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Sample records for carbon-metal composite films

  1. Electrochemical and Antimicrobial Properties of Diamondlike Carbon-Metal Composite Films

    Energy Technology Data Exchange (ETDEWEB)

    MORRISON, M. L.; BUCHANAN, R. A.; LIAW, P. K.; BERRY, C. J.; BRIGMON, R.; RIESTER, L.; JIN, C.; NARAYAN, R. J.

    2005-05-11

    Implants containing antimicrobial metals may reduce morbidity, mortality, and healthcare costs associated with medical device-related infections. We have deposited diamondlike carbon-silver (DLC-Ag), diamondlike carbon-platinum (DLC-Pt), and diamondlike carbon-silver-platinum (DLC-AgPt) thin films using a multicomponent target pulsed laser deposition process. Transmission electron microscopy of the DLC-silver and DLC-platinum composite films revealed that the silver and platinum self-assemble into nanoparticle arrays within the diamondlike carbon matrix. The diamondlike carbon-silver film possesses hardness and Young's modulus values of 37 GPa and 331 GPa, respectively. The diamondlike carbon-metal composite films exhibited passive behavior at open-circuit potentials. Low corrosion rates were observed during testing in a phosphate-buffered saline (PBS) electrolyte. In addition, the diamondlike carbon-metal composite films were found to be immune to localized corrosion below 1000 mV (SCE). DLC-silver-platinum films demonstrated exceptional antimicrobial properties against Staphylococcus bacteria. It is believed that a galvanic couple forms between platinum and silver, which accelerates silver ion release and provides more robust antimicrobial activity. Diamondlike carbon-silver-platinum films may provide unique biological functionalities and improved lifetimes for cardiovascular, orthopaedic, biosensor, and implantable microelectromechanical systems.

  2. Ceramic Composite Thin Films

    Science.gov (United States)

    Ruoff, Rodney S. (Inventor); Stankovich, Sasha (Inventor); Dikin, Dmitriy A. (Inventor); Nguyen, SonBinh T. (Inventor)

    2013-01-01

    A ceramic composite thin film or layer includes individual graphene oxide and/or electrically conductive graphene sheets dispersed in a ceramic (e.g. silica) matrix. The thin film or layer can be electrically conductive film or layer depending the amount of graphene sheets present. The composite films or layers are transparent, chemically inert and compatible with both glass and hydrophilic SiOx/silicon substrates. The composite film or layer can be produced by making a suspension of graphene oxide sheet fragments, introducing a silica-precursor or silica to the suspension to form a sol, depositing the sol on a substrate as thin film or layer, at least partially reducing the graphene oxide sheets to conductive graphene sheets, and thermally consolidating the thin film or layer to form a silica matrix in which the graphene oxide and/or graphene sheets are dispersed.

  3. Chitosan composite films. Biomedical applications.

    Science.gov (United States)

    Cárdenas, Galo; Anaya, Paola; von Plessing, Carlos; Rojas, Carlos; Sepúlveda, Jackeline

    2008-06-01

    Chitosan acetate films have been prepared using chitosans from shrimps (Pleuroncodes monodon) of low and high molecular weight (LMv = 68,000 g/mol and HMv = 232,000 g/mol) and deacetylation degree of 80 and 100%, respectively. The chitosan films were obtained by addition of several additives to acetic acid chitosan solutions, such as: glycerol, oleic acid and linoleic acid in different proportions. The pH of the solutions before casting ranged from 5.0 to 6.0. The composite film thickness are reported. The films have been analyzed by FTIR showing characteristic bands corresponding to the additives. The scanning electron microscopy (SEM) studies reveals the different morphology of the composite films. The films exhibit different physical properties depending upon the additives and/or mixture of them. The addition of glycerol to composite improves the elasticity of the films. The swelling in glucose and saline solutions for several films was evaluated, being higher in the glucose solution. The bactericide test against Staphylococcus aureus, Pseudomona aeruginosa and Acinetobacter baumanii in plates with either blood and or agar tripticase showed that the molecular weight influences on the bactericidal properties of the chitosan composite films and over its effect against gram positive and gram negative bacteria. Medical applications of the composite films were done in patients with burns, ulcers and injuries, the films containing glycerol showed good adhesion in comparison with those without it. The composite films tested were mainly three (1) chitosan acetate with glycerol, (2) chitosan acetate with oleic acid and (3) chitosan acetate with glycerol and oleic acid. Excellent results in the skin recovery were obtained after 7-10 days. Since the chitosan is biodegradable by the body enzymes it does not need to be removed and increases the gradual grows of the damage tissues. PMID:18165888

  4. Effect of the synthesis temperature of porous carbon-metal oxide composites on the gold particle morphology

    Science.gov (United States)

    Tsyganova, S. I.; Zhizhaev, A. M.; Mikhlin, Yu. L.; Patrushev, V. V.; Bondarenko, G. N.; Korol'kova, I. V.

    2014-10-01

    The state of gold deposited from a chloride solution on the surface of the porous magnetite-carbon composite obtained from modified birch saw dust at 400 and 800°C was studied by electron microscopy, X-ray photoelectron spectroscopy, and XRD analysis. The shape and size of the deposited gold crystallites depend on the synthesis temperature of the composite. The deposited gold crystallites were mainly ray-shaped at the synthesis temperature of 400°C and spheroid at 800°C.

  5. Carbon, metals and grain size correlate with bacterial community composition in sediments of a high arsenic aquifer

    Directory of Open Access Journals (Sweden)

    Teresa eLegg

    2012-03-01

    Full Text Available Bacterial communities can exert significant influence on the biogeochemical cycling of arsenic (As. This has globally important implications since As toxicity in drinking water affects the health of millions of people worldwide, including in the Ganges-Brahmaputra Delta region of Bangladesh where geogenic groundwater arsenic concentrations can be more than 10 times the World Health Organization’s limit. Thus, the goal of this research was to investigate patterns in bacterial community composition across environmental gradients in an aquifer with elevated groundwater As concentrations in Araihazar, Bangladesh. We characterized the bacterial community by pyrosequencing 16S rRNA genes from aquifer sediment samples collected at three locations along a groundwater flowpath, at a range of depths between 1.5 and 15 m. We identified significant shifts in bacterial community composition along the groundwater flowpath in the aquifer. In addition, we found that bacterial community structure was significantly related to sediment grain size, and sediment carbon (C, manganese (Mn, and iron (Fe concentrations. Deltaproteobacteria and Chloroflexi were more abundant in silty sediments with higher concentrations of C, Fe, and Mn. By contrast, Alphaproteobacteria and Betaproteobacteria were more abundant in sediments with higher concentrations of sand and Si, and lower concentrations of C and metals. Based on the phylogenetic affiliations of these taxa, these results may indicate a shift to more Fe-, Mn-, and humic substance- reducers in the high C and metal sediments. It is well-documented that C, Mn and Fe may influence the mobility of groundwater arsenic, and it is intriguing that these constituents may also structure the bacterial community.

  6. Screen Printed PZT Thick Films Using Composite Film Technology

    OpenAIRE

    Dorey, R; Whatmore, R; Beeby, S. P.; Torah, R; White, N.

    2003-01-01

    A spin coating composite sol gel technique for producing lead zirconate titanate (PZT) thick films has been modified for use with screen printing techniques. The resulting screen printing technique can be used to produce 10 ?m thick films in a single print. The resultant films are porous but the density can be increased through the use of repeated sol infiltration/pyrolysis treatments to yield a high density film. When fired at 710°C the composite screen printed films have dielectric and piez...

  7. Preparation and Properties of Polyaniline Composite Films

    Institute of Scientific and Technical Information of China (English)

    ZHANG Qing-hua

    2002-01-01

    Polyaniline (PAn) was synthesized by chemical oxidation polymerization. The conductive polymer doped by camphor sulfonic acid (CSA) and a matrix polymer,polyamide- 66, polyamide - 1010 or polyamide- 11, were dissolved in m-cresol and the blend solution was cast in a glass and dried for preparing polyaniline composite films.Conductivity was from 10 -6 to 10 0Ω-1·cm-1 with different weight fraction of PAn-CSA. The crystallizttion of the films was studied by means of differential scanning calorimeter (DSC). The treatment of the composite films in different pH value solution would result in decrease of conductivity, especially in an alkaline solution.

  8. Magnetoelectric thin film composites with interdigital electrodes

    Science.gov (United States)

    Piorra, A.; Jahns, R.; Teliban, I.; Gugat, J. L.; Gerken, M.; Knöchel, R.; Quandt, E.

    2013-07-01

    Magnetoelectric (ME) thin film composites on silicon cantilevers are fabricated using Pb(Zr0.52Ti0.45)O3 (PZT) films with interdigital transducer electrodes on the top side and FeCoSiB amorphous magnetostrictive thin films on the backside. These composites without any direct interface between the piezoelectric and magnetostrictive phase are superior to conventional plate capacitor-type thin film ME composites. A limit of detection of 2.6 pT/Hz1/2 at the mechanical resonance is determined which corresponds to an improvement of a factor of approximately 2.8 compared to the best plate type sensor using AlN as the piezoelectric phase and even a factor of approximately 4 for a PZT plate capacitor.

  9. Novel Microporous Films and Their Composites

    Directory of Open Access Journals (Sweden)

    P.C. Wu, Ph.D

    2007-04-01

    Full Text Available Cost-effective microporous films and composites can be made by using polyolefinic material and inorganic fillers. These microporous films and their composites can be designed and manufactured at high speed using commercial equipment for disposable hygiene articles, protective health care garments, building construction and many other industrial applications where air and moisture breathability is needed. The theory, formulations and methods of making these cost-effective polyolefinic-calcium carbonate compositions are discussed. Special engineering fibers and their fabrics can be combined with these novel microporous films to achieve a variety of properties for practical applications. However, one should keep intellectual property considerations in mind when contemplating the manufacture of microporous film products, their companies and their applications.

  10. Nonlinear optical properties of Au/PVP composite thin films

    Institute of Scientific and Technical Information of China (English)

    Shen Hong; Cheng Bo-Lin; Lu Guo-Wei; Wang Wei-Tian; Guan Dong-Yi; Chen Zheng-Hao; Yang Guo-Zhen

    2005-01-01

    Colloidal Au and poly(vinylpyrrolidone) (PVP) composite thin films are fabricated by spin-coating method. Linear optical absorption measurements of the Au/PVP composite films indicate an absorption peak around 530 nm due to the surface plasmon resonance of gold nanoparticles. Nonlinear optical properties are studied using standard Z-scan technique, and experimental results show large optical nonlinearities of the Au/PVP composite films. A large value of films.

  11. Preparation of composite electroheat carbon film

    Institute of Scientific and Technical Information of China (English)

    XIA Jin-tong; TU Chuan-jun; LI Yan; HU Li-min; DENG Jiu-hua

    2005-01-01

    A kind of conductive and heating unit, which can reach a high surface electroheat temperature at a low voltage, was developed in view of the traditional electroheat coating which has a low surface electroheat temperature and an insufficient heat resistance of its binder. The coating molded electroheat carbon film(CMECF) was prepared by carbonizing the coating which was prepared by adding modified resin into flake graphite and carbon fiber, coating molded onto the surface of the heat resisting matrix after dried, while the hot pressing molded electroheat thick carbon film(HPMETCF) was prepared by carbonizing the bodies whose powders were hot pressing molded directly.The surface and inner microstructure of the carbon film was characterized and analyzed by SEM and DSC/TG, while electroheat property was tested by voltage-current volume resistivity tester and electrical parameter tester. The results show that, close-packed carbon network configuration is formed within the composite electroheat carbon film film after anti-oxidizable treatment reaches a higher surface electroheat temperature than that of the existing electroheat coatings at a low voltage, and has excellent electroheat property, high thermal efficiency as well as stable physicochemical property. It is found that, at room temperature(19± 2 ℃) and 22 V for 5 min, the surface electroheat temperature of the self-produced CMECF (mfiller/mresin = 1. 8/1) reaches 112 ℃ while HPMETCF (mfiller/mresin = 3. 6/1) reaches 265 ℃.

  12. ELECTROCHEMICAL STUDIES ON CONDUCTING COMPOSITE FILMS FROM POLYURETHANE AND POLYPYRROLE

    Institute of Scientific and Technical Information of China (English)

    BI Xiantong; PEI Qibing; LI Yongfang

    1988-01-01

    A study on the electrooxidative polymerization of pyrrole onto polyurethane-coated platinum electrodes and the electrochemical properties of the composite polyurethane/polypyrrole films (PU/PPy) as-prepared is presented. It is found that polypyrrole grows layer by layer from the polyurethane/platinum interface through the polyurethane matrix, and ca. 20 wt.% of polypyrrole will fill up the matrix. Cyclic voltammograms show that the composite films are porous, and the reduction-reoxidation (redox) rate of the composite films is limited by the diffusion ofcounteranions through the films. Larger anion size leads to slower diffusion process.The composite films can also act as modified electrodes.

  13. Preparation and Characterization of Chitosan—Agarose Composite Films

    Directory of Open Access Journals (Sweden)

    Zhang Hu

    2016-09-01

    Full Text Available Nowadays, there is a growing interest to develop biodegradable functional composite materials for food packaging and biomedicine applications from renewable sources. Some composite films were prepared by the casting method using chitosan (CS and agarose (AG in different mass ratios. The composite films were analyzed for physical-chemical-mechanical properties including tensile strength (TS, elongation-at-break (EB, water vapor transmission rate (WVTR, swelling ratio, Fourier-transform infrared spectroscopy, and morphology observations. The antibacterial properties of the composite films were also evaluated. The obtained results reveal that an addition of AG in varied proportions to a CS solution leads to an enhancement of the composite film’s tensile strength, elongation-at-break, and water vapor transmission rate. The composite film with an agarose mass concentration of 60% was of the highest water uptake capacity. These improvements can be explained by the chemical structures of the new composite films, which contain hydrogen bonding interactions between the chitosan and agarose as shown by Fourier-transform infrared spectroscopy (FTIR analysis and the micro-pore structures as observed with optical microscopes and scanning electron microscopy (SEM. The antibacterial results demonstrated that the films with agarose mass concentrations ranging from 0% to 60% possessed antibacterial properties. These results indicate that these composite films, especially the composite film with an agarose mass concentration of 60%, exhibit excellent potential to be used in food packaging and biomedical materials.

  14. Synthesis of Photochromic AgCl-Urethane Resin Composite Films

    Directory of Open Access Journals (Sweden)

    Hidetoshi Miyazaki

    2012-01-01

    Full Text Available AgCl-resin photochromic composite films were prepared using AgNO3, HCl-EtOH, CuCl2 solution, and a liquid-state urethane resin as starting materials. The obtained composite films showed a photochromic property. The rate of darkening of the composite film increased after mixing with CuCl2. The AgCl particle size in the film without heat treatment was 6–20 nm, and that of the heat-treated film was 25–80 nm; these results were confirmed using TEM observations. The fading rate of the film without heat treatment was higher than that of the heat-treated films.

  15. Electrochemical Formation of Polypyrrole-carboxymethylcellulose Conducting Polymer Composite Films

    Institute of Scientific and Technical Information of China (English)

    H.N.M. Ekramul Mahmud; Anuar Kassim; Zulkarnain Zainal; Wan Mahmood Mat Yunus

    2005-01-01

    The electrochemical preparation of polypyrrole-carboxymethylcellulose (PPY-CMC) conducting polymer composite films on indium tin oxide (ITO) glass electrode from an aqueous solution containing pyrrole monomer, ptoluenesulfonate electrolyte and carboxymethylcellulose insulating polymer is reported. The characterization by Fourier transform infrared spectroscopy (FT-IR) shows that carboxymethylcellulose (CMC) has been successfully incorporated into polypyrrole structure forming PPY-CMC polymer composite films. The conductivity of the prepared composite films was found to increase with increaseing CMC concentration in pyrrole solution. The optical microscopic results show the influence of CMC concentration in the pyrrole solution over the morphological changes of the prepared films. The dynamic mechanical analysis (DMA) on the prepared PPY-CMC film reveals the higher plastic property of the PPY-CMC composite film.

  16. Surface composition analysis of PP films treated by corona discharge

    OpenAIRE

    Sellin Noeli; Campos João Sinézio de C.

    2003-01-01

    Polypropylene films (PP) surface treated by corona discharge in air was analyzed to verify the changes on surface composition. The presence of oxidized polar groups on the film surface, mainly, C=O, C-O and COH, was confirmed by infrared spectroscopy (FTIR/ATR) and atomic force microscopy (AFM) revealed a dramatic change in the morphology and provided qualitative results of the chemical composition (new structures). Contact angle (q) of the PP films decreased after corona treatment indicating...

  17. Porous carbon and carbon/metal oxide microfibers with well-controlled pore structure and interface.

    Science.gov (United States)

    Shi, Qihui; Liang, Hongjun; Feng, Dan; Wang, Jianfang; Stucky, Galen D

    2008-04-16

    A "brick-and-mortar" assembly approach for creating porous carbon and carbon/metal oxide fibers on the micron scale with well-defined pore structure and interface is presented. A series of monodisperse silica@polyacrylonitrile (PAN) and silica@metal oxide@PAN core/shell particles were synthesized by emulsion polymerization and assembled into organic-inorganic composite fibers through a simple ice-templating strategy with the assistance of polyvinyl alcohol. Porous carbon and carbon/metal oxide fibers with well-controlled pores and interfaces were created by oxidative stabilization and carbonization of composite fibers followed by removal of silica cores with hydrofluoric acid or concentrated alkali. The pore structure and the carbon/metal oxide interfaces of the fibers impart to the fibers' lightweight and potential applications in catalysis, electrochemical energy, and gas or liquid separations and storage. PMID:18355006

  18. Coassembly of gold nanoparticles and cellulose nanocrystals in composite films.

    Science.gov (United States)

    Lukach, Ariella; Thérien-Aubin, Héloïse; Querejeta-Fernández, Ana; Pitch, Natalie; Chauve, Grégory; Méthot, Myriam; Bouchard, Jean; Kumacheva, Eugenia

    2015-05-12

    Coassembly of nanoparticles with different size-, shape-, and composition-dependent properties is a promising approach to the design and fabrication of functional materials and devices. This paper reports the results of a detailed investigation of the formation and properties of free-stranding composite films formed by the coassembly of cellulose nanocrystals and shape-isotropic plasmonic gold nanoparticles. The effect of gold nanoparticle size, surface charge, and concentration on the structural and optical properties of the composite films has been studied. The composite films retained photonic crystal and chiroptical activity properties. The size and surface charge of gold nanoparticles had a minor effect on the structure and properties of the composite films, while the concentration of gold nanoparticles in the composite material played a more significant role and can be used to fine-tune the optical properties of materials derived from cellulose nanocrystals. These findings significantly broaden the range of nanoparticles that can be used for producing nanocomposite materials based on cellulose nanocrystals. The simplicity of film preparation, the abundance of cellulose nanocrystals, and the robust, free-standing nature of the composite films offer highly advantageous features and pave the way for the generation of functional materials with coupled optical properties.

  19. Tribological performances of diamond film and graphite/diamond composite film with paraffin oil lubrication

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In this paper, the tribological performances of diamond film and graphite/diamond com-posite film were compared on an SRV wear testing machine with paraffin oil lubrication. The sur-face morphologies of specimens and wear tracks were observed by SEM. The wear volumes ofwear tracks were measured by profilometer. The influence of load on the tribological performancesof different specimens was studied. The wear mechanism under paraffin oil lubrication was ana-lyzed. The results showed that with paraffin oil lubrication, the friction coefficient and wear volumeof graphite/diamond composite film specimen are lower than diamond film. Under paraffin oil lu-brication, the wear mechanisms of both diamond film and graphite/diamond composite film weremainly sub-micro-fracture.

  20. Direct Electrochemistry of Myoglobin in DDAB-Clay Composite Films

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Ordered films were made by casting a mixture of aqueous dispersions of didodecyldimethylammonium bromide (DDAB)-clay composite and myoglobin (Mb) solution on pyrolytic graphite (PG) electrodes.The Mb-DDAB-clay film electrodes showed stable and reversible cyclic voltammetric responses in buffers and can catalyze the reduction of trichloroacetic acid (TCA).

  1. Synthesis of agarose-metal/semiconductor nanoparticles having superior bacteriocidal activity and their simple conversion to metal-carbon composites

    Indian Academy of Sciences (India)

    K K R Datta; B Srinivasan; H Balaram; M Eswaramoorthy

    2008-11-01

    Agarose, a naturally occurring biopolymer is used for the stabilization of metal, semiconductor nanoparticles. Ag and Cu nanoparticles stabilized in agarose matrix show excellent antibacterial activity against E. coli bacteria. The well dispersed metal nanoparticles within the agarose composite films can be readily converted to carbon-metal composites of catalytic importance.

  2. Microstructures and thermochromic characteristics of VO2/AZO composite films

    Science.gov (United States)

    Xiao, Han; Li, Yi; Yuan, Wenrui; Fang, Baoying; Wang, Xiaohua; Hao, Rulong; Wu, Zhengyi; Xu, Tingting; Jiang, Wei; Chen, Peizu

    2016-05-01

    A vanadium dioxide (VO2) thin film was fabricated on a ZnO doped with Al (AZO) conductive glass by magnetron sputtering at room temperature followed by annealing under air atmosphere. The microstructures and optical properties of the thin film were studied. The results showed that the VO2/AZO composite film was poly-crystalline and the AZO layer did not change the preferred growth orientation of VO2. Compared to the VO2 film fabricated on soda-lime glass substrate through the same process and condition, the phase transition temperature of the VO2/AZO composite film was decreased by about 25 °C, thermal hysteresis width narrowed to 6 °C, the visible light transmittance was over 50%, the infrared transmittances before and after phase transition were 21% and 55%, respectively at 1500 nm.

  3. Drug release kinetics from carboxymethylcellulose-bacterial cellulose composite films.

    Science.gov (United States)

    Juncu, Gheorghe; Stoica-Guzun, Anicuta; Stroescu, Marta; Isopencu, Gabriela; Jinga, Sorin Ion

    2016-08-30

    Composite films of sodium carboxymethyl cellulose and bacterial cellulose (NaCMC-BC) cross-linked with citric acid (CA) were prepared by solution casting method. Ibuprofen sodium salt (IbuNa) has been used to study the mechanism of drug release from composite films. Surface morphology was investigated by scanning electron microscopy (SEM) and proved that the BC content influences the aspect of the films. Fourier transformed infrared spectroscopy (FTIR) revealed specific peaks in IR spectra of composite films which sustain that NaCMC was cross-linked with CA. Starting from swelling observations, the release kinetic of IbuNa was described using a model which neglects the volume expansion due to polymer swelling and which considers non-linear diffusion coefficients for drug and solvent. The IbuNa release is also influenced by BC content, the drug release rate was decreasing with the increase of BC content. PMID:26688041

  4. Thin Film Polymer Composite Scintillators for Thermal Neutron Detection

    Directory of Open Access Journals (Sweden)

    Andrew N. Mabe

    2013-01-01

    Full Text Available Thin film polystyrene composite scintillators containing LiF6 and organic fluors have been fabricated and tested as thermal neutron detectors. Varying fluorescence emission intensities for different compositions are interpreted in terms of the Beer-Lambert law and indicate that the sensitivity of fluorescent sensors can be improved by incorporating transparent particles with refractive index different than that of the polymer matrix. Compositions and thicknesses were varied to optimize the fluorescence and thermal neutron response and to reduce gamma-ray sensitivity. Neutron detection efficiency and neutron/gamma-ray discrimination are reported herein as functions of composition and thickness. Gamma-ray sensitivity is affected largely by changing thickness and unaffected by the amount of LiF6 in the film. The best neutron/gamma-ray discrimination characteristics are obtained for film thicknesses in the range 25–150 μm.

  5. Compositional depth profiling of TaCN thin films

    Energy Technology Data Exchange (ETDEWEB)

    Adelmann, Christoph; Conard, Thierry; Franquet, Alexis; Brijs, Bert; Munnik, Frans; Burgess, Simon; Witters, Thomas; Meersschaut, Johan; Kittl, Jorge A.; Vandervorst, Wilfried; Van Elshocht, Sven [Imec, B-3001 Leuven (Belgium); Forschungszentrum Dresden-Rossendorf, D-01314 Dresden (Germany); Oxford Instruments NanoAnalysis, High Wycombe, HP12 3SE (United Kingdom); Imec, B-3001 Leuven (Belgium); Imec, B-3001 Leuven, Belgium and Instituut voor Kern- en Stralingsfysica, Katholieke Universiteit Leuven, B-3001 Leuven (Belgium); Imec, B-3001 Leuven (Belgium)

    2012-07-15

    The composition profiling of thin TaCN films was studied. For the composition profile determination using x-ray photoemission spectrometry (XPS) in combination with Ar sputtering, preferential sputtering effects of N with respect to Ta and C were found to lead to inaccurate elemental concentrations. Sputter yield calculations for the given experimental conditions allowed for the correction of a part of the error, leading to fair accuracy by reference-free measurements. Further improvement of the accuracy was demonstrated by the calibration of the XPS compositions against elastic recoil detection analysis (ERDA) results. For Auger electron spectrometry (AES) in combination with Ar sputtering, accurate results required the calibration against ERDA. Both XPS and AES allowed for a reliable and accurate determination of the compositional profiles of TaCN-based thin films after calibration. Time-of-flight secondary-ion mass spectrometry was also used to assess the composition of the TaCN films. However, the analysis was hampered by large matrix effects due to small unintentional oxygen contents in the films. Energy-dispersive x-ray spectrometry is also discussed, and it is shown that an accurate reference-free measurement of the average film concentration can be achieved.

  6. Novel hybrid multifunctional magnetoelectric porous composite films

    Science.gov (United States)

    Martins, P.; Gonçalves, R.; Lopes, A. C.; Venkata Ramana, E.; Mendiratta, S. K.; Lanceros-Mendez, S.

    2015-12-01

    Novel multifunctional porous films have been developed by the integration of magnetic CoFe2O4 (CFO) nanoparticles into poly(vinylidene fluoride)-Trifuoroethylene (P(VDF-TrFE)), taking advantage of the synergies of the magnetostrictive filler and the piezoelectric polymer. The porous films show a piezoelectric response with an effective d33 coefficient of -22 pC/N-1, a maximum magnetization of 12 emu g-1 and a maximum magnetoelectric coefficient of 9 mV cm-1 Oe-1. In this way, a multifunctional membrane has been developed suitable for advanced applications ranging from biomedical to water treatment.

  7. Electrochromic properties of nano-composite nickel oxide film

    Energy Technology Data Exchange (ETDEWEB)

    Lin, S.-H. [Department of Engineering and System Science, National Tsing Hua University, Hsinchu 300, Taiwan (China)], E-mail: d927117@oz.nthu.edu.tw; Chen, F.-R. [Department of Engineering and System Science, National Tsing Hua University, Hsinchu 300, Taiwan (China); National Synchrotron Radiation Research Center, Hsinchu 300, Taiwan (China); Kai, J.-J. [Department of Engineering and System Science, National Tsing Hua University, Hsinchu 300, Taiwan (China)

    2008-03-30

    In this study, we develop a nano-composite nickel oxide (NNO) film on the indium tin oxide (ITO)-coated glass substrate for electrochromic applications. The NNO film is composed of the core-shell structure of NiO/conducting ITO nano-particles. High porosity in the NNO film offers large active surface area for redox reaction. Electrochromic electrodes fabricated with the NNO films produce high transmittance variation (66.2% at a wavelength of 550 nm), fast switching speed (coloring: 3.5 s; bleaching: 4 s) and good durability, which are much better than those of ones made with the traditional nickel oxide films. The structure, morphology, and electrochromic properties are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and UV-vis spectroscopy.

  8. Electrochromic properties of nano-composite nickel oxide film

    International Nuclear Information System (INIS)

    In this study, we develop a nano-composite nickel oxide (NNO) film on the indium tin oxide (ITO)-coated glass substrate for electrochromic applications. The NNO film is composed of the core-shell structure of NiO/conducting ITO nano-particles. High porosity in the NNO film offers large active surface area for redox reaction. Electrochromic electrodes fabricated with the NNO films produce high transmittance variation (66.2% at a wavelength of 550 nm), fast switching speed (coloring: 3.5 s; bleaching: 4 s) and good durability, which are much better than those of ones made with the traditional nickel oxide films. The structure, morphology, and electrochromic properties are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and UV-vis spectroscopy

  9. Physical and mechanical properties of modified bacterial cellulose composite films

    Science.gov (United States)

    Indrarti, Lucia; Indriyati, Syampurwadi, Anung; Pujiastuti, Sri

    2016-02-01

    To open wide range application opportunities of Bacterial Cellulose (BC) such as for agricultural purposes and edible film, BC slurries were blended with Glycerol (Gly), Sorbitol (Sor) and Carboxymethyl Cellulose (CMC). The physical and mechanical properties of BC composites were investigated to gain a better understanding of the relationship between BC and the additive types. Addition of glycerol, sorbitol and CMC influenced the water solubility of BC composite films. FTIR analysis showed the characteristic bands of cellulose. Addition of CMC, glycerol, and sorbitol slightly changed the FTIR spectrum of the composites. Tensile test showed that CMC not only acted as cross-linking agent where the tensile strength doubled up to 180 MPa, but also acted as plasticizer with the elongation at break increased more than 100% compared to that of BC film. On the other hand, glycerol and sorbitol acted as plasticizers that decreased the tensile strength and increased the elongation. Addition of CMC can improve film transparency, which is quite important in consumer acceptance of edible films in food industry.

  10. Nanocellulose-Zeolite Composite Films for Odor Elimination.

    Science.gov (United States)

    Keshavarzi, Neda; Mashayekhy Rad, Farshid; Mace, Amber; Ansari, Farhan; Akhtar, Farid; Nilsson, Ulrika; Berglund, Lars; Bergström, Lennart

    2015-07-01

    Free standing and strong odor-removing composite films of cellulose nanofibrils (CNF) with a high content of nanoporous zeolite adsorbents have been colloidally processed. Thermogravimetric desorption analysis (TGA) and infrared spectroscopy combined with computational simulations showed that commercially available silicalite-1 and ZSM-5 have a high affinity and uptake of volatile odors like ethanethiol and propanethiol, also in the presence of water. The simulations showed that propanethiol has a higher affinity, up to 16%, to the two zeolites compared with ethanethiol. Highly flexible and strong free-standing zeolite-CNF films with an adsorbent loading of 89 w/w% have been produced by Ca-induced gelation and vacuum filtration. The CNF-network controls the strength of the composite films and 100 μm thick zeolite-CNF films with a CNF content of less than 10 vol % displayed a tensile strength approaching 10 MPa. Headspace solid phase microextraction (SPME) coupled to gas chromatography-mass spectroscopy (GC/MS) analysis showed that the CNF-zeolite films can eliminate the volatile thiol-based odors to concentrations below the detection ability of the human olfactory system. Odor removing zeolite-cellulose nanofibril films could enable improved transport and storage of fruits and vegetables rich in odors, for example, onion and the tasty but foul-smelling South-East Asian Durian fruit.

  11. Surface composition analysis of PP films treated by corona discharge

    Directory of Open Access Journals (Sweden)

    Sellin Noeli

    2003-01-01

    Full Text Available Polypropylene films (PP surface treated by corona discharge in air was analyzed to verify the changes on surface composition. The presence of oxidized polar groups on the film surface, mainly, C=O, C-O and COH, was confirmed by infrared spectroscopy (FTIR/ATR and atomic force microscopy (AFM revealed a dramatic change in the morphology and provided qualitative results of the chemical composition (new structures. Contact angle (q of the PP films decreased after corona treatment indicating an increase in the wettability due to the polar groups formed. Extended treatment results of low molecular weight oxidized material into the surfaces and a smaller additional degree of modification in the wettability is obtained.

  12. Graphene/Ionic Liquid Composite Films and Ion Exchange

    Science.gov (United States)

    Mo, Yufei; Wan, Yunfang; Chau, Alicia; Huang, Fuchuan

    2014-06-01

    Wettability of graphene is adjusted by the formation of various ionic surfaces combining ionic liquid (IL) self-assembly with ion exchange. The functionalized ILs were designed and synthesized with the goal of obtaining adjustable wettability. The wettability of the graphene surface bearing various anions was measured systematically. The effect of solvent systems on ion exchange ratios on the graphene surface has also been investigated. Meanwhile, the mechanical properties of the graphene/IL composite films were investigated on a nanometer scale. The elasticity and adhesion behavior of the thin film was determined with respected to the indentation deformation by colloid probe nanoindentation method. The results indicate that anions played an important role in determining graphene/IL composite film properties. In addition, surface wetting and mechanics can be quantitatively determined according to the counter-anions on the surface. This study might suggest an alternate way for quantity detection of surface ions by surface force.

  13. [Characterization of inorganic nano-alundum composite film of polyimide].

    Science.gov (United States)

    Zhou, Hao-Ran; Zhao, De-Ming; Liu, Xin-Gang; Lin, Fei; Fan, Yong

    2008-03-01

    The key to the study on the regularity about the mechanical, thermology and electricities property of the inorganic nano-mingled organic composition thin film is to understand the incorporated quantity, the particle size and distribution of nano-inorganic matter in the membrane quickly and accurately. In the present paper, the chemical structure, surface morphology and the actual content of nano-Al2O3 of the nano Al2O3-composite film of polyimide were characterized by X-ray atomic fluorescent spectroscopy (XRF), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and atomic forced microscope (AFM). The results are that the organic phase of PI and the inorganic phase of Al2O3 formed a complex composite hybrid system of bond-to-bond pattern, the nano-Al2O3 particles in the film of PI are dispersed homogeneously, and the diameter of the particle is smaller than 50 nm; the weight content of Al2O3 is 7.9% by XRF. The approach we used is an effective way of analyzing the inorganic component of the organic composite film materials doped with the inorganic nano-phase materials with the merits of no pretreatment, no fed charge (for analysis of insulation materials), no-contagion, no destruction, high speed and high accuracy, etc. PMID:18536449

  14. Thin film composite nanofiltration membranes for extreme conditions

    NARCIS (Netherlands)

    Dalwani, Mayur Ramesh

    2011-01-01

    The research presented in this thesis focuses on development and performance evaluation of thin film composite (TFC) nanofiltration (NF) membranes, with special attention to extreme pH applications. In Chapter 2 a new method that allows molecular weight cut off (MWCO) characterization of NF membran

  15. Gelatin-Pectin Composite Films from Polyion Complex Hydrogels

    Science.gov (United States)

    Composite films from gelatin and low-methoxyl pectin were prepared by either ionic complexation or covalent cross-linking. The ionic interactions between positively charged gelatin and negatively charged pectin produced physically reversible hydrogels. The resultant homogeneous gels had improved mec...

  16. Action of colloidal silica films on different nano-composites

    Science.gov (United States)

    Abdalla, S.; Al-Marzouki, F.; Obaid, A.; Gamal, S.

    Nano-composite films have been the subject of extensive work to develop the energy-storage efficiency of electrostatic capacitors. Factors such as polymer purity, nano-particles size, and film morphology drastically affect the electrostatic efficiency of the dielectric material that form an insulating film between conductive electrodes of a capacitor. This in turn affects the energy storage performance of the capacitor. In the present work, we have studied the dielectric properties of 4 high pure amorphous polymer films: polymethylmethacrylate (PMMA), polystyrene, polyimide and poly-4-vinylpyridine. Comparison between the dielectric properties of these polymers has revealed that the higher break down performance is a character of polyimide PI and PMMA. Also, our experimental data shows that adding colloidal silica to PMMA and PI leads to a net decrease in the dielectric properties compared to the pure polymer.

  17. PREPARATION AND PROPERTIES OF CHITOSAN/LIGNIN COMPOSITE FILMS

    Institute of Scientific and Technical Information of China (English)

    Long Chen; Chang-yu Tang; Nan-ying Ning; Chao-yu Wang; Qiang Fu; Qin Zhang

    2009-01-01

    Biodegradable composite films based on chitosan and lignin with various composition were prepared via the solution-casting technique.FT-IR results indicate the existence of hydrogen bonding between chitosan and lignin,and SEM images show that lignin could be well dispersed in chitosan when the content of lignin is below 20 wt% due to the strong interfacial interaction.As a result of strong interaction and good dispersion,the tensile strength,storage modulus,thermal degradation temperature and glass transition temperature of chitosan have been largely improved by adding lignin.Our work provides a simple and cheap way to prepare fully biodegradable chitosan/lignin composites,which could be used as packaging films or wound dressings.

  18. Investigation of tribological properties of composite C60-LB films

    Institute of Scientific and Technical Information of China (English)

    YANG Guanghong; ZHANG Xingtang; XUN Jun; JIANG Xiaohong; ZHANG Pingyu; DU Zuliang

    2006-01-01

    Composite C60-LB films were fabricated by the Langmuir-Blodgett (LB) technique, their micro- structures, micro- and macro-tribological properties were investigated using atomic force microscope/ friction force microscope (AFM/FFM). The results showed that in the confined C60-LB films there were two kinds of structures for the special C60 assembly: grain diameters of one kind were in the range of 150-230 nm; the other was smaller than 20 nm. Mi-cro-tribological studies showed that topographical images of tiny C60 aggregates (<20 nm) were con-sistent with their frictional ones very well, namely, low friction occurred on tiny C60 aggregates compared with fatty chains LB monolayer, and 'Micro-rolling effect' was apparent; but for big large ones frictional forces were relatively high and 'ratchet mechanism' was seen apparently. Macro-tribological data proved large C60 aggregates had wear resistance and load-carrying capacities and anti-wear lives for com- posite C60-LB films were prolonged greatly with dis-persibility of C60 improved and its grain diameter re-duced. Tiny C60 aggregates were mainly the lubricating agents. Friction coefficients of composite C60-LB films gradually reduced with loads increasing having the same friction coefficient-load relations with boundary lubrication films.

  19. Special Polymer/Carbon Composite Films for Detecting SO2

    Science.gov (United States)

    Homer, Margie; Ryan, Margaret; Yen, Shiao-Pin; Kisor, Adam; Jewell, April; Shevade, Abhijit; Manatt, Kenneth; Taylor, Charles; Blanco, Mario; Goddard, William

    2008-01-01

    A family of polymer/carbon films has been developed for use as sensory films in electronic noses for detecting SO2 gas at concentrations as low as 1 part per million (ppm). Most previously reported SO2 sensors cannot detect SO2 at concentrations below tens of ppm; only a few can detect SO2 at 1 ppm. Most of the sensory materials used in those sensors (especially inorganic ones that include solid oxide electrolytes, metal oxides, and cadmium sulfide) must be used under relatively harsh conditions that include operation and regeneration at temperatures greater than 100 C. In contrast, the present films can be used to detect 1 ppm of SO2 at typical opening temperatures between 28 and 32 C and can be regenerated at temperatures between 36 and 40 C. The basic concept of making sensing films from polymer/carbon composites is not new. The novelty of the present family of polymer/carbon composites lies in formulating the polymer components of these composites specifically to optimize their properties for detecting SO2. First-principles quantum-mechanical calculations of the energies of binding of SO2 molecules to various polymer functionalities are used as a guide for selecting polymers and understanding the role of polymer functionalities in sensing. The polymer used in the polymer-carbon composite is a copolymer of styrene derivative units with vinyl pyridine or substituted vinyl pyridine derivative units. To make a substituted vinyl pyridine for use in synthesizing such a polymer, poly(2-vinyl pyridine) that has been dissolved in methanol is reacted with 3-chloropropylamine that has been dissolved in a solution of methanol. The methanol is then removed to obtain the copolymer. Later, the copolymer can be dissolved in an appropriate solvent with a suspension of carbon black to obtain a mixture that can be cast and then dried to obtain a sensory film.

  20. High Performance Thin-Film Composite Forward Osmosis Membrane

    KAUST Repository

    Yip, Ngai Yin

    2010-05-15

    Recent studies show that osmotically driven membrane processes may be a viable technology for desalination, water and wastewater treatment, and power generation. However, the absence of a membrane designed for such processes is a significant obstacle hindering further advancements of this technology. This work presents the development of a high performance thin-film composite membrane for forward osmosis applications. The membrane consists of a selective polyamide active layer formed by interfacial polymerization on top of a polysulfone support layer fabricated by phase separation onto a thin (40 μm) polyester nonwoven fabric. By careful selection of the polysulfone casting solution (i.e., polymer concentration and solvent composition) and tailoring the casting process, we produced a support layer with a mix of finger-like and sponge-like morphologies that give significantly enhanced membrane performance. The structure and performance of the new thin-film composite forward osmosis membrane are compared with those of commercial membranes. Using a 1.5 M NaCl draw solution and a pure water feed, the fabricated membranes produced water fluxes exceeding 18 L m2-h-1, while consistently maintaining observed salt rejection greater than 97%. The high water flux of the fabricated thin-film composite forward osmosis membranes was directly related to the thickness, porosity, tortuosity, and pore structure of the polysulfone support layer. Furthermore, membrane performance did not degrade after prolonged exposure to an ammonium bicarbonate draw solution. © 2010 American Chemical Society.

  1. Structural and biological properties of carbon nanotube composite films

    Energy Technology Data Exchange (ETDEWEB)

    Narayan, Roger J. [School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0245 (United States)]. E-mail: roger.narayan@mse.gatech.edu; Berry, C.J. [Environmental Biotechnology Section, Savannah River National Laboratory, Aiken, SC 29808 (United States); Brigmon, R.L. [Environmental Biotechnology Section, Savannah River National Laboratory, Aiken, SC 29808 (United States)

    2005-11-20

    Carbon nanotube composite films have been developed that exhibit unusual structural and biological properties. These novel materials have been created by pulsed laser ablation of graphite and bombardment of nitrogen ions at temperatures between 600 and 700 deg. C. High-resolution transmission electron microscopy and radial distribution function analysis demonstrate that this material consists of sp{sup 2}-bonded concentric ribbons that are wrapped approximately 15 deg. normal to the silicon substrate. The interlayer order in this material extends to approximately 15-30 A. X-ray photoelectron spectroscopy and Raman spectroscopy data suggest that this material is predominantly trigonally coordinated. The carbon nanotube composite structure results from the use of energetic ions, which allow for non-equilibrium growth of graphitic planes. In vitro testing has revealed significant antimicrobial activity of carbon nanotube composite films against Staphylococcus aureus and Staphylococcus warneri colonization. Carbon nanotube composite films may be useful for inhibiting microorganism attachment and biofilm formation in hemodialysis catheters and other medical devices.

  2. Influence of film composition on the transition temperature of FeRh films

    Science.gov (United States)

    Jiang, M.; Chen, X. Z.; Zhou, X. J.; Wang, Y. Y.; Pan, F.; Song, C.

    2016-03-01

    We investigate the influences of film composition, tuned by argon growth pressure and palladium doping, on antiferromagnetic to ferromagnetic transition temperatures of FeRh films. Employing complementary characterizations we show that the CsCl-type FeRh grows on MgO (100) substrate epitaxially with a controllable transition temperature. Lower argon pressure, a suitable palladium doping are found to effectively decrease the transition temperature. In addition, the exploration about the influence of post-annealing time on un-doped FeRh films indicates that annealing procedure is helpful to improve the growth quality. The optimized growth parameter provides an opportunity to deposit ultrathin FeRh films (5 nm) with a clear antiferromagnetic to ferromagnetic transition. The manipulation of the transition temperature of FeRh would advance its use in antiferromagnetic spintronics.

  3. Composition change and capacitance properties of ruthenium oxide thin film

    Institute of Scientific and Technical Information of China (English)

    刘泓; 甘卫平; 刘仲武; 郑峰

    2015-01-01

    RuO2·nH2O film was deposited on tantalum foils by electrodeposition and heat treatment using RuCl3·3H2O as precursor. Surface morphology, composition change and cyclic voltammetry from precursor to amorphous and crystalline RuO2·nH2O films were studied by X-ray diffractometer, Fourier transformation infrared spectrometer, differential thermal analyzer, scanning electron microscope and electrochemical analyzer, respectively. The results show that the precursor was transformed gradually from amorphous to crystalline phase with temperature. When heat treated at 300 °C for 2 h, RuO2·nH2O electrode surface gains mass of 2.5 mg/cm2 with specific capacitance of 782 F/g. Besides, it is found that the specific capacitance of the film decreased by roughly 20%with voltage scan rate increasing from 5 to 250 mV/s.

  4. Electrophoretic deposition of tannic acid-polypyrrolidone films and composites.

    Science.gov (United States)

    Luo, Dan; Zhang, Tianshi; Zhitomirsky, Igor

    2016-05-01

    Thin films of polyvinylpyrrolidone (PVP)-tannic acid (TA) complexes were prepared by a conceptually new strategy, based on electrophoretic deposition (EPD). Proof of concept investigations involved the analysis of the deposition yield, FTIR and UV-vis spectroscopy of the deposited material, and electron microscopy studies. The analysis of the deposition mechanism indicated that the limitations of the EPD in the deposition of small phenolic molecules, such as TA, and electrically neutral polymers, similar to PVP, containing hydrogen-accepting carbonyl groups, can be avoided. The remarkable adsorption properties of TA and film forming properties of the PVP-TA complexes allowed for the EPD of materials of different types, such as huntite mineral platelets and hydrotalcite clay particles, TiO2 and MnO2 oxide nanoparticles, multiwalled carbon nanotubes, TiN and Pd nanoparticles. Moreover, PVP-TA complexes were used for the co-deposition of different materials and formation of composite films. In another approach, TA was used as a capping agent for the hydrothermal synthesis of ZnO nanorods, which were then deposited by EPD using PVP-TA complexes. The fundamental adsorption and interaction mechanisms of TA involved chelation of metal atoms on particle surfaces with galloyl groups, π-π interactions and hydrogen bonding. The films prepared by EPD can be used for various applications, utilizing functional properties of TA, PVP, inorganic and organic materials of different types and their composites. PMID:26878711

  5. Thin film composition with biological substance and method of making

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, Allison A. (Kennewick, WA); Song, Lin (Richland, WA)

    1999-01-01

    The invention provides a thin-film composition comprising an underlying substrate of a first material including a plurality of attachment sites; a plurality of functional groups chemically attached to the attachment sites of the underlying substrate; and a thin film of a second material deposited onto the attachment sites of the underlying substrate, and a biologically active substance deposited with the thin-film. Preferably the functional groups are attached to a self assembling monolayer attached to the underlying substrate. Preferred functional groups attached to the underlying substrate are chosen from the group consisting of carboxylates, sulfonates, phosphates, optionally substituted, linear or cyclo, alkyl, alkene, alkyne, aryl, alkylaryl, amine, hydroxyl, thiol, silyl, phosphoryl, cyano, metallocenyl, carbonyl, and polyphosphate. Preferred materials for the underlying substrate are selected from the group consisting of a metal, a metal alloy, a plastic, a polymer, a proteic film, a membrane, a glass or a ceramic. The second material is selected from the group consisting of inorganic crystalline structures, inorganic amorphus structures, organic crystalline structures, and organic amorphus structures. Preferred second materials are phosphates, especially calcium phosphates and most particularly calcium apatite. The biologically active molecule is a protein, peptide, DNA segment, RNA segment, nucleotide, polynucleotide, nucleoside, antibiotic, antimicrobal, radioisotope, chelated radioisotope, chelated metal, metal salt, anti-inflamatory, steriod, nonsteriod anti-inflammatory, analgesic, antihistamine, receptor binding agent, or chemotherapeutic agent, or other biologically active material. Preferably the biologically active molecule is an osteogenic factor the compositions listed above.

  6. Thin film composition with biological substance and method of making

    International Nuclear Information System (INIS)

    The invention provides a thin-film composition comprising an underlying substrate of a first material including a plurality of attachment sites; a plurality of functional groups chemically attached to the attachment sites of the underlying substrate; and a thin film of a second material deposited onto the attachment sites of the underlying substrate, and a biologically active substance deposited with the thin-film. Preferably the functional groups are attached to a self assembling monolayer attached to the underlying substrate. Preferred functional groups attached to the underlying substrate are chosen from the group consisting of carboxylates, sulfonates, phosphates, optionally substituted, linear or cyclo, alkyl, alkene, alkyne, aryl, alkylaryl, amine, hydroxyl, thiol, silyl, phosphoryl, cyano, metallocenyl, carbonyl, and polyphosphate. Preferred materials for the underlying substrate are selected from the group consisting of a metal, a metal alloy, a plastic, a polymer, a proteic film, a membrane, a glass or a ceramic. The second material is selected from the group consisting of inorganic crystalline structures, inorganic amorphous structures, organic crystalline structures, and organic amorphous structures. Preferred second materials are phosphates, especially calcium phosphates and most particularly calcium apatite. The biologically active molecule is a protein, peptide, DNA segment, RNA segment, nucleotide, polynucleotide, nucleoside, antibiotic, antimicrobial, radioisotope, chelated radioisotope, chelated metal, metal salt, anti-inflammatory, steroid, nonsteroid anti-inflammatory, analgesic, antihistamine, receptor binding agent, or chemotherapeutic agent, or other biologically active material. Preferably the biologically active molecule is an osteogenic factor consisting of the compositions listed above

  7. Waste Reduction of Composite Film Line in Process Industries

    OpenAIRE

    Javid, Hafiz

    2015-01-01

    This research focuses on the waste reduction of polymeric material in a chemical process plant during the manufacturing of film composite line. The case the company is a manufacturing the company where continuous throughput and quality of product plays an important role for the profitability of the company. The new scheduling of maintenance and new techniques were needed to be introduced to reduce waste during the manufacturing of the product. This study is conducted as a case study, div...

  8. Structure of film compositions C{sub 60}-Bi

    Energy Technology Data Exchange (ETDEWEB)

    Dudkin, V.; Vus, A.; Zubaryev, E. [and others

    2001-07-01

    The structure of film compositions C{sub 60}-Bi on fluorineflogopite substrates were investigated at the relation of density of fluxes of Bi atoms and C{sub 60} moleculas from 0 to 1 over the temperature range 400 - 500 K. The quality model of bismuth segregation in the composite films is studied. In our study fullerite and composite C{sub 60}-Bi are considered as a model object (for the data on possible practical application of fullerite see, e.g. [1]). The special consideration in the study is given to the investigation of deposition conditions of perfect fullerite films on orienting substrates and to the processes of metal-fulleren composition formation in the absence of a chemical bond among the elements of the starting components. High-resolution electron microscopy (direct resolution of crystallographic planes, microdifraction) and X-ray diffractometry method (0 - 20 of scanning in Cu-K{sub {alpha}}{sub 1} radiation) were used in the study to examine the structure of pure fullerite and fulleren-bismuth composite. The composite was formed at the thermal evaporation of the components from two Knudsen cells. The density of the flux of Bi atoms varied from 0 to 1 with respect to a cluster C{sub 60} flux. The quantity of the substance being evaporated was controlled with a quartz microbalance. The plane (001) of artificial mice - fluorineflogopite (ff) was chosen as substrates. The applying process was performed in the substrate holder temperature range Tn = 400 - 500 K in vacuum approx. 10{sup -3} Pa condensed to be examined with electronic microscope PEM-U; X-ray study of the films approx. 500 nm thick was made with the help of a diffractometer DRON-3M. The microscope resolution was 0.2 nm and this was confirmed by direct resolution of (200) planes of atoms of thin monocrystalline films of gold. In the study we used the substrate holders with either constant temperature or temperature gradient held in the plane.

  9. Composition and structure of Ti-C/DLC graded composite films

    Institute of Scientific and Technical Information of China (English)

    孙明仁; 夏立芳

    2002-01-01

    The Ti-C→DLC gradient composite films were characterized systematically.The elemental depth profile and elemental chemical state evolution were determined by X-ray photoelectron spectroscopy (XPS).The transmission electron microscope (TEM) and high-resolution transmission electron microscopy (HRTEM) were used to study the structure of interfacial zone between DLC film and Ti-C layers.Results show that there are composition transition zone between DLC film and either Ti-C layer or steel substrate on condition that pre-deposited Ti layers on the steel substrate then plasma based bias deposited DLC films.In Ti-C graded layer,the chemical state of titanium and carbon are changed gradually.The structures of zone in Ti-C layer near the DLC film is consisted of random oriented nanocrystallines TiC dispersed in amorphous DLC matrix.The structure of the zone between DLC film and Ti-C graded layer is gradually changed too.

  10. Electrochemical deposition of Mg(OH)2/GO composite films for corrosion protection of magnesium alloys

    OpenAIRE

    Fengxia Wu; Jun Liang; Weixue Li

    2015-01-01

    Mg(OH)2/graphene oxide (GO) composite film was electrochemical deposited on AZ91D magnesium alloys at constant potential. The characteristics of the Mg(OH)2/GO composite film were investigated by scanning electron microscope (SEM), energy-dispersive X-ray spectrometry (EDS), X-ray diffractometer (XRD) and Raman spectroscopy. It was shown that the flaky GO randomly distributed in the composite film. Compared with the Mg(OH)2 film, the Mg(OH)2/GO composite film exhibited more uniform and compac...

  11. Formation of Al-Si Composite Oxide Film by Hydrolysis Precipitation and Anodizing

    Institute of Scientific and Technical Information of China (English)

    Zhe-Sheng Feng; Ying-Jie Xia; Jia Ding; Jin-Ju Chen

    2007-01-01

    This paper presents a new technique in the high dielectric constant composite oxide film preparation.On the basis of nanocompsite high dielectric constant aluminum oxide film growth technology, a new idea of adulterating Si oxide species into the aluminum composite film was proposed. As a result, the specific capacitance and withstanding voltage of the composite oxide film formed at the anodizing voltage of 20V are enhanced, and the leakage current of the aluminum composite oxide film is reduced through incorporation of Si oxide species.

  12. Electron field emission from screen-printed graphene/DWCNT composite films

    International Nuclear Information System (INIS)

    Highlights: ► The field emission performance improved significantly when adding graphene into DWCNTs as the emission material. ► We set up a model of pure DWCNT films and graphene/DWCNT composite films. ► We discussed the contact barrier between emission films and electric substrates by considering the Fermi energies of silver, DWCNT and graphene. - Abstract: The electron field emission properties of graphene/double-walled carbon nanotube (DWCNT) composite films prepared by screen printing have been systematically studied. Comparing with the pure DWCNT films and pure graphene films, a significant enhancement of electron emission performance of the composite films are observed, such as lower turn-on field, higher emission current density, higher field enhancement factor, and long-term stability. The optimized composite films with 20% weight ratio of graphene show the best electron emission performance with a low turn-on field of 0.62 V μm−1 (at 1 μA cm−2) and a high field enhancement factor β of 13,000. A model of the graphene/DWCNT composite films is proposed, which indicate that a certain amount of graphene will contribute the electron transmission in the silver substrate/composite films interface and in the interior of composite films, and finally improve the electron emission performance of the graphene/DWCNT composite films.

  13. Magnetic coupling mechanisms in particle/thin film composite systems

    Directory of Open Access Journals (Sweden)

    Giovanni A. Badini Confalonieri

    2010-12-01

    Full Text Available Magnetic γ-Fe2O3 nanoparticles with a mean diameter of 20 nm and size distribution of 7% were chemically synthesized and spin-coated on top of a Si-substrate. As a result, the particles self-assembled into a monolayer with hexagonal close-packed order. Subsequently, the nanoparticle array was coated with a Co layer of 20 nm thickness. The magnetic properties of this composite nanoparticle/thin film system were investigated by magnetometry and related to high-resolution transmission electron microscopy studies. Herein three systems were compared: i.e. a reference sample with only the particle monolayer, a composite system where the particle array was ion-milled prior to the deposition of a thin Co film on top, and a similar composite system but without ion-milling. The nanoparticle array showed a collective super-spin behavior due to dipolar interparticle coupling. In the composite system, we observed a decoupling into two nanoparticle subsystems. In the ion-milled system, the nanoparticle layer served as a magnetic flux guide as observed by magnetic force microscopy. Moreover, an exchange bias effect was found, which is likely to be due to oxygen exchange between the iron oxide and the Co layer, and thus forming of an antiferromagnetic CoO layer at the γ-Fe2O3/Co interface.

  14. Fabrication and characterization of silk fibroin/bioactive glass composite films

    International Nuclear Information System (INIS)

    Composite films of silk fibroin (SF) with nano bioactive glass (NBG) were prepared by the solvent casting method, and the structures and properties of the composite films were characterized. Fourier transform infrared (FT-IR) spectroscopy analysis shows that the random coil and β-sheet structure co-exist in the SF films. Results of field emission scanning electron microscope (FESEM) indicate that the NBG particles are uniformly dispersed in the SF films. The measurements of the water contact angles suggest that the incorporation of NBG into SF can improve the hydrophilicity of the composites. The bioactivity of the composite films was evaluated by soaking in 1.5 times simulated body fluid (1.5 × SBF), and formation of a hydroxycarbonate apatite (HCA) layer was determined by XRD and FESEM. The results show that the SF/NBG composite film is bioactive as it induces the formation of HCA on the surface of the composite film after soaking in 1.5 × SBF for 7 days. In vitro osteoblasts attachment and proliferation tests show that the composite film is a good matrix for the growth of osteoblasts. Consequently, the incorporation of NBG into the SF film can enhance both the bioactivity and biocompatibility of the film, which suggests that the SF/NBG composite film may be a potential biomaterial for bone tissue engineering. - Highlights: ► The incorporation of NBG into SF can improve the hydrophilicity of the SF/NBG composite films. ► The SF/NBG composite films show the better bioactivity than the pure SF film. ► The SF/NBG composite films facilitate cell growth and promote cell proliferation and differentiation.

  15. Nuclear reaction analysis for composition measurement of BN thin films

    International Nuclear Information System (INIS)

    The composition of the BN film was determined using Rutherford backscattering spectrometry (RBS) and nuclear reaction analysis (NRA). RBS can provide all the constituent concentrations in the films and the absolute determination of the number of atoms/cm2. However RBS is not suited to detection of light atoms deposited on a substrate material of higher atomic mass. On the other hand, the NRA has the advantage that it allows to measure the areal concentrations of nitrogen and boron in BNx films on Si substrates, although calibration is required using standard specimens. These experiments were carried out on the 2 MeV Van de Graaff accelerator connected to an ultra high vacuum (UHV) chamber. For RBS measurement, a 42He+ beam at 2.0 MeV, a total scattering angle of 168° and a beam incident angle to the substrate normal or 60 deg. were used. Zr and Pt films, 1150 Å to 3300 Å in thickness, deposited on vitreous carbon plates were used as a substrate. NRA was performed using a deuteron beam of 1.7 MeV and a beam incident angle of 20 deg. A peak from 10B(d,α)8Be in an NRA spectrum of a standard sample appeared clearly without significant background, however a broad signal from 11B(d, α)9Be appeared overlapping with a peak from 14N(d, α)12C. Therefore the 10B(d, α)8Be and 14N(d, α)12C yields were estimated, since the ratio of 11B : 10B measured by RBS was 0.83 : 17, which is well consistent with the natural isotopic ratio, 11B : 10B =0.802 : 0.192. In the case of calculating the 14N(d, α)12C yields, the signal from 11B(d, α)9Be was deconvoluted by taking into account the shape of 11B(d, α)9Be signal. The areal ratio 14N/10B was 7.73 and the error was -3.5 to +3.2%. These values will be used for determining composition of BN films. The conversion factor allows obtaining the composition of BN thin films on Si substrate. (author)

  16. Enhancement of Fluorescent Labeling via a Composited Thin Film

    Directory of Open Access Journals (Sweden)

    Taikei Suyama

    2014-01-01

    Full Text Available Fluorescent labeling is the prevailing imaging technique in cell biological research. When statistical investigations on a large number of cells are involved, experimental study is required for both low magnification to get a reliable statistical population and high contrast to achieve accurate diagnosis on the nature of the cells’ perturbation. As microscope objectives of low magnification generally yield low collection efficiency, such studies are limited by the fluorescence signal weakness. To overcome this technological insufficiency, Le Moal et al. proposed a method based on metal-coated substrates that enhanced the fluorescence process and improved collection efficiency in fluorescence microscope observation and that could be directly used with a common microscope setup. In this paper, we use an Ag-Si3N4-Ag multilayer film coated on the substrate and numerically analyse the optical behavior of a fluorophore which was placed above the composited film coated on the substrate. The results shows that by using an Ag-Si3N4-Ag composited film the fluorescence imaging can be enhanced remarkably.

  17. One-step synthesis of magnetic chitosan polymer composite films

    Science.gov (United States)

    Cesano, Federico; Fenoglio, Gaia; Carlos, Luciano; Nisticò, Roberto

    2015-08-01

    In this study, a magnetic iron oxide-chitosan composite film is synthesized by one-step method and thoroughly investigated in order to better understand its inorganic/organic properties. A deep physico-chemical characterization of the magnetic films has been performed. In particular, the material composition was evaluated by means of XRD and ATR-FTIR spectroscopy, whereas the thermal stability and the subsequent inorganic phase transitions involving iron oxide species were followed by TGA analyses carried out at different experimental conditions (i.e. inert and oxidative atmosphere). The magnetic properties of the films were tested at the bulk and at the surface level, performing respectively magnetization hysteresis curve and magnetic force microscopy (MFM) surface mapping. Results indicate that the synthesized material can be prepared through a very simple synthetic procedure and suggests that it can be successfully applied for instance to environmental applications, such as the adsorption of contaminants from solid and liquid media thanks to its pronounced magnetic properties, which favour its recover.

  18. Electrochemical deposition of Mg(OH2/GO composite films for corrosion protection of magnesium alloys

    Directory of Open Access Journals (Sweden)

    Fengxia Wu

    2015-09-01

    Full Text Available Mg(OH2/graphene oxide (GO composite film was electrochemical deposited on AZ91D magnesium alloys at constant potential. The characteristics of the Mg(OH2/GO composite film were investigated by scanning electron microscope (SEM, energy-dispersive X-ray spectrometry (EDS, X-ray diffractometer (XRD and Raman spectroscopy. It was shown that the flaky GO randomly distributed in the composite film. Compared with the Mg(OH2 film, the Mg(OH2/GO composite film exhibited more uniform and compact structure. Potentiodynamic polarization tests revealed that the Mg(OH2/GO composite film could significantly improve the corrosion resistance of Mg(OH2 film with an obvious positive shift of corrosion potential by 0.19 V and a dramatic reduction of corrosion current density by more than one order of magnitude.

  19. Nonlinear Analysis of Actuation Performance of Shape Memory Alloy Composite Film Based on Silicon Substrate

    Directory of Open Access Journals (Sweden)

    Shuangshuang Sun

    2014-01-01

    Full Text Available The mechanical model of the shape memory alloy (SMA composite film with silicon (Si substrate was established by the method of mechanics of composite materials. The coupled action between the SMA film and Si substrate under thermal loads was analyzed by combining static equilibrium equations, geometric equations, and physical equations. The material nonlinearity of SMA and the geometric nonlinearity of bending deformation were both considered. By simulating and analyzing the actuation performance of the SMA composite film during one cooling-heating thermal cycle, it is found that the final cooling temperature, boundary condition, and the thickness of SMA film have significant effects on the actuation performance of the SMA composite film. Besides, the maximum deflection of the SMA composite film is affected obviously by the geometric nonlinearity of bending deformation when the thickness of SMA film is very large.

  20. Transparent megahertz circuits from solution-processed composite thin films

    Science.gov (United States)

    Liu, Xingqiang; Wan, Da; Wu, Yun; Xiao, Xiangheng; Guo, Shishang; Jiang, Changzhong; Li, Jinchai; Chen, Tangsheng; Duan, Xiangfeng; Fan, Zhiyong; Liao, Lei

    2016-04-01

    Solution-processed amorphous oxide semiconductors have attracted considerable interest in large-area transparent electronics. However, due to its relative low carrier mobility (~10 cm2 V-1 s-1), the demonstrated circuit performance has been limited to 800 kHz or less. Herein, we report solution-processed high-speed thin-film transistors (TFTs) and integrated circuits with an operation frequency beyond the megahertz region on 4 inch glass. The TFTs can be fabricated from an amorphous indium gallium zinc oxide/single-walled carbon nanotube (a-IGZO/SWNT) composite thin film with high yield and high carrier mobility of >70 cm2 V-1 s-1. On-chip microwave measurements demonstrate that these TFTs can deliver an unprecedented operation frequency in solution-processed semiconductors, including an extrinsic cut-off frequency (fT = 102 MHz) and a maximum oscillation frequency (fmax = 122 MHz). Ring oscillators further demonstrated an oscillation frequency of 4.13 MHz, for the first time, realizing megahertz circuit operation from solution-processed semiconductors. Our studies represent an important step toward high-speed solution-processed thin film electronics.Solution-processed amorphous oxide semiconductors have attracted considerable interest in large-area transparent electronics. However, due to its relative low carrier mobility (~10 cm2 V-1 s-1), the demonstrated circuit performance has been limited to 800 kHz or less. Herein, we report solution-processed high-speed thin-film transistors (TFTs) and integrated circuits with an operation frequency beyond the megahertz region on 4 inch glass. The TFTs can be fabricated from an amorphous indium gallium zinc oxide/single-walled carbon nanotube (a-IGZO/SWNT) composite thin film with high yield and high carrier mobility of >70 cm2 V-1 s-1. On-chip microwave measurements demonstrate that these TFTs can deliver an unprecedented operation frequency in solution-processed semiconductors, including an extrinsic cut-off frequency (f

  1. Mechanical behaviour of composite materials made by resin film infusion

    Directory of Open Access Journals (Sweden)

    Casavola C.

    2010-06-01

    Full Text Available Innovative composite materials are frequently used in designing aerospace, naval and automotive components. In the typical structure of composites, multiple layers are stacked together with a particular sequence in order to give specific mechanical properties. Layers are organized with different angles, different sequences and different technological process to obtain a new and innovative material. From the standpoint of engineering designer it is useful to consider the single layer of composite as macroscopically homogeneous material. However, composites are non homogeneous bodies. Moreover, layers are not often perfectly bonded together and delamination often occurs. Other violations of lamination theory hypotheses, such as plane stress and thin material, are not unusual and in many cases the transverse shear flexibility and the thickness-normal stiffness should be considered. Therefore the real behaviour of composite materials is quite different from the predictions coming from the traditional lamination theory. Due to the increasing structural performance required to innovative composites, the knowledge of the mechanical properties for different loading cases is a fundamental source of concern. Experimental characterization of materials and structures in different environmental conditions is extremely important to understand the mechanical behaviour of these new materials. The purpose of the present work is to characterize a composite material developed for aerospace applications and produced by means of the resin film infusion process (RFI. Different tests have been carried out: tensile, open-hole and filled-hole tensile, compressive, openhole and filled-hole compressive. The experimental campaign has the aim to define mechanical characteristics of this RFI composite material in different conditions: environmental temperature, Hot/Wet and Cold.

  2. Silver nanowires/polycarbonate composites for conductive films

    Science.gov (United States)

    Moreno, I.; Navascues, N.; Irusta, S.; Santamaría, J.

    2012-09-01

    Silver nanowires (AgNW) with an aspect ratio of 85 were synthesized by a solvothermal process. The AgNW were characterized by SEM and XRD techniques. Nanocomposites of these silver nanowires in a polycarbonate matrix were prepared by simple solution mixing procedure in a concentration filler range 0-4.35 wt%. The obtained films were around 18 μm thick, optical microscopy and SEM characterization showed good dispersion of the nanowires in the polymeric matrix. The obtained composites presented low percolation threshold (0.04 wt%) and the maximum conductivity at 4.35 wt% filler loading was 2.3×10-2 S/cm.

  3. Optical properties and residual stress in Nb-Si composite films prepared by magnetron cosputtering.

    Science.gov (United States)

    Tang, Chien-Jen; Porter, Glen Andrew; Jaing, Cheng-Chung; Tsai, Fang-Ming

    2015-02-01

    This paper investigates Nb-Si metal composite films with various proportions of niobium in comparison to pure Nb films. Films were prepared by two-target RF-DC magnetron cosputtering deposition. The optical properties and residual stress were analyzed. A composition of Nb(0.74)Si(0.26) was chosen toward the design and fabrication of solar absorbing coatings having a high absorption in a broad wavelength range, a low residual stress, and suitable optical constants. The layer thicknesses and absorption characteristics of the Nb-Si composite films adhere more closely to the design than other coatings made of dielectric film materials. PMID:25967812

  4. Effects of Excess Cu Addition on Photochromic Properties of AgCl-Urethane Resin Composite Films

    Directory of Open Access Journals (Sweden)

    Hidetoshi Miyazaki

    2013-01-01

    Full Text Available AgCl-resin photochromic composite films were prepared using AgNO3, HCl-EtOH, CuCl2 ethanol solutions, and a urethane resin as starting materials. The AgCl particle size in the composite films, which was confirmed via TEM observations, was 23–43 nm. The AgCl composite films showed photochromic properties: coloring induced by UV-vis irradiation and bleaching induced by cessation of UV-vis irradiation. The coloring and bleaching speed of the composite film increases with increasing CuCl2 mixing ratio.

  5. Preparation and Properties of Al-Ni Composite Anodic Films on Aluminum Surface

    Institute of Scientific and Technical Information of China (English)

    ZHAO Xuhui; YE Hao; ZHANG Xiaofeng; ZUO Yu

    2012-01-01

    Ni element was introduced to aluminum surface by a simple chemical immersion method,and Al-Ni composite anodic films were obtained by following anodizing.The morphology,structure and composition of the Al-Ni anodic films were examined by scanning electron microscopy (SEM),energy disperse spectroscopy (EDS) and atomic force microscopy(AFM).The electrochemical behaviors of the films were studied by means of polarization measurement and electrochemical impedance spectroscopy (EIS).The experimental results show that the A1-Ni composite anodic film is more compact with smaller pore diameters than that of the Al anodic film.The introduction of nickel increases the impedances of both the barrier layer and the porous layer of the anodic films.In NaCl solutions,the Al-Ni composite anodic films show higher impedance values and better corrosion resistance.

  6. Polyaniline-graphite composite film glucose oxidase electrode

    Institute of Scientific and Technical Information of China (English)

    ZHOU Hai-hui; CHEN Hong; CHEN Jin-hua; KUANG Ya-fei

    2006-01-01

    A novel polyaniline-graphite composite film glucose oxidase (PGCF GOD) electrode was developed. The PGCF was synthesized by cyclic voltammetry method in 0.5 mol/L H2SO4 solution containing 1 g/L graphite powder and 0.2 mol/L aniline. The PGCF GOD electrode was prepared by doping GOD into the composite film. The morphology of the PGCF and the response property of the PGCF GOD electrode were investigated by scanning electron microscopy and electrochemical measurement,respectively. The results show that the PGCF has a porous and netty structure and the PGCF GOD electrode has excellent response property such as high sensitivity and short response time. Influences of pH value, temperature, glucose concentration and potential on the response current of the electrode were also discussed. The sensor has a maximum steady-state current density of 357.17 tA/cm2and an apparent Michaelis-Menten constant of 16.57 mmol/L. The maximum current response of the enzyme electrode occurs under the condition of pH 5.5, 0.8 V and 65 ℃.

  7. Preparation and Characterization of InAs/Si Composite Film

    Institute of Scientific and Technical Information of China (English)

    YANG Lin; LI Guang-Hai; ZHENG Mao-Jun; ZHANG Li-De

    2000-01-01

    Composite thin films consisting of nanosized InAs particles embedded in amorphous Si matrices were prepared by radio frequency co-sputtering of InAs and Si. X-ray diffraction spectra show that the particle size of InAs increases with the increasing annealing temperature, while the particle sizes of In and As reach their maximum values at the temperature of 200℃, and decrease with the further increase of the annealing temperature. In and As can not exist in the 500℃ sample due to the sublimation of In and As and the reaction In+As→InAs. The composition of the film in different levels was analyzed. We found that only in the deep level, the mole contents of As and In conform to the stoichiometric ratio and the oxidation occurs only a few nanometers from the surface. We believe that the scarcity of In and As near the surface is due to the sublimation of In and the oxide of As.

  8. Compositional analysis of silicon oxide/silicon nitride thin films

    Directory of Open Access Journals (Sweden)

    Meziani Samir

    2016-06-01

    Full Text Available Hydrogen, amorphous silicon nitride (SiNx:H abbreviated SiNx films were grown on multicrystalline silicon (mc-Si substrate by plasma enhanced chemical vapour deposition (PECVD in parallel configuration using NH3/SiH4 gas mixtures. The mc-Si wafers were taken from the same column of Si cast ingot. After the deposition process, the layers were oxidized (thermal oxidation in dry oxygen ambient environment at 950 °C to get oxide/nitride (ON structure. Secondary ion mass spectroscopy (SIMS, Rutherford backscattering spectroscopy (RBS, Auger electron spectroscopy (AES and energy dispersive X-ray analysis (EDX were employed for analyzing quantitatively the chemical composition and stoichiometry in the oxide-nitride stacked films. The effect of annealing temperature on the chemical composition of ON structure has been investigated. Some species, O, N, Si were redistributed in this structure during the thermal oxidation of SiNx. Indeed, oxygen diffused to the nitride layer into Si2O2N during dry oxidation.

  9. Characterization of whey protein-carboxymethylated chitosan composite films with and without transglutaminase treatment.

    Science.gov (United States)

    Jiang, Shu-Juan; Zhang, Xuan; Ma, Ying; Tuo, Yanfeng; Qian, Fang; Fu, Wenjia; Mu, Guangqing

    2016-11-20

    Edible composite packaging has the advantage of complementary functional properties over its each bio-components. However, reports on whey protein concentrates (WPC)-carboxymethylated chitosan (CMC) composite films have not yet been released. To investigate the preparation of WPC-CMC composite films and its functional properties, four types of WPC-CMC composite films were prepared with and without Transglutaminase (TGase) treatment by mixing WPC aqueous solutions (10%, w/v) with CMC aqueous solutions (3%, w/v) at WPC to CMC volume ratios of (100:0), (75:25), (50:50), and (25:75). SDS-PAGE confirmed that TGase catalyzed crosslinking of whey protein. Results revealed that CMC incorporation conferred a smooth and even surface microstructure on the films and markedly improved the transparency, water barrier properties, mechanical properties and solubility of the composite film. Furthermore, TGase resulted in an improvement in the water vapor barrier properties and mechanical properties of WPC-CMC (75:25 and 50:50, v/v) composite films, and there was no impairment of thermal stability of composite films. Therefore, TGase successfully facilitated the formation of WPC-CMC composite films with some improved functional properties. This offers potential applications as an alternative approach to the preparation of edible packaging films. PMID:27561482

  10. Frictional and wear properties of cobalt/multiwalled carbon nanotube composite films formed by electrodeposition

    OpenAIRE

    Arai, Susumu; Miyagawa, Kazuaki

    2013-01-01

    Carbon nanotubes (CNTs) have solid lubricity due to their unique structure, and as such, CNT composites are also expected to exhibit superior tribological properties. In this study, Co/CNT composite films were fabricated using a composite electrodeposition technique, and their tribological properties were investigated. Three different sizes of multiwalled carbon nanotubes (MWCNTs) were used as the CNTs in this study. The microstructures of the composite films were examined using scanning elec...

