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Sample records for film metal coated

  1. Formation of selenide, sulfide or mixed selenide-sulfide films on metal or metal coated substrates

    DOEpatents

    Eser, Erten; Fields, Shannon

    2012-05-01

    A process and composition for preventing cracking in composite structures comprising a metal coated substrate and a selenide, sulfide or mixed selenide sulfide film. Specifically, cracking is prevented in the coating of molybdenum coated substrates upon which a copper, indium-gallium diselenide (CIGS) film is deposited. Cracking is inhibited by adding a Se passivating amount of oxygen to the Mo and limiting the amount of Se deposited on the Mo coating.

  2. Diamond Composite Films for Protective Coatings on Metals and Method of Formation

    NASA Technical Reports Server (NTRS)

    Ong, Tiong P. (Inventor); Shing, Yuh-Han (Inventor)

    1997-01-01

    Composite films consisting of diamond crystallites and hard amorphous films such as diamond-like carbon, titanium nitride, and titanium oxide are provided as protective coatings for metal substrates against extremely harsh environments. A composite layer having diamond crystallites and a hard amorphous film is affixed to a metal substrate via an interlayer including a bottom metal silicide film and a top silicon carbide film. The interlayer is formed either by depositing metal silicide and silicon carbide directly onto the metal substrate, or by first depositing an amorphous silicon film, then allowing top and bottom portions of the amorphous silicon to react during deposition of the diamond crystallites, to yield the desired interlayer structure.

  3. Metal Coatings

    NASA Technical Reports Server (NTRS)

    1994-01-01

    During the Apollo Program, General Magnaplate Corporation developed process techniques for bonding dry lubricant coatings to space metals. The coatings were not susceptible to outgassing and offered enhanced surface hardness and superior resistance to corrosion and wear. This development was necessary because conventional lubrication processes were inadequate for lightweight materials used in Apollo components. General Magnaplate built on the original technology and became a leader in development of high performance metallurgical surface enhancement coatings - "synergistic" coatings, - which are used in applications from pizza making to laser manufacture. Each of the coatings is designed to protect a specific metal or group of metals to solve problems encountered under operating conditions.

  4. Non-stick syringe needles: Beneficial effects of thin film metallic glass coating.

    PubMed

    Chu, Jinn P; Yu, Chia-Chi; Tanatsugu, Yusuke; Yasuzawa, Mikito; Shen, Yu-Lin

    2016-01-01

    This paper reports on the use of Zr-based (Zr53Cu33Al9Ta5) thin film metallic glass (TFMG) for the coating of syringe needles and compares the results with those obtained using titanium nitride and pure titanium coatings. TFMG coatings were shown to reduce insertion forces by ∼66% and retraction forces by ∼72%, when tested using polyurethane rubber block. The benefits of TFMG-coated needles were also observed when tested using muscle tissue from pigs. In nano-scratch tests, the TFMG coatings achieved a coefficient of friction (COF) of just ∼0.05, which is about one order of magnitude lower than those of other coatings. Finite-element modeling also indicates a significant reduction in injection and retraction forces. The COF can be attributed to the absence of grain boundaries in the TFMG coating as well as a smooth surface morphology and low surface free energy. PMID:27573062

  5. Non-stick syringe needles: Beneficial effects of thin film metallic glass coating

    PubMed Central

    Chu, Jinn P.; Yu, Chia-Chi; Tanatsugu, Yusuke; Yasuzawa, Mikito; Shen, Yu-Lin

    2016-01-01

    This paper reports on the use of Zr-based (Zr53Cu33Al9Ta5) thin film metallic glass (TFMG) for the coating of syringe needles and compares the results with those obtained using titanium nitride and pure titanium coatings. TFMG coatings were shown to reduce insertion forces by ∼66% and retraction forces by ∼72%, when tested using polyurethane rubber block. The benefits of TFMG-coated needles were also observed when tested using muscle tissue from pigs. In nano-scratch tests, the TFMG coatings achieved a coefficient of friction (COF) of just ∼0.05, which is about one order of magnitude lower than those of other coatings. Finite-element modeling also indicates a significant reduction in injection and retraction forces. The COF can be attributed to the absence of grain boundaries in the TFMG coating as well as a smooth surface morphology and low surface free energy. PMID:27573062

  6. Non-stick syringe needles: Beneficial effects of thin film metallic glass coating.

    PubMed

    Chu, Jinn P; Yu, Chia-Chi; Tanatsugu, Yusuke; Yasuzawa, Mikito; Shen, Yu-Lin

    2016-08-30

    This paper reports on the use of Zr-based (Zr53Cu33Al9Ta5) thin film metallic glass (TFMG) for the coating of syringe needles and compares the results with those obtained using titanium nitride and pure titanium coatings. TFMG coatings were shown to reduce insertion forces by ∼66% and retraction forces by ∼72%, when tested using polyurethane rubber block. The benefits of TFMG-coated needles were also observed when tested using muscle tissue from pigs. In nano-scratch tests, the TFMG coatings achieved a coefficient of friction (COF) of just ∼0.05, which is about one order of magnitude lower than those of other coatings. Finite-element modeling also indicates a significant reduction in injection and retraction forces. The COF can be attributed to the absence of grain boundaries in the TFMG coating as well as a smooth surface morphology and low surface free energy.

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

    NASA Astrophysics Data System (ADS)

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

    2016-01-01

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

  8. Biocompatibility evaluation of sputtered zirconium-based thin film metallic glass-coated steels

    PubMed Central

    Subramanian, Balasubramanian; Maruthamuthu, Sundaram; Rajan, Senthilperumal Thanka

    2015-01-01

    Thin film metallic glasses comprised of Zr48Cu36Al8Ag8 (at.%) of approximately 1.5 μm and 3 μm in thickness were prepared using magnetron sputtering onto medical grade 316L stainless steel. Their structural and mechanical properties, in vitro corrosion, and antimicrobial activity were analyzed. The amorphous thin film metallic glasses consisted of a single glassy phase, with an absence of any detectable peaks corresponding to crystalline phases. Elemental composition close to the target alloy was noted from EDAX analysis of the thin film. The surface morphology of the film showed a smooth surface on scanning electron microscopy and atomic force microscopy. In vitro electrochemical corrosion studies indicated that the zirconium-based metallic glass could withstand body fluid, showing superior resistance to corrosion and electrochemical stability. Interactions between the coated surface and bacteria were investigated by agar diffusion, solution suspension, and wet interfacial contact methods. The results indicated a clear zone of inhibition against the growth of microorganisms such as Escherichia coli and Staphylococcus aureus, confirming the antimicrobial activity of the thin film metallic glasses. Cytotoxicity studies using L929 fibroblast cells showed these coatings to be noncytotoxic in nature. PMID:26491304

  9. Study of metal film coating on Sc 2O 3 mixed matrix impregnated cathodes

    NASA Astrophysics Data System (ADS)

    Yamamoto, S.; Taguchi, S.; Aida, T.; Kawase, S.

    Electron emission and surface properties of the Sc 2O 3 mixed matrix impregnated cathode coated with Ir, Os, Pt and Mo are studied. The cathode is composed of porous body of a metal matrix (5 wt% Sc 2O 3 in W) and an impregnant of 4BaO·CaO·Al 23, on which metal films of about 500 nm are evaporated. Sc atoms do not appear on the film surface even after prolonged heating at 1150°C, and the coated cathodes do not show the emission anomaly usually seen for Sc 2O 3 mixed matrix cathodes. The Mo film, however, alloys easily with W in a short heat treatment time and the Sc atoms are distributed nonuniformly over the surface. The Mo coated cathode does show the emission anomaly. A simple coating with Sc film on the ordinary W matrix cathode reveals neither the surface properties nor the emission properties of Sc 2O 3 mixed matrix cathodes.

  10. Microwave bonding of thin film metal coated substrates

    NASA Technical Reports Server (NTRS)

    Barmatz, Martin B. (Inventor); Mai, John D. (Inventor); Jackson, Henry W. (Inventor); Budraa, Nasser K. (Inventor); Pike, William T. (Inventor)

    2004-01-01

    Bonding of materials such as MEMS materials is carried out using microwaves. High microwave absorbing films are placed within a microwave cavity containing other less microwave absorbing materials, and excited to cause selective heating in the skin depth of the films. This causes heating in one place more than another. This thereby minimizes unwanted heating effects during the microwave bonding process.

  11. Electrical four-point probing of spherical metallic thin films coated onto micron sized polymer particles

    NASA Astrophysics Data System (ADS)

    Pettersen, Sigurd R.; Stokkeland, August Emil; Kristiansen, Helge; Njagi, John; Redford, Keith; Goia, Dan V.; Zhang, Zhiliang; He, Jianying

    2016-07-01

    Micron-sized metal-coated polymer spheres are frequently used as filler particles in conductive composites for electronic interconnects. However, the intrinsic electrical resistivity of the spherical thin films has not been attainable due to deficiency in methods that eliminate the effect of contact resistance. In this work, a four-point probing method using vacuum compatible piezo-actuated micro robots was developed to directly investigate the electric properties of individual silver-coated spheres under real-time observation in a scanning electron microscope. Poly(methyl methacrylate) spheres with a diameter of 30 μm and four different film thicknesses (270 nm, 150 nm, 100 nm, and 60 nm) were investigated. By multiplying the experimental results with geometrical correction factors obtained using finite element models, the resistivities of the thin films were estimated for the four thicknesses. These were higher than the resistivity of bulk silver.

  12. Stabilization of metal nanoparticle films on glass surfaces using ultrathin silica coating.

    PubMed

    Chaikin, Yulia; Kedem, Ofer; Raz, Jennifer; Vaskevich, Alexander; Rubinstein, Israel

    2013-11-01

    Metal nanoparticle (NP) films, prepared by adsorption of NPs from a colloidal solution onto a preconditioned solid substrate, usually form well-dispersed random NP monolayers on the surface. For certain metals (e.g., Au, Ag, Cu), the NP films display a characteristic localized surface plasmon resonance (LSPR) extinction band, conveniently measured using transmission or reflection ultraviolet-visible light (UV-vis) spectroscopy. The surface plasmon band wavelength, intensity, and shape are affected by (among other parameters) the NP spatial distribution on the surface and the effective refractive index (RI) of the surrounding medium. A major concern in the formation of such NP assemblies on surfaces is a commonly observed instability, i.e., a strong tendency of the NPs to undergo aggregation upon removal from the solution and drying, expressed as a drastic change in the LSPR band. Since various imaging modes and applications require dried NP films, preservation of the film initial (wet) morphology and optical properties upon drying are highly desirable. The latter is achieved in the present work by introducing a convenient and generally applicable method for preventing NP aggregation upon drying while preserving the original film morphology and optical response. Stabilization of Au and Ag NP monolayers toward drying is accomplished by coating the immobilized NPs with an ultrathin (3.0-3.5 nm) silica layer, deposited using a sol-gel reaction performed on an intermediate self-assembled aminosilane layer. The thin silica coating prevents NP aggregation and maintains the initial NP film morphology and LSPR response during several cycles of drying and immersion in water. It is shown that the silica-coated NP films retain their properties as effective LSPR transducers.

  13. Non-conductive ferromagnetic carbon-coated (Co, Ni) metal/polystyrene nanocomposites films

    NASA Astrophysics Data System (ADS)

    Takacs, H.; Viala, B.; Tortai, J.-H.; Hermán, V.; Duclairoir, F.

    2016-03-01

    This article reports non-conductive ferromagnetic properties of metal/polymer nanocomposite films intended to be used for RF applications. The nanocomposite arrangement is unique showing a core double-shell structure of metal-carbon-polystyrene: M/C//P1/P2, where M = Co, Ni is the core material, C = graphene or carbon is the first shell acting as a protective layer against oxidation, P1 = pyrene-terminated polystyrene is the second shell for electrical insulation, and P2 = polystyrene is a supporting matrix (// indicates actual grafting). The nanocomposite formulation is briefly described, and the film deposition by spin-coating is detailed. Original spin-curves are reported and analyzed. One key outcome is the achievement of uniform and cohesive films at the wafer scale. Structural properties of films are thoroughly detailed, and weight and volume fractions of M/C are considered. Then, a comprehensive overview of DC magnetic and electrical properties is reported. A discussion follows on the magnetic softness of the nanocomposites vs. that of a single particle (theoretical) and the raw powder (experimental). Finally, unprecedented achievement of high magnetization (˜0.6 T) and ultra-high resistivity (˜1010 μΩ cm) is shown. High magnetization comes from the preservation of the existing protective shell C, with no significant degradation on the particle net-moment, and high electrical insulation is ensured by adequate grafting of the secondary shell P1. To conclude, the metal/polymer nanocomposites are situated in the landscape of soft ferromagnetic materials for RF applications (i.e., inductors and antennas), by means of two phase-diagrams, where they play a crucial role.

  14. Characteristics of surface photorefractive waves in a nonlinear SBN-75 crystal coated with a metal film

    SciTech Connect

    Nurligareev, D Kh; Usievich, B A; Sychugov, V A; Ivleva, Lyudmila I

    2013-01-31

    Based on the calculation of the electrostatic field potential of space charges, we have analysed the characteristic features of light-induced scattering of extraordinary polarised light in photorefractive (PR) crystals (for example, an SBN-75 crystal). Using the method of images, the electrostatic field is analysed for surface (aperiodic) waves along the crystal - dielectric (air) interface. It is shown that the field distributions satisfying the boundary conditions can emerge only upon accumulation of a screening electric charge in a narrow transition layer of thickness {approx}1 mm, the sign of the charge being opposite that of the space charge in the illuminated region of the crystal. A model is proposed to explain the observed features of the surface PR waves in a metal-film coated PR crystal. In considering the contact potential difference at the PR crystal - film interface it is shown that in the crystal layer (adjacent to the film) enriched with charge carriers, i.e., electrons, the refractive index can be significantly reduced. In the case of small excitation angles (0 - 1.5deg ), this layer can act as an optical barrier, the reflection from which can result in near-surface waves; a characteristic difference from the previously observed oscillatory surface waves is the presence of a broadened intensity distribution shifted inside the crystal. (nonlinear optical phenomena)

  15. Antireflection of sputtered heat mirror and transparent conducting coatings by metal-oxy-fluorine films

    NASA Astrophysics Data System (ADS)

    Harding, G. L.; Hamberg, I.; Granqvist, C. G.

    1985-08-01

    Some examples of high rate sputtered low refractive index metal-oxy-fluorine materials, in particular aluminium-oxy-fluorine and tin-oxy-fluorine, have been evaluated as antireflection layers for two commercially available sputtered multilayer heat mirrors on glass, commercially available sputtered indium-tin-oxide film on polyester and laboratory produced evaporated indium-tin-oxide on glass. Improvements of approximately 9 percent in luminous transmittance, approximately 8 percent in solar transmittance, and considerably reduced luminous reflectance were achieved for the heat mirrors, with considerably less color, particularly in the reflected light. The increases achieved for the luminous transmittance of high quality laboratory produced ITO depend on the thickness of the ITO film, and range from 3 to 9 percent. Larger improvements (not less than 15 percent) are obtained for the commercially produced ITO on polyester. The thermal emittances of the heat mirrors are not affected significantly by the antireflection layers, and preliminary tests indicate that the coatings are stable under exposure to uv radiation.

  16. Thin-film metal coated insulation barrier in a Josephson tunnel junction. [Patent application

    DOEpatents

    Hawkins, G.A.; Clarke, J.

    1975-10-31

    A highly stable, durable, and reproducible Josephson tunnel junction consists of a thin-film electrode of a hard superconductor, a thin oxide insulation layer over the electrode constituting a Josephson tunnel junction barrier, a thin-film layer of stabilizing metal over the barrier, and a second thin-film hard superconductive electrode over the stabilizing film. The thin stabilizing metal film is made only thick enough to limit penetration of the electrode material through the insulation layer so as to prevent a superconductive short.

  17. Analysis of metal temperature and coolant flow with a thermal-barrier coating on a full-coverage-film-cooled turbine vane

    NASA Technical Reports Server (NTRS)

    Meitner, P. L.

    1978-01-01

    The potential benefits of combining full-coverage film cooling with a thermal-barrier coating were investigated analytically for sections on the suction and pressure sides a high-temperature, high-pressure turbine vane. Metal and ceramic coating temperatures were calculated as a function of coating thickness and coolant flow. With a thermal-barrier coating, the coolant flows required for the chosen sections were half those of an uncoated design, and the metal outer temperatures were simultaneously reduced by over 111 K (200 F). For comparison, transpiration cooling was also investigated. Full-coverage film cooling of a coated vane required more coolant flow than did transpiration cooling.

  18. Thin-film coatings

    NASA Technical Reports Server (NTRS)

    Buckley, D. H.

    1980-01-01

    Thin, adherent, high density films are discussed with respect to their application in two plasma physics techniques (ion plating and sputtering). The operation of each technique is described as well as what surfaces can be coated, and what kind of materials can be applied. The effects of these films on the mechanical properties of solid surfaces are also discussed.

  19. Omnidirectional, broadband light absorption using large-area, ultrathin lossy metallic film coatings

    PubMed Central

    Li, Zhongyang; Palacios, Edgar; Butun, Serkan; Kocer, Hasan; Aydin, Koray

    2015-01-01

    Resonant absorbers based on nanostructured materials are promising for variety of applications including optical filters, thermophotovoltaics, thermal emitters, and hot-electron collection. One of the significant challenges for such micro/nanoscale featured medium or surface, however, is costly lithographic processes for structural patterning which restricted from industrial production of complex designs. Here, we demonstrate lithography-free, broadband, polarization-independent optical absorbers based on a three-layer ultrathin film composed of subwavelength chromium (Cr) and oxide film coatings. We have measured almost perfect absorption as high as 99.5% across the entire visible regime and beyond (400–800 nm). In addition to near-ideal absorption, our absorbers exhibit omnidirectional independence for incidence angle over ±60 degrees. Broadband absorbers introduced in this study perform better than nanostructured plasmonic absorber counterparts in terms of bandwidth, polarization and angle independence. Improvements of such “blackbody” samples based on uniform thin-film coatings is attributed to extremely low quality factor of asymmetric highly-lossy Fabry-Perot cavities. Such broadband absorber designs are ultrathin compared to carbon nanotube based black materials, and does not require lithographic processes. This demonstration redirects the broadband super absorber design to extreme simplicity, higher performance and cost effective manufacturing convenience for practical industrial production. PMID:26450563

  20. Omnidirectional, broadband light absorption using large-area, ultrathin lossy metallic film coatings

    NASA Astrophysics Data System (ADS)

    Li, Zhongyang; Palacios, Edgar; Butun, Serkan; Kocer, Hasan; Aydin, Koray

    2015-10-01

    Resonant absorbers based on nanostructured materials are promising for variety of applications including optical filters, thermophotovoltaics, thermal emitters, and hot-electron collection. One of the significant challenges for such micro/nanoscale featured medium or surface, however, is costly lithographic processes for structural patterning which restricted from industrial production of complex designs. Here, we demonstrate lithography-free, broadband, polarization-independent optical absorbers based on a three-layer ultrathin film composed of subwavelength chromium (Cr) and oxide film coatings. We have measured almost perfect absorption as high as 99.5% across the entire visible regime and beyond (400-800 nm). In addition to near-ideal absorption, our absorbers exhibit omnidirectional independence for incidence angle over ±60 degrees. Broadband absorbers introduced in this study perform better than nanostructured plasmonic absorber counterparts in terms of bandwidth, polarization and angle independence. Improvements of such “blackbody” samples based on uniform thin-film coatings is attributed to extremely low quality factor of asymmetric highly-lossy Fabry-Perot cavities. Such broadband absorber designs are ultrathin compared to carbon nanotube based black materials, and does not require lithographic processes. This demonstration redirects the broadband super absorber design to extreme simplicity, higher performance and cost effective manufacturing convenience for practical industrial production.

  1. Coating of plasma polymerized film

    NASA Technical Reports Server (NTRS)

    Morita, S.; Ishibashi, S.

    1980-01-01

    Plasma polymerized thin film coating and the use of other coatings is suggested for passivation film, thin film used for conducting light, and solid body lubrication film of dielectrics of ultra insulators for electrical conduction, electron accessories, etc. The special features of flow discharge development and the polymerized film growth mechanism are discussed.

  2. Electrosynthesis of hydrogel films on metal substrates for the development of coatings with tunable drug delivery performances.

    PubMed

    De Giglio, E; Cometa, S; Satriano, C; Sabbatini, L; Zambonin, P G

    2009-03-15

    Novel polyacrylates-based hydrogel thin films were prepared by electrochemical polymerization, a new method to obtain hydrogels directly onto metal substrates. 2-Hydroxy-ethyl-methacrylate (HEMA), a macromer poly (ethylene-glycol diacrylate) (PEGDA) and PEGDA copolymerized with acrylic acid (AA) were used to obtain hydrogels. The electrosynthesized coatings were characterized by X-ray photoelectron spectroscopy, to assess their surface chemical composition, and by water content determination measurements, to characterize the swelling behavior. In particular, quartz crystal microbalance with dissipation monitoring was used to evaluate the pH-dependency of the swelling for AA-containing hydrogels. Moreover, a model protein (bovine serum albumin) and a model drug (caffeine) were entrapped within the hydrogel coatings during electrosynthesis, to examine the release performances and mechanisms of the electrosynthesized hydrogels. It was observed that all the examined polymers showed significant release properties and, in particular, AA-containing hydrogel films confirmed a strong pH-dependence as expected. These coatings seem to be promising in orthopedic field for in situ drug delivery applications.

  3. Photovoltage and stability of an n-type silicon semiconductor coated with metal or metal-free phthalocyanine thin films in aqueous redox solutions

    SciTech Connect

    Nakato, Y.; Shioji, M.; Tsubomura, H.

    1981-06-11

    An n-type silicon (n-Si) semiconductor coated with an evaporated thin film of metal phthalocyanine (MPc) or metal-free phthalocyanine (H/sub 2/Pc) worked as a fairly stable photoanode in aqueous redox solutions. The photovoltage observed for a photocell, (n-Si/CuPc/Fe/sup 3 +//Fe/sup 2 +/ aqueous solution (pH 4.2) /Pt), was 0.50 V, only slightly less than that for a p-n junction Si photocell (approx. 0.6 V). The action spectrum was similar to that of a bare n-Si electrode, except for a depression caused by photoabsorption by the CuPc film in the red region. The above wet photocell has current-voltage characteristics better than those for a solid photocell, (n-Si/CuPc/Pd).

  4. Method of forming graded polymeric coatings or films

    DOEpatents

    Liepins, Raimond

    1983-01-01

    Very smooth polymeric coatings or films graded in atomic number and density can readily be formed by first preparing the coating or film from the desired monomeric material and then contacting it with a fluid containing a metal or a mixture of metals for a time sufficient for such metal or metals to sorb and diffuse into the coating or film. Metal resinate solutions are particularly advantageous for this purpose. A metallic coating can in turn be produced on the metal-loaded film or coating by exposing it to a low pressure plasma of air, oxygen, or nitrous oxide. The process permits a metallic coating to be formed on a heat sensitive substrate without the use of elevated temperatures.

  5. LEVELING METAL COATINGS

    DOEpatents

    Gage, H.A.

    1959-02-10

    A method is described for applying metallic coatings to a cylinder of uranium. An aluminum-silicon coat is applied by a process consisting of first cleaning the article by immersion for 5 minutes in 50% nitric acid at 65 C. The article then is dipped through a flux, prepared by adding 10% sodium fluoride to 90% of a flux comprising 53% potassium chloride, 42% lithium chloride, and 5% sodium chloride at 560 for 2 minutes and then directly into a molten metal bath comprising 99% aluminun and 12% silicon at 620 C for 3 minutes. While the coating is yet molten the article is transferred to a pair of steel rollers and rolled until the coating solidifies. By varying the composition of the flux other metals such as zinc, lead or the like may be coated on uranium in a similar manner.

  6. A study of Nafion-coated bismuth-film electrodes for the determination of trace metals by anodic stripping voltammetry.

    PubMed

    Kefala, Georgia; Economou, Anastasios; Voulgaropoulos, Anastasios

    2004-11-01

    This work reports on the fabrication, characterization and applications of Nafion-coated bismuth-film electrodes (NCBFE's) for the determination of trace metals by anodic stripping voltammetry (ASV). A NCBFE was typically prepared by first applying a 5 microl drop of a 1% Nafion solution onto the surface of a glassy-carbon rotating-disk electrode. After evaporation of the solvent, the Bi film was plated on the electrode in situ(i.e. by spiking the sample with 1000 microg l(-1) of Bi(iii) and simultaneous electrolytic deposition of the metal ions and bismuth film on the electrode surface at -1.4 V) or ex-situ(i.e. by electrolytic deposition of the bismuth film in a separate solution containing 1000 microg l(-1) of Bi(iii), followed by the ASV measurement step in the sample solution). Various fabrication and operational parameters were thoroughly investigated and discussed in terms of their effect on the ASV signals. It was found that this voltammetric sensor was suitable for the determination of metals at trace levels by square-wave ASV (SWASV) due to its multi-element detection potential, improved analytical sensitivity, high resistance to surfactants, low cost, ease of fabrication, robustness, speed of analysis and low toxicity (as compared to traditional mercury electrodes). In the presence of 4 mg l(-1) of Triton X-100, the NCBFE afforded a 10-fold peak height enhancement for the Pb peak and a 14-fold enhancement for the Cd peak over a bare BFE while the determination of Zn was feasible only on the NCBFE. The limits of detection (at a signal-to-noise ratio of 3) were 0.1 microg l(-1) for Cd and Pb and 0.4 microg l(-1) for Zn for a deposition time of 10 min. Finally, the electrode was applied to different real samples (tap-water, urine and wine) for the analysis of trace metals with satisfactory results. PMID:15508038

  7. Method of forming metal hydride films

    NASA Technical Reports Server (NTRS)

    Steinberg, R.; Alger, D. L.; Cooper, D. W. (Inventor)

    1977-01-01

    The substrate to be coated (which may be of metal, glass or the like) is cleaned, both chemically and by off-sputtering in a vacuum chamber. In an ultra-high vacuum system, vapor deposition by a sublimator or vaporizer coats a cooled shroud disposed around the substrate with a thin film of hydride forming metal which getters any contaminant gas molecules. A shutter is then opened to allow hydride forming metal to be deposited as a film or coating on the substrate. After the hydride forming metal coating is formed, deuterium or other hydrogen isotopes are bled into the vacuum system and diffused into the metal film or coating to form a hydride of metal film. Higher substrate temperatures and pressures may be used if various parameters are appropriately adjusted.

  8. Method of forming metallic coatings on polymeric substrates

    DOEpatents

    Liepins, Raimond

    1984-01-01

    Very smooth polymeric coatings or films graded in atomic number and density an readily be formed by first preparing the coating or film from the desired monomeric material and then contacting it with a fluid containing a metal or a mixture of metals for a time sufficient for such metal or metals to sorb and diffuse into the coating or film. Metal resinate solutions are particularly advantageous for this purpose. A metallic coating can in turn be produced on the metal-loaded film or coating by exposing it to a low pressure plasma of air, oxygen, or nitrous oxide. The process permits a metallic coating to be formed on a heat sensitive substrate without the use of elevated temperatures.

  9. Carbonaceous film coating

    DOEpatents

    Maya, L.

    1988-04-27

    A method of making a carbonaceous film comprising heating tris(1,3,2-benzodiazaborolo)borazine or dodecahydro tris(1,3,2)diazaborine(1,2-a:1'2'-c:1''2''-e)borazine in an inert atmosphere in the presence of a substrate to a temperature at which the borazine compound decomposes, and the decomposition products deposit onto the substrate to form a thin, tenacious, highly reflective conductive coating having a narrow band gap which is susceptible of modification and a relatively low coefficient of friction.

  10. Carbonaceous film coating

    DOEpatents

    Maya, Leon

    1989-01-01

    A method of making a carbonaceous film comprising heating tris(1,3,2-benzodiazaborolo)borazine or dodecahydro tris[1,3,2]diazaborine[1,2-a:1'2'-c:1"2"-e]borazine in an inert atmosphere in the presence of a substrate to a temperature at which the borazine compound decomposes, and the decomposition products deposit onto the substrate to form a thin, tenacious, highly reflective conductive coating having a narrow band gap which is susceptible of modification and a relatively low coefficient of friction.

  11. METAL COATING BATHS

    DOEpatents

    Robinson, J.W.

    1958-08-26

    A method is presented for restoring the effectiveness of bronze coating baths used for hot dip coating of uranium. Such baths, containing a high proportion of copper, lose their ability to wet uranium surfaces after a period of use. The ability of such a bath to wet uranium can be restored by adding a small amount of metallic aluminum to the bath, and skimming the resultant hard alloy from the surface.

  12. Thin film ion conducting coating

    DOEpatents

    Goldner, Ronald B.; Haas, Terry; Wong, Kwok-Keung; Seward, George

    1989-01-01

    Durable thin film ion conducting coatings are formed on a transparent glass substrate by the controlled deposition of the mixed oxides of lithium:tantalum or lithium:niobium. The coatings provide durable ion transport sources for thin film solid state storage batteries and electrochromic energy conservation devices.

  13. Metal oxide films on metal

    DOEpatents

    Wu, Xin D.; Tiwari, Prabhat

    1995-01-01

    A structure including a thin film of a conductive alkaline earth metal oxide selected from the group consisting of strontium ruthenium trioxide, calcium ruthenium trioxide, barium ruthenium trioxide, lanthanum-strontium cobalt oxide or mixed alkaline earth ruthenium trioxides thereof upon a thin film of a noble metal such as platinum is provided.

  14. Scribable coating for plastic films

    NASA Technical Reports Server (NTRS)

    Clark, R. T.

    1967-01-01

    Scribable opaque coating for transparent plastic film tape is not affected by aging, vacuum, and moderate temperature extremes. It consists of titanium dioxide, a water-compatible acrylic polymer emulsion, and a detergent. The coating mixture is readily dispersed in water before it is dried.

  15. Polymer-assisted aqueous deposition of metal oxide films

    DOEpatents

    Li, DeQuan; Jia, Quanxi

    2003-07-08

    An organic solvent-free process for deposition of metal oxide thin films is presented. The process includes aqueous solutions of necessary metal precursors and an aqueous solution of a water-soluble polymer. After a coating operation, the resultant coating is fired at high temperatures to yield optical quality metal oxide thin films.

  16. Tailoring Thin Film-Lacquer Coatings for Space Application

    NASA Technical Reports Server (NTRS)

    Peters, Wanda C.; Harris, George; Miller, Grace; Petro, John

    1998-01-01

    Thin film coatings have the capability of obtaining a wide range of thermal radiative properties, but the development of thin film coatings can sometimes be difficult and costly when trying to achieve highly specular surfaces. Given any space mission's thermal control requirements, there is often a need for a variation of solar absorptance (Alpha(s)), emittance (epsilon) and/or highly specular surfaces. The utilization of thin film coatings is one process of choice for meeting challenging thermal control requirements because of its ability to provide a wide variety of Alpha(s)/epsilon ratios. Thin film coatings' radiative properties can be tailored to meet specific thermal control requirements through the use of different metals and the variation of dielectric layer thickness. Surface coatings can be spectrally selective to enhance radiative coupling and decoupling. The application of lacquer to a surface can also provide suitable specularity for thin film application without the cost and difficulty associated with polishing.

  17. Study of the resonant frequencies of silicon microcantilevers coated with vanadium dioxide films during the insulator-to-metal transition

    NASA Astrophysics Data System (ADS)

    Rúa, Armando; Fernández, Félix E.; Hines, Melissa A.; Sepúlveda, Nelson

    2010-03-01

    Vanadium dioxide (VO2) thin films were grown on silicon microcantilevers and companion test substrates by pulsed laser deposition followed by in situ annealing in an oxidizing atmosphere, with annealing times used to control crystallite sizes. Annealing times of 18 min produced VO2 films with average crystallite sizes of ˜10 nm or less, while those annealed for 35 min had crystallites of average size ˜90 nm, comparable to sample thickness. X-ray diffraction and x-ray photoelectron spectroscopy studies of the samples showed that films with crystallite sizes ˜40 nm or greater consisted of substoichiometric VO2 in its monoclinic phase, with preferential orientation with (011) planes parallel to the sample surface, while finer structured samples had a substantially similar composition, but showed no clear evidence of preferential orientation and were probably partially amorphous. Forced vibration experiments were performed with the cantilevers as they were thermally cycled through the VO2 insulator-to-metal transition (IMT). Very large reversible changes in the resonant frequencies of up to 5% (3.6 kHz) as well as hysteretic behavior were observed, which depend strongly on film crystallite size. The average value of Young's modulus for VO2 films with crystallite sizes of ˜90 nm was estimated from the mechanical resonance data at room temperature to be ˜120 GPa, but the large tensile stresses which develop between film and substrate through the IMT impede a similar determination for the VO2 tetragonal phase, since the commonly used relationships for cantilever frequencies derived from elasticity theory are not applicable for strongly curved composite beams. The results presented show that VO2 thin films can be useful in novel microscale and nanoscale electromechanical resonators in which effective stiffness can be tuned thermally or optically. This response can provide additional functionality to VO2—based devices which take advantage of other property changes

  18. Barrier Coatings for Refractory Metals and Superalloys

    SciTech Connect

    SM Sabol; BT Randall; JD Edington; CJ Larkin; BJ Close

    2006-02-23

    In the closed working fluid loop of the proposed Prometheus space nuclear power plant (SNPP), there is the potential for reaction of core and plant structural materials with gas phase impurities and gas phase transport of interstitial elements between superalloy and refractory metal alloy components during service. Primary concerns are surface oxidation, interstitial embrittlement of refractory metals and decarburization of superalloys. In parallel with kinetic investigations, this letter evaluates the ability of potential coatings to prevent or impede communication between reactor and plant components. Key coating requirements are identified and current technology coating materials are reviewed relative to these requirements. Candidate coatings are identified for future evaluation based on current knowledge of design parameters and anticipated environment. Coatings were identified for superalloys and refractory metals to provide diffusion barriers to interstitial transport and act as reactive barriers to potential oxidation. Due to their high stability at low oxygen potential, alumina formers are most promising for oxidation protection given the anticipated coolant gas chemistry. A sublayer of iridium is recommended to provide inherent diffusion resistance to interstitials. Based on specific base metal selection, a thin film substrate--coating interdiffusion barrier layer may be necessary to meet mission life.

  19. Metal-Coated Optical Fibers for High Temperature Applications

    NASA Technical Reports Server (NTRS)

    Zeakes, Jason; Murphy, Kent; Claus, Richard; Greene, Jonathan; Tran, Tuan

    1996-01-01

    This poster will highlight on-going research at the Virginia Tech Fiber & Electro-Optics Research Center (FEORC) in the area of thin films on optical fibers. Topics will include the sputter deposition of metals and metal; alloys onto optical fiber and fiber optic sensors for innovative applications. Specific information will be available on thin film fiber optic hydrogen sensors, corrosion sensors, and metal-coated optical fiber for high temperature aerospace applications.

  20. Metal-Coated Optical Fibers for High Temperature Applications

    NASA Technical Reports Server (NTRS)

    Zeakes, Jason; Murphy, Kent; Claus, Richard; Greene, Jonathan; Tran, Tuan

    1996-01-01

    A DC magnetron sputtering system has been used to actively coat optical fibers with hermetic metal coatings during the fiber draw process. Thin films of Inconel 625 have been deposited on optical fibers and annealed in air at 2000 F. Scanning electron microscopy and Auger electron microscopy have been used to investigate the morphology and composition of the films prior to and following thermal cycling. Issues to be addressed include film adhesion, other coating materials, and a discussion of additional applications for this novel technology.

  1. Thin film-coated polymer webs

    DOEpatents

    Wenz, Robert P.; Weber, Michael F.; Arudi, Ravindra L.

    1992-02-04

    The present invention relates to thin film-coated polymer webs, and more particularly to thin film electronic devices supported upon a polymer web, wherein the polymer web is treated with a purifying amount of electron beam radiation.

  2. Superconducting films made by spin-coating of acetate solutions

    SciTech Connect

    Balachandran, U.; Poeppel, R.B. ); dos Santos, D.I.; Carvalho, C.L.; da Silva, R.R.; Aegerter, M.A. . Inst. de Fisica e Quimica)

    1990-12-01

    Metallic silver substrates were spin-coated with several layers of mixed acetate solutions containing bismuth, lead, strontium, calcium, and copper. The viscosities of the cation solutions were modified by the addition of polyvinyl alcohol. The films were heat treated at various temperatures in air, O{sub 2}, and 1% O{sub 2} (balance N{sub 2}) atmospheres. Bismuth cuprate films with transport critical current densities {approx}500 A/cm{sup 2} were obtained in this work. New conditions of coating and sintering have been tried to produce superconducting films.

  3. Method of measuring metal coating adhesion

    DOEpatents

    Roper, John R.

    1985-01-01

    A method for measuring metal coating adhesion to a substrate material comprising the steps of preparing a test coupon of substrate material having the metal coating applied to one surface thereof, applying a second metal coating of gold or silver to opposite surfaces of the test coupon by hot hollow cathode process, applying a coating to one end of each of two pulling rod members, joining the coated ends of the pulling rod members to said opposite coated surfaces of the test coupon by a solid state bonding technique and finally applying instrumented static tensile loading to the pulling rod members until fracture of the metal coating adhesion to the substrate material occurs.

  4. STRIPPING METAL COATINGS

    DOEpatents

    Siefen, H.T.; Campbell, J.M.

    1959-02-01

    A method is described for removing aluminumuranium-silicon alloy bonded to metallic U comprising subjecting the Al-U -Si alloy to treatment with hot concentrated HNO/sun 3/ to partially dissolve and embrittle the alloy and shot- blasting the embrittled alloy to loosen it from the U.

  5. Polarization dependency of the metal-coated eccentric fiber.

    PubMed

    Liu, Jianxia; Yuan, Libo

    2015-01-01

    The transmission losses and lengths of two polarized fundamental modes for a metal-coated eccentric core optical fiber (ECOF) are considered based on the finite-element method. Three typical thin metal films (Au, Ag, and Cu) are used and deposited on the walls of the cladding of ECOF. The variations of the transmission losses and lengths are investigated with different eccentricity, core radii, and metal film species. The numerical results indicate that the optical spectrum of a metal-coated ECOF can be tuned easily by changing the structure parameters of the fiber. The fundamental mode of metal-coated ECOF shows good polarization dependency. It is forecasted that the attenuation difference between the two polarization modes may be used to design an in-fiber polarizer.

  6. Method of coating metal surfaces to form protective metal coating thereon

    DOEpatents

    Krikorian, Oscar H.; Curtis, Paul G.

    1992-01-01

    A process is disclosed for forming a protective metal coating on a metal surface using a flux consisting of an alkali metal fluoride, an alkaline earth metal fluoride, an alkali metal fluoaluminate, an alkali metal fluosilicate, and mixtures thereof. The flux, in particulate form, is mixed with particles of a metal coating material which may comprise aluminum, chromium, mixtures thereof, and alloys containing at least 50 wt. % aluminum and the particulate mixture is applied to the metal surface in a single step, followed by heating the coated metal surface to a temperature sufficient to cause the metal coating material to react with the metal surface to form a protective reaction product in the form of a metal coating bonded to the metal surface. The metal surface which reacts with the metal coating material to form the protective coating may comprise Fe, Co, Ni, Ti, V, Cr, Mn, Zr, Nb, Mo, Tc, Hf, Ta, W, Re and alloys thereof.

  7. Method of coating metal surfaces to form protective metal coating thereon

    DOEpatents

    Krikorian, O.H.; Curtis, P.G.

    1992-03-31

    A process is disclosed for forming a protective metal coating on a metal surface using a flux consisting of an alkali metal fluoride, an alkaline earth metal fluoride, an alkali metal fluoaluminate, an alkali metal fluosilicate, and mixtures thereof. The flux, in particulate form, is mixed with particles of a metal coating material which may comprise aluminum, chromium, mixtures thereof, and alloys containing at least 50 wt. % aluminum and the particulate mixture is applied to the metal surface in a single step, followed by heating the coated metal surface to a temperature sufficient to cause the metal coating material to react with the metal surface to form a protective reaction product in the form of a metal coating bonded to the metal surface. The metal surface which reacts with the metal coating material to form the protective coating may comprise Fe, Co, Ni, Ti, V, Cr, Mn, Zr, Nb, Mo, Tc, Hf, Ta, W, Re and alloys thereof. 1 figure.

  8. Coated Metal Articles and Method of Making

    DOEpatents

    Boller, Ernest R.; Eubank, Lowell D.

    2004-07-06

    The method of protectively coating metallic uranium which comprises dipping the metallic uranium in a molten alloy comprising about 20-75% of copper and about 80-25% of tin, dipping the coated uranium promptly into molten tin, withdrawing it from the molten tin and removing excess molten metal, thereupon dipping it into a molten metal bath comprising aluminum until it is coated with this metal, then promptly withdrawing it from the bath.

  9. Coated metal articles and method of making

    DOEpatents

    Boller, Ernest R.; Eubank, Lowell D.

    2004-07-06

    The method of protectively coating metallic uranium which comprises dipping the metallic uranium in a molten alloy comprising about 20-75% of copper and about 80-25% of tin, dipping the coated uranium promptly into molten tin, withdrawing it from the molten tin and removing excess molten metal, thereupon dipping it into a molten metal bath comprising aluminum until it is coated with this metal, then promptly withdrawing it from the bath.

  10. Spin-Coated Polyelectrolyte Coacervate Films.

    PubMed

    Kelly, Kristopher D; Schlenoff, Joseph B

    2015-07-01

    Thin films of complexes made from oppositely charged polyelectrolytes have applications as supported membranes for separations, cell growth substrates, anticorrosion coatings, biocompatible coatings, and drug release media, among others. The relatively recent technique of layer-by-layer assembly reliably yields conformal coatings on substrates but is impractically slow for films with thickness greater than about 1 μm, even when accelerated many fold by spraying and/or spin assembly. In the present work, thin, uniform, smooth films of a polyelectrolyte complex (PEC) are rapidly made by spin-coating a polyelectrolyte coacervate, a strongly hydrated viscoelastic liquidlike form of PEC, on a substrate. While the apparatus used to deposit the PEC film is conventional, the behavior of the coacervate, especially the response to salt concentration, is highly nontraditional. After glassification by immersion in water, spun-on films may be released from their substrates to yield free-standing membranes of thickness in the micrometer range.

  11. High-mobility ultrathin semiconducting films prepared by spin coating

    NASA Astrophysics Data System (ADS)

    Mitzi, David B.; Kosbar, Laura L.; Murray, Conal E.; Copel, Matthew; Afzali, Ali

    2004-03-01

    The ability to deposit and tailor reliable semiconducting films (with a particular recent emphasis on ultrathin systems) is indispensable for contemporary solid-state electronics. The search for thin-film semiconductors that provide simultaneously high carrier mobility and convenient solution-based deposition is also an important research direction, with the resulting expectations of new technologies (such as flexible or wearable computers, large-area high-resolution displays and electronic paper) and lower-cost device fabrication. Here we demonstrate a technique for spin coating ultrathin (~50Å), crystalline and continuous metal chalcogenide films, based on the low-temperature decomposition of highly soluble hydrazinium precursors. We fabricate thin-film field-effect transistors (TFTs) based on semiconducting SnS2-xSex films, which exhibit n-type transport, large current densities (>105Acm-2) and mobilities greater than 10cm2V-1s-1-an order of magnitude higher than previously reported values for spin-coated semiconductors. The spin-coating technique is expected to be applicable to a range of metal chalcogenides, particularly those based on main group metals, as well as for the fabrication of a variety of thin-film-based devices (for example, solar cells, thermoelectrics and memory devices).

  12. Alloy Films Deposited by Electroplating as Precursors for Protective Oxide Coatings on Solid Oxide Fuel Cells Metallic Interconnect Materials

    SciTech Connect

    Johnson, Christopher; Gemmen, R.S.; Cross, Caleb

    2006-10-01

    The successful development of stainless steel interconnects for intermediate temperature solid oxide fuel cells (SOFC) may be the materials breakthrough that makes SOFC technology truly commercial. Many of the ferritic stainless steels, however, suffer from a relatively high area specific resistance (ASR) after long exposure times at temperature and the Cr in the native oxide can evaporate and contaminate other cell components. Conductive coatings that resist oxide scale growth and chromium evaporation may prevent both of these problems. In the present study electrochemical deposition of binary alloys followed by oxidation of the alloy to form protective and conductive oxide layers is examined. Results are presented for the deposition of Mn/Co and Fe/Ni alloys via electroplating to form a precursor for spinel oxide coating formation. Analysis of the alloy coatings is done by SEM, EDS and XRD.

  13. Analysis of Hard Thin Film Coating

    NASA Technical Reports Server (NTRS)

    Shen, Dashen

    1998-01-01

    MSFC is interested in developing hard thin film coating for bearings. The wearing of the bearing is an important problem for space flight engine. Hard thin film coating can drastically improve the surface of the bearing and improve the wear-endurance of the bearing. However, many fundamental problems in surface physics, plasma deposition, etc, need further research. The approach is using electron cyclotron resonance chemical vapor deposition (ECRCVD) to deposit hard thin film an stainless steel bearing. The thin films in consideration include SiC, SiN and other materials. An ECRCVD deposition system is being assembled at MSFC.

  14. Analysis of Hard Thin Film Coating

    NASA Technical Reports Server (NTRS)

    Shen, Dashen

    1998-01-01

    Marshall Space Flight Center (MSFC) is interested in developing hard thin film coating for bearings. The wearing of the bearing is an important problem for space flight engine. Hard thin film coating can drastically improve the surface of the bearing and improve the wear-endurance of the bearing. However, many fundamental problems in surface physics, plasma deposition, etc, need further research. The approach is using Electron Cyclotron Resonance Chemical Vapor Deposition (ECRCVD) to deposit hard thin film on stainless steel bearing. The thin films in consideration include SiC, SiN and other materials. An ECRCVD deposition system is being assembled at MSFC.

  15. Self Healing Coating/Film Project

    NASA Technical Reports Server (NTRS)

    Summerfield, Burton; Thompson, Karen; Zeitlin, Nancy; Mullenix, Pamela; Calle, Luz; Williams, Martha

    2015-01-01

    Kennedy Space Center (KSC) has been developing self healing materials and technologies. This project seeks to further develop self healing functionality in thin films for applications such as corrosion protective coatings, inflatable structures, space suit materials, and electrical wire insulation.

