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Sample records for sulphide composite films

  1. Palladium sulphide (PdS) films as a new thermoelectric sulphide compound

    Energy Technology Data Exchange (ETDEWEB)

    Ares, J.R.; Diaz-Chao, P.; Clamagirand, J.; Macia, M.D.; Ferrer, I.J.; Sanchez, C. [Universidad Autonoma de Madrid (Spain). Lab. de Materiales de Interes en Energias Renovables

    2010-07-01

    Palladium sulphide (PdS) films have been prepared by direct sulphuration of 20 nm thick palladium films at different temperatures (200 C < T < 450 C). Sulphurated films exhibit an unique crystalline phase: PdS. Seebeck coefficient and electrical resistivity of these films are between -110 and -150 {mu}V/K and {proportional_to} 0.08 to 0.8 {omega}cm depending on the sulphuration temperature. Negative sign of Seebeck coefficient indicates an n type conduction in all films. Discussion is focused on the influence of atomic ratio between sulphur and palladium as well as impurities arising from the substrate on transport properties. (orig.)

  2. Optical Properties of Lead Silver Sulphide Ternary Thin Films ...

    African Journals Online (AJOL)

    Optical Properties of Lead Silver Sulphide Ternary Thin Films Deposited by Chemical Bath Method. ... The optical properties studied include reflectance, absorption coefficient, thickness, refractive index, extinction coefficient, optical conductivity and band gap energy. The films showed very high absorbance in the UV region, ...

  3. Cadmium sulphide thin film for application in gamma radiation ...

    African Journals Online (AJOL)

    Cadmium Sulphide (CdS) thin film was prepared using pyrolytic spraying technique and then irradiated at varied gamma dosage. The CdS thin film absorption before gamma irradiation was 0.6497. Absorbed doses were computed using standard equation established for an integrating dosimeter. The plot of absorbed dose ...

  4. Chemical bath deposition of indium sulphide thin films: preparation and characterization

    Energy Technology Data Exchange (ETDEWEB)

    Lokhande, C.D.; Ennaoui, A.; Patil, P.S.; Giersig, M.; Diesner, K.; Muller, M.; Tributsch, H. [Hahn-Meitner-Institut Berlin GmbH (Germany). Bereich Physikalische Chemie

    1999-02-26

    Indium sulphide (In{sub 2}S{sub 3}) thin films have been successfully deposited on different substrates under varying deposition conditions using chemical bath deposition technique. The deposition mechanism of In{sub 2}S{sub 3} thin films from thioacetamide deposition bath has been proposed. Films have been characterized with respect to their crystalline structure, composition, optical and electrical properties by means of X-ray diffraction, TEM, EDAX, optical absorption, TRMC (time resolved microwave conductivity) and RBS. Films on glass substrates were amorphous and on FTO (flourine doped tin oxide coated) glass substrates were polycrystalline (element of phase). The optical band gap of In{sub 2}S{sub 3} thin film was estimated to be 2.75 eV. The as-deposited films were photoactive as evidenced by TRMC studies. The presence of oxygen in the film was detected by RBS analysis. (orig.) 27 refs.

  5. Understanding the shrinkage of optical absorption edges of nanostructured Cd-Zn sulphide films for photothermal applications

    Energy Technology Data Exchange (ETDEWEB)

    Hossain, Md. Sohrab [Department of Physics, Jahangirnagar University, Savar, Dhaka 1342 (Bangladesh); Kabir, Humayun [Department of Physics, Jahangirnagar University, Savar, Dhaka 1342 (Bangladesh); School of Metallurgy and Materials, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom); Rahman, M. Mahbubur, E-mail: M.Rahman@Murdoch.edu.au [Department of Physics, Jahangirnagar University, Savar, Dhaka 1342 (Bangladesh); Surface Analysis and Materials Engineering Research Group, School of Engineering & Information Technology, Murdoch University, Perth, Western Australia 6150 (Australia); Hasan, Kamrul [Department of Chemistry, College of Sciences, University of Sharjah, P.O. Box 27272, Sharjah (United Arab Emirates); Bashar, Muhammad Shahriar; Rahman, Mashudur [Institute of Fuel and Research Development, Bangladesh Council for Scientific and Industrial Research, Dhanmondi, Dhaka (Bangladesh); Gafur, Md. Abdul [Pilot Plant and Process Development Center, Bangladesh Council for Scientific and Industrial Research, Dhanmondi, Dhaka (Bangladesh); Islam, Shariful [Department of Physics, Comilla University, Comilla (Bangladesh); Amri, Amun [Department of Chemical Engineering, Universitas Riau, Pekanbaru (Indonesia); Jiang, Zhong-Tao [Surface Analysis and Materials Engineering Research Group, School of Engineering & Information Technology, Murdoch University, Perth, Western Australia 6150 (Australia); Altarawneh, Mohammednoor; Dlugogorski, Bogdan Z. [School of Engineering & Information Technology, Murdoch University, Murdoch, WA 6150 (Australia)

    2017-01-15

    Highlights: • Cd-Zn sulphide films synthesized via chemical bath deposition technique. • Nanocrystalline phase of Cd-Zn sulphide films were seen in XRD studies. • Nanocrystalline structures of the films were also confirmed by the SEM. • The band gap of these films is a combination of composition and size. • E{sub U} and σ studies ascribed the shrinkage of absorption edges around the optical band-gaps. - Abstract: In this article Cd-Zn sulphide thin films deposited onto soda lime glass substrates via chemical bath deposition (CBD) technique were investigated for photovoltaic applications. The synthesized films were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), and ultraviolet visible (UV–vis) spectroscopic methodologies. A higher degree of crystallinity of the films was attained with the increase of film thicknesses. SEM micrographs exhibited a partial crystalline structure with a particulate appearance surrounded by the amorphous grain boundaries. The optical absorbance and absorption coefficient of the films were also enhanced significantly with the increase in film thicknesses. Optical band-gap analysis indicated a monotonic decrease in direct and indirect band-gaps with the increase of thicknesses of the films. The presence of direct and indirect transitional energies due to the exponential falling edges of the absorption curves may either be due to the lack of long-range order or to the existence of defects in the films. The declination of the optical absorption edges was also confirmed via Urbach energy and steepness parameters studies.

  6. Effect of annealing on the properties of spray-pyrolysed lead sulphide thin films for solar cell application

    Science.gov (United States)

    Veena, E.; Bangera, Kasturi V.; Shivakumar, G. K.

    2017-05-01

    Annealing is the most important processing parameter perhaps as it directly affects the properties of the thin films. In the present article, lead sulphide thin films composed of (2 0 0) plane-oriented nano-rods were successfully synthesized on glass substrates using spray pyrolysis technique at annealing temperature 350 °C. Films were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive analysis by X-ray (EDAX), UV-VIS-NIR spectrometry and two-probe experiments. The X-ray diffraction study confirmed that films exhibiting face-centred cubic structure with a preferred orientation along (2 0 0) plane were independent of annealing temperature. SEM photographs revealed the formation of nano-rods. The possible formation of nano-rods and its dependency on optical and electrical properties were discussed. Chemical composition in terms of atomic ratio of the constituents is determined from EDAX studies. The optical band gap of the lead sulphide thin films was found to decrease from 1.22 to 0.98 eV with an increase in annealing temperature. The electrical conductivity of the films at room temperature was of the order of 10-2 Ω-1 cm-1 with the low activation energy. Results prove that lead sulphide films grown by chemical method appeal its adoptability for potential solar cell applications.

  7. Gallium-lanthanum-sulphide amorphous thin films prepared by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Nemec, P., E-mail: Petr.Nemec@upce.cz [Department of General and Inorganic Chemistry, Faculty of Chemical Technology, University of Pardubice, Legions Sq. 565, 53210 Pardubice (Czech Republic); Nazabal, V., E-mail: virginie.nazabal@univ-rennes1.fr [Equipe Verres et Ceramiques, UMR-CNRS 6226, Sciences Chimiques de Rennes (SCR), Universite de Rennes 1, 35042 Rennes (France); Pavlista, M., E-mail: martin.pavlista@upce.cz [Department of Physics, Faculty of Chemical Technology, University of Pardubice, Studentska 84, 53210 Pardubice (Czech Republic); Moreac, A., E-mail: alain.moreac@univ-rennes1.fr [GMCM, UMR-CNRS 6626, Universite de Rennes 1, 35042 Rennes (France); Frumar, M., E-mail: miloslav.frumar@upce.cz [Department of General and Inorganic Chemistry, Faculty of Chemical Technology, University of Pardubice, Legions Sq. 565, 53210 Pardubice (Czech Republic); Vlcek, M., E-mail: milan.vlcek@upce.cz [Joint Laboratory of Solid State Chemistry of the University of Pardubice and the Institute of Macromolecular Chemistry of Acad. Sci. of the Czech Republic, Studentska 84, 53210 Pardubice (Czech Republic)

    2009-09-15

    Thin amorphous gallium-lanthanum-sulphide films were prepared by pulsed laser deposition method. The prepared layers were characterized in terms of the structure (using Raman scattering spectroscopy), chemical composition (by energy-dispersive X-ray analysis), and optical properties (employing variable angle spectroscopic ellipsometry). Following Raman spectroscopy results, it is supposed that the structure of the bulk glass and corresponding thin films is formed by GaS{sub 4} tetrahedra and LaS{sub 8} structural units. The study of photo- and thermally induced phenomena in prepared amorphous chalcogenides shows photoinduced decrease of refractive index ({approx}1-2%) under cw (473 nm) or pulsed (248 nm) laser irradiation and annealing-induced decrease of refractive index ({approx}2%), respectively.

  8. Extremophiles in Mineral Sulphide Heaps: Some Bacterial Responses to Variable Temperature, Acidity and Solution Composition

    Directory of Open Access Journals (Sweden)

    Helen R. Watling

    2015-07-01

    Full Text Available In heap bioleaching, acidophilic extremophiles contribute to enhanced metal extraction from mineral sulphides through the oxidation of Fe(II and/or reduced inorganic sulphur compounds (RISC, such as elemental sulphur or mineral sulphides, or the degradation of organic compounds derived from the ore, biota or reagents used during mineral processing. The impacts of variable solution acidity and composition, as well as temperature on the three microbiological functions have been examined for up to four bacterial species found in mineral sulphide heaps. The results indicate that bacteria adapt to sufficiently high metal concentrations (Cu, Ni, Co, Zn, As to allow them to function in mineral sulphide heaps and, by engaging alternative metabolic pathways, to extend the solution pH range over which growth is sustained. Fluctuating temperatures during start up in sulphide heaps pose the greatest threat to efficient bacterial colonisation. The large masses of ores in bioleaching heaps mean that high temperatures arising from sulphide oxidation are hard to control initially, when the sulphide content of the ore is greatest. During that period, mesophilic and moderately thermophilic bacteria are markedly reduced in both numbers and activity.

  9. High rate deposition of thin film cadmium sulphide by pulsed direct current magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Lisco, F., E-mail: F.Lisco@lboro.ac.uk [Centre for Renewable Energy Systems Technology (CREST), School of Electronic, Electrical and Systems Engineering, Loughborough University, Leicestershire LE11 3TU (United Kingdom); Kaminski, P.M.; Abbas, A.; Bowers, J.W.; Claudio, G. [Centre for Renewable Energy Systems Technology (CREST), School of Electronic, Electrical and Systems Engineering, Loughborough University, Leicestershire LE11 3TU (United Kingdom); Losurdo, M. [Institute of Inorganic Methodologies and of Plasmas, IMIP-CNR, via Orabona 4, 70126 Bari (Italy); Walls, J.M. [Centre for Renewable Energy Systems Technology (CREST), School of Electronic, Electrical and Systems Engineering, Loughborough University, Leicestershire LE11 3TU (United Kingdom)

    2015-01-01

    Cadmium Sulphide (CdS) is an important n-type semiconductor widely used as a window layer in thin film photovoltaics Copper Indium Selenide, Copper Indium Gallium (di)Selenide, Copper Zinc Tin Sulphide and Cadmium Telluride (CdTe). Cadmium Sulphide has been deposited using a number of techniques but these techniques can be slow (chemical bath deposition and Radio Frequency sputtering) or the uniformity and the control of thickness can be relatively difficult (close space sublimation). In this paper we report on the development of a process using pulsed Direct Current magnetron sputtering which allows nanometre control of thin film thickness using time only. The CdS thin films deposited in this process are highly uniform and smooth. They exhibit the preferred hexagonal structure at room temperature deposition and they have excellent optical properties. Importantly, the process is highly stable despite the use of a semi-insulating magnetron target. Moreover, the process is very fast. The deposition rate using 1.5 kW of power to a 6-inch circular magnetron was measured to be greater than 8 nm/s. This makes the process suitable for industrial deployment. - Highlights: • Pulsed DC magnetron sputtering of CdS • High deposition rate deposition • Uniform, pinhole free films.

  10. High rate deposition of thin film cadmium sulphide by pulsed direct current magnetron sputtering

    International Nuclear Information System (INIS)

    Lisco, F.; Kaminski, P.M.; Abbas, A.; Bowers, J.W.; Claudio, G.; Losurdo, M.; Walls, J.M.

    2015-01-01

    Cadmium Sulphide (CdS) is an important n-type semiconductor widely used as a window layer in thin film photovoltaics Copper Indium Selenide, Copper Indium Gallium (di)Selenide, Copper Zinc Tin Sulphide and Cadmium Telluride (CdTe). Cadmium Sulphide has been deposited using a number of techniques but these techniques can be slow (chemical bath deposition and Radio Frequency sputtering) or the uniformity and the control of thickness can be relatively difficult (close space sublimation). In this paper we report on the development of a process using pulsed Direct Current magnetron sputtering which allows nanometre control of thin film thickness using time only. The CdS thin films deposited in this process are highly uniform and smooth. They exhibit the preferred hexagonal structure at room temperature deposition and they have excellent optical properties. Importantly, the process is highly stable despite the use of a semi-insulating magnetron target. Moreover, the process is very fast. The deposition rate using 1.5 kW of power to a 6-inch circular magnetron was measured to be greater than 8 nm/s. This makes the process suitable for industrial deployment. - Highlights: • Pulsed DC magnetron sputtering of CdS • High deposition rate deposition • Uniform, pinhole free films

  11. Crystalline Indium Sulphide thin film by photo accelerated deposition technique

    Science.gov (United States)

    Dhanya, A. C.; Preetha, K. C.; Deepa, K.; Remadevi, T. L.

    2015-02-01

    Indium sulfide thin films deserve special attention because of its potential application as buffer layers in CIGS based solar cells. Highly transparent indium sulfide (InS) thin films were prepared using a novel method called photo accelerated chemical deposition (PCD). Ultraviolet source of 150 W was used to irradiate the solution. Compared to all other chemical methods, PCD scores its advantage for its low cost, flexible substrate and capable of large area of deposition. Reports on deposition of high quality InS thin films at room temperature are very rare in literature. The precursor solution was initially heated to 90°C for ten minutes and then deposition was carried out at room temperature for two hours. The appearance of the film changed from lemon yellow to bright yellow as the deposition time increased. The sample was characterized for its structural and optical properties. XRD profile showed the polycrystalline behavior of the film with mixed phases having crystallite size of 17 nm. The surface morphology of the films exhibited uniformly distributed honey comb like structures. The film appeared to be smooth and the value of extinction coefficient was negligible. Optical measurements showed that the film has more than 80% transmission in the visible region. The direct band gap energy was 2.47eV. This method is highly suitable for the synthesis of crystalline and transparent indium sulfide thin films and can be used for various photo voltaic applications.

  12. Synthesis and characterization of nanocrystalline zinc sulphide thin films by chemical spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Offor, P.O., E-mail: Peter.offor@unn.edu.ng [Metallurgical and Materials Engineering Department, University of Nigeria, Nsukka (Nigeria); Okorie, B.A. [Metallurgical and Materials Engineering Department, University of Nigeria, Nsukka (Nigeria); Ezema, F.I. [Crystal Growth and Characterization Laboratory, Department of Physics and Astronomy, University of Nigeria, Nsukka (Nigeria); Aigbodion, V.S., E-mail: victor.aigbodion@unn.edu.ng [Metallurgical and Materials Engineering Department, University of Nigeria, Nsukka (Nigeria); Daniel-Mkpume, C.C.; Omah, A.D. [Metallurgical and Materials Engineering Department, University of Nigeria, Nsukka (Nigeria)

    2015-11-25

    This work reports the structural, morphological and optical properties of zinc sulphide (ZnS) thin films obtained by chemical spray pyrolysis (CSP) technique using zinc chloride as cationic and thiourea as anionic source with ethylene-diamine tetra acetate (EDTA) complex. The ZnS thin films were deposited on glass substrate at 300 °C, 400 °C and 450 °C. The influence of the substrate temperatures on the structural, morphological and optical properties was studied. The XRD spectra show that the film is nanocrystalline with peak intensity increasing with temperature. The morphology of the films was seen by scanning electron microscopy (SEM). The films dislocation density and micro strain increased with temperature. Optical properties show a high transmittance which increased with temperature. - Highlights: • The structural, morphological and optical properties of zinc sulphide (ZnS) thin films. • The ZnS thin films were deposited on glass substrate at 300 °C, 400 °C and 450 °C. • The influence of the substrate temperatures on the structural, morphological. • The films dislocation density and micro strain increased with temperature. • Optical properties show a high transmittance which increased with temperature.

  13. Optical Properties of Silver Aluminium Sulphide Ternary Thin Films ...

    African Journals Online (AJOL)

    NaOH served as pH adjuster. The films were deposited at 300K of temperature. The deposited film properties were studied using a Janway UV – VIS spectrophotometer. From the spectral analysis of absorbance and transmittance, the optical and solid properties were obtained. The properties studied include the reflectance, ...

  14. Electron beam evaporation deposition of cadmium sulphide and cadmium telluride thin films: Solar cell applications

    International Nuclear Information System (INIS)

    Fang Li; Chen Jing; Xu Ling; Xu Jun; Ma Zhong-Yuan; Su Wei-Ning; Yu Yao

    2013-01-01

    Cadmium sulphide (CdS) and cadmium telluride (CdTe) thin films are deposited by electron beam evaporation. Atomic force microscopy (AFM) reveals that the root mean square (RMS) roughness values of the CdS films increase as substrate temperature increases. The optical band gap values of CdS films increase slightly with the increase in the substrate temperature, in a range of 2.42–2.48 eV. The result of Hall effect measurement suggests that the carrier concentration decreases as the substrate temperature increases, making the resistivity of the CdS films increase. CdTe films annealed at 300°C show that their lowest transmittances are due to their largest packing densities. The electrical characteristics of CdS/CdTe thin film solar cells are investigated in dark conditions and under illumination. Typical rectifying and photovoltaic properties are obtained. (interdisciplinary physics and related areas of science and technology)

  15. Photography - Determination of thiosulphate and other residual chemicals in processed photographic films, plates and papers - Methylene blue photometric method and silver sulphide densitometric method

    CERN Document Server

    International Organization for Standardization. Geneva

    1977-01-01

    Photography - Determination of thiosulphate and other residual chemicals in processed photographic films, plates and papers - Methylene blue photometric method and silver sulphide densitometric method

  16. Optical and electrical properties of chemical bath deposited cobalt sulphide thin films

    Energy Technology Data Exchange (ETDEWEB)

    Govindasamy, Geetha [R& D Centre, Bharathiar University, Coimbatore (India); Murugasen, Priya, E-mail: priyamurugasen15@gmail.com [Department of Physics, Saveetha Engineering, Chennai, Tamil Nadu (India); Sagadevan, Suresh [Department of Physics, AMET University, Chennai, Tamil Nadu (India)

    2017-01-15

    Cobalt sulphide (CoS) thin films were synthesized using the Chemical Bath Deposition (CBD) technique. X-ray diffraction (XRD) analysis was used to study the structure and the crystallite size of CoS thin film. Scanning Electron Microscope (SEM) studies reveal the surface morphology of these films. The optical properties of the CoS thin films were determined using UV-Visible absorption spectrum. The optical band gap of the thin films was found to be 1.6 eV. Optical constants such as the refractive index, the extinction coefficient and the electric susceptibility were determined. The dielectric studies were carried out at different frequencies and at different temperatures for the prepared CoS thin films. In addition, the plasma energy of the valence electron, Penn gap or average energy gap, the Fermi energy and electronic polarizability of the thin films were determined. The AC electrical conductivity measurement was also carried out for the thin films. The activation energy was determined by using DC electrical conductivity measurement. (author)

  17. Synthesis and characterization of copper antimony tin sulphide thin films for solar cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Ali, N., E-mail: nisar.ali@utm.my [Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, UTM Skudai, 81310 Johor (Malaysia); Department of Physics, Govt. Post Graduate Jehanzeb College Saidu Sharif, Swat, 19200 (Pakistan); Hussain, A. [Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, UTM Skudai, 81310 Johor (Malaysia); Ahmed, R., E-mail: rashidahmed@utm.my [Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, UTM Skudai, 81310 Johor (Malaysia); Wan Shamsuri, W.N. [Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, UTM Skudai, 81310 Johor (Malaysia); Fu, Y.Q., E-mail: richard.fu@northumbria.ac.uk [Department of Physics and Electrical Engineering, Faculty of Engineering & Environment, University of Northumbria, Newcastle upon Tyne, NE1 8ST (United Kingdom)

    2016-12-30

    Highlights: • A new and novel material for solar cell applications is demonstrated as a replacement for toxic and expansive compounds. • The materials used in this compound are abundant and low cost. • Compound exhibit unusual optical and electrical properties. • The band gap was found to be comparable with that of GaAs. - Abstract: Low price thin film modules based on Copper antimony tin sulphide (CATS) are introduced for solar harvesting to compete for the already developed compound semiconductors. Here, CATS thin films were deposited on soda lime glass by thermal evaporation technique followed by a rapid thermal annealing in an argon atmosphere. From Our XRD analysis, it was revealed that the annealed samples were poly-crystalline and their crystallinity was improved with increasing annealing temperature. The constituent elements and their corresponding chemical states were identified using X-ray photoelectron spectroscopy. The obtained optical band gap of 1.4 eV for CATS thin film is found nearly equal to GaAs – one of the highly efficient thin film material for solar cell technology. Furthermore, our observed good optical absorbance and low transmittance for the annealed CATS thin films in the visible region of light spectrum assured the aptness of the CATS thin films for solar cell applications.

  18. Optical properties of silver sulphide thin films formed on evaporated Ag by a simple sulphurization method

    Energy Technology Data Exchange (ETDEWEB)

    Barrera-Calva, E., E-mail: ebc@xanum.uam.m [Departamento de Ingenieria de Procesos e hidraulica, Universidad Autonoma Metropolitana - Iztapalapa, Av. Purisima Esq. Michoacan, Col. Vicentina, Mexico, D.F., 09340 (Mexico); Ortega-Lopez, M.; Avila-Garcia, A.; Matsumoto-Kwabara, Y. [Departamento de Ingenieria Electrica, Centro de Investigacion y de Estudios Avanzados del IPN, Mexico DF 07360 (Mexico)

    2010-01-31

    Silver sulphide (Ag{sub 2}S) thin films were grown on the surface of silver films (Ag) deposited on glass substrate by using a simple chemical sulphurization method. According to X-ray diffraction analysis, the Ag{sub 2}S thin films display low intensity peaks at 34.48{sup o}, 36.56{sup o}, and 44.28{sup o}, corresponding to diffraction from (100), (112) and (103) planes of the acanthite phase (monoclinic). A model of the type Ag{sub 2}S/Ag/glass was deduced from spectroscopic ellipsometric measurements. Also, the optical constants (n, k) of the system were determined. Furthermore, the optical properties as solar selective absorber for collector applications were assessed. The optical reflectance of the Ag{sub 2}S/Ag thin film systems exhibits the expected behavior for an ideal selective absorber, showing a low reflectance in the wavelength range below 2 {mu}m and a high reflectance for wavelengths higher than that value. An absorptance about 70% and an emittance about 3% or less were calculated for several samples.

  19. Natural weathering effects on the mechanical and surface properties of polyphenylene sulphide (PPS) composites

    Energy Technology Data Exchange (ETDEWEB)

    Sinmazcelik, Tamer [Mechanical Engineering Department, Kocaeli University, Veziroglu Campus, izmit 41040 (Turkey): TUBITAK-MRC, MCTRI, P.O. Box 21, 41470 Gebze (Turkey)]. E-mail: tamersc@yahoo.com

    2006-07-01

    In this paper, Natural weathering effects on the mechanical and surface properties of polyphenylene sulphide (PPS) composites were studied. Injection moulded short glass fibre and short glass fibre/calcium carbonate particle filled (hybrid) PPS composites were investigated. These specimens were subjected to natural weathering in izmit, Turkey for 3216 h. Instrumented charpy impact tests were performed on a charpy pendulum type tester. The surfaces of the samples were examined by scanning electron microscopy (SEM). It is demonstrated that particle reinforcement (additional to the random oriented short glass fibre) reduces the impact performance of composite material but the material becomes more resistant to weathering. Percentage decrease in the impact strength after natural weathering of fibre/particle filled PPS composite is smaller compared to short fibre filled PPS composite. On the other hand, surface morphology of CaCO{sub 3} particle reinforced PPS composite is affected less from natural weathering and this material should be considered for outdoor applications.

  20. Fabrication, thermal and electrical properties of polyphenylene sulphide/copper composites

    International Nuclear Information System (INIS)

    Goyal, R.K.; Kambale, K.R.; Nene, S.S.; Selukar, B.S.; Arbuj, S.; Mulik, U.P.

    2011-01-01

    Highlights: → Polyphenylene sulphide/copper composites show a low percolation threshold, i.e., about 6 vol% Cu. → Both pre- and post- glass transition coefficient of thermal expansion (CTE) of composites decreased significantly. → The microhardness was increased by more than 50% compared to pure PPS matrix. → The electrical conductivity was increased by about eight orders of magnitude for 18 vol% Cu composite. → Dielectric constant and dissipation factor of composites measured at MHz was increased to about 6-fold and 70-fold compared to PPS matrix. - Abstract: The thermal and electrical properties of high performance poly(phenylene sulphide) (PPS) composites reinforced up to 31 vol% Cu particles were investigated to be used as materials for electronic applications. The thermal stability and char yield of the composites increased significantly. Both pre- and post- glass transition coefficient of thermal expansion (CTE) of composites decreased significantly. The microhardness was increased by more than 50% compared to pure PPS matrix. Microhardness and CTE of composites correlated well with the rule of mixtures. A percolation threshold about 6 vol% Cu was obtained. The electrical conductivity was increased by about eight orders of magnitude for 18 vol% composite. Dielectric constant and dissipation factor of composites at 1 MHz was increased by about 6-fold and 70-fold compared to matrix, respectively. They decreased gradually with increasing frequency up to 1 MHz and thereafter, there was insignificant change. The scanning electron microscope showed almost uniform distribution of Cu particles in the matrix. Owing to better dimensional stability and good electrical properties, these composites are very promising for electronic applications.

  1. The Effect of Substrate Temperature on the Structural Properties of Spray Pyrolysed Lead Sulphide (PbS Thin Films

    Directory of Open Access Journals (Sweden)

    Mohammad G. Faraj

    2014-09-01

    Full Text Available Lead sulphide (PbS films were prepared by the chemical spray pyrolysis technique using a solution of Lead nitrate and thiourea. PbS films were deposited (prepared on glass substrate at varied temperature (250-350 oC. Effects of substrate temperature on the structural characteristics of the films were studied. The X-ray diffraction patterns’ results reveal that the all of PbS films have a face centered cubic structure. The X-ray diffraction study showed that irrespective of substrate temperature all the films exhibits a preferred orientation along the (200 plane. The degree of preferred orientation increased with the substrate temperature. It was observed that the increase of the substrate temperature increase the diffraction peak intensity of (200 plane which resulted in increase in grain size and good crystallinity of the films.

  2. Simultaneous Hydrogen Sulphide and Carbon Dioxide Removal from Biogas by Water–Swollen Reverse Osmosis Membrane.

    OpenAIRE

    Izák, Pavel

    2016-01-01

    The simultaneous removal of carbon dioxide and hydrogen sulphide was studied for agrobiogas pre-treatment, using water–swollen thin hydrophilic film composites (TFC) based on industrially produced membranes.

  3. Growth and characterization of tin sulphide thin films by chemical bath deposition using ethylene diamine tetra-acetic acid as the complexing agent

    Energy Technology Data Exchange (ETDEWEB)

    Jayasree, Y.; Chalapathi, U.; Sundara Raja, V., E-mail: sundararajav@rediffmail.com

    2013-06-30

    Tin sulphide (SnS), a promising, non-toxic and low-cost solar cell absorber layer, is grown using Chemical Bath Deposition technique at room temperature. The effects of concentration of ethlene diamine tetra-acetic acid, the complexing agent in the starting solution, as well as thioacetamide, the source of sulphur, on the growth of tin sulphide films are investigated to obtain single phase SnS films. The films deposited under optimized conditions are found to be near-stoichiometric, single phase SnS with orthorhombic structure. The lattice parameters are found to be a = 0.428 nm, b = 1.141 nm and c = 0.396 nm. The direct optical band gap of these films is found to be 1.55 eV. - Highlights: • Growth of SnS, a potential solar cell absorber layer, by chemical bath deposition • Ethylenediaminetetraacetic acid (EDTA) as complexing agent for SnS film growth • Effect of EDTA concentration on the growth and properties of tin sulphide films • Effect of thioacetamide concentration on the growth and properties of films • X-ray diffraction and Raman Spectra studies for phase analysis.

  4. Development of molecular precursors for deposition of indium sulphide thin film electrodes for photoelectrochemical applications.

    Science.gov (United States)

    Ehsan, Muhammad Ali; Peiris, T A Nirmal; Wijayantha, K G Upul; Olmstead, Marilyn M; Arifin, Zainudin; Mazhar, Muhammad; Lo, K M; McKee, Vickie

    2013-08-14

    Symmetrical and unsymmetrical dithiocarbamato pyridine solvated and non-solvated complexes of indium(III) with the general formula [In(S2CNRR')3]·n(py) [where py = pyridine; R,R' = Cy, n = 2 (1); R,R' = (i)Pr, n = 1.5 (2); NRR' = Pip, n = 0.5 (3) and R = Bz, R' = Me, n = 0 (4)] have been synthesized. The compositions, structures and properties of these complexes have been studied by means of microanalysis, IR and (1)H-NMR spectroscopy, X-ray single crystal and thermogravimetric (TG/DTG) analyses. The applicability of these complexes as single source precursors (SSPs) for the deposition of β-In2S3 thin films on fluorine-doped SnO2 (FTO) coated conducting glass substrates by aerosol-assisted chemical vapour deposition (AACVD) at temperatures of 300, 350 and 400 °C is studied. All films have been characterized by powder X-ray diffraction (PXRD) and energy dispersive X-ray analysis (EDX) for the detection of phase and stoichiometry of the deposit. Scanning electron microscopy (SEM) studies reveal that precursors (1)-(4), irrespective of different metal ligand design, generate comparable morphologies of β-In2S3 thin films at different temperatures. Direct band gap energies of 2.2 eV have been estimated from the UV-vis spectroscopy for the β-In2S3 films fabricated from precursors (1) and (4). The photoelectrochemical (PEC) properties of β-In2S3 were confirmed by recording the current-voltage plots under light and dark conditions. The plots showed anodic photocurrent densities of 1.25 and 0.65 mA cm(-2) at 0.23 V vs. Ag/AgCl for the β-In2S3 films made at 400 and 350 °C from the precursors (1) and (4), respectively. The photoelectrochemical performance indicates that the newly synthesised precursors are highly useful in fabricating β-In2S3 electrodes for solar energy harvesting and optoelectronic application.

  5. Preparation of copper sulphide clusters in organic–inorganic ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 113; Issue 2. Preparation of copper sulphide clusters in organic-inorganic composites of Langmuir-Blodgett films of amphiphilic Schiff bases. G Hemakanthi Aruna Dhathathreyan T Ramasami D Möbius. Physical and Theoretical Volume 113 Issue 2 April 2001 pp 147- ...

  6. Estimation of Wear Behavior of Polyphenylene Sulphide Composites Reinforced with Glass/Carbon Fibers, Graphite and Polytetrafluoroethylene, by Pin-on-disc Test

    Directory of Open Access Journals (Sweden)

    M.A.C. Besnea

    2015-03-01

    Full Text Available Wear behavior of polyphenylene sulphide composites was investigated according to load and test speed. Two types of materials were studied: first, with 40 wt% glass fiber, and second, with 10 wt% carbon fiber, 10 wt% graphite and 10 wt%. Tribological tests were performed on the universal tribometer UMT-2, using a pin-on-disc device. The friction coefficient and wear rate for the composites were analyzed. As a result of experimental tests, it was established that polymer composite with polyphenylene sulphide matrix, carbon fibers, graphite and polytetrafluorethylene exhibit good wear behavior under operating conditions.

  7. Gallium-lanthanum-sulphide amorphous thin films prepared by pulsed laser deposition

    Czech Academy of Sciences Publication Activity Database

    Němec, P.; Nazabal, V.; Pavlišta, M.; Moreac, A.; Frumar, M.; Vlček, Milan

    2009-01-01

    Roč. 117, č. 1 (2009), s. 23-25 ISSN 0254-0584 Institutional research plan: CEZ:AV0Z40500505 Keywords : chalcogenides * thin film Subject RIV: CA - Inorganic Chemistry Impact factor: 2.015, year: 2009

  8. A high-porosity carbon molybdenum sulphide composite with enhanced electrochemical hydrogen evolution and stability

    DEFF Research Database (Denmark)

    Laursen, Anders B.; Vesborg, Peter C. K.; Chorkendorff, Ib

    2013-01-01

    This work describes a highly active and stable acid activated carbon fibre and amorphous MoSx composite hydrogen evolution catalyst. The increased electrochemical-surface area is demonstrated to cause increased catalyst electrodeposition and activity. These composite electrodes also show...

  9. The effect of thermal annealing on the optical band gap of cadmium sulphide thin films, prepared by the chemical bath deposition technique

    International Nuclear Information System (INIS)

    Ampong, F. K.; Boakye, F.; Asare Donkor, N. K.

    2010-01-01

    Cadmium sulphide thin films have been prepared by the chemical bath deposition technique (ph 11, 70 degree centigrade). Two different sets of films were prepared under varied conditions and concentrations of their ions sources (Cd 2+ from cadmium nitrate, S 2- from thiourea) and Na 2 EDTA as a complexing agent. A UV mini-Schimazu UV-VIS Spectrophotometer was used to determine the optical absorbance of the films as a function of wavelength at room temperature over the wavelength range 200 - 600 nm. The samples were then thermally annealed for thirty minutes, at temperatures of 100 degree centigrade, and 200 degree centigrade, after which the absorbance of the films were again recorded. The band gap values obtained for the sample with 0.5 M CdS as deposited, annealed at 100 degree centigrade and 200 degree centigrade were 2.1 eV, 2.2 eV and 2.3 eV respectively. Whilst the values obtained for the sample 0.15 CdS as deposited, annealed at 100 degree centigrade and annealed at 200 degree centigrade were 2.0 eV, 2.01 eV and 2.02 eV respectively. The increase in band gap with annealing temperature might be attributed to the improvement in crystallinity in the films. (au)

  10. Properties of gallium lanthanum sulphide glass

    OpenAIRE

    Bastock, P.; Craig, C.; Khan, K.; Weatherby, E.; Yao, J.; Hewak, D.W.

    2015-01-01

    A series of gallium lanthanum sulphide (GLS) glasses has been studied in order to ascertain properties across the entire glass forming region. This is the first comprehensive study of GLS glass over a wide compositional range.

  11. Application of composition modulated thin films

    International Nuclear Information System (INIS)

    Hilliard, J.E.

    1979-01-01

    Film produced by evaporating two components through a rotating pinwheel shutter which cuts off the vapor first from one source and then the other are evaluated. These films have a modulated composition rather than a layered structure. Mechanical properties were determined using a bulge tester

  12. High-Performance Cellulose Nanofibril Composite Films

    Science.gov (United States)

    Yan Qing; Ronald Sabo; Yiqiang Wu; Zhiyong Cai

    2012-01-01

    Cellulose nanofibril/phenol formaldehyde (CNF/PF) composite films with high work of fracture were prepared by filtering a mixture of 2,2,6,6tetramethylpiperidine-1-oxyl (TEMPO) oxidized wood nanofibers and water-soluble phenol formaldehyde with resin contents ranging from 5 to 20 wt%, followed by hot pressing. The composites were characterized by tensile testing,...

  13. Synthesis of cadmium sulphide in pure and mixed Langmuir ...

    Indian Academy of Sciences (India)

    sodium sulphide (Na2S) with Langmuir–Blodgett (LB) films of cadmium salts of n- octadecylsuccinic acid (ODSU) and with LB films of ODSU in mixtures of octadecylamine and octadecyl alcohol. The results indicate that heterogeneous nucleation and aggregation in the pure ODSU LB films due to processes like Ostwald.

  14. Development of high energy density supercapacitor through hydrothermal synthesis of RGO/nano-structured cobalt sulphide composites.

    Science.gov (United States)

    Jana, Milan; Saha, Sanjit; Samanta, Pranab; Murmu, Naresh Chandra; Kim, Nam Hoon; Kuila, Tapas; Lee, Joong Hee

    2015-02-20

    Co9S8/reduced graphene oxide (RGO) composites were prepared on nickel foam substrate through hydrothermal reaction and used directly as supercapacitor electrode. The field emission scanning electron microscopy analysis of the composites showed the formation of Co9S8 nano-rods on the RGO surfaces. The average crystal size of the Co9S8 nano rods grown on the RGO sheets were ∼25-36 nm as calculated from x-ray diffraction analysis. The reduction of graphene oxide (GO) was confirmed by Raman and x-ray photoelectron spectroscopy analysis. The electrical conductivity of the Co9S8/RGO composite was recorded as 1690 S m(-1) at room temperature, which is much higher than that of pure GO further confirming the hydrothermal reduction of GO. Cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy were investigated to check the electrochemical performances of the Co9S8/RGO composites. The Co9S8/RGO composites supported on nickel foam showed very high specific capacitance (Sc)(1349 F g(-1) at a current density of 2.2 A g(-1)), energy density (68.6 W h kg(-1)) and power density (1319 W kg(-1)) in 6 M KOH electrolyte. The retention in Sc of the composite electrode was found to be ∼96% after 1000 charge-discharge cycles.

  15. Biotechnological sulphide removal with oxygen

    NARCIS (Netherlands)

    Buisman, C.

    1989-01-01

    This thesis deals with the development of a new process for biotechnological sulphide removal from wastewater, in which it is attempted to convert sulphide into elemental sulphur by colourless sulphur bacteria. The toxicity, corrosive properties, unpleasant odor and high oxygen demand of sulphide

  16. Investigation of sulphides in iron alloys of high purity

    International Nuclear Information System (INIS)

    Wyjadlowski, T.

    1973-01-01

    This research thesis reports the study of the morphology and composition of sulphides in iron alloys with respect to metal composition and to the nature of impurities. In order to understand the specific action of each addition on inclusion morphology, this work has started with high-purity alloys (binary alloys and then ternary alloys). The author studied whether solubility variations would entail either intergranular or intragranular or hybrid iron sulphide precipitation. He examined whether sulphide morphology is depending on thermal treatment, and whether equilibrium precipitates were different in terms of morphology and composition at high and room temperature. He studied the influence of addition elements on sulphide morphology and composition, an important issue as some elements may reduce brittleness. These elements are classified in terms of affinity with sulphur

  17. THE COMPOSITE COMPONENT PROPERTY RELATIONSHIP OF PLASTIC FILMS.

    Science.gov (United States)

    The relationship of certain properties of composite plastic films to the properties of the plastic films comprising their structure was studied. It...was ascertained that tensile, tearing strength, puncture resistance and moisture vapor transmission rates of composite films can be closely

  18. Precipitation of metal sulphides using gaseous hydrogen sulphide : mathematical modelling

    NARCIS (Netherlands)

    Tarazi, Mousa Al-; Heesink, A. Bert M.; Versteeg, Geert F.

    2004-01-01

    A mathematical model has been developed that describes the precipitation of metal sulphides in an aqueous solution containing two different heavy metal ions. The solution is assumed to consist of a well-mixed bulk and a boundary layer that is contacted with hydrogen sulphide gas. The model makes use

  19. Effect of pre-heating composites on film thickness

    OpenAIRE

    Goulart, Marcelo; Damin, Deisi Fátima; Melara, Rafael; Conceição, Andréa de Azevedo Brito

    2013-01-01

    Resin composite has been suggested as a luting material for aesthetic indirect restorations and temperature affects material viscosity. Reports of film thickness from new composites are important. The aim of this study was to analyze the influence of pre-heating two resin composites on its film thickness in order to use it as a luting agent for indirect restorations (inlays and onlays). Three materials were divided into 5 groups. Two resin composites, nanofilled (Z350 XT/3MESPE) and microhybr...

  20. Fabrication of carbon film composites for high-strength structures

    Science.gov (United States)

    Preiswerk, P. R.; Lippman, M.

    1972-01-01

    Physical and mechanical properties of fiber composite materials consisting of carbon films are described. Application of carbon film structural composites for constructing microwave filters or optical instruments is proposed. Applications in aerospace and architectural structures for high strength and low density properties are discussed.

  1. Electron beam induced modifications of bismuth sulphide (Bi{sub 2}S{sub 3}) thin films: Structural and optical properties

    Energy Technology Data Exchange (ETDEWEB)

    Subramanian, S. [M. D. T. Hindu College, Tirunelveli 627 010 (India); Balaji, M.; Chithra lekha, P. [Department of Physics, Manonmaniam Sundaranar University, Tirunelveli 627 012, Tamil Nadu (India); Sanjeev, Ganesh [Microtron Centre, Mangalore University, Mangalore 574 199 (India); Subramanian, E. [Department of Chemistry, Manonmaniam Sundaranar University, Tirunelveli 627 012 (India); Pathinettam Padiyan, D., E-mail: dppadiyan@sancharnet.i [Department of Physics, Manonmaniam Sundaranar University, Tirunelveli 627 012, Tamil Nadu (India)

    2010-11-15

    Thin films of Bi{sub 2}S{sub 3} prepared by electrodeposition method are subjected to electron beam irradiation for different doses from 0 to 100 kGy in steps of 20 kGy in air at room temperature. The changes in structural, surface morphological and optical properties that occurred before and after irradiation in Bi{sub 2}S{sub 3} thin films are studied using X-ray diffraction, scanning electron microscopy and UV-vis spectroscopy. It is shown that electron irradiation can be used as a tool to decrease the crystallite size of the irradiated films from 418 to 285 A as the dose varies from 20 to 100 kGy. The decrease in crystallinity of the films leading to the band gap energy of the films get blue shifted from unirradiated films. These results are explained in the light of thermal spike model.

  2. Cadmium sulphide (CdS) thin films deposited by chemical bath deposition (CBD) and dip coating techniques—a comparative study

    Science.gov (United States)

    Khimani, Ankurkumar J.; Chaki, Sunil H.; Malek, Tasmira J.; Tailor, Jiten P.; Chauhan, Sanjaysinh M.; Deshpande, M. P.

    2018-03-01

    The CdS thin films were deposited on glass slide substrates by Chemical Bath Deposition and dip coating techniques. The films thickness variation with deposition time showed maximum films deposition at 35 min for both the films. The energy dispersive analysis of x-ray showed both the films to be stoichiometric. The x-ray diffraction analysis confirmed the films possess hexagonal crystal structure. The transmission electron, scanning electron and optical microscopy study showed the films deposition to be uniform. The selected area electron diffraction exhibited ring patterns stating the films to be polycrystalline in nature. The atomic force microscopy images showed surface formed of spherical grains, hills and valleys. The recorded optical absorbance spectra analysis revealed the films possess direct optical bandgap having values of 2.25 eV for CBD and 2.40 eV for dip coating. The refractive index (η), extinction coefficient (k), complex dielectric constant (ε) and optical conductivity (σ 0) variation with wavelength showed maximum photon absorption till the respective wavelengths corresponding to the optical bandgap energy values. The recorded photoluminescence spectra showed two emission peaks. All the obtained results have been discussed in details.

  3. Enhanced stability and mechanical strength of sodium alginate composite films.

    Science.gov (United States)

    Liu, Sijun; Li, Yong; Li, Lin

    2017-03-15

    This work aims to study how three kinds of nanofillers: graphene oxide (GO), ammonia functionalized graphene oxide (AGO), and triethoxylpropylaminosilane functionalized silica, can affect stability and mechanical strength of sodium alginate (SA) composite films. The filler/sodium alginate (SA) solutions were first studied by rheology to reveal effects of various fillers on zero shear viscosity η 0 . SA composite films were then prepared by a solution mixing-evaporation method. The structure, morphology and properties of SA composite films were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffractometry (XRD), thermogravimetric analysis (TGA), field emission scanning electron microscopy (FESEM), contact angle and mechanical testing. Compared to GO and silica, the presence of AGO significantly improved the interaction between AGO and SA, which led to the increase in stability and mechanical strength of the resulting SA composite films. The tensile strength and elongation at break of AGO/SA composite film at 3wt% AGO loading were increased by 114.9% and 194.4%, respectively, in contrast to pure SA film. Furthermore, the stability of AGO/SA composite films at high temperatures and in a wet environment were better than that of silica/SA and GO/SA composite films. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Optical study on doped polyaniline composite films

    International Nuclear Information System (INIS)

    Li, G; Zheng, P; Wang, N L; Long, Y Z; Chen, Z J; Li, J C; Wan, M X

    2004-01-01

    Localization driven by disorder has a strong influence on the conducting properties of conducting polymers. Some authors hold the opinion that disorder in the material is homogeneous and that the conducting polymer is a disordered metal close to the Anderson-Mott metal-insulator (MI) transition, while others treat the disorder as inhomogeneous and have the opinion that conducting polymers are a composite of ordered metallic regions and disordered insulating regions. The morphology of conducting polymers is an important factor that has an influence on the type and extent of disorder. Different protonic acids used as dopants and moisture have influence on the polymer chain arrangement and interchain interactions. We performed optical reflectance measurements on several PANI-CSA/PANI-DBSA composite films with different dopant ratios and moisture contents. Optical conductivity and the real part of the dielectric function are calculated by Kramers-Kronig (KK) relations. σ 1 (ο) and ε 1 (ο) deviate from the simple Drude model in the low frequency range and the tendencies of the three sample are different and non-monotonic. The localization modified Drude model (LMD) in the framework of the Anderson-Mott theory cannot give a good fit to the experimental data. By introducing the distribution of relaxation time into the LMD, reasonable fits for all three samples are obtained. This result supports the inhomogeneous picture

  5. Interfaces study of all-polysaccharide composite films

    Czech Academy of Sciences Publication Activity Database

    Šimkovic, I.; Kelnar, Ivan; Mendichi, R.; Tracz, A.; Filip, J.; Bertók, T.; Kasák, P.

    2018-01-01

    Roč. 72, č. 3 (2018), s. 711-718 ISSN 0366-6352 Institutional support: RVO:61389013 Keywords : all-polysaccharide composites * elemental analysis * film properties study Subject RIV: JI - Composite Materials OBOR OECD: Composites (including laminates, reinforced plastics, cermets, combined natural and synthetic fibre fabrics Impact factor: 1.258, year: 2016

  6. New Fabrication Technique of Conductive Polymer / Insulating Polymer Composite Films

    Science.gov (United States)

    Abe, Yayoi; Mathur, Paramatma Chandra; Bhatnagar, Pramod Kumar; Tada, Kazuya; Onoda, Mitsuyoshi

    The electrochemical polymerization of pyrrole on an ITO (indium-tin oxide) coated glass electrode with an insulating film of poly(vinyl alcohol), PVA produces a flexible composite polymer film with electrical, optical and electrochemical properties very similar to polypyrrole (PPy). The rate of electrochemical polymerization depends on the diffusion of the electrolyte across the PVA film to the ITO electrode. Especially, the solvent with hydrophilic nature easily penetrates into the PVA film. By applying this new process, we demonstrate a unique method to form electrically conductive pattern in PVA film. It will be possible to develop electrodes for electrical stimulation of the nervous system using conducting polymer, PPy. Then, by using similar technique we have fabricated poly (3,4-ethylenedioxythiophene), PEDOT/PVA composite films and investigated their electrochemical basic properties.

  7. Corrosion of copper alloys in sulphide containing district heting systems

    DEFF Research Database (Denmark)

    Thorarinsdottir, R.I.; Maahn, Ernst Emanuel

    1999-01-01

    Copper and some copper alloys are prone to corrosion in sulphide containing geothermal water analogous to corrosion observed in district heating systems containing sulphide due to sulphate reducing bacteria. In order to study the corrosion of copper alloys under practical conditions a test...... was carried out at four sites in the Reykjavik District Heating System. The geothermal water chemistry is different at each site. The corrosion rate and the amount and chemical composition of deposits on weight loss coupons of six different copper alloys are described after exposure of 12 and 18 months......, respectively. Some major differences in scaling composition and the degree of corrosion attack are observed between alloys and water types....

  8. Thin composite films consisting of polypyrrole and polyparaphenylene

    International Nuclear Information System (INIS)

    Golovtsov, I.; Bereznev, S.; Traksmaa, R.; Opik, A.

    2007-01-01

    This study demonstrates that the combined method for the formation of thin composite films, consisting of polypyrrole (PPy) as a film forming agent and polyparaphenylene (PPP) with controlled electrical properties and high stability, enables one to avoid the low processability of PPP and to extend the possibilities for the development of electronic devices. The high temperature (250-600 deg. C) doping method was used for PPP preparation. The crystallinity and grindability of PPP was found to be increasing with the thermochemical modification. Thin composite films were prepared onto the light transparent substrates using the simple electropolymerization technique. The properties of films were characterized by the optical transmittance and temperature-dependent conductivity measurements. The morphology and thickness of the prepared films were determined using the scanning electron microscopy. The composite films showed a better adhesion to an inorganic substrate. It was found to be connected mostly with the improved properties of the high temperature doped PPP. The current-voltage characteristics of indium tin oxide/film/Au hybrid organic-inorganic structures showed the influence of the doping conditions of PPP inclusions in the obtained films

  9. 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. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Temperature-controlled transparent-film heater based on silver nanowire-PMMA composite film

    Science.gov (United States)

    He, Xin; Liu, A.'lei; Hu, Xuyang; Song, Mingxia; Duan, Feng; Lan, Qiuming; Xiao, Jundong; Liu, Junyan; Zhang, Mei; Chen, Yeqing; Zeng, Qingguang

    2016-11-01

    We fabricated a high-performance film heater based on a silver nanowire and polymethyl methacrylate (Ag NW-PMMA) composite film, which was synthesized with the assistance of mechanical lamination and an in situ transfer method. The films exhibit excellent conductivity, high figure of merit, and strong adhesion of percolation network to substrate. By controlling NW density, we prepared the films with a transmittance of 44.9-85.0% at 550 nm and a sheet resistance of 0.13-1.40 Ω sq-1. A stable temperature ranging from 130 °C-40 °C was generated at 3.0 V within 10-30 s, indicating that the resulting film heaters show a rapid thermal response, low driving voltage and stable temperature recoverability. Furthermore, we demonstrated the applications of the film heater in defrosting and a physical therapeutic instrument. A fast defrosting on the composite film with a transmittance of 88% was observed by applying a 9 V driving voltage for 20 s. Meanwhile, we developed a physical therapeutic instrument with two modes of thermotherapy and electronic-pulse massage by using the composite films as two electrodes, greatly decreasing the weight and power consumption compared to a traditional instrument. Therefore, Ag NW-PMMA film can be a promising candidate for diversified heating applications.

  11. Prediction and optimisation of Pb/Zn/Fe sulphide scales in gas production fields

    Energy Technology Data Exchange (ETDEWEB)

    Dyer, Sarah; Orski, Karine; Menezes, Carlos; Heath, Steve; MacPherson, Calum; Simpson, Caroline; Graham, Gordon

    2006-03-15

    Lead, zinc and iron sulphide scales are known to be a particular issue with gas production fields, particularly those producing from HP/HT reservoirs. However the prediction of sulphide scale and the methodologies available for their laboratory assessment are not as well developed as those for the more conventional sulphate and carbonate scales. This work examines a particular sulphide scaling regime from a North Sea high temperature gas condensate production field containing only 0.8ppm of sulphide ions. Sulphide scales were identified in the production system which was shown to be a mixture of lead and zinc sulphide, primarily lead sulphide. This formed as a result of cooling during production resulting in the over saturation of these minerals. This paper describes scale prediction and modified laboratory test protocols used to re-create the scales formed in the field prior to chemical performance testing. From the brine composition, scale prediction identified that the major scales that could be formed were calcium carbonate, iron carbonate, iron sulphide, lead sulphide and zinc sulphide. In addition, modification of the brine compositions led to prediction of primarily one scale or the other. Given the predicted over saturation of various minerals, preliminary laboratory tests were therefore conducted in order to ensure that the scale formed under laboratory conditions was representative of the field scale. Laboratory protocols were therefore developed to ensure that the scales formed in fully anaerobic dynamic performance tests and static performance tests were similar to those encountered in the field. The paper compares results from field analysis, scale predictions and laboratory scale formation tests using newly developed test protocols and shows differences between prediction and laboratory data. The paper therefore demonstrates the importance of ensuring that the correct scale is formed under laboratory test conditions and also indicates some potential

  12. [Spectroscopic study on film formation mechanism and structure of composite silanes-V-Zr passive film].

    Science.gov (United States)

    Wang, Lei; Liu, Chang-sheng; Shi, Lei; An, Cheng-qiang

    2015-02-01

    A composite silanes-V-Zr passive film was overlayed on hot-dip galvanized steel. Attenuated total reflection Fourier transformed infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectrometer (XPS) and radio frequency glow discharge optical emission spectrometry (rf-GD-OES) were used to characterize the molecular structure of the silanes-V-Zr passive film. The mechanism of film formation was discussed: The results show that the silane molecules are crosslinked as the main film former and inorganic inhibitor is even distributed in the film. The fitting peak of 100.7 eV in XPS single Si2p energy range spectra of the composite silanes-V-Zr passive film and the widening and strengthening of the Si--O infrared absorption peak at 1100 cm(-1) indicate that the silanes were adsorbed on the surface of zinc with chemical bond of Si--O--Zn, and the silane molecules were connected with each other by bond of Si--O--Si. Two characteristic absorption peaks of amide at 1650 and 1560 cm(-1) appear in the infrared spectroscopy of the composite silanes-V-Zr passive film, and a characteristic absorption peak of epoxy groups at 910 cm(-1) disappears in the infrared spectroscopy of the passive film. The results indicate that gamma-APT can be prepared through nucleophilic ring-opening of ethylene oxide in gamma-GPT molecule to form C--N covalent bonds. The rf-GD-OES results indicate that there is a oxygen enriched layer in 0.3 microm depth of the composite silanes-V-Zr passive film. Moreover, ZrF4, ZrO2 and some inorganic matter obtained by the reaction during the forming processof the composite silanes-V-Zr passive film are distributed evenly throughout the film. According to the film composition, the physical processes and chemical reactions during the film forming process were studied by using ATR-FTIR. Based on this, the film forming mechanism was proposed.

  13. Synthesis and characterization of silver-polypyrrole film composite

    Energy Technology Data Exchange (ETDEWEB)

    Ayad, Mohamad M., E-mail: mayad12000@yahoo.com [Department of Chemistry, Faculty of Science, University of Tanta, Tanta (Egypt); Zaki, Eman [Department of Chemistry, Faculty of Science, University of Tanta, Tanta (Egypt)

    2009-11-15

    In this work, we report the chemical polymerization of pyrrole to obtain thin film of polypyrrole (PPy) hydrochloride deposited onto the electrode of the quartz crystal microbalance (QCM). The film in the base form was exposed to a solution of AgNO{sub 3}. Electroless reduction for silver ions by the PPy film took place and silver particles were adsorbed onto the film surface. The silver particles content at the PPy films were analyzed by QCM and the results showed that the concentrations of silver uptakes increase as the original AgNO{sub 3} solution increases. The morphology of the surface of the PPy film and the silver-PPy film composite were studied by the scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectrometry (EDX). They showed that the obtained silver particles have spherical, cubic and tetrahedral structures. X-ray diffraction (XRD) and Fourier transformed infra-red spectroscopy (FTIR) were used to characterize the structure of the powder composite. This work reveals the capability of PPy film coating on QCM in sensing and removing silver from several environmental samples.

  14. Synthesis and characterization of silver-polypyrrole film composite

    International Nuclear Information System (INIS)

    Ayad, Mohamad M.; Zaki, Eman

    2009-01-01

    In this work, we report the chemical polymerization of pyrrole to obtain thin film of polypyrrole (PPy) hydrochloride deposited onto the electrode of the quartz crystal microbalance (QCM). The film in the base form was exposed to a solution of AgNO 3 . Electroless reduction for silver ions by the PPy film took place and silver particles were adsorbed onto the film surface. The silver particles content at the PPy films were analyzed by QCM and the results showed that the concentrations of silver uptakes increase as the original AgNO 3 solution increases. The morphology of the surface of the PPy film and the silver-PPy film composite were studied by the scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectrometry (EDX). They showed that the obtained silver particles have spherical, cubic and tetrahedral structures. X-ray diffraction (XRD) and Fourier transformed infra-red spectroscopy (FTIR) were used to characterize the structure of the powder composite. This work reveals the capability of PPy film coating on QCM in sensing and removing silver from several environmental samples.