  11. Functional chitosan-based grapefruit seed extract composite films for applications in food packaging technology

    Energy Technology Data Exchange (ETDEWEB)

    Tan, Y.M. [Department of Mechanical Engineering, National University of Singapore (Singapore); Lim, S.H.; Tay, B.Y. [Forming Technology Group, Singapore Institute of Manufacturing Technology (Singapore); Lee, M.W. [Food Innovation and Resource Centre, Singapore Polytechnic (Singapore); Thian, E.S., E-mail: mpetes@nus.edu.sg [Department of Mechanical Engineering, National University of Singapore (Singapore)

    2015-09-15

    Highlights: • Chitosan-based grapefruit seed extract (GFSE) films were solution casted. • GFSE was uniformly dispersed within all chitosan film matrices. • All chitosan-based composite films showed remarkable transparency. • Increasing amounts of GFSE incorporated increased the elongation at break of films. • Chitosan-based GFSE composite films inhibited the proliferation of fungal growth. - Abstract: Chitosan-based composite films with different amounts of grapefruit seed extract (GFSE) (0.5, 1.0 and 1.5% v/v) were fabricated via solution casting technique. Experimental results showed that GFSE was uniformly dispersed within all chitosan film matrices. The presence of GFSE made the films more amorphous and tensile strength decreased, while elongation at break values increased as GFSE content increased. Results from the measurement of light transmission revealed that increasing amounts of GFSE (from 0.5 to 1.5% v/v) did not affect transparency of the films. Furthermore, packaging of bread samples with chitosan-based GFSE composite films inhibited the proliferation of fungal growth as compared to control samples. Hence, chitosan-based GFSE composite films have the potential to be a useful material in the area of food technology.

  12. Functional chitosan-based grapefruit seed extract composite films for applications in food packaging technology

    International Nuclear Information System (INIS)

    Highlights: • Chitosan-based grapefruit seed extract (GFSE) films were solution casted. • GFSE was uniformly dispersed within all chitosan film matrices. • All chitosan-based composite films showed remarkable transparency. • Increasing amounts of GFSE incorporated increased the elongation at break of films. • Chitosan-based GFSE composite films inhibited the proliferation of fungal growth. - Abstract: Chitosan-based composite films with different amounts of grapefruit seed extract (GFSE) (0.5, 1.0 and 1.5% v/v) were fabricated via solution casting technique. Experimental results showed that GFSE was uniformly dispersed within all chitosan film matrices. The presence of GFSE made the films more amorphous and tensile strength decreased, while elongation at break values increased as GFSE content increased. Results from the measurement of light transmission revealed that increasing amounts of GFSE (from 0.5 to 1.5% v/v) did not affect transparency of the films. Furthermore, packaging of bread samples with chitosan-based GFSE composite films inhibited the proliferation of fungal growth as compared to control samples. Hence, chitosan-based GFSE composite films have the potential to be a useful material in the area of food technology

  13. Strengthening behavior of carbon/metal nanocomposites

    OpenAIRE

    Shin, S. E.; Choi, H. J.; Hwang, J. Y.; Bae, D. H.

    2015-01-01

    Nanocomposites reinforced with nano-scale reinforcements exhibit excellent mechanical properties with low volume fraction of the reinforcement. For instance, only an addition of 0.7 vol.% few-layer graphene (FLG) into the pure titanium shows strength of ~1.5 GPa, obviously much superior to that of the monolithic titanium. The strengthening efficiency of composites is determined by several factors such as reinforcement geometrical/spatial characteristics and interfacial features between the ma...

  14. Antimicrobial activity of nisin incorporated in pectin and polylactic acid composite films against Listeria monocytogenes

    Science.gov (United States)

    Extruded composite films from 20% pectin and 80% polylactic acids (PLA) were developed and nisin was loaded into films by a diffusion post extrusion. Inhibitory activities of the films against Listeria monocytogenes were evaluated in brain heart infusion (BHI) broth, liquid egg white and orange juic...

  15. Tribological behavior of in situ Ag nanoparticles/polyelectrolyte composite molecular deposition films

    International Nuclear Information System (INIS)

    Multilayer polyelectrolyte films containing silver ions were obtained by molecular deposition method on a glass plate or a quartz substrate. The in situ Ag nanoparticles were synthesized in the multilayer polyelectrolyte films which were put into fresh NaBH4 aqueous solution. The structure and surface morphology of composite molecular deposition films were observed by UV-vis spectrophotometer, X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). Tribological characteristic was investigated by AFM and micro-tribometer. It was found that the in situ Ag nanoparticles/polyelectrolyte composite molecular deposition films have lower coefficient of friction and higher anti-wear life than pure polyelectrolyte molecular deposition films.

  16. Conductive composite films composed of polyaniline thin layers on microporous polyacrylonitrile surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Zhai Guangzhao; Fan Qingqing; Tang Yue; Zhang Yu; Pan Ding; Qin Zongyi, E-mail: phqin@dhu.edu.c

    2010-10-29

    A facile approach for preparing flexible and conductive composite films by chemical polymerization of aniline monomers on the microporous polyacrylonitrile (PAN) surfaces was reported. A good adherence between polyaniline thin layer and PAN substrate was ascribed to the formation of a continuous conductive network in the film thickness along the capillary channel within PAN matrix. The electronic properties of the resulting composite films were tuned easily with the mass fraction of aniline monomer in the PAN solution or through chemical process. It is also found that the thermal stabilities of the composite films were significantly enhanced, while good mechanical properties were maintained.

  17. Enhanced piezoelectric performance of composite sol-gel thick films evaluated using piezoresponse force microscopy.

    Science.gov (United States)

    Liu, Yuanming; Lam, Kwok Ho; Kirk Shung, K; Li, Jiangyu; Zhou, Qifa

    2013-05-14

    Conventional composite sol-gel method has been modified to enhance the piezoelectric performance of ceramic thick films. Lead zirconate titanate (PZT) and lead magnesium niobate-lead titanate (PMN-PT) thick films were fabricated using the modified sol-gel method for ultrasonic transducer applications. In this work, piezoresponse force microscopy was employed to evaluate the piezoelectric characteristics of PZT and PMN-PT composite sol-gel thick films. The images of the piezoelectric response and the strain-electric field hysteresis loop behavior were measured. The effective piezoelectric coefficient (d33,eff) of the films was determined from the measured loop data. It was found that the effective local piezoelectric coefficient of both PZT and PMN-PT composite films is comparable to that of their bulk ceramics. The promising results suggest that the modified composite sol-gel method is a promising way to prepare the high-quality, crack-free ceramic thick films. PMID:23798771

  18. Detection of Carbon Monoxide Using Polymer-Carbon Composite Films

    Science.gov (United States)

    Homer, Margie L.; Ryan, Margaret A.; Lara, Liana M.

    2011-01-01

    A carbon monoxide (CO) sensor was developed that can be incorporated into an existing sensing array architecture. The CO sensor is a low-power chemiresistor that operates at room temperature, and the sensor fabrication techniques are compatible with ceramic substrates. Sensors made from four different polymers were tested: poly (4-vinylpryridine), ethylene-propylene-diene-terpolymer, polyepichlorohydrin, and polyethylene oxide (PEO). The carbon black used for the composite films was Black Pearls 2000, a furnace black made by the Cabot Corporation. Polymers and carbon black were used as received. In fact, only two of these sensors showed a good response to CO. The poly (4-vinylpryridine) sensor is noisy, but it does respond to the CO above 200 ppm. The polyepichlorohydrin sensor is less noisy and shows good response down to 100 ppm.

  19. STUDY ON COMPOSITION, MICROSTRUCTURE AND HARDNESS OF DLC FILMS BY VCAD

    Institute of Scientific and Technical Information of China (English)

    L. Chen; Z.Y. Liu; D.C. Zeng; W.Q. Qiu; Z.H. Yuan; S.S. Lin; H.J. Hou

    2003-01-01

    DLC super-hard films have been deposited on the substrates of single crystalline Si, pure Ti and stainless steel 18-8 by a method of vacuum cathode arc deposition(VCAD). The composition, microstructure and micro-hardness of the films have been studied in this paper. The results indicate that hardness of the DLC films is different on the different substrates. Hardness of the films increases with decreasing in surface roughness of the films. The maximum value of micro-hardness belongs to the DLC films deposited under the hydrogen pressure of 0.35Pa and the negative bias of 100V.

  20. Thin metal film-polymer composite for efficient optoacoustic generation (Conference Presentation)

    Science.gov (United States)

    Lee, Taehwa; Guo, L. Jay

    2016-03-01

    Photoacoustic (PA) conversion of metal film absorbers is known to be inefficient because of their low thermal expansion and high light reflectance, as compared to polymeric materials containing light absorbing fillers. Specifically, the PA signal for metal films is typically an order of magnitude lower than those for PDMS-based composites consisting of carbon materials such as carbon blacks, carbon nanotubes, and carbon fibers. However, the carbon-PDMS composites have several disadvantages, e.g., difficulty in controlling film thickness, aggregation of the carbon fillers, and poor patternablility. To overcome these issues and achieve comparable PA amplitudes, a polymer-metal film composite was developed consisting of a thin metal absorber and adjacent transparent polymer layers. The proposed structure shows efficient PA conversion. The measured PA amplitude of the metal film composite is an order of magnitude higher than that of metal-only samples, and comparable to those of the carbon-PDMS composites. The enhanced PA conversion is accomplished by using metal film of a few tens of nanometers, which greatly facilitates heat transfer from the metal film to the surrounding polymers. Moreover, integrating the metal film composite with a photonic cavity can compensate light absorption loss of the thinner metal film. Theoretical and experimental analysis is conducted for understanding the mechanism behind such improvement. This strategy could be implemented for spatial PA signal patterns, especially for deep tissue PA imaging of implants or image-guiding tools. Furthermore, this approach also provides a guideline for designing photoacoustic transmitters and contrast agents.

  1. Fabrication and performances of AI/CuO nano composite films for ignition application

    Science.gov (United States)

    Li, Yong; Gao, Yun; Jia, Xin; Zhou, Bin; Shen, Rui-Qi

    2015-07-01

    In an effort to explore the application possibility of composite films in ignition field, Al/CuO was fabricated on semiconductor bridge (SCB) chip by ion beam sputtering technique. Surface morphology and elemental composition of the composite films were analysed by scanning electron microscope (SEM) and energy dispersive spectrometer (EDS). Spatial size and duration of the products was detected with the open-air combustion experiment. The results showed that the prepared composite films surface is smooth, flat, and uniform. Element weight ratio meets the design requirements. And the chemical reaction of the Al/CuO nCFs improves output performances of ignition chip.

  2. Electrochemical preparation and electrochemical behavior of polypyrrole/carbon nanotube composite films

    Institute of Scientific and Technical Information of China (English)

    Xue-tong ZHANG; Wen-hui SONG

    2009-01-01

    Polypyirole/multiwalled carbon nanotube (MWNT) composite fihns were electrochemically depos-ited in the presence of an ionic surfactant, sodium dodecyl sulfate (SDS), acting as both supporting electrolyte and dispersant. The effects of the surfactant and the MWNT concentrations on the structure at the resulting composite films were investigated. The electrochemical behavior of the resulting polypyrrole/MWNT composite film was investigated aS well bv cyclic voltammogram. The effect of the additional alternating electric field applied during the constant direct potential electrochemical deposition on the morphology and electrochemical behavior of the resulting composite film was also investigated in this study.

  3. Structure and photochromic properties of molybdenumphosphoric acid/TiO2 composite films

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    TiO2 sol-gel composite films with dropping molybdenumphosphoric acid(PMoA) have been prepared by sol-gel method.The structure and constitute of composite thin films were studied with Fourier transforms infrared spectroscopy(FT-IR),atomic force microscopy(AFM),and X-ray diffraction(XRD) patterns,respectively.The photochromic behavior and mechanism of composite thin films were inves-tigated with ultraviolet-visible spectra(UV-vis) and electron spin resonance(ESR).FT-IR results showed that the Keggin geometry of PMoA was still preserved inside PMoA/TiO2 composite thin films,and a charge transfer bridge was built at the interface of PMoA and TiO2 through the Mo-O-Ti bond.Surface topography of the composite film showed obvious changes before/after adding PMoA,and the surface topography of composite films showed obvious changes before/after irradiating as well.Composite thin film had reversible photochromic properties.Irradiated with UV light,transparent films changed from colorless to blue and they can bleach completely with ambient air in the dark.ESR re-sults showed that TiO2 were excitated by UV light to produce electrons,which deoxidized PMoA to produce heteropolyblues.The photochromic process of PMoA/TiO2 system was carried through elec-tron transfer mechanism.

  4. Synthesis and characterization of polyaniline/activated carbon composites and preparation of conductive films

    International Nuclear Information System (INIS)

    Polyaniline was synthesized via polyaniline/activated carbon (PANI/AC) composites by in situ polymerization and ex situ solution mixing. PANI and PANI/AC composite films were prepared by drop-by-drop and spin coating methods. The electrical conductivities of HCl doped PANI film and PANI/AC composite films were measured according to the standard four-point-probe technique. The composite films exhibited an increase in electrical conductivity over neat PANI. PANI and PANI/AC composites were investigated by spectroscopic methods including UV-vis, FTIR and photoluminescence. UV-vis and FTIR studies showed that AC particles affect the quinoid units along the polymer backbone and indicate strong interactions between AC particles and quinoidal sites of PANI. The photoluminescence properties of PANI and PANI/AC composites were studied and the photoluminescence intensity of PANI/AC composites was higher than that of neat PANI. The increase of conductivity of PANI/AC composites may be partially due to the doping or impurity effect of AC, where the AC competes with chloride ions. The amount of weight loss and the thermostability of PANI and PANI/AC composites were determined from thermogravimetric analysis. The morphology of particles and films were examined by a scanning electron microscope (SEM). SEM measurements indicated that the AC particles were well dispersed and isolated in composite films.

  5. Electrophoretic deposition of composite halloysite nanotube–hydroxyapatite–hyaluronic acid films

    Energy Technology Data Exchange (ETDEWEB)

    Deen, I. [Department of Materials Science and Engineering, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4L7 (Canada); Zhitomirsky, I., E-mail: zhitom@mcmaster.ca [Department of Materials Science and Engineering, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4L7 (Canada)

    2014-02-15

    Highlights: ► Composite halloysite nanotubes–hydroxyapatite–hyaluronic acid films were prepared. ► Electrophoretic deposition method was used for deposition. ► Natural hyaluronic acid was used as a dispersing, charging and film forming agent. ► Film composition and deposition yield can be varied. ► The films can be used for biomedical implants with controlled release of drugs. -- Abstract: Electrophoretic deposition method has been developed for the deposition of biocomposite films containing halloysite nanotubes (HNTs), hydroxyapatite (HA) and hyaluronic acid. The method is based on the use of natural hyaluronate biopolymer as a dispersing and charging agent for HNT and HA and film forming agent for the fabrication of the composite films. The deposition kinetics was studied by the quartz crystal microbalance method. The composite films were studied by X-ray diffraction, thermogravimetric analysis, differential thermal analysis and electron microscopy. The composite films are promising materials for the fabrication of biomedical implants with advanced functional properties.

  6. Electrophoretic deposition of composite halloysite nanotube–hydroxyapatite–hyaluronic acid films

    International Nuclear Information System (INIS)

    Highlights: ► Composite halloysite nanotubes–hydroxyapatite–hyaluronic acid films were prepared. ► Electrophoretic deposition method was used for deposition. ► Natural hyaluronic acid was used as a dispersing, charging and film forming agent. ► Film composition and deposition yield can be varied. ► The films can be used for biomedical implants with controlled release of drugs. -- Abstract: Electrophoretic deposition method has been developed for the deposition of biocomposite films containing halloysite nanotubes (HNTs), hydroxyapatite (HA) and hyaluronic acid. The method is based on the use of natural hyaluronate biopolymer as a dispersing and charging agent for HNT and HA and film forming agent for the fabrication of the composite films. The deposition kinetics was studied by the quartz crystal microbalance method. The composite films were studied by X-ray diffraction, thermogravimetric analysis, differential thermal analysis and electron microscopy. The composite films are promising materials for the fabrication of biomedical implants with advanced functional properties

  7. KNN/BNT composite lead-free films for high-frequency ultrasonic transducer applications.

    Science.gov (United States)

    Lau, Sien Ting; Ji, Hong Fen; Li, Xiang; Ren, Wei; Zhou, Qifa; Shung, K Kirk

    2011-01-01

    Lead-free K(0.5)Na(0.5)NbO(3)/Bi(0.5)Na(0.5)TiO(3) (KNN/ BNT) films have been fabricated by a composite sol-gel technique. Crystalline KNN fine powder was dispersed in the BNT precursor solution to form a composite slurry which was then spin-coated onto a platinum-buffered Si substrate. Repeated layering and vacuum infiltration were applied to produce 5-μm-thick dense composite film. By optimizing the sintering temperature, the films exhibited good dielectric and ferroelectric properties comparable to PZT films. A 193-MHz high-frequency ultrasonic transducer fabricated from this composite film showed a -6-dB bandwidth of approximately 34%. A tungsten wire phantom was imaged to demonstrate the capability of the transducer. PMID:21244994

  8. Continuous Preparation of Copper/Carbon Nanotube Composite Films and Application in Solar Cells.

    Science.gov (United States)

    Luo, Xiao Gang; Le Wu, Min; Wang, Xiao Xia; Zhong, Xin Hua; Zhao, Ke; Wang, Jian Nong

    2016-02-01

    Realizing the continuous and large scale preparation of particle/carbon nanotube (CNT) composites with enhanced functionalities, and broad applications in energy conversion, harvesting, and storage systems, remains as a big challenge. Here, we report a scalable strategy to continuously prepare particle/CNT composite films in which particles are confined by CNT films. This is achieved by the continuous condensation and deposition of a cylindrical assembly of CNTs on a paper strip and the in situ incorporation of particles during the layer-by-layer deposition process. A Cu/CNT composite film is prepared as an example; such a film exhibits very high power conversion efficiency when it is used as a counter electrode in a solar cell, compared with previous materials under otherwise identical conditions. The proposed method can be extended to other CNT-based composite films with excellent functionalities for wide applications. PMID:26784865

  9. Bending actuation in a single-layer carbon-nanofiber/polypyrrole composite film and its fabrication

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Shuai; Kim, Cheol [Kyungpook National University, Daegu (Korea, Republic of)

    2011-07-15

    Thin CNF/PPy composite single-layer films were produced by the electrophoretic deposition and polymerization process which was developed for this study. It was demonstrated that the films could generate a bending motion subjected to an actuating electric voltage even though they consisted of only single-layer. Carbon nanofiber and polypyrrole composite films were obtained from only one side of a working electrode. Several different CNF/PPy films were synthesized, as varying the CNF weight ratios from 3%, 5%, and 7% to 10%. Conductivity of pure PPy and CNF/PPy composite films were measured. Conductivity of the films is improved linearly from 77.9S/cm (pure PPy film) to 124.3 S/cm (10% CNF/PPy) as the CNF weight ratio increases. Adding CNF was effective for improving the conductivity of PPy. As results of electromechanical actuation tests with the films, it was noticed that the strain of the films was reduced a little as the CNF weight ratio increased. Bending motions were observed for both PPy and CNF/PPy films subjected to a voltage. The tip bending deflections was in the range of 0.5 mm to 2 mm. CNF/PPy films showed a great potential to be a good candidate for small light actuators.

  10. Photocatalytic degradation of methyl orange over ITO/CdS/ZnO interface composite films

    Institute of Scientific and Technical Information of China (English)

    WEI Shouqiang; SHAO Zhongcai; LU Xudong; LIU Ying; CAO Linlin; HE Yan

    2009-01-01

    ITO/CdS/ZnO interface composite films were successfully prepared by subsequent electrodeposition of CdS and ZnO onto indium tin oxide (ITO) glass substrates. The obtained ITO/CdS/ZnO composite films were characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM), and UV-Vis spectroscopy. The photocatalytic activity of ITO/CdS/ZnO composite films were investigated using methyl orange (MO) as a model organic compound under UV light irradiation. The influence of operating parameters on MO degradation including initial concentration of MO, pH value of solution, and inorganic anion species over the composite films were examined. A blue shift of absorption threshold was observed for the ITO/CdS/ZnO film in comparison with ITO/ZnO film. ITO/CdS/ZnO composite films prepared under specific conditions showed a higher photocatalytic activity than that of ITO/ZnO films. It was also found that the photocatalytic degradation of MO on the composite filing followed pseudo-first order kinetics.

  11. Magnetic and semi-conducting nano-composite films of spinel ferrite and cubic zinc oxide

    OpenAIRE

    Presmanes, Lionel; Capdeville, Stéphanie; Bonningue, Corine; Datas, Lucien; Tailhades, Philippe

    2007-01-01

    Magnetic and semi-conducting nano-composite films have been prepared under bias polarization, by radio-frequency sputtering of a pure zinc ferrite target. These composite thin films are made of cubic Zn1 − yFeyO monoxide islands inside a spinel ferrite matrix. The relative proportion of each phase depends on the substrate polarization (i.e. bias power). When no bias is applied the films solely display the diffraction pattern of a spinel phase even if some islands inside the film can be observ...

  12. Investigation of polypyrrole/polyvinyl alcohol-titanium dioxide composite films for photo-catalytic applications

    Science.gov (United States)

    Cao, Shaoqiang; Zhang, Hongyang; Song, Yuanqing; Zhang, Jianling; Yang, Haigang; Jiang, Long; Dan, Yi

    2015-07-01

    Polypyrrole/polyvinyl alcohol-titanium dioxide (PPy/PVA-TiO2) composite films used as photo-catalysts were fabricated by combining TiO2 sol with PPy/PVA solution in which PPy was synthesized by in situ polymerization of pyrrole (Py) in polyvinyl alcohol (PVA) matrix and loaded on glass. The prepared photo-catalysts were investigated by X-ray diffraction (XRD), ultraviolet-visible diffuse reflection spectroscopy (UV-vis DRS), scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectra and photoluminescence (PL). The results indicate that the composites have same crystal structure as the TiO2 and extend the optic absorption from UV region to visible light region. By detecting the variation ratio, detected by ultraviolet-vis spectroscopy, of model pollutant rhodamine B (RhB) solution in the presence of the composite films under both UV and visible light irradiation, the photo-catalytic performance of the composite films was investigated. The results show that the PPy/PVA-TiO2 composite films show better photo-catalytic properties than TiO2 film both under UV and visible light irradiation, and the photo-catalytic degradation of RhB follows the first-order kinetics. The effects of the composition of composite films and the concentration of RhB on the photo-catalytic performance, as well as the possible photo-catalytic mechanism, were also discussed. By photo-catalytic recycle experiments, the structure stability of the PPy/PVA-TiO2 composite film was investigated and the results show that the photo-catalytic activity under both UV and visible light irradiation have no significant decrease after four times of recycle experiments, suggesting that the photo-catalyst film is stable during the photo-catalytic process, which was also confirmed by the XRD pattern and FT-IR spectra of the composite film before and after photo-catalytic.

  13. Potentiality of the composite fulleren based carbon films as the stripper foils for tandem accelerators

    CERN Document Server

    Vasin, A V; Rusavsky, A V; Totsky, Y I; Vishnevski, I N

    2001-01-01

    The problem of the radiation resistance of the carbon stripper foils is considered. The short review of the experimental data available in literature and original experimental results of the are presented. In the paper discussed is the possibility of composite fulleren based carbon films to be used for preparation of the stripper foils. Some technological methods for preparation of composite fulleren based carbon films are proposed. Raman scattering and atom force microscopy were used for investigation of the fulleren and composite films deposited by evaporation of the C sub 6 sub 0 fulleren powder.

  14. Effects of copolymer composition, film thickness, and solvent vapor annealing time on dewetting of ultrathin block copolymer films.

    Science.gov (United States)

    Huang, Changchun; Wen, Gangyao; Li, Jingdan; Wu, Tao; Wang, Lina; Xue, Feifei; Li, Hongfei; Shi, Tongfei

    2016-09-15

    Effects of copolymer composition, film thickness, and solvent vapor annealing time on dewetting of spin-coated polystyrene-block-poly(methyl methacrylate) (PS-b-PMMA) films (annealed for different times were performed using X-ray photoelectron spectroscopy and contact angle measurement. With the annealing of acetone vapor, dewetting of the films with different thicknesses occur via the spinodal dewetting and the nucleation and growth mechanisms, respectively. The PS-b-PMMA films rupture into droplets which first coalesce into large ones to reduce the surface free energy. Then the large droplets rupture into small ones to increase the contact area between PMMA blocks and acetone molecules resulting from ultimate migration of PMMA blocks to droplet surface, which is a novel dewetting process observed in spin-coated films for the first time. PMID:27309943

  15. Structural determination and magnetic properties for Co-rubrene composite films on Si(1 0 0)

    Science.gov (United States)

    Hou, Yong-Jhih; Chang, Cheng-Hsun-Tony; Yang, Chun-Kai; Hsu, Chih-Yu; Jhou, Yen-Wei; Tsay, Jyh-Shen

    2015-11-01

    Because of the potential uses toward low-cost and flexible-substrate-based electronics, semiconducting organic materials have attracted much attention. In this contribution, structures and magnetic properties of Co-rubrene composite films on Si(1 0 0) have been studied by employing atomic force microscopy (AFM) and magneto-optic Kerr effect techniques. For composite films prepared by co-depositions of Co and rubrene on Si(1 0 0), the surface is smooth while a layered distribution of Co atoms is detected. For thick composite films, surfactant effects of rubrene molecules cause smooth surfaces and reduced interaction at the film/Si interface. For thin composite films, the formation of separated Co clusters in the films results in a larger coercive force due to the imperfection introduced by rough interface to impede the magnetization reversal. By increasing the rubrene concentration, more Co/rubrene interfaces are introduced in the composite films and the more rubrene served as a surfactant enhances the quality of the films. These information are valuable for future applications combining organic semiconductor and spintronics.

  16. Preparation and multicolored fluorescent properties of CdTe quantum dots/polymethylmethacrylate composite films

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Yanni; Liu, Jianjun, E-mail: jjliu717@aliyun.com; Yu, Yingchun; Zuo, Shengli

    2015-10-25

    A new simple route was presented for the preparation of stable fluorescent CdTe/polymethylmethacrylate (CdTe/PMMA) composite films by using hydrophilic thioglycolic acid capped CdTe quantum dots (TGA-CdTe QDs) and polymethylmethacrylate (PMMA) as raw materials. The TGA-CdTe QDs were firstly exchanged with n-dodecanethiol (DDT) to become hydrophobic DDT-CdTe QDs via a ligand exchange strategy, and then incorporated into PMMA matrix to obtain fluorescent CdTe/PMMA composite films. The structure and optical properties of DDT-CdTe QDs and CdTe/PMMA composite films were investigated by XRD, IR, UV and PL techniques. The results indicated that the obtained DDT-CdTe QDs well preserved the intrinsic structure and the maximum emission wavelength of the initial water-soluble QDs and the resulting 6.10 wt% CdTe/PMMA composite film exhibited significantly enhanced PL intensity. Furthermore, the multicolored composite films with green, yellow-green, yellow and orange light emissions were well tuned by incorporating the CdTe QDs of various maximum emission wavelengths. The TEM image demonstrated that the CdTe QDs were well-dispersed in the PMMA matrix without aggregation. Superior photostability of QDs in the composite film was confirmed by fluorescence lifetime measurement. Thermo-gravimetric analysis of CdTe/PMMA composite films showed no obvious enhancement of thermal stability compared with pure PMMA. - Highlights: • Ligand-exchange strategy was used to render CdTe QDs oil-soluble. • CdTe QDs were incorporated into PMMA matrix to fabricate fluorescent films. • The resulting 6.10 wt% CdTe/PMMA film exhibited significantly enhanced PL intensity. • Fluorescent colors of films were tuned by varying the λ{sub em} of incorporated CdTe QDs.

  17. Preparation and multicolored fluorescent properties of CdTe quantum dots/polymethylmethacrylate composite films

    International Nuclear Information System (INIS)

    A new simple route was presented for the preparation of stable fluorescent CdTe/polymethylmethacrylate (CdTe/PMMA) composite films by using hydrophilic thioglycolic acid capped CdTe quantum dots (TGA-CdTe QDs) and polymethylmethacrylate (PMMA) as raw materials. The TGA-CdTe QDs were firstly exchanged with n-dodecanethiol (DDT) to become hydrophobic DDT-CdTe QDs via a ligand exchange strategy, and then incorporated into PMMA matrix to obtain fluorescent CdTe/PMMA composite films. The structure and optical properties of DDT-CdTe QDs and CdTe/PMMA composite films were investigated by XRD, IR, UV and PL techniques. The results indicated that the obtained DDT-CdTe QDs well preserved the intrinsic structure and the maximum emission wavelength of the initial water-soluble QDs and the resulting 6.10 wt% CdTe/PMMA composite film exhibited significantly enhanced PL intensity. Furthermore, the multicolored composite films with green, yellow-green, yellow and orange light emissions were well tuned by incorporating the CdTe QDs of various maximum emission wavelengths. The TEM image demonstrated that the CdTe QDs were well-dispersed in the PMMA matrix without aggregation. Superior photostability of QDs in the composite film was confirmed by fluorescence lifetime measurement. Thermo-gravimetric analysis of CdTe/PMMA composite films showed no obvious enhancement of thermal stability compared with pure PMMA. - Highlights: • Ligand-exchange strategy was used to render CdTe QDs oil-soluble. • CdTe QDs were incorporated into PMMA matrix to fabricate fluorescent films. • The resulting 6.10 wt% CdTe/PMMA film exhibited significantly enhanced PL intensity. • Fluorescent colors of films were tuned by varying the λem of incorporated CdTe QDs

  18. Preparation and characterization of keratin and chicken egg white-templated luminescent Au cluster composite film

    Science.gov (United States)

    Xing, Yao; Liu, Hongling; Yu, Weidong

    2016-02-01

    The characterization of keratin-chicken egg white-templated luminescent Au cluster composite films were studied using fourier-transform infrared spectroscopy (FTIR) to demonstrate and quantify the secondary transformation of composite films. The results showed that the secondary structure of treated films was transformed from disordered structure to ordered conformation including α-helix conformation and β-pleated-sheet conformation due to the increase of protein-templated luminescent Au cluster. The absorption features of treated films were exhibited by the UV-vis spectra. The bule-shift and decreased intensity indicated the change of microenvironment due to the concentration of protein-templated luminescent Au cluster. The transmission electron microscopy images of composite films supported the aggregation resulting from microenvironment. The effect of protein-templated luminescent Au cluster was characterized by the laser scanning confocal microscope (LSCM) images which showed the gradually intensive luminescence with increasing Au cluster and the transformation from the whiskers to nanoparticle.

  19. The nanoindentation applied to predict the interface delamination for the C/amorphous Si composite film

    Science.gov (United States)

    Han, Chang-Fu; Huang, Chao-Yu; Wu, Bo-Hsiung; Lin, Jen-Fin

    2009-10-01

    In the present study, the indentation depth corresponding to the pop-in arising in the loading process is found to be quite close to the C/amorphous Si composite film thickness, regardless of the C-film thickness. This load-depth behavior gives a clue that the occurrence of pop-in is perhaps related to the buckling of the composite film, which had already delaminated from the silicon substrate. This indentation depth of buckling predicted by the present model is quite close to the pop-in depth obtained from experimental results, regardless of the change in the C-film thickness. This characteristic reveals that the present model is developed successfully to predict the pop-in depth of a specimen, and the pop-in is indeed created due to the buckling of the composite film under a compression stress.

  20. Preparation and characterization of polyimide/silica/silver composite films

    Institute of Scientific and Technical Information of China (English)

    Ning LUO; Zhanpeng WU; Nanxiang MOU; Lizhong JIANG; Dezhen WU

    2008-01-01

    Polyimide/silica/silver hybrid films were pre-pared by the sol-gel method combined with in situ single-stage self-metallization technique.The structure of polyi-mide films in the thermal curing process and the influence of silica content on the migration and aggregation of silver particles to the surface of hybrid films were investigated.The hybrid films were characterized by transmission elec-tron microscopy,dynamic mechanical thermal analysis,Fourier transform infrared spectroscopy,ultraviolet visible spectroscopy and mechanical measurements.The results indicated that there was no degradation of the polyimide matrix after the formation of silica and silver particles.Silica acted as the nucleus for the silver particles.With increasing silica content,more and more silver particles were kept in the hybrid films instead of being migrated onto the surface of the hybrid films and the reflections of hybrid films decreased gradually.

  1. Tailoring the Composition and Properties of Sprayed CuSbS2 Thin Films by Using Polymeric Additives

    Directory of Open Access Journals (Sweden)

    Ionut Popovici

    2012-01-01

    Full Text Available CuSbS2 thin films were obtained by spray pyrolysis deposition, using polymeric additives for controlling the surface properties and film’s composition. Ternary crystalline chalcostibite compounds have been obtained without any postdeposition treatments. XRD spectra and IR spectroscopy were used to characterize films composition and interactions between components. Films morphology and surface energy were investigated using AFM microscopy and contact angle measurements. Hydrophobic and hydrophilic polymers strongly influence the composition and film morphology.

  2. Magnetic and electromagnetic properties of Pr doped strontium ferrite/polyaniline composite film

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Ying; Li, Yuqing; Wang, Yan, E-mail: wangyan287580632@126.com

    2014-11-15

    This paper reported three acid (including hydrochloric acid HCl, p-toluenesulfonic acid PTS and D-camphor-10-acid CSA) doped SrPr{sub 0.2}Fe{sub 11.8}O{sub 19}/PANI composite film and the HCl–PANI film prepared by a sol–gel method and in-situ oxidative polymerization. The characteristics of the film phase structure, surface morphology, conductivity and magnetic and electromagnetic properties were studied by using XRD, XPS, FESEM, four-probe tester, VSM and Vector Network Analyzer. The resistivity of organic acid doped composite films is higher than that of the HCl doped one. The saturation and remanent magnetization of PTS and HCl doped composite films are greater than the CSA-doped one; however, the coercivity of the three acid doped composite films is basically 5546 Oe. The saturation magnetization, remanent magnetization and coercivity of SrPr{sub 0.2}Fe{sub 11.8}O{sub 19} film are greater than those of the SrPr{sub 0.2}Fe{sub 11.8}O{sub 19}–PANI composite film. In the frequency range of 8–12 GHz, the dielectric loss of HCl–PANI film is the maximum, and the dielectric loss of SrPr{sub 0.2}Fe{sub 11.8}O{sub 19} film is the minimum; the magnetic loss of the four films is in descending order as SrPr{sub 0.2}Fe{sub 11.8}O{sub 19} film, PrSrM/(HCl–PANI) composite film, PrSrM/(CSA–PANI) and HCl–PANI film. - Highlights: • Synthesizing three acid doped SrPr{sub 0.2}Fe{sub 11.8}O{sub 19}/PANI composite films. • By sol–gel method and in-situ oxidative polymerization. • With excellent magnetic and electromagnetic properties. • The particular coating structure of PANI and Sr-ferrite. • Great interest for magnetic material and microwave absorbers.

  3. Effect of Continuous Multi-Walled Carbon Nanotubes on Thermal and Mechanical Properties of Flexible Composite Film

    Directory of Open Access Journals (Sweden)

    Ji Eun Cha

    2016-10-01

    Full Text Available To investigate the effect of continuous multi-walled carbon nanotubes (MWCNTs on the thermal and mechanical properties of composites, we propose a fabrication method for a buckypaper-filled flexible composite film prepared by a two-step process involving buckypaper fabrication using vacuum filtration of MWCNTs, and composite film fabrication using the dipping method. The thermal conductivity and tensile strength of the composite film filled with the buckypaper exhibited improved results, respectively 76% and 275% greater than those of the individual MWCNT-filled composite film. It was confirmed that forming continuous MWCNT fillers is an important factor which determines the physical characteristics of the composite film. In light of the study findings, composite films using buckypaper as a filler and polydimethylsiloxane (PDMS as a flexible matrix have sufficient potential to be applied as a heat-dissipating material, and as a flexible film with high thermal conductivity and excellent mechanical properties.

  4. Polymer compositions, polymer films and methods and precursors for forming same

    Science.gov (United States)

    Klaehn, John R; Peterson, Eric S; Orme, Christopher J

    2013-09-24

    Stable, high performance polymer compositions including polybenzimidazole (PBI) and a melamine-formaldehyde polymer, such as methylated, poly(melamine-co-formaldehyde), for forming structures such as films, fibers and bulky structures. The polymer compositions may be formed by combining polybenzimidazole with the melamine-formaldehyde polymer to form a precursor. The polybenzimidazole may be reacted and/or intertwined with the melamine-formaldehyde polymer to form the polymer composition. For example, a stable, free-standing film having a thickness of, for example, between about 5 .mu.m and about 30 .mu.m may be formed from the polymer composition. Such films may be used as gas separation membranes and may be submerged into water for extended periods without crazing and cracking. The polymer composition may also be used as a coating on substrates, such as metal and ceramics, or may be used for spinning fibers. Precursors for forming such polymer compositions are also disclosed.

  5. Deposition of multi-layer films of hexafluoropropene - ethylene composite polymer with jet-type plasma reactor at atmospheric pressure

    International Nuclear Information System (INIS)

    Multi-layer films of hexafluoropropene - ethylene composite polymer were deposited with a jet-type plasma reactor on poly (ethylene terephthalate) films, which were used as base films, at atmospheric pressure. The multi-layer films were made up by decreasing the flow rate of ethylene gas gradually and increasing that of hexafluoropropene gas simultaneously during the plasma-polymerization. Those films showed low enough peel force, whose value was near that of a Teflon sheet used as a control. Moreover, the bond strength between the multi-layer film and the base film became stronger than that between a plasma-polymerized hexatluoropropene film and the base film. (author)

  6. Strong composite films with layered structures prepared by casting silk fibroin-graphene oxide hydrogels.

    Science.gov (United States)

    Huang, Liang; Li, Chun; Yuan, Wenjing; Shi, Gaoquan

    2013-05-01

    Composite films of graphene oxide (GO) sheets and silk fibroin (SF) with layered structures have been prepared by facile solution casting of SF-GO hydrogels. The as-prepared composite film containing 15% (by weight, wt%) of SF shows a high tensile strength of 221 ± 16 MPa and a failure strain of 1.8 ± 0.4%, which partially surpass those of natural nacre. Particularly, this composite film also has a high modulus of 17.2 ± 1.9 GPa. The high mechanical properties of this composite film can be attributed to its high content of GO (85 wt%), compact layered structure and the strong hydrogen bonding interaction between SF chains and GO sheets. PMID:23538717

  7. Electrical and Dielectric Properties of Exfoliated Graphite/Polyimide Composite Films with Low Percolation Threshold

    Science.gov (United States)

    Yu, Li; Zhang, Yi-He; Shang, Jiwu; Ke, Shan-Ming; Tong, Wang-shu; Shen, Bo; Huang, Hai-Tao

    2012-09-01

    Exfoliated graphite/polyimide composite films were synthesized by in situ polymerization. The electrical and dielectric properties of composite films with different volume fraction of exfoliated graphite were investigated over the frequency range from 103 Hz to 3 × 106 Hz. The dielectric behavior of the composite films was investigated by percolation theory and a microcapacitor model. A low percolation threshold f c ≈ 3.1 vol.% was obtained due to the high aspect ratio of the exfoliated graphite. Both the dielectric constant and alternating-current (AC) conductivity showed an abrupt increase in the vicinity of the percolation threshold. The ultralarge enhancement of the dielectric constant near and beyond the percolation threshold was due to Maxwell-Wagner-Sillars (MWS) interfacial polarization between the exfoliated graphite and polyimide and interface polarization between the composite film and electrode.

  8. Preparation and properties of biodegradable films from Sterculia urens short fiber/cellulose green composites.

    Science.gov (United States)

    Jayaramudu, J; Reddy, G Siva Mohan; Varaprasad, K; Sadiku, E R; Sinha Ray, S; Varada Rajulu, A

    2013-04-01

    The development of commercially viable "green products", based on natural resources for the matrices and reinforcements, in a wide range of applications, is on the rise. The present paper focuses on Sterculia urens short fiber reinforced pure cellulose matrix composite films. The morphologies of the untreated and 5% NaOH (alkali) treated S. urens fibers were observed by SEM. The effect of 5% NaOH treated S. urens fiber (5, 10, 15 and 20% loading) on the mechanical properties and thermal stability of the composites films is discussed. This paper presents the developments made in the area of biodegradable S. urens short fiber/cellulose (SUSF/cellulose) composite films, buried in the soil and later investigated by the (POM), before and after biodegradation has taken place. SUSF/cellulose composite films have great potential in food packaging and for medical applications.

  9. Chitosan and polyvinyl alcohol composite films containing nitrofurazone: preparation and evaluation

    Directory of Open Access Journals (Sweden)

    Maryam Kouchak

    2014-01-01

    The presence of PVA improves many properties of Cs-nitrofurazone films and makes them more desirable as dressing material for burn wounds. Although nitrofurazone alone is ineffective against P. aeruginosa, it is able to increase antibacterial effect of chitosan in composite films

  10. Poly(lactic acid) and Osage Orange Wood Fiber Composites for Agricultural Mulch Films

    Science.gov (United States)

    Osage orange wood(OO)was combined with poly(lactic acid)(PLA)to form a polymer composite intended for use as an agricultural mulch film. The PLA-OO mechanical properties were comparable to existing mulch film products and had the advantage of being completely biodegradable through a single growing ...

  11. Development and Characterization of Biodegradable Composite Films Based on Gelatin Derived from Beef, Pork and Fish Sources

    OpenAIRE

    Zainal A. Nur Hanani; Eddie Beatty; Yrjo H. Roos; Mick A. Morris; Joseph P. Kerry

    2013-01-01

    The objectives of this study were to develop composite films using various gelatin sources with corn oil (CO) incorporation (55.18%) and to investigate the mechanical and physical properties of these films as potential packaging films. There were increases (p < 0.05) in the tensile strength (TS) and puncture strength (PS) of films when the concentration of gelatin increased. The mechanical properties of these films were also improved when compared with films produced without CO. Conversely, t...

  12. A dense and strong bonding collagen film for carbon/carbon composites

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Sheng; Li, Hejun, E-mail: lihejun@nwpu.edu.cn; Li, Kezhi; Lu, Jinhua; Zhang, Leilei

    2015-08-30

    Graphical abstract: - Highlights: • Significantly enhancement of biocompatibility on C/C composites by preparing a collagen film. • The dense and continuous collagen film had a strong bonding strength with C/C composites after dehydrathermal treatment (DHT) crosslink. • Numerous oxygen-containing functional groups formed on the surface of C/C composites without matrix damage. - Abstract: A strong bonding collagen film was successfully prepared on carbon/carbon (C/C) composites. The surface conditions of the modified C/C composites were detected by contact angle measurements, scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and Raman spectra. The roughness, optical morphology, bonding strength and biocompatibility of collagen films at different pH values were detected by confocal laser scanning microscope (CLSM), universal test machine and cytology tests in vitro. After a 4-h modification in 30% H{sub 2}O{sub 2} solution at 100 °C, the contact angle on the surface of C/C composites was decreased from 92.3° to 65.3°. Large quantities of hydroxyl, carboxyl and carbonyl functional groups were formed on the surface of the modified C/C composites. Then a dense and continuous collagen film was prepared on the modified C/C substrate. Bonding strength between collagen film and C/C substrate was reached to 8 MPa level when the pH value of this collagen film was 2.5 after the preparing process. With 2-day dehydrathermal treatment (DHT) crosslinking at 105 °C, the bonding strength was increased to 12 MPa level. At last, the results of in vitro cytological test showed that this collagen film made a great improvement on the biocompatibility on C/C composites.

  13. Experimental Evaluation of Biodegradable Film Compositions Based on Gelatin with Colchicine.

    Science.gov (United States)

    Bokeriya, L A; Bokeriya, O L; Sivtsev, V S; Novikova, S P; Salokhedinova, R R; Nikolashina, L N; Samsonova, N N; Gorodkov, A Yu; Serov, R A

    2016-07-01

    Biodegradable film compositions based on natural biopolymer gelatin with immobilized colchicine were prepared and their efficiency in prevention of the adhesion process in the pericardium was evaluated on rabbit model of postoperative pericarditis. The use of gelatin-based biodegradable film compositions significantly reduced the intensity of adhesion formation in the pericardial cavity, while immobilization of anti-inflammatory drug colchicine amplified their anti-adhesion activity. PMID:27496036

  14. Nonlinear Analysis of Actuation Performance of Shape Memory Alloy Composite Film Based on Silicon Substrate

    OpenAIRE

    Shuangshuang Sun; Xiance Jiang

    2014-01-01

    The mechanical model of the shape memory alloy (SMA) composite film with silicon (Si) substrate was established by the method of mechanics of composite materials. The coupled action between the SMA film and Si substrate under thermal loads was analyzed by combining static equilibrium equations, geometric equations, and physical equations. The material nonlinearity of SMA and the geometric nonlinearity of bending deformation were both considered. By simulating and analyzing the actuation perfo...

  15. Preparation of PANI/PSF conductive composite films and their characteristic

    Institute of Scientific and Technical Information of China (English)

    Yang Yuying; Shang Xiuli; Kong Chao; Zhao Hongxiao; Hu Zhong'ai

    2006-01-01

    Polyaniline (PANI)/polysulfone (PSF) composite films are successfully prepared by phase separation and one-step in-situ polymerization.It is found that the head-on face (in contact with solution) of the films is green while the back face is white.The chemical component and the surface morphology of both surfaces of the films are characterized by FT-IR spectra and SEM,respectively.The effect of the polymerization temperature,time and concentration of the reactants on the electrical properties of the films are discussed in details.The thermo-oxidative degradation of the films is studied by thermogravimetric analysis (TGA).The results indicate that the thermal stability of the PANI/PSF films is higher than that of the pure PSF film.

  16. Investigation of polypyrrole/polyvinyl alcohol–titanium dioxide composite films for photo-catalytic applications

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Shaoqiang; Zhang, Hongyang; Song, Yuanqing; Zhang, Jianling; Yang, Haigang; Jiang, Long, E-mail: jianglong@scu.edu.cn; Dan, Yi, E-mail: danyichenweiwei@163.com

    2015-07-01

    Graphical abstract: - Highlights: • The study provides an easy and convenient method to fabricate films, which will give guidance for the preparation of three-dimensional materials. • The PPy/PVA–TiO{sub 2} films can keep better photo-catalytic activities both under UV and visible light irradiation when compared with TiO{sub 2} film. • There exist electron transfers between PPy/PVA and TiO{sub 2}. - Abstract: Polypyrrole/polyvinyl alcohol–titanium dioxide (PPy/PVA–TiO{sub 2}) composite films used as photo-catalysts were fabricated by combining TiO{sub 2} sol with PPy/PVA solution in which PPy was synthesized by in situ polymerization of pyrrole (Py) in polyvinyl alcohol (PVA) matrix and loaded on glass. The prepared photo-catalysts were investigated by X-ray diffraction (XRD), ultraviolet–visible diffuse reflection spectroscopy (UV–vis DRS), scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectra and photoluminescence (PL). The results indicate that the composites have same crystal structure as the TiO{sub 2} and extend the optic absorption from UV region to visible light region. By detecting the variation ratio, detected by ultraviolet–vis spectroscopy, of model pollutant rhodamine B (RhB) solution in the presence of the composite films under both UV and visible light irradiation, the photo-catalytic performance of the composite films was investigated. The results show that the PPy/PVA–TiO{sub 2} composite films show better photo-catalytic properties than TiO{sub 2} film both under UV and visible light irradiation, and the photo-catalytic degradation of RhB follows the first-order kinetics. The effects of the composition of composite films and the concentration of RhB on the photo-catalytic performance, as well as the possible photo-catalytic mechanism, were also discussed. By photo-catalytic recycle experiments, the structure stability of the PPy/PVA–TiO{sub 2} composite film was investigated and the results show that

  17. Properties of composite film based on bigeye snapper surimi protein and lipids

    Directory of Open Access Journals (Sweden)

    Thummanoon Prodpran

    2005-12-01

    Full Text Available Lipids were incorporated into bigeye snapper surimi protein films through emulsification using Tween-20 as a surfactant to form protein/lipid composite films. The effects of lipid types (palm oil, butter or shortening and concentrations (0-100% glycerol substitution on film properties were investigated. Additionof lipids up to 75% glycerol substitution resulted in the improved water vapor barrier, lowered tensile strength (TS and increased elongation at break (EAB of the composite film (P<0.05. However, an increase in TS was observed with increasing lipid concentration, plausibly caused by increasing protein aggregation in film matrix. Transparency of films was decreased with increasing lipid concentrations used (P<0.05, especially for those added with solid lipids. Generally, the mechanical properties and water resistance of surimi protein films incorporated with palm oil were superior to those modified with butter or shortening. An increase in Tween-20, nonionic surfactant, might be associated with the decrease in non-disulfide covalent cross-links in the film. Scanning electron microscopic study revealed that dispersion of palm oil in the film was more uniform than that of butter and shortening. This might contribute to the varying properties of resulting films.

  18. Development and Characterization of Biodegradable Composite Films Based on Gelatin Derived from Beef, Pork and Fish Sources

    Directory of Open Access Journals (Sweden)

    Zainal A. Nur Hanani

    2013-01-01

    Full Text Available The objectives of this study were to develop composite films using various gelatin sources with corn oil (CO incorporation (55.18% and to investigate the mechanical and physical properties of these films as potential packaging films. There were increases (p < 0.05 in the tensile strength (TS and puncture strength (PS of films when the concentration of gelatin increased. The mechanical properties of these films were also improved when compared with films produced without CO. Conversely, the water barrier properties of composite films decreased (p < 0.05 when the concentration of gelatin in composite films increased. Comparing with pure gelatin films, water and oxygen barrier properties of gelatin films decreased when manufactured with the inclusion of CO.

  19. Metal–organic coordinated multilayer film formation: Quantitative analysis of composition and structure

    Energy Technology Data Exchange (ETDEWEB)

    Benson, Alexandra S.; Elinski, Meagan B.; Ohnsorg, Monica L.; Beaudoin, Christopher K.; Alexander, Kyle A.; Peaslee, Graham F.; DeYoung, Paul A.; Anderson, Mary E., E-mail: meanderson@hope.edu

    2015-09-01

    Metal–organic coordinated multilayers are self-assembled thin films fabricated by alternating solution–phase deposition of bifunctional organic molecules and metal ions. The multilayer film composed of α,ω-mercaptoalkanoic acid and Cu (II) has been the focus of fundamental and applied research with its robust reproducibility and seemingly simple hierarchical architecture. However, internal structure and composition have not been unambiguously established. The composition of films up to thirty layers thick was investigated using Rutherford backscattering spectrometry and particle induced X-ray emission. Findings show these films are copper enriched, elucidating a 2:1 ratio for the ion to molecule complexation at the metal–organic interface. Results also reveal that these films have an average layer density similar to literature values established for a self-assembled monolayer, indicating a robust and stable structure. The surface structures of multilayer films have been characterized by contact angle goniometry, ellipsometry, and scanning probe microscopy. A morphological transition is observed as film thickness increases from the first few foundational layers to films containing five or more layers. Surface roughness analysis quantifies this evolution as the film initially increases in roughness before obtaining a lower roughness comparable to the underlying gold substrate. Quantitative analysis of topographical structure and internal composition for metal–organic coordinated multilayers as a function of number of deposited layers has implications for their incorporation in the fields of photonics and nanolithography. - Highlights: • Layer-by-layer deposition is examined by scanning probe microscopy and ion beam analysis. • Film growth undergoes morphological evolution during foundational layer deposition. • Image analysis quantified surface features such as roughness, grain size, and coverage. • Molecular density of each film layer is found to

  20. Preparation and characterization of electrochromic tungsten oxide–titania composite thin films with different tungsten/titanium ratios

    International Nuclear Information System (INIS)

    Tungsten oxide–titania composite thin films with different W/Ti atomic ratios were prepared and characterized in this study. Surface morphology, composition and structure of the composite thin films were investigated by scanning electron microscope with an energy dispersive spectrometer, X-ray diffraction and atomic force microscope analyses. Electrochromic properties including transmittance modulation ability, coloration efficiency and coloring/bleaching response time of these thin films were examined using cyclic voltammetry and double-potential-step experiment with in-situ ultraviolet–visible spectroscopy measurement. The presence of titania in the composite thin film could inhibit the crystal growth of tungsten oxide, which enhances the transmittance modulation ability and coloration efficiency but prolongs the coloring/bleaching response time of the composite thin film. The tungsten oxide–titania composite thin film (WTi-30) with a W/Ti atomic ratio of 78/22 exhibited better transmittance modulation ability (57.5%) and coloration efficiency (49.2 cm2/C) than a pristine tungsten trioxide thin film (53.6%, 36.2 cm2/C). - Highlights: • Tungsten oxide–titania thin films with different W/Ti atomic ratios are prepared. • Tungsten oxide and titania were well mixed in the composite thin films. • Crystal growth of tungsten oxide was inhibited by the incorporation of titania. • Transmittance modulation ability of the composite thin film is increased. • Coloration efficiency of the composite thin film is enhanced

  1. Preparation and characterization of electrochromic tungsten oxide–titania composite thin films with different tungsten/titanium ratios

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Cheng-Lan, E-mail: cllin@mail.tku.edu.tw [Department of Chemical and Materials Engineering, Tamkang University, New Taipei City 25137, Taiwan (China); The Energy and Opto-Electronic Materials Research Center, Tamkang University, New Taipei City 25137, Taiwan (China); Chen, Yan-Wen; Chen, En [Department of Chemical and Materials Engineering, Tamkang University, New Taipei City 25137, Taiwan (China)

    2014-04-01

    Tungsten oxide–titania composite thin films with different W/Ti atomic ratios were prepared and characterized in this study. Surface morphology, composition and structure of the composite thin films were investigated by scanning electron microscope with an energy dispersive spectrometer, X-ray diffraction and atomic force microscope analyses. Electrochromic properties including transmittance modulation ability, coloration efficiency and coloring/bleaching response time of these thin films were examined using cyclic voltammetry and double-potential-step experiment with in-situ ultraviolet–visible spectroscopy measurement. The presence of titania in the composite thin film could inhibit the crystal growth of tungsten oxide, which enhances the transmittance modulation ability and coloration efficiency but prolongs the coloring/bleaching response time of the composite thin film. The tungsten oxide–titania composite thin film (WTi-30) with a W/Ti atomic ratio of 78/22 exhibited better transmittance modulation ability (57.5%) and coloration efficiency (49.2 cm{sup 2}/C) than a pristine tungsten trioxide thin film (53.6%, 36.2 cm{sup 2}/C). - Highlights: • Tungsten oxide–titania thin films with different W/Ti atomic ratios are prepared. • Tungsten oxide and titania were well mixed in the composite thin films. • Crystal growth of tungsten oxide was inhibited by the incorporation of titania. • Transmittance modulation ability of the composite thin film is increased. • Coloration efficiency of the composite thin film is enhanced.

  2. Surface Haze and Surface Morphology of Blown Film Compositions

    OpenAIRE

    Patel, Rajen; Ratta, Varun; Saavedra, Pepe; Li, Jing

    2005-01-01

    Abstract Reduction in surface haze is a very attractive way to improve the optical properties of most polyolefin films. This route becomes very viable for coextruded multilayer films where the inner layers may be utilized to provide the desired mechanical properties, such as high modulus, controlled shrinkage, and good tear strength while the outer 'skin' layers are utilized to give low surface and ...

  3. Composition and microhardness of CAE boron nitride films

    International Nuclear Information System (INIS)

    The paper deals with boron nitride produced by cathodic arc evaporation techniques.The films were applied on titanium and cemented carbide substrates. Their characterization was carried out using X-ray diffraction and Knoop microhardness tests. Demonstrated are the high properties of two-phase films, containing β (cubic) and γ (wurtzitic) modifications of boron nitride. (author). 7 refs., 1 fig., 3 tabs

  4. Thin Film Heat Flux Sensor Development for Ceramic Matrix Composite (CMC) Systems

    Science.gov (United States)

    Wrbanek, John D.; Fralick, Gustave C.; Hunter, Gary W.; Zhu, Dongming; Laster, Kimala L.; Gonzalez, Jose M.; Gregory, Otto J.

    2010-01-01

    The NASA Glenn Research Center (GRC) has an on-going effort for developing high temperature thin film sensors for advanced turbine engine components. Stable, high temperature thin film ceramic thermocouples have been demonstrated in the lab, and novel methods of fabricating sensors have been developed. To fabricate thin film heat flux sensors for Ceramic Matrix Composite (CMC) systems, the rough and porous nature of the CMC system posed a significant challenge for patterning the fine features required. The status of the effort to develop thin film heat flux sensors specifically for use on silicon carbide (SiC) CMC systems with these new technologies is described.

  5. PREPARATION AND CORROSION RESISTANCE OF NiP/TiO2 COMPOSITE FILM ON CARBON STEEL IN SULFURIC ACID SOLUTION

    Institute of Scientific and Technical Information of China (English)

    L.Z. Song; S.Z. Song; J. Zhao

    2006-01-01

    A NiP/TiO2 composite film on carbon steel was prepared by electroless plating and sol-gel composite process. An artificial neural network was applied to optimize the prepared condition of the composite film. Corrosion behavior of the NiP/TiO2 composite film was investigated by polarization resistance measurement, anode polarization, ESEM (environmental scanning electron microscopy)and EIS (electrochemical impedance spectroscopy) measurements. Results showed that the NiP/TiO2 composite film has a good corrosion resistance in 0.5mol/L H2SO4 solution. The element valence of the composite film was characterized by XPS (X-ray photoelectron spectroscopy) spectrum, and an anticorrosion mechanism of the composite film was discussed.

  6. Composite Films from Sodium Alginate and High Methoxyl Pectin - Physicochemical Properties and Biodegradation in Soil

    Directory of Open Access Journals (Sweden)

    Ayten O. Solak

    2014-12-01

    Full Text Available The increased public attention on the waste pollution and the awareness of the hard environmental problems is the reason for the need of new materials which are susceptible to degradation in nature for a short period of time. The biopolymer films and coatings based on renewable natural sources are suitable for obtaining of biodegradable packaging. The newly developed composite films based on sodium alginate and apple high methoxyl pectin were studied for total soluble matter, swelling in water, water vapors transmission rate and biodegradation in soil. The analysis of their behavior in water medium showed a considerably higher rate and degree of dissolution of the pectin monocomponent film compared to the composite and alginate films. The composite alginate-pectin films showed lower water vapors transmission rate even under extreme conditions (38ºC, RH 90 % compared to the monocomponent films. All investigated films degraded in soil up to 80 days. The good barrier properties to water vapors and the complete biodegradation in soil make the films based on sodium alginate and high methoxyl pectin potential ecological materials for packing and coating of foods and pharmaceutical products.

  7. Composite TiO2-Carbon nano films with enhanced photocatalytic activity

    Science.gov (United States)

    Chakarov, Dinko; Sellappan, Raja

    2011-03-01

    Composite TiO2-carbon thin films prepared by physical vapor deposition techniques on fused silica substrates show enhanced photocatalytic activity, as compared to pure TiO2 films of similar thickness, towards decomposition of methanol to CO2 and water. Raman and XRD measurements confirm that annealed TiO2 films exhibit anatase structure while the carbon layer becomes graphitic. Characteristic for the composite films is an enhanced optical absorption in the visible range. The presence of the carbon film causes a shift of the TiO2 absorption edge and modifies its grain size to be smaller. The observed enhancement is attributed to synergy effects at the carbon-TiO2 interface, resulting in smaller crystallite size and anisotropic charge carrier transport, which in turn reduces their recombination probability. Supported by N-INNER through the Solar Hydrogen project (P30938-1 Solväte).

  8. Mercuric iodide composite films using polyamide, polycarbonate and polystyrene fabricated by casting

    International Nuclear Information System (INIS)

    Mercuric iodide (HgI2) composite films were obtained by using the casting technique. Insulator polymers such as polyamide, polycarbonate and polystyrene were mixed to HgI2 crystallites forming a final sub-millimeter thick self-standing film. Fabrication temperature varied from 10 to 100 oC, and total fabrication time reached at most 5 min. The larger the fabrication temperature, the thinner the film and the smaller its electrical resistivity. Electrical characterization was performed in the dark, under UV illumination and under mammographic X-ray exposure. The final properties of the films are discussed and related to fabrication conditions. The optimized composite film might be a better candidate for use as X-ray detector for medical imaging, in place of the single HgI2 crystalline device.

  9. Properties of plasticized composite films prepared from nanofibrillated cellulose and birch wood xylan

    DEFF Research Database (Denmark)

    Hansen, Natanya Majbritt Louie; Blomfeldt, Thomas O. J.; Hedenqvist, Mikael S.;

    2012-01-01

    was combined with nanofibrillated cellulose (NFC) and films were cast with and without glycerol, sorbitol or methoxypolyethylene glycol (MPEG) as plasticizers. Microscopy revealed some NFC agglomeration in the composite films as well as a layered nanocellulose structure. Equilibrium moisture content......Xylans, an important sub-class of hemicelluloses, represent a largely untapped resource for new renewable materials derived from biomass. As with other carbohydrates, nanocellulose reinforcement of xylans is interesting as a route to new bio-materials. With this in mind, birch wood xylan...... with increased NFC content in the xylan:NFC composition range from 50:50 to 80:20 and plasticizer addition generally provided less brittle films. The oxygen permeability of unplasticized xylan-NFC films fell into a range which was similar to that for previously measured pure NFC films and was statistically...

  10. Control of composition and crystallinity in hydroxyapatite films deposited by electron cyclotron resonance plasma sputtering

    Science.gov (United States)

    Akazawa, Housei; Ueno, Yuko

    2014-01-01

    Hydroxyapatite (HAp) films were deposited by electron cyclotron resonance plasma sputtering under a simultaneous flow of H2O vapor gas. Crystallization during sputter-deposition at elevated temperatures and solid-phase crystallization of amorphous films were compared in terms of film properties. When HAp films were deposited with Ar sputtering gas at temperatures above 460 °C, CaO byproducts precipitated with HAp crystallites. Using Xe instead of Ar resolved the compositional problem, yielding a single HAp phase. Preferentially c-axis-oriented HAp films were obtained at substrate temperatures between 460 and 500 °C and H2O pressures higher than 1×10-2 Pa. The absorption signal of the asymmetric stretching mode of the PO43- unit (ν3) in the Fourier-transform infrared absorption (FT-IR) spectra was the narrowest for films as-crystallized during deposition with Xe, but widest for solid-phase crystallized films. While the symmetric stretching mode of PO43- (ν1) is theoretically IR-inactive, this signal emerged in the FT-IR spectra of solid-phase crystallized films, but was absent for as-crystallized films, indicating superior crystallinity for the latter. The Raman scattering signal corresponding to ν1 PO43- sensitively reflected this crystallinity. The surface hardness of as-crystallized films evaluated by a pencil hardness test was higher than that of solid-phase crystallized films.

  11. Influence of composition on structure and magnetic properties of epitaxial Mn-Ga films

    Energy Technology Data Exchange (ETDEWEB)

    Wu, F; Mizukami, S; Watanabe, D; Miyazaki, T [WPI-AIMR, Tohoku University 2-1-1, Katahira, Aoba-ku, Sendai (Japan); Naganuma, H; Oogane, M; Ando, Y, E-mail: fengwu@wpi-aimr.tohoku.ac.jp [Graduate School of Engineering, Tohoku University Aobayama-05, Sendai (Japan)

    2011-01-01

    In this study, influence of composition on structure and magnetic properties of epitaxial Mn-Ga films were investigated. The epitaxial Mn-Ga films with different composition were grown on metal (Pt and Cr) buffered MgO substrates by co-sputtering technique. By use of the Pt buffered MgO substrates, the D0{sub 22} phases can be obtained in the Mn-Ga films with the composition ranging from Mn{sub 65}Ga{sub 35} to Mn{sub 75}Ga{sub 25}. The crystalline quality and perpendicular magnetic anisotropic properties of the Mn-Ga films were deteriorated with increase of Mn content. The saturation magnetization decreased with the increase of Mn content, which is consistent with the reported results of bulk alloys.

  12. Novel poly (vinyl butyral) (PVB)/polyaniline-cenosphere composite film for EMI shielding

    Science.gov (United States)

    Bora, Pritom J.; Shahidsha, N.; Madras, Giridhar; Kishore, Ramamurthy, Praveen C.

    2016-05-01

    in-situ synthesis of polyaniline (PANI)/fly ash cenosphere (hollow microspheres) composite was carried out under nitrogen atmosphere at -30±2 °C. Investigated electromagnetic shielding effectiveness (EMI SE) of free standing PVB/PANI-cenosphere (PVBPC) composite films prepared by solution casting indicates an ap preciable shielding. The most effective EMI SE of 30.3 dB was obtained for 197±3 µm thicker flexible film over the frequency range 8.2-12.4 GHz. Mechanistically, absorption was found to be dominant. The obtained shielding effectiveness due to absorbance (SEA) of PVBPC film is more than two times higher than PVB/PANI composite film. In the presence of hollow PANI-cenospheres in PVB matrix the time average power of incident electromagnetic wave decreases resulting in an increase of absorbance.

  13. Optical performance of mesostructured composite silica film loaded with organic dye.

    Science.gov (United States)

    Guli, Mina; Chen, Shijian; Zhang, Dingke; Li, Xiaotian; Yao, Jianxi; Chen, Lei; Xiao, Li

    2014-01-10

    A mesoporous composite silica film loaded with organic dye has been successfully synthesized by a solgel reaction process and a simple postgrafting method at room temperature. The composite film was characterized by x-ray diffraction, transmission electron microscopy, UV-Vis, photoluminescence (PL) spectra, and laser performance, and the results confirmed the existence of dyes in the channels of the silica film. A blue-shift and fluorescence property in the PL spectrum was observed from the composite film compared with that of dye molecules in C₂H₅OH solution. The spectrum narrowing phenomena has been observed when the composite film is pumped at λp=355  nm by a Nd:YAG pulsed laser. A narrower, higher peak was observed in emission spectra from the mesostructured composite silica film compared with the PL spectrum of dye in C₂H₅OH solution. There is a substantial reduction in the full width at half-maximum of the emitting light, which results in peaks with linewidths of 26 nm or more. This collapse of the emission spectrum is one of the signatures of the presence of amplified spontaneous emission. PMID:24514063

  14. Effect of long term ageing on the photoelectrochemical properties and composition of passive films

    International Nuclear Information System (INIS)

    Long term aged passive films formed on a 17%Cr ferritic steel by annealing in H2/H2O atmosphere are investigated by using both Auger Electron Spectroscopy (AES) and Photoelectrochemistry (PEC). Ageing in pure water (up to 16 months) significantly modifies the thickness, composition and electronic properties of the film. AES shows that no film thickening occurs until at least two months ageing, but that the silicon segregation sharply decreases during the same period. On the contrary, long term ageing results in a noticeable film thickening, Cr enrichment and Fe depletion in the outer part of the film. The optical band gaps determined by PEC on long term aged passive films are close to that found on passive films formed on chromium under potentiostatic control. A transition from p- to n-type is evidenced after ''long enough'' water ageing, depending on the water content of the annealing atmosphere. Long term ageing is necessary to observe a ''true'' steady-state anodic photoresponse indicating a n-type conductivity. The potential dependence of the photoresponse still reflects the initial annealing conditions, even after one year. It is concluded that the initial formation conditions still control the PEC behaviour of the films after one year of ageing, independently of the remarkable composition changes having occurred in the film during such a long ageing period in water

  15. Mathematical modeling for the composition prediction of compound films grown by ion-assisted deposition technique and its application to TiN x film

    Science.gov (United States)

    Kim, Jae-Keun; Colligon, J. S.; Jeong, Sang-Hun

    2004-10-01

    A simple general model has been formulated to explain the composition of compound films during growth simultaneous with ion bombardment. The variables in this model are (a) the sticking probability of the background residual reactive gas in the film, (b) an ion-enhanced sticking probability of these reactive gases arising from ion-enhanced adsorption and mixing and (c) ion implantation of the energetic ions impinging on the growing film. Preferential sputtering of various components in the film is also taken into account. The model is shown to be successful in explaining the experimental variations in the composition of TiN x films produced by ion-assisted growth.

  16. Influence of Interleaved Films on the Mechanical Properties of Carbon Fiber Fabric/Polypropylene Thermoplastic Composites

    Directory of Open Access Journals (Sweden)

    Jong Won Kim

    2016-05-01

    Full Text Available A laminated composite was produced using a thermoplastic prepreg by inserting an interleaved film with the same type of matrix as the prepreg during the lay-up process to improve the low interlaminar properties, which is a known weakness of laminated composites. Carbon fiber fabric (CFF and polypropylene (PP were used to manufacture the thermoplastic prepregs. Eight prepregs were used to produce the laminated composites. Interleaved films with different thicknesses were inserted into each prepreg. The physical properties of the composite, such as thickness, density, fiber volume fraction (Vf, and void content (Vc, were examined. The tensile strength, flexural strength, interlaminar shear strength (ILSS, impact property, and scanning electron microscopy (SEM were used to characterize the mechanical properties. Compared to the composite without any inserted interleaved film, as the thickness of the inserted interleaved resin film was increased, Vc decreased by 51.45%. At the same time, however, the tensile strength decreased by 8.75%. Flexural strength increased by 3.79% and flexural modulus decreased by 15.02%. Interlaminar shear strength increased by 11.05% and impact strength increased by 15.38%. Fracture toughness of the laminated composite was improved due to insertion of interleaved film.

  17. In Situ Synthesis of Reduced Graphene Oxide-Reinforced Silicone-Acrylate Resin Composite Films Applied in Erosion Resistance

    Directory of Open Access Journals (Sweden)

    Yang Cao

    2015-01-01

    Full Text Available The reduced graphene oxide reinforced silicone-acrylate resin composite films (rGO/SAR composite films were prepared by in situ synthesis method. The structure of rGO/SAR composite films was characterized by Raman spectrum, atomic force microscope, scanning electron microscopy, and thermogravimetric analyzer. The results showed that the rGO were uniformly dispersed in silicone-acrylate resin matrix. Furthermore, the effect of rGO loading on mechanical properties of composite films was investigated by bulge test. A significant enhancement (ca. 290% and 320% in Young’s modulus and yield stress was obtained by adding the rGO to silicone-acrylate resin. At the same time, the adhesive energy between the composite films and metal substrate was also improved to be about 200%. Moreover, the erosion resistance of the composite films was also investigated as function of rGO loading. The rGO had great effect on the erosion resistance of the composite films, in which the Rcorr (ca. 0.8 mm/year of composite film was far lower than that (28.7 mm/year of pure silicone-acrylate resin film. Thus, this approach provides a novel route to investigate mechanical stability of polymer composite films and improve erosion resistance of polymer coating, which are very important to be used in mechanical-corrosion coupling environments.

  18. Significant positive magnetoresistance of graphene/carbon composite films prepared by electrospraying and subsequent heat treatment

    Energy Technology Data Exchange (ETDEWEB)

    Chen, L.Q.; Chen, J.T.; Zhang, Z.C. [Shanghai University, School of Materials Science and Engineering, Shanghai (China); Liu, X.; Wang, L.J.; Jiang, W. [Donghua University, State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Shanghai (China); Li, J.L. [Hainan University, School of Materials Science and Chemical Engineering, Haikou (China)

    2012-03-15

    Graphene/carbon composite films were prepared by electrospraying a graphene/polyacrylonitrile composite solution on SiO{sub 2}-coated silicon substrates and subsequent heat treatment. The as-produced graphene/carbon composite films had a porous structure comprising graphene layers. With a magnetic field applied perpendicularly to the sample, an unexpectedly significant positive magnetoresistance attributed to e-e interaction and weak localization has been observed, which constantly increases with the magnetic field in the temperature range of 300-50 K from 0 to 80 kOe. (orig.)

  19. Electrical conductivity and electromagnetic interference shielding characteristics of multiwalled carbon nanotube filled polyurethane composite films

    Science.gov (United States)

    Son Hoang, Anh

    2011-06-01

    Multiwalled carbon nanotubes (MWCNTs) were homogeneously dispersed in a pure polyurethane resin by grinding in a planetary ball mill. The structure and surface morphology of the MWCNTs and MWCNT/polyurethane composites were studied by filed emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) methods. The electrical conductivity at room temperature and electromagnetic interference (EMI) shielding effectiveness (SE) of the composite films with different MWCNT loadings were investigated and the measurement of EMI SE was carried out in a frequency range of 8–12 GHz (X-band). The experimental results show that with a low MWCNT concentration the composite films could achieve a high conductivity and their EMI SE has a strong dependence on MWCNT content. For the composite films with 22 wt% of MWCNTs, the EMI SE attained an average value of 20 dB, so that the shielding effect reduced the penetrating power to 1%.