  16. Bulk metallic glass coating of polymer substrates

    NASA Astrophysics Data System (ADS)

    Soinila, Erno; Sharma, Parmanand; Heino, Markku; Pischow, Kaj; Inoue, Akihisa; Hänninen, Hannu

    2009-01-01

    Bulk Metallic Glass (BMG) alloy with the composition of Zr55Cu30Al10Ni5 was deposited by sputtering as thin films on several different engineering polymers and polymer composites. Polycarbonate, polymethyl methacrylate, polyamide 12, polyarylamide (50GF=50 % glass fibers), polyphenylene sulfide (30GF) and polybutylene terephthalate (30GF) were used as substrates. The microstructure of the deposited BMG coatings was studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results of XRD and SEM studies were consistent with amorphous microstructure. Elemental compositions of the coatings were verified by energy dispersive spectroscopy (EDS). Mechanical properties of the coatings were compared to copper mould cast BMG using nano- indentation tests with similar results. According to the cross-cut tape tests good adhesion was achieved between the studied BMG alloy and all other polymer substrates except polycarbonate. Nano-indentation results showed similar mechanical properties for coating and cast BMG. The results of this study look promising as they open new opportunities for BMG- polymer composite applications.

  17. Corrosion protective coating for metallic materials

    DOEpatents

    Buchheit, Rudolph G.; Martinez, Michael A.

    1998-01-01

    Corrosion protective coatings for metallic materials, particularly aluminum and aluminum alloys, produced with simple, low-cost equipment and materials other than toxic metals or metal salts, or metal cyanides. The metallic material is cleaned, degreased, and deoxidized, the surface is converted to a substantially alkaline condition, and the surface is chemically sealed with inorganic metal compounds.

  18. Corrosion protective coating for metallic materials

    DOEpatents

    Buchheit, R.G.; Martinez, M.A.

    1998-05-26

    Corrosion protective coatings for metallic materials, particularly aluminum and aluminum alloys, produced with simple, low-cost equipment and materials other than toxic metals or metal salts, or metal cyanides is disclosed. The metallic material is cleaned, degreased, and deoxidized, the surface is converted to a substantially alkaline condition, and the surface is chemically sealed with inorganic metal compounds. 1 fig.

  19. When are thin films of metals metallic?

    NASA Astrophysics Data System (ADS)

    Plummer, E. W.; Dowben, P. A.

    1993-04-01

    There is an increasing body of experimental information suggesting that very thin films of materials, normally considered to be metals, exhibit behavior characteristic of a nonmetal. In almost all cases, there is a nonmetal-to-metal transition as a function of film density or thickness, frequently accompanied by a structural transition. Amazingly, this behavior seems to occur for metal films on metal substrates, as well as for metals on semiconductors. The identification of this phenomena and the subsequent explanation has been slow in developing, due to the inability to directly measure the conductivity of a submonolayer film. This paper will discuss the evidence accumulated from variety of spectroscopic experimental techniques for three systems: a Mott-Hubbard transition, a Peierls-like distortion, and a Wilson transition.

  20. Tailoring Thin Film-Lacquer Coatings for Space Applications

    NASA Technical Reports Server (NTRS)

    Peters, Wanda C.; Harris, George; Miller, Grace; Petro, John

    1998-01-01

    Thin film coatings have the capability of obtaining a wide range of thermal radiative properties, but the development of thin film coatings can sometimes be difficult and costly when trying to achieve highly specular surfaces. Given any space mission's then-nal control requirements, there is often a need for a variation of solar absorptance (alpha(sub s)), emittance (epsilon) and/or highly specular surfaces. The utilization of thin film coatings is one process of choice for meeting challenging thermal control requirements because of its ability to provide a wide variety of alpha(sub s)/epsilon ratios. Thin film coatings' radiative properties can be tailored to meet specific thermal control requirements through the use of different metals and the variation of dielectric layer thickness. Surface coatings can be spectrally selective to enhance radiative coupling and decoupling. The application of lacquer to a surface can also provide suitable specularity for thin film application without the cost and difficulty associated with polishing.

  1. Tantalum-based thin film coatings for wear resistant arthroprostheses.

    PubMed

    Balagna, C; Faga, M G; Spriano, S

    2011-10-01

    Cobalt-chromium-molybdenum alloys with high carbon content (HC-CoCrMo) are widely used as materials for arthroprosthesis, in particular in metal-on-metal (MoM) hip joints. In spite of their good wear and corrosion resistance, production of metallic wear particles and metal ion release will occur on a large time-scale. An enhancement of the metal ion level in the patient's blood and urine is often reported in clinical data. Hypersensitivity, inflammatory response and cell necrosis can occur as consequence. So implants on young patients and women on childbearing age are not so widespread. The aim of this research is the realization of a thin film coating in order to improve the biocompatibility of Co-based alloys and to reduce debris production, ion release and citotoxicity. The innovative process consists of a thermal treatment in molten salts, in order to obtain a tantalum enriched thin film coating. Tantalum is chosen because it is considered a biocompatible metal with high corrosion resistance and low ion release. Three HC-CoCrMo alloys, produced by different manufacturing processes, are tested as substrates. The coating is a thin film of TaC or it can be composed by a multilayer of two tantalum carbides and metallic tantalum, depending on the temperature of the treatment and on the carbon content of the substrate. The thin films as well the substrates are characterized from the structural, chemical and morphological point of view. Moreover mechanical behaviour of treated and untreated materials is analyzed by means of nanohardness, scratch and ball-on-disc wear tests. The coating increases the mechanical and tribological properties of HC-CoCrMo.

  2. Coating to enhance metal-polymer adhesion

    SciTech Connect

    Parthasarathi, A.; Mahulikar, D.

    1996-12-31

    An ultra-thin electroplated coating has been developed to enhance adhesion of metals to polymers. The coating was developed for microelectronic packaging applications where it greatly improves adhesion of metal leadframes to plastic molding compounds. Recent tests show that the coating enhances adhesion of different metals to other types of adhesives as well and may thus have wider applicability. Results of adhesion tests with this coating, as well as its other characteristics such as corrosion resistance, are discussed. The coating is a very thin transparent electroplated coating containing zinc and chromium. It has been found to be effective on a variety of metal surfaces including copper alloys, Fe-Ni alloys, Al alloys, stainless steel, silver, nickel, Pd/Ni and Ni-Sn. Contact resistance measurements show that the coating has little or no effect on electrical resistivity.

  3. Overlay metallic-cermet alloy coating systems

    NASA Technical Reports Server (NTRS)

    Gedwill, M. A.; Levine, S. R.; Glasgow, T. K. (Inventor)

    1984-01-01

    A substrate, such as a turbine blade, vane, or the like, which is subjected to high temperature use is coated with a base coating of an oxide dispersed, metallic alloy (cermet). A top coating of an oxidation, hot corrosion, erosion resistant alloy of nickel, cobalt, or iron is then deposited on the base coating. A heat treatment is used to improve the bonding. The base coating serves as an inhibitor to interdiffusion between the protective top coating and the substrate. Otherwise, the protective top coating would rapidly interact detrimentally with the substrate and degrade by spalling of the protective oxides formed on the outer surface at elevated temperatures.

  4. Flexible thin metal film thermal sensing system

    NASA Technical Reports Server (NTRS)

    Thomsen, Donald L. (Inventor)

    2010-01-01

    A flexible thin metal film thermal sensing system is provided. A self-metallized polymeric film has a polymeric film region and a metal surface disposed thereon. A layer of electrically-conductive metal is deposited directly onto the self-metallized polymeric film's metal surface. Coupled to at least one of the metal surface and the layer of electrically-conductive metal is a device/system for measuring an electrical characteristic associated therewith as an indication of temperature.

  5. Influence of Metal Properties on the Formation and Evolution of Metal Coatings During Mechanical Coating

    NASA Astrophysics Data System (ADS)

    Hao, Liang; Lu, Yun; Sato, Hiromasa; Asanuma, Hiroshi; Guo, Jie

    2013-06-01

    Powders of Cu, Ti, Ni, Fe, and Zn metals were used to prepare coatings on the surfaces of Al2O3 balls by the mechanical coating technique. The coated Al2O3 balls were characterized with XRD and SEM. The results showed that all the metal powders except Ni formed continuous metal coatings. The evolution of metal coatings during mechanical coating was also investigated. The analysis indicates that as long as continuous metal coatings can be formed, the evolution can fall into the following stages: nucleation, formation and coalescence of discrete islands, formation and thickening of continuous coatings, and exfoliation of continuous coatings. Electronegativity of the metal was shown to have a major effect on the adhesion of the tiny metal particles on the surfaces of the Al2O3 balls during the initial stage of mechanical coating. The lower the electronegativity of the metal, the greater the coverage of the metal on the Al2O3 ball and the easier the adhesion of the tiny metal particles. Further, the better the plastic deformability of metal, the easier the cold welding among metal powder particles and the greater the thickness of the continuous metal coatings.

  6. The opacity of tablet film coatings.

    PubMed

    Rowe, R C

    1984-09-01

    The opacity of tablet film coatings containing a variety of pigments and fillers has been assessed using a contrast ratio defined as the ratio of the measured reflectance of the incident light when the film is placed on a black substrate to the measured reflectance of the incident light when the film is placed on a white substrate. Films pigmented with calcium carbonate, calcium sulphate or talc had very low contrast ratios and only the inclusion of titanium dioxide imparted opacity. Films pigmented with the coloured lake pigments had contrast ratios dependent on both the parent dye and the dye concentration with the contrast ratios decreasing blue greater than red greater than orange greater than yellow. Films pigmented with the synthetic iron oxides all had very high contrast ratios. The results are consistent with the known theories of light scattering and absorption and illustrate the potential of this accurate, rapid and simple technique in the optimization of film formulations during product development.

  7. Metallic Thin-Film Bonding and Alloy Generation

    NASA Technical Reports Server (NTRS)

    Fryer, Jack Merrill (Inventor); Campbell, Geoff (Inventor); Peotter, Brian S. (Inventor); Droppers, Lloyd (Inventor)

    2016-01-01

    Diffusion bonding a stack of aluminum thin films is particularly challenging due to a stable aluminum oxide coating that rapidly forms on the aluminum thin films when they are exposed to atmosphere and the relatively low meting temperature of aluminum. By plating the individual aluminum thin films with a metal that does not rapidly form a stable oxide coating, the individual aluminum thin films may be readily diffusion bonded together using heat and pressure. The resulting diffusion bonded structure can be an alloy of choice through the use of a carefully selected base and plating metals. The aluminum thin films may also be etched with distinct patterns that form a microfluidic fluid flow path through the stack of aluminum thin films when diffusion bonded together.

  8. Thin-film metal hydrides.

    PubMed

    Remhof, Arndt; Borgschulte, Andreas

    2008-12-01

    The goal of the medieval alchemist, the chemical transformation of common metals into nobel metals, will forever be a dream. However, key characteristics of metals, such as their electronic band structure and, consequently, their electric, magnetic and optical properties, can be tailored by controlled hydrogen doping. Due to their morphology and well-defined geometry with flat, coplanar surfaces/interfaces, novel phenomena may be observed in thin films. Prominent examples are the eye-catching hydrogen switchable mirror effect, the visualization of solid-state diffusion and the formation of complex surface morphologies. Thin films do not suffer as much from embrittlement and/or decrepitation as bulk materials, allowing the study of cyclic absorption and desorption. Therefore, thin-metal hydride films are used as model systems to study metal-insulator transitions, for high throughput combinatorial research or they may be used as indicator layers to study hydrogen diffusion. They can be found in technological applications as hydrogen sensors, in electrochromic and thermochromic devices. In this review, we discuss the effect of hydrogen loading of thin niobium and yttrium films as archetypical examples of a transition metal and a rare earth metal, respectively. Our focus thereby lies on the hydrogen induced changes of the electronic structure and the morphology of the thin films, their optical properties, the visualization and the control of hydrogen diffusion and on the study of surface phenomena and catalysis.

  9. Infiltration processing of metal matrix composites using coated ceramic particulates

    NASA Astrophysics Data System (ADS)

    Leon-Patino, Carlos Alberto

    2001-07-01

    A new process was developed to fabricate particulate metal matrix composites (MMCs). The process involves three steps: (1) modifying the particulate surface by metal coating, (2) forming a particulate porous compact; and (3) introducing metal into the channel network by vacuum infiltration. MMCs with different reinforcements, volume fractions, and sizes can be produced by this technique. Powders of alumina and silicon carbide were successfully coated with nickel and copper in preparation for infiltration with molten aluminum. Electroless Ni and Cu deposition was used since it enhances the wettability of the reinforcements for composite fabrication. While Cu deposits were polycrystalline, traces of phosphorous co-deposited from the electroless bath gave an amorphous Ni-P coating. The effect of metal coating on wetting behavior was evaluated at 800°C on plain and metal-coated ceramic plates using a sessile drop technique. The metallic films eliminated the non-wetting behavior of the uncoated ceramics, leading to equilibrium contact angles in the order of 12° and below 58° for Ni and Cu coated ceramics, respectively. The spreading data indicated that local diffusion at the triple junction was the governing mechanism of the wetting process. Precipitation of intermetallic phases in the drop/ceramic interface delayed the formation of Al4C3. Infiltration with molten Al showed that the coated-particulates are suitable as reinforcing materials for fabricating MMCs, giving porosity-free components with a homogeneously distributed reinforcing phase. The coating promoted easy metal flow through the preform, compared to the non-infiltration behavior of the uncoated counterparts. Liquid state diffusion kinetics due to temperature dependent viscosity forces controlled the infiltration process. Microstructural analysis indicated the formation of intermetallic phases such as CuAl 2, in the case of Cu coating, and Ni2Al3 and NiAl 3 when Ni-coated powders were infiltrated. The

  10. Antimicrobial edible films and coatings.

    PubMed

    Cagri, Arzu; Ustunol, Zeynep; Ryser, Elliot T

    2004-04-01

    Increasing consumer demand for microbiologically safer foods, greater convenience, smaller packages, and longer product shelf life is forcing the industry to develop new food-processing, cooking, handling, and packaging strategies. Nonfluid ready-to-eat foods are frequently exposed to postprocess surface contamination, leading to a reduction in shelf life. The food industry has at its disposal a wide range of nonedible polypropylene- and polyethylene-based packaging materials and various biodegradable protein- and polysaccharide-based edible films that can potentially serve as packaging materials. Research on the use of edible films as packaging materials continues because of the potential for these films to enhance food quality, food safety, and product shelf life. Besides acting as a barrier against mass diffusion (moisture, gases, and volatiles), edible films can serve as carriers for a wide range of food additives, including flavoring agents, antioxidants, vitamins, and colorants. When antimicrobial agents such as benzoic acid, sorbic acid, propionic acid, lactic acid, nisin, and lysozyme have been incorporated into edible films, such films retarded surface growth of bacteria, yeasts, and molds on a wide range of products, including meats and cheeses. Various antimicrobial edible films have been developed to minimize growth of spoilage and pathogenic microorganisms, including Listeria monocytogenes, which may contaminate the surface of cooked ready-to-eat foods after processing. Here, we review the various types of protein-based (wheat gluten, collagen, corn zein, soy, casein, and whey protein), polysaccharide-based (cellulose, chitosan, alginate, starch, pectin, and dextrin), and lipid-based (waxes, acylglycerols, and fatty acids) edible films and a wide range of antimicrobial agents that have been or could potentially be incorporated into such films during manufacture to enhance the safety and shelf life of ready-to-eat foods.

  11. Real-time measurement of protein adsorption on electrophoretically deposited hydroxyapatite coatings and magnetron sputtered metallic films using the surface acoustic wave technique.

    PubMed

    Meininger, M; Schmitz, T; Wagner, T; Ewald, A; Gbureck, U; Groll, J; Moseke, C

    2016-04-01

    Surface acoustic wave (SAW) biosensors are highly sensitive for mass binding and are therefore used to detect protein-protein and protein-antibody interactions. Whilst the standard surface of the chips is a thin gold film, measurements on implant- or bone-like surfaces could significantly enhance the range of possible applications for this technique. The aim of this study was to establish methods to coat biosensor chips with Ti, TiN, and silver-doped TiN using physical vapor deposition as well as with hydroxyapatite by electrophoresis. To demonstrate that protein adsorption can be detected on these surfaces, binding experiments with fibronectin and fibronectin-specific antibodies have been performed with the coatings, which successfully proved the applicability of PVD and EPD for SAW biosensor functionalization.

  12. New dielectric thin film coatings for silver and copper coated hollow infrared waveguides

    NASA Astrophysics Data System (ADS)

    George, Roshan J.

    Hollow waveguides have been developed for many years but their losses are still much greater than those for solid-core fiber optics. The primary emphasis in this work is the development of new metallic and dielectric coatings which may be used as coatings for lower loss hollow waveguides. Much of the work involves the use of polymer tubing coated with Ag and Cu films overcoated with new dielectric coatings. These new metal, metal halide, and chalcogenide thin film coatings were developed and optimized for the fabrication of improved waveguides. The optical properties of the hollow waveguides were modeled and compared to measurements of the waveguide's spectral and transmission characteristics in the IR range between 1 and 15 mum. The optical loss, 2alpha in a hollow waveguide is strongly dependent on its core size, 2a, i.e. alpha ∝ 1a . We have exploited this feature to produce large bore hollow waveguides with a very low transmission loss on the order of 10 dB/km. The current thin film processing technology, used for fabricating hollow glass waveguide (HGW), was extended and several new polymer based waveguides developed. In particular, the hollow polycarbonate waveguide (PC-HPW) has excellent optical properties rivaling those of the hollow silica waveguides. The lowest measured loss was 0.017 dB/m at 10.6 mum for the 2000 mum bore guide. In fact, this is the currently the lowest reported loss for any waveguide at this wavelength. The thin film coatings used in these guides namely, silver and silver iodide, were extensively characterized in terms of the deposition kinetics, roughness of the layers, optical constants, and crystal structure. In addition to the laser loss measurements, the spectral response, polarization maintenance, output divergence, and the modal distribution were all measured. An all-new waveguide was fabricated using copper and copper iodide thin film coatings. Both silica and polycarbonate substrates were used for forming these layers. This

  13. Plasma-Spray Metal Coating On Foam

    NASA Technical Reports Server (NTRS)

    Cranston, J.

    1994-01-01

    Molds, forms, and other substrates made of foams coated with metals by plasma spraying. Foam might be ceramic, carbon, metallic, organic, or inorganic. After coat applied by plasma spraying, foam left intact or removed by acid leaching, conventional machining, water-jet cutting, or another suitable technique. Cores or vessels made of various foam materials plasma-coated with metals according to method useful as thermally insulating containers for foods, liquids, or gases, or as mandrels for making composite-material (matrix/fiber) parts, or making thermally insulating firewalls in automobiles.

  14. Characterization of Thin Films and Coatings

    SciTech Connect

    Baer, Donald R.; Thevuthasan, Suntharampillai

    2010-01-01

    Just as the numbers and types of thin films have grown dramatically, the needs and approaches for their characterization have also expanded significantly. Adequate characterization of a film or coating depends on the process to create the coating as well as the planned or potential application(s) and expected lifetime. Characterization of a coating or film necessarily requires application of methods that determine properties of the coating and not primarily the substrate. This places some focus on methods that determine properties of layers and not "bulk" material. However, the increasing importance of micro- and nano-structures in coatings and films places an increased importance in methods with high spatial resolution. The growing use of organic films and coatings and the importance of molecular functionalization of inorganic surfaces increase the importance for different types of molecular characterization tools. In most circumstances appropriate characterization requires use of a combination of tools. The purpose of this chapter is to provide an introduction to the basic methods and overview applications for some of the most important tools for characterization of films, coatings and surfaces. The chapter will be organized in six sections: • Technique Overview – This section provides a high level summary of the types of information that can be obtained by different methods and includes information about their sensitivity and resolution. • Incident Photon Methods – Techniques involving incident photons are described and some brief examples of application are shown. Methods included are: x-ray photoelectron spectroscopy (XPS), x-ray diffraction (XRD), x-ray reflectivity (XRR), Fourier transform infra-red spectroscopy (FTIR), laser Raman spectroscopy, ellipsometry, and photoluminescence spectroscopy. • Incident Ion Methods - Methods initiated by ion irradiation are summarized including: Rutherford backscattering spectrometry (RBS), nuclear reaction

  15. Formulating Precursors for Coating Metals and Ceramics

    NASA Technical Reports Server (NTRS)

    Morales, Wilfredo; Gatica, Jorge E.; Reye, John T.

    2005-01-01

    A protocol has been devised for formulating low-vapor-pressure precursors for protective and conversion coatings on metallic and ceramic substrates. The ingredients of a precursor to which the protocol applies include additives with phosphate esters, or aryl phosphate esters in solution. Additives can include iron, chromium, and/or other transition metals. Alternative or additional additives can include magnesium compounds to facilitate growth of films on substrates that do not contain magnesium. Formulation of a precursor begins with mixing of the ingredients into a high-vapor-pressure solvent to form a homogeneous solution. Then the solvent is extracted from the solution by evaporation - aided, if necessary, by vacuum and/or slight heating. The solvent is deemed to be completely extracted when the viscosity of the remaining solution closely resembles the viscosity of the phosphate ester or aryl phosphate ester. In addition, satisfactory removal of the solvent can be verified by means of a differential scanning calorimetry essay: the absence of endothermic processes for temperatures below 150 C would indicate that the residual solvent has been eliminated from the solution beyond a detectable dilution level.

  16. Introduction: Edible Coatings and Films to Improve Food Quality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This book gives a history of the development and uses of edible coatings, detailed chapters on coating caracteristics, determination of coating properties, methods for making coatings, and discription of coating film formers (polysaccharieds, lipids, resins, proteins). The book also disucsses coatin...

  17. Molecular Level Coating for Metal Oxide Particles

    NASA Technical Reports Server (NTRS)

    McDaniel, Patricia R. (Inventor); Saint Clair, Terry L. (Inventor)

    2000-01-01

    Polymer encapsulated metal oxide particles are prepared by combining a polyamide acid in a polar aprotic solvent with a metal alkoxide solution. The polymer was imidized and the metal oxide formed simultaneously in a refluxing organic solvent. The resulting polymer-metal oxide is an intimately mixed commingled blend, possessing synergistic properties of both the polymer and preceramic metal oxide. The encapsulated metal oxide particles have multiple uses including, being useful in the production of skin lubricating creams, weather resistant paints, as a filler for paper, making ultraviolet light stable filled printing ink, being extruded into fibers or ribbons, and coatings for fibers used in the production of composite structural panels.

  18. Aerosol chemical vapor deposition of metal oxide films

    DOEpatents

    Ott, Kevin C.; Kodas, Toivo T.

    1994-01-01

    A process of preparing a film of a multicomponent metal oxide including: forming an aerosol from a solution comprised of a suitable solvent and at least two precursor compounds capable of volatilizing at temperatures lower than the decomposition temperature of said precursor compounds; passing said aerosol in combination with a suitable oxygen-containing carrier gas into a heated zone, said heated zone having a temperature sufficient to evaporate the solvent and volatilize said precursor compounds; and passing said volatilized precursor compounds against the surface of a substrate, said substrate having a sufficient temperature to decompose said volatilized precursor compounds whereby metal atoms contained within said volatilized precursor compounds are deposited as a metal oxide film upon the substrate is disclosed. In addition, a coated article comprising a multicomponent metal oxide film conforming to the surface of a substrate selected from the group consisting of silicon, magnesium oxide, yttrium-stabilized zirconium oxide, sapphire, or lanthanum gallate, said multicomponent metal oxide film characterized as having a substantially uniform thickness upon said FIELD OF THE INVENTION The present invention relates to the field of film coating deposition techniques, and more particularly to the deposition of multicomponent metal oxide films by aerosol chemical vapor deposition. This invention is the result of a contract with the Department of Energy (Contract No. W-7405-ENG-36).

  19. Amorphous metallic films in silicon metallization systems

    NASA Technical Reports Server (NTRS)

    So, F.; Kolawa, E.; Nicolet, M. A.

    1985-01-01

    Diffusion barrier research was focussed on lowering the chemical reactivity of amorphous thin films on silicon. An additional area of concern is the reaction with metal overlays such as aluminum, silver, and gold. Gold was included to allow for technology transfer to gallium arsenide PV cells. Amorphous tungsten nitride films have shown much promise. Stability to annealing temperatures of 700, 800, and 550 C were achieved for overlays of silver, gold, and aluminum, respectively. The lower results for aluminum were not surprising because there is an eutectic that can form at a lower temperature. It seems that titanium and zirconium will remove the nitrogen from a tungsten nitride amorphous film and render it unstable. Other variables of research interest were substrate bias and base pressure during sputtering.

  20. METHOD FOR COATING GRAPHITE WITH METALLIC CARBIDES

    DOEpatents

    Steinberg, M.A.

    1960-03-22

    A method for producing refractory coatings of metallic carbides on graphite was developed. In particular, the graphite piece to be coated is immersed in a molten solution of 4 to 5% by weight of zirconium, titanium, or niobium dissolved in tin. The solution is heated in an argon atmosphere to above 1400 deg C, whereby the refractory metal reacts with the surface of the graphite to form a layer of metalic carbide. The molten solution is cooled to 300 to 400 deg C, and the graphite piece is removed. Excess tin is wiped from the graphite, which is then heated in vacuum to above 2300 deg C. The tin vaporizes from the graphite surface, leaving the surface coated with a tenacious layer of refractory metallic carbide.

  1. Charge transport across the metal-polymer film boundary

    NASA Astrophysics Data System (ADS)

    Yumaguzin, Yu. M.; Salikhov, T. R.; Shayakhmetov, R. U.; Salikhov, R. B.

    2016-08-01

    Thin polyaniline films were fabricated by thermal vacuum evaporation from a Knudsen effusion cell. The conducting properties of films synthesized under different evaporation conditions were studied. The enhancement of the emission capacity of a wolfram tip coated with a polyaniline film of a nanometer thickness was demonstrated experimentally. A model of the discovered effect was proposed. The obtained Fowler-Nordheim current-voltage characteristics were used to estimate the change in the electronic work function occurring when a thin film is deposited on the tip surface. The effective temperature of electrons emitted from the polyaniline film was determined based on the results of analysis of energy distributions, and the specific features of charge transport in the metal-polyaniline-vacuum system were examined. A model of energy bands of the metal-polymer film contact was also constructed.

  2. Applications of thin carbon coatings and films in injection molding

    NASA Astrophysics Data System (ADS)

    Cabrera, Eusebio Duarte

    In this research, the technical feasibility of two novel applications of thin carbon coatings is demonstrated. The first application consists of using thin carbon coatings on molds for molding ultra-thin plastic parts (<0.5 mm thickness) with lower pressures by promoting wall slip. The second application consists of a new approach to provide electromagnetic interference (EMI) shielding for plastic parts using in mold coated nanoparticle thin films or nanopapers to create a conductive top layer. During this research, the technical feasibility of a new approach was proven which provides injection molding of ultra-thin parts at lower pressures, without the need of fast heating/fast cooling or other expensive mold modification. An in-house developed procedure by other members of our group, was employed for coating the mold surface using chemical vapor deposition (CVD) resulting in a graphene coating with carbide bonding to the mold surface. The coating resulted in a significant decrease of surface friction and consequently easiness of flow when compared to their uncoated counterparts. Thermoplastic polymers and their composites are a very attractive alternative but are hindered by the non-conductive nature of polymers. There are two general approaches used to date to achieve EMI shielding for plastic products. One is to spray a conductive metal coating onto the plastic surface forming a layer that must maintain its shielding effectiveness (SE), and its adhesion to the plastic throughout the expected life of the product. However, metal coatings add undesirable weight and tend to corrode over time. Furthermore, scratching the coating may create shielding failure; therefore, a protective topcoat may be required. The other approach is to use polymer composites filled with conductive fillers such as carbon black (CB), carbon nanofiber (CNF), and carbon nanotube (CNT). While conductive fillers may increase the electrical conductivity of polymer composites, the loading of

  3. Process for fabrication of metal oxide films

    SciTech Connect

    Tracy, C.E.; Benson, D.; Svensson, S.

    1990-07-17

    This invention is comprised of a method of fabricating metal oxide films from a plurality of reactants by inducing a reaction by plasma deposition among the reactants. The plasma reaction is effective for consolidating the reactants and producing thin films of metal oxides, e.g. electro-optically active transition metal oxides, at a high deposition rate. The presence of hydrogen during the plasma reaction enhances the deposition rate of the metal oxide. Various types of metal oxide films can be produced.

  4. Extraordinary optical transmission in nanopatterned ultrathin metal films without holes

    DOE PAGESBeta

    Peer, Akshit; Biswas, Rana

    2016-02-01

    In this study, we experimentally and theoretically demonstrate that a continuous gold film on a periodically textured substrate exhibits extraordinary optical transmission, even though no holes were etched in the film. Our film synthesis started by nanoimprinting a periodic array of nanocups with a period of ~750 nm on a polystyrene film over a glass substrate. A thin non-conformal gold film was sputter-deposited on the polystyrene by angle-directed deposition. The gold film was continuous with spatial thickness variation, the film being thinnest at the bottom of the nanocup. Measurements revealed an extraordinary transmission peak at a wavelength just smaller thanmore » the period, with an enhancement of ~2.5 compared to the classically expected value. Scattering matrix simulations model well the transmission and reflectance measurements when an ultrathin gold layer (~5 nm), smaller than the skin depth is retained at the bottom of the nanocups. Electric field intensities are enhanced by >100 within the nanocup, and ~40 in the ultrathin gold layer causing transmission through it. We show a wavelength red-shift of ~30 nm in the extraordinary transmission peak when the nanocups are coated with a thin film of a few nanometers, which can be utilized for biosensing. The continuous corrugated metal films are far simpler structures to observe extraordinary transmission, circumventing the difficult process of etching the metal film. Such continuous metal films with ultrathin regions are simple platforms for non-linear optics, plasmonics, and biological and chemical sensing.« less

  5. Study of two different thin film coating methods in transmission laser micro-joining of thin Ti-film coated glass and polyimide for biomedical applications.

    PubMed

    Sultana, T; Georgiev, G L; Baird, R J; Auner, G W; Newaz, G; Patwa, R; Herfurth, H J

    2009-07-01

    Biomedical devices and implants require precision joining for hermetic sealing which can be achieved with low power lasers. The effect of two different thin metal film coating methods was studied in transmission laser micro-joints of titanium-coated glass and polyimide. The coating methods were cathodic arc physical vapor deposition (CA-PVD) and electron beam evaporation (EB-PVD). Titanium-coated glass joined to polyimide film can have neural electrode application. The improvement of the joint quality will be essential for robust performance of the device. Low power fiber laser (wave length = 1100 nm) was used for transmission laser micro-joining of thin titanium (Ti) film (approximately 200 nm) coated Pyrex borosilicate 7740 glass wafer (0.5 mm thick) and polyimide (Imidex) film (0.2 mm thick). Ti film acts as the coupling agent in the joining process. The Ti film deposition rate in the CA-PVD was 5-10 A/s and in the EB-PVD 1.5 A/s. The laser joint strength was measured by a lap shear test, the Ti film surfaces were analyzed by atomic force microscopy (AFM) and the lap shear tested joints were analyzed by optical microscopy and scanning electron microscopy (SEM). The film properties and the failure modes of the joints were correlated to joint strength. The CA-PVD produced around 4 times stronger laser joints than EB-PVD. The adhesion of the Ti film on glass by CA-PVD is better than that of the EB-PVD method. This is likely to be due to a higher film deposition rate and consequently higher adhesion or sticking coefficient for the CA-PVD particles arriving on the substrate compared to that of the EB-PVD film. EB-PVD shows poor laser bonding properties due to the development of thermal hotspots which occurs from film decohesion. PMID:19627828

  6. Metal alloy coatings and methods for applying

    DOEpatents

    Merz, Martin D.; Knoll, Robert W.

    1991-01-01

    A method of coating a substrate comprises plasma spraying a prealloyed feed powder onto a substrate, where the prealloyed feed powder comprises a significant amount of an alloy of stainless steel and at least one refractory element selected from the group consisting of titanium, zirconium, hafnium, niobium, tantalum, molybdenum, and tungsten. The plasma spraying of such a feed powder is conducted in an oxygen containing atmosphere and forms an adherent, corrosion resistant, and substantially homogenous metallic refractory alloy coating on the substrate.

  7. High temperature barrier coatings for refractory metals

    NASA Technical Reports Server (NTRS)

    Malone, G. A.; Walech, T.

    1995-01-01

    Improvements in high temperature oxidation resistant metal coating technology will allow NASA and commercial entities to develop competitive civil space transport and communication systems. The success of investigations completed in this program will have a positive impact on broadening the technology base for high temperature materials. The work reported herein describes processes and procedures for successfully depositing coherent oxidation barrier coatings on refractory metals to prevent degradation under very severe operating environments. Application of the new technology developed is now being utilized in numerous Phase 3 applications through several prominent aerospace firms. Major achievements have included: (1) development of means to deposit thick platinum and rhodium coatings with lower stress and fewer microcracks than could be previously achieved; (2) development of processes to deposit thick adherent coatings of platinum group metals on refractory substrates that remain bonded through high temperature excursions and without need for intermediate coatings (bonding processes unique to specific refractory metals and alloys have been defined; (3) demonstration that useful alloys of refractory and platinum coatings can be made through thermal diffusion means; (4) demonstration that selected barrier coatings on refractory substrates can withstand severe oxidizing environments in the range of 1260 deg and 1760 deg C for long time periods essential to the life requirements of the hardware; and (5) successful application of the processes and procedures to prototype hardware. The results of these studies have been instrumental in improved thermal oxidation barrier coatings for the NASP propulsion system. Other Phase 3 applications currently being exploited include small uncooled thrusters for spacecraft and microsatellite maneuvering systems.

  8. Metallic seal for thermal barrier coating systems

    NASA Technical Reports Server (NTRS)

    Miller, Robert A. (Inventor)

    1990-01-01

    The invention is particularly concerned with sealing thermal barrier coating systems of the type in use and being contemplated for use in diesel and other internal combustion engines. The invention also would find application in moderately high temperature regions of gas turbine engines and any other application employing a thermal barrier coating at moderate temperatures. Ni-35Cr-6Al-1Y, Ni-35Cr-6Al-1Yb, or other metallic alloy denoted as MCrAlx is applied over a zirconia-based thermal barrier overlayer. The close-out layer is glass-bead preened to densify its surface. This seals and protects the thermal barrier coating system.

  9. Metallic coating reduces thermal stress

    NASA Technical Reports Server (NTRS)

    Morgan, R. D.

    1977-01-01

    Addition of metallic outer layer deposited by standard plating method, having high thermal conductivity, substantially reduces thermal stress in high-temperature/high-strength materials, preventing structural overloads.

  10. Channel cracks in atomic-layer and molecular-layer deposited multilayer thin film coatings

    SciTech Connect

    Long, Rong; Dunn, Martin L.

    2014-06-21

    Metal oxide thin film coatings produced by atomic layer deposition have been shown to be an effective permeation barrier. The primary failure mode of such coatings under tensile loads is the propagation of channel cracks that penetrate vertically into the coating films. Recently, multi-layer structures that combine the metal oxide material with relatively soft polymeric layers produced by molecular layer deposition have been proposed to create composite thin films with desired properties, including potentially enhanced resistance to fracture. In this paper, we study the effects of layer geometry and material properties on the critical strain for channel crack propagation in the multi-layer composite films. Using finite element simulations and a thin-film fracture mechanics formalism, we show that if the fracture energy of the polymeric layer is lower than that of the metal oxide layer, the channel crack tends to penetrate through the entire composite film, and dividing the metal oxide and polymeric materials into thinner layers leads to a smaller critical strain. However, if the fracture energy of the polymeric material is high so that cracks only run through the metal oxide layers, more layers can result in a larger critical strain. For intermediate fracture energy of the polymer material, we developed a design map that identifies the optimal structure for given fracture energies and thicknesses of the metal oxide and polymeric layers. These results can facilitate the design of mechanically robust permeation barriers, an important component for the development of flexible electronics.

  11. Photobiomolecular metallic particles and films

    DOEpatents

    Hu, Zhong-Cheng

    2003-05-06

    The method of the invention is based on the unique electron-carrying function of a photocatalytic unit such as the photosynthesis system I (PSI) reaction center of the protein-chlorophyll complex isolated from chloroplasts. The method employs a photo-biomolecular metal deposition technique for precisely controlled nucleation and growth of metallic clusters/particles, e.g., platinum, palladium, and their alloys, etc., as well as for thin-film formation above the surface of a solid substrate. The photochemically mediated technique offers numerous advantages over traditional deposition methods including quantitative atom deposition control, high energy efficiency, and mild operating condition requirements.

  12. METAL COATED ARTICLES AND METHOD OF MAKING

    DOEpatents

    Eubank, L.D.

    1958-08-26

    A method for manufacturing a solid metallic uranium body having an integral multiple layer protective coating, comprising an inner uranium-aluminum alloy firmly bonded to the metallic uranium is presented. A third layer of silver-zinc alloy is bonded to the zinc-aluiminum layer and finally a fourth layer of lead-silver alloy is firmly bonded to the silver-zinc layer.

  13. Simple Methods for Production of Nanoscale Metal Oxide Films from Household Sources

    ERIC Educational Resources Information Center

    Campbell, Dean J.; Baliss, Michelle S.; Hinman, Jordan J.; Ziegenhorn, John W.; Andrews, Mark J.; Stevenson, Keith J.

    2013-01-01

    Production of thin metal oxide films was recently explored as part of an outreach program with a goal of producing nanoscale structures with household items. Household items coated with various metals or titanium compounds can be heated to produce colorful films with nanoscale thicknesses. As part of a materials chemistry laboratory experiment…

  14. Characteristics and cytocompatibility of biodegradable polymer film on magnesium by spin coating.

    PubMed

    Xu, Liping; Yamamoto, Akiko

    2012-05-01

    In recent years, magnesium and its alloys have been investigated as biodegradable metallic materials in cardiovascular stents and bone implants. However, rapid corrosion rate in the early stage of the degradation process greatly influences the cytocompatibility and hinters their application. In this research, biodegradable polymer films are prepared under same coating condition by spin coating in order to improve the early corrosion resistance and cytocompatibility of Mg. The results present that uniform, nonporous, amorphous PLLA and semi-crystalline PCL films are coated on Mg. PLLA film shows better adhesion strength to Mg substrate than that of PCL film. For both PLLA and PCL, low molecular weight (LMW) film is thinner and exhibits better adhesion strength than high molecular weight (HMW) one. SaOS-2 cells show significantly good attachment and high growth on the polymer-coated Mg, demonstrating that all the polymer films can significantly improve the cytocompatibility in the 7-day incubation. The pH measurement of the immersion medium and the quantification of released Mg(2+) during the cell culture clearly indicate that the corrosion resistance of Mg substrate is improved by the polymer films to different extents. It can be concluded that both PLLA and PCL films are promising protective coatings for improving the initial corrosion resistance and cytocompatibility.

  15. Indium doped zinc oxide nanowire thin films for antireflection and solar absorber coating applications

    SciTech Connect

    Shaik, Ummar Pasha; Krishna, M. Ghanashyam

    2014-04-24

    Indium doped ZnO nanowire thin films were prepared by thermal oxidation of Zn-In metal bilayer films at 500°C. The ZnO:In nanowires are 20-100 nm in diameter and several tens of microns long. X-ray diffraction patterns confirm the formation of oxide and indicate that the films are polycrystalline, both in the as deposited and annealed states. The transmission which is <2% for the as deposited Zn-In films increases to >90% for the ZnO:In nanowire films. Significantly, the reflectance for the as deposited films is < 10% in the region between 200 to 1500 nm and < 2% for the nanowire films. Thus, the as deposited films can be used solar absorber coatings while the nanowire films are useful for antireflection applications. The growth of nanowires by this technique is attractive since it does not involve very high temperatures and the use of catalysts.

  16. Sol-gel metal oxide and metal oxide/polymer multilayers applied by meniscus coating

    SciTech Connect

    Britten, J.A.; Thomas, I.M.

    1993-10-01

    We are developing a meniscus coating process for manufacturing large-aperture dielectric multilayer high reflectors (HR`s) at ambient conditions from liquid suspensions. Using a lab-scale coater capable of coating 150 mm square substrates, we have produced several HR`s which give 99% + reflection with 24 layers and with edge effects confined to about 10 mm. In calendar 1993 we are taking delivery of an automated meniscus coating machine capable of coating substrates up to 400 mm wide and 600 mm long. The laser-damage threshold and failure stress of sol-gel thin films can be substantially increased through the use of soluble polymers which act as binders for the metal oxide particles comprising the deposited film. Refractive index control of the film is also possible through varying the polymer/oxide ratio. Much of our present effort present is in optimizing oxide particle/binder/solvent formulations for the high-index material. Films from colloidal zirconia strengthened with polyvinylpyrollidone (PVP) have given best results to date. An increase in the laser damage threshold (LDT) for single layers has been shown to significantly increase with increased polymer loading, but as yet the LDT for multilayer stacks remains low.

  17. Thin films of mixed metal compounds

    DOEpatents

    Mickelsen, Reid A.; Chen, Wen S.

    1985-01-01

    A compositionally uniform thin film of a mixed metal compound is formed by simultaneously evaporating a first metal compound and a second metal compound from independent sources. The mean free path between the vapor particles is reduced by a gas and the mixed vapors are deposited uniformly. The invention finds particular utility in forming thin film heterojunction solar cells.

  18. Thin film hydrous metal oxide catalysts

    DOEpatents

    Dosch, Robert G.; Stephens, Howard P.

    1995-01-01

    Thin film (<100 nm) hydrous metal oxide catalysts are prepared by 1) synthesis of a hydrous metal oxide, 2) deposition of the hydrous metal oxide upon an inert support surface, 3) ion exchange with catalytically active metals, and 4) activating the hydrous metal oxide catalysts.

  19. The gravity effect on spin coating glucose thin film

    NASA Astrophysics Data System (ADS)

    Han, P.; Wang, H.

    2016-07-01

    We demonstrate the gravity effect on spin-coated glucose film by comparing properties of films fabricated by two different methods: erected spin coating (ESC) and inverted spin coating (ISC). A “Bi-Layer” model, i.e. substrate effect layer and free layer, for spin coating is proposed to analyze the gravity effect on spin coating process which offers a more accurate prediction on film thickness. The thickness and deposition pattern are different in samples fabricated by ESC and ISC methods in titrating-repeated spin coating experiment. Finally, in a glucose coating/ferromagnetic composite structure, an enhanced Kerr rotation with the enhancement factor of 2.11 is achieved by ISC method.

  20. Protective coatings of metal surfaces by cold plasma treatment

    NASA Technical Reports Server (NTRS)

    Manory, R.; Grill, A.

    1985-01-01

    The cold plasma techniques for deposition of various types of protective coatings are reviewed. The main advantage of these techniques for deposition of ceramic films is the lower process temperature, which enables heat treating of the metal prior to deposition. In the field of surface hardening of steel, significant reduction of treatment time and energy consumption were obtained. A simple model for the plasma - surface reactions in a cold plasma system is presented, and the plasma deposition techniques are discussed in view of this model.

  1. New Measurement Method for Adhesion of Hard Coating Film

    NASA Astrophysics Data System (ADS)

    Ikenaga, Kaoru; Yanagida, Akira; Azushima, Akira

    Various surface coating technologies have been applied to improve the tribological and mechanical properties of thin films. For the use of surface modified tools and parts under severe conditions, thin films with high adhesion strength are required. To quantitatively measure the adhesion of coating films on substrates a new method for the measurement of hard coating film was developed which consists of an indentation and an AE (Acoustic Emission) system. TiN coatings were deposited onto substrates using arc ion plating PVD. Indentation tests were conducted on substrates with different film thicknesses of 3, 5, and 7 μm. Two specific loads, denoted the “Critical load”, and the “Fracture load” were defined. The critical load and fracture load correlate to the initiation of delamination and film fracture. The critical load was calculated a finite element calculation and SEM observation.

  2. Sustainable films and coatings from hemicelluloses: a review.

    PubMed

    Hansen, Natanya M L; Plackett, David

    2008-06-01

    This review summarizes the results of past research on films and coatings from hemicelluloses, biopolymers that are as yet relatively unexploited commercially. The targeted uses of hemicelluloses have primarily been packaging films and coatings for foodstuffs as well as biomedical applications. Oxygen permeability of hemicellulose films, an important characteristic for food packaging, was typically comparable to values found for other biopolymer films such as amylose and amylopectin. As expected, the modification of hemicelluloses to create more hydrophobic films reduced the water vapor permeability. However, modified hemicellulose coatings intended for food still exhibited water vapor permeabilities several magnitudes higher than those of other polymers currently used for this purpose. Research on hemicelluloses for biomedical applications has included biocompatible hydrogels and coatings and material surfaces with enhanced cell affinity. Numerous possibilities exist for chemically modifying hemicelluloses, and fundamental studies of films from modified hemicelluloses have identified other potential applications, including selective membranes. PMID:18457452

  3. Protective metal matrix coating with nanocomponents

    NASA Astrophysics Data System (ADS)

    Galevsky, G. V.; Rudneva, V. V.; Cherepanov, A. N.; Galevsky, S. G.; Efimova, K. A.

    2016-09-01

    Experience of nanocrystalline chromium, titanium, silicon carbides and borides components application as nickel, zinc, chromium based electrodeposited composite coating is generalized. Electrodepositing conditions are determined. Structure and physicochemical properties of coatings, namely micro-hardness, adhesion to steel base, inherent stresses, heat resistance, corrosion currents, en-during quality, and their change during isothermal annealing are studied. As is shown, nanocomponents act as metal matrix modifier. Technological and economic feasibility study to evaluate expediency of replacing high priced nano-diamonds with nanocrystalline borides and carbides is undertaken.

  4. Development of an all-metal thick film cost affective metallization system for solar cells

    NASA Technical Reports Server (NTRS)

    Ross, B.

    1981-01-01

    An economical thick film solar cell contact for high volume production of low cost silicon solar array modules was investigated. All metal screenable pastes using base metals were studied. Solar cells with junction depths varying by a factor of 3.3, with and without a deposited oxide coating were used. Cells were screened and fired by a two step firing process. Adhesion and metallurgical results are unsatisfactory. No electrical information is obtained due to inadequate contact adhesion.