  15. Synthesis and characterization of silver-polypyrrole film composite

    Science.gov (United States)

    Ayad, Mohamad. M.; Zaki, Eman

    2009-11-01

    In this work, we report the chemical polymerization of pyrrole to obtain thin film of polypyrrole (PPy) hydrochloride deposited onto the electrode of the quartz crystal microbalance (QCM). The film in the base form was exposed to a solution of AgNO 3. Electroless reduction for silver ions by the PPy film took place and silver particles were adsorbed onto the film surface. The silver particles content at the PPy films were analyzed by QCM and the results showed that the concentrations of silver uptakes increase as the original AgNO 3 solution increases. The morphology of the surface of the PPy film and the silver-PPy film composite were studied by the scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectrometry (EDX). They showed that the obtained silver particles have spherical, cubic and tetrahedral structures. X-ray diffraction (XRD) and Fourier transformed infra-red spectroscopy (FTIR) were used to characterize the structure of the powder composite. This work reveals the capability of PPy film coating on QCM in sensing and removing silver from several environmental samples.

  16. Electrical and thermal properties of PLA/CNT composite films

    OpenAIRE

    Ceregatti, Thayara; Pecharki, Paloma; Pachekoski, Wagner M.; Becker, Daniela; Dalmolin, Carla

    2017-01-01

    ABSTRACT Conducting polymers presents many potential applications such as biosensors and biofuelcells. However, to be used in those devices, a thin film must be deposited onto a conducting and biocompatible substrate. In this work, carbon nanotubes (CNT) were mixed in a poly (lactic acid) - PLA - matrix with different compositions (from 0.25 to 5.0 %) in order to form conducting composites suitable to the deposition of a conducting polymer. Thermal properties of PLA/CNT composites were evalua...

  17. Precipitation of metal sulphides using gaseous hydrogen sulphide: mathematical modelling

    NARCIS (Netherlands)

    Al Tarazi, M.Y.M.; Heesink, Albertus B.M.; Versteeg, Geert

    2004-01-01

    A mathematical model has been developed that describes the precipitation of metal sulffides in an aqueous solution containing two different heavy metal ions. The solution is assumed to consist of a well-mixed bulk and a boundary layer that is contacted with hydrogen sulphide gas. The model makes use

  18. Digital Compositing Dalam Film Animasi 3 Dimensi

    Directory of Open Access Journals (Sweden)

    Cito Yasuki Yasuki Rahmad

    2016-01-01

    Full Text Available Animation is a technique mostly used in the film world. Nowadays it is growing intechnical animation creation. Animation has evolved from 2D animation to the nextstage in the new form, more realistic and interesting, that is the 3D animation. With thedevelopment of existing technology, the 3D animation is more amazing for the audience,especially 3D animation combined with real action (live action. With the digitalcompositing, the result of a combination of 3D and real action to make the film seemmore alive, because the animation is really close to the original in real life.

  19. Wearable near-field communication antennas with magnetic composite films

    Directory of Open Access Journals (Sweden)

    Bihong Zhan

    2017-06-01

    Full Text Available The flexible near-field communication (NFC antennas integrated with Fe3O4/ethylene-vinyl acetate copolymer (EVA magnetic films were presented, and the influence of the magnetic composite films on the performance and miniaturization capability of the NFC antennas was investigated. Theoretical analysis and experimental results show that the integration of the magnetic composite films is conducive to the miniaturization of the NFC antennas. However, the pattern design of the integrated magnetic film is very important to improve the communication performance of NFC antenna. When magnetic film covers whole antenna, the inductance (L and quality factor (Q of the NFC antenna at 13MHz are increased by 60% and 5% respectively, but the communication distance of NFC system is decreased by 70%. When the magnetic film is located at the center of the antenna, the L value, Q value and communication distance of the NFC antenna are increased by 16.5%, 15.5% and 20% respectively. It can be seen that the application of the integrated magnetic film with optimized pattern to the NFC antenna can not only reduce the size of the antenna, but also improve the overall performance of the antenna.

  20. Carbon steel protection in G.S. [Girldler sulphide] plants: Pt. 7

    International Nuclear Information System (INIS)

    Lires, Osvaldo; Delfino, Cristina; Rojo, Enrique.

    1989-01-01

    In order to protect carbon steel towers and piping of a GS experimental heavy water plant against corrosion produced by the action of aqueous solutions of hydrogen sulphide, a method, elsewhere published, was developed. Carbon steel exposed to saturated aqueous solutions of hydrogen sulphide forms iron sulphide scales. In oxygen free solutions, evolution of corrosion follows the sequence mackinawite → cubic ferrous sulphide → troilite → pyrrotite → pyrite. Scales formed by pyrrotite and pyrite are the most protective layers (these are obtained at 130 deg C, 2 MPa for a period of 14 days). During a plant shutdown procedures, the carbon steel protected with those scales is exposed to water and highly humid air; under such conditions oxidation is unavoidable. Later, treatment in plant conditions does not regenerate scales because the composition of regenerated scales involves more soluble iron sulphides such as mackinawite and troilite. Therefore, it is not recommendable to expose the protective scales to atmospherical conditions. (Author)

  1. Fabrication of polypeptide-based piezoelectric composite polymer film

    International Nuclear Information System (INIS)

    Farrar, Dawnielle; West, James E.; Busch-Vishniac, Ilene J.; Yu, Seungju M.

    2008-01-01

    A new class of molecular composite piezoelectric material was produced by simultaneous poling and curing of a homogeneous solution comprising poly(γ-benzyl α,L-glutamate) and methylmethacrylate via corona discharge methods. This film exhibited high piezoelectricity (d 33 = 23 pC N -1 ), and its mechanical characteristics (modulus = 450 MPa) were similar to those of low molecular weight poly(methylmethacrylate). As it is produced via solution-based fabrication processes, the composite film is conducive to miniaturization for small sensors with integrated electronics, and could also potentially be used in piezoelectric coating applications

  2. 3D arrays of molybdenum sulphide nanosheets on Mo meshes: Efficient electrocatalysts for hydrogen evolution reaction

    International Nuclear Information System (INIS)

    Xu, Yan; Zheng, Chong; Wang, Sibo; Hou, Yidong

    2015-01-01

    3D arrays of molybdenum sulphide nanosheets on Mo mesh exhibited enhanced electro-catalytic activity for hydrogen evolution reaction. - Highlights: • 3D arrays of molybdenum sulphide nanosheets were obtained by a facile hydrothermal method. • The mesh structure could be beneficial to promote the electrolyte diffusion onto the electrode surface and thus promote the electron transfer. • 3D arrays of molybdenum sulphide nanosheets demonstrate an enhanced HER activity with a low onset overpotential of 120 mV and a Tafel slope of 46 mV/dec. - Abstract: Molybdenum sulphide has emerged as a promising electrocatalyst for hydrogen evolution reaction (HER). Toward further improving its activity, tremendous efforts have been made to preferentially expose active edge sites of molybdenum sulphide-based catalysts by engineering their surface structure. In this work, 3D arrays of molybdenum sulphide nanosheets were synthesized by hydrothermal treatment of Mo mesh in aqueous thiourea solution. Their compositional, morphological and structural properties as well as electrocatalytic activities were investigated in details. The results reveal that 3D arrays of molybdenum sulphide nanosheets demonstrate an enhanced HER activity with a low onset overpotential of 120 mV and a Tafel slope of 46 mV/dec, which is superior to that of 2D arrays molybdenum sulphide nanosheets grown on Mo foil. The high activity for HER can be ascribed to the superstructure of the catalysts with a large fraction of edge sites and a high surface area

  3. Composite elastic magnet films with hard magnetic feature

    Science.gov (United States)

    Wang, Weisong; Yao, Zhongmei; Chen, Jackie C.; Fang, Ji

    2004-10-01

    Hard magnetic materials with high remnant magnetic moment, Mr, have unique advantages that can achieve bi-directional (push-pull) movement in an external magnetic field. This paper presents the results on the fabrication and testing of novel composite elastic permanent magnet films. The microsize hard barium ferrite powder, NdFeB powder, and different silicone elastomers have been used to fabricate various large elongation hard magnetic films. Three different fabrication methods, screen-coating processing, moulding processing and squeegee-coating processing, have been investigated, and the squeegee-coating process was proven to be the most successful method. The uniform composite elastic permanent magnet films range from 40 µm to 216 µm in thickness have been successfully fabricated. These films were then magnetized in the thickness direction after fabrication. They exhibited permanent magnet behaviour; for instance, the film (0.640 mm3 in volume) made of polydimethyl siloxane (PDMS) and hard barium ferrite powders is measured to give a coercive force, Hc, of 3.24 × 105 A m-1 and Mr of 1.023 × 10-5 A m2, and the film (0.504 mm3 in volume) made of PDMS and NdFeB powders gives 1.55 × 105 A m-1 Hc and 8.081 × 10-5 A m2 Mr. These composite elastic permanent magnet films' mechanical properties, like Young's modulus and deflection force, have been evaluated. To validate the films' Young's modulus, a finite-element computer simulation (ANSYS®) is used and one film is chosen whose Young's modulus (16.60 MPa) is confirmed by the simulation results with ANSYS®. The large elongation composite elastic permanent magnet film provides an excellent diaphragm material, which plays an important role in the micropump or valve. The movement of the 126 µm thick film with 4.5 mm diameter made of PDMS and NdFeB powders has been tested in a 0.21 Tesla external magnetic field. It was proven to have large deflection of 125 µm.

  4. Bioinspired Transparent Laminated Composite Film for Flexible Green Optoelectronics.

    Science.gov (United States)

    Lee, Daewon; Lim, Young-Woo; Im, Hyeon-Gyun; Jeong, Seonju; Ji, Sangyoon; Kim, Yong Ho; Choi, Gwang-Mun; Park, Jang-Ung; Lee, Jung-Yong; Jin, Jungho; Bae, Byeong-Soo

    2017-07-19

    Herein, we report a new version of a bioinspired chitin nanofiber (ChNF) transparent laminated composite film (HCLaminate) made of siloxane hybrid materials (hybrimers) reinforced with ChNFs, which mimics the nanofiber-matrix structure of hierarchical biocomposites. Our HCLaminate is produced via vacuum bag compressing and subsequent UV-curing of the matrix resin-impregnated ChNF transparent paper (ChNF paper). It is worthwhile to note that this new type of ChNF-based transparent substrate film retains the strengths of the original ChNF paper and compensates for ChNF paper's drawbacks as a flexible transparent substrate. As a result, compared with high-performance synthetic plastic films, such as poly(ethylene terephthalate), poly(ether sulfone), poly(ethylene naphthalate), and polyimide, our HCLaminate is characterized to exhibit extremely smooth surface topography, outstanding optical clarity, high elastic modulus, high dimensional stability, etc. To prove our HCLaminate as a substrate film, we use it to fabricate flexible perovskite solar cells and a touch-screen panel. As far as we know, this work is the first to demonstrate flexible optoelectronics, such as flexible perovskite solar cells and a touch-screen panel, actually fabricated on a composite film made of ChNF. Given its desirable macroscopic properties, we envision our HCLaminate being utilized as a transparent substrate film for flexible green optoelectronics.

  5. 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.

  6. Thin Film Composite Membranes: Mechanical and Antifouling Properties

    Directory of Open Access Journals (Sweden)

    Kassim Shaari Norin Zamiah

    2017-01-01

    Full Text Available As compared to membranes produced from pure polymer or pure inorganic materials, a hybrid membrane possesses better mechanical and thermal properties. This paper reported on the effect of incorporating silica nano-precursor (tetraethylorthosilicate as well as glycerol in the formulation of hybrid membrane on the mechanical properties and antifouling properties of the resultant thin film composite membranes. The mechanical properties were measured in terms of tensile strength, tensile strain and elastic modulus. Whereas for antifouling properties, it was evaluated through the measurements of relative flux decay (RFD and relative flux recovery (RFR, along with the permeate flux rate, percentage glycerol permeated and NaCl rejection. Results showed that the presence of silica and glycerol in hybrid membrane’s formulation had increased the tensile strength and elongation of the resultant membranes. In addition to that, the incorporation of glycerol has resulted in thin film composite with better antifouling properties as compared to the thin film composite with barrier layer from the pure polymer blend. Based on its performance, the fabricated thin film composite has a great potential to be used as a pathway for crude glycerol purification due to some advantages over the existing process that employ membrane.

  7. mwnts composite film modified glassy carbon electrode

    African Journals Online (AJOL)

    Preferred Customer

    ABSTRACT: A poly p-aminosalicylic acid (Poly(p-ASA)) and multiwall carbon nanotubes. (MWCNTs) composite modified glassy carbon (GC) electrode was constructed by casting the MWNTs on the GC electrode surface followed by electropolymerization of the p-ASA on the MWCNTs/GCE. The electrochemical behaviours ...

  8. Polyester fabric coated with Ag/ZnO composite film by magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Xiaohong, E-mail: yxhong1981_2004@126.com [Key Laboratory of Eco-Textiles, Ministry of Education, Jiangnan University, Wuxi 214122, Jiangsu (China); Faculty of Clothing and Design, Minjiang University, Fuzhou 350121, Fujian (China); Xu, Wenzheng, E-mail: xwz8199@126.com [Key Laboratory of Eco-Textiles, Ministry of Education, Jiangnan University, Wuxi 214122, Jiangsu (China); Huang, Fenglin, E-mail: windhuang325@163.com [Key Laboratory of Eco-Textiles, Ministry of Education, Jiangnan University, Wuxi 214122, Jiangsu (China); Chen, Dongsheng, E-mail: mjuchen@126.com [Faculty of Clothing and Design, Minjiang University, Fuzhou 350121, Fujian (China); Wei, Qufu, E-mail: qfwei@jiangnan.edu.cn [Key Laboratory of Eco-Textiles, Ministry of Education, Jiangnan University, Wuxi 214122, Jiangsu (China)

    2016-12-30

    Highlights: • Ag/ZnO composite film was successfully deposited on polyester fabric by magnetron sputtering technique. • Ag film was easily oxidized into Ag{sub 2}O film in high vacuum oxygen environment. • The zinc film coated on the surface of Ag film before RF reactive sputtering could protect the silver film from oxidation. • Polyester fabric coated with Ag/ZnO composite film can obtained structural color. • The anti-ultraviolet and antistatic properties of polyester fabric coated with Ag/ZnO composite film all were good. - Abstract: Ag/ZnO composite film was successfully deposited on polyester fabric by using direct current (DC) magnetron sputtering and radio frequency (RF) magnetron reaction sputtering techniques with pure silver (Ag) and zinc (Zn) targets. X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) were used to examine the deposited film on the fabric. It was found that the zinc film coated on Ag film before RF reactive sputtering could protect the silver film from oxidation. Anti-ultraviolet property and antistatic property of the coated samples using different magnetron sputtering methods were also investigated. The experimental results showed that Ag film was oxidized into in Ag{sub 2}O film in high vacuum oxygen environment. The deposition of Zn film on the surface of the fabric coated with Ag film before RF reactive sputtering, could successfully obtained Ag/ZnO composite film, and also generated structural color on the polyester fabric.

  9. Chitosan-based films composites for wound healing purposes

    International Nuclear Information System (INIS)

    Alves, Natali de O.; Silva, Gabriela T. da; Schulz, Gracelie A.S.; Fajardo, Andre R.

    2015-01-01

    Chitosan has been extensively applied in the developing of biomaterials due to its desirable good physico-chemical and biological properties. According to this, here films composite of chitosan, poly(vinyl alcohol) and bovine bone powder were prepared by casting willing to be applied in wound healing purposes. Moreover, the first step was the developing of a suitable method to obtain bovine bone powder, which was utilized here as filler. All the materials and films were fully characterized by FTIR, DRX and thermal analysis. Water uptake capacity was measured by swelling assays. (author)

  10. Aligned Carbon Nanotubes for High-Performance Films and Composites

    Science.gov (United States)

    Zhang, Liwen

    Carbon nanotubes (CNTs) with extraordinary properties and thus many potential applications have been predicted to be the best reinforcements for the next-generation multifunctional composite materials. Difficulties exist in transferring the most use of the unprecedented properties of individual CNTs to macroscopic forms of CNT assemblies. Therefore, this thesis focuses on two main goals: 1) discussing the issues that influence the performance of bulk CNT products, and 2) fabricating high-performance dry CNT films and composite films with an understanding of the fundamental structure-property relationship in these materials. Dry CNT films were fabricated by a winding process using CNT arrays with heights of 230 mum, 300 im and 360 mum. The structures of the as-produced films, as well as their mechanical and electrical properties were examined in order to find out the effects of different CNT lengths. It was found that the shorter CNTs synthesized by shorter time in the CVD furnace exhibited less structural defects and amorphous carbon, resulting in more compact packing and better nanotube alignment when made into dry films, thus, having better mechanical and electrical performance. A novel microcombing approach was developed to mitigate the CNT waviness and alignment in the dry films, and ultrahigh mechanical properties and exceptional electrical performance were obtained. This method utilized a pair of sharp surgical blades with microsized features at the blade edges as micro-combs to, for the first time, disentangle and straighten the wavy CNTs in the dry-drawn CNT sheet at single-layer level. The as-combed CNT sheet exhibited high level of nanotube alignment and straightness, reduced structural defects, and enhanced nanotube packing density. The dry CNT films produced by microcombing had a very high Young's modulus of 172 GPa, excellent tensile strength of 3.2 GPa, and unprecedented electrical conductivity of 1.8x10 5 S/m, which were records for CNT films or

  11. High performance thin-film composite forward osmosis membrane.

    Science.gov (United States)

    Yip, Ngai Yin; Tiraferri, Alberto; Phillip, William A; Schiffman, Jessica D; Elimelech, Menachem

    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 mum) 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 m(2-)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.

  12. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, A.A.; Song, L.

    1999-09-28

    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.

  14. Comparative in situ biodegradation studies of polyhydroxybutyrate film composites.

    Science.gov (United States)

    Debbarma, Prasenjit; Raghuwanshi, Shikha; Singh, Jyoti; Suyal, Deep Chandra; Zaidi, M G H; Goel, Reeta

    2017-07-01

    Application of polyhydroxybutyrate (PHB) to plastic industry has expanded over the last decades due to its attracting features over petro-based plastic, and therefore, its waste accumulation in nature is inevitable. In the present study, a total of four bacterial strains, viz., MK3, PN12, PW1, and Lna3, were formulated into a consortium and subsequently used as biological tool for degradation of biopolymers. The consortium was tested through λ max shifts under in vitro conditions for utilization of PHB as sole carbon source. Talc-based bioformulations of consortium were used for the degradation of PHB film composites under in situ conditions. After 9 months of incubation, the recovered samples were monitored through Fourier transform infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM), respectively. Analytical data, viz., changes in λ max shifts (212-219 nm), FT-IR spectra, and SEM micrographs, revealed the biodegradation potential of developed consortium against PHB film composites, i.e., higher degradation of copolymer films was found over blend films. The used consortium had enhanced the rate of natural degradation and can be further used as a natural tool to maintain and restore global environmental safety.

  15. Natural zeolite polypropylene composite film preparation and characterization

    OpenAIRE

    Özmıhçı, Filiz; Balköse, Devrim; Ülkü, Semra

    2001-01-01

    In this research, the preparation and characterization of polypropylene (PP) and natural zeolite composites were studied. Natural zeolite mined in Gördes, Turkey was used as an alternative filler to CaCO3. Films were prepared by the extrusion of PP, and surface-modified zeolite was made by polyethylene glycol 4000 with 2-4% zeolite. Zeolite-filled composites had densities between 0.73 and 0.83 g/cm3 and had void fractions of 0.07-0.20. Although the permeability of water vapour through 2% zeol...

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

    Energy Technology Data Exchange (ETDEWEB)

    Hou, Yong-Jhih; Chang, Cheng-Hsun-Tony; Yang, Chun-Kai; Hsu, Chih-Yu; Jhou, Yen-Wei; Tsay, Jyh-Shen, E-mail: jstsay@phy.ntnu.edu.tw

    2015-11-01

    Graphical abstract: - Highlights: • For Co–rubrene composite films, a layered structure is observed. • For thick composite films, surfactant effects of rubrene cause reduced interaction at the film/Si interface. • For thin composite films, the formation of separated Co clusters results in a larger coercive force. • By the rubrene concentration, rubrene enhances the quality of the films. - Abstract: 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.

  17. Effect of preheating on the film thickness of contemporary composite restorative materials

    Directory of Open Access Journals (Sweden)

    Dimitrios Dionysopoulos

    2014-12-01

    Conclusion: The film thickness of the composites tested is material dependent. The thickness of the preheated conventional composites is significantly lower than those at room temperature. The conventional composites provide film thickness values greater than those of the flowable composites regardless of preheating temperature.

  18. Zeta-potential of fouled thin film composite membrane

    Energy Technology Data Exchange (ETDEWEB)

    Ikeda, K.; Hachisuka, H.; Nakamura, T. [Nitto denko Corp., Ibaraki, (Japan); Kimura, S. [Kogakuin University, Tokyo (Japan). Dept. of Environ. Chemical Engineering; Ueyama, K. [Osaka University, Osaka (Japan). Dept. of Chemical Engineering

    1999-10-01

    The surface zeta-potential of a cross-linked polyamide thin film composite reverse osmosis membrane was measured using an electrophoresis method. It was confirmed that this method could be effectively applied to analyze the fouling of such membranes. It is known that the water flux of membranes drastically decreases as a result of fouling by surfactants. Although the surfactants adsorbed on reverse osmosis membranes could not be detected by conventional methods such as SEM, EDX and FT-IR, their presence could be clarified by the profile measurements of the surface zeta-potential. The profiles of the membrane surface zeta-potentials changed to more positive values in the measured pH range as a result of fouling by cationic or amphoteric surfactants. This measuring method of surface zeta-potentials allowed us to analyze a very small amount of fouling of a thin film composite reverse osmosis membrane. This method could be used to analyze the fouled surface of the thin film composite reverse osmosis membrane which is used for production of ultrapure water and shows a remarkable decrease in flux. It also became clear that this method is easy and effective for the reverse osmosis membrane surface analysis of adsorbed materials such as surfactants. (author)

  19. Molecular interactions in gelatin/chitosan composite films.

    Science.gov (United States)

    Qiao, Congde; Ma, Xianguang; Zhang, Jianlong; Yao, Jinshui

    2017-11-15

    Gelatin and chitosan were mixed at different mass ratios in solution forms, and the rheological properties of these film-forming solutions, upon cooling, were studied. The results indicate that the significant interactions between gelatin and chitosan promote the formation of multiple complexes, reflected by an increase in the storage modulus of gelatin solution. Furthermore, these molecular interactions hinder the formation of gelatin networks, consequently decreasing the storage modulus of polymer gels. Both hydrogen bonds and electrostatic interactions are formed between gelatin and chitosan, as evidenced by the shift of the amide-II bands of polymers. X-ray patterns of composite films indicate that the contents of triple helices decrease with increasing chitosan content. Only one glass transition temperature (T g ) was observed in composite films with different composition ratios, and it decreases gradually with an increase in chitosan proportion, indicating that gelatin and chitosan have good miscibility and form a wide range of blends. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Non-chondritic distribution of the highly siderophile elements in mantle sulphides.

    Science.gov (United States)

    Alard, O; Griffin, W L; Lorand, J P; Jackson, S E; O'Reilly, S Y

    2000-10-19

    The abundances of highly siderophile (iron-loving) elements (HSEs) in the Earth's mantle provide important constraints on models of the Earth's early evolution. It has long been assumed that the relative abundances of HSEs should reflect the composition of chondritic meteorites--which are thought to represent the primordial material from which the Earth was formed. But the non-chondritic abundance ratios recently found in several types of rock derived from the Earth's mantle have been difficult to reconcile with standard models of the Earth's accretion, and have been interpreted as having arisen from the addition to the primitive mantle of either non-chondritic extraterrestrial material or differentiated material from the Earth's core. Here we report in situ laser-ablation analyses of sulphides in mantle-derived rocks which show that these sulphides do not have chondritic HSE patterns, but that different generations of sulphide within single samples show extreme variability in the relative abundances of HSEs. Sulphides enclosed in silicate phases have high osmium and iridium abundances but low Pd/Ir ratios, whereas pentlandite-dominated interstitial sulphides show low osmium and iridium abundances and high Pd/Ir ratios. We interpret the silicate-enclosed sulphides as the residues of melting processes and interstitial sulphides as the crystallization products of sulphide-bearing (metasomatic) fluids. We suggest that non-chondritic HSE patterns directly reflect processes occurring in the upper mantle--that is, melting and sulphide addition via metasomatism--and are not evidence for the addition of core material or of 'exotic' meteoritic components.

  1. Preparation and Properties of Silver Nanowire-Based Transparent Conductive Composite Films

    Science.gov (United States)

    Tian, Ji-Li; Zhang, Hua-Yu; Wang, Hai-Jun

    2016-06-01

    Silver nanowire-based transparent conductive composite films with different structures were successfully prepared using various methods, including liquid polyol, magnetron sputtering and spin coating. The experimental results revealed that the optical transmittance of all different structural composite films decreased slightly (1-3%) compared to pure films. However, the electrical conductivity of all composite films had a great improvement. Under the condition that the optical transmittance was greater than 78% over the wavelength range of 400-800 nm, the AgNW/PVA/AgNW film became a conductor, while the AZO/AgNW/AZO film and the ITO/AgNW/ITO film showed 88.9% and 94% reductions, respectively, for the sheet resistance compared with pure films. In addition, applying a suitable mechanical pressure can improve the conductivity of AgNW-based composite films.

  2. Preparation of cu/fes nanoparticles by mechanochemical reduction of copper sulphide

    DEFF Research Database (Denmark)

    Balaz, P.; Takacs, L.; Jiang, Jianzhong

    2002-01-01

    The mechanochemical reduction of copper sulphide with elemental iron was studied. The methods of XPS, SEM, EDX, and low temperature nitrogen sorption were used to analyse the surface composition and the composite particles formed from elemental copper and hexagonal 2C-troilite. The study of the m......The mechanochemical reduction of copper sulphide with elemental iron was studied. The methods of XPS, SEM, EDX, and low temperature nitrogen sorption were used to analyse the surface composition and the composite particles formed from elemental copper and hexagonal 2C-troilite. The study...

  3. Improved sulphate removal rates at increased sulphide ...

    African Journals Online (AJOL)

    The product of the biological sulphate reduction is sulphide. High concentrations of molecular H2S (g) can be inhibitory for microbial activity, especially at a reactor pH of 6 to 7. This paper focuses on the effect of high sulphide concentrations on the sulphate reduction rates. The results of three investigations operating a ...

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

    International Nuclear Information System (INIS)

    Xu, Jinzhuo; Pan, Rong; Chen, Yiwei; Piao, Xianqin; Qian, Min; Feng, Tao; Sun, Zhuo

    2013-01-01

    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.

  5. Synthesis and characterization of polyvinyl alcohol- carboxymethyl tamarind gum based composite films.

    Science.gov (United States)

    Yadav, Indu; Rathnam, V S Sharan; Yogalakshmi, Yamini; Chakraborty, Subhabrata; Banerjee, Indranil; Anis, Arfat; Pal, Kunal

    2017-06-01

    The present study delineates the synthesis of novel composite films using polyvinyl alcohol and carboxymethyl tamarind gum. The microscopic study results confirmed the formation of composite matrices. FTIR spectroscopy suggested the occurrence of hydrogen-bonding amongst the components of the films. The extent of hydrogen bonding was composition-dependent which reached a critical higher limit at a particular composition. At the critical composition, the instantaneous and the intermediate polymer relaxation time were longer. All the films were found to be viscoelastic in nature. The melting endotherm was also highest for the composition described above. Ciprofloxacin loaded films showed excellent antimicrobial property against E. coli, suggesting that the drug was released in its active form. Cell proliferation study using human keratinocytes suggested better cell proliferation in the CMT containing films as compared to the control (PVA only) film. In gist, the developed films can be explored for skin tissue engineering and drug delivery applications. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. Polyester fabric coated with Ag/ZnO composite film by magnetron sputtering

    Science.gov (United States)

    Yuan, Xiaohong; Xu, Wenzheng; Huang, Fenglin; Chen, Dongsheng; Wei, Qufu

    2016-12-01

    Ag/ZnO composite film was successfully deposited on polyester fabric by using direct current (DC) magnetron sputtering and radio frequency (RF) magnetron reaction sputtering techniques with pure silver (Ag) and zinc (Zn) targets. X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) were used to examine the deposited film on the fabric. It was found that the zinc film coated on Ag film before RF reactive sputtering could protect the silver film from oxidation. Anti-ultraviolet property and antistatic property of the coated samples using different magnetron sputtering methods were also investigated. The experimental results showed that Ag film was oxidized into in Ag2O film in high vacuum oxygen environment. The deposition of Zn film on the surface of the fabric coated with Ag film before RF reactive sputtering, could successfully obtained Ag/ZnO composite film, and also generated structural color on the polyester fabric.

  11. Copper variation in Cu(In,Ga)Se{sub 2} solar cells with indium sulphide buffer layer

    Energy Technology Data Exchange (ETDEWEB)

    Spiering, S., E-mail: stefanie.spiering@zsw-bw.de [Zentrum für Sonnenenergie- und Wasserstoff-Forschung (ZSW) Baden-Wuerttemberg, Industriestrasse 6, 70565 Stuttgart (Germany); Paetel, S.; Kessler, F. [Zentrum für Sonnenenergie- und Wasserstoff-Forschung (ZSW) Baden-Wuerttemberg, Industriestrasse 6, 70565 Stuttgart (Germany); Igalson, M.; Abdel Maksoud, H. [Warsaw University of Technology (WUT), Faculty of Physics, Koszykowa 75, 00-662 Warszawa (Poland)

    2015-05-01

    In the manufacturing of Cu(In,Ga)Se{sub 2} (CIGS) thin film solar cells the application of a buffer layer on top of the absorber is essential to obtain high efficiency devices. Regarding the roll-to-roll production of CIGS cells and modules a vacuum deposition process for the buffer is preferable to the conventional cadmium sulphide buffer deposited in a chemical bath. Promising results have already been achieved for the deposition of indium sulphide buffer by different vacuum techniques. The solar device performance is very sensitive to the conditions at the absorber-buffer heterojunction. In view of optimization we investigated the influence of the Cu content in the absorber on the current-voltage characteristics. In this work the integral copper content was varied between 19 and 23 at.% in CIGS on glass substrates. An improvement of the cell performance by enhanced open circuit voltage was observed for a reduction to ~ 21 at.% when thermally evaporated indium sulphide was applied as the buffer layer. The influence of stoichiometry deviations on the transport mechanism and secondary barriers in the device was studied using detailed dark and light current-voltage analysis and admittance spectroscopy and compared to the reference CdS-buffered cells. We conclude that the composition of the absorber in the interface region affects current transport in In{sub x}S{sub y}-buffered and CdS-buffered cells in different ways hence optimal Cu content in those two types of devices is different. - Highlights: • Influence of Cu-variation in CIGS cells with In{sub x}S{sub y} buffer layer on cell performance • Enhanced efficiency by slight reduction of Cu-content to 21 at.% • Contribution of tunnelling-enhanced interface recombination for higher Cu-content.

  12. 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.

  13. Temperature dependence of gas sensing behaviour of TiO2 doped PANI composite thin films

    International Nuclear Information System (INIS)

    Srivastava, Subodh; Sharma, Preetam; Singh, M.; Vijay, Y. K.; Sharma, S. S.; Sharma, Vinay; Rajura, Rajveer Singh

    2014-01-01

    In the present work we have reported the effect of temperature on the gas sensing properties of TiO 2 doped PANI composite thin film based chemiresistor type gas sensors for hydrogen gas sensing application. PANI and TiO 2 doped PANI composite were synthesized by in situ chemical oxidative polymerization of aniline at low temperature. The electrical properties of these composite thin films were characterized by I-V measurements as function of temperature. The I-V measurement revealed that conductivity of composite thin films increased as the temperature increased. The changes in resistance of the composite thin film sensor were utilized for detection of hydrogen gas. It was observed that at room temperature TiO 2 doped PANI composite sensor shows higher response value and showed unstable behavior as the temperature increased. The surface morphology of these composite thin films has also been characterized by scanning electron microscopy (SEM) measurement

  14. 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.

  15. Preparation of Surlyn films reinforced with cellulose nanofibres and feasibility of applying the transparent composite films for organic photovoltaic encapsulation

    Science.gov (United States)

    Lertngim, Anantaya; Phiriyawirut, Manisara; Wootthikanokkhan, Jatuphorn; Yuwawech, Kitti; Sangkhun, Weradesh; Kumnorkaew, Pisist; Muangnapoh, Tanyakorn

    2017-10-01

    This research concerns the development of Surlyn film reinforced with micro-/nanofibrillated celluloses (MFC) for use as an encapsulant in organic photovoltaic (OPV) cells. The aim of this work was to investigate the effects of fibre types and the mixing methods on the structure-properties of the composite films. Three types of cellulose micro/nanofibrils were prepared: the as-received MFC, the dispersed MFC and the esterified MFC. The fibres were mixed with Surlyn via an extrusion process, using two different mixing methods. It was found that the extent of fibre disintegration and tensile modulus of the composite films prepared by the master-batching process was superior to that of the composite system prepared by the direct mixing method. Using the esterified MFC as a reinforcement, compatibility between polymer and the fibre increased, accompanied with the improvement of the percentage elongation of the Surlyn composite film. The percentage of light transmittance of the Surlyn/MFC films was above 88, regardless of the fibre types and fibre concentrations. The water vapour transmission rate of the Surlyn/esterified MFC film was 65% lower than that of the neat Surlyn film. This contributed to the longer lifetime of the OPV encapsulated with the Surlyn/esterified MFC film.

  16. 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.

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

    International Nuclear Information System (INIS)

    Guo Yanbao; Wang Deguo; Liu Shuhai

    2010-01-01

    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 NaBH 4 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.

  18. Modeling and analysis of film composition on mechanical properties of maize starch based edible films.

    Science.gov (United States)

    Prakash Maran, J; Sivakumar, V; Thirugnanasambandham, K; Kandasamy, S

    2013-11-01

    The present study investigates the influence of composition (content of maize starch (1-3 g), sorbitol (0.5-1.0 ml), agar (0.5-1.0 g) and tween-80 (0.1-0.5 ml)) on the mechanical properties (tensile strength, elongation, Young's modulus, puncture force and puncture deformation) of the maize starch based edible films using four factors with three level Box-Behnken design. The edible films were obtained by casting method. The results showed that, tween-80 increases the permeation of sorbitol in to the polymer matrix. Increasing concentration of sorbitol (hydrophilic nature and plasticizing effect of sorbitol) decreases the tensile strength, Young's modulus and puncture force of the films. The results were analyzed by Pareto analysis of variance (ANOVA) and second order polynomial models were obtained for all responses with high R(2) values (R(2)>0.95). 3D response surface plots were constructed to study the relationship between process variables and the responses. Copyright © 2013 Elsevier B.V. All rights reserved.

  19. 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

    2013-01-01

    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

  20. Preparation of ZnO nanoribbon–MWCNT composite film and its ...

    Indian Academy of Sciences (India)

    This composite film displayed a strong antimicrobial property and porous structure, whichhas potential application as an antimicrobial bandage material. The composite film successfully removed the Escherichiacoli bacteria from water and destroyed the bacteria retained on its surface due to the antibacterial action of ZnO ...

  1. Influence of high loading of cellulose nanocrystals in polyacrylonitrile composite films

    Science.gov (United States)

    Jeffrey Luo; Huibin Chang; Amir A. Bakhtiary Davijani; H. Clive Liu; Po-Hsiang Wang; Robert J. Moon; Satish Kumar

    2017-01-01

    Polyacrylonitrile-co-methacrylic acid (PAN-co-MAA) and cellulose nanocrystal (CNC) composite films were produced with up to 40 wt% CNC loading through the solution casting method. The rheological properties of the solution/suspensions and the structural, optical, thermal, and mechanical properties of the resulting films were investigated. The viscosity of the composite...

  2. Preparation and properties of biodegradable films from Sterculia urens short fiber/celluose green composites

    CSIR Research Space (South Africa)

    Jayaramudu, J

    2013-04-01

    Full Text Available 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...

  3. Mechanical and microstructural properties of "wet" alginate and composite films containing various carbohydrates.

    Science.gov (United States)

    Harper, B Allison; Barbut, Shai; Smith, Alexandra; Marcone, Massimo F

    2015-01-01

    Composite "wet" alginate films were manufactured from alginate-carbohydrate solutions containing 5% alginate and 0.25% pectin, carrageenan (kappa or iota), potato starch (modified or unmodified), gellan gum, or cellulose (extracted or commercial). The "wet" alginate films were used as a model to understand co-extruded alginate sausage casings that are currently being used by several sausage manufacturers. The mechanical, optical, and microstructural properties of the calcium cross-linked composite films were explored. In addition, the water holding capacity and textural profile analysis properties of the alginate-carbohydrate gels were studied. The results indicate that the mechanical properties of "wet" alginate films/casings can be modified by adding various carbohydrates to them. Alginate films with pectin, carrageenan, and modified potato starch had significantly (P < 0.05) greater elongation values than pure alginate films. The alginate-pectin films also had greater (P < 0.05) tensile strengths than the pure alginate films. Alginate films with extracted cellulose, commercial cellulose, and modified potato starch had lower (P < 0.05) puncture force, distance, and work values than the alginate control films. Transmission electron microscopy images showed a very uniform alginate network in the control films. Several large cellulose fibers were visible in the films with extracted cellulose, while the cellulose fibers in the films with commercial cellulose were difficult to distinguish. Despite these apparent differences in cellulose fiber length, the 2 cellulose films had similar puncture and tensile properties. © 2014 Institute of Food Technologists®

  4. Harnessing Compositional Marangoni Flows in Depositing Nanoparticle Films

    Science.gov (United States)

    Majumder, Mainak; Pasquali, Matteo; Monash University/Rice University Team

    2012-11-01

    Attempts at depositing uniform films of nanoparticles by drop-drying have been frustrated by the ``coffee-stain'' effect, arising from the convective macroscopic flow into the solid-liquid-vapor contact line of a droplet. We have recently demonstrated that uniform deposition of nanoparticles from aqueous suspensions can be obtained by drying the droplet in an ethanol vapor atmosphere.(.).............(Majumder et al., 2012). This technique allows the particle-laden water droplets to spread on a variety of surfaces such as glass, silicon, mica, PDMS, and even Teflon® due to absorption of ethanol from the vapor. Visualization of droplet shape and internal flow shows initial droplet spreading and strong re-circulating flow during spreading and shrinkage. During the drying phase, the vapor is saturated in ethanol, leading to preferential evaporation of water at the contact line; thereby generating a surface tension gradient (or Marangoni forces) that drive a strong recirculating flow. We show that this method can be used for depositing catalyst nanoparticles for the growth of single-walled carbon nanotubes as well as to manufacture plasmonic films of well-spaced, unaggregated gold nanoparticles. MAJUMDER, M., RENDALL, C. S., PASQUALI, M. et al. 2012. Overcoming the ``Coffee-Stain'' Effect by Compositional Marangoni-Flow-Assisted Drop-Drying. J.Phys.Chem.B, 116, 6536-6542.

  5. An asymmetric electrically conducting self-aligned graphene/polymer composite thin film for efficient electromagnetic interference shielding

    Science.gov (United States)

    Kumar, Pradip; Kumar, Asheesh; Cho, Kie Yong; Das, Tapas Kumar; Sudarsan, V.

    2017-01-01

    Here, we study the self-aligned asymmetric electrically conductive composite thin film prepared via casting of graphene oxide (GO)/poly (vinylidene-hexafluoropropylene) (PVDF-HFP) dispersion, followed by low temperature hydriodic acid reduction. The results showed that composite thin film revealed the high orientation of graphene sheets along the direction of film surface. However, graphene sheets are asymmetrically distributed along the film thickness direction in the composite film. Both sides of as prepared composite film showed different surface characteristics. The asymmetric surface properties of composite film induced distinction of surface resistivity response; top surface resistivity (21 Ohm) is ˜ 4 times higher than bottom surface resistivity (5 Ohm). This asymmetric highly electrically conducting composite film revealed efficient electromagnetic interference (EMI) shielding effectiveness of ˜ 30 dB. This study could be crucial for achieving aligned asymmetric composite thin film for high-performance EMI shielding radiation.

  6. An asymmetric electrically conducting self-aligned graphene/polymer composite thin film for efficient electromagnetic interference shielding

    Directory of Open Access Journals (Sweden)

    Pradip Kumar

    2017-01-01

    Full Text Available Here, we study the self-aligned asymmetric electrically conductive composite thin film prepared via casting of graphene oxide (GO/poly (vinylidene-hexafluoropropylene (PVDF-HFP dispersion, followed by low temperature hydriodic acid reduction. The results showed that composite thin film revealed the high orientation of graphene sheets along the direction of film surface. However, graphene sheets are asymmetrically distributed along the film thickness direction in the composite film. Both sides of as prepared composite film showed different surface characteristics. The asymmetric surface properties of composite film induced distinction of surface resistivity response; top surface resistivity (21 Ohm is ∼ 4 times higher than bottom surface resistivity (5 Ohm. This asymmetric highly electrically conducting composite film revealed efficient electromagnetic interference (EMI shielding effectiveness of ∼ 30 dB. This study could be crucial for achieving aligned asymmetric composite thin film for high-performance EMI shielding radiation.

  7. Superhydrophobicity and regeneration of PVDF/SiO2 composite films

    Science.gov (United States)

    Liu, Tao; Li, Xianfeng; Wang, Daohui; Huang, Qinglin; Liu, Zhen; Li, Nana; Xiao, Changfa

    2017-02-01

    Superhydrophobicity of polymers is easily destroyed by careless touching due to the softness of microstructures. In this study, based on a well-constructed polyvinylidene fluoride (PVDF) surface, a novel superhydrophobic PVDF/SiO2 composite film was fabricated by adding hydrophobic SiO2 nanoparticle and solvent into a coagulation bath. The water contact angle of the composite film reached 162.3° and the sliding angle was as low as 1.5°. More importantly, the composite film could be regenerated only through immersing the composite film in the designed regeneration agent. The composition of the designed regeneration agent ensured that SiO2 nanoparticles were firmly adhered on the film surface even under the ultrasonic cleaning. Hence, the superhydrophobicity and self-cleaing property could be regenerated and maintained effectively, and moreover, these propeties could resist a proper pressure. In addition, after many rubbing-regenerating cycles, the regeneration method was still valid.

  8. Composite film fabricated on biomedical material with corona streamer plasma processing to mitigate bacterial adhesion

    Science.gov (United States)

    Alhamarneh, Ibrahim; Pedrow, Patrick; Eskhan, Asma; Abu-Lail, Nehal

    2011-10-01

    Composite films might control bacterial adhesion and concomitant biofouling that afflicts biomedical materials. Different size molecules of polyethylene glycol (PEG) with nominal molecular weights 600, 2000, and 20000 g/mol were used to synthesize composite films with plasma processing and dip-coating procedures on surgical-grade 316L stainless steel. Before dip-coating, the substrate was pre-coated with plasma-polymerized di(ethylene glycol) vinyl ether (pp-EO2V) in an atmospheric pressure corona streamer plasma reactor. The PEG dip-coating step followed immediately in the same chamber due to the finite lifetime of radicals associated with freshly deposited pp-EO2V. Morphology of the composite film was investigated with an ESEM. FTIR confirmed incorporation of pp-EO2V and PEG species into the composite film. More investigations on the composite film were conducted by XPS measurements. Adhesion of the composite film was evaluated with a standard peel-off test. Stability of the composite film in buffer solution was evaluated by AFM. AFM was also used to measure the film roughness and thickness. Polar and non-polar contact angle measurements were included.

  9. 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.

  10. Composição químico-bromatológica da casca de café tratada com amônia anidra e sulfeto de sódio Chemical-bromatologic composition of coffee peel treated with anhydrous ammonia and sodium sulphide

    Directory of Open Access Journals (Sweden)

    Alexandre Lima de Souza

    2001-06-01

    Full Text Available Um experimento foi conduzido para avaliar os efeitos de diferentes combinações de amônia anidra (0,0; 2,2; 3,2; e 4,2% na matéria seca e sulfeto de sódio (0,0; 2,1; 3,1; e 4,1% sobre a composição químico-bromatológica e a digestibilidade in vitro da matéria seca da casca de café (DIVMS. O teor de proteína bruta aumentou em função dos níveis crescentes de amônia anidra. A retenção de nitrogênio diminuiu com os aumentos dos níveis de amônia e de sulfeto. Os teores de nitrogênio insolúvel em detergente neutro e nitrogênio insolúvel em detergente ácido em relação ao nitrogênio total foram sensivelmente reduzidos em função dos níveis crescentes de amônia, sendo, porém, pouco alterados pela adição de sulfeto. Apesar de a aplicação de amônia anidra e sulfeto de sódio nas diferentes combinações utilizadas ter elevado a quantidade de nitrogênio disponível e reduzido os teores de hemicelulose, estas mudanças não foram suficientes para aumentar a DIVMS da casca de café.An experiment was conducted to evaluate the effects of different combination of levels of ammonia (0.0, 2.2, 3.2, 4.2% by weight of dry matter and sodium sulphide (0.0, 2.1, 3.1, 4.1% on chemical-bromatologic composition and "in vitro" dry matter digestibility (IVDMD of coffee peel with 30% of moisture. The crude protein (CP content increased due to the crescent levels of anhydrous ammonia. The nitrogen retention (NR decreased as the ammonia and sulphide levels increased. The contents of insoluble nitrogen in neutral and acid detergent related to the total nitrogen were reduced as levels of ammonia increased; however they were little altered by the addition of sodium sulphide. Although the application of anhydrous ammonia and sodium sulphide when combined have increased soluble nitrogen and reduced the hemicellusose contents, the changes were not sufficient to increase the IVDMD of coffee peel.

  11. Effect of cross linking of PVA/starch and reinforcement of modified barley husk on the properties of composite films.

    Science.gov (United States)

    Mittal, Aanchal; Garg, Sangeeta; Kohli, Deepak; Maiti, Mithu; Jana, Asim Kumar; Bajpai, Shailendra

    2016-10-20

    Barley husk (BH) was graft copolymerized by palmitic acid. The crystalline behavior of BH decreased after grafting. Poly vinyl alcohol (PVA)/starch (St) blend film, urea formaldehyde cross linked PVA/St films and composite films containing natural BH, grafted BH were prepared separately. The effect of urea/starch ratio, content of BH and grafted BH on the mechanical properties, water uptake (%), and biodegradability of the composite films was observed. With increase in urea: starch ratio from 0 to 0.5 in the blend, tensile strength of cross linked film increased by 40.23% compared to the PVA/St film. However, in grafted BH composite film, the tensile strength increased by 72.4% than PVA/St film. The degradation rate of natural BH composite film was faster than PVA/St film. Various films were characterized by SEM, FT-IR and thermal analysis. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Pyroelectric composite film for X-ray intensity detection

    Directory of Open Access Journals (Sweden)

    Walter Katsumi Sakamoto

    2012-04-01

    Full Text Available Composite material obtained with modified lead titanate (Pz34 ferroelectric ceramic and polyether-ether-ketone (PEEK polymer matrix was used as sensitive component to measure X-ray intensity in a novel detection system. The sensing element works as a thermal transducer, converting a non-quantified thermal flux into an output measurable quantity of electrical voltage. The samples were obtained up to 60 vol.% of ceramic, by hot pressing the mixture of Pz34 and PEEK powders at 368 °C and applying 12 MPa pressure for 2.0 hours. The sensor response varies from 2.70 to 0.80 V in the energy fluence rate range of 6.30 to 37.20 W.m-2. The absorbed incident energy was analyzed as a function of the ionizing energy. Furthermore, by measuring the pyroelectric activity of the composite film it was observed that there is no degradation of the sensor after the irradiation.

  13. 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.

  14. Quantitative characterization of the composition, thickness and orientation of thin films in the analytical electron microscope

    International Nuclear Information System (INIS)

    Williams, D.B.; Watanabe, M.; Papworth, A.J.; Li, J.C.

    2003-01-01

    Compositional variations in thin films can introduce lattice-parameter changes and thus create stresses, in addition to the more usual stresses introduced by substrate-film mismatch, differential thermal expansion, etc. Analytical electron microscopy comprising X-ray energy-dispersive spectrometry within a probe-forming field-emission gun scanning transmission electron microscope (STEM) is one of the most powerful methods of composition measurement on the nanometer scale, essential for thin-film analysis. Recently, with the development of improved X-ray collection efficiencies and quantitative computation methods it has proved possible to map out composition variations in thin films with a spatial resolution approaching 1-2 nm. Because the absorption of X-rays is dependent on the film thickness, concurrent composition and film thickness determination is another advantage of X-ray microanalysis, thus correlating thickness and composition variations, either of which may contribute to stresses in the film. Specific phenomena such as segregation to interfaces and boundaries in the film are ideally suited to analysis by X-ray mapping. This approach also permits multiple boundaries to be examined, giving some statistical certainty to the analysis particularly in nano-crystalline materials with grain sizes greater than the film thickness. Boundary segregation is strongly affected by crystallographic misorientation and it is now possible to map out the orientation between many different grains in the (S)TEM

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

    International Nuclear Information System (INIS)

    Deen, I.; Zhitomirsky, I.

    2014-01-01

    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

  16. Preparation and Characterazition of Copolyimide/Carboxylated Multiple-walled Carbon Nanotubes Composite Films

    Science.gov (United States)

    Xing, Liangchen; Chen, Xiaoqi; Zhou, Mengmeng; Xiao, Jijun; Li, Yantao

    2018-01-01

    The copolyimide/MWCNTs-COOH composites were synthesized by pyromellitic dianhydride (PMDA), 3,3'4,4'-biphenyltetracarboxylic dianhydride (BPDA), 4,4'-diaminodiphenyl ether (ODA) and the carboxylated multiple-walled carbon nanotubes (MWCNTs-COOH) through ultrasonic dispersion in situ polymerization. And the mechanical and thermal properties of the composite films were studied. The results showed that the carbon nanotubes were well dispersed in the polyimide composite films, the tensile properties and thermal stability were improved significantly.

  17. 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

    2013-04-01

    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.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. Electronic supplementary information (ESI) available: XPS spectrum of the SF-GO hybrid film, SEM images of lyophilized GO dispersion and the failure surface of GO film. See DOI: 10.1039/c3nr00196b

  18. 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.

  19. PEO + PVP blended polymer composite films for multifunctional ...

    Indian Academy of Sciences (India)

    has been noticed from PEO + PVP : Ni2+ polymer film at 373 K. Emission analysis of Co2+: PEO + PVP poly- mer film has exhibited a ... suggested that these TM ions doped PEO + PVP polymer films are found to be potential multifunctional materi- ..... tion of semicircle with the real axis the bulk resistance of the polymer ...

  20. Physical, structural, antioxidant and antimicrobial properties of gelatin-chitosan composite edible films.

    Science.gov (United States)

    Jridi, Mourad; Hajji, Sawssan; Ayed, Hanen Ben; Lassoued, Imen; Mbarek, Aïcha; Kammoun, Maher; Souissi, Nabil; Nasri, Moncef

    2014-06-01

    Physico-chemical and mechanical properties of cuttlefish skin gelatin (G), chitosan (C) from shrimp (Penaeus kerathurus) and composite films (G75/C25, G50/C50, G25/C75) plasticized with glycerol were investigated. The results indicated that chitosan film had higher tensile strength and lower elongation at break when compared with the other films. Composite films show no significant difference in tensile strength (TS), thickness and transparency. The structural properties evaluated by FTIR and DSC showed total miscibility between both polymers. DSC scans showed that the increase of chitosan content in the composite films increases the transition temperature (Tg) and enthalpy (ΔHg) of films. The morphology study of gelatin, chitosan and composite films showed a compact and homogenous structure. In addition, gelatin and G75/C25 films demonstrated a high antioxidant activities monitored by β-carotene bleaching, DPPH radical-scavenging and reducing power activities, while films contained chitosan exhibited higher antimicrobial activity against Gram-positive than Gram-negative bacteria. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Films of post-consumer polypropylene composites for the support layer in synthetic paper

    Directory of Open Access Journals (Sweden)

    Cristiano R. de Santi

    2006-06-01

    Full Text Available Composite films were studied as possible candidates for the central or support layer of synthetic paper in a multilayer structure. Recycled post-consumer polypropylene films were reinforced with inorganic fillers at various compositions and under several processing conditions, with the aim of optimizing the physical and mechanical properties of rigidity and low density. Three types of CaCO3, with and without surface treatment of the particles, were used, but only the treated ones were suitable for use in paper films. These samples were then used to analyze possible correlations of properties with composition and processing conditions, varying the CaCO3 particle size distribution and the film processing method, from casting extrusion (flat die to blown-film extrusion (tubular die. An increase in film stiffness was observed as a function of CaCO3 content and a concentration of 30% CaCO3 was found to be best for the specific application. The flat films were stiffer than the tubular ones. The densities of all the composite films were considered high, compared to a pulp-based paper and a commercial synthetic paper. No significant effect on the physical-mechanical properties analyzed was observed when the CaCO3 particle size distribution was varied. Microcavities were found to form at the surface of flat films submitted to a bi-orientation process performed at laboratory scale; no other sample showed this surface morphology.

  2. Rapid erasing of wettability patterns based on TiO2-PDMS composite films

    International Nuclear Information System (INIS)

    Nakata, Kazuya; Udagawa, Keizo; Ochiai, Tsuyoshi; Sakai, Hideki; Murakami, Taketoshi; Abe, Masahiko; Fujishima, Akira

    2011-01-01

    Research highlights: → TiO 2 -PDMS composite films are prepared using the sol-gel method. → The films show wettability conversion by irradiation with oxygen plasma. → Hydrophobic-superhydrophilic patterns based on the TiO 2 -PDMS films are fabricated. → The wettability patterns are rapidly erasable upon plasma irradiation for 1 s. - Abstract: TiO 2 -polydimethylsiloxane (TiO 2 -PDMS) composite films are prepared using the sol-gel method from a Ti(OBu) 4 -benzoylacetone solution containing PDMS. The prepared films are cured by irradiation with ultraviolet (UV) light. Structural changes in the films after UV irradiation are confirmed by UV-vis absorption experiments, which show that an absorption band characteristic of the benzoylacetonate chelate rings disappears. This finding is ascribed to structural changes associated with the dissociation of the chelate rings. The IR spectra of the thin films exhibit a broad absorption band after UV irradiation, indicating that a Ti-O-Ti network forms in the thin film. Contact angles are measured for the TiO 2 -PDMS thin films, showing wettability conversion from hydrophobic to superhydrophilic states by irradiation with oxygen plasma for 1 s. This phenomenon is explained by XPS experiments which reveal that the number of carbon atoms decreases, whereas the number of oxygen atoms increases on the surface of the TiO 2 -PDMS composite films. Finally, hydrophobic-superhydrophilic patterns are fabricated based on a patterned TiO 2 -PDMS composite film. The film displays a rapid change to superhydrophilicity over the whole film surface upon plasma irradiation for 1 s, which means that the wettability patterns are rapidly erasable.

  3. Preparation of reduced graphene oxide/gelatin composite films with reinforced mechanical strength

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Wenchao [School of Science, Tianjin University, Tianjin (China); Wang, Zhipeng [School of Science, Tianjin University, Tianjin (China); School of Chemical Engineering, Tianjin University, Tianjin (China); Liu, Yu; Li, Nan [School of Science, Tianjin University, Tianjin (China); Wang, Wei [School of Chemical Engineering, Tianjin University, Tianjin (China); Gao, Jianping, E-mail: jianpingg@eyou.com [School of Chemical Engineering, Tianjin University, Tianjin (China)

    2012-09-15

    Highlights: ► We used and compared different proportion of gelatin and chitosan as reducing agents. ► The mechanical properties of the films are investigated, especially the wet films. ► The cell toxicity of the composite films as biomaterial is carried out. ► The water absorption capabilities of the composite films also studied. -- Abstract: Graphene oxide (GO) was reduced by chitosan/gelatin solution and added to gelatin (Gel) to fabricate reduced graphene oxide/gelatin (RGO/Gel) films by a solvent-casting method using genipin as cross-linking agent. The structure and properties of the films were characterized by scanning electron microscopy (SEM), X-ray powder diffraction (XRD), thermogravimetric analysis (TGA) and UV–vis spectroscopy. The addition of RGO increased the tensile strength of the RGO/Gel films in both dry and wet states, but decreased their elongation at break. The incorperation of RGO also decreased the swelling ability of the films in water. Cell cultures were carried out in order to test the cytotoxicity of the films. The cells grew and reproduced well on the RGO/Gel films, indicating that the addition of RGO has no negative effect on the compatibility of the gelatin. Therefore, the reduced graphene oxide/gelatin composite is a promising biomaterial with excellent mechanical properties and good cell compatibility.