  20. High-performance flexible hydrogen sensor made of WS₂ nanosheet-Pd nanoparticle composite film.

    Science.gov (United States)

    Kuru, Cihan; Choi, Duyoung; Kargar, Alireza; Liu, Chin Hung; Yavuz, Serdar; Choi, Chulmin; Jin, Sungho; Bandaru, Prabhakar R

    2016-05-13

    We report a flexible hydrogen sensor, composed of WS2 nanosheet-Pd nanoparticle composite film, fabricated on a flexible polyimide substrate. The sensor offers the advantages of light-weight, mechanical durability, room temperature operation, and high sensitivity. The WS2-Pd composite film exhibits sensitivity (R 1/R 2, the ratio of the initial resistance to final resistance of the sensor) of 7.8 to 50,000 ppm hydrogen. Moreover, the WS2-Pd composite film distinctly outperforms the graphene-Pd composite, whose sensitivity is only 1.14. Furthermore, the ease of fabrication holds great potential for scalable and low-cost manufacturing of hydrogen sensors. PMID:27040653

  1. High-performance flexible hydrogen sensor made of WS2 nanosheet–Pd nanoparticle composite film

    Science.gov (United States)

    Kuru, Cihan; Choi, Duyoung; Kargar, Alireza; Liu, Chin Hung; Yavuz, Serdar; Choi, Chulmin; Jin, Sungho; Bandaru, Prabhakar R.

    2016-05-01

    We report a flexible hydrogen sensor, composed of WS2 nanosheet–Pd nanoparticle composite film, fabricated on a flexible polyimide substrate. The sensor offers the advantages of light-weight, mechanical durability, room temperature operation, and high sensitivity. The WS2–Pd composite film exhibits sensitivity (R 1/R 2, the ratio of the initial resistance to final resistance of the sensor) of 7.8 to 50 000 ppm hydrogen. Moreover, the WS2–Pd composite film distinctly outperforms the graphene–Pd composite, whose sensitivity is only 1.14. Furthermore, the ease of fabrication holds great potential for scalable and low-cost manufacturing of hydrogen sensors.

  2. Plasma deposition of polymer composite films incorporating nanocellulose whiskers

    Science.gov (United States)

    Samyn, P.; Airoudj, A.; Laborie, M.-P.; Mathew, A. P.; Roucoules, V.

    2011-11-01

    In a trend for sustainable engineering and functionalization of surfaces, we explore the possibilities of gas phase processes to deposit nanocomposite films. From an analysis of pulsed plasma polymerization of maleic anhydride in the presence of nanocellulose whiskers, it seems that thin nanocomposite films can be deposited with various patterns. By specifically modifying plasma parameters such as total power, duty cycle, and monomer gas pressure, the nanocellulose whiskers are either incorporated into a buckled polymer film or single nanocellulose whiskers are deposited on top of a polymeric film. The density of the latter can be controlled by modifying the exact positioning of the substrate in the reactor. The resulting morphologies are evaluated by optical microscopy, AFM, contact angle measurements and ellipsometry.

  3. Innovative Composite Films of Chitosan, Methylcellulose, and Nanoparticles

    OpenAIRE

    Mura, Stefania; Corrias, Francesco; Stara, Giuseppe; Piccinini, Massimo; Secchi, Nicola; Marongiu, Daniela; Innocenzi, Plinio; Irudayaraj, Joseph; Greppi, Gian F.

    2011-01-01

    Plastic is readily available and inexpensive, so it is becoming the main material for packaging. Unfortunately plastics do not biodegrade and, if reduced in small pieces, contaminate soil and waterways. In the present work, natural films composed of chitosan, methylcellulose, and silica (SiO(2)) nanoparticles (NPs) were developed as new packaging materials. The effect of the incorporation of NPs into the polymeric film matrix was evaluated. An excellent improvement of the mechanical propertie...

  4. Plasma deposition of polymer composite films incorporating nanocellulose whiskers

    OpenAIRE

    Samyn, P; Airoudj, A.; Laborie, M.-P.; Mathew, A. P.; Roucoules, V.

    2011-01-01

    Abstract In a trend for sustainable engineering and functionalization of surfaces, we explore the possibilities of gas phase processes to deposit nanocomposite films. From an analysis of pulsed plasma polymerization of maleic anhydride in the presence of nanocellulose whiskers, it seems that thin nanocomposite films can be deposited with various patterns. By specifically modifying plasma parameters such as total power, duty cycle, and monomer gas pressure, the nanocellulose whisker...

  5. Effect of Structure, Composition, and Micromorphology on the Hydrophobic Property of F-DLC Film

    Directory of Open Access Journals (Sweden)

    Aihua Jiang

    2013-01-01

    Full Text Available Fluorinated diamond-like carbon (F-DLC films were prepared by radio frequency plasma-enhanced chemical vapor deposition technique with CF4 and CH4 as source gases under different deposition conditions. The chemical bonding structure and composition of the films were detected by Raman, Fourier transform infrared absorption spectrometry (FTIR, and X-ray photoelectron spectroscopy (XPS characterization. The micromorphology and surface roughness of the film were observed and analyzed by atomic force microscopy (AFM. The results indicated that all the prepared films presented a diamond-like carbon structure. The relative content of fluorine in the films increased, containing more CF2 groups. The ratio of hybrid structure sp3/sp2 decreased. The surface roughness of the films increased when the gas flow ratio R (R = CF4/[CH4 + CF4] or the deposition power increased. The contact angle of water with the surface of the F-DLC film was measured with a static drop-contact angle/surface tension measuring instrument. The hydrophobic property of the F-DLC films was found to be dependent on the sp2 structure, fluorine content, and surface roughness of the films. The contact angle increased when the relative content of fluorine in the films and sp2 content increased, whereas the contact angle first increased and then decreased with the surface roughness.

  6. Study of the physical properties of whey protein isolate and gelatin composite films.

    Science.gov (United States)

    Jiang, Yanfeng; Li, Yanxia; Chai, Zhi; Leng, Xiaojing

    2010-04-28

    The relationships between the microstructural and physical properties of the whey protein isolate and gelatin (WPI/gelatin) composite films were investigated in the present work. Through the electrostatic effects at pH 8, WPI and gelatin molecules could form compact aggregates in solution, where a remarkable shrinkage of the gelatin molecules was observed, when the WPI/gelatin mass ratio was close to 50W:50G. FT-IR analysis indicated that hydrogen bonding also involved the aggregation and film-forming process. The melting temperature of the 50W:50G composite film increased by 9 degrees C compared with the single component films. However, this aggregation process also made the film network microstructure discontinuous, and led to a decline of the puncture strength of the film near 50W:50G; in contrast, the deformation and water vapor permeability of the composite films increased with the gelatin content, while the moisture content and solubility did not show significant variations.

  7. Friction and Wear Performance of Boron Doped, Undoped Microcrystalline and Fine Grained Composite Diamond Films

    Institute of Scientific and Technical Information of China (English)

    WANG Xinchang; WANG Liang; SHEN Bin; SUN Fanghong

    2015-01-01

    Chemical vapor deposition (CVD) diamond films have attracted more attentions due to their excellent mechanical properties. Whereas as-fabricated traditional diamond films in the previous studies don’t have enough adhesion or surface smoothness, which seriously impact their friction and wear performance, and thus limit their applications under extremely harsh conditions. A boron doped, undoped microcrystalline and fine grained composite diamond (BD-UM-FGCD) film is fabricated by a three-step method adopting hot filament CVD (HFCVD) method in the present study, presenting outstanding comprehensive performance, including the good adhesion between the substrate and the underlying boron doped diamond (BDD) layer, the extremely high hardness of the middle undoped microcrystalline diamond (UMCD) layer, as well as the low surface roughness and favorable polished convenience of the surface fine grained diamond (FGD) layer. The friction and wear behavior of this composite film sliding against low-carbon steel and silicon nitride balls are studied on a ball-on-plate rotational friction tester. Besides, its wear rate is further evaluated under a severer condition using an inner-hole polishing apparatus, with low-carbon steel wire as the counterpart. The test results show that the BD-UM-FGCD film performs very small friction coefficient and great friction behavior owing to its high surface smoothness, and meanwhile it also has excellent wear resistance because of the relatively high hardness of the surface FGD film and the extremely high hardness of the middle UMCD film. Moreover, under the industrial conditions for producing low-carbon steel wires, this composite film can sufficiently prolong the working lifetime of the drawing dies and improve their application effects. This research develops a novel composite diamond films owning great comprehensive properties, which have great potentials as protecting coatings on working surfaces of the wear-resistant and anti

  8. Effects of antibacterial nanostructured composite films on vascular stents: hemodynamic behaviors, microstructural characteristics, and biomechanical properties.

    Science.gov (United States)

    Cheng, Han-Yi; Hsiao, Wen-Tien; Lin, Li-Hsiang; Hsu, Ya-Ju; Sinrang, Andi Wardihan; Ou, Keng-Liang

    2015-01-01

    The purpose of this research was to investigate stresses resulting from different thicknesses and compositions of hydrogenated Cu-incorporated diamond-like carbon (a-C:H/Cu) films at the interface between vascular stent and the artery using three-dimensional reversed finite element models (FEMs). Blood flow velocity variation in vessels with plaques was examined by angiography, and the a-C:H/Cu films were characterized by transmission electron microscopy to analyze surface morphology. FEMs were constructed using a computer-aided reverse design system, and the effects of antibacterial nanostructured composite films in the stress field were investigated. The maximum stress in the vascular stent occurred at the intersections of net-like structures. Data analysis indicated that the stress decreased by 15% in vascular stents with antibacterial nanostructured composite films compared to the control group, and the stress decreased with increasing film thickness. The present results confirmed that antibacterial nanostructured composite films improve the biomechanical properties of vascular stents and release abnormal stress to prevent restenosis. The results of the present study offer the clinical benefit of inducing superior biomechanical behavior in vascular stents.

  9. Kinetics of Photocatalytic Degradation of Formic Acid over Silica Composite Films Based on Polyoxometalates

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The composite films, XW11O39n-/SiO2, (X refers to Si, Ge or P, respectively) were prepared by tetraethoxysilane (TEOS) hydrolysis sol-gel method via spin-coating technique. Formation of the composite films is due to strong chemical reaction of organic silanol group with the surface oxygen atoms of XW11O39n-, resulted in the saturation of the surface of the lacunary polyoxometalates (POMs). Therefore, the coordination structural model of the films was proposed. As for the films, retention of the primary Keggin structure was confirmed by UV-vis, FT-IR spectra and MAS NMR. The surface morphology of the films was characterized by SEM, indicating that the film surface is relatively uniform, and the layer thickness is in the range of 250~350 nm. Aqueous formic acid (FA) (0-20 mmol/L) was degraded into CO2 and H2O by irradiating the films in the near-UV area. The results show that all the films have photocatalytic activities and the degradation reaction follows Langmuir-Hinshelwood first order kinetics.

  10. Biocidal Silver and Silver/Titania Composite Films Grown by Chemical Vapour Deposition

    Directory of Open Access Journals (Sweden)

    D. W. Sheel

    2008-01-01

    Full Text Available This paper describes the growth and testing of highly active biocidal films based on photocatalytically active films of TiO2, grown by thermal CVD, functionally and structurally modified by deposition of nanostructured silver via a novel flame assisted combination CVD process. The resulting composite films are shown to be highly durable, highly photocatalytically active and are also shown to possess strong antibacterial behaviour. The deposition control, arising from the described approach, offers the potential to control the film nanostructure, which is proposed to be crucial in determining the photo and bioactivity of the combined film structure, and the transparency of the composite films. Furthermore, we show that the resultant films are active to a range of organisms, including Gram-negative and Gram-positive bacteria, and viruses. The very high-biocidal activity is above that expected from the concentrations of silver present, and this is discussed in terms of nanostructure of the titania/silver surface. These properties are especially significant when combined with the well-known durability of CVD deposited thin films, offering new opportunities for enhanced application in areas where biocidal surface functionality is sought.

  11. Vanadium oxide-carbon nanotube composite films characterized by spectroscopic ellipsometry

    Science.gov (United States)

    He, Qiong; Xu, Xiangdong; Gu, Yu; Wang, Meng; Yao, Jie; Jiang, Yadong; Sun, Minghui; Ao, Tianhong; Lian, Yuxiang; Wang, Fu; Li, Xinrong

    2016-10-01

    Spectroscopic ellipsometry (SE) is utilized to characterize the vanadium oxide (VO x )-single walled carbon nanotube (SWCNT) composite films prepared by sol-gel. Five Tauc-Lorentz oscillators model is employed to describe the dispersions in the optical responses of VO x and VO x -SWCNT thin films. Results reveal that if the SWCNT concentration in the composite film is increased, the refractive index is decreased, while the extinction coefficient is increased. Moreover, higher SWCNT content leads to lower optical band gap (E g) but larger localized state (E e). Interestingly, both E g and E e values reach saturated at a SWCNT content of ~8 wt%. Particularly, the peak transition energies of the 5 Tauc-Lorentz oscillators have been assigned to the specific transitions according to the band structures of VO x . This work reveals the feasibility of investigating the optical properties and microstructures of VO x -SWCNT composite films by SE. These experimental results will be helpful for better understanding the VO x -SWCNT composite films, and promoting future characterizations of other SWCNT-based composites by SE.

  12. First Orange Fluorescence Composite Film Based on Sm-Substituted Tungstophosphate and Its Electrofluorochromic Performance.

    Science.gov (United States)

    Gao, Wenmei; Yu, Tian; Du, Yu; Wang, Ruiqiang; Wu, Lixin; Bi, Lihua

    2016-05-11

    We chose a Sm-containing sandwich-type tungstophosphate K3Cs8[Sm(PW11O39)2]·10H2O (SmPW11) as a molecular dyad, which contains photoluminescence and electrochromism components in a skeletal structure, and investigated its electrofluorochromic performance both in solution and in composite films. First, the electrochemical activity and luminescence property of SmPW11 were studied in different pH solutions to determine the optimal pH solution medium; and then, the electrofluorochromic performance of SmPW11 was investigated under the optimized pH solution medium. Subsequently, the composite films containing SmPW11 were prepared on quartz substrates and conductive ITO substrates through a layer-by-layer (LbL) assembly method, using PDDA and PEI as molecular linkers. Characterization methods of the composite films include UV-vis spectra, fluorescence spectroscopy, cyclic voltammetry (CV), bulk electrolysis with coulometry, chronoamperometry, X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM). Finally, in situ UV-vis and fluorescence spectroelectrochemical systems were used to research electrofluorochromic properties for the composite films under electrochemical modulation. The results indicate that the composite films display not only orange luminescence emission but also reversible orange luminescence switching behaviors manipulated by the redox process of tungstophosphate species PW11 via the energy transfer between the orange luminescence component Sm and electroreduced species of tungstophosphate PW11. PMID:27088254

  13. Immobilization and Bioelectrochemistry of Hemoglobin Based on Carrageenan and Room Temperature Ionic Liquid Composite Film

    Institute of Scientific and Technical Information of China (English)

    盛春; 张洋; 王璐; 贾能勤

    2012-01-01

    A novel biopolymer/room-temperature ionic liquid composite film based on carrageenan, room temperature ionic liquid (IL) [1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM]BF4)] was explored for immobilization of hemoglobin (Hb) and construction of biosensor. Direct electrochemistry and electrocatalytic behaviors of Hb entrapped in the IL-carrageenan composite film on the surface of glassy carbon electrode (GCE) were investigated. UV-vis spectroscopy demonstrated that Hb in the IL-carrageenan composite film could retain its native secondary structure. A pair of well-defined redox peaks of Hb was obtained at the Hb-IL-carrageenan composite film modified electrode through direct electron transfer between the protein and the underlying electrode. The heterogeneous electron transfer rate constant (ks) was 2.02 s 1, indicating great facilitation of the electron transfer between Hb and IL-carrageenan composite film modified electrode. The modified electrode showed excellent electrocatalytic activity toward reduction of hydrogen peroxide with a linear range of 5.0 × 10-6 to 1.5 ×10-4 mol/L and the detection limit was 2.12 ×10 7 mol/L (S/N= 3). The apparent Michaelis-Menten constant KM^app for hydrogen peroxide was estimated to be 0.02 mmol/L, indicating that the biosensor possessed high affinity to hydrogen peroxide. In addition, the proposed biosensor showed good reproducibility and stability.

  14. Effects of Two Different Cellulose Nanofiber Types on Properties of Poly(vinyl alcohol Composite Films

    Directory of Open Access Journals (Sweden)

    Kitti Yuwawech

    2015-01-01

    Full Text Available This work concerns a study on the effects of fiber types and content of cellulose nanofiber on mechanical, thermal, and optical properties polyvinyl alcohol (PVA composites. Two different types of cellulose nanofibers, which are nanofibrillated cellulose (NFC and bacterial cellulose (BC, were prepared under various mechanical treatment times and then incorporated into the PVA prior to the fabrication of composite films. It was found that tensile modulus of the PVA film increased with nanofibers content at the expense of its percentage elongation value. DSC thermograms indicate that percentage crystallinity of PVA increased after adding 2–4 wt% of the fibers. This contributed to the better mechanical properties of the composites. Tensile toughness values of the PVA/BC nanocomposite films were also superior to those of the PVA/NFC system containing the same fiber loading. SEM images of the composite films reveal that tensile fractured surface of PVA/BC experienced more ductile deformation than the PVA/NFC analogue. The above discrepancies were discussed in the light of differences between the two types of fibers in terms of diameter and their intrinsic properties. Lastly, percentage total visible light transmittance values of the PVA composite films were greater than 90%, regardless of the fiber type and content.

  15. Combinatorial matrix-assisted pulsed laser evaporation: Single-step synthesis of biopolymer compositional gradient thin film assemblies

    Science.gov (United States)

    Sima, F.; Axente, E.; Sima, L. E.; Tuyel, U.; Eroglu, M. S.; Serban, N.; Ristoscu, C.; Petrescu, S. M.; Toksoy Oner, E.; Mihailescu, I. N.

    2012-12-01

    We introduce a combinatorial approach for the fabrication of organic biopolymer thin films. Structures with compositional gradient are obtained by simultaneous laser vaporization of two distinct targets. Matrix-assisted pulsed laser evaporation deposition method was applied to obtain a compositional library of levan and oxidized levan in form of thin film. The gradient of film composition and structure was demonstrated by infrared spectroscopy while in vitro cell culture assays illustrated characteristic responses of cells to specific surface regions. The method can rapidly generate discrete areas of organic film compositions with improved properties than starting materials.

  16. Development and characterization of an edible composite film based on chitosan and virgin coconut oil with improved moisture sorption properties.

    Science.gov (United States)

    Binsi, P K; Ravishankar, C N; Srinivasa Gopal, T K

    2013-04-01

    An edible composite film was prepared from an emulsion system based on chitosan and virgin coconut oil (VCO). The effect of incorporation of VCO was evaluated at various concentrations and the optimum concentration was chosen based on resultant changes in the properties of the film. Addition of VCO in film forming solution resulted in increase in film thickness and marginal reduction in film transparency. Compatibility of VCO with chitosan was better at lower concentration of VCO as indicated by the microstructure of composite film in scanning electron micrographs. Phase separation was evident at higher level of oil incorporation and the optimal oil/chitosan ratio was determined to be at 0.5 to 1 mL/g chitosan. Furthermore, chemical interaction took place between VCO and chitosan as revealed by Fourier transform infrared spectroscopy data. Even though control chitosan films exhibited superior gas barrier properties, composite film with optimum VCO concentration revealed better mechanical and moisture sorption properties.

  17. Multilayer Au/TiO2 Composite Films with Ultrafast Third-Order Nonlinear Optical Properties

    Institute of Scientific and Technical Information of China (English)

    LONG Hua; YANG Guang; CHEN Ai-Ping; LI Yu-Hua; LU Pei-Xiang

    2008-01-01

    We report on the ultrafast third-order optical nonlinearity in multilayer Au/TiO2 composite films fabricated on quartz substrates by pulsed laser deposition technique. The linear optical properties of the films are determined and optical absorption peaks due to surface plasmon resonance of Au particles are observed at about 59Onm.The third-order optical nonlinearities of the films are investigated by z-scan method using a femtosecond laser(50 fs) at the wavelength of 800 nm. The sample showed fast nonlinear optical responses with nonlinear absorption coefficient and nonlinear refractive index being -3.66×10-10 m/W and -2.95×10-17 m2/W, respectively. The results also show that the nonlinear optical effects increase with the increasing Au concentration in the composite films.

  18. Electromagnetic interference shielding effectiveness of nanoreinforced polymer composites deposited with conductive metallic thin films

    International Nuclear Information System (INIS)

    The effect of using conductive metallic thin films deposited on high density polyethylene (HDPE) and styrene butadiene copolymer (SBC) in conjunction with carbon nanofiber (CNF) reinforcement of HDPE and SBC was investigated in order to improve the electromagnetic interference shielding effectiveness (EMI SE) of the structures. Thin films of copper, silver and aluminum were deposited by thermal evaporation onto the polymeric matrices and its composites (0–20 wt.% of CNFs). Results show a synergistic effect of the two approaches (metallic coating and CNF reinforcement) toward improving the EMI SE. The chemical composition, surface morphology, carbon nanofiber distribution, thickness and microstructure of metallic coated polymers are examined using X-Ray Diffraction and Scanning Electron Microscopy. - Highlights: ► Metallic thin films were evaporated on carbon nanofiber reinforced polymers. ► The electromagnetic shielding effectiveness of the structures was evaluated. ► Thin films and carbon nanofibers synergistically improved the shielding effectiveness.

  19. Compositional, structural and mechanical characteristics of nc-TiC/a-C:H nanocomposite films

    International Nuclear Information System (INIS)

    Nanocomposite nc-TiC/a-C:H films, with an unusual combination of superhardness, high elastic modulus and high elastic recovery, are prepared by filtered cathodic vacuum arc technique using the C2H2 gas as the precursor. The effects of filter coil current on compositional, structural and mechanical properties of the nc-TiC/a-C:H films have been investigated by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), energy disperse spectroscopy (EDS), microindentation and tribotester measurements. XPS and Raman analyses show that composition and nanostructure of the nc-TiC/a-C:H films can be changed by varying the filter coil current. By selecting the proper value of filter coil current, 2.5 A, one can remarkably enhance the mechanical properties of films such as superhardness (43.6 GPa). The superhardness can be ascribed to the phase variation and the nanostructure.

  20. The Effect of the Melt Viscosity and Impregnation of a Film on the Mechanical Properties of Thermoplastic Composites

    Directory of Open Access Journals (Sweden)

    Jong Won Kim

    2016-06-01

    Full Text Available Generally, to produce film-type thermoplastic composites with good mechanical properties, high-performance reinforcement films are used. In this case, films used as a matrix are difficult to impregnate into tow due to their high melt viscosity and high molecular weight. To solve the problem, in this paper, three polypropylene (PP films with different melt viscosities were used separately to produce film-type thermoplastic composites. A film with a low melt viscosity was stacked so that tow was impregnated first and a film with a higher melt viscosity was then stacked to produce the composite. Four different composites were produced by regulating the pressure rising time. The thickness, density, fiber volume fraction (Vf, and void content (Vc were analyzed to identify the physical properties and compare them in terms of film stacking types. The thermal properties were identified by using differential scanning calorimetry (DSC and dynamical mechanical thermal analysis (DMTA. The tensile property, flexural property, interlaminar shear strength (ILSS, and scanning electron microscopy (SEM were performed to identify the mechanical properties. For the films with low molecular weight, impregnation could be completed fast but showed low strength. Additionally, the films with high molecular weight completed impregnation slowly but showed high strength. Therefore, appropriate films should be used considering the forming process time and their mechanical properties to produce film-type composites.

  1. Relative performances of effective medium formulations in interpreting specific composite thin films optical properties

    International Nuclear Information System (INIS)

    Several powerful effective medium formulations/approximation (EMA) and associated theories with different origins and concepts have been discussed and utilized here in order to model the experimental refractive index evolutions of ZrO2-SiO2 and Gd2O3-SiO2 composite films with respect to their compositional mixings. Amongst these formulations, the Boettcher's generalized theory has been noticed to have more versatility and can simulate varieties of experimental observations incorporating a form factor parameter to account for the grain structure and morphology to a great extent. The refractive index modeling results of most of the available theories were compared with respect to their functional evolutions and limitations. It was noticed that at higher silica fractions (>20%) in our composite films, the effective experimental refractive index parameters have remained close to the most modeling results and Boettcher's expression has shown to fit the observable parameters very accurately. However, under low silica compositions (<20%) the refractive index values of the composite films depicted different functional evolutions. Such deviations have been attributed to the various morphological, grain structure and band gap supremacies observed in these specific composite films which are not accounted by the effective medium formulations and approximations. These observations are well supported by the atomic force microscopy results

  2. Surface plasmon effect in nanocrystalline copper/DLC composite films by electrodeposition technique

    Indian Academy of Sciences (India)

    S Hussain; A K Pal

    2006-11-01

    Composite films of nanocrystalline copper embedded in DLC matrix prepared by electrodeposition technique were studied for their optical properties. Particle size and metal volume fractions were tailored by varying the amount of copper containing salt in the electrolyte. Blue-shift of the surface plasmon resonance peak in the absorbance spectra of the films was observed with the reduction in size and volume fraction of metal particles. Mie theory was found to describe the experimental spectra quite well.

  3. Development of polyhydroxyalkanoate/beer spent grain fibers composites for film blowing applications

    OpenAIRE

    Cunha, Mara; Berthet, Marie-Alix; Pereira, Ricardo; Covas, José A.; Vicente, António A.; Hilliou, Loïc

    2015-01-01

    The high cost, narrow processing window, and poor mechanical properties of polyhydroxyalkanoates hamper their use as films for food packaging applications. We report the preparation, characterization, and film blowing of polyhydroxybutyrate-valerate (PHBV)/beer spent grain fibers (BSGF) composites. Beer spent grains are by-products of the beer industry submitted to an acid/caustic treatment and to successive grinding to achieve fibers with typical size of 30 microns. ...

  4. Compositional influence on the electrical performance of zinc indium tin oxide transparent thin-film transistors

    OpenAIRE

    Marsal Vinade, Albert; Carreras Seguí, Paz; Puigdollers i González, Joaquim; Voz Sánchez, Cristóbal; Galindo Lorente, Sergi; Alcubilla González, Ramón; Bertomeu Balaguero, Joan; Antony, Aldrin

    2014-01-01

    In this work, zinc indium tin oxide layers with different compositions are used as the active layer of thin film transistors. This multicomponent transparent conductive oxide is gaining great interest due to its reduced content of the scarce indium element. Experimental data indicate that the incorporation of zinc promotes the creation of oxygen vacancies, which results in a higher free carrier density. In thin-film transistors this effect leads to a higher off current and threshold voltage v...

  5. Application of Al2O3-based polyimide composite thick films to integrated substrates using aerosol deposition method

    International Nuclear Information System (INIS)

    Al2O3-based polyimide composite thick films were successfully fabricated with reduction of residual stress and improvement in plasticity for integrated substrates at room temperature by aerosol deposition method. Scanning electron microscopy and energy dispersive spectroscopy mappings exhibited a high content of Al2O3 evenly distributed in the composite thick films. The relative dielectric permittivity and loss tangent of Al2O3-based polyimide composite thick films were 7.6 and 0.007, respectively. There was almost no change in the crystallite size of Al2O3-based polyimide composite thick films compared with that of starting powder due to the reduction of kinetic energy by polyimide during collision on the substrates. Moreover, it was confirmed that the residual stress of Al2O3-based polyimide composite thick films remarkably decreased compared with that of Al2O3 thick films.

  6. Methods of making copper selenium precursor compositions with a targeted copper selenide content and precursor compositions and thin films resulting therefrom

    Science.gov (United States)

    Curtis, Calvin J.; Miedaner, Alexander; van Hest, Marinus Franciscus Antonius Maria; Ginley, David S.; Leisch, Jennifer; Taylor, Matthew; Stanbery, Billy J.

    2011-09-20

    Precursor compositions containing copper and selenium suitable for deposition on a substrate to form thin films suitable for semi-conductor applications. Methods of forming the precursor compositions using primary amine solvents and methods of forming the thin films wherein the selection of temperature and duration of heating controls the formation of a targeted species of copper selenide.

  7. Black tea leaf extract derived Ag nanoparticle-PVA composite film: Structural and dielectric properties

    Energy Technology Data Exchange (ETDEWEB)

    Uddin, Md Jamal [Department of Solid State Physics, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 032 (India); Chaudhuri, Biswadeep; Pramanik, Krishna [Department of Biotechnology and Biomedical Engineering, NIT Rourkela, Orisa (India); Middya, Tapas Ranjan [Department of Physics, Jadavpur University, Kolkata 700 032 (India); Chaudhuri, Bijaykrishna, E-mail: sspbkc@rediffmail.com [Department of Solid State Physics, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 032 (India)

    2012-12-01

    Highlights: Black-Right-Pointing-Pointer Black tea leaf extracts-PVA/silver nanocomposite (EPSNP) films have been prepared by biogenic synthesis approach. Black-Right-Pointing-Pointer The results demonstrated a remarkable enhancement of dielectric permittivity ({approx}900) with low loss ({approx}0.14). Black-Right-Pointing-Pointer Electrical conductivity as high as 5.98 Multiplication-Sign 10{sup -5} S/m for15 EPSNP composite film at 1 kHz and room temperature. Black-Right-Pointing-Pointer Such nanocomposite film might be important for technological applications. - Abstract: Biosynthesized metal (Ag) nanoparticles have been used to prepare high dielectric polymer composite film of technological importance. Different amounts of the tea leaf extract (E) (mother leaker prepared by soaking 2 g tea leaf in 100 ml boiled water for 3 min) were used to synthesize silver nanoparticles from 10{sup -3} M AgNO{sub 3} solution. Such a resultant solution containing Ag nanoparticles was mixed with 20 ml PVA solution (5 g PVA in 100 ml water) was used to make anhydrous Ag/PVA composite film where spherical silver nanoparticles (AgNPs) of average diameter 10 nm are well dispersed in the composite. The Ag particle size in the composite was found to enhance with the increase of E content in PVA. XRD, SEM, TEM, FT-IR, UV-vis, TGA and DSC studies are made to characterize the nanoparticles. Detailed frequency and E concentration dependent electrical and dielectric properties of the nanocomposites have been made showing low loss ({approx}0.14) and high dielectric property of these films. Maximum value of dielectric permittivity ({approx}900 which is almost 170 times higher than that of pure PVA {approx} 5.2) have been observed for 15 ml E-AgNPs/PVA nanocomposite film at 1 kHz and room temperature. Present study establishes the importance of the biosynthesized metal nanoparticles for industrial applications as in capacitors.

  8. Nano-mechanical properties of nano-gold/DLC composite thin films

    Science.gov (United States)

    Paul, Rajib; Bhadra, Nilanjana; Mukhopadhyay, Anup Kumar; Bhar, Radhaballav; Pal, Arun Kumar

    2014-11-01

    Diamond-like-Carbon composite films, with embedded gold nanoparticles, were deposited onto glass substrates by using capacitively coupled plasma chemical vapour deposition (CCP-CVD) technique. The volume fraction of the metal nanoparticles in the films as well as the size of the nanoparticles was varied by varying the percentage of argon in the methane + argon mixture during the deposition. Bonding environments in these films were obtained from Raman and GIXRD. The nanomechanical and nanotribological properties of the Au-DLC nanocomposite films were evaluated. In situ SPM imaging was utilized to depict deformation characteristics developed during the static and dynamic contact events. Influence of metal incorporation on the extent of sp2/sp3 hybridization and thereby on the nanomechanical and nanotribological properties of the DLC films was studied.

  9. Composition and Microstructure of Magnetron Sputtering Deposited Ti-containing Amorphous Carbon Films

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Ti-containing carbon films were deposited by using magnetron sputtering deposition. The composition and microstructure of the carbon films were characterized in detail by combining the techniques of Rutherford backscattering spectrometry (RBS), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and transmission electron microscopy (TEM). It is found that carbon films contain Ti 18 at pct; after Ti incorporation, the films consist of titanium carbide; C1s peak appears at 283.4 eV and it could be divided into 283.29 and 284.55 eV, representing sp2 and sp3, respectively, and sp2 is superior to sp3. This Ti-containing film with dominating sp2 bonds is nanocomposites with nanocrystalline TiC clusters embedded in an amorphous carbon matrix, which could be proved by XRD and TEM.

  10. A novel composite coating mesh film for oil-water separation

    Institute of Scientific and Technical Information of China (English)

    Futao QIN; Zhijia YU; Xinhui FANG; Xinghua LIU; Xiangyu SUN

    2009-01-01

    Polytetrafluoroethylene-polyphenylene sulfide composite coating mesh film was successfully prepared by a simple layered transitional spray-plasticizing method on a stainless steel mesh. It shows super-hydrophobic and super-oleophilic properties. The contact angle of this mesh film is 156.3° for water, and close to 0° for diesel oil and kerosene. The contact angle hysteresis of water on the mesh film is 4.3°. The adhesive force between the film and substrate is grade 0, the flexibility is 1 mm and the pencil hardness is 4H. An oil-water separation test was car-fled out for oil-contaminated water in a six-stage super-hydrophobic film separator. The oil removal rate can reach about 99%.

  11. Novel green nano composites films fabricated by indigenously synthesized graphene oxide and chitosan.

    Science.gov (United States)

    Khan, Younus H; Islam, Atif; Sarwar, Afsheen; Gull, Nafisa; Khan, Shahzad M; Munawar, Muhammad A; Zia, Saba; Sabir, Aneela; Shafiq, Muhammad; Jamil, Tahir

    2016-08-01

    Graphene oxide (GO) was indigenously synthesized from graphite using standard Hummers method. Chitosan-graphene oxide green composite films were fabricated by mixing aqueous solution of chitosan and GO using dilute acetic acid as a solvent for chitosan. Chitosan of different viscosity and calculated molecular weight was used keeping amount of GO constant in each composite film. The structural properties, thermal stability and mechanical properties of the composite films were investigated using Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and tensile test. FTIR studies revealed the successful synthesis of GO from graphite powder and it was confirmed that homogenous blending of chitosan and GO was promising due to oxygenated functional groups on the surface of GO. XRD indicated effective conversion of graphite to GO as its strong peak observed at 11.06° as compared to pristine graphite which appeared at 26°. Moreover, mechanical analysis confirmed the effect of molecular weight on the mechanical properties of chitosan-GO composites showing that higher molecular weight chitosan composite (GOCC-1000) showed best strength (higher than 3GPa) compared to other composite films. Thermal stability of GOCC-1000 was enhanced for which residual content increased up to 56% as compared to the thermal stability of GOCC-200 whose residue was restricted to only 24%. The morphological analysis of the composites sheets by SEM was smooth having dense structure and showed excellent interaction, miscibility, compatibility and dispersion of GO with chitosan. The prepared composite films find their applications as biomaterials in different biomedical fields. PMID:27112859

  12. Densely Packed Linear Assembles of Carbon Nano tube Bundles in Polysiloxane-Based Nano composite Films

    International Nuclear Information System (INIS)

    Linear assemblies of carbon nano tubes (LACNTs) were fabricated and controlled in polysiloxane-based nano composite films and the effects of the LACNTs on the thermal and electrical properties of the films were investigated. CNTs were dispersed by mechanical stirring and sonication in a prepolymer of polysiloxane. Homogeneous suspensions were cast on polyamide spacers and oriented by linear-assembly by applying DC and switching DC electric fields before the mixture became cross-linked. Densely packed LACNTs that fixed the composite film surfaces were fabricated with various structures and thicknesses that depended on the DC and switching DC conditions. Polymer nano composites with different LACNT densities exhibited enhanced thermal and electrical conductivities and high optical transmittances. They are considered promising structural materials for electronic sectors in automotive and aerospace applications

  13. Preparation of Composite Films of a Conjugated Polymer and C60NWs and Their Photovoltaic Application

    Directory of Open Access Journals (Sweden)

    Takatsugu Wakahara

    2016-01-01

    Full Text Available Composite films of conjugated polymers, such as poly[2-methoxy-5-(3′,7′-dimethyloctyloxy-1,4-phenylenevinylene] (MDMO-PPV and poly(3-hexylthiophene (P3HT, with C60 nanowhiskers (C60NWs were prepared. The photoluminescence originating from the conjugated MDMO-PPV polymers was effectively quenched in the composite film, indicating a strong interaction between the conjugated polymer and C60NWs. The photovoltaic devices were fabricated using C60NW (conjugated polymer composite films, resulting in a power conversion efficiency of ~0.01% for P3HT with short length thin C60NWs, which is higher than that previously reported for thick C60 nanorods. The present study gives new guidance on the selection of the type of C60NWs and the appropriate polymer for new photovoltaic devices.

  14. Synthesis of TiO2-doped SiO2 composite films and its applications

    Indian Academy of Sciences (India)

    Xiaojun Zhang; Huagui Zheng

    2008-10-01

    The TiO2-doped SiO2 composite films were prepared by two-step sol–gel method and then it was applied in the degradation of methylene red (MR) as photocatalysts. In XRD, FT–IR, and TEM investigations of these TiO2-doped SiO2 composite films, the titanium oxide species are highly dispersed in the SiO2 matrixes and exist in a tetrahedral form. And special attention has been focused on the relationship between the local structure of the titanium oxide species in the TiO2-doped SiO2 composite films and the photocatalytic reactivity in order to provide vital information for the design and application of such highly efficient photocatalytic systems in the degradation of toxic compounds diluted in a liquid phase.

  15. A study on photocatalytic activity of micro-arc oxidation TiO{sub 2} films and Ag{sup +}/MAO-TiO{sub 2} composite films

    Energy Technology Data Exchange (ETDEWEB)

    Xiang, N. [School of Materials Science and Engineering, Changzhou University, Changzhou 213164 (China); Jiangsu Key Laboratory of Materials Surface Science and Technology, Changzhou University, Changzhou 213164 (China); Jiangsu Collaborative Innovation Center of Photovolatic Science and Engineering, Changzhou University, Changzhou 213164, Jiangsu (China); Song, R.G., E-mail: songrg@hotmail.com [School of Materials Science and Engineering, Changzhou University, Changzhou 213164 (China); Jiangsu Key Laboratory of Materials Surface Science and Technology, Changzhou University, Changzhou 213164 (China); Jiangsu Collaborative Innovation Center of Photovolatic Science and Engineering, Changzhou University, Changzhou 213164, Jiangsu (China); Xiang, B.; Li, H.; Wang, Z.X.; Wang, C. [School of Materials Science and Engineering, Changzhou University, Changzhou 213164 (China); Jiangsu Key Laboratory of Materials Surface Science and Technology, Changzhou University, Changzhou 213164 (China); Jiangsu Collaborative Innovation Center of Photovolatic Science and Engineering, Changzhou University, Changzhou 213164, Jiangsu (China)

    2015-08-30

    Highlights: • The optimum voltage and concentration of micro-arc oxidation (MAO) for photocatalytic activity have been studied. • The most superior treatment time and concentration for Ag{sup +} impregnation have been discussed under the optimum MAO condition above. • Mechanism of influence on impregnation time for Ag+MAO-TiO{sub 2} composite films have been well investigated. • MAO-TiO{sub 2} films and Ag+MAO-TiO{sub 2} composite films were compared each other on photocatalytic efficiency. - Abstract: First, micro-arc oxidation (MAO) TiO{sub 2} films have been prepared on pure titanium in a phosphate-based electrolyte, and then the Ag{sup +}/MAO-TiO{sub 2} composite films have been fabricated by Ag{sup +} impregnation in this paper. The microstructure and composition of MAO-TiO{sub 2} films and Ag{sup +}/MAO-TiO{sub 2} composite films have been studied by means of scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy-dispersive X-ray spectroscopy (EDS). The photocatalytic activity of both films was evaluated by photocatalytic decolorization of methylene blue (MB) in aqueous solution as a model pollutant under sunlight irradiation simulation with homemade ultraviolet–visible spectroscopy (UV–vis). The results showed that the photocatalytic activity of MAO-TiO{sub 2} films increased with increasing the applied voltage and concentration in a certain scope. The morphology of Ag{sup +}/MAO-TiO{sub 2} composite films were of significantly difference and superior photocatalytic activity compared to the MAO-TiO{sub 2} film. Also, Ag{sup +} impregnation was able to enhance the photocatalytic efficiency of MAO-TiO{sub 2} film.

  16. Preparations and characterization of alginate/silver composite films: Effect of types of silver particles.

    Science.gov (United States)

    Shankar, Shiv; Wang, Long-Feng; Rhim, Jong-Whan

    2016-08-01

    Alginate-based films reinforced with different types of silver particles such as metallic silver (AgM), silver zeolite (AgZ), citrate reduced silver nanoparticles (AgNP(C)), laser ablated silver nanoparticles (AgNP(LA)), and silver nitrate (AgNO3) were prepared using a solvent casting method and the effect of silver particles on the optical, mechanical, water vapor barrier, and antimicrobial properties the composite films was evaluated. Size and shape of the silver particles were varied depending on the types of silver source and the preparation method. The alginate films incorporated with AgNP(C), AgNP(LA), and AgNO3 showed a characteristic surface plasmon resonance absorption peaks of AgNPs around 420nm. Film properties such as mechanical, optical, and water vapor barrier properties were greatly influenced by the types of AgNPs used. Alginate/AgNPs composite films except AgM and AgNP(LA) incorporated ones exhibited strong antimicrobial activity against two food-borne pathogenic bacteria, Escherichia coli and Listeria monocytogenes. The developed films have a high potential for the application as antimicrobial food packaging films. PMID:27112867

  17. Synthesis, characterization and antibacterial activity of biodegradable starch/PVA composite films reinforced with cellulosic fibre.

    Science.gov (United States)

    Priya, Bhanu; Gupta, Vinod Kumar; Pathania, Deepak; Singha, Amar Singh

    2014-08-30

    Cellulosic fibres reinforced composite blend films of starch/poly(vinyl alcohol) (PVA) were prepared by using citric acid as plasticizer and glutaraldehyde as the cross-linker. The mechanical properties of cellulosic fibres reinforced composite blend were compared with starch/PVA crossed linked blend films. The increase in the tensile strength, elongation percentage, degree of swelling and biodegradability of blend films was evaluated as compared to starch/PVA crosslinked blend films. The value of different evaluated parameters such as citric acid, glutaraldehyde and reinforced fibre to starch/PVA (5:5) was found to be 25 wt.%, 0.100 wt.% and 20 wt.%, respectively. The blend films were characterized using Fourier transform-infrared spectrophotometry (FTIR), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA/DTA/DTG). Scanning electron microscopy illustrated a good adhesion between starch/PVA blend and fibres. The blend films were also explored for antimicrobial activities against pathogenic bacteria like Staphylococcus aureus and Escherichia coli. The results confirmed that the blended films may be used as exceptional material for food packaging.

  18. Preparation and photocatalytic activity of PANI/TiO2 composite film

    Institute of Scientific and Technical Information of China (English)

    GAO Jinzhang; LI Shengying; YANG Wu; ZHAO Guohu; BO Lili; SONG Li

    2007-01-01

    A PANI/TiO2 composite film deposited on the glass surface was successfully prepared using sol-gel dip-coating technique and chemical oxidation method.The film was characterized using XRD, AFM,and UV.The result showed that the TiO2 film consists of both cuboid-shaped and anatase-phased TiO2 nanoparticles.The average grain size of TiO2 in the film was approximately 20 nm.After coating with PANI,the particle was changed into irregular spherical-shaped and the size was increased up to approximately 35 nm in diameter.UV-Vis spectroscopy analysis indicated that the coating of TiO2 with PANI would result in an enhancement of photocatalytic efficiency and an extension of the photoresponse of TiO2.The band gap of the PANI/TiO2 film was 3.18 eV.The photocatalytic property of the film was evaluated by the degradation of rhodamine-B.It was found that 67.1% and 83.2% of rhodamine-B could be degraded under sunlight and UV irradiation within 120 min using the PANI/TiO2 composite film as photocatalyst.

  19. Superconducting properties and chemical composition of NbTiN thin films with different thickness

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, L.; Peng, W.; You, L. X.; Wang, Z., E-mail: zwang@mail.sim.ac.cn [State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology (SIMIT), Chinese Academy of Sciences (CAS), Shanghai 200050 (China)

    2015-09-21

    In this research, we systematically investigated the superconducting properties and chemical composition of NbTiN thin films prepared on single-crystal MgO substrates. The NbTiN thin films with different thicknesses (4–100 nm) were deposited by reactive DC magnetron sputtering at ambient temperature. We measured and analyzed the crystal structure and thickness dependence of the chemical composition using X-ray diffraction and X-ray photoelectron spectroscopy depth profiles. The films exhibited excellent superconducting properties, with a high superconducting critical temperature of 10.1 K, low resistivity (ρ{sub 20} = 93 μΩ cm), and residual resistivity ratio of 1.12 achieved for 4-nm-thick ultrathin NbTiN films prepared at the deposition current of 2.4 A. The stoichiometry and electrical properties of the films varied gradually between the initial and upper layers. A minimum ρ{sub 20} of 78 μΩ cm and a maximum residual resistivity ratio of 1.15 were observed for 12-nm-thick films, which significantly differ from the properties of NbN films with the same NaCl structure.

  20. Films based on neutralized chitosan citrate as innovative composition for cosmetic application.

    Science.gov (United States)

    Libio, Illen C; Demori, Renan; Ferrão, Marco F; Lionzo, Maria I Z; da Silveira, Nádya P

    2016-10-01

    In this work, citrate and acetate buffers, were investigated as neutralizers to chitosan salts in order to provide biocompatible and stable films. To choose the appropriate film composition for this study, neutralized chitosan citrate and acetate films, with and without the plasticizer glycerol, were prepared and characterized by thickness, moisture content, degree of swelling, total soluble matter in acid medium, simultaneous thermal analysis and differential scanning calorimetry. Chitosan films neutralized in citrate buffer showed greater physical integrity resulted from greater thicknesses, lower moisture absorbance, lower tendency to solubility in the acid medium, and better swelling capacities. According to thermal analyses, these films had higher interaction with water which is considered an important feature for cosmetic application. Since the composition prepared in citrate buffer without glycerol was considered to present better physical integrity, it was applied to investigate hyaluronic acid release in a skin model. Skins treated with those films, with or without hyaluronic acid, show stratum corneum desquamation and hydration within 10min. The results suggest that the neutralized chitosan citrate film prepared without glycerol promotes a cosmetic effect for skin exfoliation in the presence or absence of hyaluronic acid. PMID:27287105

  1. Thermally stimulated discharge conductivity in polymer composite thin films

    Indian Academy of Sciences (India)

    V S Sangawar; P S Chikhalikar; R J Dhokne; A U Ubale; S D Meshram

    2006-08-01

    This paper describes the results of thermally stimulated discharge conductivity study of activated charcoal–polyvinyl chloride (PVC) thin film thermoelectrets. TSDC has been carried out in the temperature range 308–400°K and at four different polarizing fields. Results are discussed on the basis of mobility of activated charcoal and polyvinyl chloride chains.

  2. Properties of polyvinyl alcohol/xylan composite films with citric acid.

    Science.gov (United States)

    Wang, Shuaiyang; Ren, Junli; Li, Weiying; Sun, Runcang; Liu, Shijie

    2014-03-15

    Composite films of xylan and polyvinyl alcohol were produced with citric acid as a new plasticizer or a cross-linking agent. The effects of citric acid content and polyvinyl alcohol/xylan weight ratio on the mechanical properties, thermal stability, solubility, degree of swelling and water vapor permeability of the composite films were investigated. The intermolecular interactions and morphology of composite films were characterized by FTIR spectroscopy and SEM. The results indicated that polyvinyl alcohol/xylan composite films had good compatibility. With an increase in citric acid content from 10% to 50%, the tensile strength reduced from 35.1 to 11.6 MPa. However, the elongation at break increased sharply from 15.1% to 249.5%. The values of water vapor permeability ranged from 2.35 to 2.95 × 10(-7)g/(mm(2)h). Interactions between xylan and polyvinyl alcohol in the presence of citric acid become stronger, which were caused by hydrogen bond and ester bond formation among the components during film forming.

  3. OPTICAL BAND GAP AND CONDUCTIVITY MEASUREMENTS OF POLYPYRROLE-CHITOSAN COMPOSITE THIN FILMS

    Institute of Scientific and Technical Information of China (English)

    Mahnaz M.Abdi; H.N.M.Ekramul Mahmud; Luqman Chuah Abdullah; Anuar Kassim; Mohamad Zaki Ab.Rahman; Josephine Liew Ying Chyi

    2012-01-01

    Electrical conductivity and optical properties of polypyrrole-chitosan (PPy-CHI) conducting polymer composites have been investigated to determine the optical transition characteristics and energy band gap of composite films.The two electrode method and Ⅰ-Ⅴ characteristic technique were used to measure the conductivity of the PPy-CHI thin films,and the optical band gap was obtained from their ultraviolet absorption edges.Depending upon experimental parameter,the optical band gap (Eg) was found within 1.30-2.32 eV as estimated from optical absorption data.The band gap of the composite films decreased as the CHI content increased.The room temperature electrical conductivity of PPy-CHI thin films was found in the range of 5.84 × 10-7-15.25 × 10-7 S.cm-1 depending on the chitosan content.The thermogravimetry analysis (TGA)showed that the CHI can improve the thermal stability of PPy-CHI composite films.

  4. Topographic guidance based on microgrooved electroactive composite films for neural interface.

    Science.gov (United States)

    Shi, Xiaoyao; Xiao, Yinghong; Xiao, Hengyang; Harris, Gary; Wang, Tongxin; Che, Jianfei

    2016-09-01

    Topographical features are essential to neural interface for better neuron attachment and growth. This paper presents a facile and feasible route to fabricate an electroactive and biocompatible micro-patterned Single-walled carbon nanotube/poly(3,4-ethylenedioxythiophene) composite films (SWNT/PEDOT) for interface of neural electrodes. The uniform SWNT/PEDOT composite films with nanoscale pores and microscale grooves significantly enlarged the electrode-electrolyte interface, facilitated ion transfer within the bulk film, and more importantly, provided topology cues for the proliferation and differentiation of neural cells. Electrochemical analyses indicated that the introduction of PEDOT greatly improved the stability of the SWNT/PEDOT composite film and decreased the electrode/electrolyte interfacial impedance. Further, in vitro culture of rat pheochromocytoma (PC12) cells and MTT testing showed that the grooved SWNT/PEDOT composite film was non-toxic and favorable to guide the growth and extension of neurite. Our results demonstrated that the fabricated microscale groove patterns were not only beneficial in the development of models for nervous system biology, but also in creating therapeutic approaches for nerve injuries. PMID:27295493

  5. Preparation of ZnO-Zn2TiO4 Sol Composite Films and Its Photocatalytic Activities

    Directory of Open Access Journals (Sweden)

    Xiujuan Qin

    2013-01-01

    Full Text Available Ti-doped ZnO sol-composite films were prepared on the glass substrate by the two-step sol-gel technique. X-ray diffraction, Uv-Vis spectrophotometer, and FS spectrum of composite films were used to help make structure characterization and optical performance testing. The results showed that the composite was a mixture of ZnO + Zn2TiO4. Because of synergistic effect of both semiconductor oxides, composite films had a wide range of spectral response in the visible region, and the absorption band edge was about 510 nm, and the Green Belt of composite films luminous significantly enhanced. Photocatalytic oxidation experiments showed that using the composite films treatment (16.5 ml, l0 mg/L methyl orange aqueous solution/cm2, the decolorization rate of methyl-orange was 90% after 3 hours irradiation.

  6. Potentiometric study of polyaniline film synthesized with various dopants and composite-dopant: A comparative study

    Indian Academy of Sciences (India)

    P D Gaikwad; D J Shirale; V K Gade; P A Savale; K P Kakde; H J Kharat; M D Shirsat

    2006-08-01

    The potentiometric study of polyaniline (PANI) film synthesized with dopants viz. polyvinyl sulfonic acid (PVS), -toluene sulfonic acid (TS), dodecyl benzene sulfonic acid (DBS) and composite-dopants viz. PVS–TS and PVS–DBS, has been carried out. The synthesized PANI films were characterized by electrochemical technique, UV-visible spectroscopy, Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM) and conductivity measurement. It was found that the PANI doped with PVS gives good electrochemical properties, conductivity as well as surface morphology as compared to TS and DBS, whereas in composite dopants the PANI doped with PVS–TS gives good polymer matrix as compared to PVS–DBS.

  7. Fabrication of titania thin film with composite nanostructure and its ability to photodegrade rhodamine B in water

    Institute of Scientific and Technical Information of China (English)

    Gaojie ZHANG; Jinming WU; Shaoguang LIU; Mi YAN

    2008-01-01

    A titania nanorod film was synthesized by direct oxidation of metallic Ti with hydrogen peroxide solution under a low temperature. Titania nanoparticles were then filled into the gaps among the nanorods through an infiltration sol-gel procedure to form a composite titania film with an ordered nanostructure. X-ray diffraction spectra indicate that the composite film was a mixture of anatase and rutile while the titania film obtained by only using a sol-gel procedure was pure anatase. Field emission scanning electron microscopy observations show that titania nanoparticles were embedded into the titania nanorod film. Photoluminescence spectra suggest the enhanced separation of electron and hole pairs for the obtained composite titania film over the corresponding titania nanorod film. The composite titania film exhibited improved ability to photodegrade rhodamine B in water compared with the titania nanorod film. The apparent photodegradation rate constant, fitting a pseudo-first-order, was 3 times of that obtained by the sol-gel derived titania film at the same weight. The improved photocata-lytic activity for the composite titania film could be attributed to the enhanced separation of electron and hole pairs due to the embedding of the titania nanoparticles within the titania nanorods.

  8. Improved thermal stability of polylactic acid (PLA) composite film via PLA-β-cyclodextrin-inclusion complex systems.

    Science.gov (United States)

    Byun, Youngjae; Rodriguez, Katia; Han, Jung H; Kim, Young Teck

    2015-11-01

    The effects of the incorporation of PLA-β-cyclodextrin-inclusion complex (IC) and β-cyclodextrin (β-CD) on biopolyester PLA films were investigated. Thermal stability, surface morphology, barrier, and mechanical properties of the films were measured at varying IC (1, 3, 5, and 7%) and β-CD (1 and 5%) concentrations. The PLA-IC-composite films (IC-PLA-CFs) showed uniform morphological structure, while samples containing β-CD (β-CD-PLA-CFs) showed high agglomeration of β-CD due to poor interfacial interaction between β-CD and PLA moieties. According to the thermal property analysis, the 5% IC-PLA-CFs showed 6.6 times lower dimensional changes (6.5%) at the temperature range of 20-80°C than that of pure PLA film (43.0%). The increase of IC or β-CD content in the PLA-composite films shifted the glass transition and crystallization temperature to higher temperature regions. The crystallinity of both composite films improved by increasing IC or β-CD content. Both composite films had higher oxygen and water vapor permeability as IC or β-CD content increased in comparison to pure PLA film. All the composite films had less flexibility and lower tensile strength than the pure PLA film. In conclusion, this study shows that the IC technique is valuable to improve the thermal expansion stability of PLA-based films.

  9. Gravity-assisted pulsed laser ablation for fabrication of compositional gradient thin film

    International Nuclear Information System (INIS)

    A compositional gradient thin film of Fe/Si was fabricated by gravity-assisted pulsed laser ablation under a gravity field of 5.3 × 104 m/s2. Systematic experiments were conducted by varying the values of several parameters including the gravity, distance between the target and the substrate, and laser fluence. The atomic fraction of Fe was measured by scanning electron microscopy/energy dispersive X-ray spectroscopy. We found that the atomic fraction of Fe increases along the gravity direction, i.e., it exhibits an apparent spatial gradient. We also found the optimal laser fluence at which a thin film having the largest possible spatial compositional gradient is obtained. It is shown that the surface energy density on the substrate surface is the key parameter to control the compositional distribution. The relatively high laser fluence as well as the very narrow space between the target and the substrate are found to be essential to sputter the film material. A plausible model is presented to explain the experimental data. - Highlights: • Gravity-assisted pulsed laser ablation method (GAPLA) is established. • A compositional gradient thin film is fabricated by GAPLA under 5.3 × 104 m/s2 condition. • The surface energy density is an important parameter for GAPLA. • A compositional gradient is generated by selective reevaporation and not diffusion

  10. Microstructural and Mechanical Studies of PVA Doped with ZnO and WO3 Composites Films

    Directory of Open Access Journals (Sweden)

    N. B. Rithin Kumar

    2014-01-01

    Full Text Available Polymer composites of ZnO and WO3 nanoparticles doped polyvinyl alcohol (PVA matrix have been prepared using solvent casting method. The microstructural properties of prepared films were studied using FTIR, XRD, SEM, and EDAX techniques. In the doped PVA, many irregular shifts in the FTIR spectra have been observed and these shifts in bands can be understood on the basis of intra/intermolecular hydrogen bonding with the adjacent OH group of PVA. The chemical composition, phase homogeneity, and morphology of the polymer composites of the polymer film were studied using EDAX and SEM. These data indicate that the distribution of nanosized ZnO and WO3 dopants is uniform and confirm the presence of ZnO and WO3 in the film. The crystal structure and crystallinity of polymer composites were studied by XRD. It was found that the change in structural repositioning and crystallinity of the composites takes place due to the interaction of dopants and also due to complex formation. The mechanical studies of doped polymer films were carried out using universal testing machine (UTM at room temperature, indicating that the addition of the ZnO and WO3 with weight percentage concentration equal to 14% increases the tensile strength and Young’s modulus.

  11. Fiber optic humidity sensor based on the graphene oxide/PVA composite film

    Science.gov (United States)

    Wang, Youqing; Shen, Changyu; Lou, Weimin; Shentu, Fengying

    2016-08-01

    Fiber optic humidity sensor based on an in-fiber Mach-Zehnder interferometer (MZI) coated with graphene oxide (GO)/PVA composite film was investigated. The MZI is constructed of two waist-enlarged tapers. The length between two waist-enlarged tapers is 20 mm. By comparing the experiment results of MZI coated with different GO/PVA composite films, composite film formed by the ratio of 0.3 g PVA mixed with 10 ml GO dispersion shows a better performance of relative humidity sensing. By using the molecular structure model of the composited GO/PVA, the operation mechanism between GO/PVA composite film and water molecules was illustrated. The sensitivity of 0.193 dB/%RH with a linear correlation coefficient of 99.1% and good stability under the relative humidity range of 25-80% was obtained. Temperature effect on the proposed fiber optic humidity sensor was also considered and analyzed. According to the repetitive experimental results, the proposed humidity sensor shows a good repeatability.

  12. Three-dimensional microporous polypyrrole/polysulfone composite film electrode for supercapacitance performance

    Science.gov (United States)

    Feng, Xiaojuan; Shi, Yanlong; Jin, Shuping

    2015-10-01

    The three-dimensional microporous polypyrrole/polysulfone (PPY/PSF) composite film was fabricated via a simple polymerization method. The morphology structure and chemical composition of the composite film were characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR), respectively. The electrochemical properties of the composite film electrode were evaluated by cyclic voltammetry, galvanostatic charging-discharging and electrochemical impedance spectroscopy. The material exhibits excellent capacitance performance including high capacitance of 500 F g-1 at 0.3 A g-1 current density, good cycle stability in 800 continuous cycles (only 4.5% decay after 800 cycles at 0.3 A g-1), and low inter resistance. The good property of the PPY/PSF electrode should be attributed to its structural features, including two-layer microporous structure which facilitates the penetration of electrolytes into the inner surface, high surface area which provides more active sites. These results show that the composite film is a promising candidate for high energy electrochemical capacitors.

  13. Tuning cationic composition of La:EuTiO3−δ films

    Directory of Open Access Journals (Sweden)

    Andrey Shkabko

    2013-11-01

    Full Text Available Eu1−xLaxTiO3−δ (x = 0, 0.3, 0.5 films were deposited in a p(Ar(96%/H2(4% = 4 × 10−4 mbar atmosphere on (LaAlO30.3-(Sr2AlTaO60.7 vicinal substrates (0.1°. Reflection high-energy electron diffraction oscillation characteristics of a layer-by-layer growth mode were observed for stoichiometric and Ti-rich films and the laser fluence suited to deposit stoichiometric films was identified to be 1.25 J/cm2 independent of the La content. The variety of resulting film compositions follows the general trend of Eu-enrichment for low laser and Ti-enrichment for high laser fluence. X-ray diffraction confirms that all the films are compressively strained with a general trend of an increase of c-axis elongation for non-stoichiometric films. The surfaces of non-stoichiometric films have an increased roughness, the highest sheet resistances, exhibit the presence of islands, and are Eu3+ rich for films deposited at low laser fluence.

  14. Preparation of sensitive and recyclable porous Ag/TiO2 composite films for SERS detection

    Science.gov (United States)

    Zhang, Zhengyi; Yu, Jiajie; Yang, Jingying; Lv, Xiang; Wang, Tianhe

    2015-12-01

    Porous Ag/TiO2 composite films were prepared by spin coating of titania on normal glass slides and subsequent photochemical deposition of silver nanoparticles (AgNPs). The films were characterized by XRD and FESEM to reveal micro structural and morphological differences between films obtained under varied conditions. The SERS properties of these films were investigated using aqueous crystal violet (CV) as probe molecules. The results indicate that the content of polyethylene glycol (PEG) and photo-reduction time had significant influences on both the microstructure and SERS performance of Ag/TiO2 films. The highest SERS sensitivity that allowed as low as 10-10 M aqueous CV to be detected, was achieved with the PEG/(C4H9O)4Ti molar ratio being 0.08% and with 30 min of UV irradiation. With this film a linear relationship was established through experiment between SERS intensity and CV concentration from 10-10 to 10-5 M, which could be used as a calibration curve for CV concentration measurement. In addition, the film could be reused as a SERS substrate for up to four times without significantly losing SERS sensitivity if a simple regeneration was followed. It is visualized that the Ag/TiO2 film on glass has potentials for being developed into a practical SERS substrate with high sensitivity and good reusability.

  15. A Novel Approach Toward Fabrication of High Performance Thin Film Composite Polyamide Membranes

    OpenAIRE

    Behnam Khorshidi; Thomas Thundat; Fleck, Brian A.; Mohtada Sadrzadeh

    2016-01-01

    A practical method is reported to enhance water permeability of thin film composite (TFC) polyamide (PA) membranes by decreasing the thickness of the selective PA layer. The composite membranes were prepared by interfacial polymerization (IP) reaction between meta-phenylene diamine (MPD)-aqueous and trimesoyl chloride (TMC)-organic solvents at the surface of polyethersulfone (PES) microporous support. Several PA TFC membranes were prepared at different temperatures of the organic solution ran...

  16. Morphological and compositional engineering of Ni/carbon nanotube composite film via a novel cyclic voltammetric route

    Indian Academy of Sciences (India)

    Yu Jun Yang

    2012-08-01

    Ni/multi-walled carbon nanotubes (MWCNTs) composite films were deposited on the glassy carbon electrode (GCE) by a Ni plating bath containing homogeneously dispersed MWCNTs using polyvinylpyrrolidone (PVP) as dispersion additive. Incorporation of MWCNTs into Ni matrix was greatly enhanced by the application of cyclic voltammetric (CV) deposition technique. The structure and nature of the Ni/MWCNT were characterized by field emission scanning electron microscope (FE-SEM) and X-ray diffraction (XRD). The results show that the content of MWCNT and the morphology of the deposited Ni/MWCNT composite film can be controlled by selecting the appropriate electroplating conditions. Further study indicates that the obtained Ni/MWCNT showed excellent electro-catalytic activity for the oxidation of ethanol in alkaline solution.

  17. Linear Assembles of BN Nanosheets, Fabricated in Polymer/BN Nanosheet Composite Film

    Directory of Open Access Journals (Sweden)

    Hong-Baek Cho

    2011-01-01

    Full Text Available Linear assembles of BN nanosheets (LABNs were fabricated in polysiloxane/BN nanosheet composite film under a high DC electric field. The hexagonal BN nanosheets were dispersed by sonication in a prepolymer mixture of polysiloxane followed by a high-speed mixing. The homogeneous suspension was cast on a spacer of microscale thickness and applied to a high DC electric field before it became cross-linked. X-ray diffraction, scanning electron microscopy, and digital microscopy revealed that LABNs formed in the polysiloxane matrix and that the BN nanosheets in the LABNs were aligned perpendicular to the film plane with high anisotropy. This is the first time that linear assemblies of nanosheets have been fabricated in an organic-inorganic hybrid film by applying a DC electric field. The enhanced thermal conductivity of the composite film is attributed to the LABNs. The LABN formation and heat conduction mechanisms are discussed. The polysiloxane/BN nanosheet composite film has the potential to be used semiconductor applications that require both a high thermal conductivity and a high electric insulation.

  18. ZnO micro-nano composite hydrophobic film prepared by the three-step method

    Institute of Scientific and Technical Information of China (English)

    Ma Kai; Li Hua; Zhang Han; Xu Xiao-Liang; Gong Mao-Gang; Yang Zhou

    2009-01-01

    The hydrophobicity of the lotus leaf is mainly due to its surface micro-nano composite structure. In order to mimic the lotus structure, ZnO micro-nano composite hydrophobic films were prcpared via the three-step method. On thin buffer films of SiO2, which were first fabricated on glass substrates by the sol gel dip-coating method, a ZnO seed layer was deposited via RF magnetron sputtering. Then two different ZnO films, micro-nano and micro-only flower-like structures, were grown by the hydrothermal method. The prepared films have different hydrophobic properties after surface modification. The structures of the obtained ZnO films were characterized using x-ray diffraction and field-emission scanning electron microscopy. A conclusion that a micro-nano composite structure is more beneficial to hydrophobicity than a micro-only structure was obtained through research into the effect of structure on hydrophobic properties.

  19. ZnO micro-nano composite hydrophobic film prepared by the three-step method

    Science.gov (United States)

    Ma, Kai; Li, Hua; Zhang, Han; Xu, Xiao-Liang; Gong, Mao-Gang; Yang, Zhou

    2009-05-01

    The hydrophobicity of the lotus leaf is mainly due to its surface micro-nano composite structure. In order to mimic the lotus structure, ZnO micro-nano composite hydrophobic films were prepared via the three-step method. On thin buffer films of SiO2, which were first fabricated on glass substrates by the sol-gel dip-coating method, a ZnO seed layer was deposited via RF magnetron sputtering. Then two different ZnO films, micro-nano and micro-only flower-like structures, were grown by the hydrothermal method. The prepared films have different hydrophobic properties after surface modification. The structures of the obtained ZnO films were characterized using x-ray diffraction and field-emission scanning electron microscopy. A conclusion that a micro-nano composite structure is more beneficial to hydrophobicity than a micro-only structure was obtained through research into the effect of structure on hydrophobic properties.

  20. Nano-composite thermochromic thin films and their application in energy-efficient glazing

    Energy Technology Data Exchange (ETDEWEB)

    Saeli, Manfredi [Universita degli Studi di Palermo - Dipartimento di Progetto e Costruzione Edilizia (DPCE), Viale delle Scienze, 90128 Palermo (Italy); Piccirillo, Clara; Parkin, Ivan P.; Binions, Russell [University College London - Department of Chemistry - Christopher Ingold Laboratories, 20 Gordon Street, WC1H 0AJ London (United Kingdom); Ridley, Ian [Barlett School of Graduate Studies, University College London, Wates House, 22 Gordon Street, WC1H 0QB London (United Kingdom)

    2010-02-15

    A hybrid atmospheric pressure and aerosol-assisted chemical vapour deposition strategy is presented as a facile route for the production of vanadium dioxide nano-composite thin films. The effect of the inclusion of gold nanoparticles and the use of a surfactant molecule, tetraoctylammonium bromide, is discussed. The films were fully characterised using a wide variety of techniques, including scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and UV/vis/NIR spectroscopy. It is shown that micro-structural changes brought about by careful control of film growth conditions, and/or the use of surfactant, lead to an enhancement of thermochromic properties. Gold nanoparticle incorporation leads to a significant change in the colour of the films from a yellow-brown colour to a variety of greens and blues depending on the gold nanoparticle concentration. The films become more reflective in the infra-red with increased gold nanoparticle incorporation. Optical data are used in energy modelling studies to elucidate the film potential as an energy-saving coating in architectural glazing. The energy modelling results suggest that for warmer climates the thermochromic nano-composites investigated here lead to significant energy savings when compared with plain glass and other standard industry products. (author)

  1. Composite Ag/C:H:N films prepared by planar magnetron deposition

    Energy Technology Data Exchange (ETDEWEB)

    Hlidek, P. [Charles University, Faculty of Mathematics and Physics, Praha (Czech Republic)], E-mail: hlidek@karlov.mff.cuni.cz; Hanus, J.; Biederman, H.; Slavinska, D.; Pesicka, J. [Charles University, Faculty of Mathematics and Physics, Praha (Czech Republic)

    2008-05-30

    Composite Ag/C:H:N films were deposited by means of an unbalanced magnetron operated in a gas mixture of nitrogen and n-hexane. Composition of the films was controlled by electric power delivered to the magnetron and by ratio of nitrogen and n-hexane in the working gas mixture. The films were characterized using transmission electron microscopy, by the absorption spectra in visible and near infrared regions and by Fourier transform infrared spectroscopy. Immediately after film deposition and without breaking vacuum (in situ) corresponding vibration infrared spectra were scanned and their evolution during ageing of the films was monitored. Wettability as determined from water contact angle was improved with raising nitrogen contents, i.e. with increasing the electric power and the ratio of nitrogen/n-hexane in the working gas mixture. The increased wettability is likely caused by presence of NH{sub x} groups in Ag/C:H:N films. The incorporation of nitrogen effectively prevents the formation of carboxylate groups on the silver inclusions surfaces during the aging in the open air. In addition, the oxidation mechanism of the polymer matrix is modified.

  2. Green synthesis of high conductivity silver nanoparticle-reduced graphene oxide composite films

    Science.gov (United States)

    Dinh, D. A.; Hui, K. S.; Hui, K. N.; Cho, Y. R.; Zhou, Wei; Hong, Xiaoting; Chun, Ho-Hwan

    2014-04-01

    A green facile chemical approach to control the dimensions of Ag nanoparticles-graphene oxide (AgNPs/GO) composites was performed by the in situ ultrasonication of a mixture of AgNO3 and graphene oxide solutions with the assistance of vitamin C acting as an environmentally friendly reducing agent at room temperature. With decreasing ultrasonication time, the size of the Ag nanoparticles decreased and became uniformly distributed over the surface of the GO nanosheets. The as-prepared AgNPs/rGO composite films were then formed using a spin coating method and reduced at 500 °C under N2/H2 gas flow for 1 h. Four-point probe measurements showed that the sheet resistance of the AgNPs/rGO films decreased with decreasing AgNPs size. The lowest sheet resistance of 270 Ω/sq was obtained in the film corresponding to 1 min of ultrasonication, which showed a 40 times lower resistivity than the rGO film (10.93 kΩ/sq). The formation mechanisms of the as-prepared AgNPs/rGO films are proposed. This study provides a guide to controlling the dimensions of AgNPs/rGO films, which might hold promise as advanced materials for a range of analytical applications, such as catalysis, sensors and microchips.

  3. Radiopacity evaluation of composite restorative resins and bonding agents using digital and film x-ray systems

    OpenAIRE

    Oztas, Bengi; Kursun, Sebnem; Dinc, Gul; Kamburoglu, Kıvanc

    2012-01-01

    Objective: The purpose of this in vitro study was to explore the radiopacity of composite resins and bonding materials using film and phosphor plates. Methods: Nine composite dental resin specimens and human tooth slices were exposed together with an aluminium stepwedge using dental film and phosphor plates. Eight dentin bonding specimens were prepared and exposed in a similar manner. Their radiopacity on film was assessed using a transmission densitometer, and the radiopacity with phosphor p...

  4. Method for fabricating composite carbon foam

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, Steven T. (San Leandro, CA); Pekala, Richard W. (Pleasant Hill, CA); Kaschmitter, James L. (Pleasanton, CA)

    2001-01-01

    Carbon aerogels used as a binder for granularized materials, including other forms of carbon and metal additives, are cast onto carbon or metal fiber substrates to form composite carbon thin film sheets. The thin film sheets are utilized in electrochemical energy storage applications, such as electrochemical double layer capacitors (aerocapacitors), lithium based battery insertion electrodes, fuel cell electrodes, and electrocapacitive deionization electrodes. The composite carbon foam may be formed by prior known processes, but with the solid particles being added during the liquid phase of the process, i.e. prior to gelation. The other forms of carbon may include carbon microspheres, carbon powder, carbon aerogel powder or particles, graphite carbons. Metal and/or carbon fibers may be added for increased conductivity. The choice of materials and fibers will depend on the electrolyte used and the relative trade off of system resistivity and power to system energy.

  5. Capacitor with a composite carbon foam electrode

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, S.T.; Pekala, R.W.; Kaschmitter, J.L.

    1999-04-27

    Carbon aerogels used as a binder for granularized materials, including other forms of carbon and metal additives, are cast onto carbon or metal fiber substrates to form composite carbon thin film sheets. The thin film sheets are utilized in electrochemical energy storage applications, such as electrochemical double layer capacitors (aerocapacitors), lithium based battery insertion electrodes, fuel cell electrodes, and electrocapacitive deionization electrodes. The composite carbon foam may be formed by prior known processes, but with the solid particles being added during the liquid phase of the process, i.e. prior to gelation. The other forms of carbon may include carbon microspheres, carbon powder, carbon aerogel powder or particles, graphite carbons. Metal and/or carbon fibers may be added for increased conductivity. The choice of materials and fibers will depend on the electrolyte used and the relative trade off of system resistivity and power to system energy. 1 fig.

  6. Capacitor with a composite carbon foam electrode

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, Steven T. (San Leandro, CA); Pekala, Richard W. (Pleasant Hill, CA); Kaschmitter, James L. (Pleasanton, CA)

    1999-01-01

    Carbon aerogels used as a binder for granularized materials, including other forms of carbon and metal additives, are cast onto carbon or metal fiber substrates to form composite carbon thin film sheets. The thin film sheets are utilized in electrochemical energy storage applications, such as electrochemical double layer capacitors (aerocapacitors), lithium based battery insertion electrodes, fuel cell electrodes, and electrocapacitive deionization electrodes. The composite carbon foam may be formed by prior known processes, but with the solid partides being added during the liquid phase of the process, i.e. prior to gelation. The other forms of carbon may include carbon microspheres, carbon powder, carbon aerogel powder or particles, graphite carbons. Metal and/or carbon fibers may be added for increased conductivity. The choice of materials and fibers will depend on the electrolyte used and the relative trade off of system resistivity and power to system energy.