  5. Metal-Enhanced Fluorescence: Ultrafast Energy Transfer from Dyes in a Polymer Film to Metal Nanoparticles.

    PubMed

    Lee, Jaebeom; Pang, Yoonsoo

    2016-02-01

    Fluorescence from dye molecules dispersed in thin polymer layers increases by 20-25 times when a silver island film exists beneath the layer. Polymer layers of <100 nm thick cover the silver island film to minimize emission quenching from direct contact and also keep the dye molecules in close proximity to the metal nanosurface for possible fluorescence enhancements by silver island film. We report an ultrafast radiation process of ~400 ps lifetime from the surface plasmons of silver nanoparticles observed in time-resolved fluorescence of rhodamine 6G and DCM in thin polymer films coated on silver island surface. The ultrafast energy transfer and fluorescence from metal nanoparticles might be strongly related to the efficiency of metal-enhanced fluorescence. PMID:27433635

  6. Bioactive glass coatings for orthopedic metallic implants

    SciTech Connect

    Lopez-Esteban, Sonia; Saiz, Eduardo; Fujino, Sigheru; Oku, Takeo; Suganuma, Katsuaki; Tomsia, Antoni P.

    2003-06-30

    The objective of this work is to develop bioactive glass coatings for metallic orthopedic implants. A new family of glasses in the SiO2-Na2O-K2O-CaO-MgO-P2O5 system has been synthesized and characterized. The glass properties (thermal expansion, softening and transformation temperatures, density and hardness) are in line with the predictions of established empirical models. The optimized firing conditions to fabricate coatings on Ti-based and Co-Cr alloys have been determined and related to the glass properties and the interfacial reactions. Excellent adhesion to alloys has been achieved through the formation of 100-200 nm thick interfacial layers (Ti5Si3 on Ti-based alloys and CrOx on Co-Cr). Finally, glass coatings, approximately 100 mu m thick, have been fabricated onto commercial Ti alloy-based dental implants.

  7. One-step graphene coating of heteroepitaxial GaN films.

    PubMed

    Choi, Jae-Kyung; Huh, Jae-Hoon; Kim, Sung-Dae; Moon, Daeyoung; Yoon, Duhee; Joo, Kisu; Kwak, Jinsung; Chu, Jae Hwan; Kim, Sung Youb; Park, Kibog; Kim, Young-Woon; Yoon, Euijoon; Cheong, Hyeonsik; Kwon, Soon-Yong

    2012-11-01

    Today, state-of-the-art III-Ns technology has been focused on the growth of c-plane nitrides by metal-organic chemical vapor deposition (MOCVD) using a conventional two-step growth process. Here we show that the use of graphene as a coating layer allows the one-step growth of heteroepitaxial GaN films on sapphire in a MOCVD reactor, simplifying the GaN growth process. It is found that the graphene coating improves the wetting between GaN and sapphire, and, with as little as ~0.6 nm of graphene coating, the overgrown GaN layer on sapphire becomes continuous and flat. With increasing thickness of the graphene coating, the structural and optical properties of one-step grown GaN films gradually transition towards those of GaN films grown by a conventional two-step growth method. The InGaN/GaN multiple quantum well structure grown on a GaN/graphene/sapphire heterosystem shows a high internal quantum efficiency, allowing the use of one-step grown GaN films as 'pseudo-substrates' in optoelectronic devices. The introduction of graphene as a coating layer provides an atomic playground for metal adatoms and simplifies the III-Ns growth process, making it potentially very useful as a means to grow other heteroepitaxial films on arbitrary substrates with lattice and thermal mismatch.

  8. Method of producing thermally sprayed metallic coating

    DOEpatents

    Byrnes, Larry Edward; Kramer, Martin Stephen; Neiser, Richard A.

    2003-08-26

    The cylinder walls of light metal engine blocks are thermally spray coated with a ferrous-based coating using an HVOF device. A ferrous-based wire is fed to the HVOF device to locate a tip end of the wire in a high temperature zone of the device. Jet flows of oxygen and gaseous fuel are fed to the high temperature zone and are combusted to generate heat to melt the tip end. The oxygen is oversupplied in relation to the gaseous fuel. The excess oxygen reacts with and burns a fraction of the ferrous-based feed wire in an exothermic reaction to generate substantial supplemental heat to the HVOF device. The molten/combusted metal is sprayed by the device onto the walls of the cylinder by the jet flow of gases.

  9. Method of coating graphite tubes with refractory metal carbides

    DOEpatents

    Wohlberg, C.

    1973-12-11

    A method of coating graphite tubes with a refractory metal carbide is described. An alkali halide is reacted with a metallic oxide, the metallic portion being selected from the IVth or Vth group of the Periodic Table, the resulting salt reacting in turn with the carbon to give the desired refractory metal carbide coating. (Official Gazette)

  10. Instrumental color control for metallic coatings

    NASA Astrophysics Data System (ADS)

    Chou, W.; Han, Bing; Cui, Guihua; Rigg, Bryan; Luo, Ming R.

    2002-06-01

    This paper describes work investigating a suitable color quality control method for metallic coatings. A set of psychological experiments was carried out based upon 50 pairs of samples. The results were used to test the performance of various color difference formulae. Different techniques were developed by optimising the weights and/or the lightness parametric factors of colour differences calculated from the four measuring angles. The results show that the new techniques give a significant improvement compared to conventional techniques.

  11. Studies on Nanostructure Aluminium Thin Film Coatings Deposited using DC magnetron Sputtering Process

    NASA Astrophysics Data System (ADS)

    Singh M, Muralidhar; G, Vijaya; MS, Krupashankara; Sridhara, B. K.; Shridhar, T. N.

    2016-09-01

    Nanostructured thin film metallic coatings has become an area of intense research particularly in applications related solar, sensor technologies and many other optical applications such as laser windows, mirrors and reflectors. Thin film metallic coatings were deposited using DC magnetron sputtering process. The deposition rate was varied to study its influence on optical behavior of Aluminum thin films at a different argon flow rate. Studies on the optical response of these nanostructure thin film coatings were characterized using UV-VIS-NIR spectrophotometer with integrating sphere in the wavelength range of (250-2500nm) and Surface morphology were carried out using atomic force microscope with roughness ranging from 2 to 20nm and thickness was measured using Dektak measuring instrument. The reflection behavior of aluminium coatings on polycarbonate substrates has been evaluated. UV-VIS-NIR Spectrophotometer analysis indicates higher reflectance of 96% for all the films in the wavelength range of 250 nm to 2500 nm. Nano indentation study revealed that there was a considerable change in hardness values of the films prepared at different conditions.

  12. Optoacoustic method for determination of submicron metal coating properties: Theoretical consideration

    SciTech Connect

    Pelivanov, Ivan M.; Kopylova, Daria S.; Podymova, Natalia B.; Karabutov, Alexander A.

    2009-07-01

    The goal of this work is theoretical consideration of the optoacoustic (OA) conversion in the system consisting of a metal film deposited on a transparent dielectric substrate and covered by a transparent liquid. This consideration implies a method for nondestructive evaluation of submicron metal coatings. The main principle of the method is the following. Irradiation of the metal film by a nanosecond laser pulse leads to transient heating and expansion of the film that in turn results in the generation of an acoustic signal. The waveform of the signal results from two contributions: the 'primary' signal from the thermal expansion of the metal film, which repeats the temporal profile of the laser pulse envelope, and the 'secondary' signal, which originates from the thermal expansion of the adjacent liquid layer. Due to low thermal conductivity of liquid compared to metal, the liquid accumulates heat that is released in metal and produces that secondary contribution into the OA conversion. This contribution is very sensitive to the properties of the film. The influence of the film thickness and its thermophysical parameters on the frequency-dependent efficiency of OA conversion and on the temporal profile of excited OA signals is discussed in detail. Based on these results, the method for nondestructive evaluation of submicron metal coatings properties is proposed.

  13. Metal-Film Hall-Effect Devices

    NASA Technical Reports Server (NTRS)

    Peters, Palmer N.

    1994-01-01

    Large positive and negative Hall coefficients achievable. Family of Hall-effect devices made from multilayer metal films instead of semiconductor materials. Metal films easier to fabricate; formed by deposition on variety of substrates, and leads readily attached to them. Fabricated with larger areas, potentially more reliable, and less affected by impurities. Also used to measure magnetic fields. Devices especially useful at low temperatures.

  14. Liquid Galvanic Coatings for Protection of Imbedded Metals

    NASA Technical Reports Server (NTRS)

    MacDowell, Louis G. (Inventor); Curran, Joseph J. (Inventor)

    2003-01-01

    Coating compositions and methods of their use are described herein for the reduction of corrosion in imbedded metal structures. The coatings are applied as liquids to an external surface of a substrate in which the metal structures are imbedded. The coatings are subsequently allowed to dry. The liquid applied coatings provide galvanic protection to the imbedded metal structures. Continued protection can be maintained with periodic reapplication of the coating compositions, as necessary, to maintain electrical continuity. Because the coatings may be applied using methods similar to standard paints, and because the coatings are applied to external surfaces of the substrates in which the metal structures are imbedded, the corresponding corrosion protection may be easily maintained. The coating compositions are particularly useful in the protection of metal-reinforced concrete.

  15. Electrochemical Characterization of Ultrathin Cross-Linked Metal Nanoparticle Films.

    PubMed

    Han, Chu; Percival, Stephen J; Zhang, Bo

    2016-09-01

    Here we report the preparation, characterization, and electrochemical study of conductive, ultrathin films of cross-linked metal nanoparticles (NPs). Nanoporous films ranging from 40 to 200 nm in thickness composed of gold and platinum NPs of ∼5 nm were fabricated via a powerful layer-by-layer spin coating process. This process allows preparation of uniform NP films as large as 2 × 2 cm(2) with precise control over thickness, structure, and electrochemical and electrocatalytic properties. Gold, platinum, and bimetallic NP films were fabricated and characterized using cyclic voltammetry, scanning electron microscopy, and conductance measurements. Their electrocatalytic activity toward the oxygen reduction reaction (ORR) was investigated. Our results show that the electrochemical activity of such NP films is initially hindered by the presence of dense thiolate cross-linking ligands. Both electrochemical cycling and oxygen plasma cleaning are effective means in restoring their electrochemical activity. Gold NP films have higher electric conductivity than platinum possibly due to more uniform film structure and closer particle-particle distance. The electrochemical and electrocatalytic performance of platinum NP films can be greatly enhanced by the incorporation of gold NPs. This work focuses on electrochemical characterization of cross-linked NP films and demonstrates several unique properties. These include quick and easy preparation, ultrathin and uniform film thickness, tunable structure and composition, and transferability to many other substrates.

  16. Flexible Thin Metal Film Thermal Sensing System

    NASA Technical Reports Server (NTRS)

    Thomsen, Donald Laurence (Inventor)

    2012-01-01

    A flexible thin metal film thermal sensing system is provided. A thermally-conductive film made from a thermally-insulating material is doped with thermally-conductive material. At least one layer of electrically-conductive metal is deposited directly onto a surface of the thermally-conductive film. One or more devices are coupled to the layer(s) to measure an electrical characteristic associated therewith as an indication of temperature.

  17. A Study of Deposition Coatings Formed by Electroformed Metallic Materials.

    PubMed

    Hayashi, Shoji; Sugiyama, Shuta; Shimura, Kojiro; Tobayama, Go; Togashi, Toshio

    2016-01-01

    Major joining methods of dental casting metal include brazing and laser welding. However, brazing cannot be applied for electroformed metals since heat treatment could affect the fit, and, therefore, laser welding is used for such metals. New methods of joining metals that do not impair the characteristics of electroformed metals should be developed. When new coating is performed on the surface of the base metal, surface treatment is usually performed before re-coating. The effect of surface treatment is clinically evaluated by peeling and flex tests. However, these testing methods are not ideal for deposition coating strength measurement of electroformed metals. There have been no studies on the deposition coating strength and methods to test electroformed metals. We developed a new deposition coating strength test for electroformed metals. The influence of the negative electrolytic method, which is one of the electrochemical surface treatments, on the strength of the deposition coating of electroformed metals was investigated, and the following conclusions were drawn: 1. This process makes it possible to remove residual deposits on the electrodeposited metal surface layer. 2. Cathode electrolysis is a simple and safe method that is capable of improving the surface treatment by adjustments to the current supply method and current intensity. 3. Electrochemical treatment can improve the deposition coating strength compared to the physical or chemical treatment methods. 4. Electro-deposition coating is an innovative technique for the deposition coating of electroformed metal. PMID:27326757

  18. A Study of Deposition Coatings Formed by Electroformed Metallic Materials

    PubMed Central

    Shimura, Kojiro; Tobayama, Go; Togashi, Toshio

    2016-01-01

    Major joining methods of dental casting metal include brazing and laser welding. However, brazing cannot be applied for electroformed metals since heat treatment could affect the fit, and, therefore, laser welding is used for such metals. New methods of joining metals that do not impair the characteristics of electroformed metals should be developed. When new coating is performed on the surface of the base metal, surface treatment is usually performed before re-coating. The effect of surface treatment is clinically evaluated by peeling and flex tests. However, these testing methods are not ideal for deposition coating strength measurement of electroformed metals. There have been no studies on the deposition coating strength and methods to test electroformed metals. We developed a new deposition coating strength test for electroformed metals. The influence of the negative electrolytic method, which is one of the electrochemical surface treatments, on the strength of the deposition coating of electroformed metals was investigated, and the following conclusions were drawn: 1. This process makes it possible to remove residual deposits on the electrodeposited metal surface layer. 2. Cathode electrolysis is a simple and safe method that is capable of improving the surface treatment by adjustments to the current supply method and current intensity. 3. Electrochemical treatment can improve the deposition coating strength compared to the physical or chemical treatment methods. 4. Electro-deposition coating is an innovative technique for the deposition coating of electroformed metal. PMID:27326757

  19. Abrasion resistance of biaxially oriented polypropylene films coated with nanocomposite hard coatings

    NASA Astrophysics Data System (ADS)

    Wang, Jing; Zhu, Yaofeng; Fu, Yaqin

    2013-11-01

    KMnO4-treated, functionalized, biaxially oriented polypropylene (BOPP) films coated with nano-silica hybrid material were synthesized. The abrasion resistance of the films was examined using a reciprocating fabric abrasion tester. Functional groups were confirmed by Fourier-transform infrared spectroscopy. Contact angle measurements were performed on the BOPP film surface to quantify the effectiveness of the functionalization. Results indicate that the abrasion resistance and roughness of the composite film were significantly affected by the modification of the BOPP film. Water surface contact angle of the modified BOPP films decreased from 90.1° to 71.4°,when KMnO4 concentration increased from 0 M to 0.25 M. Wettability of the BOPP films clearly improved after KMnO4 treatment. Abrasion resistance of the functionalized films coated with hybrid materials improved by 27.4% compared with that of the original film.

  20. Memristive behaviour of spin coated titania thin film

    NASA Astrophysics Data System (ADS)

    Kamarozaman, N. S.; Herman, S. H.; Mahmudin, M. A.

    2014-08-01

    This paper presents the memristive behaviour of spin coated titania thin films. The precursor molarity of titania thin film was varied from 0.05 to 0.4 M to study the effect of precursor molarity on the memristive behaviour of the thin films. From the observation, although the film thickness increased with the precursor molarity, the resistance ratios of the best switching loop for all samples showed no significant differences. However, it was found that the sample with less precursor molarity (device that having thinner film) required lesser time to produce the stable switching loop compared to the sample with higher precursor molarity (device that having thicker film).

  1. Controlling film topography to form highly hydrophobic waterborne coatings.

    PubMed

    López, Ana B; de la Cal, José C; Asua, José M

    2016-08-17

    Coatings have a tremendous impact on economy as they reduce corrosion that has an estimated cost of 3% of the world's GDP. Hydrophobic coatings are particularly efficient for this purpose and the challenge is to produce cost effective and environmentally friendly, highly hydrophobic, cohesive and non-porous coatings applicable to large and irregular surfaces. This work shows that this goal can be achieved by forming wrinkles on the surface of waterborne coatings through fine-tuning of the film forming conditions. The proof of concept was demonstrated by using waterborne dispersions of copolymers of 1H,1H,2H,2H-perfluorodecyl acrylate and 2-ethylhexyl acrylate, and using the temperature and hardness of the copolymer as control variables during film formation. This allowed the formation of transparent films with a wrinkled surface that had a contact angle of 133°, which represents an increase of 20° with respect to the film cast under standard conditions.

  2. Controlling film topography to form highly hydrophobic waterborne coatings.

    PubMed

    López, Ana B; de la Cal, José C; Asua, José M

    2016-08-17

    Coatings have a tremendous impact on economy as they reduce corrosion that has an estimated cost of 3% of the world's GDP. Hydrophobic coatings are particularly efficient for this purpose and the challenge is to produce cost effective and environmentally friendly, highly hydrophobic, cohesive and non-porous coatings applicable to large and irregular surfaces. This work shows that this goal can be achieved by forming wrinkles on the surface of waterborne coatings through fine-tuning of the film forming conditions. The proof of concept was demonstrated by using waterborne dispersions of copolymers of 1H,1H,2H,2H-perfluorodecyl acrylate and 2-ethylhexyl acrylate, and using the temperature and hardness of the copolymer as control variables during film formation. This allowed the formation of transparent films with a wrinkled surface that had a contact angle of 133°, which represents an increase of 20° with respect to the film cast under standard conditions. PMID:27476531

  3. Electrodes synthesized from carbon nanostructures coated with a smooth and conformal metal adlayer

    DOEpatents

    Adzic, Radoslav; Harris, Alexander

    2014-04-15

    High-surface-area carbon nanostructures coated with a smooth and conformal submonolayer-to-multilayer thin metal films and their method of manufacture are described. The preferred manufacturing process involves the initial oxidation of the carbon nanostructures followed by a surface preparation process involving immersion in a solution with the desired pH to create negative surface dipoles. The nanostructures are subsequently immersed in an alkaline solution containing a suitable quantity of non-noble metal ions which adsorb at surface reaction sites. The metal ions are then reduced via chemical or electrical means. The nanostructures are exposed to a solution containing a salt of one or more noble metals which replace adsorbed non-noble surface metal atoms by galvanic displacement. The process can be controlled and repeated to obtain a desired film coverage. The resulting coated nanostructures may be used, for example, as high-performance electrodes in supercapacitors, batteries, or other electric storage devices.

  4. Metallic coatings on silicon substrates, and methods of forming metallic coatings on silicon substrates

    DOEpatents

    Branagan, Daniel J.; Hyde, Timothy A.; Fincke, James R.

    2008-03-11

    The invention includes methods of forming a metallic coating on a substrate which contains silicon. A metallic glass layer is formed over a silicon surface of the substrate. The invention includes methods of protecting a silicon substrate. The substrate is provided within a deposition chamber along with a deposition target. Material from the deposition target is deposited over at least a portion of the silicon substrate to form a protective layer or structure which contains metallic glass. The metallic glass comprises iron and one or more of B, Si, P and C. The invention includes structures which have a substrate containing silicon and a metallic layer over the substrate. The metallic layer contains less than or equal to about 2 weight % carbon and has a hardness of at least 9.2 GPa. The metallic layer can have an amorphous microstructure or can be devitrified to have a nanocrystalline microstructure.

  5. Transmission enhancement based on strong interference in metal-semiconductor layered film for energy harvesting

    NASA Astrophysics Data System (ADS)

    Li, Qiang; Du, Kaikai; Mao, Kening; Fang, Xu; Zhao, Ding; Ye, Hui; Qiu, Min

    2016-07-01

    A fundamental strategy to enhance optical transmission through a continuous metallic film based on strong interference dominated by interface phase shift is developed. In a metallic film coated with a thin semiconductor film, both transmission and absorption are simultaneously enhanced as a result of dramatically reduced reflection. For a 50-nm-thick Ag film, experimental transmission enhancement factors of 4.5 and 9.5 are realized by exploiting Ag/Si non-symmetric and Si/Ag/Si symmetric geometries, respectively. These planar layered films for transmission enhancement feature ultrathin thickness, broadband and wide-angle operation, and reduced resistance. Considering one of their potential applications as transparent metal electrodes in solar cells, a calculated 182% enhancement in the total transmission efficiency relative to a single metallic film is expected. This strategy relies on no patterned nanostructures and thereby may power up a wide spectrum of energy-harvesting applications such as thin-film photovoltaics and surface photocatalysis.

  6. Aerosol chemical vapor deposition of metal oxide films

    DOEpatents

    Ott, K.C.; Kodas, T.T.

    1994-01-11

    A process of preparing a film of a multicomponent metal oxide including: forming an aerosol from a solution comprised of a suitable solvent and at least two precursor compounds capable of volatilizing at temperatures lower than the decomposition temperature of said precursor compounds; passing said aerosol in combination with a suitable oxygen-containing carrier gas into a heated zone, said heated zone having a temperature sufficient to evaporate the solvent and volatilize said precursor compounds; and passing said volatilized precursor compounds against the surface of a substrate, said substrate having a sufficient temperature to decompose said volatilized precursor compounds whereby metal atoms contained within said volatilized precursor compounds are deposited as a metal oxide film upon the substrate is disclosed. In addition, a coated article comprising a multicomponent metal oxide film conforming to the surface of a substrate selected from the group consisting of silicon, magnesium oxide, yttrium-stabilized zirconium oxide, sapphire, or lanthanum gallate, said multicomponent metal oxide film characterized as having a substantially uniform thickness upon said substrate.

  7. Platinum-coated non-noble metal-noble metal core-shell electrocatalysts

    DOEpatents

    Adzic, Radoslav; Zhang, Junliang; Mo, Yibo; Vukmirovic, Miomir

    2015-04-14

    Core-shell particles encapsulated by a thin film of a catalytically active metal are described. The particles are preferably nanoparticles comprising a non-noble core with a noble metal shell which preferably do not include Pt. The non-noble metal-noble metal core-shell nanoparticles are encapsulated by a catalytically active metal which is preferably Pt. The core-shell nanoparticles are preferably formed by prolonged elevated-temperature annealing of nanoparticle alloys in an inert environment. This causes the noble metal component to surface segregate and form an atomically thin shell. The Pt overlayer is formed by a process involving the underpotential deposition of a monolayer of a non-noble metal followed by immersion in a solution comprising a Pt salt. A thin Pt layer forms via the galvanic displacement of non-noble surface atoms by more noble Pt atoms in the salt. The overall process is a robust and cost-efficient method for forming Pt-coated non-noble metal-noble metal core-shell nanoparticles.

  8. High Precision Metal Thin Film Liftoff Technique

    NASA Technical Reports Server (NTRS)

    Brown, Ari D. (Inventor); Patel, Amil A. (Inventor)

    2015-01-01

    A metal film liftoff process includes applying a polymer layer onto a silicon substrate, applying a germanium layer over the polymer layer to create a bilayer lift off mask, applying a patterned photoresist layer over the germanium layer, removing an exposed portion of the germanium layer, removing the photoresist layer and a portion of the polymer layer to expose a portion of the substrate and create an overhanging structure of the germanium layer, depositing a metal film over the exposed portion of the substrate and the germanium layer, and removing the polymer and germanium layers along with the overlaying metal film.

  9. Process for ultra smooth diamond coating on metals and uses thereof

    NASA Technical Reports Server (NTRS)

    Vohra, Yogesh K. (Inventor); Catledge, Shane A. (Inventor)

    2001-01-01

    The present invention provides a new process to deposit well adhered ultra smooth diamond films on metals by adding nitrogen gas to the methane/hydrogen plasma created by a microwave discharge. Such diamond coating process is useful in tribological/wear resistant applications in bio-implants, machine tools, and magnetic recording industry.

  10. Reflective Self-Metallizing Polyimide Films

    NASA Technical Reports Server (NTRS)

    Thompson, David W. (Inventor); Caplan, Maggie L. (Inventor); St.Clair, Anne (Inventor)

    1997-01-01

    A silver organic complex, such as silver acetate, is solubilized in a polyamic acid resin or soluble polyimide solution using a suitable solvent such as hexafluoroacetyl acetone. The mixture is stable and can be applied to both flat and contoured surfaces. Application can be performed by casting, dip-coating, spraying, or other suitable techniques. In addition, the mixture can be cast or extruded as a polyimide film which is not applied to an underlying substrate. Upon curing, a flexible silver coated polyimide film is produced.

  11. Spray coating of superhydrophobic and angle-independent coloured films.

    PubMed

    Ge, Dengteng; Yang, Lili; Wu, Gaoxiang; Yang, Shu

    2014-03-01

    Angle-independent coloured films with superhydrophobicity were fabricated from quasi-amorphous arrays of monodispersed fluorinated silica nanoparticles via one-step spray coating. The film exhibited a high contact angle (>150°) and a low roll-off angle (~2°) and the colour could be tuned to blue, green and moccasin by varying the size of the nanoparticles.

  12. Micro Structure of Nickel in Spin Coated Thin Film Magnets

    NASA Astrophysics Data System (ADS)

    Vides, Katherine; Dahanayake, Rasika; Samarasekara, Pubudu; Dehipawala, Sunil

    2014-03-01

    Micro-Structure of Nickel compounds in thin film magnets was investigated using Extended X ray Absorption Fine Structure (EXAFS) and X-ray Absorption Near Edge Structure (XANES). These thin film magnets were prepared by spin coating several layers of precursor containing iron and Nickel on a glass substrate. Thickness of the films was controlled by spin rate. Several magnets were prepared with different thicknesses and each film was annealed to either 200C or 350c in air. Variation of oxidation state and nearest neighbor bond lengths of each magnet was measured to characterize Ni in the film.

  13. FORMING PROTECTIVE FILMS ON METAL

    DOEpatents

    Gurinsky, D.H.; Kammerer, O.F.; Sadofsky, J.; Weeks, J.R.

    1958-12-16

    Methods are described of inhibiting the corrosion of ferrous metal by contact with heavy liquid metals such as bismuth and gallium at temperatures above 500 icient laborato C generally by bringing nltrogen and either the metal zirconium, hafnium, or titanium into reactlve contact with the ferrous metal to form a thin adherent layer of the nitride of the metal and thereafter maintaining a fractional percentage of the metal absorbed in the heavy liquid metal in contact with the ferrous metal container. The general purpose for uslng such high boiling liquid metals in ferrous contalners would be as heat transfer agents in liquid-metal-fueled nuclear reactors.

  14. Thin film coatings for space electrical power system applications

    NASA Technical Reports Server (NTRS)

    Gulino, Daniel A.

    1988-01-01

    This paper examines some of the ways in which thin film coatings can play a role in aerospace applications. Space systems discussed include photovoltaic and solar dynamic electric power generation systems, including applications in environmental protection, thermal energy storage, and radiator emittance enhancement. Potential applications of diamondlike films to both atmospheric and space based systems are examined. Also, potential uses of thin films of the recently discovered high-temperature superconductive materials are discussed.

  15. Thin film coatings for space electrical power system applications

    NASA Technical Reports Server (NTRS)

    Gulino, Daniel A.

    1989-01-01

    This paper examines some of the ways in which thin film coatings can play a role in aerospace applications. Space systems discussed include photovoltaic and solar dynamic electric power generation systems, including applications in environmental protection, thermal energy storage, and radiator emittance enhancement. Potential applications of diamondlike films to both atmospheric and space based systems are examined. Also, potential uses of thin films of the recently discovered high-temperature superconductive materials are discussed.

  16. Adhesion and friction of thin metal films

    NASA Technical Reports Server (NTRS)

    Buckley, D. H.

    1976-01-01

    Sliding friction experiments were conducted in vacuum with thin films of titanium, chromium, iron, and platinum sputter deposited on quartz or mica substrates. A single crystal hemispherically tipped gold slider was used in contact with the films at loads of 1.0 to 30.0 and at a sliding velocity of 0.7 mm/min at 23 C. Test results indicate that the friction coefficient is dependent on the adhesion of two interfaces, that between the film and its substrate and the slider and the film. There exists a relationship between the percent d bond character of metals in bulk and in thin film form and the friction coefficient. Oxygen can increase adhesive bonding of a metal film (platinum) to a substrate.

  17. Metallic glass thin films for potential biomedical applications.

    PubMed

    Kaushik, Neelam; Sharma, Parmanand; Ahadian, Samad; Khademhosseini, Ali; Takahashi, Masaharu; Makino, Akihiro; Tanaka, Shuji; Esashi, Masayoshi

    2014-10-01

    We introduce metallic glass thin films (TiCuNi) as biocompatible materials for biomedical applications. TiCuNi metallic glass thin films were deposited on the Si substrate and their structural, surface, and mechanical properties were investigated. The fabricated films showed good biocompatibility upon exposure to muscle cells. Also, they exhibited an average roughness of <0.2 nm, high wear resistance, and high mechanical properties (hardness ∼6.9 GPa and reduced modulus ∼130 GPa). Top surface of the TiCuNi films was shown to be free from Ni and mainly composed of a thin titanium oxide layer, which resulted in the high surface biocompatibility. In particular, there was no cytotoxicity effect of metallic glass films on the C2C12 myoblasts and the cells were able to proliferate well on these substrates. Low cost, viscoelastic behavior, patternability, high electrical conductivity, and the capability to coat various materials (e.g., nonbiocompatible materials) make TiCuNi as an attractive material for biomedical applications.

  18. Assessment of ceramic coatings for metal fuel melting crucible

    SciTech Connect

    Kim, Ki-Hwan; Song, Hoon; Kim, Jong-Hwan; Oh, Seok-Jin; Kim, Hyung-Tae; Lee, Chan-Bock

    2013-07-01

    The objective of this study is to develop a coating method and material for crucibles to prevent material interactions with the U-Zr/U-TRU-Zr fuels during the manufacturing of SFR fuels. Refractory coatings were applied to niobium substrates by vacuum plasma-spray coating method. Melt dipping tests conducted were the coated rods lowered into the fuel melt at 1600 C. degrees, and withdrawn and cooled outside the crucible in the inert atmosphere of the induction furnace. Melt dipping tests of the coated Nb rods indicated that plasma-sprayed Y{sub 2}O{sub 3} coating doesn't form significant reaction layer between fuel melt and coating layer. Melt dipping tests of the coated Nb rods showed that TiC, TaC, and Y{sub 2}O{sub 3} coatings exhibited the promising performance among other ceramic coatings. These materials could be promising candidate materials for the reusable melt crucible of metal fuel for SFR. In addition, in order to develop the vacuum plasma-spray coating method for re-usable crucible of metal fuel slugs to be overcome the issue of thermal expansion mismatch between coating material and crucible, various combinations of coating conditions were investigated to find the bonding effect on the substrate in pursuit of more effective ways to withstand the thermal stresses. It is observed that most coating methods maintained sound coating state in U-Zr melt. (authors)

  19. Solid-gel precursor solutions and methods for the fabrication of polymetallicsiloxane coating films

    DOEpatents

    Toshifumi Sugama.

    1993-04-06

    Solutions and preparation methods necessary for the fabrication of metal oxide cross-linked polysiloxane coating films are disclosed. The films are useful in provide heat resistance against oxidation, wear resistance, thermal insulation, and corrosion resistance of substrates. The sol-gel precursor solution comprises a mixture of a monomeric organoalkoxysilane, a metal alkoxide M(OR)[sub n] (wherein M is Ti, Zr, Ge or Al; R is CH[sub 3], C[sub 2]H[sub 5] or C[sub 3]H[sub 7]; and n is 3 or 4), methanol, water, HCl and NaOH. The invention provides a sol-gel solution, and a method of use thereof, which can be applied and processed at low temperatures (i.e., < 1,000 C.). The substrate can be coated by immersing it in the above mentioned solution at ambient temperature. The substrate is then withdrawn from the solution. Next, the coated substrate is heated for a time sufficient and at a temperature sufficient to yield a solid coating. The coated substrate is then heated for a time sufficient, and temperature sufficient to produce a polymetallicsiloxane coating.

  20. Solid-gel precursor solutions and methods for the fabrication of polymetallicsiloxane coating films

    DOEpatents

    Sugama, Toshifumi

    1993-01-01

    Solutions and preparation methods necessary for the fabrication of metal oxide cross-linked polysiloxane coating films are disclosed. The films are useful in provide heat resistance against oxidation, wear resistance, thermal insulation, and corrosion resistance of substrates. The sol-gel precursor solution comprises a mixture of a monomeric organoalkoxysilane, a metal alkoxide M(OR).sub.n (wherein M is Ti, Zr, Ge or Al; R is CH.sub.3, C.sub.2 H.sub.5 or C.sub.3 H.sub.7 ; and n is 3 or 4), methanol, water, HCl and NaOH. The invention provides a sol-gel solution, and a method of use thereof, which can be applied and processed at low temperatures (i.e., <1000.degree. C.). The substrate can be coated by immersing it in the above mentioned solution at ambient temperature. The substrate is then withdrawn from the solution. Next, the coated substrate is heated for a time sufficient and at a temperature sufficient to yield a solid coating. The coated substrate is then heated for a time sufficient, and temperature sufficient to produce a polymetallicsiloxane coating.

  1. Solid-gel precursor solutions and methods for the fabrication of polymetallicsiloxane coating films

    DOEpatents

    Sugama, Toshifumi

    1992-01-01

    Solutions and preparation methods necessary for the fabrication of metal oxide cross-linked polysiloxane coating films are disclosed. The films are useful in provide heat resistance against oxidation, wear resistance, thermal insulation, and corrosion resistance of substrates. The sol-gel precursor solution comprises a mixture of a monomeric organoalkoxysilane, a metal alkoxide M(OR).sub.n (wherein M is Ti, Zr, Ge or Al; R is CH.sub.3, C.sub.2 H.sub.5 or C.sub.3 H.sub.7 ; and n is 3 or 4), methanol, water, HCl and NaOH. The invention provides a sol-gel solution, and a method of use thereof, which can be applied and processed at low temperatures (i.e., <1000.degree. C.). The substrate can be coated by immersing it in the above mentioned solution at ambient temperature. The substrate is then withdrawn from the solution. Next, the coated substrate is heated for a time sufficient and at a temperature sufficient to yield a solid coating. The coated substrate is then heated for a time sufficient, and temperature sufficient to produce a polymetallicsiloxane coating.

  2. Research on thin film anticounterfeiting coatings at the National Research Council of Canada.

    PubMed

    Dobrowolski, J A; Ho, F C; Waldorf, A

    1989-07-15

    After a brief description of the threats which face the issuers of documents and valuable papers, the concept of thin film anticounterfeiting coatings proposed by the NRCC is explained. The colorimetric considerations which govern the design of such devices are reviewed. Typical coating designs suitable for use in transmission and reflection are discussed. Reflection coatings can be constructed with and without an integral black absorber coating. The need for geometric patterns in the anticounterfeiting coating is explained. Various methods for producing such logos are proposed. Mention is made of the various numerical tools developed for the design and investigation of single films and multilayers, their desensitization to construction errors, and for the investigation of different process control strategies. During the duration of the project, experiments were performed on the optical constants and nonoptical properties of a number of metal and dielectric films considered for use in the anticounterfeiting coatings. These and some of the processes and equipment investigated during the development of a prototype production facility are reviewed. Finally, some security and economic aspects of the devices are considered.

  3. Metal current collect protected by oxide film

    DOEpatents

    Jacobson, Craig P.; Visco, Steven J.; DeJonghe, Lutgard C.

    2004-05-25

    Provided are low-cost, mechanically strong, highly electronically conductive current collects and associated structures for solid-state electrochemical devices, techniques for forming these structures, and devices incorporating the structures. The invention provides solid state electrochemical devices having as current interconnects a ferritic steel felt or screen coated with a protective oxide film.

  4. Metal films on the surfaces and within diamond crystals from Arkhangelskaya and Yakutian diamond provinces

    NASA Astrophysics Data System (ADS)

    Makeev, A. B.; Kriulina, G. Yu.

    2012-12-01

    Representative samples of diamonds from five kimberlite pipes (Lomonosovskaya, Archangel'sk, Snegurochka, XXIII Congress of the Communist Party of the Soviet Union (CPSU), and Internationalnaya) of the Arkhangelskaya and Yakutian diamond provinces in Russia have been studied. Thirty-three varieties of metal films have been identified as syngenetic associated minerals. The films consist of 15 chemical elements that occur in the form of native metals and their natural alloys. Remnants of metal films were detected within diamond crystals. The metal films coating diamonds are a worldwide phenomenon. To date, these films have been described from Europe, Asia, South America, and Africa. Native metals, their alloys, and intermetallides are actual companion minerals of diamond.

  5. Microstructural modeling and design optimization of adaptive thin-film nanocomposite coatings for durability and wear

    NASA Astrophysics Data System (ADS)

    Pearson, James Deon

    Adaptive thin-film nanocomposite coatings comprised of crystalline ductile phases of gold and molybdenum disulfide, and brittle phases of diamond like carbon (DLC) and ytrria stabilized zirconia (YSZ) have been investigated by specialized microstructurally-based finite-element techniques. A new microstructural computational technique for efficiently creating models of nanocomposite coatings with control over composition, grain size, spacing and morphologies has been developed to account for length scales that range from nanometers to millimeters for efficient computations. The continuum mechanics model at the nanometer scale was verified with molecular dynamic models for nanocrystalline diamond. Using this new method, the interrelated effects of microstructural characteristics such as grain shapes and sizes, matrix thicknesses, local material behavior due to interfacial stresses and strains, varying amorphous and crystalline compositions, and transfer film adhesion and thickness on coating behavior have been investigated. A mechanistic model to account for experimentally observed transfer film adhesion modes and changes in thickness was also developed. One of the major objectives of this work is to determine optimal crystalline and amorphous compositions and behavior related to wear and durability over a wide range of thermo-mechanical conditions. The computational predictions, consistent with experimental observations, indicate specific interfacial regions between DLC and ductile metal inclusions are critical regions of stress and strain accumulation that can be precursors to material failure and wear. The predicted results underscore a competition between the effects of superior tribological properties associated with MoS 2 and maintaining manageable stress levels that would not exceed the coating strength. Varying the composition results in tradeoffs between lubrication, toughness, and strength, and the effects of critical stresses and strains can be controlled

  6. Incorporation of Metallic Nanoparticles into Conducting Polymer Actuator Films

    NASA Astrophysics Data System (ADS)

    Costa, Alexsandro Santos; Li, Kwong-Chi; Kilmartin, Paul A.; Travas-Sejdic, Jadranka

    2009-07-01

    Nanocomposites of conducting polymer films (CP) with metal nanoparticles have been prepared. Electropolymerization of pyrrole on stainless steel electrodes was undertaken galvanostatically until the thickness of the polypyrrole (PPy) film reached around 7.5 μm, which is suitable for the future application of these films in micropumps and microvalves. Subsequently platinum nanoparticles were deposited from a solution of a platinum precursor (K2PtCl6) onto the PPy coated stainless steel electrodes by applying a potential of -0.1 V for between 3 and 15 s. The length of the deposition time led to significant differences in the morphology and size of the particles obtained. The actuation of the free standing films was studied by electrochemomechanical deformation measurements (ECMD) on strips of films cycled in NaPF6. Depending upon the test conditions, the strain rate and ultimate strain of films containing Pt nanoparticles could be increased by a factor of 2 or more compared to those of pristine PPy films.

  7. Nano-enabled tribological thin film coatings: global patent scenario.

    PubMed

    Sivudu, Kurva S; Mahajan, Yashwant R; Joshi, Shrikant V

    2014-01-01

    The aim of this paper is to present current status and future prospects of nano-enabled tribological thin film coatings based on worldwide patent landscape analysis. The study also presents an overview of technological trends by carrying out state-of-the-art literature analysis, including survey of corporate websites. Nanostructured tribological coatings encompass a wide spectrum of nanoscale microstructures, including nanocrystalline, nanolayered, nano-multilayered, nanocomposite, nanogradient structures or their unique combinations, which are composed of single or multi-component phases. The distinct microstructural features of the coatings impart outstanding tribological properties combined with multifunctional attributes to the coated components. Their unique combination of remarkable properties make them ideal candidates for a wide range of applications in diverse fields such as cutting and metalworking tools, biomedical devices, automotive engine components, wear parts, hard disc drives etc. The patent landscape analysis has revealed that nano-enabled tribological thin film coatings have significant potential for commercial applications in view of the lion's share of corporate industry in patenting activity. The largest patent portfolio is held by Japan followed by USA, Germany, Sweden and China. The prominent players involved in this field are Mitsubishi Materials Corp., Sandvik Aktiebolag, Hitachi Ltd., Sumitomo Electric Industries Ltd., OC Oerlikon Corp., and so on. The outstanding potential of nanostructured thin film tribological coatings is yet to be fully unravelled and, therefore, immense opportunities are available in future for microstructurally engineered novel coatings to enhance their performance and functionality by many folds. PMID:24962377

  8. Nano-enabled tribological thin film coatings: global patent scenario.

    PubMed

    Sivudu, Kurva S; Mahajan, Yashwant R; Joshi, Shrikant V

    2014-01-01

    The aim of this paper is to present current status and future prospects of nano-enabled tribological thin film coatings based on worldwide patent landscape analysis. The study also presents an overview of technological trends by carrying out state-of-the-art literature analysis, including survey of corporate websites. Nanostructured tribological coatings encompass a wide spectrum of nanoscale microstructures, including nanocrystalline, nanolayered, nano-multilayered, nanocomposite, nanogradient structures or their unique combinations, which are composed of single or multi-component phases. The distinct microstructural features of the coatings impart outstanding tribological properties combined with multifunctional attributes to the coated components. Their unique combination of remarkable properties make them ideal candidates for a wide range of applications in diverse fields such as cutting and metalworking tools, biomedical devices, automotive engine components, wear parts, hard disc drives etc. The patent landscape analysis has revealed that nano-enabled tribological thin film coatings have significant potential for commercial applications in view of the lion's share of corporate industry in patenting activity. The largest patent portfolio is held by Japan followed by USA, Germany, Sweden and China. The prominent players involved in this field are Mitsubishi Materials Corp., Sandvik Aktiebolag, Hitachi Ltd., Sumitomo Electric Industries Ltd., OC Oerlikon Corp., and so on. The outstanding potential of nanostructured thin film tribological coatings is yet to be fully unravelled and, therefore, immense opportunities are available in future for microstructurally engineered novel coatings to enhance their performance and functionality by many folds.

  9. Plasma sprayed and electrospark deposited zirconium metal diffusion barrier coatings

    SciTech Connect

    Hollis, Kendall J; Pena, Maria I

    2010-01-01

    Zirconium metal coatings applied by plasma spraying and electrospark deposition (ESD) have been investigated for use as diffusion barrier coatings on low enrichment uranium fuel for research nuclear reactors. The coatings have been applied to both stainless steel as a surrogate and to simulated nuclear fuel uranium-molybdenum alloy substrates. Deposition parameter development accompanied by coating characterization has been performed. The structure of the plasma sprayed coating was shown to vary with transferred arc current during deposition. The structure of ESD coatings was shown to vary with the capacitance of the deposition equipment.

  10. Mesoscopically structured nanocrystalline metal oxide thin films

    NASA Astrophysics Data System (ADS)

    Carretero-Genevrier, Adrian; Drisko, Glenna L.; Grosso, David; Boissiere, Cédric; Sanchez, Clement

    2014-11-01

    This review describes the main successful strategies that are used to grow mesostructured nanocrystalline metal oxide and SiO2 films via deposition of sol-gel derived solutions. In addition to the typical physicochemical forces to be considered during crystallization, mesoporous thin films are also affected by the substrate-film relationship and the mesostructure. The substrate can influence the crystallization temperature and the obtained crystallographic orientation due to the interfacial energies and the lattice mismatch. The mesostructure can influence the crystallite orientation, and affects nucleation and growth behavior due to the wall thickness and pore curvature. Three main methods are presented and discussed: templated mesoporosity followed by thermally induced crystallization, mesostructuration of already crystallized metal oxide nanobuilding units and substrate-directed crystallization with an emphasis on very recent results concerning epitaxially grown piezoelectric structured α-quartz films via crystallization of amorphous structured SiO2 thin films.

  11. Process for forming a metal compound coating on a substrate

    DOEpatents

    Sharp, D.J.; Vernon, M.E.; Wright, S.A.

    1988-06-29

    A method of coating a substrate with a thin layer of a metal compound by forming a dispersion of an electrophoretically active organic colloid and a precursor of the metal compound in an electrolytic cell in which the substrate is an electrode. Upon application of an electric potential, the electrode is coated with a mixture of the organic colloid and the precursor to the metal compound, and the coated substrate is then heated in the presence of an atmosphere or vacuum to decompose the organic colloid and form a coating of either a combination of metal compound and carbon, or optionally forming a porous metal compound coating by heating to a temperature high enough to chemically react the carbon.

  12. Process for forming a metal compound coating on a substrate

    DOEpatents

    Sharp, Donald J.; Vernon, Milton E.; Wright, Steven A.

    1991-01-01

    A method of coating a substrate with a thin layer of a metal compound by forming a dispersion of an electrophoretically active organic colloid and a precursor of the metal compound in an electrolytic cell in which the substrate is an electrode. Upon application of an electric potential, the electrode is coated with a mixture of the organic colloid and the precursor to the metal compound, and the coated substrate is then heated in the presence of an atmosphere or vacuum to decompose the organic colloid and form a coating of either a combination of metal compound and carbon, or optionally forming a porous metal compound coating by heating to a temperature high enough to chemically react the carbon.

  13. Thin films of mixed metal compounds

    DOEpatents

    Mickelsen, R.A.; Chen, W.S.

    1985-06-11

    Disclosed is a thin film heterojunction solar cell, said heterojunction comprising a p-type I-III-IV[sub 2] chalcopyrite substrate and an overlying layer of an n-type ternary mixed metal compound wherein said ternary mixed metal compound is applied to said substrate by introducing the vapor of a first metal compound to a vessel containing said substrate from a first vapor source while simultaneously introducing a vapor of a second metal compound from a second vapor source of said vessel, said first and second metals comprising the metal components of said mixed metal compound; independently controlling the vaporization rate of said first and second vapor sources; reducing the mean free path between vapor particles in said vessel, said gas being present in an amount sufficient to induce homogeneity of said vapor mixture; and depositing said mixed metal compound on said substrate in the form of a uniform composition polycrystalline mixed metal compound. 5 figs.

  14. Application of hybrid organic/inorganic polymers as coatings on metallic substrates

    NASA Astrophysics Data System (ADS)

    Augustinho, T. R.; Motz, G.; Ihlow, S.; Machado, R. A. F.