  4. Electrochemical preparation of Photosystem I-polyaniline composite films for biohybrid solar energy conversion.

    Science.gov (United States)

    Gizzie, Evan A; LeBlanc, Gabriel; Jennings, G Kane; Cliffel, David E

    2015-05-13

    In this work, we report for the first time the entrapment of the biomolecular supercomplex Photosystem I (PSI) within a conductive polymer network of polyaniline via electrochemical copolymerization. Composite polymer-protein films were prepared on gold electrodes through potentiostatic electropolymerization from a single aqueous solution containing both aniline and PSI. This study demonstrates the controllable integration of large membrane proteins into rapidly prepared composite films, the entrapment of such proteins was observed through photoelectrochemical analysis. PSI's unique function as a highly efficient biomolecular photodiode generated a significant enhancement in photocurrent generation for the PSI-loaded polyaniline films, compared to pristine polyaniline films, and dropcast PSI films. A comprehensive study was then performed to separately evaluate film thickness and PSI concentration in the initial polymerization solution and their effects on the net photocurrent of this novel material. The best performing composite films were prepared with 0.1 μM PSI in the polymerization solution and deposited to a film thickness of 185 nm, resulting in an average photocurrent density of 5.7 μA cm(-2) with an efficiency of 0.005%. This photocurrent output represents an enhancement greater than 2-fold over bare polyaniline films and 200-fold over a traditional PSI multilayer film of comparable thickness.

  5. 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.

  6. Preparation of ZnO nanoribbon–MWCNT composite film and its ...

    Indian Academy of Sciences (India)

    2017-07-28

    Jul 28, 2017 ... A zinc oxide nanoribbon (ZnO NR)–multiwall carbon nanotube (MWCNT) composite film was prepared by filtration technique. ... carbon fibre composites imparted fire shielding property to the composite, where the ... in applications like electromagnetic induction shielding and packaging of integrated circuits ...

  7. Application of ZnO Nanoparticle as Sulphide Gas Sensor Using UV/VIS/NIR-Spectrophotometer

    Science.gov (United States)

    Juliasih, N.; Buchari; Noviandri, I.

    2017-04-01

    The nanoparticle of metal oxides has great unique characteristics that applicable to the wide industrial as sensors and catalysts for reducing environmental pollution. Sulphide gas monitors and detectors are required for assessing safety aspects, due to its toxicity level. A thin film of ZnO as the sulphide gas sensor was synthesised by the simple method of chemical liquid deposition with variation of annealing temperature from 200 ºC to 500 ºC, and characterised by Scanning Electron Microscope (SEM), X-Ray Diffraction (XRD), and UV/VIS/NIR-Spectrophotometer. Characterization studies showed nanoparticle size from the range 62 - 92 nm of diameters. The application this ZnO thin film to sulfide gas, detected by UV/VIS/NIR Spectrophotometer with diffuse reflectance, showed specific chemical reaction by the shifting of maximum % Reflectance peak. The gas sensing using this method is applicable at room.

  8. 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.

  9. Composition changes in sputter deposition of Y-Ba-Cu-O films

    International Nuclear Information System (INIS)

    Hoshi, Y.; Naoe, M.

    1989-01-01

    The authors discuss the mechanism of the composition change in sputter deposition of Y-BA-Cu-O film from YBa 2 Cu 3 O 7-chi target investigated by means of a rf planar magnetron sputtering apparatus. Film composition changes significantly with not only substrate temperature Ts and sputtering gas pressure, but also substrate position. Lack of Cu and Ba content is significant in the film deposited at the substrate position just above the erosion area of the sputtering target. Suppression of bombardment of the substrate surface by negative ions emitted from the target and substrate is effective in increasing Cu and Ba content in the film. These results indicate not only that the sticking probability of the sputtered particles changes with Ts and incident particle energy, but also that high energy particle bombardment of the substrate surface plays an important role in the change of the film composition

  10. Wet chemically grown composite thin film for room temperature LPG sensor

    Science.gov (United States)

    Birajadar, Ravikiran; Desale, Dipalee; Shaikh, Shaheed; Mahajan, Sandip; Upadhye, Deepak; Ghule, Anil; Sharma, Ramphal

    2014-04-01

    We have synthesized thin film of zinc oxide-polyaniline (ZnO/PANI) composite using a simple wet chemical approach. As-synthesized ZnO/PANI composite thin film studied using different characterization techniques. The optical study reveals the penetration and interaction of PANI molecules with ZnO thin film. Prominent blue shift in UV-vis due to interaction between ZnO and PANI indicate presence of zinc oxide in polyaniline matrix. It is observed that ZnO thin film is not sensitive to LPG (liquefied petroleum gas) at room temperature. On the other hand ZnO/PANI composite thin film shows good response and recovery behaviors at room temperature.

  11. First principle study of manganese doped cadmium sulphide sheet

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Sanjeev, E-mail: drskumar11@gmail.com [Department of Physics, St. Bede' s College, Shimla-171002 (India); Kumar, Ashok; Ahluwalia, P. K. [Department of Physics, Himachal Pradesh University, Shimla-171005 (India)

    2014-04-24

    First-principle electronic structure calculations for cadmium sulphide (CdS) sheet in hexagonal phase, with Manganese substitution and addition, as well as including the Cd defects, are investigated. The lattice constants calculated for CdS sheet agrees fairly well with results reported for thin films experimentally. The calculations of total spin density of states and partial density of states in different cases shows substantial magnetic dipole moments acquired by the sheet. A magnetic dipole moment 5.00612 μ{sub B} and band gap of the order 1 eV are found when cadmium atom is replaced by Manganese. The magnetism acquired by the sheet makes it functionally important candidate in many applications.

  12. Combustion synthesis of cadmium sulphide nanomaterials

    Indian Academy of Sciences (India)

    Anion-doped cadmium sulphide nanomaterials have been synthesized by using combustionmethod at normal atmospheric conditions. Oxidant/fuel ratios have been optimized in order to obtain CdS with best characteristics. Formation of CdS and size of crystallite were identified by X-ray diffraction and confirmed by ...

  13. Behaviour of six sulphided iron hydroliquefaction catalysts

    International Nuclear Information System (INIS)

    Cook, P.S.; Cashion, J.D.; Bell, A.P.

    1994-01-01

    Five iron ore samples and a synthetic magnetite were added to Wandoan bituminous coal as hydroliquefaction catalysts. Catalyst transformations after sulphiding and after subsequent hydrogenation were analysed. The conversion efficiency increased with decreasing particle size or increased crystallographic disorder and showed that different catalytic mechanisms operate in the hydroliquefaction of brown and black coals. (orig.)

  14. Fatal hydrogen sulphide poisoning in unconfined spaces.

    Science.gov (United States)

    Nogué, S; Pou, R; Fernández, J; Sanz-Gallén, P

    2011-05-01

    Fatal hydrogen sulphide poisoning usually occurs in confined spaces. We report two fatal accidents in unconfined spaces. The first accident caused the death of three workers who entered an unconfined room in a silo of sludge at the same time that a truck dumped several tons of sludge from water purification stations. The hydrogen sulphide that had accumulated inside the silo spilled out into the interior of the room due to a 'splashing effect' caused by the impact of the dumped sludge. The second accident occurred when the foreman of a wastewater treatment plant entered one of the substations to perform routine checks and suddenly lost consciousness. Although he was rapidly transferred to an intensive care unit, death occurred a few hours later. Hydrogen sulphide production was, in this case, due to an 'embolism effect' produced by the displacement of wastewater when the substation pumps were activated. We suggest ways in which accidents such as these caused by sudden release of hydrogen sulphide can be prevented.

  15. Structures and properties of vanadium sulphides

    NARCIS (Netherlands)

    Vries, Ajran Brugt de

    1972-01-01

    The chalcogenides ( sulphides, selenides, tellurides ) of the transition metals have received considerable attention in the last decennia. This is a consequence of the fact that these materials show a great variety of magnetic and electrical properties. The large number of compounds that can occur

  16. 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.

  17. Determination of sulphides in cements by using potentiometry with a selective electrode of sulphides

    Directory of Open Access Journals (Sweden)

    Bernal, José Luis

    1988-03-01

    Full Text Available A procedure for the determination of sulphides attackable by HCI (1 :3 in cements by means of a potentiometric determination with a selective electrodo of sulphides, is proposed.

    Se propone un método para la determinación de sulfuros, basado en el ataque con HCI (1:3, destilación y posterior medida potenciométrica con un electrodo selectivo de sulfuros.

  18. 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.

  19. 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.

  20. 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.

  1. Physical and mechanical properties of gelatin-CMC composite films under the influence of electrostatic interactions.

    Science.gov (United States)

    Esteghlal, Sara; Niakousari, Mehrdad; Hosseini, Seyed Mohammad Hashem

    2018-03-17

    The objective of current study was to examine the electrostatic interactions between gelatin and carboxymethyl cellulose (CMC) as a function of pH and mixing ratio (MR) and to observe how the physical and mechanical properties of gelatin-CMC composite films are affected by these interactions. The interaction between biopolymers was studied using turbidometric analysis at different gelatin: CMC MRs and pH values. A reduction in pH and MR enhanced the electrostatic interactions; while, decreased the relative viscosity of mixed system. Physical and mechanical properties of resultant composite films were examined and compared with those of control gelatin films. Changes in the intensity of interactions between the two biopolymers resulted in films with different properties. Polymer complexation led to formation of resistant film networks of less solubility and swellability. Water vapor permeability (WVP) was not significantly (P≤0.05) influenced by incorporating CMC into continuous gelatin films. Composite films prepared at MR of 9:1 and pH opt (corresponding to the maximum amount of interaction) revealed different characteristics such as maximum amounts of WVP and swelling and minimum amounts of tensile strength and solubility. FTIR spectra of composite films confirmed that gelatin and CMC were not covalently bonded. Copyright © 2018. Published by Elsevier B.V.

  2. A Facile Pathway to Modify Cellulose Composite Film by Reducing Wettability and Improving Barrier towards Moisture

    Directory of Open Access Journals (Sweden)

    Xiaorong Hu

    2017-01-01

    Full Text Available The hydrophilic property of cellulose is a key limiting factor for its wide application. Here, a novel solution impregnation pathway was developed to increase the hydrophobic properties of cellulose. When compared with the regenerated cellulose (RC, the composite films showed a decrease in water uptake ability towards water vapor, and an increase of the water contact angle from 29° to 65° with increasing resin content in the composites, with only a slight change in the transmittance. Furthermore, the Young’s modulus value increased from 3.2 GPa (RC film to 5.1 GPa (RCBEA50 film. The results indicated that the composites had combined the advantages of cellulose and biphenyl A epoxy acrylate prepolymer (BEA resin. The presented method has great potential for the preparation of biocomposites with improved properties. The overall results suggest that composite films can be used as high-performance packaging materials.

  3. Growth of BaTiO3-PVDF composite thick films by using aerosol deposition

    Science.gov (United States)

    Cho, Sung Hwan; Yoon, Young Joon

    2016-01-01

    Barium titanate (BaTiO3)-polyvinylidene fluoride (PVDF) composite thick films were grown by using aerosol deposition at room temperature with BaTiO3 and PVDF powders. To produce a uniform composition in ceramic and polymer composite films, which show a substantial difference in specific gravity, we used PVDF-coated BaTiO3 powders as the starting materials. An examination of the microstructure confirmed that the BaTiO3 were well distributed in the PVDF matrix in the form of a 0 - 3 compound. The crystallite size in the BaTiO3-PVDF composite thick films was 5 ˜ 50 times higher than that in pure BaTiO3 thick films. PVDF plays a role in suppressing the fragmentation of BaTiO3 powder during the aerosol deposition process and in controlling the relative permittivity.

  4. One-step synthesis of PbSe-ZnSe composite thin film

    Directory of Open Access Journals (Sweden)

    Abe Seishi

    2011-01-01

    Full Text Available Abstract This study investigates the preparation of PbSe-ZnSe composite thin films by simultaneous hot-wall deposition (HWD from multiple resources. The XRD result reveals that the solubility limit of Pb in ZnSe is quite narrow, less than 1 mol%, with obvious phase-separation in the composite thin films. A nanoscale elemental mapping of the film containing 5 mol% PbSe indicates that isolated PbSe nanocrystals are dispersed in the ZnSe matrix. The optical absorption edge of the composite thin films shifts toward the low-photon-energy region as the PbSe content increases. The use of a phase-separating PbSe-ZnSe system and HWD techniques enables simple production of the composite package.

  5. 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.

  6. 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.

  7. SnO2: CuO based hydrogen sulphide sensor on LTCC substrates

    Science.gov (United States)

    Kaur, Manmeet; Ganapathi, S. Kailasa; Chaware, Varsha; Rane, Vivek; Ramgir, Niranjan; Datta, Niyanta; Giramkar, Vijaya; Phatak, Girish; Aswal, D. K.; Gupta, S. K.

    2012-06-01

    Dependence of the resistance of metal-oxides thin films on environment is generally used to detect toxic gases at ppm levels. In order to obtain a fast response and recovery, sensing films are heated to high temperatures (upto 300°C). The heater assembly used to raise the film temperature not only makes the sensor bulky but also consumes high power. In our efforts to reduce the size of sensors, we have deposited SnO2: CuO thin film directly onto low-temperature co-fired ceramic (LTCC) substrates with integrated heater and temperature sensor. Sensor films were investigated for their compatibility with LTCC substrate and results show a stable response towards hydrogen sulphide gas for over a year. The stability of heater and thermistor embedded in LTCC substrate has also been monitored. The results of our study show films on LTCC substrate can be successfully applied in sensor technology.

  8. 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

  9. An evolutionary perspective on the immunomodulatory role of hydrogen sulphide.

    Science.gov (United States)

    Rivers-Auty, J

    2015-11-01

    Most preclinical studies on endogenous hydrogen sulphide signalling have given little consideration to the fact that the human body contains more bacterial cells than human cells, and that evolution provides the context for all biology. Whether hydrogen sulphide is pro or anti-inflammatory is heavily debated within the literature, yet researchers have not fully considered that invasive bacteria produce hydrogen sulphide, often at levels far above the endogenous levels of the host. Here I argue that if hydrogen sulphide is an endogenous signalling molecule with immunomodulatory functions, then it must have evolved in the presence of virulent bacteria which produce hydrogen sulphide. This context leads to two competing theories about the evolution of endogenous hydrogen sulphide signalling. The detectable emission theory proposes that bacteria produce hydrogen sulphide as part of normal metabolism and hosts which evolved to detect and respond to this hydrogen sulphide would gain a selective survival advantage. This predicts that the endogenous production of hydrogen sulphide is a mechanism which amplifies the bacterial hydrogen sulphide signal. The opposing protective agent theory predicts that bacterial hydrogen sulphide is an effective defence against the bactericidal mechanisms of the host's immune response. In this case, endogenous hydrogen sulphide production is either at inconsequential levels to alter the immune response, or is involved in the inflammation resolution process. Evidence suggests that the direct interactions of hydrogen sulphide with the bactericidal mechanisms of the innate immune system are most congruent with the protective agent theory. Therefore, I argue that if hydrogen sulphide is an immunomodulatory endogenous signalling molecule its effects are most likely anti-inflammatory. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. PEO + PVP blended polymer composite films for multifunctional ...

    Indian Academy of Sciences (India)

    polymeric materials have been characterized by vibrating sample magnetometre (VSM) system in understanding their magnetic properties. Further, these materials exhibit a para- magnetic behaviour from the host film and ferromagnetism from the doped films. In addition, ionic conductivity and dielectric properties have also ...

  11. Organization of copper nanoclusters in Langmuir–Blodgett films

    Indian Academy of Sciences (India)

    Stable nanoclusters of Cu were synthesized using Langmuir–Blodgett films of octadecylsuccinic acid (ODSA) as template. The Langmuir–Blodgett films of ODSA formed from subphase containing copper ions were first subjected to sulphidation (S) using sodium sulphide and then hydrogenated (H) using hydrogen gas.

  12. Characterization of multilayered and composite edible films from chitosan and beeswax.

    Science.gov (United States)

    Velickova, Elena; Winkelhausen, Eleonora; Kuzmanova, Slobodanka; Moldão-Martins, Margarida; Alves, Vitor D

    2015-03-01

    Chitosan-based edible films were prepared and subjected to cross-linking reactions using sodium tripolyphosphate and/or to beeswax coating on both films interfaces. In addition, chitosan-beeswax emulsion-based films were produced. The goal of these modifications of the chitosan films was the improvement of their barrier to water vapor and to decrease their affinity to liquid water maintaining or improving the mechanical and optical properties of the original chitosan films. The cross-linking with tripolyphosphate decreased both the water vapor permeability and the water absorption capacity to about 55% and 50% of that of the original chitosan films, respectively. However, there was an increase in the films stiffness, revealed by the increased Young modulus from 42 kPa up to 336 kPa. The multilayered wax-chitosan-wax films exhibited a similar improvement of the barrier properties to water vapor, with the advantage of maintaining the mechanical properties of the original chitosan films. However, these wax-coated films showed a higher water absorption capacity, which is believed to be a consequence of water entry into small pores between the film and the wax layers. Regarding the film samples subjected to cross-linking and further coating with beeswax, a similar behavior as the uncoated cross-linked films was observed. The emulsion-based composite films were characterized by a substantial decrease of the water vapor permeability (40%), along with a decrease in their stiffness. Regarding the optical properties, all films presented a yellowish color with similar values of lightness, chroma, and hue. © The Author(s) 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  13. Structure and properties of composite films formed by cellulose nanocrystals and charged latex nanoparticles.

    Science.gov (United States)

    Thérien-Aubin, Héloïse; Lukach, Ariella; Pitch, Natalie; Kumacheva, Eugenia

    2015-04-21

    We report the structural and optical properties of composite films formed from mixed suspensions of cellulose nanocrystals (CNCs) and fluorescent latex nanoparticles (NPs). We explored the effect of NP concentration, size, surface charge, glass transition temperature and film processing conditions on film structure and properties. The chiral nematic order, typical of CNC films, was preserved in films with up to 50 wt% of negatively-charged latex NPs. Composite films were characterized by macroscopically close-to-uniform fluorescence, birefringence, and circular dichroism properties. In contrast, addition of positively charged latex NPs led to gelation of CNC-latex suspensions and disruption of the chiral nematic order in the composite films. Large latex NPs disrupted the chiral nematic order to a larger extend than small NPs. Furthermore, the glass transition of latex NPs had a dramatic effect on the structure of CNC-latex films. Latex particles in the rubbery state were easily incorporated in the ordered CNC matrix and improved the structural integrity of its chiral nematic phase.

  14. Properties and Applications of High Emissivity Composite Films Based on Far-Infrared Ceramic Powder

    Directory of Open Access Journals (Sweden)

    Yabo Xiong

    2017-11-01

    Full Text Available Polymer matrix composite materials that can emit radiation in the far-infrared region of the spectrum are receiving increasing attention due to their ability to significantly influence biological processes. This study reports on the far-infrared emissivity property of composite films based on far-infrared ceramic powder. X-ray fluorescence spectrometry, Fourier transform infrared spectroscopy, thermogravimetric analysis, and X-ray powder diffractometry were used to evaluate the physical properties of the ceramic powder. The ceramic powder was found to be rich in aluminum oxide, titanium oxide, and silicon oxide, which demonstrate high far-infrared emissivity. In addition, the micromorphology, mechanical performance, dynamic mechanical properties, and far-infrared emissivity of the composite were analyzed to evaluate their suitability for strawberry storage. The mechanical properties of the far-infrared radiation ceramic (cFIR composite films were not significantly influenced (p ≥ 0.05 by the addition of the ceramic powder. However, the dynamic mechanical analysis (DMA properties of the cFIR composite films, including a reduction in damping and shock absorption performance, were significant influenced by the addition of the ceramic powder. Moreover, the cFIR composite films showed high far-infrared emissivity, which has the capability of prolonging the storage life of strawberries. This research demonstrates that cFIR composite films are promising for future applications.

  15. Mango kernel starch-gum composite films: Physical, mechanical and barrier properties.

    Science.gov (United States)

    Nawab, Anjum; Alam, Feroz; Haq, Muhammad Abdul; Lutfi, Zubala; Hasnain, Abid

    2017-05-01

    Composite films were developed by the casting method using mango kernel starch (MKS) and guar and xanthan gums. The concentration of both gums ranged from 0% to 30% (w/w of starch; db). Mechanical properties, oxygen permeability (OP), water vapor permeability (WVP), solubility in water and color parameters of composite films were evaluated. The crystallinity and homogeneity between the starch and gums were also evaluated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The scanning electron micrographs showed homogeneous matrix, with no signs of phase separation between the components. XRD analysis demonstrated diminished crystalline peak. Regardless of gum type the tensile strength (TS) of composite films increased with increasing gum concentration while reverse trend was noted for elongation at break (EAB) which found to be decreased with increasing gum concentration. The addition of both guar and xanthan gums increased solubility and WVP of the composite films. However, the OP was found to be lower than that of the control with both gums. Furthermore, addition of both gums led to changes in transparency and opacity of MKS films. Films containing 10% (w/w) xanthan gum showed lower values for solubility, WVP and OP, while film containing 20% guar gum showed good mechanical properties. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Preparation and properties of Starch-g-PLA/poly(vinyl alcohol) composite film.

    Science.gov (United States)

    Hu, Yingmo; Wang, Qingling; Tang, Mingru

    2013-07-25

    Starch/lactic acid graft copolymer (Starch-g-PLA) was prepared by the in situ copolymerization of starch grafted with lactic acid catalyzed with sodium hydroxide, and then mixed with poly(vinyl alcohol) (PVA) to get composite films. The structures of the graft copolymer and composite films were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The mechanical properties, water resistance, and thermal stability were also investigated. It was found that the compatibility of Starch-g-PLA and PVA was better than that of starch and PVA in the composite films. The tensile strength and elongation at break of the Starch-g-PLA/PVA composite film increased by 69.15% and 84.22%, respectively, while the water absorption decreased by 50.39%, which overcame the shortcomings of hydrophilicity and poor mechanical properties of Starch/PVA film. Thermogravimetric analysis (TGA) also showed that the thermal stability of Starch-g-PLA/PVA film was improved compared with Starch/PVA film. Copyright © 2013 Elsevier Ltd. All rights reserved.

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

    International Nuclear Information System (INIS)

    Ugucioni, J.C.; Ghilardi Netto, T.; Mulato, M.

    2010-01-01

    Mercuric iodide (HgI 2 ) composite films were obtained by using the casting technique. Insulator polymers such as polyamide, polycarbonate and polystyrene were mixed to HgI 2 crystallites forming a final sub-millimeter thick self-standing film. Fabrication temperature varied from 10 to 100 o C, 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 HgI 2 crystalline device.

  18. PEDOT: PSS/PEDOT composite film for high performance electrochemical electrode

    Science.gov (United States)

    Lu, Fei; Chen, Yan; Mao, Xiling; Xu, Lu; Xu, Jianhua

    2017-01-01

    Micro-supercapacitors are promising energy storage devices that can complement batteries in miniaturized portable electronics and microelectromechanical systems. Here, we develop a facile method to fabricate a hierarchically structured film as electrode material of supercapacitor. The hybrid PEDOT: PSS/PEDOT film is prepared via a two-step process: PEDOT: PSS film was spin-coated on the substrate in the first step and followed by the vapor phase polymerization (VPP) of PEDOT film on the PEDOT: PSS film in the second step. Each component in the hybrid film provides unique and crucial function to achieve optimized electrochemical properties. Volumetric capacity of composite film (238.63 F/cm3) is much higher than that of pure VPP PEDOT film (87.36 F/cm3). The hybrid film also exhibits excellent charge/discharge rate and good cycling stability, retaining 90.2% of its initial charge after 5500 cycles. The enhanced electrochemical performances of such composites indicate a promising future as electrode material for electrochemical energy storage devices.

  19. Synthesis and characterization of Au-MWCNT/PEDOT: PSS composite film for optoelectronic applications

    Science.gov (United States)

    Jasna, M.; Anjana, R.; Jayaraj, M. K.

    2017-08-01

    Recently, flexible organic optoelectronics have got great attention because of their light weight, mechanical flexibility and cost effective fabrication process. Conjugated polymers like PEDOT: PSS are widely used for the transparent electrode applications due to its chemical stability, high conductivity, flexibility and optical transparency in the visible region. Conductivity of the PEDOT: PSS polymer can be enhanced by adding organic solvents or conducting nano fillers like CNT, graphene, etc. Carbon nanotubes are good nano fillers to enhance the conductivity and mechanical strength of PEDOT: PSS composite film. Inthe present work, the effect of gold nano particles in PEDOT: PSS/CNT composite is studied. The conductivity enhancement in PEDOT: PSS/CNT thin films can be attributed to the formation of CNT network in the polymer matrix and conformational change of the PEDOT from benzoid to quinoid structure. Even though the conductivity was enhanced, the transparency of the composite thin films decreased with increase in CNT concentration. To overcome this problem, gold nano particles were attached to CNT walls via chemical route. AuMWCNT/PEDOT: PSS composite films were prepared by spin coating method. TEM images confirmed the decoration of gold nano particles on CNT walls. Electrical and optical properties of the composite films were studied. This simple solution processed conducting films are suitable for optoelectronic applications

  20. Synthesis of PVDF/SBT composite thin films by spin coating technology and their ferroelectric properties

    Directory of Open Access Journals (Sweden)

    Chen Changchun

    2016-09-01

    Full Text Available Ferroelectric composite thin films of x-SBT/PVDF with different SBT content (weight ratios of SBT to PVDF, x = 0 %, 5 %, 10 %, 15 %, 20 % were prepared by spin-coating method. The crystal structures of x-SBT/PVDF films were analyzed by X-ray diffraction (XRD measurements and Fourier transform-infrared spectroscopy (FT-IR, respectively. Experimental results demonstrated that both α, β-phases PVDF and the layered perovskite SBT co-existed in the x-SBT/PVDF samples. With an increase of SBT content in the x-SBT/PVDF thin films, both the dielectric constant and the saturated polarization were also increased, compared with those of pure PVDF thin film. More importantly, when the SBT content in the x-SBT/PVDF thin films was larger than 15 %, the coercive field of x-SBT/PVDF thin films was also decreased.

  1. Patterns of Macroinvertebrate and Fish Diversity in Freshwater Sulphide Springs

    Directory of Open Access Journals (Sweden)

    Ryan Greenway

    2014-09-01

    Full Text Available Extreme environments are characterised by the presence of physicochemical stressors and provide unique study systems to address problems in evolutionary ecology research. Sulphide springs provide an example of extreme freshwater environments; because hydrogen sulphide’s adverse physiological effects induce mortality in metazoans even at micromolar concentrations. Sulphide springs occur worldwide, but while microbial communities in sulphide springs have received broad attention, little is known about macroinvertebrates and fish inhabiting these toxic environments. We reviewed qualitative occurrence records of sulphide spring faunas on a global scale and present a quantitative case study comparing diversity patterns in sulphidic and adjacent non-sulphidic habitats across replicated river drainages in Southern Mexico. While detailed studies in most regions of the world remain scarce, available data suggests that sulphide spring faunas are characterised by low species richness. Dipterans (among macroinvertebrates and cyprinodontiforms (among fishes appear to dominate the communities in these habitats. At least in fish, there is evidence for the presence of highly endemic species and populations exclusively inhabiting sulphide springs. We provide a detailed discussion of traits that might predispose certain taxonomic groups to colonize sulphide springs, how colonizers subsequently adapt to cope with sulphide toxicity, and how adaptation may be linked to speciation processes.

  2. Chitosan-based films composites for wound healing purposes; Filmes compositos de quitosana para aplicacao no revestimento de ferimentos

    Energy Technology Data Exchange (ETDEWEB)

    Alves, Natali de O.; Silva, Gabriela T. da; Schulz, Gracelie A.S.; Fajardo, Andre R., E-mail: natalioliveiraalves@gmail.com [Universidade Federal de Pelotas (LaCoPol/UFPel), Pelotas, RS (Brazil). Centro de Ciencias Quimicas, Farmaceuticas e de Alimentos. Lab. de Tecnologia e Desenvolvimento de Compositos e Materiais Polimericos

    2015-07-01

    Chitosan has been extensively applied in the developing of biomaterials due to its desirable good physico-chemical and biological properties. According to this, here films composite of chitosan, poly(vinyl alcohol) and bovine bone powder were prepared by casting willing to be applied in wound healing purposes. Moreover, the first step was the developing of a suitable method to obtain bovine bone powder, which was utilized here as filler. All the materials and films were fully characterized by FTIR, DRX and thermal analysis. Water uptake capacity was measured by swelling assays. (author)

  3. Electrochemical Reduction of CO2 on Compositionally Variant Au-Pt Bimetallic Thin Films

    DEFF Research Database (Denmark)

    Ma, Ming; Hansen, Heine Anton; Valenti, Marco

    2017-01-01

    by a magnetron sputtering co-deposition technique with tunable composition. It was found that the syngas ratio (CO:H2) on the Au-Pt films is able to be tuned by systematically controlling the binary composition. This tunable catalytic selectivity is attributed to the variation of binding strength of COOH and CO...

  4. 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.

  5. Polyethylene-Carbon Nanotube Composite Film Deposited by Cold Spray Technique

    Science.gov (United States)

    Ata, Nobuhisa; Ohtake, Naoto; Akasaka, Hiroki

    2017-10-01

    Carbon nanotubes (CNTs) are high-performance materials because of their superior electrical conductivity, thermal conductivity, and self-lubrication, and they have been studied for application to polymer composite materials as fillers. However, the methods of fabricating polymer composites with CNTs, such as injection molding, are too complicated for industrial applications. We propose a simple cold spray (CS) technique to obtain a polymer composite of polyethylene (PE) and CNTs. The composite films were deposited by CS on polypropylene and nano-porous structured aluminum substrates. The maximum thickness of the composite film was approximately 1 mm. Peaks at G and D bands were observed in the Raman spectra of the films. Scanning electron microscopy images of the film surface revealed that PE particles were melted by the acceleration gas and CNTs were attached with melted PE. The PE particles solidified after contact with the substrate. These results indicate that PE-CNT composite films were successfully deposited on polypropylene and nano-porous structured aluminum substrates by CS.

  6. 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.

  7. 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.

  8. Thermally evaporated thin films of SnS for application in solar cell devices

    International Nuclear Information System (INIS)

    Miles, Robert W.; Ogah, Ogah E.; Zoppi, Guillaume; Forbes, Ian

    2009-01-01

    SnS (tin sulphide) is of interest for use as an absorber layer and the wider energy bandgap phases e.g. SnS 2 , Sn 2 S 3 and Sn/S/O alloys of interest as Cd-free buffer layers for use in thin film solar cells. In this work thin films of tin sulphide have been thermally evaporated onto glass and SnO 2 :coated glass substrates with the aim of optimising the properties of the material for use in photovoltaic solar cell device structures. In particular the effects of source temperature, substrate temperature, deposition rate and film thickness on the chemical and physical properties of the layers were investigated. Energy dispersive X-ray analysis was used to determine the film composition, X-ray diffraction to determine the phases present and structure of each phase, transmittance and reflectance versus wavelength measurements to determine the energy bandgap and scanning electron microscopy to observe the surface topology and topography and the properties correlated to the deposition parameters. Using the optimised conditions it is possible to produce thin films of tin sulphide that are pinhole free, conformal to the substrate and that consist of densely packed columnar grains. The composition, phases present and the optical properties of the layers deposited were found to be highly sensitive to the deposition conditions. Energy bandgaps in the range 1.55 eV-1.7 eV were obtained for a film thickness of 0.8 μm, and increasing the film thickness to > 1 μm resulted in a reduction of the energy bandgap to less than 1.55 eV. The applicability of using these films in photovoltaic solar cell device structures is also discussed.

  9. Direct electrochemistry and electrocatalysis of hemoglobin protein entrapped in graphene and chitosan composite film.

    Science.gov (United States)

    Xu, Huifeng; Dai, Hong; Chen, Guonan

    2010-04-15

    A novel, biocompatible sensing strategy based on graphene and chitosan composite film for immobilizing the hemoglobin protein was firstly adopted. The direct electron transfer and bioelectrocatalytic activity of hemoglobin after incorporation into the composite film were investigated. A pair of reversible redox waves of hemoglobin was appeared, and hemoglobin could exhibit its bioelectrocatalytic activity toward H(2)O(2) in a long term. Such results indicated that graphene and chitosan composite could be a friendly biocompatible interface for immobilizing biomolecules and keeping their native structure. Furthermore, the appearance of graphene in the composite film could facilitate the electron transfer between matrix and the electroactive center of hemoglobin. Hence, this graphene and chitosan based protocol would be a promising platform for protein immobilization and biosensor preparation. (c) 2010 Elsevier B.V. All rights reserved.

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

    International Nuclear Information System (INIS)

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

    2016-01-01

    We report a flexible hydrogen sensor, composed of WS 2 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 WS 2 –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 WS 2 –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. (paper)

  11. 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.

  12. Friction and wear performance of boron doped, undoped microcrystalline and fine grained composite diamond films

    Science.gov (United States)

    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

  13. Preparation of the flexible ZrO{sub 2}/C composite nanofibrous film via electrospinning

    Energy Technology Data Exchange (ETDEWEB)

    Yin, Xin; Song, Lixin; Xie, Xueyao; Zhou, Yangyang; Guan, Yingli; Xiong, Jie [Zhejiang Sci-Tech University, College of Materials and Textiles, Hangzhou (China); Zhejiang Sci-Tech University, Key Laboratory of Advanced Textile Materials and Manufacturing Technology of Ministry of Education, Hangzhou (China)

    2016-07-15

    The flexible ZrO{sub 2}/C composite nanofibrous film was fabricated by electrospinning and thermal treatment. Field-emission scanning electron microscopy, transmission electron microscopy, X-ray diffractometer, and Fourier transform infrared spectra were used to characterize the morphology and microstructure of the ZrO{sub 2}/C composite nanofibrous film. The ZrO{sub 2}/C nanofibers exhibited rough surface and had the average diameter of about 230 ± 35 nm. And the ZrO{sub 2} nanoparticles were incorporated in carbon matrix and in tetragonal and monoclinic. The flexural property of the ZrO{sub 2}/C composite nanofibrous film was investigated in detail. The results showed that the flexural property of the nanofibrous film was greatly improved with addition of the ZrO{sub 2} nanoparticles. Besides, with the increase of the contents of ZrO{sub 2} nanoparticles, the flexural modulus of the nanofibrous film decreased, reached a lowest value, and then increased. The lowest flexural modulus of the ZrO{sub 2}/C composite nanofibrous film in precursor concentration of 7.0 wt% was 8.55 ± 0.06 MPa. (orig.)

  14. Late Jurassic ocean anoxic event: evidence from voluminous sulphide deposition and preservation in the Panthalassa.

    Science.gov (United States)

    Nozaki, Tatsuo; Kato, Yasuhiro; Suzuki, Katsuhiko

    2013-01-01

    The historically productive copper-bearing Besshi-type sulphide deposits in the Japanese accretionary complex were formed as volcanogenic massive sulphide deposits on the deep-sea floor of the Panthalassa Ocean. Here we report that eleven typical Besshi-type deposits yielded Re-Os isochron ages around 150 Ma (148.4 ± 1.4 Ma from the composite isochron) in Late Jurassic time. This date coincides with the lowest marine (87)Sr/(86)Sr ratio and highest atmospheric CO2 concentration of the past 300 million years. We infer that intense mid-ocean ridge hydrothermal and volcanic activity in the Late Jurassic produced huge sulphide deposits and large emissions of CO2 gas, leading to global warming and a stratified Panthalassa Ocean with anoxic deep seas that favored preservation of sulphides in the pelagic environment. The emergence of ocean anoxia triggered by seafloor volcanism is also consistent with a positive δ(13)C excursion and widespread deposition of petroleum source rocks and black shales.

  15. Investigation of the explosion hazards of hydrogen sulphide

    International Nuclear Information System (INIS)

    Saber, A.J.; Sulmistras, A.; Moen, I.O.; Thibault, P.A.

    1986-03-01

    The results of Phase I of an investigation directed towards quantifying the explosion hazards of hydrogen sulphide in air are described. The first phase is focussed on detonation in free hydrogen sulphide/air clouds. Detonation properties, including velocity and pressure, have been calculated and compared with experimental results. The observed detonation structure together with critical tube tests tests are used to assess the detonability of hydrogen sulphide/air mixtures relative to hydrogen and common hydrocarbon gases. Detailed chemical kinetic modelling of hydrogen sulphide combustion in air has been performed to correlate the detonation cell size data and to determine the influence of water vapour on the detonability of hydrogen sulphide in air. Calculations of the blast wave properties for detonation of a hydrogen sulphide/air cloud provide the data required to assess the blast effects of such explosions

  16. Photoelectric Properties of Film Composites Based on Poly(Vinyl Butyral) and Heterometallic Complexes

    Science.gov (United States)

    Davidenko, N. A.; Kokozay, V. N.; Studzinsky, S. L.; Petrusenko, S. R.; Plyuta, N. I.; Davidenko, I. I.

    2018-01-01

    Photosensitive polymeric film composites based on nonphotoconducting poly(vinyl butyral) doped with heterometallic Cu/M complexes (M = Ca, Sr) were synthesized and investigated. These composites possessed photoconducting and photovoltaic properties and electron-type photoconductivity. The greater photocurrent for composites with complexes having shorter distances between the nearest Cu metal centers was attributed to the greater probability of electron transfer between these centers.

  17. Evaluation of structure and mechanical properties of Ni-rich NiTi/Kapton composite film

    Energy Technology Data Exchange (ETDEWEB)

    Mohri, Maryam [Institute of Nanotechnology (INT), Karlsruhe Institute of Technology (KIT), Karlsruhe (Germany); School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, Tehran (Iran, Islamic Republic of); Nili-Ahmadabadi, Mahmoud [School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, Tehran (Iran, Islamic Republic of); PouryazdanPanah, Mohsen; Hahn, Horst [Institute of Nanotechnology (INT), Karlsruhe Institute of Technology (KIT), Karlsruhe (Germany); Joint Research Labaratory Nanomaterials, Technische Universität Darmstadt, Darmstadt (Germany)

    2016-06-21

    NiTi thin films are usually sputtered on silicon wafers by magnetron sputtering. But the systems composed of thin film on flexible polymeric substrate are used in many applications such as micro electro-mechanical systems (MEMS). Investigation on mechanical properties of thin films has attracted much attention due to their widespread applications. In this paper, the mechanical properties of 1 µm-thick crystallized Ni-49.2 at%Ti thin film alloy deposited by DC magnetron sputtering on Kapton substrate are investigated by using tensile test. The as-deposited thin films are in amorphous state, then for crystallization, the thin film was annealed at 450 °C for 30 min. Formation of the austenite phase after annealing was confirmed by X-ray diffractometry (XRD) and differential scanning calorimetry (DSC). The surface morphology of as deposited and crystallized thin films were examined by scanning electron microscopy (SEM). Stress-strain curves of the NiTi alloy thin film were obtained by subtracting of the stress-strain Kapton curves from the corresponding curves of the NiTi/Kapton composite. The XRD results revealed that the NiTi thin film deposited on the Kapton is austenitic and presents super-elastic effect at room temperature. This pseudo elastic effect leads to more recoverable strain in NiTi/Kapton composite film compared with Kapton foils on loading/unloading test. Furthermore, it was concluded that nanostructure of the NiTi thin film is responsible for remarkable improvement of ultimate tensile strength (1.4 GPa) at a strain of 30% compared with the bulk material.

  18. Magnetic Composite Thin Films of FexOy Nanoparticles and Photocrosslinked Dextran Hydrogels

    International Nuclear Information System (INIS)

    Brunsen, Annette; Utech, Stefanie; Maskos, Michael; Knoll, Wolfgang; Jonas, Ulrich

    2012-01-01

    Magnetic hydrogel composites are promising candidates for a broad field of applications from medicine to mechanical engineering. Here, surface-attached composite films of magnetic nanoparticles (MNP) and a polymeric hydrogel (HG) were prepared from magnetic iron oxide nanoparticles and a carboxymethylated dextran with photoreactive benzophenone substituents. A blend of the MNP and the dextran polymer was prepared by mixing in solution, and after spin-coating and drying the blend film was converted into a stable MNP–HG composite by photocrosslinking through irradiation with UV light. The bulk composite material shows strong mobility in a magnetic field, imparted by the MNPs. By utilizing a surface layer of a photoreactive adhesion promoter on the substrates, the MNP–HG films were covalently immobilized during photocrosslinking. The high stability of the composite was documented by rinsing experiments with UV–Vis spectroscopy, while surface plasmon resonance and optical waveguide mode spectroscopy was employed to investigate the swelling behavior in dependence of the nanoparticle concentration, the particle type, and salt concentration. - Highlights: ► blending of iron oxide nanoparticles with photocrosslinkable carboxymethyldextran. ► UV irradiation of blend yields surface-attached, magnetic hydrogel films. ► film characterization by surface plasmon resonance/optical waveguide spectroscopy. ► swelling decreases with increasing nanoparticle content. ► swelling decreases with increasing NaCl salt concentration in the aqueous medium.

  19. 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.

  20. Enhanced thermoelectric properties of PEDOT/PSS/Te composite films treated with H2SO4

    International Nuclear Information System (INIS)

    Song, Haijun; Cai, Kefeng; Shen, Shirley

    2016-01-01

    Firstly, tellurium (Te) nanorods with a high Seebeck coefficient have been integrated into a conducting polymer PEDOT/PSS to form PEDOT/PSS/Te composite films. The Seebeck coefficient of the PEDOT/PSS/Te (90 wt.%) composite films is ~191 μV/K, which is about 13 times greater than that of pristine PEDOT/PSS. Then, H 2 SO 4 treatment has been used to further tune the thermoelectric properties of the composite films by adjusting the doping level and increasing the carrier concentration. After the acid treatment, the electrical conductivity of the composite films has increased from 0.22 to 1613 S/cm due to the removal of insulating PSS and the structural rearrangement of PEDOT. An optimized power factor of 42.1 μW/mK 2 has been obtained at room temperature for a PEDOT/PSS/Te (80 wt.%) sample, which is about ten times larger than that of the untreated PEDOT/PSS/Te composite film.

  1. Automated Fiber Placement of PEEK/IM7 Composites with Film Interleaf Layers

    Science.gov (United States)

    Hulcher, A. Bruce; Banks, William I., III; Pipes, R. Byron; Tiwari, Surendra N.; Cano, Roberto J.; Johnston, Norman J.; Clinton, R. G., Jr. (Technical Monitor)

    2001-01-01

    The incorporation of thin discrete layers of resin between plies (interleafing) has been shown to improve fatigue and impact properties of structural composite materials. Furthermore, interleafing could be used to increase the barrier properties of composites used as structural materials for cryogenic propellant storage. In this work, robotic heated-head tape placement of PEEK/IM7 composites containing a PEEK polymer film interleaf was investigated. These experiments were carried out at the NASA Langley Research Center automated fiber placement facility. Using the robotic equipment, an optimal fabrication process was developed for the composite without the interleaf. Preliminary interleaf processing trials indicated that a two-stage process was necessary; the film had to be tacked to the partially-placed laminate then fully melted in a separate operation. Screening experiments determined the relative influence of the various robotic process variables on the peel strength of the film-composite interface. Optimization studies were performed in which peel specimens were fabricated at various compaction loads and roller temperatures at each of three film melt processing rates. The resulting data were fitted with quadratic response surfaces. Additional specimens were fabricated at placement parameters predicted by the response surface models to yield high peel strength in an attempt to gage the accuracy of the predicted response and assess the repeatability of the process. The overall results indicate that quality PEEK/lM7 laminates having film interleaves can be successfully and repeatability fabricated by heated head automated fiber placement.

  2. Theory of magnetoelectric coupling in 2-2-type magnetostrictive/piezoelectric composite film with texture

    International Nuclear Information System (INIS)

    Liu Chaoqian; Fei Weidong; Li Weili

    2008-01-01

    It is well accepted that textures in polycrystalline films have significant effects on film properties. The magnetoelectric (ME) coupling in a 2-2-type multiferroic composite film was theoretically discussed using Landau-Ginsburg-Devonshire theory, where the influences of dispersive texture and residual stress were considered. As an example, the 2-2-type CoFe 2 O 4 /BaTiO 3 composite film was theoretically analysed, wherein the case of both the magnetostrictive phase and the piezoelectric phase with (0 0 1)-oriented texture was considered. Our results show that the ME coupling is enhanced with the texture degree of the piezoelectric phase and/or the magnitude of the residual tensile stress, but weakened with the magnitude of residual compressive stress. With increasing texture degree of the magnetostrictive phase, the ME coupling is enhanced when the texture degree is smaller than a critical value, but weakened when the texture degree is larger than the critical value

  3. Change in the Crystallite Orientation of Poly(ethylene oxide)/Cellulose Nanofiber Composite Films.

    Science.gov (United States)

    Fukuya, Miki Noda; Senoo, Kazunobu; Kotera, Masaru; Yoshimoto, Mamoru; Sakata, Osami

    2017-12-11

    The crystallite orientation and crystallographic domain structure of poly(ethylene oxide) (PEO) in cellulose nanofiber-incorporated (CNF-incorporated) PEO films developed for packaging materials were observed using wide-angle X-ray diffraction for different CNF filling ratios. When a CNF filling ratio of 50 wt %, the PEO molecular chains were oriented in a direction parallel to the surface of the film. The fiber axis of the CNFs became parallel to the surface of the PEO/CNF composite film when the filling ratio was >25 wt %. The change in the orientation of the PEO crystals occurred because increasing the amount of CNF in the composite films decreased the space in which the PEO could be crystallized. Furthermore, the hydrogen bonds between the PEO and the CNF may behave as crystallization nuclei for the PEO. Our results thus pave the way toward the development of packaging materials that are more impermeable to gases than the current materials.

  4. Structural, chemical and electrical characterisation of conductive graphene-polymer composite films

    Energy Technology Data Exchange (ETDEWEB)

    Brennan, Barry; Spencer, Steve J.; Belsey, Natalie A. [National Physical Laboratory, Teddington, TW11 0LW (United Kingdom); Faris, Tsegie [DZP Technologies Ltd., Future Business Centre, Cambridge, CB4 2HY (United Kingdom); Cronin, Harry [DZP Technologies Ltd., Future Business Centre, Cambridge, CB4 2HY (United Kingdom); Advanced Technology Institute (ATI), University of Surrey, Guildford, GU2 7XH (United Kingdom); Silva, S. Ravi P. [Advanced Technology Institute (ATI), University of Surrey, Guildford, GU2 7XH (United Kingdom); Sainsbury, Toby; Gilmore, Ian S. [National Physical Laboratory, Teddington, TW11 0LW (United Kingdom); Stoeva, Zlatka [DZP Technologies Ltd., Future Business Centre, Cambridge, CB4 2HY (United Kingdom); Pollard, Andrew J., E-mail: andrew.pollard@npl.co.uk [National Physical Laboratory, Teddington, TW11 0LW (United Kingdom)

    2017-05-01

    Graphical abstract: Secondary Ion Mass Spectrometry (SIMS) imaging of the dispersion of graphene within graphene-polymer composites using the Na{sup +} signal. - Highlights: • Relation of properties of graphene flakes with electrical properties of composite. • Standardised characterisation method for structural properties of graphene flakes. • Structural and chemical characterisation of commercial graphene flakes. • ToF-SIMS used to determine dispersion of graphene in polymer. - Abstract: Graphene poly-acrylic and PEDOT:PSS nanocomposite films were produced using two alternative commercial graphene powders to explore how the graphene flake dimensions and chemical composition affected the electrical performance of the film. A range of analytical techniques, including scanning electron microscopy (SEM), atomic force microscopy (AFM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS), were employed to systematically analyse the initial graphene materials as well as the nanocomposite films. Electrical measurements indicated that the sheet resistance of the films was affected by the properties of the graphene flakes used. To further explore the composition of the films, ToF-SIMS mapping was employed and provided a direct means to elucidate the nature of the graphene dispersion in the films and to correlate this with the electrical analysis. These results reveal important implications for how the dispersion of the graphene material in films produced from printable inks can be affected by the type of graphene powder used and the corresponding effect on electrical performance of the nanocomposites. This work provides direct evidence for how accurate and comparable characterisation of the graphene material is required for real-world graphene materials to develop graphene enabled films and proposes a measurement protocol for comparing graphene materials that can be used for international

  5. Low temperature composite bolometers using RuO2 films as a thermistor

    International Nuclear Information System (INIS)

    Chapellier, M.; Rasmussen, F.B.

    1989-01-01

    Results from a massive composite bolometer made of a sapphire crystal and ruthenium oxide films are presented. The properties of such RuO 2 films, in the temperature range [50 mK, 200 mK] have been studied. Individual particle detections, using an 241 Am source, have been used to calibrate the system in this temperature interval. Improvements in the performances of such detectors lead to consider them as realistic candidates for the detection of Dark Matter

  6. Electrochemical reduction of graphene oxide in electrically conducting poly(3,4-ethylenedioxythiophene) composite films

    International Nuclear Information System (INIS)

    Lindfors, Tom; Österholm, Anna; Kauppila, Jussi; Pesonen, Markus

    2013-01-01

    Here we show that the graphene oxide (GO) can be electrochemically reduced in composite films of poly(3,4-ethylenedioxythiophene) (PEDOT) and GO. EDOT was electropolymerized in an aqueous GO dispersion at a constant potential resulting in the incorporation of GO in the PEDOT matrix. Scanning electron microscopy (SEM) images revealed that the formed PEDOT–GO films had a layered structure. X-ray photoelectron spectra measured after 10, 20 and 30 min of electrochemical reduction at −0.85 V, verified that the reduction efficiently removed the epoxy and hydroxyl groups from the GO surface. The number of oxygen-containing functional groups decreased considerably already after 10 min of electrochemical reduction and the C:O ratio of the composite films increased with increasing reduction time confirming that GO was successfully reduced in the polymer matrix. In contrast to chemical reduction in 0.15 M NaBH 4 , we show that the PEDOT matrix withstands the electrochemical reduction without any degradation in electroactivity. We also studied the effect of pH of the GO dispersion on the subsequent redox behavior of the PEDOT–GO films. Increasing the pH from 2.5 to 4.5 improved the electroactivity of the films and also facilitated film formation probably due to the presence of a higher amount of ionized carboxylic groups on the GO surface. Electrochemical impedance measurements showed that increasing the pH of the GO dispersion resulted in films with a higher redox capacitance. Atomic force microscopy measurements revealed that the electrochemical reduction slightly increased the surface roughness of the composite films. The simple and fully electrochemical synthesis and reduction procedure of the PEDOT–GO films are expected to be useful in the fabrication of interfacial materials for electrochemical all-solid-state devices where it is desirable to have reversible ion-to-electron transduction in combination with high redox capacitance

  7. Composition and corrosion properties of high-temperature oxide films on steel type 18-10

    International Nuclear Information System (INIS)

    Vakulenko, B.F.; Morozov, O.N.; Chernysheva, M.V.

    1985-01-01

    The composition and propeties of oxide films, formed in the process of tube production of steel type 18-10, as well as the behaviour of the steels coated with oxide films under operating conditions of NPP heat-exchange equipment at the 20-300 deg C temperatures are determined. It is found, that the films have a good adhesion to the steel surface and repeat the metal structure without interfering with, the surface defect determination. Introduction of the NaNO 2 corrosion inhibitor decreases the film destruction rate to the level of the base metal corrosion. It is found acceptable to use tubes of steel 18-10 coated with dense oxide films in the heat-exchange and water supply systems of NPP

  8. Composite Films of Arabinoxylan and Fibrous Sepiolite: Morphological, Mechanical, and Barrier Properties

    DEFF Research Database (Denmark)

    Sárossy, Zsuzsa; Blomfeldt, J.O.; Hedenqvist, Mikael S.

    2012-01-01

    in the arabinoxylan films and sepiolite fiber aggregation was not found. FT-IR spectroscopy provided some evidence for hydrogen bonding between sepiolite and arabinoxylan. Consistent with these findings, mechanical testing showed increases in film stiffness and strength with sepiolite addition and the effect of poly......Hemicelluloses represent a largely unutilized resource for future bioderived films in packaging and other applications. However, improvement of film properties is needed in order to transfer this potential into reality. In this context, sepiolite, a fibrous clay, was investigated as an additive...... to enhance the properties of rye flour arabinoxylan. Composite films cast from arabinoxylan solutions and sepiolite suspensions in water were transparent or semitransparent at additive loadings in the 2.5−10 wt % range. Scanning electron microscopy showed that the sepiolite was well dispersed...

  9. Structure, phase analysis and component composition of multilayer films depositing in T-10 tokamak

    International Nuclear Information System (INIS)

    Guseva, M.I.; Gureev, V.M.; Khimchenko, L.N.; Kolbasov, B.N.; Vukolov, K.Yu.

    2005-01-01

    The structure and composition of the deuterocarbon films, formed on the internal surfaces of the T-10 tokamak vacuum chamber and on the stainless steel mirror-specimens positioned inside the T-10 tokamak upper stub pipe during the experimental campaigns in spring-summer of 2002 and autumn of 2003, are compared. Before the 2003 experimental campaign the ring diaphragm made of MPG-8 graphite was removed from the tokamak and MPG-8 graphite in the movable limiter was replaced by RGT-91 graphite. All the films have a multilayer structure. In the 2002 campaign all the films had homogeneous layer structure and smooth surface without any signs of physical sputtering. The films formed on the chamber walls in both campaigns were 'soft' and had reddish-brown colour. The average atomic D/C ratio in these films during 2002 campaign was of 0.66. The 'soft' film formation was caused by the plasma-wall interaction during the vacuum chamber conditioning under deuterium discharges. Preliminary X-ray diffraction analysis suggests that these films have amorphous structure and contain from 4 to 10 % fullerene-like substance with lattice constant in the range of 1.2-1.4 nm. Mirror surfaces could be screened during chamber conditioning and exposed to plasma only during working discharges. The films on mirrors were thinner than those on the vacuum chamber walls and, as a rule, semitransparent. The films deposited on the mirror surface, exposed to plasma only during working discharges, in 2002 were 'hard' with D/C = 0.26. Two crystalline phases with interplanar spacings of 0.359 and 0.304 nm at the Bragg angles 2θ of 24.8 and 28.8 deg respectively were revealed in a diffractogram of these films. In the 2003 campaign both types of films (formed on vacuum chamber walls and deposited on mirror specimens) were 'soft' with D/C ratio of 0.57 and 1.55 respectively. Deuterium concentration in the films is determined by the temperature of film formation - <370 K on mirror specimens and ∼520 K

  10. Compositional tuning of yttrium iron garnet film properties by multi-beam pulsed laser deposition

    International Nuclear Information System (INIS)

    Sposito, Alberto; Stenning, Gavin B.G.; Gregory, Simon A.; Groot, Peter A.J. de; Eason, Robert W.

    2014-01-01

    We report an investigation of the effects of variation of composition on the properties of yttrium iron garnet films grown on yttrium aluminium garnet substrates by multi-beam pulsed laser deposition. The ferromagnetic resonance linewidth is used as a quality factor: a significant variation is noticed from changing composition, with an experimentally observed optimum at Y 3.5 Fe 4.5 O 12 . - Highlights: • Compositional tuning of materials is demonstrated via multi-pulsed laser deposition. • YIG (yttrium iron garnet) films with variable composition are prepared. • Variation of YIG properties with changing composition is investigated. • Growth dynamics of YIG is investigated to optimise FMR (ferromagnetic resonance). • FMR linewidth is minimised approximately at Y 3.5 Fe 4.5 O 12

  11. Compositional tuning of yttrium iron garnet film properties by multi-beam pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Sposito, Alberto, E-mail: as11g10@orc.soton.ac.uk [Optoelectronics Research Centre, University of Southampton, Southampton SO171BJ (United Kingdom); Stenning, Gavin B.G.; Gregory, Simon A.; Groot, Peter A.J. de [Physics and Astronomy, University of Southampton, Southampton SO171BJ (United Kingdom); Eason, Robert W. [Optoelectronics Research Centre, University of Southampton, Southampton SO171BJ (United Kingdom)

    2014-10-01

    We report an investigation of the effects of variation of composition on the properties of yttrium iron garnet films grown on yttrium aluminium garnet substrates by multi-beam pulsed laser deposition. The ferromagnetic resonance linewidth is used as a quality factor: a significant variation is noticed from changing composition, with an experimentally observed optimum at Y{sub 3.5}Fe{sub 4.5}O{sub 12}. - Highlights: • Compositional tuning of materials is demonstrated via multi-pulsed laser deposition. • YIG (yttrium iron garnet) films with variable composition are prepared. • Variation of YIG properties with changing composition is investigated. • Growth dynamics of YIG is investigated to optimise FMR (ferromagnetic resonance). • FMR linewidth is minimised approximately at Y{sub 3.5}Fe{sub 4.5}O{sub 12}.

  12. The Formation Mechanism and Corrosion Resistance of a Composite Phosphate Conversion Film on AM60 Alloy.

    Science.gov (United States)

    Chen, Jun; Lan, Xiangna; Wang, Chao; Zhang, Qinyong

    2018-03-08

    Magnesium alloy AM60 has high duc and toughness, which is expected to increase in demand for automotive applications. However, it is too active, and coatings have been extensively studied to prevent corrosion. In this work, a Ba-containing composite phosphate film has been prepared on the surface of AM60. The composition and formation mechanism of the film have been investigated using a scanning electronic microscope equipped with energy dispersive X-ray spectroscopy, Fourier transform infrared, X-ray photoelectron spectroscopy, and X-ray diffractometry tests. The corrosion resistance of the film has been measured by electrochemical and immersion tests. The results show that the deposition film has fully covered the substrate but there are some micro-cracks. The structure of the film is complex, and consists of MgHPO₄·3H₂O, MnHPO₄·2.25H₂O, BaHPO₄·3H₂O, BaMg₂(PO₄)₂, Mg₃(PO₄)₂·22H₂O, Ca₃(PO₄)₂·xH₂O, and some amorphous phases. The composite phosphate film has better anticorrosion performance than the AM60 and can protect the bare alloy from corrosion for more than 12 h in 0.6 M NaCl.