  7. Substrate and composition effects on BSCCO thin films deposited by aerosol MOCVD

    International Nuclear Information System (INIS)

    Superconductor thin films of the BSCCO system were deposited by aerosol-MOCVD on LaAlO3 and MgO substrates at a high deposition rate. The X-ray diffraction patterns of the deposited films reveal intergrowths between the 2212/2223 phases. The application of the precision plot model to a Bi-22(n-1)n heterostructure allowed the quantification of the intergrowths in terms of the n value (non-integer). A phase with n=2, Bi-2212 phase, is isolated from a phase with 2< n<3, meaning intergrowths between Bi-2212 and Bi-2223 phases. The n values were correlated with the compositions of the films with Sr/(Sr+Ca+Cu) compositional ratios close to 0.28 leading to a value of n near 3. (orig.)

  8. Sensitive electrochemical detection of Salmonella with chitosan-gold nanoparticles composite film.

    Science.gov (United States)

    Xiang, Cuili; Li, Ran; Adhikari, Bimalendu; She, Zhe; Li, Yongxin; Kraatz, Heinz-Bernhard

    2015-08-01

    An ultrasensitive electrochemical immunosensor for detection of Salmonella has been developed based on using high density gold nanoparticles (GNPs) well dispersed in chitosan hydrogel and modified glassy carbon electrode. The composite film has been oxidized in NaCl solution and used as a platform for the immobilization of capture antibody (Ab1) for biorecognition. After incubation in Salmonella suspension and horseradish peroxidase (HRP) conjugated secondary antibody (Ab2) solution, a sandwich electrochemical immunosensor has been constructed. The electrochemical signal was obtained and improved by comparing the composite film with chitosan film. The result has shown that the constructed sensor provides a wide linear range from 10 to 10(5) CFU/mL with a low detection limit of 5 CFU/mL (at the ratio of signal to noise, S/N=3:1). Furthermore, the proposed immunosensor has demonstrated good selectivity and reproducibility, which indicates its potential in the clinical diagnosis of Salmonella contaminations. PMID:26048833

  9. Composite films from pectin and fish skin gelatin or soybean flour protein

    Science.gov (United States)

    Composite films were prepared from pectin and fish skin gelatin (FSG) or pectin and soybean flour protein (SFP). The inclusion of protein promoted molecular interactions, resulting in a well-organized homogeneous structure, as revealed by scanning electron microscopy and fracture-acoustic emission ...

  10. Properties of dry film lubricants prepared by spray application of aqueous starch-oil composites

    Science.gov (United States)

    Aqueous dispersions of starch-soybean oil (SBO) and starch-jojoba oil (JO) composites, prepared by excess steam jet cooking, form effective dry film lubricants when applied as thick coatings to metal surfaces by doctor blade. This application method necessitates long drying times, is wasteful, requ...

  11. Composition-Dependent Luminescent Properties of GeO2-Eu2O3-Ag Films

    Science.gov (United States)

    Bokshyts, Yu. V.

    2013-05-01

    An effect of Eu3+-precursor on the luminescent properties of GeO2-Eu2O3-Ag films was studied. This effect can be attributed to the different phase compositions of europium compounds after heat treatment and the change of structural parameters of the environment for europium ions.

  12. pH stable thin film composite polyamine nanofiltration membranes by interfacial polymerisation

    NARCIS (Netherlands)

    Lee, Kah P.; Zheng, Jumeng; Bargeman, Gerrald; Kemperman, Antoine J.B.; Benes, N.E.

    2015-01-01

    In this work polyamine membranes are presented that are prepared by the interfacial polymerisation of polyethylenimine and cyanuric chloride on porous polyethersulfone supports. The thin film composite polyamine membranes have superior pH stability as compared to conventional polyamide membranes tha

  13. Electrical Conductance Tuning and Bistable Switching in Poly(N-vinylcarbazole)-Carbon Nanotube Composite Films.

    Science.gov (United States)

    Liu, Gang; Ling, Qi-Dan; Teo, Eric Yeow Hwee; Zhu, Chun-Xiang; Chan, D Siu-Hung; Neoh, Koon-Gee; Kang, En-Tang

    2009-07-28

    By varying the carbon nanotube (CNT) content in poly(N-vinylcarbazole) (PVK) composite thin films, the electrical conductance behavior of an indium-tin oxide/PVK-CNT/aluminum (ITO/PVK-CNT/Al) sandwich structure can be tuned in a controlled manner. Distinctly different electrical conductance behaviors, such as (i) insulator behavior, (ii) bistable electrical conductance switching effects (write-once read-many-times (WORM) memory effect and rewritable memory effect), and (iii) conductor behavior, are discernible from the current density-voltage characteristics of the composite films. The turn-on voltage of the two bistable conductance switching devices decreases and the ON/OFF state current ratio of the WORM device increases with the increase in CNT content of the composite film. Both the WORM and rewritable devices are stable under a constant voltage stress or a continuous pulse voltage stress, with an ON/OFF state current ratio in excess of 10(3). The conductance switching effects of the composite films have been attributed to electron trapping in the CNTs of the electron-donating/hole-transporting PVK matrix.

  14. Thick film magnetic nanoparticulate composites and method of manufacture thereof

    Science.gov (United States)

    Ma, Xinqing (Inventor); Zhang, Yide (Inventor); Ge, Shihui (Inventor); Zhang, Zongtao (Inventor); Yan, Dajing (Inventor); Xiao, Danny T. (Inventor)

    2009-01-01

    Thick film magnetic/insulating nanocomposite materials, with significantly reduced core loss, and their manufacture are described. The insulator coated magnetic nanocomposite comprises one or more magnetic components, and an insulating component. The magnetic component comprises nanometer scale particles (about 1 to about 100 nanometers) coated by a thin-layered insulating phase. While the intergrain interaction between the immediate neighboring magnetic nanoparticles separated by the insulating phase provides the desired soft magnetic properties, the insulating material provides high resistivity, which reduces eddy current loss.

  15. Optical absorption properties of Ag/SiO sub 2 composite films induced by gamma irradiation

    CERN Document Server

    Pan, A L; Yang, Z P; Liu, F X; Ding, Z J; Qian, Y T

    2003-01-01

    Mesoporous SiO sub 2 composite films with small Ag particles or clusters dispersed in them were prepared by a new method: first the matrix SiO sub 2 films were prepared by the sol-gel process combined with the dip-coating technique; then they were soaked in AgNO sub 3 solutions; this was followed by irradiation with gamma-rays at room temperature and ambient pressure. The structure of these films was examined by high-resolution transmission electron microscopy, and their optical absorption spectra were examined. It has been shown that the Ag particles grown within the porous SiO sub 2 films are very small and are highly dispersed. On increasing the soaking concentration and subjecting the samples to an additional annealing, a different peak-shift effect for the surface plasmon resonance was observed in the optical absorption measurement. Possible mechanisms of this behaviour are discussed in this paper.

  16. ARTICLES: Preparation and Characterization of Nanostructured Ni-TiN Composite Films

    Science.gov (United States)

    Wang, Jie; Cai, Chao; Ma, Shi-liang; Cao, Fa-he; Zhang, Zhao; Zhang, Jian-qing

    2010-06-01

    Ni-TiN nanocomposite films were produced from a Ni plating bath containing TiN nanoparticles by using dc electroplating method. The structure and surface morphology of Ni-TiN composite coatings were analyzed by atom force microscope, X-ray diffraction, and transmission electron microscopy. Meanwhile, the anti-corrosion properties, hardness and thermostability of Ni-TiN nanocomposite films were also investigated and compared with the traditional polycrystalline Ni coatings. The results show that, compared with the traditional polycrystalline Ni film, Ni-TiN nanocomposite coatings display much better corrosion resistance, higher film hardness, and thermal stability. In addition, the hardness of Ni-TiN nanocomposite coatings decreases slightly with the increase of electroplating current density, which may be due to the synergism of hydrogen evolution and faster nucleation/growth rate of nickel crystallites.

  17. Elaboration of m-cresol polyamide12/ polyaniline composite films for antistatic applications

    International Nuclear Information System (INIS)

    The present work deals with the preparation of transparent antistatic films from an extreme dilution of an intrinsically conducting polymer (ICP) with not coloured polymers. Our approach is based on the chemical polymerization of a very thin layer of Polyaniline (PANI) around particles of an insulating polymer (PA12). Films were obtained by dissolving the synthesized core-shell particles in m-Cresol. The electric property and structure relationships were investigated by using dielectric relaxation spectroscopy, X-ray diffraction and micro-Raman spectroscopy. Composite films exhibited a well established dc conductivity over all the frequency range for 10 wt. % of PANI concentration related to the conductive properties of the PANI clusters. X-ray diffraction data show broader and lower intensity of PA12 peaks when increasing PANI content, probably due to the additional doping effect of m- cresol. The doping of PA12/PANI films with Dodecyl benzene sulfonic acid (DBSA) was unequivocally verified by Raman spectroscopy

  18. Flexible nano-ZnO/polyvinylidene difluoride piezoelectric composite films as energy harvester

    Science.gov (United States)

    Bhunia, Ritamay; Das, Shirsendu; Dalui, Saikat; Hussain, Shamima; Paul, Rajib; Bhar, Radhaballav; Pal, Arun Kumar

    2016-07-01

    Nanogenerators (NGs) which harvest energy from mechanical vibration have attracted more attention in the past decade. Piezoelectric materials are the most promising candidates for developing NGs. Flexible free-standing nano-ZnO/PVDF composite films are prepared by incorporating different amounts of nano-ZnO fillers in PVDF matrix using sol-gel technique. Poled films show enhanced dielectric constant. The above free-standing films, with appropriate contacts, are subjected to energy harvesting studies. The output voltage increases with nano-ZnO loading in the PVDF matrix and shows enhanced effect for the poled films. Piezoelectric properties are investigated by measuring the piezoelectric charge constant ( d 33) and piezoelectric voltage constant ( g 33). A maximum AC output voltage ~4 V and output power of the order of few nanowatts are recorded for the nanogenerator which is used to light a red LED using a rectifying circuit through the discharging of a capacitor.

  19. A laser ultrasound transducer using carbon nanofibers–polydimethylsiloxane composite thin film

    Energy Technology Data Exchange (ETDEWEB)

    Hsieh, Bao-Yu; Kim, Jinwook; Li, Sibo; Jiang, Xiaoning, E-mail: xjiang5@ncsu.edu [Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, North Carolina 27695 (United States); Zhu, Jiadeng; Zhang, Xiangwu [Fiber and Polymer Science Program, Department of Textile Engineering, Chemistry and Science, North Carolina State University, Raleigh, North Carolina 27695 (United States)

    2015-01-12

    The photoacoustic effect has been broadly applied to generate high frequency and broadband acoustic waves using lasers. However, the efficient conversion from laser energy to acoustic power is required to generate acoustic waves with high intensity acoustic pressure (>10 MPa). In this study, we demonstrated laser generated high intensity acoustic waves using carbon nanofibers–polydimethylsiloxane (CNFs-PDMS) thin films. The average diameter of the CNFs is 132.7 ± 11.2 nm. The thickness of the CNFs film and the CNFs-PDMS composite film is 24.4 ± 1.43 μm and 57.9 ± 2.80 μm, respectively. The maximum acoustic pressure is 12.15 ± 1.35 MPa using a 4.2 mJ, 532 nm Nd:YAG pulsed laser. The maximum acoustic pressure using the CNFs-PDMS composite was found to be 7.6-fold (17.62 dB) higher than using carbon black PDMS films. Furthermore, the calculated optoacoustic energy conversion efficiency K of the prepared CNFs-PDMS composite thin films is 15.6 × 10{sup −3 }Pa/(W/m{sup 2}), which is significantly higher than carbon black-PDMS thin films and other reported carbon nanomaterials, carbon nanostructures, and metal thin films. The demonstrated laser generated high intensity ultrasound source can be useful in ultrasound imaging and therapy.

  20. Sandwich-Architectured Poly(lactic acid)-Graphene Composite Food Packaging Films.

    Science.gov (United States)

    Goh, Kunli; Heising, Jenneke K; Yuan, Yang; Karahan, Huseyin E; Wei, Li; Zhai, Shengli; Koh, Jia-Xuan; Htin, Nanda M; Zhang, Feimo; Wang, Rong; Fane, Anthony G; Dekker, Matthijs; Dehghani, Fariba; Chen, Yuan

    2016-04-20

    Biodegradable food packaging promises a more sustainable future. Among the many different biopolymers used, poly(lactic acid) (PLA) possesses the good mechanical property and cost-effectiveness necessary of a biodegradable food packaging. However, PLA food packaging suffers from poor water vapor and oxygen barrier properties compared to many petroleum-derived ones. A key challenge is, therefore, to simultaneously enhance both the water vapor and oxygen barrier properties of the PLA food packaging. To address this issue, we design a sandwich-architectured PLA-graphene composite film, which utilizes an impermeable reduced graphene oxide (rGO) as the core barrier and commercial PLA films as the outer protective encapsulation. The synergy between the barrier and the protective encapsulation results in a significant 87.6% reduction in the water vapor permeability. At the same time, the oxygen permeability is reduced by two orders of magnitude when evaluated under both dry and humid conditions. The excellent barrier properties can be attributed to the compact lamellar microstructure and the hydrophobicity of the rGO core barrier. Mechanistic analysis shows that the large rGO lateral dimension and the small interlayer spacing between the rGO sheets have created an extensive and tortuous diffusion pathway, which is up to 1450-times the thickness of the rGO barrier. In addition, the sandwiched architecture has imbued the PLA-rGO composite film with good processability, which increases the manageability of the film and its competency to be tailored. Simulations using the PLA-rGO composite food packaging film for edible oil and potato chips also exhibit at least eight-fold extension in the shelf life of these oxygen and moisture sensitive food products. Overall, these qualities have demonstrated the high potential of a sandwich-architectured PLA-graphene composite film for food packaging applications.

  1. Sandwich-Architectured Poly(lactic acid)-Graphene Composite Food Packaging Films.

    Science.gov (United States)

    Goh, Kunli; Heising, Jenneke K; Yuan, Yang; Karahan, Huseyin E; Wei, Li; Zhai, Shengli; Koh, Jia-Xuan; Htin, Nanda M; Zhang, Feimo; Wang, Rong; Fane, Anthony G; Dekker, Matthijs; Dehghani, Fariba; Chen, Yuan

    2016-04-20

    Biodegradable food packaging promises a more sustainable future. Among the many different biopolymers used, poly(lactic acid) (PLA) possesses the good mechanical property and cost-effectiveness necessary of a biodegradable food packaging. However, PLA food packaging suffers from poor water vapor and oxygen barrier properties compared to many petroleum-derived ones. A key challenge is, therefore, to simultaneously enhance both the water vapor and oxygen barrier properties of the PLA food packaging. To address this issue, we design a sandwich-architectured PLA-graphene composite film, which utilizes an impermeable reduced graphene oxide (rGO) as the core barrier and commercial PLA films as the outer protective encapsulation. The synergy between the barrier and the protective encapsulation results in a significant 87.6% reduction in the water vapor permeability. At the same time, the oxygen permeability is reduced by two orders of magnitude when evaluated under both dry and humid conditions. The excellent barrier properties can be attributed to the compact lamellar microstructure and the hydrophobicity of the rGO core barrier. Mechanistic analysis shows that the large rGO lateral dimension and the small interlayer spacing between the rGO sheets have created an extensive and tortuous diffusion pathway, which is up to 1450-times the thickness of the rGO barrier. In addition, the sandwiched architecture has imbued the PLA-rGO composite film with good processability, which increases the manageability of the film and its competency to be tailored. Simulations using the PLA-rGO composite food packaging film for edible oil and potato chips also exhibit at least eight-fold extension in the shelf life of these oxygen and moisture sensitive food products. Overall, these qualities have demonstrated the high potential of a sandwich-architectured PLA-graphene composite film for food packaging applications. PMID:27028268

  2. pH Sensitivity of Novel PANI/PVB/PS3 Composite Films

    Directory of Open Access Journals (Sweden)

    Olga Korostynska

    2007-12-01

    Full Text Available This paper reports on the results from the investigation into the pH sensitivity ofnovel PANI/PVB/PS3 composite films. The conductimetric sensing mode was chosen as itis one of the most promising alternatives to the mainstream pH-sensing methods and it is theleast investigated due to the popularity of other approaches. The films were deposited usingboth screen-printing and a drop-coating method. It was found that the best response to pHwas obtained from the screen-printed thick films, which demonstrated a change inconductance by as much as three orders of magnitude over the pH range pH2-pH11. Thedevices exhibited a stable response over 96 hours of operation. Several films were immersedin buffer solutions of different pH values for 96 hours and these were then investigated usingXPS. The resulting N 1s spectra for the various films confirmed that the change inconductance was due to deprotonation of the PANI polymer backbone. SEM andProfilometry were also undertaken and showed that no considerable changes in themorphology of the films took place and that the films did not swell or contract due toexposure to test solutions.

  3. Preparation, characterization and electrochromic properties of composite thin films incorporation of polyaniline

    Science.gov (United States)

    Farasat, Mahshid; Golzan, M. Maqsood; Farhadi, Khalil; Shojaei, S. H. Reza; Gheisvandi, Sorayya

    2016-05-01

    Two different electrochromic composite films consisting of aniline/sodium molybdate (S1) and aniline/ferric nitrate (S2) were obtained by electrochemical polymerization method on indium tin oxide (ITO) coated glass substrates in oxalic acid (H2C2O4ṡ2H2O) aqueous solution. The electrochromic properties of the resulting thin films were investigated by spectroelectrochemical measurement and cyclic voltammetry (CV). Under a square electrical potential, they show capacitive current characteristic and represent electrochromic performance, with maximum optical attenuations (ΔT%) of 30.8% at 355nm and 28.3% at 400nm for aniline/ferric nitrate and aniline/sodium molybdate thin films, respectively. Optical behavior of thin films was examined by UV-Vis spectrophotometry technique. The doped films indicated multiple color changes (yellow; green; and bluish green). The spectra also showed that produced layers have high absorption of UV radiation with respect to pure polyaniline (PANI) films. The optical band gap energy of PANI film decreased by dopant injection. Due to their decent transparency and electrochromic behavior, they are promising materials for electrochromic devices.

  4. Fabrication and Surface Properties of Composite Films of SAM/Pt/ZnO/SiO 2

    KAUST Repository

    Yao, Ke Xin

    2008-12-16

    Through synthetic architecture and functionalization with self-assembled monolayers (SAMs), complex nanocomposite films of SAM/Pt/ZnO/SiO2 have been facilely prepared in this work. The nanostructured films are highly uniform and porous, showing a wide range of tunable wettabilities from superhydrophilicity to superhydrophobicity (water contact angles: 0° to 170°). Our approach offers synthetic flexibility in controlling film architecture, surface topography, coating texture, crystallite size, and chemical composition of modifiers (e.g., SAMs derived from alkanethiols). For example, wettability properties of the nanocomposite films can be finely tuned with both inorganic phase (i.e., ZnO/SiO2 and Pt/ZnO/SiO2) and organic phase (i.e., SAMs on Pt/ZnO/SiO2). Due to the presence of catalytic components Pt/ZnO within the nanocomposites, surface reactions of the organic modifiers can further take place at room temperature and elevated temperatures, which provides a means for SAM formation and elimination. Because the Pt/ZnO forms an excellent pair of metal-semiconductors for photocatalysis, the anchored SAMs can also be modified or depleted by UV irradiation (i.e., the films possess self-cleaning ability). Potential applications of these nanocomposite films have been addressed. Our durability tests also confirm that the films are thermally stable and structurally robust in modification- regeneration cycles. © 2008 American Chemical Society.

  5. Fabrication and biocompatibility in vitro of potassium titanate biological thin film/titanium alloy biological composite

    Institute of Scientific and Technical Information of China (English)

    QI Yumin; HE Yun; CUI Chunxiang; LIU Shuangjin; WANG Huifen

    2007-01-01

    A potassium titanate biological thin film/titanium alloy biological composite was fabricated by way of bionic chemistry.The biocompatibility fn vitro of Ti-15Mo-3Nb and the potassium titanate biological thin film/titanium alloy was studied using simulated body fluid cultivation,kinetic clotting of blood and osteoblast cell cultivation experiments in vitro.By comparing the biological properties of both materials,the following conclusions can be obtained:(1)The deposition of a calcium phosphate layer was not found on the surface of Ti-15Mo-3Nb,so it was bioinert.Because the network of potassium titanate biological thin film could induce the deposition of a calcium phosphate layer,this showed that it had excellent bioactivity.(2)According to the values of kinetic clotting,the blood coagulation time of the potassium titanate biological thin film was more than that of Ti-15Mo-3Nb.It was obvious that the potassium titanate biological thin film possessed good hemocompatibility.(3)The cell compatibility of both materials was very good.However,the growth trend and multiplication of osteoblast cells on the surface of potassium titanate biological thin film was better,which made for the concrescence of wounds during the earlier period.As a result,the potassium titanate biological thin film/titanium alloy showed better biocompatibility and bioactivity.

  6. Composite film polarizer based on the oriented assembly of electrospun nanofibers.

    Science.gov (United States)

    Hu, Zhongliang; Ma, Zhijun; Peng, Mingying; He, Xin; Zhang, Hang; Li, Yang; Qiu, Jianrong

    2016-04-01

    Polarizers are widely applied in antiglare glasses, planner displays, photography filters and optical communications, etc. In this investigation, we propose a new strategy for the preparation of a flexible film polarizer based on the electrospinning technique. An aligned assembly of polyvinyl acetate (PVA) nanofibers was electrospun and collected by a fast-rotating drum, then soaked in polymethyl methacrylate (PMMA) solution and dried thoroughly to obtain a transparent PVA-PMMA composite film polarizer. The morphology, structure and optical performance of the PVA nanofibers and the film polarizers were characterized with a scanning electron microscope, UV-vis-IR spectrometer and polarized Raman spectra, etc. The PVA-PMMA film polarizer demonstrated efficient polarizing activity toward visible and near-infrared light, while keeping fair transparency in the range of 400-1400 nm. Due to the protection from the hydrophobic PMMA matrix, the PVA-PMMA film polarizers show high moisture resistance, making it applicable in a humid environment. Considering the scalability and versatility of the strategy employed here, the PVA-PMMA film polarizer prepared could replace the conventional film polarizers in a wide range of applications.

  7. Composite film polarizer based on the oriented assembly of electrospun nanofibers

    Science.gov (United States)

    Hu, Zhongliang; Ma, Zhijun; Peng, Mingying; He, Xin; Zhang, Hang; Li, Yang; Qiu, Jianrong

    2016-04-01

    Polarizers are widely applied in antiglare glasses, planner displays, photography filters and optical communications, etc. In this investigation, we propose a new strategy for the preparation of a flexible film polarizer based on the electrospinning technique. An aligned assembly of polyvinyl acetate (PVA) nanofibers was electrospun and collected by a fast-rotating drum, then soaked in polymethyl methacrylate (PMMA) solution and dried thoroughly to obtain a transparent PVA-PMMA composite film polarizer. The morphology, structure and optical performance of the PVA nanofibers and the film polarizers were characterized with a scanning electron microscope, UV-vis-IR spectrometer and polarized Raman spectra, etc. The PVA-PMMA film polarizer demonstrated efficient polarizing activity toward visible and near-infrared light, while keeping fair transparency in the range of 400-1400 nm. Due to the protection from the hydrophobic PMMA matrix, the PVA-PMMA film polarizers show high moisture resistance, making it applicable in a humid environment. Considering the scalability and versatility of the strategy employed here, the PVA-PMMA film polarizer prepared could replace the conventional film polarizers in a wide range of applications.

  8. Vibration analysis of magnetostrictive thin-film composite cantilever actuator

    Science.gov (United States)

    Xu, Yan; Shang, Xinchun

    2016-09-01

    The transverse vibration of a composed cantilever beam with magnetostrictive layer is analyzed, which is employed to simulate dynamic response of an actuator. The high-order shear deformation theory of beam and the coupling magnetoelastic constitutive relationship are introduced to construct the governing equations, all interface conditions between magnetostrictive film and elastic substrate as well as the free stress condition on the top and bottom surfaces of the beam can be satisfied. In order to demonstrate validity of the presented mathematical modeling, the verification examples are also given. Furthermore, the effect of geometry and material parameters on dynamic characteristics of magnetostrictive cantilever beam, such as the nature frequency and amplitude, is discussed. Moreover, through computing the magneto-mechanical coupling factor of the beam structure, the variation tendency curves of the factor along with different parameters and frequencies of magnetostrictive cantilever beam actuator have been presented. These numerical results should be useful for the design of beam-type with magnetostrictive thin-film actuators.

  9. Constitution of novel polyamic acid/polypyrrole composite films by in-situ electropolymerization

    International Nuclear Information System (INIS)

    The preparation and characterization of polyamic acid-polypyrrole (PAA/PPy) composite films are reported in this paper. The thin films were synthesized by electrochemical method from a solution containing controlled molar ratio of chemically synthesized polyamic acid (PAA) and pyrrole monomer. Homogenous films were obtained by incorporating PAA into electropolymerized polypyrrole (PPy) thin film. The concentration of PAA (1.37 × 10−6 M) was kept fixed throughout the composite ratio analysis, whilst the concentration of PPy was varied from 1.90 × 10−3 M to 9.90 × 10−3 M. The PAA/PPy thin films were electrodeposited at a glassy carbon electrode (GCE) and characterized using Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, Atomic force microscopy (AFM), Scanning electron microscopy (SEM) and voltammetry. The composition that best represented the homogenous incorporation of PAA into PPy matrix was observed at a PAA/PPy ratio of 1: 4.13 × 10−3. This composite was observed to have two sets of coupled peaks with formal potential 99 mV and 567 mV respectively. The De determined from cyclic voltammetry using the anodic peak currents were found to be twice as high (5.82 × 10−4 cm2/s) compared to the De calculated using the cathodic peak currents (2.60 × 10−4 cm2/s), indicating that the composite favours anodic electron mobility. Surface morphology and spectroscopy data support the formation of a homogenous polymer blend at the synthesis ratio of 1: 4.13 × 10−3

  10. Green synthesis of high conductivity silver nanoparticle-reduced graphene oxide composite films

    Energy Technology Data Exchange (ETDEWEB)

    Dinh, D.A. [School of Materials Science and Engineering, Pusan National University, San 30 Jangjeon-dong, Geumjeong-gu, Busan 609-735 (Korea, Republic of); Hui, K.S., E-mail: kshui@hanyang.ac.kr [Department of Mechanical Engineering, Hanyang University, 17 Haengdang-dong, Seongdong-gu, Seoul 133-791 (Korea, Republic of); Hui, K.N., E-mail: bizhui@pusan.ac.kr [School of Materials Science and Engineering, Pusan National University, San 30 Jangjeon-dong, Geumjeong-gu, Busan 609-735 (Korea, Republic of); Cho, Y.R. [School of Materials Science and Engineering, Pusan National University, San 30 Jangjeon-dong, Geumjeong-gu, Busan 609-735 (Korea, Republic of); Zhou, Wei [Department of Mechanical and Electrical Engineering, Xiamen University, Xiamen 361005 (China); Hong, Xiaoting [School of Chemistry and Environment, South China Normal University, Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education, Guangzhou 510006 (China); Chun, Ho-Hwan [Global Core Research Center for Ships and Offshore Plants (GCRC-SOP), Pusan National University, San 30 Jangjeon-dong, Geumjeong-gu, Busan 609-735 (Korea, Republic of)

    2014-04-01

    Graphical abstract: - Highlights: • A green facile chemical approach to control the dimensions of Ag nanoparticles–graphene oxide (AgNPs/GO) composites was performed at room temperature. • With decreasing ultrasonication time, the size of the Ag nanoparticles decreased and became uniformly distributed over the surface of the GO nanosheets. • The as-prepared AgNPs/rGO composite films were then formed using a spin coating method and reduced at 500 °C under N{sub 2}/H{sub 2} gas flow for 1 h. • The lowest sheet resistance of 270 Ω/sq was obtained in the film corresponding to 1 min of ultrasonication, which showed a 40 times lower resistivity than the rGO film (10.93 kΩ/sq). - Abstract: A green facile chemical approach to control the dimensions of Ag nanoparticles–graphene oxide (AgNPs/GO) composites was performed by the in situ ultrasonication of a mixture of AgNO{sub 3} and graphene oxide solutions with the assistance of vitamin C acting as an environmentally friendly reducing agent at room temperature. With decreasing ultrasonication time, the size of the Ag nanoparticles decreased and became uniformly distributed over the surface of the GO nanosheets. The as-prepared AgNPs/rGO composite films were then formed using a spin coating method and reduced at 500 °C under N{sub 2}/H{sub 2} gas flow for 1 h. Four-point probe measurements showed that the sheet resistance of the AgNPs/rGO films decreased with decreasing AgNPs size. The lowest sheet resistance of 270 Ω/sq was obtained in the film corresponding to 1 min of ultrasonication, which showed a 40 times lower resistivity than the rGO film (10.93 kΩ/sq). The formation mechanisms of the as-prepared AgNPs/rGO films are proposed. This study provides a guide to controlling the dimensions of AgNPs/rGO films, which might hold promise as advanced materials for a range of analytical applications, such as catalysis, sensors and microchips.

  11. Nickel-niobium alloy formation process of electroless nickel composite plating film using niobium nano-power

    International Nuclear Information System (INIS)

    Composite plating improves functionalities of wear resistance, corrosion resistance, lubricity, etc. through co-deposition with suitable particles. For this study, reactive metallic particles were introduced intentionally as a dispersant. Heat treatment was used to form an alloy with a plated matrix. Composite plating films were formed using electroless Ni-P plating with Nb powder of two types as dispersants: nanopowder (ca. 300 nm diameter) and micropowder (ca. 50 μm diameter). The composite plating film was alloyed using heat treatment at 800degC for 1 hour under vacuum conditions. X-ray diffraction (XRD) analysis confirmed that the proportion of alloy to reactive composite film with nanopowder was much larger than that with micropowder. Results of X-ray photoelectron spectroscopy (XPS) analyses suggest that a selective Nb oxide was formed on the composite film surface when using Nb nanopowder. On the other hand, almost no Nb micropowder was changed to alloy or oxide in the composite films. Using nanopowder, much of the composite plating film formed reactive composite plating film alloy during heat treatment. (author)

  12. Biomimetic heterogeneous multiple ion channels: a honeycomb structure composite film generated by breath figures

    Science.gov (United States)

    Han, Keyu; Heng, Liping; Wen, Liping; Jiang, Lei

    2016-06-01

    We design a novel type of artificial multiple nanochannel system with remarkable ion rectification behavior via a facile breath figure (BF) method. Notably, even though the charge polarity in the channel wall reverses under different pH values, this nanofluidic device displays the same ionic rectification direction. Compared with traditional nanochannels, this composite multiple ion channel device can be more easily obtained and has directional ionic rectification advantages, which can be applied in many fields.We design a novel type of artificial multiple nanochannel system with remarkable ion rectification behavior via a facile breath figure (BF) method. Notably, even though the charge polarity in the channel wall reverses under different pH values, this nanofluidic device displays the same ionic rectification direction. Compared with traditional nanochannels, this composite multiple ion channel device can be more easily obtained and has directional ionic rectification advantages, which can be applied in many fields. Electronic supplementary information (ESI) available: Pore size distribution histograms of the AAO substrates; SEM images of the side view of pure AAO membranes and top view of the flat PI/AAO composite film; the current-time curves of the flat composite film; the current-voltage characteristics curves of pure AAO nanochannels with different mean pore diameters; CA of the two surfaces of the composite PI/AAO film, the structural formula of the polymer polyimide resin (PI), and solid surface zeta potential. See DOI: 10.1039/c6nr02506d

  13. Electrical conductivity and electromagnetic interference shielding characteristics of multiwalled carbon nanotube filled polyacrylate composite films

    International Nuclear Information System (INIS)

    Multiwalled carbon nanotubes (MWCNTs) were homogeneously dispersed in pure acrylic emulsion by ultrasonication to prepare MWCNT/polyacrylate composites applied on building interior wall for electromagnetic interference (EMI) shielding applications. The structure and surface morphology of the MWCNTs and MWCNT/polyacrylate composites were studied by field emission scanning microscopy (FESEM) and transmission electron microscopy (TEM). The electrical conductivity at room temperature and EMI shielding effectiveness (SE) of the composite films on concrete substrate with different MWCNT loadings were investigated and the measurement of EMI SE was carried out in two different frequency ranges of 100-1000 MHz (radio frequency range) and 8.2-12.4 GHz (X-band). The experimental results show that a low mass concentration of MWCNTs could achieve a high conductivity and the EMI SE of the MWCNT/polyacrylate composite films has a strong dependence on MWCNTs content in both two frequency ranges. The SE is higher in X-band than that in radio frequency range. For the composite films with 10 wt.% MWCNTs, the EMI SE of experiment agrees well with that of theoretical prediction in far field

  14. Carrot fiber (CF) composite films for antioxidant preservation: Particle size effect.

    Science.gov (United States)

    Idrovo Encalada, Alondra M; Basanta, Maria F; Fissore, Eliana N; De'Nobili, Maria D; Rojas, Ana M

    2016-01-20

    The effect of particle size (53, 105 and 210 μm) of carrot fiber (CF) on their hydration properties and antioxidant capacity as well as on the performance of the CF-composite films developed with commercial low methoxyl pectin (LMP) was studied. It was determined that CF contained carotenoids and phenolics co-extracted with polysaccharides (80%), rich in pectins (15%). CF showed antioxidant activity and produced homogeneous calcium-LMP-based composites. The 53-μm-CF showed the lowest hydration capability and produced the least elastic and deformable composite film due probably to CF bridged by calcium-crosslinked LMP chains. Antioxidant activity associated to the loaded CF was found in composites. When L-(+)-ascorbic acid (AA) was also loaded, its hydrolytic stability increased with the decrease in CF-particle size, showing the lowest stability in the 0%-CF- and 210 μm-CF-LMP films. Below ≈ 250 μm, the particle size determined the hydration properties of pectin-containing CF, affecting the microstructure and water mobility in composites. PMID:26572445

  15. Nanoscale electrical and mechanical characteristics of conductive polyaniline network in polymer composite films.

    Science.gov (United States)

    Jafarzadeh, Shadi; Claesson, Per M; Sundell, Per-Erik; Pan, Jinshan; Thormann, Esben

    2014-11-12

    The presence and characteristics of a connected network of polyaniline (PANI) within a composite coating based on polyester acrylate (PEA) has been investigated. The bulk electrical conductivity of the composite was measured by impedance spectroscopy. It was found that the composite films containing PANI have an electrical conductivity level in the range of semiconductors (order of 10(-3) S cm(-1)), which suggests the presence of a connected network of the conductive phase. The nanoscopic distribution of such a network within the cured film was characterized by PeakForce tunneling atomic force microscopy (AFM). This method simultaneously provides local information about surface topography and nanomechanical properties, together with electrical conductivity arising from conductive paths connecting the metallic substrate to the surface of the coating. The data demonstrates that a PEA-rich layer exists at the composite-air interface, which hinders the conductive phase to be fully detected at the surface layer. However, by exposing the internal structure of the composites using a microtome, a much higher population of a conductive network of PANI, with higher elastic modulus than the PEA matrix, was observed and characterized. Local current-voltage (I-V) spectroscopy was utilized to investigate the conduction mechanism within the nanocomposite films, and revealed non-Ohmic characteristics of the conductive network. PMID:25295701

  16. Electrical conductivity and electromagnetic interference shielding characteristics of multiwalled carbon nanotube filled polyacrylate composite films

    Energy Technology Data Exchange (ETDEWEB)

    Li Yong [Navy Logistic Technology and Equipment Institute of PLA, Beijing 100072 (China)], E-mail: liyong1897@163.com; Chen Changxin [National Key Laboratory of Nano/Micro Fabrication Technology, Key Laboratory for Thin Film and Microfabrication of the Ministry of Education, Institute of Micro/Nano Science and Technology, Shanghai Jiao Tong University, Shanghai 200240 (China)], E-mail: chen.c.x@hotmail.com; Zhang Song; Ni Yuwei; Huang Jie [Navy Logistic Technology and Equipment Institute of PLA, Beijing 100072 (China)

    2008-07-15

    Multiwalled carbon nanotubes (MWCNTs) were homogeneously dispersed in pure acrylic emulsion by ultrasonication to prepare MWCNT/polyacrylate composites applied on building interior wall for electromagnetic interference (EMI) shielding applications. The structure and surface morphology of the MWCNTs and MWCNT/polyacrylate composites were studied by field emission scanning microscopy (FESEM) and transmission electron microscopy (TEM). The electrical conductivity at room temperature and EMI shielding effectiveness (SE) of the composite films on concrete substrate with different MWCNT loadings were investigated and the measurement of EMI SE was carried out in two different frequency ranges of 100-1000 MHz (radio frequency range) and 8.2-12.4 GHz (X-band). The experimental results show that a low mass concentration of MWCNTs could achieve a high conductivity and the EMI SE of the MWCNT/polyacrylate composite films has a strong dependence on MWCNTs content in both two frequency ranges. The SE is higher in X-band than that in radio frequency range. For the composite films with 10 wt.% MWCNTs, the EMI SE of experiment agrees well with that of theoretical prediction in far field.

  17. Synthesis and characterizations of microwave sintered ferrite powders and their composite films for practical applications

    Science.gov (United States)

    Shannigrahi, S. R.; Pramoda, K. P.; Nugroho, F. A. A.

    2012-01-01

    Phase pure single phase ferrite powders of (NixR1-x)0.5Zn0.5Fe2O4 (R=Mn, Co, Cu; x=0, 0.5) were manufactured using microwave sintering at 930 °C for 10 min in air atmosphere. The powders were characterized for their structure, microstructure, thermal, and magnetic properties. Selected powders were used as fillers to prepare their composite films using polymethyl methacrylate polymers as matrix. The composite films were prepared using the melt blending approach and were tested for their microstructure, thermal, and magnetic hysteresis loop as well as 3D magnetic field space mappings using an electromagnetic compatibility scanner. Among the studied ferrites, cobalt doped ferrites and their composites showed the best electromagnetic interference (EMI) shielding effectiveness value and have potential for practical EMI shielding applications.

  18. Enhanced mechanical properties and morphological characterizations of poly(vinyl alcohol) carbon nanotube composite films

    Science.gov (United States)

    Chen, Wei; Tao, Xiaoming; Xue, Pu; Cheng, Xiaoyin

    2005-12-01

    Tensile tests were carried out on free-standing composite films of poly(vinyl alcohol) (PVA) and multiwall carbon nanotubes (MWNTs) for different loading levels. Results show that overall mechanical properties of the composite were greatly improved as compared to the neat PVA film. For PVA-based materials at significant high loading level such as 9.1 wt.% MWNTs, considerable increases in Young's modulus, tensile strength and toughness by factors of 4.5, 2.7 and 4.1, respectively, were achieved. Raman, SEM, TEM, and DSC techniques were used to evaluate the PVA/MWNTs composite system. Strong acid-modification of the pristine MWNTs and the subsequent ultrasonication processing allowed good distribution of the nanotubes in the matrix. SEM together with DSC result shows apparent good wetting of the nanotubes by the PVA matrix, which are supportive of good interfacial bonding between the modified carbon nanotubes and the hosting polymer matrix.

  19. Minocycline-loaded cellulose nano whiskers/poly(sodium acrylate) composite hydrogel films as wound dressing.

    Science.gov (United States)

    Bajpai, S K; Pathak, V; Soni, Bhawna

    2015-08-01

    In this work, antibiotic drug Minocycline (Mic) loaded cellulose nano-whiskers (CNWs)/poly(sodium acrylate) hydrogel films were prepared and investigated for their drug releasing capacity in physiological buffer solution (PBS) at 37 °C. The (CNWs)/poly(sodium acrylate) film, containing 9.7% (w/w) of CNWs, demonstrated Mic release of 2500 μg/g while the plain poly(acrylate) film showed 3100 μg/g of drug release. In addition, with the increase in the concentration of cross-linker N,N'-methylene bisacrylamide (MB) from to, the drug release from the resulting films decreased from 507 to 191 μg/g. The release exponent 'n' for films with different compositions was found in the range of 0.45 to 0.89, thus indicating non-Fickian release mechanism. The Schott model was employed to interpret the kinetic drug release data successfully. The film samples poly(SA) and CNWs/poly(SA) (both not containing drug) showed thrombus formation of 0.010±0.001 g and 0.007±0.001 g, respectively, thus showing the non-thrombogenic behavior. In percent Hemolysis, both of the film samples of 1.136±0.012 and 0.5±0.020, respectively, thus indicating non-hemolytic behavior. In addition, both of the film samples demonstrated protein adsorption of 49.02±0.59μ g/μL and 51.20±0.51 μg/μL per cm(2), thus revealing a fair degree of protein adsorption. Finally, the Mic-loaded films showed fair anti-fungal and antibacterial properties.

  20. /UV Synergistic Aging of Polyester Polyurethane Film Modified by Composite UV Absorber

    Directory of Open Access Journals (Sweden)

    Yanzhi Wang

    2013-01-01

    Full Text Available The pure polyester polyurethane (TPU film and the modified TPU (M-TPU film containing 2.0 wt.% inorganic UV absorbers mixture (nano-ZnO/CeO2 with weight ratio of 3 : 2 and 0.5 wt.% organic UV absorbers mixture (UV-531/UV-327 with weight ratio of 1 : 1 were prepared by spin-coating technique. The accelerated aging tests of the films exposed to constant UV radiation of 400 ± 20 µW/cm2 (313 nm with an ozone atmosphere of 100 ± 2 ppm were carried out by using a self-designed aging equipment at ambient temperature and relative humidity of 20%. The aging resistance properties of the films were evaluated by UV-Vis spectra, Fourier transform infrared spectra (FT-IR, photooxidation index, and carbonyl index analysis. The results show that the composite UV absorber has better protection for TPU system, which reduces distinctly the degradation of TPU film. O3/UV aging of the films increases with incremental exposure time. PI and CI of TPU and M-TPU films increase with increasing exposure time, respectively. PI and CI of M-TPU films are much lower than that of TPU film after the same time of exposure, respectively. Distinct synergistic aging effect exists between ozone aging and UV aging when PI and CI are used as evaluation index, respectively. Of course, the formula of these additives needs further improvement for industrial application.

  1. Polyethylene/silver-nanofiber composites: A material for antibacterial films.

    Science.gov (United States)

    Zapata, Paula A; Larrea, Maialen; Tamayo, Laura; Rabagliati, Franco M; Azócar, M Ignacio; Páez, Maritza

    2016-12-01

    Silver nanofibers (Ag-Nfbs)~80nm in diameter were synthesized by hydrothermal treatment. The nanofibers (3 and 5wt%) were added in the initial feed together with the catalytic system. Polymerizations in an ethylene atmosphere were performed, yielding PE nanocomposites in situ with 3 and 5wt% content of Ag-Nfbs. The antibacterial effect of the silver-nanofiber composites was evaluated after incubation of Escherichia coli ATCC 25923 for 8h on their surface. Bacterial viability tests showed that the silver-nanofiber composites inhibited the growth of Escherichia coli ATCC 25923 by 88 and 56%. This behavior is attributed to increased silver ions release from the nanocomposite. TEM analysis showed that the antibacterial effect is associated with membrane disruption but not with changes in shape. PMID:27612828

  2. Controllable coherent perfect absorption in a composite film

    CERN Document Server

    Dutta-Gupta, Shourya; Gupta, S Dutta; Agarwal, G S

    2011-01-01

    We exploit the versatility provided by metal--dielectric composites to demonstrate controllable coherent perfect absorption (CPA) in a slab of heterogeneous medium. The slab is illuminated by coherent light from both sides, at the same angle of incidence and the conditions required for CPA are investigated as a function of the different geometrical parameters. The simultaneous realization of CPA at two distinct frequencies is also shown. Finally, our calculations clearly elucidate the role of absorption as a necessary prerequisite for CPA.

  3. Sol-gel derived bioactive hydroxyapatite/titania composite films on Ti6Al4V

    Institute of Scientific and Technical Information of China (English)

    Bing Su; Guoqing Zhang; Xudong Yu; Chengtao Wang

    2006-01-01

    The composite films consisting of the titania gel impregnated with hydroxyapatite (HAP) submicron particles were prepared on commercial Ti6Al4V plates processed by a sol-gel route. HAP powders were synthesized based on wet chemical precipitation method with Ca(NO3)2.4H2O and (NH4)2HPO4 as starting reagents. After being calcined at 900℃, HAP powders were ultrasonically scattered in ethanol to produce HAP sol. The titania sol was prepared using titanium (Ⅳ) isopropoxide {Ti[OCH(CH3)2]4} as precursor. Both the titania sol and the HAP/titania mixture were sequentially spin-coated on the substrates and calcined at various temperatures.The characteristics and mechanical adhesion of the composite films were investigated. The results show that the as-prepared films are dense, homogeneous, well-crystallized, and there is a good interfacial adhesion between the film and the substrate. The in vitro bioactivities of these films were discussed based on the analysis of the variations of Ca and P concentrations in the simulated body fluid and their surface morphologies against immersion time.

  4. Co nanoparticles induced resistive switching and magnetism for the electrochemically deposited polypyrrole composite films.

    Science.gov (United States)

    Xu, Zedong; Gao, Min; Yu, Lina; Lu, Liying; Xu, Xiaoguang; Jiang, Yong

    2014-10-22

    The resistive switching behavior of Co-nanoparticle-dispersed polypyrrole (PPy) composite films is studied. A novel design method for resistive random access memory (ReRAM) is proposed. The conducting polymer films with metal nanocrystal (NC)-dispersed carbon chains induce the spontaneous oxidization of the conducting polymer at the surface. The resistive switching behavior is achieved by an electric field controlling the oxygen ion mobility between the metal electrode and the conducting polymer film to realize the mutual transition between intrinsic conduction (low resistive state) and oxidized layer conduction (high resistive state). Furthermore, the formation process of intrinsic conductive paths can be effectively controlled in the conducting polymer ReRAM using metal NCs in films because the inner metal NCs induce electric field lines converging around them and the intensity of the electric field at the tip of NCs can greatly exceed that of the other region. Metal NCs can also bring new characteristics for ReRAM, such as magnetism by dispersing magnetic metal NCs in polymer, to obtain multifunctional electronic devices or meet some special purpose in future applications. Our works will enrich the application fields of the electromagnetic PPy composite films and present a novel material for ReRAM devices.

  5. Effects of rf power on chemical composition and surface roughness of glow discharge polymer films

    Science.gov (United States)

    Zhang, Ling; He, Xiaoshan; Chen, Guo; Wang, Tao; Tang, Yongjian; He, Zhibing

    2016-03-01

    The glow discharge polymer (GDP) films for laser fusion targets were successfully fabricated by plasma enhanced chemical vapor deposition (PECVD) at different radio frequency (rf) powers. The films were deposited using trans-2-butene (T2B) mixed with hydrogen as gas sources. The composition and state of plasma were diagnosed by quadrupole mass spectrometer (QMS) and Langmuir probe during the deposition process. The composition, surface morphology and roughness were investigated by Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM) and white-light interferometer (WLI), respectively. Based on these observation and analyses, the growth mechanism of defects in GDP films were studied. The results show that, at low rf power, there is a larger probability for secondary polymerization and formation of multi-carbon C-H species in the plasma. In this case, the surface of GDP film turns to be cauliflower-like. With the increase of rf power, the degree of ionization is high, the relative concentration of smaller-mass hydrocarbon species increases, while the relative concentration of larger-mass hydrocarbon species decreases. At higher rf power, the energy of smaller-mass species are high and the etching effects are strong correspondingly. The GDP film's surface roughness shows a trend of decrease firstly and then increase with the increasing rf power. At rf power of 30 W, the surface root-mean-square roughness (Rq) drops to the lowest value of 12.8 nm, and no "void" defect was observed.

  6. Effect of electrodeposition potential on composition and morphology of CIGS absorber thin film

    Indian Academy of Sciences (India)

    N D Sang; P H Quang; L T Tu; D T B Hop

    2013-08-01

    CuInGaSe (CIGS) thin films were deposited on Mo/soda-lime glass substrates by electrodeposition at different potentials ranging from −0.3 to −1.1 V vs Ag/AgCl. Cyclic voltammetry (CV) studies of unitary Cu, Ga, In and Se systems, binary Cu–Se, Ga–Se and In–Se systems and quaternary Cu–In–Ga–Se were carried out to understand the mechanism of deposition of each constituent. Concentration of the films was determined by energy dispersive spectroscopy. Structure and morphology of the films were characterized by X-ray diffraction and scanning electron microscope. The underpotential deposition mechanism of Cu–Se and In–Se phases was observed in voltammograms of binary and quaternary systems. Variation in composition with applied potentials was explained by cyclic voltammetry (CV) data. A suitable potential range from −0.8 to −1.0 V was found for obtaining films with desired and stable stoichiometry. In the post-annealing films, chalcopyrite structure starts forming in the samples deposited at −0.5 V and grows on varying the applied potential towards negative direction. By adjusting the composition of electrolyte, we obtained the desired stoichiometry of Cu(In0.7Ga0.3)Se2.

  7. Laboratory analogues simulating Titan's atmospheric aerosols: Compared chemical compositions of grains and thin films

    Science.gov (United States)

    Carrasco, Nathalie; Jomard, François; Vigneron, Jackie; Etcheberry, Arnaud; Cernogora, Guy

    2016-09-01

    Two sorts of solid organic samples can be produced in laboratory experiments simulating Titan's atmospheric reactivity: grains in the volume and thin films on the reactor walls. We expect that grains are more representative of Titan's atmospheric aerosols, but films are used to provide optical indices for radiative models of Titan's atmosphere. The aim of the present study is to address if these two sorts of analogues are chemically equivalent or not, when produced in the same N2-CH4 plasma discharge. The chemical compositions of both these materials are measured by using elemental analysis, XPS analysis and Secondary Ion Mass Spectrometry. The main parameter probed is the CH4/N2 ratio to explore various possible chemical regimes. We find that films are homogeneous but significantly less rich in nitrogen and hydrogen than grains produced in the same experimental conditions. This surprising difference in their chemical compositions could be explained by the efficient etching occurring on the films, which stay in the discharge during the whole plasma duration, whereas the grains are ejected after a few minutes. The higher nitrogen content in the grains possibly involves a higher optical absorption than the one measured on the films, with a possible impact on Titan's radiative models.

  8. Tuning the optical bandgap of TiO2-TiN composite films as photocatalyst in the visible light

    Directory of Open Access Journals (Sweden)

    Zheng Xie

    2013-06-01

    Full Text Available TiO2-TiN composite catalysts were prepared by oxidizing the TiN films in air at 350 °C. By adjusting the oxidation time to control the oxidation stage of TiN films, the optical band gap of the TiO2-TiN composites can be varied in a wide range from 1.68 eV to 3.23 eV. These composite films all showed red shift in photo-response towards the visible region, and depending on the optical band gap, some composite films exhibited good catalytic activity in the visible light region. This study provides a simple but effective method to prepare film photocatalyst working in visible light.

  9. An effective combination of electrodeposition and layer-by-layer assembly to construct composite films with luminescence switching behavior.

    Science.gov (United States)

    Gao, Wenmei; Ma, Hongwei; Zheng, Daming; Dong, Zhaojun; Wu, Lixin; Bi, Lihua

    2015-09-01

    This article presents a combination strategy of electrodeposition and a layer-by-layer assembly to fabricate functional composite films with luminescence switching behavior. Firstly, a novel green luminescence film consisting of 8-hydroxypyrene-1,3,6-trisulfonic acid trisodium salt (HOPTS) was first obtained on ITO by a facile electrodeposition method. Then, the multilayer films containing different layers of tungstophosphate K12.5Na1.5[NaP5W30O110]·15H2O (P5W30) were further fabricated on the green luminescence film to form the composite films [(HOPTS)50/(PDDA/P5W30)n] (n = 10, film 1; n = 27, film 2; n = 57, film 3). Cyclic voltammetry and fluorescence spectroscopy were used to characterize the electrochemical activity of P5W30 and the luminescence property of HOPTS in the composite films, respectively. Lastly, in situ UV-Vis spectroelectrochemical and fluorescence spectroelectrochemical measurements were applied to investigate the luminescence switching behaviors of the composite films controlled by the electrochromism component of P5W30 upon electrochemical modulation. In summary, the investigation results revealed that the electrodeposition method is convenient and rapid, and thus-prepared composite films showed improved luminescence switching performance in terms of switching process, activation cycles, coloration efficiency, and bleached-state transparency as well as good stability, wide voltage range and good reversibility. Therefore, the present study offers a new fabrication route for the multifunctional composite films through an effective combination of electrodeposition and layer-by-layer assembly technique. PMID:26219637

  10. Effect of crystalline microstructure on the photophysical performance of polymer/perylene composite films

    Institute of Scientific and Technical Information of China (English)

    封伟; 徐友龙; 易文辉; 周峰; 王晓工; 吉野勝美

    2003-01-01

    To obtain high carrier mobility, better charge injection capability, and high photovoltaic device conversion efficiency, a powerful strategy is to improve the morphology of the polymer/dye composite films. Conjugated conducting polymer (CP) thin films doped with perylene derivative (PV) of various concentrations were prepared by spin-casting method, and their morphology and photovoltaic characteristics were examined. The change in morphology and molecular reorientation occurring in CP-PV composite films upon annealing at different temperatures was investigated using scanning electron microscopy, x-ray diffraction, Fourier transform infrared and UV-vis absorption. By changing the annealing temperature, PV microcrystallines of 8-10μm in size lying parallel to the substrate surface can be obtained.Annealing effect improved the photovoltaic performance of ITO/CP-PV/A1 Schottky-type solar cells, which can be attributed to the formation of an electron conducting PV crystal network. Preliminary studies indicate that the morphological structure in CP-PV composite films has an important influence to their photovoltaic properties.

  11. Effect of crystalline microstructure on the photophysical performance of polymer/perylene composite films

    Institute of Scientific and Technical Information of China (English)

    FengWei; XuYou-Long; YiWen-Hui; ZhouFeng; WangXiao-Gong; YoshinoKatsumi

    2003-01-01

    To obtain high carrier mobility, better charge injection capability, and high photovoltaic device conversion efficiency a powerful stratergy is to improve the morphology of the polymer/dye composite films. Conjugated conducting polymer (CP) thin films doped with perylene derivative (PV) of various concentrations were prepared by spin-casting method, and their morphology and photovoltaic characteristics were examined. The change in morphology and molecular reorientation occurring in CP-PV composite films upon annealing at different temperatures was investigated using scanning electron microscopy, x-ray diffraction, Fourier transform infrared and UV-vis absorption. By changing the annealing temperature, PV microcrystallines of 8-10μm in size lying parallel to the substrate surface can be obtained. Annealing effect improved the photovoltaic performance of ITO/CP-PV/Al Schottky-type solar cells, which can be attributed to the formation of an electron conducting PV crystal network. Preliminary studies indicate that the morphological structure in CP-PV composite films has an important influence to their photovoltaic properties.

  12. Polylactide-based renewable composites from natural products residues by encapsulated film bag: characterization and biodegradability.

    Science.gov (United States)

    Wu, Chin-San

    2012-09-01

    In the present study, the biodegradability, morphology, and mechanical properties of composite materials consisting of acrylic acid-grafted polylactide (PLA-g-AA) and natural products residues (corn starch, CS) were evaluated. Composites containing acrylic acid-grafted PLA (PLA-g-AA/CS) exhibited noticeably superior mechanical properties due to their greater compatibility with CS compared with PLA/CS. The feasibility of using PLA-g-AA/CS as a film bag material to facilitate the controlled release of an encapsulated phosphate-solubilizing bacterium (PSB) Burkholderia cepacia as a fertilizer use promoter was then evaluated. For purposes of comparison and accurate characterization, a PLA film bag was also assessed. The results showed that the bacterium completely degraded both the PLA and the PLA-g-AA/CS composite film bags, resulting in cell release. The PLA-g-AA/CS (20 wt%) film bags were more biodegradable than those made of PLA, and displayed a higher loss of molecular weight and intrinsic viscosity, indicating a strong connection between these characteristics and biodegradability. PMID:24751080

  13. Low temperature charge transport and microwave absorption of carbon coated iron nanoparticles–polymer composite films

    International Nuclear Information System (INIS)

    Highlights: ► Carbon coated Fe nanoparticle–PVC composite films were prepared by solution casting method. ► A low electrical percolation threshold of 2.2 was achieved. ► The low temperature electrical conductivity follows variable range hopping type conduction. ► An EMI shielding of 18 dB was achieved in 200 micron thick film. -- Abstract: In this paper, the low temperature electrical conductivity and microwave absorption properties of carbon coated iron nanoparticles–polyvinyl chloride composite films are investigated for different filler fractions. The filler particles are prepared by the pyrolysis of ferrocene at 980 °C and embedded in polyvinyl chloride matrix. The high resolution transmission electron micrographs of the filler material have shown a 5 nm thin layer graphitic carbon covering over iron particles. The room temperature electrical conductivity of the composite film changes by 10 orders of magnitude with the increase of filler concentration. A percolation threshold of 2.2 and an electromagnetic interference shielding efficiency (EMI SE) of ∼18.6 dB in 26.5–40 GHz range are observed for 50 wt% loading. The charge transport follows three dimensional variable range hopping conduction.

  14. Preparation and photocatalytic activity of cuprous oxide/carbon nanofibres composite films

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yuanqian; Liu, Lin; Cai, Yurong; Chen, Jianjun [The Key Laboratory of Advanced Textile Materials and Manufacturing Technology of Ministry of Education, College of Materials and Textiles, Zhejiang Sci-Tech University, Xiasha Higher Education Park, Hangzhou 310018 (China); Yao, Juming, E-mail: yaoj@zstu.edu.cn [The Key Laboratory of Advanced Textile Materials and Manufacturing Technology of Ministry of Education, College of Materials and Textiles, Zhejiang Sci-Tech University, Xiasha Higher Education Park, Hangzhou 310018 (China)

    2013-04-01

    Cuprous oxide (Cu{sub 2}O) nanocrystals have been successfully synthesized using copper acetate as precursors via a polyol process. The as-synthesized products were easily deposited on the surface of carbon nanofibres (CNFs) and then were characterized through XRD, FESEM, TEM and FTIR, etc. The photocatalytic performance of these composite films was evaluated using methyl orange as a model organic compound under visible light irradiation. Results showed that the shape of Cu{sub 2}O nanparticles could be changed from irregular nanoparticle to cubic, flower-like particle assembled by Cu{sub 2}O nanocubes with the change of the reaction conditions. All of these Cu{sub 2}O/CNFs composite films showed the satisfied photocatalytic activity to methyl orange even after 3 cycles of degradation experiment due to the protectable function of carbon fibre films to the Cu{sub 2}O nanocrystals. The Cu{sub 2}O/CNFs composite films may offer a feasible method for the potential application of Cu{sub 2}O nanocrystals in the treatment of organic contamination.

  15. PMN-PT-PZT composite films for high frequency ultrasonic transducer applications.

    Science.gov (United States)

    Hsu, Hsiu-Sheng; Benjauthrit, Vatcharee; Zheng, Fan; Chen, Rumin; Huang, Yuhong; Zhou, Qifa; Shung, K Kirk

    2012-06-01

    We have successfully fabricated x(0.65PMN-0.35PT)-(1 - x)PZT (xPMN-PT-(1 - x)PZT), where x is 0.1, 0.3, 0.5, 0.7 and 0.9, thick films with a thickness of approximately 9 µm on platinized silicon substrate by employing a composite sol-gel technique. X-ray diffraction analysis and scanning electron microscopy revealed that these films are dense and creak-free with well-crystallized perovskite phase in the whole composition range. The dielectric constant can be controllably adjusted by using different compositions. Higher PZT content of xPMN-PT-(1 - x)PZT films show better ferroelectric properties. A representative 0.9PMN-PT-0.1PZT thick film transducer is built. It has 200 MHz center frequency with a -6 dB bandwidth of 38% (76 MHz). The measured two-way insertion loss is 65 dB. PMID:23750072

  16. Preparation and photocatalytic activity of cuprous oxide/carbon nanofibres composite films

    International Nuclear Information System (INIS)

    Cuprous oxide (Cu2O) nanocrystals have been successfully synthesized using copper acetate as precursors via a polyol process. The as-synthesized products were easily deposited on the surface of carbon nanofibres (CNFs) and then were characterized through XRD, FESEM, TEM and FTIR, etc. The photocatalytic performance of these composite films was evaluated using methyl orange as a model organic compound under visible light irradiation. Results showed that the shape of Cu2O nanparticles could be changed from irregular nanoparticle to cubic, flower-like particle assembled by Cu2O nanocubes with the change of the reaction conditions. All of these Cu2O/CNFs composite films showed the satisfied photocatalytic activity to methyl orange even after 3 cycles of degradation experiment due to the protectable function of carbon fibre films to the Cu2O nanocrystals. The Cu2O/CNFs composite films may offer a feasible method for the potential application of Cu2O nanocrystals in the treatment of organic contamination.

  17. Amine Enrichment of Thin-Film Composite Membranes via Low Pressure Plasma Polymerization for Antimicrobial Adhesion.

    Science.gov (United States)

    Reis, Rackel; Dumée, Ludovic F; He, Li; She, Fenghua; Orbell, John D; Winther-Jensen, Bjorn; Duke, Mikel C

    2015-07-15

    Thin-film composite membranes, primarily based on poly(amide) (PA) semipermeable materials, are nowadays the dominant technology used in pressure driven water desalination systems. Despite offering superior water permeation and salt selectivity, their surface properties, such as their charge and roughness, cannot be extensively tuned due to the intrinsic fabrication process of the membranes by interfacial polymerization. The alteration of these properties would lead to a better control of the materials surface zeta potential, which is critical to finely tune selectivity and enhance the membrane materials stability when exposed to complex industrial waste streams. Low pressure plasma was employed to introduce amine functionalities onto the PA surface of commercially available thin-film composite (TFC) membranes. Morphological changes after plasma polymerization were analyzed by SEM and AFM, and average surface roughness decreased by 29%. Amine enrichment provided isoelectric point changes from pH 3.7 to 5.2 for 5 to 15 min of plasma polymerization time. Synchrotron FTIR mappings of the amine-modified surface indicated the addition of a discrete 60 nm film to the PA layer. Furthermore, metal affinity was confirmed by the enhanced binding of silver to the modified surface, supported by an increased antimicrobial functionality with demonstrable elimination of E. coli growth. Essential salt rejection was shown minimally compromised for faster polymerization processes. Plasma polymerization is therefore a viable route to producing functional amine enriched thin-film composite PA membrane surfaces.

  18. Eco-nano composite films containing copper as potential antimicrobial active packaging

    Energy Technology Data Exchange (ETDEWEB)

    Bruna, Julio E.; Gonzalez, Valeska; Rodriguez, Francisco; Guarda, Abel; Galotto, Maria Jose, E-mail: julio.bruna@usach.cl [Center for the Development of Nanoscience and Nanotechnology, Packaging Laboratory, University of Santiago de Chile. Santiago (Chile)

    2011-07-01

    The antimicrobial efficiency of Cellulose Acetate/MMTCu and Chitosan/MMTCu nano composites against Escherichia Coli 0157:H7 n/t has been studied in the present work. The MMT modified with copper were obtained using cation interchange in solution and the nano composites films were prepared using casting solution technique, being the biodegradable polymer (Cellulose Acetate or Chitosan) the main component and the montmorillonite modified with copper, the minority component. Characterization of MMTCu and the nano composites (CA/MMTCu and Ch/MMTCu), were carried out using XRD, AA, TGA, DSC and microbiological analysis. The nano composites showed to be more stable at higher temperature, resulting from the incorporation of MMTCu into the polymer. On the other hand, the results indicated that the antibacterial effect of nano composite increased with the proportion of MMTCu added. (author)

  19. Bioelectrochemical Response and Kinetics of Choline Oxidase Entrapped in Polyaniline—Polyacrylonitrile Composite Film

    Institute of Scientific and Technical Information of China (English)

    薛怀国; 沈芝荃

    2002-01-01

    A novel choline oxidase electrode was constructed by entrapping choline oxidase into polyaniline-polyacrylonitrile composite film,The enzyme film was prepared by in situ electropolyme-ritztion of aniline into porous polyacrylonitrile-coated platinum electrode in the presence of choline oxidase ,the enzyme electrode exhibited sensitive and stable electrochemical response to choline ,The kinetics analysis,showed that the mass transport is partially rate-liniting.The influences of pH,applied potential and temperature on the response of the enzyme electrode were also desribed.

  20. Nonlinear photoinduced anisotropy and modifiable optical image display in a bacteriorhodopsin/polymer composite film

    Science.gov (United States)

    Wei, Lai; Luo, Jia; Zhu, Jiang; Lu, Ming; Zhao, You-yuan; Ma, De-wang; Ding, Jian-dong

    2007-04-01

    The nonlinear photoinduced anisotropy with large birefringence in a bacteriorhodopsin/polymer composite (bR/PC) film was observed. The contrast ratio, a ratio of the maximum to the minimum intensity of transmitted probe light through the bR/PC film within the linear gray scale range could reach ˜350:1. An all-optical image display in different colors was performed. The intensity of the transmitted signal could be modulated by adjusting the multibeam polarization states and intensities. Therefore, the positive image, negative image, and image erasure in display were demonstrated.

  1. Bioelectrochemical Response and Kinetics of Choline Oxidase Entrapped in Polyaniline-Polyacrylonitrile Composite Film

    Institute of Scientific and Technical Information of China (English)

    XUE,Huai-Guo(薛怀国); SHEN,Zhi-Quan(沈之荃)

    2002-01-01

    A novel choline oxidase electrode was constructed by entrapping choline oxidase into polyaniline-polyacrylonitrile composite film. The enzyme film was prepared by in situ electropolymerization of aniline into porous polyacrylonitrile-coated platinum electrode in the presence of choline oxidase. The enzyme electrode exhibited sensitive and stable electrochemical response to choline. The kinetics analysis showed that the mass transport is partially rate-limiting. The influences of pH, applied potential and temperature on the response of the enzyme electrode were also described.

  2. Optimal composition of europium gallium oxide thin films for device applications

    International Nuclear Information System (INIS)

    Europium gallium oxide (EuxGa1-x)2O3 thin films were deposited on sapphire substrates by pulsed laser deposition with varying Eu content from x=2.4 to 20 mol %. The optical and physical effects of high europium concentration on these thin films were studied using photoluminescence (PL) spectroscopy, x-ray diffraction (XRD), and Rutherford backscattering spectrometry. PL spectra demonstrate that emission due to the 5D0 to 7FJ transitions in Eu3+ grows linearly with Eu content up to 10 mol %. Time-resolved PL indicates decay parameters remain similar for films with up to 10 mol % Eu. At 20 mol %, however, PL intensity decreases substantially and PL decay accelerates, indicative of parasitic energy transfer processes. XRD shows films to be polycrystalline and beta-phase for low Eu compositions. Increasing Eu content beyond 5 mol % does not continue to modify the film structure and thus, changes in PL spectra and decay cannot be attributed to structural changes in the host. These data indicate the optimal doping for optoelectronic devices based on (EuxGa1-x)2O3 thin films is between 5 and 10 mol %.

  3. Water-in-model oil emulsions studied by small-angle neutron scattering: interfacial film thickness and composition.

    Science.gov (United States)

    Verruto, Vincent J; Kilpatrick, Peter K

    2008-11-18

    The ever-increasing worldwide demand for energy has led to the upgrading of heavy crude oil and asphaltene-rich feedstocks becoming viable refining options for the petroleum industry. Traditional problems associated with these feedstocks, particularly stable water-in-petroleum emulsions, are drawing increasing attention. Despite considerable research on the interfacial assembly of asphaltenes, resins, and naphthenic acids, much about the resulting interfacial films is not well understood. Here, we describe the use of small-angle neutron scattering (SANS) to elucidate interfacial film properties from model emulsion systems. Modeling the SANS data with both a polydisperse core/shell form factor as well as a thin sheet approximation, we have deduced the film thickness and the asphaltenic composition within the stabilizing interfacial films of water-in-model oil emulsions prepared in toluene, decalin, and 1-methylnaphthalene. Film thicknesses were found to be 100-110 A with little deviation among the three solvents. By contrast, asphaltene composition in the film varied significantly, with decalin leading to the most asphaltene-rich films (30% by volume of the film), while emulsions made in toluene and methylnaphthalene resulted in lower asphaltenic contents (12-15%). Through centrifugation and dilatational rheology, we found that trends of decreasing water resolution (i.e., increasing emulsion stability) and increasing long-time dilatational elasticity corresponded with increasing asphaltene composition in the film. In addition to the asphaltenic composition of the films, here we also deduce the film solvent and water content. Our analyses indicate that 1:1 (O/W) emulsions prepared with 3% (w/w) asphaltenes in toluene and 1 wt % NaCl aqueous solutions at pH 7 and pH 10 resulted in 80-90 A thick films, interfacial areas around 2600-3100 cm (2)/mL, and films that were roughly 25% (v/v) asphaltenic, 60-70% toluene, and 8-12% water. The increased asphaltene and water film

  4. Compositional-induced structural change in ZrxNi100−x thin film metallic glasses

    International Nuclear Information System (INIS)

    Highlights: • A composite ZrNi target is used to accurately tune ZrNi thin film composition. • The atomic structure of metallic glass films is determined for several compositions. • Short and medium range order is inferred for amorphous compositions. • Crystallization phenomena are detected for Zr-rich specimens. • Crystallization is justified on the basis Nagel and Tauc criterion. - Abstract: The structure of ZrxNi100−x thin film metallic glasses (TFMGs) has been studied for a variety of compositions obtained by DC magnetron sputtering using a composite ZrNi target. The crystallization has been characterized by X-ray diffraction and transmission electron microscopy revealing also short and medium range order for amorphous compositions. The TFMGs thermodynamic stability has been evaluated by exploiting the Nagel and Tauc criterion, justifying the occurrence of crystallization in the Zr-rich specimens

  5. Cementitious Composites Engineered with Embedded Carbon Nanotube Thin Films for Enhanced Sensing Performance

    Science.gov (United States)

    Loh, Kenneth J.; Gonzalez, Jesus

    2015-07-01

    Cementitious composites such as concrete pavements are susceptible to different damage modes, which are primarily caused by repeated loading and long-term deterioration. There is even greater concern that damage could worsen and occur more frequently with the use of heavier vehicles or new aircraft carrying greater payloads. Thus, the objective of this research is to engineer cementitious composites with capabilities of self-sensing or detecting damage. The approach was to enhance the damage sensitivity of cementitious composites by incorporating multi-walled carbon nanotubes (MWNT) as part of the mix design and during casting. However, as opposed to directly dispersing MWNTs in the cement matrix, which is the current state-of-art, MWNT-based thin films were airbrushed and coated onto sand particles. The film-coated sand was then used as part of the mix design for casting mortar specimens. Mortar specimens were subjected to compressive cyclic loading tests while their electrical properties were recorded simultaneously. The results showed that the electrical properties of these cementitious composites designed with film-coated sand exhibited extremely high strain sensitivities. The electrical response was also stable and consistent between specimens.

  6. Antimicrobial activity of allyl isothiocyanate used to coat biodegradable composite films as affected by storage and handling conditions.

    Science.gov (United States)

    Li, Weili; Liu, Linshu; Jin, Tony Z

    2012-12-01

    We evaluated the effects of storage and handling conditions on the antimicrobial activity of biodegradable composite films (polylactic acid and sugar beet pulp) coated with allyl isothiocyanate (AIT). Polylactic acid and chitosan were incorporated with AIT and used to coat one side of the film. The films were subjected to different storage conditions (storage time, storage temperature, and packed or unpacked) and handling conditions (washing, abrasion, and air blowing), and the antimicrobial activity of the films against Salmonella Stanley in tryptic soy broth was determined. The films (8.16 μl of AIT per cm(2) of surface area) significantly (P packaging.

  7. Design of step composition gradient thin film transistor channel layers grown by atomic layer deposition

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Cheol Hyoun; Hee Kim, So; Gu Yun, Myeong; Koun Cho, Hyung, E-mail: chohk@skku.edu [School of Advanced Materials Science and Engineering, Sungkyunkwan University, 2066 Seobu-ro, Jangan-gu, Suwon, Gyeonggi-do 440-746 (Korea, Republic of)

    2014-12-01

    In this study, we proposed the artificially designed channel structure in oxide thin-film transistors (TFTs) called a “step-composition gradient channel.” We demonstrated Al step-composition gradient Al-Zn-O (AZO) channel structures consisting of three AZO layers with different Al contents. The effects of stacking sequence in the step-composition gradient channel on performance and electrical stability of bottom-gate TFT devices were investigated with two channels of inverse stacking order (ascending/descending step-composition). The TFT with ascending step-composition channel structure (5 → 10 → 14 at. % Al composition) showed relatively negative threshold voltage (−3.7 V) and good instability characteristics with a reduced threshold voltage shift (Δ 1.4 V), which was related to the alignment of the conduction band off-set within the channel layer depending on the Al contents. Finally, the reduced Al composition in the initial layer of ascending step-composition channel resulted in the best field effect mobility of 4.5 cm{sup 2}/V s. We presented a unique active layer of the “step-composition gradient channel” in the oxide TFTs and explained the mechanism of adequate channel design.

  8. Atmospheric Environment Fabrication of Composite Films by Ethanol Catalytic Combustion and Its Use as Counter Electrodes for Dye-Sensitized Soar Cells

    Directory of Open Access Journals (Sweden)

    Xiaoping Zou

    2014-01-01

    Full Text Available The composite films which consist of amorphous carbon, carbon nanotube, and iron nanoparticles were prepared by ethanol catalytic combustion in atmospheric environment. The as-prepared composite films have good electrocatalytic activity and high conductivity which is due to their particular structure. The efficiency of the composite films based dye-sensitized soar cells (DSSCs is closed to that of the Pt based one. Most importantly, the DSSC employing the composite films presents a higher FF than those of Pt based solar cell. In addition, it is a simple method for mass production of composite films counter electrode (CE which is expected to reduce the cost of fabricating DSSCs.