    2016-09-01

    Acrylic polymers, particularly poly (methyl methacrylate) (PMMA), have certain specific properties, such as good film formation, transparency, and good mechanical properties, which have been widely used in paints, coatings and adhesives. However, the limited chemical and physical stability of these pure polymers limits their applications when exposed to hostile conditions, as in ship hulls, for example. A suitable way to enhance PMMA properties is the addition of silicon polymers with very good protective characteristics. In this study, a PMMA and HTT 1800 (commercial silazane) copolymer were applied on metallic substrate and compared to pure PMMA and HTT 1800. All the materials were applied as coatings. They were applied on stainless steel via dip-coating to investigate the coating properties. Thermal cycling was employed to analyze coating durability at high temperatures (50 °C to 600 °C). Optical microscopy (OM) and scanning electron microscopy (SEM) were used to characterize the coated surfaces, and the adhesion of pure PMMA, pure HTT 1800 and PMMA/HTT 1800 coatings on metallic substrate was investigated by Cross-Cut-Test (ASTM D 3359). The sessile drop method was used to determine the contact angle. PMMA coatings presented complete degradation from 250 °C, while hybrid coatings of PMMA and HTT 1800 have good protection until 400 °C. The adherence of the coating on metallic substrate showed improvement in all synthesized materials when compared to pure PMMA, obtaining the best adherence possible. The contact angle test showed that the hydrophobicity of the hybrid coatings is higher than that of the pure coatings.

  15. Deposition and Characterization of Thin Films on Metallic Substrates

    NASA Technical Reports Server (NTRS)

    Gatica, Jorge E.

    2005-01-01

    A CVD method was successfully developed to produce conversion coatings on aluminum alloys surfaces with reproducible results with a variety of precursors. A well defined protocol to prepare the precursor solutions formulated in a previous research was extended to other additives. It was demonstrated that solutions prepared following such a protocol could be used to systematically generate protective coatings onto aluminum surfaces. Experiments with a variety of formulations revealed that a refined deposition protocol yields reproducible conversion coatings of controlled composition. A preliminary correlation between solution formulations and successful precursors was derived. Coatings were tested for adhesion properties enhancement for commercial paints. A standard testing method was followed and clear trends were identified. Only one precursors was tested systematically. Anticipated work on other precursors should allow a better characterization of the effect of intermetallics on the production of conversion/protective coatings on metals and ceramics. The significance of this work was the practical demonstration that chemical vapor deposition (CVD) techniques can be used to systematically generate protective/conversion coating on non-ferrous surfaces. In order to become an effective approach to replace chromate-based pre- treatment processes, namely in the aerospace or automobile industry, the process parameters must be defined more precisely. Moreover, the feasibility of scale-up designs necessitates a more comprehensive characterization of the fluid flow, transport phenomena, and chemical kinetics interacting in the process. Kinetic characterization showed a significantly different effect of magnesium-based precursors when compared to iron-based precursors. Future work will concentrate on refining the process through computer simulations and further experimental studies on the effect of other transition metals to induce deposition of conversion/protective films

  16. Effect of Annealing on the Optical Properties of Transition Metal Doped ZnO Thin Films

    NASA Astrophysics Data System (ADS)

    Mathew, Jijoy P.; Varghese, George; Mathew, Jacob

    2015-02-01

    A group of transition metal (Co,Cu,Ni) doped ZnO thin films were prepared by a low cost dip coating method. To study the effect of annealing temperature on the structural and optical properties of the grown films each film is subjected to three different annealing temperatures. From the calculation of structural parameters from the XRD spectrum, it was found that each film possesses a tensile strain and this tensile strain increases as the annealing temperature increases. This dominant behavior of tensile strain affects the optical properties of the grown film in a greater extent.

  17. Durable silver thin film coating for diffraction gratings

    DOEpatents

    Wolfe, Jesse D.; Britten, Jerald A.; Komashko, Aleksey M.

    2006-05-30

    A durable silver film thin film coated non-planar optical element has been developed to replace Gold as a material for fabricating such devices. Such a coating and resultant optical element has an increased efficiency and is resistant to tarnishing, can be easily stripped and re-deposited without modifying underlying grating structure, improves the throughput and power loading of short pulse compressor designs for ultra-fast laser systems, and can be utilized in variety of optical and spectrophotometric systems, particularly high-end spectrometers that require maximized efficiency.

  18. Evaluation of colorless polyimide film for thermal control coating applications

    NASA Technical Reports Server (NTRS)

    St.clair, A. K.; Slemp, W. S.

    1985-01-01

    A series of essentially colorless aromatic polyimide films was synthesized and characterized with the objective of obtaining maximum optical transparency for applications in space. Optical transparency is a requirement for high performance polymeric films used in second surface mirror coatings on thermal control systems. The intensity in color of aromatic polyimide films was lowered by reducing the electronic interaction between chromophoric centers in the polymer molecular structure and by using highly purified monomers. The resulting lightly colored to colorless polyimide films were characterized by UV-visible and infrared spectroscopy before and after exposure to 300 equivalent solar hours UV irradiation and varying doses of 1 MeV electron irradiation. After irradiation, the films were found to be 2 to 2.5 times more transparent than commercial polyimide film of the same thickness.

  19. Cellular response to titanium discs coated with polyelectrolyte multilayer films

    NASA Astrophysics Data System (ADS)

    Zhan, Jing; Luo, Qiao-jie; Huang, Ying; Li, Xiao-dong

    2014-09-01

    The purpose of this study was to investigate the effects of polyelectrolyte multilayer (PEM) coatings on the biological behavior of titanium (Ti) substrates. Collagen type Ι/hyaluronic acid (Col/HA) and chitosan/hyaluronic acid (Chi/HA) multilayer PEM coatings were introduced onto Ti substrates using layer-by-layer assembly. Contact angle instruments and quartz crystal microbalance were used for film characterization. The results obtained showed that both Col/HA and Chi/HA surfaces had high hydrophilicity and promoted cell adhesion in MC3T3-E1 pre-osteoblast and human gingival fibroblast cells. In addition, the synthesis of function-related proteins and gene expression levels in both MC3T3-E1 and fibroblast cells was higher for the Col/HA coating compared with the Chi/HA coating, indicating better cellular response to the Col/HA coating.

  20. Electrical properties of nanoscale metallic thin films on dielectric elastomer at various strain rates

    NASA Astrophysics Data System (ADS)

    Faisal, Md. Shahnewaz Sabit; Ye, Zhihang; Chen, Zheng; Asmatulu, Ramazan

    2015-04-01

    Dielectric elastomers (DEs) have significant applications in artificial muscle and other biomedical equipment and device fabrications. Metallic thin films by thin film transfer and sputter coating techniques can provide conductive surfaces on the DE samples, and can be used as electrodes for the actuators and other biomedical sensing devices. In the present study, 3M VHB 4910 tape was used as a DE for the coating and electrical characterization tests. A 150 nm thickness of gold was coated on the DE surfaces by sputter coating under vacuum with different pre-strains, ranging from 0 to 100%. Some of the thin films were transferred to the surface of the DEs. Sputter coating, and direct transferring gold leaf coating methods were studied and the results were analyzed in detail in terms of the strain rates and electrical resistivity changes. Initial studies indicated that the metallic surfaces remain conductive even though the DE films were considerably elongated. The coated DEs can be used as artificial muscle by applying electrical stimulation through the conductive surfaces. This study may provide great benefits to the readers, researchers, as well as companies involved in manufacturing of artificial muscles and actuators using smart materials.

  1. Coalescence and percolation in thin metal films

    SciTech Connect

    Yu, X.; Duxbury, P.M.; Jeffers, G.; Dubson, M.A. Center for Fundamental Materials Research, Michigan State University, East Lansing, Michigan 48824-1116 )

    1991-12-15

    Metals thermally evaporated onto warm insulating substrates evolve to the thin-film state via the morphological sequence: compact islands, elongated islands, percolation, hole filling, and finally the thin-film state. The coverage at which the metal percolates ({ital p}{sub {ital c}}) is often considerably higher than that predicted by percolation models, such as inverse swiss cheese or lattice percolation. Using a simple continuum model, we show that high-{ital p}{sub {ital c}}'s arise naturally in thin films that exhibit a crossover from full coalescence of islands at early stages of growth to partial coalescence at later stages. In this interrupted-coalescence model, full coalescence of islands occurs up to a critical island radius {ital R}{sub {ital c}}, after which islands overlap, but do not fully coalesce. We present the morphology of films and the critical area coverages generated by this model.

  2. Process optimization of ultrasonic spray coating of polymer films.

    PubMed

    Bose, Sanjukta; Keller, Stephan S; Alstrøm, Tommy S; Boisen, Anja; Almdal, Kristoffer

    2013-06-11

    In this work we have performed a detailed study of the influence of various parameters on spray coating of polymer films. Our aim is to produce polymer films of uniform thickness (500 nm to 1 μm) and low roughness compared to the film thickness. The coatings are characterized with respect to thickness, roughness (profilometer), and morphology (optical microscopy). Polyvinylpyrrolidone (PVP) is used to do a full factorial design of experiments with selected process parameters such as temperature, distance between spray nozzle and substrate, and speed of the spray nozzle. A mathematical model is developed for statistical analysis which identifies the distance between nozzle and substrate as the most significant parameter. Depending on the drying of the sprayed droplets on the substrate, we define two broad regimes, "dry" and "wet". The optimum condition of spraying lies in a narrow window between these two regimes, where we obtain a film of desired quality. Both with increasing nozzle-substrate distance and temperature, the deposition moves from a wet state to a dry regime. Similar results are also achieved for solvents with low boiling points. Finally, we study film formation during spray coating with poly (D,L-lactide) (PDLLA). The results confirm the processing knowledge obtained with PVP and indicate that the observed trends are identical for spraying of other polymer films.

  3. Process optimization of ultrasonic spray coating of polymer films.

    PubMed

    Bose, Sanjukta; Keller, Stephan S; Alstrøm, Tommy S; Boisen, Anja; Almdal, Kristoffer

    2013-06-11

    In this work we have performed a detailed study of the influence of various parameters on spray coating of polymer films. Our aim is to produce polymer films of uniform thickness (500 nm to 1 μm) and low roughness compared to the film thickness. The coatings are characterized with respect to thickness, roughness (profilometer), and morphology (optical microscopy). Polyvinylpyrrolidone (PVP) is used to do a full factorial design of experiments with selected process parameters such as temperature, distance between spray nozzle and substrate, and speed of the spray nozzle. A mathematical model is developed for statistical analysis which identifies the distance between nozzle and substrate as the most significant parameter. Depending on the drying of the sprayed droplets on the substrate, we define two broad regimes, "dry" and "wet". The optimum condition of spraying lies in a narrow window between these two regimes, where we obtain a film of desired quality. Both with increasing nozzle-substrate distance and temperature, the deposition moves from a wet state to a dry regime. Similar results are also achieved for solvents with low boiling points. Finally, we study film formation during spray coating with poly (D,L-lactide) (PDLLA). The results confirm the processing knowledge obtained with PVP and indicate that the observed trends are identical for spraying of other polymer films. PMID:23631433

  4. Transient coating of substrates with variable topography by viscous films

    NASA Astrophysics Data System (ADS)

    Lampropoulos, Nikos; Dimakopoulos, Yiannis; Tsamopoulos, John

    2015-11-01

    We study the transient coating of substrates exhibiting orthogonal trenches. We use the VoF method via OpenFOAM to solve the transient NS eqs on an unstructured grid, which dynamically undergoes local refinement around the interfaces. An Euler implicit method is used with adjustable time-step. The computational cost is reduced by parallel execution via MPI. Completely different wetting patterns result depending on the 3 dimensions of the topography, the capillary and Reynolds numbers and the dynamic contact angle. On one hand, continuous coating can be achieved in which the thin film of fluid wets the entire trench, while a steady flow is established upstream and downstream the topography. This is the desirable pattern in coating microelectronic devices for their protection and planarization. The other extreme possibility is that the film completely bypasses the trench, entrapping air inside it. This pattern reduces the drag coefficient on the film and, therefore, it is desirable in super-hydrophobic surfaces for microfluidic applications. Between these two extremes, a large variety of patterns exists in which the film partially wets the trench forming an air inclusion all along its bottom surface or its upstream or downstream inner corners or the film may breakup periodically. We produce comprehensive maps of film configurations covering a wide range of parameter values. GSRT of Greece via the program ``Excellence,'' Grant 1918.

  5. Molecular structure and optical properties of PTFE-based nanocomposite polymer-metal coatings

    NASA Astrophysics Data System (ADS)

    Rahachou, A. V.; Rogachev, A. A.; Yarmolenko, M. A.; Xiao-Hong, Jiang; Bo, Liu Zhu

    2012-01-01

    The molecular organization of polytetrafluoroethylene (PTFE) thin coatings with incorporated Ag, Cu, and Mo nanoparticles that are deposited from an active gas component has been studied. Polyethylene terephtalate film coated by aluminium served as a substrate. The active gas component was produced by electron beam dispersion of original components in vacuum. The effect of metal particle size and its nature on the molecular structure of coatings have been investigated. Dichroism of thin nanocomposite coatings has been examined by polarized Fourier transform infrared spectroscopy using an attenuated total reflection unit. The morphology of the coatings has been analyzed by transmission (TEM), atomic-force (AFM), and scanning electron (SEM) microscopy. It is found that introduction of a metal (Ag or Cu) yields oriented layers at a lesser efficient thickness of a coating. The surface plasmon resonance of such structures was studied by measuring optical absorption of the coatings in the ultraviolet and visible ranges. The results show that the composite coatings containing Ag clusters are diameter less than 30 nm and absorb within the short-wave range from 400 to 550 nm.

  6. THE PENETRABILITY OF A THIN METALLIC FILM INSIDE THE RF FIELD.

    SciTech Connect

    ZHAO, Y.; BEN-ZVI, I.; CHANG, X.; RAO, T.; CHEN, W.; DINARDO, R.; BEUTENMULLER, R.

    2005-05-16

    Thin metallic film was widely applied in various areas. Especially, recently we are planning to apply it in a ''Secondary emission enhanced photo-injector'', in which a diamond cathode is coated with a metallic film on its back to serve as a current path. The thickness of the film is originally considered to be in the order of 10 nm, which is much less than the skin depth, by a factor of almost 200. One would think intuitively that the RF filed would penetrate such a thin film. However, we found it is not true. The film will block most of the field. This paper addresses theoretical analysis as well as the experimental results, and demonstrates that the penetrability of a thin film is very poor. Consequently, most of the RF current will flow on the thin film causing a serious heating problem.

  7. Mixed metal films with switchable optical properties

    SciTech Connect

    Richardson, Thomas J.; Slack, Jonathan L.; Farangis, Baker; Rubin, Michael D.

    2001-10-16

    Thin, Pd-capped metallic films containing magnesium and first row transition metals (Mn, Fe, Co) switch reversibly from their initial reflecting state to visually transparent states when exposed to gaseous hydrogen or following cathodic polarization in an alkaline electrolyte. Reversion to the reflecting state is achieved by exposure to air or by anodic polarization. The films were prepared by co-sputtering from one magnesium target and one manganese, iron, or cobalt target. Both the dynamic optical switching range and the speed of the transition depend on the magnesium-transition metal ratio. Infrared spectra of films in the transparent, hydrided (deuterided) states support the presence of the intermetallic hydride phases Mg3MnH7, Mg2FeH6, and Mg2CoH5.

  8. Ion beam sputter-deposited thin film coatings for protection of spacecraft polymers in low earth orbit

    NASA Technical Reports Server (NTRS)

    Banks, B. A.; Mirtich, M. J.; Rutledge, S. K.; Swec, D. M.; Nahra, H. K.

    1985-01-01

    Ion beam sputter-deposited thin films at Al2O3, SiO2, and a codeposited mixture of predominantly SiO2 with small amounts of fluoropolymer were evaluated both in laboratory plasma ashing tests and in space on board Shuttle flight STS-8 for effectiveness in preventing oxidation of polyimide Kapton. Measurements of mass loss and optical performance of coated and uncoated polyimide samples exposed to the low earth orbital environment are presented. Optical techniques were used to measure loss rates of protective films exposed to atomic oxygen. Results of the analysis of the space flight exposed samples indicate that thin film metal oxide coatings are very effective in protecting the polyimide. Metal oxide coatings with a small amount of fluoropolymer codeposited have the additional benefit of great flexibility.

  9. Ion beam sputter-deposited thin film coatings for protection of spacecraft polymers in low Earth orbit

    NASA Technical Reports Server (NTRS)

    Banks, B. A.; Mirtich, M. J.; Rutledge, S. K.; Swec, D. M.; Nahra, H. K.

    1985-01-01

    Ion beam sputter-deposited thin films of Al2O3, SiO2, and a codeposited mixture of predominantly SiO2 with small amounts of a fluoropolymer were evaluated both in laboratory plasma ashing tests and in space on board shuttle flight STS-8 for effectiveness in preventing oxidation of polyimide Kapton. Measurements of mass loss and optical performance of coated and uncoated polyimide samples exposed to the low Earth orbital environment are presented. Optical techniques were used to measure loss rates of protective films exposed to atomic oxygen. Results of the analysis of the space flight exposed samples indicate that thin film metal oxide coatings are very effective in protecting the polyimide. Metal oxide coatings with a small amount of fluoropolymer codeposited have the additional benefit of great flexibility.

  10. Development of metal based thermal barrier coatings

    NASA Astrophysics Data System (ADS)

    Shin, Dong-Il

    In this work, metal-based thermal barrier coatings (MBTBCs) have been produced, using high frequency induction plasma spraying (IPS) of iron-based nanostructured alloy powders. Important advances have been made over recent years to the development of ceramic-based thermal barrier coatings (TBCs) for internal combustion engines application, but they are not yet applied in mass production situations. Besides the important economic considerations, the reliability of ceramic: TBCs is also an issue, being associated with the difficulty of predicting their "in-service" lifetime. Through engineering of the nano/amorphous structure of MBTBCs, their thermal conductivity can be made as low as those of ceramic-based TBCs, with reduced mean free paths of the electrons/phonons scattering. In this work, nano/amorphous structured coatings were deposited by IPS using the following spray parameters: spraying distance (210 ˜ 270 mm), plasma gas composition (Ar/N2), IPS torch power (24kW), and powder feed-rate (16g/min.). The structure and properties of the deposited layers were characterized through SEM (Scanning Electron Microscopy) observations. The thermal diffusivity (alpha) properties of the MBTBCs were measured using a laser flash method. Density (rho) and specific heat (Cp) of the MBTBCs were also measured, and their thermal conductivity (k) calculated (k =alpharhoCp). The thermal conductivity of MBTBCs was found to be as low as 1.99 W/m/K. The heat treatment study showed that crystal structure changes, and grain size growth from a few nanometers to tenth of nanometers occurred at 550°C under static exposure conditions. Thermal expansion coefficient (TEC) of MBTBCs was 13E-6/K, which is close to the TEC of cast iron and thus, closer to the TEC values of aluminium alloys than are conventional TBCs. Fracture toughness of MBTBCs has also been assessed by use of Vickers hardness tests, with a 500 g load for 15 s, and the results show that there are no measurable crack

  11. Superconducting YBa 2Cu 3O 7- δ thin film grown on metallic film evaporated on MgO

    NASA Astrophysics Data System (ADS)

    Verdyan, A.; Azoulay, J.; Lapsker, I.

    2001-03-01

    At present it is commonly accepted that thin film formation of YBa 2Cu 3O 7- δ (YBCO) on conducting substrate is one of the keys to further development of advanced devices in the microelectronic and other applications. We have grown YBCO thin films by resistive evaporation technique on MgO coated with metallic layers (Ni or Ag). A simple inexpensive vacuum system equipped with resistively heated boats for metal and precursor mixture of yttrium, copper and barium fluoride powders was used. X-ray diffraction (XRD) and scanning electron microscopy techniques were used for texture, morphology and surface analyses respectively. Electrical and magnetical properties were determined by a standard dc four-probe method. The way of heating process is shown to be critical parameter in the film quality. The physical and electrical properties of the YBCO films are discussed in light of the fact that XRD measurements done on the metallic buffer layers have revealed a multicrystalline structure.

  12. Evaluation of volatile organic compound reduction technologies for metal coatings

    SciTech Connect

    Wang, Y.; Huang, E.W.

    1997-12-31

    Under the sponsorship of California Air Resources Board, AeroVironment Environmental Services, Inc. (AVES) is currently conducting a study to demonstrate a new zero-VOC Industrial Maintenance Metal Coating. This new technology can help the coating industry reduce emissions of volatile organic compounds (VOCs) and hazardous air pollutants (HAPs). In a previous study conducted by AVES, current VOCs technologies available on the market for metal parts and product coatings were evaluated for compliance with the South Coast Air Quality Management District (SCAQMD) proposed Rule 1107 (Metal Parts and Product Coatings). There are low-VOC coating products available for industries of interest. For general metal coating applications, certain coating products can comply with current SCAQMD Rule 1107 VOC limits. Some of the low-VOC products that are considered as a substitute or an alternative to high-VOC petroleum-based products are summarized. The current available emerging technologies offer a great opportunity for emission reduction through a gradual shift from high to low/no VOC coatings. By phasing in low/no VOC coatings, industries will be able to reduce energy use and air emissions without installation of add-on controls.

  13. High temperature glass coatings for superalloys and refractory metals

    NASA Technical Reports Server (NTRS)

    Chapman, J. W.; Grekila, R. B.; Hirayama, C.; Mattox, D. M.

    1970-01-01

    New glasses are used as protective coatings on metals and alloys susceptible to oxidation at high temperatures in oxidizing atmospheres. Glasses are stable and solid at temperatures up to 1000 deg C, adhere well to metal surfaces, and are usable for metals with broad range of expansion coefficients.

  14. Metallic and ceramic thin film thermocouples for gas turbine engines.

    PubMed

    Tougas, Ian M; Amani, Matin; Gregory, Otto J

    2013-11-08

    Temperatures of hot section components in today's gas turbine engines reach as high as 1,500 °C, making in situ monitoring of the severe temperature gradients within the engine rather difficult. Therefore, there is a need to develop instrumentation (i.e., thermocouples and strain gauges) for these turbine engines that can survive these harsh environments. Refractory metal and ceramic thin film thermocouples are well suited for this task since they have excellent chemical and electrical stability at high temperatures in oxidizing atmospheres, they are compatible with thermal barrier coatings commonly employed in today's engines, they have greater sensitivity than conventional wire thermocouples, and they are non-invasive to combustion aerodynamics in the engine. Thin film thermocouples based on platinum:palladium and indium oxynitride:indium tin oxynitride as well as their oxide counterparts have been developed for this purpose and have proven to be more stable than conventional type-S and type-K thin film thermocouples. The metallic and ceramic thin film thermocouples described within this paper exhibited remarkable stability and drift rates similar to bulk (wire) thermocouples.

  15. Metallic and ceramic thin film thermocouples for gas turbine engines.

    PubMed

    Tougas, Ian M; Amani, Matin; Gregory, Otto J

    2013-01-01

    Temperatures of hot section components in today's gas turbine engines reach as high as 1,500 °C, making in situ monitoring of the severe temperature gradients within the engine rather difficult. Therefore, there is a need to develop instrumentation (i.e., thermocouples and strain gauges) for these turbine engines that can survive these harsh environments. Refractory metal and ceramic thin film thermocouples are well suited for this task since they have excellent chemical and electrical stability at high temperatures in oxidizing atmospheres, they are compatible with thermal barrier coatings commonly employed in today's engines, they have greater sensitivity than conventional wire thermocouples, and they are non-invasive to combustion aerodynamics in the engine. Thin film thermocouples based on platinum:palladium and indium oxynitride:indium tin oxynitride as well as their oxide counterparts have been developed for this purpose and have proven to be more stable than conventional type-S and type-K thin film thermocouples. The metallic and ceramic thin film thermocouples described within this paper exhibited remarkable stability and drift rates similar to bulk (wire) thermocouples. PMID:24217356

  16. Metallic and Ceramic Thin Film Thermocouples for Gas Turbine Engines

    PubMed Central

    Tougas, Ian M.; Amani, Matin; Gregory, Otto J.

    2013-01-01

    Temperatures of hot section components in today's gas turbine engines reach as high as 1,500 °C, making in situ monitoring of the severe temperature gradients within the engine rather difficult. Therefore, there is a need to develop instrumentation (i.e., thermocouples and strain gauges) for these turbine engines that can survive these harsh environments. Refractory metal and ceramic thin film thermocouples are well suited for this task since they have excellent chemical and electrical stability at high temperatures in oxidizing atmospheres, they are compatible with thermal barrier coatings commonly employed in today's engines, they have greater sensitivity than conventional wire thermocouples, and they are non-invasive to combustion aerodynamics in the engine. Thin film thermocouples based on platinum:palladium and indium oxynitride:indium tin oxynitride as well as their oxide counterparts have been developed for this purpose and have proven to be more stable than conventional type-S and type-K thin film thermocouples. The metallic and ceramic thin film thermocouples described within this paper exhibited remarkable stability and drift rates similar to bulk (wire) thermocouples. PMID:24217356

  17. Size and rate dependent necking in thin metallic films

    NASA Astrophysics Data System (ADS)

    Pardoen, T.

    2014-01-01

    The control of the ductility of thin metallic films is a major issue in a variety of technologies involving flexible electronics, MEMS and deformable coatings. An enhanced closed form 1D imperfection based localization analysis is developed in order to investigate the mechanics of diffuse necking in metallic films. The model relies on a description of the localization process in a finite length specimen using either a 2- or 3-zone model, under plane stress or plane strain tension conditions. A strain gradient plasticity contribution to the stabilization of the localization process is taken into account in the hardening response through a simple estimate of the deformation gradient inside the necking zone. The model, with gradient plasticity effects, is validated towards 2D finite element simulations. The response of the material involves both strain-hardening and rate sensitivity, as well as possible creep relaxation. The plastic flow parameters are related to the grain size and film thickness. The model shows, in agreement with experiments, that the ductility can either drop to small values for very small grain sizes and/or film thickness due to the high strength and to the presence of imperfections, or can remain constant or even increase owing to an increased rate sensitivity resulting from thermally activated mechanisms. This last stabilization effect can be reinforced by gradient plasticity effects if allowed by the dominant deformation mechanism.

  18. Electroless (autocatalytic) nickel-cobalt thin films as solar control coatings

    SciTech Connect

    John, S.; Srinivasan, K.N.; Selvam, M.; Anuradha, S.; Rajendran, S.

    1994-12-31

    This paper describes the deposition of nickel-cobalt-phosphorus coatings by the electroless deposition technique for use as solar control coatings in architectural glazing of buildings. Electroless deposition is characterized by the autocatalytic deposition of a metal/alloy from an aqueous solution of its ions by interaction with a chemical reducing agent. The reducing agent provides electrons for the metal ions to be neutralized. The reduction is initiated by the catalyzed surface of the substrate and continued by the self catalytic activity of the deposited metal/alloy as long as the substrate is immersed in the electroless bath and operating conditions are maintained. Electroless nickel-cobalt-phosphorus thin films were deposited from a solution containing 15 g/l nickel sulphate, 5 g/l cobalt sulphate, 60 g/l ammonium citrate and 25 g/l sodium hypophosphite operating at 30 C, at a pH of 9.5 for two minutes. Electroless nickel-cobalt-phosphorus coatings are found to satisfy the basic requirements of solar control coatings. Autocatalytic deposition technique offers the possibilities of producing large area coatings with low capital investment, stability and good adhesion to glass substrates.

  19. Soap-film coating: High-speed deposition of multilayer nanofilms

    PubMed Central

    Zhang, Renyun; Andersson, Henrik A.; Andersson, Mattias; Andres, Britta; Edlund, Håkan; Edström, Per; Edvardsson, Sverker; Forsberg, Sven; Hummelgård, Magnus; Johansson, Niklas; Karlsson, Kristoffer; Nilsson, Hans-Erik; Norgren, Magnus; Olsen, Martin; Uesaka, Tetsu; Öhlund, Thomas; Olin, Håkan

    2013-01-01

    The coating of thin films is applied in numerous fields and many methods are employed for the deposition of these films. Some coating techniques may deposit films at high speed; for example, ordinary printing paper is coated with micrometre-thick layers of clay at a speed of tens of meters per second. However, to coat nanometre thin films at high speed, vacuum techniques are typically required, which increases the complexity of the process. Here, we report a simple wet chemical method for the high-speed coating of films with thicknesses at the nanometre level. This soap-film coating technique is based on forcing a substrate through a soap film that contains nanomaterials. Molecules and nanomaterials can be deposited at a thickness ranging from less than a monolayer to several layers at speeds up to meters per second. We believe that the soap-film coating method is potentially important for industrial-scale nanotechnology. PMID:23503102

  20. Electrochemical Deposition of Metal-ceramic Composite Coating

    NASA Astrophysics Data System (ADS)

    Kan, Hong-Min; Feng, Xiao-Jun; Wu, Yuan-Yuan; Tian, Ping-Ping; Zhang, Ning

    2016-05-01

    Nano-composite electrodeposition can improve the organizational structure of composite coatings and significantly improve the quality of the coating. Metal-ceramic composite coatings have improved mechanical, chemical and oxidation resistance properties, such as corrosion resistance, abrasion resistance and heat resistance. Content and distribution of codeposited particles determine the quality and performance of the coating. The factors which influenced the amount and distribution of codeposited particles were reviewed. The amount and distribution of codeposited particles are influenced by many process parameters, such as electrolyte composition and operating parameters. Finally an insight of the coming efforts to develop metal-ceramic composite coating is provided. It is the focus of future research to resolve reunion nanoparticles and improve codeposition amount and uniformly distributed nanoparticles of the coating.

  1. Thin film synthesis using miniature pulsed metal vapor vacuum arc plasma guns

    SciTech Connect

    Godechot, X.; Salmeron, M.B.; Ogletree, D.F.; Galvin, J.E.; MacGill, R.A.; Dickinson, M.R.; Yu, K.M.; Brown, I.G.

    1990-04-01

    Metallic coatings can be fabricated using the intense plasma generated by the metal vapor vacuum arc. We have made and tested an embodiment of vacuum arc plasma source that operates in a pulsed mode, thereby acquiring precise control over the plasma flux and so also over the deposition rate, and that is in the form of a miniature plasma gun, thereby allowing deposition of metallic thin films to be carried out in confined spaces and also allowing a number of such guns to be clustered together. The plasma is created at the cathode spots on the metallic cathode surface, and is highly ionized and of directed energy a few tens of electron volts. Adhesion of the film to the substrate is thus good. Virtually all of the solid metals of the Periodic Table can be used, including highly refractory metals like tantalum and tungsten. Films, including multilayer thin films, can be fabricated of thickness from Angstroms to microns. We have carried out preliminary experiments using several different versions of miniature, pulsed, metal vapor vacuum arc plasma guns to fabricate metallic thin films and multilayers. Here we describe the plasma guns and their operation in this application, and present examples of some of the thin film structures we have fabricated, including yttrium and platinum films of thicknesses from a few hundred Angstroms up to 1 micron and an yttrium-cobalt multilayer structure of layer thickness about 100 Angstroms. 33 refs., 5 figs.

  2. Magnetoelastic sensor for characterizing properties of thin-film/coatings

    NASA Technical Reports Server (NTRS)

    Bachas, Leonidas G. (Inventor); Barrett, Gary (Inventor); Grimes, Craig A. (Inventor); Kouzoudis, Dimitris (Inventor); Schmidt, Stefan (Inventor)

    2004-01-01

    An apparatus for determining elasticity characteristics of a thin-film layer. The apparatus comprises a sensor element having a base magnetostrictive element at least one surface of which is at least partially coated with the thin-film layer. The thin-film layer may be of a variety of materials (having a synthetic and/or bio-component) in a state or form capable of being deposited, manually or otherwise, on the base element surface, such as by way of eye-dropper, melting, dripping, brushing, sputtering, spraying, etching, evaporation, dip-coating, laminating, etc. Among suitable thin-film layers for the sensor element of the invention are fluent bio-substances, thin-film deposits used in manufacturing processes, polymeric coatings, paint, an adhesive, and so on. A receiver, preferably remotely located, is used to measure a plurality of values for magneto-elastic emission intensity of the sensor element in either characterization: (a) the measure of the plurality of values is used to identify a magneto-elastic resonant frequency value for the sensor element; and (b) the measure of the plurality of successive values is done at a preselected magneto-elastic frequency.

  3. Antifouling coating of cellulose acetate thin films with polysaccharide multilayers.

    PubMed

    Mohan, Tamilselvan; Kargl, Rupert; Tradt, Karin Eva; Kulterer, Martin R; Braćić, Matej; Hribernik, Silvo; Stana-Kleinschek, Karin; Ribitsch, Volker

    2015-02-13

    In this investigation, partially deacetylated cellulose acetate (DCA) thin films were prepared and modified with hydrophilic polysaccharides with the layer-by-layer (LbL) technique. As polysaccharides, chitosan (CHI) and carboxymethyl cellulose (CMC) were used. DCA thin films were manufactured by exposing spin coated cellulose acetate to potassium hydroxide solutions for various times. The deacetylation process was monitored by attenuated total reflectance-infrared spectroscopy, film thickness and static water contact angle measurements. A maximum of three bilayers was created from the alternating deposition of CHI and CMC on the DCA films under two different conditions namely constant ionic strengths and varying pH values of the CMC solutions. Precoatings of CMC at pH 2 were used as a base layer. The sequential deposition of CMC and CHI was investigated with a quartz crystal microbalance with dissipation, film thickness, static water contact angle and atomic force microscopy (AFM) measurements. The versatility and applicability of the developed functional coatings was shown by removing the multilayers by rinsing with mixtures containing HCl/NaCl. The developed LbL coatings are used for studying the fouling behavior of bovine serum albumin (BSA).

  4. 21 CFR 175.320 - Resinous and polymeric coatings for polyolefin films.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... films. 175.320 Section 175.320 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND... for polyolefin films. Resinous and polymeric coatings may be safely used as the food-contact surface... coating is applied as a continuous film over one or both sides of a base film produced from one or more...

  5. Microtribological Performance of Metal-doped Molybdenum Disulfide Coatings

    NASA Astrophysics Data System (ADS)

    Stoyanov, Pantcho

    2011-07-01

    The mechanical and tribological properties of pure MoS2, pure Au, Au-MoS2 and Ti-MoS2 coatings were evaluated and examined at a microscopic scale. The metal doped MoS2 coatings had varying metal content, 5-10at% for Ti and 10-90% for Au. Reciprocating sliding wear tests were performed with a range of initial Hertzian contact pressures from 0.41 to 3.5 GPa and in air at two humidity levels (i.e. "low" being 3-5%RH and "high" being 30-40%RH). Titanium and gold were chosen for this study as metal additives due to their positive influence on the mechanical properties of the coating. The friction and wear behavior at the micro-scale were directly compared to tribological properties at the macro-scale, which were performed using an in situ tribometer. Reciprocating micro- and macro- wear tests were performed with spherical diamond tip (with 10 and 50 mum radii) and a sapphire tip (with a radius of 3.175 mm), respectively. The range of initial Hertzian contact pressures for macro-scale (i.e. between 0.41GPa and 1.2GPa) overlapped with that for micro-scale. However, the initial Hertzian contact diameters (2*a) were very different (i.e. 0.8-2.3 mum for micro-scale and 60-180 mum for macro-scale). It was observed that the small addition of Ti or Au to MoS2 improved the microtribological properties (i.e. lower friction and less wear) compared to pure MoS2 coatings. The improved microtribological properties with metal additions were attributed to an increase in the mechanical properties, decrease in adhesion, and a decrease in the interfacial shear strength. In terms of the different length scales, lower steady state friction was observed for macrotribology compared to microtribology. The higher friction at the micro- scale was explained by the greater adhesion effects and additional velocity accommodation modes (e.g. microplowing or plowing). The microplowing or plowing at the microscopic scale was attributed to the tip roughness and the inability to sustain a stable

  6. Anti-diffusion metal coated O-rings

    DOEpatents

    Biallas, George Herman; Boyce, James Reid

    2016-03-22

    A method for inhibiting diffusion of gases and/or transmission of photons through elastomeric seals and a diffusion inhibiting elastomeric seal wherein at least a portion of the surface of a diffusion inhibiting elastomeric seal is coated with a compatibly-deformable, malleable metal coating.

  7. Metal flame spray coating protects electrical cables in extreme environment

    NASA Technical Reports Server (NTRS)

    Brady, R. D.; Fox, H. A.

    1967-01-01

    Metal flame spray coating prevents EMF measurement error in sheathed instrumentation cables which are externally attached to cylinders which were cooled on the inside, but exposed to gamma radiation on the outside. The coating provides a thermoconductive path for radiation induced high temperatures within the cables.

  8. Precious-Metal Salt Coatings for Detecting Hydrazines

    NASA Technical Reports Server (NTRS)

    Dee, Louis A.; Greene, Benjamin

    2004-01-01

    Substrates coated with a precious-metal salt KAuCl4 have been found to be useful for detecting hydrazine vapors in air at and above a concentration of the order of 0.01 parts per million (ppm). Upon exposure to air containing a sufficient amount of hydrazine for a sufficient time, the coating material undergoes a visible change in color.

  9. Spray forming polymer membranes, coatings and films

    DOEpatents

    McHugh, Kevin M.; Watson, Lloyd D.; McAtee, Richard E.; Ploger, Scott A.

    1993-01-01

    A method of forming a polymer film having controlled physical and chemical characteristics, wherein a plume of nebulized droplets of a polymer or polymer precursor is directed toward a substrate from a converging/diverging nozzle having a throat at which the polymer or a precursor thereof is introduced and an exit from which the nebulized droplets of the polymer or precursor thereof leave entrained in a carrier gas. Relative movement between the nozzle and the substrate is provided to form a polymer film. Physical and chemical characteristics can be controlled by varying the deposition parameters and the gas and liquid chemistries. Semipermeable membranes of polyphosphazene films are disclosed, as are a variety of other polymer systems, both porous and non-porous.

  10. Spray forming polymer membranes, coatings and films

    DOEpatents

    McHugh, K.M.; Watson, L.D.; McAtee, R.E.; Ploger, S.A.

    1993-10-12

    A method is described for forming a polymer film having controlled physical and chemical characteristics, wherein a plume of nebulized droplets of a polymer or polymer precursor is directed toward a substrate from a converging/diverging nozzle having a throat at which the polymer or a precursor thereof is introduced and an exit from which the nebulized droplets of the polymer or precursor thereof leave entrained in a carrier gas. Relative movement between the nozzle and the substrate is provided to form a polymer film. Physical and chemical characteristics can be controlled by varying the deposition parameters and the gas and liquid chemistries. Semipermeable membranes of polyphosphazene films are disclosed, as are a variety of other polymer systems, both porous and non-porous. 4 figures.

  11. Optical and electrical transport properties of semicontinuous metallic films

    NASA Astrophysics Data System (ADS)

    Seal, Katyayani

    Semicontinuous metallic films posses unique optical and electrical transport properties. The strong localization and large enhancement of electric fields demonstrated by these films make them interesting in terms of a fundamental understanding of these phenomena as well as potentially useful in a large variety of applications. The field distributions and electrical transport properties of these films depend on the structural geometry and morphology of the samples and therefore also on the metal concentration, with distinctive properties near the percolation threshold where an insulator-to-metal transition occurs. This dissertation focuses on an experimental investigation of the optical, electrical transport and structural properties of semicontinuous silver-glass composites near the percolation threshold. Particular emphasis is placed on the optical enhancement observed in these films in terms of their near-field optical intensity distribution. The samples were synthesized by pulsed laser ablation and the percolation threshold was identified in terms of structural properties using transmission electron microscopy as well as electrical resistivity and optical transmission through in-situ measurements during sample synthesis. The optical intensity distributions were measured using near-field optical microscopy (NSOM) and found to depend strongly on metal concentration and wavelength. The degree of localization was found to increase as metal concentrations was varied above and below the percolation threshold and also found to increase with increase in wavelength. Comparisons of the experimental results with theoretical calculations of the local field distributions obtained using the block elimination method showed good agreement. In addition, composite systems involving the coupling of enhancement from semicontinuous films with two other resonance phenomena are also studied viz. semicontinuous films (1) with random subwavelength apertures and (2) deposited on

  12. Instabilities of structured metal films on nanoscale

    NASA Astrophysics Data System (ADS)

    Dong, Nanyi; Wu, Yueying; Fowlkes, Jason; Rack, Philip; Kondic, Lou

    2014-11-01

    We consider instabilities of metal films on nanoscale, with particular focus on the interplay between the initial geometry and instability development. In experiments, metal films are deposited lithographically, allowing for precise control of the initial shape, and then exposed to laser pulses that liquefy them. The considered geometries involve various shapes (cylinders or prisms) superimposed on top of a flat film. We consider this problem within the framework of the long wave (lubrication) theory. Our simulations show that the main features of the instability development could be captured, as long as destabilizing liquid-solid interaction is considered in the model. We conclude by discussing the influence of the distance between the imposed perturbations, their shape, as well as experimental noise on the evolution. Supported by NSF Grant No. CBET-1235710.

  13. One-step surface selective modification of UV-curable hard coatings with photochemical metal organics

    NASA Astrophysics Data System (ADS)

    Lee, Yoon Kwang; Park, Chang-Sun; Park, Hyung-Ho

    2016-12-01

    An organic-inorganic hybrid bi-layer film with a selective distribution of inorganic components was synthesized from a one-pot process of UV irradiation. A photochemical metal oxide precursor (Sr 2-ethylhexanoate) varying from 0 to 4 wt% was dispersed in UV-curable coating materials. Under UV exposure, the bi-layer started reacting simultaneously but at different rates due to differences in the two UV-condensable components' reactivity. The effects of the dispersed inorganic component on the surface morphology and mechanical properties were investigated by atomic force microscopy and nanoindentation, respectively. The reaction process and rates were studied from linkage change using Fourier transform infrared spectroscopy at various UV exposure times (0-30 min). The elemental distribution and the interface on the coating layer were characterized by X-ray photoelectron spectroscopy from Ar etching, revealing continuous and gradual composition changes in depth. The results showed that a flattened and surface-selectively hardened SrO containing the coating film could be obtained by this simple process. Consequently, a small ratio of photochemical metal oxide reinforced the organic hard coating film's mechanical properties through the formation of an effective SrO top layer.

  14. Carbon-coated silicon nanowire array films for high-performance lithium-ion battery anodes

    NASA Astrophysics Data System (ADS)

    Huang, Rui; Fan, Xing; Shen, Wanci; Zhu, Jing

    2009-09-01

    Carbon-coated silicon nanowire array films prepared by metal catalytic etching of silicon wafers and pyrolyzing of carbon aerogel were used for lithium-ion battery anodes. The films exhibited an excellent first discharge capacity of 3344 mAh g-1 with a Coulombic efficiency of 84% at a rate of 150 mA g-1 between 2 and 0.02 V and a significantly enhanced cycling performance, i.e., a reversible capacity of 1326 mAh g-1 was retained after 40 cycles. These improvements were attributed to the uniform and continuous carbon coatings, which increased electronic contact and conduction and buffered large volume changes during lithium ion insertion/extraction.

  15. Preparation and characterization of YBCO coating on metallic RABiT substrates by pulsed laser deposition

    NASA Astrophysics Data System (ADS)

    Gonal, M. R.; Prajapat, C. L.; Igalwar, P. S.; Maji, B. C.; Singh, M. R.; Krishnan, M.

    2016-05-01

    Superconducting YBCO films are coated on metallic Rolling Assisted Bi-axially Textured Substrates (RABiTS) Ni-5wt % W (NiW) (002) substrate using pulsed laser deposition (PLD) system. Targets of YBa2Cu3O7-δ (YBCO) and buffer layers of Ceria and 8 mole % Yttria Stabilized Zirconia (YSZ) of high density are synthesized. At each stage of deposition coatings are characterized by XRD. Transport studies show superconducting nature of YBCO only when two successive buffer layers of YSZ and CeO2 are used.

  16. Protective lithium ion conducting ceramic coating for lithium metal anodes and associate method

    DOEpatents

    Bates, John B.

    1994-01-01

    A battery structure including a cathode, a lithium metal anode and an electrolyte disposed between the lithium anode and the cathode utilizes a thin-film layer of lithium phosphorus oxynitride overlying so as to coat the lithium anode and thereby separate the lithium anode from the electrolyte. If desired, a preliminary layer of lithium nitride may be coated upon the lithium anode before the lithium phosphorous oxynitride is, in turn, coated upon the lithium anode so that the separation of the anode and the electrolyte is further enhanced. By coating the lithium anode with this material lay-up, the life of the battery is lengthened and the performance of the battery is enhanced.

  17. Antireflective coatings applied from metal-organic derived liquid precursors.

    PubMed

    Yoldas, B E; O'Keeffe, T W

    1979-09-15

    Antireflective (AR) coatings, which are produced from organometallic driven solutions containing oxide constituents in a chemically polymerized form, are presented. These solutions leave a film on substrates which, upon heat treatment, converts to a glasslike oxide film having the desired optical thickness and index of refraction. The index can be varied continuously from 1.4 to 2.4; thus the AR coatings can be fine-tuned for different substrates and for specific wavelengths of light. Silicon solar cells AR-coated by this technique showed as much as 49% improvement in efficiency over the uncoated state. The real advantage of the process, however, lies in the fact that it is simple, well-suited for automated mass production of photovoltaic cells, and reduces the cost of coating application from an estimated $0.20 per W-package to about $0.01 per W-package. PMID:20212817

  18. Dynamics of discontinuous coating and drying of nanoparticulate films.

    SciTech Connect

    Schunk, Peter Randall; Dunphy, Darren Robert; Brinker, C. Jeffrey; Tjiptowidjojo, Kristianto

    2010-09-01

    Heightened interest in micro-scale and nano-scale patterning by imprinting, embossing, and nano-particulate suspension coating stems from a recent surge in development of higher-throughput manufacturing methods for integrated devices. Energy-applications addressing alternative, renewable energy sources offer many examples of the need for improved manufacturing technology for micro and nano-structured films. In this presentation we address one approach to micro- and nano-pattering coating using film deposition and differential wetting of nanoparticles suspensions. Rather than print nanoparticle or colloidal inks in discontinuous patches, which typically employs ink jet printing technology, patterns can be formed with controlled dewetting of a continuously coated film. Here we report the dynamics of a volatile organic solvent laden with nanoparticles dispensed on the surfaces of water droplets, whose contact angles (surface energy) and perimeters are defined by lithographic patterning of initially (super)hydrophobic surfaces.. The lubrication flow equation together with averaged particle transport equation are employed to predict the film thickness and particle average concentration profiles during subsequent drying of the organic and water solvents. The predictions are validated by contact angle measurements, in situ grazing incidence small angle x-ray scattering experiments, and TEM images of the final nanoparticle assemblies.