  13. Effect of Fermented Chitin Nano whiskers on Properties of Polylactic Acid Bio composite Films

    International Nuclear Information System (INIS)

    Syazeven Effatin Azma Mohd Asri; Zainoha Zakaria

    2014-01-01

    The fermented chitin nano whiskers (FCNW) filled polylactic acid (PLA) bio composite films were successfully produced using solution casting method. The bio composite films were characterized in terms of tensile properties. The Young's modulus increased with increasing FCNW content while the tensile strength increased and reached the maximum value at 4 phr FCNW loading. Therefore it can be concluded that the optimum loading of FCNW is at 4 phr and further addition of FCNW may lead to agglomeration resulting in a decrease in tensile strength. The elongation at break of the bio composite films decreased rapidly upon addition of FCNW into PLA. From the Atomic Force Microscopy, the surface morphology of the PLA changed upon addition of FCNW and tendency for agglomeration of FCNW at high loading was observed. (author)

  14. Dielectric and Energy Storage Properties of the Heterogeneous P(VDF-HFP)/PC Composite Films

    Science.gov (United States)

    Zhao, Xiaojia; Peng, Guirong; Zhan, Zaiji

    2017-12-01

    Polymer-based materials with a high discharge energy and low energy loss have attracted considerable attention for energy storage applications. A new class of polymer-based composite films composed of amorphous polycarbonate (PC) and poly(vinylidene fluoride-hexafluoropropylene) [P(VDF-HFP)] has been fabricated by simply solution blending followed by thermal treatment under vacuum. The results show that the diameter of the spherical phase for PC and the melting temperature of P(VDF-HFP) increase, and the crystallinity and crystallization temperature of P(VDF-HFP) decrease with increasing PC content. The phase transition from the polar β phase to weak polarity γ phase is induced by PC addition. Moreover, the Curie temperature of the P(VDF-HFP)/PC composite films shifts to a lower temperature. With the addition of PC, the permittivity, polarization and discharge energy of the P(VDF-HFP)/PC composite films slightly decrease. However, the energy loss is significantly reduced.

  15. 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.

  16. Large built-in electric fields due to flexoelectricity in compositionally graded ferroelectric thin films

    Science.gov (United States)

    Karthik, J.; Mangalam, R. V. K.; Agar, J. C.; Martin, L. W.

    2013-01-01

    We investigate the origin of large built-in electric fields that have been reported in compositionally graded ferroelectric thin films using PbZr1-xTixO3 (0.2material. Using a Ginzburg-Landau-Devonshire phenomenological formalism that includes the effects of compositional gradients, mechanical strain relaxation, and flexoelectricity, we demonstrate that the flexoelectric coupling between the out-of-plane polarization and the gradient of the epitaxial strain throughout the thickness of the film, not other inhomogeneities (i.e., composition or polarization), is directly responsible for the observed voltage offsets. This work demonstrates the importance of flexoelectricity in influencing the properties of ferroelectric thin films and provides a powerful mechanism to control their properties.

  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. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. 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. Copyright © 2013. Published by Elsevier Ltd.

  19. Quantifying Local Thickness and Composition in Thin Films of Organic Photovoltaic Blends by Raman Scattering

    KAUST Repository

    Rodríguez-Martínez, Xabier

    2017-07-06

    We report a methodology based on Raman spectroscopy that enables the non-invasive and fast quantitative determination of local thickness and composition in thin films (from few monolayers to hundreds of nm) of one or more components. We apply our methodology to blends of organic conjugated materials relevant in the field of organic photovoltaics. As a first step, we exploit the transfer-matrix formalism to describe the Raman process in thin films including reabsorption and interference effects of the incoming and scattered electric fields. This allows determining the effective solid-state Raman cross-section of each material by studying the dependence of the Raman intensity on film thickness. These effective cross sections are then used to estimate the local thickness and composition in a series of polymer:fullerene blends. We find that the model is accurate within ±10 nm in thickness and ±5 vol% in composition provided that (i) the film thickness is kept below the thickness corresponding to the first maximum of the calculated Raman intensity oscillation; (ii) the materials making up the blend show close enough effective Raman cross-sections; and (iii) the degree of order attained by the conjugated polymer in the blend is similar to that achieved when cast alone. Our methodology opens the possibility to make quantitative maps of composition and thickness over large areas (from microns to centimetres squared) with diffraction-limited resolution and in any multi-component system based thin film technology.

  20. Fabrication of superhydrophobic sol-gel composite films using hydrophobically modified colloidal zinc hydroxide.

    Science.gov (United States)

    Lakshmi, R V; Basu, Bharathibai J

    2009-11-15

    A superhydrophobic sol-gel composite film was fabricated by incorporating hydrophobically modified colloidal zinc hydroxide (CZH) in sol-gel matrix. CZH was prepared by controlled precipitation and modified by treatment with stearic acid. The concentration of stearic acid and stirring time were optimized to obtain modified CZH with very high water contact angle (WCA) of 165 degrees and sliding angle (SA)superhydrophobic surfaces. FTIR spectrum also confirmed the presence of zinc stearate in the composite film. The method is simple and cost-effective and does not involve any expensive chemicals or equipments.

  1. 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. Published by Elsevier B.V.

  2. Barium Titanate Film Interfaces for Hybrid Composite Energy Harvesters.

    Science.gov (United States)

    Bowland, Christopher C; Malakooti, Mohammad H; Sodano, Henry A

    2017-02-01

    Energy harvesting utilizing piezoelectric materials has become an attractive approach for converting mechanical energy into electrical power for low-power electronics. Structural composites are ideally suited for energy scavenging due to the large amount of mechanical energy they are subjected to. Here, a multifunctional composite with embedded sensing and energy harvesting is developed by integrating an active interface into carbon fiber reinforced polymer composites. By modifying the composite matrix, both rigid and flexible multifunctional composites are fabricated. Through electromechanical testing of a cantilever beam of the rigid composite, it reveals a power density of 217 pW/cc from only 1 g root-mean-square acceleration when excited at its resonant frequency of 47 Hz. Electromechanical sensor testing of the flexible multifunctional composite reveals an average voltage generation of 23.5 mV/g at its resonant frequency of 96 Hz. This research introduces a route for integrating nonstructural functionality into structural fiber composites by utilizing BaTiO 3 coated woven carbon fiber fabrics with power scavenging and passive sensing capabilities.

  3. Composite films prepared from agricultural by-products

    Czech Academy of Sciences Publication Activity Database

    Šimkovic, I.; Kelnar, Ivan; Mendichi, R.; Bertok, T.; Filip, J.

    2017-01-01

    Roč. 156, 20 January (2017), s. 77-85 ISSN 0144-8617 Institutional support: RVO:61389013 Keywords : sugar beet residue * bagasse * holocellulose Subject RIV: JI - Composite Materials OBOR OECD: Composites (including laminates, reinforced plastics, cermets, combined natural and synthetic fibre fabrics Impact factor: 4.811, year: 2016

  4. 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.

  5. Enhancement of Moisture Protective Properties and Stability of Pectin through Formation of a Composite Film: Effects of Shellac and Plasticizer.

    Science.gov (United States)

    Luangtana-Anan, Manee; Soradech, Sitthiphong; Saengsod, Suthep; Nunthanid, Jurairat; Limmatvapirat, Sontaya

    2017-12-01

    The aim of this investigation was to develop the high moisture protective ability and stable pectin through the design of composite films based on varying shellac concentrations. A film casting method was applied to prepare a free film. The moisture protective properties and mechanical properties were investigated. The findings was the composite films exhibited the reductions in the hydrophilicity, water vapor permeability, and the moisture content compared with pectin films. The single and composite films were then study for their stability at 40 °C and 75% RH for 90 d. Among the concentrations of shellac, 50% (w/w) could improve stability in terms of moisture protection after 90 d of storage, whereas lower concentrations of shellac (10% to 40%) could not achieve this. However, the higher shellac content also contributed to weaker mechanical properties. The mechanical improvement and stability of composite films with the incorporation of plasticizers were further investigated. Polyethylene glycol 400 and diethyl phthalate at a concentration of 10% were used. The results indicated that both plasticizers could enhance the mechanical characteristics and had a slight effect on moisture protection. The stability of pectin in terms of moisture protective properties could, therefore, be modified through the fabrication of composite films with hydrophobic polymers, that is, shellac and the addition of proper plasticizers to enhance mechanical properties, which could offer wide applications for edible film in food, agro, and pharmaceutical industries. The composite film with 50% shellac could improve moisture protective properties of pectin film. Adding a plasticizer could build up the higher mechanical characteristics of composite film. Stability of pectin could be modified by fabrication of composite films with proper content of shellac and plasticizer. © 2017 Institute of Food Technologists®.

  6. Plasmonic properties of silver nanoparticles embedded in diamond like carbon films: Influence of structure and composition

    Energy Technology Data Exchange (ETDEWEB)

    Meškinis, Š., E-mail: sarunas.meskinis@fei.lt [Kaunas University of Technology, Institute of Materials Science, Savanoriu Ave. 271, Kaunas LT-50131 (Lithuania); Čiegis, A.; Vasiliauskas, A.; Tamulevičienė, A.; Šlapikas, K. [Kaunas University of Technology, Institute of Materials Science, Savanoriu Ave. 271, Kaunas LT-50131 (Lithuania); Juškėnas, R.; Niaura, G. [Institute of Chemistry, Center for Physical Sciences and Technology, Goštauto Str. 9, Vilnius LT-01108 (Lithuania); Tamulevičius, S. [Kaunas University of Technology, Institute of Materials Science, Savanoriu Ave. 271, Kaunas LT-50131 (Lithuania)

    2014-10-30

    Highlights: • Optical properties of DLC films containing silver (DLC:Ag) depends on substrate bias. • Position of the plasmonic peak depends on composition of DLC:Ag films. • Position of the plasmonic peak depends on structure of Ag nanoclusters. • Influence of composition prevails influence of the structure of DLC matrix. - Abstract: In the present study optical properties of hydrogenated diamond like carbon nanocomposite films containing silver nanoparticles (DLC:Ag) deposited by direct current (DC) unbalanced reactive magnetron sputtering were studied in 180–1100 nm range. Different substrate bias was used during deposition of the films. Structure of the films was investigated by multiwavelength Raman scattering spectroscopy and X-ray diffractometry (XRD). Chemical composition of the samples was studied by X-ray photoelectron spectroscopy (XPS), surface morphology was investigated by atomic force microscopy (AFM). Red shift of the surface plasmon resonance peak of DLC:Ag films with the increase of Ag atomic concentration was observed. It was found that high atomic concentration of oxygen in DLC:Ag films results in some redshift of the plasmonic peak, too. Such a behavior is explained by increase of the refractive index of the dielectric medium surrounding silver nanoparticle due to possible presence of the silver oxide interlayer at the Ag nanocluster and diamond like carbon matrix interface. It was demonstrated that influence of the increased Ag atomic concentration on position of the surface plasmon resonance peak of DLC:Ag films clearly prevails influence of the increased sp{sup 3}/sp{sup 2} ratio of the diamond like carbon matrix. Correlation between the structure of Ag nanocrystallites studied by XRD and position of the surface plasmon resonance peak position was observed.

  7. Optical Properties and Surface Morphology of Nano-composite PMMA: TiO2 Thin Films

    International Nuclear Information System (INIS)

    Lyly Nyl Ismail; Ahmad Fairoz Aziz; Habibah Zulkefle

    2011-01-01

    There are two nano-composite PMMA: TiO 2 solutions were prepared in this research. First solution is nano-composite PMMA commercially available TiO 2 nanopowder and the second solution is nano-composite PMMA with self-prepared TiO 2 powder. The self-prepared TiO 2 powder is obtained by preparing the TiO 2 sol-gel. Solvo thermal method were used to dry the TiO 2 sol-gel and obtained TiO 2 crystal. Ball millers were used to grind the TiO 2 crystal in order to obtained nano sized powder. Triton-X was used as surfactant to stabilizer the composite between PMMA: TiO 2 . Besides comparing the nano-composite solution, we also studied the effect of the thin films thickness on the optical properties and surface morphology of the thin films. The thin films were deposited by sol-gel spin coating method on glass substrates. The optical properties and surface characterization were measured with UV-VIS spectrometer equipment and atomic force microscopy (AFM). The result showed that nano-composite PMMA with self prepared TiO 2 give high optical transparency than nano-composite PMMA with commercially available TiO 2 nano powder. The results also indicate as the thickness is increased the optical transparency are decreased. Both AFM images showed that the agglomerations of TiO 2 particles are occurred on the thin films and the surface roughness is increased when the thickness is increased. High agglomeration particles exist in the AFM images for nano-composite PMMA: TiO 2 with TiO 2 nano powder compare to the other nano-composite solution. (author)

  8. Properties of cellulose/Thespesia lampas short fibers bio-composite films.

    Science.gov (United States)

    Ashok, B; Reddy, K Obi; Madhukar, K; Cai, J; Zhang, L; Rajulu, A Varada

    2015-01-01

    Cellulose was dissolved in pre cooled environment friendly solvent (aq.7% sodium hydroxide+12% urea) and regenerated with 5%H2SO4 as coagulation bath. Using cellulose as matrix and alkali treated short natural fibers extracted from the newly identified Thespesia lampas plant as fillers the green composite films were prepared. The films were found to be non toxic. The effect of fiber loading on the tensile properties and thermal stability was studied. The fractographs indicated better interfacial bonding between the fibers and cellulose. The crystallinity of the composite films was found to be lower than the matrix and decreased with increasing fiber content. In spite of better interfacial bonding, the tensile properties of the composites were found to be lower than those of the matrix and decreased with increasing fiber content and this behavior was attributed to the random orientation of the fibers in the composites. The thermal stability of the composite films was higher than the matrix and increased with fiber content. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Modification of natural matrix lac-bagasse for matrix composite films

    Science.gov (United States)

    Nurhayati, Nanik Dwi; Widjaya, Karna; Triyono

    2016-02-01

    Material technology continues to be developed in order to a material that is more efficient with composite technology is a combination of two or more materials to obtain the desired material properties. The objective of this research was to modification and characterize the natural matrix lac-bagasse as composite films. The first step, natural matrix lac was changed from solid to liquid using an ethanol as a solvent so the matrix homogenly. Natural matrix lac was modified by adding citric acid with concentration variation. Secondly, the bagasse delignification using acid hydrolysis method. The composite films natural matrix lac-bagasse were prepared with optimum modified the addition citric acid 5% (v/v) and delignification bagasse optimum at 1,5% (v/v) in hot press at 80°C 6 Kg/cm-1. Thirdly, composite films without and with modification were characterized functional group analysis using FTIR spectrophotometer and mechanical properties using Universal Testing Machine. The result of research showed natural matrix lac can be modified by reaction with citric acid. FTIR spectra showed without and with modification had functional groups wide absorption 3448 cm-1 group -OH, C=O ester strong on 1712 cm-1 and the methylene group -CH2 on absorption 1465 cm-1. The mechanical properties showed tensile strength 0,55 MPa and elongation at break of 0,95 %. So that composite films natural matrix lac can be made with reinforcement bagasse for material application.

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

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Xiaojuan, E-mail: cherry-820@163.com; Shi, Yanlong; Jin, Shuping

    2015-10-30

    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{sup −1} at 0.3 A g{sup −1} current density, good cycle stability in 800 continuous cycles (only 4.5% decay after 800 cycles at 0.3 A g{sup −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.

  11. Development of the floating sulphur biofilm reactor for sulphide ...

    African Journals Online (AJOL)

    Development of the floating sulphur biofilm reactor for sulphide oxidation in biological water treatment systems. ... water interface of anaerobic, organically loaded and actively sulphate reducing systems. ... The effect of influent sulphide concentrations, flow rate and reactor dimensions on the sulphur biofilm formation were

  12. Indicator minerals as guides to base metal sulphide mineralisation ...

    Indian Academy of Sciences (India)

    Zn-bearing minerals that act as indicator minerals for base metal sulphide mineralization from the Proterozoic Betul Belt,central India with special emphasis on their genetic significance have been discussed.Sulphide mineralisation is hosted by the felsic volcanic rocks and has similarities with volcanic-hosted massive ...

  13. Thermoplastic Cassava Starch-PVA Composite Films with Cellulose Nanofibers from Oil Palm Empty Fruit Bunches as Reinforcement Agent

    Directory of Open Access Journals (Sweden)

    Farah Fahma

    2017-01-01

    Full Text Available Thermoplastic starch-polyvinyl alcohol composite films were prepared by casting method with cellulose nanofibers as reinforcement agent and glycerol as plasticizer. The obtained cellulose nanofibers with a diameter of 27.23±8.21 nm were isolated from oil palm empty fruit bunches (OPEFBs by mechanical treatment. The addition of cellulose nanofibers until 3 wt% increased tensile strength and crystallinity of the composite films. In contrast, it decreased their elongation at break and water vapor transmission rate. Meanwhile, the addition of glycerol increased elongation at break and water vapor transmission rate of film matrix but lowers tensile strength of composite films.

  14. Fluorine-containing composition for forming anti-reflection film on resist surface and pattern formation method

    Science.gov (United States)

    Nishi, Mineo; Makishima, Hideo

    1996-01-01

    A composition for forming anti-reflection film on resist surface which comprises an aqueous solution of a water soluble fluorine compound, and a pattern formation method which comprises the steps of coating a photoresist composition on a substrate; coating the above-mentioned composition for forming anti-reflection film; exposing the coated film to form a specific pattern; and developing the photoresist, are provided. Since the composition for forming anti-reflection film can be coated on the photoresist in the form of an aqueous solution, not only the anti-reflection film can be formed easily, but also, the film can be removed easily by rinsing with water or alkali development. Therefore, by the pattern formation method according to the present invention, it is possible to form a pattern easily with a high dimensional accuracy.

  15. Nanodiamond embedded ta-C composite film by pulsed filtered vacuum arc deposition from a single target

    Science.gov (United States)

    Iyer, Ajai; Etula, Jarkko; Ge, Yanling; Liu, Xuwen; Koskinen, Jari

    2016-11-01

    Detonation Nanodiamonds (DNDs) are known to have sp3 core, sp2 shell, small size (few nm) and are gaining importance as multi-functional nanoparticles. Diverse methods have been used to form composites, containing detonation nanodiamonds (DNDs) embedded in conductive and dielectric matrices for various applications. Here we show a method, wherein DND-ta-C composite film, consisting of DNDs embedded in ta-C matrix have been co-deposited from the same cathode by pulsed filtered cathodic vacuum arc method. Transmission Electron Microscope analysis of these films revel the presence of DNDs embedded in the matrix of amorphous carbon. Raman spectroscopy indicates that the presence of DNDs does not adversely affect the sp3 content of DND-ta-C composite film compared to ta-C film of same thickness. Nanoindentation and nanowear tests indicate that DND-ta-C composite films possess improved mechanical properties in comparison to ta-C films of similar thickness.

  16. Al–Ni–Y–X (X = Cu, Ta, Zr) metallic glass composite thin films for broad-band uniform reflectivity

    International Nuclear Information System (INIS)

    Chang, C.M.; Wang, C.H.; Hsu, J.H.; Huang, J.C.

    2014-01-01

    The Al–Ni–Y–X (X = Cu, Ta, Zr) thin film metallic glasses are manufactured by sputtering, and their optical reflectivity characteristics are explored. The relationship among composition, atomic structure and reflectivity performance is established. Compared with pure Al films, the Al–Ni–Y film surface roughness is much lower and hardness is much higher, more suitable for optical reflector applications. For composite Al–Ni–Y films, the reflectance varies within 80–91%. For fully amorphous films, the reflectivity exhibits unusual uniform reflection at ∼ 70%, perfect for broad-band reflector. - Highlights: • The optical reflection properties of the Al–Ni–Y based sputtered thin films are examined. • The highest reflection level of the Al–Ni–Y film can reach 91%. • The fully amorphous Al–Ni–Y based films exhibit unusual highly uniform reflectivity

  17. Fotocromismo em filmes finos de óxidos de tungstênio de diferentes composições Photochromism in tungsten oxide thin films of different compositions

    Directory of Open Access Journals (Sweden)

    José R. Galvão

    2003-08-01

    Full Text Available Tungsten oxide thin films with three different compositions were deposited by reactive sputtering in an oxygen-argon plasma. In a system composed of a home made photochemical reactor coupled with an optic fiber spectrophotometer, the photochromic effect was studied in these oxide films as function of UV irradiation time, in ethanol, methanol and formaldehyde atmospheres. It was observed that the photochromic efficiency depends on the vapor chemical nature where the film is irradiated as well as the film composition. Kinetic analysis suggest that two kinds of optical absorption centers should respond by the photochromic effect in these films, one generated at film surface and other inside it, which one presenting a different time constant.

  18. Synthesis of zinc sulphide nanoparticles from thermal decomposition of zinc N-ethyl cyclohexyl dithiocarbamate complex

    International Nuclear Information System (INIS)

    Abdullah, Nurul Hidayah; Zainal, Zulkarnain; Silong, Sidik; Tahir, Mohamed Ibrahim Mohamed; Tan, Kar-Ban; Chang, Sook-Keng

    2016-01-01

    Synthesis of nanostructured semiconductor materials from various single source precursors has been massively explored for potential applications in modern technology. Thermal decomposition method has been employed to prepare nanoparticles zinc sulphide from zinc N-ethyl cyclohexyl dithiocarbamate precursor. Effect of heat treatment at different calcination duration on the structural, morphological, compositional and band gap properties of zinc sulphide were investigated. The obtained samples were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and energy dispersive X-ray (EDX) analysis. XRD showed the precursor was decomposed to hexagonal zinc sulphide after 2–6 h of calcination duration at 400 °C. The sizes of zinc sulphide (ZnS) nanoparticles obtained from TEM analysis were about 6–11 nm. The existence of the hexagonal ZnS phase is not affected by the calcination duration, while only a slight difference in the crystallinity and crystallite size of ZnS is observed from XRD analysis. EDX analyses reveal that the as-prepared ZnS nanoparticles have an approximate composition of Zn and S close to 1:1, giving a possible composition of ZnS. Besides, direct band gap energy of ZnS was found to be around 3.78–3.95 eV. - Highlights: • Zinc N-ethyl cyclohexyl dithiocarbamate was used as single source precursor. • No surfactant was used in the preparation of ZnS nanoparticles. • Pure phase nanostructured ZnS is obtained. • A good stoichiometric sample with an average atomic ratio of Zn:S close to 1:1.

  19. Synthesis of zinc sulphide nanoparticles from thermal decomposition of zinc N-ethyl cyclohexyl dithiocarbamate complex

    Energy Technology Data Exchange (ETDEWEB)

    Abdullah, Nurul Hidayah [Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor (Malaysia); Materials Synthesis and Characterization Laboratory, Institute of Advanced Technology, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor (Malaysia); Zainal, Zulkarnain, E-mail: zulkar@upm.edu.my [Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor (Malaysia); Materials Synthesis and Characterization Laboratory, Institute of Advanced Technology, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor (Malaysia); Silong, Sidik [UiTM Negeri Sembilan, Kampus Kuala Pilah, Pekan Parit Tinggi, 72000 Kuala Pilah, Negeri Sembilan (Malaysia); Tahir, Mohamed Ibrahim Mohamed; Tan, Kar-Ban [Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor (Malaysia); Chang, Sook-Keng [Materials Synthesis and Characterization Laboratory, Institute of Advanced Technology, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor (Malaysia)

    2016-04-15

    Synthesis of nanostructured semiconductor materials from various single source precursors has been massively explored for potential applications in modern technology. Thermal decomposition method has been employed to prepare nanoparticles zinc sulphide from zinc N-ethyl cyclohexyl dithiocarbamate precursor. Effect of heat treatment at different calcination duration on the structural, morphological, compositional and band gap properties of zinc sulphide were investigated. The obtained samples were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and energy dispersive X-ray (EDX) analysis. XRD showed the precursor was decomposed to hexagonal zinc sulphide after 2–6 h of calcination duration at 400 °C. The sizes of zinc sulphide (ZnS) nanoparticles obtained from TEM analysis were about 6–11 nm. The existence of the hexagonal ZnS phase is not affected by the calcination duration, while only a slight difference in the crystallinity and crystallite size of ZnS is observed from XRD analysis. EDX analyses reveal that the as-prepared ZnS nanoparticles have an approximate composition of Zn and S close to 1:1, giving a possible composition of ZnS. Besides, direct band gap energy of ZnS was found to be around 3.78–3.95 eV. - Highlights: • Zinc N-ethyl cyclohexyl dithiocarbamate was used as single source precursor. • No surfactant was used in the preparation of ZnS nanoparticles. • Pure phase nanostructured ZnS is obtained. • A good stoichiometric sample with an average atomic ratio of Zn:S close to 1:1.

  20. Composition and growth procedure-dependent properties of electrodeposited CuInSe 2 thin films

    Science.gov (United States)

    Babu, S. Moorthy; Ennaoui, A.; Lux-Steiner, M. Ch.

    2005-02-01

    CuInSe 2 thin films were deposited on molybdenum-coated glass substrates by electrodeposition. Deposition was carried out with a variety of electrochemical bath compositions. The quality of the deposits depends very much on the source materials as well as the concentration of the same in the electrolyte. The deposition potential was varied from -0.4 to -0.75 V vs. SCE. The pH of the solution was adjusted to 1.5-2 using diluted sulphuric acid. Chloride salts containing bath yield good surface morphology, but there is always excess of the metallic content in the deposited films. Different growth procedures, like initial metallic layers of copper or indium, layers of copper selenide or indium selenide before the actual deposition of ternary chalcopyrite layers were attempted. Fabrication pathway, morphological and compositional changes due to the different precursor route has been analysed. The quality of the deposits prepared by one-step electrodeposition is better than the deposits with a two-stage process. The deposited films were characterized with XRD, SEM-EDAX, UV-visible spectroscopy and I- V characteristics. The deposited films were annealed in air as well as in nitrogen atmosphere. The influence of annealing temperature, environment and annealing time on the properties of the films are evaluated. Attempts were made to fabricate solar cell structure from the deposited absorber films. The structure of Mo/CuInSe 2/CdS/ZnO/Ni was characterized with surface, optical and electrical studies.

  1. SnO{sub 2}/reduced graphene oxide composite films for electrochemical applications

    Energy Technology Data Exchange (ETDEWEB)

    Bondarenko, E.A. [Belarusian State University, Nezalezhnastsi Av. 4, Minsk 220030 (Belarus); Mazanik, A.V., E-mail: mazanikalexander@gmail.com [Belarusian State University, Nezalezhnastsi Av. 4, Minsk 220030 (Belarus); Streltsov, E.A. [Belarusian State University, Nezalezhnastsi Av. 4, Minsk 220030 (Belarus); Kulak, A.I., E-mail: kulak@igic.bas-net.by [Institute of General and Inorganic Chemistry, National Academy of Sciences of Belarus, Surganova str., 9/1, Minsk 220072 (Belarus); Korolik, O.V. [Belarusian State University, Nezalezhnastsi Av. 4, Minsk 220030 (Belarus)

    2015-12-15

    Highlights: • SnO{sub 2}/GO composites with mass fraction of carbon phase 0.01% ≤ w{sub C} ≤ 80% have been formed. • 400 °C annealing was applied for GO reduction in the composites. • SnO{sub 2}/rGO composites demonstrate a high electrocatalytic activity in anodic processes. • Exchange current density grows linearly with carbon phase concentration at w{sub C} ≤ 10%. - Abstract: SnO{sub 2}/GO (GO is graphene oxide) composite films with GO mass fraction w{sub C} ranging from 0.01 to 80% have been prepared using colloidal solutions. Heat treatment of SnO{sub 2}/GO films in Ar atmosphere at 400 °C leads to GO reduction accompanied by partial exfoliation and decreasing of the particle thickness. SnO{sub 2}/rGO (rGO is reduced GO) film electrodes demonstrate a high electrocatalytic activity in the anodic oxidation of inorganic (iodide-, chloride-, sulfite-anions) and organic (ascorbic acid) substances. The increase of the anodic current in these reactions is characterized by overpotential inherent to the individual rGO films and exchange current density grows linearly with rGO concentration at w{sub C} ≤ 10% indicating that the rGO particles in composites act as sites of electrochemical process. The SnO{sub 2}/rGO composite films, in which the chemically stable oxide matrix encapsulates the rGO inclusions, can be considered as a promising material for applied electrochemistry.

  2. Nanocellulose reinforced chitosan composite films as affected by nanofiller loading and plasticizer content.

    Science.gov (United States)

    Azeredo, Henriette M C; Mattoso, Luiz Henrique C; Avena-Bustillos, Roberto J; Filho, Gino Ceotto; Munford, Maximiliano L; Wood, Delilah; McHugh, Tara H

    2010-01-01

    Chitosan is a biopolymer obtained by N-deacetylation of chitin, produced from shellfish waste, which may be employed to elaborate edible films or coatings to enhance shelf life of food products. This study was conducted to evaluate the effect of different concentrations of nanofiller (cellulose nanofibers, CNF) and plasticizer (glycerol) on tensile properties (tensile strength-TS, elongation at break-EB, and Young's modulus-YM), water vapor permeability (WVP), and glass transition temperature (T(g)) of chitosan edible films, and to establish a formulation to optimize their properties. The experiment was conducted according to a central composite design, with 2 variables: CNF (0 to 20 g/100 g) and glycerol (0 to 30 g/100 g) concentrations in the film (on a dry basis), which was produced by the so-called casting technique. Most responses (except by EB) were favored by high CNF concentrations and low glycerol contents. The optimization was based on maximizing TS, YM, and T(g), and decreasing WVP, while maintaining a minimum acceptable EB of 10%. The optimum conditions were defined as: glycerol concentration, 18 g/100 g; and CNF concentration, 15 g/100 g. AFM imaging of films suggested good dispersion of the CNF and good CNF-matrix interactions, which explains the good performance of the nanocomposite films. Chitosan is a biodegradable polymer which may be used to elaborate edible films or coatings to enhance shelf life of foods. This study demonstrates how cellulose nanofibers (CNF) can improve the mechanical and water vapor barrier properties of chitosan films. A nanocomposite film with 15% CNF and plasticized with 18% glycerol was comparable to some synthetic polymers in terms of strength and stiffness, but with poorer elongation and water vapor barrier, indicating that they can be used for applications that do not require high flexibility and/or water vapor barrier. The more important advantage of such films when compared to synthetic polymer films is their

  3. Preparation of poly (arylene ether nitrile)/NzdFeB composite film with excellent thermal properties and tensile strength

    Science.gov (United States)

    Pan, Hai; Xu, Mingzhen; Liu, Xiaobo

    2017-12-01

    PEN/NdFeB composite films were prepared by the solution casting method. The thermal properties, fracture morphology and tensile strength of the composite films were tested by DSC, TGA, SEM and electromechanical universal testing machine, respectively. The results reveal that the composite film has good thermal properties and tensile strength. Glass-transition temperature and decomposition temperatures at weight loss of 5% ot the composite films retain at 166±1 C and 462±4 C, respectively. The composite film with 5 wt.% NdFeB has the best tensile strength value for 100.5 MPa. In addition, it was found that the NdFeB filler was well dispersed in PEN matrix by SEM analysis.

  4. Ag induced suppression of irradiation response in YBCO/Ag composite thin films

    International Nuclear Information System (INIS)

    Behera, D.; Mohanty, T.; Mohanta, D.; Patnaik, K.; Mishra, N.C.; Senapati, L.; Kanjilal, D.; Mehta, G.K.; Pinto, R.

    1999-01-01

    Practical application of cuprate superconductors in radiation environment demands that these systems remain insensitive to the irradiation induced defects. The cuprate superconductors however are many orders of magnitude more sensitive than the conventional low T c superconductors. To suppress the irradiation sensitivity of cuprates we consider a crystal engineering approach where metal ions as Ag is made to occupy inter and intra-granular sites of YBa 2 Cu 3 O 7 thin films. We show that superconducting and normal state properties of YBCO/Ag composite thin films prepared by laser ablation remain unchanged under 140 MeV Si ion irradiation up to fluence of 8 x 10 14 ions/cm 2 . The inter- and intra-granular occupancy of Ag is shown to induce microstructural modifications and rigidity to the CuO chains respectively which in turn lead to the radiation insensitivity of the composite films. (author)

  5. POLYMER COMPOSITE FILMS WITH SIZE-SELECTED METAL NANOPARTICLES FABRICATED BY CLUSTER BEAM TECHNIQUE

    DEFF Research Database (Denmark)

    Ceynowa, F. A.; Chirumamilla, Manohar; Popok, Vladimir

    2017-01-01

    Formation of polymer films with size-selected silver and copper nanoparticles (NPs) is studied. Polymers are prepared by spin coating while NPs are fabricated and deposited utilizing a magnetron sputtering cluster apparatus. The particle embedding into the films is provided by thermal annealing...... after the deposition. The degree of immersion can be controlled by the annealing temperature and time. Together with control of cluster coverage the described approach represents an efficient method for the synthesis of thin polymer composite layers with either partially or fully embedded metal NPs....... Combining electron beam lithography, cluster beam deposition and thermal annealing allows to form ordered arrays of metal NPs on polymer films. Plasticity and flexibility of polymer host and specific properties added by coinage metal NPs open a way for different applications of such composite materials...

  6. 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.

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

    Science.gov (United States)

    Mezdour, D.; Tabellout, M.; Sahli, S.; Bardeau, J.-F.

    2013-12-01

    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.

  8. Residual stress and Young's modulus of pulsed laser deposited PZT thin films: Effect of thin film composition and crystal direction of Si cantilevers

    NARCIS (Netherlands)

    Nazeer, H.; Nguyen, Duc Minh; Rijnders, Augustinus J.H.M.; Abelmann, Leon; Sardan Sukas, Ö.

    2016-01-01

    We investigated the residual stress and Young's modulus of Pb(ZrxTi1 - x)O3 (PZT) thin films with a (110) preferred orientation and a composition x ranging from 0.2 to 0.8. The films are grown by pulsed laser deposition on silicon cantilevers aligned along the <110> and <100> silicon crystal

  9. Perfluorocyclobutyl polymer thin-film composite membrane fabrication, plasticization and physical aging

    Science.gov (United States)

    Zhou, Jinxiang

    My research consists of three parts: 1) study of perfluorocyclobutyl (PFCB) thin film formation, 2) development and characterization of PFCB thin-film composite membranes, and 3) elucidation of the roles that plasticization and physical aging play on PFCB thin-film performance. In part 1, I conducted comprehensive research to understand how PFCB thin films form by the method of dip coating. Through the control of solvents, polymer solution concentrations, and withdrawal speeds, a series of PFCB thin films were formed on silicon wafers. Film thickness and refractive index were characterized by ellipsometry. Results suggested that when the withdrawal speeds are higher than 50 mm/min, film thickness increases with increasing withdrawal speeds, as it is predicted in the proposed extension of the Landau-Levich model. When the withdrawal speeds are lower than 50 mm/min, film thickness increases with decreasing withdrawal speeds, which could be explained by the phenomenon of PFCB surface excess. Subsequent surface tension studies proved the existence of this surface excess. Surface images of these films were measured by atomic force microscope. Films prepared from tetrahydrofuran and chloroform yielded uniform nanolayers. However, films prepared using acetone as solvent yielded a partial dewetting pattern, which could be explained by a surface depletion layer of pure solvent between the bulk PFCB/acetone solution and the substrate. Based on the knowledge generated in part 1, I developed, from scratch, procedures to prepare PFCB TFC membranes that were free of major defects. I used mathematical models based on resistance in series to predict composite membrane performance. In many cases, surface defects are the major reason for poor separation ability of TFC membranes. Mathematical analysis showed that the surface defects are less critical in thinner films but are still an important factor causing selectivity loss. Surface defects occur mainly from polymer dewetting on the

  10. Synthesis of TiO 2-doped SiO 2 composite films and its applications

    Indian Academy of Sciences (India)

    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 ... Anhui Key Laboratory of Functional Molecular Solids, College of Chemistry and Materials Science, Anhui Normal University, Wuhu 241000, P.R. China ...

  11. Thermal and structural stability of composite systems based on polyaniline deposited on porous polyethylene films

    Czech Academy of Sciences Publication Activity Database

    Elyashevich, G. K.; Sidorovich, A. V.; Smirnov, M. A.; Kuryndin, I. S.; Bobrova, N. V.; Trchová, Miroslava; Stejskal, Jaroslav

    2006-01-01

    Roč. 91, č. 11 (2006), s. 2786-2792 ISSN 0141-3910 Grant - others:Russian Foundation for Basic Research 04-03-32229 Institutional research plan: CEZ:AV0Z40500505 Keywords : polyaniline * polyethylene porous films * composites Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.174, year: 2006

  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...

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

    Indian Academy of Sciences (India)

    Wintec

    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 reactiv- ity in order to provide vital information for the design and application of such highly efficient photocatalytic systems in the degradation of ...

  14. Synthesis and characterization of MoO3–WO3 composite thin films ...

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science; Volume 36; Issue 1. Synthesis and characterization of MoO3–WO3 composite thin films by liquid phase deposition technique: Investigation of its photochromic properties. H M Farveez Ahmed Noor Shahina Begum. Volume 36 Issue 1 February 2013 pp 45-49 ...

  15. Composite films of arabinoxylan and fibrous sepiolite: Morphological, mechanical, and barrier properties

    CSIR Research Space (South Africa)

    Sarossy, Z

    2012-06-01

    Full Text Available fibrous clay, was investigated as an additive to enhance the properties of rye flour arabinoxylan. Composite films cast from arabinoxylan solutions and sepiolite suspensions in water were transparent or semitransparent at additive loadings in the 2.5-10 wt...

  16. Development of Biopolymer Composite Films Using a Microfluidization Technique for Carboxymethylcellulose and Apple Skin Particles

    Directory of Open Access Journals (Sweden)

    Inyoung Choi

    2017-06-01

    Full Text Available Biopolymer films based on apple skin powder (ASP and carboxymethylcellulose (CMC were developed with the addition of apple skin extract (ASE and tartaric acid (TA. ASP/CMC composite films were prepared by mixing CMC with ASP solution using a microfluidization technique to reduce particle size. Then, various concentrations of ASE and TA were incorporated into the film solution as an antioxidant and an antimicrobial agent, respectively. Fourier transform infrared (FTIR, optical, mechanical, water barrier, and solubility properties of the developed films were then evaluated to determine the effects of ASE and TA on physicochemical properties. The films were also analyzed for antioxidant effect on 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity and antimicrobial activities against Listeria monocytogenes, Staphylococcus aureus, Salmonella enterica, and Shigella flexneri. From the results, the ASP/CMC film containing ASE and TA was revealed to enhance the mechanical, water barrier, and solubility properties. Moreover, it showed the additional antioxidant and antimicrobial properties for application as an active packaging film.

  17. Angular dependence of preferential sputtering and composition in aluminum--copper thin films

    International Nuclear Information System (INIS)

    Rudeck, P.J.; Harper, J.M.E.; Fryer, P.M.

    1989-01-01

    The copper concentration in aluminum--copper alloys can be altered by ion bombardment during film deposition. We have measured the sputtering yields of aluminum and copper in Al--Cu alloys as a function of the Cu concentration (5--13 at. %) and the angle of ion incidence (0--40 0 from normal). During deposition, the films were partially resputtered by 500-eV Ar + ion bombardment from a Kaufman ion source. We found that the Cu sputtering yield decreases by up to a factor of 10 in the alloy, relative to elemental Cu. The Al sputtering yield remains close to the elemental value. The net effect is a strong preferential sputtering of Al relative to Cu, which enhances the Cu concentration in an ion bombarded film. The Al/Cu sputtering yield ratio for normal incidence ion bombardment ranges from 3 to 5 as a function of Cu concentration. This ratio decreases with increasing angle of incidence to as low as 2 for 40 0 incident ions. However, since a higher fraction of the film is resputtered from a sloping surface, a higher Cu concentration is found on a sloping surface relative to a flat surface. These results show that in multicomponent film deposition under ion bombardment, the film composition will vary as a function of the surface topography. We will also show how the level of argon left trapped in the films varies inversely with respect to the ion flux

  18. 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.

  19. 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.

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

    International Nuclear Information System (INIS)

    Hess, Euodia H.; Waryo, Tesfaye; Sadik, Omowunmi A.; Iwuoha, Emmanuel I.; Baker, Priscilla G.L.

    2014-01-01

    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 D e determined from cyclic voltammetry using the anodic peak currents were found to be twice as high (5.82 × 10 −4 cm 2 /s) compared to the D e calculated using the cathodic peak currents (2.60 × 10 −4 cm 2 /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

  1. 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.

  2. Effect of blend ratio and pH on the physical properties of edible composite films prepared from silver carp surimi and skin gelatin.

    Science.gov (United States)

    Tao, Zhong; Weng, Wu-Yin; Cao, Min-Jie; Liu, Guang-Ming; Su, Wen-Jin; Osako, Kazufumi; Tanaka, Munehiko

    2015-03-01

    The effect of blend ratio and pH on the physical properties of surimi-gelatin composite films was investigated. Tensile strength (TS), film water solubility and soluble proteins of composite films increased with the increasing proportion of gelatin, while elongation at break (EAB) decreased. The TS of neutral films with the same ratio of surimi and gelatin were lowest, while increased at acidic or alkaline conditions. Similar tendency was also found in protein solubility and surface hydrophobicity of the film-forming solutions. On the other hand, the film water solubility and soluble proteins of neutral composite films were higher than those of acidic and alkaline films. Furthermore, it was revealed that the dissolved surimi and gelatin proteins could form strong composite films, which were insoluble in water. These results suggested that dissolved proteins were mainly involved in the formation of surimi-gelatin composite films.

  3. /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.

  4. Composition and structure variation for magnetron sputtered tantalum oxynitride thin films, as function of deposition parameters

    Energy Technology Data Exchange (ETDEWEB)

    Cristea, D.; Pătru, M.; Crisan, A.; Munteanu, D. [Department of Materials Science, Transilvania University, 500036 Brasov (Romania); Crăciun, D. [Laser Department, National Institute for Laser, Plasma, and Radiation Physics, Magurele (Romania); Barradas, N.P. [Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, E.N. 10 ao km 139,7, 2695-066 Bobadela LRS (Portugal); Alves, E. [Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, E.N. 10 ao km 139,7, 2695-066 Bobadela LRS (Portugal); Apreutesei, M. [Université de Lyon, Institut des Nanotechnologies de Lyon INL-UMR 5270, CNRS, Ecole Centrale de Lyon, Ecully F-69134 (France); MATEIS Laboratory-INSA de Lyon, Bât. B. Pascal, 7 Avenue Jean Capelle, 69621 Villeurbanne Cedex (France); Moura, C. [Center of Physics, University of Minho, Campus de Gualtar, 4710-057 Braga (Portugal); Cunha, L., E-mail: lcunha@fisica.uminho.pt [Center of Physics, University of Minho, Campus de Gualtar, 4710-057 Braga (Portugal)

    2015-12-15

    Highlights: • Structural evolution from β-Ta, to fcc-Ta(O,N), to amorphous Ta{sub 2}O{sub 5} with increasing P(N{sub 2} + O{sub 2}). • The substrate bias influences the N content, but does not influence the O content of the films. • The structural features of the films appear at lower P(N{sub 2} + O{sub 2}) when produced with grounded substrate. - Abstract: Tantalum oxynitride thin films were produced by magnetron sputtering. The films were deposited using a pure Ta target and a working atmosphere with a constant N{sub 2}/O{sub 2} ratio. The choice of this constant ratio limits the study concerning the influence of each reactive gas, but allows a deeper understanding of the aspects related to the affinity of Ta to the non-metallic elements and it is economically advantageous. This work begins by analysing the data obtained directly from the film deposition stage, followed by the analysis of the morphology, composition and structure. For a better understanding regarding the influence of the deposition parameters, the analyses are presented by using the following criterion: the films were divided into two sets, one of them produced with grounded substrate holder and the other with a polarization of −50 V. Each one of these sets was produced with different partial pressure of the reactive gases P(N{sub 2} + O{sub 2}). All the films exhibited a O/N ratio higher than the N/O ratio in the deposition chamber atmosphere. In the case of the films produced with grounded substrate holder, a strong increase of the O content is observed, associated to the strong decrease of the N content, when P(N{sub 2} + O{sub 2}) is higher than 0.13 Pa. The higher Ta affinity for O strongly influences the structural evolution of the films. Grazing incidence X-ray diffraction showed that the lower partial pressure films were crystalline, while X-ray reflectivity studies found out that the density of the films depended on the deposition conditions: the higher the gas pressure, the

  5. LTCC Phase Shifters Based on Tunable Ferroelectric Composite Thick Films

    Science.gov (United States)

    Nikfalazar, M.; Kohler, C.; Heunisch, A.; Wiens, A.; Zheng, Y.; Schulz, B.; Mikolajek, M.; Sohrabi, M.; Rabe, T.; Binder, J. R.; Jakoby, R.

    2015-11-01

    This paper presents, the investigation of tunable components based on LTCC technology, implementing ferroelectric tunable thick-film dielectric. The tunable loaded line phase shifters are fabricated with metal-insulator-metal (MIM) varactors to demonstrate the capabilities of this method for packaging of the tunable components. The MIM varactors consist of one tunable dielectric paste layer that is printed between two silver layers. The tunable ferroelectric paste is optimized for LTCC sintering temperature around 850°C. The phase shifters are fabricated in two different process. They were achieved a figure of merit of 24°/dB (phase shift 192°) at 3 GHz and 18°/dB (phase shift 98°) at 4.4 GHz by using seven unit cells that each unit cell consisting of two MIM varactors.

  6. Spray pyrolysis synthesized Cu(In,Al)(S,Se)2 thin films solar cells

    Science.gov (United States)

    Aamir Hassan, Muhammad; Mujahid, Mohammad; Woei, Leow Shin; Wong, Lydia Helena

    2018-03-01

    Cu(In,Al)(S,Se)2 thin films are prepared by the Spray pyrolysis of aqueous precursor solutions of copper, indium, aluminium and sulphur sources. The bandgap of the films was engineered by aluminium (Al) doping in CISSe films deposited on molybdenum (Mo) coated glass substrate. The as-sprayed thin films were selenized at 500 °C for 10 min. Cadmium sulphide (CdS) buffer layer was deposited by chemical bath deposition process. Solar cell devices were fabricated with configuration of glass/Mo/CIASSe/CdS/i-ZnO/AZO. The solar cell device containing thin film of Cu(In,Al)(S,Se)2 with our optimized composition shows j-V characteristics of Voc = 0.47 V, jsc = 21.19 mA cm-2, FF = 52.88% and power conversion efficiency of 5.27%, under AM 1.5, 100 mW cm-2 illumination.

  7. Luminescent Polymer Composite Films Containing Coal-Derived Graphene Quantum Dots.

    Science.gov (United States)

    Kovalchuk, Anton; Huang, Kewei; Xiang, Changsheng; Martí, Angel A; Tour, James M

    2015-12-02

    Luminescent polymer composite materials, based on poly(vinyl alcohol) (PVA), as a matrix polymer and graphene quantum dots (GQDs) derived from coal, were prepared by casting from aqueous solutions. The coal-derived GQDs impart fluorescent properties to the polymer matrix, and the fabricated composite films exhibit solid state fluorescence. Optical, thermal, and fluorescent properties of the PVA/GQD nanocomposites have been studied. High optical transparency of the composite films (78 to 91%) and excellent dispersion of the nanoparticles are observed at GQD concentrations from 1 to 5 wt %. The maximum intensity of materials photoluminescence has been achieved at 10 wt % GQD content. These materials could be used in light emitting diodes (LEDs), flexible electronic displays, and other optoelectronic applications.

  8. Formulation and characterization of novel composite semi-refined iota carrageenan-based edible film incorporating palmitic acid

    Science.gov (United States)

    Praseptiangga, Danar; Giovani, Sarah; Manuhara, Godras Jati; Muhammad, Dimas Rahadian Aji

    2017-09-01

    Novel composite films based on semi-refined iota-carrageenan (SRIC) incorporating palmitic acid (PA) were prepared by an emulsification method. Palmitic acid (PA) as hydrophobic material was incorporated into semi-refined iota-carrageenan edible films in order to improve water vapor barrier properties. Composite SRIC-based films with varying concentrations of PA (10%, 20%, and 30% w/w) were obtained by a solvent casting method. Their mechanical and barrier properties were investigated. Results showed that the incorporation of PA in films caused a significant increase (p films improved the tensile strength (TS). Interestingly, the TS value increased to a peak at 20% w/w PA. However, the TS value showed a decrease when PA were added at 30% w/w. Elongation-at-break (EAB) were significantly (p films increased (from 10% to 30% w/w). Furthermore, the incorporation of PA also affected the water vapor barrier properties of the films. Water vapor transmission rate (WVTR) of the composite semi-refined iota-carrageenan-based edible film decreased significantly (p edible film incorporating 30% w/w of PA presented better water vapor barrier properties as compared to other films with 10% and 20% w/w PA incorporation. Thus, formulation containing 30% w/w palmitic acid promoted films with a highly beneficial to improve water vapor barrier properties and it has the potential for food packaging applications.

  9. Effects of mechanical properties of polymer on ceramic-polymer composite thick films fabricated by aerosol deposition

    OpenAIRE

    Kwon, Oh-Yun; Na, Hyun-Jun; Kim, Hyung-Jun; Lee, Dong-Won; Nam, Song-Min

    2012-01-01

    Two types of ceramic-polymer composite thick films were deposited on Cu substrates by an aerosol deposition process, and their properties were investigated to fabricate optimized ceramic-based polymer composite thick films for application onto integrated substrates with the advantage of plasticity. When polymers with different mechanical properties, such as polyimide (PI) and poly(methyl methacrylate) (PMMA), are used as starting powders together with α-Al2O3 powder, two types of composite fi...

  10. Thin film bismuth(III) sulfide/zinc sulfide composites deposited by spray pyrolysis

    Science.gov (United States)

    Benattou, H.; Benramdane, N.; Berouaken, M.

    (Bi2S3)(x)(ZnS)(1-x) composites in thin films were successfully grown on glass substrates by the spray pyrolysis technique. The films growth were prepared by the reaction of aqueous solutions of bismuth(III) chloride (BiCl3) and zinc chloride (ZnCl) with Thiourea on substrates heated to a temperature of 280 °C. The structural properties have been identified using X-ray diffraction spectra. The deposited films are of polycrystalline natures. The both of the two phases mixed (Bi2S3 and ZnS) were well observed in the X-ray diffraction plots. The optical properties were also studied using transmittance and reflectance measurements in the wavelength range (200-2500 nm). Optical gaps were evaluated; we are found that (Bi2S3)(x)(ZnS)(1-x) (x = 0-1) composites in thin films are characterized by two optical gaps limited between the gap of Bi2S3 and that of ZnS films in the pure phase.

  11. Antimicrobial property and microstructure of micro-emulsion edible composite films against Listeria.

    Science.gov (United States)

    Guo, Mingming; Jin, Tony Z; Yadav, Madhav P; Yang, Ruijin

    2015-09-02

    Edible antimicrobial composite films from micro-emulsions containing all natural compounds were developed and their antimicrobial properties and microstructures were investigated. Chitosan, allyl isothiocyanate (AIT), barley straw arabinoxylan (BSAX), and organic acids (acetic, lactic and levulinic acids) were used as film-forming agent, antimicrobial agent, emulsifier, and solvent, respectively. Micro-emulsions were obtained using high pressure homogenization (HPH) processing at 138MPa for 3cycles. The composite films made from the micro-emulsions significantly (p<0.05) inactivated Listeria innocua in tryptic soy broth (TSB) and on the surface of ready-to-eat (RTE) meat samples, achieving microbial reductions of over 4logCFU/ml in TSB after 2days at 22°C and on meat samples after 35days at 10°C. AIT was a major contributor to the antimicrobial property of the films and HPH processing further enhanced its antimicrobial efficacy, while the increase of chitosan from 1.5% to 3%, or addition of acetic acid to the formulations didn't result in additional antimicrobial effects. This study demonstrated an effective approach to developing new edible antimicrobial films and coatings used for food applications. Published by Elsevier B.V.

  12. 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.

  13. Multiple sulphur and lead sources recorded in hydrothermal exhalites associated with the Lemarchant volcanogenic massive sulphide deposit, central Newfoundland, Canada

    Science.gov (United States)

    Lode, Stefanie; Piercey, Stephen J.; Layne, Graham D.; Piercey, Glenn; Cloutier, Jonathan

    2017-01-01

    Metalliferous sedimentary rocks (mudstones, exhalites) associated with the Cambrian precious metal-bearing Lemarchant Zn-Pb-Cu-Au-Ag-Ba volcanogenic massive sulphide (VMS) deposit, Tally Pond volcanic belt, precipitated both before and after VMS mineralization. Sulphur and Pb isotopic studies of sulphides within the Lemarchant exhalites provide insight into the sources of S and Pb in the exhalites as a function of paragenesis and evolution of the deposit and subsequent post-depositional modification. In situ S isotope microanalyses of polymetallic sulphides (euhedral and framboidal pyrite, anhedral chalcopyrite, pyrrhotite, galena and euhedral arsenopyrite) by secondary ion mass spectrometry (SIMS) yielded δ34S values ranging from -38.8 to +14.4 ‰, with an average of ˜ -12.8 ‰. The δ34S systematics indicate sulphur was predominantly biogenically derived via microbial/biogenic sulphate reduction of seawater sulphate, microbial sulphide oxidation and microbial disproportionation of intermediate S compounds. These biogenic processes are coupled and occur within layers of microbial mats consisting of different bacterial/archaeal species, i.e., sulphate reducers, sulphide oxidizers and those that disproportionate sulphur compounds. Inorganic processes or sources (i.e., thermochemical sulphate reduction of seawater sulphate, leached or direct igneous sulphur) also contributed to the S budget in the hydrothermal exhalites and are more pronounced in exhalites that are immediately associated with massive sulphides. Galena Pb isotopic compositions by SIMS microanalysis suggest derivation of Pb from underlying crustal basement (felsic volcanic rocks of Sandy Brook Group), whereas less radiogenic Pb derived from juvenile sources leached from mafic volcanic rocks of the Sandy Brook Group and/or Tally Pond group. This requires that the hydrothermal fluids interacted with juvenile and evolved crust during hydrothermal circulation, which is consistent with the existing

  14. Organization of copper nanoclusters in Langmuir–Blodgett films

    Indian Academy of Sciences (India)

    The Langmuir–Blodgett films of ODSA formed from subphase containing copper ions were first subjected to sulphidation (S) using sodium sulphide and then hydrogenated (H) using hydrogen gas. Diffuse reflectance UV-visible spectroscopy (DIR-UV-vis), X-ray photoelectron spectroscopy (XPS) and transmission electron ...

  15. Electric conductance of films prepared from polymeric composite nanoparticles

    Czech Academy of Sciences Publication Activity Database

    Hain, J.; Pich, A.; Adler, H. J.; Rais, David; Nešpůrek, Stanislav

    2008-01-01

    Roč. 268, č. 1 (2008), s. 61-65 ISSN 1022-1360. [Microsymposium on Advanced Polymer Materials for Photonics and Electronics /47./. Prague, 15.07.2007-19.07.2007] R&D Projects: GA AV ČR KAN400720701; GA MŠk OC 138 Institutional research plan: CEZ:AV0Z40500505 Keywords : coatings * composites * conducting polymers Subject RIV: BM - Solid Matter Physics ; Magnetism

  16. Cadmium-manganese oxide composite thin films: Synthesis, characterization and photoelectrochemical properties

    Energy Technology Data Exchange (ETDEWEB)

    Mansoor, M.A. [Department of Chemistry, Faculty of Science, University of Malaya, Kuala Lumpur 50603 (Malaysia); Low Dimensional Materials Research Centre, Department of Physics, University of Malaya, Faculty of Science, Kuala Lumpur 50603 (Malaysia); Ebadi, M. [Solar Energy Research Institute, University Kebangsaan Malaysia, Bangi 43600, Selangor (Malaysia); Mazhar, M., E-mail: mazhar42pk@yahoo.com [Department of Chemistry, Faculty of Science, University of Malaya, Kuala Lumpur 50603 (Malaysia); Huang, N.M. [Low Dimensional Materials Research Centre, Department of Physics, University of Malaya, Faculty of Science, Kuala Lumpur 50603 (Malaysia); Mun, L.K.; Misran, M. [Department of Chemistry, Faculty of Science, University of Malaya, Kuala Lumpur 50603 (Malaysia); Basirun, W.J. [Department of Chemistry, Faculty of Science, University of Malaya, Kuala Lumpur 50603 (Malaysia); Institute of Nanotechnology and Catalysis (NanoCat), University Malaya, Kuala Lumpur 50603 (Malaysia)

    2017-01-15

    Ceramic composite CdO–Mn{sub 2}O{sub 3} thin films have been deposited on fluorine doped tin oxide (FTO) coated glass substrates by aerosol assisted chemical vapour deposition (AACVD) using a 1:1 mixture of cadmium complex, [Cd(dmae){sub 2}(OAc){sub 2}]·H{sub 2}O (1) (where dmae = 2-dimethylaminoethanolato and OAc = acetato), and diacetatomanganese (II). The phase purity, stoichiometry and thickness of the films were examined by X-ray diffraction (XRD), Fourier transformed infra-red (FTIR), Raman spectroscopy, field emission gun scanning electron microscopy (FEG-SEM), energy dispersive X-ray spectroscopy (EDX), UV–Vis spectroscopy and profilometer. The FEG-SEM analysis illustrated that the morphology of the fabricated films was influenced by the type of solvent. The optical direct band gap of the film fabricated from THF solution was 1.95 eV. From the current–voltage characteristics it is evident that the CdO–Mn{sub 2}O{sub 3} composite semiconductor electrode exhibits n-type behaviour and the photocurrent density was found to be dependent on the deposition medium. The film deposited from THF solution displayed maximum photocurrent density of 4.80 mA cm{sup −2} at 0.65 V vs. Ag/AgCl/3 M KCl (∼1.23 V vs. RHE) in 0.5 M NaOH electrolyte. - Highlights: • Single crystal X-ray structure of [Cd(dmae){sub 2}(OAc){sub 2}]·H{sub 2}O (1). • CdO-Mn{sub 2}O{sub 3} composite photoanode thin films. • Optical band gap of CdO-Mn{sub 2}O{sub 3} photoanode. • Photoelectrochemical and EIS studies.

