of the pellets from 81.2% to 86.0% and close ˜50% of the open pores. The pore size distribution showed that most of the remaining open pores had diameters smaller than 10 nm. The successive second PIP cycle is not as effective on either the density or the pore size distribution because the small pores present before the second PIP cycle made the infiltration process difficult.

  20. Research on air sprays and unique foam application methods. Thirty third monthly report, May 1-31, 1984

    SciTech Connect

    Not Available

    1984-07-19

    The construction of the longwall mockup gallery has been completed. Testing has been completed and the data analyzed for the air sprays system. A maximum of 75% air spray effectiveness was obtained from the data analysis. Laboratory tests on pick face foaming and flushing foam through scroll sprays were successfully completed. The first underground testing of the foam system through the scroll sprays as well as external sprays located on the lead ranging arm was conducted. Data analysis revealed a 58% reduction in dust concentration at the operator's position for the 40 gpm foam system as compared to the existing 80 gpm water spray system. Dust samples analyzed by Consol personnel provided a greater than 60% reduction of dust concentration at the operator's position. The second field test of the foam system was very successful and the mining company was considering using the system on a long-term basis. However, the operating cost of the system was higher than the cost the mining company was willing to afford, and consequently further operation of the foam system was suspended.

  1. The synthesis and optical property of solid-state-prepared YAG:Ce phosphor by a spray-drying method

    SciTech Connect

    Lee, H.-M.; Cheng, C.-C. [Department of Resources Engineering, National Cheng Kung University, No. 1 University Road, Tainan 70101, Taiwan (China); Huang, C.-Y. [Department of Resources Engineering, National Cheng Kung University, No. 1 University Road, Tainan 70101, Taiwan (China)], E-mail: cyhuang@mail.ncku.edu.tw

    2009-05-06

    Ce{sup 3+}-activated yttrium aluminum garnet (Y{sub 3}Al{sub 5}O{sub 12}:Ce, YAG:Ce) powder as luminescent phosphor was synthesized by the solid-state reaction method. The phase identification, microstructure and photoluminescent properties of the products were investigated by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), absorption spectrum and photoluminescence (PL) analysis. Spherical phosphor particle is considered better than irregular-shaped particle to improve PL property and application, so this phosphor was granulated into a sphere-like shape by a spray-drying device. After calcinating at 1500 deg. C for 0, 4, and 8 h, the product was identified as YAG and CeO{sub 2} phases. The CeO{sub 2} phase content is decreased by increasing the calcination time or decreasing the Ce{sup 3+} doping content. The product showed higher emission intensity resulted from more Ce{sup 3+} content and larger grain size. The product with CeO{sub 2} was found to have lower emission intensity. This paper presents the crystal structures of Rietveld refinement results of powder XRD data.

  2. Toxicity of pyrolysis gases from polytetrafluoroethylene

    NASA Technical Reports Server (NTRS)

    Hilado, C. J.; Schneider, J. E.

    1979-01-01

    A sample of polytetrafluoroethylene was evaluated for toxicity of pyrolysis gases, using various test conditions of the toxicity screening test method developed at the University of San Francisco. Time to death appears to be affected by the material of which the pyrolysis tube is made, with Monel tending to give longer times to death than quartz. When quartz tubes are used, time to death seems to be related to carbon monoxide concentration. When Monel tubes are used, carbon monoxide does not appear to be the principal toxicant.

  3. [On the regeneration of transforming reagents in the spray method for the determination of ammonium concentration].

    PubMed

    Korableva, A A; Kolobashkina, T B

    1997-01-01

    Aerosol method detecting low concentrations of ammonium involves passage of the analysed gas over crystal hydrate of iron nitrate with consequent registration of the aerosol obtained. The method is sensitive and precise due to direct correlation between concentration of the dispersed substance and ammonium level. For precise evaluation and its effectiveness, the crystal hydrate of iron nitrate should be kept over 55-65% nitric acid solution before the analysis. PMID:9574989

  4. Microemulsion flame pyrolysis for hopcalite nanoparticle synthesis: a new concept for catalyst preparation.

    PubMed

    Biemelt, T; Wegner, K; Teichert, J; Kaskel, S

    2015-04-01

    A new route to highly active hopcalite catalysts via flame spray pyrolysis of an inverse microemulsion precursor is reported. The nitrate derived nanoparticles are around 15 nm in diameter and show excellent conversion of CO under ambient conditions, outperforming commercial reference hopcalite materials produced by co-precipitation. PMID:25726946

  5. Toxicity of pyrolysis gases from foam plastics

    NASA Technical Reports Server (NTRS)

    Hilado, C. J.; Cumming, H. J.; Casey, C. J.

    1980-01-01

    Twenty-three samples of flexible foams and twelve samples of rigid foams were evaluated for toxicity of pyrolysis gases, using the USF toxicity screening test method. Polychloroprene among the flexible foams, and polystyrene among the rigid foams, appeared to exhibit the least toxicity under these particular test conditions.

  6. Toxicity of pyrolysis gases from polypropylene

    NASA Technical Reports Server (NTRS)

    Hilado, C. J.; Schneider, J. E.; Brauer, D. F.

    1979-01-01

    A sample of polypropylene was evaluated for toxicity of pyrolysis gases, using the toxicity screening test method developed at the University of San Francisco. The gases from this sample appeared to be equivalent or less toxic than the gases from a sample of polyethylene under these particular test conditions. Carbon monoxide appeared to be the principal toxicant.

  7. Processing of damage-tolerant, oxidation-resistant ceramic matrix composites by a precursor infiltration and pyrolysis method

    Microsoft Academic Search

    F. F. Lange; W. C. Tu; A. G. Evans

    1995-01-01

    Damage-tolerant, continuous fiber ceramic matrix composites have been produced by an inexpensive method. According to this method, the space between the fibers is filled with a powder. The powder particles are heat treated to form a porous framework without shrinkage, which is then strengthened with an inorganic synthesized from a precursor. High particle packing densities can be achieved within the

  8. Plasma spraying method for forming diamond and diamond-like coatings

    DOEpatents

    Holcombe, C.E.; Seals, R.D.; Price, R.E.

    1997-06-03

    A method and composition is disclosed for the deposition of a thick layer of diamond or diamond-like material. The method includes high temperature processing wherein a selected composition including at least glassy carbon is heated in a direct current plasma arc device to a selected temperature above the softening point, in an inert atmosphere, and is propelled to quickly quenched on a selected substrate. The softened or molten composition crystallizes on the substrate to form a thick deposition layer comprising at least a diamond or diamond-like material. The selected composition includes at least glassy carbon as a primary constituent and may include at least one secondary constituent. Preferably, the secondary constituents are selected from the group consisting of at least diamond powder, boron carbide (B{sub 4}C) powder and mixtures thereof. 9 figs.

  9. Development of an efficient transformation method by Agrobacterium tumefaciens and high throughput spray assay to identify transgenic plants for woodland strawberry (Fragaria vesca) using NPTII selection.

    PubMed

    Pantazis, Christopher J; Fisk, Sarah; Mills, Kerri; Flinn, Barry S; Shulaev, Vladimir; Veilleux, Richard E; Dan, Yinghui

    2013-03-01

    KEY MESSAGE : We developed an efficient Agrobacterium -mediated transformation method using an Ac/Ds transposon tagging construct for F. vesca and high throughput paromomycin spray assay to identify its transformants for strawberry functional genomics. Genomic resources for Rosaceae species are now readily available, including the Fragaria vesca genome, EST sequences, markers, linkage maps, and physical maps. The Rosaceae Genomic Executive Committee has promoted strawberry as a translational genomics model due to its unique biological features and transformability for fruit trait improvement. Our overall research goal is to use functional genomic and metabolic approaches to pursue high throughput gene discovery in the diploid woodland strawberry. F. vesca offers several advantages of a fleshy fruit typical of most fruit crops, short life cycle (seed to seed in 12-16 weeks), small genome size (206 Mbb/C), small plant size, self-compatibility, and many seeds per plant. We have developed an efficient Agrobacterium tumefaciens-mediated strawberry transformation method using kanamycin selection, and high throughput paromomycin spray assay to efficiently identify transgenic strawberry plants. Using our kanamycin transformation method, we were able to produce up to 98 independent kanamycin resistant insertional mutant lines using a T-DNA construct carrying an Ac/Ds transposon Launchpad system from a single transformation experiment involving inoculation of 22 leaf explants of F. vesca accession 551572 within approx. 11 weeks (from inoculation to soil). Transgenic plants with 1-2 copies of a transgene were confirmed by Southern blot analysis. Using our paromomycin spray assay, transgenic F. vesca plants were rapidly identified within 10 days after spraying. PMID:23160638

  10. Spray pyrolysed microporous TiO2 thin films by optimisation of substrate temperature for ‘all sprayed’ solar cells

    NASA Astrophysics Data System (ADS)

    Santhosh, M. V.; Deepu, D. R.; Geethu, R.; Rajeev Kumar, K.; Sudha Kartha, C.; Vijayakumar, K. P.

    2014-11-01

    Titanium dioxide thin films were deposited on glass substrate at temperatures ranging from 300 °C to 500 °C by a simple, cost effective spray pyrolysis method using commercially available TiO2 powder (Degussa P25). Analyses using scanning electron microscopy (SEM) and atomic force microscopy (AFM) reveal the microporous nature of the films at 350 °C. X-ray diffraction (XRD) and Raman studies reveal that these films are amorphous in nature. The films were subsequently annealed at 500 °C for 2 h, resulting in crystallisation (the tetragonal anatase phase). XPS analysis was effectively used to study the chemical composition of the samples. Finally, optimized microporous TiO2 thin films were used for the fabrication of an ‘all-sprayed’ solar cell utilizing well-established CuInS2 as the absorber layer. The best device under this study has an open-circuit voltage of 409 mV and a short-circuit current density of 3.90 mA cm?2. The efficiency and fill factor were 0.61% and 38%, respectively.

  11. ENGINEERING BULLETIN: PYROLYSIS TREATMENT

    EPA Science Inventory

    Pyrolysis is formally defined as chemical decomposition induced in organic materials by heat in the absence of oxygen. In practice, it is not possible to achieve a completely oxygen-free atmosphere; actual pyrolytic systems are operated with less than stoichiometric quantities of...

  12. Pyrolysis of Table Sugar

    PubMed Central

    Karagöz, Selhan

    2013-01-01

    Table sugars were pyrolyzed at different temperatures (300, 400, and 500°C) in a fixed-bed reactor. The effect of pyrolysis temperature on yields of liquid, solid, and gaseous products was investigated. As expected the yield of liquid products gradually increased and the yield of solid products gradually decreased when the pyrolysis temperature was raised. The yield of liquid products was greatest (52?wt%) at 500°C. The composition of bio-oils extracted with diethyl ether was identified by means of gas chromatography mass spectrometry (GC-MS), nuclear magnetic resonance (1H-NMR), and Fourier transform infrared spectroscopy (FTIR). The following compounds were observed in bio-oils produced from the pyrolysis of table sugar at 500°C: 1,4:3,6-dianhydro-?-d-glucopyranose, 5-(hydroxymethyl) furfural, 5-acetoxymethyl-2-furaldehyde, and cyclotetradecane liquid product. The relative concentration of 5-(hydroxymethyl) furfural was the highest in bio-oils obtained from pyrolysis of table sugars at 500°C. PMID:24223500

  13. Rapid method for hydrocarbon-type analysis of heavy oils and synthetic fuels by pyrolysis thin layer chromatography

    Microsoft Academic Search

    M. A. Poirier; A. E. George

    1982-01-01

    This work describes a rapid method for hydrocargon-type analysis applying thin layer chromatography (TLC) to the pentane-soluble fraction *malthenes) of the petroleum and synthetic fuels boiling above 200°C. The principal component types encountered in this paper are saturates (SA), aromatics (AR), (mono and di together) polynuclear aromatics (PNA) and polar material (PO). The method uses a Iatroscan TLC pyrolyzer which

  14. Fluticasone Nasal Spray

    MedlinePLUS

    ... spray it into your eyes or mouth.Each bottle of fluticasone nasal spray should only be used ... has been used, the remaining sprays in the bottle might not contain the correct amount of medication. ...