  9. A New Method with Sandwiched Composite Films for Encapsulating Flexible OLEDs

    Institute of Scientific and Technical Information of China (English)

    LI Yang; WANG Li-Duo; DUAN Lian; QIU Yong

    2005-01-01

    @@ We introduce a novel method for sandwiched-composite-film encapsulation that successfully extends the lifetime of flexible organic light-emitting diodes (FOLEDs). The encapsulation layers include two parts: one is a thin multilayer barrier coating, which is made up of two applications of alternating layers composed of a polymer layer (consisting of UV capable resins) and a ceramic layer (consisting of titanium nitride with excellent barrier performance), and the other is a thick polymer film of approximately 70μm in thickness fabricated by a doctor blade onto the thin encapsulation film described above. FOLEDs encapsulated by this novel method have a longer lifetime, and this lifetime is 74 times as much as the lifetime of unencapsulated ones.

  10. Surface morphology and composition studies in InGaN/GaN film grown by MOCVD

    Institute of Scientific and Technical Information of China (English)

    Tao Tao; Han Ping; Shi Yi; Zheng Youdou; Zhang Zhao; Liu Lian; Su Hui; Xie Zili; Zhang Rong; Liu Bin; Xiu Xiangqian; Li Yi

    2011-01-01

    InGaN filmsweredepositedon(0001)sapphiresubstrates with GaN buffer layers under different growth temperatures by metalorganic chemical vapor deposition.The In-composition of InGaN film was approximately controlled by changing the growth temperature.The connection between the growth temperature,In content,surface morphology and defect formation was obtained by X-ray diffraction,scanning electron microscopy (SEM) and atomic force microscopy (AFM).Meanwhile,by comparing the SEM and AFM surface morphology images,we proposed several models of three different defects and discussed the mechanism of formation.The prominent effect of higher growth temperature on the quality of the InGaN films and defect control were found by studying InGaN films at various growth temperatures.

  11. Structure and composition of Zn(x)Cd(1-xS) films synthesized through chemical bath deposition.

    Science.gov (United States)

    Tosun, B Selin; Pettit, Chelsea; Campbell, Stephen A; Aydil, Eray S

    2012-07-25

    Zinc cadmium sulfide (ZnxCd1-xS) thin films grown through chemical bath deposition are used in chalcopyrite solar cells as the buffer layer between the n-type zinc oxide and the p-type light absorbing chalcopyrite film. To optimize energetic band alignment and optical absorption, advanced solar cell architectures require the ability to manipulate x as a function of distance from the absorber-ZnCdS interface. Herein, we investigate the fundamental factors that govern the evolution of the composition as a function of depth in the film. By changing the initial concentrations of Zn and Cd salts in the bath, the entire range of overall compositions ranging from primarily cubic ZnS to primarily hexagonal CdS could be deposited. However, films are inhomogeneous and x varies significantly as function of distance from the film-substrate interface. Films with high overall Zn concentration (x > 0.5) exhibit a Cd-rich layer near the film-substrate interface because Cd is more reactive than Zn. This layer is typically beneath a nearly pure ZnS film that forms after the Cd-rich layers are deposited and Cd is depleted in the bath. In films with high overall Cd concentration (x < 0.5) the Zn concentration rises towards the film's surface. Fortunately, these gradients are favorable for solar cells based on low band gap chalcopyrite films.

  12. Deterministic aperiodic composite lattice-structured silicon thin films for photon management

    CERN Document Server

    Xavier, Jolly; Becker, Christiane

    2016-01-01

    Exotic manipulation of the flow of photons in nanoengineered semiconductor materials with an aperiodic distribution of nanostructures plays a key role in efficiency-enhanced and industrially viable broadband photonic technologies. Through a generic deterministic nanotechnological route, in addition to periodic, transversely quasicrystallographic or disordered random photonic lattices, here we show scalable nanostructured semiconductor thin films on large area nanoimprinted substrates up to 4cm^2 with advanced functional features of aperiodic composite nanophotonic lattices having tailorable supercell tiles. The richer Fourier spectra of the presented artificially nanostructured materials with well-defined lattice point morphologies are designed functionally akin to two-dimensional incommensurate intergrowth aperiodic lattices-comprising periodic photonic crystals and in-plane quasicrystals as subgroups. The composite photonic lattice-structured crystalline silicon thin films with tapered nanoholes or nanocone...

  13. Determination of the effective refractive index of porous silicon/polymer composite films

    Institute of Scientific and Technical Information of China (English)

    Zhenhong Jia

    2005-01-01

    The equation for calculating the effective refractive index of porous silicon inserted polymer was obtained by three-component Bruggeman effective medium model. The dependence of the effective refractive index of porous silicon/polymer composite films on the polymer fraction with various initial porosity was given theorically and experimentally respectively. The porous silicon and polymer polymethylmetacrylate based dispersive red one (PMMA/DR1) composite films were fabricated in our experiments. It is found that the measured effective refractive index of porous silicon inserted polymer was slightly lower than the calculated result because of the oxidization of porous silicon. The effective refractive index of oxidized porous silicon inserted polymer also was analyzed by four-component medium system.

  14. Green and biodegradable composite films with novel antimicrobial performance based on cellulose.

    Science.gov (United States)

    Wu, Yuehan; Luo, Xiaogang; Li, Wei; Song, Rong; Li, Jing; Li, Yan; Li, Bin; Liu, Shilin

    2016-04-15

    In order to obtain a safe and biodegradable material with antimicrobial properties from cellulose for food packaging, we presented a facile way to graft chitosan onto the oxidized cellulose films. The obtained films had a high transparent property of above 80% transmittance, excellent barrier properties against oxygen and antimicrobial properties against Escherichia coli and Staphylococcus aureus. The antimicrobial properties, mechanical properties, and water vapor permeability of composites are essential characteristics in determining their applicability as food-packaging materials. Moreover, using a sausage model, it was shown that the composites exhibited better performance than traditional polyethylene packaging material and demonstrated good potential as food packaging materials. The results presented a new insight into the development of green materials for food packaging.

  15. Green and biodegradable composite films with novel antimicrobial performance based on cellulose.

    Science.gov (United States)

    Wu, Yuehan; Luo, Xiaogang; Li, Wei; Song, Rong; Li, Jing; Li, Yan; Li, Bin; Liu, Shilin

    2016-04-15

    In order to obtain a safe and biodegradable material with antimicrobial properties from cellulose for food packaging, we presented a facile way to graft chitosan onto the oxidized cellulose films. The obtained films had a high transparent property of above 80% transmittance, excellent barrier properties against oxygen and antimicrobial properties against Escherichia coli and Staphylococcus aureus. The antimicrobial properties, mechanical properties, and water vapor permeability of composites are essential characteristics in determining their applicability as food-packaging materials. Moreover, using a sausage model, it was shown that the composites exhibited better performance than traditional polyethylene packaging material and demonstrated good potential as food packaging materials. The results presented a new insight into the development of green materials for food packaging. PMID:26616947

  16. Composite materials obtained by the ion-plasma sputtering of metal compound coatings on polymer films

    Science.gov (United States)

    Khlebnikov, Nikolai; Polyakov, Evgenii; Borisov, Sergei; Barashev, Nikolai; Biramov, Emir; Maltceva, Anastasia; Vereshchagin, Artem; Khartov, Stas; Voronin, Anton

    2016-01-01

    In this article, the principle and examples composite materials obtained by deposition of metal compound coatings on polymer film substrates by the ion-plasma sputtering method are presented. A synergistic effect is to obtain the materials with structural properties of the polymer substrate and the surface properties of the metal deposited coatings. The technology of sputtering of TiN coatings of various thicknesses on polyethylene terephthalate films is discussed. The obtained composites are characterized by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), atomic force microscopy (AFM), and scanning tunneling microscopy (STM) is shown. The examples of application of this method, such as receiving nanocomposite track membranes and flexible transparent electrodes, are considered.

  17. Scanning probe microscopy for the analysis of composite Ti/hydrocarbon plasma polymer thin films

    Science.gov (United States)

    Choukourov, A.; Grinevich, A.; Slavinska, D.; Biederman, H.; Saito, N.; Takai, O.

    2008-03-01

    Composite Ti/hydrocarbon plasma polymer films with different Ti concentration were deposited on silicon by dc magnetron sputtering of titanium in an atmosphere of argon and hexane. As measured by Kelvin force microscopy and visco-elastic atomic force microscopy, respectively, surface potential and hardness increase with increasing Ti content. Adhesion force to silicon and to fibrinogen molecules was stronger for the Ti-rich films as evaluated from the AFM force-distance curves. Fibrinogen forms a very soft layer on these composites with part of the protein molecules embedded in the outermost region of the plasma polymer. An increase of the surface charge due to fibrinogen adsorption has been observed and attributed to positively charged αC domains of fibrinogen molecule.

  18. Thin-film composite crosslinked polythiosemicarbazide membranes for organic solvent nanofiltration (OSN)

    KAUST Repository

    Aburabie, Jamaliah

    2015-01-01

    In this work we report a new class of solvent stable thin-film composite (TFC) membrane fabricated on crosslinked polythiosemicarbazide (PTSC) as substrate that exhibits superior stability compared with other solvent stable polymeric membranes reported up to now. Integrally skinned asymmetric PTSC membranes were prepared by the phase inversion process and crosslinked with an aromatic bifunctional crosslinker to improve the solvent stability. TFC membranes were obtained via interfacial polymerization using trimesoyl chloride (TMC) and diaminopiperazine (DAP) monomers. The membranes were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and contact angle measurement.The membranes exhibited high fluxes toward solvents like tetrahydrofuran (THF), dimethylformamide (DMF) and dimethylsulfoxide (DMSO) ranging around 20L/m2 h at 5bar with a molecular weight cut off (MWCO) of around 1000g/mol. The PTSC-based thin-film composite membranes are very stable toward polar aprotic solvents and they have potential applications in the petrochemical and pharmaceutical industry.

  19. Nanofiber supported thin-film composite membrane for pressure-retarded osmosis.

    Science.gov (United States)

    Bui, Nhu-Ngoc; McCutcheon, Jeffrey R

    2014-04-01

    Sustainable energy can be harnessed from fluids of differing salinity using a process known as pressure-retarded osmosis (PRO). We address one of the critical challenges of advance PRO by introducing a novel electrospun nanofiber-supported thin-film composite PRO membrane platform. The support was tiered with layers of nanofibers of different diameters to better withstand hydraulic pressure. The membranes successfully withstood an applied hydraulic pressure of 11.5 bar and exhibited performance that would produce an equivalent peak power density near 8.0 W/m(2) under real conditions (using 0.5 M NaCl and deionized water as the draw and feed solutions, respectively). This result shows the immense promise of nanofiber supported thin-film composite membranes for use in PRO. PMID:24387600

  20. Single walled carbon nanotube network—Tetrahedral amorphous carbon composite film

    Energy Technology Data Exchange (ETDEWEB)

    Iyer, Ajai, E-mail: ajai.iyer@aalto.fi; Liu, Xuwen; Koskinen, Jari [Department of Materials Science and Engineering, School of Chemical Technology, Aalto University, POB 16200, 00076 Espoo (Finland); Kaskela, Antti; Kauppinen, Esko I. [NanoMaterials Group, Department of Applied Physics, School of Science, Aalto University, POB 15100, 00076 Espoo (Finland); Johansson, Leena-Sisko [Department of Forest Products Technology, School of Chemical Technology, Aalto University, POB 16400, 00076 Espoo (Finland)

    2015-06-14

    Single walled carbon nanotube network (SWCNTN) was coated by tetrahedral amorphous carbon (ta-C) using a pulsed Filtered Cathodic Vacuum Arc system to form a SWCNTN—ta-C composite film. The effects of SWCNTN areal coverage density and ta-C coating thickness on the composite film properties were investigated. X-Ray photoelectron spectroscopy measurements prove the presence of high quality sp{sup 3} bonded ta-C coating on the SWCNTN. Raman spectroscopy suggests that the single wall carbon nanotubes (SWCNTs) forming the network survived encapsulation in the ta-C coating. Nano-mechanical testing suggests that the ta-C coated SWCNTN has superior wear performance compared to uncoated SWCNTN.

  1. Charge transport and photoresponses in a single-stranded DNA/single-walled carbon nanotube composite film

    Science.gov (United States)

    Hong, Wonseon; Lee, Eunmo; Kue Park, Jun; Eui Lee, Cheol

    2013-06-01

    Electrical conductivity and photoresponse measurements have been carried out on a single-stranded DNA (ssDNA)/single-walled carbon nanotube (SWNT) composite film in comparison to those of a SWNT film. While the temperature-dependent electrical conductivity of the pristine SWNT film was described well by the combined mechanism of a three-dimensional variable-range hopping and hopping conduction, that of the ssDNA/SWNT composite film followed a fluctuation-induced tunneling model. Besides, competition of photoexcited charge carrier generation and oxygen adsorption/photodesorption in the photoresponses of the films was observed and discussed in view of the role of the DNA wrapping. Thus, the biopolymer coating of the SWNTs is shown to play a significant role in modifying the charge dynamics of the composite system.

  2. Structure and Elemental Composition of Pb1 – xSnxS Films

    Directory of Open Access Journals (Sweden)

    P.V. Koval

    2015-06-01

    Full Text Available In this paper by the methods of diffractometry, scanning and atomic force microscopy, X-ray characteristic radiation induced by focused proton beam (PIXE, Rutherford backscattering of helium-4 ions we have investigated Pb1 – xSnxS films obtained by "hot wall". It was found that layers obtained by condensation in the temperature range of Ts = (268-382 °C have virtually a single phase orthorhombic crystal structure with lattice parameters which vary in the range of a = (0.4214-0.4293 nm, b = (1.1246-1.1313 nm, c = (0.3980-0.4015 nm. CSD sizes in the films are equal to L(040 = (35.5-47.5 nm, L(131 = (44.4-51.5 nm. The distribution of the components of a compound of films (μ-PIXE and their elemental composition (PIXE are determined. It was found that some samples were depleted by sulfur in comparison with the stoichiometric composition. Atomic concentration of the components of the solid solution varies in the range of СPb = 12.71-19.13; CSn = 40.29-44.46; CS = 38.36-42.75 at. %. By increasing the substrate temperature, the lead content in the films increases and the sulfur content decreases, the atomic concentration of tin in this case varies slightly.

  3. Preparation and photoelectrochemical performance of TiO2/Ag2Se interface composite film

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Coupling TiO2 with a narrow band gap semiconductor acting as the photosensitizer has attracted much attention in solar energy exploitation. In this work,the porous TiO2 film was first formed on the conducting glass plate (CGP) substrate by the decomposition of polyethylene glycol (PEG) mixing in titanium hydroxide sol at 450℃. Then,the TiO2/Ag2Se interface composite film was fabricated by interface reaction of AgNO3 with NaSeSO3 on the activated surface of porous TiO2 film. The results of SEM and XRD analyses indicated that the porous TiO2 layer was made up of the anatase crystal,and the Ag2Se layer was made up of congregative small particles that have low-temperature α-phase structure. Due to its efficient charge separation for the photo-induced electron-hole pairs,the TiO2/Ag2Se interface composite film as-prepared has good photovoltaic property and high photocurrent response for visible light,which have been confirmed by the photoelectrochemical measurements.

  4. Enhancement effects of two kinds of carbon black on piezoelectricity of PVDF-HFP composite films

    Science.gov (United States)

    Hu, Bin; Hu, Ning; Wu, Liangke; Cui, Hao; Ying, Ji

    2015-12-01

    Two kinds of carbon black (CB) (i.e., CB#300 and CB#3350) were added into poly(vinylidene fluoride-hexafluoropropylene) (PVDF-HFP), respectively, to improve its piezoelectricity. The results revealed that when 0.5 wt.% CB was added, the best performance of the PVDF-HFP/CB composite films was obtained. The calibrated open circuit voltage and the density of harvested power of 0.5 wt.% CB#3350 contained composite films were 204%, and 464% (AC) and 561% (DC) of those of neat PVDF-HFP films. Similarly, for 0.5 wt.% CB#300 contained films, they were 211%, and 475% (AC) and 624% (DC), respectively. The enhancement mechanisms of piezoelectricity were clarified by the observation of Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and scanning electron microscope (SEM). We found that the added CBs act as nucleate agents to promote the formation of elongated, oriented and fibrillar β-phase crystals during the fabrication process, which increase the piezoelectricity. Overdosed CBs lead to a lower crystallinity degree, resulting in the lower piezoelectricity. Compared with CB#3350, CB#300 performs slightly better, which may be ascribed to its higher specific surface area.

  5. Grain Size and Wettability of TiO2/SiO2 Photocatalytic Composite Thin Films

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The uniform transparent TiO2/SiO2 photocatalytic composite thin films are prepared by sol-gel method on the soda lime glass substrates, and characterized by UV-visible spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), BET surface area, FTIR spectroscopy and X-ray photoelectron spectroscopy (XPS). It was found that the addition of SiO2 to TiO2 thin films can suppress the grain growth of TiO2 crystal, increase the hydroxyl content on the surface of TiO2 films, lower the contact angle for water on TiO2 films and enhance the hydrophilic property of TiO2 films. The super-hydrophilic TiO2/SiO2 photocatalytic composite thin films with the contact angle of 0-° are obtained by the addition of 10%-20% SiO2 in mole fraction.

  6. All-natural composite wound dressing films of essential oils encapsulated in sodium alginate with antimicrobial properties.

    Science.gov (United States)

    Liakos, Ioannis; Rizzello, Loris; Scurr, David J; Pompa, Pier Paolo; Bayer, Ilker S; Athanassiou, Athanassia

    2014-03-25

    We present natural polymeric composite films made of essential oils (EOs) dispersed in sodium alginate (NaAlg) matrix, with remarkable anti-microbial and anti-fungal properties. Namely, elicriso italic, chamomile blue, cinnamon, lavender, tea tree, peppermint, eucalyptus, lemongrass and lemon oils were encapsulated in the films as potential active substances. Glycerol was used to induce plasticity and surfactants were added to improve the dispersion of EOs in the NaAlg matrix. The topography, chemical composition, mechanical properties, and humidity resistance of the films are presented analytically. Antimicrobial tests were conducted on films containing different percentages of EOs against Escherichia coli bacteria and Candida albicans fungi, and the films were characterized as effective or not. Such diverse types of essential oil-fortified alginate films can find many applications mainly as disposable wound dressings but also in food packaging, medical device protection and disinfection, and indoor air quality improvement materials, to name a few. PMID:24211443

  7. Anticorrosion Coating of Carbon Nanotube/Polytetrafluoroethylene Composite Film on the Stainless Steel Bipolar Plate for Proton Exchange Membrane Fuel Cells

    OpenAIRE

    Yoshiyuki Show; Toshimitsu Nakashima; Yuta Fukami

    2013-01-01

    Composite film of carbon nanotube (CNT) and polytetrafluoroethylene (PTFE) was formed from dispersion fluids of CNT and PTFE. The composite film showed high electrical conductivity in the range of 0.1–13 S/cm and hydrophobic nature. This composite film was applied to stainless steel (SS) bipolar plates of the proton exchange membrane fuel cell (PEMFC) as anticorrosion film. This coating decreased the contact resistance between the surface of the bipolar plate and the membrane electrode assemb...

  8. Self-bonded composite films based on cellulose nanofibers and chitin nanocrystals as antifungal materials.

    Science.gov (United States)

    Robles, Eduardo; Salaberria, Asier M; Herrera, Rene; Fernandes, Susana C M; Labidi, Jalel

    2016-06-25

    Cellulose nanofibers and chitin nanocrystals, two main components of agricultural and aquacultural by-products, were obtained from blue agave and yellow squat lobster industrial residues. Cellulose nanofibers were obtained using high pressure homogenization, while chitin nanocrystals were obtained by hydrolysis in acid medium. Cellulose nanofibers and chitin nanocrystals were characterized by X-ray diffraction, Atomic Force Microscopy and Infrared spectroscopy. Self-bonded composite films with different composition were fabricated by hot pressing and their properties were evaluated. Antifungal activity of chitin nanocrystals was studied using a Cellometer(®) cell count device, mechanical properties at tension were measured with a universal testing machine, water vapor permeability was evaluated with a thermohygrometer and surface tension with sessile drop contact angle method. The addition of chitin nanocrystals reduced slightly the mechanical properties of the composite. Presence of chitin nanocrystals influenced the growth of Aspergillus sp fungus in the surface of the composites as expected. PMID:27083791

  9. Structure and phase composition of deposited tantalum-carbon films

    Science.gov (United States)

    Tuleushev, Yu. Zh.; Volodin, V. N.; Zhakanbaev, E. A.; Alimzhan, B.

    2016-08-01

    Ion plasma sputtering and the subsequent codeposition of ultrafine tantalum and carbon particles were used to prepare coatings with 4.6-71.5 at % C. Structural studies of the coatings showed the existence of carbon solid solutions in β Ta at carbon contents to 4.6 at %, carbon solid solutions in α Ta at carbon contents of 4.6-10.3 at %, and direct synthesis of TaC at carbon contents of 44.7-71.5 at %. During heat treatments to 700°C, the substantial concentration widening of regions of the existence of Ta2C and TaC was found. The lattice parameters of hexagonal Ta2C and fcc TaC carbides were determined for composition ranges of the existence of phases during heating to 700°C. Upon heating above 600°C, the progressive transition of quasiamorphous Ta2C carbide into the crystalline Ta2C carbide was found to take place. The possibility of applying the direct synthesis of TaC carbide in engineering was noted.

  10. Structural and electrical properties of amorphous carbon–sulfur composite films

    Indian Academy of Sciences (India)

    Latha Kumari; S V Subramanyam

    2004-06-01

    In this paper, we discuss the synthesis of carbon–sulfur composite (-C:S) films by vapour phase pyrolysis of maleic anhydride and sulfur. Structural changes in the system are analysed by scanning electron microscopy and powder X-ray diffraction. Microhardness test depicts an increase in the value of hardness with an increase in sulfur concentration. Electrical conductivity of composite samples varies with sulfur concentration. Magnetoresistance (MR) measurements show a drastic increase in the value of MR for the samples prepared at < 900°C. Thermal stability of these samples is analysed by thermogravimetric analysis, which depends on the host structure and the amount of intercalated species.

  11. Influence of superconductor film composition on adhesion strength of coated conductors

    Energy Technology Data Exchange (ETDEWEB)

    Kesgin, Ibrahim; Khatri, Narayan; Liu, Yuhao; Delgado, Louis; Galstyan, Eduard; Selvamanickam, Venkat

    2015-11-20

    The effect of high temperature superconductor (HTS) film composition on the adhesion strength of rare- earth barium copper oxide coated conductors (CCs) has been studied. It has been found that the mechanical integrity of the superconductor layer is very susceptible to the defects especially those along the ab plane, probably due to the weak interfaces between the defects and the matrix. Gd and Y in the standard composition were substituted with Sm and the number of in-plane defects was drastically reduced. Consequently, a four-fold increase in adhesion or peeling strength in Sm-based CCs was achieved compared to the standard GdYBCO samples.

  12. Exploring the structure-properties relationships of novel polyamide thin film composite membranes

    DEFF Research Database (Denmark)

    Briceño, Kelly; Javakhishvili, Irakli; Guo, Haofei;

    Polysulfone (PSU) is a material widely used in the fabrication of membranes for ultrafiltration and as a support for nanofiltration and reverse osmosis membranes. Interfacial polymerization usually combines amine and acid chloride monomers for the fabrication of thin film composite membranes[1] ....... of UF membranes includes: Negatively charged PSF surfaces that could be less prone to biofouling Scale up process for the modification of PSU. An alternative to costly and technically challenging processes as in situ interfacial polymerization [3]....

  13. Thin Film Composite Membrane for Effective Raw Biogas Upgrading to Pipeline Quality Methane

    OpenAIRE

    Kárászová, Magda

    2012-01-01

    In this contribution we propose a method to upgrade biogas to the same quality of fuel standard natural gas. The latter contains more than 95 vol. % of methane. Using traditional membranes, such concentration of methane in the retentate could only be achieved using a multistep process. A recently proposed method for raw biogas purification from impurities and carbon dioxide by condensing water on swollen thin film composite membranes was found to be highly effective. The hydrophilic reverse ...

  14. Exploring the structure-properties relationships of novel polyamide thin film composite membranes

    OpenAIRE

    Briceño, Kelly; Javakhishvili, Irakli; Guo, Haofei; Søtoft, Lene; Villy Christensen, Knud; Norddahl, Birgir; Hvilsted, Søren; Lipnizki, Jens

    2015-01-01

    Polysulfone (PSU) is a material widely used in the fabrication of membranes for ultrafiltration and as a support for nanofiltration and reverse osmosis membranes. Interfacial polymerization usually combines amine and acid chloride monomers for the fabrication of thin film composite membranes[1] . However, only few publications describe it’s usage for the modification of supports for the fabrication of ultrafiltration membranes [2]. This research focuses on the modification of PSU supports to ...

  15. Zinc oxide-potassium ferricyanide composite thin film matrix for biosensing applications

    International Nuclear Information System (INIS)

    Thin film of zinc oxide-potassium ferricyanide (ZnO-KFCN) composite has been deposited on indium tin oxide (ITO) coated corning glass using pulsed laser deposition (PLD). The composite thin film electrode has been exploited for amperometric biosensing in a mediator-free electrolyte. The composite matrix has the advantages of high iso-electric point of ZnO along with enhanced electron communication due to the presence of a redox species in the matrix itself. Glucose oxidase (GOx) has been chosen as the model enzyme for studying the application of the developed matrix to biosensing. The sensing response of the bio-electrode, GOx/ZnO-KFCN/ITO/glass, towards glucose was studied using cylic voltammetry (CV) and photometric assay. The bio-electrode exhibits good linearity from 2.78 mM to 11.11 mM glucose concentration. The low value of Michaelis-Menten constant (1.69 mM) indicates an enhanced affinity of the immobilized enzyme towards its substrate. A quassireversible system is obtained with the composite matrix. The results confirm promising application of the ZnO-KFCN composite matrix for amperometric biosensing applications in a mediator-less electrolyte that could lead to the realization of an integrated lab-on-chip device.

  16. Natural fiber composites with EMI shielding function fabricated using VARTM and Cu film magnetron sputtering

    Science.gov (United States)

    Xia, Changlei; Ren, Han; Shi, Sheldon Q.; Zhang, Hualiang; Cheng, Jiangtao; Cai, Liping; Chen, Kathleen; Tan, Hwa-Shen

    2016-01-01

    To fabricate kenaf fiber composites with electromagnetic interference (EMI) shielding function, the technique of vacuum-assisted resin transfer molding (VARTM) and Cu film magnetron sputtering were employed. The EMI shielding effectiveness (SE) and composite surface characteristics were examined with PNA Network Analyzer, Quanta 200 environmental scanning electron microscope and OCA20 contact angle meter. After being Cu-sputter coated for 0.5 h, 1 h, 2 h, and 3 h, the EMI SE values were increased to be 23.8 dB, 32.5 dB, 43.3 dB, and 48.3 dB, which denoted 99.5799%, 99.9437%, 99.9953%, or 99.9985% incident signal was blocked, respectively. The SEM observations revealed that the smoother surface of the composites was obtained by longer time sputtering, resulting in the SE improvement. The contact angle increased from 49.6° to 129.5° after 0.5 h sputtering, which indicated that the coated Cu film dramatically improved the hydrophobic property of composite. When the coating time increased to 3 h, the contact angle decreased to 51.0° because the composite surface roughness decreased with the increase in coating time.

  17. Au/CeO{sub 2}-chitosan composite film for hydrogen peroxide sensing

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Wei [Key Laboratory of Medical Diagnostics, Ministry of Education, College of Laboratory Medicine, Chongqing Medical University, Chongqing 400016 (China); Xie Guoming, E-mail: guomingxie@cqmu.edu.cn [Key Laboratory of Medical Diagnostics, Ministry of Education, College of Laboratory Medicine, Chongqing Medical University, Chongqing 400016 (China); Li Shenfeng; Lu Lingsong; Liu Bei [Key Laboratory of Medical Diagnostics, Ministry of Education, College of Laboratory Medicine, Chongqing Medical University, Chongqing 400016 (China)

    2012-08-01

    Au nanoparticles (AuNPs) were in situ synthesized at the cerium dioxide nanoparticles (CeO{sub 2}NPs)-chitosan (CS) composite film by one-step direct chemical reduction, and the resulting Au/CeO{sub 2}-CS composite were further modified for enzyme immobilization and hydrogen peroxide (H{sub 2}O{sub 2}) biosensing. Transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), UV-vis spectra and electrochemical techniques have been utilized for characterization of the prepared composite. The stepwise assembly process and electrochemical performances of the biosensor were characterized by means of cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and typical amperometric response (i-t). The Au/CeO{sub 2}-CS composite exhibited good conductibility and biocompatibility, and the developed biosensor exhibited excellent response to hydrogen peroxide in the linear range of 0.05-2.5 mM (r = 0.998) with the detection limit of 7 {mu}M (S/N = 3). Moreover, the biosensor presented high affinity (K{sub m}{sup app}=1.93mM), good reproducibility and storage stability. All these results demonstrate that the Au/CeO{sub 2}-CS composite film can provide a promising biointerface for the biosensor designs and other biological applications.

  18. A Solid Film Lubricant Composition for Use at High Sliding Velocities in Liquid Nitrogen

    Science.gov (United States)

    Wisander, D. W.; Johnson, R. L.

    1960-01-01

    Solid-lubricant-containing compositions can be of value as films and solid bodies for bearing and seal surfaces in low-temperature liquefied gases. An experimental composition including polytetrafluoroethylene (PTFE), an epoxy resin, and lithium-alumina-silicate was studied in friction, wear, and endurance experiments in liquid nitrogen (-320 F). This composition was formulated to approximate the thermal expansion of metals used in cryogenic systems. Hemisphere (3/6-in. radius) rider specimens were used and in most experiments the load was 1000 g. Films (0.005-in. thick) on disk specimens gave good endurance life, low rider wear, and desirable friction (f = 0.02 to 0.07). They functioned at a higher sliding velocity (no failure at 16, 000 ft/min) with copper rider specimens than with stainless steel riders (failure at 9000 ft/min). Solid rider material of the experimental composition had good friction and wear properties at sliding velocities above 4000 ft/min. It is important to use the experimental composition with mating materials having good thermal conductivity.

  19. Enhanced luminescence properties of hybrid Alq{sub 3}/ZnO (organic/inorganic) composite films

    Energy Technology Data Exchange (ETDEWEB)

    Cuba, M.; Muralidharan, G., E-mail: muraligru@gmail.com

    2014-12-15

    Pristine tris-(8-hydroxyquionoline)aluminum(Alq{sub 3}) and (Alq{sub 3}/ZnO hybrid) composites containing different weight percentages (5 wt%, 10 wt%, 20 wt%, 30 wt%, 40 wt% and 50 wt%) of ZnO in Alq{sub 3} were synthesized and coated on to a glass substrate using the dip coating method. The optimum concentration of ZnO in Alq{sub 3} films to get the best luminescence yield has been identified. XRD pattern reveals the amorphous nature of pure Alq{sub 3} film. The Alq{sub 3} films containing different weight percentages of ZnO show the presence of crystalline ZnO in Alq{sub 3}/ZnO composite films. The FTIR spectrum confirms the formation of quinoline with absorption in the region 600−800 cm{sup −1}. The hybrid Alq{sub 3}/ZnO composite films indicate the presence of Zn−O vibration band along with the corresponding Alq{sub 3} band. The band gap (HOMO–LUMO) of Alq{sub 3} film was calculated using absorption spectra and it is 2.87 eV for pristine films while it is 3.26 eV, 3.21 eV, 3.14 eV, 3.10 eV, 3.13 eV and 3.20 eV for the composite films containing 5–50 wt% of ZnO. The photoluminescence (PL) spectra of Alq{sub 3} films show a maximum PL intensity at 514 nm when excited at 390 nm. The ZnO incorporated composite films (Alq{sub 3}/ZnO) exhibit an emission in 485 nm and 514 nm. The composite films containing 30 wt% of ZnO exhibit maximum luminescence yield. - Highlights: • The pure Alq{sub 3} and Alq{sub 3}/ZnO composite were synthesized and coated on to a glass substrate using dip coating method. • Alq{sub 3}/ZnO composite film containing 30 wt% of ZnO exhibits two fold increases in luminescence intensity. • The shielding effect of ZnO on the Alq{sub 3} material suppresses the interactions among the host molecules in the excited state. • This leads to enhance the luminescence intensity in composite films.

  20. Two-step preparation of laser-textured Ni/FTO bilayer composite films with high photoelectric properties

    International Nuclear Information System (INIS)

    Highlights: • A two-step strategy was proposed to prepare laser-textured Ni/FTO composite films. • Ni/FTO film with a 10-nm-thick Ni layer (Ni10/FTO film) had the best performance. • The Ni10/FTO film underwent magnetic-field-assisted and -free laser irradiations. • All the magnetic laser-irradiated (MLI-NF) films were textured and annealed. • The MLI-NF film using a fluence of 1.0 J/cm2 showed the highest figure of merit. - Abstract: A two-step strategy, i.e. sputtering Ni layers on FTO glass combined with magnetic-field-assisted laser irradiation, was proposed to prepare laser-textured Ni/FTO bilayer composite films. By analyzing surface morphology, crystal structure and photoelectric properties of Ni/FTO films with different Ni layer thicknesses, the Ni/FTO film with a 10-nm-thick Ni layer (Ni10/FTO film), which had the best overall photoelectric property, was chosen to undergo magnetic-field-assisted laser irradiation with different laser fluences. Magnetic-field-free laser irradiation of the Ni10/FTO film was also carried out for comparison purpose. It was found that magnetic-field-assisted laser irradiation using a fluence of 1.0 J/cm2 was more effective for simultaneously achieving texturing and annealing, resulting in formation of ideal grating textures and significantly increased grain size. The corresponding film (MLI-NF1.0 film) showed the highest figure of merit of 22.8 × 10−3 Ω−1 compared to 13.1 × 10−3 Ω−1 of the FTO glass and 1.4 × 10−3 Ω−1 of the Ni10/FTO film, suggesting that the two-step strategy is excellent for preparing textured Ni/FTO films with high photoelectric properties

  1. Effect of structure and phase composition on the properties of BixSb2-xTe3 films

    International Nuclear Information System (INIS)

    Investigation into structures and phase composition of BixSb2-xTe-3 films, into dependence of KT tensosensitivity coefficient, resistance temperature coefficient (RTC) on thermodynamic parameters of film production and substrate type, as well as, investigation into effect of doping of BixSb2-xTex film initial batch by acceptor impurities on Rt and RTC represent the aim of the paper

  2. The effect of composition on structural and electronic properties in polycrystalline CuGaSe2 thin film

    Institute of Scientific and Technical Information of China (English)

    Zhang Li; He Qing; Xu Chuan-Ming; Xue Yu-Ming; Li Chang-Jian; Sun Yun

    2008-01-01

    Polycrystalline CuGaSe2 thin films on Mo-coated soda-lime glass substrates have been synthesized by co-evaporation process from Cu, Ga and Se sources. Structural and electrical properties of the as-grown CuGaSe2 films strongly depend on the film composition. Stoichiometric CuGaSe2 is fabricated, as indicated by x-ray diffraction spec-troscope (XRD) and x-ray fluorescence (XRF). A two-phase region is composed of CuGaSe2 and Cu2-xSe phases for Cu-rich films, and CuGaSe2 and CuGa3Se5 phases for Ga-rich films, respectively. Morphological properties are de-tected by scanning electron microscope (SEM) for various compositional films, the grain sizes of the CuGaSe2films decrease with the extent of deviation from stoichiometric composition. Raman spectroscopy of Cu-rich samples shows that there exist large Cu-Se particles on the film surface. The results from Hall effect measurements for typical samples indicate that CuGaSe2 films are always of p-type semiconductor from Cu-rich to Ga-rich. Stoichiometric CuGaSe2 films exhibit relatively large mobility than any other compositional films. Finally, polycrystalline CuGaSe2 thin film solar cell with a best conversion efficiency of 6.02% has been achieved under the standard air mass (AM)1.5 spectrum for 100 mW/cm2 at room temperature (aperture area, 0.24cm2). The open circuit voltage of the CuGaSe2 solar cells is close to770 mV.

  3. Synthesis and surface properties of polyamide-CuxSe composite thin films

    Science.gov (United States)

    Ivanauskas, Remigijus; Baltrusaitis, Jonas

    2013-10-01

    A study of copper selenide (CuxSe) thin film deposition on PA 6 polymer surface via adsorption/diffusion method and the resulting surface properties is presented. A two stage process used to deposit these thin films involves (a) selenization in 0.1 M K2SeS2O6 at pH 2.15 and 60 °C followed by (b) treatment with 0.34 M Cu(II) and 0.06 M Cu(I) salt solution at 80 °C. Resulting chemical and physical properties of CuxSe films were investigated using XRD, XPS, SEM and sheet resistivity measurements. XRD data showed a complex mixture of CuxSe phases with peaks due to the elemental Se present at longer exposures. Thin film bulk elemental composition varied with the exposure time whereas XPS analysis showed surface to be slightly copper enriched. Additionally, mostly Cusbnd Se bonds were observed on the surface with minor oxidation products. SEM crossectional analysis showed distinct CuxSe film formation on PA 6 surface with thickness of ∼1-5 μm. Finally, it was found that sheet resistance of 150 ± 10 Ω/□ was achieved after 120 min of selenization for all samples and remained constant after longer exposures.

  4. Composition-dependent nanostructure of Cu(In,Ga)Se{sub 2} powders and thin films

    Energy Technology Data Exchange (ETDEWEB)

    Schnohr, C.S., E-mail: c.schnohr@uni-jena.de [Institut für Festkörperphysik, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena (Germany); Kämmer, H.; Steinbach, T.; Gnauck, M. [Institut für Festkörperphysik, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena (Germany); Rissom, T.; Kaufmann, C.A.; Stephan, C. [Helmholtz-Zentrum Berlin für Materialien und Energie, Hahn-Meitner-Platz 1, 14109 Berlin (Germany); Schorr, S. [Helmholtz-Zentrum Berlin für Materialien und Energie, Hahn-Meitner-Platz 1, 14109 Berlin (Germany); Institut für Geologische Wissenschaften, Freie Universität Berlin, Malteserstr. 74-100, 12249 Berlin (Germany)

    2015-05-01

    Atomic-scale structural parameters of Cu(In,Ga)Se{sub 2} powders and polycrystalline thin films were determined as a function of the In and Cu contents using X-ray absorption spectroscopy. No difference in the two sample types is observed for the average bond lengths demonstrating the strong tendency towards bond length conservation typical for tetrahedrally coordinated semiconductors. In contrast, the bond length variation is significantly smaller in the thin films than in the powders, particularly for Cu-poor material. This difference in the nanostructure is proposed to originate from differences in the preparation conditions, most prominently from the different history of Cu composition. - Highlights: • Cu(In,Ga)Se{sub 2} powders and thin films are studied with X-ray absorption spectroscopy. • Structural parameters are determined as a function of the In and Cu contents. • The element-specific average bond lengths are identical for powders and thin films. • The Ga-Se/In-Se bond length variation is smaller for thin films than for powders. • The differences are believed to stem from the different history of the Cu content.

  5. Nanostructures on spin-coated polymer films controlled by solvent composition and polymer molecular weight

    Energy Technology Data Exchange (ETDEWEB)

    Dario, Aline F.; Macia, Henrique B.; Petri, Denise F.S., E-mail: dfsp@iq.usp.br

    2012-12-01

    In this study we systematically investigated how the solvent composition used for polymer dissolution affects the porous structures of spin-coated polymers films. Cellulose acetate butyrate (CAB) and poly(methyl methacrylate) with low (PMMA-L) and high (PMMA-H) molecular weights were dissolved in mixtures of acetone (AC) and ethyl acetate (EA) at constant polymer concentration of 10 g/L The films were spin-coated at a relative air humidity of 55 {+-} 5%, their thickness and index of refraction were determined by means of ellipsometry and their morphology was analyzed by atomic force microscopy. The dimensions and frequency of nanocavities on polymer films increased with the acetone content ({phi}{sub AC}) in the solvent mixture and decreased with increasing polymer molecular weight. Consequently, as the void content increased in the films, their apparent thicknesses increased and their indices of refraction decreased, creating low-cost anti-reflection surface. The void depth was larger for PMMA-L than for CAB. This effect was attributed to different activities of EA and AC in CAB or PMMA-L solution, the larger mobility of chains and the lower polarity of PMMA-L in comparison to CAB. - Highlights: Black-Right-Pointing-Pointer Nanostructures in spin-coated polymer films depend on the solvent vapor pressure. Black-Right-Pointing-Pointer Anti-reflection polymer films are produced at high solvent vapor pressure. Black-Right-Pointing-Pointer Only shallow cavities are obtained in films of polymers with high molecular weight.

  6. The equipment for controlling the structure and functional properties of nanostructured composite films

    Science.gov (United States)

    Burov, V. G.; Plotnikova, N. V.; Prokhorenko, E. V.; Smirnov, A. I.

    2016-04-01

    The article is devoted to the creation of an instrumental system allowing evaluating the functional properties and current-voltage characteristics of nanostructured composite films at different temperatures and other environmental parameters. The system is based on an assessment of current-voltage characteristics of a nanostructured film material. The main components of the system are a chamber and a unit for current-voltage characteristics measuring. The stage with the test material and the contact system are provided with a heating element and a cooling system thus allowing warming to 150 °C and fast cooling to negative temperatures by liquid nitrogen circulating. The chamber body leak proofness against the external environment allows forming a composition of the atmosphere at a predetermined humidity level, which is essential for the measurement of current-voltage characteristics of polymer materials. The article describes the design features of the instrumental system and results of its application used for determining the properties of polymer nanostructured composite films.

  7. Towards Enhanced Performance Thin-film Composite Membranes via Surface Plasma Modification

    Science.gov (United States)

    Reis, Rackel; Dumée, Ludovic F.; Tardy, Blaise L.; Dagastine, Raymond; Orbell, John D.; Schutz, Jürg A.; Duke, Mikel C.

    2016-07-01

    Advancing the design of thin-film composite membrane surfaces is one of the most promising pathways to deal with treating varying water qualities and increase their long-term stability and permeability. Although plasma technologies have been explored for surface modification of bulk micro and ultrafiltration membrane materials, the modification of thin film composite membranes is yet to be systematically investigated. Here, the performance of commercial thin-film composite desalination membranes has been significantly enhanced by rapid and facile, low pressure, argon plasma activation. Pressure driven water desalination tests showed that at low power density, flux was improved by 22% without compromising salt rejection. Various plasma durations and excitation powers have been systematically evaluated to assess the impact of plasma glow reactions on the physico-chemical properties of these materials associated with permeability. With increasing power density, plasma treatment enhanced the hydrophilicity of the surfaces, where water contact angles decreasing by 70% were strongly correlated with increased negative charge and smooth uniform surface morphology. These results highlight a versatile chemical modification technique for post-treatment of commercial membrane products that provides uniform morphology and chemically altered surface properties.

  8. Superior environment resistance of quartz crystal microbalance with anatase TiO{sub 2}/ZnO nanorod composite films

    Energy Technology Data Exchange (ETDEWEB)

    Qiang, Wei, E-mail: weiqiang.tju@163.com [Tianjin Key Laboratory of Composite and Functional Materials, School of Materials Science and Engineering, Tianjin University, 92 Weijin Road, Tianjin (China); Wei, Li; Shaodan, Wang [Tianjin Key Laboratory of Composite and Functional Materials, School of Materials Science and Engineering, Tianjin University, 92 Weijin Road, Tianjin (China); Yu, Bai [Beijing Institute of Spacecrafts Environment Engineering, Beijing 100094 (China)

    2015-08-30

    Graphical abstract: ZnO nanorod array being prepared by an in situ method on the QCM coated with Au film via hydrothermal process and surface modification with coated TiO{sub 2} by sol–gel methods to form a superhydrophobic TiO{sub 2}/ZnO composite film the anatase TiO{sub 2}/ZnO nanorod composite film with a sharp, pencil-like structure exhibiting excellent superhydrophobicity (water contact angle of 155°), non-sticking water properties, and an autonomous cleaning property under UV irradiation. The anatase TiO{sub 2}/ZnO nanorod composite film facilitates the precise measurement and extended lifetime of the QCM for the detection of organic gas molecules. - Highlights: • This work combines, for the first time, the advantage of the TiO{sub 2}/ZnO composite film on photocatalysis and reversible super-hydrophobic and super-hydrophilic transition, and puts forward a solution to satisfy weatherability of quartz crystal microbalance in long-term application. • The anatase TiO{sub 2}/ZnO nanorod composite film with pencil structure exhibit excellent super-hydrophobicity (water contact angle can reach 155°), no-sticking water properties and self-cleaning property under UV irradiation. • The photocatalysis and reversible super-hydrophobic and super-hydrophilic transition of the TiO{sub 2}/ZnO nanorod composite film is stable in long-term application. - Abstract: The precise measurement of quartz crystal microbalance (QCM) in the detection and weighing of organic gas molecules is achieved due to excellent superhydrophobicity of a deposited film composite. Photocatalysis is utilized as a method for the self-cleaning of organic molecules on the QCM for extended long-term stability in the precision of the instrument. In this paper, ZnO nanorod array is prepared via in situ methods on the QCM coated with Au film via hydrothermal process. Subsequently, a TiO{sub 2}/ZnO composite film is synthesized by surface modification with TiO{sub 2} via sol–gel methods. Results

  9. Synergistic effect of bias and target currents for magnetron sputtered MoS2-Ti composite films

    International Nuclear Information System (INIS)

    In terms of modification of the properties of MoS2-Ti composite films, especially tribological properties, significant advances have recently been recorded. However, the commercially production of MoS2-Ti composite films is still limited, because the production of desirable MoS2-Ti composite coating is only possible by using closed field unbalanced magnetron systems and by the selection of convenient deposition parameters. This requirement has focused the researchers' attention on optimization of deposition parameters. This study is concentrating on the effect of the bias voltage and the target currents for MoS2-Ti composite films deposited by pulsed magnetron sputtering (PMS). It is found that the bias and the target currents clearly affect the mechanical, structural and tribological properties of MoS2-Ti films.

  10. Synergistic effect of bias and target currents for magnetron sputtered MoS{sub 2}-Ti composite films

    Energy Technology Data Exchange (ETDEWEB)

    Buelbuel, Ferhat; Efeoglu, Ihsan [Ataturk Univ., Erzurum (Turkey). Dept. of Mechanical Engineering

    2016-07-01

    In terms of modification of the properties of MoS{sub 2}-Ti composite films, especially tribological properties, significant advances have recently been recorded. However, the commercially production of MoS{sub 2}-Ti composite films is still limited, because the production of desirable MoS{sub 2}-Ti composite coating is only possible by using closed field unbalanced magnetron systems and by the selection of convenient deposition parameters. This requirement has focused the researchers' attention on optimization of deposition parameters. This study is concentrating on the effect of the bias voltage and the target currents for MoS{sub 2}-Ti composite films deposited by pulsed magnetron sputtering (PMS). It is found that the bias and the target currents clearly affect the mechanical, structural and tribological properties of MoS{sub 2}-Ti films.

  11. Effect of lignin on water vapor barrier, mechanical, and structural properties of agar/lignin composite films.

    Science.gov (United States)

    Shankar, Shiv; Reddy, Jeevan Prasad; Rhim, Jong-Whan

    2015-11-01

    Biodegradable composite films were prepared using two renewable resources based biopolymers, agar and lignin alkali. The lignin was used as a reinforcing material and agar as a biopolymer matrix. The effect of lignin concentration (1, 3, 5, and 10wt%) on the performance of the composite films was studied. In addition, the mechanical, water vapor barrier, UV light barrier properties, FE-SEM, and TGA of the films were analyzed. The agar/lignin films exhibited higher mechanical and UV barrier properties along with lower water vapor permeability compared to the neat agar film. The FTIR and SEM results showed the compatibility of lignin with agar polymer. The swelling ratio and moisture content of agar/lignin composite films were decreased with increase in lignin content. The thermostability and char content of agar/lignin composite films increased with increased lignin content. The results suggested that agar/lignin films have a potential to be used as a UV barrier food packaging material for maintaining food safety and extending the shelf-life of the packaged food. PMID:26271435

  12. Antimicrobial activity of allyl isothiocyanate used to coat biodegradable composite films as affected by storage and handling conditions

    Science.gov (United States)

    We evaluated the effects of storage and handling conditions on the antimicrobial activity of biodegradable composite films (polylactic acid and sugar beet pulp) coated with allyl isothiocyanate (AIT). Polylactic acid (PLA) and chitosan were incorporated with AIT and coated on one side of the film. T...

  13. Phase map, composition and resistivity of reactively magnetron sputtered and annealed Ta–N films

    Science.gov (United States)

    Salamon, K.; Radić, N.; Bogdanović Radović, I.; Očko, M.

    2016-05-01

    Thin films of tantalum nitride (Ta–N) have been prepared by reactive magnetron deposition under various nitrogen partial pressures p{{\\text{N}}2} (0-1) and subsequently annealed (T a   =  450–950 °C). The structure, density, composition and electrical resistivity of the prepared films were systematically investigated. A p{{\\text{N}}2}-{{T}a} phase map was constructed from the results of structural analysis. With increasing of p{{\\text{N}}2} from 0 to 0.2, a single-phase or two-phase mixture films of tetragonal Ta, Ta2N ({{T}a}≥slant 450 °C), ɛ-TaN ({{T}a}≥slant 850 °C), θ-TaN ({{T}a}≥slant 850 °C) and fcc δ-TaN are sequentially observed. For p{{\\text{N}}2}=0.25 –0.45, the as grown and annealed films exhibit δ-TaN structure. Amorphous films grown in the p{{\\text{N}}2}=0.45 –0.75 range crystallize as cubic Ta2N3 upon annealing at {{T}a}≥slant 650 °C or as δ-TaN at {{T}a}≥slant 850 °C. A cubic Ta2N3 is grown at highest p{{\\text{N}}2} (≥slant 0.85), which decomposes to δ-TaN at {{T}a}≥slant 850 °C. The N     / Ta atomic ratio in the film linearly increases for p{{\\text{N}}2}=0 –0.5, ranging from 0 to 2.1, while the mass density monotonically decreases with p{{\\text{N}}2} . Upon annealing, a part of N atoms out-diffuses from the films deposited at p{{\\text{N}}2}≥slant 0.3 . The electrical resistivity strongly depends on both p{{\\text{N}}2} and T a . However, in the as grown and annealed δ-TaN films the resistivity was of the order of 100–1000 μ Ω cm. In these films, a correlation between the resistivity and the average number of defects (Ta vacancies and N atom excess) is observed. Finally, the influence of thermally introduced oxygen on the films resistivity has been revealed.

  14. Ferrimagnetic Tb-Fe Alloy Thin Films: Composition and Thickness Dependence of Magnetic Properties and All-Optical Switching

    Directory of Open Access Journals (Sweden)

    Birgit eHebler

    2016-02-01

    Full Text Available Ferrimagnetic rare earth - transition metal Tb-Fe alloy thin films exhibit a variety of different magnetic properties, which depends strongly on composition and temperature. In this study, first the influence of the film thickness (5 - 85 nm on the sample magnetic properties was investigated in a wide composition range between 15 at.% and 38 at.% of Tb. From our results, we find that the compensation point, remanent magnetization, and magnetic anisotropy of the Tb-Fe films depend not only on the composition but also on the thickness of the magnetic film up to a critical thickness of about 20-30 nm. Beyond this critical thickness, only slight changes in magnetic properties are observed. This behavior can be attributed to a growth-induced modification of the microstructure of the amorphous films, which affects the short range order. As a result, a more collinear alignment of the distributed magnetic moments of Tb along the out-of-plane direction with film thickness is obtained. This increasing contribution of the Tb sublattice magnetization to the total sample magnetization is equivalent to a sample becoming richer in Tb and can be referred to as an effective composition. Furthermore, the possibility of all-optical switching, where the magnetization orientation of Tb-Fe can be reversed solely by circularly polarized laser pulses, was analyzed for a broad range of compositions and film thicknesses and correlated to the underlying magnetic properties.

  15. Characterization of CuInS{sub 2} nanoparticles and composite films for application in an electrochemical photovoltaic cell

    Energy Technology Data Exchange (ETDEWEB)

    Cirtiu, C.M.; Taibi, R.; Hammami, A.; Marsan, B. [Quebec Univ., Montreal, PQ (Canada). Dept. of Chemistry

    2008-07-01

    Copper indium disulfide (CuInS{sub 2}) is a promising material for the absorber layer in photovoltaic devices. This paper reported on the structural properties of CuInS{sub 2} particles obtained by a colloidal method in which metallic salts were used as the precursors and N-methylimidazole was used as the solvent. X-ray diffraction (XRD), inductively coupled plasma- atomic emission spectroscopy (ICP-AES), energy dispersive X-ray (EDX), scanning electron microscopy (SEM) and UV-Visible spectroscopy were used to characterize the particles. The optical, semiconducting and electrochemical properties of CuInS{sub 2}-containing composite films were also described. The study showed that CuInS{sub 2} particles are of nanometric size and crystallize in a chalcopyrite phase. The band gap energy is 1.5 eV. The slight excess of In suggests an n-type semiconductivity. Composite films containing CuInS{sub 2} particles and polyvinylidene fluoride (PVDF) or polypyrrole (PPy) as a binder, and Ebonex particles for some films containing PVDF, were formed onto an ITO-coated glass support. An examination of the electrochemical behaviour of various composite films revealed an improvement in the electrochemical response when composite films contain Ebonex particles, which contribute to the increase of the film conductivity. Electrochemical impedance spectroscopy revealed that film composition influences the CuInS{sub 2} Fermi level. 8 refs.

  16. Photoluminescence properties of ZnSe/SiO2 composite thin films prepared by sol-gel method

    Institute of Scientific and Technical Information of China (English)

    JIANG Hai-qing; CHE Jun; YAO Xi

    2006-01-01

    ZnSe/SiO2 composite thin films was prepared by sol-gel method. XRD results indicate the phase structure of ZnSe particles embedded in ZnSe/SiO2 composite thin films is sphalerite (cubic ZnS). Spectroscopic ellipsometers were used to investigated the dependences of ellipsometric angle with wavelength of ZnSe/SiO2 composite thin films. The optical constant,thickness,porosity and the concentration of ZnSe of ZnSe/SiO2 thin composite films were fitted according to Maxwell-Garnett effective medium theory. The thickness of ZnSe/SiO2 composite thin thin films was also measured through surface profile. The photoluminescence properties of ZnSe/SiO2 thin composite thin films was investigated through fluorescence spectrometer. The photoluminescence results show that the emission peak at 487 nm (2.5 eV) is excited at 395 nm corresponds to the band-to-band emission of sphalerite ZnSe crystal(2.58 eV). The strength free exciton emission and other emission peaks correlating to ZnSe lattice defect were also observed.

  17. Grain-to-Grain Compositional Variations and Phase Segregation in Copper-Zinc-Tin-Sulfide Films.

    Science.gov (United States)

    Alvarez Barragan, Alejandro; Malekpour, Hoda; Exarhos, Stephen; Balandin, Alexander A; Mangolini, Lorenzo

    2016-09-01

    We have performed a rigorous investigation of the structure and composition of individual grains in copper-zinc-tin-sulfide (CZTS) films realized by sulfurization of a sputtered metal stack. Although on average close to the ideal CZTS stoichiometry, elemental analysis shows significant grain-to-grain variations in composition. High-resolution Raman spectroscopy indicates that this is accompanied by grain-to-grain structural variations as well. The intensity from the 337 cm(-1) Raman peak, generally assigned to the kesterite phase of CZTS, remains constant over a large area of the sample. On the other hand, signals from secondary phases at 376 cm(-1) (copper-tin-sulfide) and 351 cm(-1) (zinc-sulfide) show significant variation over the same area. These results confirm the great complexity inherent to this material system. Moreover, structural and compositional variations are recognized in the literature as a factor limiting the efficiency of CZTS photovoltaic devices. This study demonstrates how a seemingly homogeneous CZTS thin film can actually have considerable structural and compositional variations at the microscale, and highlights the need for routine microscale characterization in this material system. PMID:27538122

  18. Highly conductive, printable and stretchable composite films of carbon nanotubes and silver.

    Science.gov (United States)

    Chun, Kyoung-Yong; Oh, Youngseok; Rho, Jonghyun; Ahn, Jong-Hyun; Kim, Young-Jin; Choi, Hyouk Ryeol; Baik, Seunghyun

    2010-12-01

    Conductive films that are both stretchable and flexible could have applications in electronic devices, sensors, actuators and speakers. A substantial amount of research has been carried out on conductive polymer composites, metal electrode-integrated rubber substrates and materials based on carbon nanotubes and graphene. Here we present highly conductive, printable and stretchable hybrid composites composed of micrometre-sized silver flakes and multiwalled carbon nanotubes decorated with self-assembled silver nanoparticles. The nanotubes were used as one-dimensional, flexible and conductive scaffolds to construct effective electrical networks among the silver flakes. The nanocomposites, which included polyvinylidenefluoride copolymer, were created with a hot-rolling technique, and the maximum conductivities of the hybrid silver-nanotube composites were 5,710 S cm⁻¹ at 0% strain and 20 S cm⁻¹ at 140% strain, at which point the film ruptured. Three-dimensional percolation theory reveals that Poisson's ratio for the composite is a key parameter in determining how the conductivity changes upon stretching. PMID:21113161

  19. Microstructure and tribological properties of NbN-Ag composite films by reactive magnetron sputtering

    Science.gov (United States)

    Ju, Hongbo; Xu, Junhua

    2015-11-01

    Recently, the chameleon thin films were developed with the purpose of adjusting their chemistry at self-mating interfaces in response to environmental changes at a wide temperature range. However, very few studies have focused on what state the lubricious noble metal exists in the films and the tribological properties at room temperature (RT). Composite NbN-Ag films with various Ag content (Ag/(Nb + Ag)) were deposited using reactive magnetron sputtering to investigate the crystal structure, mechanical and tribological properties. A combination of X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and high resolution transmission electron microscopy (HRTEM) analyses showed that face-centered cubic (fcc) NbN, hexagonal close-packed (hcp) NbN and fcc silver coexisted in NbN-Ag films. The incorporation of soft Ag into NbN matrix led to the hardness decrease from 29.6 GPa at 0 at.% Ag to 11.3 GPa at 19.9 at.% Ag. Tribological properties of NbN-Ag films performed using dry pin-on-disc wear tests against Al2O3 depended on Ag content to a large extent. The average friction coefficient and wear rate of NbN-Ag films decreased as Ag content increased from 4.0 to 9.2 at.%. With a further increase of Ag content, the average friction coefficient further decreased, while the wear rate increased gradually. The optimal Ag content was found to be 9.2-13.5 at.%, which showed low average friction coefficient values of 0.46-0.40 and wear rate values of 1.1 × 10-8 to 1.7 × 10-8 mm3/(mm N). 3D Profiler and Raman spectroscopy measurements revealed that the lubricant tribo-film AgNbO3 detected on the surface of the wear tracks could lead to the friction coefficient curve stay constant and decrease the average friction coefficients. The decrease of wear rate was mainly attributed to the lubricant tribo-film AgNbO3 as Ag content increased from 4.0 to 9.2 at.%; with a further increase in Ag content, the wear rate increased with increasing Ag content in NbN-Ag films because a

  20. TiO2-BASED Composite Films for the Photodegradation of Oxytetracycline

    Science.gov (United States)

    Li, Hui; Guan, Ling-Xiao; Feng, Ji-Jun; Li, Fang; Yao, Ming-Ming

    2015-02-01

    The spread of the antibiotic oxytetracycline (OTC) has been thought as a threat to the safety of drinking water. In this paper, the photocatalytic activity of the nanocrystalline Fe/Ca co-doped TiO2-SiO2 composite film for the degradation of OTC was studied. The films were characterized by field emission scanning electron microscopy (FE-SEM) equipped with energy-dispersive spectroscopy (EDS), N2 adsorption/desorption isotherms, photoluminescence (PL) spectra, and UV-Vis diffraction reflectance absorption spectra (DRS). The FE-SEM results indicated that the Fe/Ca co-doped TiO2-SiO2 film was composed of smaller nanoparticles compared to pure TiO2 or TiO2-SiO2 film. The BET surface area results showed that the specific surface area of the pure TiO2, TiO2-SiO2 and Ca2+/Fe3+ co-doped TiO2-SiO2 is 118.3 m2g-1, 294.3 m2g-1 and 393.7 m2g-1, respectively. The DRS and PL spectra revealed that the Fe/Ca co-doped TiO2-SiO2 film had strong visible light adsorption and diminished electrons/holes recombination. Experimental results showed that the Fe/Ca co-doped TiO2-SiO2 film is effective in the degradation of OTC under both UV and visible light irradiation.

  1. Magnetic studies of polystyrene/iron-filled multi-wall carbon nanotube composite films

    Science.gov (United States)

    Makarova, T. L.; Zakharchuk, I.; Geydt, P.; Lahderanta, E.; Komlev, A. A.; Zyrianova, A. A.; Kanygin, M. A.; Sedelnikova, O. V.; Suslyaev, V. I.; Bulusheva, L. G.; Okotrub, A. V.

    2016-10-01

    Polystyrene/iron-filled multi-wall carbon nanotube composite films were prepared by solution processing, forge-rolling and stretching methods. Elongated iron carbide nanoparticles formed because of catalytic growth are situated inside the hollow cavity of the nanotubes. Magnetic susceptibility measurements as well as records of isothermal hysteresis loops performed in three perpendicular directions of magnetic field confirmed that the nanotubes have a preferential alignment in the matrix. Strong diamagnetic anisotropy in the composites emerges not only from the MWCNTs but also from the polystyrene matrix. The polymer sticks to the honeycomb lattice through the interaction of the π-orbitals of the phenyl ring and those of the carbon nanotube, contributing to anisotropic diamagnetic response. The contribution of iron nanoparticles to overall magnetic response strongly depends on nanotube concentration in the composite as well as on matrix-filler non-covalent stacking, which influences magnetic interparticle interactions.

  2. Performance of diffusive gradients in thin films for measurement of the isotopic composition of soluble Zn

    International Nuclear Information System (INIS)

    The application of diffusive gradients in thin films (DGT) samplers for measurements of the isotopic composition of soluble Zn by multi-collector inductively coupled plasma mass spectrometry (MC-ICPMS) was tested under laboratory conditions. The effect of diffusion in hydrogels as a possible source of fractionation was investigated by measuring Zn isotope ratios for different fractions of Zn accumulated by DGT and comparing with the bulk isotope composition of the solution. An important finding of this study is that, provided quantitative elution is obtained, no fractionation of Zn isotopes due to the diffusion process is detectable within the reported precision of MC-ICPMS measurements. Consequently, DGT samplers are suitable for studies of the Zn isotopic composition in natural waters

  3. Nanoparticulate cerium dioxide and cerium dioxide-titanium dioxide composite thin films on glass by aerosol assisted chemical vapour deposition

    International Nuclear Information System (INIS)

    Two series of composite thin films were deposited on glass by aerosol assisted chemical vapour deposition (AACVD)-nanoparticulate cerium dioxide and nanoparticulate cerium dioxide embedded in a titanium dioxide matrix. The films were analysed by a range of techniques including UV-visible absorption spectroscopy, X-ray diffraction, scanning electron microscopy and energy dispersive analysis by X-rays. The AACVD prepared films showed the functional properties of photocatalysis and super-hydrophilicity. The CeO2 nanoparticle thin films displaying photocatalysis and photo-induced hydrophilicity almost comparable to that of anatase titania.

  4. The influence of the surface composition of mixed monolayer films on the evaporation coefficient of water.

    Science.gov (United States)

    Miles, Rachael E H; Davies, James F; Reid, Jonathan P

    2016-07-20

    We explore the dependence of the evaporation coefficient of water from aqueous droplets on the composition of a surface film, considering in particular the influence of monolayer mixed component films on the evaporative mass flux. Measurements with binary component films formed from long chain alcohols, specifically tridecanol (C13H27OH) and pentadecanol (C15H31OH), and tetradecanol (C14H29OH) and hexadecanol (C16H33OH), show that the evaporation coefficient is dependent on the mole fractions of the two components forming the monolayer film. Immediately at the point of film formation and commensurate reduction in droplet evaporation rate, the evaporation coefficient is equal to a mole fraction weighted average of the evaporation coefficients through the equivalent single component films. As a droplet continues to diminish in surface area with continued loss of water, the more-soluble, shorter alkyl chain component preferentially partitions into the droplet bulk with the evaporation coefficient tending towards that through a single component film formed simply from the less-soluble, longer chain alcohol. We also show that the addition of a long chain alcohol to an aqueous-sucrose droplet can facilitate control over the degree of dehydration achieved during evaporation. After undergoing rapid gas-phase diffusion limited water evaporation, binary aqueous-sucrose droplets show a continued slow evaporative flux that is limited by slow diffusional mass transport within the particle bulk due to the rapidly increasing particle viscosity and strong concentration gradients that are established. The addition of a long chain alcohol to the droplet is shown to slow the initial rate of water loss, leading to a droplet composition that remains more homogeneous for a longer period of time. When the sucrose concentration has achieved a sufficiently high value, and the diffusion constant of water has decreased accordingly so that bulk phase diffusion arrest occurs in the monolayer

  5. Synthesis of Ag-TiO{sub 2} composite nano thin film for antimicrobial application

    Energy Technology Data Exchange (ETDEWEB)

    Yu Binyu; Guo Qiuquan; Yang Jun [Biomedical Engineering Graduate Program, University of Western Ontario, London, ON, N6A 5B9 (Canada); Leung, Kar Man [Department of Mechanical and Materials Engineering, University of Western Ontario, London, ON, N6A 5B9 (Canada); Lau, Woon Ming [Surface Science Western, University of Western Ontario, London, ON, N6A 5B9 (Canada)

    2011-03-18

    TiO{sub 2} photocatalysts have been found to kill cancer cells, bacteria and viruses under mild UV illumination, which offers numerous potential applications. On the other hand, Ag has long been proved as a good antibacterial material as well. The advantage of Ag-TiO{sub 2} nanocomposite is to expand the nanomaterial's antibacterial function to a broader range of working conditions. In this study neat TiO{sub 2} and Ag-TiO{sub 2} composite nanofilms were successfully prepared on silicon wafer via the sol-gel method by the spin-coating technique. The as-prepared composite Ag-TiO{sub 2} and TiO{sub 2} films with different silver content were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), x-ray diffraction (XRD) and x-ray photoelectron spectroscopy (XPS) to determine the topologies, microstructures and chemical compositions, respectively. It was found that the silver nanoparticles were uniformly distributed and strongly attached to the mesoporous TiO{sub 2} matrix. The morphology of the composite film could be controlled by simply tuning the molar ratio of the silver nitrate aqueous solution. XPS results confirmed that the Ag was in the Ag{sup 0} state. The antimicrobial effect of the synthesized nanofilms was carried out against gram-negative bacteria (Escherichia coli ATCC 29425) by using an 8 W UV lamp with a constant relative intensity of 0.6 mW cm{sup -2} and in the dark respectively. The synthesized Ag-TiO{sub 2} thin films showed enhanced bactericidal activities compared to the neat TiO{sub 2} nanofilm both in the dark and under UV illumination.

  6. Fabrication of a novel bone ash-reinforced gelatin/alginate/hyaluronic acid composite film for controlled drug delivery.

    Science.gov (United States)

    Alemdar, Neslihan

    2016-10-20

    In this study, a novel pH-sensitive composite film with enhanced thermal and mechanical properties was prepared by the incorporation of bone ash at varying concentrations from 0 to 10v.% into gelatin/sodium alginate/hyaluronic acid (Gel/SA/HyA) polymeric structure for colon-specific drug delivery system. Films were characterized by FT-IR, SEM, and XRD analyses. Thermal and mechanical performances of films were determined by DSC, TGA and universal mechanical tester, respectively. Results proved that thermal stability and mechanical properties of bone ash-reinforced composite films improved significantly with respect to that of neat Gel/SA/HyA film. Cytotoxicity assay for composite films was carried out by using L929 cells. Water uptake capacity of films was determined by swelling test. Herein, release experiments of 5-Fluorouracil (5-FU) were performed in two different solutions (pH 2.1 and 7.4). The results assured that Gel/SA/HyA film containing BA could be considered as a potential biomaterial for controlled drug delivery systems. PMID:27474650

  7. Effect of Gallic acid on mechanical and water barrier properties of zein-oleic acid composite films.

    Science.gov (United States)

    Masamba, Kingsley; Li, Yue; Hategekimana, Joseph; Liu, Fei; Ma, Jianguo; Zhong, Fang

    2016-05-01

    In this study, the effect of gallic acid on mechanical and water barrier properties of zein-oleic acid 0-4 % composite films was investigated. Molecular weight distribution analysis was carried out to confirm gallic acid induced cross linking through change in molecular weight in fraction containing zein proteins. Results revealed that gallic acid treatment increased tensile strength from 17.9 MPa to 26.0 MPa, decreased water vapour permeability from 0.60 (g mm m(-2) h(-1) kPa(-1)) to 0.41 (g mm m(-2) h(-1) kPa(-1)), increased solubility from 6.3 % to 10.2 % and marginally increased elongation at break from 3.7 % to 4.2 % in zein films only. However, gallic acid treatment in zein-oleic composite films did not significantly influence mechanical and water barrier properties and in most instances irrespective of oleic acid concentration, the properties were negatively affected. Results from scanning electron microscopy showed that both gallic acid treated and untreated zein films and composite films containing 3 % oleic acid had a compact and homogeneous structure while those containing 4 % oleic acid had inhomogeneous structure. The findings have demonstrated that gallic acid treatment can significantly improve mechanical and water barrier properties especially in zein films only as opposed to when used in composite films using zein and oleic acid. PMID:27407188

  8. Compositional analysis of polycrystalline hafnium oxide thin films by heavy-ion elastic recoil detection analysis

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, F.L. [Departamento de Electronica y Tecnologia de Computadoras, Universidad Politecnica de Cartagena, Campus Universitario Muralla del Mar, E-30202 Cartagena (Spain)]. E-mail: Felix.Martinez@upct.es; Toledano, M. [Departamento de Fisica Aplicada III, Universidad Complutense de Madrid, E-28025 Madrid (Spain); San Andres, E. [Departamento de Fisica Aplicada III, Universidad Complutense de Madrid, E-28025 Madrid (Spain); Martil, I. [Departamento de Fisica Aplicada III, Universidad Complutense de Madrid, E-28025 Madrid (Spain); Gonzalez-Diaz, G. [Departamento de Fisica Aplicada III, Universidad Complutense de Madrid, E-28025 Madrid (Spain); Bohne, W. [Hahn-Meitner-Institut Berlin, Abteilung SF-4, D-14109 Berlin (Germany); Roehrich, J. [Hahn-Meitner-Institut Berlin, Abteilung SF-4, D-14109 Berlin (Germany); Strub, E. [Hahn-Meitner-Institut Berlin, Abteilung SF-4, D-14109 Berlin (Germany)

    2006-10-25

    The composition of polycrystalline hafnium oxide thin films has been measured by heavy-ion elastic recoil detection analysis (HI-ERDA). The films were deposited by high-pressure reactive sputtering (HPRS) on silicon wafers using an oxygen plasma at pressures between 0.8 and 1.6 mbar and during deposition times between 0.5 and 3.0 h. Hydrogen was found to be the main impurity and its concentration increased with deposition pressure. The composition was always slightly oxygen-rich, which is attributed to the oxygen plasma. Additionally, an interfacial silicon oxide thin layer was detected and taken into account. The thickness of the hafnium oxide film was found to increase linearly with deposition time and to decrease exponentially with deposition pressure, whereas the thickness of the silicon oxide interfacial layer has a minimum as a function of pressure at around 1.2 mbar and increases slightly as a function of time. The measurements confirmed that this interfacial layer is formed mainly during the early stages of the deposition process.

  9. Formation of Ultrananocrystalline Diamond/Amorphous Carbon Composite Films in Vacuum Using Coaxial Arc Plasma Gun

    Science.gov (United States)

    Hanada, Kenji; Yoshida, Tomohiro; Nakagawa, You; Yoshitake, Tsuyoshi

    2010-12-01

    Ultrananocrystalline diamond (UNCD)/nonhydrogenated amorphous carbon (a-C) composite films were grown in vacuum using a coaxial arc plasma gun. From the X-ray diffraction measurement, the UNCD crystallite size was estimated to be 1.6 nm. This size is dramatically reduced from that (2.3 nm) of UNCD/hydrogenated amorphous carbon (a-C:H) composite films grown in a hydrogen atmosphere. The sp3/(sp3 + sp2) value, which was estimated from the X-ray photoemission spectrum, was also reduced to be 41%. A reason for it might be the reduction in the UNCD crystallite size. From the near-edge X-ray absorption fine-structure (NEXAFS) spectrum, it was found that the π*C=C and π*C≡C bonds are preferentially formed instead of the σ*C-H bonds in the UNCD/a-C:H films. Since the extremely small UNCD crystallites (1.6 nm) correspond to the nuclei of diamond, we consider that UNCD crystallite formation should be due predominantly to nucleation. The supersaturated condition required for nucleation is expected to be realized in the deposition using the coaxial arc plasma gun.

  10. Broadband epsilon-near-zero metamaterials based on metal-polymer composite thin films

    Science.gov (United States)

    Pinchuk, Pavlo; Jiang, Ke

    2015-10-01

    Epsilon-near-zero (ENZ) metamaterials are designed to exhibit a near-zero response for the real part of the dielectric permittivity at a given frequency or in a specific frequency range. Typically, this frequency range is relatively small. In this paper, we present an approach to broaden this range by controlling the size of the nanoparticles embedded in a thin film. Noble metal nanoparticles exhibit an external size effect that redshifts the Surface Plasmon Resonance frequency with an increase of the size of the particles. The absorption spectrum of a material can be directly related to its dielectric permittivity via the Kramers-Kronig relations. We use the Kramers-Kronig relations to retrieve the complex effective dielectric permittivity of a composite film, which is designed to exhibit ENZ behavior over a broad frequency range. We synthesize a composite thin film embedded with metal nanoparticles of a broad size distribution. Such a material exhibits a broad SPR, and, in turn, broadband ENZ behavior.