  19. Recent innovations in the area of edible films and coatings.

    PubMed

    Maftoonazad, Neda; Badii, Fojan; Shahamirian, Maryam

    2013-12-01

    Edible films/coatings have been considered as one of the potential technologies that can be used to increase the storability of foods and to improve the existent packaging technology, helping to ensure the microbial safety and the preservation of food from the influence of external factors. Innovations constantly appear in food packaging, always aiming at creating a more efficient quality preservation system while improving foods' attractiveness and marketability. The utilization of renewable sources for packaging materials, such as hydrocolloids and lipids from biological origin, is one the main trends of the industry. These films should have acceptable sensory characteristics, appropriate barrier properties (CO2, O2, water, oil), microbial, biochemical and physicochemical stability, they should be safe, and produced by simple technology in low cost. Also they can act as effective carrier for antioxidant, flavor, color and nutritional or anti-microbial additives. Nowadays, a great discussion exists about the potential applications of edible films/coatings on food products. The general trend is to find the correct combination between the food product and the edible film/coating, which will ensure the success of the technology.

  20. ''Green'' Biopolymers for Improved Decontamination of Metals from Surfaces: Sorptive Characterization and Coating Properties

    SciTech Connect

    Davison, Brian H.; Kurtiz,Tanya

    1999-06-01

    The proposed research aims to develop a fundamental understanding of important biological and physical chemical parameters for effective decontamination of metal surfaces using environmentally benign aqueous-based biopolymer solutions. Understanding how heavy metal-chelating biopolymers coat and interact with contaminated surfaces will benefit the development of novel, safe, easy-to-apply decontamination methodologies for removal of radionuclides and heavy metals. The benefits of these methodologies will include the following: (1) decreased exposure hazards for workers; (2) decreased secondary waste generation; (3) increased efficiency of decontamination; (4) positive public appeal and development of novel, nature-friendly business opportunities; and (5) lower cost of cleanup to the government. We propose to use aqueous biopolymer solutions to coat a contaminated metal surface (i.e., steel), solubilize the heavy metals (e.g., uranium) from the surface, and bind the heavy metals into the biopolymer. The biopolymer coating (containing the immobilized hazardous metal contaminants) will then be removed as a viscous film, as a dry powder, or by washing. This ''apply, wait, and remove'' procedure will reduce the amount of worker time spent in decontamination activities.

  1. ''Green'' Biopolymers for Improved Decontamination of Metals from Surfaces: Sorptive Characterization and Coating Properties

    SciTech Connect

    Davison, Brian H.

    2002-04-30

    The proposed research aimed to develop a fundamental understanding of important biological and physical chemical parameters for effective decontamination of metal surfaces using environmentally benign aqueous-based biopolymer solutions. Understanding how heavy metal-chelating biopolymers coat and interact with contaminated surfaces will benefit the development of novel, safe, easy-to-apply decontamination methodologies for removal of radionuclides and heavy metals. The benefits of these methodologies include the following: decreased exposure hazards for workers; decreased secondary waste generation; increased efficiency of decontamination; positive public appeal and development of novel, nature-friendly business opportunities; and lower cost of cleanup to the government. We proposed to use aqueous biopolymer solutions to coat a contaminated metal surface (i.e., steel), solubilize the heavy metals (e.g., uranium) from the surface, and bind the heavy metals into the biopolymer. The biopolymer coating (containing the immobilized hazardous metal contaminants) was to be removed as a viscous film, as a dry powder, or by washing. This ''apply, wait, and remove'' procedure will reduce the amount of worker time spent in decontamination activities.

  2. ''Green'' Biopolymers for Improved Decontamination of Metals from Surfaces: Sorptive Characterization and Coating Properties

    SciTech Connect

    Davison, Brian H.; Kuritz, Tanya

    2000-06-01

    The proposed research aims to develop a fundamental understanding of important biological and physical chemical parameters for effective decontamination of metal surfaces using environmentally benign aqueous-based biopolymer solutions. Understanding how heavy metal-chelating biopolymers coat and interact with contaminated surfaces will benefit the development of novel, safe, easy-to-apply decontamination methodologies for removal of radionuclides and heavy metals. The benefits of these methodologies will include the following: (1) decreased exposure hazards for workers; (2) decreased secondary waste generation; (3) increased efficiency of decontamination; (4) positive public appeal and development of novel, nature-friendly business opportunities; and (5) lower cost of cleanup to the government. We propose to use aqueous biopolymer solutions to coat a contaminated metal surface (i.e., steel), solubilize the heavy metals (e.g., uranium) from the surface, and bind the heavy metals into the biopolymer. The biopolymer coating (containing the immobilized hazardous metal contaminants) will then be removed as a viscous film, as a dry powder, or by washing. This ''apply, wait, and remove'' procedure will reduce the amount of worker time spent in decontamination activities.

  3. Transparent binary-thickness coatings on metal substrates that produce binary patterns of orthogonal elliptical polarization states in reflected light

    NASA Astrophysics Data System (ADS)

    Azzam, Rasheed M. A.; Angel, Wade W.

    1992-12-01

    A reflective division-of-wavefront polarizing beam splitter is described that uses a dual- thickness transparent thin-film coating on a metal substrate. A previous design that used a partially clad substrate at the principal angle of the metal [Azzam, JOSA A 5, 1576 (1988)] is replaced by a more general one in which the substrate is coated throughout and the film thickness alternates between two non-zero levels. The incident linear polarization azimuth is chosen near, but not restricted to, 45 degree(s) (measured from the plane of incidence), and the angle of incidence may be selected over a range of values. The design procedure, which uses the two-dimensional Newton-Raphson method, is applied to the SiO2-Au film- substrate system at 633 nm wavelength, as an example, and the characteristics of the various possible coatings are presented.

  4. Coatings Preserve Metal, Stone, Tile, and Concrete

    NASA Technical Reports Server (NTRS)

    2014-01-01

    John B. Schutt, a chemist at Goddard Space Flight Center, created a coating for spacecraft that could resist corrosion and withstand high heat. After retiring from NASA, Schutt used his expertise to create new formulations for Daytona Beach, Florida-based Adsil Corporation, which now manufactures a family of coatings to preserve various surfaces. Adsil has created 150 jobs due to the products.

  5. Measurements and Diagnostics of Diamond Films and Coatings

    NASA Technical Reports Server (NTRS)

    Miyoshi, Kazuhisa; Wu, Richard L. C.

    1999-01-01

    The commercial potential of chemical-vapor-deposited (CVD) diamond films has been established and a number of applications have been identified through university, industry, and government research studies. This paper discusses the methodologies used for property measurement and diagnostic of CVD diamond films and coatings. Measurement and diagnostic techniques studied include scanning electron microscopy, transmission electron microscopy, atomic force microscopy, stylus profilometry, x-ray diffraction, electron diffraction, Raman spectroscopy, Rutherford backscattering, elastic recoil spectroscopy, and friction examination. Each measurement and diagnostic technique provides unique information. A combination of techniques can provide the technical information required to understand the quality and properties of CVD diamond films, which are important to their application in specific component systems and environments. In this study the combination of measurement and diagnostic techniques was successfully applied to correlate deposition parameters and resultant diamond film composition, crystallinity, grain size, surface roughness, and coefficient of friction.

  6. Coatings and films derived from clay/wax nanocomposites

    DOEpatents

    Chaiko, David J.; Leyva, Argentina A.

    2006-11-14

    The invention provides methods for making clay/wax nanocomposites and coatings and films of same with improved chemical resistance and gas barrier properties. The invention further provides methods for making and using emulsions of such clay/wax nanocomposites. Typically, an organophillic clay is combined with a wax or wax/polymer blend such that the cohesion energy of the clay matches that of the wax or wax/polymer blend. Suitable organophilic clays include mica and phyllosilicates that have been surface-treated with edge or edge and surface modifying agents. The resulting nanocomposites have applications as industrial coatings and in protective packaging.

  7. Molecular insights into shellac film coats from different aqueous shellac salt solutions and effect on disintegration of enteric-coated soft gelatin capsules.

    PubMed

    Al-Gousous, J; Penning, M; Langguth, P

    2015-04-30

    The purpose of this investigation was to study the effect of using different salts of shellac on the disintegration properties of shellac-based enteric coatings. In the last two decades, shellac has been increasingly used as an aqueous solution for enteric coating purposes, with the ammonium salt being the form typically used. Little investigation has been performed on using other salts, and therefore, this was the focus of our work. Enteric coatings, based on different shellac salts (ammonium, sodium, potassium and composite ammonium-sodium), were applied onto soft gelatin capsules. Disintegration testing of the coated soft gelatin capsules showed that alkali metal salts promote faster disintegration than ammonium salts. In order to determine the causes behind these differences, the solubility, thermal and spectroscopic properties of films cast from the different salts were investigated. The results show that films cast from ammonium-based salts of shellac are, unlike those cast from alkali metal-based salts, water-insoluble. Spectroscopic evidence suggests that this might be due to partial salt dissociation resulting in loss of ammonium as ammonia and reduced degree of shellac ionization during drying. In addition, oxidation of shellac aldehyde groups of the ammonium-based shellac salts could also play a role. And possible higher extent of shellac hydrolysis during the preparation of alkali metal salts might also be a factor. Therefore, the nature of the shellac salt used in the preparation of shellac-based aqueous coating solutions is a significant formulation factor affecting product performance. PMID:25578368

  8. Plasma-sprayed ceramic coatings for protection against molten metal.

    SciTech Connect

    Hollis, K. J.; Peters, M. I.; Bartram, B. D.

    2002-01-01

    Molten metal environments pose a special demand on materials due to the high temperature corrosion effects and thermal expansion mismatch induced stress effects. A solution that has been successfully employed is the use of a base material for the mechanical strength and a coating material for the chemical compatibility with the molten metal. The work described here used such an approach coating tungsten rods with aluminum oxide, yttria-stabilized zirconia, yttrium oxide, and erbium oxide deposited by atmospheric plasma spraying. The ceramic materials were deposited under varying conditions to produce different structures. Measurement of particle characteristics was performed to correlate to material properties. The coatings were tested in a thermal cycling environment to simulate the metal melting cycle expected in service. Results of the testing indicate the effect of material composition and spray conditions on the thermal cycle crack resistance of the coatings.

  9. Nanoscale growth twins in sputtered metal films

    SciTech Connect

    Misra, Amit; Anderoglu, Osman; Hoagland, Richard G; Zhang, X

    2008-01-01

    We review recent studies on the mechanical properties of sputtered Cu and 330 stainless steel films with {l_brace}1 1 1{r_brace} nanoscale growth twins preferentially oriented perpendicular to growth direction. The mechanisms of formation of growth twins during sputtering and the deformation mechanisms that enable usually high strengths in nanotwinned structures are highlighted. Growth twins in sputtered films possess good thermal stability at elevated temperature, providing an approach to extend the application of high strength nanostructured metals to higher temperatures.

  10. 21 CFR 888.3358 - Hip joint metal/polymer/metal semi-constrained porous-coated uncemented prosthesis.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Hip joint metal/polymer/metal semi-constrained... Devices § 888.3358 Hip joint metal/polymer/metal semi-constrained porous-coated uncemented prosthesis. (a) Identification. A hip joint metal/polymer/metal semi-constrained porous-coated uncemented prosthesis is a...

  11. 21 CFR 888.3358 - Hip joint metal/polymer/metal semi-constrained porous-coated uncemented prosthesis.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Hip joint metal/polymer/metal semi-constrained... Devices § 888.3358 Hip joint metal/polymer/metal semi-constrained porous-coated uncemented prosthesis. (a) Identification. A hip joint metal/polymer/metal semi-constrained porous-coated uncemented prosthesis is a...

  12. 21 CFR 888.3358 - Hip joint metal/polymer/metal semi-constrained porous-coated uncemented prosthesis.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Hip joint metal/polymer/metal semi-constrained... Devices § 888.3358 Hip joint metal/polymer/metal semi-constrained porous-coated uncemented prosthesis. (a) Identification. A hip joint metal/polymer/metal semi-constrained porous-coated uncemented prosthesis is a...

  13. 21 CFR 888.3358 - Hip joint metal/polymer/metal semi-constrained porous-coated uncemented prosthesis.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Hip joint metal/polymer/metal semi-constrained... Devices § 888.3358 Hip joint metal/polymer/metal semi-constrained porous-coated uncemented prosthesis. (a) Identification. A hip joint metal/polymer/metal semi-constrained porous-coated uncemented prosthesis is a...

  14. 21 CFR 888.3358 - Hip joint metal/polymer/metal semi-constrained porous-coated uncemented prosthesis.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Hip joint metal/polymer/metal semi-constrained... Devices § 888.3358 Hip joint metal/polymer/metal semi-constrained porous-coated uncemented prosthesis. (a) Identification. A hip joint metal/polymer/metal semi-constrained porous-coated uncemented prosthesis is a...

  15. Battery-powered thin film deposition process for coating telescope mirrors in space

    NASA Astrophysics Data System (ADS)

    Sheikh, David A.

    2016-07-01

    Aluminum films manufactured in the vacuum of space may increase the broadband reflectance response of a space telescope operating in the EUV (50-nm to 115-nm) by eliminating absorbing metal-fluorides and metal-oxides, which significantly reduce aluminum's reflectance below 115-nm. Recent developments in battery technology allow small lithium batteries to rapidly discharge large amounts of energy. It is therefore conceivable to power an array of resistive evaporation filaments in a space environment, using a reasonable mass of batteries and other hardware. This paper presents modeling results for coating thickness as a function of position, for aluminum films made with a hexagonal array of battery powered evaporation sources. The model is based on measured data from a single battery-powered evaporation source.

  16. Solar Selective Coatings Prepared From Thin-Film Molecular Mixtures and Evaluated

    NASA Technical Reports Server (NTRS)

    Jaworske, Don A.

    2003-01-01

    Thin films composed of molecular mixtures of metal and dielectric are being considered for use as solar selective coatings for a variety of space power applications. By controlling molecular mixing during ion-beam sputter deposition, researchers can tailor the solar selective coatings to have the combined properties of high solar absorptance and low infrared emittance. On orbit, these combined properties simultaneously maximize the amount of solar energy captured by the coating and minimize the amount of thermal energy radiated. The solar selective coatings are envisioned for use on minisatellites, for applications where solar energy is used to power heat engines or to heat remote regions in the interior of the spacecraft. Such systems may be useful for various missions, particularly those to middle Earth orbit. Sunlight must be concentrated by a factor of 100 or more to achieve the desired heat inlet operating temperature. At lower concentration factors, the temperature of the heat inlet surface of the heat engine is too low for efficient operation, and at high concentration factors, cavity type heat receivers become attractive. The an artist's concept of a heat engine, with the annular heat absorbing surface near the focus of the concentrator coated with a solar selective coating is shown. In this artist's concept, the heat absorbing surface powers a small Stirling convertor. The astronaut's gloved hand is provided for scale. Several thin-film molecular mixtures have been prepared and evaluated to date, including mixtures of aluminum and aluminum oxide, nickel and aluminum oxide, titanium and aluminum oxide, and platinum and aluminum oxide. For example, a 2400- Angstrom thick mixture of titanium and aluminum oxide was found to have a solar absorptance of 0.93 and an infrared emittance of 0.06. On the basis of tests performed under flowing nitrogen at temperatures as high as 680 C, the coating appeared to be durable at elevated temperatures. Additional durability

  17. Hydrous silica coatings: occurrence, speciation of metals, and environmental significance.

    PubMed

    Schindler, Michael; Durocher, Jennifer L; Abdu, Yassir; Hawthorne, Frank C

    2009-12-01

    Si-enriched coatings form on the surface of silicate minerals under acidic conditions. Although they are often only a few nanometers thick, their large specific surface area may control the interaction between silicate minerals in acidic soils, aquifers, and mine tailings. Micrometer thick, hydrous-silica coatings occur on the surface of a granite outcrop in contact with acidic pond water at the Coppercliff mine-tailings area in the Greater City of Sudbury, Ontario, and are ideal to study the concentration and speciation of metals and metalloids inside Si-enriched coatings. These coatings have higher average concentrations of Cr, Mn, Co, Ni, Cu, Zn, and Pb than coatings composed of schwertmannite, Fe(8)O(8)(OH)(4.4)(SO(4))(1.8) (H(2)O)(8.4). Microscopic and spectroscopic examination of the hydrous-silica coating indicates the occurrence of Fe- and Cu-Zn-oxy-hydroxide particles, tetrahedrally coordinated Fe(3+) and a high proportion of M-O-Si bonds (M = metal). These observations suggest that metals occur either finely distributed in the hydrous-silica matrix or in oxy-hydroxide particles. The latter particles are products of the diffusion of metals into the hydrous silica and the subsequent nucleation of oxy-hydroxide phases.

  18. Photobiomolecular deposition of metallic particles and films

    DOEpatents

    Hu, Zhong-Cheng

    2005-02-08

    The method of the invention is based on the unique electron-carrying function of a photocatalytic unit such as the photosynthesis system I (PSI) reaction center of the protein-chlorophyll complex isolated from chloroplasts. The method employs a photo-biomolecular metal deposition technique for precisely controlled nucleation and growth of metallic clusters/particles, e.g., platinum, palladium, and their alloys, etc., as well as for thin-film formation above the surface of a solid substrate. The photochemically mediated technique offers numerous advantages over traditional deposition methods including quantitative atom deposition control, high energy efficiency, and mild operating condition requirements.

  19. Emerging polyheterocyclic films, coatings and resins - Thermoplastic polyquinolines

    NASA Technical Reports Server (NTRS)

    Hendricks, Neil H.; Marrocco, Matthew L.; Garver, Lee C.; St. Clair, Anne K.; Proctor, Mason; Soane, David S.; Monk, David J.

    1991-01-01

    The processing and performance characteristics of a soluble, thermoplastic polyquinoline suggest its utility in a variety of high performance applications. The polymer is characterized by excellent thermal and oxidative stability, very low moisture absorption, good mechanical properties, very low dielectric constant, and an unusually low thermal expansion coefficient. This polymer, designated PQ-100 (TM), can be cast into strong, transparent, free standing films from common solvents. Coatings of variable thickness can be spin-coated on to silicon and other surfaces. After processing into films, PQ-100 (TM) can be rendered insoluble in a wide range of solvents using a proprietary process. The low CTE contributes to very low residual stress when the polymer is spin-coated onto silicon wafers. PQ-100 (TM) is currently under evaluation for use as an interlayer dielectric substrate in high-density interconnect applications, including multichip modules. Many of the characteristics of the polymer also suggest its utility as a high-performance film and as a matrix resin for specialty composite applications.

  20. Fabrication of the nanostructure metal film

    NASA Astrophysics Data System (ADS)

    Mi, Zhiqiang; Xu, Xiaoxuan; Li, Junmei; Wang, Bin; Wang, Yufang

    2009-07-01

    With the use of nano-structure metal film and the angle incident laser which has specific wavelength and polarization, it will form surface plasma resonance, and we can see several orders of SERS phenomenon. This phenomenon can be widely used in the area of military. Such as the detection of the mine, the investigation of the concentration of toxic gas. This paper mainly describes a way of fabrication of the nano-structure metal film: at first fabricate a honeycomb structures of aluminum oxide template, the second plate the alumina template with silver, at last dissolve the alumina template with hydrochloric acid. Thus ordered silver nano arrays is formed. Experiment prove it is a very well substrate for SERS.

  1. Structured metal film as a perfect absorber.

    PubMed

    Xiong, Xiang; Jiang, Shang-Chi; Hu, Yu-Hui; Peng, Ru-Wen; Wang, Mu

    2013-08-01

    A new type of absorber, a four-tined fish-spear-like resonator (FFR), constructed by the two-photon polymerization process, is reported. An absorbance of more than 90% is experimentally realized and the resonance occurs in the space between the tines. Since a continuous layer of metallic thin film covers the structure, it is perfectly thermo- and electroconductive, which is the mostly desired feature for many applications. PMID:23661582

  2. Method for growth of CVD diamond on thin film refractory coatings and glass ceramic materials

    NASA Astrophysics Data System (ADS)

    Moran, Mark B.; Johnson, Linda F.; Klemm, Karl A.

    1994-09-01

    This paper describes a new method for significantly improving diamond film quality and growth rate on insulating substrates and thin films. The usual method of abrading the substrate surface with diamond particles yields good quality CVD diamond films at reasonable deposition rates on semiconducting materials like silicon. However, on insulating materials like fused silica and sapphire, the conventional method of diamond seeding and surface abrasion almost always results in slow growth rates and poor quality films. Current in-house diamond nucleation and growth studies have focused on depositing CVD diamond on substrates such as fused silica, sapphire, and glass ceramics. Diamond was grown successfully on these types of materials using a sacrificial metal layer method called metal induced nucleation of diamond (MIND). This technique offers a way to deposit diamond on glassy materials with improved adhesion and at lower deposition temperatures (less than 650 degree(s)C). In addition, the MIND technique can be used in combination with metal masking and conventional etching to deposit patterns of diamond. The MIND method was combined with another in-house developed technique called sputtered refractory interlayer nucleation technique (SPRINT). Diamond-crystallite size and orientation can be controlled with SPRINT to fabricate low-scatter diamond films. Both techniques are discussed. A reliable, efficient method for growing diamond on insulating materials significantly enhances the feasibility for practical applications of CVD diamond technology. For example, further development of the MIND technique may provide low-scatter, protective diamond films on sapphire and glass ceramics for visible-wavelength windows and missile domes. For electronic applications, reduction in the growth temperature makes CVD diamond more compatible with existing semiconductor processes. The lower growth temperature also helps to alleviate diffusion problems in metal alloys and facilitates

  3. Structural characterization and comparison of iridium, platinum and gold/palladium ultra-thin film coatings for STM of biomolecules

    SciTech Connect

    Sebring, R.; Arendt, P.; Imai, B.; Bradbury, E.M.; Gatewood, J.; Panitz, J.; Yau, P.

    1997-10-30

    Scanning tunneling microscopy (STM) is capable of atomic resolution and is ideally suited for imaging surfaces with uniform work function. A biological sample on a conducting substrate in air does not meet this criteria and requires a conductive coating for stable and reproducible STM imaging. In this paper, the authors describe the STM and transmission electron microscopy (TEM) characterization of ultra-thin ion-beam sputtered films of iridium and cathode sputtered gold/palladium and platinum films on highly ordered pyrolytic graphite (HOPG) which were developed for use as biomolecule coatings. The goals were the development of metal coatings sufficiently thin and fine grained that 15--20 {angstrom} features of biological molecules could be resolved using STM, and the development of a substrate/coating system which would allow complementary TEM information to be obtained for films and biological molecules. The authors demonstrate in this paper that ion-beam sputtered iridium on highly ordered pyrolytic graphite (HOPG) has met both these goals. The ion-beam sputtered iridium produced a very fine grained (< 10 {angstrom}) continuous film at 5--6 {angstrom} thickness suitable for stable air STM imaging. In comparison, cathode sputtered platinum produced 16 {angstrom} grains with the thinnest continuous film at 15 {angstrom} thickness, and the sputtered gold/palladium produced 25 {angstrom} grains with the thinnest continuous film at 18 {angstrom} thickness.

  4. Direct observation and mechanism of increased emission sites in Fe-coated microcrystalline diamond films

    SciTech Connect

    Panda, Kalpataru; Sundaravel, B.; Panigrahi, B. K.; Huang, Pin-Chang; Shih, Wen-Ching; Chen, Huang-Chin; Lin, I-Nan

    2012-06-15

    The electron field emission (EFE) properties of microcrystalline diamond (MCD) films are significantly enhanced due to the Fe coating and post-annealing processes. The 900 Degree-Sign C post-annealed Fe coated diamond films exhibit the best EFE properties, with a turn on field (E{sub 0}) of 3.42 V/{mu}m and attain EFE current density (J{sub e}) of 170 {mu}A/cm{sup 2} at 7.5 V/{mu}m. Scanning tunnelling spectroscopy (STS) in current imaging tunnelling spectroscopy mode clearly shows the increased number density of emission sites in Fe-coated and post-annealed MCD films than the as-prepared ones. Emission is seen from the boundaries of the Fe (or Fe{sub 3}C) nanoparticles formed during the annealing process. In STS measurement, the normalized conductance (dI/dV/I/V) versus V curves indicate nearly metallic band gap, at the boundaries of Fe (or Fe{sub 3}C) nanoparticles. Microstructural analysis indicates that the mechanism for improved EFE properties is due to the formation of nanographite that surrounds the Fe (or Fe{sub 3}C) nanoparticles.

  5. 21 CFR 175.365 - Vinylidene chloride copolymer coatings for polycarbonate film.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... polycarbonate film. 175.365 Section 175.365 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH... chloride copolymer coatings for polycarbonate film. Vinylidene chloride copolymer coatings identified in this section and applied on polycarbonate film may be safely used as food-contact surfaces,...

  6. 21 CFR 175.360 - Vinylidene chloride copolymer coatings for nylon film.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... film. 175.360 Section 175.360 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND... coatings for nylon film. Vinylidene chloride copolymer coatings identified in this section and applied on nylon film may be safely used as food-contact surfaces, in accordance with the following...

  7. Laser Assisted Additively Manufactured Transition Metal Coating on Aluminum

    NASA Astrophysics Data System (ADS)

    Vora, Hitesh D.; Rajamure, Ravi Shanker; Roy, Anurag; Srinivasan, S. G.; Sundararajan, G.; Banerjee, Rajarshi; Dahotre, Narendra B.

    2016-07-01

    Various physical and chemical properties of surface and subsurface regions of Al can be improved by the formation of transition metal intermetallic phases (Al x TM y ) via coating of the transition metal (TM). The lower equilibrium solid solubility of TM in Al (<1 at.%) is a steep barrier to the formation of solid solutions using conventional alloying methods. In contrast, as demonstrated in the present work, surface engineering via a laser-aided additive manufacturing approach can effectively synthesize TM intermetallic coatings on the surface of Al. The focus of the present work included the development of process control to achieve thermodynamic and kinetic conditions necessary for desirable physical, microstructural and compositional attributes. A multiphysics finite element model was developed to predict the temperature profile, cooling rate, melt depth, dilution of W in Al matrix and corresponding micro-hardness in the coating, and the interface between the coating and the base material and the base material.

  8. Superhydrophobic anti-ultraviolet films by doctor blade coating

    SciTech Connect

    Cai, Chang-Yun; Yang, Hongta; Lin, Kun-Yi Andrew

    2014-11-17

    This article reports a scalable technology for fabricating polymer films with excellent water-repelling and anti-ultraviolet properties. A roll-to-roll compatible doctor blade coating technology is utilized to prepare silica colloidal crystal-polymer composites. The silica microspheres can then be selectively removed to create flexible self-standing macroporous polymer films with crystalline arrays of pores. The void sizes are controlled by tuning the duration of a reactive ion etching process prior to the removal of the templating silica microspheres. After surface modification, superhydrophobic surface can be achieved. This study further demonstrates that the as-prepared transparent porous films with 200 nm of pores exhibit diffraction of ultraviolet lights originated from the Bragg's diffractive of light from the three-dimensional highly ordered air cavities.

  9. Magnetic metal nanoparticles coated polyacrylonitrile textiles as microwave absorber

    NASA Astrophysics Data System (ADS)

    Akman, O.; Kavas, H.; Baykal, A.; Toprak, M. S.; Çoruh, Ali; Aktaş, B.

    2013-02-01

    Polyacrylonitrile (PAN) textiles with 2 mm thickness are coated with magnetic nanoparticles in coating baths with Ni, Co and their alloys via an electroless metal deposition method. The crystal structure, morphology and magnetic nature of composites are investigated by X-ray Powder diffraction, Scanning Electron Microscopy, and dc magnetization measurement techniques. The frequency dependent microwave absorption measurements have been carried out in the frequency range of 12.4-18 GHz (X and P bands). Diamagnetic and ferromagnetic properties are also investigated. Finally, the microwave absorption of composites is found strongly dependent on the coating time. One absorption peak is observed between 14.3 and 15.8 GHz with an efficient absorption bandwidth of 3.3-4.1 GHz (under -20 dB reflection loss limit). The Reflection loss (RL) can be achieved between -30 and -50 dB. It was found that the RL is decreasing and absorption bandwidth is decreasing with increasing coating time. While absorption peak moves to lower frequencies in Ni coated PAN textile, it goes higher frequencies in Co coated ones. The Ni-Co alloy coated composites have fluctuating curve of absorption frequency with respect to coating time. These results encourage further development of magnetic nanoparticle coated textile absorbers for broadband applications.

  10. Surface coating for prevention of metallic seed migration in tissues

    SciTech Connect

    Lee, Hyunseok; Park, Jong In; Lee, Won Seok; Park, Min; Son, Kwang-Jae; Bang, Young-bong; Choy, Young Bin E-mail: sye@snu.ac.kr; Ye, Sung-Joon E-mail: sye@snu.ac.kr

    2015-06-15

    Purpose: In radiotherapy, metallic implants often detach from their deposited sites and migrate to other locations. This undesirable migration could cause inadequate dose coverage for permanent brachytherapy and difficulties in image-guided radiation delivery for patients. To prevent migration of implanted seeds, the authors propose a potential strategy to use a biocompatible and tissue-adhesive material called polydopamine. Methods: In this study, nonradioactive dummy seeds that have the same geometry and composition as commercial I-125 seeds were coated in polydopamine. Using scanning electron microscopy and x-ray photoelectron spectroscopy, the surface of the polydopamine-coated and noncoated seeds was characterized. The detachment stress between the two types of seeds and the tissue was measured. The efficacy of polydopamine-coated seed was investigated through in vitro migration tests by tracing the seed location after tissue implantation and shaking for given times. The cytotoxicity of the polydopamine coating was also evaluated. Results: The results of the coating characterization have shown that polydopamine was successfully coated on the surface of the seeds. In the adhesion test, the polydopamine-coated seeds had 2.1-fold greater detachment stress than noncoated seeds. From the in vitro test, it was determined that the polydopamine-coated seed migrated shorter distances than the noncoated seed. This difference was increased with a greater length of time after implantation. Conclusions: The authors suggest that polydopamine coating is an effective technique to prevent migration of implanted seeds, especially for permanent prostate brachytherapy.

  11. Supercritical Fluid Immersion Deposition: A New Process for Selective Deposition of Metal Films on Silicon Substrates

    SciTech Connect

    Ye, Xiangrong; Wai, Chien M.; Lin, Yuehe; Young, James S.; Engelhard, Mark H.

    2005-01-01

    Supercritical CO2 is used as a new solvent for immersion deposition, a galvanic displacement process traditionally carried out in aqueous HF solutions containing metal ions, to selectively develop metal films on featured or non-featured silicon substrates. Components of supercritical fluid immersion deposition (SFID) solutions for fabricating Cu and Pd films on silicon substrates are described along with the corresponding experimental setup and procedure. Only silicon substrates exposed and reactive to SFID solutions can be coated. The highly pressurized and gas-like supercritical CO2, combined with the galvanic displacement property of immersion deposition, enables the SFID technique to selectively deposit metal films in small features. SFID may also provide a new method to fabricate palladium silicide in small features or to metallize porous silicon.

  12. Deposition Technique For Chemical Free Black Coatings On Metals

    NASA Astrophysics Data System (ADS)

    Carton, J. G.; Cobbe, N.; O'Donoghue, J.; Pambaguian, L.; Norman, A.; Liedtke, V.; McCaul, T.

    2012-07-01

    Coatings having specific thermo-optical properties are necessary to manage the temperature equilibrium in space hardware. Incumbent black body coatings have a need to extend their operating temperature as well as increase the range of substrate materials that can be coated; in addition, issues relating to outgassing can limit the application of black body coatings. In this paper a relatively new coating technology, CoBlast, is used to deposit material on to titanium substrates, to produce a black body surface; SolarBlack. CoBlast, replaces the oxide layer of reactive metals with a fused thin surface. The process is uniquely non-complex, requiring no thermal input, no wet chemistry and is performed in an ambient temperature and pressure environment. Thermo optical and micro-structure analysis of SolarBlack was completed and the characterisation results including thermo cycling, up to 700°C, are discussed.

  13. Graded coatings for metallic implant alloys

    SciTech Connect

    Saiz, Eduardo; Tomsia, Antoni P.; Fujino, Shigeru; Gomez-Vega, Jose M.

    2002-08-01

    Graded glass and glass-hydroxyapatite coatings on Ti-based and Co-Cr alloys have been prepared using a simple enameling technique. The composition of the glasses has been tailored to match the thermal expansion of the alloys. By controlling the firing time, and temperature, it has been possible to control the reactivity between the glass and the alloy and to fabricate coatings (25 to 150 mu m thick) with excellent adhesion to the substrate, resistant to corrosion and able to precipitate hydroxyapatite during in vitro tests in simulated body fluid.

  14. Optical bistability in a nonlinear-shell-coated metallic nanoparticle

    PubMed Central

    Chen, Hongli; Zhang, Youming; Zhang, Baile; Gao, Lei

    2016-01-01

    We provide a self-consistent mean field approximation in the framework of Mie scattering theory to study the optical bistability of a metallic nanoparticle coated with a nonlinear shell. We demonstrate that the nanoparticle coated with a weakly nonlinear shell exhibits optical bistability in a broad range of incident optical intensity. This optical bistability critically relies on the geometry of the shell-coated nanoparticle, especially the fractional volume of the metallic core. The incident wavelength can also affect the optical bistability. Through an optimization-like process, we find a design with broader bistable region and lower threshold field by adjusting the size of the nonlinear shell, the fractional volume of the metallic core, and the incident wavelength. These results may find potential applications in optical bistable devices such as all-optical switches, optical transistors and optical memories. PMID:26907967

  15. Process for the preparation of metal-containing nanostructured films

    NASA Technical Reports Server (NTRS)

    Lu, Yunfeng (Inventor); Wang, Donghai (Inventor)

    2006-01-01

    Metal-containing nanostructured films are prepared by electrodepositing a metal-containing composition within the pores of a mesoporous silica template to form a metal-containing silica nanocomposite. The nanocomposite is annealed to strengthen the deposited metal-containing composition. The silica is then removed from the nanocomposite, e.g., by dissolving the silica in an etching solution to provide a self-supporting metal-containing nanostructured film. The nanostructured films have a nanowire or nanomesh architecture depending on the pore structure of the mesoporous silica template used to prepare the films.

  16. Protective coatings for metal alloys and methods incorporating the same

    SciTech Connect

    Seabaugh, Matthew M.; Ibanez, Sergio; Swartz, Scott L.

    2015-06-09

    An electrochemical device having one or more solid oxide fuel cells (SOFCs), each of the SOFCs including a cathode, an anode, and an electrolyte layer positioned between the cathode and anode; and at least one additional component comprising a metallic substrate having an electronically conductive, chromium-free perovskite coating deposited directly thereon. The perovskite coating has the formula ABO.sub.3, wherein A is a lanthanide element or Y, and B is a mixture of two or more transition elements, with the A site undoped by any alkaline earth element, and the perovskite coating exhibits limited or no ionic transport of oxygen.

  17. Preparing oxidizer coated metal fuel particles

    NASA Technical Reports Server (NTRS)

    Shafer, J. I.; Simmons, G. M. (Inventor)

    1974-01-01

    A solid propellant composition of improved efficiency is described which includes an oxidizer containing ammonium perchlorate, and a powered metal fuel, preferably aluminum or beryllium, in the form of a composite. The metal fuel is contained in the crystalline lattice framework of the oxidizer, as well as within the oxidizer particles, and is disposed in the interstices between the oxidizer particles of the composition. The propellant composition is produced by a process comprising the crystallization of ammonium perchlorate in water, in the presence of finely divided aluminum or beryllium. A suitable binder is incorporated in the propellant composition to bind the individual particles of metal with the particles of oxidizer containing occluded metal.

  18. Silicon nitride films for the protective functional coating: blood compatibility and biomechanical property study.

    PubMed

    Shi, Zhifeng; Wang, Yingjun; Du, Chang; Huang, Nan; Wang, Lin; Ning, Chengyun

    2012-12-01

    Behaviors of silicon nitride films and their relation to blood compatibility and biomechanical have been interesting subjects to researchers. A systematic blood compatibility and biomechanical property investigation on the deposition of silicon-nitride films under varying N₂ and CF₄ flows was carried out by direct current unbalanced magnetron sputtering techniques. Significant role of surface property, chemical bonding state of silicon nitride film and blood compatibility, mechanical properties for the films were observed. The chemical bonding configurations, surface topography, contact angle and mechanical properties were characterized by means of X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and nano-indentation technique and CSEM pin-on-disk tribometer. Blood compatibility of the films was evaluated by platelet adhesion investigation. The results of the platelet adhesion tests shown that the effect of fluorine and nitrogen-doped revealed an intimate relationship between the ratio of polar component and dispersion component of the surface energy and its hemocompatibility. Si-N-O coating can be a great candidate for developing antithrombogenic surfaces in blood contacting materials. The chemical bonding state made an adjustment in microstructured surfaces, once in the totally wettable configuration, may improve the initial contact between platelet and biomedical materials, due to the appropriate ratio of dispersion component and polar component. To resist wear, biomedical components require coatings that are tough and hard, have low friction, and are bio-inert. The study suggests that by Si-N coating the metal surfaces could be a choice to prolong the life of the sliding pair Co-Cr-Mo alloy/UHMWPE implants.

  19. Pentek metal coating removal system: Baseline report

    SciTech Connect

    1997-07-31

    The Pentek coating removal technology was tested and is being evaluated at Florida International University (FIU) as a baseline technology. In conjunction with FIU`s evaluation of efficiency and cost, this report covers evaluation conducted for safety and health issues. It is a commercially available technology and has been used for various projects at locations throughout the country. The Pentek coating removal system consisted of the ROTO-PEEN Scaler, CORNER-CUTTER{reg_sign}, and VAC-PAC{reg_sign}. They are designed to remove coatings from steel, concrete, brick, and wood. The Scaler uses 3M Roto Peen tungsten carbide cutters while the CORNER-CUTTER{reg_sign} uses solid needles for descaling activities. These hand tools are used with the VAC-PAC{reg_sign} vacuum system to capture dust and debris as removal of the coating takes place. The safety and health evaluation during the testing demonstration focused on two main areas of exposure: dust and noise. Dust exposure minimal, but noise exposure was significant. Further testing for each exposure is recommended because of the environment where the testing demonstration took place. It is feasible that the dust and noise levels will be higher in an enclosed operating environment of different construction. In addition, other areas of concern found were arm-hand vibration, whole-body, ergonomics, heat stress, tripping hazards, electrical hazards, machine guarding, and lockout/tagout.

  20. Ultrathin phase-change coatings on metals for electrothermally tunable colors

    NASA Astrophysics Data System (ADS)

    Bakan, Gokhan; Ayas, Sencer; Saidzoda, Tohir; Celebi, Kemal; Dana, Aykutlu

    2016-08-01

    Metal surfaces coated with ultrathin lossy dielectrics enable color generation through strong interferences in the visible spectrum. Using a phase-change thin film as the coating layer offers tuning the generated color by crystallization or re-amorphization. Here, we study the optical response of surfaces consisting of thin (5-40 nm) phase-changing Ge2Sb2Te5 (GST) films on metal, primarily Al, layers. A color scale ranging from yellow to red to blue that is obtained using different thicknesses of as-deposited amorphous GST layers turns dim gray upon annealing-induced crystallization of the GST. Moreover, when a relatively thick (>100 nm) and lossless dielectric film is introduced between the GST and Al layers, optical cavity modes are observed, offering a rich color gamut at the expense of the angle independent optical response. Finally, a color pixel structure is proposed for ultrahigh resolution (pixel size: 5 × 5 μm2), non-volatile displays, where the metal layer acting like a mirror is used as a heater element. The electrothermal simulations of such a pixel structure suggest that crystallization and re-amorphization of the GST layer using electrical pulses are possible for electrothermal color tuning.

  1. Electrochemical Synthesis of Nanostructured Noble Metal Films for Biosensing

    NASA Astrophysics Data System (ADS)

    Bhattarai, Jay K.

    Nanostructures of noble metals (gold and silver) are of interest because of their important intrinsic properties. Noble metals by themselves are physically robust, chemically inert, highly conductive, and possess the capability to form strong bonds with thiols or dithiol molecules present in organic compounds, creating self-assembled monolayers with tunable functional groups at exposed interfaces. However, when the nanostructures are formed, they in addition possess high surface area and unique optical properties which can be tuned by adjusting the shape and the size of the nanostructures. All of these properties make nanostructures of noble metals suitable candidates to be used as a transducer for optical and electrochemical biosensing. Individual nanostructures might be easier to prepare but difficult to handle to use as a transducer. Therefore, we prepared and analyzed nanostructured films/coating of noble metals and used them as a transducer for optical and electrochemical biosensing. We have electrochemically prepared nanoporous gold (NPG) on gold wire varying different dependable parameters (deposition potential, time, and compositional ratio) to obtain an optimal structure in term of stability, morphology, and better surface area. NPG prepared using a deposition potential of --1.0 V for 10 min from 30:70% 50 mM potassium dicyanoaurate(I) and 50 mM potassium dicyanoargentate(I) was used as an optimal surface for protein immobilization, and to perform square wave voltammetry (SWV) based enzyme-linked lectinsorbent assays. On flat gold surfaces, adjacent protein molecules sterically block their active sites due to high-density packing, which can be minimized using NPG as a substrate. NPG can also show significant peak current in SWV experiments, a sensitive electrochemical technique that minimizes non-Faradaic current, which is difficult to obtain using a flat gold surface. These all make NPG a suitable substrate, electrode, and transducer to be used in

  2. Self-cleaning diffractive macroporous films by doctor blade coating.

    PubMed

    Yang, Hongta; Jiang, Peng

    2010-08-01

    Here we report a scalable bottom-up technology for creating three-dimensionally highly ordered macroporous polymer films with excellent water-repelling and optical diffractive properties. A simple doctor blade coating process is first utilized to create silica colloidal crystal-polymer nanocomposites. The close-packed silica spheres are selectively removed to fabricate flexible macroporous polymer films with crystalline arrays of voids which are interconnected through small nanopores. The size of the voids can be easily controlled by tuning the duration of an oxygen reactive-ion etching process prior to the removal of the templating silica spheres. After surface functionalization with fluorosilane, superhydrophobic surface with large apparent water contact angle and small sliding angle can be obtained. The water-repelling property can be quantitatively explained by adapting the Cassie's dewetting model. We further demonstrate that self-cleaning functionality can be achieved on superhydrophobic macroporous coatings by preventing bacterial contamination. The high crystalline quality of the macroporous polymers also enables strong optical diffraction from the periodic lattice. The optical properties are evaluated by normal-incidence reflectance measurements and theoretical calculation using a scalar-wave approximation model. A good agreement between theory and experiment has been obtained. The simultaneous achievement of controlled dewetting and strong optical diffraction by templated porous films could open new applications in self-cleaning diffractive optics.

  3. Dynamics of polymer film formation during spin coating

    SciTech Connect

    Mouhamad, Y.; Clarke, N.; Jones, R. A. L.; Geoghegan, M.; Mokarian-Tabari, P.

    2014-09-28

    Standard models explaining the spin coating of polymer solutions generally fail to describe the early stages of film formation, when hydrodynamic forces control the solution behavior. Using in situ light scattering alongside theoretical and semi-empirical models, it is shown that inertial forces (which initially cause a vertical gradient in the radial solvent velocity within the film) play a significant role in the rate of thinning of the solution. The development of thickness as a function of time of a solute-free liquid (toluene) and a blend of polystyrene and poly(methyl methacrylate) cast from toluene were fitted to different models as a function of toluene partial pressure. In the case of the formation of the polymer blend film, a concentration-dependent (Huggins) viscosity formula was used to account for changes in viscosity during spin coating. A semi-empirical model is introduced, which permits calculation of the solvent evaporation rate and the temporal evolution of the solute volume fraction and solution viscosity.

  4. Development of a flexible nanocomposite TiO2 film as a protective coating for bioapplications of superelastic NiTi alloys

    NASA Astrophysics Data System (ADS)

    Aun, Diego Pinheiro; Houmard, Manuel; Mermoux, Michel; Latu-Romain, Laurence; Joud, Jean-Charles; Berthomé, Gregory; Buono, Vicente Tadeu Lopes

    2016-07-01

    An experimental procedure to coat superelastic NiTi alloys with flexible TiO2 protective nanocomposite films using sol-gel technology was developed in this work to improve the metal biocompatibility without deteriorating its superelastic mechanical properties. The coatings were characterized by scanning and transmission electron microscopy, X-ray photoelectron spectroscopy, Raman spectroscopy, and glazing incidence X-ray diffraction. The elasticity of the film was tested in coated specimens submitted to three-point bending tests. A short densification by thermal treatment at 500 °C for 10 min yielded a bilayer film consisting of a 50 nm-thick crystallized TiO2 at the inner interface with another 50-nm-thick amorphous oxide film at the outer interface. This bilayer could sustain over 6.4% strain without cracking and could thus be used to coat biomedical instruments as well as other devices made with superelastic NiTi alloys.

  5. Refractive-index change caused by electrons in amorphous AsS and AsSe thin films doped with different metals by photodiffusion

    SciTech Connect

    Nordman, Olli; Nordman, Nina; Pashkevich, Valfrid

    2001-08-01

    The refractive-index change caused by electrons was measured in amorphous AsS and AsSe thin films. Films were coated with different metals. Diffraction gratings were written by electron-beam lithography. The interactions of electrons in films with and without the photodiffusion of overcoated metal were compared. Incoming electrons caused metal atom and ion diffusion in both investigated cases. The metal diffusion was dependent on the metal and it was found to influence the refractive index. In some cases lateral diffusion of the metal was noticed. The conditions for applications were verified. {copyright} 2001 Optical Society of America

  6. Frictional and morphological characteristics of ion plated soft, metallic films

    NASA Technical Reports Server (NTRS)

    Spalvins, T.; Buzek, B.

    1981-01-01

    Ion plated metallic films in contrast to films applied by other deposition techniques offer a lower friction coefficient, longer endurance lives and exhibit a gradual increase in friction coefficient after the film has been worn off. The friction coefficients of metallic films are affected by the degree of adherence, thickness and nucleation and growth characteristics during ion plating lead to a fine, continuous crystalline structure, which contributes to a lower friction coefficient.