  15. Evaluation of various spraying equipment for effective application of fungicides to control Asian soybean rust1

    Microsoft Academic Search

    H E OZKAN; H ZHU; R C DERKSEN; H GULER; C. KRAUSE

    Summary Fungicides manufactured to control soybean rust are effective; however, successful control of this disease will mostly depend on proper application methods. Spray coverage and deposition from 10 application equipment\\/spray nozzles were analysed. In general, the spray treatments with air assistance were more effective in spraying rust fungicides than the treatments with the conventional boom sprayer. Spray performances from the

  16. Effect of whey protein isolate and ?-cyclodextrin wall systems on stability of microencapsulated vanillin by spray-freeze drying method.

    PubMed

    Hundre, Swetank Y; Karthik, P; Anandharamakrishnan, C

    2015-05-01

    Vanillin flavour is highly volatile in nature and due to that application in food incorporation is limited; hence microencapsulation of vanillin is an ideal technique to increase its stability and functionality. In this study, vanillin was microencapsulated for the first time by non-thermal spray-freeze-drying (SFD) technique and its stability was compared with other conventional techniques such as spray drying (SD) and freeze-drying (FD). Different wall materials like ?-cyclodextrin (?-cyd), whey protein isolate (WPI) and combinations of these wall materials (?-cyd + WPI) were used to encapsulate vanillin. SFD microencapsulated vanillin with WPI showed spherical shape with numerous fine pores on the surface, which in turn exhibited good rehydration ability. On the other hand, SD powder depicted spherical shape without pores and FD encapsulated powder yielded larger particle sizes with flaky structure. FTIR analysis confirmed that there was no interaction between vanillin and wall materials. Moreover, spray-freeze-dried vanillin + WPI sample exhibited better thermal stability than spray dried and freeze-dried microencapsulated samples. PMID:25529646

  17. In situ fuel concentration measurement near a spark plug in a spray-guided direct-injection spark-ignition engine using infrared absorption method

    NASA Astrophysics Data System (ADS)

    Kawahara, Nobuyuki; Tomita, Eiji; Kadowaki, Takuya; Honda, Tetsuya; Katashiba, Hideaki

    2010-10-01

    Vaporized fuel concentration in a spray-guided direct-injection spark-ignition (SG-DISI) engine was measured using an optical sensor installed in a spark plug. A laser infrared absorption method was applied to quantify the instantaneous gasoline concentration near the spark plug. This paper discusses the feasibility of obtaining in situ air-fuel ratio measurements with this sensor installed inside an SG-DISI engine cylinder. First, the effects of the spray plume from a multi-hole injector on the vaporized fuel concentration measurements near the spark-plug sensor were examined using a visible laser. We determined the best position for the sensor in the engine, which was critical due to the spray and vapor plume formation. Then, a 3.392-?m He-Ne laser that coincided with the absorption line of the hydrocarbons was used as a light source to examine the stratified mixture found during ultra-lean engine operation. A combustible mixture existed around the spark plug during the injection period when a preset air-fuel ratio of 45.0 was used with different fuel injection timings and net mean effect pressure conditions. The effects of the orientation of the spark plug on the measured results and ignitability of the SG-DISI engine were examined. Orienting the spark plug vertically to one of the spray plumes provided more accurate results and better engine reliability. The study demonstrated that it was possible to qualify the air-fuel ratio near the spark plug during the injection period using the developed spark-plug sensor in an SG-DISI engine.

  18. Method of forming a leak proof plasma sprayed interconnection layer on an electrode of an electrochemical cell

    DOEpatents

    Kuo, Lewis J. H. (Monroeville, PA); Vora, Shailesh D. (Monroeville, PA)

    1995-01-01

    A dense, substantially gas-tight, electrically conductive interconnection layer is formed on an electrode structure of an electrochemical cell by: (A) providing an electrode structure; (B) forming on a selected portion of the electrode surface, an interconnection layer having the general formula La.sub.1-x M.sub.x Cr.sub.1-y N.sub.y O.sub.3, where M is a dopant selected from the group of Ca, Sr, Ba, and mixtures thereof, and where N is a dopant selected from the group of Mg, Co, Ni, Al, and mixtures thereof, and where x and y are each independently about 0.075-0.25, by thermally spraying, preferably plasma arc spraying, a flux added interconnection spray powder, preferably agglomerated, the flux added powder comprising flux particles, preferably including dopant, preferably (CaO).sub.12. (Al.sub.2 O.sub.3).sub.7 flux particles including Ca and Al dopant, and LaCrO.sub.3 interconnection particles, preferably undoped LaCrO.sub.3, to form a dense and substantially gas-tight interconnection material bonded to the electrode structure by a single plasma spraying step; and, (C) heat treating the interconnection layer at from about 1200.degree. to 1350.degree. C. to further densify and heal the micro-cracks and macro-cracks of the thermally sprayed interconnection layer. The result is a substantially gas-tight, highly doped, electrically conductive interconnection material bonded to the electrode structure. The electrode structure can be an air electrode, and a solid electrolyte layer can be applied to the unselected portion of the air electrode, and further a fuel electrode can be applied to the solid electrolyte, to form an electrochemical cell for generation of electrical power.

  19. Method of forming a leak proof plasma sprayed interconnection layer on an electrode of an electrochemical cell

    DOEpatents

    Kuo, L.J.H.; Vora, S.D.

    1995-02-21

    A dense, substantially gas-tight, electrically conductive interconnection layer is formed on an electrode structure of an electrochemical cell by: (A) providing an electrode structure; (B) forming on a selected portion of the electrode surface, an interconnection layer having the general formula La{sub 1{minus}x}M{sub x}Cr{sub 1{minus}y}N{sub y}O{sub 3}, where M is a dopant selected from the group of Ca, Sr, Ba, and mixtures thereof, and where N is a dopant selected from the group of Mg, Co, Ni, Al, and mixtures thereof, and where x and y are each independently about 0.075--0.25, by thermally spraying, preferably plasma arc spraying, a flux added interconnection spray powder, preferably agglomerated, the flux added powder comprising flux particles, preferably including dopant, preferably (CaO){sub 12}(Al{sub 2}O{sub 3}){sub 7} flux particles including Ca and Al dopant, and LaCrO{sub 3} interconnection particles, preferably undoped LaCrO{sub 3}, to form a dense and substantially gas-tight interconnection material bonded to the electrode structure by a single plasma spraying step; and (C) heat treating the interconnection layer at from about 1,200 to 1,350 C to further densify and heal the micro-cracks and macro-cracks of the thermally sprayed interconnection layer. The result is a substantially gas-tight, highly doped, electrically conductive interconnection material bonded to the electrode structure. The electrode structure can be an air electrode, and a solid electrolyte layer can be applied to the unselected portion of the air electrode, and further a fuel electrode can be applied to the solid electrolyte, to form an electrochemical cell for generation of electrical power. 4 figs.

  20. Pyrolysis process and apparatus

    DOEpatents

    Lee, Chang-Kuei (Sewell, NJ)

    1983-01-01

    This invention discloses a process and apparatus for pyrolyzing particulate coal by heating with a particulate solid heating media in a transport reactor. The invention tends to dampen fluctuations in the flow of heating media upstream of the pyrolysis zone, and by so doing forms a substantially continuous and substantially uniform annular column of heating media flowing downwardly along the inside diameter of the reactor. The invention is particularly useful for bituminous or agglomerative type coals.

  1. Titanium dioxide thin films: the effect of the preparation method in their photocatalytic properties

    Microsoft Academic Search

    Dwight R. Acosta; Arturo I. Martínez; Alcidez A. López; Carlos R. Magaña

    2005-01-01

    Titanium dioxide thin films were deposited by DC reactive magnetron sputtering and spray pyrolysis methods on glass and glass coated with fluorine tin oxide (FTO). The films were characterized by X-ray diffraction, scanning and transmission electron microscopy, atomic force microscopy and UV–vis spectroscopy. The influence of a reactive atmosphere: a 50\\/50 Ar–O2 mixture on TiO2 thin films deposited by sputtering

  2. Diagnostic measurements of fuel spray dispersion

    NASA Astrophysics Data System (ADS)

    Tishkoff, J. M.; Hammond, D. C., Jr.; Chraplyvy, A. R.

    1980-11-01

    Plume shape, vaporization, droplet size distribution and number density of a fuel spray were studied with conventional and novel measurement techniques. Minor differences in spray plume shape were observed by measurements with photography, pulsed laser shadowgraphy and inline infrared spectroscopy. Laser Mie scattering showed the dispersion of small numbers of droplets beyond spray boundaries as determined by other measurements. A new optical method for nonintrusive, local, time-averaged measurement of vapor concentration, droplet size distribution and number density within a spray is introduced. For the spray studied this method showed that vaporization is confined within the spray plume and that vapor concentration and the concentration of small-diameter droplets exhibit analogous behavior.

  3. Non-isothermal pyrolysis kinetics of three Turkish oil shales

    Microsoft Academic Search

    Ö. Murat Do?an; B. Zühtü Uysal

    1996-01-01

    A non-isothermal experimental study using thermogravimetric analysis (t.g.a.) was conducted to determine the overall kinetics of pyrolysis of three Turkish oil shales: Beypazari, Seyitömer and Himmeto?lu. The integral method was used in the analysis of the t.g.a. data to determine first-order pyrolysis kinetics. Particle sizes of 0.7, 1.3 and 2.6 mm and final temperatures of 400, 550 and 700°C were

  4. Onsite Wastewater Treatment Systems: Spray Distribution System

    E-print Network

    Lesikar, Bruce J.

    2008-10-23

    it working To perform well, spray systems require proper operation and main- tenance. They must clean the waste- water to a secondary-quality effluent. Check the operation and mainte- nance requirements for your par- ticular type of treatment system... re- ? moves pathogens (disease-caus- ing organisms) from the waste- water. Chlorination is the most common disinfection method; A pump tank, which collects and ? holds the water until it is sprayed over the landscape; and Spray heads, which...

  5. Preserve the Investment-Antibiological Spray

    E-print Network

    Reidenbach, R.

    "PRESERVE THE INVESTMENT - ANTIBIOLOGICAL SPRAY" by ROBERT REIDENBACH Spraying Services, Inc. Houston, TX ABSTRACT Annual preservative spray applications to the plenum area combined with a good water treatment program will extend... biological attack once it is put into service. The initial pre-treatment of the wood by the pressure treatment method is generally inade quate for the long-term protection of the framework and other wood components from the devastation of internal wood...

  6. Detection of segmentation cracks in top coat of thermal barrier coatings during plasma spraying by non-contact acoustic emission method

    NASA Astrophysics Data System (ADS)

    Ito, Kaita; Kuriki, Hitoshi; Araki, Hiroshi; Kuroda, Seiji; Enoki, Manabu

    2014-06-01

    Numerous cracks can be observed in the top coat of thermal barrier coatings (TBCs) deposited by the atmospheric plasma spraying (APS) method. These cracks can be classified into vertical and horizontal ones and they have opposite impact on the properties of TBCs. Vertical cracks reduce the residual stress in the top coat and provide strain tolerance. On the contrary, horizontal cracks trigger delamination of the top coat. However, monitoring methods of cracks generation during APS are rare even though they are strongly desired. Therefore, an in situ, non-contact and non-destructive evaluation method for this objective was developed in this study with the laser acoustic emission (AE) technique by using laser interferometers as a sensor. More AE events could be detected by introducing an improved noise reduction filter and AE event detection procedures with multiple thresholds. Generation of vertical cracks was successfully separated from horizontal cracks by a newly introduced scanning pattern of a plasma torch. Thus, generation of vertical cracks was detected with certainty by this monitoring method because AE events were detected only during spraying and a positive correlation was observed between the development degree of vertical cracks and the total AE energy in one experiment.