  11. Frequency control of sol–gel composite films fabricated by stencil printing for nondestructive testing applications

    Science.gov (United States)

    Kaneko, Tsukasa; Kibe, Taiga; Kimoto, Keisuke; Nishimura, Ryota; Kobayashi, Makiko

    2016-07-01

    Ultrasonic transducers made of sol–gel composites have been developed for nondestructive testing (NDT) applications in various industrial fields. Stencil printing of sol–gel composite films has been developed for the reduction of fabrication time and cost. However, it was necessary to develop low frequency (ultrasonic transducers for inspecting industrial structures under severe high-temperature conditions, because high-frequency components suffer attenuation effect caused by high temperature. To realize this, increasing the thickness of Pb(Zr,Ti)O3 (PZT)/PZT films fabricated by stencil printing was attempted in this study. The samples were fabricated by single-layer stencil printing with a thick stencil mask and multilayer pure stencil printing with prespraying and postspraying. The film thicknesses were 150–185 µm, and the center frequencies of ultrasonic responses were 6.0–6.4 MHz. Throughout three thermal cycles of up to 370 K, the ultrasonic performance was stable, and the frequency characteristics were not markedly different from the beginning to the end of the test. Therefore, low-frequency ultrasonic transducers were successfully manufactured using a stencil-printing-based technique.

  12. Luminescence study of ZnSe/PVA (polyvinyl alcohol) composite film

    Science.gov (United States)

    Lahariya, Vikas

    2016-05-01

    The ZnSe nanocrystals have been prepared into poly vinyl alcohol(PVA) polymer matrix on glass using ZnCl2 and Na2SeSO3 as zinc and selenium source respectively. Poly vinyl Alcohol (PVA) used as polymer matrix cum capping agent due to their high viscosity and water solubility. It is transparent for visible region and prevents Se- ions to photo oxidation. The ZnSe/PVA composite film was deposited on glass substrate. The film was characterized by X Ray Diffraction (XRD) and UV-Visible absorption Spectroscopy and Photoluminescence. The X Ray Diffraction (XRD) study confirms the nanometer size (10 nm) particle formation within PVA matrix with cubic zinc blend crystal structure. The UV-Visible Absorption spectrum of ZnSe/PVA composite film shown blue shift in absorption edge indicating increased band gap due to quantum confinement. The calculated energy band gap from the absorption edge using Tauc relation is 3.4eV. From the Photoluminescence study a broad peak at 435 nm has been observed in violet blue region due to recombination of surface states.

  13. Composition and morphological characteristics of chemically sprayed fluorine-doped zinc oxide thin films deposited on Si(1 0 0)

    Energy Technology Data Exchange (ETDEWEB)

    Castaneda, L. [Centro de Ciencias Aplicadas y Desarrollo Tecnologico, Universidad Nacional Autonoma de Mexico, Apartado Postal 70-186, 04510 D. F. (Mexico); Departamento de Fisica y Matematicas, Division de Ciencia, Arte y Tecnologia, Universidad Iberoamericana, Av. Prolongacion Paseo de la Reforma 880, Santa Fe 012100, D. F. (Mexico); Maldonado, A. [Depto. de Ing. Electrica, CINVESTAV IPN, SEES, Apartado Postal 14740, Mexico, D.F. 07000 (Mexico); Cheang-Wong, J.C. [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, Apartado Postal 20-364, Mexico, D.F. 01000 (Mexico); Terrones, M. [Advanced Materials Department, IPICYT, Camino a la Presa San Jose 2055, Col. Lomas, 4a. seccion, San Luis Potosi, 78216 (Mexico); Departamento de Fisica y Matematicas, Division de Ciencia, Arte y Tecnologia, Universidad Iberoamericana, Av. Prolongacion Paseo de la Reforma 880, Santa Fe 012100, D. F. (Mexico); Olvera, M. de la L [Depto. de Ing. Electrica, CINVESTAV IPN, SEES, Apartado Postal 14740, Mexico, D.F. 07000 (Mexico)]. E-mail: molvera@cinvestav.mx

    2007-03-01

    Fluorine-doped zinc oxide thin films (ZnO:F) were deposited on Si(1 0 0) substrates by the chemical spray technique (CST) from an aged-solution. The effect of the substrate temperature on the morphology and composition of the ZnO:F thin films was studied. The films were polycrystalline, with a preferential growth along the ZnO (0 0 2) plane, irrespective of the deposition temperature. The average crystal size within the films was ca. 35 nm and the morphology of the surface was found to be dependent on the substrate temperature. At low substrate temperatures irregular-shaped grains were observed, whereas at higher temperatures uniform flat grains were obtained. Elemental analysis showed that the composition of the films is close to stoichiometric ZnO and that samples contain quite a low fluorine concentration, which decreases as a function of the deposition temperature.

  14. Preparation and optical properties of composite thin films with embedded InP nanoparticles

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    InP nanoparticles embedded in SiO2 thin films were prepared by radio-frequency magnetron co-sputtering. We analyzed the structure and growth behavior of the composite films under different preparation conditions. X-ray diffraction and Raman spectroscopy analyses indicate that InP nanoparticles have a polycrystalline structure. The aver-age size of InP nanoparticles is in the range of 3-10 nm. The broadening and red shift of the Raman peaks were observed,which can be interpreted by the phonon confinement model. Optical transmission spectra indicate that the optical absorp-tion edges of the films can be modulated in the visible light range. The marked blue shift of the absorption edge with respect to that of bulk InP is explained by the quantum con-finement effect. The theoretical values of the blue shift pre-dicted by the effective mass approximation model are differ-ent from the experimental results for the InP-SiO2 system. Analyses indicate that the exciton effective mass of the InP nanoparticles is not constant and is inverse relative to the particles radius,which may be the main reason that results in the discrepancy between the theoretical and the experi-mental result. We discussed the possible transition of the direct band gap to the indirect band gap for InP nanoparti-cles embedded in SiO2 thin films.

  15. Fabrication and application of flexible graphene silk composite film electrodes decorated with spiky Pt nanospheres.

    Science.gov (United States)

    Liang, Bo; Fang, Lu; Hu, Yichuan; Yang, Guang; Zhu, Qin; Ye, Xuesong

    2014-04-21

    A free-standing graphene silk composite (G/S) film was fabricated via vacuum filtration of a mixed suspension of graphene oxide and silk fibres, followed by chemical reduction. Spiky structured Pt nanospheres were grown on the film substrate by cyclic voltammetry electrodeposition. The electrical and mechanical performance of a single graphene coated silk fibre was investigated. The conductivity of a single graphene coated silk fibre is 57.9 S m(-1). During 1000 bending measurements, the conductivity was stable and showed negligible variation. The G/S film has a sheet resistivity of 90 Ω □(-1) with a porous and hierarchical structure. The spiky Pt nanosphere decorated G/S film was directly used as a H₂O₂ electrode with a sensitivity of 0.56 mA mM(-1) cm(-2), a linear range of 0-2.5 mM and an ultralow detection limit of 0.2 μM (S/N = 3). A glucose biosensor electrode was further fabricated by enzyme immobilization. The results show a sensitivity of 150.8 μA mM(-1) cm(-2) and a low detection limit of 1 μM (S/N = 3) for glucose detection. The strategy of coating graphene sheets on a silk fibre surface provides a new approach for developing electrically conductive biomaterials, tissue engineering scaffolds, bendable electrodes, and wearable biomedical devices. PMID:24615460

  16. Fabrication and application of flexible graphene silk composite film electrodes decorated with spiky Pt nanospheres.

    Science.gov (United States)

    Liang, Bo; Fang, Lu; Hu, Yichuan; Yang, Guang; Zhu, Qin; Ye, Xuesong

    2014-04-21

    A free-standing graphene silk composite (G/S) film was fabricated via vacuum filtration of a mixed suspension of graphene oxide and silk fibres, followed by chemical reduction. Spiky structured Pt nanospheres were grown on the film substrate by cyclic voltammetry electrodeposition. The electrical and mechanical performance of a single graphene coated silk fibre was investigated. The conductivity of a single graphene coated silk fibre is 57.9 S m(-1). During 1000 bending measurements, the conductivity was stable and showed negligible variation. The G/S film has a sheet resistivity of 90 Ω □(-1) with a porous and hierarchical structure. The spiky Pt nanosphere decorated G/S film was directly used as a H₂O₂ electrode with a sensitivity of 0.56 mA mM(-1) cm(-2), a linear range of 0-2.5 mM and an ultralow detection limit of 0.2 μM (S/N = 3). A glucose biosensor electrode was further fabricated by enzyme immobilization. The results show a sensitivity of 150.8 μA mM(-1) cm(-2) and a low detection limit of 1 μM (S/N = 3) for glucose detection. The strategy of coating graphene sheets on a silk fibre surface provides a new approach for developing electrically conductive biomaterials, tissue engineering scaffolds, bendable electrodes, and wearable biomedical devices.

  17. Room-temperature growth of Ni-Zn-Cu ferrite/PTFE composite thick films on PET via aerosol deposition

    Science.gov (United States)

    Kim, Hyung-Jun; Kwon, Oh-Yun; Jang, Chan-Ick; Kim, Tae Kyoung; Oh, Jun Rok; Yoon, Young Joon; Kim, Jong-Hee; Nam, Song-Min; Koh, Jung-Hyuk

    2013-11-01

    Ni-Zn-Cu ferrite and Ni-Zn-Cu ferrite/poly-tetra-fluoro-ethylene (PTFE) composite-thick-films were grown at room temperature on polyethylene terephthalate (PET) sheets via aerosol deposition (AD) as a magnetic shielding sheet for near-field communication. An 80 µm-thick Ni-Zn-Cu ferrite/PTFE composite-thick-film was grown on the PET sheet when 2.0 wt. % PTFE starting powder was used. The real relative permeability µ r ' and the imaginary permeability µ r ″ of the Ni-Zn-Cu ferrite thick film were 10.1 and 2.1 at 13.56 MHz, respectively. In the case of the composite thick film, µ r ' and µ r ″ decreased to 3.9 and 1.3, respectively, at 13.56 MHz; with the addition of the PTFE.

  18. Complex structure/composition relationship in thin films of AlCoCrCuFeNi high entropy alloy

    International Nuclear Information System (INIS)

    We have studied the deposition of AlCoCrCuFeNi high entropy alloy (HEA) thin films on Si (1 0 0) substrates by DC magnetron sputtering process. Three mosaic targets have been used for easily tailoring the film composition. Energy dispersive X-ray spectrometry analysis has shown that chemical composition can be modified around the nominal value by tuning the ratio of the powers applied to the magnetron targets. The deposition rate is directly related to the power sum. Moreover, various surface morphologies have been evidenced by scanning electron microscopy and correlated to the crystalline phases present in the films. Morphology and crystalline structure have been found to depend on the chemical composition. Wetting contact angle has been measured with water droplets, showing that the hydrophobic properties of the thin films depend on their characteristics.

  19. Synthesis of nano-crystalline zirconium aluminium oxynitride (ZrAlON) composite films by dense plasma Focus device

    International Nuclear Information System (INIS)

    Zirconium aluminium oxynitride multiphase composite film is deposited on zirconium substrate using energetic nitrogen ions delivered from dense plasma Focus device. X-ray diffractometer (XRD) results show that five Focus shots are sufficient to initiate the nucleation of ZrN and Al2O3 whereas 10 Focus shots are sufficient to initiate the nucleation of AlN. XRD results reveal that crystal growth of nitrides/oxides increases by increasing Focus shots (up to 30 Focus shots) and resputtering of the previously deposited film is taken place by further increase in Focus shots (40 Focus shots). Scanning electron microscopic (SEM) results indicate the uniform distribution of spherical grains (∼35 nm). A smoother surface is observed for 20 Focus shots at 0 deg. angular position. SEM results also show a net-type microstructure (thread like features) of the sample treated for 30 Focus shots whereas rough surface morphology is observed for 40 Focus shots. Energy dispersive spectroscopic profiles show the distribution of different elements present in the deposited composite films. A typical microhardness value of the deposited composite films is 5255 ± 10 MPa for 10 grams imposed load which is 3.3 times than the microhardness values of unexposed sample. The microhardness values of the exposed samples increases with increasing Focus shots (up to 30 Focus shots) and decreases for 40 Focus shots treatment due to resputtering of the previously deposited composite film. The microhardness values of the composite films decreases by increasing the sample's angular position.

  20. Transmission of terahertz radiation by anisotropic MWCNT/polystyrene composite films

    Energy Technology Data Exchange (ETDEWEB)

    Okotrub, A.V.; Bulusheva, L.G. [Nikolaev Institute of Inorganic Chemistry, SB RAS, 3 Acad. Lavrentiev Ave., 630090 Novosibirsk (Russian Federation); Novosibirsk State Technical University, 20 Karl Marx Ave., 630092 Novosibirsk (Russian Federation); Kubarev, V.V. [Budker Institute of Nuclear Physics, SB RAS, 11 Acad. Lavrentiev Ave., 630090 Novosibirsk (Russian Federation); Novosibirsk State University, 2 Pirogova st., 630090 Novosibirsk (Russian Federation); Kanygin, M.A.; Sedelnikova, O.V. [Nikolaev Institute of Inorganic Chemistry, SB RAS, 3 Acad. Lavrentiev Ave., 630090 Novosibirsk (Russian Federation)

    2011-11-15

    Anisotropic composite materials have been prepared by repeated forge rolling of polystyrene and carbon nanotubes (CNTs) with length of {proportional_to}65 {mu}m. Transmission spectra of the composites were recorded for two different polarizations of the electric field. Obtained data indicated that the forge rolling resulted in a predominant orientation of CNTs in polymer matrix. Anisotropic response of the composites was measured at 130 {mu}m wavelength on the Novosibirsk terahertz free electron laser and angular dependence of the transmitted light was determined. Absorption spectrum showed no strong resonance features and it was interpreted by CNTs breaking and agglomeration of CNT fragments during the composite fabrication procedure. Based on classical theory of scattering, considered the scatters as electromagnetic antennas, the size distribution of CNTs in composites was found. Anisotropy of terahertz radiation transmitted from MWCNT/polystyrene composite film on the Novosibirsk free electron laser at 130 {mu}m wavelength. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  1. Electrocatalytic Hydrogen Evolution from Molybdenum Sulfide-Polymer Composite Films on Carbon Electrodes.

    Science.gov (United States)

    Lattach, Youssef; Deronzier, Alain; Moutet, Jean-Claude

    2015-07-29

    The design of more efficient catalytic electrodes remains an important objective for the development of water splitting electrolyzers. In this context a structured composite cathode material has been synthesized by electrodeposition of molybdenum sulfide (MoSx) into a poly(pyrrole-alkylammonium) matrix, previously coated onto carbon electrodes by oxidative electropolymerization of a pyrrole-alkylammonium monomer. The composite material showed an efficient electrocatalytic activity toward proton reduction and the hydrogen evolution reaction (HER). Data from Tafel plots have demonstrated that the electron transfer rate in the composite films is fast, in agreement with the high catalytic activity of this cathode material. Bulk electrolysis of acidic water at carbon foam electrodes modified with the composite have shown that the cathodes display a high catalytic activity and a reasonable operational stability, largely exceeding that of regular amorphous MoSx electrodeposited on naked carbon foam. The enhanced catalytic performances of the composite electrode material were attributed to the structuration of the composite, which led to a homogeneous distribution of the catalyst on the carbon foam network, as shown by SEM characterizations. PMID:26147828

  2. Exchange bias and anisotropy analysis of nano-composite Co{sub 84}Zr{sub 16}N thin films

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Jitendra, E-mail: jitendra@ceeri.ernet.in [CSIR-Central Electronics Engineering Research Institute, Pilani, Rajasthan 333031 (India); Academy of Scientific and Innovative Research, Chennai 600113 (India); Taube, William Ringal [CSIR-Central Electronics Engineering Research Institute, Pilani, Rajasthan 333031 (India); Academy of Scientific and Innovative Research, Chennai 600113 (India); Ansari, Akhtar Saleem [Department of Applied Physics, Aligarh Muslim University, Aligarh 202002 (India); Gupta, Sanjeev Kumar [Academy of Scientific and Innovative Research, Chennai 600113 (India); Kulriya, Pawan Kumar [Inter-University Accelerator Centre, New Delhi 110067 (India); Akhtar, Jamil [CSIR-Central Electronics Engineering Research Institute, Pilani, Rajasthan 333031 (India); Academy of Scientific and Innovative Research, Chennai 600113 (India)

    2015-03-15

    Nano-composite Co{sub 84}Zr{sub 16}N (CZN) films were prepared by reactive co-sputter deposition. As-deposited CZN films have not shown any exchange bias effect. But annealed (390 K) and field cooled samples have shown exchange bias phenomena. The observed exchange bias is attributed to inter-cluster exchange coupling between ferromagnetic and antiferromagnetic nano-composite phase. High resolution transmission electron microscope study reveals that, the CZN films are composed of ordered and crystalline ferromagnetic Cobalt nano-clusters embedded in an antiferromagnetic matrix. X-ray diffraction confirms the poly-crystalline growth of the CZN films with a preferred fcc (622) phase formation. In-plane anisotropy of the exchange biased films was investigated by rotational magnetization curve, and the analysis shows that the magnetization reversal behaves according to the coherent rotation of the magnetic moment vector. Effectively, exchange bias effect in such single layer films could be attributed to co-existing antiferromagnetic and ferromagnetic phase within the single layer. Such single layer nano-composite films can be a possible alternative to the bilayer combination of antiferromagnetic/ferromagnetic exchange biased films and are ideally suited for spintronics and tunnel junction applications. - Highlights: • Exchange bias effect observed in 390 K annealed and field cooled single layer nanocomposite Co{sub 84}Zr{sub 16}N (CZN) thin films. • CZN films are composed of ordered and crystalline ferromagnetic Cobalt nano-clusters embedded in antiferromagnetic matrix. • Uniaxial magnetic anisotropy investigated by rotational magnetization curve, and magnetization reversal behaves according to coherent rotation of magnetic moment vector. • Co-existing FM and AF phases in composite matrix are lead to extraordinary EB behavior.

  3. DESIGN OF FILM THICKNESS INSTRUMENT FOR FIBRE POLYMER COMPOSITES TRIBOLOGICAL EXPERIMENTS

    Directory of Open Access Journals (Sweden)

    B. F. YOUSIF

    2014-04-01

    Full Text Available New technique to measure film thickness in tribological experiments is presented in the current study. The technique is based on strain gauges circuit fixed on a lever of the block on ring (BOR machine. Conversion of strain gauge readings was made to determine the film thickness values. For testing purposes, experiments were conducted using the new machine to investigate the wear performance of glass/polyester composites. The tests were performed against aluminium counterface at different applied loads (0.5 N to 3 N for 10 minutes sliding time under wet contact conditions. From the results, the new technique highly assisted to analysis the tribological results. The SEM showed different damage features.

  4. Recent Progress in Evaluation Techniques and Device Applications of Organic and Composite Thin Films

    Science.gov (United States)

    Kato, Keizo; Shinbo, Kazunari; Okamoto, Tetsushi; Aoki, Yusuke; Iechi, Hiroyuki

    Evaluation techniques and the device applications of organic and composite thin films are described. One of the evaluation techniques is the surface plasmon resonance (SPR) spectroscopy. It has become a widely accepted method for the characterization and study of ultrathin films, interfaces and kinetic processes at surfaces, and it has been investigated in the applications of SPR sensors and plasmonic novel devices. Properties, functionalization and various applications of hybrid materials, nanocomposites, and nanoparticles are also introduced, and the application to industry is mentioned. Moreover, electronic device application of monolithic organic logic circuit using a stacked structure of two organic static induction transistors is explained. The advantages of this novel device structure are the controllability of the operational characteristics and simple device fabrication process.

  5. Hydrophilic nanofibers as new supports for thin film composite membranes for engineered osmosis.

    Science.gov (United States)

    Bui, Nhu-Ngoc; McCutcheon, Jeffrey R

    2013-02-01

    Engineered osmosis (e.g., forward osmosis, pressure-retarded osmosis, direct osmosis) has emerged as a new platform for applications to water production, sustainable energy, and resource recovery. The lack of an adequately designed membrane has been the major challenge that hinders engineered osmosis (EO) development. In this study, nanotechnology has been integrated with membrane science to build a next generation membrane for engineered osmosis. Specifically, hydrophilic nanofiber, fabricated from different blends of polyacrylonitrile and cellulose acetate via electrospinning, was found to be an effective support for EO thin film composite membranes due to its intrinsically wetted open pore structure with superior interconnectivity. The resulting composite membrane exhibits excellent permselectivity while also showing a reduced resistance to mass transfer that commonly impacts EO processes due to its thin, highly porous nanofiber support layer. Our best membrane exhibited a two to three times enhanced water flux and 90% reduction in salt passage when compared to a standard commercial FO membrane. Furthermore, our membrane exhibited one of the lowest structural parameters reported in the open literature. These results indicate that hydrophilic nanofiber supported thin film composite membranes have the potential to be a next generation membrane for engineered osmosis.

  6. Preparation and characterization of PVP-PVA-ZnO blend polymer nano composite films

    Science.gov (United States)

    Divya, S.; Saipriya, G.; Hemalatha, J.

    2016-05-01

    Flexible self-standing films of PVP-PVA blend composites are prepared by using ZnO as a nano filler at different concentrations. The structural, compositional, morphological and optical studies made with the help of X-ray diffraction (XRD), Fourier Transform Infra-Red spectroscopy (FTIR), Scanning electron microscope (SEM), Atomic Force Microscopy (AFM), Ultraviolet-visible spectroscopy (UV-vis) and Photoluminescence (PL) spectra are presented in this paper. The results of XRD indicate that ZnO nanoparticles are formed with hexagonal phase in the polymeric matrix. SEM images show the dispersion of ZnO nano filler in the polymer matrix. UV-vis spectra reveal that the absorption peak is centered around 235nm and 370nm for the nano composite films. The blue shift is observed with decrease in the concentration of the nano filler. PL spectra shows the excitation wavelength is given at 320nm.The emission peaks were observed at 383 nm ascribing to the electronic transitions between valence band and conduction band and the peak at 430 nm.

  7. Thin Film Nanofibrous Composite Membrane for Dead-End Seawater Desalination

    Directory of Open Access Journals (Sweden)

    Baturalp Yalcinkaya

    2016-01-01

    Full Text Available The aim of the study was to prepare a thin film nanofibrous composite membrane utilized for nanofiltration technologies. The composite membrane consists of a three-layer system including a nonwoven part as the supporting material, a nanofibrous scaffold as the porous surface, and an active layer. The nonwoven part and the nanofibrous scaffold were laminated together to improve the mechanical properties of the complete membrane. Active layer formations were done successfully via interfacial polymerization. A filtration test was carried out using solutions of MgSO4, NaCl, Na2SO4, CaCl2, and real seawater using the dead-end filtration method. The results indicated that the piperazine-based membrane exhibited higher rejection of divalent salt ions (>98% with high flux. In addition, the m-phenylenediamine-based membrane exhibited higher rejection of divalent and monovalent salt ions (>98% divalent and >96% monovalent with reasonable flux. The desalination of real seawater results showed that thin film nanofibrous composite membranes were able to retain 98% of salt ions from highly saline seawater without showing any fouling. The electrospun nanofibrous materials proved to be an alternative functional supporting material instead of the polymeric phase-inverted support layer in liquid filtration.

  8. Thin polymer films of block copolymers and blend/nanoparticle composites

    Science.gov (United States)

    Kalloudis, Michail

    In this thesis, atomic force microscopy (AFM), transmission electron microscopy (TEM) and optical microscopy techniques were used to investigate systematically the self-assembled nanostructure behaviour of two different types of spin-cast polymer thin films: poly(isoprene-b-ethylene oxide), PI-b-PEO diblock copolymers and [poly(9,9-dioctylfluorene-co-benzothiadiazole)]:poly[9,9- dioctyfluorene-co-N-(4-butylphenyl)-diphenylamine], F8BT:TFB conjugated polymer blends. In the particular case of the polymer blend thin films, the morphology of their composites with cadmium selenide (CdSe) quantum dot (QD) nanoparticles was also investigated. For the diblock copolymer thin films, the behaviour of the nanostructures formed and the wetting behaviour on mica, varying the volume fraction of the PEO block (fPEO) and the average film thickness was explored. For the polymer blend films, the effect of the F8BT/TFB blend ratio (per weight), spin-coating parameters and solution concentration on the phase-separated nanodomains was investigated. The influence of the quantum dots on the phase separation when these were embedded in the F8BT:TFB thin films was also examined. It was found that in the case of PI-b-PEO copolymer thin films, robust nanostructures, which remained unchanged after heating/annealing and/or ageing, were obtained immediately after spin coating on hydrophilic mica substrates from aqueous solutions. The competition and coupling of the PEO crystallisation and the phase separation between the PEO and PI blocks determined the ultimate morphology of the thin films. Due to the great biocompatible properties of the PEO block (protein resistance), robust PEO-based nanostructures find important applications in the development of micro/nano patterns for biological and biomedical applications. It was also found that sub-micrometre length-scale phase-separated domains were formed in F8BT:TFB spin cast thin films. The nanophase-separated domains of F8BT-rich and TFB-rich areas

  9. Fabrication of micro-structures on a PVDF/TiO{sub 2} nano-composite film using photocatalytic lithography

    Energy Technology Data Exchange (ETDEWEB)

    An Ningli [State Key Laboratory for Manufacturing Systems Engineering, Xi' an Jiaotong University, Xi' an 710049 (China); Liu Hongzhong, E-mail: hzliu@mail.xjtu.edu.cn [State Key Laboratory for Manufacturing Systems Engineering, Xi' an Jiaotong University, Xi' an 710049 (China); Ding Yucheng; Lu Bingheng [State Key Laboratory for Manufacturing Systems Engineering, Xi' an Jiaotong University, Xi' an 710049 (China); Zhang Min [College of Chemistry and Chemical Engineering, Shaanxi University of Science and Technology, Xi' an 710021 (China)

    2012-04-01

    In the present study, a poly(vinylidene fluoride) (PVDF)/TiO{sub 2} nano-composite film was prepared by coating a substrate with an acetone/DMF solution, which was then evaporated at a temperature of 110 Degree-Sign C. Micro-structure patterns were fabricated on a PVDF/TiO{sub 2} nano-composite film with photocatalytic lithography. The morphological and chemical compositions of the micro-structure were investigated by optical microscope, SEM and XPS. Experimental results show that the micro-structure patterns can be directly replicated on the PVDF/TiO{sub 2} nano-composite film with photocatalytic lithography. The micro-structure is approximately 4 {mu}m in depth which is obtained during the water phase of the process with UV-LED irradiation in 5 h. The results indicate that the fabrication methodology can be potentially applied towards the large-scale fabrication of actuators and sensor devices.

  10. Characterization of nanocellulose reinforced semi-interpenetrating polymer network of poly(vinyl alcohol) & polyacrylamide composite films.

    Science.gov (United States)

    Mandal, Arup; Chakrabarty, Debabrata

    2015-12-10

    Semi-interpenetrating polymer network (semi-IPN) of poly(vinyl alcohol)/polyacrylamide was reinforced with various doses of nanocellulose. The different composite films thus prepared were characterized with respect to their mechanical, thermal, morphological and barrier properties. The composite film containing 5 wt.% of nanocellulose showed the highest tensile strength. The semi-interpenetrating polymer network of poly(vinyl alcohol)/polyacrylamide; and its various composites with nanocellulose were almost identical in their thermal stability. Each of the composites however exhibited much superior stability with respect to the linear poly(vinyl alcohol) and crosslinked polyacrylamide. The scanning electron microscopy (SEM) and atomic force microscopy (AFM) studies exhibited phase separated morphology where agglomerates of nanocellulose were found to be dispersed in the matrix of the semi-IPN. The moisture vapor transmission rate (MVTR) was the lowest for the film containing 5 wt.% of nanocellulose. PMID:26428121

  11. Ultrafast nonlinear optical response of Ag:BaTiO3 composite films at the near-ultraviolet wavelengths

    Institute of Scientific and Technical Information of China (English)

    Dongyi Guan; Zhenghao Chen; Kuijuan Jin; Guozhen Yang

    2006-01-01

    The ultrafast nonlinear optical response of Ag:BaTiO3 composite films synthesized by pulse laser deposition (PLD) is studied at the near-ultraviolet (400 nm) wavelength. The pulse duration of the laser used in the measurement is 200 fs. The real and imaginary parts of the third-order nonlinear susceptibility x(3) of the composite materials are measured. The composite films indicate self-focusing effect and nonlinear saturation, the values of Rex(3) and Imx(3) are measured to be 3.42 × 10-10 and -1.37 × 10-10 esu respectively, which are much lower than those reported before. It is mainly because that the duration of the laser used in the measurements is too short to induce the hot electron excitation and the thermal effect. The ultrafast nonlinear saturated absorption response of the Ag:BaTiO3 composite films may have potential applications for femtosecond laser mode locking.

  12. Crack-free and scalable transfer of carbon nanotube arrays into flexible and highly thermal conductive composite film.

    Science.gov (United States)

    Wang, Miao; Chen, Hongyuan; Lin, Wei; Li, Zhuo; Li, Qiang; Chen, Minghai; Meng, Fancheng; Xing, Yajuan; Yao, Yagang; Wong, Ching-ping; Li, Qingwen

    2014-01-01

    Carbon nanotube (CNT) arrays show great promise in developing anisotropic thermal conductive composites for efficiently dissipating heat from high-power devices along thickness direction. However, CNT arrays are always grown on some substrates and liable to be deformed and broken into pieces during transfer and solution treatment. In the present study, we intentionally synthesized well-crystallized and large-diameter (~80 nm) multiwalled CNT (MWCNT) arrays by floating catalyst chemical vapor deposition (FCCVD) method. Such arrays provided high packing density and robust structure from collapse and crack formation during post solution treatment and therefore favored to maintain original thermal and electrical conductive paths. Under optimized condition, the CNT arrays can be transferred into flexible composite films. Furthermore, the composite film also exhibited excellent thermal conductivity at 8.2 W/(m·K) along thickness direction. Such robust, flexible, and highly thermal conductive composite film may enable some prospective applications in advanced thermal management.

  13. Hard coating of ultrananocrystalline diamond/nonhydrogenated amorphous carbon composite films on cemented tungsten carbide by coaxial arc plasma deposition

    Science.gov (United States)

    Naragino, Hiroshi; Egiza, Mohamed; Tominaga, Aki; Murasawa, Koki; Gonda, Hidenobu; Sakurai, Masatoshi; Yoshitake, Tsuyoshi

    2016-08-01

    Ultrananocrystalline diamond (UNCD)/nonhydrogenated amorphous carbon (a-C) composite (UNCD/a-C) films were deposited on cemented carbide containing Co by coaxial arc plasma deposition. With decreasing substrate temperature, the hardness was enhanced accompanied by an enhancement in the sp3/(sp2 + sp3). Energy-dispersive X-ray and secondary ion mass spectrometry spectroscopic measurements exhibited that the diffusion of Co atoms from the substrates into the films hardly occurs. The film deposited at room temperature exhibited the maximum hardness of 51.3 GPa and Young's modulus of 520.2 GPa, which evidently indicates that graphitization induced by Co in the WC substrates, and thermal deformation from sp3 to sp2 bonding are suppressed. The hard UNCD/a-C films can be deposited at a thickness of approximately 3 μm, which is an order larger than that of comparably hard a-C films. The internal compressive stress of the 51.3-GPa film is 4.5 GPa, which is evidently smaller than that of comparably hard a-C films. This is a reason for the thick deposition. The presence of a large number of grain boundaries in the film, which is a structural specific to UNCD/a-C films, might play a role in releasing the internal stress of the films.

  14. Plasma-enhanced growth, composition, and refractive index of silicon oxy-nitride films

    DEFF Research Database (Denmark)

    Mattsson, Kent Erik

    1995-01-01

    Secondary ion mass spectrometry and refractive index measurements have been carried out on silicon oxy-nitride produced by plasma-enhanced chemical vapor deposition (PECVD). Nitrous oxide and ammonia were added to a constant flow of 2% silane in nitrogen, to produce oxy-nitride films with atomic......-product. A model, that combine the chemical net reaction and the stoichiometric rules, is found to agree with measured deposition rates for given material compositions. Effects of annealing in a nitrogen atmosphere has been investigated for the 400 °C– 1100 °C temperature range. It is observed that PECVD oxy...

  15. Self-diffraction in Porous Silicon/PMMA-DR1 Composite Films

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Two-layer structure consisting of PS/PMMA-DR1 composite film planar waveguide layer on porous silicon cladding layer was fabricated in our experiment. The induced grating based on the third nonlinear optical properties was formed by interaction of two Nd∶YAG laser beams at 1064nm in the porous silicon/PMMA-DR1 waveguide. The diffraction efficiency of the first order diffracted light is measured to be about 0.2% of the total output.

  16. Monolithic Pellets, Composites and Thick Films of Hydroxyapatite: Correlation of Mechanical Properties with Microstructure.

    Science.gov (United States)

    Wang, Pauchiu Either

    Hydroxyapatite Ca_{10}(PO _4)_6(OH)_2 (abbreviated as HA) has great biocompatibility. Poor mechanical properties of HA implants and decomposition of HA during processing are the major obstacles for widespread uses of HA. In the present thesis we have attempted to understand the sintering behavior of monolithic HA and metal-reinforced HA-matrix composites, and the mechanism of formation of HA coating in the solutions at the normal temperature. The powders of two calcium phosphates, namely hydroxyapatite and dicalcium phosphate (DCP: chemical formula Ca_2P_2O_7), were sintered at various temperatures and in various environments. The density, flexural strength and knoop hardness of both phosphates sintered in air for 4 h initially increased with the sintering temperature, reaching maxima at around 1000-1150 ^circC, and then decreased due to decomposition. To reduce dehydroxylation, HA powder was sintered in moisture at various temperatures up to 1350^circ C and X-ray diffraction study did not indicate any decomposition at the highest sintering temperature. It is seen that dehydroxylation did not hinder sintering, but decomposition obstructed sintering of both HA and DCP. Ductile-phase reinforcement of hydroxyapatite was achieved by addition of silver particulates (5-30 vol.%) in HA powder compacts. A composite made by sintering 10 vol.% Ag and balance HA at 1200^circ C for 1 h in air had flexural strength of 75 +/- 7 MPa, which was almost double that of pure HA sintered under an identical condition. Silver in the composite melted during sintering, but due to poor wetting, did not spread in between HA particles. The increase in the flexural strength of the composites was thought to be due to crack-bridging and crack-arrest by silver inclusions. Thick films (several μm) of hydroxyapatite were deposited on silicon single crystal placed in close proximity to a plate of apatite- and wollastonite -containing glass and dipped into a simulated body fluid (SBF) at 36^circ

  17. Photoinduced Birefringence and Broadband All-Optical Photonic Switch in a Bacteriorhodopsin/Polymer Composite Film

    Institute of Scientific and Technical Information of China (English)

    WEI Lai; TENG Xue-Lei; Lu Ming; ZHAO You-Yuan; MA De-Wang; DING Jian-Dong

    2007-01-01

    Photoinduced birefringence with large optical nonlinearity in a bacteriorhodopsin/polymer composite film is observed.A high refractive index change of 8.5×10-5 photoinduced by 476nm pumping beam is reached at the low intensity of 6.5mW/cm2.Based on it,a broadband all-optical photonic switch is realized with an optical controlling switch system.Because of controlling beam's selectivity in switching,the transporting beams of different wavelengths with different intensities and shapes can be modulated by adjusting the wavelength and intensity of the controlling beam.

  18. Microwave sintering of sol–gel composite films using a domestic microwave oven

    Science.gov (United States)

    Kobayashi, Makiko; Matsumoto, Makoto

    2016-07-01

    Feasibility study of sol–gel composite microwave sintering using a domestic microwave oven was carried out. Two kinds of lead zirconate titanate (PZT) powders were mixed with PZT sol–gel solution and the mixture was sprayed onto 3-mm-thick titanium substrate. The films were sintered by 700 W domestic oven for 10 min. Ultrasonic measurement was carried out in pulse–echo mode and clear multiple echoes were confirmed. It would be suitable method to fabricate high frequency broadband focused ultrasonic transducers. Further research is required to improve sintering degree.

  19. Nanostructured Multilayer Composite Films of Manganese Dioxide/Nickel/Copper Sulfide Deposited on Polyethylene Terephthalate Supporting Substrate

    Directory of Open Access Journals (Sweden)

    Awangku Nabil Syafiq Bin Awangku Metosen

    2015-01-01

    Full Text Available Nanostructured multilayer manganese dioxide/nickel/copper sulfide (MnO2/Ni/CuS composite films were successfully deposited onto supporting polyethylene terephthalate (PET substrate through the sequential deposition of CuS, Ni, and MnO2 thin films by chemical bath deposition, electrodeposition, and horizontal submersion deposition techniques, respectively. Deposition of each thin-film layer was optimized by varying deposition parameters and conditions associated with specific deposition technique. Both CuS and Ni thin films were optimized for their electrical conductivity whereas MnO2 thin film was optimized for its microstructure and charge capacity. The electrochemical properties of nanostructured multilayer MnO2/Ni/CuS composite films were evaluated by cyclic voltammetry as electrode materials of an electrochemical capacitor prototype in a dual-planar device configuration. Cyclic voltammogram in mild Na2SO4 aqueous electrolyte exhibited a featureless and almost rectangular shape which was indicative of the ideal capacitive behavior and high cycling reversibility of the electrochemical capacitor prototype. Nanostructured multilayer MnO2/Ni/CuS composite films on supporting polyethylene terephthalate (PET substrate could potentially be utilized as electrode materials for the fabrication of high performance electrochemical capacitors.

  20. Incorporation of vitamin E in poly(3hydroxybutyrate)/Bioglass composite films: effect on surface properties and cell attachment

    OpenAIRE

    Misra, Superb K; Philip, Sheryl E.; Chrzanowski, Wojciech; Nazhat, Showan N; Roy, Ipsita; Knowles, Jonathan C; Salih, Vehid; Boccaccini, Aldo R.

    2008-01-01

    This study investigated the possibility of incorporating α-tocopherol (vitamin E) into poly(3hydroxybutyrate) (P(3HB))/Bioglass composites, which are being developed for bone tissue engineering matrices. P(3HB) films with 20 wt% Bioglass and 10 wt% vitamin E were prepared using the solvent casting technique. Addition of vitamin E significantly improved the hydrophilicity of the composites along with increasing the total protein adsorption. The presence of protein adsorbed on the composite sur...

  1. Formation of an adherent polyacrylonitrile/carbon nanotubes composite film onto a polyacrylonitrile brush electrografted on copper.

    Science.gov (United States)

    Vast, L; Rochez, O; Azoulay, L; Fonseca, A; Nagy, J B; Deniau, G; Palacin, S; Delhalle, J; Mekhalif, Z

    2007-10-01

    An adherent polymer film based on a composite of polyacrylonitrile/multiwall carbon nanotubes (PAN/MWNTs) have been elaborated on a copper substrate. The first layer is an electrografted PAN brush on which of a subsequent layer of PAN/carbon nanotubes composite has been deposited by simple dipping from solution in dimethylformamide (DMF). MWNTs have been previously chemically functionalized with 3-cyanopropyltrichlorosilane to promote de-bundling and homogeneous dispersion of the carbon nanotubes in the composite. PMID:18330148

  2. Swift heavy ion irradiation induced phase transformation in undoped and niobium doped titanium dioxide composite thin films

    Science.gov (United States)

    Gautam, Subodh K.; Chettah, Abdelhak; Singh, R. G.; Ojha, Sunil; Singh, Fouran

    2016-07-01

    Study reports the effect of swift heavy ion (SHI) irradiation induced phase transformation in undoped and Niobium doped anatase TiO2 composite thin films. Investigations were carried out at different densities of electronic excitations (EEs) using 120 MeV Ag and 130 MeV Ni ions irradiations. Films were initially annealed at 900 °C and results revealed that undoped films were highly stable in anatase phase, while the Nb doped films showed the composite nature with the weak presence of Niobium penta-oxide (Nb2O5) phase. The effect at low density of EEs in undoped film show partial anatase to rutile phase transformation; however doped film shows only further growth of Nb2O5 phase beside the anatase to rutile phase transformation. At higher density of EEs induced by Ag ions, registered continuous ion track of ∼3 nm in lattice which leads to nano-crystallization followed by decomposition/amorphization of rutile TiO2 and Nb2O5 phases in undoped and doped films, respectively. However, Ni ions are only induced discontinuous sequence of ion tracks with creation of damage and disorder and do not show amorphization in the lattice. The in-elastic thermal spike calculations were carried out for anatase TiO2 phase to understand the effect of EEs on anatase to rutile phase transformation followed by amorphization in NTO films in terms of continuous and discontinuous track formation by SHI irradiation.

  3. Surface Composition and Corrosion Property of TiNi Alloys Coated with Tantalum Films

    Institute of Scientific and Technical Information of China (English)

    Yan CHENG; Wei CAI; Liancheng ZHAO

    2004-01-01

    Multi-arc ion plating method was employed to coat TiNi alloys with Ta in order to improve radiopacity and corrosion resistance property. The surface composition, corrosion resistance property and Ni ions release amount of TiNi alloys coated with Ta films compared with TiNi alloys, are investigated by means of X-ray photoelectron spectrometry (XPS), electrochemical measurements and atomic absorption spectrophotometry (AAS), respectively. The results show that the coated surface composition is composed of Ta and O and the corrosion resistance is improved, whereas the Ni ions release amount of the coated sample is lower than that of the uncoated samples in the whole immersion period, indicating that Ta coating can improve the biocompatibility of TiNi alloys.

  4. Temperature dependence of nanostructure in PbSe–ZnSe composite thin film

    International Nuclear Information System (INIS)

    The nanostructure of PbSe–ZnSe composite thin films prepared by the hot-wall deposition (HWD) method was investigated using small-angle x-ray (SAXS) scattering. The SAXS profiles indicate the formation of two kinds of nanoparticles: large nanoparticles that vanish and small particles that increase in size with increasing temperature. At high substrate temperatures, the volume fraction of all the nanoparticles estimated from SAXS is consistent with that of PbSe obtained by chemical analysis. This shows that PbSe forms nanoparticles at high substrate temperatures. On the other hand, the same analysis for the volume fraction at low substrate temperatures reveals that the chemical composition of the nanoparticles differs from PbSe. Pb nanoparticles are probably formed at low substrate temperatures and disappear with increasing substrate temperature. (paper)

  5. Elements Provide a Clue: Nanoscale Characterization of Thin-Film Composite Polyamide Membranes.

    Science.gov (United States)

    Lu, Xinglin; Nejati, Siamak; Choo, Youngwoo; Osuji, Chinedum O; Ma, Jun; Elimelech, Menachem

    2015-08-12

    In this study, we exploit the nitrogen-sulfur elemental contrast of thin-film composite (TFC) polyamide membranes and present, for the first time, the application of two elemental analysis techniques, scanning transmission electron microscopy-energy-dispersive X-ray spectroscopy (STEM-EDX) and X-ray photoelectron spectroscopy (XPS) C60+ ion-beam sputtering, to elucidate the nanoscale structure and chemical composition of the polyamide-polysulfone interface. Although STEM-EDX elemental mapping depicts the presence of a dense polyamide layer at the interface, it is incapable of resolving the elemental contrast at nanoscale resolution at the interfacial zone. Depth-resolved XPS C60+ ion-beam sputtering enabled nanoscale characterization of the polyamide-polysulfone interface and revealed the presence of a heterogeneous layer that contains both polyamide and polysulfone signatures. Our results have important implications for future studies to elucidate the structure-property-performance relationship of TFC membranes. PMID:26213850

  6. Corrosion and drug release properties of EN-plating/PLGA composite coating on MAO film

    International Nuclear Information System (INIS)

    The electroless nickel plating/poly(DL-lactide-co-glycolide) composite coating (EN-plating/PLGA composite coating) was fabricated on the surface of the micro-arc oxidation (MAO) film of the magnesium alloy AZ81 to double control the corrosion and drug release in the hanks' solution. The EN-plating was fabricated on the MAO coating to improve the corrosion resistance by overlaying most pores and micro-cracks on the surface of the MAO film. Meanwhile, a double layered organic poly(DL-lactide-co-glycolide)/paclitaxel (PLGA/PTX) drug releasing coating with a top layered PLGA drug controlled releasing coating on EN plating was prepared to control the drug release rate by adjusting the different lactide: glycolide (LA:GA) ratio of PLGA. Scanning electron microscopy (SEM) and the X-ray powder diffraction (XRD) were used to analyze the morphology and the composition of the EN-plating. The corrosion behavior of the magnesium alloy substrate and the status of the drug in the PLGA matrix were respectively evaluated by Potentiodynamic polarization and Differential scanning calorimetry (DSC). The drug release was determined by ultraviolet-visible (UV-visible) spectrophotometer. EN-plating coating which was composed of compact cauliflower nodules was uniform in size and defect free with no pores or cracks. EN-plating could seal the microcracks and microholes on the outer layer of the MAO coating effectively. The corrosion resistance was improved by preventing the corrosive ions from diffusing to the magnesium alloy substrate. The drug release rate of PTX exhibited a nearly linear sustained-release profile with no significant burst releases. - Research highlights: → An organic and in organic EN-plating/PLGA composite coating was first fabricated on the surface of the MAO film. → This composite coating the magnesium alloy AZ81could double control the corrosion and drug release in the hanks' solution. → The drug release rate could be controlled by LG:GA ratio and the PTX

  7. Development of polyelectrolyte multilayer thin film composite membrane for water desalination application

    KAUST Repository

    Fadhillah, F.

    2013-06-01

    Thin film composite membranes were fabricated via spin assisted layer by layer (SA-LbL) assembly by depositing alternate layers of poly(allyl amine hydrochloride) (PAH) and poly(acrylic acid) (PAA) on a polysulfone (PSF) ultrafiltration membrane as support. The suitability of these membranes for potential water purification applications was explored by testing the stability of the deposited thin films and their permeation characteristic using cross-flow permeation cell. Permeation test conducted at a pressure of 40bar, temperature of 25°C, pH of 6 and feed water concentration of 2000ppm NaCl demonstrated that the PAH/PAA multilayer film deposited on polysulfone support remained stable and intact under long-term test conditions. The 120 bilayers of PAH/PAA membrane tested at the above condition showed flux of 15L/m2.h and salt rejection of 65%. The membrane performance evaluation also revealed that SA-LbL PAH/PAA membrane follows the characteristics of the solution diffusion membrane. © 2013 Elsevier B.V.

  8. Effect of sputtering parameters and substrate composition on the structure of tantalum thin films

    Energy Technology Data Exchange (ETDEWEB)

    Hallmann, Lubica, E-mail: lubica.hallmann@zzm.uzh.c [Clinic of Fixed and Removable Prosthodontics and Dental Material Science, Center of Dental Medicine, University of Zürich (Switzerland); Ulmer, Peter [Institute of Geochemistry and Petrology, ETH Zürich (Switzerland)

    2013-10-01

    The crystallographic properties of tantalum films deposited as a bioactive coating on Co–Cr–Mo and Ti–Al–Nb alloys have been investigated. The desired tough and ductile alpha phase of tantalum has been obtained by DC magnetron sputtering on Co–Cr–Mo and Ti–Al–Nb substrates. The thickness of the tantalum layer was between 20 and 600 nm. The crystallographic structure of tantalum thin film was dependent on the sputtering parameters such as DC power, bias voltage and gas impurities. Oxygen is an important factor for the stabilization of the tantalum alpha phase on Co–Cr–Mo substrate. The crystallographic structure and texture of tantalum thin films was found to be additionally dependent on the substrate composition. For Ti–Al–Nb substrate, oxygen content was not an important factor for the stabilization of the alpha phase. The observed shift of X-ray diffraction peaks to lower 2(θ) is an indication of stress evolving during the sputtering process and was dependent on bias voltage and oxygen content of the carrier gas.

  9. Plasma interactions determine the composition in pulsed laser deposited thin films

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Jikun; Stender, Dieter; Conder, Kazimierz; Wokaun, Alexander; Schneider, Christof W.; Lippert, Thomas, E-mail: thomas.lippert@psi.ch [Paul Scherrer Institute, CH-5232 Villigen PSI (Switzerland); Döbeli, Max [Laboratory of Ion Beam Physics, ETH Zurich, CH-8093 Zurich (Switzerland)

    2014-09-15

    Plasma chemistry and scattering strongly affect the congruent, elemental transfer during pulsed laser deposition of target metal species in an oxygen atmosphere. Studying the plasma properties of La{sub 0.6}Sr{sub 0.4}MnO{sub 3}, we demonstrate for as grown La{sub 0.6}Sr{sub 0.4}MnO{sub 3-δ} films that a congruent transfer of metallic species is achieved in two pressure windows: ∼10{sup −3} mbar and ∼2 × 10{sup −1} mbar. In the intermediate pressure range, La{sub 0.6}Sr{sub 0.4}MnO{sub 3-δ} becomes cation deficient and simultaneously almost fully stoichiometric in oxygen. Important for thin film growth is the presence of negative atomic oxygen and under which conditions positive metal-oxygen ions are created in the plasma. This insight into the plasma chemistry shows why the pressure window to obtain films with a desired composition and crystalline structure is narrow and requires a careful adjustment of the process parameters.

  10. Compositional influence on the electrical performance of zinc indium tin oxide transparent thin-film transistors

    Energy Technology Data Exchange (ETDEWEB)

    Marsal, A. [Dept Enginyeria Electronica and Center of Research in Nanoengineering, Universitat Politècnica Catalunya, Barcelona (Spain); Carreras, P. [Dept Física Aplicada i Òptica, Universitat de Barcelona, Barcelona (Spain); Puigdollers, J.; Voz, C.; Galindo, S.; Alcubilla, R. [Dept Enginyeria Electronica and Center of Research in Nanoengineering, Universitat Politècnica Catalunya, Barcelona (Spain); Bertomeu, J. [Dept Física Aplicada i Òptica, Universitat de Barcelona, Barcelona (Spain); Antony, A. [Dept Física Aplicada i Òptica, Universitat de Barcelona, Barcelona (Spain); Indian Institute of Technology, Bombay (India)

    2014-03-31

    In this work, zinc indium tin oxide layers with different compositions are used as the active layer of thin film transistors. This multicomponent transparent conductive oxide is gaining great interest due to its reduced content of the scarce indium element. Experimental data indicate that the incorporation of zinc promotes the creation of oxygen vacancies, which results in a higher free carrier density. In thin-film transistors this effect leads to a higher off current and threshold voltage values. The field-effect mobility is also strongly degraded, probably due to coulomb scattering by ionized defects. A post deposition annealing in air reduces the density of oxygen vacancies and improves the field-effect mobility by orders of magnitude. Finally, the electrical characteristics of the fabricated thin-film transistors have been analyzed to estimate the density of states in the gap of the active layers. These measurements reveal a clear peak located at 0.3 eV from the conduction band edge that could be attributed to oxygen vacancies. - Highlights: • Zinc promotes the creation of oxygen vacancies in zinc indium tin oxide transistors. • Post deposition annealing in air reduces the density of oxygen. • Density of states reveals a clear peak located at 0.3 eV from the conduction band.

  11. Composite silicon nanostructure arrays fabricated on optical fibre by chemical etching of multicrystal silicon film

    International Nuclear Information System (INIS)

    Integrating nanostructures onto optical fibers presents a promising strategy for developing new-fashioned devices and extending the scope of nanodevices’ applications. Here we report the first fabrication of a composite silicon nanostructure on an optical fiber. Through direct chemical etching using an H2O2/HF solution, multicrystal silicon films with columnar microstructures are etched into a vertically aligned, inverted-cone-like nanorod array embedded in a nanocone array. A faster dissolution rate of the silicon at the void-rich boundary regions between the columns is found to be responsible for the separation of the columns, and thus the formation of the nanostructure array. The morphology of the nanorods primarily depends on the microstructure of the columns in the film. Through controlling the microstructure of the as-grown film and the etching parameters, the structural control of the nanostructure is promising. This fabrication method can be extended to a larger length scale, and it even allows roll-to-roll processing. (paper)

  12. Compositional influence on the electrical performance of zinc indium tin oxide transparent thin-film transistors

    International Nuclear Information System (INIS)

    In this work, zinc indium tin oxide layers with different compositions are used as the active layer of thin film transistors. This multicomponent transparent conductive oxide is gaining great interest due to its reduced content of the scarce indium element. Experimental data indicate that the incorporation of zinc promotes the creation of oxygen vacancies, which results in a higher free carrier density. In thin-film transistors this effect leads to a higher off current and threshold voltage values. The field-effect mobility is also strongly degraded, probably due to coulomb scattering by ionized defects. A post deposition annealing in air reduces the density of oxygen vacancies and improves the field-effect mobility by orders of magnitude. Finally, the electrical characteristics of the fabricated thin-film transistors have been analyzed to estimate the density of states in the gap of the active layers. These measurements reveal a clear peak located at 0.3 eV from the conduction band edge that could be attributed to oxygen vacancies. - Highlights: • Zinc promotes the creation of oxygen vacancies in zinc indium tin oxide transistors. • Post deposition annealing in air reduces the density of oxygen. • Density of states reveals a clear peak located at 0.3 eV from the conduction band

  13. Enhanced performance of dye-sensitized solar cells based on P25/Ta2O5 composite films

    Science.gov (United States)

    Jiang, Qingsong; Gao, Jian; Yi, Lin; Hu, Guang; Zhang, Jun

    2016-04-01

    In this paper, novel titanium dioxide/tantalum pentoxide (P25/Ta2O5) composite films have been successfully fabricated and applied to dye-sensitized solar cells (DSSCs). Ta2O5 nanoparticles are synthesized by a simple low-temperature solvothermal method. The influence of Ta2O5 nanoparticles on photovoltaic performance of DSSCs is systematically investigated. As a result, the DSSC based on 10 wt% Ta2O5 incorporated P25 film exhibits excellent photovoltaic performance with a power conversion efficiency (PCE) as high as 5.85 %. Compared to a reference DSSC based on the pure P25 film (4.93 %), the PCE of DSSCs has been remarkably enhanced by 19 %. Such enhancement can be mainly attributed to the higher electron collection efficiency in P25/Ta2O5 composite films, which result from the suppression of the electron recombination at the photoanode/electrolyte interface.

  14. Effects of Mineral Tourmaline Particles on Photocatalytic Activities of RE/TiO2 Composite Thin Films

    Institute of Scientific and Technical Information of China (English)

    Meng Junping; Liang Jinsheng; Ding Yan; Xu Gangke

    2004-01-01

    The composite TiO2 films containing the mineral tourmaline particles and rare earth elements (T/RE/TiO2 )were prepared by a sol-gel method using Ti( OC4H9 )4 as raw material. The microstructure and forming mechanism of T/RE/TiO2 films were studied by scanning electron microscope (SEM). Effects of tourmaline on the photocatalytic activities of RE/TiO2 were determined by photocatalytic degradation of formaldehyde. The results show that the photocatalytic degradation ratio of formaldehyde increases by 44.2% with the composite films of Ce/TiO2 containing 0.04%tourmaline, more than that with the thin films of Ce/TiO2 under UV irradiation.

  15. Study of the composition of vacuum deposited thin films of CuInSe2 using PIXE and their properties

    International Nuclear Information System (INIS)

    Thin film samples of CuInSe2 commonly referred to as CIS produced by vacuum deposition have been studied using the PIXE method. It is observed that there are substantial matrix dependent effects on x-ray yields even at thickness less than 500 μg/cm2. It is necessary to correct for these to get accurate composition of CIS films by the PIXE method. It is seen that considerable quantity of Se in the films is lost during annealing of the samples. It is, therefore, necessary to start with higher quantities of Se to get right stoichiometry in the finished samples. Some effects of the composition variations on the optical properties of the films are reported. 13 refs, 5 tables, 5 figs

  16. Controlling the photoluminescence of ZnO:Si nano-composite films by heat-treatment

    International Nuclear Information System (INIS)

    Nano-composite thin films of silicon and zinc oxide were deposited on glass substrates using thermal co-evaporation. On heating the films at different temperatures and different atmospheric pressures, the photoluminescence (PL) emission spectra become broad, giving emissions in UV-Blue, Green and Red region. Analyses reveal that defect-dominated structure of ZnO contributes to the broad PL spectra observed. X-ray diffraction and Raman spectra analysis show that the defects caused by oxygen vacancies decrease with heating which is accompanied by a competing process of decrease in grain size made possible by surrounding silicon reacting at the surface of the ZnO nano-cluster grains giving new bonds, possibly O-Si-Zn bonds. Crystallinity of nano-grains and defects contribute different emission peaks that depending on relative contributions can give comparable peaks resulting in broad emission spectra. The study shows that simple post-deposition process can lead to fabrication of white light emitting devices based on these nano-composites. Best emission spectra are obtained by heating at a temperature of 250 oC in low vacuum.

  17. Highly mobile ferroelastic domain walls in compositionally graded ferroelectric thin films.

    Science.gov (United States)

    Agar, J C; Damodaran, A R; Okatan, M B; Kacher, J; Gammer, C; Vasudevan, R K; Pandya, S; Dedon, L R; Mangalam, R V K; Velarde, G A; Jesse, S; Balke, N; Minor, A M; Kalinin, S V; Martin, L W

    2016-05-01

    Domains and domain walls are critical in determining the response of ferroelectrics, and the ability to controllably create, annihilate, or move domains is essential to enable a range of next-generation devices. Whereas electric-field control has been demonstrated for ferroelectric 180° domain walls, similar control of ferroelastic domains has not been achieved. Here, using controlled composition and strain gradients, we demonstrate deterministic control of ferroelastic domains that are rendered highly mobile in a controlled and reversible manner. Through a combination of thin-film growth, transmission-electron-microscopy-based nanobeam diffraction and nanoscale band-excitation switching spectroscopy, we show that strain gradients in compositionally graded PbZr1-xTixO3 heterostructures stabilize needle-like ferroelastic domains that terminate inside the film. These needle-like domains are highly labile in the out-of-plane direction under applied electric fields, producing a locally enhanced piezoresponse. This work demonstrates the efficacy of novel modes of epitaxy in providing new modalities of domain engineering and potential for as-yet-unrealized nanoscale functional devices. PMID:26878312

  18. Hydrogen evolution at nanoporous gold/tungsten sulfide composite film and its optimization

    International Nuclear Information System (INIS)

    Graphical abstract: Display Omitted -- Highlights: •Thin tungsten sulfide layers were electro-deposited onto nanoporous gold surfaces. •The resultant composites showed good activity for hydrogen evolution in acid. •The thickness of deposition layer can be tuned by controlling the deposition time. •The catalytic performance was sensitive to the thickness of deposition layer. -- Abstract: Development of efficient and economical electrochemical systems for water splitting is a key part of renewable energy technology. Amorphous films of tungsten sulfide have been deposited by electrochemical reduction of tetrathiotungstate ions (WS42−) on dealloyed nanoporous gold (NPG) for electrochemical hydrogen evolution reaction (HER). The electrocatalytic performance has been proved to be sensitive to the thickness of the deposited layer, with an optimal deposition time of 600 s identified. The bi-continuous nanoporous morphology of the composites has been confirmed by transmission electron microscopy (TEM), and is beneficial for high exposure of catalytic sites and electrolyte access to the electrode surface. High-resolution TEM (HRTEM) has been employed to characterize the strong adhesion between the ultrathin film (less than 1 nm) and gold skeleton, allowing rapid charge transfer and long-term stability. The measured Tafel slope of 74 mV dec−1 implies an underlying Volmer-Heyrovsky HER mechanism

  19. Large-scale graphene-based composite films for flexible transparent electrodes fabricated by electrospray deposition

    Science.gov (United States)

    Kim, Woo Sik; Moon, Sook Young; Kim, Hui Jin; Park, Sungjin; Koyanagi, Jun; Huh, Hoon

    2014-12-01

    Large-scale transparent conducting electrodes were fabricated using the electrospray method on a glass wafer and polyethylene terephthalate film using chemically reduced graphene oxide and poly (3,4-ethylenedioxythiophene) (PEDOT). Graphene oxide (GO) is prepared by the modified Hummers method, and reduced GO (RG) is prepared at low temperature. By varying the concentration of RG and PEDOT of the composite material on the substrate, the electrical conductivity and transmittance of the electrode was controlled. The optical transmittance values of the graphene-based electrode at a wavelength of 550 nm were between 81 and 95% and had sheet resistances from 370 to 5400 Ω sq-1. After 1000 cycles of a bending test, the sheet resistances of the graphene-based composite films were unchanged. Different types of graphene and graphene-based electrodes were characterized by field-emission scanning electron microscopy, high-resolution transmission electron microscopy, high-resolution Raman spectroscopy, x-ray photoelectron spectroscopy, x-ray diffraction, transmittance, and electrical conductivity measurements.

  20. Highly mobile ferroelastic domain walls in compositionally graded ferroelectric thin films

    Science.gov (United States)

    Agar, J. C.; Damodaran, A. R.; Okatan, M. B.; Kacher, J.; Gammer, C.; Vasudevan, R. K.; Pandya, S.; Dedon, L. R.; Mangalam, R. V. K.; Velarde, G. A.; Jesse, S.; Balke, N.; Minor, A. M.; Kalinin, S. V.; Martin, L. W.

    2016-05-01

    Domains and domain walls are critical in determining the response of ferroelectrics, and the ability to controllably create, annihilate, or move domains is essential to enable a range of next-generation devices. Whereas electric-field control has been demonstrated for ferroelectric 180° domain walls, similar control of ferroelastic domains has not been achieved. Here, using controlled composition and strain gradients, we demonstrate deterministic control of ferroelastic domains that are rendered highly mobile in a controlled and reversible manner. Through a combination of thin-film growth, transmission-electron-microscopy-based nanobeam diffraction and nanoscale band-excitation switching spectroscopy, we show that strain gradients in compositionally graded PbZr1-xTixO3 heterostructures stabilize needle-like ferroelastic domains that terminate inside the film. These needle-like domains are highly labile in the out-of-plane direction under applied electric fields, producing a locally enhanced piezoresponse. This work demonstrates the efficacy of novel modes of epitaxy in providing new modalities of domain engineering and potential for as-yet-unrealized nanoscale functional devices.

  1. A Novel Approach Toward Fabrication of High Performance Thin Film Composite Polyamide Membranes

    Science.gov (United States)

    Khorshidi, Behnam; Thundat, Thomas; Fleck, Brian A.; Sadrzadeh, Mohtada

    2016-02-01

    A practical method is reported to enhance water permeability of thin film composite (TFC) polyamide (PA) membranes by decreasing the thickness of the selective PA layer. The composite membranes were prepared by interfacial polymerization (IP) reaction between meta-phenylene diamine (MPD)-aqueous and trimesoyl chloride (TMC)-organic solvents at the surface of polyethersulfone (PES) microporous support. Several PA TFC membranes were prepared at different temperatures of the organic solution ranging from -20 °C to 50 °C. The physico-chemical and morphological properties of the synthesized membranes were carefully characterized using serval analytical techniques. The results confirmed that the TFC membranes, synthesized at sub-zero temperatures of organic solution, had thinner and smoother PA layer with a greater degree of cross-linking and wettability compared to the PA films prepared at 50 °C. We demonstrated that reducing the temperature of organic solution effectively decreased the thickness of the PA active layer and thus enhanced water permeation through the membranes. The most water permeable membrane was prepared at -20 °C and exhibited nine times higher water flux compared to the membrane synthesized at room temperature. The method proposed in this report can be effectively applied for energy- and cost-efficient development of high performance nanofiltration and reverse osmosis membranes.

  2. Fabrication and application of flexible graphene silk composite film electrodes decorated with spiky Pt nanospheres

    Science.gov (United States)

    Liang, Bo; Fang, Lu; Hu, Yichuan; Yang, Guang; Zhu, Qin; Ye, Xuesong

    2014-03-01

    A free-standing graphene silk composite (G/S) film was fabricated via vacuum filtration of a mixed suspension of graphene oxide and silk fibres, followed by chemical reduction. Spiky structured Pt nanospheres were grown on the film substrate by cyclic voltammetry electrodeposition. The electrical and mechanical performance of a single graphene coated silk fibre was investigated. The conductivity of a single graphene coated silk fibre is 57.9 S m-1. During 1000 bending measurements, the conductivity was stable and showed negligible variation. The G/S film has a sheet resistivity of 90 Ω □-1 with a porous and hierarchical structure. The spiky Pt nanosphere decorated G/S film was directly used as a H2O2 electrode with a sensitivity of 0.56 mA mM-1 cm-2, a linear range of 0-2.5 mM and an ultralow detection limit of 0.2 μM (S/N = 3). A glucose biosensor electrode was further fabricated by enzyme immobilization. The results show a sensitivity of 150.8 μA mM-1 cm-2 and a low detection limit of 1 μM (S/N = 3) for glucose detection. The strategy of coating graphene sheets on a silk fibre surface provides a new approach for developing electrically conductive biomaterials, tissue engineering scaffolds, bendable electrodes, and wearable biomedical devices.A free-standing graphene silk composite (G/S) film was fabricated via vacuum filtration of a mixed suspension of graphene oxide and silk fibres, followed by chemical reduction. Spiky structured Pt nanospheres were grown on the film substrate by cyclic voltammetry electrodeposition. The electrical and mechanical performance of a single graphene coated silk fibre was investigated. The conductivity of a single graphene coated silk fibre is 57.9 S m-1. During 1000 bending measurements, the conductivity was stable and showed negligible variation. The G/S film has a sheet resistivity of 90 Ω □-1 with a porous and hierarchical structure. The spiky Pt nanosphere decorated G/S film was directly used as a H2O2 electrode with a

  3. The structural properties of BaTiO3: TiO2: PMMA composite films at room temperature

    Science.gov (United States)

    Dey, Subhrangsu; Singh, S.; Singh, S. M.; Rajput, Nikhil; Kumar, Neeraj

    2016-05-01

    Present works based on the performance of the composite films of Barium Titanate (BaTiO3) with Titanium Dioxide (TiO2) and Poly (methyl methacrylate) (PMMA) prepared by simple solution casting technique. Different wt. % compositions of BaTiO3 have been selected to find out the best optimized condition for further investigations. The structural properties have been carried out at room temperature using X-ray crystallography (XRD). The average crystallite size of the BaTiO3 particles in the composite films has been found to be lies in between ˜ 20 -70 nm. It has been found that the peak intensities increase with increasing the wt. % of BaTiO3 in the composite films at room temperature (RT). The XRD analysis revealed that the addition of TiO2 has played a crucial role to enhance the crystalline nature of the composite films at room temperature. Efforts have been made to correlate the results with investigated XRD results of pure BaTiO3 and its composites as observed by other workers at room temperature.

  4. Compositional and physicochemical factors governing the viability of Lactobacillus rhamnosus GG embedded in starch-protein based edible films

    OpenAIRE

    Soukoulis, Christos; Singh, Poonam; MacNaughtan, William; Parmenter, Chistopher; Fisk, Ian D.

    2016-01-01

    Probiotic incorporation in edible films and coatings has been shown recently to be an efficient strategy for the delivery of probiotics in foods. In the present work, the impact of the compositional, physicochemical and structural properties of binary starch-protein edible films on Lactobacillus rhamnosus GG viability and stability was evaluated. Native rice and corn starch, as well as bovine skin gelatine, sodium caseinate and soy protein concentrate were used for the fabrication of the prob...

  5. Dielectric properties: A gateway to antibacterial assay-A case study of low-density polyethylene/chitosan composite films.

    Digital Repository Service at National Institute of Oceanography (India)

    Sunilkumar, M.; Gafoor, A.A.; Anas, A.; Haseena, A.P.; Sujith, A.

    properties. 9, 10 It does not require a carrier, and can also be used as a coating or can be cast into polymer films with good strength, barrier properties and biocompatibility. The poly cationic nature of chitosan interferes with the negatively charged...-composite films for food packaging because of its good mechanical, oxygen barrier properties and antimicrobial activities. The antibacterial and antifungal activity of chitosan, arising from its polycationic nature, is well known for a variety of bacteria...

  6. Inhibition of postharvest penicillium molds of oranges by antifungal hydroxypropyl methylcellulose-lipid edible composite films and coatings

    OpenAIRE

    Silvia A. Valencia-Chamorro; Pérez-Gago, María B.; del Río, Miguel A.; Palou, Lluís

    2010-01-01

    New hydroxypropyl methylcellulose (HPMC)-lipid edible composite films and coatings containing low-toxicity chemicals with antifungal properties were developed. Tested antifungal chemicals were mainly salts of organic acids, salts of parabens, and other compounds, most of them classified as food additives or generally recognized as safe (GRAS) compounds. Stand-alone edible films were used for in vitro evaluation of their antifungal activity against the pathogens Penicillium digitat...

  7. Effect of compositional variations on the optical properties of Sb-Ge-Se thin films

    Energy Technology Data Exchange (ETDEWEB)

    Shaaban, E R; Moustafa, El Sayed; Adel, A [Physics Department, Faculty of Science, Al-Azhar University, PO 71452, Assiut (Egypt); Kaid, M A [Physics Department, Faculty of Science, El-Minia University, El-Minia (Egypt)], E-mail: esam_ramadan2005@yahoo.com

    2008-06-21

    Compositional dependences of the optical and physical properties of as-deposited amorphous Sb{sub x}Ge{sub 25-x}Se{sub 75} films (x = 0, 5, 10, 15 and 20 at%), prepared by thermal evaporation, have been studied. The refractive index, n, and film thickness, d, have been determined from the upper and lower envelopes of the transmission spectra, measured at normal incidence, in the spectral range from 400 to 2500 nm. An optical characterization method for uniform films based on Swanepoel's ideas has been employed, and it has allowed us to determine the average thickness, d-bar, and the refractive index, n, of the films, with accuracies better than 1%. It has been found that the refractive index of the Sb{sub x}Ge{sub 25-x}Se{sub 7} samples increases with increasing x, over the entire spectral range, which is related to the increased polarizability of the larger Sb atomic radius 1.38 A compared with the Ge atomic radius 1.22 A. The dispersion parameters such as E{sub 0} (single-oscillator energy) and E{sub d} (dispersive energy) were discussed in terms of the single-oscillator Wemple-DiDomenico model. The absorption coefficient, {alpha}, and therefore the extinction coefficient, k, have been determined from the transmittance and reflectance spectra in the strong absorption region. The optical energy gap E{sub g}{sup opt} is derived from Tauc's extrapolation and a decrease in E{sub g}{sup opt} with increasing Se content. Finally, in terms of the chemical bond approach, cohesive energy has been applied to interpret the decrease in the glass optical gap with increasing Sb content in Sb{sub x}Ge{sub 25-x}Se{sub 75}.

  8. Preparation and characterization of CoFe2O4/TiO2 magnetic composite films

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    CoFe2O4/TiO2 magnetic composite films were prepared using the sol-gel method with tetrabutyltitanate and metallic chlorates as starting materials. The effects of heat treatment temperatures on micro- structures and on magnetic properties were studied. The microstructure and properties of the samples at different heat treatment temperatures were characterized by X-ray diffraction, Raman spectrum, scanning electron microscopy, polarized microscopy and vibrating sample magnetometry. The results show that crystals of different substances grow up independently. Cobalt ferrite is evenly embedded into the titanium dioxide matrix in the prepared composite films. The magnetism of the composite films is enhanced with an increase of the heat temperature.

  9. Enhanced sensitivity for biosensors: Functionalized P1,5-diaminonaphthalene-multiwall carbon nanotube composite film-modified electrode

    International Nuclear Information System (INIS)

    A homogeneous electroactive poly(1,5-diaminonaphthalene) (P1,5DAN) and multiwalled carbon nanotube (MWNT) composite film-modified electrode was fabricated by cyclic voltammetry and a casting method. The dispersion and morphology of the MWNTs/P1,5DAN composite film were investigated by scanning electron microscopy. The cyclic voltammograms of the electrode modified by the MWNTs/P15DAN composite film strongly depended on the film thickness and pH of the electrolyte solution. Two absolutely isolated oxidation potentials were found as the MWCNTs were immobilized onto the surface of P1,5DAN film in a pH 6.8 buffer solution containing ascorbic acid (AA) and uric acid (UA). Both peak currents linearly increased with increased concentrations. The electrochemical behavior of UA was not interrupted even in the presence of high-concentration AA given that AA had no observable electrochemical changes at the immobilized concentration. The electrocatalytic behavior of H2O2 was also investigated by steady-state amperometry for the immobilization of horseradish peroxidase on the P1,5DAN film. The plot of the response current vs. H2O2 concentration was linear over the wide concentration range of 0.015–5.37 mM.

  10. Two-step preparation of laser-textured Ni/FTO bilayer composite films with high photoelectric properties

    Energy Technology Data Exchange (ETDEWEB)

    Li, Bao-jia, E-mail: li_bjia@126.com [School of Materials Science and Engineering, Jiangsu University, Zhenjiang 212013 (China); Jiangsu Provincial Key Laboratory for Science and Technology of Photon Manufacturing, Jiangsu University, Zhenjiang 212013 (China); Huang, Li-jing [School of Materials Science and Engineering, Jiangsu University, Zhenjiang 212013 (China); Jiangsu Provincial Key Laboratory for Science and Technology of Photon Manufacturing, Jiangsu University, Zhenjiang 212013 (China); Ren, Nai-fei [Jiangsu Provincial Key Laboratory for Science and Technology of Photon Manufacturing, Jiangsu University, Zhenjiang 212013 (China); School of Mechanical Engineering, Jiangsu University, Zhenjiang 212013 (China); Kong, Xia; Cai, Yun-long; Zhang, Jie-lu [Jiangsu Tailong Reduction Box Co. Ltd, Taixing 225400 (China)

    2015-08-15

    Highlights: • A two-step strategy was proposed to prepare laser-textured Ni/FTO composite films. • Ni/FTO film with a 10-nm-thick Ni layer (Ni{sub 10}/FTO film) had the best performance. • The Ni{sub 10}/FTO film underwent magnetic-field-assisted and -free laser irradiations. • All the magnetic laser-irradiated (MLI-NF) films were textured and annealed. • The MLI-NF film using a fluence of 1.0 J/cm{sup 2} showed the highest figure of merit. - Abstract: A two-step strategy, i.e. sputtering Ni layers on FTO glass combined with magnetic-field-assisted laser irradiation, was proposed to prepare laser-textured Ni/FTO bilayer composite films. By analyzing surface morphology, crystal structure and photoelectric properties of Ni/FTO films with different Ni layer thicknesses, the Ni/FTO film with a 10-nm-thick Ni layer (Ni{sub 10}/FTO film), which had the best overall photoelectric property, was chosen to undergo magnetic-field-assisted laser irradiation with different laser fluences. Magnetic-field-free laser irradiation of the Ni{sub 10}/FTO film was also carried out for comparison purpose. It was found that magnetic-field-assisted laser irradiation using a fluence of 1.0 J/cm{sup 2} was more effective for simultaneously achieving texturing and annealing, resulting in formation of ideal grating textures and significantly increased grain size. The corresponding film (MLI-NF1.0 film) showed the highest figure of merit of 22.8 × 10{sup −3} Ω{sup −1} compared to 13.1 × 10{sup −3} Ω{sup −1} of the FTO glass and 1.4 × 10{sup −3} Ω{sup −1} of the Ni{sub 10}/FTO film, suggesting that the two-step strategy is excellent for preparing textured Ni/FTO films with high photoelectric properties.