  17. Crystallographic Textures and Morphologies of Solution Cast Ibuprofen Composite Films at Solid Surfaces

    Science.gov (United States)

    2014-01-01

    The preparation of thin composite layers has promising advantages in a variety of applications like transdermal, buccal, or sublingual patches. Within this model study the impact of the matrix material on the film forming properties of ibuprofen–matrix composite films is investigated. As matrix materials polystyrene, methyl cellulose, or hydroxyl-ethyl cellulose were used. The film properties were either varied by the preparation route, i.e., spin coating or drop casting, or via changes in the relative ratio of the ibuprofen and the matrix material. The resulting films were investigated via X-ray diffraction and atomic force microscope experiments. The results show that preferred (100) textures can be induced via spin coating with respect to the glass surface, while the drop casting results in a powder-like behavior. The morphologies of the films are strongly impacted by the ibuprofen amount rather than the preparation method. A comparison of the various matrix materials in terms of their impact on the dissolution properties show a two times faster zero order release from methyl cellulose matrix compared to a polystyrene matrix. The slowest rate was observed within the hydroxyl ethyl cellulose as the active pharmaceutical ingredients (APIs) release is limited by diffusion through a swollen matrix. The investigation reveals that the ibuprofen crystallization and film formation is only little effected by the selected matrix material than that compared to the dissolution. A similar experimental approach using other matrix materials may therefore allow to find an optimized composite layer useful for a defined application. PMID:25275801

  18. Production of porous PTFE-Ag composite thin films by pulsed laser deposition

    International Nuclear Information System (INIS)

    Kecskeméti, Gabriella; Hopp, Béla; Smausz, Tomi; Tóth, Zsolt; Szabó, Gábor

    2012-01-01

    The suitability of pulsed laser deposition technique for preparation of polytetrafluoroethylene (PTFE) and silver (Ag) composite thin films was demonstrated. Disk-shaped targets combined from silver and Teflon with various percentages were ablated with pulses of an ArF excimer laser. The chemical composition of the deposited layers was estimated based on deposition rates determined for the pure PTFE and Ag films. EDX and SEM analyses using secondary electron and backscattered electron images proved that the morphology of the layers is determined by the PTFE which is the main constituent and it is transferred mostly in form of grains and clusters forming a sponge-like structure with high specific surface. The Ag content is distributed over the surface of the PTFE structure. Contact angle measurements showed that with increasing the amount of Ag in the deposited layers the surface significantly enhanced the wetting properties. Conductivity experiments demonstrated that when the average silver content of the layers was increased from 0.16 to 3.28 wt% the resistance of our PTFE-Ag composite films decreased with about three orders of magnitudes (from ∼10 MΩ to ∼10 kΩ). The properties of these films suggest as being a good candidate for future electrochemical sensor applications.

  19. High-loading Fe2O3/SWNT composite films for lithium-ion battery applications

    Science.gov (United States)

    Wang, Ying; Guo, Jiahui; Li, Li; Ge, Yali; Li, Baojun; Zhang, Yingjiu; Shang, Yuanyuan; Cao, Anyuan

    2017-08-01

    Single-walled carbon nanotube (SWNT) films are a potential candidate as porous conductive electrodes for energy conversion and storage; tailoring the loading and distribution of active materials grafted on SWNTs is critical for achieving maximum performance. Here, we show that as-synthesized SWNT samples containing residual Fe catalyst can be directly converted to Fe2O3/SWNT composite films by thermal annealing in air. The mass loading of Fe2O3 nanoparticles is tunable from 63 wt% up to 96 wt%, depending on the annealing temperature (from 450 °C to 600 °C), while maintaining the porous network structure. Interconnected SWNT networks containing high-loading active oxides lead to synergistic effect as an anode material for lithium ion batteries. The performance is improved consistently with increasing Fe2O3 loading. As a result, our Fe2O3/SWNT composite films exhibit a high reversible capacity (1007.1 mA h g-1 at a current density of 200 mA g-1), excellent rate capability (384.9 mA h g-1 at 5 A g-1) and stable cycling performance with the discharge capacity up to 567.1 mA h g-1 after 600 cycles at 2 A g-1. The high-loading Fe2O3/SWNT composite films have potential applications as nanostructured electrodes for various energy devices such as supercapacitors and Li-ion batteries.

  20. 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.

  1. Optimization of arc evaporated (Ti,Al)N film composition for cutting tool applications

    Energy Technology Data Exchange (ETDEWEB)

    Coll, B.F.; Sathrum, P.; Fontana, R. (Multi-Arc Scientific Coatings, Rockaway, NJ (United States)); Peyre, J.P.; Duchateau, D. (CETIM, 60 - Senlis (France)); Benmalek, M. (CRV S.A., Pechiney Group, 38 - Voreppe (France))

    1992-03-15

    The arc evaporation process is commonly used to deposit TiN coatings for protection against wear and friction. The suitability of this established process for depositing ternary compound films of (Ti{sub x}Al{sub 1-x})N by using alloyed Ti-Al cathodes of various compositions is presented. The influence of the coating parameters on the final composition of the (Ti,Al)N films has been investigated. The bias voltage appears to be the main parameter controlling the final composition. Graded films with three different Al:Ti ratios (0.2, 0.3 and 0.8) have been prepared and comparative four-point-bending tests show a ductility of around 1.2%-1.5% for the (Ti,Al)N coatings. Comparative cutting tool experiments show the superior performance of (Ti,Al)N films for milling difficult-to-machine materials such as titanium alloys, stainless steels and nickel-based superalloys. (orig.).

  2. Novel composite films based on amidated pectin for cationic dye adsorption.

    Science.gov (United States)

    Nesic, Aleksandra R; Velickovic, Sava J; Antonovic, Dusan G

    2014-04-01

    Pectin, with its tendency to gel in the presence of metal ions has become a widely used material for capturing the metal ions from wastewaters. Its dye-capturing properties have been much less investigated, and this paper is the first to show how films based on amidated pectin can be used for cationic dye adsorption. In the present study amidated pectin/montmorillonite composite films were synthesized by membrane casting, and they are stable in aqueous solution both below and above pectin pKa. FTIR, thermogravimetry and SEM-EDAX have confirmed the presence of montmorillonite in the cast films and the interactions between the two constituents. In order to evaluate the cationic dye adsorption of these films Basic Yellow 28 was used, showing that the films have higher adsorption capacity compared to the others reported in the literature. The results were fitted into Langmuir, Freundlich and Temkin isotherms indicating an exothermic process and setting the optimum amount of montmorillonite in the films to 30% of pectin mass. According to the Langmuir isotherm the maximum adsorption capacity is 571.4 mg/g. Copyright © 2013 Elsevier B.V. All rights reserved.

  3. Growth Aspects of Thin-Film Composite Heterostructures of Oxide Multicomponent Perovskites for Electronics

    Science.gov (United States)

    Endo, Kazuhiro; Badica, Petre; Arisawa, Shunichi; Kezuka, Hiroshi; Endo, Tamio

    2012-11-01

    We review, based on our results, the problems and solutions for the growth of thin films and composite heterostructures emphasizing the general growth aspects and principles vs specifics for each material or heterostructure. The materials used in our examples are Bi2Sr2Ca2Cu3O10, Bi2Sr2CaCu2O8, YBa2Cu3O7, (Sr, Ca)CuO2, (Ba, Ca)CuO2, and Bi4Ti3O12. The growth method was metal organic chemical vapor deposition (MOCVD). The presented thin films or heterostructures have c- and non-c-axis orientations. We discuss the implications of the film-substrate lattice relationships, paying attention to film-substrate lattice mismatch anisotropy and to film-film lattice mismatch, which has a significant influence on the quality of the non-c-axis heterostructures. We also present growth control through the use of vicinal substrates and two-temperature (template) and interrupted growth routes allowing significant quality improvements or optimization. Other key aspects of the growth mechanism, that is, roughness, morphology, and interdiffusion, are addressed. It is concluded that the requirements for the growth of non-c-axis heterostructures are more severe than those for the c-axis ones.

  4. Controlling compositional homogeneity and crystalline orientation in Bi0.8Sb0.2 thermoelectric thin films

    Science.gov (United States)

    Rochford, C.; Medlin, D. L.; Erickson, K. J.; Siegal, M. P.

    2015-12-01

    Compositional-homogeneity and crystalline-orientation are necessary attributes to achieve high thermoelectric performance in Bi1-xSbx thin films. Following deposition in vacuum, and upon air exposure, we find that 50%-95% of the Sb in 100-nm thick films segregates to form a nanocrystalline Sb2O3 surface layer, leaving the film bulk as Bi-metal. However, we demonstrate that a thin SiN capping layer deposited prior to air exposure prevents Sb-segregation, preserving a uniform film composition. Furthermore, the capping layer enables annealing in forming gas to improve crystalline orientations along the preferred trigonal axis, beneficially reducing electrical resistivity.

  5. 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

  6. Effects of mechanical properties of polymer on ceramic-polymer composite thick films fabricated by aerosol deposition

    Science.gov (United States)

    Kwon, Oh-Yun; Na, Hyun-Jun; Kim, Hyung-Jun; Lee, Dong-Won; Nam, Song-Min

    2012-05-01

    Two types of ceramic-polymer composite thick films were deposited on Cu substrates by an aerosol deposition process, and their properties were investigated to fabricate optimized ceramic-based polymer composite thick films for application onto integrated substrates with the advantage of plasticity. When polymers with different mechanical properties, such as polyimide (PI) and poly(methyl methacrylate) (PMMA), are used as starting powders together with α-Al2O3 powder, two types of composite films are formed with different characteristics - surface morphologies, deposition rates, and crystallite size of α-Al2O3. Through the results of micro-Vickers hardness testing, it was confirmed that the mechanical properties of the polymer itself are associated with the performances of the ceramic-polymer composite films. To support and explain these results, the microstructures of the two types of polymer powders were observed after planetary milling and an additional modeling test was carried out. As a result, we could conclude that the PMMA powder is distorted by the impact of the Al2O3 powder, so that the resulting Al2O3-PMMA composite film had a very small amount of PMMA and a low deposition rate. In contrast, when using PI powder, the Al2O3-PI composite film had a high deposition rate due to the cracking of PI particles. Consequently, it was revealed that the mechanical properties of polymers have a considerable effect on the properties of the resulting ceramic-polymer composite thick films.

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

    International Nuclear Information System (INIS)

    Bruna, Julio E.; Gonzalez, Valeska; Rodriguez, Francisco; Guarda, Abel; Galotto, Maria Jose

    2011-01-01

    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)

  8. Electro–optical properties of poly(vinyl acetate)/polyindole composite film

    International Nuclear Information System (INIS)

    Bhagat, D. J.; Dhokane, G. R.; Bajaj, N. S.

    2016-01-01

    In present work, electrical and optical properties of poly(vinyl acetate)/polyindole (PVAc/PIN) composite film are reported. The prepared composite was characterized via X–ray diffraction (XRD), UV–Vis spectroscopy and DC conductivity measurements. The polymer chain separation was determined using XRD analysis. An attempt has been made to study the temperature dependence of DC conductivity of PVAc/PIN composite in temperature range 308–373 K. The DC conductivity initially increases and reaches to 2.45×10–7 S/cm. The optical band gap value of composite is determined as 4.77 eV. The semiconducting nature of composite observed from electronic as well as optical band gap and Arrhenius behavior of DC plot.

  9. An Observation of Diamond-Shaped Particle Structure in a Soya Phosphatidylcohline and Bacteriorhodopsin Composite Langmuir Blodgett Film Fabricated by Multilayer Molecular Thin Film Method

    Science.gov (United States)

    Tsujiuchi, Y.; Makino, Y.

    A composite film of soya phosphatidylcohline (soya PC) and bacteriorhodopsin (BR) was fabricated by the multilayer molecular thin film method using fatty acid and lipid on a quartz substrate. Direct Force Microscopy (DFM), UV absorption spectra and IR absorption spectra of the film were characterized on the detail of surface structure of the film. The DFM data revealed that many rhombus (diamond-shaped) particles were observed in the film. The spectroscopic data exhibited the yield of M-intermediate of BR in the film. On our modelling of molecular configuration indicate that the coexistence of the strong inter-molecular interaction and the strong inter-molecular interaction between BR trimmers attributed to form the particles.

  10. Preparation, Characterization and Thermal Degradation of Polyimide (4-APS/BTDA/SiO2 Composite Films

    Directory of Open Access Journals (Sweden)

    Arash Dehzangi

    2012-04-01

    Full Text Available Polyimide/SiO2 composite films were prepared from tetraethoxysilane (TEOS and poly(amic acid (PAA based on aromatic diamine (4-aminophenyl sulfone (4-APS and aromatic dianhydride (3,3,4,4-benzophenonetetracarboxylic dianhydride (BTDA via a sol-gel process in N-methyl-2-pyrrolidinone (NMP. The prepared polyimide/SiO2 composite films were characterized using X-ray diffraction (XRD, Fourier transform infrared spectroscopy (FTIR, scanning electron microscope (SEM and thermogravimetric analysis (TGA. The FTIR results confirmed the synthesis of polyimide (4-APS/BTDA and the formation of SiO2 particles in the polyimide matrix. Meanwhile, the SEM images showed that the SiO2 particles were well dispersed in the polyimide matrix. Thermal stability and kinetic parameters of the degradation processes for the prepared polyimide/SiO2 composite films were investigated using TGA in N2 atmosphere. The activation energy of the solid-state process was calculated using Flynn–Wall–Ozawa’s method without the knowledge of the reaction mechanism. The results indicated that thermal stability and the values of the calculated activation energies increased with the increase of the TEOS loading and the activation energy also varied with the percentage of weight loss for all compositions.

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

    International Nuclear Information System (INIS)

    Loh, Kenneth J; Gonzalez, Jesus

    2015-01-01

    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. (paper)

  12. 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.

  13. Cobalt and precious metals in sulphides of peridotite xenoliths and inferences concerning their distribution according to geodynamic environment: A case study from the Scottish lithospheric mantle

    Science.gov (United States)

    Hughes, Hannah S. R.; McDonald, Iain; Faithfull, John W.; Upton, Brian G. J.; Loocke, Matthew

    2016-01-01

    Abundances of precious metals and cobalt in the lithospheric mantle are typically obtained by bulk geochemical analyses of mantle xenoliths. These elements are strongly chalcophile and the mineralogy, texture and trace element composition of sulphide phases in such samples must be considered. In this study we assess the mineralogy, textures and trace element compositions of sulphides in spinel lherzolites from four Scottish lithospheric terranes, which provide an ideal testing ground to examine the variability of sulphides and their precious metal endowments according to terrane age and geodynamic environment. Specifically we test differences in sulphide composition from Archaean-Palaeoproterozoic cratonic sub-continental lithospheric mantle (SCLM) in northern terranes vs. Palaeozoic lithospheric mantle in southern terranes, as divided by the Great Glen Fault (GGF). Cobalt is consistently elevated in sulphides from Palaeozoic terranes (south of the GGF) with Co concentrations > 2.9 wt.% and Co/Ni ratios > 0.048 (chondrite). In contrast, sulphides from Archaean cratonic terranes (north of the GGF) have low abundances of Co (globally significant Co mineralisation is associated with ophiolites (e.g., Bou Azzer, Morocco and Outokumpu, Finland) or in oceanic peridotite-floored settings at slow-spreading ridges. Thus we suggest an oceanic affinity for the Co enrichment in the southern terranes of Scotland, likely directly related to the subduction of Co-enriched oceanic crust during the Caledonian Orogeny. Further, we identify a distinction between Pt/Pd ratio across the GGF, such that sulphides in the cratonic SCLM have Pt/Pd ≥ chondrite whilst Palaeozoic sulphides have Pt/Pd rich sulphides with discrete Pt-minerals (e.g., PtS) are associated with carbonate and phosphates in two xenolith suites north of the GGF. This three-way immiscibility (carbonate-sulphide-phosphate) indicates carbonatitic metasomatism is responsible for Pt-enrichment in this (marginal) cratonic

  14. Optical and structural properties of ZnO/ZnMgO composite thin films prepared by sol–gel technique

    International Nuclear Information System (INIS)

    Xu, Linhua; Su, Jing; Chen, Yulin; Zheng, Gaige; Pei, Shixin; Sun, Tingting; Wang, Junfeng; Lai, Min

    2013-01-01

    Highlights: ► ZnMgO thin film and ZnO/ZnMgO composite thin film have been prepared by sol–gel method. ► The intensity of ultraviolet emission of ZnMgO thin film is enhanced two times compared with that of pure ZnO thin film. ► Compared with ZnMgO thin film, ZnO/ZnMgO composite thin film shows better crystallization and optical properties. ► ZnO/ZnMgO composite thin films prepared by sol–gel method have potential applications in many optoelectronic devices. - Abstract: In this study, pure ZnO thin film, Mg-doped ZnO (ZnMgO) thin film, ZnO/ZnMgO and ZnMgO/ZnO composite thin films were prepared by sol–gel technique. The structural and optical properties of the samples were analyzed by X-ray diffraction, scanning electron microscopy, UV–visible spectrophotometer, ellipsometer and photoluminescence spectra, respectively. The results showed that the incorporation of Mg increased the strain, broadened the optical bandgap, and improved the intensity of ultraviolet emission of ZnO thin film. The full width at half maximum (FWHM) of the ultraviolet emission peak was also increased due to Mg-doping at the same time. Compared with pure ZnO and ZnMgO thin films, the ZnO/ZnMgO thin film showed better crystalline quality and ultraviolet emission performance, smaller strains and higher transmittance in the visible range.

  15. Growth of cadmium oxide whiskers on cadmium sulphide single crystals with copper as growth activator

    International Nuclear Information System (INIS)

    Koparanova, N.; Simov, S.

    1985-01-01

    Some results on the growth and morphology of cadmium oxide whiskers, obtained on cadmium sulphide single crystals with copper as a growth activator, are presented in this work. Cadmium oxide whiskers have been obtained on brace 112-bar0 brace faces of cadmium sulphide plates with a copper layer deposited in advance. The whiskers grew during the annealing of the plates in a weak stream of technically pure argon at temperatures 670 to 730 deg C for 15 min to 3.5 h. Details about the procedure have been given elsewhere. The composition and morphology of the whiskers have been studied by an X-ray microanalyser JEOL 35 DDS and a scanning electron microscope JEOL, JSM 35. The optical microscopic observations have shown that after annealing, a gray-black granular layer is formed on the cadmium sulphide single crystals and this layer can easily be separated from the crystal substrate. Under the granular layer the crystal is heavily damaged. The whiskers grow on the granular layer and they are coloured yellow-brown or red-brown. The maximum whisker length attains several hundreds of micrometres and in some cases up to 1 mm or more. (author)

  16. Growth of cadmium oxide whiskers on cadmium sulphide single crystals with copper as growth activator

    Energy Technology Data Exchange (ETDEWEB)

    Koparanova, N.; Simov, S. (Bylgarska Akademiya na Naukite, Sofia. Inst. po Fizika na Tvyrdoto Tyalo); Genchev, D. (Bylgarska Akademiya na Naukite, Sofia. Inst. za Yadrena Izsledvaniya i Yadrena Energetika); Metchenov, G. (Research Inst. of Criminalistics and Criminology, Sofia (Bulgaria))

    1985-02-01

    Some results on the growth and morphology of cadmium oxide whiskers, obtained on cadmium sulphide single crystals with copper as a growth activator, are presented in this work. Cadmium oxide whiskers have been obtained on brace 112-bar0 brace faces of cadmium sulphide plates with a copper layer deposited in advance. The whiskers grew during the annealing of the plates in a weak stream of technically pure argon at temperatures 670 to 730 deg C for 15 min to 3.5 h. Details about the procedure have been given elsewhere. The composition and morphology of the whiskers have been studied by an X-ray microanalyser JEOL 35 DDS and a scanning electron microscope JEOL, JSM 35. The optical microscopic observations have shown that after annealing, a gray-black granular layer is formed on the cadmium sulphide single crystals and this layer can easily be separated from the crystal substrate. Under the granular layer the crystal is heavily damaged. The whiskers grow on the granular layer and they are coloured yellow-brown or red-brown. The maximum whisker length attains several hundreds of micrometres and in some cases up to 1 mm or more.

  17. Multiscale mechanics of graphene oxide and graphene based composite films

    Science.gov (United States)

    Cao, Changhong

    The mechanical behavior of graphene oxide is length scale dependent: orders of magnitude different between the bulk forms and monolayer counterparts. Understanding the underlying mechanisms plays a significant role in their versatile application. A systematic multiscale mechanical study from monolayer to multilayer, including the interactions between layers of GO, can provide fundamental support for material engineering. In this thesis, an experimental coupled with simulation approach was used to study the multiscale mechanics of graphene oxide (GO) and the methods developed for GO study are proved to be applicable also to mechanical study of graphene based composites. GO is a layered nanomaterial comprised of hierarchical units whose characteristic dimension lies between monolayer GO (0.7 nm - 1.2 nm) and bulk GO papers (≥ 1 mum). Mechanical behaviors of monolayer GO and GO nanosheets (10 nm- 100 nm) were comprehensively studied this work. Monolayer GO was measured to have an average strength of 24.7 GPa,, orders of magnitude higher than previously reported values for GO paper and approximately 50% of the 2D intrinsic strength of pristine graphene. The huge discrepancy between the strength of monolayer GO and that of bulk GO paper motivated the study of GO at the intermediate length scale (GO nanosheets). Experimental results showed that GO nanosheets possess high strength in the gigapascal range. Molecular Dynamic simulations showed that the transition in the failure behavior from interplanar fracture to intraplanar fracture was responsible for the huge strength discrepancy between nanometer scale GO and bulk GO papers. Additionally, the interfacial shear strength between GO layers was found to be a key contributing factor to the distinct mechanical behavior among hierarchical units of GO. The understanding of the multiscale mechanics of GO is transferrable in heterogeneous layered nanomaterials, such as graphene-metal oxide based anode materials in Li

  18. Investigations of microelectronic humidity sensors made of composite oxides thin films

    International Nuclear Information System (INIS)

    Pogossyan, A.S.; Arutyunyan, V.M.

    1996-01-01

    Basic characteristics (the moisture sensitivity, lag, hysteresis and stability) of humidity sensors made of Fe 2 O 3 thin films with different K 2 content, as well as CaSiO 3 and NaBiTi 2 O 6 films,-new materials for the humidity sensors, are investigated. A composition Fe 2 O 3 (K) is found to be optimal with respect to high moisture sensitivity, speed of response, and a linearity in a wide range of the relative humidity. A mechanism of the moisture-sensitivity of films investigated is discussed. Criteria for the design parameters of the high-impedance humidity sensors are defined with the aim to broadening of the working range of the relative humidity in a side way of low values of the humidity.10 refs

  19. The role of film composition and nanostructuration on the polyphenol sensor performance

    Directory of Open Access Journals (Sweden)

    Cibely Silva Martin

    2016-12-01

    Full Text Available The recent advances in the supramolecular control in nanostructured films have improved the performance of organic-based devices. However, the effect of different supramolecular arrangement on the sensor or biosensor performance is poorly studied yet. In this paper, we show the role of the composition and nanostructuration of the films on the impedance and voltammetric-based sensor performance to catechol detection. The films here studied were composed by a perylene derivative (PTCD-NH2 and a metallic phthalocyanine (FePc, using Langmuir-Blodgett (LB and physical vapor deposition (PVD techniques. The deposition technique and intrinsic properties of compounds showed influence on electrical and electrocatalytic responses. The PVD PTCD-NH2 shows the best sensor performance to the detection of catechol. Quantification of catechol contents in mate tea samples was also evaluated, and the results showed good agreement compared with Folin-Ciocalteu standard method for polyphenol detection.

  20. Thin film of lignocellulosic nanofibrils with different chemical composition for QCM-D study.

    Science.gov (United States)

    Kumagai, Akio; Lee, Seung-Hwan; Endo, Takashi

    2013-07-08

    Thin films of lignocellulosic nanofibrils (LCNFs) with different chemical compositions were prepared for real-time observation of their enzymatic adsorption and degradation behavior by using a quartz crystal microbalance with dissipation monitoring (QCM-D). LCNFs were obtained by disk milling followed by high-pressure homogenization of Hinoki cypress. The lignin contents were adjusted by the sodium chlorite treatment. The film thickness was adjusted by controlling the concentration of the LCNF suspension, which was determined from its proportional relationship to the UV absorbance of lignin. The enzymatic degradation behavior was investigated with a commercial enzyme mixture. The results of the QCM-D showed that changes in frequency and dissipation in the initial reaction stage were different from the typical changes reported for pure cellulose. To the best of our knowledge, this is the first report of the preparation of thin films of LCNFs with high lignin and hemicellulose contents and their application in a QCM-D study.

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

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Ling; He, Xiaoshan; Chen, Guo; Wang, Tao; Tang, Yongjian; He, Zhibing, E-mail: hezhibing802@163.com

    2016-03-15

    Graphical abstract: - Highlights: • The growth mechanism of defects in GDP films was studied upon plasma diagnosis. • Increasing rf power enhanced the etching effects of smaller-mass species. • The “void” defect was caused by high energy hydrocarbons bombardment on the surface. • The surface roughness was only 12.76 nm, and no “void” defect was observed at 30 W. - Abstract: 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 (T{sub 2}B) 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.

  2. Structural and magnetic studies on heavy-metal-adsorbing iron sulphide nanoparticles produced by sulphate-reducing bacteria

    International Nuclear Information System (INIS)

    Watson, J.H.P; Cressey, B.A.; Roberts, A.P.; Ellwood, D.C.; Charnock, J.M.; Soper, A.K.

    2000-01-01

    In previous and in work to be published, it has been shown that iron sulphide material, produced by sulphate-reducing bacteria (SRB), is an excellent adsorbent for a wide range of heavy metals. The material adsorbs between 100 and 400 mg g -1 and residual levels in solutions can be of the order of pg per litre. Further, strongly magnetic forms of this material can now be produced which can be effectively and cheaply removed from suspension together with the adsorbate by magnetic separation. This paper examines the structure of weakly magnetic and strongly magnetic iron sulphide material produced by SRB with a view to increasing the understanding of its adsorbent and the magnetic properties. The structural properties have been examined using high-resolution imaging and electron diffraction in a transmission electron microscope (TEM), the measurements of magnetisation versus field and temperature, extended X-ray absorption fine-structure (EXAFS) spectroscopy, X-ray absorption near-edge structure (XANES) spectroscopy and neutron diffraction. Before drying the surface area of both the weakly magnetic and the strongly magnetic iron sulphide is of the order of 400-500 m 2 g -1 as revealed by the magnetic properties, neutron scattering and the adsorption of a number of heavy metals. After freeze-drying the surface area falls to between 18 and 19 m 2 g -1 . The initial inocula came from a semi-saline source and when fed with nutrient containing Fe 2+ and Fe 3+ produced a weakly magnetic iron sulphide (Watson et al., Minerals Eng. 8 (1995) 1097) and a few % of a more strongly magnetic material. Further work using a novel method (Keller-Besrest, Collin, J. Solid State Chem. 84 (1990) 211) produced a strongly magnetic iron sulphide material. EXAFS and XANES spectroscopy revealed (Keller-Besrest and Collin, 1990) that the weakly magnetic iron sulphide material had the Ni-As structure in which the Fe is tetrahedrally coordinated with the composition Fe 1-x S. The strongly

  3. Study on Photoelectric Properties of Composite Films of Graphene/Ti02 Nanorods

    Directory of Open Access Journals (Sweden)

    JIN Guo-li

    2017-02-01

    Full Text Available TiOZ nanorods have large specific surface area and the ability of directional transmission electron, based on which can reduce recombination probability of light-generated electrons and holes,and improve the photoelectric conversion efficiency of DSSC. As graphene has low resistivity,good stability and excellent transparency,it can be introduced into anode film to improve the electronic transmission. The TiOZ nanorods were prepared by hydrothermal method,mixed with different quality of graphene. Its length range was 200-300 nm,with a diameter of about 20 nm. The porous graphene/TiOZ nanorods composite film were prepared by using electro- hydrodynamic technique(EHDand compositing TiOZ nanorods with different quality of grapheme. The photoelectric conversion efficiency of the DSSC device prepared with the photo-anode film with graphene mass content of 3 % was 4. 23 %,the photoelectric conversion efficiency increased by 36%,relative to that of no graphene doped TiOZ nanorods photo-anode film.

  4. Electrodeposited MnO(x)/PEDOT Composite Thin Films for the Oxygen Reduction Reaction.

    Science.gov (United States)

    Vigil, Julian A; Lambert, Timothy N; Eldred, Kaitlyn

    2015-10-21

    Manganese oxide (MnOx) was anodically coelectrodeposited with poly(3,4-ethylenedioxythiophene) (PEDOT) from an aqueous solution of Mn(OAc)2, 3,4-ethylenedioxythiophene, LiClO4 and sodium dodecyl sulfate to yield a MnOx/PEDOT composite thin film. The MnOx/PEDOT film showed significant improvement over the MnOx only and PEDOT only films for the oxygen reduction reaction, with a >0.2 V decrease in onset and half-wave overpotential and >1.5 times increase in current density. Furthermore, the MnOx/PEDOT films were competitive with commercial benchmark 20% Pt/C, outperforming it in the half-wave ORR region and exhibiting better electrocatalytic selectivity for the oxygen reduction reaction upon methanol exposure. The high activity of the MnOx/PEDOT composite is attributed to synergistic charge transfer capabilities, attained by coelectrodepositing MnOx with a conductive polymer while simultaneously achieving intimate substrate contact.

  5. 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.

  6. Light illumination effects in ambipolar FETs based on poly(3-hexylthiophene) and fullerene derivative composite films

    International Nuclear Information System (INIS)

    Shibao, Miho; Morita, Takeomi; Takashima, Wataru; Kaneto, Keiichi

    2008-01-01

    The effects of light illumination on field effect transistors based on poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C 61 -butyric methyl ester (PCBM) composite films have been studied. It is found that the light illumination on pure P3HT and PCBM generally resulted in decrease of the threshold voltages and increase of the mobilities by a little. In the composite film at the PCBM contents of x = [P3HT] / ([P3HT] + [PCBM]) = 0.67 ∼ 0.9, an ambipolar field transport appeared. The light illumination effect was observed remarkably in the shift of threshold voltage for the hole generation at x = 0.75. Variations of Hole and electron mobilities and threshold voltage of electron generation upon light illumination were basically similar to those of the pure materials. The results were discussed in terms of the light assisted carrier generation in field effects

  7. Self-assembled thin films of Fe3O4-Ag composite nanoparticles for spintronic applications

    Science.gov (United States)

    Jiang, Chengpeng; Leung, Chi Wah; Pong, Philip W. T.

    2017-10-01

    Controlled self-assembly of multi-component magnetic nanoparticles could lead to nanomaterial-based magnetic devices with novel structures and intriguing properties. Herein, self-assembled thin films of Fe3O4-Ag composite nanoparticles (CNPs) with hetero-dimeric shapes were fabricated using interfacial assembly method. The CNP-assembled thin films were further transferred to patterned silicon substrates followed by vacuum annealing, producing CNP-based magnetoresistive (MR) devices. Due to the presence of intra-particle interfaces and inter-particle barriers, an enhanced MR ratio and a non-linear current-voltage relation were observed in the device. The results of this work can potentially pave the way to the future exploration and development of spintronic devices built from composite nanomaterials.

  8. Vacuum-assisted bilayer PEDOT:PSS/cellulose nanofiber composite film for self-standing, flexible, conductive electrodes.

    Science.gov (United States)

    Ko, Youngsang; Kim, Dabum; Kim, Ung-Jin; You, Jungmok

    2017-10-01

    Sustainable cellulose nanofiber (CNF)-based composites as functional conductive materials have garnered considerable attention recently for their use in soft electronic devices. In this work, self-standing, highly flexible, and conductive PEDOT:PSS-CNF composite films were developed using a simple vacuum-assisted filtration method. Two different composite films were successfully fabricated and then tested: 1) a single-layer composite composed of a mixture of PEDOT:PSS and CNF phases and 2) a bilayer composite composed of an upper PEDOT:PSS membrane layer and a CNF matrix sub-layer. The latter composite was constructed by electrostatic/hydrogen bonding interactions between PEDOT:PSS and CNFs coupled with sequential vacuum-assisted filtration. Our results demonstrated that the resultant bilayer composite film exhibited a competitive electrical conductivity (ca. 22.6Scm -1 ) compared to those of previously reported cellulose-based composites. Furthermore, decreases in the electrical properties were not observed in the composite films when they were bent up to 100 times at an angle of 180° and bent multiple times at an angle of 90°, clearly demonstrating their excellent mechanical flexibility. This study provides a straightforward method of fabricating highly flexible, lightweight, and conductive films, which have the potential to be used in high-performance soft electronic systems. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Water-driven stabilization of cadmium sulphide nanoparticles

    Science.gov (United States)

    Goswami, Navendu; Sen, P.

    2017-12-01

    Water driven stabilization of cadmium sulphide (CdS) nanoparticles, synthesized through a novel and facile electro-explosion of wire (EEW) technique, is reported by us. The transformation of prepared material was visually evident; as greenish black colour of the colloidal as well as the powder particles, obtained just after the synthesis, changed to orange colour after one month. Cubic Hawleyite phase CdS nanoparticles with 2.3-13.4 nm average crystallite size were ascertained by XRD analysis. HRTEM and AFM analysis collectively confirmed the formation of stable CdS nanoparticles. The crucial S-H vibrational mode, a signature interaction of CdS nanoparticles with surrounding water molecules, was revealed by FTIR analysis. The composition of prepared nanoparticles was accessed through XPS analysis. Not only structural but optical properties of nanoparticles also altered due to aging of nanoparticles. Enhanced band gap of CdS nanoparticles and gradual prominence of absorption energy with aging were demonstrated through UV-vis analysis. Complementary to this, PL spectroscopic analysis revealed the photophysics of CdS nanoparticles by providing details of radiative recombination channels. Thus, intricacies of CdS nanoparticles stabilization in aqueous environment were unravelled on the basis of variations in crystallinity, local chemical environment, alterations in electronic structure and optical processes occurring therein.

  10. Cationic guar gum orchestrated environmental synthesis for silver nano-bio-composite films.

    Science.gov (United States)

    Abdullah, Md Farooque; Ghosh, Sumanta Kumar; Basu, Sreyasree; Mukherjee, Arup

    2015-12-10

    This work is meant for environmentally friendly synthesis and functional evaluation of silver nanoparticles in a newer cationic guar biopolymer (GGAA). Assembly of molecules in lower size range (∼ 10 nm) was attained in a biopolymer entrapped bottom-up synthesis. Guar gum is a filming biopolymer. Nanoparticles encaged in cationic guar (GGAgnC) were preserved as films for months without any significant effect on particle size, distribution or plasmonic intensity. The new nano-bio-composite and films were characterized fully in FTIR, XRD, SEM and TEM studies. Silver nanoparticles induced surface water repellency remarkably and lowered moisture permeability. GGAgnC film water contact angle was recorded as 115° while, that in case of GGAA was 59°. GGAgnC expressed intense antimicrobial activity when tested against a range of microorganisms. Immobilized silver nanoparticles in GGAA can feasibly be used as filming microbicidals suitable for textiles, packaging and biomedical device applications. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Structural, morphological, compositional and optical studies of plasma polymerized 2-furaldehyde amorphous thin films

    Science.gov (United States)

    Kabir, Humayun; Rahman, M. Mahbubur; Uddin, Kabir M.; Bhuiyan, A. H.

    2017-11-01

    Plasma synthesized 2-furaldehyde (PPFDH) amorphous polymer thin films of varying thicknesses were prepared in optimum conditions by a capacitively coupled parallel plate glow discharge reactor at room temperature. The structure, morphology, composition and optical properties of deposited PPFDH thin films have been investigated using X-Ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, Scanning electron microscopy (SEM), Energy dispersive X-Ray spectroscopy (EDS), as well as Ultraviolet-visible (UV-vis) absorption spectroscopy. XRD results confirmed the amorphous nature of the films. The smooth and uniform nature of the PPFDH thin films were observed by SEM images. FTIR analyses of monomer FDH and PPFDH thin films show that structural rearrangement has occurred due to the synthesis process taking place in the chemical structure. IR stretching bands obtained from DFT calculations of the optimized structures of monomer and polymer of 2-furaldehyde are in good agreement with the experimental results. UV-vis absorption spectra in transmittance as well as reflectance mode was utilized to compute absorption coefficient, allowed direct and indirect transition energy gaps, band edge sharpness, Urbach energy, steepness parameter, extinction coefficient, and dispersion and oscillator energy. The oscillator strength, moments of optical spectra, refractive index at infinite wavelength, high frequency dielectric constant, average oscilator strength, complex refractive index, dissipation factor, optical conductivity and skin depth were also determined by using measured UV-vis transmittance and reflectance spectra.

  12. Synovial fluid lubrication of artificial joints: protein film formation and composition.

    Science.gov (United States)

    Fan, Jingyun; Myant, Connor; Underwood, Richard; Cann, Philippa

    2012-01-01

    Despite design improvements, wear of artificial implants remains a serious health issue particularly for Metal-on-Metal (MoM) hips where the formation of metallic wear debris has been linked to adverse tissue response. Clearly it is important to understand the fundamental lubrication mechanisms which control the wear process. It is usually assumed that MoM hips operate in the ElastoHydrodynamic Lubrication (EHL) regime where film formation is governed by the bulk fluid viscosity; however there is little experimental evidence of this. The current paper critically examines synovial fluid lubrication mechanisms and the effect of synovial fluid chemistry. Two composition parameters were chosen; protein content and pH, both of which are known to change in diseased or post-operative synovial fluid. Film thickness and wear tests were carried out for a series of model synovial fluid solutions. Two distinct film formation mechanisms were identified; an adsorbed surface film and a high-viscosity gel. The entrainment of this gel controls film formation particularly at low speeds. However wear of the femoral head still occurs and this is thought to be due primarily to a tribo-corrosion mechanisms. The implications of this new lubrication mechanism and the effect of different synovial fluid chemistries are examined. One important conclusion is that patient synovial fluid chemistry plays an important role in determining implant wear and the likelihood of failure.

  13. Composite films of polydopamine-Alcian Blue for colored coating with new physical properties.

    Science.gov (United States)

    Ponzio, Florian; Bour, Jérôme; Ball, Vincent

    2015-12-01

    Polydopamine (PDA) coatings appear as a universal functionalization methodology allowing to coat the surface of almost all kinds of known materials with a conformal, stable, robust and reactive material. Relatively few investigations were dedicated to the incorporation of other molecules in PDA coatings during their deposition from dopamine solutions under oxidative conditions. Herein we rely on the assumption that the basic building blocks of PDA could be porphyrin like tetramers (as well as higher order oligomers) of 5,6-dihydroxyindole and we investigate the influence of a cationic Cu(II) phtalocyanine, namely Alcian Blue (AB), on the deposition kinetics and on the properties of PDA films. We demonstrate that AB is indeed incorporated in the PDA films to yield a composite PDA-AB coating displaying the optical features of both PDA and AB. The amount of incorporated dye depends on its concentration in solution. The obtained PDA-AB films have a smaller thickness than their related PDA counterparts, a different morphology and a higher permeability to the anionic hexacyanoferrate redox probe. In addition, the incorporation of AB in the films is not homogeneous through their thickness as inferred by means of X-ray photoelectron spectroscopy. The reason for this interesting finding is discussed on the basis of the interactions between AB and PDA as well as on the basis of the structure of PDA films. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. Dendrimeric Thin-Film Composite Membranes: Free Volume, Roughness, and Fouling Resistance

    KAUST Repository

    Phuoc, Duong

    2017-11-10

    Copolyamide films with a thickness from 50 to 780 nm were fabricated by interfacial polymerization between mixtures of m-phenylene diamine and primary amine-terminated polyamidoamine dendrimers (PAMAM) in the aqueous phase and trimesoyl chloride (TMC) in the organic phase. Different PAMAM generations (G0, d = 15 Å, Z = 4; G3, d = 36 Å, Z = 32; and G5, d = 54, Z = 128, where d is the measured diameter and Z is the number of terminal groups) and concentrations were used to obtain copolyamide films with different crosslinked structures. The influences of the concentration and degree of branching (PAMAM generation) on free volume were analysed via positon annihilation spectroscopy (PAS) and correlated with the separation properties of copolyamide films. Besides, surface and intrinsic properties of copolyamide films under different conditions were compared. The high hydrophilicity of PAMAM in the copolyamide network leads to the formation of a hydration layer on the copolyamide surface, which minimizes fouling. The separation performance of copolyamide membranes with various PAMAM networks was investigated in forward osmosis (FO) experiments. Understanding the correlation between the PAMAM structure/concentration, free volume, thickness, and surface intrinsic properties leads to the design of suitable fouling resistant thin-film composite membranes in a single interfacial polymerization process.

  15. Optical properties of PLT films with various composition on quartz and modifications of their surfaces

    CERN Document Server

    Yoon, Y S; Koh, S K; Jung, H J

    1999-01-01

    (Pb sub 1 sub - sub x La sub x)TiO sub 3 (PLT) films with various compositions of La were deposited by using the sol-gel process on quartz substrates in order to study their optical properties. X-ray patterns indicated that the pseudocubic phase of the PLT film dominated with increased La concentration due to a decrease in the lattice constant of the c-axis. Three-dimensional atomic force microscopy images revealed that the grain size and root mean square (r.m.s) surface roughness were decreased by adding of La. The optical band gap of the as-deposited films became wider when Pb was replaced with La, which could be calculated from the transmittance of an UV-visible spectrometer. The addition of La increased the transparency of the PbTiO sub 3 film and shifted the threshold to shorter wavelengths for initiation of absorption. In addition, we modified the surfaces of the PLT films with La concentrations of 5 % by using an oxygen-ion beam with an oxygen-ion energy of 1 kV at different doses. The optical band gap...

  16. Polyamide Thin-Film Composite Membranes for Potential Raw Biogas Purification: Experiments and Modelling.

    Czech Academy of Sciences Publication Activity Database

    Šimčík, Miroslav; Růžička, Marek; Kárászová, Magda; Sedláková, Zuzana; Vejražka, Jiří; Veselý, M.; Čapek, P.; Friess, K.; Izák, Pavel

    2016-01-01

    Roč. 167, JUL 14 (2016), s. 163-173 ISSN 1383-5866 R&D Projects: GA ČR GA14-12695S; GA TA ČR TE01020080; GA MŠk(CZ) LD13018; GA MŠk LH14006 Institutional support: RVO:67985858 Keywords : thin film composite membrane * biogas membrane separation * transport model ing Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 3.359, year: 2016

  17. Polyamide Thin-Film Composite Membranes for Potential Raw Biogas Purification: Experiments and Modelling.

    Czech Academy of Sciences Publication Activity Database

    Šimčík, Miroslav; Růžička, Marek; Kárászová, Magda; Sedláková, Zuzana; Vejražka, Jiří; Veselý, M.; Čapek, P.; Friess, K.; Izák, Pavel

    2016-01-01

    Roč. 167, JUL 14 (2016), s. 163-173 ISSN 1383-5866 R&D Projects: GA ČR GA14-12695S; GA TA ČR TE01020080; GA MŠk(CZ) LD13018; GA MŠk LH14006 Institutional support: RVO:67985858 Keywords : thin film composite membrane * biogas membrane separation * transport modeling Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 3.359, year: 2016

  18. Effect of Addition of Colloidal Silica to Films of Polyimide, Polyvinylpyridine, Polystyrene, and Polymethylmethacrylate Nano-Composites

    OpenAIRE

    Abdalla, Soliman; Al-Marzouki, Fahad; Obaid, Abdullah; Gamal, Salah

    2016-01-01

    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...

  19. 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.

  20. 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.

  1. Polyaniline-stabilized electromagnetic wave absorption composites of reduced graphene oxide on magnetic carbon nanotube film.

    Science.gov (United States)

    Li, Jinsong; Duan, Yan; Lu, Weibang; Chou, Tsu-Wei

    2018-04-02

    A multi-layered composite with exceptionally high electromagnetic wave-absorbing capacity and performance stability was fabricated via the facile electrophoresis of a reduced graphene oxide network on carbon nanotube (CNT)-Fe 3 O 4 -polyaniline (PANI) film. Minimum reflection loss (RL) of -53.2 dB and absorbing bandwidth of 5.87 GHz (< -10 dB) are achieved, surpassing most recently reported CNT- and graphene-based absorbers. In particular, comparing to the original composites, the minimum RL and bandwidth (< -10 dB) maintains 82.5% and 99.7%, respectively, after 20 h charge/discharge cycling, demonstrating high environmental suitability.

  2. 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.

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

    International Nuclear Information System (INIS)

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

    2016-01-01

    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. (paper)

  4. Polyaniline-stabilized electromagnetic wave absorption composites of reduced graphene oxide on magnetic carbon nanotube film

    Science.gov (United States)

    Li, Jinsong; Duan, Yan; Lu, Weibang; Chou, Tsu-Wei

    2018-04-01

    A multi-layered composite with exceptionally high electromagnetic wave-absorbing capacity and performance stability was fabricated via the facile electrophoresis of a reduced graphene oxide network on carbon nanotube (CNT)-Fe3O4-polyaniline (PANI) film. Minimum reflection loss (RL) of -53.2 dB and absorbing bandwidth of 5.87 GHz (< -10 dB) are achieved, surpassing most recently reported CNT- and graphene-based absorbers. In particular, comparing to the original composites, the minimum RL and bandwidth (< -10 dB) maintains 82.5% and 99.7%, respectively, after 20 h charge/discharge cycling, demonstrating high environmental suitability.

  5. Rheological and structural characterization of HA/PVA-SbQ composites film-forming solutions and resulting films as affected by UV irradiation time.

    Science.gov (United States)

    Bai, Huiyu; Sun, Yunlong; Xu, Jing; Dong, Weifu; Liu, Xiaoya

    2015-01-22

    Hyaluronan (HA)/poly (vinyl alcohol) bearing styrylpyridinium groups (PVA-SbQ) composites film-forming solutions were prepared by a negatively charged HA and an oppositely charged PVA-SbQ. The rheological properties and structural characterization of HA/PVA-SbQ composites in aqueous solution were investigated. Zeta potential measurements and TEM were utilized to explore the formation of HA/PVA-SbQ complex micelles in aqueous solution. UV spectra and DLS experiments confirmed that the micelles are photo-crosslinkable. HA/PVA-SbQ composites films were prepared by a casting method. The microstructure and properties of the film were analyzed by SEM, optical transmittance, DSC, XRD and tensile testing. The crosslinked HA/PVA-SbQ composites films exhibited higher UV light shielding and visible light transparency and better mechanical and water vapor barrier properties as well as thermal stability than the uncrosslinked HA/PVA-SbQ composites films, indicating the formation of three-dimensional network structure. This work provided a good way for increasing the mechanical, thermal, water vapor barrier, and optical properties of HA materials for the packaging material. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. 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. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Au/CeO2-chitosan composite film for hydrogen peroxide sensing

    International Nuclear Information System (INIS)

    Zhang Wei; Xie Guoming; Li Shenfeng; Lu Lingsong; Liu Bei

    2012-01-01

    Au nanoparticles (AuNPs) were in situ synthesized at the cerium dioxide nanoparticles (CeO 2 NPs)-chitosan (CS) composite film by one-step direct chemical reduction, and the resulting Au/CeO 2 -CS composite were further modified for enzyme immobilization and hydrogen peroxide (H 2 O 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 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 μM (S/N = 3). Moreover, the biosensor presented high affinity (K m app =1.93mM), good reproducibility and storage stability. All these results demonstrate that the Au/CeO 2 -CS composite film can provide a promising biointerface for the biosensor designs and other biological applications.

  8. 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.

  9. Optical waveguide based on amorphous Er{sup 3+}-doped Ga-Ge-Sb-S(Se) pulsed laser deposited thin films

    Energy Technology Data Exchange (ETDEWEB)

    Nazabal, V., E-mail: virginie.nazabal@univ-rennes1.f [Sciences Chimiques de Rennes (SCR), UMR CNRS 6226, Equipe Verres et Ceramiques, Universite de Rennes 1, Rennes (France); Nemec, P. [Department of General and Inorganic Chemistry and Research Center, Faculty of Chemical Technology, University of Pardubice, Legions Sq. 565, 53210, Pardubice (Czech Republic); Jurdyc, A.M [Laboratoire de Physico-Chimie des Materiaux Luminescents (LPCML), UMR CNRS 5620, Universite Claude Bernard-Lyon 1, Villeurbanne (France); Zhang, S.; Charpentier, F. [Sciences Chimiques de Rennes (SCR), UMR CNRS 6226, Equipe Verres et Ceramiques, Universite de Rennes 1, Rennes (France); Lhermite, H. [IETR-Microelectronique, UMR CNRS 6251, Universite de Rennes 1, 35042 Rennes (France); Charrier, J. [FOTON, UMR 6082-ENSSAT, UMR CNRS 6251, Universite de Rennes 1, 35042 Rennes (France); Guin, J.P. [LARMAUR, UMR CNRS 6251, Universite de Rennes 1, 35042 Rennes (France); Moreac, A. [Institut de Physique de Rennes, UMR CNRS 6251, Universite de Rennes 1, 35042 Rennes (France); Frumar, M. [Department of General and Inorganic Chemistry and Research Center, Faculty of Chemical Technology, University of Pardubice, Legions Sq. 565, 53210, Pardubice (Czech Republic); Adam, J.-L. [Sciences Chimiques de Rennes (SCR), UMR CNRS 6226, Equipe Verres et Ceramiques, Universite de Rennes 1, Rennes (France)

    2010-06-30

    Amorphous chalcogenide films play a motivating role in the development of integrated planar optical circuits due to their potential functionality in near infrared (IR) and mid-IR spectral regions. More specifically, the photoluminescence of rare earth ions in amorphous chalcogenide films can be used in laser and amplifier devices in the IR spectral domain. The aim of the present investigation was to optimize the deposition conditions for the fabrication of undoped and Er{sup 3+} doped sulphide and selenide thin films with nominal composition Ga{sub 5}Ge{sub 20}Sb{sub 10}S(Se){sub 65} or Ga{sub 5}Ge{sub 23}Sb{sub 5}S{sub 67} by pulsed laser deposition (PLD). The study of compositional, morphological and structural characteristics of the layers was realized by scanning electron microscopy-energy dispersive spectroscopy, atomic force microscopy and Raman spectroscopy analyses, respectively. Some optical properties (transmittance, index of refraction, optical band gap, etc.) of prepared chalcogenide films and optical losses were investigated as well. The clear identification of near-IR photoluminescence of Er{sup 3+} ions was obtained for both selenide and sulphide films. The decay of the {sup 4}I{sub 13/2} {yields} {sup 4}I{sub 15/2} transition at 1.54 {mu}m in Er{sup 3+} doped Ga{sub 5}Ge{sub 20}Sb{sub 10}S{sub 65} PLD sulphide films was studied to assess the effects of film thickness, rare earth concentration and multilayer PLD deposition on their spectroscopic properties.

  10. REMOVAL OF CU (II AND FE (II IONS THROUGH THIN FILM COMPOSITE (TFC WITH HYBRID MEMBRANE

    Directory of Open Access Journals (Sweden)

    NURUL AIDA SULAIMAN

    2016-07-01

    Full Text Available In recent years, there has been rising concern about environmental issues and specifically about the presence of heavy metal in water. Therefore, the removal of heavy metal ions from wastewater is very important with respect to the ecological health and public health. This paper presents the possibility of removing metal ions by using a hybrid membrane through thin film composite (TFC membrane which represents an integrated polymer complexation method. The hybrid membrane was formulated from blended poly(vinyl alcohol (PVA and chitosan which was cross linked with various concentration of tetraethyl orthosilicate (TEOS such as 1%, 3% w/w and 5%w/w through using sol-gel technique under acidic condition. The hybrid membrane was coated on polysulfone membrane as the porous support. The separation process was conducted on the different heavy metal solutions containing Cu (II and Fe (II ions at various concentrations (50,100,150,200,250 ppm.The properties of the thin film composite (TFC membranes were characterized by using Fourier Transform Infrared (FTIR spectroscopy and hermogravimetric Analysis (TGA. The influence of TEOS concentration and Cu (II and Fe (II ion concentration was investigated with the aim to identify on the removal percentage efficiency of Cu (II and Fe (II ions. Result showed that the fabricated thin film composites with higher concentrations of TEOS were able to remove higher percentage Cu (II and Fe (II from the feed solution.

  11. C-QDs@UiO-66-(COOH)2Composite Film via Electrophoretic Deposition for Temperature Sensing.

    Science.gov (United States)

    Feng, Ji-Fei; Gao, Shui-Ying; Shi, Jianlin; Liu, Tian-Fu; Cao, Rong

    2018-03-05

    Temperature plays a crucial role in both scientific research and industry. However, traditional temperature sensors, such as liquid-filled thermometers, thermocouples, and transistors, require contact to obtain heat equilibrium between the probe and the samples during the measurement. In addition, traditional temperature sensors have limitations when being used to detect the temperature change of fast-moving samples at smaller scales. Herein, the carbon quantum dots (C-QDs) functionalized metal-organic framework (MOF) composite film, a novel contactless solid optical thermometer, has been prepared via electrophoretic deposition (EPD). Instead of terephthalic acid (H 2 BDC), 1',2',4',5'-benzenetetracarboxylic (H 4 BTEC) acid was employed to construct a UiO-66 framework to present two uncoordinated carboxylic groups decorated on the pore surface. The uncoordinated carboxylic groups can generate negative charges, which facilitates the deposition of film on the positive electrode during the EPD process. Moreover, UiO-66-(COOH) 2 MOFs can absorb C-QDs from the solution and prevent C-QDs from aggregating, and the well-dispersed C-QDs impart fluorescence characteristics to composites. As-synthesized composite film was successfully used to detect temperature change in the range of 97-297 K with a relative sensitivity up to 1.3% K -1 at 297 K.

  12. Strain-dependent electrical resistance of multi-walled carbon nanotube/polymer composite films

    International Nuclear Information System (INIS)

    Park, Myounggu; Kim, Hyonny; Youngblood, Jeffrey P

    2008-01-01

    The strain-dependent electrical resistance characteristics of multi-walled carbon nanotube (MWCNT)/polymer composite films were investigated. In this research, polyethylene oxide (PEO) is used as the polymer matrix. Two representative volume fractions of MWCNT/PEO composite films were selected: 0.56 vol% (near the percolation threshold) and 1.44 vol% (away from the percolation threshold) of MWCNT. An experimental setup which can measure electrical resistance and strain simultaneously and continuously has been developed. Unique and repeatable relationships in resistance versus strain were obtained for multiple specimens with different volume fractions of MWCNT. The overall pattern of electrical resistance change versus strain for the specimens tested consists of linear and nonlinear regions. A resistance change model to describe the combination of linear and nonlinear modes of electrical resistance change as a function of strain is suggested. The unique characteristics in electrical resistance change for different volume fractions imply that MWCNT/PEO composite films can be used as tunable strain sensors and for application into embedded sensor systems in structures

  13. Optimization of Conductive Thin Film Epoxy Composites Properties Using Desirability Optimization Methodology

    Directory of Open Access Journals (Sweden)

    C. P. Khor

    2016-01-01

    Full Text Available Multiwalled carbon nanotubes (MWCNTs/epoxy thin film nanocomposites were prepared using spin coating technique. The effects of process parameters such as sonication duration (5–35 min and filler loadings (1-2 vol% were studied using the design of experiment (DOE. Full factorial design was used to create the design matrix for the two factors with three-level experimentation, resulting in a total of 9 runs (32 of experimentation. Response surface methodology (RSM combined with E.C. Harrington’s desirability function called desirability optimization methodology (DOM was used to optimize the multiple properties (tensile strength, elastic modulus, elongation at break, thermal conductivity, and electrical conductivity of MWCNTs/epoxy thin film composites. Based on response surface analysis, quadratic model was developed. Analysis of variance (ANOVA, R-squared (R-Sq, and normal plot of residuals were applied to determine the accuracy of the models. The range of lower and upper limits was determined in an overlaid contour plot. Desirability function was used to optimize the multiple responses of MWCNTs/epoxy thin film composites. A global solution of 12.88 min sonication and 1.67 vol% filler loadings was obtained to have maximum desired responses with composite desirability of 1.