  7. Biodegradable/biocompatible coated metal implants for orthopedic applications.

    PubMed

    Saleh, Mohamed M; Touny, A H; Al-Omair, Mohammed A; Saleh, M M

    2016-05-12

    Biocompatible metals have been suggested as revolutionary biomaterials for bone-grafting therapies. Although metals and their alloys are widely and successfully used in producing biomedical implants due to their good mechanical properties and corrosion resistance, they have a lack in bioactivity. Therefore coating of the metal surface with calcium phosphates (CaP) is a benign way to achieve well bioactivity and get controlled corrosion properties. The biocompatibility and bioactivity calcium phosphates (CaP) in bone growth were guided them to biomedical treatment of bone defects and fractures. Many techniques have been used for fabrication of CaP coatings on metal substrates such as magnesium and titanium. The present review will focus on the synthesis of CaP and their relative forms using different techniques especially electrochemical techniques. The latter has always been known of its unique way of optimizing the process parameters that led to a control in the structure and characteristics of the produced materials.

  8. 21 CFR 175.365 - Vinylidene chloride copolymer coatings for polycarbonate film.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... conditions: (a) The coating is applied as a continuous film over one or both sides of a base film produced... acrylate, and acrylic acid. The finished copolymers contain at least 50 weight-percent of polymer...

  9. Metallic oxide switches using thick film technology

    NASA Technical Reports Server (NTRS)

    Patel, D. N.; Williams, L., Jr.

    1974-01-01

    Metallic oxide thick film switches were processed on alumina substrates using thick film technology. Vanadium pentoxide in powder form was mixed with other oxides e.g., barium, strontium copper and glass frit, ground to a fine powder. Pastes and screen printable inks were made using commercial conductive vehicles and appropriate thinners. Some switching devices were processed by conventional screen printing and firing of the inks and commercial cermet conductor terminals on 96% alumina substrates while others were made by applying small beads or dots of the pastes between platinum wires. Static, and dynamic volt-ampere, and pulse tests indicate that the switching and self-oscillatory characteristics of these devices could make them useful in memory element, oscillator, and automatic control applications.

  10. FUSED SALT METHOD FOR COATING URANIUM WITH A METAL

    DOEpatents

    Eubank, L.D.

    1959-02-01

    A method is presented for coating uranium with a less active metal such as Cr, Ni, or Cu comprising immersing the U in a substantially anhydrous molten solution of a halide of these less active metals in a ternary chloride composition which consists of selected percentages of KCl, NaCl and another chloride such as LiCl or CaCl/sub 2/.

  11. Antibacterial Performance of Alginic Acid Coating on Polyethylene Film

    PubMed Central

    Karbassi, Elika; Asadinezhad, Ahmad; Lehocký, Marian; Humpolíček, Petr; Vesel, Alenka; Novák, Igor; Sáha, Petr

    2014-01-01

    Alginic acid coated polyethylene films were examined in terms of surface properties and bacteriostatic performance against two most representative bacterial strains, that is, Escherichia coli and Staphylococcus aureus. Microwave plasma treatment followed by brush formation in vapor state from three distinguished precursors (allylalcohol, allylamine, hydroxyethyl methacrylate) was carried out to deposit alginic acid on the substrate. Surface analyses via various techniques established that alginic acid was immobilized onto the surface where grafting (brush) chemistry influenced the amount of alginic acid coated. Moreover, alginic acid was found to be capable of bacterial growth inhibition which itself was significantly affected by the brush type. The polyanionic character of alginic acid as a carbohydrate polymer was assumed to play the pivotal role in antibacterial activity. The cell wall composition of two bacterial strains along with the substrates physicochemical properties accounted for different levels of bacteriostatic performance. PMID:25196604

  12. Antibacterial performance of alginic acid coating on polyethylene film.

    PubMed

    Karbassi, Elika; Asadinezhad, Ahmad; Lehocký, Marian; Humpolíček, Petr; Vesel, Alenka; Novák, Igor; Sáha, Petr

    2014-01-01

    Alginic acid coated polyethylene films were examined in terms of surface properties and bacteriostatic performance against two most representative bacterial strains, that is, Escherichia coli and Staphylococcus aureus. Microwave plasma treatment followed by brush formation in vapor state from three distinguished precursors (allylalcohol, allylamine, hydroxyethyl methacrylate) was carried out to deposit alginic acid on the substrate. Surface analyses via various techniques established that alginic acid was immobilized onto the surface where grafting (brush) chemistry influenced the amount of alginic acid coated. Moreover, alginic acid was found to be capable of bacterial growth inhibition which itself was significantly affected by the brush type. The polyanionic character of alginic acid as a carbohydrate polymer was assumed to play the pivotal role in antibacterial activity. The cell wall composition of two bacterial strains along with the substrates physicochemical properties accounted for different levels of bacteriostatic performance. PMID:25196604

  13. Robotic burnishing system for solid film lubricant coated parts

    SciTech Connect

    Fureigh, M.L.

    1986-05-01

    A robotic burnishing system in the Painting Department reduced the operation average standard hour content by 64% and maintains a good part-to-part quality level for a group of parts coated with solid film lubricant. Required to be safe and simple to operate, the system uses a small PUMA 260 robot to process coated axisymmetrical pieceparts. Special tooling and seven pairs of robotic fingers were designed and built to handle 24 different small pieceparts. Individual robotic programs were created for each part and stored on 5-1/4 in. floppy disks with backup copies in Numerical Control. The operators and the manufacturing department readily accepted the robotic system. Additional part geometries will be developed for robotic processing. 12 figs.

  14. Transmission enhancement based on strong interference in metal-semiconductor layered film for energy harvesting

    PubMed Central

    Li, Qiang; Du, Kaikai; Mao, Kening; Fang, Xu; Zhao, Ding; Ye, Hui; Qiu, Min

    2016-01-01

    A fundamental strategy to enhance optical transmission through a continuous metallic film based on strong interference dominated by interface phase shift is developed. In a metallic film coated with a thin semiconductor film, both transmission and absorption are simultaneously enhanced as a result of dramatically reduced reflection. For a 50-nm-thick Ag film, experimental transmission enhancement factors of 4.5 and 9.5 are realized by exploiting Ag/Si non-symmetric and Si/Ag/Si symmetric geometries, respectively. These planar layered films for transmission enhancement feature ultrathin thickness, broadband and wide-angle operation, and reduced resistance. Considering one of their potential applications as transparent metal electrodes in solar cells, a calculated 182% enhancement in the total transmission efficiency relative to a single metallic film is expected. This strategy relies on no patterned nanostructures and thereby may power up a wide spectrum of energy-harvesting applications such as thin-film photovoltaics and surface photocatalysis. PMID:27404510

  15. Transmission enhancement based on strong interference in metal-semiconductor layered film for energy harvesting.

    PubMed

    Li, Qiang; Du, Kaikai; Mao, Kening; Fang, Xu; Zhao, Ding; Ye, Hui; Qiu, Min

    2016-01-01

    A fundamental strategy to enhance optical transmission through a continuous metallic film based on strong interference dominated by interface phase shift is developed. In a metallic film coated with a thin semiconductor film, both transmission and absorption are simultaneously enhanced as a result of dramatically reduced reflection. For a 50-nm-thick Ag film, experimental transmission enhancement factors of 4.5 and 9.5 are realized by exploiting Ag/Si non-symmetric and Si/Ag/Si symmetric geometries, respectively. These planar layered films for transmission enhancement feature ultrathin thickness, broadband and wide-angle operation, and reduced resistance. Considering one of their potential applications as transparent metal electrodes in solar cells, a calculated 182% enhancement in the total transmission efficiency relative to a single metallic film is expected. This strategy relies on no patterned nanostructures and thereby may power up a wide spectrum of energy-harvesting applications such as thin-film photovoltaics and surface photocatalysis. PMID:27404510

  16. Characterization of quaternary metal oxide films by synchrotron x-ray fluorescence microprobe

    SciTech Connect

    Perry, D.L.; Thompson, A.C.; Russo, R.E.

    1997-04-01

    A high demand for thin films in industrial technology has been responsible for the creation of new techniques for the fabrication of such films. One highly effective method for the syntheses of variable composition thin films is pulsed-laser deposition (PLD). The technique has a large number of characteristics which make it an attractive approach for making films. It offers rapid deposition rates, congruent material transfer, simple target requirements from which to make the films, in situ multilayer deposition, and no gas composition or pressure requirements. Additionally, the technique can also afford crystalline films and films with novel structures. Pulsed-laser deposition can be used to make films of semiconductors, insulators, high-temperature superconductors, diamond-like films, and piezoelectric materials. Quaternary metal oxides involving calcium, nickel, and potassium have been shown to be quite effective in the catalysis of coal gasification and methane coupling. One approach to incorporating all three of the metal oxides into one phase is the use of laser ablation to prepare films of the catalysts so that they may be used for coatings, smooth surfaces on which to conduct detailed studies of gas-solid interface reactions that are involved in catalytic processes, and other applications. The problem of dissimilar boiling points of the three metal oxides system is overcome, since the laser ablation process effects the volatilization of all three components from the laser target essentially simultaneously. There is strong interest in gaining an understanding of the chemical and morphological aspects of the films that are deposited. Phenomena such as lattice defects and chemical heterogeneity are of interest. The experimental data discussed here are restricted to the matrix homogeneity of the films themselves for films which were void of microparticles.

  17. Physicochemical properties of film-coated melt-extruded pellets.

    PubMed

    Young, Chistopher R; Crowley, Michael; Dietzsch, Caroline; McGinity, James W

    2007-02-01

    The purpose of this study was to investigate the physicochemical properties of poly(ethylene oxide) (PEO) and guaifenesin containing beads prepared by a melt-extrusion process and film-coated with a methacrylic acid copolymer. Solubility parameter calculations, thermal gravimetric analysis (TGA), scanning electron microscopy (SEM), modulated differential scanning calorimetry (MDSC), X-ray powder diffraction (XRPD) and high performance liquid chromatography (HPLC) were used to determine drug/polymer miscibility and/or the thermal processibility of the systems. Powder blends of guaifenesin, PEO and functional excipients were processed using a melt-extrusion and spheronization technique and then film-coated in a fluidized bed apparatus. Solubility parameter calculations were used to predict miscibility between PEO and guaifenesin, and miscibility was confirmed by SEM and observation of a single melting point for extruded drug/polymer blends during MDSC investigations. The drug was stable following melt-extrusion as determined by TGA and HPLC; however, drug release rate from pellets decreased upon storage in sealed HDPE containers with silica desiccants at 40 degrees C/75% RH. The weight loss on drying, porosity and tortuosity determinations were not influenced by storage. Recrystallization of guaifenesin and PEO was confirmed by SEM and XRPD. Additionally, the pellets exhibited a change in adhesion behaviour during dissolution testing. The addition of ethylcellulose to the extruded powder blend decreased and stabilized the drug release rate from the thermally processed pellets. The current study also demonstrated film-coating to be an efficient process for providing melt-extruded beads with pH-dependent drug release properties that were stable upon storage at accelerated conditions.

  18. Ascorbic acid-containing whey protein film coatings for control of oxidation.

    PubMed

    Min, Seacheol; Krochta, John M

    2007-04-18

    A formulation for the whey protein isolate film or coating incorporating ascorbic acid (AA-WPI film or coating) was developed. Tensile and oxygen-barrier properties of the AA-WPI film were measured. Antioxidant effects of the AA-WPI coating on roasted peanuts were studied by comparing the values of peroxide (PO), thiobarbituric acid reactive substance (TBARS), and free-radical-scavenging activity, determined with noncoated peanuts and peanuts coated with WPI with and without ascorbic acid during storage at 21% relative humidity (RH) and 23, 35, and 50 degrees C. The incorporation of AA reduced elongation of WPI films. The oxygen-barrier property of the WPI film was significantly improved by incorporation of AA. The AA-WPI coating retarded lipid oxidation in peanuts significantly at 23, 35, and 50 degrees C. The AA-WPI coated peanuts were more red than noncoated peanuts at all storage temperatures.

  19. Metal coatings for laser fusion targets by electroplating

    SciTech Connect

    Illige, J.D.; Yu, C.M.; Letts, S.A.

    1980-08-26

    Metal coated laser fusion targets must be dense, uniform spherically symmetric to within a few percent of their diameters and smooth to better than a few tenths of a micron. Electroplating offers some unique advantages including low temperature deposition, a wide choice of elements and substantial industrial plating technology. We have evaluatd electroless and electroplating systems for gold and copper, identified the factors responsible for small grain size, and plated glass microspheres with both metals to achieve smooth surfaces and highly symmetric coatings. We have developed plating cells which sustain the microspheres in continuous random motion during plating. We have established techniques for deposition of the initial conductive adherent layer on the glass microsphere surface. Coatings as thick as 15 ..mu..m have been made. The equipment is simple, relatively inexpensive and may be adopted for high volume production of laser fusion targets.

  20. Titanium acoustic diaphragm coated with polycrystal diamond film

    SciTech Connect

    Zhiwei Zhang; Zhen Yan; Hesun Zhu

    1995-12-31

    The spherical titanium diaphragm, which is widely used in high frequency loudspeaker, coat with polycrystal diamond film (DF) was prepared for the first time in China by the method of DC arc plasma jet. Its acoustic performance was remarkably upgraded, as confirmed by Raman Shift Spectrum and frequency response curve. Its sensibility was improved by 3-6 dB and frequency widened by 5x10{sup 3}Hz. The frequency range extended from 2.2x10{sup 3}Hz to 25x10{sup 3}Hz. The preparation and process of DF is discussed.

  1. Intergranular metal phase increases thermal shock resistance of ceramic coating

    NASA Technical Reports Server (NTRS)

    Carpenter, H. W.

    1966-01-01

    Dispersed copper phase increases the thermal shock resistance of a plasma-arc-sprayed coating of zirconia used as a heat barrier on a metal substrate. A small amount of copper is deposited on the granules of the zirconia powder before arc-spraying the resultant powder composite onto the substrate.

  2. Coated metal sintering carriers for fuel cell electrodes

    DOEpatents

    Donelson, R.; Bryson, E.S.

    1998-11-10

    A carrier is described for conveying components of a fuel cell to be sintered through a sintering furnace. The carrier comprises a metal sheet coated with a water-based carbon paint, the water-based carbon paint comprising water, powdered graphite, an organic binder, a wetting agent, a dispersing agent and a defoaming agent.

  3. Coated metal sintering carriers for fuel cell electrodes

    SciTech Connect

    Donelson, Richard; Bryson, E. S.

    1998-01-01

    A carrier for conveying components of a fuel cell to be sintered through a sintering furnace. The carrier comprises a metal sheet coated with a water-based carbon paint, the water-based carbon paint comprising water, powdered graphite, an organic binder, a wetting agent, a dispersing agent and a defoaming agent.

  4. Metallic biomaterials TiN-coated: corrosion analysis and biocompatibility.

    PubMed

    Paschoal, André Luís; Vanâncio, Everaldo Carlos; Canale, Lauralice de Campos Franceschini; da Silva, Orivaldo Lopes; Huerta-Vilca, Domingos; Motheo, Artur de Jesus

    2003-05-01

    Corrosion processes due to contact with the physiological environment should be avoided or minimized in orthopedic implants. Four metallic substrates frequently used as biomaterials: pure Ti, Ti-6Al-4V alloy, ASTM F138 stainless steel, and Co-Cr-Mo alloy, were coated with TiN using the physical vapor deposition (PVD) technique. These coatings have been screened by polarization curves in physiological solutions. TiN prepared by PVD is efficient as coating for stainless steel. On titanium and alloy there are no benefits concerning the corrosion resistance compared to the bare Ti-materials. TiN coatings have been screened according to ISO 10993 standard tests for biocompatibility and exhibited no cytotoxicity, dermal irritation, or acute systemic toxicity response.

  5. Deposition and characterization of aluminum magnesium boride thin film coatings

    NASA Astrophysics Data System (ADS)

    Tian, Yun

    Boron-rich borides are a special group of materials possessing complex structures typically comprised of B12 icosahedra. All of the boron-rich borides sharing this common structural unit exhibit a variety of exceptional physical and electrical properties. In this work, a new ternary boride compound AlMgB14, which has been extensively studied in bulk form due to its novel mechanical properties, was fabricated into thin film coatings by pulsed laser deposition (PLD) technology. The effect of processing conditions (laser operating modes, vacuum level, substrate temperature, and postannealing, etc.) on the composition, microstructure evolution, chemical bonding, and surface morphology of AlMgB14 thin film coatings has been investigated by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), atomic force microscopy (AFM) and Fourier transform infrared (FTIR) spectrometry; the mechanical, electrical, and optical properties of AlMgB14 thin films have been characterized by nanoindentation, four-point probe, van der Pauw Hall measurement, activation energy measurement, and UV-VIS-NIR spectrophotometer. Experimental results show that AlMgB14 films deposited in the temperature range of 300 K - 873 K are amorphous. Depositions under a low vacuum level (5 x 10-5 Torr) can introduce a significant amount of C and O impurities into AlMgB14 films and lead to a complex oxide glass structure. Orthorhombic AlMgB14 phase cannot be obtained by subsequent high temperature annealing. By contrast, the orthorhombic AlMgB 14 crystal structure can be attained via high temperature-annealing of AlMgB14 films deposited under a high vacuum level (< 3 x 10-6 Torr), accompanied by strong texture formation. Low vacuum level-as deposited AlMgB14 films have low hardness (10 GPa), but high vacuum level-as deposited AlMgB14 films exhibit an extremely high hardness (45 GPa - 51 GPa), and the higher deposition temperature results in still higher hardness

  6. Inclined-substrate deposition of biaxially textured magnesium oxide thin films for YBCO coated conductors.

    SciTech Connect

    Ma, B.; Li, M.; Jee, Y. A.; Koritala, R. E.; Fisher, B. L.; Balachandran, U.; Energy Technology

    2002-02-01

    Highly textured MgO films were grown by the inclined-substrate deposition (ISD) technique at a high deposition rate. A columnar grain with a roofing-tile-shaped surface was observed in these MgO films. X-ray pole figure, and {phi}- and {omega}-scan were used to characterize in-plane and out-of-plane textures. MgO films deposited when the incline angle {alpha} was 55 and 30 degrees exhibited the best in-plane and out-of-plane texture, respectively. High-quality YBCO films were epitaxially grown on ISD-MgO-buffered Hastelloy C substrates by pulsed laser deposition. {Tc}=88 K, with sharp transition, and j{sub c} values of {approx}2x10{sup 5} A/cm{sup 2} at 77 K in zero field were observed on films 5 mm wide and 1 cm long. This work has demonstrated that biaxially textured ISD MgO buffer layers deposited on metal substrates are excellent candidates for fabrication of high-quality YBCO coated conductors.

  7. Method for the preparation of protective coatings by low-temperature metal--organic chemical vapor deposition (MOCVD)

    SciTech Connect

    Kaloyeros, A.E.; Williams, W.S.; Constant, G.

    1988-07-01

    A simple and effective method is reported for the deposition of protective coatings of titanium carbide using low-temperature (as low as 150 /sup 0/C) metal--organic chemical vapor deposition. This method is based on the thermolysis of metal--organic molecules containing titanium and does not require the high temperature (<1100 /sup 0/C) involved in the standard TiC--CVD technique. Furthermore, the structure of the films produced (crystalline or amorphous) and their purity (inclusion of organic clusters or hydrogen) can be tailored easily by simple variations in the deposition parameters. This technique permits the coating of polymers and low-melting metals that are thermally too fragile for other deposition techniques. The process could be applied to produce films of other materials, e.g., niobium carbide, silicon carbide, titanium diboride, and gallium arsenide.

  8. Spin-coated kesterite CZTS thin films for photovoltaic applications

    NASA Astrophysics Data System (ADS)

    Majula, L.; Mlyuka, N. R.; Samiji, M. E.; Bryce, R. S.; Kim, D. Y.; Kim, S. H.; Lee, H. J.; Choi, H. J.

    2015-09-01

    Copper zinc tin-sulfide (CZTS) films have been widely studied over recent years due to the inherent advantages of low cost, high absorption coefficient (≥ 104 cm-1), suitable band gap (˜1.5 eV) and nontoxicity. In this work, spin coating was used to obtain CZTS films of various compositions and degrees of crystallization on glass substrates, which were then annealed at 500 °C in a N2 atmosphere by using a rapid thermal processing (RTP) furnace in order to optimize their structure. Non-stoichiometric precursors and low spinning speeds resulted in a lower sheet resistance, which is considered to be a result of lower degree of crystallization. Furthermore, the non-stoichiometric films had a high optical band gap (> 1.66 eV) whereas the band gap of the stoichiometric films (1.4 to 1.6 eV) was close to the optimal value (1.5 eV) for solar-cell applications.

  9. Coating of metal implant materials with strontium.

    PubMed

    Frank, Matthias J; Walter, Martin S; Tiainen, Hanna; Rubert, Marina; Monjo, Marta; Lyngstadaas, S Petter; Haugen, Håvard J

    2013-11-01

    The aim of this study was to show that cathodic polarization can be used for coating commercial implant surfaces with an immobilized but functional and bioavailable surface layer of strontium (Sr). Moreover, this study assessed the effect of fluorine on Sr-attachment. X-ray photoelectron spectroscopy revealed that addition of fluorine (F) to the buffer during coating increased surface Sr-amounts but also changed the chemical surface composition by adding SrF2 alongside of SrO whereas pre-treatment of the surface by pickling in hydrofluoric acid appeared to hinder Sr-attachment. Assessment of the bio-availability hinted at a positive effect of Sr on cell differentiation given that the surface reactivity of the original surface remained unchanged. Additional SrF2 on the surface appeared to reduce undesired surface contamination while maintaining the surface micro-topography and micro-morphology. Anyhow, this surface modification revealed to create nano-nodules on the surface. PMID:23888353

  10. Method For Improving The Oxidation Resistance Of Metal Substrates Coated With Thermal Barrier Coatings

    DOEpatents

    Thompson, Anthony Mark; Gray, Dennis Michael; Jackson, Melvin Robert

    2003-05-13

    A method for providing a protective coating on a metal-based substrate is disclosed. The method involves the application of an aluminum-rich mixture to the substrate to form a discontinuous layer of aluminum-rich particles, followed by the application of a second coating over the discontinuous layer of aluminum-rich particles. Aluminum diffuses from the aluminum-rich layer into the substrate, and into any bond coat layer which is subsequently applied. Related articles are also described. A method for providing a protective coating on a metal-based substrate is disclosed. The method involves the application of an aluminum-rich mixture to the substrate to form a discontinuous layer of aluminum-rich particles, followed by the application of a second coating over the discontinuous layer of aluminum-rich particles. Aluminum diffuses from the aluminum-rich layer into the substrate, and into any bond coat layer which is subsequently applied. Related articles are also described.

  11. SILANE-BASED CONVERSION COATING FOR METALS

    EPA Science Inventory

    For the past three years, a project to develop new pretreatment rinses for metals was carried out by the U.S. Environmental Protection Agency and the University of Cincinnati. The project involved optimization of laboratory rinses with dilute aqueous solutions organofunctional s...

  12. Fabrication of antiferroelectric PLZT films on metal foils.

    SciTech Connect

    Ma, B.; Kwon, D.-K.; Narayanan, M.; Balachandran, U.; Energy Systems

    2009-01-01

    Fabrication of high-dielectric-strength antiferroelectric (AFE) films on metallic foils is technically important for advanced power electronics. To that end, we have deposited crack-free Pb{sub 0.92}La{sub 0.08}Zr{sub 0.95}Ti{sub 0.05}O{sub 3} (PLZT 8/95/5) films on nickel foils by chemical solution deposition. To eliminate the parasitic effect caused by the formation of a low-permittivity interfacial oxide, a conductive buffer layer of lanthanum nickel oxide (LNO) was coated by chemical solution deposition on the nickel foil before the deposition of PLZT. Use of the LNO buffer allowed high-quality film-on-foil capacitors to be processed in air. With the PLZT 8/95/5 deposited on LNO-buffered Ni foils, we observed field- and thermal-induced phase transformations of AFE to ferroelectric (FE). The AFE-to-FE phase transition field, E{sub AF} = 225 kV/cm, and the reverse phase transition field, E{sub FA} = 190 kV/cm, were measured at room temperature on a {approx}1.15 {micro}m-thick PLZT 8/95/5 film grown on LNO-buffered Ni foils. The relative permittivities of the AFE and FE states were {approx}600 and {approx}730, respectively, with dielectric loss {approx}0.04 at room temperature. The Curie temperature was {approx}210 C. The thermal-induced transition of AFE-to-FE phase occurred at {approx}175 C. Breakdown field strength of 1.2 MV/cm was measured at room temperature.

  13. Fabrication of antiferroelectric PLZT films on metal foils

    SciTech Connect

    Ma Beihai Kwon, Do-Kyun; Narayanan, Manoj; Balachandran, U.

    2009-01-08

    Fabrication of high-dielectric-strength antiferroelectric (AFE) films on metallic foils is technically important for advanced power electronics. To that end, we have deposited crack-free Pb{sub 0.92}La{sub 0.08}Zr{sub 0.95}Ti{sub 0.05}O{sub 3} (PLZT 8/95/5) films on nickel foils by chemical solution deposition. To eliminate the parasitic effect caused by the formation of a low-permittivity interfacial oxide, a conductive buffer layer of lanthanum nickel oxide (LNO) was coated by chemical solution deposition on the nickel foil before the deposition of PLZT. Use of the LNO buffer allowed high-quality film-on-foil capacitors to be processed in air. With the PLZT 8/95/5 deposited on LNO-buffered Ni foils, we observed field- and thermal-induced phase transformations of AFE to ferroelectric (FE). The AFE-to-FE phase transition field, E{sub AF} = 225 kV/cm, and the reverse phase transition field, E{sub FA} = 190 kV/cm, were measured at room temperature on a {approx}1.15 {mu}m-thick PLZT 8/95/5 film grown on LNO-buffered Ni foils. The relative permittivities of the AFE and FE states were {approx}600 and {approx}730, respectively, with dielectric loss {approx}0.04 at room temperature. The Curie temperature was {approx}210 deg. C. The thermal-induced transition of AFE-to-FE phase occurred at {approx}175 deg. C. Breakdown field strength of 1.2 MV/cm was measured at room temperature.

  14. Carbonaceous thin film coating with Fe-N4 site for enhancement of dioxovanadium ion reduction

    NASA Astrophysics Data System (ADS)

    Maruyama, Jun; Hasegawa, Takahiro; Iwasaki, Satoshi; Fukuhara, Tomoko; Orikasa, Yuki; Uchimoto, Yoshiharu

    2016-08-01

    It has been found that carbonaceous materials containing a transition metal coordinated by 4 nitrogens in the square-planar configuration (metal-N4 site) on the surface possessed a catalytic activity for various electrochemical reactions related to energy conversion and storage; i.e., oxygen reduction, hydrogen evolution, and quite recently, the electrode reactions in vanadium redox flow batteries (VRFB). The catalyst for the VRFB positive electrode discharge reaction, i.e., the dioxovanadium ion reduction, was formed by coating the surface of cup-stack carbon nanotubes with a carbonaceous thin film with the Fe-N4 site generated by the sublimation, deposition, and pyrolysis of iron phthalocyanine. In this study, the influence of the physical properties of the catalyst on the electrochemical reactions was investigated to optimize the coating. With an increase in the coating, the specific surface area increased, whereas the pore size decreased. The surface Fe concentration was increased in spite of the Fe aggregation inside the carbon matrix. The catalytic activity enhancement was achieved due to the increase in the specific surface area and the surface Fe concentration, but was lowered due to the decrease in the pore size, which was disadvantageous for the penetration of the electrolyte and the mass transfer.

  15. The Electronic Structure of Transition Metal Coated Fullerenes

    NASA Astrophysics Data System (ADS)

    Patton, David C.; Pederson, Mark R.; Kaxiras, Efthimios

    1998-03-01

    Clusters composed of fullerene molecules with an outer shell of transition metal atoms in the composition C_60M_62 (M being a transition metal) have been produced with laser vaporisation techniques(F. Tast, N. Malinowski, S. Frank, M. Heinebrodt, I.M.L. Billas, and T. P. Martin, Z. Phys D 40), 351 (1997).. We have studied several of these very large systems with a parallel version of the all-electron NRLMOL cluster code. Optimized geometries of the metal encased fullerenes C_60Ti_62 and C_60V_62 are presented along with their HOMO-LUMO gaps, electron affinities, ionization energies, and cohesive energies. We compare the stability of these clusters to relaxed met-car structures (e.g. Ti_8C_12) and to relaxed rocksalt metal-carbide fragments (TiC)n with n=8 and 32. In addition to metal-coated fullerenes we consider the possibility of a trilayered structure consisting of a small shell of metal atoms enclosed by a metal coated fullerene. The nature of bonding in these systems is analyzed by studying the electronic charge distributions.

  16. Investigation of Cu coatings deposited by kinetic metallization

    SciTech Connect

    Han, Y.K.; Birbilis, N.; Spencer, K.; Zhang, M.-X.; Muddle, B.C.

    2010-11-15

    Interfacial characterisation of Kinetic Metallization (KM) sprayed Cu coatings applied on metal substrates was performed using optical and electron microscopy, as well as microindentation hardness testing and microchemical analysis. The interfacial characterisation of KM coatings remains scarce to date. Cross sectional observations of KM coatings on light metal substrates revealed an undulating, patelliform profile with thin-lipped cusps at the interface. Pure Al and Mg substrates exhibited a mechanically impinged zone <{approx}5 {mu}m on the substrate material, approximately the size of deformed Cu powder particles. Examination of the Cu side of the interface indicated there was no long range interaction in the coating. On the substrate side of the interface, the KM process induced phase transformations (i.e. recrystallisation and an alloyed zone) in thin layers contiguous to the interface on pure Al and Mg substrates. Zones of elemental interdiffusion were identified at the interface upon Al and Mg substrates using scanning TEM. The width of intermixing zones was in the vicinity of < 1 {mu}m. This metallurgical interaction at the interface occurred on the length scales involving the initial single layer of Cu particles bonded on the substrate.

  17. 21 CFR 520.88a - Amoxicillin trihydrate film-coated tablets.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Amoxicillin trihydrate film-coated tablets. 520.88a Section 520.88a Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... Amoxicillin trihydrate film-coated tablets. (a) Specifications. Each tablet contains amoxicillin...

  18. 21 CFR 520.88g - Amoxicillin trihydrate and clavulanate potassium film-coated tablets.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Amoxicillin trihydrate and clavulanate potassium film-coated tablets. 520.88g Section 520.88g Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... ANIMAL DRUGS § 520.88g Amoxicillin trihydrate and clavulanate potassium film-coated tablets....

  19. [Dental implantations of ceramics-coated metals].

    PubMed

    Cini, L; Gasparini, F; Michieli, S; Pizzoferrato, A; Sandrolini-Cortesi, S

    1975-01-01

    Recent studies and personal experience of the Authors in the field of dental implants have encountered the same fundamental problem which arises with orthopedic prosthesis procedures. The basic problem is that of adhesion between the bone tissue and the metal implant. Chrome-cobalt alloy, Tantalum and Titanium are the metals of most recent use. The Authors therefore proceeded to investigate the behaviour of alveolar bone tissue in the proximity of artificial teeth made of alloy (platinum-gold) covered with ceramic, as used in prosthetic dentistry. The experiment was carried out in a dog and a man. In the dog, two of its mandibular teeth were substituted with the same ceramic-gold implants: the first, a replica of natural tooth, was placed in the socket and held in place by metal splint and mandibular circumferential wirings. The other implant, without a replicated crown, was left free, within the alveolus, without contacting the near or opposing teeth. A solid smooth surfaced alumina device, shaped like a small cylinder, was implanted in the upper femoral epiphysis of the same animal.

  20. Metallurgical coatings and thin films; Proceedings of the International Conference, 18th, San Diego, CA, Apr. 22-26, 1991. Vols. 1 & 2

    NASA Technical Reports Server (NTRS)

    Mcguire, Gary E. (Editor); Mcintyre, Dale C. (Editor); Hofmann, Siegfried (Editor)

    1991-01-01

    A conference on metallurgical coatings and thin films produced papers in the areas of coatings for use at high temperatures; hard coatings and deposition technologies; diamonds and related materials; tribological coatings/surface modifications; thin films for microelectronics and high temperature superconductors; optical coatings, film characterization, magneto-optics, and guided waves; and methods for characterizing films and modified surfaces.

  1. Ni-based Metal Matrix Composite Functionally Graded Coatings

    NASA Astrophysics Data System (ADS)

    Amado, J. M.; Montero, J.; Tobar, M. J.; Yáñez, A.

    Functional graded materials (FGMs) are a class of composites that have a continuous variation of material properties. One of the aims of such variation is to relieve the stress concentrations that appear in laminated materials. Coating techniques using powder as filler material can be adapted for the manufacture of composition gradients by means of a mixing unit in a powder feed system which is the basis of the laser cladding technology. The aim of this paper is to get coats with layers of the highest possible ceramic concentration on a metal matrix composite (MMC) with the help of the FGM methodology.

  2. Linking Precursor Alterations to Nanoscale Structure and Optical Transparency in Polymer Assisted Fast-Rate Dip-Coating of Vanadium Oxide Thin Films

    PubMed Central

    Glynn, Colm; Creedon, Donal; Geaney, Hugh; Armstrong, Eileen; Collins, Timothy; Morris, Michael A.; Dwyer, Colm O’

    2015-01-01

    Solution processed metal oxide thin films are important for modern optoelectronic devices ranging from thin film transistors to photovoltaics and for functional optical coatings. Solution processed techniques such as dip-coating, allow thin films to be rapidly deposited over a large range of surfaces including curved, flexible or plastic substrates without extensive processing of comparative vapour or physical deposition methods. To increase the effectiveness and versatility of dip-coated thin films, alterations to commonly used precursors can be made that facilitate controlled thin film deposition. The effects of polymer assisted deposition and changes in solvent-alkoxide dilution on the morphology, structure, optoelectronic properties and crystallinity of vanadium pentoxide thin films was studied using a dip-coating method using a substrate withdrawal speed within the fast-rate draining regime. The formation of sub-100 nm thin films could be achieved rapidly from dilute alkoxide based precursor solutions with high optical transmission in the visible, linked to the phase and film structure. The effects of the polymer addition was shown to change the crystallized vanadium pentoxide thin films from a granular surface structure to a polycrystalline structure composed of a high density of smaller in-plane grains, resulting in a uniform surface morphology with lower thickness and roughness. PMID:26123117

  3. Metal oxide coatings for piezoelectric exhaust gas sensors

    SciTech Connect

    Anderson, M.T.; Cernosek, R.W.

    1996-06-01

    We have deposited ZrO{sub 2}, TiO{sub 2}, and SnO{sub 2} films on ST-cut quartz surface acoustic wave (SAW) devices via sol-gel techniques. The films range from 100 to 300 nm thick and have porosities after calcination at 300{degrees}C that range from 82-88 % for ZrO{sub 2}, 77-81% for TiO{sub 2}, and 57-66% for SnO{sub 2}. In all cases, we have varied the synthesis and processing parameters over a wide range to optimize film properties: metal ion concentration (0.05-1.0 M), the H{sub 2}O:metal ratio (0.3-5.3), the acid concentration in the sol (0.02-0.7 M), the modifier ligand:metal ratio (r = 0.0-1.0), the processing conditions (100-900{degrees}C). The modifier ligand, triethanolamine (TEA), is added to each solution to allow multilayer films to be made crack free. The multilayer films are studied by optical microscopy, ellipsometry, X-ray diffraction, and N{sub 2} sorption. Preliminary high temperature frequency response measurements to target gases, such as, H{sub 2}, NO, NO{sub 2}, and propylene indicate limited sensitivity for the configurations tested.

  4. CW laser compaction of aqueous solution deposited metal oxide films

    SciTech Connect

    Exarhos, G.J.; Dennis, T.

    1997-12-01

    Zirconium dioxide films were spin cast onto silica or silicon substrates from an aqueous solution comprised of the precursor metal nitrate and an organic complexant such as glycine. The hydrated films so derived consist of an amorphous organic phase in which the metal cations and nitrate anions are homogeneously dispersed. Heating to temperatures above 200 {degrees}C leads to film dehydration followed by an auto-catalyzed oxidation reaction whereby the bound nitrate oxidizes the organic matrix leaving behind an intact stoichiometric and crystalline metal oxide film. Films are characterized using AFM, XRD, and optical methods. Transformation processes in these films have been studied in detail by means of spectroscopic ellipsometry and laser induced fluorescence from films doped with a suitable rare earth probe ion such as SM{sup +3}. In the latter case, the measured fluorescence emission spectra are used to identify the hydrated, dehydrated, amorphous and crystalline metal oxide phases which evolve during processing. These transformations also have been induced upon visible CW laser irradiation at fluences in excess of 1 MW/cm{sup 2}. Under these conditions, the film dehydrates and compacts within the footprint of the incident laser beam rendering this region of the film water insoluble. Post irradiation washing of the film with water removes all vestiges of the film outside of the beam footprint suggesting a possible use of this technique for lithography applications. Films subjected to laser irradiation and post irradiation heating have been characterized with respect to thickness, phase composition, crystallite size and optical constants.

  5. Analysis of the drude model in metallic films.

    PubMed

    Li, H Y; Zhou, S M; Li, J; Chen, Y L; Wang, S Y; Shen, Z C; Chen, L Y; Liu, H; Zhang, X X

    2001-12-01

    A method, believed to be new, to simulate Drude parameters for collective oscillation of the free carriers in metallic films is proposed. Plasma resonance frequency and relaxation were simulated simultaneously from both the real and the imaginary parts of the dielectric function of a metallic film after consideration of their correlation in the Drude model. As examples, the contributions of the electrons in Ag films and of the free carriers in metallic silicide, NbSi(2) and TaSi(2), films have been studied. PMID:18364937

  6. Ultraselective Gas Separation by Nanoporous Metal-Organic Frameworks Embedded in Gas-Barrier Nanocellulose Films.

    PubMed

    Matsumoto, Makoto; Kitaoka, Takuya

    2016-03-01

    Metal-organic frameworks (MOFs) are synthesized at carboxy groups on crystalline TEMPO-oxidized cellulose nanofibers (TOCNs). MOF-TOCN films coated on a paper filter have a hierarchical structure from the nano- to macroscale, and demonstrate a high CO2 /CH4 selectivity, over 120 for CO2 at a high gas flux, by the combination of the nanoporous MOFs and the gas-barrier TOCNs, which have strong affinity with each other. PMID:26669724

  7. Boosting the Transparency of Thin Layers by Coatings of Opposing Susceptibility: How Metals Help See Through Dielectrics

    PubMed Central

    Shakhs, Mohammed Al; Augusto, Lucian; Markley, Loïc; Chau, Kenneth J.

    2016-01-01

    We propose a hypothesis that a very thin layer can be made more transparent by adding a thin coating with susceptibility of opposing sign. Two experimental tests backed by a theoretical model support this hypothesis. First, we show that the visible and near-infrared transmission through a semi-transparent silver film can be enhanced by up to ~70% and spectrally tailored depending on the type and thickness of the dielectric coating. Material types explored as dielectric coating layers include conventional metal oxides (titanium dioxide) and lesser-explored elemental semiconductors (undoped silicon, p-type silicon, and germanium). Second, and more surprisingly, we show that coating a 50-nm-thick silicon nitride membrane with a 10-nm-thick silver layer can modestly enhance the transmission by up to 6 ± 1% in the blue part of the spectrum. Transmission enhancements are observed for three silver-coated membranes in different configurations. Thinner silver coatings are theoretically capable of enhancement factors greater than 10%, but implementation is restricted by challenges in making smooth and continuous silver films below 10 nm in thickness. This study is important because it is the first demonstration of reciprocity with respect to the transmission enhancements achieved by combining thin metallic and dielectric layers. PMID:26860979

  8. Boosting the Transparency of Thin Layers by Coatings of Opposing Susceptibility: How Metals Help See Through Dielectrics.

    PubMed

    Al Shakhs, Mohammed; Augusto, Lucian; Markley, Loïc; Chau, Kenneth J

    2016-02-10

    We propose a hypothesis that a very thin layer can be made more transparent by adding a thin coating with susceptibility of opposing sign. Two experimental tests backed by a theoretical model support this hypothesis. First, we show that the visible and near-infrared transmission through a semi-transparent silver film can be enhanced by up to ~70% and spectrally tailored depending on the type and thickness of the dielectric coating. Material types explored as dielectric coating layers include conventional metal oxides (titanium dioxide) and lesser-explored elemental semiconductors (undoped silicon, p-type silicon, and germanium). Second, and more surprisingly, we show that coating a 50-nm-thick silicon nitride membrane with a 10-nm-thick silver layer can modestly enhance the transmission by up to 6 ± 1% in the blue part of the spectrum. Transmission enhancements are observed for three silver-coated membranes in different configurations. Thinner silver coatings are theoretically capable of enhancement factors greater than 10%, but implementation is restricted by challenges in making smooth and continuous silver films below 10 nm in thickness. This study is important because it is the first demonstration of reciprocity with respect to the transmission enhancements achieved by combining thin metallic and dielectric layers.

  9. Soldering of Thin Film-Metallized Glass Substrates

    SciTech Connect

    Hosking, F.M.; Hernandez, C.L.; Glass, S.J.

    1999-03-31

    The ability to produce reliable electrical and structural interconnections between glass and metals by soldering was investigated. Soldering generally requires premetallization of the glass. As a solderable surface finish over soda-lime-silicate glass, two thin films coatings, Cr-Pd-Au and NiCr-Sn, were evaluated. Solder nettability and joint strengths were determined. Test samples were processed with Sn60-Pb40 solder alloy at a reflow temperature of 210 C. Glass-to-cold rolled steel single lap samples yielded an average shear strength of 12 MPa. Solder fill was good. Control of the Au thickness was critical in minimizing the formation of AuSn{sub 4} intermetallic in the joint, with a resulting joint shear strength of 15 MPa. Similar glass-to-glass specimens with the Cr-Pd-Au finish failed at 16.5 MPa. The NiCr-Sn thin film gave even higher shear strengths of 20-22.5 MPa, with failures primarily in the glass.

  10. Hydrophobic coating of solid materials by plasma-polymerized thin film using tetrafluoroethylene

    NASA Technical Reports Server (NTRS)

    Hozumi, K.; Kitamura, K.; Kitade, T.

    1980-01-01

    Glass slides were coated with plasma-polymerized tetrafluoroethylene films of different thickness using the glow discharge technique in a tube-shaped chamber, and the plasma conditions, film growth rates, light permeability of the polymer films, and particle bond strength in the polymer films were studied. Ashed sections of mouse organs and ashed bacillus spores were also coated to give them hydrophobic treatment without damaging their shapes or appearance. The hydrophobic coating of the specimens was successful, and the fine ash patterns were strongly fixed onto the glass slides, making permanent preparations.

  11. Metal matrix coated fiber composites and the methods of manufacturing such composites

    DOEpatents

    Weeks, Jr., Joseph K.; Gensse, Chantal

    1993-01-01

    A fiber coating which allows ceramic or metal fibers to be wetted by molten metals is disclosed. The coating inhibits degradation of the physical properties caused by chemical reaction between the fiber and the coating itself or between the fiber and the metal matrix. The fiber coating preferably includes at least a wetting layer, and in some applications, a wetting layer and a barrier layer between the fiber and the wetting layer. The wetting layer promotes fiber wetting by the metal matrix. The barrier layer inhibits fiber degradation. The fiber coating permits the fibers to be infiltrated with the metal matrix resulting in composites having unique properties not obtainable in pure materials.

  12. Structure and properties of moisture-resistant konjac glucomannan films coated with shellac/stearic acid coating.

    PubMed

    Wei, Xueqin; Pang, Jie; Zhang, Changfeng; Yu, Chengcheng; Chen, Han; Xie, Bingqing

    2015-03-15

    A series of moisture-resistant konjac glucomannan films were prepared by coating shellac/stearic acid emulsion on deacetylated konjac glucomannan films (dKGM). The effect of stearic acid content on structure and properties of the coated films were investigated by field emission scanning electron microscopy (FE SEM), Fourier transform infrared spectroscopy (FT-IR), ultraviolet spectroscopy (UV), water vapor permeability (WVP), water uptake, water contact angle, and tensile testing. The results revealed that shellac in the coating adhered intimately to the surface of dKGM film, and provided a substrate for the dispersion of stearic acid which played an important role in enhancement of the moisture barrier properties and mechanical properties of the coated films. The WVP of the coated films decreased from 2.63×10(-11) to 0.37×10(-11)g/(msPa) and the water contact angle increased from 68° to 101.2° when stearic acid content increased from 0wt% to 40wt%, showing the potential applications in food preservation.

  13. Cyclic nanoindentation studies on CrN thin films prepared by RF sputtering on Zr-based metallic glass

    SciTech Connect

    Jellad, A.; Benameur, T.; Labdi, S.

    2011-01-17

    Cyclic nanoindentation tests were carried out to study the influence of the chromium nitride thin films on the mechanical properties of Zr-based metallic glass. Chromium nitride thin coatings have been deposited on Zr{sub 50}Cu{sub 40}Al{sub 10} metallic glass substrate by RF sputtering. The deposition process was done at room temperature under nitrogen reactive gas using a metallic chromium target. The CrN films have a thickness of 300 nm. Several cyclic nanoindentation measurements were conducted on CrN films and Zr{sub 50}Cu{sub 40}Al{sub 10} metallic glass substrate samples at various loading rate values. We have found that the coated metallic glass sample shows high mechanical properties such as hardness and reduced elastic modulus. Cyclic nanoindentation results show a hardening behaviour for these CrN coatings. Moreover, the CrN coated on Zr-based metallic glass was found to have a high value of resistance to crack propagation, as being analysed through the SEM pictures of the residual Vickers indentation impressions.

  14. Quantifying Pharmaceutical Film Coating with Optical Coherence Tomography and Terahertz Pulsed Imaging: An Evaluation.