  11. IMPULSE PHOTON ANNEALING EFFECT ON STRUCTURE AND PHASE COMPOSITION OF THIN FILM SYSTEMS ON BASIS OF SILICON AND TRANSITION METALS

    Directory of Open Access Journals (Sweden)

    M. Markevich

    2012-01-01

    Full Text Available The present paper investigates element composition,  regularities of structural and phase transformations in Si–Fe–Si and TiN–Ti–Si thin film systems in the process of impulse photon annealing depending on radiation energy density while applying such methods as transmission  electron microscopy, electron  diffraction analysis and energy dispersive x-ray microanalysis. Optimum characteristics of impulse photon annealing for formation FeSi2 thin films of β-modification on silicon and TiSi2 films in C54 modification have been determined in the paper.

  12. Studies of the composition, mechanical and electrical properties of N-doped carbon films prepared by DC-MFCAD

    International Nuclear Information System (INIS)

    N-doped carbon films were prepared on Si(1 0 0) and Ti-6Al-4V substrates using direct current magnetically filtered cathodic arc deposition (DC-MFCAD) at room temperature for various different N2 pressures. The structure and composition of the films were characterized by Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). Ball-on-disk and microhardness tests were used to characterize the mechanical properties of the films, and Hall effect tests were employed to study the electrical properties

  13. Effect of applied dc bias voltage on composition, chemical bonding and mechanical properties of carbon nitride films prepared by PECVD

    Institute of Scientific and Technical Information of China (English)

    LI Hong-xuan; XU Tao; HAO Jun-ying; CHEN Jian-min; ZHOU Hui-di; XUE Qun-ji; LIU Hui-wen

    2004-01-01

    Carbon nitride films were deposited on Si (100) substrates using plasma-enhanced chemical vapor deposition (PECVD) technique from CH4 and N2 at different applied dc bias voltage. The microstructure, composition and chemical bonding of the resulting films were characterized by Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). The mechanical properties such as hardness and elastic modulus of the films were evaluated using nano-indentation. As the results, the Raman spectra, showing the G and D bands, indicate the amorphous structure of the films. XPS and FTIR measurements demonstrate the existence of various carbon-nitride bonds in the films and the hydrogenation of carbon nitride phase. The composition ratio of N to C, the nano-hardness and the elastic modulus of the carbon nitride films increase with increasing dc bias voltage and reach the maximums at a dc bias voltage of 300 V, then they decrease with further increase of the dc bias voltage. Moreover, the XRD analyses indicate that the carbon nitride film contains some polycrystalline C3N4 phase embedded in the amorphous matrix at optimized deposition condition of dc bias voltage of 300 V.

  14. Spray Layer-by-Layer Assembled Clay Composite Thin Films as Selective Layers in Reverse Osmosis Membranes.

    Science.gov (United States)

    Kovacs, Jason R; Liu, Chaoyang; Hammond, Paula T

    2015-06-24

    Spray layer-by-layer assembled thin films containing laponite (LAP) clay exhibit effective salt barrier and water permeability properties when applied as selective layers in reverse osmosis (RO) membranes. Negatively charged LAP platelets were layered with poly(diallyldimethylammonium) (PDAC), poly(allylamine) (PAH), and poly(acrylic acid) (PAA) in bilayer and tetralayer film architectures to generate uniform films on the order of 100 nm thick that bridge a porous poly(ether sulfone) support to form novel RO membranes. Nanostructures were formed of clay layers intercalated in a polymeric matrix that introduced size-exclusion transport mechanisms into the selective layer. Thermal cross-linking of the polymeric matrix was used to increase the mechanical stability of the films and improve salt rejection by constraining swelling during operation. Maximum salt rejection of 89% was observed for the tetralayer film architecture, with an order of magnitude increase in water permeability compared to commercially available TFC-HR membranes. These clay composite thin films could serve as a high-flux alternative to current polymeric RO membranes for wastewater and brackish water treatment as well as potentially for forward osmosis applications. In general, we illustrate that by investigating the composite systems accessed using alternating layer-by-layer assembly in conjunction with complementary covalent cross-linking, it is possible to design thin film membranes with tunable transport properties for water purification applications.

  15. Structural, microstructural and compositional analysis of Pb1-xSrxTiO3 nanostructure thin films

    International Nuclear Information System (INIS)

    Pb1-xSrxTiO3 nanostructure thin films with composition (0.102/Si substrates using a metal organic decomposition method. The advantage of this process is high purity, uniform particle size and controlled grain shape. The crystallization the PST thin films was achieved by heat treatment at 650℃ for two hours. The structural and micro structural modifications in the films were studied using X-ray (XRD), scanning electron microscope (SEM) and atomic force microscopy (AFM), respectively. Compositional analyses were studied by EDAX. The XRD study shows that the lattice parameters of polycrystalline PST thin films calculated indicate a decrease in lattice tetragonality with the increase in strontium content in these films. This indicates a gradual change from tetragonal to pseudo cubic structure. By atomic force microscopy analysis, the average grain size of the thin films was systematically reduced with the increase in Sr content. Thickness of nanostructure thin film were investigated by cross-sectional view of SEM (378nm), particle size calculated by Scherrer formula, which is also consistented with AFM. (author)

  16. Controllable degradation of medical magnesium by electrodeposited composite films of mussel adhesive protein (Mefp-1) and chitosan.

    Science.gov (United States)

    Jiang, Ping-Li; Hou, Rui-Qing; Chen, Cheng-Dong; Sun, Lan; Dong, Shi-Gang; Pan, Jin-Shan; Lin, Chang-Jian

    2016-09-15

    To control the degradation rate of medical magnesium in body fluid environment, biocompatible films composed of Mussel Adhesive Protein (Mefp-1) and chitosan were electrodeposited on magnesium surface in cathodic constant current mode. The compositions and structures of the films were characterized by atomic force microscope (AFM), scanning electron microscope (SEM) and infrared reflection absorption spectroscopy (IRAS). And the corrosion protection performance was investigated using electrochemical measurements and immersion tests in simulated body fluid (Hanks' solution). The results revealed that Mefp-1 and chitosan successfully adhered on the magnesium surface and formed a protective film. Compared with either single Mefp-1 or single chitosan film, the composite film of chitosan/Mefp-1/chitosan (CPC (chitosan/Mefp-1/chitosan)) exhibited lower corrosion current density, higher polarization resistance and more homogenous corrosion morphology and thus was able to effectively control the degradation rate of magnesium in simulated body environment. In addition, the active attachment and spreading of MC3T3-E1 cells on the CPC film coated magnesium indicated that the CPC film was significantly able to improve the biocompatibility of the medical magnesium. PMID:27309944

  17. Preparation of TiO2-based nanotubes/nanoparticles composite thin film electrodes for their electron transport properties

    International Nuclear Information System (INIS)

    The composite thin film electrodes were prepared with one-dimensional (1D) TiO2-B nanotubes (NTs) and zero-dimensional TiO2 nanoparticles (NPs) based on different weight ratios. The electron transport properties of the NTs/NPs composite thin film electrodes applied for dye-sensitized solar cells had been investigated systematically. The results indicated that although the amount of dye adsorption decreased slightly, the devices with the NTs/NPs composite thin film electrodes could obtain higher open-circuit voltage and overall conversion efficiency compared to devices with pure TiO2 NPs electrodes by rational tuning the weight ratio of TiO2-B NTs and TiO2 NPs. When the weight ratio of TiO2-B NTs in the NTs/NPs composite thin film electrodes increased, the density of states and recombination rate decreased. The 1D structure of TiO2-B NTs can provide direct paths for electron transport, resulting in higher electron lifetime, electron diffusion coefficient and electron diffusion length. The composite thin film electrodes possess the merits of the rapid electron transport of TiO2-B NTs and the high surface area of TiO2 NPs, which has great applied potential in the field of photovoltaic devices. - Highlights: • The composite thin film electrodes (CTFEs) were prepared with nanotubes and nanoparticles. • The CTFEs possess the rapid electron transport and high surface area. • The CTFEs exhibit lower recombination rate and longer electron life time. • The CTFEs have great applied potential in the field of photovoltaic devices

  18. Lithium intercalation/de-intercalation behavior of a composite Sn/C thin film fabricated by magnetron sputtering

    Institute of Scientific and Technical Information of China (English)

    ZHAO Lingzhi; HU Shejun; LI Weishan; LI Liming; HOU Xianhua

    2008-01-01

    A tin film of 320 nm in thickness on Cu foil and its composite film with graphite of~50 nm in thickness on it were fabricated by magnetron sputtering.The surface morphology,composition,surface distributions of alloy elements,and lithium intercalation/de-intercalation behaviors of the fabricated films were characterized by X-ray diffraction (XRD),scanning electron microscopy (SEM),electron probe microanalyzer (EPMA),X-ray photoelectron spectroscopy (XPS),inductively coupled plasma atomic emission spectrometry (ICP),cyclic voltammetry (CV),and galvanostatic charge/discharge (GC) measurements.It is found that the lithium intercalation/de-intercalation behavior of the Sn film can be significantly improved by its composite with graphite.With cycling,the discharge capacity of the Sn film without composite changes from 570 mAh/g of the 2nd cycle to 270 mAh/g of the 20th cycle,and its efficiency for the discharge and charge is between 90% and 95%.Nevertheless,the discharge capacity of the composite Sn/C film changes from 575 mAh/g of the 2nd cycle to 515 mAh/g of the 20th cycle,and its efficiency for the discharge and charge is between 95% and 100%.The performance improvement of tin by its composite with graphite is ascribed to the retardation of the bulk fin cracking from volume change during lithium intercalation and de-intercalation,which leads to the pulverization of fin.

  19. Influence of electroformation regime on the specific properties of cobalt oxide‒platinum composite films deposited on conductive diamond

    International Nuclear Information System (INIS)

    Two straightforward electrochemical methods were used in the present work for depositing cobalt oxide-platinum composite films on boron-doped diamond substrates in order to put into evidence the effect of the electroformation regime on the morphological and electrochemical features of these hybrid systems. The shift from potentiostatic to potentiodynamic deposition enabled not only a significant improvement of the Pt particles dispersion but also a much higher surface concentration of oxygenated species of platinum. For similar Co3O4 and Pt loadings, the specific capacitance of the composite films deposited by cyclic voltammetry was with ca. 8% higher than that of the potentiostatically obtained ones. Additional advantage of potentiodynamic deposition is the improved resistance to fouling during methanol anodic oxidation of Pt particles, tentatively ascribed to the higher surface concentration of oxygenated species of platinum. - Highlights: • Cobalt oxide-platinum composite films were electrodeposited on conductive diamond. • Composite films formed by cyclic voltammetry exhibit enhanced specific capacitance. • Potentiodynamic deposition enables higher concentration of oxygenated Pt species. • Co3O4–Pt films prepared by cyclic voltammetry are less susceptible to CO poisoning

  20. Facile preparation of ion-imprinted composite film for selective electrochemical removal of nickel(II) ions.

    Science.gov (United States)

    Du, Xiao; Zhang, Hao; Hao, Xiaogang; Guan, Guoqing; Abudula, Abuliti

    2014-06-25

    A facile unipolar pulse electropolymerization (UPEP) technique is successfully applied for the preparation of ion-imprinted composite film composed of ferricyanide-embedded conductive polypyrrole (FCN/PPy) for the selective electrochemical removal of heavy metal ions from wastewater. The imprinted heavy metal ions are found to be easily removed in situ from the growing film only by tactfully applying potential oscillation due to the unstable coordination of FCN to the imprinted ions. The obtained Ni(2+) ion-imprinted FCN/PPy composite film shows fast uptake/release ability for the removal of Ni(2+) ions from aqueous solution, and the adsorption equilibrium time is less than 50 s. The ion exchange capacity reaches 1.298 mmol g(-1) and retains 93.5% of its initial value even after 1000 uptake/release cycles. Separation factors of 6.3, 5.6, and 6.2 for Ni(2+)/Ca(2+), Ni(2+)/K(+), and Ni(2+)/Na(+), respectively, are obtained. These characteristics are attributed to the high identification capability of the ion-imprinted composite film for the target ions and the dual driving forces resulting from both PPy and FCN during the redox process. It is expected that the present method can be used for simple preparation of other ion-imprinted composite films for the separation and recovery of target heavy metal ions as well.

  1. Preparation and magnetic properties of CoFe2O4/TiO2 composite films

    Institute of Scientific and Technical Information of China (English)

    TIAN XiaoXia; QU ShaoBo; PEI ZhiBin; WANG BinKe

    2008-01-01

    Using (Ti(OC4H9)4) and metal chlorates as starting materials, CoFe2O4/TiO2 composite films were pre-pared by sol-gel method. The effects of heat treatment temperature and pH of the precursor on micro-structure and magnetic properties were studied. The phase structure of the samples was examined by X-ray diffraction. The microstructure was examined by scanning electron microscope, atomic force microscope and polarized microscope. The magnetic property was measured by vibrating sample magnetometer. The results show that the crystals of different phases grow up independently. CoFe2O4 is uniformly embedded into the TiO2 matrix in the prepared composite films, and the growth of com-posite films is dependent on the heat treatment temperatures and PH of the precursor. The average size of CoFe2O4 crystal is 19 nm in Nanocomposite film prepared when the heat treatment temperature is 800℃ and the pH of the precursor is between 2 and 3. The magnetism of the composite films is en-hanced as the heat treatment temperature increases.

  2. Building up Graphene-Based Conductive Polymer Composite Thin Films Using Reduced Graphene Oxide Prepared by γ-Ray Irradiation

    Directory of Open Access Journals (Sweden)

    Siyuan Xie

    2013-01-01

    Full Text Available In this paper, reduced graphene oxide (RGO was prepared by means of γ-ray irradiation of graphene oxide (GO in a water/ethanol mix solution, and we investigated the influence of reaction parameters, including ethanol concentration, absorbed dose, and dose rate during the irradiation. Due to the good dispersibility of the RGO in the mix solution, we built up flexible and conductive composite films based on the RGO and polymeric matrix through facile vacuum filtration and polymer coating. The electrical and optical properties of the obtained composite films were tested, showing good electrical conductivity with visible transmittance but strong ultraviolet absorbance.

  3. Self Focusing SIMS: Probing thin film composition in very confined volumes

    Science.gov (United States)

    Franquet, Alexis; Douhard, Bastien; Melkonyan, Davit; Favia, Paola; Conard, Thierry; Vandervorst, Wilfried

    2016-03-01

    The continued downscaling of micro and nanoelectronics devices has increased the importance of novel materials and their interfaces very strongly thereby necessitating the availability of adequate metrology and very tight process control as well. For instance, the introduction of materials like SiGe or III-V compounds leads to the need for the determination of the exact composition and thickness of the resulting thin films. Concurrent with this trend, one is faced with layer growth concepts such as aspect ratio trapping, which exploit the reduced dimensionality of the devices. As this leads to films with very different characteristics as compared to their blanket counterparts, characterization now has to be performed on thin films grown in very confined volumes (with dimensions ranging down to less than 10-20 nm) and standard analysis methods like X-Ray Photoelectron Spectroscopy, Secondary Ion Mass Spectrometry (SIMS) and Rutherford Backscattering Spectrometry, no longer seem applicable due to a lack of spatial resolution. On the other hand, techniques with appropriate spatial resolution like Atom Probe Tomography or Transmission Electron Microscopy are time consuming and suffer from a lack of sensitivity due to their highly localized analysis volume. In this paper, a novel concept termed Self Focusing SIMS, is presented which overcomes the spatial resolution limitations of SIMS without sacrificing the sensitivity. The concept is based on determining the composition of a specific compound using cluster ions which contain the constituents of the compound. Their formation mechanism implies that all cluster constituents originate from the same collision cascade and are emitted in close proximity (<0.5 nm). As such, the composition information becomes confined (i.e. self focused) to the areas where all constituents are simultaneously present. The examples shown in this work are based on SiGe compounds and demonstrate that it becomes feasible to determine the

  4. Fabrication of high conductivity dual multi-porous poly (L-lactic acid)/polypyrrole composite micro/nanofiber film

    Energy Technology Data Exchange (ETDEWEB)

    Yu Qiaozhen, E-mail: w2003yqz@126.com [Faculty of Materials and Textiles, Jiaxing Key Lab of Modern Textile and Garment, Jiaxing University, Jiaxing, Zhejiang 314001 (China); Dai Zhengwei; Lan Ping [Faculty of Materials and Textiles, Jiaxing Key Lab of Modern Textile and Garment, Jiaxing University, Jiaxing, Zhejiang 314001 (China)

    2011-07-25

    Highlights: > PLLA/H{sub 2}SO{sub 4}-doped PPy composite micro/nano fibers dual multi-pore membranes with high conductivity were fabricated by combining electrospinning with in situ polymerization.These composite fibers have a core-shell structure, the PPy is the core and the PLLA/PPy is the shell. > The size and shape of the pores in this PPy composite fiber membrane can be tuned by polymerization parameters. The largest size of the pores is about 250 {mu}m. > The conductivity of this composite fiber membrane can be adjusted by polymerization parameters. The highest conductivity is 179.0 S cm{sup -1}. The PLLA fibers act as the template in the pyrrole polymerization process and contributed to the increase of the conductivity. - Abstract: Dual multi-porous PLLA (poly(L-lactic acid))/H{sub 2}SO{sub 4}-doped PPy (polypyrrole) composite micro/nano fiber films were fabricated by combining electrospinning with in situ polymerization. The morphologies and structures of the resulting samples were analyzed by scanning electron microscopy (SEM). It was found that the composite micro/nano fibers exhibited a core-shell structure and the composite fiber film had a dual multi-pore structure composed of pores both in the fibers and among the fibers. Semiconductor parameter analyzer was used to characterize the electrical properties of the samples. It was interesting to find that all the PLLA/H{sub 2}SO{sub 4}-doped PPy composite micro/nano fiber films had higher conductivity than H{sub 2}SO{sub 4}-doped PPy particles when the polymerization time up to 180 min. Effects of the pyrrole synthesis conditions on the pore size and the conductivity of PLLA/PPy composite fiber film were assessed. By optimizing the polymerization conditions, the max conductivity of this composite fiber film was about 179.0 S cm{sup -1} with a pore size of about 250 {mu}m. The possible mechanism of PLLA/H{sub 2}SO{sub 4}-doped PPy composite micro/nano fiber films had much higher conductivity than H{sub 2

  5. Novel Bi-substituted Yttrium Iron Garnet Film/Crystal Composite for Magneto-optical Applications

    Institute of Scientific and Technical Information of China (English)

    HUANG Min; XU Zhi-cheng; ZHOU Wei-zhen

    2004-01-01

    The novel Bi-substituted rare-earth iron garnet films were grown by the modified liquid phase epitaxy (LPE) technique for use as a 45° Faraday rotator in optical isolators. First, single crystals of Y3 Fe5 O12(YIG), with a lattice constant of 1. 237 8 nm, were grown by means of the Czochralski method. Using the seed crystal of YIG instead of the conventional non-magnetic garnet of Gd3Ga5O12 (GGG) as a substrate,a film of BiYbIG was grown by means of the LPE method from Bi2O3 - B2O3 fluxes. The structural, magnetic and magneto-optical properties of BiYbIG LPE film/YIG crystal composite have been investigated using directional X-ray diffraction (XRD), electron probe microanalysis (EPMA), vibrating sample magnetometer (VMS) and near-infrared transmission spectrometry. The saturation magnetization 4πMs has been estimated to be about 1.2×10 6 A/m. The Faraday rotation spectrum was measured by the method of rotating analyzer ellipsometry (RAE) with the wavelength varied from 800 nm to 1 700 nm. The resultant Bi0.37 Yb2.63 Fe5 O12LPE film/YIG crystal composite showed an increased Faraday rotation coefficient due to doping Bi3+ ions into the dodecahedral sites of the magnetic garnet without increasing absorption loss, therefore a good magnetooptic figure of merit,defined by the ratio of Faraday rotation and optical absorption loss, has been achieved of 21.5 and 30.2 (°)/dB at 1 300 and 1 550 nm wavelengths respectively and room temperature. Since Yb3+ and Y3+ ions provide the opposite contribution to the wideband and temperature characteristics of Faraday rotation,the values of Faraday rotation wavelength and temperature coefficients were reduced to 0.06 %/nm and 0.007(°)/℃ at 1 550 nm wavelength, respectively.

  6. Direct electrochemistry of glucose oxidase on the hydroxyapatite/Nafion composite film modified electrode and its application for glucose biosensing

    Institute of Scientific and Technical Information of China (English)

    MA RongNa; WANG Bin; LIU Yan; LI Jing; ZHAO Qian; WANG GuoTao; JIA WenLi; WANG HuaiSheng

    2009-01-01

    A novel glucose biosensor was constructed by immobilizing the glucose oxidase (GOD) on a hydroxyapatite (Hap)/Nafion composite film modified glassy carbon electrode (GCE) and applied to the highly selective and sensitive determination of glucose.With the cooperation of Hap and Nation,the composite film played an important role in enhancing the stability and sensitivity of the biosensor.The results demonstrate that the GOD adsorbed onto the Hap/Nation composite film exhibits a pair of welldefined nearly reversible redox peaks and fine catalysis to the oxidation of glucose companied with the consumption of dissolved oxygen.On the basis of the decrease of the reduction current of dissolved oxygen at the applied potential of-0.80 V (vs.SCE) upon the addition of glucose,the concentration of glucose could be detected sensitively and selectively.The decreased reduction current was linear with the concentration of glucose in the range of 0.12-2.16 mM.The detection limit and sensitivity were 0.02 mM (S/N=3) and 6.75 mA·M~(-1),respectively.All the results demonstrate that Hap/Nafion composite film provides a novel and efficient platform for the immobilization of enzymes end realizes the direct electrochemistry.The composite materials should have potential applications in the fabrication of third-generation biosensors.

  7. Direct electrochemistry of glucose oxidase on the hydroxyapatite/Nafion composite film modified electrode and its application for glucose biosensing

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    A novel glucose biosensor was constructed by immobilizing the glucose oxidase(GOD) on a hydroxyapatite(HAp)/Nafion composite film modified glassy carbon electrode(GCE) and applied to the highly selective and sensitive determination of glucose.With the cooperation of HAp and Nafion,the composite film played an important role in enhancing the stability and sensitivity of the biosensor.The results demonstrate that the GOD adsorbed onto the HAp/Nafion composite film exhibits a pair of welldefined nearly reversible redox peaks and fine catalysis to the oxidation of glucose companied with the consumption of dissolved oxygen.On the basis of the decrease of the reduction current of dissolved oxygen at the applied potential of -0.80 V(vs.SCE) upon the addition of glucose,the concentration of glucose could be detected sensitively and selectively.The decreased reduction current was linear with the concentration of glucose in the range of 0.12―2.16 mM.The detection limit and sensitivity were 0.02 mM(S/N=3) and 6.75 mA·M-1,respectively.All the results demonstrate that HAp/Nafion composite film provides a novel and efficient platform for the immobilization of enzymes and realizes the direct electrochemistry.The composite materials should have potential applications in the fabrication of third-generation biosensors.

  8. Enhancing characteristics of a composite film by combination of vanadium-substituted molybdophosphate and platinum nanoparticles for an electrochemical sensor

    International Nuclear Information System (INIS)

    Graphical abstract: A proposed electrochemical sensor has highly selective, sensitive, stable and fast determination of dopamine, as well as no interference from the common interfering species at an applied potential of 0.8 V. -- Abstract: A composite film based on a vanadium-substituted molybdophosphate H6[PMo9V3O40] (PMo9V3) decorated by platinum nanoparticles (Pt) has been prepared by the layer-by-layer self-assembly method. The growth process of the composite film was monitored by UV–vis spectroscopy, and the elemental composition and surface morphology were surveyed by X-ray photoelectron spectra (XPS) and atomic force microscopy (AFM), respectively. Comparative experiments revealed that the electrocatalytic efficiency and amperometric response of this composite film toward oxidation of dopamine at physiological conditions were markedly enhanced by synergistic contributions of PMo9V3 and Pt. The sensing performance for dopamine detection was investigated in detail. At physiological conditions, the composite film exhibited high sensitivity of 1.2 μM/μA dopamine, fast response time (−7 M), and a wide linear range from 4.2 × 10−7 to 1.3 × 10−3 M toward amperometric sensing of dopamine, as well as no interference from the common interfering species such as ascorbic acid, glucose, uric acid and L-cysteine

  9. Influence of Methacrylic-Acrylic Copolymer Composition on Plasticiser-free Optode Films for pH Sensors

    Directory of Open Access Journals (Sweden)

    Musa Ahmad

    2003-03-01

    Full Text Available In this work we have examined the use of plasticiser-free polymeric films incorporating a proton selective chromoionophore for optical pH sensor. Four types of methacrylic-acrylic copolymers containing different compositions of n-butyl acrylate (nBA and methyl methacrylate (MMA were synthesised for use as optical sensor films. The copolymers were mixed with appropriate amounts of chromoionophore (ETH5294 and a lipophilic salt before spin coated on glass slides to form films for the evaluation of pH response using spectrophotometry. Co-polymer films with high nBA content gave good response and the response time depended on the film thickness. A preliminary evaluation of the optical films of high nBA content with pHs from 2 - 14 showed distinguishable responses from pH 5 - 9. However, the adhesion of the pH sensitive film was good for copolymers with higher content of MMA but not for films with high nBA.

  10. Characterization and DC Conductivity of Novel CuO doped Polyvinyl Alcohol (PVA Nano-composite Films

    Directory of Open Access Journals (Sweden)

    Chivukula Srikanth

    2014-10-01

    Full Text Available DC conductivity of PVA-CuO nano-composite films have been studied in the present work. The composites were prepared by solution-casting technique. The prepared PVA-CuO composites have been characterized by X-ray diffraction (XRD analysis, Fourier Transform Infrared Spectroscopy (FT-IR, Scanning Electron Microscopy (SEM and Energy Dispersive X-ray Spectroscopy (EDXS; which confirmed the presence of CuO in polyvinyl alcohol and the formation of the composite. DC conductivity studies show thermally activated behavior of all the composites. The conductivity was found to increase with the increase in temperature indicating the semiconducting behavior of all the compositions. The activation energy increases as the content of CuO nanoparticles increases from 1 to 4 in wt% in the PVA- CuO nano-composites. Maximum conductivity was observed in 4 wt% of CuO in polyvinyl alcohol.

  11. Evaluation of RTM370 Polyimide Composites by Resin Film Infusion (RFI)

    Science.gov (United States)

    Chuang, Kathy C.; Yip, Thomas A.; Kollmansberger, Ronald B.; Tsotsis, Thomas K.

    2014-01-01

    RTM370 imide oligomer based on 2,3,3',4'-biphenyl dianhydride (a-BPDA), 3,4'-oxydianiline (3,4'-ODA) and terminated with the 4-phenylethynylphthalic (PEPA) endcap has been shown to exhibit a low melt viscosity (10-30 poise) at 280 C with a pot-life of 1-2 h and a high cured glass-transition temperature (Tg) of 370 C. RTM370 resin has been successfully infused into fiberglass-stitched T650-35 carbon-fabric preforms (ranged from 3- to 6-mm thick) by resin film infusion (RFI). The resulting composite panels were inspected by ultrasonic C-scan and by photomicrographs before and after post-curing as a quality control. Mechanical tests such as unnotched compression (UNC), open-hole compression (OHC), and short-beam shear strength (SBS) at ambient and elevated temperatures were performed before and after isothermal aging at 288 C for 1000 h to assess high-temperature performance. Thermal cycling of RTM370 stitched composites was also conducted from -54 C to 288 C for up to 1600 cycles to evaluate the microcrack resistance of RTM370 polyimide composites fabricated by RFI.

  12. Synthesis of Au microwires by selective oxidation of Au–W thin-film composition spreads

    Directory of Open Access Journals (Sweden)

    Sven Hamann, Hayo Brunken, Steffen Salomon, Robert Meyer, Alan Savan and Alfred Ludwig

    2013-01-01

    Full Text Available We report on the stress-induced growth of Au microwires out of a surrounding Au–W matrix by selective oxidation, in view of a possible application as 'micro-Velcro'. The Au wires are extruded due to the high compressive stress in the tungsten oxide formed by oxidation of elemental W. The samples were fabricated as a thin-film materials library using combinatorial sputter deposition followed by thermal oxidation. Sizes and shapes of the Au microwires were investigated as a function of the W to Au ratio. The coherence length and stress state of the Au microwires were related to their shape and plastic deformation. Depending on the composition of the Au–W precursor, the oxidized samples showed regions with differently shaped Au microwires. The Au48W52 composition yielded wires with the maximum length to diameter ratio due to the high compressive stress in the tungsten oxide matrix. The values of wire length (35 μm and diameter (2 μm achieved at the Au48W52 composition are suitable for micro-Velcro applications.

  13. Synthesis, characterization and hydrophilic properties of ZnFe2O4–TiO2 composite film

    International Nuclear Information System (INIS)

    Highlights: • ZnFe2O4–TiO2 composite films have been successfully prepared via a sol–gel method. • It was deposited on glass slides through dip coating process. • 7% ZnFe2O4–TiO2 film exhibits a superhydrophilic property with a contact angle 0°. • The self-cleaning glasses also display antifogging property. - Abstract: ZnFe2O4–TiO2 composite films have been successfully prepared via a sol–gel method and deposited on glass slides through dip coating process. The hydrophilicity of ZnFe2O4–TiO2 composite films was investigated by the contact angles measurements under different conditions, including heat treatment temperature, molar ratios of ZnFe2O4 to TiO2 and coating layers. The results revealed that the 7 mol% ZnFe2O4-TiO2 composite film exhibits an excellent superhydrophilic performance with a contact angle 0°. Compared with normal glass, the self-cleaning glasses also display antifogging property. The transmittance of ZnFe2O4–TiO2 composite films was characterized by UV–vis spectra in details. Coating layers and different molar percents of ZnFe2O4 all have impact on the light transmittance. Moreover, the structure and morphology of the ZnFe2O4–TiO2 sample were investigated by means of X-ray diffraction (XRD), energy dispersive X-ray spectrometry (EDS) and scanning electron microscopy (SEM)

  14. Direct Electrochemistry of Glucose Oxidase on Novel Free-Standing Nitrogen-Doped Carbon Nanospheres@Carbon Nanofibers Composite Film

    OpenAIRE

    Xueping Zhang; Dong Liu; Libo Li; Tianyan You

    2015-01-01

    We have proposed a novel free-standing nitrogen-doped carbon nanospheres@carbon nanofibers (NCNSs@CNFs) composite film with high processability for the investigation of the direct electron transfer (DET) of glucose oxidase (GOx) and the DET-based glucose biosensing. The composites were simply prepared by controlled thermal treatment of electrospun polypyrrole nanospheres doped polyacrylonitrile nanofibers (PPyNSs@PAN NFs). Without any pretreatment, the as-prepared material can directly serve ...

  15. Preparation and Characterization of Thin-Film Composite Membrane with Nanowire-Modified Support for Forward Osmosis Process

    OpenAIRE

    Ze-Xian Low; Qi Liu; Ezzatollah Shamsaei; Xiwang Zhang; Huanting Wang

    2015-01-01

    Internal concentration polarization (ICP) in forward osmosis (FO) process is a characteristic problem for asymmetric thin-film composite (TFC) FO membrane which leads to lower water flux. To mitigate the ICP effect, modification of the substrates’ properties has been one of the most effective methods. A new polyethersulfone-based ultrafiltration membrane with increased surface porosity and high water flux was recently produced by incorporating Zn2GeO4 nanowires. The composite membrane was use...

  16. Thickness Determination for a Two-Layered Composite of a Film and a Plate by Low-Frequency Ultrasound

    Institute of Scientific and Technical Information of China (English)

    MAO Jie; LI Ming-Xuan; WANG Xiao-Min

    2007-01-01

    We present an ultrasonic method for determining the thickness of a composite consisting of a soft thin film attached to a hard plate substrate, by resonance spectra in the low frequency region. The interrogating waves can be incident only to the two-layered composite from the substrate side. The reflection spectra are obtained by FFT analysis of the compressive pulsed echoes from the composite, and the thicknesses of the film and the substrate are simultaneously inversed by the simulated annealing method from the resonant frequencies knowing other acoustical parameters in prior. The sensitivity of the method to individual thickness, its convergence and stability against experimental noises are studied. Experiment with interrogating wavelength 4 times larger than the film thickness in a sample of a polymer film (0.054 mm) on an aluminium plate (6.24 mm) verifies the validity of the method. The average relative errors in the measurement of the thicknesses of the film and the substrate are found to be -4.1% and -0.62%, respectively.

  17. Voltammetric determination of theophylline at a Nafion/multi-wall carbon nanotubes composite film-modified glassy carbon electrode

    Indian Academy of Sciences (India)

    Suling Yang; Ran Yang; Gang Li; Jianjun Li; Lingbo Qu

    2010-11-01

    A Nafion/multi-wall carbon nanotubes (MWNTs) composite film-modified electrode was fabricated and applied to the sensitive and convenient determination of theophylline (TP). Multi-wall carbon nanotubes (MWNTs) were easily dispersed homogeneously into 0.1% Nafion methanol solution by sonication. Appropriate amount of Nafion/MWNTs suspension was coated on a glassy carbon electrode. After evaporating methanol, a Nafion/MWNTs composite film-modified electrode was achieved. TP could effectively accumulate at Nafion/MWNTs composite film-modified electrode and cause a sensitive anodic peak at around 1180 mV (vs SCE) in 0.01 mol/L H2SO4 medium (pH 1.8). In contrast with the bare glassy carbon electrode, Nafion film-modified electrode, Nafion/MWNTs film-modified electrode could remarkably increase the anodic peak current and decreased the overpotential of TP oxidation. Under the optimized conditions, the anodic peak current was proportional to TP concentration in the range of 8.0 × 10-8-6.0 × 10-5 mol/L, with a detection limit of 2.0 × 10-8 mol/L. This newly developed method was used to determine TP in drug samples with good percentage of recoveries.

  18. New fabrication technique of conductive polymer/insulating polymer composite films and evaluation of biocompatibility in neuron cultures

    International Nuclear Information System (INIS)

    Poly(vinyl alcohol), PVA, produces a flexible composite polymer film with electrical, optical and electrochemical properties very similar to those of polypyrrole (PPy). The rate of electrochemical polymerization depends on the diffusion rate of the electrolyte across the PVA film to the indium tin oxide (ITO) electrode. In particular, a solvent with a hydrophilic nature easily penetrates into the PVA film. By applying this new process, we demonstrate a unique method of forming an electrically conductive pattern in PVA film. It will be possible to develop electrodes for electrical stimulation of the nervous system using the conducting polymer, PPy. Then, by applying a similar technique, we fabricated poly(3,4-ethylenedioxythiophene), PEDOT/PVA, composite films and investigated their basic electrochemical properties. Moreover, in this study, in order to develop a novel cell-culture system which makes it possible to communicate with cultured cells, fibroblasts were cultured on PPy- and PEDOT-coated ITO conductive glass plates for 7 days. The result reveals that the PPy and PEDOT films support the secretory functions of the cells cultured on its surface. The PPy- and PEDOT-coated electrodes may be useful to culture the cells on.

  19. Corrosion Resistance of Sintered NdFeB Permanent Magnet With Ni-P/TiO2 Composite Film

    Institute of Scientific and Technical Information of China (English)

    SONG Lai-zhou; YANG Zhi-yong

    2009-01-01

    The Ni-P/TiO2 composite film on sintered NdFeB permanent magnet was investigated by X-ray diffraction (XRD), environmental scanning electron microscopy (ESEM), and energy dispersive X-ray spectrometer (EDX).The corrosion resistance of Ni-P/TiO2 film coated on NdFeB magnet, in 0. 5 mol/L NaCl solution, was studied by potentiodynamic polarization, salt spray test and electrochemical impedance spectroscopy (EIS) techniques. The selfcorrosion current density (icorr) and the polarization resistance (Rp) of Ni-P/TiO2 film are 0. 22 μA/cm2 (about 14% of that of Ni-P coating), and 120 kΩ·cm2 (about 2 times of that of Ni-P coating), respectively. The anti-salt spray time of Ni-P/TiO2 film is about 2.5 times of that of the Ni-P coating. The results indicate that Ni-P/TiO2 film has a better corrosion resistance than Ni-P coating, and the composite film increases the corrosion resistance of NdFeB magnet markedly.

  20. TiAgx thin films for lower limb prosthesis pressure sensors: Effect of composition and structural changes on the electrical and thermal response of the films

    Science.gov (United States)

    Lopes, C.; Gonçalves, C.; Pedrosa, P.; Macedo, F.; Alves, E.; Barradas, N. P.; Martin, N.; Fonseca, C.; Vaz, F.

    2013-11-01

    Titanium-silver, Ti-Ag, thin films display excellent biocompatibility and reveal great potential to be used as conductive materials for prosthesis pressure sensors. In the frame of this work, TiAgx thin films were deposited onto silicon and glass substrates by DC magnetron sputtering, using a pure Ti target containing different amounts of Ag pellets. The films display Ag/Ti ratios varying from 0 up to 0.36, resulting in relatively large range of composition, which gave rise to varied morphological, structural and some selected property responses. For Ag/Ti ratios below 3.0 × 10-3, the TiAgx films exhibited similar behavior to those of standard Ti films. Above this critical value, the role of Ag becomes crucial on the crystallographic structure evolution, as well as on the surface morphology changes of the films. A gradual increase of the Ag/Ti ratio leads to the growth of Ti-Ag crystalline phases, whereas the long range order of Ti grains was reduced from 22 nm down to 7 nm. Similarly, a denser microstructure was developed with a reduction of the sharpness of the surface morphology. This critical Ag/Ti ratio (<3.0 × 10-3) also corresponded to an enhanced electrical resistivity, which reached a value of ρ300K = 72 μΩ cm. The thermal characterization revealed a similar trend, with the existence of two clear distinct zones, related again with the different critical composition ratios and the correspondent changes in both morphology and structural features.

  1. Cross-linked PAN-based thin-film composite membranes for non-aqueous nanofiltration

    KAUST Repository

    Pérez-Manríquez, Liliana

    2015-01-01

    A new approach on the development of cross-linked PAN based thin film composite (TFC) membranes for non-aqueous application is presented in this work. Polypropylene backed neat PAN membranes fabricated by phase inversion process were cross-linked with hydrazine to get excellent solvent stability toward dimethylformamide (DMF). By interfacial polymerization a selective polyamide active layer was coated over the cross-linked PAN using N,N′-diamino piperazine (DAP) and trimesoyl chloride (TMC) as monomers. Permeation and molecular weight cut off (MWCO) experiments using various dyes were done to evaluate the performance of the membranes. Membranes developed by such method show excellent solvent stability toward DMF with a permeance of 1.7 L/m2 h bar and a molecular weight cut-off of less than 600 Da.

  2. STUDY ON THE DESALINATION BEHAVIORS OF PA/PSF THIN FILM COMPOSITE

    Institute of Scientific and Technical Information of China (English)

    TIAN Guojun; ZHANG Yufeng; ZHANG Yan; DU Qiyun; XIAO Changfa; GUO Hao

    2006-01-01

    A polypiperazine amide (PA)/polysulfone (PSF) thin film composite (TFC) was prepared by interfacial polymerization (IP) using a trimesoyl chloride hexane solution as the oil phase and a piperazine aqueous solution as the water phase on a porous polysulfone hollow fiber substrate. Its separating behaviors were investigated systematically to various salts such as NaCl, KCI, Na2SO4,MgCl2, CaCl2 and MgSO4, showing the highest rejection rate to Na2SO4, the second to MgSO4, the third to MgCl2 and CaCl2, and the lowest to KCI, NaCl, being 99%, 98%, 70%, 60%, 15% and 10% respectively. Under an increasing pressure or with time, the rejection rate of the TFC rises to a plateau. To various concentration of the feed, the rejection rate reduced gradually with the higher concentration.

  3. Mechanisms of High Coercivity in Ni/NiO Composite Films by Post Annealing

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A coercivity as large as 2.4 kOe has been achieved in the Ni/NiO composite film after an annealing under a magnetic field of 10 kOe and an O2 partial pressure of 0.001 torr. The coercivity was attributed to the strong exchange coupling of Ni and NiO. Small grain size of Ni and NiO was observed after the post-annealing. The enhanced coercivity is probably associated with the domain wall pinning by local energy minima, the distribution of Ni and NiO, and the domain structure in the interface of Ni/NiO generated under the presence of the magnetic field during the post-annealing.

  4. Crosslinked cellulose thin film composite nanofiltration membranes with zero salt rejection

    KAUST Repository

    Puspasari, Tiara

    2015-05-14

    We report a new synthetic route of fabricating regenerated cellulose nanofiltration membranes. The membranes are composite membranes with a thin selective layer of cellulose, which was prepared by regeneration of trimethylsilyl cellulose (a hydrophobic cellulose derivative) film followed by crosslinking. Filtration experiments using mixtures of sugar and sodium chloride showed that solutes above 300 Da were highly rejected whereas practically no rejection was observed for NaCl. This is a big advantage for a complete desalination as the existing commercial nanofiltration membranes typically exhibit NaCl rejection in the range of 30–60%. Membranes with zero NaCl rejection are required for recovery and purification applications in food, chemical and pharmaceutical industry.

  5. Composition and corrosion resistance of cerium conversion films on 2195Al-Li alloy

    Institute of Scientific and Technical Information of China (English)

    SONG Dong; FENG Xingguo; SUN Mingren; MA Xinxin; TANG Guangze

    2012-01-01

    The Ce conversion films on 2195Al-Li alloy without and with post-treatment were studied and the corrosion resistance was evaluated as well.The surface morphology was observed by scanning electron microscopy (SEN),and the chemical composition was characterized by X-ray photoelectron spectroscopy (XPS).The corrosion behaviors of 2195Al-Li alloy and conversion coating were assessed by means of potentiodynamic polarization curves.The experimental results indicated that after post-treatment the surface quality was improved significantly.According to XPS,the conversion coating after post-treatment was mainly composed of CeO2,Ce2O3,Ce-OH and a little MoO3 and MoO2.The results of potentiodynamic polarization curves revealed that the conversion coating with post-treatment possessed better corrosion resistance than bare alloy and Ce conversion coating without post-treatment.

  6. Direct synthesis of RGO/Cu{sub 2}O composite films on Cu foil for supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Xiangmao; Wang, Kun [Key Laboratory for Ultrafine Materials of the Ministry of Education, Shanghai Key Laboratory of Advanced Polymeric Materials, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China); Zhao, Chongjun, E-mail: chongjunzhao@ecust.edu.cn [Key Laboratory for Ultrafine Materials of the Ministry of Education, Shanghai Key Laboratory of Advanced Polymeric Materials, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China); Institute for Superconducting and Electronic Materials, University of Wollongong, Wollongong 2500 (Australia); Qian, Xiuzhen [Key Laboratory for Ultrafine Materials of the Ministry of Education, Shanghai Key Laboratory of Advanced Polymeric Materials, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China); Chen, Shi [School of Information Engineering, Wuhan University of Technology, Wuhan 430070 (China); Li, Zhen, E-mail: zhenl@uow.edu.au [Institute for Superconducting and Electronic Materials, University of Wollongong, Wollongong 2500 (Australia); Liu, Huakun; Dou, Shixue [Institute for Superconducting and Electronic Materials, University of Wollongong, Wollongong 2500 (Australia)

    2014-02-15

    Graphical abstract: RGO/Cu{sub 2}O/Cu composites were synthesized by simple hydrothermal treatment of copper foils with graphene oxide, in which the reduction of graphene oxide and the formation of Cu{sub 2}O nanoparticles simultaneously happened in one-pot reaction. These composites can be directly used as electrodes of supercapacitors with the highest specific capacitance of 98.5 F/g at 1 A g{sup −1}, which is much better than that of CuO or Cu{sub 2}O electrodes. -- Highlights: • The RGO/Cu{sub 2}O/Cu composites were obtained by a friendly method in one step. • Improved capacitance performance is realized by the hydrothermal treatment of graphene oxides with Cu foils. • RGO/Cu{sub 2}O/Cu-200 composites exhibit the largest specific capacitance of 98.5 F g{sup −1} at 1 A g{sup −1}. -- Abstract: Reduced graphene oxide/cuprous oxide (RGO/Cu{sub 2}O) composite films were directly synthesized on the surface of copper foil substrates through a straight redox reaction between GO and Cu foil via a hydrothermal approach. Characterization of the resultant composites with X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, and field emission scanning electron microscope (FESEM) confirms the formation of Cu{sub 2}O and reduction of GO, in which Cu{sub 2}O nanoparticles were well covered by RGO. The resultant composites (referred to as RGO/Cu{sub 2}O/Cu) were directly used as electrodes for supercapacitors, and their electrochemical performance was assessed by cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), and electrochemical impedance spectrometry (EIS) in 1 M KOH aqueous solution. A specific capacitance of 98.5 F g{sup −1} at 1 A g{sup −1} was obtained, which is much higher than that of pure Cu{sub 2}O prepared under the same conditions, due to the presence of RGO.

  7. Inkjet printing of multi-walled carbon nanotube/polymer composite thin film for interconnection.

    Science.gov (United States)

    Lok, Boon Keng; Ng, You Min; Liang, Yen Nan; Hu, Xiao

    2010-07-01

    In this paper, multi-walled carbon nanotube (MWCNT) ink was selectively patterned by inkjet printing on substrates to form conductive traces and electrodes for interconnection application. MWCNT was firstly functionalized using concentrated acid and dispersed in deionized water to form a colloidal solution. Various concentrations of MWCNT were formulated to test the stability of the solution. The printability of the MWCNT ink was examined against printing temperature, ink concentration and ink droplet pitch. Rheological properties of the ink were determined by rheometer and sessile drop method. The electrical conductivity of the MWCNT pattern was measured against multiple printing of MWCNT on the same pattern (up to 10 layers). While single layer printing pattern exhibited highest resistance, the CNT entangled together and formed a random network with more printed layers has higher conductivity. The electrical properties of the printed film was compared to a composite ink of CNT and conducting polymer (CNT ink was mixed with conductive polymer solution, Poly(3,4-ethylenedioxythiophene)-Poly(styrenesulfonate) (PEDOT:PSS)). Scanning electron microscopy (SEM) was used to observe the surface structure and atomic force microscopy (AFM) was used to study the morphology of the printed film under different conditions.

  8. Degradation and miscibility of poly(DL-lactic acid)/poly(glycolic acid) composite films: Effect of poly(DL-lactic-co-glycolic acid)

    Indian Academy of Sciences (India)

    Zhigang Ma; Na Zhao; Chengdong Xiong

    2012-08-01

    The in vitro degradation behaviour of poly(glycolic acid) (PGA) and its composite films containing poly(DL-lactic acid) (PDLLA) and poly(DL-lactic-co-glycolic acid) (PDLGA) were investigated via mass loss, scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). All the films were prepared by solution casting, using 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) as the solvent. Since the degradation rate of PDLLA is lower than that of PGA, those of the PDLLA/PGA composite films decreased. As a compatibilizer, PDLGA improved the compatibility and hydrolytic stability of PDLLA/PGA composite films. Changes in the composite films indicate that this kind of PGA-based composite biomaterial may be applicable to device design for clinical application in the future.

  9. Reduction of bacterial adhesion on dental composite resins by silicon-oxygen thin film coatings.

    Science.gov (United States)

    Mandracci, Pietro; Mussano, Federico; Ceruti, Paola; Pirri, Candido F; Carossa, Stefano

    2015-01-29

    Adhesion of bacteria on dental materials can be reduced by modifying the physical and chemical characteristics of their surfaces, either through the application of specific surface treatments or by the deposition of thin film coatings. Since this approach does not rely on the use of drugs or antimicrobial agents embedded in the materials, its duration is not limited by their possible depletion. Moreover it avoids the risks related to possible cytotoxic effects elicited by antibacterial substances released from the surface and diffused in the surrounding tissues. In this work, the adhesion of Streptococcus mutans and Streptococcus mitis was studied on four composite resins, commonly used for manufacturing dental prostheses. The surfaces of dental materials were modified through the deposition of a-SiO(x) thin films by plasma enhanced chemical vapor deposition. The chemical bonding structure of the coatings was analyzed by Fourier-transform infrared spectroscopy. The morphology of the dental materials before and after the coating deposition was assessed by means of optical microscopy and high-resolution mechanical profilometry, while their wettability was investigated by contact angle measurements. The sample roughness was not altered after coating deposition, while a noticeable increase of wettability was detected for all the samples. Also, the adhesion of S. mitis decreased in a statistically significant way on the coated samples, when compared to the uncoated ones, which did not occur for S. mutans. Within the limitations of this study, a-SiO(x) coatings may affect the adhesion of bacteria such as S. mitis, possibly by changing the wettability of the composite resins investigated.

  10. Functionalized Antimicrobial Composite Thin Films Printing for Stainless Steel Implant Coatings

    Directory of Open Access Journals (Sweden)

    Laura Floroian

    2016-06-01

    Full Text Available In this work we try to address the large interest existing nowadays in the better understanding of the interaction between microbial biofilms and metallic implants. Our aimed was to identify a new preventive strategy to control drug release, biofilm formation and contamination of medical devices with microbes. The transfer and printing of novel bioactive glass-polymer-antibiotic composites by Matrix-Assisted Pulsed Laser Evaporation into uniform thin films onto 316 L stainless steel substrates of the type used in implants are reported. The targets were prepared by freezing in liquid nitrogen mixtures containing polymer and antibiotic reinforced with bioglass powder. The cryogenic targets were submitted to multipulse evaporation by irradiation with an UV KrF* (λ = 248 nm, τFWHM ≤ 25 ns excimer laser source. The prepared structures were analyzed by infrared spectroscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy and profilometry, before and after immersion in physiological fluids. The bioactivity and the release of the antibiotic have been evaluated. We showed that the incorporated antibiotic underwent a gradually dissolution in physiological fluids thus supporting a high local treatment efficiency. Electrochemical measurements including linear sweep voltammetry and impedance spectroscopy studies were carried out to investigate the corrosion resistance of the coatings in physiological environments. The in vitro biocompatibility assay using the MG63 mammalian cell line revealed that the obtained nanostructured composite films are non-cytotoxic. The antimicrobial effect of the coatings was tested against Staphylococcus aureus and Escherichia coli strains, usually present in implant-associated infections. An anti-biofilm activity was evidenced, stronger against E. coli than the S. aureus strain. The results proved that the applied method allows for the fabrication of implantable biomaterials which shield metal ion release

  11. Functionalized Antimicrobial Composite Thin Films Printing for Stainless Steel Implant Coatings.

    Science.gov (United States)

    Floroian, Laura; Ristoscu, Carmen; Mihailescu, Natalia; Negut, Irina; Badea, Mihaela; Ursutiu, Doru; Chifiriuc, Mariana Carmen; Urzica, Iuliana; Dyia, Hussien Mohammed; Bleotu, Coralia; Mihailescu, Ion N

    2016-01-01

    In this work we try to address the large interest existing nowadays in the better understanding of the interaction between microbial biofilms and metallic implants. Our aimed was to identify a new preventive strategy to control drug release, biofilm formation and contamination of medical devices with microbes. The transfer and printing of novel bioactive glass-polymer-antibiotic composites by Matrix-Assisted Pulsed Laser Evaporation into uniform thin films onto 316 L stainless steel substrates of the type used in implants are reported. The targets were prepared by freezing in liquid nitrogen mixtures containing polymer and antibiotic reinforced with bioglass powder. The cryogenic targets were submitted to multipulse evaporation by irradiation with an UV KrF* (λ = 248 nm, τFWHM ≤ 25 ns) excimer laser source. The prepared structures were analyzed by infrared spectroscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy and profilometry, before and after immersion in physiological fluids. The bioactivity and the release of the antibiotic have been evaluated. We showed that the incorporated antibiotic underwent a gradually dissolution in physiological fluids thus supporting a high local treatment efficiency. Electrochemical measurements including linear sweep voltammetry and impedance spectroscopy studies were carried out to investigate the corrosion resistance of the coatings in physiological environments. The in vitro biocompatibility assay using the MG63 mammalian cell line revealed that the obtained nanostructured composite films are non-cytotoxic. The antimicrobial effect of the coatings was tested against Staphylococcus aureus and Escherichia coli strains, usually present in implant-associated infections. An anti-biofilm activity was evidenced, stronger against E. coli than the S. aureus strain. The results proved that the applied method allows for the fabrication of implantable biomaterials which shield metal ion release and possess

  12. A new approach of synthesis and morphological control of poly(ethylene terephthalate)-g-polyacrylonitrile composite film with a porous surface

    Science.gov (United States)

    Xu, Yongfei; Wang, Yunlong; Wang, Mozhen; Wu, Qichao; Zhou, Xiao; Ge, Xuewu

    2015-01-01

    Poly(ethylene terephthalate)-g-polyacrylonitrile (PET-g-PAN) composite film with a porous surface was fabricated via gamma-ray-radiation-induced graft polymerization on PET film in an aqueous solution system. The original PET film was first irradiated by gamma ray in the aqueous solution of acrylic acid. Next, the graft polymerization of acrylonitrile (AN) was induced by gamma ray on the surface of the above modified PET film in an aqueous solution of AN. The prepared PET-g-PAN composite film has a smaller static water contact angle than the original PET film. The SEM and AFM images show that the grafted PAN layer on the surface of PET-g-PAN composite film is composed of closely-arranged spherical PAN microspheres with an average diameter of 30 nm. The gaps between the PAN microspheres form fine pores (less than 30 nm) on the surface. The gas barrier property of the PET-g-PAN composite film is much better than that of the original PET film. This work provides a facile and green method to prepare PET-g-PAN composite film with a controllable porous surface morphology by taking advantage of the radiation-induced graft polymerization technique in an aqueous solution system.

  13. Ascorbate electro-oxidation by modified electrodes: Polypyrrole and polypyrrole/Ni(OH){sub 2} composite thin films

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues da Silva, Marcelo [Faculdade de Engenharia/Colegio Tecnico Industrial, UNESP, CP 473, 17033-360 Bauru, SP (Brazil); Ferreira, Marcelo Silva [Departamento de Quimica, Centro de Ciencias Exatas, UEL, CP 6001, 86051-980 Londrina, PR (Brazil); Dall' Antonia, Luiz Henrique, E-mail: luizh@uel.br [Departamento de Quimica, Centro de Ciencias Exatas, UEL, CP 6001, 86051-980 Londrina, PR (Brazil)

    2012-08-01

    The present paper describes the utilization of polypyrrole and the composite of polypyrrole doped with nickel hydroxide modified electrodes toward the catalytic oxidation of ascorbate. Films were potentiostatically deposited onto a glassy carbon surface and Fluor-doped tin oxide glass for different times. The physical characterization was performed using the low angle X-ray diffraction technique. Furthermore, the films were electrochemically characterized using cyclic voltammetry. The X-ray diffraction results show the existence of different polymorphic phases of nickel hydroxide in the polymer matrix, and the {beta}-Ni(OH){sub 2} phase appears to be dominant. The cyclic voltammetry profile in KOH solution shows the presence of two redox peaks that are related to the Ni{sup II}/Ni{sup III} and Ni{sup III}/Ni{sup II} couples, at approximately 0.5 and 0.35 V, respectively. The reversible electro-oxidation of ascorbate was observed on the surface of the polypyrrole and composite films. The analytical curves obtained using voltammetric techniques show a linear relationship between the faradaic current and the increase of the ascorbic acid concentration. The sensitivity of these films, which is obtained from the slope of the analytical curves, shows that the composite film is more electroactive than the polypyrrole film: 133.4 mA L mol{sup -1} cm{sup -2} and 83.8 mA L mol{sup -1} cm{sup -2}, respectively. The rate constants of the catalytic ascorbate electro-oxidation were also reported, where the mean values were found to be 217.74 M{sup -1} s{sup -1} and 54.37 M{sup -1} s{sup -1}, for the composite and polypyrrole films, respectively. The low cost of polypyrrole doped with Ni(OH){sub 2} composite electrodes presents a more selective and high sensitivity to determine ascorbic acid concentration. - Highlights: Black-Right-Pointing-Pointer Electrochemical synthesis of polypyrrole and nickel hydroxide composite thin films Black-Right-Pointing-Pointer High sensitivity

  14. Analysis of Electrodeposited Nickel-Iron Alloy Film Composition Using Particle-Induced X-Ray Emission

    Directory of Open Access Journals (Sweden)

    Alyssa A. Frey

    2011-01-01

    Full Text Available The elemental composition of electrodeposited NiFe thin films was analyzed with particle-induced X-ray emission (PIXE. The thin films were electrodeposited on polycrystalline Au substrates from a 100 mM NiSO4, 10 mM FeSO4, 0.5 M H3BO3, and 1 M Na2SO4 solution. PIXE spectra of these films were analyzed to obtain relative amounts of Ni and Fe as a function of deposition potential and deposition time. The results show that PIXE can measure the total deposited metal in a sample over at least four orders of magnitude with similar fractional uncertainties. The technique is also sensitive enough to observe the variations in alloy composition due to sample nonuniformity or variations in deposition parameters.

  15. Influence of Annealing on the Surface Morphologies and Elemental Compositions of Nanocrystalline Cu2SnSe3 Thin Films

    International Nuclear Information System (INIS)

    Ternary compound of semiconductor nano crystals Copper Tin Selenide, Cu2SnSe3, thin films have been prepared by vacuum thermal evaporation technique on well-cleaned glass substrate and annealed in purified nitrogen atmosphere from room temperature to 500 degree Celsius for different annealing temperature. The annealing effects on surface morphologies and elemental compositions of these films have been investigated using Scanning Electron Microscope (SEM) and Energy Dispersive X-ray (EDX). EDX studies shows increasing the annealing temperature resulted in drastic loss of Cu content. It is observed that elemental compositions of the Cu2SnSe3 thin films were close to the ideal stoichiometric value 2:1:3. (author)

  16. Electric field modulation of magnetic anisotropy and microwave absorption properties in Fe50Ni50/Teflon composite films

    Science.gov (United States)

    Xia, Zhenjun; He, Jun; Ou, Xiulong; Wang, Yu; He, Shuli; Zhao, Dongliang; Yu, Guanghua

    2016-05-01

    Fe50Ni50 nanoparticle films with the size about 6 nm were deposited by a high energetic cluster deposition source. An electric field of about 0 - 40 kV was applied on the sample platform when the films were prepared. The field assisted deposition technique can dramatically induce in-plane magnetic anisotropy. To probe the microwave absorption properties, the Fe50Ni50 nanoparticles were deliberately deposited on the dielectric Teflon sheet. Then the laminated Fe50Ni50/Teflon composites were used to do reflection loss scan. The results prove that the application of electric field is an effective avenue to improve the GHz microwave absorption performance of our magnetic nanoparticles films expressed by the movement of reflection loss peak to high GHz region for the composites.

  17. Morphology and Photoelectrochemical Characterization of MEH-PPV/PCBM Composite Film Doped with TiO2 Nanoparticles

    Institute of Scientific and Technical Information of China (English)

    Farid Habelhames; Zerguine Wided; Leila Lamiri; Belkacem Nessark; Hassina Derbal-Habak

    2013-01-01

    Poly[2-methoxy-5-(20-ethylhexyloxy)-p-phenylenevinylene] (MEH-PPV),[6,6]-phenyl-C61-butyric acid methyl ester (PCBM) and titanium dioxide (TiO2) nanoparticles (n-type) were dissolved,mixed and deposited by physical methods (spin-coating) on indium tin-oxide (ITO) substrate.The incorporation of the titanium dioxide nanoparticles changed the morphology and increased the roughness of polymers film (MEH-PPV/PCBM),and the photocurrent density of the composite (MEH-PPV/PCBM +n-TiO2) was higher than that of single MEHPPV/PCBM film.The study showed that the presence of n-TiO2 particles in the polymeric film improves the photoelectrochemical properties of MEH-PPV/PCBM composite.

  18. Electric field modulation of magnetic anisotropy and microwave absorption properties in Fe50Ni50/Teflon composite films

    Directory of Open Access Journals (Sweden)

    Zhenjun Xia

    2016-05-01

    Full Text Available Fe50Ni50 nanoparticle films with the size about 6 nm were deposited by a high energetic cluster deposition source. An electric field of about 0 - 40 kV was applied on the sample platform when the films were prepared. The field assisted deposition technique can dramatically induce in-plane magnetic anisotropy. To probe the microwave absorption properties, the Fe50Ni50 nanoparticles were deliberately deposited on the dielectric Teflon sheet. Then the laminated Fe50Ni50/Teflon composites were used to do reflection loss scan. The results prove that the application of electric field is an effective avenue to improve the GHz microwave absorption performance of our magnetic nanoparticles films expressed by the movement of reflection loss peak to high GHz region for the composites.

  19. Superhydrophilic Thin-Film Composite Forward Osmosis Membranes for Organic Fouling Control: Fouling Behavior and Antifouling Mechanisms

    KAUST Repository

    Tiraferri, Alberto

    2012-10-16

    This study investigates the fouling behavior and fouling resistance of superhydrophilic thin-film composite forward osmosis membranes functionalized with surface-tailored nanoparticles. Fouling experiments in both forward osmosis and reverse osmosis modes are performed with three model organic foulants: alginate, bovine serum albumin, and Suwannee river natural organic matter. A solution comprising monovalent and divalent salts is employed to simulate the solution chemistry of typical wastewater effluents. Reduced fouling is consistently observed for the superhydrophilic membranes compared to control thin-film composite polyamide membranes, in both reverse and forward osmosis modes. The fouling resistance and cleaning efficiency of the functionalized membranes is particularly outstanding in forward osmosis mode where the driving force for water flux is an osmotic pressure difference. To understand the mechanism of fouling, the intermolecular interactions between the foulants and the membrane surface are analyzed by direct force measurement using atomic force microscopy. Lower adhesion forces are observed for the superhydrophilic membranes compared to the control thin-film composite polyamide membranes. The magnitude and distribution of adhesion forces for the different membrane surfaces suggest that the antifouling properties of the superhydrophilic membranes originate from the barrier provided by the tightly bound hydration layer at their surface, as well as from the neutralization of the native carboxyl groups of thin-film composite polyamide membranes. © 2012 American Chemical Society.

  20. WO3 nanopaticles and PEDOT:PSS/WO3 composite thin films studied for photocatalytic and electrochromic applications

    Science.gov (United States)

    Ivanov Boyadjiev, Stefan; Manduca, Bruno; Szűcs, Júlia; Miklós Szilágyi, Imre

    2016-03-01

    WO3 is a widely studied material for electrochromic and photocatalytic applications. In the present study, WO3 nanoparticles with a controlled structure (monoclinic or hexagonal) were obtained by controlled thermal decomposition of hexagonal ammonium tungsten bronze in air at 500 °C and 600 °C, respectively. The formation, morphology, structure and composition of the as-prepared nanoparticles were studied by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy combined with energy-dispersive X-ray spectroscopy (SEM-EDX). The photocatalytic activity of the monoclinic and hexagonal WO3 nanoparticles was studied by decomposing methyl orange in aqueous solution under UV light irradiation. In order to study the electrochromic properties of the WO3 nanoparticles, as well to introduce them for self-cleaning photocatalytic surface applications, thin films were prepared from the WO3 particles together with a conductive polymer. For this, PEDOT:PSS was used, which gives excellent opportunities for obtaining transparent and conductive thin films, suitable for both electrochromic and photocatalytic applications. By spin-coating, transparent PEDOT:PSS/WO3 composite thin films were prepared, on which cyclic voltammetry measurements were performed, and the coloring and bleaching states were studied. Our initial results for the PEDOT:PSS/WO3 composite thin films are promising, suggesting that such composites, after further development, might be successfully used in electrochromic devices and photocatalysis.

  1. Preparation and properties of self-reinforced cellulose composite films from Agave microfibrils using an ionic liquid.

    Science.gov (United States)

    Reddy, K Obi; Zhang, Jinming; Zhang, Jun; Rajulu, A Varada

    2014-12-19

    The applications of natural fibers and their microfibrils are increasing rapidly due to their environment benefits, specific strength properties and renewability. In the present work, we successfully extracted cellulose microfibrils from Agave natural fibers by chemical method. The extracted microfibrils were characterized by chemical analysis. The cellulose microfibrils were found to dissolve in an ionic liquid 1-allyl-3-methylimidazolium chloride (AmimCl) to larger extent along with little quantity of undissolved microfibrils. Using this solution, the self-reinforced regenerated cellulose composite films were prepared. The raw fiber, extracted cellulose microfibrils and regenerated cellulose composite films were characterized by FTIR, (13)C CP-MAS NMR, XRD, TGA and SEM techniques. The average tensile strength, modulus and elongation at break of the self-reinforced cellulose composite films were found to be 135 MPa, 8150 MPa and 3.2%, respectively. The high values of tensile strength and modulus were attributed to the self-reinforcement of Agave fibers in their generated matrix. These self-reinforced cellulose biodegradable composite films prepared from renewable source can find applications in packaging field.

  2. Preparation and properties of self-reinforced cellulose composite films from Agave microfibrils using an ionic liquid.

    Science.gov (United States)

    Reddy, K Obi; Zhang, Jinming; Zhang, Jun; Rajulu, A Varada

    2014-12-19

    The applications of natural fibers and their microfibrils are increasing rapidly due to their environment benefits, specific strength properties and renewability. In the present work, we successfully extracted cellulose microfibrils from Agave natural fibers by chemical method. The extracted microfibrils were characterized by chemical analysis. The cellulose microfibrils were found to dissolve in an ionic liquid 1-allyl-3-methylimidazolium chloride (AmimCl) to larger extent along with little quantity of undissolved microfibrils. Using this solution, the self-reinforced regenerated cellulose composite films were prepared. The raw fiber, extracted cellulose microfibrils and regenerated cellulose composite films were characterized by FTIR, (13)C CP-MAS NMR, XRD, TGA and SEM techniques. The average tensile strength, modulus and elongation at break of the self-reinforced cellulose composite films were found to be 135 MPa, 8150 MPa and 3.2%, respectively. The high values of tensile strength and modulus were attributed to the self-reinforcement of Agave fibers in their generated matrix. These self-reinforced cellulose biodegradable composite films prepared from renewable source can find applications in packaging field. PMID:25263924

  3. Superhydrophilic thin-film composite forward osmosis membranes for organic fouling control: fouling behavior and antifouling mechanisms.

    Science.gov (United States)

    Tiraferri, Alberto; Kang, Yan; Giannelis, Emmanuel P; Elimelech, Menachem

    2012-10-16

    This study investigates the fouling behavior and fouling resistance of superhydrophilic thin-film composite forward osmosis membranes functionalized with surface-tailored nanoparticles. Fouling experiments in both forward osmosis and reverse osmosis modes are performed with three model organic foulants: alginate, bovine serum albumin, and Suwannee river natural organic matter. A solution comprising monovalent and divalent salts is employed to simulate the solution chemistry of typical wastewater effluents. Reduced fouling is consistently observed for the superhydrophilic membranes compared to control thin-film composite polyamide membranes, in both reverse and forward osmosis modes. The fouling resistance and cleaning efficiency of the functionalized membranes is particularly outstanding in forward osmosis mode where the driving force for water flux is an osmotic pressure difference. To understand the mechanism of fouling, the intermolecular interactions between the foulants and the membrane surface are analyzed by direct force measurement using atomic force microscopy. Lower adhesion forces are observed for the superhydrophilic membranes compared to the control thin-film composite polyamide membranes. The magnitude and distribution of adhesion forces for the different membrane surfaces suggest that the antifouling properties of the superhydrophilic membranes originate from the barrier provided by the tightly bound hydration layer at their surface, as well as from the neutralization of the native carboxyl groups of thin-film composite polyamide membranes. PMID:23002900

  4. Development of Antibacterial Composite Films Based on Isotactic Polypropylene and Coated ZnO Particles for Active Food Packaging

    Directory of Open Access Journals (Sweden)

    Clara Silvestre

    2016-01-01

    Full Text Available This study was aimed at developing new films based on isotactic polypropylene (iPP for food packaging applications using zinc oxide (ZnO with submicron dimension particles obtained by spray pyrolysis. To improve compatibility with iPP, the ZnO particles were coated with stearic acid (ZnOc. Composites based on iPP with 2 wt % and 5 wt % of ZnOc were prepared in a twin-screw extruder and then filmed by a calender. The effect of ZnOc on the properties of iPP were assessed and compared with those obtained in previous study on iPP/ZnO and iPP/iPPgMA/ZnO. For all composites, a homogeneous distribution and dispersion of ZnOc was obtained indicating that the coating with stearic acid of the ZnO particles reduces the surface polarity mismatch between iPP and ZnO. The iPP/ZnOc composite films have relevant zinc oxide with respect to E. coli, higher thermal stability and improved mechanical and impact properties than the pure polymer and the composites iPP/ZnO and iPP/iPPgMA/ZnO. This study demonstrated that iPP/ZnOc films are suitable materials for potential application in the active packaging field.

  5. Effect of Addition of Colloidal Silica to Films of Polyimide, Polyvinylpyridine, Polystyrene, and Polymethylmethacrylate Nano-Composites

    Directory of Open Access Journals (Sweden)

    Soliman Abdalla

    2016-02-01

    Full Text Available Nano-composite films have been the subject of extensive work for developing the energy-storage efficiency of electrostatic capacitors. Factors such as polymer purity, nanoparticle size, and film morphology drastically affect the electrostatic efficiency of the dielectric material that forms the insulating film between the conductive electrodes of a capacitor. This in turn affects the energy storage performance of the capacitor. In the present work, we have studied the dielectric properties of four highly pure amorphous polymer films: polymethyl methacrylate (PMMA, polystyrene, polyimide and poly-4-vinylpyridine. Comparison between the dielectric properties of these polymers has revealed that the higher breakdown performance is a character of polyimide (PI and PMMA. Also, our experimental data shows that adding colloidal silica to PMMA and PI leads to a net decrease in the dielectric properties compared to the pure polymer.

  6. Improvement on wear resistance property of polyurethane film by compositing plasma-treated multi-walled carbon nanotubes

    Science.gov (United States)

    Ogawa, Daisuke; Nakamura, Keiji

    2016-01-01

    We investigated the effect of plasma-treated multi-walled carbon nanotubes (CNTs) that are composited into a polyurethane (PU) film. In this journal article, we especially focused on one of mechanical properties of PU film, the wear resistance, to find how the plasma-treated CNTs give contributions to improve the resistance. Our experimental results showed that plasma-treated CNTs enhanced the wear resistance, in particular, when the CNTs treated with the plasma that was made of nitrogen-oxygen mixture gas. Then, we made measurements with infrared absorption spectroscopy to find the possible causes of the improvement. The measurement showed that the surface of the CNTs treated with nitrogen-oxygen plasma had an indication of isocyanate group, which generally hardens PU film. The plasma likely attached the functional group on CNTs, and then the CNTs added extra wear resistance of a polyurethane film.

  7. Influences of arc current on composition and properties of MgO thin films prepared by cathodic vacuum arc deposition

    International Nuclear Information System (INIS)

    MgO thin films with high optical transmittances (more than 90%) were prepared by cathodic vacuum arc deposition technique. With the increase of arc current from 40 to 80 A, the deposition pressure decreases and the film thickness increases; the atomic ratio of Mg/O in MgO thin films (obtained by RBS) increases from 0.97 to 1.17, giving that deposited at 50 A most close to the stoichiometric composition of the bulk MgO; the grains of MgO thin films grow gradually as shown in SEM images. XRD patterns show that MgO (1 1 0) orientation is predominant for films prepared at the arc currents ranged from 50 to 70 A. The MgO (1 0 0) orientation is much enhanced and comparable to that of MgO (1 1 0) for films prepared at the arc current of 80 A. The secondary electron emission coefficient of MgO thin film increases with arc current ranged from 50 to 70 A.

  8. Surface and interface analysis of HAP/TiO2 composite films on Ti6Al4V

    Institute of Scientific and Technical Information of China (English)

    SU Bing; ZHANG Weng-guang; YU Xu-dong; WANG Cheng-tao

    2004-01-01

    The composite films constituted of hydroxyapatite (HAP) submicron particles embedded in the gel composed of the titania nanoparticles were prepared on commercial Ti6Al4V plates with titania buffer layer obtained by a spin-coating technique. The films were annealed in air at 450 ℃, 550 ℃ and 650 ℃, respectively. The phase formation, surface morphology, andinterfacial microstructure of the films were investigated by X-ray diffraction(XRD),Fourier transform infrared spectroscopy (FT-IR), field emission-scanning electron microscopy(FE-SEM) and energy dispersive X-ray (EDS) analysis. The results show that the as-prepared films are all well-crystallized, dense,homogeneous, and there was a close interfacial bond between the film and the substrate. The results of adhesion test indicate that there is a good bonding strength between the film and the substrate. The bone-like apatite formation on the surface of the films after immersion in acellular simulatedbody fluid(SBF) validated their bioactivities.