  7. Kelvin spray ionization.

    PubMed

    Özdemir, Abdil; Lin, Jung-Lee; Gillig, Kent J; Chen, Chung-Hsuan

    2013-11-21

    A novel self-powered dual spray ionization source has been developed for applications in mass spectrometry. This new source does not use any power supply and produces both positive and negative ions simultaneously. The idea behind this ionization source comes from the Kelvin water dropper. The source employs one or two syringes, two pneumatic sprays operated over a range of flow rates (0.15-15 ?L min(-1)) and gas pressures (0-150 psi), and two double layered metal screens for ion formation. A variable electrostatic potential from 0 to 4 kV can be produced depending on solvent and gas flow rates that allow gentle ionization of compounds. There are several parameters that affect the performance during ionization of molecules including the flow rate of solvent, gas pressure, solvent acidity, position of spray and metal screens with respect to each other and distance between metal screens and the counter electrode. This ionization method has been successfully applied to solutions of peptides, proteins and non-covalent complexes. In comparison with ESI, the charge number of the most populated state is lower than that from ESI. It indicates that this is a softer ionization technique and it produces more protein ions with folded structures. The unique features of Kelvin spray ionization (KeSI) are that the method is self-powered and ionization occurs at very low potentials by providing very low internal energy to the ions. This advantage can be used for the ionization of very fragile molecules and investigation of non-covalent interactions. PMID:24080942

  8. Development of biodegradable co-poly( d,l-lactic\\/glycolic acid) microspheres for the controlled release of 5FU by the spray drying method

    Microsoft Academic Search

    Ywu-Jang Fu; Shin-Shing Shyu; Fu-Hu Su; Pih-Chen Yu

    2002-01-01

    The water-soluble anti-cancer drug, 5-fluorouracil (5-fluoro-2,4-pyrimidinedione) (5-FU) is encapsulated into biodegradable co-poly (d,l-lactic\\/glycolic acid) (PLGA) using the spray drying method for the development of long-lasting controlled release systems. In this study, the effects of both polymeric composition and technological parameters on release profiles of 5-FU were investigated. The degradation of various microspheres was also investigated. The mixture of dichloromethane\\/chloroform\\/methanol (1:1:2

  9. Synthesis and electrochemical properties of spinel LiCo 1\\/6Mn 11\\/6O 4 powders by a spray-drying method

    Microsoft Academic Search

    W. K. Zhang; C. Wang; H. Huang; Y. P. Gan; H. M. Wu; J. P. Tu

    2008-01-01

    Co-substituted LiCo1\\/6Mn11\\/6O4 powders were prepared by a spray-drying method for positive electrodes of lithium ion batteries. The heat treating process, crystal structure and electrochemical properties of the synthesized materials were investigated by TG\\/DTG, DSC, XRD, SEM, slow rate cyclic voltammetry (CV) and galvanostatic charge\\/discharge cycling tests. The final powders were identified as single-phase spinel LiCo1\\/6Mn11\\/6O4 with high degree of crystallization

  10. Electrochromism in spray deposited iridium oxide thin films

    Microsoft Academic Search

    P. S. Patil; R. K. Kawar; S. B. Sadale

    2005-01-01

    Electrochromic iridium oxide thin films were deposited onto fluorine doped tin oxide coated glass substrates from an aqueous iridium chloride solution by pneumatic spray pyrolysis technique. The as-deposited samples were X-ray amorphous. The electrochromic properties of thin films were studied in an aqueous electrolyte (0.5N H2SO4) using cyclic voltammetry (CV), chronoamperometry (CA) and spectrophotometry. Iridium oxide films show pronounced anodic

  11. Thickness-dependent properties of sprayed cobalt oxide thin films

    Microsoft Academic Search

    L. D Kadam; P. S Patil

    2001-01-01

    Cobalt oxide thin films with variable thickness were deposited by pneumatic spray pyrolysis technique (PSPT) onto the amorphous glass substrates kept at 300°C. The quantity of cobalt chloride solution was varied to obtain cobalt oxide thin films with thickness ranging from 0.9 to 1.7?m. The effect of film thickness on structural, electrical and optical properties was studied. The X-ray diffraction

  12. Kinetics of scrap tyre pyrolysis under vacuum conditions

    SciTech Connect

    Lopez, Gartzen; Aguado, Roberto [Departamento de Ingenieria Quimica, Universidad del Pais Vasco, Apartado 644, 48080 Bilbao (Spain); Olazar, Martin [Departamento de Ingenieria Quimica, Universidad del Pais Vasco, Apartado 644, 48080 Bilbao (Spain)], E-mail: martin.olazar@ehu.es; Arabiourrutia, Miriam; Bilbao, Javier [Departamento de Ingenieria Quimica, Universidad del Pais Vasco, Apartado 644, 48080 Bilbao (Spain)

    2009-10-15

    Scrap tyre pyrolysis under vacuum is attractive because it allows easier product condensation and control of composition (gas, liquid and solid). With the aim of determining the effect of vacuum on the pyrolysis kinetics, a study has been carried out in thermobalance. Two data analysis methods have been used in the kinetic study: (i) the treatment of experimental data of weight loss and (ii) the deconvolution of DTG (differential thermogravimetry) curve. The former allows for distinguishing the pyrolysis of the three main components (volatile components, natural rubber and styrene-butadiene rubber) according to three successive steps. The latter method identifies the kinetics for the pyrolysis of individual components by means of DTG curve deconvolution. The effect of vacuum in the process is significant. The values of activation energy for the pyrolysis of individual components of easier devolatilization (volatiles and NR) are lower for pyrolysis under vacuum with a reduction of 12 K in the reaction starting temperature. The kinetic constant at 503 K for devolatilization of volatile additives at 0.25 atm is 1.7 times higher than that at 1 atm, and that corresponding to styrene-butadiene rubber at 723 K is 2.8 times higher. Vacuum enhances the volatilization and internal diffusion of products in the pyrolysis process, which contributes to attenuating the secondary reactions of the repolymerization and carbonization of these products on the surface of the char (carbon black). The higher quality of carbon black is interesting for process viability. The large-scale implementation of this process in continuous mode requires a comparison to be made between the economic advantages of using a vacuum and the energy costs, which will be lower when the technologies used for pyrolysis require a lower ratio between reactor volume and scrap tyre flow rate.

  13. Corrosivity Of Pyrolysis Oils

    SciTech Connect

    Keiser, James R [ORNL] [ORNL; Bestor, Michael A [ORNL] [ORNL; Lewis Sr, Samuel Arthur [ORNL] [ORNL; Storey, John Morse [ORNL] [ORNL

    2011-01-01

    Pyrolysis oils from several sources have been analyzed and used in corrosion studies which have consisted of exposing corrosion coupons and stress corrosion cracking U-bend samples. The chemical analyses have identified the carboxylic acid compounds as well as the other organic components which are primarily aromatic hydrocarbons. The corrosion studies have shown that raw pyrolysis oil is very corrosive to carbon steel and other alloys with relatively low chromium content. Stress corrosion cracking samples of carbon steel and several low alloy steels developed through-wall cracks after a few hundred hours of exposure at 50 C. Thermochemical processing of biomass can produce solid, liquid and/or gaseous products depending on the temperature and exposure time used for processing. The liquid product, known as pyrolysis oil or bio-oil, as produced contains a significant amount of oxygen, primarily as components of water, carboxylic acids, phenols, ketones and aldehydes. As a result of these constituents, these oils are generally quite acidic with a Total Acid Number (TAN) that can be around 100. Because of this acidity, bio-oil is reported to be corrosive to many common structural materials. Despite this corrosive nature, these oils have the potential to replace some imported petroleum. If the more acidic components can be removed from this bio-oil, it is expected that the oil could be blended with crude oil and then processed in existing petroleum refineries. The refinery products could be transported using customary routes - pipelines, barges, tanker trucks and rail cars - without a need for modification of existing hardware or construction of new infrastructure components - a feature not shared by ethanol.

  14. Vapor phase pyrolysis

    NASA Technical Reports Server (NTRS)

    Steurer, Wolfgang

    1992-01-01

    The vapor phase pyrolysis process is designed exclusively for the lunar production of oxygen. In this concept, granulated raw material (soil) that consists almost entirely of metal oxides is vaporized and the vapor is raised to a temperature where it dissociates into suboxides and free oxygen. Rapid cooling of the dissociated vapor to a discrete temperature causes condensation of the suboxides, while the oxygen remains essentially intact and can be collected downstream. The gas flow path and flow rate are maintained at an optimum level by control of the pressure differential between the vaporization region and the oxygen collection system with the aid of the environmental vacuum.

  15. Studies on pyrolysis of Nomex polyaramid fibers

    Microsoft Academic Search

    S. Villar-Rodil; A. Mart??nez-Alonso; J. M. D. Tascón

    2001-01-01

    The pyrolysis behavior of Nomex [poly(m-phenylene isophtalamide)] fibers under argon was studied using thermoanalytical and infrared spectroscopic methods to get direct information on the progressive changes undergone by the solid material and its carbon fiber residues. Simultaneous thermogravimetry (TG)–differential thermal analysis (DTA) measurements were carried out in a thermobalance in order to establish the different steps in the thermal degradation

  16. Extent of pyrolysis impacts on fast pyrolysis biochar properties.

    PubMed

    Brewer, Catherine E; Hu, Yan-Yan; Schmidt-Rohr, Klaus; Loynachan, Thomas E; Laird, David A; Brown, Robert C

    2012-01-01

    A potential concern about the use of fast pyrolysis rather than slow pyrolysis biochars as soil amendments is that they may contain high levels of bioavailable C due to short particle residence times in the reactors, which could reduce the stability of biochar C and cause nutrient immobilization in soils. To investigate this concern, three corn ( L.) stover fast pyrolysis biochars prepared using different reactor conditions were chemically and physically characterized to determine their extent of pyrolysis. These biochars were also incubated in soil to assess their impact on soil CO emissions, nutrient availability, microorganism population growth, and water retention capacity. Elemental analysis and quantitative solid-state C nuclear magnetic resonance spectroscopy showed variation in O functional groups (associated primarily with carbohydrates) and aromatic C, which could be used to define extent of pyrolysis. A 24-wk incubation performed using a sandy soil amended with 0.5 wt% of corn stover biochar showed a small but significant decrease in soil CO emissions and a decrease in the bacteria:fungi ratios with extent of pyrolysis. Relative to the control soil, biochar-amended soils had small increases in CO emissions and extractable nutrients, but similar microorganism populations, extractable NO levels, and water retention capacities. Corn stover amendments, by contrast, significantly increased soil CO emissions and microbial populations, and reduced extractable NO. These results indicate that C in fast pyrolysis biochar is stable in soil environments and will not appreciably contribute to nutrient immobilization. PMID:22751053

  17. Vacuum pyrolysis of PVC I. Kinetic study

    Microsoft Academic Search

    Rosa Miranda; Jin Yang; Christian Roy; Cornelia Vasile

    1999-01-01

    Vacuum pyrolysis of PVC has been studied emphasizing two aspects: the kinetics of PVC pyrolysis reactions and the yields of pyrolysis products. The purpose of the kinetic study is to identify each apparent reaction involved in PVC pyrolysis. Three stages of weight loss have been evidenced by TG analysis during PVC decomposition both under vacuum and in nitrogen atmosphere, while

  18. Biocrude from biomass: pyrolysis of cottonseed cake

    Microsoft Academic Search

    N Özbay; A. E Pütün; B. B Uzun; E Pütün

    2001-01-01

    Fixed-bed pyrolysis experiments have been conducted on a sample of cottonseed cake to determine the possibility of being a potential source of renewable fuels and chemicals feedstocks, in two different reactors, namely a tubular and a Heinze retort. Pyrolysis atmosphere and pyrolysis temperature effects on the pyrolysis product yields and chemical composition have been investigated. The maximumm oil yield of

  19. Application methods and evaluations of ultra-low-volume sprays for controlling the bollworm, tobacco budworm and boll weevil

    E-print Network

    Nemec, Stanley Joseph

    1967-01-01

    approach for controiiing Lnsectsp most of the present reports pertaining to mitre-Xow-vc4ums sprays sre from stulies male usler field conliticxcs using msiniy cdrcreft to ~ mgathion, Ssy of 1'he present spgiicat1on ms?hole for uUra-iow- voiuxm egrmys..., asn sttsin specie suf- ficient to 6siivsr ~tee us Low ss 3 fxuM- ouncls psr sere~ xn crossing t' he speal of' the eppiicuting mechhe . hes been the xxukn msthol usel for reluaing sprnV voiume psr ears-. 'Zhiei of course, hse iimita6 the uae of gros...

  20. Determination of triamcinolone in human plasma by a sensitive HPLC-ESI-MS/MS method: application for a pharmacokinetic study using nasal spray formulation.