  14. 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.

  15. 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

  16. Superior environment resistance of quartz crystal microbalance with anatase TiO2/ZnO nanorod composite films

    International Nuclear Information System (INIS)

    Qiang, Wei; Wei, Li; Shaodan, Wang; Yu, Bai

    2015-01-01

    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 2 by sol–gel methods to form a superhydrophobic TiO 2 /ZnO composite film the anatase TiO 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 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 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 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 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 2 /ZnO composite film is synthesized by surface modification with TiO 2 via sol–gel methods. Results show the anatase TiO 2 /ZnO nanorod

  17. Compositional dependence of the Young's modulus and piezoelectric coefficient of (110)-oriented pulsed laser deposited PZT thin films

    NARCIS (Netherlands)

    Nazeer, H.; Nguyen, Duc Minh; Rijnders, Augustinus J.H.M.; Sardan Sukas, Ö.; Abelmann, Leon; Elwenspoek, Michael Curt

    2014-01-01

    In this contribution, we report on the compositional dependence of the mechanical and piezoelectric properties of Pb(ZrₓTi₿₋ₓ)O₃ (PZT) thin films fabricated by pulsed laser deposition (PLD). These films grow epitaxially on silicon with a (110) preferred orientation and have excellent piezoelectric

  18. Swift heavy ions induced surface modifications in Ag-polypyrrole composite films synthesized by an electrochemical route

    International Nuclear Information System (INIS)

    Kumar, Vijay; Ali, Yasir; Sharma, Kashma; Kumar, Vinod; Sonkawade, R.G.; Dhaliwal, A.S.; Swart, H.C.

    2014-01-01

    Highlights: • Two steps electrochemical synthesis for the fabrication of Ag-polypyrrole composite films. • Surface modifications by swift heavy ion beam. • SEM image shows the formation of craters and humps after irradiation. • Detailed structural analysis by Raman spectroscopy. - Abstract: The general aim of this work was to study the effects of swift heavy ions on the properties of electrochemically synthesized Ag-polypyrrole composite thin films. Initially, polypyrrole (PPy) films were electrochemically synthesized on indium tin oxide coated glass surfaces using a chronopotentiometery technique, at optimized process conditions. The prepared PPy films have functioned as working electrodes for the decoration of submicron Ag particles on the surface of the PPy films through a cyclicvoltammetry technique. Towards probing the effect of swift heavy ion irradiation on the structural and morphological properties, the composite films were subjected to a 40 MeV Li 3+ ion beam irradiation for various fluences (1 × 10 11 , 1 × 10 12 and 1 × 10 13 ions/cm 2 ). Comparative microstructural investigations were carried out after the different ion fluences using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy and micro-Raman spectroscopy techniques. Raman and SEM studies revealed that the structure of the films became disordered after irradiation. The SEM studies of irradiated composite films show significant changes in their surface morphologies. The surface was smoother at lower fluence but craters were observed at higher fluence

  19. Swift heavy ions induced surface modifications in Ag-polypyrrole composite films synthesized by an electrochemical route

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Vijay, E-mail: vijays_phy@rediffmail.com [Department of Physics, University of the Free State, P.O. Box 339, Bloemfontein ZA 9300 (South Africa); Ali, Yasir [Department of Physics, Sant Longowal Institute of Engineering and Technology, Longowal, District Sangrur 148106, Punjab (India); Sharma, Kashma [Department of Physics, University of the Free State, P.O. Box 339, Bloemfontein ZA 9300 (South Africa); Department of Chemistry, Shoolini University of Biotechnology and Management Sciences, Solan 173212 (India); Kumar, Vinod [Department of Physics, University of the Free State, P.O. Box 339, Bloemfontein ZA 9300 (South Africa); Sonkawade, R.G. [Inter University Accelerator Center, Aruna Asif Ali Marg, New Delhi 110067 (India); Dhaliwal, A.S. [Department of Physics, Sant Longowal Institute of Engineering and Technology, Longowal, District Sangrur 148106, Punjab (India); Swart, H.C., E-mail: swarthc@ufs.ac.za [Department of Physics, University of the Free State, P.O. Box 339, Bloemfontein ZA 9300 (South Africa)

    2014-03-15

    Highlights: • Two steps electrochemical synthesis for the fabrication of Ag-polypyrrole composite films. • Surface modifications by swift heavy ion beam. • SEM image shows the formation of craters and humps after irradiation. • Detailed structural analysis by Raman spectroscopy. - Abstract: The general aim of this work was to study the effects of swift heavy ions on the properties of electrochemically synthesized Ag-polypyrrole composite thin films. Initially, polypyrrole (PPy) films were electrochemically synthesized on indium tin oxide coated glass surfaces using a chronopotentiometery technique, at optimized process conditions. The prepared PPy films have functioned as working electrodes for the decoration of submicron Ag particles on the surface of the PPy films through a cyclicvoltammetry technique. Towards probing the effect of swift heavy ion irradiation on the structural and morphological properties, the composite films were subjected to a 40 MeV Li{sup 3+} ion beam irradiation for various fluences (1 × 10{sup 11}, 1 × 10{sup 12} and 1 × 10{sup 13} ions/cm{sup 2}). Comparative microstructural investigations were carried out after the different ion fluences using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy and micro-Raman spectroscopy techniques. Raman and SEM studies revealed that the structure of the films became disordered after irradiation. The SEM studies of irradiated composite films show significant changes in their surface morphologies. The surface was smoother at lower fluence but craters were observed at higher fluence.

  20. A simple route to Develop Highly porous Nano Polypyrrole/Reduced Graphene Oxide Composite film for Selective Determination of Dopamine

    International Nuclear Information System (INIS)

    Daniel Arulraj, Abraham; Arunkumar, Arumugam; Vijayan, Muthunanthevar; Balaji Viswanath, Kamatchirajan; Vasantha, Vairathevar Sivasamy

    2016-01-01

    A highly selective sensor was developed for dopamine with electrochemically treated sodium dodecyl benzene sulfonate doped nano polypyrrole (ET-SDBS-NPPy)/reduced graphene oxide (RGO) film. First, graphene oxide (GO) was reduced on the electrode surface electrochemically and then, SDBS-NPPy film was polymerized electrochemically on the ERGO coated GCE and bare GCE also. The SDBS-NPPy/ERGO and SDBS-NPPy films were treated electrochemically in phosphate buffer solution to replace macro SDBS- anions by smaller phosphate anions. Then, the physical properties of the above composite films were characterized by scanning electron microscope (SEM) and water wettability test. The replacement of SDBS- anions by phosphate anions leaves porous structure in the polymer films and also increases the hydrophobicity in the films. Then, these composite films were applied for the determination of dopamine in the presence of ascorbic acid and uric acid. Under the optimal conditions, the linear range for dopamine detection is 0.1 μM-100.0 μM with the detection limit of 20 nM at S/N = 3. Generally, conducting polypyrrole film could sense ascorbic acid and dopamine simultaneously. However, we have proposed a simple route to synthesis a porous and hydrophobic polypyrrole composite film for selective determination of dopamine in the presence of higher concentration (five orders) of ascorbic acid and uric acid.

  1. 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.

  2. Investigation the interaction between the pulsed ultraviolet laser beams and PEDOT:PSS/graphene composite films

    Energy Technology Data Exchange (ETDEWEB)

    Tseng, Shih-Feng, E-mail: tsengsf@itrc.narl.org.tw [Instrument Technology Research Center, National Applied Research Laboratories, Hsinchu 30076, Taiwan (China); Hsiao, Wen-Tse; Chung, Chien-Kai [Instrument Technology Research Center, National Applied Research Laboratories, Hsinchu 30076, Taiwan (China); Chang, Tien-Li [Department of Mechatronic Engineering, National Taiwan Normal University, Taipei 10610, Taiwan (China)

    2015-11-30

    Highlights: • This research aims to investigate the interaction between pulsed ultraviolet laser beams and transparent PEDOT:PSS/graphene composite films. • The laser ablated microstructure on film surfaces provides the electrical isolation. • The surface roughness, microhardness, spectrum and cross-sectional view of PEDOT:PSS/graphene composite film were measured and analyzed. • The focused UV laser beam was irradiated along line patterns with an overlapping rate of 60%. • The applied laser fluences much over the ablation thresholds of 1.27 J/cm{sup 2} to 3.82 J/cm{sup 2}. - Abstract: This research aims to investigate the interaction between pulsed ultraviolet (UV) laser beams and transparent PEDOT:PSS/graphene composite films. The laser ablated microstructure on film surfaces provides the electrical isolation and prevents the electrical contact from each location for the projected capacitive touch screen. Before the laser processing, the surface roughness, microhardness, spectrum and cross-sectional view of PEDOT:PSS/graphene composite film were measured by an atomic force microscope, a nanoindenter, a spectrometer and a scanning electron microscope, respectively. The focused UV laser beam was irradiated along line patterns with an overlapping rate of 60% and the applied laser fluences much over the ablation thresholds of 1.27 J/cm{sup 2} to 3.82 J/cm{sup 2}. The surface morphology, three-dimensional topography, and cross-sectional profile of isolated lines and electrode structures after laser microstructuring were measured by a confocal laser scanning microscope. By increasing the laser fluence from 1.27 J/cm{sup 2} to 3.82 J/cm{sup 2}, the ablated line widths and depths increased from 12.17 ± 0.24 μm to 21 ± 0.37 μm and from 190 ± 9 nm to 227 ± 15 nm, respectively. Moreover, the ablated lines of microstructuring electrodes had a clear and regular ablated edge quality.

  3. The determination of cadmium in sulphide materials

    International Nuclear Information System (INIS)

    Solomons, M.

    1986-01-01

    A spectrophotometric method was developed for the determination of cadmium in sulphide materials containing up to 200 mg of copper, iron, lead, or zinc individually or 100 mg of each of these four elements in admixture. In the method, an initial liquid-liquid extraction of cadmium from the matrix into a solution of tri-n-octylamine in benzene is followed by stripping into nitric acid. The cadmium is measured spectrophotometrically as the dithizone complex in chloroform at 518 nm. For a sample of 0,5 g, the range of the method is 2 to 24 μg of cadmium per gram of sample. The relative standard deviation and accuracy of the method were determined on a reference material of lead concentrate with a certified lead content of 64 per cent and cadmium content of 143 +- 5 μg/g (95 per cent confidence level). The accuracy of the method was found to be about 97 per cent, and the relative standard deviation was 0,018

  4. Design and characterization of chitosan/zeolite composite films — Effect of zeolite type and zeolite dose on the film properties

    Energy Technology Data Exchange (ETDEWEB)

    Barbosa, Gustavo P.; Debone, Henrique S. [Instituto de Ciências Ambientais, Químicas e Farmacêuticas, Universidade Federal de São Paulo, Diadema (Brazil); Severino, Patrícia [Universidade Tiradentes, Instituto de Tecnologia e Pesquisa, Aracaju (Brazil); Souto, Eliana B. [Department of Pharmaceutical Technology, Faculty of Pharmacy, University of Coimbra (FFUC), Pólo das Ciências da Saúde, Azinhaga de Santa Comba, 3000-548, Coimbra (Portugal); Center for Neuroscience and Cell Biology & Institute for Biomedical Imaging and Life Sciences (CNC-IBILI), University of Coimbra, Pólo das Ciências da Saúde, Azinhaga de Santa Comba, 3000-548, Coimbra (Portugal); Silva, Classius F. da, E-mail: cfsilva@unifesp.br [Instituto de Ciências Ambientais, Químicas e Farmacêuticas, Universidade Federal de São Paulo, Diadema (Brazil)

    2016-03-01

    Chitosan films can be used as wound dressings for the treatment of chronic wounds and severe burns. The antimicrobial properties of these films may be enhanced by the addition of silver. Despite the antimicrobial activity of silver, several studies have reported the cytotoxicity as a factor limiting its biomedical applications. This problem may, however, be circumvented by the provision of sustained release of silver. Silver zeolites can be used as drug delivery platforms to extend the release of silver. The objective of this study was to evaluate the addition of clinoptilolite and A-type zeolites in chitosan films. Sodium zeolites were initially subjected to ion-exchange in a batch reactor. Films were prepared by casting technique using a 2% w/w chitosan solution and two zeolite doses (0.1 or 0.2% w/w). Films were characterized by thermal analysis, color analysis, scanning electron microscopy, X-ray diffraction, and water vapor permeation. The results showed that films present potential for application as dressing. The water vapor permeability is one of the main properties in wound dressings, the best results were obtained for A-type zeolite/chitosan films, which presented a brief reduction of this property in relation to zeolite-free chitosan film. On the other hand, the films containing clinoptilolite showed lower water vapor permeation, which may be also explained by the best distribution of the particles into the polymer which also promoted greater thermal resistance. - Highlights: • Zeolite/chitosan composite films were prepared by casting technique. • Micrographs showed slight difference according to the content and A-type zeolite. • The barrier properties of the films were suitable to the dressing application. • Film characterization suggested that zeolites interacted with the chitosan chain.

  5. Controlled surface chemistry of diamond/β-SiC composite films for preferential protein adsorption.

    Science.gov (United States)

    Wang, Tao; Handschuh-Wang, Stephan; Yang, Yang; Zhuang, Hao; Schlemper, Christoph; Wesner, Daniel; Schönherr, Holger; Zhang, Wenjun; Jiang, Xin

    2014-02-04

    Diamond and SiC both process extraordinary biocompatible, electronic, and chemical properties. A combination of diamond and SiC may lead to highly stable materials, e.g., for implants or biosensors with excellent sensing properties. Here we report on the controllable surface chemistry of diamond/β-SiC composite films and its effect on protein adsorption. For systematic and high-throughput investigations, novel diamond/β-SiC composite films with gradient composition have been synthesized using the hot filament chemical vapor deposition (HFCVD) technique. As revealed by scanning electron microscopy (SEM), the diamond/β-SiC ratio of the composite films shows a continuous change from pure diamond to β-SiC over a length of ∼ 10 mm on the surface. X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS) was employed to unveil the surface termination of chemically oxidized and hydrogen treated surfaces. The surface chemistry of the composite films was found to depend on diamond/β-SiC ratio and the surface treatment. As observed by confocal fluorescence microscopy, albumin and fibrinogen were preferentially adsorbed from buffer: after surface oxidation, the proteins preferred to adsorb on diamond rather than on β-SiC, resulting in an increasing amount of proteins adsorbed to the gradient surfaces with increasing diamond/β-SiC ratio. By contrast, for hydrogen-treated surfaces, the proteins preferentially adsorbed on β-SiC, leading to a decreasing amount of albumin adsorbed on the gradient surfaces with increasing diamond/β-SiC ratio. The mechanism of preferential protein adsorption is discussed by considering the hydrogen bonding of the water self-association network to OH-terminated surfaces and the change of the polar surface energy component, which was determined according to the van Oss method. These results suggest that the diamond/β-SiC gradient film can be a promising material for biomedical applications which

  6. Thermo-electrical properties of composite semiconductor thin films composed of nanocrystalline graphene-vanadium oxides.

    Science.gov (United States)

    Jung, Hye-Mi; Um, Sukkee

    2014-12-01

    This paper presents an experimental comparative study involving the characterization of the thermo-electrical and structural properties of graphene-based vanadium oxide (graphene-VOx) composite thin films on insulating and conducting surfaces (i.e., fused quartz and acrylic resin-impregnated graphite) produced by a sol-gel process via dipping-pyrolysis. A combination of FE-SEM and XPS analyses revealed that the graphene-VOx composite thin films (coated onto fused quartz) exhibiting the microstructure of 2-graded nanowire arrays with a diameter of 40-80 nm were composed of graphene, a few residual oxygen-containing functional groups (i.e., C-O and C=O), and the VO2 Magnéli phase. The temperature-dependent electrical resistance measured on the as-deposited thin films clearly demonstrated that the graphene-VOx composite nanowire arrays thermally grown on fused quartz act as a semiconductor switch, with a transition temperature of 64.7 degrees C in the temperature range of -20 degrees C to 140 degrees C, resulting from the contributions of graphene and graphene oxides. In contrast, the graphene-VOx composite thin films deposited onto acrylic resin-impregnated graphite exhibit a superlinear semiconducting property of extremely low electrical resistance with negative temperature coefficients (i.e., approximately four orders of magnitude lower than that of the fused quartz), despite the similar microstructural and morphological characteristics. This difference is attributed to the synergistic effects of the paramagnetic metal feature of the tightly stacked nanowire arrays consisting of hexagonal V2O3 on the intrinsic electrical properties of the acrylic resin-impregnated graphite substrate, as revealed by FE-SEM, EDX, AFM, and XRD measurements. Although the thermo-sensitive electrical properties of the graphene-VOx composite thin films are very substrate specific, the applicability of graphene sheets can be considerably effective in the formation of highly planar arrays

  7. Preparation and properties of in situ amino-functionalized graphene oxide/polyimide composite films

    Science.gov (United States)

    Lu, Yunhua; Hao, Jican; Xiao, Guoyong; Chen, Lin; Wang, Tonghua; Hu, Zhizhi

    2017-11-01

    The pure light-colored and transparent polyimide (PI) film was prepared from aromatic dianhydride 4,4‧-(hexafluoroisopropylidene)diphthalic anhydride (6FDA) and diamine 1,4-bis(4-amino-2-trifluoromethylphenoxy)benzene (6FAPB) in the solvent of DMAc via two-step method. Graphene oxide (GO) was in situ grafted with 6FAPB and directly used as a functional inorganic nanofiller to further synthesize poly(amic acid) (PAA)/GO solution. Then, PI/GO composite films with different loadings of GO were prepared by the thermal imidization. The mechanical, thermal, optical, electrical, surface properties, and electrochemical behavior were characterized. The FTIR and XPS results indicate that amino groups can be successfully grafted on the surface of GO. The tensile strength and Young's modulus of the PI-1.0%GO composite film were increased to 118.4 MPa and 2.91 GPa, respectively, which was an approximate improvement of 30.8% and 39.9% compared with pure PI film. These PI/GO composites showed around 256 °C for the glass transition temperature, and around 535 °C for the 5% thermal decomposition temperature, respectively. However, the optical transmittance was significantly decreased from 81.5% (pure PI) to 0.8% (PI-1.0%GO). Besides, the electrical conductivity increased from 1.6 × 10-13 S/m (pure PI) to 2.5 × 10-9 S/m (PI-1.0%GO). Furthermore, when the incorporation of GO was 1.0 wt%, an obvious reduction from 1.08% (pure PI) to 0.65% in the water uptake was observed for the PI/GO composite films, and the water surface contact angle raised from 72.5° (pure PI) to 83.5°. The electrochemical behavior showed that the ability of oxygen atom on the imide ring to gain and loss electron was increased due to incorporation of GO. These results indicated that the strong interfacial interaction between GO and PAA as well as uniform dispersion of GO in PI matrix were benefit to improve the mechanical, thermal, electrical properties and so on. The in situ amino-functionalized approach

  8. Non-Vacuum Processed Polymer Composite Antireflection Coating Films for Silicon Solar Cells

    Directory of Open Access Journals (Sweden)

    Abdullah Uzum

    2016-08-01

    Full Text Available A non-vacuum processing method for preparing polymer-based ZrO2/TiO2 multilayer structure antireflection coating (ARC films for crystalline silicon solar cells by spin coating is introduced. Initially, ZrO2, TiO2 and surface deactivated-TiO2 (SD-TiO2 based films were examined separately and the effect of photocatalytic properties of TiO2 film on the reflectivity on silicon surface was investigated. Degradation of the reflectance performance with increasing reflectivity of up to 2% in the ultraviolet region was confirmed. No significant change of the reflectance was observed when utilizing SD-TiO2 and ZrO2 films. Average reflectance (between 300 nm–1100 nm of the silicon surface coated with optimized polymer-based ZrO2 single or ZrO2/SD-TiO2 multilayer composite films was decreased down to 6.5% and 5.5%, respectively. Improvement of photocurrent density (Jsc and conversion efficiency (η of fabricated silicon solar cells owing to the ZrO2/SD-TiO2 multilayer ARC could be confirmed. The photovoltaic properties of Jsc, the open-circuit photo voltage (VOC, the fill factor (FF, and the η were 31.42 mA cm−2, 575 mV, 71.5% and 12.91%. Efficiency of the solar cells was improved by the ZrO2-polymer/SD-TiO2 polymer ARC composite layer by a factor of 0.8% with an increase of Jsc (2.07 mA cm−2 compared to those of fabricated without the ARC.

  9. Fully integrated carbon nanotube composite thin film strain sensors on flexible substrates for structural health monitoring

    Science.gov (United States)

    Burton, A. R.; Lynch, J. P.; Kurata, M.; Law, K. H.

    2017-09-01

    Multifunctional thin film materials have opened many opportunities for novel sensing strategies for structural health monitoring. While past work has established methods of optimizing multifunctional materials to exhibit sensing properties, comparatively less work has focused on their integration into fully functional sensing systems capable of being deployed in the field. This study focuses on the advancement of a scalable fabrication process for the integration of multifunctional thin films into a fully integrated sensing system. This is achieved through the development of an optimized fabrication process that can create a broad range of sensing systems using multifunctional materials. A layer-by-layer deposited multifunctional composite consisting of single walled carbon nanotubes (SWNT) in a polyvinyl alcohol and polysodium-4-styrene sulfonate matrix are incorporated with a lithography process to produce a fully integrated sensing system deposited on a flexible substrate. To illustrate the process, a strain sensing platform consisting of a patterned SWNT-composite thin film as a strain-sensitive element within an amplified Wheatstone bridge sensing circuit is presented. Strain sensing is selected because it presents many of the design and processing challenges that are core to patterning multifunctional thin film materials into sensing systems. Strain sensors fabricated on a flexible polyimide substrate are experimentally tested under cyclic loading using standard four-point bending coupons and a partial-scale steel frame assembly under lateral loading. The study reveals the material process is highly repeatable to produce fully integrated strain sensors with linearity and sensitivity exceeding 0.99 and 5 {{V}}/{ε }, respectively. The thin film strain sensors are robust and are capable of high strain measurements beyond 3000 μ {ε }.

  10. [The effect of C-SiO2composite films on corrosion resistance of dental Co-Cr alloy].

    Science.gov (United States)

    Huang, Yi; Hu, Jing-Yu; Liu, Yu-Pu; Zhao, Dong-Yuan; Yu, You-Cheng; Bi, Wei

    2016-10-01

    To study the effect of carbon-silica composite films on corrosion resistance of Co-Cr alloy in simulated oral environment and provide evidences for clinical application of this new material. Co-Cr alloy specimens were cut into appropriate size of 20 mm × 20 mm × 0.5 mm. Then, the carbon-silica composite films were spin-coated onto the specimens. Subsequently, ICP-AES was used to observe the Co, Cr, Mo ion concentrations. Finally, Tafel polarization curves of the specimens were used to measure the electrochemical corrosion resistance by electrochemical workstation. SAS8.0 software package was used for statistical analysis. The results of ICP-AES showed that the ion concentrations of Co, Cr, Mo of specimens coated with composite films in the testing liquid were significantly smaller than that of Co-Cr alloy specimens. Tafel polarization curves showed that in the specimens coated with composite films, the corrosion potential moved in the positive direction and increased from -0.261 V to -0.13 V. At the same time, the corrosion current density decreased from -5.0017μA/cm 2 to -5.3006 μA/cm 2 . Carbon-silica composite films (silica=61.71wt %) can reduce the release of metal ions significantly and improve the corrosion resistance of Co-Cr alloys effectively. Carbon-silica composite films may be a promising dental material.

  11. Sulphide fluxes and concentrations in the spent nuclear fuel repository at Olkiluoto

    International Nuclear Information System (INIS)

    Wersin, P.; Alt-Epping, P.; Pitkaenen, P.

    2014-01-01

    Sulphide may act as corrodant for the copper canister in the KBS-3 disposal concept. Sulphide fluxes at repository level are affected by various sources in the host rock, the backfill and the buffer. Hydrogen sulphide is effectively immobilised by Fe to form insoluble iron sulphide minerals. Thus, dissolved sulphide levels in reducing environment and also in Olkiluoto groundwaters are generally low. In zones favourable for sulphate reducing bacteria (SRB), however, temporarily more elevated sulphide concentrations are possible. The sulphate reduction and subsequent iron sulphide precipitation process depends on geochemical conditions, microbial activity and mass transfer of the reactants and is thus highly system-specific. The overall objective of the work presented in this report is to provide a thorough background for the sulphide concentrations and sulphide fluxes in the near field and the far field used in the performance assessment 2012

  12. Nonstoichiometric composition shift in physical vapor deposition of CdTe thin films

    Science.gov (United States)

    Chin, Ken K.; Cheng, Zimeng; Delahoy, Alan E.

    2015-05-01

    While it is being debated whether Cd vacancy is an effective p-dopant in CdTe, and whether CdTe thin film in solar energy application should be Cd-deficient or Cd-rich, in the theory of CdTe physical vapor deposition (PVD) it has been assumed that both the source material and the thin film product is stoichiometric. To remediate the lack of effective theory, a new PVD model for CdTe photovoltaic (PV) modules is presented in this work, in which the composition of the CdTe thin film under growth is a parameter determined by the source CdTe composition as well as the growth condition. The solid phase Cd1-δTe1+δ compound under deposition temperature is treated as a solid solution with a mole of excess pure Te or Cd as solute and one mole of congruently grown CdTe as solvent. Assuming that the vapor pressure of Te2 can be calculated by using the law of solid solution PTe=H0+aH1+a2H2 round the congruent composition, where the molar number a and the constants H0, H1 and H2 as functions of temperature T are extracted from the experimental data. Thus, the mole fraction of solute in the grown CdTe thin film as well as the growth rate, as a function of the solute mole fraction in the source CdTe can be determined.

  13. A double Fe-Ti oxide and Fe-sulphide liquid immiscibility in the Itsindro Gabbro Complex, Madagascar

    Science.gov (United States)

    Augé, Thierry; Bailly, Laurent; Roig, Jean-Yves

    2017-11-01

    The petrology and mineralogy of the Itsindro complex in south-central Madagascar has been investigated through samples obtained from the 320.7 m-deep Lanjanina borehole. The section consists of a 254 m-thick pyroxenite unit with interbedded gabbro layers that overlies a gabbro unit and is itself overlain by a 19 m-thick granite unit. Most of the structures are sub-horizontal. A weak magmatic layering is locally observed but at the scale of the core, the intrusion does not appear to be a layered complex. Pyroxenite and gabbro show a systematic disseminated mineralization consisting of Fe-Ti-P oxides and Fe-(Cu-Ni) sulphides that takes the form of ilmenite-titanomagnetite ± apatite and pyrrhotite ± chalcopyrite ± pentlandite. In the upper zone, from 90 to 72 m, sub-massive centimetre-to decimetre-sized layers of oxides and sulphides comprise a total of 16 m of sub-massive sulphide (the main mineralized zone). In this mineralized zone the oxide/sulphide ratio is close to 1/1. The sulphide is strongly dominated by pyrrhotite, which may locally contain inclusions of molybdenite crystals with the Re sulphide rheniite (ReS2). Oxides are generally euhedral, included in or attached to the Fe-sulphide, and also locally form sub-massive centimetre-sized bands. Apatite as a cumulus phase is ubiquitous. Locally it may account for 30% of the ore-rich samples and some samples consist of apatite-Fe-Ti oxides-Fe-Cu-Ni sulphides with virtually no silicate. Apatite is the main REE carrier but the total REE content remains low (<90 ppm). Mineral compositions and whole rock geochemistry indicate that the rocks are highly differentiated, and in spite of a relatively limited thickness, the differentiation process is observed. Two zones can be distinguished: from the bottom to 162.8 m we see a decrease in the Mg number of olivine and pyroxene, and a drop in TiO2 and Al2O3 for the latter. A reverse trend is then observed within the pyroxenite unit from the 162.8 m level upwards. The

  14. Effect of castor oil emulsion eyedrops on tear film composition and stability.

    Science.gov (United States)

    Maïssa, Cécile; Guillon, Michel; Simmons, Peter; Vehige, Joseph

    2010-04-01

    An emulsion eyedrop containing castor oil has been shown to modify the tear film lipid layer and increase tear film stability. The primary objectives of this investigation were to measure the prevalence of castor oil in the tear fluid over time and quantify the effects on the lipid layer. A secondary objective was to quantify the initial effects on ocular symptomatology. The investigation was an open label pilot study on 5 normal and 10 dry eye subjects. A single eyedrop (Castor oil emulsion, Allergan) was instilled in each eye; the tear film appearance and composition were monitored for 4h via in vivo visualisation using the Tearscope and post in vivo tear samples analysis by HPLC. Combined results for both normal and dry eye subjects showed that castor oil was detected up to 4h after a single eyedrop instillation and associated with an increase in the level of tear film lipid. The relative amount of various lipid families was also changed. An increase in tear lipid layer thickness was significant up to one hour post-instillation for the symptomatic sub-population. The changes in tear film characteristics were associated with significantly lower symptoms up to four hours post-instillation for the symptomatic sub-population. This pilot investigation showed that castor oil eyedrops achieved a residence time of at least four hours post-instillation, producing a more stable tear film and an associated significant decrease in ocular symptoms over the entire follow-up period for the symptomatic subjects. 2009 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  15. Nd composition dependence of microstructure and magnetic properties for gradient sputtered NdFeB films

    Energy Technology Data Exchange (ETDEWEB)

    Li Shandong [Department of Physics, Fujian Normal University, Fuzhou 350007 (China)], E-mail: dylsd007@yahoo.com.cn; Wang Dawei [Department of Physics, Fujian Normal University, Fuzhou 350007 (China); Fang Jianglin [Center for Materials Analysis, Nanjing University, Nanjing 210093 (China); Duh, J.-G. [Department of Materials Science and Engineering, National TsingHua Universtiy, Hsinchu, Taiwan (China); Wang Yinying; Wu Yizhi; Huang Junheng; Zheng Hongjun [Department of Physics, Fujian Normal University, Fuzhou 350007 (China)

    2008-08-15

    NdFeB films with Nd compositions varied from 13.34 to 24.30 at% were deposited by DC gradient sputtering using targets Nd{sub 12.5}Fe{sub 71.5}B{sub 16} and Nd. The hard magnetic properties, grain growth direction and magnetic domain structures were dramatically influenced by Nd composition. The samples with intermediate Nd concentrations exhibited optimal magnetic properties and microstructures, such as large squareness ratio over 0.9, large energy product up to 174 kJ/m{sup 3}, and vertical domain structure. However, the samples with higher and lower Nd compositions showed almost isotropic loops. (0 0 l) as main X-ray diffraction peaks in the optimal Nd composition region indicated most of Nd{sub 2}Fe{sub 14}B grains with c-axis perpendicular to the film plane, while NdFeB grains in other region are almost random growth. The good magnetic properties can be attributed to the vertical growth of Nd{sub 2}Fe{sub 14}B grains.

  16. Nd composition dependence of microstructure and magnetic properties for gradient sputtered NdFeB films

    International Nuclear Information System (INIS)

    Li Shandong; Wang Dawei; Fang Jianglin; Duh, J.-G.; Wang Yinying; Wu Yizhi; Huang Junheng; Zheng Hongjun

    2008-01-01

    NdFeB films with Nd compositions varied from 13.34 to 24.30 at% were deposited by DC gradient sputtering using targets Nd 12.5 Fe 71.5 B 16 and Nd. The hard magnetic properties, grain growth direction and magnetic domain structures were dramatically influenced by Nd composition. The samples with intermediate Nd concentrations exhibited optimal magnetic properties and microstructures, such as large squareness ratio over 0.9, large energy product up to 174 kJ/m 3 , and vertical domain structure. However, the samples with higher and lower Nd compositions showed almost isotropic loops. (0 0 l) as main X-ray diffraction peaks in the optimal Nd composition region indicated most of Nd 2 Fe 14 B grains with c-axis perpendicular to the film plane, while NdFeB grains in other region are almost random growth. The good magnetic properties can be attributed to the vertical growth of Nd 2 Fe 14 B grains

  17. Optical properties of YbF3-CaF2 composite thin films deposited by electron-beam evaporation

    Science.gov (United States)

    Wang, Songlin; Mi, Gaoyuan; Zhang, Jianfu; Yang, Chongmin

    2018-03-01

    We studied electron-beam evaporated YbF3-CaF2 composite films on ZnS substrate at different deposition parameters. The optical properties of films have been fitted, the surface roughness have been measured by AFM. The results of experiments indicated that increased the refractive indices, extinction coefficients, and surface roughness at higher deposition rate. The refractive index of composite film deposited by electron-beam evaporation with assisted-ion source was obviously higher than it without assisted-ion source.

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

    International Nuclear Information System (INIS)

    Qureshi, Uzma; Dunnill, Charles W.; Parkin, Ivan P.

    2009-01-01

    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 CeO 2 nanoparticle thin films displaying photocatalysis and photo-induced hydrophilicity almost comparable to that of anatase titania.

  19. 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

  20. Spider dragline silk composite films doped with linear and telechelic polyalanine: Effect of polyalanine on the structure and mechanical properties.

    Science.gov (United States)

    Tsuchiya, Kousuke; Ishii, Takaoki; Masunaga, Hiroyasu; Numata, Keiji

    2018-02-26

    Spider dragline silks have attracted intensive attention as eco-friendly tough materials because of their excellent mechanical property and biomass-based origin. Composite films based on a recombinant spider dragline silk protein (ADF3) from Araneus diadematus were prepared by doping with linear or telechelic poly(L-alanine) (L- or T-polyA, respectively) as a reinforcing agent. Higher tensile strength and toughness of the composite films were achieved with the addition of polyA compared with the tensile strength and toughness of the silk-only film. The difference in the reinforcing behavior between L- and T-polyA was associated with their primary structures, which were revealed by wide angle X-ray diffraction analysis. L-polyA showed a tendency to aggregate in the composite films and induce crystallization of the inherent silk β-sheet to afford rigid but brittle films. By contrast, T-polyA dispersion in the composite films led to the formation of β-sheet crystal of both T-polyA and the inherent silk, which imparted high strength and toughness to the silk films.

  1. Composition and morphological characteristics of chemically sprayed fluorine-doped zinc oxide thin films deposited on Si(1 0 0)

    International Nuclear Information System (INIS)

    Castaneda, L.; Maldonado, A.; Cheang-Wong, J.C.; Terrones, M.; Olvera, M. de la L

    2007-01-01

    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

  2. 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.

  3. Uniformly-dispersed nanohydroxapatite-reinforced poly(ε-caprolactone) composite films for tendon tissue engineering application.

    Science.gov (United States)

    Tong, Shi Yun; Wang, Zuyong; Lim, Poon Nian; Wang, Wilson; Thian, Eng San

    2017-01-01

    Regeneration of injuries at tendon-to-bone interface (TBI) remains a challenging issue due to the complex tissue composition involving both soft tendon tissues and relatively hard bone tissues. Tissue engineering using polymeric/ceramic composites has been of great interest to generate scaffolds for tissue's healing at TBI. Herein, we presented a novel method to blend polymers and bioceramics for tendon tissue engineering application. A homogeneous composite comprising of nanohydroxyapatite (nHA) particles in poly(ε-caprolactone) (PCL) matrix was obtained using a combination of solvent and mechanical blending process. X-ray diffraction analysis showed that the as-fabricated PCL/nHA composite film retained phase-pure apatite and semi-crystalline properties of PCL. Infrared spectroscopy spectra confirmed that the PCL/nHA composite film exhibited the characteristics functional groups of PCL and nHA, without alteration to the chemical properties of the composite. The incorporation of nHA resulted in PCL/nHA composite film with improved mechanical properties such as Young's Modulus and ultimate tensile stress, which were comparable to that of the native human rotator tendon. Seeding with human tenocytes, cells attached on the PCL/nHA composite film, and after 14days of culturing, these cells could acquire elongated morphology without induced cytotoxicity. PCL/nHA composite film could also result in increased cell metabolism with prolonged culturing, which was comparable to that of the PCL group and higher than that of the nHA group. All these results demonstrated that the developed technique of combining solvent and mechanical blending could be applied to fabricate composite films with potential for tendon tissue engineering applications. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. 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.

  5. Luminescence study of ZnSe/PVA (polyvinyl alcohol) composite film

    Energy Technology Data Exchange (ETDEWEB)

    Lahariya, Vikas [Amity School of Applied Science, Amity University Haryana Panchgaon, Manesar, Haryana 122413 (India)

    2016-05-06

    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 3.4 eV. From the Photoluminescence study a broad peak at 435 nm has been observed in violet blue region due to recombination of surface states.

  6. PVDF:TiO2 Composite Thin Films for Capacitive Energy Storage

    Science.gov (United States)

    Ewen, Crystal; Dillingham, Randy; Stufflebeam, Terry; Brickley, Eric

    2014-03-01

    Thin films composed of the polymer polyvinylidene fluoride (PVDF) and the ceramic nanoparticle titanium dioxide (TiO2) are fabricated via thermal vapor deposition. This combination is ideal since it is light weight and improves the energy density. The elemental composition of the films are determined with energy dispersive x-ray spectroscopy using a scanning electron microscope. Elemental mapping of the films shows that the polymer and nanoparticles are homogeneously distributed. The ideal initial concentrations of PVDF and TiO2 were determined to be 83 % and 17 % respectively. The final films yield a Ti weight percent of 20. Parallel plate capacitors were fabricated by combining thermal vapor deposition and sputter coating. For the electrodes the parallel plates are gold-palladium (AuPd) with PVDF:TiO2 as the dielectric. The AuPd electrodes were deposited via sputter coating. Each electrode was sputtered for 100s, which yields a thickness of 33nm. Current research is working to improve the amount of Ti deposited by varying the temperature and deposition time, obtain more accurate thickness measurements, and improve on its electrical properties.

  7. Dual-analyte spectroscopic sensing in sol-gel derived polyelectrolyte-silica composite thin films.

    Science.gov (United States)

    Shi, Y; Seliskar, C J; Heineman, W R

    1998-12-01

    Ferrozine (3-(2-pyridyl)-5,6-diphenyl-1,2,4-triazine-p,p'-disulfonic acid, monosodium salt hydrate), an iron indicator, and HTPS (8-hydroxyl-1,3,6-pyrenetrisulfonic acid, trisodium salt), a pH indicator, were immobilized in sol-gel derived PDMDAAC-SiO(2) (where PDMDAAC stands for poly(dimethyldiallylammonium chloride), composite thin films via ion-exchange. The two indicators were immobilized in two adjacent sections of the same PDMDAAC-SiO(2) film which was supported on a glass optical substrate. The spectroscopic response of the film to both Fe(2+) and H(+) in solutions was investigated by attenuated total reflection (ATR) spectrometry at two well-separated wavelengths, 562 nm for Fe(2+) and 460 nm for H(+). The Ferrozine/HPTS immobilized PDMDAAC-SiO(2) films had the following characteristics: linear range, 2.5x10(-6)-5.0x10(-5) M for Fe(2+), pH 4.1-6.8 for H(+); sensitivity, 2.2x10(4) DeltaA/M for Fe(2+), 0.583 DeltaA/pH for H(+).

  8. Composition and formation mechanism of zirconium oxynitride films produced by reactive direct current magnetron sputtering

    International Nuclear Information System (INIS)

    Ngaruiya, J.M.; Kappertz, O.; Liesch, C.; Wuttig, M.; Mueller, P.; Dronskowski, R.

    2004-01-01

    Direct current magnetron sputtered zirconium oxynitride films show an improvement in both deposition rate and physical properties compared to zirconium oxide. Here we seek to understand these beneficial effects and report on the film composition and crystallographic structure. Based on a thermochemical description together with a modeling of formation kinetics we propose a film formation mechanism, which explains many of the observations. Rutherford backscattering spectroscopy (RBS) shows early nitrogen incorporation at 64% N 2 flow in disagreement with the predictions of thermochemistry. The stoichiometry is only successfully simulated with the use of an expanded Berg-Larsson model with a low replacement coefficient of about 0.1 of nitrogen by oxygen after metal-nitrogen bond formation. The deviation from complete replacement as predicted by thermodynamics illustrates the importance of kinetics in film formation. The model further successfully predicts the variation of the mass deposition rate. The X-ray diffraction analyses suggest that, within the crystalline phase, nitrogen atoms occupy oxygen sites, resulting in an unchanged zirconium oxide structure. (copyright 2004 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  9. Composition and formation mechanism of zirconium oxynitride films produced by reactive direct current magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Ngaruiya, J.M. [I. Physikalisches Institut der RWTH Aachen, 52056 Aachen (Germany); Jomo Kenyatta University of Agric. and Technol., Box 62000 Nairobi (Kenya); Kappertz, O.; Liesch, C.; Wuttig, M. [I. Physikalisches Institut der RWTH Aachen, 52056 Aachen (Germany); Mueller, P.; Dronskowski, R. [Institut f. Anorganische Chemie der RWTH Aachen, 52056 Aachen (Germany)

    2004-04-01

    Direct current magnetron sputtered zirconium oxynitride films show an improvement in both deposition rate and physical properties compared to zirconium oxide. Here we seek to understand these beneficial effects and report on the film composition and crystallographic structure. Based on a thermochemical description together with a modeling of formation kinetics we propose a film formation mechanism, which explains many of the observations. Rutherford backscattering spectroscopy (RBS) shows early nitrogen incorporation at 64% N{sub 2} flow in disagreement with the predictions of thermochemistry. The stoichiometry is only successfully simulated with the use of an expanded Berg-Larsson model with a low replacement coefficient of about 0.1 of nitrogen by oxygen after metal-nitrogen bond formation. The deviation from complete replacement as predicted by thermodynamics illustrates the importance of kinetics in film formation. The model further successfully predicts the variation of the mass deposition rate. The X-ray diffraction analyses suggest that, within the crystalline phase, nitrogen atoms occupy oxygen sites, resulting in an unchanged zirconium oxide structure. (copyright 2004 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  10. Self Focusing SIMS: Probing thin film composition in very confined volumes

    International Nuclear Information System (INIS)

    Franquet, Alexis; Douhard, Bastien; Melkonyan, Davit; Favia, Paola; Conard, Thierry; Vandervorst, Wilfried

    2016-01-01

    Graphical abstract: - Highlights: • SiGe layers were grown in trenches of various widths (down to 20 nm) on Si substrate and surrounded by SiO 2 films. • Standard SIMS analysis to probe the composition in narrow trenches fails at dimensions less than a micron. • Self Focusing SIMS able to probe thin film composition in very confined volumes (dimension < 20 nm). - Abstract: 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

  11. Rationally Designed, Multifunctional Self-Assembled Nanoparticles for Covalently Networked, Flexible and Self-Healable Superhydrophobic Composite Films.

    Science.gov (United States)

    Lee, Yujin; You, Eun-Ah; Ha, Young-Geun

    2018-03-21

    For constructing bioinspired functional films with various superhydrophobic functions, including self-cleaning, anticorrosion, antibioadhesion, and oil-water separation, hydrophobic nanomaterials have been widely used as crucial structural components. In general, hydrophobic nanomaterials, however, cannot form strong chemical bond networks in organic-inorganic hybrid composite films because of the absence of chemically compatible binding components. Herein, we report the rationally designed, multifunctional self-assembled nanoparticles with tunable functionalities of covalent cross-linking and hydrophobicity for constructing three-dimensionally interconnected superhydrophobic composite films via a facile solution-based fabrication at room temperature. The multifunctional self-assembled nanoparticles allow the systematic control of functionalities of composite films, as well as the stable formation of covalently linked superhydrophobic composite films with excellent flexibility (bending radii of 6.5 and 3.0 mm, 1000 cycles) and self-healing ability (water contact angle > 150°, ≥10 cycles). The presented strategy can be a versatile and effective route to generating other advanced functional films with covalently interconnected composite networks.

  12. SULPHIDE MINERALIZATION IN UPPER WESTPHALIAN COAL SEAMS FROM THE EASTERN PART OF THE UPPER SILESIAN COAL BASIN

    Directory of Open Access Journals (Sweden)

    Lipiarski Ireneusz

    1997-10-01

    Full Text Available Morphologically diversified sulphide mineralization has been found in No. 301 and 302 coal seams (Westphalian B. The main sulphide is pyrite which forms veinlets cross-cutting the sedimentary fabrics of the coal, encrusts the cellular structures and intergrowths with oxysulphides. Two generations of pyrites were observed: the preceding and the following the oxysulphides. Pyrite composition is stoichiometric, rare admixtures are up to(in wt.%: Mn - 0.19, Co - 0.48, Ni - 0.42 and As - 1.41. Iron oxysulphides contain up to 35.06 wt.% oxygen. Their composition varies between FeS2O and FeS2O3. Increased contents of As (up to 1.46 wt.% and Pb (up to 0.96 wt.% were detected.

  13. SR-Site - sulphide content in the groundwater at Forsmark

    International Nuclear Information System (INIS)

    Tullborg, E-L; Smellie, J; Nilsson, A-Ch; Gimeno, M J; Auque, LF; Bruchert, V; Molinero, J

    2010-12-01

    Sulphide concentrations in groundwater play a key role in the long-term reliability of the metal canisters containing the radioactive waste within a disposal facility for nuclear waste. This is because sulphide in the groundwaters circulating in the vicinity of the deposition tunnels can react with copper in the canisters causing corrosion and therefore reducing their expected lifetime; in a worst case scenario erosion of the bentonite buffer material will expose the canister more rapidly to the fracture groundwater.Sulphide in the groundwater is predominantly microbially produced and thereby controlled by the content of oxidised sulphur sources, organics (carbon sources), reductants (mainly Fe(II), DOC, H 2 and CH 4 ), and also flow and mixing of different groundwater types. In addition, achieved saturation in respect to amorphous Fe-monosulphide will control the possible maximum values and will also limit the Fe 2+ and S 2- values in the groundwater. The aim of this report is to assess realistic, representative and reliable sulphide groundwater concentrations at present conditions in Forsmark and also to evaluate possible changes during different climatic conditions covering the repository operation period (some tens to hundreds of years), post closure conditions (some thousand of years) and the proceeding temperate period (some tens of thousands of years) which may be extended due to enhanced greenhouse effects etc. It is expected that this period will be followed by the onset of the next glaciation during which periglacial (permafrost), glacial and postglacial conditions may succeed each other. To achieve these aims, an evaluation is performed of all the sulphide-related data reported from the Forsmark site investigations /Laaksoharju et al. 2008/ and later monitoring campaigns, all of which are stored in the Sicada database. This evaluation shows that values from the Complete Chemical Characterisation (CCC) sampling are usually lower than those measured during

  14. SR-Site - sulphide content in the groundwater at Forsmark

    Energy Technology Data Exchange (ETDEWEB)

    Tullborg, E-L (Terralogica (Sweden)); Smellie, J (Conterra (Sweden)); Nilsson, A-Ch (Geosigma (Sweden)); Gimeno, M J; Auque, LF (Univ. of Zaragoza (Spain)); Bruchert, V (Stockholms Universitet (Sweden)); Molinero, J (Amphos21 (Spain))

    2010-12-15

    Sulphide concentrations in groundwater play a key role in the long-term reliability of the metal canisters containing the radioactive waste within a disposal facility for nuclear waste. This is because sulphide in the groundwaters circulating in the vicinity of the deposition tunnels can react with copper in the canisters causing corrosion and therefore reducing their expected lifetime; in a worst case scenario erosion of the bentonite buffer material will expose the canister more rapidly to the fracture groundwater.Sulphide in the groundwater is predominantly microbially produced and thereby controlled by the content of oxidised sulphur sources, organics (carbon sources), reductants (mainly Fe(II), DOC, H{sub 2} and CH{sub 4}), and also flow and mixing of different groundwater types. In addition, achieved saturation in respect to amorphous Fe-monosulphide will control the possible maximum values and will also limit the Fe2+ and S2- values in the groundwater. The aim of this report is to assess realistic, representative and reliable sulphide groundwater concentrations at present conditions in Forsmark and also to evaluate possible changes during different climatic conditions covering the repository operation period (some tens to hundreds of years), post closure conditions (some thousand of years) and the proceeding temperate period (some tens of thousands of years) which may be extended due to enhanced greenhouse effects etc. It is expected that this period will be followed by the onset of the next glaciation during which periglacial (permafrost), glacial and postglacial conditions may succeed each other. To achieve these aims, an evaluation is performed of all the sulphide-related data reported from the Forsmark site investigations /Laaksoharju et al. 2008/ and later monitoring campaigns, all of which are stored in the Sicada database. This evaluation shows that values from the Complete Chemical Characterisation (CCC) sampling are usually lower than those measured

  15. Composition and properties of nanocrystalline Zn S thin films prepared by a new chemical bath deposition route

    International Nuclear Information System (INIS)

    Sahraei, R.; Goudarzi, A.; Ahmadpoor, H.; Motedayen Aval, Gh.

    2006-01-01

    Zinc sulfide nanocrystalline thin films were prepared by a new chemical bath deposition route on soda lime glass and quartz substrates using a weak acidic bath, in which disodium salt of ethylenediaminetetraacetic acid (EDTA) acts as a complexing agent and thioacetamide acts as a source of sulfide ions. The thickness of the films varied from a few nm to 500 nm. The chemical composition of films was studied by energy-dispersive X-ray analyzer and Fourier transform infrared spectroscopy. The films are very close to Zinc sulfide stoichiometry and we did not observed any organic compounds in the impurity form in them. X-ray diffraction indicates that the film and powder formed in the same reaction bath have cubic zinc blende structure. The films have high transmittance of about 75% in the visible region. The optical band-gap energy (E g ) was determined to be 3.75 eV from the absorption spectrophotometry measurements.

  16. The influence of methane/argon plasma composition on the formation of the hydrogenated amorphous carbon films

    International Nuclear Information System (INIS)

    Chen, Hsin-Hung; Liao, Jiunn-Der; Weng, Chih-Chiang; Hsieh, Jui-Fu; Chang, Chia-Wei; Lin, Chao-Hsien; Cho, Ting-Pin

    2011-01-01

    The quality of the a-C:H films was particularly correlated with the mixed ratio of methane/argon plasma. For a constant supply of energy and flowing rate, the optical emission from H α intensity linearly increased with the addition of methane in argon plasma, while that from intensities of radiation of diatmoic radicals (CH*and C 2 *) exponentially decreased. For the a-C:H films, the added methane in argon plasma tended to raise the quantity of hydrogenated carbon or sp 3 C-H structure, which exponentially decreased the nano-hardness and friction coefficient of the films. In contrast, the electric resistance of the films enlarged dramatically with the increase of the methane content in argon plasma. It is therefore advantageous to balance the mechanical properties and electrical resistance of the a-C:H film by adjusting plasma composition in the course of the film-growing process.

  17. 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)

  18. Entropy driven spontaneous formation of highly porous films from polymer-nanoparticle composites

    International Nuclear Information System (INIS)

    Korampally, Venumadhav; Yun, Minseong; Rajagopalan, Thiruvengadathan; Gangopadhyay, Keshab; Gangopadhyay, Shubhra; Dasgupta, Purnendu K

    2009-01-01

    Nanoporous materials have become indispensable in many fields ranging from photonics, catalysis and semiconductor processing to biosensor infrastructure. Rapid and energy efficient process fabrication of these materials is, however, nontrivial. In this communication, we describe a simple method for the rapid fabrication of these materials from colloidal dispersions of Polymethyl Silsesquioxane nanoparticles. Nanoparticle-polymer composites above the decomposition temperature of the polymer are examined and the entropic gain experienced by the nanoparticles in this rubric is harnessed to fabricate novel highly porous films composed of nanoparticles. Optically smooth, hydrophobic films with low refractive indices (as low as 1.048) and high surface areas (as high as 1325 m 2 g -1 ) have been achieved with this approach. In this communication we address the behavior of such systems that are both temperature and substrate surface energy dependent. The method is applicable, in principle, to a variety of nanoparticle-polymer systems to fabricate custom nanoporous materials.

  19. Synthetic Reference Materials Based on Polymer Films for the Control of Welding Fumes Composition

    Science.gov (United States)

    Kuznetsova, O. V.; Kuznetsova, A. N.; Begunova, L. A.

    2017-04-01

    Analysis of the current hygienic situation in the welding production showed that the intensification of welding processes involves the deterioration of air quality, which negatively affects the welders health. Welders are exposed to a variety of metal fumes, including manganese that may elevate the risk for neurological diseases. The control of metals concentration in the air of the working area is difficult due to the lack of reference materials. The creation of reference materials of welding fumes composition is a challenge due to chemical characteristics of their physical properties. Synthetic samples in a form of the polymer film containing powder particles of welding fumes were create. Studies on the selection of the polymer were done. Experiments proved that the qualitative materials of synthetic welding fumes are obtained by using polyvinyl alcohol. The metals concentration in the samples was determined by X-ray fluorescence analysis. The obtained data demonstrates indirectly the uniform distribution of welding fumes powder particles on the polymer film.

  20. 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

    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 was comb......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...... 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...

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

    Energy Technology Data Exchange (ETDEWEB)

    Ju, Hongbo; Xu, Junhua, E-mail: jhxu@just.edu.cn

    2015-11-15

    Highlights: • NbN-Ag films were deposited by reactive magnetron sputtering. • The fcc-NbN, hcp-NbN and fcc-Ag coexisted in NbN-Ag films. • The incorporation of Ag into NbN matrix led to the decrease of hardness. • The films (9.2–13.5 at.% Ag) were found to be optimized for wear resistance tools. - Abstract: 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 Al{sub 2}O{sub 3} 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{sup −8} to 1.7 × 10{sup −8} mm{sup 3}/(mm N). 3D Profiler and Raman spectroscopy measurements revealed that the lubricant tribo-film AgNbO{sub 3} detected on the surface of the

  2. Typology of mafic-ultramafic complexes in Hoggar, Algeria: Implications for PGE, chromite and base-metal sulphide mineralisation

    Science.gov (United States)

    Augé, Thierry; Joubert, Marc; Bailly, Laurent

    2012-02-01

    With the aims to bring new information about the typology and mineral potential of mafic-ultramafic complexes of the Hoggar, detailed petrological and chemical characterisation were performed on serpentinite bands and layered intrusions. The serpentinite bands locally contain pods, layers and disseminations of chromite showing all the characteristics (mode of occurrence, composition, nature and composition of silicate inclusions, etc.) of an "ophiolite" chromite. Some chromite concentrations in the serpentinite bands also contain inclusions of platinum-group minerals (described for the first time in the Hoggar) such as ruarsite (RuAsS), an Os, Ru, Ir alloy, and complex Os, Ir, Ru sulfarsenides and arsenides. The serpentinite probably corresponds to remnants of oceanic lithosphere—more specifically from the upper part of the mantle sequence, generally where chromitite pods are most abundant, and the basal part of the cumulate series with stratiform chromite concentrations—and marks suture zones; the rest of the oceanic crust has not been preserved. Considering the typology of the serpentinites bands, their potential for precious- and base-metals is suspected to be low. Of the two layered mafic-ultramafic intrusions that were studied, the In Tedeini intrusion has a wehrlite core intruded by olivine gabbronorite and surrounded by an olivine gabbro aureole; three orthocumulate units, containing disseminated magmatic base-metal sulphides and with a plagioclase composition varying around An 58.1 and An 63.3, that could have been derived from a single magma. The East Laouni intrusion has a basal unit of olivine gabbronorite with specific silicate oxide intergrowths, and an upper unit of more differentiated gabbro, both units containing disseminated magmatic Ni-Cu sulphides indicative of early sulphide immiscibility; the mineral composition of these two cumulate units indicates that they also could have been derived from a single magmatic episode. The characteristic of

  3. Optical properties of zirconium oxynitride films: The effect of composition, electronic and crystalline structures

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, P. [Centro de Física, Universidade do Minho, 4710-057 Braga (Portugal); Borges, J., E-mail: joelborges@fisica.uminho.pt [Centro de Física, Universidade do Minho, 4710-057 Braga (Portugal); Department of Control Engineering, Faculty of Electrical Engineering, Czech Technical University in Prague, Technická 2, Prague 6 (Czech Republic); Rodrigues, M.S. [Centro de Física, Universidade do Minho, 4710-057 Braga (Portugal); Barradas, N.P. [Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, E.N. 10 (km 139,7), 2695-066 Bobadela LRS (Portugal); Alves, E. [Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisbon (Portugal); Espinós, J.P.; González-Elipe, A.R. [Instituto de Ciencia de Materiales de Sevilla (CSIC-University Sevilla), Avda. Américo Vespucio 49, 41092 Sevilla (Spain); Cunha, L.; Marques, L.; Vasilevskiy, M.I.; Vaz, F. [Centro de Física, Universidade do Minho, 4710-057 Braga (Portugal)

    2015-12-15

    Highlights: • Optical behaviour of ZrO{sub x}N{sub y} films were correlated with structural properties. • A continuous depopulation of the d-band and an opening of an energy gap was observed. • Drude–Lorentz parameters changed for the metallic samples. • Optical bandgap of the films increases with non-metallic elements incorporation. - Abstract: This work is devoted to the investigation of zirconium oxynitride (ZrO{sub x}N{sub y}) films with varied optical responses prompted by the variations in their compositional and structural properties. The films were prepared by dc reactive magnetron sputtering of Zr, using Ar and a reactive gas mixture of N{sub 2} + O{sub 2} (17:3). The colour of the films changed from metallic-like, very bright yellow-pale and golden yellow, for low gas flows to red-brownish for intermediate gas flows. Associated to this colour change there was a significant decrease of brightness. With further increase of the reactive gas flow, the colour of the samples changed from red-brownish to dark blue or even to interference colourations. The variations in composition disclosed the existence of four different zones, which were found to be closely related with the variations in the crystalline structure. XRD analysis revealed the change from a B1 NaCl face-centred cubic zirconium nitride-type phase for films prepared with low reactive gas flows, towards a poorly crystallized over-stoichiometric nitride phase, which may be similar to that of Zr{sub 3}N{sub 4} with some probable oxygen inclusions within nitrogen positions, for films prepared with intermediate reactive gas flows. For high reactive gas flows, the films developed an oxynitride-type phase, similar to that of γ-Zr{sub 2}ON{sub 2} with some oxygen atoms occupying some of the nitrogen positions, evolving to a ZrO{sub 2} monoclinic type structure within the zone where films were prepared with relatively high reactive gas flows. The analysis carried out by reflected electron energy

  4. Chemical cross-linked polyvinyl alcohol/cellulose nanocrystal composite films with high structural stability by spraying Fenton reagent as initiator.