  9. Analysis of solid-liquid fluid dynamics about the characteristics of electrotyping diamond-nickel composite film

    Institute of Scientific and Technical Information of China (English)

    Fang Lili; Zhang Binglin

    2007-01-01

    In this paper,super-thin free-standing diamond grains-nickel composite film in large area were prepared by using electrotyping method,which were used to make super-thin cutting blades.Scanning electron microscope (SEM) were used to analyse the characteristics of the film.It was found that the agitation velocity and the place of impeller strongly affected the content and uniformity of diamond grains in deposited composite film when the other parameters were the same.The best film was deposited when agitation velocity was 180-220 r/m and the impeller Was placed in the lower part of the solution.The obliquity of cathode strongly affected the content of diamond grains in the film,and the content reached maximum when the obliquity was kept at 45 degree.The hanging orientation of cathode strongly affected the uniformity of the thickness of the film,and uniform films were deposited when cathode was intermissively circumrotated by 90 degree in the:plane itself during deposition.The fluid field in solid-liquid stirred electrolytic solution was analysed by using Computational Fluid Dynamics (CFD).And the influences of agitation veloeity,the place of impeller and the obliquity of cathode on the content of diamond grains in the film were explained.With Euler-Lagrange model,the just-suspended speed of impeller in solid-liquid stirred electrolytic tank Was predicted by using Zwietering formula,the predicted speed was and it was consistent with experimental result.

  10. Crystallographic, optical and electrical properties of low zinc content cadmium zinc sulphide composite thin films for photovoltaic applications

    International Nuclear Information System (INIS)

    Graphical abstract: The DC conductivity of the screen-printed Cd0.9Zn0.1S films was measured in vacuum by a two probe technique. The plot of ln σDC against 1000/T for Cd0.9Zn0.1S film is a straight line indicating that conduction in the film is through thermally activated process. Highlights: ► The method of preparing films of low zinc content i.e. Cd0.9Zn0.1S alloy by screen printing method is cost effective and reasonably accurate. ► The structural, optical and electrical studies of these films indicate that the films are quite suitable for photovoltaic device fabrication. ► The prepared films of Cd0.9Zn0.1S alloy are found to be polycrystalline in nature and have hexagonal (wurtzite) structure. ► The absorption coefficient of these films is high and is suitable for efficient absorption in the visible region of solar spectrum. ► It has been observed that the conduction in Cd0.9Zn0.1S films is through thermally activated process. - Abstract: In this paper a screen-printing method has been employed for the deposition of low zinc content cadmium zinc sulphide (Cd0.9Zn0.1S) composite thin films on ultra clean glass substrate. Cadmium sulphide, zinc sulphide and cadmium chloride have been used as the basic source material. With these basic source materials, the optimum conditions for preparing good quality screen-printed films have been found. X-ray diffraction studies revealed that the films are polycrystalline in nature, single phase exhibiting wurtzite (hexagonal) structure with strong preferential orientation of grains along the (1 0 1) direction. SEM/EDAX analysis confirms the formation of ternary compound. The optical band gap (Eg) of the films has been studied by using reflection spectra in wavelength range 350–600 nm. The DC conductivity of the films has been measured in vacuum by a two probe technique.

  11. Magnetic and Optical Properties of the TiO2-Co-TiO2 Composite Films Grown by Magnetron Sputtering

    Institute of Scientific and Technical Information of China (English)

    LIU Fa-min; DING Peng; SHI Wei-mei; WANG Tian-min

    2007-01-01

    The TiO2-Co-TiO2 sandwich films were successfully grown on glass and silicon substrata making alternate use of radio frequency reactive magnetron sputtering and direct current magnetron sputtering. The structures and properties of these films were identified with X-ray diffraction (XRD), Raman spectra and X-ray photoemission spectra (XPS). It is shown that the sandwich film consists of two anatase TiO2 films with an embedded Co nano-film. The fact that, when the Co nano-film thickens, varied red shifts appear in optical absorption spectra may well be explained by the quantum confinement and tunnel effects. As for magnetic properties, the saturation magnetization, remnant magnetic induction and coercivity vary with the thickness of the Co nano-films. Moreover, the Co nano-film has a critical thickness of about 8.6 nm, which makes the coercivity of the composite film reach the maximum of about 1413 Oe.

  12. Rapid mixing chemical oxidative polymerization: an easy route to prepare PANI coated small-diameter CNTs/PANI nanofibres composite thin film

    Indian Academy of Sciences (India)

    G Venkata Ramana; Balaji Padya; Vadali V S S Srikanth; P K Jain

    2014-05-01

    Composite thin film containing polyaniline (PANI) coated small diameter carbon nanotubes (SDCNTs)/PANI nanofibres (NFs) has been prepared using an easy in situ rapid mixing chemical oxidative polymerization method. SDCNTs thin film was obtained using thermal chemical vapour deposition method in a separate experiment, whilst PANI NFs are formed in situ during the synthesis of composite. In the composite, PANI coated SDCNTs are uniformly distributed among PANI NFs. The presence of SDCNTs during the composite synthesis does not influence the nucleation and growth of PANI NFs. Raman analysis shows a good interaction between PANI and SDCNTs. Room temperature d.c. electrical sheet resistance of SDCNTs/PANI NFs composite thin film surface is three orders lesser than that of PANI NFs thin film (PANI NFs have the same morphology as in the composite) synthesized using the same method but without the presence of SDCNTs.

  13. Stretchable conducting gold films prepared with composite MWNT/PDMS substrates

    Science.gov (United States)

    Manzoor, M. U.; Lemoine, P.; Dixon, D.; Hamilton, J. W. J.; Maguire, P. D.

    2015-10-01

    Novel stretchable conducting films were prepared by depositing gold layers onto polymer nano-composites substrates formed by in-situ crosslinking of polydimethylsiloxane (PDMS) in the presence of multiwall carbon nanotubes (MWNT). The MWNT content interferes with the PDMS cure reaction giving variations in thermal degradation, solvent swelling, mechanical and electrical properties. Tensile cycling experiments were carried out on the gold-coated PDMS and nano-composite substrates SEM analysis and electrical measurements demonstrated that the crack widening and increased electrical resistance observed during strain cycling were reversible. The inclusion of 8 % MWNT into PDMS brought more micro-cracking in the gold layer yet reduced the electrical resistance of the gold-coated samples by 172X at 5 % strain, 38X at 10 % strain and 19X at 20 %. Hence, this improvement in conduction is attributed to assisted-conduction through the MWNT loaded substrate. This mechanism results in a more stable and reproducible electrical behaviour, making electrical conduction less critically dependent on defects in the gold layer.

  14. Crossover from negative to positive magnetoresistance in superconductor/ferromagnet composites thick films

    Energy Technology Data Exchange (ETDEWEB)

    Paredes, O. [Centro de Materiales, Facultad de Ingenieria, Universidad de Narino, Ciudad Universitaria Torobajo, Pasto (Colombia); Baca, E. [Grupo de Ingenieria de Nuevos Materiales, Departamento de Fisica, Universidad del Valle, A.A. 25360 Cali (Colombia); Fuchs, D. [Karlsruhe Institute of Technology, Institut fuer Festkoerperphysik, P.O. Box 3640, Karlsruhe (Germany); Moran, O., E-mail: omoranc@unal.edu.c [Laboratorio de Materiales Ceramicos y Vitreos, Departamento de Fisica, Universidad Nacional de Colombia, Sede Medellin, A.A. 568 Medellin (Colombia)

    2010-11-15

    Thick films of ((Bi, Pb){sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub x}){sub 0.95}/(LaSr{sub 0.7}Mn{sub 0.3}O{sub 3}){sub 0.05} [(Bi-2223){sub 0.95}(LSMO){sub 0.05}] composites were fabricated on (0 0 1)-oriented LaAlO{sub 3} substrates by a simple melting-quenching-annealing method and their structural, morphological and magnetoelectrical properties carefully studied. Analysis of the X-ray diffraction patterns suggested a highly oriented growth along the c-axis of LSMO. This preferred orientation, with the crystal c-axis being perpendicular to the plane of the substrate, was considered to be indicative of a textured growth mode. Electrical and magnetic measurements showed the presence of ferromagnetism and superconductivity in the composite at temperatures above room temperature and below T{approx}50 K, respectively. A clear crossover from negative to positive magnetoresistance was observed at {approx}80 K in a magnetic field as strong as 5 T.

  15. Physical and biological properties of the ion beam irradiated PMMA-based composite films

    Energy Technology Data Exchange (ETDEWEB)

    Shanthini, G.M.; Martin, Catherine Ann; Sakthivel, N.; Veerla, Sarath Chandra; Elayaraja, K. [Crystal Growth Centre, Anna University, Chennai 600025 (India); Lakshmi, B.S. [Department of Biotechnology, Anna University, Chennai 600025 (India); Asokan, K.; Kanjilal, D. [Materials Science Group, Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110067 (India); Kalkura, S. Narayana, E-mail: kalkurasn@annauniv.edu [Crystal Growth Centre, Anna University, Chennai 600025 (India)

    2015-02-28

    Highlights: • First report of swift heavy ion irradiation on PMMA-HAp as bioceramic composite. • Augmented protein adsorption of about 400% was attained due to irradiation. • Tailored surface morphology, topography, roughness, wettability and crystallinity. • Irradiation transformed the hydrophobic surface into hydrophilic surface. • Better blood and cell–material interaction leading to improved biocompatibility. - Abstract: Polymethyl methacrylate (PMMA) and PMMA-hydroxyapatite (PMMA-HAp) composite films, prepared by the solvent evaporation method were irradiated with 100 MeV Si{sup 7+} ions. Crystallographic, morphological and the functional groups of the pristine and irradiated samples were studied using glancing incident X-ray diffraction (GIXRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy-attenuated total reflectance (FTIR-ATR) respectively. SEM reveals the creation of pores, along with an increase in porosity and cluster size on irradiation. Decrease in crystalline nature and crystallite size with an increase in ion fluence was observed from GIXRD patterns. The surface roughness and the wettability of the material were also enhanced, which could favour the cell–material interaction. The irradiated samples adsorbed significantly greater amount of proteins than pristine. Also, irradiation does not produce any toxic byproducts or leachants, and maintains the viability of 3T3 cells. The response of the irradiated samples towards biomedical applications was demonstrated by the improved antimicrobial activity, haemocompatibility and cytocompatibility. Swift heavy ion irradiation (SHI) could be an effective tool to modify and engineer the surface properties of the polymers to enhance the biocompatibility.

  16. Highly Hydrophilic Thin-Film Composite Forward Osmosis Membranes Functionalized with Surface-Tailored Nanoparticles

    KAUST Repository

    Tiraferri, Alberto

    2012-09-26

    Thin-film composite polyamide membranes are state-of-the-art materials for membrane-based water purification and desalination processes, which require both high rejection of contaminants and high water permeabilities. However, these membranes are prone to fouling when processing natural waters and wastewaters, because of the inherent surface physicochemical properties of polyamides. The present work demonstrates the fabrication of forward osmosis polyamide membranes with optimized surface properties via facile and scalable functionalization with fine-tuned nanoparticles. Silica nanoparticles are coated with superhydrophilic ligands possessing functional groups that impart stability to the nanoparticles and bind irreversibly to the native carboxyl moieties on the membrane selective layer. The tightly tethered layer of nanoparticles tailors the surface chemistry of the novel composite membrane without altering the morphology or water/solute permeabilities of the membrane selective layer. Surface characterization and interfacial energy analysis confirm that highly hydrophilic and wettable membrane surfaces are successfully attained. Lower intermolecular adhesion forces are measured between the new membrane materials and model organic foulants, indicating the presence of a bound hydration layer at the polyamide membrane surface that creates a barrier for foulant adhesion. © 2012 American Chemical Society.

  17. Highly hydrophilic thin-film composite forward osmosis membranes functionalized with surface-tailored nanoparticles.

    Science.gov (United States)

    Tiraferri, Alberto; Kang, Yan; Giannelis, Emmanuel P; Elimelech, Menachem

    2012-09-26

    Thin-film composite polyamide membranes are state-of-the-art materials for membrane-based water purification and desalination processes, which require both high rejection of contaminants and high water permeabilities. However, these membranes are prone to fouling when processing natural waters and wastewaters, because of the inherent surface physicochemical properties of polyamides. The present work demonstrates the fabrication of forward osmosis polyamide membranes with optimized surface properties via facile and scalable functionalization with fine-tuned nanoparticles. Silica nanoparticles are coated with superhydrophilic ligands possessing functional groups that impart stability to the nanoparticles and bind irreversibly to the native carboxyl moieties on the membrane selective layer. The tightly tethered layer of nanoparticles tailors the surface chemistry of the novel composite membrane without altering the morphology or water/solute permeabilities of the membrane selective layer. Surface characterization and interfacial energy analysis confirm that highly hydrophilic and wettable membrane surfaces are successfully attained. Lower intermolecular adhesion forces are measured between the new membrane materials and model organic foulants, indicating the presence of a bound hydration layer at the polyamide membrane surface that creates a barrier for foulant adhesion. PMID:22948042

  18. Conductive ZnO:Zn Composites for High-Rate Sputtering Deposition of ZnO Thin Films

    Science.gov (United States)

    Zhou, Li Qin; Dubey, Mukul; Simões, Raul; Fan, Qi Hua; Neto, Victor

    2015-02-01

    We report an electrically conductive composite prepared by sintering ZnO and metallic Zn powders. Microstructure analysis combined with electrical conductivity studies indicated that when the proportion of metallic Zn reached a threshold (˜20 wt.%), a metal matrix was formed in accordance with percolation theory. This composite has potential as a sputtering target for deposition of high-quality ZnO. Use of the ZnO:Zn composite completely eliminates target poisoning effects in reactive sputtering of the metal, and enables deposition of thin ZnO films at rates much higher than those obtained by sputtering of pure ZnO ceramic targets. The optical transmittance of the ZnO films prepared by use of this composite is comparable with that of films produced by radio frequency sputtering of pure ZnO ceramic targets. The sputtering characteristics of the conductive ZnO:Zn composite target are reported, and possible mechanisms of the high rate of deposition are also discussed.

  19. Improving the Performance and Antifouling Properties of Thin-Film Composite Membranes for Water Separation Technologies

    Science.gov (United States)

    Tiraferri, Alberto

    Membrane-based water separation processes utilize semi-permeable membranes to retain dissolved solids and contaminants. Deployment of these technologies for desalination and wastewater reuse has the potential to sustainably increase the supply of potable, agricultural, and industrial water. Despite considerable development of semi-permeable membranes in the last decades, several design obstacles hampering their progress have yet to be overcome. Specifically, major membrane improvements are currently sought with respect to their performance and productivity, as well as their resistance to fouling. This dissertation research aims at the advancement of semi-permeable membranes by rational optimization of their design to: (i) understand and improve their transport properties and (ii) reduce fouling by organic molecules and delay biofouling by microorganisms. In particular, thin-film composite polyamide membranes for both reverse osmosis and forward osmosis processes are the main target of the investigation. The structural and physicochemical properties of thin-film composite membranes are both characterized and tailored through implementation of original techniques and novel functionalization protocols. The membrane structure and morphology are rationally modified to enhance the mass transport within the support layer. The influence of fabrication conditions on support layer formation and on its final structure is elucidated. The intricate interrelationship among the performance of the different layers of the composite membrane is highlighted and a new protocol is developed to characterize the transport properties of membranes deployed in forward osmosis processes. Novel approaches to impart targeted properties to the active surface of thin-film composite membranes are also proposed. The functionalization is achieved by exploiting the inherent moieties of the polyamide layer to irreversibly bind nanomaterials with desired properties. An experimental method to determine

  20. AES study on the chemical composition of ferroelectric BaTiO3 thin films RF sputter-deposited on silicon

    Science.gov (United States)

    Dharmadhikari, V. S.; Grannemann, W. W.

    1983-01-01

    AES depth profiling data are presented for thin films of BaTiO3 deposited on silicon by RF sputtering. By profiling the sputtered BaTiO3/silicon structures, it was possible to study the chemical composition and the interface characteristics of thin films deposited on silicon at different substrate temperatures. All the films showed that external surface layers were present, up to a few tens of angstroms thick, the chemical composition of which differed from that of the main layer. The main layer had stable composition, whereas the intermediate film-substrate interface consisted of reduced TiO(2-x) oxides. The thickness of this intermediate layer was a function of substrate temperature. All the films showed an excess of barium at the interface. These results are important in the context of ferroelectric phenomena observed in BaTiO3 thin films.

  1. Effect of postdeposition annealing on the structure, composition, and the mechanical and optical characteristics of niobium and tantalum oxide films.

    Science.gov (United States)

    Cetinörgü-Goldenberg, Eda; Klemberg-Sapieha, Jolanta-Ewa; Martinu, Ludvik

    2012-09-20

    Optical, mechanical, and thermal properties of optical thin films are very important for a reliable device performance. In the present work, the effect of annealing on the stability and the characteristics of niobium and tantalum oxide films grown at room temperature (RT) by dual ion beam sputtering were studied. The refractive index (n(λ)), extinction coefficient (k(λ)), hardness (H), reduced Young's modulus (E(r)), and film stress (σ) were investigated as a function of the annealing temperature (T(A)). X-ray diffraction analysis showed that all as-deposited films were amorphous, and crystallization was observed only after annealing at 700°C. Compositional analyses confirmed that the atomic ratio of oxygen to metal in as-deposited and annealed films was close to 2.5, indicating that the films were stoichiometric pentoxides of Nb and Ta. The properties of Nb(2)O(5) and Ta(2)O(5) films were, respectively, affected by postdeposition annealing: n(λ) values (at 550 nm) decreased from 2.30 to 2.20 and from 2.14 to 2.08, the average H and E(r) values increased from 5.6 to 7.4 GPa, and from 121 to 132 GPa for Nb(2)O(5), and from 6.5 to 8.3 GPa, and from 132 to 144 GPa for Ta(2)O(5), and the initial low compressive stress for both materials changed to tensile. We explain the variation of the coating material properties in terms of film stoichiometry, crystallinity, electronic structure, and possible reactions at the film-substrate interface. PMID:23033019

  2. Direct electrochemistry and electrocatalysis of hemoglobin in graphene oxide and ionic liquid composite film

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Wei, E-mail: swyy26@hotmail.com [College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou 571158 (China); Gong, Shixing [College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042 (China); Shi, Fan [College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou 571158 (China); Cao, Lili; Ling, Luyang [College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042 (China); Zheng, Weizhe; Wang, Wencheng [College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou 571158 (China)

    2014-07-01

    In this paper a novel sensing platform based on graphene oxide (GO), ionic liquid (IL) 1-ethyl-3-methylimidazolium tetrafluoroborate and Nafion for the immobilization of hemoglobin (Hb) was adopted with a carbon ionic liquid electrode (CILE) as the substrate electrode, which was denoted as Nafion/Hb–GO–IL/CILE. Spectroscopic results suggested that Hb molecules were not denatured in the composite. A pair of well-defined redox peaks appeared on the cyclic voltammogram, which was attributed to the realization of direct electron transfer of Hb on the electrode. Electrochemical behaviors of Hb entrapped in the film were carefully investigated by cyclic voltammetry with the electrochemical parameters calculated. Based on the catalytic ability of the immobilized Hb, Nafion/Hb–GO–IL/CILE exhibited excellent electrocatalytic behavior towards the reduction of different substrates such as trichloroacetic acid in the concentration range from 0.01 to 40.0 mM with the detection limit as 3.12 μM (3σ), H{sub 2}O{sub 2} in the concentration range from 0.08 to 635.0 μM with the detection limit as 0.0137 μM (3σ) and NaNO{sub 2} in the concentration range from 0.5 to 800.0 μM with the detection limit as 0.0104 μM (3σ). So the proposed bioelectrode could be served as a new third-generation electrochemical sensor without mediator. - Highlights: • A graphene oxide, 1-ethyl-3-methylimidazolium tetrafluoroborate and hemoglobin composite were prepared. • Composite modified carbon ionic liquid electrode was fabricated. • Direct electrochemistry of hemoglobin was realized on the modified electrode. • Bioelectrocatalytic reduction of the modified electrode to different substrates was studied.

  3. Direct electrochemistry and electrocatalysis of hemoglobin in graphene oxide and ionic liquid composite film

    International Nuclear Information System (INIS)

    In this paper a novel sensing platform based on graphene oxide (GO), ionic liquid (IL) 1-ethyl-3-methylimidazolium tetrafluoroborate and Nafion for the immobilization of hemoglobin (Hb) was adopted with a carbon ionic liquid electrode (CILE) as the substrate electrode, which was denoted as Nafion/Hb–GO–IL/CILE. Spectroscopic results suggested that Hb molecules were not denatured in the composite. A pair of well-defined redox peaks appeared on the cyclic voltammogram, which was attributed to the realization of direct electron transfer of Hb on the electrode. Electrochemical behaviors of Hb entrapped in the film were carefully investigated by cyclic voltammetry with the electrochemical parameters calculated. Based on the catalytic ability of the immobilized Hb, Nafion/Hb–GO–IL/CILE exhibited excellent electrocatalytic behavior towards the reduction of different substrates such as trichloroacetic acid in the concentration range from 0.01 to 40.0 mM with the detection limit as 3.12 μM (3σ), H2O2 in the concentration range from 0.08 to 635.0 μM with the detection limit as 0.0137 μM (3σ) and NaNO2 in the concentration range from 0.5 to 800.0 μM with the detection limit as 0.0104 μM (3σ). So the proposed bioelectrode could be served as a new third-generation electrochemical sensor without mediator. - Highlights: • A graphene oxide, 1-ethyl-3-methylimidazolium tetrafluoroborate and hemoglobin composite were prepared. • Composite modified carbon ionic liquid electrode was fabricated. • Direct electrochemistry of hemoglobin was realized on the modified electrode. • Bioelectrocatalytic reduction of the modified electrode to different substrates was studied

  4. Modeling and optimization of antibacterial activity of the chitosan-based hydrogel films using central composite design.

    Science.gov (United States)

    Lahooti, Behnaz; Khorram, Mohammad; Karimi, Gholamreza; Mohammadi, Aliakbar; Emami, Amir

    2016-10-01

    In the present study, hydrogel films composed of chitosan-poly(vinyl alcohol)-gelatin-thyme honey were successfully prepared by casting method, and their anti-bacterial properties were modeled and optimized. Antibacterial properties of the prepared films were analyzed by applying agar diffusion method. Staphylococcus aureus and Pseudomonas aeruginosa were tested as Gram-positive and Gram-negative bacteria, respectively. In order to obtain the composition of the film with maximum inhibition zone against both above-mentioned bacterial strains, the experiments were designed using response surface methodology based on five-level central composite design with four parameters, including concentrations of chitosan, poly(vinyl alcohol), gelatin, and honey. The results indicated that the prepared samples had good antibacterial activities against these two studied bacteria strains. Response surface method is conducted to develop mathematical models for process responses. Variance analysis on the experimental data shows that inhibition zone can be predicted effectively with quadratic models. In addition, swelling properties and rate of water vapor transmission of the prepared hydrogel films were studied. Due to the successful results, this hydrogel film has an excellent potential to be explored further as a wound healing material. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2544-2553, 2016. PMID:27241899

  5. Preparation and dielectric properties of compositionally graded (Ba,Sr)TiO3 thin film by sol-gel technique

    Institute of Scientific and Technical Information of China (English)

    ZHANG Tian-jin; WANG Jun; ZHANG Bai-shun; WANG Jin-zhao; WAN Neng; HU Lan

    2006-01-01

    Compositional graded BaxSr1-xTiO3 (x=0.6,0.7,0.8,0.9,1.0) (BST) thin films (less than 400 nm) were fabricated on Si and Pt/Ti/SiO2/Si substrates by sol-gel technique. A special heating treatment was employed to form the uniform composition gradients at 700 ℃. The microstructures of the films were studied by means of X-ray diffraction,atomic force microscope and field emission scanning electron microscopy. The results show that the films have uniform and crack-free surface morphology with perovskite structure phase. The small signal dielectric constant (εr) and dielectric loss (tanδ) are found to be 335 and 0.045 at room temperature and 200 kHz. The dielectric properties change significantly with applied dc bias,and the graded thin film show high tunability of 42.3% at an applied field of 250 kV/cm. All the results indicate that the graded BST thin films prepared by sol-gel technique have a promising candidate for microelectronic device.

  6. Free surface liquid films of binary mixtures. Two-dimensional steady structures at off-critical compositions

    Science.gov (United States)

    Bribesh, Fathi A. M.; Madruga, Santiago

    2016-03-01

    We present steady non-linear solutions of films of confined polymer blends deposited on a solid substrate at off-critical concentrations with a free deformable surface. The solutions are obtained numerically using a variational form of the Cahn-Hilliard equation in the static limit, which allows for internal diffuse interfaces between the two components of the mixture. Existence of most of the branches of non-linear solutions at off-critical concentrations can be predicted from the knowledge of the branching points obtained with a linear stability analysis plus the non-linear solutions at critical concentrations. However, some families of solutions are found not to have correspondence at critical compositions. We take a value for surface tension that allows strong deformations at the sharp free upper surface. Varying the average composition and the length and thickness of the films we find a rich morphology of static films in the form of laterally structure films, layered films, droplets on the substrate, droplets at the free surface, and checkerboard structures. We show that laterally structured solutions are energetically favorable over homogeneous and other structured solutions within the whole spinodal region and even close to the absolute stability binodal boundary.

  7. Investigation of Regenerated Cellulose/Poly(acrylic acid Composite Films for Potential Wound Healing Applications: A Preliminary Study

    Directory of Open Access Journals (Sweden)

    Manjula Bajpai

    2014-01-01

    Full Text Available Regenerated cellulose/poly(acrylic acid composite films have been synthesized for wound dressing applications. The water absorbency of these films was studied as a function of amount of cross-linker N,N′-methylenebisacrylamide and cellulose contents in the feed mixture. The samples, having different compositions, showed tensile strength and percent elongation in the range of 9.98×105 to 13.40×105 N/m2 and 110 to 265, respectively. The water vapor transmission rate (WVTR for various films was found to be in the range of 2.03 to 7.18 mg/cm2/h. These films were loaded with antibacterial drug miconazole nitrate and their release was studied in the physiological pH at 37°C. The release data was found to fit well the diffusion controlled Higuchi model. Finally the films demonstrated fair antibacterial and antifungal action, thus establishing their strong candidature as wound dressing materials.

  8. Electrostatic spray deposition of nanoporous CoO/Co composite thin films as anode materials for lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Sun Yi; Du Chun; Feng Xuyong; Yu Yan [CAS Key Laboratory of Materials for Energy Conversions, Department of Materials Science and Engineering, University of Science and Technology of China, Anhui, Hefei 230026 (China); Lieberwirth, Ingo [Max Planck Institute for Polymer Research, Mainz 55128 (Germany); Chen Chunhua, E-mail: cchchen@ustc.edu.cn [CAS Key Laboratory of Materials for Energy Conversions, Department of Materials Science and Engineering, University of Science and Technology of China, Anhui, Hefei 230026 (China)

    2012-10-15

    Highlights: Black-Right-Pointing-Pointer The films are made of in situ produced hollow spheres consisting of conductive Co and electrochemically active CoO. Black-Right-Pointing-Pointer The homogeneous distribution of Co revealed by EELS in the film is important for the good rate capability. Black-Right-Pointing-Pointer The CoO/Co composite films exhibit excellent rate performance with 69.5% of capacity retention at 10C. - Abstract: Cobalt alkoxide suspension is obtained by heating a mixed polyalcohol solution of cobalt acetate in an oil bath at 170 Degree-Sign C. Thermogravimetric analysis is adopted to determine the chemical formula of the alkoxide powder in the suspension. With the suspension precursors, CoO/Co composite thin films are fabricated by electrostatic spray deposition and subsequent heat treatment in nitrogen. They are characterized by scanning electron microscopy, transmission electron microscopy and X-ray diffraction. Electron energy loss spectroscopy mapping is applied to determine the lateral two-dimensional chemical distribution of metallic Co in the nanocomposites. The thin film can deliver a high reversible capacity of 1182.1 mAh g{sup -1} at 70th cycle and retain 69.5% of the initial capacity at 10C. The in situ production of metallic cobalt and the unique hollow structure of the particles can account for the good electrochemical performance.

  9. Bench Scale Thin Film Composite Hollow Fiber Membranes for Post-Combustion Carbon Dioxide Capture

    Energy Technology Data Exchange (ETDEWEB)

    Glaser, Paul [General Electric Global Research, Niskayuna, NY (United States); Bhandari, Dhaval [General Electric Global Research, Niskayuna, NY (United States); Narang, Kristi [General Electric Global Research, Niskayuna, NY (United States); McCloskey, Pat [General Electric Global Research, Niskayuna, NY (United States); Singh, Surinder [General Electric Global Research, Niskayuna, NY (United States); Ananthasayanam, Balajee [General Electric Global Research, Niskayuna, NY (United States); Howson, Paul [General Electric Global Research, Niskayuna, NY (United States); Lee, Julia [General Electric Global Research, Niskayuna, NY (United States); Wroczynski, Ron [General Electric Global Research, Niskayuna, NY (United States); Stewart, Frederick [Idaho National Lab. (INL), Idaho Falls, ID (United States); Orme, Christopher [Idaho National Lab. (INL), Idaho Falls, ID (United States); Klaehn, John [Idaho National Lab. (INL), Idaho Falls, ID (United States); McNally, Joshua [Idaho National Lab. (INL), Idaho Falls, ID (United States); Rownaghi, Ali [Georgia Inst. of Technology, Atlanta, GA (United States); Lu, Liu [Georgia Inst. of Technology, Atlanta, GA (United States); Koros, William [Georgia Inst. of Technology, Atlanta, GA (United States); Goizueta, Roberto [Georgia Inst. of Technology, Atlanta, GA (United States); Sethi, Vijay [Western Research Inst., Laramie, WY (United States)

    2015-04-01

    GE Global Research, Idaho National Laboratory (INL), Georgia Institute of Technology (Georgia Tech), and Western Research Institute (WRI) proposed to develop high performance thin film polymer composite hollow fiber membranes and advanced processes for economical post-combustion carbon dioxide (CO2) capture from pulverized coal flue gas at temperatures typical of existing flue gas cleanup processes. The project sought to develop and then optimize new gas separations membrane systems at the bench scale, including tuning the properties of a novel polyphosphazene polymer in a coating solution and fabricating highly engineered porous hollow fiber supports. The project also sought to define the processes needed to coat the fiber support to manufacture composite hollow fiber membranes with high performance, ultra-thin separation layers. Physical, chemical, and mechanical stability of the materials (individual and composite) towards coal flue gas components was considered via exposure and performance tests. Preliminary design, technoeconomic, and economic feasibility analyses were conducted to evaluate the overall performance and impact of the process on the cost of electricity (COE) for a coal-fired plant including capture technologies. At the onset of the project, Membranes based on coupling a novel selective material polyphosphazene with an engineered hollow fiber support was found to have the potential to capture greater than 90% of the CO2 in flue gas with less than 35% increase in COE, which would achieve the DOE-targeted performance criteria. While lab-scale results for the polyphosphazene materials were very promising, and the material was incorporated into hollow-fiber modules, difficulties were encountered relating to the performance of these membrane systems over time. Performance, as measured by both flux of and selectivity for CO2 over other flue gas constituents was found to deteriorate over time, suggesting a system that was

  10. Anticorrosion Coating of Carbon Nanotube/Polytetrafluoroethylene Composite Film on the Stainless Steel Bipolar Plate for Proton Exchange Membrane Fuel Cells

    Directory of Open Access Journals (Sweden)

    Yoshiyuki Show

    2013-01-01

    Full Text Available Composite film of carbon nanotube (CNT and polytetrafluoroethylene (PTFE was formed from dispersion fluids of CNT and PTFE. The composite film showed high electrical conductivity in the range of 0.1–13 S/cm and hydrophobic nature. This composite film was applied to stainless steel (SS bipolar plates of the proton exchange membrane fuel cell (PEMFC as anticorrosion film. This coating decreased the contact resistance between the surface of the bipolar plate and the membrane electrode assembly (MEA of the PEMFC. The output power of the fuel cell is increased by 1.6 times because the decrease in the contact resistance decreases the series resistance of the PEMFC. Moreover, the coating of this composite film protects the bipolar plate from the surface corrosion.

  11. Dye-sensitized solar cells based on anatase TiO 2 hollow spheres/carbon nanotube composite films

    Science.gov (United States)

    Yu, Jiaguo; Fan, Jiajie; Cheng, Bei

    Dye-sensitized solar cells (DSSCs) based on anatase TiO 2 hollow spheres (TiO2HS)/multi-walled carbon nanotubes (CNT) nanocomposite films are prepared by a directly mechanical mixing and doctor blade method. The prepared samples are characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, UV-vis absorption spectroscopy and N 2 adsorption-desorption isotherms. The photoelectric conversion performances of the DSSCs based on TiO2HS/CNT composite film electrodes are also compared with commercial-grade Degussa P25 TiO 2 nanoparticles (P25)/CNT composite solar cells at the same film thickness. The results indicate that the photoelectric conversion efficiencies (η) of the TiO2HS/CNT composite DSSCs are dependent on CNT loading in the electrodes. A small amount of CNT clearly enhances DSSC efficiency, while excessive CNT loading significantly lowers their performance. The former is because CNT enhance the transport of electrons from the films to FTO substrates. The latter is due to high CNT loading shielding the visible light from being adsorbed by dyes.

  12. Au-C allotrope nano-composite films at extreme conditions generated by intense ultra-short laser

    Science.gov (United States)

    Khan, Saif A.; Saravanan, K.; Tayyab, M.; Bagchi, S.; Avasthi, D. K.

    2016-07-01

    Structural evolution of gold-carbon allotrope nano-composite films under relativistically intense, ultra-short laser pulse irradiation is studied in this work. Au-C nano-composite films, having 4 and 10 at.% of Au, were deposited by co-sputtering technique on silicon substrates. Au-C60 NC films with 2.5 at.% Au were deposited on 12 μm thick Al foil using co-evaporation technique. These samples were radiated with single pulse from 45 fs, 10 TW Ti:Sapphire Laser at RRCAT at an intensity of 3 × 1018 W cm-2. The morphological and compositional changes were investigated using scanning electron microscopy (SEM) and Rutherford back-scattering spectrometry (RBS) techniques. Laser pulse created three morphologically distinct zones around the point of impact on samples with silicon substrates. The gold content in 600 μm circular region around a point of impact is found to reduce by a factor of five. Annular rings of ∼70 nm in diameter were observed in case of Au-C NC film after irradiation. Laser pulse created a hole of about 400 μm in the sample with Al foil as substrate and wavy structures of 6 μm wavelength are found to be created around this hole. The study shows radial variation in nano-structure formation with varying local intensity of laser pulse.

  13. Preparation of Composited Graphene/PEDOT:PSS Film for Its Possible Application in Graphene-based Organic Solar Cells

    Institute of Scientific and Technical Information of China (English)

    YU Yue; LI Meicheng; CHU Lihua; YU Hakki; Wodtke A M; ZHAO Yan; ZHANG Zhongmo

    2015-01-01

    The interface between graphene and organic layers is a key factor responsible for the performance of gra-phene-based organic solar cells (OSCs). In this paper, we focus on coating PEDOT:PSS onto the surface of graphene. We demonstrate two approaches, applying UV/Ozone treatment on graphene and modifying PEDOT:PSS with Zonyl, to get a PEDOT:PSS well-coated graphene film . Our results prove that both methods can be effective to solve the interface issue between graphene and PEDOT: PSS. Thereby it shows a positive application of the composited gra-phene/PEDOT:PSS film on graphene-based OSCs.

  14. Preparation of porous TiO{sub 2}/ZnO composite film and its photocathodic protection properties for 304 stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Hongmei; Liu, Wei, E-mail: weiliu@ouc.edu.cn; Cao, Lixin; Su, Ge; Duan, Ruijing

    2014-05-01

    Highlights: • Porous TiO{sub 2}/ZnO composite films were prepared on the 304 stainless steel. • The preparation parameters of the composite films were optimized. • Porous TiO{sub 2}/ZnO composite films provide an effective photogenerated cathodic protection for 304 stainless steel. - Abstract: TiO{sub 2}/ZnO composite films with porous structure were prepared on the 304 stainless steel (304SS) by the sol-gel method and heating treatment. The crystalline phase and morphology of as-prepared TiO{sub 2}/ZnO composite films were characterized systematically by X-ray diffraction (XRD), scanning electron microscope (SEM) and ultraviolet–visible (UV–vis) spectroscopy, respectively. The influences of Ti/Zn molar ratio and the annealing temperature on the photoelectric property of the samples have been investigated and their photocathodic protection performances for 304 stainless steel under dark and UV conditions have also been evaluated in 3.0% NaCl solution by the electrochemical measurements. The results indicate that porous TiO{sub 2}/ZnO composite film has a great enhancement of the light absorption and photoelectric property under UV illumination. This can be ascribed to the mutual effect of TiO{sub 2}/ZnO heterojunctions and the porous structures in the composite films, which provide a better photogenerated cathodic protection for 304SS.

  15. High dielectric, dynamic mechanical and thermal properties of polyimide composite film filled with carbon-coated silver nanowires

    Science.gov (United States)

    Wang, Lisi; Piao, Xiaoyu; Zou, Heng; Wang, Ya; Li, Hengfeng

    2015-01-01

    High dielectric permittivity materials are much desirable in the electric industry. Filling polymer matrix with conductive powders to form percolative composites is one of the most promising methods to achieve high dielectric permittivity. However, they do not always provide high mechanical properties and thermal stability, which seriously limit their applications. In this study, we present the preparation of functional core-shell structured silver nanowires/polyimide (AgNWs/PI) hybrid film with high dielectric permittivity and low loss dielectric. The core-shell structure of AgNWs was characterized by transmission electric microscopy. The dynamical mechanical analysis showed that AgNWs/PI hybrid films had relative high dynamic mechanical properties with storage modules over 1 Gpa. Moreover, the hybrid films exhibited excellent thermal stability with 5 % weight-loss temperature above 500 °C. The dielectric properties of the carbon-coated AgNWs hybrid films were remarkably improved. The maximum dielectric permittivity of hybrid films is 126 at 102 Hz, which was 39 times higher than that of pure PI matrix, while the dielectric loss of that is still remained at a low value. This study showed a new method to improve the dielectric, dynamic mechanical and thermal properties of films.

  16. Microstructure, dielectric and optical properties of compositionally graded Ba1-xSrxTiO3 thin film

    International Nuclear Information System (INIS)

    Compositionally graded Ba1-xSrxTiO3 (BST) (x: 0.6-1.0) were prepared on silicon, Pt/Ti/SiO2/Si and fused quartz substrates by sol-gel technique. The microstructure of the graded BST film was characterized by glancing-incidence X-ray diffraction (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM). The results showed that the graded film had uniform and crack-free surface morphology with a perovskite structure. The small signal dielectric constant and dielectric loss were found to be 245.6 and 0.036, respectively at room temperature and 100 kHz. The dielectric properties changed significantly with applied dc bias, and the tunability of the graded BST film was 36.2% at an applied field of 375 kV/cm. The transmission spectrum of the graded film was measured by spectrophotometer. The refractive index and thickness of the graded BST film was calculated using envelope method from the transmission spectrum. It showed that the refractive index increased from 1.89 to 2.13 as wavelength decreased from 850 nm to 400 nm. These results show the potential of using the graded BST thin films as an electro-optical novel material

  17. Morphology, composition and electrical properties of SnO{sub 2}:Cl thin films grown by atomic layer deposition

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Hsyi-En, E-mail: sean@mail.stust.edu.tw; Wen, Chia-Hui; Hsu, Ching-Ming [Department of Electro-Optical Engineering, Southern Taiwan University of Science and Technology, Tainan 71005, Taiwan (China)

    2016-01-15

    Chlorine doped SnO{sub 2} thin films were prepared using atomic layer deposition at temperatures between 300 and 450 °C using SnCl{sub 4} and H{sub 2}O as the reactants. Composition, structure, surface morphology, and electrical properties of the as-deposited films were examined. Results showed that the as-deposited SnO{sub 2} films all exhibited rutile structure with [O]/[Sn] ratios between 1.35 and 1.40. The electrical conductivity was found independent on [O]/[Sn] ratio but dependent on chlorine doping concentration, grain size, and surface morphology. The 300 °C-deposited film performed a higher electrical conductivity of 315 S/cm due to its higher chlorine doping level, larger grain size, and smoother film surface. The existence of Sn{sup 2+} oxidation state was demonstrated to minimize the effects of chlorine on raising the electrical conductivity of films.

  18. Investigation of elastic and optical properties of electron beam evaporated ZrO2–MgO composite thin films

    International Nuclear Information System (INIS)

    Thin films of composite materials are being progressively explored for achieving tunability in the optical constants for application in multilayer optical devices. In the present study, a set of ZrO2–MgO binary mixed composite thin films have been prepared by reactive electron beam evaporation of solid solution of ZrO2 and MgO at different oxygen partial pressures. Since elastic properties of the thin films are very important for their environmental stability under high power laser application, elastic moduli (indentation moduli) of the films have been measured by atomic force acoustic microscopy measurements. The optical properties especially refractive index of such films has been determined from the optical transmission measurement using an inverse synthesis method, while the density of such films has been measured by grazing incidence X-ray reflectivity. The variation of the elastic moduli of the thin films as a function of oxygen partial pressure used during deposition has been studied and the above variation has been corroborated with the variation of density and refractive index of the thin films. - Highlights: • Indentation modulus of ZrO2–MgO films estimated by atomic force acoustic microscopy • The thin film deposited without oxygen pressure depicts highest indentation modulus. • Indentation modulus of the films decreases monotonically with oxygen pressure. • Correlation between indentation modulus, refractive index and film density established

  19. Compositional-induced structural change in Zr{sub x}Ni{sub 100−x} thin film metallic glasses

    Energy Technology Data Exchange (ETDEWEB)

    Ghidelli, Matteo, E-mail: matteo.ghidelli@simap.grenoble-inp.fr [Science and Engineering of Materials and Processes, SIMaP, Université de Grenoble/CNRS, UJF/Grenoble INP, BP46, 38402 Saint-Martin d’Hères (France); Institute of Mechanics, Materials and Civil Engineering, IMMC, Université catholique de Louvain, B-1348 Louvain-la-Neuve (Belgium); Institute of Information and Communication Technologies, Electronics and Applied Mathematics, ICTEAM, Université catholique de Louvain, B-1348 Louvain-la-Neuve (Belgium); Gravier, Sébastien; Blandin, Jean-Jacques [Science and Engineering of Materials and Processes, SIMaP, Université de Grenoble/CNRS, UJF/Grenoble INP, BP46, 38402 Saint-Martin d’Hères (France); Pardoen, Thomas [Institute of Mechanics, Materials and Civil Engineering, IMMC, Université catholique de Louvain, B-1348 Louvain-la-Neuve (Belgium); Raskin, Jean-Pierre [Institute of Information and Communication Technologies, Electronics and Applied Mathematics, ICTEAM, Université catholique de Louvain, B-1348 Louvain-la-Neuve (Belgium); Mompiou, Frédéric [CEMES-CNRS, Université de Toulouse, 29, rue J. Marvig, 31005 Toulouse (France)

    2014-12-05

    Highlights: • A composite ZrNi target is used to accurately tune ZrNi thin film composition. • The atomic structure of metallic glass films is determined for several compositions. • Short and medium range order is inferred for amorphous compositions. • Crystallization phenomena are detected for Zr-rich specimens. • Crystallization is justified on the basis Nagel and Tauc criterion. - Abstract: The structure of Zr{sub x}Ni{sub 100−x} thin film metallic glasses (TFMGs) has been studied for a variety of compositions obtained by DC magnetron sputtering using a composite ZrNi target. The crystallization has been characterized by X-ray diffraction and transmission electron microscopy revealing also short and medium range order for amorphous compositions. The TFMGs thermodynamic stability has been evaluated by exploiting the Nagel and Tauc criterion, justifying the occurrence of crystallization in the Zr-rich specimens.

  20. Toward compositional design of reticular type porous films by mixing and coating titania-based frameworks with silica

    Directory of Open Access Journals (Sweden)

    T. Kimura

    2015-12-01

    Full Text Available A recently developed reticular type porous structure, which can be fabricated as the film through the soft colloidal block copolymer (e.g., PS-b-PEO templating, is very promising as the porous platform showing high-performance based on its high surface area as well as high diffusivity of targeted organic molecules and effective accommodation of bulky molecules, but the compositional design of oxide frameworks has not been developed so enough to date. Here, I report reliable synthetic methods of the reticular type porous structure toward simple compositional variations. Due to the reproducibility of reticular type porous titania films from titanium alkoxide (e.g., TTIP; titanium tetraisopropoxide, a titania-silica film having similar porous structure was obtained by mixing silicon alkoxide (e.g., tetraethoxysilane and TTIP followed by their pre-hydrolysis, and the mixing ratio of Ti to Si composition was easily reached to 1.0. For further compositional design, a concept of surface coating was widely applicable; the reticular type porous titania surfaces can be coated with other oxides such as silica. Here, a silica coating was successfully achieved by the simple chemical vapor deposition of silicon alkoxide (e.g., tetramethoxysilane without water (with water at the humidity level, which was also utilized for pore filling with silica by the similar process with water.

  1. Toward compositional design of reticular type porous films by mixing and coating titania-based frameworks with silica

    Science.gov (United States)

    Kimura, T.

    2015-12-01

    A recently developed reticular type porous structure, which can be fabricated as the film through the soft colloidal block copolymer (e.g., PS-b-PEO) templating, is very promising as the porous platform showing high-performance based on its high surface area as well as high diffusivity of targeted organic molecules and effective accommodation of bulky molecules, but the compositional design of oxide frameworks has not been developed so enough to date. Here, I report reliable synthetic methods of the reticular type porous structure toward simple compositional variations. Due to the reproducibility of reticular type porous titania films from titanium alkoxide (e.g., TTIP; titanium tetraisopropoxide), a titania-silica film having similar porous structure was obtained by mixing silicon alkoxide (e.g., tetraethoxysilane) and TTIP followed by their pre-hydrolysis, and the mixing ratio of Ti to Si composition was easily reached to 1.0. For further compositional design, a concept of surface coating was widely applicable; the reticular type porous titania surfaces can be coated with other oxides such as silica. Here, a silica coating was successfully achieved by the simple chemical vapor deposition of silicon alkoxide (e.g., tetramethoxysilane) without water (with water at the humidity level), which was also utilized for pore filling with silica by the similar process with water.

  2. Combinatorial fabrication and high-throughput characterization of a Ti-Ni-Cu shape memory thin film composition spread

    Energy Technology Data Exchange (ETDEWEB)

    Loebel, R. [Combinatorial Material Science group, Caesar, Ludwig-Erhard-Allee 2, 53175 Bonn (Germany); Ruhr-University Bochum, Institute of Materials, 44780 Bochum (Germany)], E-mail: robert.loebel@ruhr-uni-bochum.de; Thienhaus, S. [Combinatorial Material Science group, Caesar, Ludwig-Erhard-Allee 2, 53175 Bonn (Germany); Ruhr-University Bochum, Institute of Materials, 44780 Bochum (Germany); Savan, A. [Combinatorial Material Science group, Caesar, Ludwig-Erhard-Allee 2, 53175 Bonn (Germany); Ludwig, A. [Combinatorial Material Science group, Caesar, Ludwig-Erhard-Allee 2, 53175 Bonn (Germany); Ruhr-University Bochum, Institute of Materials, 44780 Bochum (Germany)

    2008-05-25

    The phase transformation properties of Ti-Ni-Cu shape memory thin films prepared in the form of a continuous composition spread were investigated. The thin film materials library was fabricated from elemental targets using an ultra-high vacuum combinatorial magnetron sputter-deposition system. Alternating wedge-type layers of Ti, Ni, and Cu were deposited on a thermally oxidized Si wafer and subsequently annealed at 500 deg. C for 1 h in situ. Automated temperature-dependent resistance measurements (R(T)), energy dispersive X-ray analysis and X-ray diffraction measurements revealed the compositional region in the ternary phase diagram where thermoelastic transformations occur. The transformation temperatures and the thermal hysteresis were determined from R(T) measurements. Within the composition spread an extended transformation region was found. For Ni-rich compositions, a two-stage B2 {yields} R {yields} B19' phase transformation was observed. Among others, compositions of Ti{sub 51}Ni{sub 49-x}Cu{sub x} (at.%) show a single-stage transformation for a Cu-content <6.5 at.% (B2 {yields} B19') and >14 at.% (B2 {yields} B19). In the intermediate composition range two-stage transformations (B2 {yields} B19 {yields} B19') were found. The dependency of the thermal hysteresis on the Cu-content as described in the literature was confirmed.

  3. Comparison analysis on the properties of the phosphor film according to the various composition ratio of phosphor slurry

    Science.gov (United States)

    Park, Jeong Yeon; Lee, Jeong Won; Heo, Young Moo; Won, Si Tae; Yoon, Gil Sang

    2016-03-01

    The conventional method of making a phosphor layer on the LED package by using a dispensing method is difficult to implement the specific color coordinate, color temperature and optical efficiency because the thickness of the phosphor layer is non-uniform due to precipitation of the phosphor. Besides, the dispensing method consume a large amount of phosphor and silicone to fill the LED package. Thus, studies that manufacture phosphor layer with a uniform thickness such as spray coating, screen printing, electrophoresis are active recently. The purpose of this study is to perform the basic research about the change of the characteristics of phosphor film that is molded with uniform thickness using the phosphor slurry according to various silicone resin and phosphor composition ratio. It is expected to be used as useful information for the fabricating properties when production environment of phosphor layer is changed dispensing method into phosphor film fabrication. In the experiment, it was selected three kinds of methyl-phenyl silicone based resin as the phosphor slurry constituents, and mixed with phosphor various amount of 20 ˜ 60wt% content per one silicone resin. Using this mixed phosphor slurry, it was molded the phosphor film with 300 μm thickness and analyzed the mechanical properties and optical properties of the phosphor film. Finally, the results of this study are presented below: (a) As the phenyl group content is increased, the total heat of reaction need to cure the silicone resin is decrease, and also lower the durometer hardness of the phosphor sheet. On the other hand, it was confirmed that there is no relationship between the phenyl group content in the phosphor film and optical characteristics of the phosphor film. (b) If the amount of the phosphor within the film are increased, then the values of shore hardness and CIE color coordinates are increased gradually but the value of CIE color temperature is decreased gradually in case of being

  4. On the Novel Biaxial Strain Relaxation Mechanism in Epitaxial Composition Graded La1−xSrxMnO3 Thin Film Synthesized by RF Magnetron Sputtering

    Directory of Open Access Journals (Sweden)

    Yishu Wang

    2015-11-01

    Full Text Available We report on a novel method to fabricate composition gradient, epitaxial La1−xSrxMnO3 thin films with the objective to alleviate biaxial film strain. In this work, epitaxial, composition gradient La1−xSrxMnO3, and pure LaMnO3 and La0.67Sr0.33MnO3 thin films were deposited by radio frequency (RF magnetron sputtering. The crystalline and epitaxy of all films were first studied by symmetric θ–2θ X-ray diffraction (XRD and low angle XRD experiments. Detailed microstructural characterization across the film thickness was conducted by high-resolution transmission electron microscopy and electron diffraction. Four compositional gradient domains were observed in the La1−xSrxMnO3 film ranging from LaMnO3 rich to La0.67Sr0.33MnO3 at the surface. A continuous reduction in the lattice parameter was observed accompanied by a significant reduction in the out-of-plane strain in the film. Fabrication of the composition gradient La1−xSrxMnO3 thin film was found to be a powerful method to relieve biaxial strain under critical thickness. Besides, the coexistence of domains with a composition variance is opening up various new possibilities of designing new nanoscale structures with unusual cross coupled properties.

  5. Radiochromic film for dosimetric measurements in radiation shielding composites synthesized for applied in radiology procedures of high dose

    Energy Technology Data Exchange (ETDEWEB)

    Fontainha, C. C. P. [Universidade Federal de Minas Gerais, Departamento de Engenharia Nuclear, Av. Pte. Antonio Carlos 6627, 31270-901 Belo Horizonte, Minas Gerais (Brazil); Baptista N, A. T.; Faria, L. O., E-mail: crissia@gmail.com [Centro de Desenvolvimento da Tecnologia Nuclear / CNEN, Av. Pte. Antonio Carlos 6627, 31270-901 Belo Horizonte, Minas Gerais (Brazil)

    2015-10-15

    Full text: Medical radiology offers great benefit to patients. However, although specifics procedures of high dose, as fluoroscopy, Interventional Radiology, Computed Tomography (CT) make up a small percent of the imaging procedures, they contribute to significantly increase dose to population. The patients may suffer tissue damage. The probability of deterministic effects incidence depends on the type of procedure performed, exposure time, and the amount of applied dose at the irradiated area. Calibrated radiochromic films can identify size and distribution of the radiated fields and measure intensities of doses. Radiochromic films are sensitive for doses ranging from 0.1 to 20 c Gy and they have the same response for X-rays effective energies ranging from 20 to 100 keV. New radiation attenuators materials have been widely investigated resulting in dose reduction entrance skin dose. In this work, Bi{sub 2}O{sub 3} and ZrO{sub 2}:8 % Y{sub 2}O{sub 3} composites were obtained by mixing them with P(VDF-Tr Fe) copolymers matrix from casting method and then characterized by Ftir. Dosimetric measurements were obtained with Xr-Q A2 Gafchromic radiochromic films. In this setup, one radiochromic film is directly exposed to the X-rays beam and another one measures the attenuated beam were exposed to an absorbed dose of 10 mGy of RQR5 beam quality (70 kV X-ray beam). Under the same conditions, irradiated Xr-Q A2 films were stored and scanned measurement in order to obtain a more reliable result. The attenuation factors, evaluated by Xr-Q A2 radiochromic films, indicate that both composites are good candidates for use as patient radiation shielding in high dose medical procedures. (Author)

  6. Chemical composition and corrosion protection of silane films modified with CeO2 nanoparticles

    International Nuclear Information System (INIS)

    The present work aims at understanding the role of CeO2 nanoparticles (with and without activation in cerium(III) solutions) used as fillers for hybrid silane coatings applied on galvanized steel substrates. The work reports the improved corrosion protection performance of the modified silane films and discusses the chemistry of the cerium-activated nanoparticles, the mechanisms involved in the formation of the surface coatings and its corrosion inhibition ability. The anti-corrosion performance was investigated using electrochemical impedance spectroscopy (EIS), the scanning vibrating electrode technique (SVET) and d.c. potentiodynamic polarization. The chemical composition of silanised nanoparticles and the chemical changes of the silane solutions due to the presence of additives were studied using X-ray photoelectron spectroscopy (XPS) and nuclear magnetic resonance spectroscopy (NMR), respectively. The NMR and XPS data revealed that the modified silane solutions and respective coatings have enhanced cross-linking and that silane-cerium bonds are likely to occur. Electrochemical impedance spectroscopy showed that the modified coatings have improved barrier properties and the SVET measurements highlight the corrosion inhibition effect of ceria nanoparticles activated with Ce(III) ions. Potentiodynamic polarization curves demonstrate an enhanced passive domain for zinc, in the presence of nanoparticles, in solutions simulating the cathodic environment.

  7. Surface Functionalization of Thin-Film Composite Membranes with Copper Nanoparticles for Antimicrobial Surface Properties

    KAUST Repository

    Ben-Sasson, Moshe

    2014-01-07

    Biofouling is a major operational challenge in reverse osmosis (RO) desalination, motivating a search for improved biofouling control strategies. Copper, long known for its antibacterial activity and relatively low cost, is an attractive potential biocidal agent. In this paper, we present a method for loading copper nanoparticles (Cu-NPs) on the surface of a thin-film composite (TFC) polyamide RO membrane. Cu-NPs were synthesized using polyethyleneimine (PEI) as a capping agent, resulting in particles with an average radius of 34 nm and a copper content between 39 and 49 wt.%. The positive charge of the Cu-NPs imparted by the PEI allowed a simple electrostatic functionalization of the negatively charged RO membrane. We confirmed functionalization and irreversible binding of the Cu-NPs to the membrane surface with SEM and XPS after exposing the membrane to bath sonication. We also demonstrated that Cu-NP functionalization can be repeated after the Cu-NPs dissolve from the membrane surface. The Cu-NP functionalization had minimal impact on the intrinsic membrane transport parameters. Surface hydrophilicity and surface roughness were also maintained, and the membrane surface charge became positive after functionalization. The functionalized membrane exhibited significant antibacterial activity, leading to an 80-95% reduction in the number of attached live bacteria for three different model bacterial strains. Challenges associated with this functionalization method and its implementation in RO desalination are discussed. © 2013 American Chemical Society.

  8. Enhanced surface hydrophilicity of thin-film composite membranes for nanofiltration: an experimental and DFT study.

    Science.gov (United States)

    Lv, Zhiwei; Hu, Jiahui; Zhang, Xuan; Wang, Lianjun

    2015-10-01

    In the current study, thin-film composite (TFC) nanofiltration membranes desirable for water softening were successfully developed through interfacial polymerization using N-(2-hydroxyethyl)ethylenediamine (HEDA) as the amine monomer in the aqueous phase. The hydrophilicity of the membrane surface was greatly enhanced with the introduction of the residual hydroxyl groups during the fabrication process. The TFC membranes possessed a permeate flux of 15.8 L m(-2) h(-1) under 0.6 MPa, with a rejection of 85.9%, 73.8%, and 99.8% for Na2SO4, MgSO4 and Congo red, respectively. The interplays of the solvent, solute and polymer matrix on the separation performance were investigated by means of the solubility parameter study. Moreover, density functional theory was employed to calculate the Fukui function by the Hirshfeld charge, which gave the global and local softness values to predict the reactivity of the atomic sites in the HEDA molecule. The findings of this study support the possible forming mechanism of the barrier layer for the first time. The TFC membrane was found to be stable and displayed good separation ability over a week-long filtration process. The combined results of this work suggest that these HEDA/TMC TFC nanofiltration membranes are promising candidates for various applications, such as desalination and dye removal from wastewater. PMID:26327592

  9. Exchange bias in zinc ferrite-FeNiMoB based metallic glass composite thin films

    Energy Technology Data Exchange (ETDEWEB)

    R, Lisha; P, Geetha; B, Aravind P.; Anantharaman, M. R., E-mail: mraiyer@yahoo.com [Cochin University of Science and Technology, Cochin-682022 (India); T, Hysen [Christian College, Chengannur, Kerala-689121 (India); Ojha, S.; Avasthi, D. K. [Inter University Accelerator Centre, Vasant Kunj, New Delhi-110067 (India); Ramanujan, R. V. [School of Materials Science and Engineering, Nanyang Technological University (Singapore)

    2015-06-24

    The Exchange bias phenomenon and methods to manipulate the bias field in a controlled manner are thrust areas in magnetism due to its sophisticated theoretical concepts as well as advanced technological utility in the field of spintronics. The Exchange bias effect is observed as a result of ferromagnetic-antiferromagnetic (FM-AFM) exchange interaction, usually observed as a loop shift on field cooling below the Neel temperature of AFM. In the present study, we have chosen zinc ferrite which is a well known antiferromagnet, and FeNiMoB based metallic glass as the ferromagnet. The films were prepared by RF sputtering technique. The thickness and composition was obtained by RBS. The magnetic studies using SQUID VSM indicate exchange bias effect in the system. The effect of thermal annealing on exchange bias effect was studied. The observed exchange bias in the zinc ferrite-FeNiMoB system is not due to FM-AFM coupling but due to spin glass-ferromagnetic interaction.

  10. Sustainable Antibiofouling Properties of Thin Film Composite Forward Osmosis Membrane with Rechargeable Silver Nanoparticles Loading.

    Science.gov (United States)

    Liu, Zhongyun; Hu, Yunxia

    2016-08-24

    Microbial attachment and biofilm formation on filtration membrane can greatly compromise its flux and separation efficiency. Here, a simple and facile approach has been developed to in situ generate silver nanoparticles (Ag NPs) on the thin film composite forward osmosis (TFC FO) membrane for sustainable antibiofouling performances. Mussel-inspired dopamine chemistry was applied to grow polydopamine coating on both surfaces of FO membranes, followed by the generation of Ag NPs upon a simple dip coating in silver nitrate aqueous solution. Furthermore, the Ag NPs deposited membranes had a long-term silver release profile with rechargability for multiple times upon their depletion, and exhibited strong sustainable bactericidal efficacy against Gram-negative bacteria and Gram-positive bacteria. The Ag NPs had a controllable effect on the membrane performances including the water flux and reverse salt flux in the FO test mode. Our practicable antibacterial strategy may apply to other types of filtration membranes with diverse material surfaces and may pave a new way to achieve the sustainable membrane antibiofouling performance on a large scale. PMID:27467542

  11. A study of the barrier properties of polyethylene coated with a nanocellulose/magnetite composite film

    Directory of Open Access Journals (Sweden)

    Đorđević Nenad

    2016-01-01

    Full Text Available The morphological, thermal and barrier properties of low-density polyethylene/polycaprolactone-modified nanocellulose hybrid materials were investigated in this paper. Nanonocelulose/magnetite (NC-Fe3O4 nanocomposite and maleic acid functionalized NC/magnetite (NCMA-Fe3O4 nanocomposite were prepared and used as filler at various concentrations (5, 10 and 15 wt. % in polycaprolactone (PCL layer. PE was coated with PCL/NC/magnetite layer. The addition of the filler did not unfavorably affect the inherent properties of the polymer, especially its barrier properties. Oxygen permeation measurements show that the oxygen barrier properties of magnetite enriched PCL film were improved due to chemical activity of added material. The highest level of barrier capacity was observed for PE samples coated with PCL based composite with NCMA-Fe3O4 micro/-nanofiller, which implies the significant contribution of nanocellulose surface modification with maleic anhydride residue to improved barrier properties. [Projekat Ministarstva nauke Republike Srbije, br. III45019 i br. OI172013

  12. Relating performance of thin-film composite forward osmosis membranes to support layer formation and structure

    KAUST Repository

    Tiraferri, Alberto

    2011-02-01

    Osmotically driven membrane processes have the potential to treat impaired water sources, desalinate sea/brackish waters, and sustainably produce energy. The development of a membrane tailored for these processes is essential to advance the technology to the point that it is commercially viable. Here, a systematic investigation of the influence of thin-film composite membrane support layer structure on forward osmosis performance is conducted. The membranes consist of a selective polyamide active layer formed by interfacial polymerization on top of a polysulfone support layer fabricated by phase separation. By systematically varying the conditions used during the casting of the polysulfone layer, an array of support layers with differing structures was produced. The role that solvent quality, dope polymer concentration, fabric layer wetting, and casting blade gate height play in the support layer structure formation was investigated. Using a 1M NaCl draw solution and a deionized water feed, water fluxes ranging from 4 to 25Lm-2h-1 with consistently high salt rejection (>95.5%) were produced. The relationship between membrane structure and performance was analyzed. This study confirms the hypothesis that the optimal forward osmosis membrane consists of a mixed-structure support layer, where a thin sponge-like layer sits on top of highly porous macrovoids. Both the active layer transport properties and the support layer structural characteristics need to be optimized in order to fabricate a high performance forward osmosis membrane. © 2010 Elsevier B.V.

  13. Solvent resistant thin film composite nanofiltration membrane: Characterization and permeation study

    International Nuclear Information System (INIS)

    The present investigation reports the fabrication of thin film composite nanofiltration (TFC-NF) membranes using interfacial polymerization technique for desalination. Ethylene diamine (EDA) and terephthaloyl chloride (TPC) were employed as aqueous and organic phase monomers, respectively to develop polyamide thin layer on the surface of Celgard 2400. The prepared membranes were characterized through Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and atomic force microscopy (AFM). The molecular weight cutoff of TFC-NF membranes was estimated to be below 342 Da using dextrose, sucrose and raffinose solutions. A low cost dead end NF Cell was designed and manufactured domestically to conduct permeation experiments. The effect of different reaction conditions including concentration of monomers, residence time in each monomer and curing temperature on the membrane performance (water flux and MgCl2 rejection) was also studied. The water flux was augmented linearly at higher applied pressure while MgCl2 rejection was remained constant. The obtained water flux and MgCl2 rejection were measured 33 L/m2 h and 90%, respectively at 7 bar applied pressure. Beside this, membrane stability was analyzed, which confirmed the excellent constancy of ethanol and n-hexane fluxes even after an extended period. Hagen–Poiseuille equation was applied to estimate the TFC-NF membrane pore size ∼0.45 nm.

  14. Selective determination of dopamine with a cibacron blue/poly-1,5-diaminonaphthalene composite film

    Energy Technology Data Exchange (ETDEWEB)

    Abdelwahab, Adel A.; Lee, Hak-Myoung [Department of Chemistry and Center for Innovative BioPhysio Sensor Technology, Pusan National University, Busan 609-735 (Korea, Republic of); Shim, Yoon-Bo, E-mail: ybshim@pusan.ac.kr [Department of Chemistry and Center for Innovative BioPhysio Sensor Technology, Pusan National University, Busan 609-735 (Korea, Republic of)

    2009-09-21

    A selective detection method for dopamine (DA) was developed by incorporating cibacron blue (F3GA) into poly-1,5-diaminonaphthalene (PDAN) layer. Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and cyclic voltammetry (CV) were employed to characterize the modified surfaces. The modified electrode was effective in selectively facilitating the electron transfer of DA and blocking the interferences of negatively charged species attributed to the sulfonate groups in the F3GA/PDAN composite film. This method enabled the determination of DA in the presence of various interfering species, including ascorbic acid (AA), in a phosphate buffer solution (pH 7.4). The modified electrode demonstrated good performance in the detection of DA in a concentration range of 5.0-100 {mu}M, with a detection limit (k = 3) of 0.1 {+-} 0.01 {mu}M. The application was conducted for the determination of DA in a human urine sample and the sensor was proven to be rapid, has excellent selectivity, and stable amperometric response.

  15. Multifunctional carbon nanotube thin film composites by layer-by-layer assembly technique

    Science.gov (United States)

    Shim, Bong Sup

    Polymeric layer-by-layer (LBL) assembly offers a pathway for multifunctional/multicomponent materials with molecular-scale control of stratified structures. Among the wide variety nanoscale building blocks such as nanowires and nanodots, single-walled carbon nanotubes (SWNTs) are regarded as one of the most versatile because of their superior mechanical and electrical properties as well as geometrical perfection. In this thesis, LBL assembled SWNT thin film nanocomposites with high mechanical strength/toughness and with high electrical/optical properties are presented. Exceptional exfoliation state of SWNTs and controlled nm-thick layered structures are the basis for achieving tunable physical properties. Highly anisotropic features of SWNTs are translated into 2 dimensional alignments by meniscus combing technique during LBL assemblies. Advanced LBL assemblies by dewetting methods are also introduced, which significantly accelerate the process with improved lateral organization of nanowires. Furthermore, SWNT composite coating on commodity cotton yarns produced intelligent electronic textiles (e-textiles) with intrinsic humidity sensibility. This e-textile has been further combined with antigen/antibody sensing capability in order to develop a selective albumin biosensor which provides a direct route for the application of these materials as wearable biomonitoring and telemedicine sensors.

  16. Sustainable Antibiofouling Properties of Thin Film Composite Forward Osmosis Membrane with Rechargeable Silver Nanoparticles Loading.

    Science.gov (United States)

    Liu, Zhongyun; Hu, Yunxia

    2016-08-24

    Microbial attachment and biofilm formation on filtration membrane can greatly compromise its flux and separation efficiency. Here, a simple and facile approach has been developed to in situ generate silver nanoparticles (Ag NPs) on the thin film composite forward osmosis (TFC FO) membrane for sustainable antibiofouling performances. Mussel-inspired dopamine chemistry was applied to grow polydopamine coating on both surfaces of FO membranes, followed by the generation of Ag NPs upon a simple dip coating in silver nitrate aqueous solution. Furthermore, the Ag NPs deposited membranes had a long-term silver release profile with rechargability for multiple times upon their depletion, and exhibited strong sustainable bactericidal efficacy against Gram-negative bacteria and Gram-positive bacteria. The Ag NPs had a controllable effect on the membrane performances including the water flux and reverse salt flux in the FO test mode. Our practicable antibacterial strategy may apply to other types of filtration membranes with diverse material surfaces and may pave a new way to achieve the sustainable membrane antibiofouling performance on a large scale.

  17. Solvent resistant thin film composite nanofiltration membrane: Characterization and permeation study

    Science.gov (United States)

    Minhas, Fozia T.; Memon, Shahabuddin; Bhanger, M. I.; Iqbal, Nadeem; Mujahid, M.

    2013-10-01

    The present investigation reports the fabrication of thin film composite nanofiltration (TFC-NF) membranes using interfacial polymerization technique for desalination. Ethylene diamine (EDA) and terephthaloyl chloride (TPC) were employed as aqueous and organic phase monomers, respectively to develop polyamide thin layer on the surface of Celgard 2400. The prepared membranes were characterized through Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and atomic force microscopy (AFM). The molecular weight cutoff of TFC-NF membranes was estimated to be below 342 Da using dextrose, sucrose and raffinose solutions. A low cost dead end NF Cell was designed and manufactured domestically to conduct permeation experiments. The effect of different reaction conditions including concentration of monomers, residence time in each monomer and curing temperature on the membrane performance (water flux and MgCl2 rejection) was also studied. The water flux was augmented linearly at higher applied pressure while MgCl2 rejection was remained constant. The obtained water flux and MgCl2 rejection were measured 33 L/m2 h and 90%, respectively at 7 bar applied pressure. Beside this, membrane stability was analyzed, which confirmed the excellent constancy of ethanol and n-hexane fluxes even after an extended period. Hagen-Poiseuille equation was applied to estimate the TFC-NF membrane pore size ∼0.45 nm.

  18. Surface functionalization of thin-film composite membranes with copper nanoparticles for antimicrobial surface properties.

    Science.gov (United States)

    Ben-Sasson, Moshe; Zodrow, Katherine R; Genggeng, Qi; Kang, Yan; Giannelis, Emmanuel P; Elimelech, Menachem

    2014-01-01

    Biofouling is a major operational challenge in reverse osmosis (RO) desalination, motivating a search for improved biofouling control strategies. Copper, long known for its antibacterial activity and relatively low cost, is an attractive potential biocidal agent. In this paper, we present a method for loading copper nanoparticles (Cu-NPs) on the surface of a thin-film composite (TFC) polyamide RO membrane. Cu-NPs were synthesized using polyethyleneimine (PEI) as a capping agent, resulting in particles with an average radius of 34 nm and a copper content between 39 and 49 wt.%. The positive charge of the Cu-NPs imparted by the PEI allowed a simple electrostatic functionalization of the negatively charged RO membrane. We confirmed functionalization and irreversible binding of the Cu-NPs to the membrane surface with SEM and XPS after exposing the membrane to bath sonication. We also demonstrated that Cu-NP functionalization can be repeated after the Cu-NPs dissolve from the membrane surface. The Cu-NP functionalization had minimal impact on the intrinsic membrane transport parameters. Surface hydrophilicity and surface roughness were also maintained, and the membrane surface charge became positive after functionalization. The functionalized membrane exhibited significant antibacterial activity, leading to an 80-95% reduction in the number of attached live bacteria for three different model bacterial strains. Challenges associated with this functionalization method and its implementation in RO desalination are discussed. PMID:24308843

  19. Solvent resistant thin film composite nanofiltration membrane: Characterization and permeation study

    Energy Technology Data Exchange (ETDEWEB)

    Minhas, Fozia T. [National Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan); Memon, Shahabuddin, E-mail: shahabuddinmemon@yahoo.com [National Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan); Bhanger, M.I. [HEJ Research Institute of Chemistry, University of Karachi, Karachi 75270 (Pakistan); Iqbal, Nadeem; Mujahid, M. [School of Chemical and Materials Engineering (SCME), National University of Sciences and Technology, H-12, 44000, Islamabad (Pakistan)

    2013-10-01

    The present investigation reports the fabrication of thin film composite nanofiltration (TFC-NF) membranes using interfacial polymerization technique for desalination. Ethylene diamine (EDA) and terephthaloyl chloride (TPC) were employed as aqueous and organic phase monomers, respectively to develop polyamide thin layer on the surface of Celgard 2400. The prepared membranes were characterized through Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and atomic force microscopy (AFM). The molecular weight cutoff of TFC-NF membranes was estimated to be below 342 Da using dextrose, sucrose and raffinose solutions. A low cost dead end NF Cell was designed and manufactured domestically to conduct permeation experiments. The effect of different reaction conditions including concentration of monomers, residence time in each monomer and curing temperature on the membrane performance (water flux and MgCl{sub 2} rejection) was also studied. The water flux was augmented linearly at higher applied pressure while MgCl{sub 2} rejection was remained constant. The obtained water flux and MgCl{sub 2} rejection were measured 33 L/m{sup 2} h and 90%, respectively at 7 bar applied pressure. Beside this, membrane stability was analyzed, which confirmed the excellent constancy of ethanol and n-hexane fluxes even after an extended period. Hagen–Poiseuille equation was applied to estimate the TFC-NF membrane pore size ∼0.45 nm.

  20. Quantitative compositional analysis of organic thin films using transmission NEXAFS spectroscopy in an X-ray microscope

    Energy Technology Data Exchange (ETDEWEB)

    Collins, Brian A. [Department of Physics, NCSU, Raleigh, NC 27695-8202 (United States); Ade, Harald, E-mail: harald_ade@ncsu.edu [Department of Physics, NCSU, Raleigh, NC 27695-8202 (United States)

    2012-08-15

    Highlights: Black-Right-Pointing-Pointer Common sources of error in transmission NEXAFS spectra in a STXM identified and shown to be significant. Black-Right-Pointing-Pointer Three facile methods to characterize and eliminate or limit errors are detailed. Black-Right-Pointing-Pointer Appropriate spectra processing methods are discussed and demonstrated. Black-Right-Pointing-Pointer Quantitative compositional analysis of organic thin films is conducted and shown to be robust. -- Abstract: Near edge X-ray absorption fine structure (NEXAFS) spectroscopy is well suited for the quantitative determination of the composition of soft matter thin films. Combined with the high spatial resolution of a scanning transmission X-ray microscope, compositional maps of submicron morphologies can be derived and have been used successfully to characterize a number of materials systems. However, multiple sources of known systematic errors limit the accuracy and are frequently not taken into account. We show that these errors can be significant (more than 10%) and demonstrate simple methods to eliminate them. With suitable precautions, a compositional measurement can be made on a thin film sample in a matter of minutes with sub-micron spatial resolution and sub-percent compositional precision. NEXAFS measurements are furthermore known to be sensitive to anisotropic molecular orientation and a strategy to account for that and extract preferential molecular orientation relative to a reference is presented. The spatial resolution of the measurement can be increased to below 100 nm at the expense of compositional precision, depending on the point spread function of the zone plate focusing optics of the microscope.