    PubMed

    César, Isabela Costa; Byrro, Ricardo Martins Duarte; de Santana e Silva Cardoso, Fabiana Fernandes; Mundim, Iram Moreira; de Souza Teixeira, Leonardo; de Sousa, Weidson Carlo; Gomes, Sandro Antônio; Bellorio, Karini Bruno; Brêtas, Juliana Machado; Pianetti, Gerson Antônio

    2011-03-01

    A liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS) method for the quantitation of triamcinolone in human plasma after nasal spray application was developed and validated. Betamethasone was used as internal standard (IS). The analytes were extracted by a liquid-liquid procedure and separated on a Zorbax Eclipse XDB C(18) column with a mobile phase composed of 2 mM aqueous ammonium acetate pH 3.2 and acetonitrile (55:45). Selected reaction monitoring was performed using the transitions m/z 435 ? 415 and m/z 393 ? 373 to quantify triamcinolone acetonide and betamethasone, respectively. Calibration curve was constructed over the range of 20-2000 pg/ml for triamcinolone acetonide. The lower limit of quantitation was 20 pg/ml. The mean RSD values were 4.6% and 5.7% for the intra-run and inter-run precision, respectively. The mean accuracy value was 98.5% and a recovery rate corresponding to 97.5% was achieved. No matrix effect was detected in the samples. The validated method was successfully applied to determine the plasma concentrations of triamcinolone acetonide in healthy volunteers, in a pharmacokinetic study with nasal spray formulation. PMID:21394848

  1. Surface characteristic of chemically converted graphene coated low carbon steel by electro spray coating method for polymer electrolyte membrane fuel cell bipolar plate.

    PubMed

    Kim, Jungsoo; Kim, Yang Do; Nam, Dae Geun

    2013-05-01

    Graphene was coated on low carbon steel (SS400) by electro spray coating method to improve its properties of corrosion resistance and contact resistance. Exfoliated graphite was made of the graphite by chemical treatment (Chemically Converted Graphene, CCG). CCG is distributed using dispersing agent, and low carbon steel was coated with diffuse graphene solution by electro spray coating method. The structure of the CCG was analyzed using XRD and the coating layer of surface was analyzed using SEM. Analysis showed that multi-layered graphite structure was destroyed and it was transformed in to fine layers graphene structure. And the result of SEM analysis on the surface and the cross section, graphene layer was uniformly formed with 3-5 microm thickness on the surface of substrate. Corrosion resistance test was applied in the corrosive solution which is similar to the polymer electrolyte membrane fuel cell (PEMFC) stack inside. And interfacial contact resistance (ICR) test was measured to simulate the internal operating conditions of PEMFC stack. As a result of measuring corrosion resistance and contact resistance, it could be confirmed that low carbon steel coated with CCG was revealed to be more effective in terms of its applicability as PEMFC bipolar plate. PMID:23858864

  2. Thin layer chromatography-spray mass spectrometry: a method for easy identification of synthesis products and UV filters from TLC aluminum foils.

    PubMed

    Himmelsbach, Markus; Waser, Mario; Klampfl, Christian W

    2014-06-01

    A straightforward procedure for direct mass spectrometric (MS) analysis of spots from thin layer chromatography (TLC) plates, without the need of an external ion source, was developed using the aluminum plate backing as spray tip. The spots were cut out shaped as a tip with a 60° angle, mounted in front of the MS orifice, and after addition of a spray solvent spectra were obtained immediately. A high-resolution time-of-flight MS was used since the method is of particular interest for rapid identification or confirmation of spots from TLC plates. The practical benefits of this technique were demonstrated by detection of by-products of organic reactions, by identification of degradation products, and by accurate confirmation of spots when UV filters in sunscreens were analyzed by TLC. Employing the described method TLC spots can be evaluated fast without the need of an external ion source or devices for analyte transfer from TLC to MS, only a basic MS instrument and a high-voltage power supply is required. PMID:24500757

  3. Empirical modeling of soot formation in shock-tube pyrolysis of aromatic hydrocarbons

    NASA Technical Reports Server (NTRS)

    Frenklach, M.; Clary, D. W.; Matula, R. A.

    1986-01-01

    A method for empirical modeling of soot formation during shock-tube pyrolysis of aromatic hydrocarbons is developed. The method is demonstrated using data obtained in pyrolysis of argon-diluted mixtures of toluene behind reflected shock waves. The developed model is in good agreement with experiment.

  4. Very Large Eddy Simulations of a Jet-A Spray Reacting Flow in a Single Element LDI Injector With and Without Invoking an Eulerian Scalar DWFDF Method

    NASA Technical Reports Server (NTRS)

    Shih, Tsan-Hsing; Liu, Nan-Suey

    2013-01-01

    This paper presents the very large eddy simulations (VLES) of a Jet-A spray reacting flow in a single element lean direct injection (LDI) injector by using the National Combustion Code (NCC) with and without invoking the Eulerian scalar DWFDF method, in which DWFDF is defined as the density weighted time filtered fine grained probability density function. The flow field is calculated by using the time filtered compressible Navier-Stokes equations (TFNS) with nonlinear subscale turbulence models, and when the Eulerian scalar DWFDF method is invoked, the energy and species mass fractions are calculated by solving the equation of DWFDF. A nonlinear subscale model for closing the convection term of the Eulerian scalar DWFDF equation is used and will be briefly described in this paper. Detailed comparisons between the results and available experimental data are carried out. Some positive findings of invoking the Eulerian scalar DWFDF method in both improving the simulation quality and maintaining economic computing cost are observed.

  5. Fast Pyrolysis of Agricultural Wastes in a Fluidized Bed Reactor

    NASA Astrophysics Data System (ADS)

    Wang, X. H.; Chen, H. P.; Yang, H. P.; Dai, X. M.; Zhang, S. H.

    Solid biomass can be converted into liquid fuel through fast pyrolysis, which is convenient to be stored and transported with potential to be used as a fossil oil substitute. In China, agricultural wastes are the main biomass materials, whose pyrolysis process has not been researched adequately compared to forestry wastes. As the representative agricultural wastes in China, peanut shell and maize stalk were involved in this paper and pine wood sawdust was considered for comparing the different pyrolysis behaviors of agricultural wastes and forestry wastes. Fast pyrolysis experiments were carried out in a bench-scale fluidized-bed reactor. The bio-oil yieldsof peanut shell and maize stalk were obviously lower than that ofpine sawdust. Compared with pine sawdust, the char yields of peanut shell and maize stalk were higher but the heating value of uncondensable gaswas lower. This means that the bio-oil cost will be higher for agricultural wastes if taking the conventional pyrolysis technique. And the characteristic and component analysis resultsof bio-oil revealed that the quality of bio-oil from agricultural wastes, especially maize stalk, was worse than that from pine wood. Therefore, it is important to take some methods to improve the quality of bio-oilfrom agricultural wastes, which should promote the exploitation of Chinese biomass resources through fast pyrolysis in afluidized bed reactor.

  6. Spray-dried multilayered emulsions as a delivery method for omega-3 fatty acids into food systems.

    PubMed

    Shaw, Lauren A; McClements, D Julian; Decker, Eric A

    2007-04-18

    Emulsion can be produced with electrostatic layer-by-layer deposition technologies to have cationic, thick multilayer interfacial membranes that are effective at inhibiting the oxidation of omega-3 fatty acids. This study investigated the stability of spray-dried multilayer emulsion upon reconstitution into an aqueous system. The primary (lecithin) and multilayered secondary emulsions (lecithin and chitosan) were spray-dried with corn syrup solids (1-20 wt %). The lecithin-chitosan multilayer interfacial membrane remained intact on the emulsion droplets upon reconstitution into an aqueous system. Reconstituted secondary (lecithin-chitosan) emulsions were more oxidatively stable than reconstituted primary (lecithin) emulsions. A minimum of 5 wt % corn syrup solids was needed to microencapsulate the secondary emulsion droplets. Maximum oxidative stability of both the powder and the reconstituted secondary emulsions was observed in samples with 5% and 20% corn syrup solids. Addition of EDTA (25 microM) inhibited oxidation of reconstituted primary and secondary emulsions. These studies suggest that a microencapsulated multilayered emulsion system could be used as a delivery system for omega-3 fatty acids in functional foods. PMID:17371041

  7. Dynamic characteristics of pulsed supersonic fuel sprays

    NASA Astrophysics Data System (ADS)

    Pianthong, K.; Matthujak, A.; Takayama, K.; Milton, B. E.; Behnia, M.

    2008-06-01

    This paper describes the dynamic characteristics of pulsed, supersonic liquid fuel sprays or jets injected into ambient air. Simple, single hole nozzles were employed with the nozzle sac geometries being varied. Different fuel types, diesel fuel, bio-diesel, kerosene, and gasoline were used to determine the effects of fuel properties on the spray characteristics. A vertical two-stage light gas gun was employed as a projectile launcher to provide a high velocity impact to produce the liquid jet. The injection pressure was around 0.88-1.24 GPa in all cases. The pulsed, supersonic fuel sprays were visualized by using a high-speed video camera and shadowgraph method. The spray tip penetration and velocity attenuation and other characteristics were examined and are described here. An instantaneous spray tip velocity of 1,542 m/s (Mach number 4.52) was obtained. However, this spray tip velocity can be sustained for only a very short period (a few microseconds). It then attenuates very quickly. The phenomenon of multiple high frequency spray pulses generated by a single shot impact and the changed in the angle of the shock structure during the spray flight, which had already been observed in previous studies, is again noted. Multiple shock waves from the conical nozzle spray were also clearly captured.

  8. Concentration-response data on toxicity of pyrolysis gases from some natural and synthetic polymers

    NASA Technical Reports Server (NTRS)

    Hilado, C. J.; Huttlinger, N. V.

    1978-01-01

    Concentration-response data are presented on the toxic effects of the pyrolysis gases from some natural and synthetic polymers, using the toxicity screening test method developed at the University of San Francisco. The pyrolysis gases from wool, red oak, Douglas fir, polycaprolactam, polyether sulfone, polyaryl sulfone, and polyphenylene sulfide appeared to exhibit the concentration-response relationships commonly encountered in toxicology. Carbon monoxide seemed to be an important toxicant in the pyrolysis gases from red oak, Douglas fir, and polycaprolactam, but did not appear to have been the principal toxicant in the pyrolysis gases from polyether sulfone and polyphenylene sulfide.

  9. Effect of pyrolysis temperature on toxicity of gases from a polyethylene polymer

    NASA Technical Reports Server (NTRS)

    Hilado, C. J.; Kosola, K. L.

    1978-01-01

    A polyethylene polymer was evaluated for time of toxic effect to occur as the result of exposure to gases generated by pyrolysis at various temperatures, using the toxicity screening test method developed at the University of San Francisco. Times to various animal responses decreased with increasing pyrolysis temperature over the range from 400 C to 800 C. Responses at a pyrolysis temperature of 350 C were more rapid than would be expected from the other data, and may indicate the predominance of different pyrolysis reactions in this particular temperature region.

  10. Spray-deposited black nickel selective absorber surfaces for solar thermal conversion

    Microsoft Academic Search

    M. Madhusudana; H. K. Sehgal

    1982-01-01

    A low cost, single-step process employing spray pyrolysis has been developed to deposit selective black nickel coatings on commercially available aluminium and galvanised iron substrates. Parameters for growth have been optimised by a comparative study of the structural, optothermal and optical properties of these films. Optimised films of black nickel on aluminium have alpha = 0.92 and emittance (100 C)

  11. Structural, morphological, optical and photoluminescent properties of spray-deposited ZnSe thin film

    NASA Astrophysics Data System (ADS)

    Lohar, G. M.; Shinde, S. K.; Fulari, V. J.

    2014-11-01

    ZnSe thin films are successfully deposited by spray pyrolysis deposition technique. Deposited thin films are characterized by X-ray diffraction study, and it reveals that spray-deposited ZnSe thin films are polycrystalline with hexagonal crystal structure. Surface morphology is carried out by scanning electron microscopy. It shows cotton-like morphology, and optical properties, such as absorbance, transmittance, reflectance, band gap, refractive index, extinction coefficient are studied. Photoluminescence shows strong emission at 497 nm. Also, spray-deposited ZnSe thin films are hydrophilic in nature, which is shown by contact angle meter.