    Science.gov (United States)

    Song, Meili; Yu, Houyong; Gu, Jiping; Ye, Shounuan; Zhou, Yuwei

    2018-02-20

    Cross-linked polyvinyl alcohol (PVA) composite films with high structural stability were prepared by free radical copolymerization between cellulose nanocrystal (CNC) and maleic anhydride (MAH) modified PVA through spraying Fenton free radical as initiator. The influence of chemical cross-linked and physical network structure on mechanical, thermal and water absorption properties of the composite films were investigated. Compared to PVA and PVA/CNC composite film, significant improvements in the mechanical, thermal and water uptake properties of the cross-linked composite film were found. The tensile strength of the cross-linked composite film was enhanced from 23.1MPa (neat PVA film) and 32.6MPa (PVA/CNC-10%) to 42.5MPa, and the maximum thermal degradation temperature was increased from 266.8°C and 281.2°C to 366.7°C (cross-linked composite film). Besides, the water absorption was reduced from 385.9% and 220.6% to 175.7% for cross-linked composite film. It indicates that compared with physical network structure in PVA/CNC composite film, the multiple cross-linked networks showed excellent thermal stability, resistance of water swelling and structural stability at the same CNC loading level. Thus, the PVA/CNC composite film with the multiple cross-linked network shows greater property reinforcements. Copyright © 2018 Elsevier B.V. All rights reserved.

  5. Hydrophilic nanofibers as new supports for thin film composite membranes for engineered osmosis.

    Science.gov (United States)

    Bui, Nhu-Ngoc; McCutcheon, Jeffrey R

    2013-02-05

    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. Superstretchable Nacre-Mimetic Graphene/Poly(vinyl alcohol) Composite Film Based on Interfacial Architectural Engineering.

    Science.gov (United States)

    Zhao, Nifang; Yang, Miao; Zhao, Qian; Gao, Weiwei; Xie, Tao; Bai, Hao

    2017-05-23

    Through designing hierarchical structures, particularly optimizing the chemical and architectural interactions at its inorganic/organic interface, nacre has achieved an excellent combination of contradictory mechanical properties such as strength and toughness, which is highly demanded yet difficult to achieve by most synthetic materials. Most techniques applied to develop nacre-mimetic composites have been focused on mimicking the "brick-and-mortar" structure, but the interfacial architectural features, especially the asperities and mineral bridges of "bricks", have been rarely concerned, which are of equal importance for enhancing mechanical properties of nacre. Here, we used a modified bidirectional freezing method followed by uniaxial pressing and chemical reduction to assemble a nacre-mimetic graphene/poly(vinyl alcohol) composite film, with both asperities and bridges introduced in addition to the lamellar layers to mimic the interfacial architectural interactions found in nacre. As such, we have developed a composite film that is not only strong (up to ∼150.9 MPa), but also tough (up to ∼8.50 MJ/m 3 ), and highly stretchable (up to ∼10.44%), difficult to obtain by other methods. This was all achieved by only interfacial architectural engineering within the traditional "brick-and-mortar" structure, without introducing a third component or employing chemical cross-linker as in some other nacre-mimetic systems. More importantly, we believe that the design principles and processing strategies reported here can also be applied to other material systems to develop strong and stretchable materials.

  7. Fabrication and Crystal Structure of Sol-Gel Deposited BST Thin Films with Compositional Gradient

    Directory of Open Access Journals (Sweden)

    Czekaj D.

    2017-06-01

    Full Text Available In the present research technology of compositionally graded barium strontium titanate Ba1-xSrxTiO3 thin films deposited on stainless steel substrates by sol-gel spin coating followed with thermal annealing at T = 650°C is reported. Results of thermal behavior of the sol-gel derived powders with compositions used for fabrication of graded structure (i.e. with Sr mole fraction x = 0.5, 0.4 and 0.3 are described. X-ray diffraction studies of the phase composition and crystal structure of such complex thin film configuration are given. It was found that gel powders exhibited a large total weight loss of about Δm ≈ 44-47%. Three stages of weight loss took place at temperature ranges: below T ≈ 300°C, at ΔT ≈ 300-500°C and between T = 600°C and T = 800°C. Phase analysis has shown that the dominating phase is Ba0.67Sr0.33TiO3 compound while the second phase is Ba0.7Sr0.3TiO3 or Ba0.5Sr0.5TiO3 for “up-graded” and “down-graded” structure, respectively.

  8. Preparation and characterization of PVP-PVA–ZnO blend polymer nano composite films

    Energy Technology Data Exchange (ETDEWEB)

    Divya, S., E-mail: divi.fysics@gmail.com; Saipriya, G.; Hemalatha, J., E-mail: hemalatha@nitt.edu [Advanced Materials Lab, Department of Physics, National Institute Of Technology, Tiruchirappalli, Tamilnadu, India - 620 015 (India)

    2016-05-23

    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 235 nm and 370 nm 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 320 nm.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.

  9. 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.

  10. A new concept in polymeric thin-film composite nanofiltration membranes with antibacterial properties.

    Science.gov (United States)

    Mollahosseini, Arash; Rahimpour, Ahmad

    2013-01-01

    A new, thin film, biofouling resistant, nanofiltration (NF) membrane was fabricated with two key characteristics, viz. a low rate of silver (Ag) release and long-lasting antibacterial properties. In the new approach, nanoparticles were embedded completely in a polymeric thin-film layer. A comparison was made between the new thin-film composite (TFC), NF membrane and thin-film nanocomposite (TFN), and antibacterial NF membranes. Both types of NF membrane were fabricated by interfacial polymerization on a polysulphone sublayer using m-phenylenediamine and trimesoyl chloride as an amine monomer and an acid chloride monomer, respectively. Energy dispersive X-ray (EDX) microanalysis demonstrated the presence of Ag nanoparticles. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used to study the cross-sectional and surface morphological properties of the NF membranes. Permeability and salt rejection were tested using a dead-end filtration cell. Ag leaching from the membranes was measured using inductively coupled mass spectrometry (ICP-MS). Morphological studies showed that the TFC NF membranes had better thin-film formation (a more compact structure and a smoother surface) than TFN NF membranes. Performance experiments on TFC NF membranes revealed that permeability was good, without sacrificing salt rejection. The antibacterial properties of the fabricated membranes were tested using the disk diffusion method and viable plate counts. The antibiofouling properties of the membranes were examined by measuring the quantity of bacterial cells released from the biofilm formed (as a function of the amount of biofilm present). A more sensitive surface was observed compared to that of a typical antibacterial NF membrane. The Ag leaching rates were low, which will likely result in long-lasting antibacterial and biofouling resistant properties.

  11. 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. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. 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.

  13. Composite films of oxidized multiwall carbon nanotube and poly(3,4-ethylenedioxythiophene): polystyrene sulfonate (PEDOT:PSS) as a contact electrode for transistor and inverter devices.

    Science.gov (United States)

    Yun, Dong-Jin; Rhee, Shi-Woo

    2012-02-01

    Composite films of multiwall carbon nanotube (MWNT)/poly(3,4-ethylenedioxythiophene) polymerized with poly(4-styrenesulfonate) (PEDOT:PSS) were prepared by spin-coating a mixture solution. The effect of the MWNT loading and the MWNT oxidation, with acid solution or ultraviolet (UV)-ozone treatment, on the film properties such as surface roughness, work function, surface energy, optical transparency and conductivity were studied. Also pentacene thin film transistors and inverters were made with these composite films as a contact metal and the device characteristics were measured. The oxidation of MWNT reduced the conductivity of MWNT/PEDOT:PSS composite film but increased the work function and transparency. UV-ozone treated MWNT/PEDOT:PSS composite film showed higher conductivity (14000 Ω/□) and work function (4.9 eV) than acid-oxidized MWNT/PEDOT:PSS composite film and showed better performance as a source/drain electrode in organic thin film transistor (OTFT) than other types of MWNT/PEDOT:PSS composite films. Hole injection barrier of the UV-ozone treated MWNT/PEDOT:PSS composite film with pentacene was significantly lower than any other films because of the higher work function.

  14. Nonlinear optical properties of polyaniline and poly (o-toluidine) composite thin films with multi walled carbon nano tubes

    Energy Technology Data Exchange (ETDEWEB)

    Nagaraja, K.K. [National University of Science and Technology “MISiS”, Leninskii pr. 4, Moscow 119049 (Russian Federation); Pramodini, S. [Department of Physics, School of Engineering and Technology, Jain University, Jakkasandra Post, Bengaluru 5621112, Karnataka (India); Poornesh, P., E-mail: poorneshp@gmail.com [Nonlinear Optics Research Laboratory, Department of Physics, Manipal Institute of Technology, Manipal University, Manipal 576 104, Karnataka (India); Telenkov, M.P. [National University of Science and Technology “MISiS”, Leninskii pr. 4, Moscow 119049 (Russian Federation); Kityk, I.V. [Electrical Engineering Department, Czestochowa University Technology, Czestochowa (Poland)

    2017-05-01

    We report the improved third-order nonlinear optical properties of polyaniline and poly (o-toluidine) with different doping concentrations of multi walled carbon nano tube (MWCNTs) composite thin films investigated using z-scan technique and continuous wave He–Ne laser at 633 nm wavelength was used as source of excitation. Thin films were prepared by spin coating technique on glass substrate. The structural properties of the composite films were analysed by X-ray diffraction studies and the characteristic peaks corresponding to MWCNTs and polymers have been observed. The surface morphology of the deposited films was analysed using scanning electron microscopy and it confirms that the polymer in the composites has been coated on the MWCNTs homogeneously. The z-scan results reveal that the films exhibit reverse saturable absorption and self-defocusing nonlinearity. The third-order nonlinear optical susceptibility χ{sup (3)} is found to be of the order of 10{sup −3} esu. Also, optical power limiting and clamping experiment was performed. The clamping values increases with increase in concentration and the lowest clamping observed for composite films are 1 mW and 0.7 mW.

  15. Ultraflexible Transparent Film Heater Made of Ag Nanowire/PVA Composite for Rapid-Response Thermotherapy Pads.

    Science.gov (United States)

    Lan, Wei; Chen, Youxin; Yang, Zhiwei; Han, Weihua; Zhou, Jinyuan; Zhang, Yue; Wang, Junya; Tang, Guomei; Wei, Yupeng; Dou, Wei; Su, Qing; Xie, Erqing

    2017-02-22

    Ultraflexible transparent film heaters have been fabricated by embedding conductive silver (Ag) nanowires into a thin poly(vinyl alcohol) film (AgNW/PVA). A cold-pressing method was used to rationally adjust the sheet resistance of the composite films and thus the heating powers of the AgNW/PVA film heaters at certain biases. The film heaters have a favorable optical transmittance (93.1% at 26 Ω/sq) and an outstanding mechanical flexibility (no visible change in sheet resistance after 10 000 bending cycles and at a radius of curvature ≤1 mm). The film heaters have an environmental endurance, and there is no significant performance degradation after being kept at high temperature (80 °C) and high humidity (45 °C, 80% humidity) for half a year. The efficient Joule heating can increase the temperature of the film heaters (20 Ω/sq) to 74 °C in ∼20 s at a bias of 5 V. The fast-heating characteristics at low voltages (a few volts) associated with its transparent and flexibility properties make the poly(dimethylsiloxane)/AgNW/PVA composite film a potential candidate in medical thermotherapy pads.

  16. Hemicyanine LB film—Silver nanoparticle composite: contrasting fluorescence responses sensitive to the ultrathin film assembly sequence

    Science.gov (United States)

    Maganti, Lasya; Dwivedi, Itisha; Jose, Anju; Radhakrishnan, T. P.

    2017-07-01

    Fluorescence emission of molecules is strongly influenced by the plasmonic field of metal nanoparticles, with significant enhancement induced under optimal conditions. Nanocomposite ultrathin films fabricated with citrate-stabilized Ag nanoparticles and LB film of a cationic hemicyanine amphiphile, are shown to produce opposing fluorescence emission trends upon subtle variation in the assembly sequence. Monolayer LB films of the pure amphiphile show aggregation-induced quenching with increasing deposition pressure. Composite films formed by adsorption of Ag nanoparticles on the Langmuir film (self-assembly together with steered assembly) followed by LB transfer, show further quenching. However, adsorption of Ag nanoparticles on the pre-formed amphiphile LB film (self-assembly following steered assembly), causes the fluorescence to increase with the extent of adsorption. Spectroscopy and microscopy provide insight into the contrasting, tunable emission. Formation of Ag nanoparticle chains on the Langmuir film and their direct contact with the monolayer cause the fluorescence quenching; adsorption of isolated Ag nanoparticles on the LB film along with multilayer formation leads to the enhancement. The study illustrates the versatility of LB film—metal nanoparticle composites in producing distinct materials responses through subtle changes in the mode of assembly.

  17. Methylammonium lead mixed halide films processed with a new composition for planar perovskite solar cells

    Science.gov (United States)

    Park, Ban-Suk; Lee, Seojun; Yoon, Saemon; Ha, Tae-Jun; Kang, Dong-Won

    2018-01-01

    In this work, we propose a new mixed halide precursor composition for MAPbI3-xClx organic/inorganic perovskite (PRV) solar cells. PRV films made with a new precursor composition of (MAI: PbCl2: PbI2 = 2 : 1 : 1) could be crystallized at lower temperature (70 °C) and shorter annealing duration (60 min), whereas previous standard composition (MAI: PbCl2 = 3 : 1) requires multi-step and high temperature (from 75 °C to 130 °C) annealing for longer durations (∼100 min). By adopting the suggested composition, much uniform surface morphology of PRV light harvester was obtained even though non-polar solvent washing was not introduced yet. Also, when the suitable toluene washing treatment was introduced, PRV surfaces of highly compact and large crystallites with regular distribution were achieved without any pinhole, which offered significant improvements in fill factor (41 → 65%) and power conversion efficiency (5.85 → 9.39%) of PRV cells. The suggested new precursor composition contributing for surface topography can be widely utilized for inverted planar PRV devices with low-temperature and simple processing.

  18. Study of morphology and mechanical properties of hydrophilic films based on compositions of poly(acrylic acid) and poly(2-hydroxy ethylvinylether)

    International Nuclear Information System (INIS)

    Bitekenova, A.; Dzhusupbekova, A.; Khutoryanskij, V.; Nurkeeva, Z.

    2003-01-01

    The hydrophilic films based on compositions of poly(acrylic acid) and poly(2-hydroxy ethylvinylether) were obtained from blend of the corresponding monomers. Radiation crosslinking of composite materials are realize by γ-irradiation method and the gelation doses were calculated. It was shown that mechanical properties of films depend on composition (content of notion component) and conditions of crosslinking. The morphology of polymeric films was investigated by scanning electron microscopy

  19. Magnetic Composite Thin Films of Fe{sub x}O{sub y} Nanoparticles and Photocrosslinked Dextran Hydrogels

    Energy Technology Data Exchange (ETDEWEB)

    Brunsen, Annette, E-mail: brunsen@mpip-mainz.mpg.de [Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz (Germany); Department of Chemistry, Technical University Darmstadt, Petersenstr. 22, 64287 Darmstadt (Germany); Utech, Stefanie, E-mail: utech@uni-mainz.de [Johannes Gutenberg University Mainz, Institute of Physical Chemistry, Jakob-Welder-Weg 11, 55099 Mainz (Germany); Institut fuer Mikrotechnik Mainz GmbH (IMM), Carl-Zeiss-Str. 18-20, 55129 Mainz, German (Germany); Maskos, Michael, E-mail: maskos@uni-mainz.de [Institut fuer Mikrotechnik Mainz GmbH (IMM), Carl-Zeiss-Str. 18-20, 55129 Mainz, German (Germany); Knoll, Wolfgang, E-mail: Wolfgang.Knoll@ait.ac.at [Austrian Institute of Technology, Tech Gate Vienna, Donau-City-Str. 1, 1220 Wien (Austria); Jonas, Ulrich, E-mail: jonas@mpip-mainz.mpg.de [Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz (Germany) and Macromolecular Chemistry, Department Chemistry - Biology, University of Siegen, Adolf-Reichwein-Str. 2, 57076 Siegen (Germany) and Foundation for Research and Technology - Hellas - FORTH, Institute of Electronic Structure and Laser (IESL), Bio-Organic Materials Chemistry Laboratory - BOMCLab, Nikolaou Plastira 100, Vassilika Vouton, 71110 Heraklion, Crete (Greece)

    2012-04-15

    Magnetic hydrogel composites are promising candidates for a broad field of applications from medicine to mechanical engineering. Here, surface-attached composite films of magnetic nanoparticles (MNP) and a polymeric hydrogel (HG) were prepared from magnetic iron oxide nanoparticles and a carboxymethylated dextran with photoreactive benzophenone substituents. A blend of the MNP and the dextran polymer was prepared by mixing in solution, and after spin-coating and drying the blend film was converted into a stable MNP-HG composite by photocrosslinking through irradiation with UV light. The bulk composite material shows strong mobility in a magnetic field, imparted by the MNPs. By utilizing a surface layer of a photoreactive adhesion promoter on the substrates, the MNP-HG films were covalently immobilized during photocrosslinking. The high stability of the composite was documented by rinsing experiments with UV-Vis spectroscopy, while surface plasmon resonance and optical waveguide mode spectroscopy was employed to investigate the swelling behavior in dependence of the nanoparticle concentration, the particle type, and salt concentration. - Highlights: Black-Right-Pointing-Pointer blending of iron oxide nanoparticles with photocrosslinkable carboxymethyldextran. Black-Right-Pointing-Pointer UV irradiation of blend yields surface-attached, magnetic hydrogel films. Black-Right-Pointing-Pointer film characterization by surface plasmon resonance/optical waveguide spectroscopy. Black-Right-Pointing-Pointer swelling decreases with increasing nanoparticle content. Black-Right-Pointing-Pointer swelling decreases with increasing NaCl salt concentration in the aqueous medium.

  20. Enhanced thermoelectric properties of PEDOT/PSS/Te composite films treated with H{sub 2}SO{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Song, Haijun; Cai, Kefeng, E-mail: kfcai@tongji.edu.cn [Tongji University, Key Laboratory of Advanced Civil Engineering Materials of Ministry of Education, School of Materials Science and Engineering (China); Shen, Shirley [CSIRO Manufacturing (Australia)

    2016-12-15

    Firstly, tellurium (Te) nanorods with a high Seebeck coefficient have been integrated into a conducting polymer PEDOT/PSS to form PEDOT/PSS/Te composite films. The Seebeck coefficient of the PEDOT/PSS/Te (90 wt.%) composite films is ~191 μV/K, which is about 13 times greater than that of pristine PEDOT/PSS. Then, H{sub 2}SO{sub 4} treatment has been used to further tune the thermoelectric properties of the composite films by adjusting the doping level and increasing the carrier concentration. After the acid treatment, the electrical conductivity of the composite films has increased from 0.22 to 1613 S/cm due to the removal of insulating PSS and the structural rearrangement of PEDOT. An optimized power factor of 42.1 μW/mK{sup 2} has been obtained at room temperature for a PEDOT/PSS/Te (80 wt.%) sample, which is about ten times larger than that of the untreated PEDOT/PSS/Te composite film.

  1. 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...... nitrogen concentrations between 2 and 10 at. %. A simple atomic valence model is found to describe both the measured atomic concentrations and published material compositions for silicon oxy-nitride produced by PECVD. A relation between the Si–N bond concentration and the refractive index is found......-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...

  2. Corrosion and drug release properties of EN-plating/PLGA composite coating on MAO film

    International Nuclear Information System (INIS)

    Lu Ping; Liu Yin; Guo Meiqing; Fang Haidong; Xu Xinhua

    2011-01-01

    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

  3. Corrosion and drug release properties of EN-plating/PLGA composite coating on MAO film

    Energy Technology Data Exchange (ETDEWEB)

    Lu Ping [School of Materials Science and Engineering, and Tianjin Key Laboratory of Composite and Functional Materials, Tianjin University, Tianjin 300072 (China); Liu Yin [Department of Cardiology, Tianjin Chest Hospital, Tianjin 300051 (China); Guo Meiqing; Fang Haidong [School of Materials Science and Engineering, and Tianjin Key Laboratory of Composite and Functional Materials, Tianjin University, Tianjin 300072 (China); Xu Xinhua, E-mail: xhxu_tju@eyou.com [School of Materials Science and Engineering, and Tianjin Key Laboratory of Composite and Functional Materials, Tianjin University, Tianjin 300072 (China)

    2011-10-10

    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: {yields} An organic and in organic EN-plating/PLGA composite coating was first fabricated on the surface of the MAO film. {yields} This composite coating the magnesium alloy AZ81could double control the corrosion and drug release in the hanks' solution. {yields} The drug release rate could be controlled by LG

  4. Initial Study on Thin Film Preparation of Carbon Nanodots Composites as Luminescence Material

    Science.gov (United States)

    Iskandar, F.; Aimon, A. H.; Akmaluddin, A. R.; Nuryadin, B. W.; Abdullah, M.

    2016-08-01

    Nowadays, the developments of phosphors materials require elements without noble metals and simple production process. Carbon nanodots (C-dots) are one of phosphor materials with wide range of emission band, and high biocompatibility. In this research thin film carbon nanodots composite have been prepared by spin coating method. Prior deposition, powder carbon nanodots were synthesized from a mixture of commercial urea as the nitrogen sources and citric acid as a carbon source by using hydrothermal and microwave-assisted heating method. The prepared powder was dispersed in transparent epoxy resin and then coated on glass substrate. The photoluminescence result for sample with 0.035 g citric acid exhibited an intense, single, homogeneous and broad spectrum with yellowish emission upon excitation at 365 nm. The Fourier Transform Infrared Spectroscopy (FTIR) result showed the existences of C=C, C-H, C=O, N-H and O-H functional groups which confirmed the quality of the sample. Further, based on UV-Vis measurement, the prepared thin film was highly transparent (transmittance 90%) with estimated film thickness around 764 nm. This result may open an opportunity for optoelectronic devices.

  5. Pulsed laser deposition of semiconductor-ITO composite films on electric-field-applied substrates

    International Nuclear Information System (INIS)

    Narazaki, Aiko; Sato, Tadatake; Kawaguchi, Yoshizo; Niino, Hiroyuki; Yabe, Akira; Sasaki, Takeshi; Koshizaki, Naoto

    2002-01-01

    The DC electric-field effect on the crystallinity of II-VI semiconductor in composite systems has been investigated for CdS-ITO films fabricated via alternative pulsed laser deposition (PLD) of CdS and indium tin oxide (ITO) on electric-field-applied substrates. The alternative laser ablation was performed under irradiation of ArF excimer laser in mixture gas of helium and oxygen. The application of electric-field facilitated the preferential crystal-growth of CdS in nanometer scale at low pressure, whereas all the films grown without the field were amorphous. There is a large difference in the crystallization between the films grown on field-applied and heated substrates; the latter showed the crystal-growth with random orientations. This difference indicates that the existence of electric-field has an influence on the transformation from amorphous to crystalline phase of CdS. The driving force for the field-induced crystallization is also discussed in the light of the Joule heat

  6. Structure and composition evaluation of heavily Ge-doped ZnO nanocrystal films

    Science.gov (United States)

    Zhu, Wenliang; Kammuri, Takuya; Kitamura, Shoichiro; Sturaro, Marco; Martucci, Alessandro; Pezzotti, Giuseppe

    2018-02-01

    A series of high quality zinc oxide (ZnO) nanocrystal films doped with Ge at different Ge/Zn molar ratios were synthesized by the sol-gel method, and structural and compositional changes induced by Ge doping in the ZnO films were analyzed by x-ray diffraction, x-ray photoelectron spectroscopy and cathodoluminescence spectroscopy. Heavy Ge doping in ZnO was found to effectively reduce intrinsic defects in the films and suppress free exciton emission and defect-related emissions in the visible green-red region, by the substitution of Ge at Zn sites and the formation of non-radiative deep-level traps (GeZn)+. The generation of such non-radiative traps was found to be suppressed with respect to the dopant increase, because of a reduction in carrier concentration along with a formation of stable defect complex GeZn–VZn at high doping content. The clarification of defect alterations in Ge-doped ZnO lays the foundation of quantitative evaluation of defect effects on the electrical and optical properties for improving the quality of GeZnO devices.

  7. 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.

  8. 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.

  9. CO2-Philic Thin Film Composite Membranes: Synthesis and Characterization of PAN-r-PEGMA Copolymer

    KAUST Repository

    Karunakaran, Madhavan

    2017-07-06

    In this work, we report the successful fabrication of CO2-philic polymer composite membranes using a polyacrylonitrile-r-poly(ethylene glycol) methyl ether methacrylate (PAN-r-PEGMA) copolymer. The series of PAN-r-PEGMA copolymers with various amounts of PEG content was synthesized by free radical polymerization in presence of AIBN initiator and the obtained copolymers were used for the fabrication of composite membranes. The synthesized copolymers show high molecular weights in the range of 44-56 kDa. We were able to fabricate thin film composite (TFC) membranes by dip coating procedure using PAN-r-PEGMA copolymers and the porous PAN support membrane. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were applied to analyze the surface morphology of the composite membranes. The microscopy analysis reveals the formation of the defect free skin selective layer of PAN-r-PEGMA copolymer over the porous PAN support membrane. Selective layer thickness of the composite membranes was in the range of 1.32-1.42 mu m. The resulting composite membrane has CO2 a permeance of 1.37 x 10(-1) m(3)/m(2).h.bar and an ideal CO2/N-2, selectivity of 65. The TFC membranes showed increasing ideal gas pair selectivities in the order CO2/N-2 > CO2/CH4 > CO2/H-2. In addition, the fabricated composite membranes were tested for long-term single gas permeation measurement and these membranes have remarkable stability, proving that they are good candidates for CO2 separation.

  10. CO2-Philic Thin Film Composite Membranes: Synthesis and Characterization of PAN-r-PEGMA Copolymer

    Directory of Open Access Journals (Sweden)

    Madhavan Karunakaran

    2017-07-01

    Full Text Available In this work, we report the successful fabrication of CO2-philic polymer composite membranes using a polyacrylonitrile-r-poly(ethylene glycol methyl ether methacrylate (PAN-r-PEGMA copolymer. The series of PAN-r-PEGMA copolymers with various amounts of PEG content was synthesized by free radical polymerization in presence of AIBN initiator and the obtained copolymers were used for the fabrication of composite membranes. The synthesized copolymers show high molecular weights in the range of 44–56 kDa. We were able to fabricate thin film composite (TFC membranes by dip coating procedure using PAN-r-PEGMA copolymers and the porous PAN support membrane. Scanning electron microscopy (SEM and atomic force microscopy (AFM were applied to analyze the surface morphology of the composite membranes. The microscopy analysis reveals the formation of the defect free skin selective layer of PAN-r-PEGMA copolymer over the porous PAN support membrane. Selective layer thickness of the composite membranes was in the range of 1.32–1.42 μm. The resulting composite membrane has CO2 a permeance of 1.37 × 10−1 m3/m2·h·bar and an ideal CO2/N2, selectivity of 65. The TFC membranes showed increasing ideal gas pair selectivities in the order CO2/N2 > CO2/CH4 > CO2/H2. In addition, the fabricated composite membranes were tested for long-term single gas permeation measurement and these membranes have remarkable stability, proving that they are good candidates for CO2 separation.

  11. Influence of processing conditions on the structure, composition and ferroelectric properties of sputtered PZT thin films on Ti-substrates

    Science.gov (United States)

    Bose, Ankita; Sreemany, Monjoy

    2014-01-01

    PZT thin (∼500 nm) films are synthesized on titanium (Ti) substrates by r.f. magnetron sputtering under various processing conditions. Present work aims to investigate the influence of working pressure and post-annealing temperature on the quality of the films. Phase evolution, surface morphology with local chemical composition and dielectric/ferroelectric properties of PZT films have been studied as the functions of working pressure and post-annealing temperature. A working pressure of ∼0.7 Pa and a post-crystallization temperature of ∼650 °C are found to be the optimum processing conditions for growing perovskite PZT films on Ti-substrates. Irrespective of processing conditions, however, all PZT films on Ti-substrates show poor electrical response. Depth dependent change in the chemical states of Pb, Zr, Ti and oxygen within the PZT films and across the PZT/Ti interfaces has also been scrutinized by XPS depth profiling. It is observed that within PZT films, Pb exists both in Pb2+ and Pb0 (metallic-Pb) states. Surfaces of the PZT films are found to be enriched with a thin (∼60 nm) Pb-deficient and Zr-rich pyrochlore/fluorite (Py/Fl) phase. Existence of a thin titanium oxide layer in the form of a TiO2/TiO stack has also been confirmed at the PZT/Ti interface. Processing conditions dependant structural modifications have been correlated with the dielectric and ferroelectric properties of the films.

  12. Photocatalysis of composite film PDMS-PMN-PT@TiO2 greatly improved via spatial electric field

    Science.gov (United States)

    Dai, Baoying; Zhang, Ling; Huang, Hengming; Lu, Chunhua; Kou, Jiahui; Xu, Zhongzi

    2017-05-01

    Efficient charge separation is quite significant to obtain high photocatalytic performance. In this work, piezoelectric-based composite photocatalyst film PDMS-PMN-PT@TiO2 possessing high recoverability was prepared. The spatial electric field of PMN-PT was introduced into photocatalyst system by ultrasonic wave vibration to accelerate charge separation. Compared with magnetic stirring, ultrasonic wave vibration greatly improved the photocatalytic degradation efficiency of rhodamine B (RhB) over PDMS-PMN-PT@TiO2 film by about 55%. A possible improvement mechanism that spatial electric field promotes charge separation was presented herein. The piezoelectric potential output demonstrated the piezoelectricity of composite film. The durability experiments of PDMS-PMN-PT@TiO2 film indicated its great stability over several runs.

  13. Controlling compositional homogeneity and crystalline orientation in Bi0.8Sb0.2 thermoelectric thin films

    Directory of Open Access Journals (Sweden)

    C. Rochford

    2015-12-01

    Full Text Available Compositional-homogeneity and crystalline-orientation are necessary attributes to achieve high thermoelectric performance in Bi1−xSbx thin films. Following deposition in vacuum, and upon air exposure, we find that 50%–95% of the Sb in 100-nm thick films segregates to form a nanocrystalline Sb2O3 surface layer, leaving the film bulk as Bi-metal. However, we demonstrate that a thin SiN capping layer deposited prior to air exposure prevents Sb-segregation, preserving a uniform film composition. Furthermore, the capping layer enables annealing in forming gas to improve crystalline orientations along the preferred trigonal axis, beneficially reducing electrical resistivity.

  14. Investigation of the composition-structure-property relationship of AsxTe100 - x films prepared by plasma deposition

    Science.gov (United States)

    Mochalov, Leonid; Dorosz, Dominik; Nezhdanov, Aleksey; Kudryashov, Mikhail; Zelentsov, Sergey; Usanov, Dmitry; Logunov, Alexandr; Mashin, Aleksandr; Gogova, Daniela

    2018-02-01

    AsxTe100 - x amorphous films of different chemical content were prepared by Plasma-Enhanced Chemical Vapor Deposition (PECVD). For the first time the optical properties of As-Te chalcogenide materials have been measured in UV-VIS-IR ranges (from 0.2 to 25 μm) for a very wide range of chemical compositions (20-80 at.% As). As-Te films have been tuned from 0.80 to 1.10 eV. The IR results obtained have been juxtaposed with the Raman spectroscopy findings to establish the correlation between optical and structural properties of the materials developed. Reversible and irreversible changes in the phase composition of the As-Te films under annealing of the surface by laser irradiation have been demonstrated and studied. In order to determine the potential areas of application of the prepared As-Te films the thermal and photo sensitivity has been also investigated.

  15. SR-Site - sulphide content in the groundwater at Laxemar

    Energy Technology Data Exchange (ETDEWEB)

    Tullborg, E-L (Terralogica, Graabo (Sweden)); Smellie, J. (Conterra, Uppsala (Sweden)); Nilsson, A-Ch (Geosigma, Uppsala (Sweden)); Gimeno, M.J.; Auque, L.F. (Univ. of Zaragoza (Spain)); Wallin, B. (Geokema, Lidingoe (Sweden)); Bruechert, V. (Stockholm Univ. (Sweden)); Molinero, J. (Amphos21, Barcelona (Spain))

    2010-12-15

    Sulphide concentrations in groundwater play a key role in the long term reliability of the metal canisters containing the radioactive waste within a disposal facility for nuclear waste. This is because sulphide in the groundwaters circulating in the vicinity of the deposition tunnels can react with copper in the canisters causing corrosion and therefore reducing their expected lifetime; in a worst case scenario erosion of the bentonite buffer material will expose the canister more rapidly to the fracture groundwater. Sulphide in the groundwater is predominantly microbially produced and thereby controlled by the content of oxidised sulphur sources, organics (carbon sources), reductants (mainly Fe(II), DOC, H{sub 2} and CH{sub 4}), and also flow. In addition, achieved saturation in respect to amorphous Fe-monosulphide will control the possible maximum values and thus limit the Fe2+ and S2- values in the groundwater. The aim of this report is to assess realistic, representative and reliable sulphide groundwater concentrations at present conditions in Laxemar to be considered for use in (future) safety assessments. To achieve this, an evaluation is performed of all the sulphide related data reported from the Laxemar site investigations /Laaksoharju et al. 2009/ and later monitoring campaigns, all of which are stored in the Sicada database. This evaluation shows that values from the Complete Chemical Characterisation (CCC) (i.e. in situ sampling from one or more borehole sections using mobile equipment) are usually lower than those measured during the monitoring phase (i.e. in situ sampling from one borehole section using permanently installed equipment). An exception is borehole KLX01, where values generally lie within the same range as the monitoring samples. For most of the CCC and monitoring sections the last sample in the time series is suggested as representing the 'best possible' sulphide value. When both initial values from CCC (or samples taken with

  16. SR-Site - sulphide content in the groundwater at Laxemar

    International Nuclear Information System (INIS)

    Tullborg, E-L; Smellie, J.; Nilsson, A-Ch; Gimeno, M.J.; Auque, L.F.; Wallin, B.; Bruechert, V.; Molinero, J.

    2010-12-01

    Sulphide concentrations in groundwater play a key role in the long term reliability of the metal canisters containing the radioactive waste within a disposal facility for nuclear waste. This is because sulphide in the groundwaters circulating in the vicinity of the deposition tunnels can react with copper in the canisters causing corrosion and therefore reducing their expected lifetime; in a worst case scenario erosion of the bentonite buffer material will expose the canister more rapidly to the fracture groundwater. Sulphide in the groundwater is predominantly microbially produced and thereby controlled by the content of oxidised sulphur sources, organics (carbon sources), reductants (mainly Fe(II), DOC, H 2 and CH 4 ), and also flow. In addition, achieved saturation in respect to amorphous Fe-monosulphide will control the possible maximum values and thus limit the Fe 2+ and S 2- values in the groundwater. The aim of this report is to assess realistic, representative and reliable sulphide groundwater concentrations at present conditions in Laxemar to be considered for use in (future) safety assessments. To achieve this, an evaluation is performed of all the sulphide related data reported from the Laxemar site investigations /Laaksoharju et al. 2009/ and later monitoring campaigns, all of which are stored in the Sicada database. This evaluation shows that values from the Complete Chemical Characterisation (CCC) (i.e. in situ sampling from one or more borehole sections using mobile equipment) are usually lower than those measured during the monitoring phase (i.e. in situ sampling from one borehole section using permanently installed equipment). An exception is borehole KLX01, where values generally lie within the same range as the monitoring samples. For most of the CCC and monitoring sections the last sample in the time series is suggested as representing the 'best possible' sulphide value. When both initial values from CCC (or samples taken with the hydrotest

  17. 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

  18. Study of the composition transfer in the pulsed laser deposition of silicon substituted hydroxyapatite thin films

    Science.gov (United States)

    Solla, E. L.; Borrajo, J. P.; González, P.; Serra, J.; Chiussi, S.; León, B.; López, J. García

    2007-07-01

    The field of biomaterials has lately been showing an important interest in the production of bioactive ceramic coatings capable of improving the adhesion of metal prostheses to the living tissue. Among these ceramics, the most notable is hydroxyapatite (HA) due to its similarities with the mineral part of the bone. The need to emphasize these resemblances led to the production of silicon substituted HA (Si-HA), a material which has shown better biological performance compared to the traditional HA. Coatings were prepared by pulsed laser deposition (PLD) technique, starting from mixtures of pure HA with Si powders. The laser-matter interaction successfully transferred the Si-HA to the substrate incorporating the Si atoms within its structure. The Si-HA thin films were characterized in terms of structure and chemical composition by many different techniques such as Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XPS), energy dispersive spectroscopy (EDS) and ion beam spectroscopy techniques such as Rutherford back scattering (RBS), particle induced X-ray emission (PIXE), elastic recoil detection (ERD) and nuclear reaction analysis (NRA). The analysis demonstrated that Si is efficiently transferred to the HA structure in the form of SiO 44- groups. The dependence of the target composition on the film growth and on the Si content of the coatings is also presented.

  19. Effect of ablation geometry on the dynamics, composition, and geometrical shape of thin film plasma

    Science.gov (United States)

    Mondal, Alamgir; Singh, R. K.; Kumar, Ajai

    2018-01-01

    The characteristics of plasma plume produced by front and back ablation of thin films have been investigated using fast imaging and optical emission spectroscopy. Ablation geometry dependence of the plume dynamics, its geometrical aspect and composition is emphasized. Also, the effect of an ambient environment and the beam diameter of an ablating laser on the front and back ablations is briefly discussed. Analysis of time resolved images and plasma parameters indicates that the energetic and spherical plasma formed by front ablation is strikingly different in comparison to the slow and nearly cylindrical plasma plume observed in the case of back ablation. Further shock formation, plume confinement, thermalization and validity of different expansion models in these two ablation geometries are also presented. The present study demonstrates the manipulation of kinetic energy, shape, ion/neutral compositions and directionality of the expanding plume by adjusting the experimental configuration, which is highly relevant to its utilization in various applications e.g., generation of energetic particles, tokamak edge plasma diagnostics, thin film deposition, etc.

  20. Surface modification of thin film composite reverse osmosis membrane by glycerol assisted oxidation with sodium hypochlorite

    Science.gov (United States)

    Raval, Hiren D.; Samnani, Mohit D.; Gauswami, Maulik V.

    2018-01-01

    Need for improvement in water flux of thin film composite (TFC) RO membrane has been appreciated by researchers world over and surface modification approach is found promising to achieve higher water flux and solute rejection. Thin film composite RO membrane was exposed to 2000 mg/l sodium hypochlorite solution with varying concentrations of glycerol ranging from 1 to 10%. It was found that there was a drop in concentration of sodium hypochlorite after the addition of glycerol because of a new compound resulted from the oxidation of glycerol with sodium hypochlorite. The water flux of the membrane treated with 1% glycerol with 2000 mg/l sodium hypochlorite for 1 h was about 22% more and salt rejection was 1.36% greater than that of only sodium hypochlorite treated membrane for the same concentration and time. There was an increase in salt rejection of membrane with increase in concentration of glycerol from 1% to 5%, however, increasing glycerol concentration further up to 10%, the salt rejection declined. The water flux was found declining from 1% glycerol solution to 10% glycerol solution. The membrane samples were characterized to understand the change in chemical structure and morphology of the membrane.

  1. Bio-inspired nacre-like composite films based on graphene with superior mechanical, electrical, and biocompatible properties.

    Science.gov (United States)

    Li, Yuan-Qing; Yu, Ting; Yang, Tian-Yi; Zheng, Lian-Xi; Liao, Kin

    2012-07-03

    Bio-inspired multifunctional composite films based on reduced poly(vinyl alcohol)/graphene oxide (R-PVA/GO) layers are prepared by a facile solution casting method followed by a reduction procedure. The resulting films with nacre-like, bricks-and-mortar microstructure have excellent mechanical properties, electrical conductivity, and biocompatibility. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Preparation and characterization of graphene-based vanadium oxide composite semiconducting films with horizontally aligned nanowire arrays

    International Nuclear Information System (INIS)

    Jung, Hye-Mi; Um, Sukkee

    2016-01-01

    Highly oriented crystalline hybrid thin films primarily consisting of Magnéli-phase VO 2 and conductive graphene nanoplatelets are fabricated by a sol–gel process via dipping pyrolysis. A combination of chemical, microstructural, and electrical analyses reveals that graphene oxide (GO)-templated vanadium oxide (VO x ) nanocomposite films exhibit a vertically stacked multi-lamellar nanostructure consisting of horizontally aligned vanadium oxide nanowire (VNW) arrays along the (hk0) set of planes on a GO template, with an average crystallite size of 41.4 Å and a crystallographic tensile strain of 0.83%. In addition, GO-derived VO x composite semiconducting films, which have an sp 3 /sp 2 bonding ratio of 0.862, display thermally induced electrical switching properties in the temperature range of − 20 °C to 140 °C, with a transition temperature of approximately 65 °C. We ascribe these results to the use of GO sheets, which serve as a morphological growth template as well as an electrochemically tunable platform for enhancing the charge-carrier mobility. Moreover, the experimental studies demonstrate that graphene-based Magnéli-phase VO x composite semiconducting films can be used in advanced thermo-sensitive smart sensing/switching applications because of their outstanding thermo-electrodynamic properties and high surface charge density induced by the planar-type VNWs. - Highlights: • VO x -graphene oxide composite (G/VO x ) films were fabricated by sol–gel process. • The G/VO x films mainly consisted of Magnéli-phase VO 2 and reduced graphene sheets. • The G/VO x films exhibited multi-lamellar textures with planar VO x nanowire arrays. • The G/VO x films showed the thermo-sensitive electrical switching properties. • Effects of GOs on the electrical characteristics of the G/VO x films were discussed.

  3. Structure and composition of zirconium carbide thin-film grown by ion beam sputtering for optical applications

    Science.gov (United States)

    Singh, Amol; Modi, Mohammed H.; Dhawan, Rajnish; Lodha, G. S.

    2014-04-01

    Thin film of compound material ZrC was deposited on Si (100) wafer using ion beam sputtering method. The deposition was carried out at room temperature and at base pressure of 3×10-5 Pa. X-ray photoelectron spectroscopy (XPS) measurements were performed for determining the surface chemical compositions. Grazing incidence x-ray reflectivity (GIXRR) measurements were performed to study the film thickness, roughness and density. From GIXRR curve roughness value of the film was found less than 1 nm indicating smooth surface morphology. Films density was found 6.51 g/cm3, which is close to bulk density. Atomic force microscopy (AFM) measurements were performed to check the surface morphology. AFM investigation showed that the film surface is smooth, which corroborate the GIXRR data. Figure 2 of the original article PDF file, as supplied to AIP Publishing, contained a PDF processing error. This article was updated on 12 May 2014 to correct that error.

  4. Conductive films of silver nanoparticles as novel susceptors for induction welding of thermoplastic composites

    Science.gov (United States)

    Dermanaki Farahani, Rouhollah; Janier, Mathieu; Dubé, Martine

    2018-03-01

    In the present work, a conductive film of silver nanoparticles (nAg) as a novel heating element type, called susceptor, was developed and tested for induction welding of carbon fiber/polyphenylene sulfide (CF/PPS) thermoplastic composites, i.e., unidirectional pre-impregnated 16 plies of CF/PPS compression-molded in a quasi-isotropic stacking sequence. The nAg were synthesized, dispersed in deionized (DI) water and casted onto a pure PPS film, resulting in a conductive film upon the evaporation of DI water and thermal post-annealing. The thermal annealing at 250 °C significantly (by 7 orders) decreased the film’s electrical resistivity from 9.4 × 103 down to 3.1 × 10‑4 Ω cm. The new susceptors led to fast heating rates in induction welding when compared to the standard stainless steel mesh susceptors under similar welding conditions. Lap shear mechanical testing revealed that the apparent lap shear strength (LSS) is sensitive to the susceptors’ resistivity and the input current. A relatively high LSS value was achieved for the specimens welded using the new susceptors which exceeded the value of those welded using stainless steel mesh susceptors (28.3 MPa compared to 20 MPa). The weld interface and specimens’ cross-section observation revealed that the nAg were dispersed and embedded into the resin upon welding. This study contains preliminary results that show high potential of nanoparticles as effective susceptors to further improve the mechanical performance of the joints in welding of thermoplastic composites.

  5. High-energy helium backscattering for the compositional analysis of thin-film oxide-superconductors

    International Nuclear Information System (INIS)

    Hubbard, K.M.; Martin, J.A.; Muenchausen, R.E.; Tesmer, J.R.; Nastasi, M.

    1989-01-01

    Recent experiments have demonstrated that the broad elastic-scattering resonance for 8.8 MeV helium bombardment of oxygen can be exploited to measure the oxygen content of YBaCuO thin films. A potential difficulty with such measurements is distortion of the backscattering spectrum due to resonant scattering from the substrate elements, which could prevent the accurate integration of peak areas. We have measured the elastic scattering cross sections for Sr and Ti, relative to Gd, with He ions in the energy range of 2.2--8.8 MeV, and a scattering angle of 166 degree. The results verify that resonant scattering from the substrate does not interfere with the high-energy compositional analysis of YBaCuO films deposited on SrTiO 3 . Scattering cross sections for Ca, measured relative to Ba, have also been determined for application to the analysis of BiSrCaCuO and TlCaBaCuO films. Because of resonant scattering from Ca at beam energies above 6 MeV, two backscattering measurements are required for these materials: one at 8.8 MeV to determine the O content, and one at or below 6 MeV to determine the Ca content. Anticipating a more general applicability of this technique to the analysis of metal-oxide films, data are also presented for a number of elements, as an empirical guideline, which give the beam energies above which scattering cross sections deviate from their Rutherford values, and must be determined experimentally. 10 refs., 6 figs., 4 tabs

  6. Film

    OpenAIRE

    Jones, Sarah

    2002-01-01

    This book looks at the movie industry and at the labour intensive but fascinating process of making a feature film. It examines each stage in the production of a film, from initial idea through to the final cut and screening, and highlights the main activities that take place along the way. The book not only looks at the work of prominent people in the film world, such as directors and actors, but also describes the equally important but less high profile contributions of the gaffer, best boy...

  7. Photovoltaic Properties of Selenized CuGa/In Films with Varied Compositions

    Energy Technology Data Exchange (ETDEWEB)

    Muzzillo, Christopher P.; Mansfield, Lorelle M.; Ramanathan, Kannan; McGoffin, J. Tyler; Anderson, Timothy J.

    2016-11-21

    Thin CuGa/In films with varied compositions were deposited by co-evaporation and then selenized in situ with evaporated selenium. The selenized Cu(In, Ga)Se2 absorbers were used to fabricate 390 solar cells. Cu/(Ga+In) and Ga/(Ga+In) (Cu/III and Ga/III) were independently varied, and photovoltaic performance was optimal at Cu/III of 77-92% for all Ga/III compositions studied (Ga/III ~ 30, 50, and 70%). The best absorbers at each Ga/III composition were characterized with time-resolved photoluminescence, scanning electron microscopy, and secondary ion mass spectrometry, and devices were studied with temperature-dependent current density-voltage, light and electrical biased quantum efficiency, and capacitance-voltage. The best cells with Ga/III ~ 30, 50, and 70% had efficiencies of 14.5, 14.4, and 12.2% and maximum power temperature coefficients of -0.496, -0.452, and -0.413%/degrees C, respectively. This resulted in the Ga/III ~ 50% champion having the highest efficiency at temperatures greater than 40 degrees C, making it the optimal composition for practical purposes. This optimum is understood as a result of the absorber's band gap grading- where minimum band gap dominates short-circuit current density, maximum space charge region band gap dominates open-circuit voltage, and average absorber band gap dominates maximum power temperature coefficient.

  8. Preparation of graphene-enhanced nickel-phosphorus composite films by ultrasonic-assisted electroless plating

    Science.gov (United States)

    Yu, Qian; Zhou, Tianfeng; Jiang, Yonggang; Yan, Xing; An, Zhonglie; Wang, Xibin; Zhang, Deyuan; Ono, Takahito

    2018-03-01

    To improve the mechanical properties of nickel-phosphorus (Ni-P) mold material for glass molding, an ultrasonic-assisted electroless plating method is proposed for the synthesis of graphene-enhanced nickel-phosphorus (G-Ni-P) composite films on heat-resistant stainless steel (06Cr25Ni20). Graphene flakes are prepared by an electrochemical exfoliation method. The surface roughness of the as-plated G-Ni-P composite plating is Ra 2.84 μm, which is higher than that of the Ni-P plating deposited using the same method. After annealing at 400 ºC for 2 h, the main phase of the G-Ni-P composite is transformed to crystalline Ni3P with an average grain size of 32.8 nm. The Vickers hardness and Young's modulus of the G-Ni-P composite are increased by 8.0% and 8.2% compared with the values of Ni-P, respectively. The detailed plating process is of great significance for the fabrication of G-Ni-P mold materials with enhanced mechanical properties.

  9. Electrical and mechanical behavior of PMN-PT/CNT based polymer composite film for energy harvesting

    Science.gov (United States)

    Das, Satyabati; Biswal, Asutya Kumar; Parida, Kalpana; Choudhary, R. N. P.; Roy, Amritendu

    2018-01-01

    The pyrochlore-free 30-PMN-PT/CNT/PVDF based piezoelectric flexible composite film has been synthesized for potential application in piezoelectric energy harvesting. Electrical characterization reveals that the maximum output voltage and current generated by the 30 vol.% PMN-PT/CNT/PVDF composite is ∼4 V and 30 nA respectively, comparable with the available literature. Further, impedance analysis has revealed a significant improvement in permittivity at low frequency and high temperature with a minimal dielectric loss. AC conductivity behavior fits well with Johnscher's universal power law that predicts the motion of the charge carriers is translational with sudden hopping. The Nyquist plots indicate the contributions of both grain and grain boundaries at lower temperature (25-100 °C) and additional electrode effect of higher temperature (100-150 °C) on the capacitive and resistive properties of the composite. Mechanical characterization of the composite shows an increase in Young's modulus of 705 MPa compared to 597 MPa in pure PVDF.

  10. Compositional effects on plasma-enhanced metalorganic chemical vapor deposition of YBa2Cu3O(7-x) thin films

    Science.gov (United States)

    Zhao, J.; Chern, C. S.; Li, Y. Q.; Norris, P.; Gallois, B.

    1991-06-01

    Epitaxial YBa2Cu3O(7-x) superconducting thin films with a zero resistance transition temperatures of about 90 K have been prepared, in situ, on LaAlO3 by a plasma-enhanced metalorganic chemical vapor deposition process at a substrate temperature of 670 C in 1 torr partial pressure of N2O. The composition of the films was varied systematically to investigate the effect of changes in the Ba/Y and Cu/Y ratio on the film properties. The results indicated that superconducting current densities exceeding 10 to the 6th A/sq cm, measured at 77 K by a transport method, could be obtained on films with an anomalously wide range of film compositions. Excess Cu (up to 60 percent and deficiency in Ba (down to 30 percent) from their stoichiometric values did not significantly degrade the superconducting properties of the films. As the composition approached the Y-Ba-Cu ratio of 1-2-3, an improvement in surface morphology and a decrease in superconducting transition temperature were found.

  11. Poly(ethylene glycol)/carbon quantum dot composite solid films exhibiting intense and tunable blue–red emission

    International Nuclear Information System (INIS)

    Hao, Yanling; Gan, Zhixing; Xu, Jiaqing; Wu, Xinglong; Chu, Paul K.

    2014-01-01

    Highlights: • Poly(ethylene glycol)/carbon quantum dots (PEG/CQDs) composite solid films exhibiting strong and tunable blue–red emission were prepared. Successful preparation of tunable emitting CQDs solid films can extend the application of carbon quantum dots in photoelectric devices. • The mechanism of the tunable emission from the PEG/CQDs composite solid films was discussed. • On the basis of the characteristics of the PL from solid films in this work, the complex PL origins of CQDs were further defined. The PL mechanism provides insights into the fluorescence mechanism of CQDs and may promotes their applications. • Poly(ethylene glycol); carbon quantum dots; Strong and tunable blue-red emission; The fluorescent quantum yield of 12.6%. - Abstract: Although carbon quantum dots (CQDs) possess excellent luminescence properties, it is a challenge to apply water-soluble CQDs to tunable luminescent devices. Herein, quaternary CQDs are incorporated into poly(ethylene glycol) to produce poly(ethylene glycol)/CQD composite solid films which exhibit strong and tunable blue–red emission. The fluorescent quantum yield reaches 12.6% which is comparable to that of many liquid CQDs and the photoluminescence characteristics are determined to elucidate the fluorescence mechanism. The CQD solid films with tunable optical properties bode well for photoelectric devices especially displays

  12. Fluoropolymer/SiO2 composite films with switchable superoleophilicity and high oleophobicity for “on–off” oil permeation

    International Nuclear Information System (INIS)

    Yang, Hao; Hu, Xiaojing; Chen, Rong; Liu, Shantang; Pi, Pihui; Yang, Zhuo-ru

    2013-01-01

    In this work, fluoropolymer/SiO 2 composite films with switchable superoleophilicity and high oleophobicity have been successfully prepared on stainless steel mesh. Tunable wettability could be easily realized by merely reversing the feeding order of the perfluorinated monomer in the polymerization. The effects of surface roughness and chemical composition on the wettability of the films were investigated by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The results indicate that the distribution of low surface energy groups plays a crucial role in determining the surface oleophobicity or oleophilicity. The porous stainless steel mesh with fluoropolymer/SiO 2 composite could construct dual-scale roughness, leading to less wetting of the solid. The stainless steel mesh coated with the proposed as-prepared polymer films may lead to an oil–water separation membrane. This work provides an interesting insight into the design of novel functional devices that are relevant to oil/water separation.

  13. The enhanced piezoelectricity in compositionally graded ferroelectric thin films under electric field: A role of flexoelectric effect

    Science.gov (United States)

    Qiu, Ye; Wu, Huaping; Wang, Jie; Lou, Jia; Zhang, Zheng; Liu, Aiping; Chai, Guozhong

    2018-02-01

    Compositionally graded ferroelectric thin films are found to produce large strain gradients, which can be used to tune the physical properties of materials through the flexoelectric effect, i.e., the coupling of polarization and the strain gradient. The influences of the flexoelectric effect on the polarization distribution and the piezoelectric properties in compositionally graded Ba1-xSrxTiO3 ferroelectric thin films are investigated by using an extended thermodynamic theory. The calculation results show that the presence of the flexoelectric effect tends to enhance and stabilize polarization components. The polarization rotation induced by the flexoelectric field has been predicted, which is accompanied by more uniform and orderly polarization components. A remarkable enhancement of piezoelectricity is obtained when the flexoelectric field is considered, suggesting that compositionally graded Ba1-xSrxTiO3 ferroelectric thin films with a large strain gradient are promising candidates for piezoelectric devices.

  14. Effect of organic additives on silver release from nanosilver-polyethylene composite films to acidic food simulant.

    Science.gov (United States)

    Su, Qi-Zhi; Lin, Qin-Bao; Chen, Chao-Fang; Wu, Li-Bing; Wang, Zhi-Wei

    2017-08-01

    The effects of organic additives (Irgafos 168, Irganox 1076, Tinuvin 622, Chimassorb 944, UV-P, and UV-531) on silver release from nanosilver-polyethylene composite films into an acidic food simulant (3% acetic acid) were investigated using inductively coupled plasma mass spectrometry. The limits of detection and quantification, coefficient of determination, and recoveries of the method used were 3.7ngL -1 , 12.4ngL -1 , 0.999, and 89-113%, respectively. The results indicated that additives can affect silver release via two simultaneous processes: (i) reactions between organic additives and silver that promote silver release from the composite film to the acidic food simulant; and (ii) the promotion or inhibition of silver release by affecting silver oxidation. High temperature and humidity treatment of the composite films was found to significantly increase silver release by promoting silver oxidation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Film

    OpenAIRE

    Bould, M.

    2014-01-01

    A critical overview of critical-theoretical understandings of sf film, especially those promulgated by critics devoted to sf as a prose fiction form. It also considers adaptation, spectacle and special effects.