    PubMed

    Lin, Hungyen; Dong, Yue; Shen, Yaochun; Zeitler, J Axel

    2015-10-01

    Spectral domain optical coherence tomography (OCT) has recently attracted a lot of interest in the pharmaceutical industry as a fast and non-destructive modality for quantification of thin film coatings that cannot easily be resolved with other techniques. Because of the relative infancy of this technique, much of the research to date has focused on developing the in-line measurement technique for assessing film coating thickness. To better assess OCT for pharmaceutical coating quantification, this paper evaluates tablets with a range of film coating thickness measured using OCT and terahertz pulsed imaging (TPI) in an off-line setting. In order to facilitate automated coating quantification for film coating thickness in the range of 30-200 μm, an algorithm that uses wavelet denoising and a tailored peak finding method is proposed to analyse each of the acquired A-scan. Results obtained from running the algorithm reveal an increasing disparity between the TPI and OCT measured intra-tablet variability when film coating thickness exceeds 100 μm. The finding further confirms that OCT is a suitable modality for characterising pharmaceutical dosage forms with thin film coatings, whereas TPI is well suited for thick coatings.

  15. Quantifying Pharmaceutical Film Coating with Optical Coherence Tomography and Terahertz Pulsed Imaging: An Evaluation

    PubMed Central

    Lin, Hungyen; Dong, Yue; Shen, Yaochun; Zeitler, J Axel

    2015-01-01

    Spectral domain optical coherence tomography (OCT) has recently attracted a lot of interest in the pharmaceutical industry as a fast and non-destructive modality for quantification of thin film coatings that cannot easily be resolved with other techniques. Because of the relative infancy of this technique, much of the research to date has focused on developing the in-line measurement technique for assessing film coating thickness. To better assess OCT for pharmaceutical coating quantification, this paper evaluates tablets with a range of film coating thickness measured using OCT and terahertz pulsed imaging (TPI) in an off-line setting. In order to facilitate automated coating quantification for film coating thickness in the range of 30–200 μm, an algorithm that uses wavelet denoising and a tailored peak finding method is proposed to analyse each of the acquired A-scan. Results obtained from running the algorithm reveal an increasing disparity between the TPI and OCT measured intra-tablet variability when film coating thickness exceeds 100 μm. The finding further confirms that OCT is a suitable modality for characterising pharmaceutical dosage forms with thin film coatings, whereas TPI is well suited for thick coatings. © 2015 The Authors. Journal of Pharmaceutical Sciences published by Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 104:3377–3385, 2015 PMID:26284354

  16. Solgel derived tantalum pentoxide films as ultraviolet antireflective coatings for silicon.

    PubMed

    Rehg, T J; Ochoa-Tapia, J A; Knoesen, A; Higgins, B G

    1989-12-15

    A solgel process is described to produce Ta(2)O(5) films as short wavelength antireflective (AR) coatings for silicon. The AR coatings were optimized for 370 nm by controlling the acid catalyzed hydrolysis of Ta(OC(2)H(5))(5), the spin coating parameters, and the heat treatment process (rapid thermal processing (RTP) and muffle furnace). Film thickness uniformity across the wafer was better than 1%, and all the coatings tested passed the standard scotch tape test before and after heat treatment and exhibited no change in optical properties after submersion in liquid N(2). Several heat treatment protocols for densifying the films were studied. Spin coated films heat treated in a muffle furnace at 275 degrees C yielded Ta(2)O(5) AR coatings that reduced the reflectance losses from silicon at 370 nm by 86%, the reduction being within 1% of the theoretical value. Films subjected to RTP at temperatures ranging from 300 to 1000 degrees C reduced the reflectance loss in some cases by as much as 95%. The results demonstrate that spin coated solgel derived Ta(2)O(5) films subjected to a low temperature (<300 degrees C) heat treatment can form durable films suitable for near UV AR coatings for high index silicon devices, such as charge couple imagers and photovoltaic cells. PMID:20556030

  17. Interfacial interactions of poly(ether ketone ketone) polymer coatings onto oxide-free phosphate films on an aluminum surface

    SciTech Connect

    Asunskis, A. L.; Sherwood, P. M. A.

    2007-07-15

    This article continues a series of papers that shows how thin (10 nm or less) oxide-free phosphate films can be formed on a number of metals. The films formed have potential as corrosion resistant films. Previous papers have shown that it is possible to extend the range of the surface coatings that can be formed by placing a thin polymer layer over the phosphate layer. In this work it is shown how the water insoluble polymer poly(ether ketone ketone) (PEKK) can be placed over a thin oxide-free phosphate film on aluminum metal. The surface and the interfaces involved were studied by valence band and core level x-ray photoelectron spectroscopy. Difference spectra in the valence band region were used to show that there is a chemical interaction between the PEKK and phosphate thin films on the aluminum metal. Three different phosphate film compositions were studied using different phosphorous containing acids, H{sub 3}PO{sub 4}, H{sub 3}PO{sub 3}, and H{sub 3}PO{sub 2}. This type of interaction illustrates the potential of phosphates to act as adhesion promoters. The valence band spectra are interpreted by calculations.

  18. Reaction mechanism of electroless metal deposition using ZnO thin film (I): Process of catalyst formation

    SciTech Connect

    Yoshiki, Hajime; Hashimoto, Kazuhito; Fujishima, Akira

    1995-02-01

    The reaction mechanism of electroless metal deposition proceeding selectively on a ZnO thin film coated on a glass substrate was investigated by X-ray diffraction, X-ray photoelectron spectroscopy, and inductively coupled plasma measurements. The ZnO thin film was activated for electroless metal deposition just by immersion in 1.1 mM PdCl{sub 2} solution adjusted to pH 2.5. In this process, PD(II) was selectively adsorbed on the ZnO thin film while simultaneously the ZnO underwent dissolution. The dissolution of ZnO thin film easily occurred on the (002) face with polarity. The strongly adsorbed Pd(II) was reduced to Pd(0) by a reducing agent in the electroless plating bath and this served as a catalyst center. As a result, metal layers were obtained selectively on the ZnO thin film in the electroless plating bath.

  19. Starch-based edible film with gum arabic for fruits coating

    NASA Astrophysics Data System (ADS)

    Razak, Aqeela Salfarina; Lazim, Azwan Mat

    2015-09-01

    Packaging waste forms a significant part of municipal solid waste and has caused increasing environmental concerns, resulting in a strengthening of various regulations aimed at reducing the amounts generated. The introduction of biodegradable materials such as edible film and coating which can be disposed directly into the soil, can be one possible solution to this problem. Edible coating is defined as a thin layer of edible material form as a film on the surface of the fruits and vegetables. This coating can affect the respiration and moisture loss. In this study, edible film and coating were used as fruit coating. The edible film were prepared with different ratios which is 2:2, 3:1, and 1:3 of starch and gum Arabic with 10% of glycerol and sorbitol as plasticiser. A study of practical application for the edible film and coating from starch with gum Arabic for fruit coating was conducted. Banana were coated with an aqueous solution of starch with gum Arabic and stored at ambient temperature (26 ± 1°C; 70 ± 10% RH). The results indicate that with the coating application, the fruits lost about 30% less weight than the uncoated fruits. The coating application was also effective in retaining the firmness of the banana and slow down the ripening process.

  20. Promising antimicrobial capability of thin film metallic glasses.

    PubMed

    Chu, Y Y; Lin, Y S; Chang, C M; Liu, J-K; Chen, C H; Huang, J C

    2014-03-01

    Thin film metallic glasses (TFMGs) are demonstrated to exhibit excellent surface flatness, high corrosion resistance and satisfactory hydrophobic properties. Moreover, the antimicrobial and biocompatibility abilities of TFMGs are examined and the results are compared with the behavior of pure Ag and 316L stainless steel. Three TFMGs, Al48Ag37Ti15, Zr54Ti35Si11, and Zr59Ti22Ag19, are prepared by sputtering to assess the antimicrobial performance against Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa, which are the most common nosocomial infection pathogens. Experimental results show that the antimicrobial effect of the Al- or Ag-containing AlAgTi and ZrTiAg TFMGs is similar to that of the pure Ag coating. The ZrTiSi TFMG with no Ag or Al shows poor antimicrobial capability. The physical properties of highly smooth surface and hydrophobic nature alone are not sufficient to result in promising antimicrobial ability. The chemical metal ion release still plays a major role, which should be born in mind in designing biomedical devices.

  1. Repairing Chipped Silicide Coatings on Refractory Metal Substrates

    NASA Technical Reports Server (NTRS)

    Youngquist, Robert

    2006-01-01

    The space shuttle orbiter s reaction control system (RCS) is a series of small thrusters that use hypergolic fuels to orient the orbiter in space. The RCS thrusters are constructed from a special niobium-based alloy -- the C-103. This alloy retains excellent mechanical properties from cryogenic temperature all the way up to 2,500 F (1,370 C). C-103 is susceptible to rapid oxidation at elevated temperatures. The authors have developed two methods to repair damaged R512a coatings on C-103. For the first repair technique, metal foundries, semiconductor manufacturers, and many other industries have developed and routinely use coatings that can easily be painted on metal to protect it from corrosion, including oxidation, to temperatures in excess of 2,500 F (1,370 C). This first repair technique is considered somewhat temporary. The second repair technique is based on using the native coating material of the RCS nozzles. the chipped area is ground out and a "green" R512a coating is applied to the repair area. Both repair techniques can be applied for moderate protection until the permanent laser-repair technique is available to the repair area.

  2. Mechanical behaviour of metallic thin films on polymeric substrates and the effect of ion beam assistance on crack propagation

    SciTech Connect

    George, M. , E-Mail: matthieu.george@bnfl.com; Coupeau, C.; Colin, J.; Grilhe, J.

    2005-01-10

    The mechanisms of crack propagation in metallic films on polymeric substrates have been studied through in situ atomic force microscopy observations of thin films under tensile stresses and finite element stress calculations. Two series of films - ones deposited with ion beam assistance, the others without - have been investigated. The observations and stress calculations show that ion beam assistance can change drastically the propagation of cracks in coated materials: by improving the adhesion film/substrate, it slows down the delamination process, but in the same time enhances the cracks growth in the thickness of the material.

  3. Friction Properties of Polished Cvd Diamond Films Sliding against Different Metals

    NASA Astrophysics Data System (ADS)

    Lin, Zichao; Sun, Fanghong; Shen, Bin

    2016-11-01

    Owing to their excellent mechanical and tribological properties, like the well-known extreme hardness, low coefficient of friction and high chemical inertness, chemical vapor deposition (CVD) diamond films have found applications as a hard coating for drawing dies. The surface roughness of the diamond films is one of the most important attributes to the drawing dies. In this paper, the effects of different surface roughnesses on the friction properties of diamond films have been experimentally studied. Diamond films were fabricated using hot filament CVD. The WC-Co (Co 6wt.%) drawing dies were used as substrates. A gas mixture of acetone and hydrogen gas was used as the feedstock gas. The CVD diamond films were polished using mechanical polishing. Polished diamond films with three different surface roughnesses, as well as the unpolished diamond film, were fabricated in order to study the tribological performance between the CVD diamond films and different metals with oil lubrication. The unpolished and polished CVD diamond films are characterized with scanning electron microscope (SEM), atomic force microscope (AFM), surface profilometer, Raman spectrum and X-ray diffraction (XRD). The friction examinations were carried out by using a ball-on-plate type reciprocating friction tester. Low carbide steel, stainless steel, copper and aluminum materials were used as counterpart balls. Based on this study, the results presented the friction coefficients between the polished CVD films and different metals. The friction tests demonstrate that the smooth surface finish of CVD diamond films is beneficial for reducing their friction coefficients. The diamond films exhibit low friction coefficients when slid against the stainless steel balls and low carbide steel ball, lower than that slid against copper ball and aluminum ball, attributed to the higher ductility of copper and aluminum causing larger amount of wear debris adhering to the sliding interface and higher adhesive

  4. Characteristics of indirect laser-induced plasma from a thin film of oil on a metallic substrate

    NASA Astrophysics Data System (ADS)

    Xiu, Jun-Shan; Bai, Xue-Shi; Motto-Ros, Vincent; Yu, Jin

    2015-04-01

    Optical emissions from the major and trace elements embodied in a transparent gel prepared from cooking oil were detected after the gel was spread in a thin film on a metallic substrate. Such emissions are due to the indirect breakdown of the coating layer. The generated plasma, a mixture of substances from the substrate, the layer, and the ambient gas, was characterized using emission spectroscopy. The characteristics of the plasma formed on the metal with and without the coating layer were investigated. The results showed that Al emission induced from the aluminum substrates coated with oil films extends away from the target surface to ablate the oil film. This finally formed a bifurcating circulation of aluminum vapor against a spherical confinement wall in the front of the plume, which differed from the evolution of the plasma induced from the uncoated aluminum target. The strongest emissions of elements from the oil films can be observed at 2 mm above the target after a detection delay of 1.0 μs. A high temperature zone has been observed in the plasma after the delay of 1.0 μs for the plasma induced from the coated metal. This higher temperature determined in the plasma allows the consideration of the sensitive detection of trace elements in liquids, gels, biological samples, or thin films.

  5. Mechanical Behavior of Spray-Coated Metallic Laminates

    NASA Astrophysics Data System (ADS)

    Vackel, Andrew; Nakamura, Toshio; Sampath, Sanjay

    2016-06-01

    Thermal spray (TS) coatings have been extensively utilized for various surface modifications such as enhancing wear/erosion resistance and thermal protection. In the present study, a new function of TS material is explored by studying its load-carrying capability. Due to the inherent microstructures containing voids and interfaces, it has been presumed TS materials were not suitable to bear loads. However, the recent advances in TS technology to manufacture near fully dense TS coatings have expanded their potential applications. In the current experiments, TS nickel coatings are deposited onto metallic substrates, and their mechanical behaviors are closely examined. Based on the measured data, the estimated elastic modulus of TS Ni is about 130 GPa (35% less than bulk value), and the maximum tensile strength is about 500 MPa (comparable to bulk value). It was found that such a high value is attainable because the coating is deposited onto a substrate, enabling a load-transfer mechanism and preventing coating failure at a much lower stress level. Three distinct deformation stages are identified to describe this behavior. Such a clarification is critical for enabling TS process to restore structural parts as well as to additively manufacture load-bearing components.

  6. Quantitative analysis of electroplated nickel coating on hard metal.

    PubMed

    Wahab, Hassan A; Noordin, M Y; Izman, S; Kurniawan, Denni

    2013-01-01

    Electroplated nickel coating on cemented carbide is a potential pretreatment technique for providing an interlayer prior to diamond deposition on the hard metal substrate. The electroplated nickel coating is expected to be of high quality, for example, indicated by having adequate thickness and uniformity. Electroplating parameters should be set accordingly for this purpose. In this study, the gap distances between the electrodes and duration of electroplating process are the investigated variables. Their effect on the coating thickness and uniformity was analyzed and quantified using design of experiment. The nickel deposition was carried out by electroplating in a standard Watt's solution keeping other plating parameters (current: 0.1 Amp, electric potential: 1.0 V, and pH: 3.5) constant. The gap distance between anode and cathode varied at 5, 10, and 15 mm, while the plating time was 10, 20, and 30 minutes. Coating thickness was found to be proportional to the plating time and inversely proportional to the electrode gap distance, while the uniformity tends to improve at a large electrode gap. Empirical models of both coating thickness and uniformity were developed within the ranges of the gap distance and plating time settings, and an optimized solution was determined using these models.

  7. Quantitative Analysis of Electroplated Nickel Coating on Hard Metal

    PubMed Central

    Wahab, Hassan A.; Noordin, M. Y.; Izman, S.

    2013-01-01

    Electroplated nickel coating on cemented carbide is a potential pretreatment technique for providing an interlayer prior to diamond deposition on the hard metal substrate. The electroplated nickel coating is expected to be of high quality, for example, indicated by having adequate thickness and uniformity. Electroplating parameters should be set accordingly for this purpose. In this study, the gap distances between the electrodes and duration of electroplating process are the investigated variables. Their effect on the coating thickness and uniformity was analyzed and quantified using design of experiment. The nickel deposition was carried out by electroplating in a standard Watt's solution keeping other plating parameters (current: 0.1 Amp, electric potential: 1.0 V, and pH: 3.5) constant. The gap distance between anode and cathode varied at 5, 10, and 15 mm, while the plating time was 10, 20, and 30 minutes. Coating thickness was found to be proportional to the plating time and inversely proportional to the electrode gap distance, while the uniformity tends to improve at a large electrode gap. Empirical models of both coating thickness and uniformity were developed within the ranges of the gap distance and plating time settings, and an optimized solution was determined using these models. PMID:23997678

  8. New chemistry for the growth of first-row transition metal films by atomic layer deposition

    NASA Astrophysics Data System (ADS)

    Klesko, Joseph Peter

    Thin films containing first-row transition metals are widely used in microelectronic, photovoltaic, catalytic, and surface-coating applications. In particular, metallic films are essential for interconnects and seed, barrier, and capping layers in integrated circuitry. Traditional vapor deposition methods for film growth include PVD, CVD, or the use of plasma. However, these techniques lack the requisite precision for film growth at the nanoscale, and thus, are increasingly inadequate for many current and future applications. By contrast, ALD is the favored approach for depositing films with absolute surface conformality and thickness control on 3D architectures and in high aspect ratio features. However, the low-temperature chemical reduction of most first-row transition metal cations to their zero-valent state is very challenging due to their negative electrochemical potentials. A lack of strongly-reducing coreagents has rendered the thermal ALD of metallic films an intractable problem for many elements. Additionally, several established ALD processes for metal films are plagued by low growth rates, impurity incorporation, poor nucleation, high surface roughness, or the need for hazardous coreagents. Finally, stoichiometric control of ternary films grown by ALD is rare, but increasingly important, with emerging applications for metal borate films in catalysis and lithium ion batteries. The research herein is focused toward the development of new ALD processes for the broader application of metal, metal oxide, and metal borate thin films to future nanoscale technologies. These processes display self-limited growth and support the facile nucleation of smooth, continuous, high-purity films. Bis(trimethylsilyl) six-membered rings are employed as strongly-reducing organic coreagents for the ALD of titanium and antimony metal films. Additionally, new processes are developed for the growth of high-purity, low-resistivity cobalt and nickel metal films by exploiting the

  9. Alumina coating on dense tungsten powder by fluidized bed metal organic chemical vapour deposition.

    PubMed

    Rodriguez, Philippe; Caussat, Brigitte; Ablitzer, Carine; Iltis, Xavière; Brothier, Meryl

    2011-09-01

    In order to study the feasibility of coating very dense powders by alumina using Fluidized Bed Metal Organic Chemical Vapour Deposition (FB-MOCVD), experiments were performed on a commercial tungsten powder, 75 microm in median volume diameter and 19,300 kg/m3 in grain density. The first part of the work was dedicated to the experimental study of the tungsten powder fluidization using argon as carrier gas at room temperature and at 400 degrees C. Due to the very high density of the tungsten powder, leading to low initial fixed bed heights and low bed expansions, different weights of powder were tested in order to reach satisfactory temperature profiles along the fluidized bed. Then, using argon as a fluidized bed former and aluminium acetylacetonate Al(C5O2H7)3 as a single source precursor, alumina thin films were deposited on tungsten particles at a low temperature range (e.g., 370-420 degrees C) by FB-MOCVD. The influence of the weight of powder, bed temperature and run duration was studied. Characterizations of the obtained samples were performed by various techniques including scanning electron microscopy (SEM) coupled with Energy Dispersive X-ray Spectroscopy (EDS) analyses, Field Emission Gun SEM (FEG-SEM) and Fourier Transform InfraRed (FT-IR) spectroscopy. The different analyses indicated that tungsten particles were uniformly coated by a continuous alumina thin film. The thickness of the film ranged between 25 and 80 nm, depending on the coating conditions. The alumina thin films were amorphous and contained carbon contamination. This latter may correspond to the adsorption of species resulting from incomplete decomposition of the precursor at so low deposition temperature. PMID:22097534

  10. Influence of Surface Coating on Metal Ion Release: Evaluation in Patients With Metal Allergy.

    PubMed

    Thomas, Peter; Weik, Thomas; Roider, Gabriele; Summer, Burkhard; Thomsen, Marc

    2016-05-01

    Nickel, chromium, and cobalt in stainless steel and Cobalt-chrome-molybdenum (CoCrMo) alloys may induce allergy. The objectives of this study were to evaluate surface coating regarding ion release, patch test reactivity, and arthroplasty performance. Materials and methods included patch test in 31 patients with metal allergy and 30 patients with no allergy to stainless steel and CoCrMo disks that are uncoated or coated by titanium nitride/zirconium nitride (TiN/ZrN). Assessment include atomic absorption spectrometry of released nickel, cobalt, and chromium from the disks after exposure to distilled water, artificial sweat and culture medium. Results showed that both coatings reduced the nickel and chromium release from stainless steel and CoCrMo disks and mostly the cobalt release from the disks (maximally 11.755 µg/cm(2)/5 d to 1.624 by Ti-N and to 0.442 by ZrN). Six of the 31 patients with metal allergy reacted to uncoated disks, but none reacted to the coated disks. The current authors report on exemplary patients with metal allergy who had symptom relief by revision with surface-coated arthroplasty. The authors concluded that the surface coating may prevent cutaneous and peri-implant allergic reactions. [Orthopedics. 2016; 39(3):S24-S30.].

  11. Influence of Surface Coating on Metal Ion Release: Evaluation in Patients With Metal Allergy.

    PubMed

    Thomas, Peter; Weik, Thomas; Roider, Gabriele; Summer, Burkhard; Thomsen, Marc

    2016-05-01

    Nickel, chromium, and cobalt in stainless steel and Cobalt-chrome-molybdenum (CoCrMo) alloys may induce allergy. The objectives of this study were to evaluate surface coating regarding ion release, patch test reactivity, and arthroplasty performance. Materials and methods included patch test in 31 patients with metal allergy and 30 patients with no allergy to stainless steel and CoCrMo disks that are uncoated or coated by titanium nitride/zirconium nitride (TiN/ZrN). Assessment include atomic absorption spectrometry of released nickel, cobalt, and chromium from the disks after exposure to distilled water, artificial sweat and culture medium. Results showed that both coatings reduced the nickel and chromium release from stainless steel and CoCrMo disks and mostly the cobalt release from the disks (maximally 11.755 µg/cm(2)/5 d to 1.624 by Ti-N and to 0.442 by ZrN). Six of the 31 patients with metal allergy reacted to uncoated disks, but none reacted to the coated disks. The current authors report on exemplary patients with metal allergy who had symptom relief by revision with surface-coated arthroplasty. The authors concluded that the surface coating may prevent cutaneous and peri-implant allergic reactions. [Orthopedics. 2016; 39(3):S24-S30.]. PMID:27219723

  12. The electrical conductivity of polycrystalline metallic films

    NASA Astrophysics Data System (ADS)

    Moraga, Luis; Arenas, Claudio; Henriquez, Ricardo; Bravo, Sergio; Solis, Basilio

    2016-10-01

    We calculate the electrical conductivity of polycrystalline metallic films by means of a semi-numerical procedure that provides solutions of the Boltzmann transport equation, that are essentially exact, by summing over classical trajectories according to Chambers' method. Following Mayadas and Shatzkes (MS), grain boundaries are modeled as an array of parallel plane barriers situated perpendicularly to the direction of the current. Alternatively, according to Szczyrbowski and Schmalzbauer (SS), the model consists in a triple array of these barriers in mutual perpendicular directions. The effects of surface roughness are described by means of Fuchs' specularity parameters. Following SS, the scattering properties of grain boundaries are taken into account by means of another specularity parameter and a probability of coherent passage. The difference between the sum of these and one is the probability of diffuse scattering. When this formalism is compared with the approximate formula of Mayadas and Shatzkes (Phys. Rev. B 1, 103 (1986)) it is shown that the latter greatly overestimates the film resistivity over most values of the reflectivity of the grain boundaries. The dependence of the conductivity of thin films on the probability of coherent passage and grain diameters is examined. In accordance with MS we find that the effects of disorder in the distribution of grain diameters is quite small. Moreover, we find that it is not safe to neglect the effects of the scattering by the additional interfaces created by stacked grains. However, when compared with recent resitivity-thickness data, it is shown that all three formalisms can provide accurate fits to experiment. In addition, it is shown that, depending on the respective reflectivities and distance from a surface, some of these interfaces may increase or diminish considerably the conductivity of the sample. As an illustration of this effect, we show a tentative fit of resistivity data of gold films measured by

  13. Advanced Fabrication Method for the Preparation of MOF Thin Films: Liquid-Phase Epitaxy Approach Meets Spin Coating Method.

    PubMed

    Chernikova, Valeriya; Shekhah, Osama; Eddaoudi, Mohamed

    2016-08-10

    Here, we report a new and advanced method for the fabrication of highly oriented/polycrystalline metal-organic framework (MOF) thin films. Building on the attractive features of the liquid-phase epitaxy (LPE) approach, a facile spin coating method was implemented to generate MOF thin films in a high-throughput fashion. Advantageously, this approach offers a great prospective to cost-effectively construct thin-films with a significantly shortened preparation time and a lessened chemicals and solvents consumption, as compared to the conventional LPE-process. Certainly, this new spin-coating approach has been implemented successfully to construct various MOF thin films, ranging in thickness from a few micrometers down to the nanometer scale, spanning 2-D and 3-D benchmark MOF materials including Cu2(bdc)2·xH2O, Zn2(bdc)2·xH2O, HKUST-1, and ZIF-8. This method was appraised and proved effective on a variety of substrates comprising functionalized gold, silicon, glass, porous stainless steel, and aluminum oxide. The facile, high-throughput and cost-effective nature of this approach, coupled with the successful thin film growth and substrate versatility, represents the next generation of methods for MOF thin film fabrication. Therefore, paving the way for these unique MOF materials to address a wide range of challenges in the areas of sensing devices and membrane technology. PMID:27415640

  14. Switchable photoluminescence liquid crystal coated bacterial cellulose films with conductive response.

    PubMed

    Tercjak, Agnieszka; Gutierrez, Junkal; Barud, Hernane S; Ribeiro, Sidney J L

    2016-06-01

    Three different low molecular weight nematic liquid crystals (LCs) were used to impregnate bacterial cellulose (BC) film. This simple fabrication pathway allows to obtain highly transparent BC based films. The coating of BC film with different liquid crystals changed transmittance spectra in ultraviolet-visible region and allows to design UVC and UVB shielding materials. Atomic force microscopy results confirmed that liquid crystals coated BC films maintain highly interconnected three-dimensional network characteristic of BC film and simultaneously, transversal cross-section scanning electron microscopy images indicated penetration of liquid crystals through the three-dimensional network of BC nanofibers. Investigated BC films maintain nematic liquid crystal properties being switchable photoluminiscence as a function of temperature during repeatable heating/cooling cycles. Conductive response of the liquid crystal coated BC films was proved by tunneling atomic force microscopy measurement. Moreover, liquid crystal coated BC films maintain thermal stability and mechanical properties of the BC film. Designed thermoresponsive materials possessed interesting optical and conductive properties opening a novel simple pathway of fabrication liquid crystal coated BC films with tuneable properties. PMID:27083359

  15. Switchable photoluminescence liquid crystal coated bacterial cellulose films with conductive response.

    PubMed

    Tercjak, Agnieszka; Gutierrez, Junkal; Barud, Hernane S; Ribeiro, Sidney J L

    2016-06-01

    Three different low molecular weight nematic liquid crystals (LCs) were used to impregnate bacterial cellulose (BC) film. This simple fabrication pathway allows to obtain highly transparent BC based films. The coating of BC film with different liquid crystals changed transmittance spectra in ultraviolet-visible region and allows to design UVC and UVB shielding materials. Atomic force microscopy results confirmed that liquid crystals coated BC films maintain highly interconnected three-dimensional network characteristic of BC film and simultaneously, transversal cross-section scanning electron microscopy images indicated penetration of liquid crystals through the three-dimensional network of BC nanofibers. Investigated BC films maintain nematic liquid crystal properties being switchable photoluminiscence as a function of temperature during repeatable heating/cooling cycles. Conductive response of the liquid crystal coated BC films was proved by tunneling atomic force microscopy measurement. Moreover, liquid crystal coated BC films maintain thermal stability and mechanical properties of the BC film. Designed thermoresponsive materials possessed interesting optical and conductive properties opening a novel simple pathway of fabrication liquid crystal coated BC films with tuneable properties.

  16. Critical current behavior of Ag-coated YBa2Cu3O(7-x) thin films

    NASA Astrophysics Data System (ADS)

    Ono, R. H.; Beall, J. A.; Harvey, T. E.; Reintsema, C. D.; Johansson, M.

    1991-03-01

    The authors studied the behavior of high-quality YBa2Cu3O(7-x) (YBCO) thin films with Ag overlayers. The authors chose to study Ag in detail because of its widespread use as contact metallization and because of their earlier studies of proximity effects in YBCO. The details of transport critical current measurements are presented. It is shown that the Ag coatings can reduce normal state resistance while not degrading the critical current density. The key technological result is that the various thicknesses of Ag that were used did not reduce Jc or Jc(H). Critical current densities in excess of 106 A/sq cm have been achieved at temperatures greater than 76 K. An unusual effect was seen in Jc(H) when the field was oriented perpendicular to the c axis of the film. The Jc at 1 T was higher in samples with 10-nm coatings of Ag than in similar uncoated samples. It was also shown that the composite resistance of Ag-YBCO bilayers can be much lower than the resistance of uncoated YBCO.

  17. Influence of plasticizer type and coat level on Surelease film properties.

    PubMed

    Rohera, Bhagwan D; Parikh, Nilesh H

    2002-11-01

    Two commercially available formulations of aqueous ethylcellulose dispersion differing in their plasticizer, i.e., Surelease/E-7-7050 containing dibutyl sebacate (DBS) and Surelease/E-7-7060 containing glyceryl tricaprylate/caprate (GTC), were evaluated and compared for their film properties as a function of polymeric coat level. Ibuprofen tablets were coated at 1, 2, 3, and 5% w/w levels using each Surelease formulation, and the coated tablets were evaluated for their drug release characteristics, coat reflectivity (gloss), surface texture, Brinell hardness, and elastic modulus. The drug release was dependent on the coat level and followed Hixson-Crowell cube-root model at 1% coat level. However, at > or = 2% coat levels, the release from tablets coated with GTC plasticized formulation appeared to be best described by non-Fickian release mechanism and that from tablets coated with DBS plasticized formulation appeared to follow apparent zero-order release mechanism. At equal coat levels, tablets coated with GTC plasticized Surelease yielded lower drug release rates, higher reflectivity (gloss), lower surface roughness, higher Brinell hardness, and lower elastic modulus than those coated with DBS plasticized formulation. A good correlation was observed between the drug release rates and the reflectivity and surface texture of the coated tablets. The film-coats of GTC plasticized formulation were harder and more elastic than those of DBS plasticized formulation indicating better mechanical integrity.

  18. Ethanol-resistant polymeric film coatings for controlled drug delivery.

    PubMed

    Rosiaux, Y; Muschert, S; Chokshi, R; Leclercq, B; Siepmann, F; Siepmann, J

    2013-07-10

    The sensitivity of controlled release dosage forms to the presence of ethanol in the gastro intestinal tract is critical, if the incorporated drug is potent and exhibits severe side effects. This is for instance the case for most opioid drugs. The co-ingestion of alcoholic beverages can lead to dose dumping and potentially fatal consequences. For these reasons the marketing of hydromorphone HCl extended release capsules (Palladone) was suspended. The aim of this study was to develop a novel type of controlled release film coatings, which are ethanol-resistant: even the presence of high ethanol concentrations in the surrounding bulk fluid (e.g., up to 40%) should not affect the resulting drug release kinetics. Interestingly, blends of ethylcellulose and medium or high viscosity guar gums provide such ethanol resistance. Theophylline release from pellets coated with the aqueous ethylcellulose dispersion Aquacoat® ECD 30 containing 10 or 15% medium and high viscosity guar gum was virtually unaffected by the addition of 40% ethanol to the release medium. Furthermore, drug release was shown to be long term stable from this type of dosage forms under ambient and stress conditions (without packaging material), upon appropriate curing.

  19. Western blotting by thin-film direct coating.

    PubMed

    Yen, Yi-Kuang; Jiang, Yi-Wei; Chang, Shih-Chung; Wang, An-Bang

    2014-05-20

    A novel thin-film direct coating (TDC) technique was developed to markedly reduce the amount of antibody required for Western blotting (WB). Automatic application of the technique for a few seconds easily and homogeneously coats the specific primary antibody on the polyvinylidene fluoride (PVDF) membrane. While conventional WB requires 0.4 μg of the primary antibody, the proposed technique only uses 4 × 10(-2) μg, which can be reduced further to 4 × 10(-5) μg by reducing the coater width. Moreover, the proposed process reduces antibody probing times from 60 to 10 min. The quantification capability of TDC WB showed high linearity within a 4-log2 dynamic range for detecting target antigen glutathione-S-transferase. Furthermore, TDC WB can specifically detect the extrinsic glutathione-S-transferase added in the Escherichia coli or 293T cell lysate with better staining sensitivity than conventional WB. TDC WB can also clearly probe the intrinsic β-actin, α-tubulin, and glyceraldehyde 3-phosphate dehydrogenase, which are usually used as control proteins in biological experiments. This novel technique has been shown to not only have valuable potential for increasing WB efficiency but also for providing significant material savings for future biomedical applications. PMID:24773468

  20. A novel powder coating process for attaining taste masking and moisture protective films applied to tablets.

    PubMed

    Cerea, Matteo; Zheng, Weijia; Young, Christopher R; McGinity, James W

    2004-07-26

    A novel powder coating process was developed for the application of taste masking and moisture protective films on tablets while avoiding the use of solvents or water. The coalescence of particles to form a polymeric film was investigated through studies of dry powder layering of micronized acrylic polymer (E PO) to produce free films. Theophylline containing tablets were coated with the same acrylic polymer in a laboratory scale spheronizer using a powder coating technique. The dry powder layer delayed the onset of drug release in pH 6.8 medium, depending on the coating level, while no delay was observed in pH 1.0 medium. The presence of hydrophilic polymers in the acrylic coating layer decreased the lag time for drug release in pH 6.8 medium, while only the presence of HPMC in the film slowed the drug release rate in acidic medium. The dry coating process was demonstrated to be a reliable alternative to solvent or aqueous film coating technologies for applying taste masking and moisture protective film coats onto compressed tablets. A controlled drug release profile was achieved in pH 6.8 media.

  1. Tribological coatings for complex mechanical elements produced by supersonic cluster beam deposition of metal dichalcogenide nanoparticles

    NASA Astrophysics Data System (ADS)

    Piazzoni, C.; Buttery, M.; Hampson, M. R.; Roberts, E. W.; Ducati, C.; Lenardi, C.; Cavaliere, F.; Piseri, P.; Milani, P.

    2015-07-01

    Fullerene-like MoS2 and WS2 nanoparticles can be used as building blocks for the fabrication of fluid and solid lubricants. Metal dichalcogenide films have a very low friction coefficient in vacuum, therefore they have mostly been used as solid lubricants in space and vacuum applications. Unfortunately, their use is significantly hampered by the fact that in the presence of humidity, oxygen and moisture, the low-friction properties of these materials rapidly degrade due to oxidation. The use of closed-cage MoS2 and WS2 nanoparticles may eliminate this problem, although the fabrication of lubricant thin films starting from dichalcogenide nanoparticles is, to date, a difficult task. Here we demonstrate the use of supersonic cluster beam deposition for the coating of complex mechanical elements (angular contact ball bearings) with nanostructured MoS2 and WS2 thin films. We report structural and tribological characterization of the coatings in view of the optimization of tribological performances for aerospace applications.

  2. Single crystal growth in spin-coated films of polymorphic phthalocyanine derivative under solvent vapor

    SciTech Connect

    Higashi, T.; Ohmori, M.; Ramananarivo, M. F.; Fujii, A. Ozaki, M.

    2015-12-01

    The effects of solvent vapor on spin-coated films of a polymorphic phthalocyanine derivative were investigated. Growth of single crystal films via redissolving organic films under solvent vapor was revealed by in situ microscopic observations of the films. X-ray diffraction measurement of the films after exposing to solvent vapor revealed the phase transition of polymorphs under solvent vapor. The direction of crystal growth was clarified by measuring the crystal orientation in a grown monodomain film. The mechanism of crystal growth based on redissolving organic films under solvent vapor was discussed in terms of the different solubilities of the polymorphs.

  3. Liquid source metal-organic chemical-vapor deposition of high-quality YBa2Cu3O7-x films on polycrystalline silver substrates

    NASA Astrophysics Data System (ADS)

    Studebaker, D. B.; Zhang, J.; Marks, T. J.; Wang, Y. Y.; Dravid, V. P.; Schindler, J. L.; Kannewurf, C. R.

    1998-03-01

    High-temperature superconducting YBa2Cu3O7-x films were grown by liquid delivery metal-organic chemical-vapor deposition on silver-coated stainless-steel substrates. The films are highly c-axis oriented, have a Tc above 90 K, and exhibit a surface resistance of 110 μΩ at 77 K and 3 GHz.

  4. Measurement of Thin-film Coating Hardness in the Presence of Contamination and Roughness: Implications for Tribology

    NASA Astrophysics Data System (ADS)

    Demas, Nicholaos G.; Lorenzo-Martin, Cinta; Ajayi, Oyelayo O.; Erck, Robert A.; Shareef, Iqbal

    2016-04-01

    Standard nanoindentation measurements on commercially available TiAlN, CrN, metal-containing diamond-like carbon, and TiN coatings, deposited on steel substrates were performed to determine coating hardness and elastic modulus. It was found that the coating surface roughness/morphology present after deposition can significantly affect the measurements of nanomechanical properties so that measurements of these properties on the as-deposited coating surface may be significantly different from the bulk. In addition, a surface measurement may produce a lower nanohardness due to the existence of a soft surface contamination layer. A simple method was developed to enable accurate measurement of the nanomechanical properties of coatings, while avoiding errors introduced by surface topography and the presence of superficial contamination layers on thin films. Friction and wear behavior, as well as the wear mechanisms in dry reciprocating sliding contact of the various coatings with a steel ball can be correlated to the surface attributes of each coating in terms of roughness and the presence of contamination layers, both of which are shown to also affect the nanohardness measurements.

  5. Thickness dependent electronic structure and morphology of rubrene thin films on metal, semiconductor, and dielectric substrates

    NASA Astrophysics Data System (ADS)

    Sinha, Sumona; Mukherjee, M.

    2013-08-01

    The evolution of the electronic structure and morphology of rubrene thin films on noble-metal, semiconductor and dielectric substrates have been investigated as a function of thickness of deposited films by using photoelectron spectroscopy and atomic force microscopy. The clean polycrystalline Au and Ag were used as noble-metals, whereas, H passivated and SiO2 coated Si (100) were used as semiconductors and dielectric substrates. Discussion and comparison on interface dipole, energy level alignment, and surface morphology for the four cases are presented. The formation of dipole at metallic interfaces is found to occur due to push back effect. S parameter obtained from the variation of barrier height with the change of work function of the contacting metal indicates moderately weak interaction between rubrene and the metal substrates. The thickness dependent energy level alignment of the physisorbed rubrene films on different substrates is explained by a dielectric model in terms of electrostatic screening of photo-holes or photoemission final state relaxation energy. Films on all the substrates are found to grow following Stranski-Krastnov type growth mode and are more ordered at higher coverage.

  6. Temperature-dependent phonon conduction and nanotube engagement in metalized single wall carbon nanotube films.

    PubMed

    Panzer, Matthew A; Duong, Hai M; Okawa, Jun; Shiomi, Junichiro; Wardle, Brian L; Maruyama, Shigeo; Goodson, Kenneth E

    2010-07-14

    Interfaces dominate the thermal resistances in aligned carbon nanotube arrays. This work uses nanosecond thermoreflectance thermometry to separate interface and volume resistances for 10 microm thick aligned SWNT films coated with Al, Ti, Pd, Pt, and Ni. We interpret the data by defining the nanotube-metal engagement factor, which governs the interface resistance and is extracted using the measured film heat capacity. The metal-SWNT and SWNT-substrate resistances range between 3.8 and 9.2 mm(2)K/W and 33-46 mm(2)K/W, respectively. The temperature dependency of the heat capacity data, measured between 125 and 300 K, is in good agreement with theoretical predictions. The temperature dependence demonstrated by the metal-SWNT interface resistance data suggests inelastic phonon transmission.

  7. Characterization of a water-dispersible metal protective coating with Fourier transform infrared spectroscopy, modulated differential scanning calorimetry, and ellipsometry.

    PubMed

    Boyatzis, Stamatis C; Douvas, Antonios M; Argyropoulos, Vassilike; Siatou, Amalia; Vlachopoulou, Marilena

    2012-05-01

    An ethylene-methacrylic acid copolymer, formulated by BASF as a waterborne suspension of its alkylammonium salt and used, among other applications, in art conservation as a temporary protective coating was characterized using Fourier transform infrared (FT-IR) spectroscopy aided by modulated differential scanning calorimetry (MDSC) and ellipsometry. The thermal conversion of thin copolymer films from the freshly applied state, where carboxylic acid and carboxylate ion functional groups co-exist, to a purely acidic working state was spectroscopically followed. Transmission mid-infrared data of the working state showed a 1 : 12 ratio of methacrylic acid towards ethylene units. The glass transition temperature (T(g)) in the same state was found at 45 °C. Copolymer films spin-coated on mechanically polished bronze and iron coupons were characterized with transflection infrared spectroscopy and compared to corresponding transmission mid-infrared spectra of copolymer films spin-coated on silicon wafers. In the case of bronze coupons, evidence for interaction of the carboxylate ion with the copper substrate was obtained. The chemical structure and the thermal behavior of the coating, as well as some implications on its protective capability towards iron and copper alloys, is discussed as this material has received considerable attention in the field of metal conservation and coatings.

  8. Novel low-molecular-weight hypromellose polymeric films for aqueous film coating applications.

    PubMed

    Bruce, Hollie F; Sheskey, Paul J; Garcia-Todd, Paula; Felton, Linda A

    2011-12-01

    The concentration of hypromellose (HPMC) is known to significantly impact the viscosity of coating solutions. The purpose of this study was to determine the viscosity of novel low-molecular-weight (LMW) HPMC products as a function of polymer concentration. The mechanical properties and water vapor permeability of free films prepared from these novel LMW HPMC polymers were also determined and the results were compared with films prepared with conventional HPMC. Solutions of LMW and conventional HPMC 2910 and 2906 containing up to 40% polyethylene glycol (PEG) 400 were prepared and the viscosities were measured using a Brookfield viscometer. Solutions were then cast onto glass plates and stored at 30?C and 50% relative humidity until films were formed. A Chatillon digital force gauge attached to a motorized test stand was used to quantify the mechanical properties of the films, whereas water vapor permeabilities were determined according to the ASTM E96 M-05 water method. As expected, the novel LMW polymer solutions exhibited significantly lower viscosities than the conventional comparators at equivalent polymer concentrations. Film strength of the LMW materials was lower than films prepared from the conventional HPMC solutions, although this effect was not as evident for the HPMC 2906 chemistry. Increasing concentrations of the plasticizer resulted in decreased tensile strength and Young?s modulus and increased elongation as well as increased water vapor permeability, irrespective of polymer type. No statistical difference was found between the tensile strength to Young?s modulus ratios of the F chemistry LMW and conventional HPMC polymer films.

  9. Relative humidity sensing using dye-doped polymer thin-films on metal substrates

    NASA Astrophysics Data System (ADS)

    Kumari, Madhuri; Ding, Boyang; Blaikie, Richard

    2015-12-01

    We demonstrate humidity sensors based on optical resonances sustained in sub-wavelength thick dye-doped polymer coatings on reflecting surfaces. As a result of coupling between dye molecular absorption and Fabry-Perot resonances in the air-coating-surface cavity, the absorption spectra of such thin-film structures show a strong resonant peak under certain illumination conditions. These resonances are sensitive to the structural and material properties of the thin-film, metal underlayer and ambient conditions and hence can be used for gas and vapor sensing applications. Specifically, we present our proof of principle experimental results for humidity sensing using a thin-film structure comprising Rhodamine6G-doped polyvinyl alcohol (PVA) films on silver substrates. Depending on the PVA film thickness, dye-concertation and angle of incidence, the resonant absorption peak can undergo either red-shift or blue-shift as RH level increases in the range 20% to 60%. Also, the absorption magnitude at certain wavelengths near to resonance show almost linear reduction which can be used as the sensing signal. Our simulation studies show a very good agreement with the experimental data. The spectral and temporal sensitivity of this thin-film structure is attributed to the changes in the thickness of the PVA layer which swells by absorbing water molecules

  10. Oxide film on metal substrate reduced to form metal-oxide-metal layer structure

    NASA Technical Reports Server (NTRS)

    Youngdahl, C. A.

    1967-01-01

    Electrically conductive layer of zirconium on a zirconium-oxide film residing on a zirconium substrate is formed by reducing the oxide in a sodium-calcium solution. The reduced metal remains on the oxide surface as an adherent layer and seems to form a barrier that inhibits further reaction.

  11. Preparation, Functionality, and Application of Metal Oxide-coated Noble Metal Nanoparticles.

    PubMed

    Liu, Shuhua; Regulacio, Michelle D; Tee, Si Yin; Khin, Yin Win; Teng, Choon Peng; Koh, Leng Duei; Guan, Guijian; Han, Ming-Yong

    2016-08-01

    With their remarkable properties and wide-ranging applications, nanostructures of noble metals and metal oxides have been receiving significantly increased attention in recent years. The desire to combine the properties of these two functional materials for specific applications has naturally prompted research in the design and synthesis of novel nanocomposites, consisting of both noble metal and metal-oxide components. In this review, particular attention is given to core-shell type metal oxide-coated noble metal nanostructures (i.e., metal@oxide), which display potential utility in applications, including photothermal therapy, catalytic conversions, photocatalysis, molecular sensing, and photovoltaics. Emerging research directions and areas are envisioned at the end to solicit more attention and work in this regard. PMID:27291595

  12. Development, mechanical evaluation and surface characteristics of chitosan/polyvinyl alcohol based polymer composite coatings on titanium metal.