  12. Triamcinolone Nasal Spray

    MedlinePLUS

    ... eyes, rinse your eyes well with water.Each bottle of triamcinolone nasal spray should only be used ... have been used, the remaining sprays in the bottle might not contain the correct amount of medication. ...

  13. Nicotine Nasal Spray

    MedlinePLUS

    ... in the circles on the side of the bottle. To prime the pump before the first use, hold the bottle in front of a tissue or paper towel. Pump the spray bottle six to eight times until a fine spray ...

  14. Hydrodechlorination of dichlorobiphenyls over Ni-Mo/Al2O3 catalysts prepared by spray-drying method.

    PubMed

    Gryglewicz, G; Stolarski, M; Gryglewicz, S; Klijanienko, A; Piechocki, W; Hoste, S; Van Driessche, I; Carleer, R; Yperman, J

    2006-01-01

    The hydrodechlorination (HDCl) process of 2,3-, 2,4- and 2,5-dichlorobiphenyls was studied over a sulphided Ni-Mo/Al(2)O(3) catalyst in a stirred autoclave at a hydrogen pressure of 3 MPa. The catalysts were prepared by spray-drying. They were characterized by N(2) adsorption, thermogravimetry and scanning electron microscopy with X-ray microanalysis. The reaction temperature of the catalytic HDCl process was varied in the range of 230-290 degrees C. Polychlorinated biphenyls (PCBs) free transformer oil was used as reaction medium. The HDCl degree of dichlorobiphenyl isomers was in the range of 82-93%. The efficiency in the chlorine removal was found to be related to the position of the substituted chlorine atom and decreased as follows 2,4-dichlorobiphenyl approximately 2,5-dichlorobiphenyl>2,3-dichlorobiphenyl. For comparison, the HDCl process of 2,3-dichlorobiphenyl (2,3-PCB) without catalyst was also studied. The chlorine removal was 85% for the catalytic HDCl of 2,3-PCB whereas non-catalytic process led only to 16% of dechlorination in the same operating conditions, i.e. at 290 degrees C after 120 min. Monodichlorobiphenyls were not detected in the reaction products. The data for both catalytic and non-catalytic conversion of 2,3-PCB fit to a first-order model. Kinetic constants and the activation energy of the overall HDCl reaction of 2,3-PCB to biphenyl were evaluated. Compared to non-catalytic process, a nearly threefold decrease in the activation energy was observed in the presence of Ni-Mo/Al(2)O(3) catalyst prepared by spray-drying (48 kJ mol(-1) vs. 124 kJ mol(-1)). PMID:15949837

  15. Catalytic partial oxidation of pyrolysis oils

    NASA Astrophysics Data System (ADS)

    Rennard, David Carl

    2009-12-01

    This thesis explores the catalytic partial oxidation (CPO) of pyrolysis oils to syngas and chemicals. First, an exploration of model compounds and their chemistries under CPO conditions is considered. Then CPO experiments of raw pyrolysis oils are detailed. Finally, plans for future development in this field are discussed. In Chapter 2, organic acids such as propionic acid and lactic acid are oxidized to syngas over Pt catalysts. Equilibrium production of syngas can be achieved over Rh-Ce catalysts; alternatively mechanistic evidence is derived using Pt catalysts in a fuel rich mixture. These experiments show that organic acids, present in pyrolysis oils up to 25%, can undergo CPO to syngas or for the production of chemicals. As the fossil fuels industry also provides organic chemicals such as monomers for plastics, the possibility of deriving such species from pyrolysis oils allows for a greater application of the CPO of biomass. However, chemical production is highly dependent on the originating molecular species. As bio oil comprises up to 400 chemicals, it is essential to understand how difficult it would be to develop a pure product stream. Chapter 3 continues the experimentation from Chapter 2, exploring the CPO of another organic functionality: the ester group. These experiments demonstrate that equilibrium syngas production is possible for esters as well as acids in autothermal operation with contact times as low as tau = 10 ms over Rh-based catalysts. Conversion for these experiments and those with organic acids is >98%, demonstrating the high reactivity of oxygenated compounds on noble metal catalysts. Under CPO conditions, esters decompose in a predictable manner: over Pt and with high fuel to oxygen, non-equilibrium products show a similarity to those from related acids. A mechanism is proposed in which ethyl esters thermally decompose to ethylene and an acid, which decarbonylates homogeneously, driven by heat produced at the catalyst surface. Chapter 4 details the catalytic partial oxidation of glycerol without preheat: droplets of glycerol are sprayed directly onto the top of the catalyst bed, where they react autothermally with contact times on the order of tau ? 30 ms. The reactive flash volatilization of glycerol results in equilibrium syngas production over Rh-Ce catalysts. In addition, water can be added to the liquid glycerol, resulting in true autothermal reforming. This highly efficient process can increase H2 yields and alter the H2 to CO ratio, allowing for flexibility in syngas quality depending on the purpose. Chapter 5 details the results of a time on stream experiment, in which optimal syngas conditions are chosen. Although conversion is 100% for 450 hours, these experiments demonstrate the deactivation of the catalyst over time. Deactivation is exhibited by decreases in H2 and CO 2 production accompanied by a steady increase in CO and temperature. These results are explained as a loss of water-gas shift equilibration. SEM images suggest catalyst sintering may play a role; EDS indicates the presence of impurities on the catalyst. In addition, the instability of quartz in the reactor is demonstrated by etching, resulting in a hole in the reactor tube at the end of the experiment. These results suggest prevaporization may be desirable in this application, and that quartz is not a suitable material for the reactive flash volatilization of oxygenated fuels. In Chapter 6, pyrolysis oil samples from three sources - poplar, pine, and hardwoods - are explored in the context of catalytic partial oxidation. Lessons derived from the tests with model compounds are applied to reactor design, resulting in the reactive flash vaporization of bio oils. Syngas is successfully produced, though deactivation due to coke and ash deposition keeps H2 below equlibrium. Coke formation is observed on the reactor walls, but is avoided between the fuel injection site and catalyst by increasing the proximity of these in the reactor design. Low temperatures are maintained in the fuel delivery system utilizing a water-

  16. Pyrolysis characteristics of the mixture of printed circuit board scraps and coal powder.

    PubMed

    Hao, Juan; Wang, Haifeng; Chen, Shuhe; Cai, Bin; Ge, Linhan; Xia, Wencheng

    2014-10-01

    Thermogravimetric (TG) analysis and infrared spectroscopy were used to analyze the pyrolysis characteristics of printed circuit board scraps (PCBs), coal powder and their mixtures under nitrogen atmosphere. The experimental results show that there is a large difference between waste PCBs and coal powder in pyrolysis processing. The pyrolysis properties of the mixing samples are the result of interaction of the PCBs and coal powder, which is influenced by the content of mixture. The degree of pyrolysis and pyrolysis properties of the mixture are much better than that of the single component. The TG and the differential thermogravimetric (DTG) curves of the PCBs mixed with coal powder move towards the high-temperature zone with increasing amount of coal powder and subsequently the DTG peak also becomes wider. The Coats-Redfern integral method was used to determine the kinetic parameters of pyrolysis reaction mechanism with the different proportion of mixture. The gas of pyrolysis mainly composes of CO2, CO, H2O and some hydrocarbon. The bromide characteristic absorption peak has been detected obviously in the pyrolysis gas of PCBs. On the contrary, the absorption peak of the bromide is not obvious in pyrolysis gas of the PCBs samples adding 40% coal powder. PMID:24269060

  17. Remotely controlled spray gun

    NASA Technical Reports Server (NTRS)

    Cunningham, William C. (inventor)

    1987-01-01

    A remotely controlled spray gun is described in which a nozzle and orifice plate are held in precise axial alignment by an alignment member, which in turn is held in alignment with the general outlet of the spray gun by insert. By this arrangement, the precise repeatability of spray patterns is insured.

  18. Spray application technology

    Microsoft Academic Search

    K. M. Jones; S. A. Bound; M. J. Oakford

    2000-01-01

    Spray application technology on perennial tree crops has been a poorly researched subject. Many of the nozzles and sprayers were originally developed for use on row crops which have an even, flat profile and spraying is downward. Some of the short-comings of these systems were exposed when tree crops were sprayed, particularly the large and dense trees of 30 years

  19. Structures of soot generated by laser induced pyrolysis of metal-graphite composite targets

    Microsoft Academic Search

    E. Muñoz; A. M. Benito; L. C. Estepa; J. Fernández; Y. Maniette; M. T. Martínez; G. F. de la Fuente

    1998-01-01

    The first results of a novel laser induced pyrolysis (LIP) method for high yield production of fullerene and single walled nanotubes are reported. The pyrolysis process of graphite targets is carried out by means of a continuous CO2 laser under a flowing argon atmosphere. The vaporization of the targets and the deposition of the generated soot take place in a

  20. Products and bioenergy from the pyrolysis of rice straw via radio frequency plasma and its kinetics

    Microsoft Academic Search

    Wen-Kai Tu; Je-Lung Shie; Ching-Yuan Chang; Chiung-Fen Chang; Cheng-Fang Lin; Sen-Yeu Yang; Jing T. Kuo; Dai-Gee Shaw; Yii-Der You; Duu-Jong Lee

    2009-01-01

    The radio frequency plasma pyrolysis technology, which can overcome the disadvantages of common pyrolysis methods such as less gas products while significant tar formation, was used for pyrolyzing the biomass waste of rice straw. The experiments were performed at various plateau temperatures of 740, 813, 843 and 880K with corresponding loading powers of 357, 482, 574 and 664W, respectively. The

  1. Plasma Pyrolysis Assembly Regeneration Evaluation

    NASA Technical Reports Server (NTRS)

    Medlen, Amber; Abney, Morgan B.; Miller, Lee A.

    2011-01-01

    In April 2010 the Carbon Dioxide Reduction Assembly (CRA) was delivered to the International Space Station (ISS). This technology requires hydrogen to recover oxygen from carbon dioxide. This results in the production of water and methane. Water is electrolyzed to provide oxygen to the crew. Methane is vented to space resulting in a loss of valuable hydrogen and unreduced carbon dioxide. This is not critical for ISS because of the water resupply from Earth. However, in order to have enough oxygen for long-term missions, it will be necessary to recover the hydrogen to maximize oxygen recovery. Thus, the Plasma Pyrolysis Assembly (PPA) was designed to recover hydrogen from methane. During operation, the PPA produces small amounts of carbon that can ultimately reduce performance by forming on the walls and windows of the reactor chamber. The carbon must be removed, although mechanical methods are highly inefficient, thus chemical methods are of greater interest. The purpose of this effort was to determine the feasibility of chemically removing the carbon from the walls and windows of a PPA reactor using a pure carbon dioxide stream.

  2. Characterization of sprays

    NASA Astrophysics Data System (ADS)

    Chigier, N.; Mao, C.-P.

    It is pointed out that most practical power generation and propulsion systems involve the burning of different types of fuel sprays, taking into account aircraft propulsion, industrial furnaces, boilers, gas turbines, and diesel engines. There has been a lack of data which can serve as a basis for spray model development and validation. A major aim of the present investigation is to fill this gap. Experimental apparatus and techniques for studying the characteristics of fuel sprays are discussed, taking into account two-dimensional still photography, cinematography, holography, a laser diffraction particle sizer, and a laser anemometer. The considered instruments were used in a number of experiments, taking into account three different types of fuel spray. Attention is given to liquid fuel sprays, high pressure pulsed diesel sprays, and coal-water slurry sprays.

  3. Development and validation of a stability indicative HPLC-PDA method for kaurenoic acid in spray dried extracts of Sphagneticola trilobata (L.) Pruski, Asteraceae.