  16. Preparation of TiO2-based nanotubes/nanoparticles composite thin film electrodes for their electron transport properties

    International Nuclear Information System (INIS)

    Zhao, Wanyu; Fu, Wuyou; Chen, Jingkuo; Li, Huayang; Bala, Hari; Wang, Xiaodong; Sun, Guang; Cao, Jianliang; Zhang, Zhanying

    2015-01-01

    The composite thin film electrodes were prepared with one-dimensional (1D) TiO 2 -B nanotubes (NTs) and zero-dimensional TiO 2 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 TiO 2 NPs electrodes by rational tuning the weight ratio of TiO 2 -B NTs and TiO 2 NPs. When the weight ratio of TiO 2 -B NTs in the NTs/NPs composite thin film electrodes increased, the density of states and recombination rate decreased. The 1D structure of TiO 2 -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 TiO 2 -B NTs and the high surface area of TiO 2 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

  17. Spectroscopic Study of the Surface Oxidation of Mechanically Activated Sulphides

    Czech Academy of Sciences Publication Activity Database

    Godočíková, E.; Baláž, P.; Bastl, Zdeněk; Brabec, Libor

    2002-01-01

    Roč. 200, č. 1 (2002), s. 36-47 ISSN 0169-4332 Institutional research plan: CEZ:AV0Z4040901 Keywords : mechanical activation * surface oxidation * sulphide minerals Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.295, year: 2002

  18. Fungal-Transformation of Surrogate Sulphides and Carbonaceous ...

    African Journals Online (AJOL)

    In the recovery of gold from refractory gold ores, pretreatment is required to decompose sulphides and liberate occluded gold before cyanidation, and to deactivate carbonaceous matter and prevent it from adsorbing dissolved gold. Until the past three decades, most commercial pretreatment processes had been by abiotic ...

  19. Pengaruh Penggunaan Konsentrasi Amonium Sulphide pada Pewarnaan Kerajinan Logam Perak

    Directory of Open Access Journals (Sweden)

    Dwi Suheryanto

    2016-04-01

    Full Text Available Proses pewarnaan kerajinan logam perak dengan amonium sulphide dapat memberikan hasil yang memberi kesan dekoratif dan menarik, karena proses tersebut merupakan hasil reaksi antara zat tersebut dengan logam perak sebagai benda kerja.Proses pewarnaan logam perak menggunakan variasi konsentrasi ammonium sulphide 100 cc, 125 cc, dan 125 cc per 850 cc air dengan variasi waktu 5 menit; 7,5 menit; dan 10 menit. Logam perak yang digunakan perak 925 ukuran 2 x 3 cm berat 25 gram, dan teknik yang digunakan dengan cara merendam benda kerja pada larutan ammonium sulphide pada suhu 50o C.Hasil pengujian terhadap ketahanan atau perubahan warna dan ketuaan warna menunjukkan bahwa proses pewarnaan logam perak 925 pada temperatur 50o C, dengan konsentrasi 125 cc dengan waktu 7,5 menit memberikan hasil ketuaan dan ketahanan warna yang baik dengan nilai rata – rata 1 dan menimbulkan warna hitam keabu – abuan dengan nilai rata – rata 1 – 2. Kata kunci : ammonium sulphide, perak, pewarnaan

  20. 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.

  1. Phase transition of iron sulphide minerals under hydrothermal conditions

    Science.gov (United States)

    Chen, Y. H.; Li, S. H.; Lee, J. J.; Sheu, H. S.

    2017-12-01

    Iron sulphide minerals have been used in industrial applications for many years, and more recently, there has been increasing interest in the use of iron sulphide nanomaterials because of their useful properties and low cost. Previous studies have mainly focused on the synthesis of iron sulphides, but their phase transition and micro-magnetic properties are still unclear. In this study, iron sulphide minerals were synthesized via a hydrothermal method and their phase transition mechanisms and magnetic properties were investigated. Ex situ and in situ X-ray diffraction results of the iron-sulphur system under hydrothermal conditions suggested that the transformation sequence followed the order of mackinawite (FeS) → greigite (Fe3S4) → smythite (Fe9S11) → pyrrhotite (Fe9S10). Pure greigite and pyrrhotite were obtained during the synthesis processes, after 1 h at 120°C and 160°C, respectively. Greigite showed a granular morphology with particle diameters around 30 nm, and pyrrhotite was comprised of stacked hexagonal sheets with thousands of nanometers in width. Pyrrhotite showed anti-ferromagnetic behavior; however, it did not saturate up to magnetic field of 7 T. Greigite was ferrimagnetic, with a high saturation magnetization of 62.7 Am2kg-1 and coercive magnetic field of 27.6 mT. Magnetic force microscope measurements of greigite revealed that its magnetic structure belonged to a spin canted single domain. Overall, this study provides new information on the phase transition mechanism, related reaction formulas, and magnetic properties of iron sulphides, and it emphasizes the important role played by temperature/time in phase transitions.

  2. Friction characteristics of Cd-rich carbonate films on calcite surfaces: implications for compositional differentiation at the nanometer scale

    Directory of Open Access Journals (Sweden)

    Cubillas Pablo

    2009-06-01

    Full Text Available Abstract Lateral Force Microscopy (LFM studies were carried out on cleaved calcite sections in contact with solutions supersaturated with respect to otavite (CdCO3 or calcite-otavite solid solutions (SS as a means to examine the potential for future application of LFM as a nanometer-scale mineral surface composition mapping technique. Layer-by-layer growth of surface films took place either by step advancement or by a surface nucleation and step advancement mechanisms. Friction vs. applied load data acquired on the films and the calcite substrate were successfully fitted to the Johnson Kendall Roberts (JKR model for single asperity contacts. Following this model, friction differences between film and substrate at low loads were dictated by differences in adhesion, whereas at higher load they reflect differences in contact shear strength. In most experiments at fixed load, the film showed higher friction than the calcite surface, but the friction-load dependence for the different surfaces revealed that at low loads (0–40 nN, a calcian otavite film has lower friction than calcite; a result that is contrary to earlier LFM reports of the same system. Multilayer films of calcian-otavite displayed increasing friction with film thickness, consistent with the expectation that the film surface composition will become increasingly Cd-rich with increasing thickness. Both load- and thickness-dependence trends support the hypothesis that the contact shear strength correlates with the hydration enthalpy of the surface ions, thereby imparting friction sensitivity in the LFM to mineral-water interface composition.

  3. Multilayered ordered mesoporous platinum/titania composite films: does the photocatalytic activity benefit from the film thickness?

    Czech Academy of Sciences Publication Activity Database

    Ismail, A. A.; Bahnemann, D.; Rathouský, Jiří; Yarovyi, V.; Wark, M.

    2011-01-01

    Roč. 21, č. 21 (2011), s. 7802-7810 ISSN 0959-9428 Institutional research plan: CEZ:AV0Z40400503 Keywords : titanium dioxide films * TiO2 thin films * sol-gel method Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 5.968, year: 2011

  4. Photoelectrochemical properties of ZnO nanocrystals/MEH-PPV composite: The effects of nanocrystals synthetic route, film deposition and electrolyte composition

    Energy Technology Data Exchange (ETDEWEB)

    Petrella, A. [Dipartimento di Ingegneria Civile, Ambientale, del Territorio, Edile e Chimica, Politecnico di Bari, Via Orabona 4, 70125 Bari (Italy); Curri, M.L.; Striccoli, M. [CNR IPCF Sez. Bari c/o Dip. Chimica, Università di Bari, Via Orabona 4, 70126 Bari (Italy); Agostiano, A. [Dipartimento di Chimica, Università di Bari, via Orabona 4, 70126 Bari (Italy); CNR IPCF Sez. Bari c/o Dip. Chimica, Università di Bari, Via Orabona 4, 70126 Bari (Italy); Cosma, P., E-mail: pinalysa.cosma@uniba.it [Dipartimento di Chimica, Università di Bari, via Orabona 4, 70126 Bari (Italy); CNR IPCF Sez. Bari c/o Dip. Chimica, Università di Bari, Via Orabona 4, 70126 Bari (Italy)

    2015-11-30

    This paper reports a study on the photoelectrochemical processes occurring at the interface of ZnO nanocrystals/MEH-PPV composites. Colloidal chemical routes were used to obtain size controlled non-hydrolytic ZnO nanocrystals (NCs) dispersible in organic solvents, while a low molecular weight poly[2-methoxy-5-(2′-ethyl-hexyloxy)phenylene vinylene] (MEH-PPV), characterized by high degree of structural order, was synthesized via an organometallic method. The optical properties of the nanocomposite material were comprehensively investigated on solution and on films deposited by spin coating. Remarkably, a significant fluorescence quenching of the polymer at the MEH-PPV/ZnO junction was observed. Photoelectrochemical measurements demonstrated that the photoactivity of the composite material was significantly improved in the case of non-hydrolytic NCs with respect to hydrolytic route prepared ZnO. Moreover, the effective role of the organic/inorganic blend to improve the charge transfer with respect to the double layer hetero-junction was confirmed, thanks to the extended interfaces which enable an effective electron transfer between the hetero-junction components. The system was also studied at different film thicknesses and electrolyte compositions. The results indicated that film photoactivity increased with film thickness up to 300 nm due to the presence of a large number of interfaces, while the change of cation size influenced the ionic conductivity through the nanocomposite film. It was shown that efficient photoconductivity requires not only efficient charge separation, but also efficient transport of the carriers to the electrodes without recombination. - Highlights: • The photoelectrochemical processes at ZnO nanocrystals/MEH-PPV hetero-junction were studied. • Fluorescence quenching of the polymer at the MEH-PPV/ZnO interface was observed. • Non-hydrolytic ZnO junction showed higher photocurrents than hydrolytic equivalent. • The blends showed

  5. Thermochromic Oxide-Based Thin Films and Nanoparticle Composites for Energy-Efficient Glazings

    Directory of Open Access Journals (Sweden)

    Claes G. Granqvist

    2016-12-01

    Full Text Available Today’s advances in materials science and technology can lead to better buildings with improved energy efficiency and indoor conditions. Particular attention should be directed towards windows and glass facades—jointly known as “glazings”—since current practices often lead to huge energy expenditures related to excessive inflow or outflow of energy which need to be balanced by energy-intensive cooling or heating. This review article outlines recent progress in thermochromics, i.e., it deals with materials whose optical properties are strongly dependent on temperature. In particular, we discuss oxide-based thin surface coatings (thin films and nanoparticle composites which can be deposited onto glass and are able to regulate the throughput of solar energy while the luminous (visible properties remain more or less unaltered. Another implementation embodies lamination materials incorporating thermochromic (TC nanoparticles. The thin films and nanocomposites are based on vanadium dioxide (VO2, which is able to change its properties within a narrow temperature range in the vicinity of room temperature and either reflects or absorbs infrared light at elevated temperatures, whereas the reflectance or absorptance is much smaller at lower temperatures. The review outlines the state of the art for these thin films and nanocomposites with particular attention to recent developments that have taken place in laboratories worldwide. Specifically, we first set the scene by discussing environmental challenges and their relationship with TC glazings. Then enters VO2 and we present its key properties in thin-film form and as nanoparticles. The next part of the article gives perspectives on the manufacturing of these films and particles. We point out that the properties of pure VO2 may not be fully adequate for buildings and we elaborate how additives, antireflection layers, nanostructuring and protective over-coatings can be employed to yield improved

  6. Analysis of Zinc Sulphide (ZnS) and Cadmium Sulphide (CdS) thin ...

    African Journals Online (AJOL)

    Absorbance (A) spectra data were measured by a single beam spectrophotometer at wavelength range 200nm to 900nm. Other optical and solid state properties were calculated using the data and compared with other deposited thin films. Average optical and solid state properties of ZnS thin films include absorbance ...

  7. Composition and crystalline properties of TiNi thin films prepared by pulsed laser deposition under vacuum and in ambient Ar gas.

    Science.gov (United States)

    Cha, Jeong Ok; Nam, Tae Hyun; Alghusun, Mohammad; Ahn, Jeung Sun

    2012-01-05

    TiNi shape memory alloy thin films were deposited using the pulsed laser deposition under vacuum and in an ambient Ar gas. Our main purpose is to investigate the influences of ambient Ar gas on the composition and the crystallization temperature of TiNi thin films. The deposited films were characterized by energy-dispersive X-ray spectrometry, a surface profiler, and X-ray diffraction at room temperature. In the case of TiNi thin films deposited in an ambient Ar gas, the compositions of the films were found to be very close to the composition of target when the substrate was placed at the shock front. The in-situ crystallization temperature (ca. 400°C) of the TiNi film prepared at the shock front in an ambient Ar gas was found to be lowered by ca. 100°C in comparison with that of a TiNi film prepared under vacuum.

  8. Detection of Carbon Monoxide Using Polymer-Composite Films with a Porphyrin-Functionalized Polypyrrole

    Science.gov (United States)

    Homer, Margie L.; Ryan, Margaret A.; Yen, Shiao-Ping S.; Lara, Liana M.; Shevade, Abhijit V.; Kisor, Adam

    2012-01-01

    Post-fire air constituents that are of interest to NASA include CO and some acid gases (HCl and HCN). CO is an important analyte to be able to sense in human habitats since it is a marker for both prefire detection and post-fire cleanup. The need exists for a sensor that can be incorporated into an existing sensing array architecture. The CO sensor needs to be a low-power chemiresistor that operates at room temperature; the sensor fabrication techniques must be compatible with ceramic substrates. Early work on the JPL ElectronicNose indicated that some of the existing polymer-carbon black sensors might be suitable. In addition, the CO sensor based on polypyrrole functionalized with iron porphyrin was demonstrated to be a promising sensor that could meet the requirements. First, pyrrole was polymerized in a ferric chloride/iron porphyrin solution in methanol. The iron porphyrin is 5, 10, 15, 20-tetraphenyl-21H, 23Hporphine iron (III) chloride. This creates a polypyrrole that is functionalized with the porphyrin. After synthesis, the polymer is dried in an oven. Sensors were made from the functionalized polypyrrole by binding it with a small amount of polyethylene oxide (600 MW). This composite made films that were too resistive to be measured in the device. Subsequently, carbon black was added to the composite to bring the sensing film resistivity within a measurable range. A suspension was created in methanol using the functionalized polypyrrole (90% by weight), polyethylene oxide (600,000 MW, 5% by weight), and carbon black (5% by weight). The sensing films were then deposited, like the polymer-carbon black sensors. After deposition, the substrates were dried in a vacuum oven for four hours at 60 C. These sensors showed good response to CO at concentrations over 100 ppm. While the sensor is based on a functionalized pyrrole, the actual composite is more robust and flexible. A polymer binder was added to help keep the sensor material from delaminating from the

  9. 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.

  10. In-situ fabrication of cobalt oxide / sulphide mixed phase nanoparticles in Polyphenylenesulphide matrix

    Directory of Open Access Journals (Sweden)

    Narendra Rumale

    2013-03-01

    Full Text Available A novel approach for the in-situ fabrication of combined cobalt oxide / sulphide nanoparticles in sulphur containing polymer polyphenylenesulphide (PPS by polymer inorganic solid-solid reaction technique is reported here. At present, there is considerable interest in polymer-metal chalcogenides / oxides based nano-composites on account of their optical, magnetic, electronic and catalytic properties. We have demonstrated the suitability of solid-solid reaction methodology by reacting commonly available cobalt precursors with engineering thermoplastic PPS. The cobalt precursor was reacted with PPS in 1:1, 1:5, 1:10, and 1:15 molar ratios, respectively, by heating the mixture at the melting temperature of the polymer (285 ºC for six hours. The resultant products were characterized by X-ray diffractometry (XRD, Field-emission scanning electron microscopy (FESEM, Thermogravimetric analysis (TGA, Differential scanning calorimetry (DSC, Diffuse reflectance spectroscopy (DRS techniques and High resolution transmission electron microscope (HRTEM. The shift in melting temperature of PPS was observed. Increase in absorption peak is observed in the range of 320 to 370 nm with the increase in PPS concentration. Resultant nanoparticles of cobalt sulphide and cobalt oxide embedded in the PPS matrix showed spherical and distorted rod like morphology.

  11. Layer-by-layer composite film of nickel phthalocyanine and montmorillonite clay for synergistic effect on electrochemical detection of dopamine

    Science.gov (United States)

    de Lucena, Nathalia C.; Miyazaki, Celina M.; Shimizu, Flávio M.; Constantino, Carlos J. L.; Ferreira, Marystela

    2018-04-01

    Dopamine (DA) abnormal levels are related to diseases which makes important the development of fast, reliable, low-cost and sensitive devices for diagnosis and pharmaceutical controls. Nanostructured film composite of sodium montmorillonite clay (Na+MMT) and nickel phthalocyanine (NiTsPc) was self-assembled by layer-by-layer (LbL) technique and applied as electrochemical sensor for DA in the presence of common natural interferents as ascorbic acid (AA) and uric acid (UA). Three different LbL architecture films were investigated: LbL films of clay (PEI/Na+MMT) and phthalocyanine (PEI/NiTsPc) in a bilayer structure with a conventional polyelectrolyte (PEI) and a composite film formed by both materials to verify the synergistic effect in the LbL film in a quadri-layer assembly (PEI/Na+MMT/PEI/NiTsPc). Structural characterization indicated molecular level interactions between the layers forming the LbL films. The ITO/(PEI/Na+MMT/PEI/NiTsPc)10 electrode exhibited a LOD of 1.0 μmol L-1 and linear range 5-150 μmol L-1.

  12. New fabrication technique of conductive polymer/insulating polymer composite films and evaluation of biocompatibility in neuron cultures

    International Nuclear Information System (INIS)

    Onoda, Mitsuyoshi; Abe, Yayoi; Tada, Kazuya

    2009-01-01

    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.

  13. New fabrication technique of conductive polymer/insulating polymer composite films and evaluation of biocompatibility in neuron cultures

    Energy Technology Data Exchange (ETDEWEB)

    Onoda, Mitsuyoshi, E-mail: onoda@eng.u-hyogo.ac.j [Department of Electrical Engineering and Computer Sciences, Graduate School of Engineering, University of Hyogo, Himwji Shosha Campus, 2167 Shosha, Himeji, Hyogo 671-2280 (Japan); Abe, Yayoi; Tada, Kazuya [Department of Electrical Engineering and Computer Sciences, Graduate School of Engineering, University of Hyogo, Himwji Shosha Campus, 2167 Shosha, Himeji, Hyogo 671-2280 (Japan)

    2009-11-30

    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.

  14. Near-infrared spectroscopy for the determination of testosterone in thin-film composites.

    Science.gov (United States)

    Fountain, William; Dumstorf, Karen; Lowell, Amanda E; Lodder, Robert A; Mumper, Russell J

    2003-09-19

    More rapid, reproducible, and cost-effective methods to control product quality in the pharmaceutical industry continue to be a major emphasis, particularly with the FDA through its recent process analytical technologies (PAT) initiative. Many different methods have been used to determine the stability and content uniformity of a drug in various dosage forms; however, most of these methods include the destruction of the sample. Therefore, the development of nondestructive methods that allow the analysis of each individual dosage form has become the basis of much research. A new assay for the nondestructive determination of testosterone content in mucoadhesive bi-layer thin-film composites (TFCs) using near-infrared spectroscopy (NIR) was developed. Five sets of the circular films (n=5) with theoretical testosterone content of 0, 1, 2, 3, and 4 mg per 3/8th in. diameter disks were scanned in the near-infrared region of 1100-2500 nm to determine testosterone content. The NIR results were directly compared with those obtained using a previously developed ultraviolet assay for testosterone at 240 nm. Principal component regression (PCR) was performed to calibrate the NIR assay. This correlation produced r2=0.99 with a standard error of estimate (SEE)=0.18 mg, and a standard error of performance (SEP)=0.18 on cross validation with an equal number of samples (F test passed at P=0.05). Though the UV assay showed a slightly better r2 value, the NIR assay was much quicker, easier, and nondestructive. Therefore, the NIR assay may have significant potential for use in the quality control of pharmaceutical films containing drugs.

  15. Development of Chitosan/Bacterial Cellulose Composite Films Containing Nanodiamonds as a Potential Flexible Platform for Wound Dressing

    Directory of Open Access Journals (Sweden)

    Fatemeh Ostadhossein

    2015-09-01

    Full Text Available Chitosan/bacterial cellulose composite films containing diamond nanoparticles (NDs with potential application as wound dressing are introduced. Microstructural studies show that NDs are uniformly dispersed in the matrix, although slight agglomeration at concentrations above 2 wt % is seen. Fourier transform infrared spectroscopy reveals formation of hydrogen bonds between NDs and the polymer matrix. X-ray diffraction analysis indicates reduced crystallinity of the polymer matrix in the presence of NDs. Approximately 3.5-fold increase in the elastic modulus of the composite film is obtained by the addition of 2 wt % NDs. The results of colorimetric analysis show that the composite films are transparent but turn to gray-like and semitransparent at high ND concentrations. Additionally, a decrease in highest occupied molecular orbital (HOMO and lowest unoccupied molecular orbital (LUMO gap is also seen, which results in a red shift and higher absorption intensity towards the visible region. Mitochondrial activity assay using L929 fibroblast cells shows that the nanocomposite films are biocompatible (>90% after 24 h incubation. Multiple lamellapodia and cell-cell interaction are shown. The results suggest that the developed films can potentially be used as a flexible platform for wound dressing.

  16. A comparative study on electrochemical co-deposition and capacitance of composite films of conducting polymers and carbon nanotubes

    International Nuclear Information System (INIS)

    Peng Chuang; Jin Jun; Chen, George Z.

    2007-01-01

    Composite films of carbon nanotubes (CNTs) with polyaniline (PANI), polypyrrole (PPY) or poly[3,4-ethylenedioxythiophene] (PEDOT) were prepared via electrochemical co-deposition from solutions containing acid treated CNTs and the corresponding monomer. In the cases of PPY and PEDOT, CNTs served as the charge carriers during electro-deposition, and also acted as both the backbone of a three-dimensional micro- and nano-porous structure and the effective charge-balancing dopant within the polymer. All the composites showed improved mechanical integrity, higher electronic and ionic conductivity (even when the polymer was reduced), and exhibited larger electrode specific capacitance than the polymer alone. Under similar conditions, the capacitance was enhanced significantly in as-prepared PPY-CNT and PEDOT-CNT films. However, the fresh PANI-CNT film was electrochemically similar to PANI, but PPY-CNT and PEDOT-CNT differed noticeably from the respective polymers alone. In continuous potential cycling tests, unlike the pure polymer and other composite films, PANI-CNT performed much better in retaining the capacitance of the as-prepared film, and the possible cause is analysed

  17. Impact of the homogenization process on the structure and antioxidant properties of chitosan-lignin composite films.

    Science.gov (United States)

    Crouvisier-Urion, Kevin; Lagorce-Tachon, Aurélie; Lauquin, Camille; Winckler, Pascale; Tongdeesoontorn, Wirongrong; Domenek, Sandra; Debeaufort, Frédéric; Karbowiak, Thomas

    2017-12-01

    This work investigated the impact of two homogenization treatments, High Shear (HS) and High Pressure (HP), on the structure and antioxidant activity of chitosan-lignin bio-composite films. Laser light scattering analysis revealed that smaller lignin particles were obtained after HP processing, around 0.6μm, compared to HS treatment, between 2.5 and 5μm. Moreover, these particles were more homogeneously distributed in the chitosan film matrix after HP process, while some aggregates remained after HS treatment, as highlighted by two-photon microscopy. The surface hydrophobicity of the composite films, as measured by water contact angle, increased after the two homogenization treatments. Finally, the antioxidant activity of the composite films was determined using the DPPH· assay. No significant difference in the radical scavenging activity was noticeable, neither after HS nor HP processing. However, a migration of lignin residues from the film to the extraction medium was noticed, particularly for HP process. Copyright © 2017. Published by Elsevier Ltd.

  18. Interaction between sulphide and H 2O in silicate melts

    Science.gov (United States)

    Stelling, Jan; Behrens, Harald; Wilke, Max; Göttlicher, Jörg; Chalmin-Aljanabi, Emilie

    2011-06-01

    Reaction between dissolved water and sulphide was experimentally investigated in soda-lime-silicate (NCS) and sodium trisilicate (NS3) melts at temperatures from 1000 to 1200 °C and pressures of 100 or 200 MPa in internally heated gas pressure vessels. Diffusion couple experiments were conducted at water-undersaturated conditions with one half of the couple being doped with sulphide (added as FeS or Na 2S; 1500-2000 ppm S by weight) and the other with H 2O (˜3.0 wt.%). Additionally, two experiments were performed using a dry NCS glass cylinder and a free H 2O fluid. Here, the melt was water-saturated at least at the melt/fluid interface. Profiling by electron microprobe (sulphur) and infrared microscopy (H 2O) demonstrate that H 2O diffusion in the melts is faster by 1.5-2.3 orders of magnitude than sulphur diffusion and, hence, H 2O can be considered as a rapidly diffusing oxidant while sulphur is quasi immobile in these experiments. In Raman spectra a band at 2576 cm -1 appears in the sulphide - H 2O transition zone which is attributed to fundamental S-H stretching vibrations. Formation of new IR absorption bands at 5025 cm -1 (on expense of the combination band of molecular H 2O at 5225 cm -1) and at 3400 cm -1 was observed at the front of the in-diffusing water in the sulphide bearing melt. The appearance and intensity of these two IR bands is correlated with systematic changes in S K-edge XANES spectra. A pre-edge excitation at 2466.5 eV grows with increasing H 2O concentration while the sulphide peak at 2474.0 eV decreases in intensity relative to the peak at 2477.0 eV and the feature at 2472.3 eV becomes more pronounced (all energies are relative to the sulphate excitation, calibrated to 2482.5 eV). The observations by Raman, IR and XANES spectroscopy indicate a well coordinated S 2- - H 2O complex which was probably formed in the glasses during cooling at the glass transition. No oxidation of sulphide was observed in any of the diffusion couple

  19. The effect of film thickness and molecular structure on order and disorder in thin films of compositionally asymmetric block copolymers

    Science.gov (United States)

    Mishra, Vindhya

    Directed self-assembly of thin film block copolymers offer a high throughput-low cost route to produce next generation lithographic devices, if one can bring the defect densities in the self assembled patterns below tolerance limits. However, the ability to control the nanoscale structure or morphology in thin film block copolymers presents challenges due to confinement effects on equilibrium behavior. Using structure characterization techniques such as grazing incidence small angle X-ray scattering (GISAXS), transmission electron and atomic force microscopy as well as self-consistent field theory, we have investigated how film thickness, annealing temperature and block copolymer structure affects the equilibrium behavior of asymmetric block copolymer films. Our studies have revealed the complicated dependence of order-disorder transitions, order-order transitions and symmetry transitions on film thickness. We found that the thickness dependent transition in the packing symmetry of spherical morphology diblock copolymers can be suppressed by blending with a small amount of majority block homopolymer, which allowed us to resolve the driving force behind this transition. Defect densities in, and the order-disorder transition temperature of, thin films of graphoepitaxially aligned diblock copolymer cylinders showed surprising sensitivity to the microdomain spacing. Methods to mitigate defect formation in thin films have been identified. The challenge of quantification of structural order in these systems was overcome using GISAXS, which allowed us to study the phenomena of disordering in two and three dimensions. Through studies on block copolymers which exhibit an order-order transition in bulk, we found that that subtle differences in the packing frustration of the spherical and cylindrical phases as well as the higher configurational entropy of free chain ends at the surface can drive the equilibrium configuration in thin films away from the stable bulk structure

  20. Factors Affecting the Physical Properties of Edible Composite Film Prepared from Zein and Wheat Gluten

    Directory of Open Access Journals (Sweden)

    Yuxiang Ma

    2012-03-01

    Full Text Available The effects of zein ratio, concentration of glycerol, liquid-solid ratio, ethanol concentration, pH and heat-treatment temperature on the properties of zein/wheat gluten composite films were researched. The results showed that elongation (E increased with an increase in glycerol or ethanol concentrations, but it first increased and then decreased with increasing zein/wheat gluten ratio, heat-treatment temperature, pH and the ratio of liquid to solid; Tensile strength (TS increased with the increase in heat-treatment temperature and pH, and decreased with the increase in glycerol or ethanol concentrations, and it reached a maximum value when the ratio of zein/wheat gluten was 20%, but had a minimum value when the ratio of liquid to solid was 8:1; Water Vapor Permeability (WVP increased with an increase of glycerol concentration and the ratio of liquid to solid and ethanol concentration, but it decreased with increasing zein/wheat gluten ratio, heat treatment temperature, and pH of the film forming solution.

  1. Application of X-ray fluorescence (WDXRF): thickness and chemical composition determination of thin films

    International Nuclear Information System (INIS)

    Scapin, Valdirene de Oliveira.

    2004-01-01

    In this work a procedure is described for thickness and quantitative chemical composition of thin films by wavelength dispersion X-ray fluorescence (WDXRF) using Fundamental Parameters method. This method was validated according to quality assurance standard and applied sample Al, Cr, TiO2, Ni, ZrO2 (single thickness) and Ni/Cr (double thickness) on glass; Ni on steel and metallic zinc and TiO2 on metallic iron (single thickness), all the sample were prepared for physical deposition of vapor (PVD). The thickness had been compared with Absorption (FRX-A) and Rutherford Backscattering Spectrometry (RBS) methods; the result showed good efficiency of the fundamental parameters method. Sample structural characteristics analyzed by X ray diffraction (XRD) showed any influence in the thickness determinations. (author)

  2. X-ray fluorescence system for thin film composition analysis during deposition

    International Nuclear Information System (INIS)

    Formica, Sarah P.; Lee, Susanne M.

    2005-01-01

    A fast-response-time X-ray fluorescence (XRF) system was designed with a monolithic polycapillary focusing optic for in situ composition profiling during materials deposition. The polycapillary optic produced 10 5 times more intensity at the sample than a pinhole, allowing the detector placement to be outside most deposition chambers. The resultant XRF signals were so strong that measurement times were comparable to monolayer growth times. XRF line scans from Ge 1-x Sn x thin films were used to map Sn concentration versus surface position with a 10 μm resolution. The extrapolated instrumental detection limit using a 20 W Cu source was 10 12 atoms (ng). XRF from a 100-nm ion-implanted Ge 0.72 Sn 0.28 sample demonstrated the system's ability to monitor initial growth stages during deposition

  3. 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.

  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. Electrocatalysis of hemoglobin in ionic liquid BMIMPF6 and CuS nanosphere composite films

    Directory of Open Access Journals (Sweden)

    Wei Sun

    2011-12-01

    Full Text Available Ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate (BMIMPF6 was mixed homogeneously with nanometer-sized semiconductor CuS sphere to form a new nanocomposite material, which was further used for the immobilization of hemoglobin (Hb on the surface of carbon paste electrode (CPE. Direct electrochemistry of Hb in BMIMPF6-CuS composite film was carefully investigated with a pair of quasi-reversible redox peaks appeared and the formal potential (E0' was got as -135 mV (vs. SCE in pH 7.0 phosphate buffer solution, which was due to the enhanced direct electron transfer rate of Hb in the biocompatible matrix. The BMIMPF6-CuS-Hb/CPE showed excellent electrocatalytic activity to the reduction of hydrogen peroxide with the kinetic parameters for the electrocatalytic reaction evaluated. The results indicated that the BMIMPF6-CuS nanocomposite could be used for the preparation of electrochemical biosensor.

  6. The Stability of Magnetite and its Significance as a Passivating Film in the Repository Environment

    International Nuclear Information System (INIS)

    Hermansson, Hans-Peter

    2004-01-01

    A literature review was made in order to highlight if magnetite could be formed as a passivating film on iron in the expected repository environment. The possibility to form other types of passivating films has also been regarded, e.g. other iron oxides or mixed oxides of iron and copper and also sulfides. The conditions for the formation of different types of films have been discussed as well as their compositions and properties. It is concluded that magnetite could certainly be formed on iron at repository combinations of Eh and pH in the absence of sulphide and chloride. However, magnetite could easily be outnumbered by other solid phases that could be formed at the simultaneous presence of copper. CuFeO 2 is such a phase that could appear in a simple Fe-Cu-O-H system. As soon as sulphide and chloride are present other phases like CuFeS 2 could also be responsible for the passivation of iron. The probability that magnetite is the passivating film on cast iron at the actual conditions is therefore not very large. It is more likely that the passivating film instead consists of CuFeO 2 and/or CuFeS 2 , the latter depending on the concentration of sulphur in the system. The protective ability of the alternate compounds as passivating films could be discussed. A suggested ranking order of the protective ability is given in the discussion part. If magnetite is not stable, the integrity of the cast iron insert could therefore in such cases be dependent on the protection by less effective passivating substances. The hypothesis of the formation and nature of alternative passivating films should be tested at relevant conditions in laboratory experiments

  7. Reduction of bacterial adhesion on dental composite resins by silicon–oxygen thin film coatings

    International Nuclear Information System (INIS)

    Mandracci, Pietro; Pirri, Candido F; Mussano, Federico; Ceruti, Paola; Carossa, Stefano

    2015-01-01

    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. (paper)

  8. 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.

  9. 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

  10. Hydrogen evolution from a copper(I) oxide photocathode coated with an amorphous molybdenum sulphide catalyst

    Science.gov (United States)

    Morales-Guio, Carlos G.; Tilley, S. David; Vrubel, Heron; Grätzel, Michael; Hu, Xile

    2014-01-01

    Concerns over climate change resulting from accumulation of anthropogenic carbon dioxide in the atmosphere and the uncertainty in the amount of recoverable fossil fuel reserves are driving forces for the development of renewable, carbon-neutral energy technologies. A promising clean solution is photoelectrochemical water splitting to produce hydrogen using abundant solar energy. Here we present a simple and scalable technique for the deposition of amorphous molybdenum sulphide films as hydrogen evolution catalyst onto protected copper(I) oxide films. The efficient extraction of excited electrons by the conformal catalyst film leads to photocurrents of up to -5.7mAcm-2 at 0V versus the reversible hydrogen electrode (pH 1.0) under simulated AM 1.5 solar illumination. Furthermore, the photocathode exhibits enhanced stability under acidic environments, whereas photocathodes with platinum nanoparticles as catalyst deactivate more rapidly under identical conditions. The work demonstrates the potential of earth-abundant light-harvesting material and catalysts for solar hydrogen production.

  11. Aluminum-thin-film packaged fiber Bragg grating probes for monitoring the maximum tensile strain of composite materials.

    Science.gov (United States)

    Im, Jooeun; Kim, Mihyun; Choi, Ki-Sun; Hwang, Tae-Kyung; Kwon, Il-Bum

    2014-06-10

    In this paper, new fiber Bragg grating (FBG) sensor probes are designed to intermittently detect the maximum tensile strain of composite materials, so as to evaluate the structural health status. This probe is fabricated by two thin Al films bonded to an FBG optical fiber and two supporting brackets, which are fixed on the surface of composite materials. The residual strain of the Al packaged FBG sensor probe is induced by the strain of composite materials. This residual strain can indicate the maximum strain of composite materials. Two types of sensor probes are prepared-one is an FBG with 18 μm thick Al films, and the other is an FBG with 36 μm thick Al films-to compare the thickness effect on the detection sensitivity. These sensor probes are bonded on the surfaces of carbon fiber reinforced plastics composite specimens. In order to determine the strain sensitivity between the residual strain of the FBG sensor probe and the maximum strain of the composite specimen, tensile tests are performed by universal testing machine, under the loading-unloading test condition. The strain sensitivities of the probes, which have the Al thicknesses of 18 and 36 μm, are determined as 0.13 and 0.23, respectively.

  12. 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.

  13. Influence of Annealing on the Surface Morphologies and Elemental Compositions of Nanocrystalline Cu2SnSe3 Thin Films

    International Nuclear Information System (INIS)

    Mohd Amirul Syafiq Mohd Yunos; Mohd Amirul Syafiq Mohd Yunos; Zainal Abidin Talib; Wan Mahmood Mat Yunus

    2011-01-01

    Ternary compound of semiconductor nano crystals Copper Tin Selenide, Cu 2 SnSe 3 , 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 Cu 2 SnSe 3 thin films were close to the ideal stoichiometric value 2:1:3. (author)

  14. Localized deep levels in AlxGa1−xN epitaxial films with various Al compositions

    International Nuclear Information System (INIS)

    Shi Li-Yang; Shen Bo; Wang Ping; Yan Jian-Chang; Wang Jun-Xi

    2014-01-01

    By using high-temperature deep-level transient spectroscopy (HT-DLTS) and other electrical measurement techniques, localized deep levels in n-type Al x Ga 1−x N epitaxial films with various Al compositions (x = 0, 0.14, 0.24, 0.33, and 0.43) have been investigated. It is found that there are three distinct deep levels in Al x Ga 1−x N films, whose level position with respect to the conduction band increases as Al composition increases. The dominant defect level with the activation energy deeper than 1.0 eV below the conduction band closely follows the Fermi level stabilization energy, indicating that its origin may be related to the defect complex, including the anti-site defects and divacancies in Al x Ga 1−x N films. (condensed matter: structural, mechanical, and thermal properties)

  15. 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.

  16. Effect of antioxidants and light stabilisers on silver migration from nanosilver-polyethylene composite packaging films into food simulants.

    Science.gov (United States)

    Su, Qi-Zhi; Lin, Qin-Bao; Chen, Chao-Fang; Wu, Yu-Mei; Wu, Li-Bing; Chen, Xiao-Qing; Wang, Zhi-Wei

    2015-01-01

    The effect of exposure time, temperature and food simulants, especially additives, on the release of silver from nanosilver-polyethylene composite films to food simulants was studied. Two different type of nanosilver-polyethylene composite films (with or without additives) were chosen to conduct the experiment with the aim of exploring the behaviour of silver migration. It was shown that the migration of silver into 50% ethanol at 40 and 70°C was much less than that into 3% acetic acid. With the increase of exposure time and temperature, the release of silver increased. The migration even continued after a long exposure time (14 days at 20°C, 10 days at 40°C, and 6 days at 70°C respectively). Only about 0.15‰ of silver migrated from composite films with the additives into 3% acetic acid after 6 days of exposure at 70°C, while about 1.3% of silver migrated from composite films that did not contain additives under the same conditions. This could be because the addition of the antioxidants and light stabilisers prevents silver from being oxidised, which is an important way for the release of silver.

  17. The quest for highly sensitive QCM humidity sensors: the coating of CNT/MOF composite sensing films as case study

    KAUST Repository

    Chappanda, Karumbaiah. N.

    2017-11-01

    The application of metal-organic frameworks (MOFs) as a sensing layer has been attracting great interest over the last decade, due to their uniform properties in terms of high porosity and tunability, which provides a large surface area and/or centers for trapping/binding a targeted analyte. Here we report the fabrication of a highly sensitive humidity sensor that is based on composite thin films of HKUST-1 MOF and carbon nanotubes (CNT). The composite sensing films were fabricated by spin coating technique on a quartz-crystal microbalance (QCM) and a comparison of their shift in resonance frequencies to adsorbed water vapor (5 to 75% relative humidity) is presented. Through optimization of the CNT and HKUST-1 composition, we could demonstrate a 230% increase in sensitivity compared to plain HKUST-1 film. The optimized CNT-HKUST-1 composite thin films are stable, reliable, and have an average sensitivity of about 2.5×10−5 (Δf/f) per percent of relative humidity, which is up to ten times better than previously reported QCM-based humidity sensors. The approach presented here is facile and paves a promising path towards enhancing the sensitivity of MOF-based sensors.

  18. Effect of pH on the performance of polyamide/polyacrylonitrile based thin film composite membranes

    NARCIS (Netherlands)

    Dalwani, M.R.; Benes, Nieck Edwin; Bargeman, Gerrald; Stamatialis, Dimitrios; Wessling, Matthias

    2011-01-01

    In this study the effect of pH on the performance of thin film composite (TFC) nanofiltration (NF) membranes has been investigated at the relevant pH conditions, in the range of pH 1–13. TFC polyamide NF membranes have been fabricated on a polyacrylonitrile support via interfacial polymerization

  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. 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.

  1. Experience of using film-forming compositions for radiation situation improvement during initial period after the Chernobyl' accident

    International Nuclear Information System (INIS)

    Karataev, B.A.; Konstantinov, E.A.; Sorokin, N.M.; Finogenov, V.A.

    1989-01-01

    Film-formiing (FF) compositions were used for radioactive contamination localization, for decontaminating surfaces of rooms and equipment and for their prevention from secondary contamination after decontamination. The FF compounds were used also for isolating reinforced-concrete plates after their laying at the operating site of the Chernobyl' NPP

  2. 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.

  3. Flexible and Responsive Chiral Nematic Cellulose Nanocrystal/Poly(ethylene glycol) Composite Films with Uniform and Tunable Structural Color.

    Science.gov (United States)

    Yao, Kun; Meng, Qijun; Bulone, Vincent; Zhou, Qi

    2017-07-01

    The fabrication of responsive photonic structures from cellulose nanocrystals (CNCs) that can operate in the entire visible spectrum is challenging due to the requirements of precise periodic modulation of the pitch size of the self-assembled multilayer structures at the length scale within the wavelength of the visible light. The surface charge density of CNCs is an important factor in controlling the pitch size of the chiral nematic structure of the dried solid CNC films. The assembly of poly(ethylene glycol) (PEG) together with CNCs into smaller chiral nematic domains results in solid films with uniform helical structure upon slow drying. Large, flexible, and flat photonic composite films with uniform structure colors from blue to red are prepared by changing the composition of CNCs and PEG. The CNC/PEG(80/20) composite film demonstrates a reversible and smooth structural color change between green and transparent in response to an increase and decrease of relative humidity between 50% and 100% owing to the reversible swelling and dehydration of the chiral nematic structure. The composite also shows excellent mechanical and thermal properties, complementing the multifunctional property profile. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Influences of arc current on composition and properties of MgO thin films prepared by cathodic vacuum arc deposition

    International Nuclear Information System (INIS)

    Zhu Daoyun; Zheng Changxi; Wang Mingdong; Liu Yi; Chen Dihu; He Zhenhui; Wen Lishi; Cheung, W.Y.

    2010-01-01

    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.

  5. Preparation of multilayered nanocrystalline thin films with composition-modulated interfaces

    International Nuclear Information System (INIS)

    Biro, D.; Barna, P.B.; Szekely, L.; Geszti, O.; Hattori, T.; Devenyi, A.

    2008-01-01

    The properties of multilayer thin film structures depend on the morphology and structure of interfaces. A broad interface, in which the composition is varying, can enhance, e.g., the hardness of multilayer thin films. In the present experiments multilayers of TiAlN and CrN as well as TiAlN, CrN and MoS 2 were studied by using unbalanced magnetron sputter sources. The sputter sources were arranged side by side on an arc. This arrangement permits development of a transition zone between the layers, where the composition changes continuously. The multilayer system was deposited by one-fold oscillating movement of substrates in front of sputter sources. Thicknesses of layers could be changed both by oscillation frequency and by the power applied to sputter sources. Ti/Al: 50/50 at%, pure chromium and MoS 2 targets were used in the sputter sources. The depositions were performed in an Ar-N 2 mixture at 0.22 Pa working pressure. The sputtering power of the TiAl source was feed-back adjusted in fuzzy-logic mode in order to avoid fluctuation of the TiAl target sputter rate due to poisoning of the target surface. Structure characterization of films deposited on Si wafers covered by thermally grown SiO 2 was performed by cross-sectional transmission electron microscopy. At first a 100 nm thick Cr base layer was deposited on the substrate to improve adhesion, which was followed by a CrN transition layer. The CrN transition layer was followed by a 100 nm thick TiAlN/CrN multilayer system. The TiAlN/CrN/MoS 2 multilayer system was deposited on the surface of this underlayer system. The underlayer systems Cr, CrN and TiAlN/CrN were crystalline with columnar structure according to the morphology of zone T of the structure zone models. The column boundaries contained segregated phases showing up in the under-focused TEM images. The surface of the underlayer system was wavy due to dome-shaped columns. The nanometer-scaled TiAlN/CrN/MoS 2 multilayer system followed this waviness

  6. Stretchable conducting gold films prepared with composite MWNT/PDMS substrates

    Directory of Open Access Journals (Sweden)

    M. U. Manzoor

    2015-10-01

    Full Text Available 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.

  7. 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.

  8. 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.

  9. Composite structure of ZnO films coated with reduced graphene oxide: structural, electrical and electrochemical properties

    Science.gov (United States)

    Shuai, Weiqiang; Hu, Yuehui; Chen, Yichuan; Hu, Keyan; Zhang, Xiaohua; Zhu, Wenjun; Tong, Fan; Lao, Zixuan

    2018-02-01

    ZnO films coated with reduced graphene oxide (RGO-ZnO) were prepared by a simple chemical approach. The graphene oxide (GO) films transferred onto ZnO films by spin coating were reduced to RGO films by two steps (exposed to hydrazine vapor for 12 h and annealed at 600 °C). The crystal structures, electrical and photoluminescence properties of RGO-ZnO films on quartz substrates were systematically studied. The SEM images illustrated that RGO layers have successfully been coated on the ZnO films very tightly. The PL properties of RGO-ZnO were studied. PL spectra show two sharp peaks at 390 nm and a broad visible emission around 490 nm. The resistivity of RGO-ZnO films was measured by a Hall measurement system, RGO as nanofiller considerably decrease the resistivity of ZnO films. An electrode was fabricated, using RGO-ZnO films deposited on Si substrate as active materials, for super capacitor application. By comparison of different results, we conclude that the RGO-ZnO composite material couples possess the properties of super capacitor. Project supported by the National Natural Science Foundation of China (Nos. 61464005, 51562015), the Natural Science Foundation of Jiangxi Province (Nos. 20143ACB21004, 20151BAB212008, 20171BAB216015), the Jiangxi Province Foreign Cooperation Projects, China (No. 20151BDH80031), the Leader Training Object Project of Major Disciplines Academic and Technical of Jiangxi Province (No. 20123BCB22002), and the Key Technology R & D Program of the Jiangxi Provine of Science and Technology (No. 20171BBE50053).

  10. Switching and memory effects in composite films of semiconducting polymers with particles of graphene and graphene oxide

    Science.gov (United States)

    Krylov, P. S.; Berestennikov, A. S.; Aleshin, A. N.; Komolov, A. S.; Shcherbakov, I. P.; Petrov, V. N.; Trapeznikova, I. N.

    2015-08-01

    The effects of switching were investigated in composite films based on multifunctional polymers. i.e., derivatives of carbazole (PVK) and fluorene (PFD), as well as based on particles of graphene (Gr) and graphene oxide (GO). The concentration of Gr and GO particles in the PVK(PFD) matrix was varied in the range of 2-3 wt %, which corresponded to the percolation threshold in these systems. The atomic composition of the composite films PVK: GO was examined using X-ray photoelectron spectroscopy. It was found that the effect of switching in structures of the form Al/PVK(PFD): GO(Gr)/ITO/PET manifests itself in a sharp change of the electrical resistance of the composite film from a low-conducting state to a relatively high-conducting state when applying a bias to Al-ITO electrodes of ˜0.1-0.3 V ( E ˜ 3-5 × 104 V/cm), which is below the threshold switching voltages for similar composites. The mechanism of resistance switching, which is associated with the processes of capture and accumulation of charge carriers by Gr (GO) particles introduced into the matrices of the high-molecular-weight (PVK) and relatively low-molecular-weight (PFD) polymers, was discussed.

  11. Structural and electrical characterization of bamboo-shaped C-N nanotubes-poly ethylene oxide (PEO) composite films

    Energy Technology Data Exchange (ETDEWEB)

    Yadav, Ram Manohar, E-mail: rmanohar28@yahoo.co.in; Dobal, Pramod S. [VSSD College, Department of Physics (India)

    2012-10-15

    We have prepared bamboo-shaped C-N nanotubes-polyethylene oxide (PEO) composite films by solution cast technique and investigated their structural/microstructural and electrical properties and developed a correlation between them. The formation of clean compartmentalized bamboo-shaped C-N nanotubes was confirmed by TEM. SEM investigations revealed a homogeneous dispersion of nanotubes in PEO matrix. Enhanced electrical conductivity was observed for the C-N nanotubes-PEO composites than bare PEO. The conductivity measurements on the C-N nanotubes-PEO composite films with {approx}20 wt % concentration of C-N nanotubes showed an increase of eight orders ({approx}7.5 Multiplication-Sign 10{sup -8} to 6.2 S cm{sup -1}) of magnitude in conductivity from bare PEO film. Raman spectra showed the stress-free nature of the composites and established the bonding of nanotubes with PEO, which resulted in the variation of Raman parameters. The Raman data of composites corroborate the findings of variation in electrical conductivity.

  12. Semiconducting properties of layered cadmium sulphide-based hybrid nanocomposites

    Directory of Open Access Journals (Sweden)

    Sotomayor Torres Clivia

    2011-01-01

    Full Text Available Abstract A series of hybrid cadmium salt/cationic surfactant layered nanocomposites containing different concentrations of cadmium sulphide was prepared by exchanging chloride by sulphide ions in the layered precursor CdX x (OH y (CnTA z in a solid phase/gas reaction, resulting in a series of layered species exhibiting stoichiometries corresponding to CdS v X x (OH y (CnTA z , constituted by two-dimensional CdCl2/CdS ultra-thin sheets sandwiched between two self-assembled surfactant layers. The electronic structure of CdS in the nanocomposite is similar to that of bulk, but showing the expected features of two-dimensional confinement of the semiconductor. The nanocomposite band gap is found to depend in a non-linear manner on both the length of the hydrocarbon chain of the surfactant and the concentration of the sulphide in the inorganic sheet. The products show photocatalytic activity at least similar and usually better than that of "bulk" CdS in a factor of two.

  13. Montmorillonite@chitosan-poly (ethylene oxide) nanofibrous membrane enhancing poly (vinyl alcohol-co-ethylene) composite film.

    Science.gov (United States)

    Wang, Peng; Wang, Hualin; Liu, Jingrong; Wang, Pengfei; Jiang, Suwei; Li, Xingjiang; Jiang, Shaotong

    2018-02-01

    A montmorillonite@chitosan-poly (ethylene oxide) nanofibrous membrane (MMT@CPF) enhancing poly (vinyl alcohol-co-ethylene) (EVOH-MMT@CPF) composite film was developed by using a space-filling embedding method. The structure of EVOH-MMT@CPF was characterized, and the thermal stability, mechanical and barrier properties of the films were investigated. The CPF was fabricated via electrospinning technique and the self-assembly of MMT nano-platelets on CPF was achieved by the driving of electrostatic interactions between MMT nano-platelet and CPF. The experimental results indicated that the well-kept MMT@CPF after embedding in the EVOH matrix significantly improved the thermal stability and mechanical properties of the film, and also endowed the film with outstanding oxygen barrier (0.2×10 -16 cm 3 cmcm -2 s -1 Pa -1 ) and good moisture barrier (4.6×10 -6 gmm -2 s -1 atm -1 under a relative humidity of 90%) by prolonging the tortuous paths for molecule penetration. The composite film may have a great potential application in food packaging. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Monitoring of composite structures using a network of integrated PVDF film transducers

    Science.gov (United States)

    Guzmán, Enrique; Cugnoni, Joël; Gmür, Thomas

    2015-05-01

    Aiming to reduce costs, polyvinylidene difluoride (PVDF) film patches are an emerging alternative to more classic piezoelectric technologies, like ceramic patches, as transducers to measure local deformation in many structural applications. This choice is supported by advantages such as the low weight and mechanical flexibility of PVDF, making this polymer suitable for embedding inside full scale polymer based composite structures. Piezoelectric transducer patches can be used as actuators to dynamically excite full-scale composite structures, and as sensors to measure the strain. The main objective of this paper is to verify that the PVDF transducers can provide exploitable signals in the context of structural health monitoring. In order to do so, two aspects of the design of transducer network are investigated: the optimization of the sensor network, for which the effective independence method is proposed, and the use of operational modal analysis (OMA), since it is a simple method to extract the natural frequencies of a structure from a time series. The results of the analysis are compared to a reference set issued from experimental modal analysis (EMA), a simple, well-known, classic method, which is carried out using accelerometers and an impact hammer. By statistical means, it is shown that there is no significant difference between the two methods, and an optimized PVDF transducer network combined with OMA can perform the dynamic analysis of a structure as well as a classic EMA setup would do. This leads the way to the use of low-cost PVDF embedded transducer networks for robust composite material characterization.

  15. 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.

  16. Influence of Thermal Treatments on In-depth Compositional Uniformity of CuIn(S,Se)2 Thin Films

    Science.gov (United States)

    Xie, Hai-bing; Liu, Wei-feng; Jiang, Guo-shun; Li, Xin-yi; Yan, Fei; Zhu, Chang-fei

    2012-08-01

    CuIn(S,Se)2 thin films were prepared by thermal crystallization of co-sputtered Cu-In alloy precursors in S/Se atmosphere. In-depth compositional uniformity is an important prerequisite for obtaining device-quality CuIn(S,Se)2 absorber thin films. In order to figure out the influence of heat treatments on in-depth composition uniformity of CuIn(S,Se)2 thin films, two kinds of reaction temperature profiles were investigated. One process is “one step profile", referring to formation of CuIn(S,Se)2 thin films just at elevated temperature (e.g. 500 °C). The other is “two step profile", which allows for slow diffusion of S and Se elements into the alloy precursors at a low temperature before the formation and re-crystallization of CuIn(S,Se)2 thin films at higher temperature (e.g. first 250 °C then 500 °C). X-ray diffraction studies reveal that there is a discrepancy in the shape of (112) peak. Samples annealed with “one step profile" have splits on (112) peaks, while samples annealed with “two step profile" have relatively symmetrical (112) peaks. Grazing incident X-ray diffraction and energy dispersive spectrum measurements of samples successively etched in bromine methanol show that CuIn(S,Se)2 thin films have better in-depth composition uniformity after “two step profile" annealing. The reaction mechanism during the two thermal processing was also investigated by X-ray diffraction and Raman spectra.

  17. Model Amphiphilic Block Copolymers with Tailored Molecular Weight and Composition in PDMS-Based Films to Limit Soft Biofouling

    Energy Technology Data Exchange (ETDEWEB)

    Wenning, Brandon M. [Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Pisa 56124, Italy; Martinelli, Elisa [Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Pisa 56124, Italy; Mieszkin, Sophie [School of Biosciences, The University of Birmingham, Edgbaston, Birmingham B15 5TT, U.K.; Finlay, John A. [School of Biosciences, The University of Birmingham, Edgbaston, Birmingham B15 5TT, U.K.; Fischer, Daniel [National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States; Callow, James A. [School of Biosciences, The University of Birmingham, Edgbaston, Birmingham B15 5TT, U.K.; Callow, Maureen E. [School of Biosciences, The University of Birmingham, Edgbaston, Birmingham B15 5TT, U.K.; Leonardi, Amanda K.; Ober, Christopher K.; Galli, Giancarlo [Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Pisa 56124, Italy

    2017-05-02

    A set of controlled surface composition films was produced utilizing amphiphilic block copolymers dispersed in a cross-linked poly(dimethylsiloxane) network. These block copolymers contained oligo(ethylene glycol) (PEGMA) and fluoroalkyl (AF6) side chains in selected ratios and molecular weights to control surface chemistry including antifouling and fouling-release performance. Such properties were assessed by carrying out assays using two algae, the green macroalga Ulva linza (favors attachment to polar surfaces) and the unicellular diatom Navicula incerta (favors attachment to nonpolar surfaces). All films performed well against U. linza and exhibited high removal of attached sporelings (young plants) under an applied shear stress, with the lower molecular weight block copolymers being the best performing in the set. The composition ratios from 50:50 to 60:40 of the AF6/PEGMA side groups were shown to be more effective, with several films exhibiting spontaneous removal of the sporelings. The cells of N. incerta were also removed from several coating compositions. All films were characterized by surface techniques including captive bubble contact angle, atomic force microscopy, and near edge X-ray absorption fine structure spectroscopy to correlate surface chemistry and morphology with biological performance.

  18. Chitosan/alginate multilayer film for controlled release of IDM on Cu/LDPE composite intrauterine devices.

    Science.gov (United States)

    Tian, Kuan; Xie, Changsheng; Xia, Xianping

    2013-09-01

    To reduce such side effects as pain and bleeding caused by copper-containing intrauterine device (Cu-IUD), a novel medicated intrauterine device, which is coated with an indomethacin (IDM) delivery system on the surface of copper/low-density polyethylene (Cu/LDPE) composite intrauterine device, has been proposed and developed in the present work. The IDM delivery system is a polyelectrolyte multilayer film, which is composed of IDM containing chitosan and alginate layer by layer, is prepared by using self-assembled polyelectrolyte multilayer method, and the number of the layers of this IDM containing chitosan/alginate multilayer film can be tailored by controlling the cyclic repetition of the deposition process. After the IDM containing chitosan/alginate multilayer film is obtained on the surface of Cu/LDPE composite intrauterine device, its release behavior of both IDM and cupric ion has been studied in vitro. The results show that the release duration of IDM increase with the increasing of thickness of the IDM containing chitosan/alginate multilayer film, and the initial burst release of cupric ion cannot be found in this novel medicated Cu/LDPE composite IUD. These results can be applied to guide the design of novel medicated Cu-IUD with minimal side effects for the future clinical use. Copyright © 2013 Elsevier B.V. All rights reserved.

  19. Au–C allotrope nano-composite films at extreme conditions generated by intense ultra-short laser

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Saif A., E-mail: khansaifahmad@gmail.com [Inter-University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110067 (India);