    PubMed

    Fucina, Giovana; Block, Luciana Catia; Baccarin, Thaisa; Ribeiro, Thiago Ruiz Gutierrez; Quintão, Nara Lins Meira; Filho, Valdir Cechinel; Silva, Ruth Meri Lucinda; Bresolin, Tania Mari Bellé

    2012-11-15

    A gradient stability indicative HPLC-UV method was developed and validated for assay of the marker kaurenoic acid (KA) in spray dried extract of Sphagneticola trilobata (L.) Pruski. The marker, and another unidentified polar component, were separated on a Luna Phenomenex C(18) column (250×4.6 mm, 5 ?m) with mobile phase composed of acetonitrile:acidified water pH 3.0 with phosphoric acid, in a gradient run of 40 min; at a flow rate of 1.0 mL min(-1), 35 °C, using wavelengths of 210 and 338 nm. The method was linear over a KA concentration range of 4.5-30.0 ?g mL(-1), without interference of the herbal matrix on the linearity of the method. The RSD% values for the intra- and inter-day precision studies were <2.0 and <8.0% for inter-laboratorial study. The method showed excellent KA recovery (99.0%). The LOQ value was found to be 1.13 ?g mL(-1) and the method proved to be robust for small, deliberate changes in temperature and pH of the mobile phase with RSD%<2.5% for the KA assay. A forced degradation study of S. trilobata dried extract was conducted under conditions of visible light (1.200.000 l×h(-1)) and UV (200 Whm(-2)) irradiation, acid (0.5 mol L(-1) HCl, 30 min), basic (1 mol L(-1) NaOH, 2 h) and oxidative (30% H(2)O(2), 4h) hydrolysis, in order to develop a gradient stability-indicating LC-UV method for KA quantification, the selected marker, and also to detect the major polar components of the extract, under investigation. The KA contents remaining after these stress conditions were 72.3, 70.0, 97.6, 65.8 and 87.0%, respectively. The alkaline conditions resulted in higher degradation for the unknown polar components of the extract, without interference of supplementary peaks at the retention time of the KA. This method can be used for the KA assay and qualitative analysis of polar components in stability study of spray dried extracts of S. trilobata, for subsequent use in the quality control of dosage forms. PMID:23158359

  4. Pyrolysis process with feed pretreatment

    SciTech Connect

    Durai-swamy, K.

    1982-04-13

    In a process for recovery of values contained in solid carbonaceous material, a solid carbonaceous material is comminuted and then treated at an elevated temperature with a capping agent which is at treating conditions either a liquid or a gas. The treating conditions are such that the capping agent is sorbed by the solid particulate carbonaceous material. The solid particulate carbonaceous material containing the sorbed capping agent is then subjected to pyrolysis preferably in the presence of a solid particulate source of heat and a transport gas in a transport flash pyrolysis reactor, to form a pyrolysis product stream. The solid particulate carbonaceous feed material is pyrolyzed and newly formed volatilized hydrocarbon free radicals are substantially simultaneously terminated by the sorbed capping agent as such radicals are formed, to form a pyrolysis product stream. The pyrolysis product stream contains a gaseous mixture and particulate solids which are separated from the gaseous mixture to form a substantially particulate solids-free gaseous mixture stream which contains capping agent terminated volatilized hydrocarbon free radicals, hydrogen depleted capping agent, pyrolysis product vapors and a transport gas. Hydrocarbons of four or more carbon atoms in the gaseous mixture stream are condensed. A liquid stream containing the stabilized liquid product is then treated or separated into various fractions. A liquid containing the hydrogen depleted capping agent is hydrogenated to form a regenerated capping agent, at least a portion of which is recycled to the pyrolysis zone. In another embodiment the capping agent is produced by the process, separated from the liquid product mixture, and recycled.

  5. Method of creating starch-like ultra-fine rice flour and effect of spray drying on formation of free fatty acid.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice flour from long, medium, and short grain cultivars were processed by passing a 32% rice flour slurry through a microfluidizer at 100 MPa, and spray dryer at three different outlet temperatures, OT (50°C, 80°C, and 115°C). Spray drying conditions were controlled by the flow-rate of the slurry ...

  6. Effect of Spray Parameters on the Corrosion Behavior of HVOF Sprayed WC-Co-Cr Coatings

    NASA Astrophysics Data System (ADS)

    Hong, Sheng; Wu, Yuping; Zheng, Yugui; Wang, Bo; Gao, Wenwen; Li, Gaiye; Ying, Guobing; Lin, Jinran

    2014-04-01

    WC-10Co-4Cr cermet coatings were deposited on the substrate of AISI 1045 steel by using high-velocity oxygen-fuel (HVOF) thermal spraying process. The Taguchi method including the signal-to-noise (S/N) ratio and the analysis of variance (ANOVA) was employed to optimize the porosity and, in turn, the corrosion resistance of the coatings. The spray parameters evaluated in this study were spray distance, oxygen flow, and kerosene flow. The results indicated that the important sequence of spray parameters on the porosity of the coatings was spray distance > oxygen flow > kerosene flow, and the spray distance was the only significant factor. The optimum spraying condition was 300 mm for the spray distance, 1900 scfh for the oxygen flow, and 6.0 gph for the kerosene flow. The results showed the significant influence of the microstructure on the corrosion resistance of the coatings. Potentiodynamic polarization and electrochemical impendence spectroscopy (EIS) results showed that the WC-10Co-4Cr cermet coating obtained by the optimum spraying condition with the lowest porosity exhibits the best corrosion resistance and seems to be an alternative to hard chromium coating.

  7. Comprehensive utilization of the pyrolysis products from sewage sludge.

    PubMed

    Xu, W Y; Wu, D

    2015-07-01

    Bio-oils were produced from pyrolysis of sewage sludge in a horizontal tubular furnace under the anoxic or anaerobic conditions, by varying operating parameters and moisture content (MC) of the feedstock. Physicochemical properties of the obtained bio-oil (such as density, acid value, kinematical viscosity, high heating value and flash point) were analysed and compared with Chinese fuel standards. Tend, RT and ? were found critical to control the yield and physico-chemical properties of bio-oil products. The relative importance of various parameters such as Tend, RT, ? and MC was determined and the optimum values for the lowest kinematic viscosity and acid value and the highest yield of the bio-oil were achieved using the orthogonal matrix method. The parameters 550°C, 45?min, 5°C?min(-1) and MC of 10% were found effective in producing the bio-oils with most of the desirable physico-chemical properties and yield. Benefit analysis was conducted to further optimize the operating parameters, considering pyrolysis treatment, comprehensive utilization of the pyrolysis products and final disposal of sewage sludge; the results showed the best economy of the pyrolysis parameters 450°C, 75?min, 3°C?min(-1) and MC of 10%. The char obtained under this condition may serve as a microporous liquid adsorbent, while the bio-oil may serve as a low grade fuel oil after upgrading it with conventional fuel oil and deacidification. Pyrolysis products may become economically competitive in addition to being environment friendly. PMID:25609547

  8. Experimental Research of Pyrolysis Gases Cracking on Surface of Charcoal

    NASA Astrophysics Data System (ADS)

    Kosov, Valentin; Kosov, Vladimir; Zaichenko, Victor

    For several years, in the Joint Institute for High Temperatures of Russian Academy of Sciences, two-stage technology of biomass processing has been developing [1]. The technology is based on pyrolysis of biomass as the first stage. The second stage is high-temperature conversion of liquid fraction of the pyrolysis on the surface of porous charcoal matrix. Synthesis gas consisted of carbon monoxide and hydrogen is the main products of the technology. This gas is proposed to be used as fuel for gas-engine power plant. For practical implementation of the technology it is important to know the size of hot char filter for full cracking of the pyrolysis gases on the surface of charcoal. Theoretical determination of the cracking parameters of the pyrolysis gases on the surface of coal is extremely difficult because the pyrolysis gases include tars, whose composition and structure is complicated and depends on the type of initial biomass. It is also necessary to know the surface area of the char used in the filter, which is also a difficult task. Experimental determination of the hot char filter parameters is presented. It is shown that proposed experimental method can be used for different types of biomass.

  9. Effect of annealing time on the physical properties of ultrasonically sprayed CdS:In thin films

    NASA Astrophysics Data System (ADS)

    Karakaya, S.; Gency?lmaz, O.; Ozbas, O.

    2012-09-01

    In this work, CdS and In doped CdS films were prepared by ultrasonic spray pyrolysis (USP) technique and were annealed at 450 °C in an air atmoshpere. The optical constants (n and k) and thicknesses of the films were determined by spectroscopic ellipsometry. Transmission and absorbance spectra were taken by UV spectrophotometer. Optical method was used to determine the band gap value of the films. Atomic force microscope (AFM) images were taken to see the effect of annealing time on surface topography and roughness of the films. Electrical resistivities of the films were analyzed by four probe technique. As a result, the application potential of annealed CdS:In films for photovoltaic solar cells and optoelectronic applications were investigated.

  10. Toxicity of pyrolysis gases from wood

    NASA Technical Reports Server (NTRS)

    Hilado, C. J.; Huttlinger, N. V.; Oneill, B. A.; Kourtides, D. A.; Parker, J. A.

    1977-01-01

    The toxicity of the pyrolysis gases from nine wood samples was investigated. The samples of hardwoods were aspen poplar, beech, yellow birch, and red oak. The samples of softwoods were western red cedar, Douglas fir, western hemlock, eastern white pine, and southern yellow pine. There was no significant difference between the wood samples under rising temperature conditions, which are intended to simulate a developing fire, or under fixed temperature conditions, which are intended to simulate a fully developed fire. This test method is used to determine whether a material is significantly more toxic than wood under the preflashover conditions of a developing fire.

  11. Numerical parametric studies of spray combustion instability

    NASA Technical Reports Server (NTRS)

    Pindera, M. Z.

    1993-01-01

    A coupled numerical algorithm has been developed for studies of combustion instabilities in spray-driven liquid rocket engines. The model couples gas and liquid phase physics using the method of fractional steps. Also introduced is a novel, efficient methodology for accounting for spray formation through direct solution of liquid phase equations. Preliminary parametric studies show marked sensitivity of spray penetration and geometry to droplet diameter, considerations of liquid core, and acoustic interactions. Less sensitivity was shown to the combustion model type although more rigorous (multi-step) formulations may be needed for the differences to become apparent.

  12. Concentration-response data on toxicity of pyrolysis gases from six synthetic polymers

    NASA Technical Reports Server (NTRS)

    Hilado, C. J.; Huttlinger, N. V.

    1978-01-01

    Concentration-response data are presented on the toxic effects of the pyrolysis gases from six synthetic polymers on Swiss Webster male mice, using a toxicity screening test method. The polymers consisted of one sample each of polycarbonate and polystyrene, and two samples each of polyethylene and acrylonitrile-butadiene-styrene (ABS). All six samples were evaluated using the rising temperature program, and three samples were evaluated using the fixed temperature program. The pyrolysis gases from polycarbonate, polyethylene, and ABS appeared to exhibit the concentration-response relationships commonly encountered in toxicology. The polystyrene sample gave variable results; probably due to poor reproducibility of the essentially anaerobic pyrolysis. Carbon monoxide seemed to be the principal toxicant in the pyrolysis gases from polycarbonate and polyethylene, but did not appear to be the principal toxicant in the pyrolysis gases from ABS.

  13. Comparison of apatite-coated titanium prepared by blast coating and flame spray methods--evaluation using simulated body fluid and initial histological study.

    PubMed

    Mano, Takamitsu; Ishikawa, Kunio; Harada, Koji; Umeda, Hirotsugu; Ueyama, Yoshiya

    2011-01-01

    It has previously been demonstrated that apatite may be coated on the surface of titanium (Ti) at room temperature when the titanium is blasted with apatite powder. This method is known as the blast coating (BC) method. In this study, the osteoconductivity and tissue response to Ti implants blast-coated with apatite (BC implants) were evaluated using apatite-coated Ti implants produced using the flame spraying (FS) method (FS implants) and pure Ti implants as a control. Initial evaluation using simulated body fluid demonstrated higher osteoconductivity in BC implants than in FS implants. Therefore, specimens were implanted in rat tibias for 1, 3 and 6 weeks. At one week after implantation, BC implants showed much higher bone contact ratio when compared with FS implants; the bone contact ratio of BC implants was 75.7%, while the FS and pure Ti implants had ratios of 30.8% and 5.5%, respectively. The difference in bone contact ratio between BC and FS implants decreased with implantation time and the ratios were equal after 6 weeks. In conclusion, BC implants show higher osteoconductivity than FS implants, and thus BC implants are beneficial for early fixation of implants to bone tissue. PMID:21778611

  14. Fuel spray diagnostics

    NASA Technical Reports Server (NTRS)

    Bosque, M. A.

    1984-01-01

    Several laser measurement methods are being studied to provide the capability to make droplet size and velocity measurements under a variety of spray conditions. The droplet sizing interferometer (DSI) promises to be a successful technique because of its capability for rapid data acquisition, compilation and analysis. Its main advantage is the ability to obtain size and velocity measurements in air-fuel mixing studies and hot flows. The existing DSI at NASA Lewis is a two-color, two-component system. Two independent orthogonal measurements of size and velocity components can be made simultaneously. It also uses an off-axis large-angle light scatter detection. The fundamental features of the system are optics, signal processing and data management system. The major component includes a transmitter unit, two receiver units, two signal processors, two data management systems, two Bragg cell systems, two printer/plotters, a laser, power supply and color monitor.

  15. LSPRAY-IV: A Lagrangian Spray Module

    NASA Technical Reports Server (NTRS)

    Raju, M. S.

    2012-01-01

    LSPRAY-IV is a Lagrangian spray solver developed for application with parallel computing and unstructured grids. It is designed to be massively parallel and could easily be coupled with any existing gas-phase flow and/or Monte Carlo Probability Density Function (PDF) solvers. The solver accommodates the use of an unstructured mesh with mixed elements of either triangular, quadrilateral, and/or tetrahedral type for the gas flow grid representation. It is mainly designed to predict the flow, thermal and transport properties of a rapidly vaporizing spray. Some important research areas covered as a part of the code development are: (1) the extension of combined CFD/scalar-Monte- Carlo-PDF method to spray modeling, (2) the multi-component liquid spray modeling, and (3) the assessment of various atomization models used in spray calculations. The current version contains the extension to the modeling of superheated sprays. The manual provides the user with an understanding of various models involved in the spray formulation, its code structure and solution algorithm, and various other issues related to parallelization and its coupling with other solvers.

  16. Vertical-bed pyrolysis system. [Tech-Air Pyrolysis System

    Microsoft Academic Search

    M. D. Bowen; E. D. Smyly; J. A. Knight; K. R. Purdy

    1978-01-01

    The development of the Tech-Air pyrolysis system has been briefly traced from the initial laboratory work in the 1960's through the construction and operation of four pilot plants, two large scale field test systems and one large, commercial prototype plant, the Cordele plant. This work was accomplished over a ten year period and culminated in 1977 with the successful demonstration

  17. Simplifying pyrolysis; using gasification to produce corn stover and wheat straw biochar for sorptive and horitcultural media

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biochar is a renewable, useful material that can be utilized in many different applications. Biochar is commonly produced via pyrolysis methods using a retort-style oven with inert gas. Gasification is another method that can utilize pyrolysis to produce biochar, but with the advantage of not requir...

  18. Comparative pyrolysis and combustion kinetics of oil shales

    Microsoft Academic Search

    Mustafa Versan Kök; M. Reha Pamir

    2000-01-01

    In this research, thermal characteristics and kinetic parameters of eight Turkish oil shale samples were determined by thermogravimetry (TG\\/DTG) at non-isothermal heating conditions both for pyrolysis and combustion processes. A general computer program was developed and the methods are compared with regard to their accuracy and the ease of interpretation of the kinetics of thermal decomposition. Activation energies of the

  19. Study of the hydrodynamics and disperse structure of a jet spray by the method of laser diagnosis

    Microsoft Academic Search

    V. A. Borodulya; A. Z. Grebenkov; I. V. Khodan; V. I. Rubezhanskii

    1985-01-01

    The use of contact methods and photography does not give a complete representation of flow hydrodynamics in empirical determinations of the gasdynamic characteristics of two-phase flows. Thus, contactless methods are being used more and more to study liquid atomization processes. One of these is the laser-Doppler method which makes it possible to obtain quantitative information on the dynamic characteristics and

  20. Initial Stages of Pyrolysis of Polyethylene

    NASA Astrophysics Data System (ADS)

    Popov, Konstantin V.

    Combustion and flammability of plastics are important topics of practical interest directly related to fire safety and recycling of polymeric materials; pyrolysis of the solid is the initial step of its combustion. One of the main ways to study such complicated processes is through detailed mechanistic modeling, in which the process is represented by a set of many elementary reactions. Mechanistic modeling of combustion of plastics is considerably hindered by the lack of necessary kinetic data. In virtually all existing models of polymer pyrolysis the majority of kinetic data used are derived from the corresponding gas phase values of smaller species. The use of gas phase rate constants is, generally, not justified without an experimental justification. In the first part of the work the influence of condensed phase on the rate of scission of a carbon-carbon bond (the reaction that initiates pyrolysis and combustion) in polyethylene (PE) was studied using the method of Reactive Molecular Dynamics (RMD). A method based on a two-step kinetic mechanism was developed to decouple the cage effect from the kinetics of the reaction under study. It was observed that under the conditions of condensed phase the rate constant of C-C bond scission in PE decreased by an order of magnitude compared to that obtained in vacuum. It was also shown that under the conditions of polymer melt the rate constant does not depend on the length of the polymer chain. In the second part of the work the kinetics of liquid phase and gas phase products of PE pyrolysis were studied experimentally using Gas Chromatography and Nuclear Magnetic Resonance. Based on the assumption of applicability of gas phase kinetic data for C-C scission reaction and beta-scission reaction under the conditions of polymer melt, rate constants of hydrogen transfer, radical addition to double bonds, and radical recombination were determined via kinetic modeling of the experimental results. The obtained values of the rate constants were found to be in reasonable agreement with the constants of similar reactions of smaller molecules in the gas phase.

  1. Spray Technology in Perennial Tree Crops

    Microsoft Academic Search

    Sally A. Bound

    There has been phenomenal progress in spray technology over the last 30 years. An increased awareness of the issues relating\\u000a to spray efficiency has led researchers to re-examine factors such as air velocity and pattern, nozzle placement in relation\\u000a to the crop, and methods of reducing chemical dosage rates. Advances have been made in understanding many of the factors involved

  2. A comparison of the sliding wear behavior of a hypereutectic Al–Si alloy prepared by spray-deposition and conventional casting methods

    Microsoft Academic Search

    Feng Wang; Yajun Ma; Zhengye Zhang; Xiaohao Cui; Yuansheng Jin

    2004-01-01

    In this study a hypereutectic Al–20Si (wt.%) alloy was synthesized using two different routes: the spray-deposition technique and the conventional casting process. The dry sliding wear behavior of the alloys was investigated under four loads; namely, 8.9, 17.8, 26.7 and 35.6N. It showed that spray-deposited alloy exhibited an improved wear resistance at the entire applied load range in comparison to

  3. Carbon nanoparticles from laser pyrolysis

    Microsoft Academic Search

    Aymeric Galvez; Nathalie Herlin-Boime; Cécile Reynaud; Christian Clinard; Jean-Noël Rouzaud

    2002-01-01

    Carbon nanoparticles synthesised by laser pyrolysis of hydrocarbons in a flow reactor have been investigated as a function of laser power. Samples are cross-characterised by high resolution transmission electron microscopy (HRTEM) and infrared (IR) spectroscopy. Nanoparticles appear highly aromatic in character in all the experimental conditions explored here. As the flame temperature in the interaction zone increases, the nanoparticles evolve

  4. SPRAY CALCINATION REACTOR

    Microsoft Academic Search

    Johnson

    1963-01-01

    A spray calcination reactor for calcining reprocessin- g waste solutions ; is described. Coaxial within the outer shell of the reactor is a shorter inner ; shell having heated walls and with open regions above and below. When the ; solution is sprayed into the irner shell droplets are entrained by a current of ; gas that moves downwardly within

  5. Pyrolysis-combustion 14C dating of soil organic matter

    USGS Publications Warehouse

    Wang, H.; Hackley, K.C.; Panno, S.V.; Coleman, D.D.; Liu, J.C.-L.; Brown, J.

    2003-01-01

    Radiocarbon (14C) dating of total soil organic matter (SOM) often yields results inconsistent with the stratigraphic sequence. The onerous chemical extractions for SOM fractions do not always produce satisfactory 14C dates. In an effort to develop an alternative method, the pyrolysis-combustion technique was investigated to partition SOM into pyrolysis volatile (Py-V) and pyrolysis residue (Py-R) fractions. The Py-V fractions obtained from a thick glacigenic loess succession in Illinois yielded 14C dates much younger but more reasonable than the counterpart Py-R fractions for the soil residence time. Carbon isotopic composition (??13C) was heavier in the Py-V fractions, suggesting a greater abundance of carbohydrate- and protein-related constituents, and ??13C was lighter in the Py-R fractions, suggesting more lignin- and lipid-related constituents. The combination of 14C dates and ??13C values indicates that the Py-V fractions are less biodegradation resistant and the Py-R fractions are more biodegradation resistant. The pyrolysis-combustion method provides a less cumbersome approach for 14C dating of SOM fractions. With further study, this method may become a useful tool for analyzing unlithified terrestrial sediments when macrofossils are absent. ?? 2003 University of Washington. Published by Elsevier Inc. All rights reserved.

  6. Spray measurement technology: a review

    NASA Astrophysics Data System (ADS)

    Fansler, Todd D.; Parrish, Scott E.

    2015-01-01

    Sprays are among the most intellectually challenging and practically important topics in fluid mechanics. This paper reviews needs, milestones, challenges, and a broad array of techniques for spray measurement. In addition, tabular summaries provide cross-referenced entry points to the vast literature by organizing over 300 citations according to key spray phenomena, physical parameters and measurement techniques for each of the principal spray regions (nozzle internal flow, near-field spray-formation region, far-field developed spray, and spray-wall interaction). The article closes with perspectives on some current issues in spray research, including the cost and complexity of apparatus for spray physics and spray engineering, the need for simultaneous diagnostic measurements under application-relevant conditions, and the effective comparison of spray measurements and numerical simulations.

  7. Li EXCESS Li4+xTi5-xO12-?/C COMPOSITE USING SPRAY-DRYING METHOD AND ITS ELECTRODE PROPERTIES

    NASA Astrophysics Data System (ADS)

    Yoshikawa, Daisuke; Suzuki, Norio; Kadoma, Yoshihiro; Ui, Koichi; Kumagai, Naoaki

    2012-03-01

    We have prepared a lithium excess carbon composite material, Li4+xTi5-xO12-?/C (LTO/C), using various amounts of sucrose as a carbon source by the spray-drying method. The prepared materials were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and elemental analysis. The prepared material had the Li4Ti5O12 phase including 3.9-18.4 wt.% carbon. Transmission electron microscopy images and the selected area diffraction (SAD) pattern showed that the prepared materials consisted of a carbon nanonetwork in the LTO/C composite. The charge-discharge cycling tests were carried out using the R2032 coin-type cell under the following conditions; 1.2-3.0 V, 0.1 C-10 C (1 C = 175 mA g-1), 25°C. Based on the electrochemical results, the electrode performance of the prepared material was improved with increasing amounts of residual carbon, in particular, LTO/C including 6.2 wt.% residual carbon exhibited the best electrode performance of 156 mAh g-1 at 1 C during 50 cyclings when compared to the other materials.

  8. Effects of Thermal Treatment on Crystallographic and Electrical Properties of Transparent Conductive ZnO Films Deposited by Spin-Spray Method

    NASA Astrophysics Data System (ADS)

    Hong, JeongSoo; Wagata, Hajime; Katsumata, Ken-ichi; Okada, Kiyoshi; Matsushita, Nobuhiro

    2013-11-01

    ZnO films were deposited by a novel aqueous solution process named the spin-spray method and thermally treated at different temperatures from 100 to 300 °C. All films had a high transmittance of 80% in the visible range and exhibited conductivity after UV illumination for 24 h. The dependence of thermal treatment temperature before UV illumination on their crystallographic and electrical properties was investigated in this study. The XRD peak intensity increased and the full width at half maximum of the (101) peak decreased from 0.35 to 0.26° for the sample thermally treated at 100 °C. From the Fourier transform infrared (FT-IR) spectra, decreases in Vas (COO-) and Vs (COO-) intensities with increasing thermal treatment temperature were observed. The resistivity after the UV illumination of the sample without thermal treatment was 4.1×10-2 ? cm, and it decreased to 1.6×10-2 ? cm in the sample thermally treated at 100 °C. The sample with the lowest resistivity exhibited a relatively high mobility of 3.3 cm2 V-1 s-1 and a very high carrier concentration of 1.1×1020 cm-3 as the solution-processed ZnO film.

  9. Spray Rolling Aluminum Strip

    SciTech Connect

    Lavernia, E.J.; Delplanque, J-P; McHugh, K.M.

    2006-05-10

    Spray forming is a competitive low-cost alternative to ingot metallurgy for manufacturing ferrous and non-ferrous alloy shapes. It produces materials with a reduced number of processing steps, while maintaining materials properties, with the possibility of near-net-shape manufacturing. However, there are several hurdles to large-scale commercial adoption of spray forming: 1) ensuring strip is consistently flat, 2) eliminating porosity, particularly at the deposit/substrate interface, and 3) improving material yield. Through this program, a new strip/sheet casting process, termed spray rolling, has been developed, which is an innovative manufacturing technique to produce aluminum net-shape products. Spray rolling combines the benefits of twin-roll casting and conventional spray forming, showing a promising potential to overcome the above hurdles associated with spray forming. Spray rolling requires less energy and generates less scrap than conventional processes and, consequently, enables the development of materials with lower environmental impacts in both processing and final products. Spray Rolling was developed as a collaborative project between the University of California-Davis, the Colorado School of Mines, the Idaho National Engineering and Environmental Laboratory, and an industry team. The following objectives of this project were achieved: (1) Demonstration of the feasibility of the spray rolling process at the bench-scale level and evaluation of the materials properties of spray rolled aluminum strip alloys; and (2) Demonstration of 2X scalability of the process and documentation of technical hurdles to further scale up and initiate technology transfer to industry for eventual commercialization of the process.

  10. Experimental study of the spray characteristics of biodiesel based on inedible oil.

    PubMed

    Gao, Yuan; Deng, Jun; Li, Chunwang; Dang, Fengling; Liao, Zhuo; Wu, Zhijun; Li, Liguang

    2009-01-01

    We studied the spray characteristics of inedible oil using experimental and simulation methods. Spray penetration, spray cone angle and spray tip speed were measured at different biodiesel ratios in a constant volume vessel with wide visualization and high back pressure, using a high-speed camera. The characteristics of biodiesel spray were simulated under the same conditions using Star-CD software. The experimental results showed that, as the ratio of biodiesel in the blends increased, spray penetration and spray speed increased, but the spray cone angle decreased. Throughout the spray injection period, the region at 0.05-0.475S (spray tip penetration) was a key area affecting spray cone angle. From 0.8 ms after injection, the spray penetration deviation ratios started to increase with increasing biodiesel blend ratios. Simulation results showed similar macroscopic spray characteristics to the experimental results for jatropha oil. The results also showed that the Sauter mean diameter of blend fuels was greater than that of diesel, and spray was more concentrated, due to the higher viscosity and surface tension of the biodiesel, compared with conventional diesel fuel. The macroscopic and microscopic spray properties of blended fuels containing 5%, 10% and 20% biodiesel were similar to diesel. PMID:19409479

  11. Kinetic studies on the pyrolysis of pinewood.

    PubMed

    Mishra, Garima; Kumar, Jitendra; Bhaskar, Thallada

    2015-04-01

    The kinetic study for pyrolysis of pine wood has been studied by a thermogravimetric analyzer in an inert atmosphere. Non isothermal model free kinetic methods were used to evaluate kinetics at six different heating rates of 5-40°C/min. Three zones can be detected from the iso-conversional plot of pine with average activation energy values of 134.32kJ/mol, 146.89kJ/mol and 155.76kJ/mol in the conversion range of 1-22%, 24-84% and 85-90%, respectively. The activation energy values were used to determine the reaction mechanism using master plots and compensation parameters. The results show that the pyrolysis process of pine wood can be described by two dimensional diffusion reaction mechanism in a wide range of conversion up to 0.7, followed by close to one and half order reaction mechanism. The kinetic results were validated by making isothermal predictions from non-isothermal data. PMID:25704102

  12. Combustion, pyrolysis, gasification, and liquefaction of biomas

    NASA Astrophysics Data System (ADS)

    Reed, T. B.

    1980-09-01

    The advantages of biomass as a feedstock are examined and biomass conversion techniques are described. Combustion is the simplest method of producing heat from biomass, using either the traditional fixed bed combustion on a grate or the fluidized bed and suspended combustion techniques now being developed. Pyrolysis of biomass is a particularly attractive process if all three products gas, wood tars, and charcoal can be used. Gasification of biomass with air is perhaps the most flexible and best developed process for conversion of biomass to fuel, yielding a low energy gas that can be burned in existing gas/oil boilers or in engines. Oxygen gasification yields a gas with higher energy content that can be used in pipelines or to fire turbines. In addition, this gas can be used for producing methanol, ammonia, or gasoline by indirect liquefaction. Fast pyrolysis of biomass produces a gas rich in ethylene that can be used to make alcohols or gasoline. Finally, treatment of biomass with high pressure hydrogen can yield liquid fuels through direct liquefaction.

  13. Experimental toxicology of pyrolysis and combustion hazards.

    PubMed

    Cornish, H H; Hahn, K J; Barth, M L

    1975-06-01

    Data are presented on the acute toxicity (mortality only) of the thermal degradation products of polymers obtained by two methods of degradation. One system utilized a slowly increasing temperature (5 degrees C/min) and gradual degradation of the polymer with the rats being exposed to degradation products as they were evolved. In this system the more toxic polymers included wool, polypropylene, poly(vinyl chloride), and urethane foam. The second system utilized conditions of rapid combustion and exposure of rats to the total products of combustion for a period of 4 hr. In this system the more toxic materials included red oak, cotton, acrylonitrile-butadiene-styrene (ABS), and styrene-acrylonitrile. It is of interest to note that the natural product wool is among the least toxic under these rapid combustion conditions and among the most toxic under slow pyrolysis conditions. Other materials also vary in the comparative toxicity of their thermal degradation products, depending upon the conditions of degradation and animal exposure. The two experimental techniques presented here may well represent the two extreme conditions of rapid combustion versus slow pyrolysis. Intermediate types of fire situations might be expected to result in relative acute toxicities somewhere between these two extremes. This report deals with acute toxicity on the basis of mortality data only and does not include other parameters of toxicity such as organ weights and histopathology. PMID:1175552

  14. High mass throughput particle generation using multiple nozzle spraying

    DOEpatents

    Pui, David Y.H.; Chen, Da-Ren

    2004-07-20

    Spraying apparatus and methods that employ multiple nozzle structures for producing multiple sprays of particles, e.g., nanoparticles, for various applications, e.g., pharmaceuticals, are provided. For example, an electrospray dispensing device may include a plurality of nozzle structures, wherein each nozzle structure is separated from adjacent nozzle structures by an internozzle distance. Sprays of particles are established from the nozzle structures by creating a nonuniform electrical field between the nozzle structures and an electrode electrically isolated therefrom.

  15. High mass throughput particle generation using multiple nozzle spraying

    DOEpatents

    Pui, David Y. H. (Plymouth, MN); Chen, Da-Ren (Creve Coeur, MO)

    2009-03-03

    Spraying apparatus and methods that employ multiple nozzle structures for producing multiple sprays of particles, e.g., nanoparticles, for various applications, e.g., pharmaceuticals, are provided. For example, an electrospray dispensing device may include a plurality of nozzle structures, wherein each nozzle structure is separated from adjacent nozzle structures by an internozzle distance. Sprays of particles are established from the nozzle structures by creating a nonuniform electrical field between the nozzle structures and an electrode electrically isolated therefrom.

  16. Spray drift mitigation with spray mix adjuvants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Numerous drift reduction adjuvants and spray deposition aids are available to applicators of crop production and protection chemicals. Performance of many of the newly introduced drift control adjuvants has not been well documented for aerial application. Four new drift control adjuvants were sele...

  17. Numerical modeling of electrostatic spray

    SciTech Connect

    Okuda, H. [Princeton Univ., NJ (United States). Plasma Physics Lab.; Kelly, A.J.

    1995-12-31

    Electrostatic powder painting in which aerosolized paint particles are charged up by an electron beam injected into air has been shown to be very promising in many applications including automobile painting. Behavior of low energy electrons ({approximately} 10 keV) interacting with air and powder particles at one atmospheric pressure, however, is not well understood and the detailed information of the interaction is essential in designing commercial paint spray. In order to understand the above process, the authors use a three-dimensional electrostatic particle simulation model in which an electron beam is injected into the air. Various ionization processes are included in the model by means of Monte-Carlo method. Preliminary results of the simulations indicate that a beam electron can generate a few hundred secondary electrons as well as negative ions that are important in charging the paint powder. Results of the simulations are presented and compared with data available from the powder spray experiment.

  18. The effect of online catalytic pyrolysis on the yield of light liquid products

    NASA Astrophysics Data System (ADS)

    Zhao, Gangwei

    2014-06-01

    Hydro-catalytic pyrolysis on Yunnan lignite were studied in a fixed bed to determine their effects on high-value raw materials, such as BTX, PCX and lower naphthalene, in liquid products. Ni and Mo were chosen as active pyrolysis centers through thermogravimetry, after which their catalytic effects were analyzed in a fixed bed. The results showed that different concentrations of impregnated Ni and Mo solution can significantly increase the yield of high-value products and enable catalyst separating and recycling with this method of online catalytic pyrolysis.

  19. A Novel Energy-Efficient Pyrolysis Process: Self-pyrolysis of Oil Shale Triggered by Topochemical Heat in a Horizontal Fixed Bed

    PubMed Central

    Sun, You-Hong; Bai, Feng-Tian; Lü, Xiao-Shu; Li, Qiang; Liu, Yu-Min; Guo, Ming-Yi; Guo, Wei; Liu, Bao-Chang

    2015-01-01

    This paper proposes a novel energy-efficient oil shale pyrolysis process triggered by a topochemical reaction that can be applied in horizontal oil shale formations. The process starts by feeding preheated air to oil shale to initiate a topochemical reaction and the onset of self-pyrolysis. As the temperature in the virgin oil shale increases (to 250–300°C), the hot air can be replaced by ambient-temperature air, allowing heat to be released by internal topochemical reactions to complete the pyrolysis. The propagation of fronts formed in this process, the temperature evolution, and the reaction mechanism of oil shale pyrolysis in porous media are discussed and compared with those in a traditional oxygen-free process. The results show that the self-pyrolysis of oil shale can be achieved with the proposed method without any need for external heat. The results also verify that fractured oil shale may be more suitable for underground retorting. Moreover, the gas and liquid products from this method were characterised, and a highly instrumented experimental device designed specifically for this process is described. This study can serve as a reference for new ideas on oil shale in situ pyrolysis processes. PMID:25656294

  20. A Novel Energy-Efficient Pyrolysis Process: Self-pyrolysis of Oil Shale Triggered by Topochemical Heat in a Horizontal Fixed Bed

    NASA Astrophysics Data System (ADS)

    Sun, You-Hong; Bai, Feng-Tian; Lü, Xiao-Shu; Li, Qiang; Liu, Yu-Min; Guo, Ming-Yi; Guo, Wei; Liu, Bao-Chang

    2015-02-01

    This paper proposes a novel energy-efficient oil shale pyrolysis process triggered by a topochemical reaction that can be applied in horizontal oil shale formations. The process starts by feeding preheated air to oil shale to initiate a topochemical reaction and the onset of self-pyrolysis. As the temperature in the virgin oil shale increases (to 250-300°C), the hot air can be replaced by ambient-temperature air, allowing heat to be released by internal topochemical reactions to complete the pyrolysis. The propagation of fronts formed in this process, the temperature evolution, and the reaction mechanism of oil shale pyrolysis in porous media are discussed and compared with those in a traditional oxygen-free process. The results show that the self-pyrolysis of oil shale can be achieved with the proposed method without any need for external heat. The results also verify that fractured oil shale may be more suitable for underground retorting. Moreover, the gas and liquid products from this method were characterised, and a highly instrumented experimental device designed specifically for this process is described. This study can serve as a reference for new ideas on oil shale in situ pyrolysis processes.