    PubMed

    Mishra, Sandeep K; Kannan, S

    2014-12-01

    Mechanical properties of orthopedic implants play important role in the regeneration and cell growth of the diseased body part. The present investigation was aimed at the development of a biocompatible, biodegradable and mechanically stable coating of chitosan (CS)-polyvinyl alcohol (PVA) polymer composite on Titanium (Ti) metal by employing a simple methodology at ambient conditions. The PVA to CS concentrations were maintained in fixed ratios of 1:4 weight/weight (w/w) for the development of all the coatings on Ti metal. Four different concentrations of the polymers ranging in the order of 5%, 10%, 15% and 20% weight/volume (w/v) solution of CS were selected in an aim to test their efficacy on mechanical stability. The results obtained from the analysis confirmed considerable improvement in mechanical properties of the composite polymer film comprising CS and PVA on Ti metal with the four different concentrations showing variable elastic modulus and hardness. The difference in mechanical properties of both dehydrated and hydrated coatings demonstrates the effective and efficient shielding of high mechanical properties of Ti metal in physiological conditions. The scratch tests performed on the coated specimens also indicated a good adhesion of the polymer on the Ti metal surface.

  13. Thick REBaCuO superconducting films through single-coating of low-fluorine metallorganic solution

    NASA Astrophysics Data System (ADS)

    Boubeche, M.; Cai, C. B.; Jian, H. B.; Li, M. J.; Yang, W. T.; Liu, Z. Y.; Bai, C. Y.

    2016-10-01

    A high critical current Ic is crucial for the application of high temperature superconductors YBa2Cu3O7-δ in energy efficient power devices and wires. In this paper we report the fabrication of thick (YGd)1.3Ba2Cu3O7-x films on a metal substrate using low-fluorine metal organic deposition method. The effects of the film thickness on the microstructure, texture and superconductivity properties of the films were evaluated. In order to increase the film thicknesses by single coating, the influence of withdrawal speed during the dip coating on resulting thickness are investigated with the other processing parameters fixed. It is revealed that there is a maximum thickness for a certain starting solution. Here we used 3 different solutions, Conventional Low Fluorine solutions with 2 M and 2.5 M, and super low-fluorine solution with 2.5 M. The maximum thicknesses of about 710 nm, 1280 nm and 1460 nm were obtained, respectively.

  14. Monolayer and/or few-layer graphene on metal or metal-coated substrates

    DOEpatents

    Sutter, Peter Werner; Sutter, Eli Anguelova

    2015-04-14

    Disclosed is monolayer and/or few-layer graphene on metal or metal-coated substrates. Embodiments include graphene mirrors. In an example, a mirror includes a substrate that has a surface exhibiting a curvature operable to focus an incident beam onto a focal plane. A graphene layer conformally adheres to the substrate, and is operable to protect the substrate surface from degradation due to the incident beam and an ambient environment.

  15. Measuring the thickness of protective coatings on historic metal objects using nanosecond and femtosecond laser induced breakdown spectroscopy depth profiling

    NASA Astrophysics Data System (ADS)

    Pouli, P.; Melessanaki, K.; Giakoumaki, A.; Argyropoulos, V.; Anglos, D.

    2005-08-01

    Depth profile analysis by means of laser induced breakdown spectroscopy (LIBS) was investigated with respect to its potential to measure the thickness of different types of thin organic films used as protective coatings on historical and archaeological metal objects. For the materials examined, acrylic varnish and microcrystalline wax, the output from a nanosecond ArF excimer laser at 193 nm was found appropriate for performing a reliable profiling of the coating films leading to accurate determination of the coating thickness on the basis of the number of laser pulses required to penetrate the coating and on the ablation etch rate of the corresponding coating material under the same irradiation conditions. Nanosecond pulses at 248 nm proved inadequate to profile the coatings because of their weak absorption at the laser wavelength. In contrast, femtosecond irradiation at 248 nm yielded well-resolved profiles as a result of efficient ablation achieved through the increased non-linear absorption induced by the high power density of the ultrashort pulses.

  16. Origin of Shear Stability and Compressive Ductility Enhancement of Metallic Glasses by Metal Coating

    PubMed Central

    Sun, B. A.; Chen, S. H.; Lu, Y. M.; Zhu, Z. G.; Zhao, Y. L.; Yang, Y.; Chan, K. C.; Liu, C. T.

    2016-01-01

    Metallic glasses (MGs) are notorious for the poor macroscopic ductility and to overcome the weakness various intrinsic and extrinsic strategies have been proposed in past decades. Among them, the metal coating is regarded as a flexible and facile approach, yet the physical origin is poorly understood due to the complex nature of shear banding process. Here, we studied the origin of ductile enhancement in the Cu-coating both experimentally and theoretically. By examining serrated shear events and their stability of MGs, we revealed that the thin coating layer plays a key role in stopping the final catastrophic failure of MGs by slowing down shear band dynamics and thus retarding its attainment to a critical instable state. The mechanical analysis on interplay between the coating layer and shear banding process showed the enhanced shear stability mainly comes from the lateral tension of coating layer induced by the surface shear step and the bonding between the coating layer and MGs rather than the layer thickness is found to play a key role in contributing to the shear stability. PMID:27271435

  17. Origin of Shear Stability and Compressive Ductility Enhancement of Metallic Glasses by Metal Coating.

    PubMed

    Sun, B A; Chen, S H; Lu, Y M; Zhu, Z G; Zhao, Y L; Yang, Y; Chan, K C; Liu, C T

    2016-01-01

    Metallic glasses (MGs) are notorious for the poor macroscopic ductility and to overcome the weakness various intrinsic and extrinsic strategies have been proposed in past decades. Among them, the metal coating is regarded as a flexible and facile approach, yet the physical origin is poorly understood due to the complex nature of shear banding process. Here, we studied the origin of ductile enhancement in the Cu-coating both experimentally and theoretically. By examining serrated shear events and their stability of MGs, we revealed that the thin coating layer plays a key role in stopping the final catastrophic failure of MGs by slowing down shear band dynamics and thus retarding its attainment to a critical instable state. The mechanical analysis on interplay between the coating layer and shear banding process showed the enhanced shear stability mainly comes from the lateral tension of coating layer induced by the surface shear step and the bonding between the coating layer and MGs rather than the layer thickness is found to play a key role in contributing to the shear stability. PMID:27271435

  18. Origin of Shear Stability and Compressive Ductility Enhancement of Metallic Glasses by Metal Coating

    NASA Astrophysics Data System (ADS)

    Sun, B. A.; Chen, S. H.; Lu, Y. M.; Zhu, Z. G.; Zhao, Y. L.; Yang, Y.; Chan, K. C.; Liu, C. T.

    2016-06-01

    Metallic glasses (MGs) are notorious for the poor macroscopic ductility and to overcome the weakness various intrinsic and extrinsic strategies have been proposed in past decades. Among them, the metal coating is regarded as a flexible and facile approach, yet the physical origin is poorly understood due to the complex nature of shear banding process. Here, we studied the origin of ductile enhancement in the Cu-coating both experimentally and theoretically. By examining serrated shear events and their stability of MGs, we revealed that the thin coating layer plays a key role in stopping the final catastrophic failure of MGs by slowing down shear band dynamics and thus retarding its attainment to a critical instable state. The mechanical analysis on interplay between the coating layer and shear banding process showed the enhanced shear stability mainly comes from the lateral tension of coating layer induced by the surface shear step and the bonding between the coating layer and MGs rather than the layer thickness is found to play a key role in contributing to the shear stability.

  19. Characteristic properties of the Casimir free energy for metal films deposited on metallic plates

    NASA Astrophysics Data System (ADS)

    Klimchitskaya, G. L.; Mostepanenko, V. M.

    2016-04-01

    The Casimir free energy and pressure of thin metal films deposited on metallic plates are considered using the Lifshitz theory and the Drude and plasma model approaches to the role of conduction electrons. The bound electrons are taken into account by using the complete optical data of film and plate metals. It is shown that for films of several tens of nanometers thickness the Casimir free energy and pressure calculated using these approaches differ by hundreds and thousands percent and can be easily discriminated experimentally. According to our results, the free energy of a metal film does not vanish in the limiting case of ideal metal if the Drude model approach is used in contradiction with the fact that the fluctuating field cannot penetrate in its interior. Numerical computations of the Casimir free energy and pressure of Ag and Au films deposited on Cu and Al plates have been performed using both theoretical approaches. It is shown that the free energy of a film can be both negative and positive depending on the metals used. For a Au film on a Ag plate and vice versa the Casimir energy of a film changes its sign with increasing film thickness. Applications of the obtained results for resolving the Casimir puzzle and the problem of stability of thin films are discussed.

  20. Plasma-sprayed metal-glass fluoride coatings for lubrication to 1170 K (1650 F)

    NASA Technical Reports Server (NTRS)

    Sliney, H. E.

    1974-01-01

    Plasma spray of Nichrome matrix composite contains dispersed glass for oxidation protection and calcium fluoride for lubrication. Coatings can be applied to bearing journals and bearing bores. Coating was easily machinable and had excellent bond strength on substrate metal.

  1. Ellipsometry study on gold-nanoparticle-coated gold thin film for biosensing application

    PubMed Central

    Moirangthem, Rakesh Singh; Chang, Yia-Chung; Wei, Pei-Kuen

    2011-01-01

    The amplified plasmonic response from various distributions of gold nanoparticles (AuNPs) coated on top of gold thin film was studied via ellipsometry under total internal reflection mode. The surface plasmon resonance dip can be tuned from the visible to near infrared by simply varying the AuNP concentration. Theoretical modeling based on effective medium theory with a multi-slice model has been employed to fit the experimental results. Additionally, this experimental tool has been further extended to study bio-molecular interactions with metal surfaces as well as in studying protein-protein interaction without any labeling. Hence, this technique could provide a non-destructive way of designing tunable label-free optical biosensors with very high sensitivity. PMID:21991549

  2. Electrocatalytic determination of paraquat using a nafion film coated glassy carbon electrode.

    PubMed

    Lu, T H; Sun, I W

    2000-11-01

    A nafion film coated glassy carbon electrode (NFGCE) was employed for the determination of paraquat. Paraquat was accumulated onto NFGCE by the cation-exchange feature of nafion at open circuit potential in basic medium followed by cathodic differential pulse voltammetric (CDPV) determination in a medium containing permanganate ions. The sensitivity for the determination of paraquat was improved through the electrocatalytic reduction of permanganate by the reduced paraquat. With 3-min accumulation, the analytical signal versus concentration dependence was linear from 1.0 to 100 ppb with a detection limit of 0.5 ppb. The interference from common metal ions was minimized by addition of ethylenediaminetetraacetate (EDTA) into the sample solution. The use of nafion also improves the resistance to interference from surfactants.

  3. Method of applying a bond coating and a thermal barrier coating on a metal substrate, and related articles

    DOEpatents

    Hasz, Wayne Charles; Borom, Marcus Preston

    2002-01-01

    A method for applying at least one bond coating on a surface of a metal-based substrate is described. A foil of the bond coating material is first attached to the substrate surface and then fused thereto, e.g., by brazing. The foil is often initially prepared by thermally spraying the bond coating material onto a removable support sheet, and then detaching the support sheet. Optionally, the foil may also include a thermal barrier coating applied over the bond coating. The substrate can be a turbine engine component.

  4. Apatite coating on anionic and native collagen films by an alternate soaking process.

    PubMed

    Góes, J C; Figueiró, S D; Oliveira, A M; Macedo, A A M; Silva, C C; Ricardo, N M P S; Sombra, A S B

    2007-09-01

    The present study focuses on apatite coating on collagen films, with various different densities of carboxyl groups, using an alternate soaking process. Anionic collagen (AC), which has different densities of carboxylic groups compared to native collagen (NC), was obtained by hydrolysis of carboxyamides of asparagine and glutamine residues. From X-ray diffraction analysis, apatite was found to be coated on AC and NC films. Peaks ascribed to apatite were observed at 26 degrees and 32 degrees in the diffraction patterns of hydroxyapatite crystals. The amount of apatite coated on both AC and NC collagen films continued to increase up to 100 reaction cycles. However, there is a significant difference in apatite coating between the two films. The amount of apatite formed on the surface of AC film increased 1.24 times faster than on NC film. The scanning electron photomicrograph images of the mineralized NC and the AC film coatings formed after 100cycles show that regular porous apatite coating had formed within the collagen fibrils. These results suggest that the higher content of carboxyl groups in AC plays an effective role in the heterogeneous nucleation of apatite in the body environment.

  5. Protecting BOPP film from UV degradation with an atomic layer deposited titanium oxide surface coating

    NASA Astrophysics Data System (ADS)

    Lahtinen, Kimmo; Maydannik, Philipp; Seppänen, Tarja; Cameron, David C.; Johansson, Petri; Kotkamo, Sami; Kuusipalo, Jurkka

    2013-10-01

    Titanium oxide layers were deposited onto a BOPP film by atomic layer deposition in order to prevent UV degradation of the film. The coatings were deposited in a low-temperature process at 80 °C by using tetrakis(dimethylamido)titanium and ozone as titanium and oxygen precursors, respectively. UV block characteristics of the coatings and their effect on the polymer were measured by using UV-vis and IR spectrometry, and differential scanning calorimetry. According to the results, the coatings provided a considerable decrease in the photodegradation of the BOPP film during UV exposure. IR spectra showed that during a 6-week UV exposure, a 67 nm titanium oxide coating was able to almost completely prevent the formation of photodegradation products in the film. The mechanical properties of the film were also protected by the coating, but as opposed to what the IR study suggested they were still somewhat compromised by the UV light. After a 6-week exposure, the tensile strength and elongation at break of the 67 nm titanium oxide coated film decreased to half of the values measured before the treatment. This should be compared to the complete degradation suffered by the uncoated base sheet already after only 4 weeks of treatment. The results show that nanometre scale inorganic films deposited by ALD show a promising performance as effective UV protection for BOPP substrates.

  6. On the use, characterization and performance of silane coupling agents between organic coatings and metallic or ceramic substrates

    NASA Astrophysics Data System (ADS)

    van Ooij, W. J.; Zhang, B. C.; Conners, K. D.; Hörnström, S.-E.

    1996-01-01

    Examples are given of the use of organofunctional silane coupling agents for promoting bonding between organic coatings and metallic or ceramic (i.e. oxide) substrates. The orientation of the silane molecules and the type of bonding with the metal oxide can be determined successfully by Time-of-Flight SIMS. Oriented films of aminosilanes are demonstrated to be unstable in air. A prerinse with an inorganic silicate is introduced as a suitable method for masking the ubiquitous carbonaceous contamination at the metal surface, thus promoting the proper orientation and covalent bonding. Some practical applications are described, such as the pretreatment of Galvalume■ surfaces as a replacement of existing chromate treatments in coil coating applications. Electrochemical Impedance Spectroscopy (EIS) is shown to be a powerful tool for studying the performance of the silane treatment under a paint.

  7. Quartz crystal microbalance sample stage for in situ characterization of thickness and surface morphology of spin coated polymer films

    SciTech Connect

    Rao Nanxia; Xie Xin; Wielizcka, David; Zhu Daming

    2006-11-15

    A miniature spin coating stage is developed for in situ characterization of the thickness and the surface morphology of spin coated polymer films using quartz crystal microbalance (QCM) and atomic force microscopy. The spin coated polystyrene films deposited on gold surfaces from solutions using the stage were found to be uniform; the thickness of the films varied linearly with the polystyrene concentration in solution. The film thickness determined by the QCM agree with that from ellipsometry measurements.

  8. Understanding Solidification of Polythiophene Thin Films during Spin-Coating: Effects of Spin-Coating Time and Processing Additives

    PubMed Central

    Na, Jin Yeong; Kang, Boseok; Sin, Dong Hun; Cho, Kilwon; Park, Yeong Don

    2015-01-01

    Spin-coating has been used extensively in the fabrication of electronic devices; however, the effects of the processing parameters have not been fully explored. Here, we systematically characterize the effects of the spin-coating time on the microstructure evolution during semiconducting polymer solidification in an effort to establish the relationship between this parameter and the performances of the resulting polymer field-effect transistors (FETs). We found that a short spin-coating time of a few seconds dramatically improve the morphology and molecular order in a conjugated polymer thin film because the π-π stacking structures formed by the polymer molecules grow slowly and with a greater degree of order due to the residual solvent present in the wet film. The improved ordering is correlated with improved charge carrier transport in the FETs prepared from these films. We also demonstrated the effects of various processing additives on the resulting FET characteristics as well as on the film drying behavior during spin-coating. The physical properties of the additives are found to affect the film drying process and the resulting device performance. PMID:26299676

  9. Understanding Solidification of Polythiophene Thin Films during Spin-Coating: Effects of Spin-Coating Time and Processing Additives

    NASA Astrophysics Data System (ADS)

    Na, Jin Yeong; Kang, Boseok; Sin, Dong Hun; Cho, Kilwon; Park, Yeong Don

    2015-08-01

    Spin-coating has been used extensively in the fabrication of electronic devices; however, the effects of the processing parameters have not been fully explored. Here, we systematically characterize the effects of the spin-coating time on the microstructure evolution during semiconducting polymer solidification in an effort to establish the relationship between this parameter and the performances of the resulting polymer field-effect transistors (FETs). We found that a short spin-coating time of a few seconds dramatically improve the morphology and molecular order in a conjugated polymer thin film because the π-π stacking structures formed by the polymer molecules grow slowly and with a greater degree of order due to the residual solvent present in the wet film. The improved ordering is correlated with improved charge carrier transport in the FETs prepared from these films. We also demonstrated the effects of various processing additives on the resulting FET characteristics as well as on the film drying behavior during spin-coating. The physical properties of the additives are found to affect the film drying process and the resulting device performance.

  10. 21 CFR 888.3565 - Knee joint patellofemorotibial metal/polymer porous-coated uncemented prosthesis.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Knee joint patellofemorotibial metal/polymer... Devices § 888.3565 Knee joint patellofemorotibial metal/polymer porous-coated uncemented prosthesis. (a) Identification. A knee joint patellofemorotibial metal/polymer porous-coated uncemented prosthesis is a...

  11. 21 CFR 888.3565 - Knee joint patellofemorotibial metal/polymer porous-coated uncemented prosthesis.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Knee joint patellofemorotibial metal/polymer... Devices § 888.3565 Knee joint patellofemorotibial metal/polymer porous-coated uncemented prosthesis. (a) Identification. A knee joint patellofemorotibial metal/polymer porous-coated uncemented prosthesis is a...

  12. 21 CFR 888.3565 - Knee joint patellofemorotibial metal/polymer porous-coated uncemented prosthesis.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Knee joint patellofemorotibial metal/polymer... Devices § 888.3565 Knee joint patellofemorotibial metal/polymer porous-coated uncemented prosthesis. (a) Identification. A knee joint patellofemorotibial metal/polymer porous-coated uncemented prosthesis is a...

  13. 21 CFR 888.3565 - Knee joint patellofemorotibial metal/polymer porous-coated uncemented prosthesis.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Knee joint patellofemorotibial metal/polymer... Devices § 888.3565 Knee joint patellofemorotibial metal/polymer porous-coated uncemented prosthesis. (a) Identification. A knee joint patellofemorotibial metal/polymer porous-coated uncemented prosthesis is a...

  14. 21 CFR 888.3565 - Knee joint patellofemorotibial metal/polymer porous-coated uncemented prosthesis.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Knee joint patellofemorotibial metal/polymer... Devices § 888.3565 Knee joint patellofemorotibial metal/polymer porous-coated uncemented prosthesis. (a) Identification. A knee joint patellofemorotibial metal/polymer porous-coated uncemented prosthesis is a...

  15. Functionalized Antimicrobial Composite Thin Films Printing for Stainless Steel Implant Coatings.

    PubMed

    Floroian, Laura; Ristoscu, Carmen; Mihailescu, Natalia; Negut, Irina; Badea, Mihaela; Ursutiu, Doru; Chifiriuc, Mariana Carmen; Urzica, Iuliana; Dyia, Hussien Mohammed; Bleotu, Coralia; Mihailescu, Ion N

    2016-01-01

    In this work we try to address the large interest existing nowadays in the better understanding of the interaction between microbial biofilms and metallic implants. Our aimed was to identify a new preventive strategy to control drug release, biofilm formation and contamination of medical devices with microbes. The transfer and printing of novel bioactive glass-polymer-antibiotic composites by Matrix-Assisted Pulsed Laser Evaporation into uniform thin films onto 316 L stainless steel substrates of the type used in implants are reported. The targets were prepared by freezing in liquid nitrogen mixtures containing polymer and antibiotic reinforced with bioglass powder. The cryogenic targets were submitted to multipulse evaporation by irradiation with an UV KrF* (λ = 248 nm, τFWHM ≤ 25 ns) excimer laser source. The prepared structures were analyzed by infrared spectroscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy and profilometry, before and after immersion in physiological fluids. The bioactivity and the release of the antibiotic have been evaluated. We showed that the incorporated antibiotic underwent a gradually dissolution in physiological fluids thus supporting a high local treatment efficiency. Electrochemical measurements including linear sweep voltammetry and impedance spectroscopy studies were carried out to investigate the corrosion resistance of the coatings in physiological environments. The in vitro biocompatibility assay using the MG63 mammalian cell line revealed that the obtained nanostructured composite films are non-cytotoxic. The antimicrobial effect of the coatings was tested against Staphylococcus aureus and Escherichia coli strains, usually present in implant-associated infections. An anti-biofilm activity was evidenced, stronger against E. coli than the S. aureus strain. The results proved that the applied method allows for the fabrication of implantable biomaterials which shield metal ion release and possess

  16. Deposition of Metal Oxide Films from Metal-EDTA Complexes by Flame Spray Technique

    NASA Astrophysics Data System (ADS)

    Komatsu, Keiji; Sekiya, Tetsuo; Toyama, Ayumu; Hasebe, Yasuhiro; Nakamura, Atsushi; Noguchi, Masahiro; Li, Yu; Ohshio, Shigeo; Akasaka, Hiroki; Muramatsu, Hiroyuki; Saitoh, Hidetoshi

    2014-06-01

    R2O3 (R = Y, Eu, Er) metal oxides were synthesized from metal-ethylenediaminetetraacetic acid (EDTA) complexes using a flame spray technique. As this technique enables high deposition rates, films with thickness of several tens of micrometers were obtained. Films of yttria, europia, and erbia phase were synthesized on stainless-steel substrates with reaction assistance by H2-O2 combustion gas. The oxide films consisted of the desired crystalline phase with micropores. The porosity of the films was in the range of 6-15%, varying with the metal used. These results suggest that the true density of the metal oxide obtained from metal-EDTA powder through the thermal reaction process plays an important role in achieving film with the desired porosity.

  17. Solid film lubricants and thermal control coatings flown aboard the EOIM-3 MDA sub-experiment

    SciTech Connect

    Murphy, T.J.; David, K.E.; Babel, H.W.

    1995-02-01

    Additional experimental data were desired to support the selection of candidate thermal control coatings and solid film lubricants for the McDonnell Douglas Aerospace (MDA) Space Station hardware. The third Evaluation of Oxygen Interactions With Materials Mission (EOIM-3) flight experiment presented an opportunity to study the effects of the low Earth orbit environment on thermal control coatings and solid film lubricants. MDA provided five solid film lubricants and two anodic thermal control coatings for EOIM-3. The lubricant sample set consisted of three solid film lubricants with organic binders one solid film lubricant with an inorganic binder, and one solid film lubricant with no binder. The anodize coating sample set consisted of undyed sulfuric acid anodize and cobalt sulfide dyed sulfuric acid anodize, each on two different substrate aluminum alloys. The organic and inorganic binders in the solid film lubricants experienced erosion, and the lubricating pigments experienced oxidation. MDA is continuing to assess the effect of exposure to the low Earth orbit environment on the life and friction properties of the lubricants. Results to date support the design practice of shielding solid film lubricants from the low Earth orbit environment. Post-flight optical property analysis of the anodized specimens indicated that there were limited contamination effects and some atomic oxygen and ultraviolet radiation effects. These effects appeared to be within the values predicted by simulated ground testing and analysis of these materials, and they were different for each coating and substrate.

  18. Solid film lubricants and thermal control coatings flown aboard the EOIM-3 MDA sub-experiment

    NASA Technical Reports Server (NTRS)

    Murphy, Taylor J.; David, Kaia E.; Babel, Hank W.

    1995-01-01

    Additional experimental data were desired to support the selection of candidate thermal control coatings and solid film lubricants for the McDonnell Douglas Aerospace (MDA) Space Station hardware. The third Evaluation of Oxygen Interactions With Materials Mission (EOIM-3) flight experiment presented an opportunity to study the effects of the low Earth orbit environment on thermal control coatings and solid film lubricants. MDA provided five solid film lubricants and two anodic thermal control coatings for EOIM-3. The lubricant sample set consisted of three solid film lubricants with organic binders one solid film lubricant with an inorganic binder, and one solid film lubricant with no binder. The anodize coating sample set consisted of undyed sulfuric acid anodize and cobalt sulfide dyed sulfuric acid anodize, each on two different substrate aluminum alloys. The organic and inorganic binders in the solid film lubricants experienced erosion, and the lubricating pigments experienced oxidation. MDA is continuing to assess the effect of exposure to the low Earth orbit environment on the life and friction properties of the lubricants. Results to date support the design practice of shielding solid film lubricants from the low Earth orbit environment. Post-flight optical property analysis of the anodized specimens indicated that there were limited contamination effects and some atomic oxygen and ultraviolet radiation effects. These effects appeared to be within the values predicted by simulated ground testing and analysis of these materials, and they were different for each coating and substrate.

  19. Layer-by-Layer Deposition with Polymers Containing Nitrilotriacetate, A Convenient Route to Fabricate Metal- and Protein-Binding Films.

    PubMed

    Wijeratne, Salinda; Liu, Weijing; Dong, Jinlan; Ning, Wenjing; Ratnayake, Nishanka Dilini; Walker, Kevin D; Bruening, Merlin L

    2016-04-27

    This paper describes a convenient synthesis of nitrilotriacetate (NTA)-containing polymers and subsequent layer-by-layer adsorption of these polymers on flat surfaces and in membrane pores. The resulting films form NTA-metal-ion complexes and capture 2-3 mmol of metal ions per mL of film. Moreover, these coatings bind multilayers of polyhistidine-tagged proteins through association with NTA-metal-ion complexes. Inclusion of acrylic acid repeat units in NTA-containing copolymers promotes swelling to increase protein binding in films on Au-coated wafers. Adsorption of NTA-containing films in porous nylon membranes gives materials that capture ∼46 mg of His-tagged ubiquitin per mL. However, the binding capacity decreases with the protein molecular weight. Due to the high affinity of NTA for metal ions, the modified membranes show modest leaching of Ni(2+) in binding and rinsing buffers. Adsorption of NTA-containing polymers is a simple method to create metal- and protein-binding films and may, with future enhancement of stability, facilitate development of disposable membranes that rapidly purify tagged proteins. PMID:27042860

  20. Method of synthesizing metal doped diamond-like carbon films

    NASA Technical Reports Server (NTRS)

    Ueno, Mayumi (Inventor); Sunkara, Mahendra Kumar (Inventor)

    2003-01-01

    A method of synthesizing metal doped carbon films by placing a substrate in a chamber with a selected amount of a metalorganic compound. An electron cyclotron resonance is applied to the chamber in order to vaporize the metalorganic compound. The resonance is applied to the chamber until a metal doped carbon film is formed. The metalorganic compound is preferably selected from the group consisting of an organic salt of ruthenium, palladium, gold or platinum.

  1. Osmium conductive metal coating for SEM specimen using sublimated osmium tetroxide in negative glow phase of DC glow discharge.

    PubMed

    Tanaka, A

    1994-08-01

    A new method of osmium conductive metal coating for scanning electron microscopy specimens using osmium tetroxide in direct current glow discharge and its apparatus have been devised. Anode and cathode plates are placed in a gas reactor, sublimated osmium tetroxide is introduced, and glow discharge is generated. As a result, the gas between the electrodes instantaneously becomes plasma. At the specimen surface, which is placed in the negative glow phase on the cathode plate, positively ionized osmium molecules are directly adhered and deposited, thereby leaving a completely amorphous metal coating of osmium. As a result, the formed coating precisely matched the fine structure of the specimen surface, and even when irradiated with a strong electron beam was free of heat damage, electrification and contamination. The secondary electron emission efficiency of the coating was also good. Furthermore, no granularity of the film surface was observed even when viewed at a high magnification. In this way, a superior osmium conductive metal coating was obtained. PMID:7996076

  2. Shear-alignment of metal-containing block copolymer thin films for nanofabrication

    NASA Astrophysics Data System (ADS)

    Kim, So Youn; Register, Richard; Gwyther, Jessica; Manners, Ian; Chaikin, Paul

    2013-03-01

    Cylinder-forming block copolymers can be used as etch masks for the fabrication of nanowire grids, with both fine resolution and scalability. However, achieving a high aspect ratio in these nanostructures, where reactive ion etching is employed for pattern transfer, requires strong etch contrast between two blocks of the copolymer. We achieve this strong contrast by using metal-containing block copolymers: materials which either contain metal as synthesized, or which can be selectively metallized after deposition as thin films. In the first case, iron-containing polystyrene-b-poly(ferrocenylisopropylmethylsilane) (PS-PFS) forming PFS cylinders was employed, and a spin-coated film was aligned by shearing with a polydimethylsiloxane pad. In the second case, polystyrene-b-poly-2-vinylpyridine (PS-P2VP) was deposited as a film, shear-aligned, and then platinum was selectively sequestered within the P2VP cylinders by brief soaking in an aqueous solution of a Pt salt. In both cases, shear stress produced alignment over centimeter-scale areas; this alignment was retained for PS-P2VP during the selective metallization. The line pattern in these aligned block copolymer thin films is then transferred via reactive ion etching into amorphous silicon deposited onto a quartz wafer to fabricate silicon nanowire grid polarizers which can operate at deep ultraviolet wavelengths.

  3. Transferred metal electrode films for large-area electronic devices

    SciTech Connect

    Yang, Jin-Guo; Kam, Fong-Yu; Chua, Lay-Lay

    2014-11-10

    The evaporation of metal-film gate electrodes for top-gate organic field-effect transistors (OFETs) limits the minimum thickness of the polymer gate dielectric to typically more than 300 nm due to deep hot metal atom penetration and damage of the dielectric. We show here that the self-release layer transfer method recently developed for high-quality graphene transfer is also capable of giving high-quality metal thin-film transfers to produce high-performance capacitors and OFETs with superior dielectric breakdown strength even for ultrathin polymer dielectric films. Dielectric breakdown strengths up to 5–6 MV cm{sup −1} have been obtained for 50-nm thin films of polystyrene and a cyclic olefin copolymer TOPAS{sup ®} (Zeon). High-quality OFETs with sub-10 V operational voltages have been obtained this way using conventional polymer dielectrics and a high-mobility polymer semiconductor poly[2,5-bis(3-tetradecylthiophene-2-yl)thieno[3,2-b]thiophene-2,5-diyl]. The transferred metal films can make reliable contacts without damaging ultrathin polymer films, self-assembled monolayers and graphene, which is not otherwise possible from evaporated or sputtered metal films.

  4. Rotary feeding system for metallic coating installation by electrodeposition

    NASA Astrophysics Data System (ADS)

    Stănescu, A.; Alecusan, A. M.; Dimitescu, A.

    2016-08-01

    The paper aims to present an alternative feeding system for metallic coatings lines by electrodeposition which lends itself to the circular arrangement of the cuvettes used in such plants. The novelty lies both, in the arrangement of the electrodeposition installation components and mechanical feeding and transport system for parts to be electrodeposited. The control and actuation system of this type of installation simplifies. Nevertheless, all these increase the system reliability and run lower maintenance costs, without adversely affecting the quality of the end product. The paper presents the justification for reducing the total energy consumption in the electrodeposition process, too.

  5. Time-resolved thermal transport in compositionally modulated metal films

    SciTech Connect

    Clemens, B.M.; Eesley, G.L.; Paddock, C.A.

    1988-01-15

    We report on investigations of one-dimensional thermal transport in compositionally modulated metal films produced with a systematic variation in atomic lattice mismatch. In the case of Ni-Cu, Ni-Mo, Ni-Ti, and Ni-Zr, we observe the relative effects of interfacial disorder on thermal diffusion. Our observations demonstrate the thermal impedance of a single metal-metal interface and indicate that thermal diffusion in a bilayer film is strongly influenced by the interface between contacting metal pairs. This study is made possible by picosecond time-resolved thermoreflectance measurements which probe thermal transport perpendicular to the film plane. This technique can impact on our understanding of electron scattering and transport across metallic boundaries, and it provides a means of inferring electrical transport properties.

  6. Ubiquitous pentacene monolayer on metals deposited onto pentacene films.

    PubMed

    Jaeckel, B; Sambur, J B; Parkinson, B A

    2007-11-01

    Photoelectron spectroscopy (XPS and UPS) was used to study the deposition of metal layers (Ag, Cu, and Au) onto pentacene films. Very low work functions were measured (PhiAg = 3.91 eV, PhiCu = 3.93 eV, and PhiAu = 4.3 eV) for all of the metals, in agreement with results from the literature. The intensities of the C 1s core-level signals from pentacene that were monitored during stepwise metal deposition leveled off at a value of about 30% of a thick pentacene film. This C 1s intensity is comparable to that of one monolayer of pentacene deposited onto the respective metal. The valence band spectra of metals deposited onto pentacene and spectra collected for pentacene deposited onto bare metal surfaces are very similar. These findings lead to the conclusion that approximately one monolayer of pentacene is always present on top of the freshly deposited metal film, which explains the very low work function of the metals when they are deposited onto organic films. We expect similar behavior with other nonreactive metals deposited onto stable organic layers.

  7. Tamarindus indica pectin blend film composition for coating tablets with enhanced adhesive force strength.

    PubMed

    Khurana, Rajneet; Singh, Kuldeep; Sapra, Bharti; Tiwary, A K; Rana, Vikas

    2014-02-15

    Tablet coating is the most useful method to improve tablet texture, odour and mask taste. Thus, the present investigation was aimed at developing an industrially acceptable aqueous tablet coating material. The physico-chemical, electrical and SEM investigations ensures that blending of Tamarindus indica (Linn.) pectin (TP) with chitosan gives water resistant film texture. Therefore, CH-TP (60:40) spray coated tablets were prepared. The evaluation of CH-TP coated tablets showed enhanced adhesive force strength (between tablet surface to coat) and negligible cohesive force strength (between two tablets) both evaluated using texture analyzer. The comparison of CH-TP coated tablets with Eudragit coated tablets further supported superiority of the former material. Thus, the findings pointed towards the potential of CH-TP for use as a tablet coating material in food as well as pharmaceutical industry.

  8. Plasma treatment of thin film coated with graphene flakes for the reduction of sheet resistance.

    PubMed

    Kim, Sung Hee; Oh, Jong Sik; Kim, Kyong Nam; Seo, Jin Seok; Jeon, Min Hwan; Yang, Kyung Chae; Yeom, Geun Young

    2013-12-01

    We investigated the effects of plasma treatment on the sheet resistance of thin films spray-coated with graphene flakes on polyethylene terephthalate (PET) substrates. Thin films coated with graphene flakes show high sheet resistance due to defects within graphene edges, domains, and residual oxygen content. Cl2 plasma treatment led to decreased sheet resistance when treatment time was increased, but when thin films were treated for too long the sheet resistance increased again. Optimum treatment time was related to film thickness. The reduction of sheet resistance may be explained by the donation of holes due to forming pi-type covalent bonds of Cl with carbon atoms on graphene surfaces, or by C--Cl bonding at the sites of graphene defects. However, due to radiation damage caused by plasma treatment, sheet resistance increased with increased treatment time. We found that the sheet resistance of PET film coated with graphene flakes could be decreased by 50% under optimum conditions. PMID:24266197

  9. Evaluation of an Innovative Use of Removable Thin Film Coating Technology for the Abatement of Hazardous Contaminants

    PubMed Central

    Lumia, Margaret E.; Gentile, Charles; Gochfeld, Michael; Efthimion, Philip; Robson, Mark

    2015-01-01

    This study evaluates a new decontamination technique for the mitigation and abatement of hazardous particulates. The traditional decontamination methods used to clean facilities and equipment are time-consuming, prolonging workers' exposure time, may generate airborne hazards, and can be expensive. The use of removable thin film coating as a decontamination technique for surface contamination proved to be a more efficient method of decontamination. This method was tested at three different sites on different hazardous metals. One application of the coating reduced the levels of these metals 90% and had an average reduction of one magnitude. The paired t-tests that were performed for each metal demonstrated that there was a statistically significant reduction of the metal after the use of the coating: lead (p = 0.03), beryllium (p = 0.05), aluminum (p = 0.006), iron (p = 0.0001), and copper (p = 0.004). The Kendall tau-b correlation coefficient demonstrates that there was a positive correlation between the initial levels of contamination and the removal efficiency for all the samples taken from different locations on the floor for each of the three sites. This new decontamination technique worked efficiently, requiring only one application, which decreased exposure time and did not generate any airborne dust. PMID:19437305

  10. Sol-gel antireflective coating on plastics

    DOEpatents

    Ashley, Carol S.; Reed, Scott T.

    1990-01-01

    An antireflection film made from a reliquified sol-gel hydrolyzation, condensation polymeric reaction product of a silicon, alkoxides and/or metal alkoxides, or mixtures thereof. The film is particularly useful for coating plastics.

  11. Sol-gel antireflective coating on plastics

    DOEpatents

    Ashley, C.S.; Reed, S.T.

    1988-01-26

    An antireflection film made from reliquified sol-gel hydrolyzation, condensation polymeric reaction product of a silicon, alkoxides and/or metal alkoxides, or mixtures thereof. The film is particularly useful for coating plastics.

  12. 21 CFR 888.3670 - Shoulder joint metal/polymer/metal nonconstrained or semi-constrained porous-coated uncemented...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Shoulder joint metal/polymer/metal nonconstrained... ORTHOPEDIC DEVICES Prosthetic Devices § 888.3670 Shoulder joint metal/polymer/metal nonconstrained or semi-constrained porous-coated uncemented prosthesis. (a) Identification. A shoulder joint...

  13. 21 CFR 888.3670 - Shoulder joint metal/polymer/metal nonconstrained or semi-constrained porous-coated uncemented...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Shoulder joint metal/polymer/metal nonconstrained... ORTHOPEDIC DEVICES Prosthetic Devices § 888.3670 Shoulder joint metal/polymer/metal nonconstrained or semi-constrained porous-coated uncemented prosthesis. (a) Identification. A shoulder joint...

  14. 21 CFR 888.3670 - Shoulder joint metal/polymer/metal nonconstrained or semi-constrained porous-coated uncemented...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Shoulder joint metal/polymer/metal nonconstrained... ORTHOPEDIC DEVICES Prosthetic Devices § 888.3670 Shoulder joint metal/polymer/metal nonconstrained or semi-constrained porous-coated uncemented prosthesis. (a) Identification. A shoulder joint...

  15. Silica coated noble metal nanoparticle hydrosols as supported catalyst precursors.

    PubMed

    Kong, Tung Shing Adam; Yu, Kai Man Kerry; Tsang, Shik Chi

    2006-04-01

    Synthesis of well-defined nanoparticles has been intensively pursued not only for their fundamental scientific interest, but also for many technological applications. One important development of the nanomaterial is in the area of chemical catalysis. We have now developed a new aqueous-based method for the synthesis of silica encapsulated noble metal nanoparticles in controlled dimensions. Thus, colloid stable silica encapsulated approximately 5 nm platinum nanoparticle is synthesized by a multi-step method. The thickness of the silica coating could be controlled using a different amount of silica precursor. These particles supported on a high surface area alumina are also demonstrated to display a superior hydrogenation activity and stability against metal sintering after thermal activation.

  16. [Coating of metal implants with the bioactive glass ceramics Ceravital].

    PubMed

    Strunz, V; Bunte, M; Gross, U M; Männer, K; Brömer, H; Deutscher, K

    1978-12-01

    The bioactive glass ceramic Ceravital forms a physicochemical bonding with bone which is capable of withstanding stress caused by tension. This glass ceramic may already be put to clinical use as replacement for minor osseous parts. However, physical data are limited for maximum stress withstanding or gracile whole ceramic implants. In this study, metal cylinders from an alloy of CoCrMo are initially coated with a bio-compatible adhesive layer of enamel, approximately 0,2 to 0,3 mm thick. The adhesive strength of this kind of enamel amounts to about 120 to 140 kp/cm2. After the enamelling process, the glass ceramic is pressed into the enamel in granules at a particle size of 100 to 200 micrometer. As the first results show, this new process is suitable for the combination of metal implant stability and tissue compatibility of glass ceramic.

  17. High-quality substrate for fluorescence enhancement using agarose-coated silica opal film.

    PubMed

    Xu, Ming; Li, Juan; Sun, Liguo; Zhao, Yuanjin; Xie, Zhuoying; Lv, Linli; Zhao, Xiangwei; Xiao, Pengfeng; Hu, Jing; Lv, Mei; Gu, Zhongze

    2010-08-01

    To improve the sensitivity of fluorescence detection in biochip, a new kind of substrates was developed by agarose coating on silica opal film. In this study, silica opal film was fabricated on glass substrate using the vertical deposition technique. It can provide stronger fluorescence signals and thus improve the detection sensitivity. After coating with agarose, the hybrid film could provide a 3D support for immobilizing sample. Comparing with agarose-coated glass substrate, the agarose-coated opal substrates could selectively enhance particular fluorescence signals with high sensitivity when the stop band of the silica opal film in the agarose-coated opal substrate overlapped the fluorescence emission wavelength. A DNA hybridization experiment demonstrated that fluorescence intensity of special type of agarose-coated opal substrates was about four times that of agarose-coated glass substrate. These results indicate that the optimized agarose-coated opal substrate can be used for improving the sensitivity of fluorescence detection with high quality and selectivity.

  18. Determination of tackiness of chitosan film-coated pellets exploiting minimum fluidization velocity.

    PubMed

    Fernández Cervera, M; Heinämäki, J; Räsänen, E; Antikainen, O; Nieto, O M; Iraizoz Colarte, A; Yliruusi, J

    2004-08-20

    The tackiness of aqueous chitosan film coatings and effects of anti-sticking agents on sticking tendency, were evaluated. A novel rapid method exploiting minimum fluidization velocity to determine tackiness was introduced and tested. The pressure difference over the miniaturized fluidized-bed was precisely recorded as a function of velocity of fluidization air. High molecular weight chitosan plasticized with glycerol was used as a film-forming agent. Magnesium stearate, titanium dioxide, colloidal silicon dioxide and glyceryl-1-monostearate (GMS) were studied as anti-sticking agents. Film coatings were performed in a miniaturized top-spray coater. The incorporation of anti-sticking agents led to a clear decrease in tackiness of the chitosan films, and magnesium stearate and GMS were shown the most effective. Film-coated pellets containing magnesium stearate and GMS as an anti-sticking agent were very easily fluidized (showing very low values of minimum fluidization velocity) and were thus classified as the best flowing and the least sticking samples. Both these additives were found anti-sticking agents of choice for aqueous chitosan film coatings. Determination of the experimental minimum fluidization velocity in a fluidized bed, is a useful and sensitive method of measuring the tackiness tendency of film-coated pellets. PMID:15288349

  19. Determination of tackiness of chitosan film-coated pellets exploiting minimum fluidization velocity.

    PubMed

    Fernández Cervera, M; Heinämäki, J; Räsänen, E; Antikainen, O; Nieto, O M; Iraizoz Colarte, A; Yliruusi, J

    2004-08-20

    The tackiness of aqueous chitosan film coatings and effects of anti-sticking agents on sticking tendency, were evaluated. A novel rapid method exploiting minimum fluidization velocity to determine tackiness was introduced and tested. The pressure difference over the miniaturized fluidized-bed was precisely recorded as a function of velocity of fluidization air. High molecular weight chitosan plasticized with glycerol was used as a film-forming agent. Magnesium stearate, titanium dioxide, colloidal silicon dioxide and glyceryl-1-monostearate (GMS) were studied as anti-sticking agents. Film coatings were performed in a miniaturized top-spray coater. The incorporation of anti-sticking agents led to a clear decrease in tackiness of the chitosan films, and magnesium stearate and GMS were shown the most effective. Film-coated pellets containing magnesium stearate and GMS as an anti-sticking agent were very easily fluidized (showing very low values of minimum fluidization velocity) and were thus classified as the best flowing and the least sticking samples. Both these additives were found anti-sticking agents of choice for aqueous chitosan film coatings. Determination of the experimental minimum fluidization velocity in a fluidized bed, is a useful and sensitive method of measuring the tackiness tendency of film-coated pellets.

  20. Pentek metal coating removal system: Baseline report; Summary

    SciTech Connect

    1997-07-31

    The Pentek metal coating removal system consists of the ROTO-PEEN Scaler, CORNER-CUTTER(R), and VAC-PAC(R). The system is designed to remove coatings from steel, concrete, brick, and wood. The Scaler uses 3M ROTO-PEEN tungsten carbide cutters, while the CORNER-CUTTER(R) uses solid needles for descaling activities. These are used with the VAC-PAC(R) vacuum system to capture dust and debris as removal of the coating takes place. The safety and health evaluation during the testing demonstration focused on two main areas of exposure: dust and noise. Dust exposure was minimal, but noise exposure was significant. Further testing for each exposure is recommended, since the outdoor environment where the testing demonstration took place may skew the results. It is feasible that dust and noise levels will be higher in an enclosed operating environment. Other areas of concern found were arm-hand vibration, whole-body vibration, ergonomics, heat stress, tripping hazards, electrical hazards, machine guarding, and lockout/tagout.

  1. In vitro biocompatibility response of Ti-Zr-Si thin film metallic glasses

    NASA Astrophysics Data System (ADS)

    Ke, J. L.; Huang, C. H.; Chen, Y. H.; Tsai, W. Y.; Wei, T. Y.; Huang, J. C.

    2014-12-01

    In this study, the bio-electrochemical response of the Ti-Zr-Si thin film metallic glasses (TFMGs) in simulated body fluid with different contents of titanium is measured via potentiostat. According to the results of bio-corrosion potential and current, as well as the polarization resistance, it is concluded that the Ti66Zr25Si9 TFMGs possess the highest bio-electrochemical resistance. With increasing content of titanium, the corrosion resistance becomes progressively higher. The passive current results reveal that amorphous alloys can form a more protective and denser passive film on the metallic glass surface than the crystalline materials. In addition, the mechanical performance of the Ti-Zr-Si TFMGs is better than the crystalline counterparts. As a result, the Ti-based TFMGs are considered to be potential materials for bio-coating applications.

  2. Dewetting Properties of Metallic Liquid Film on Nanopillared Graphene

    PubMed Central

    Li, Xiongying; He, Yezeng; Wang, Yong; Dong, Jichen; Li, Hui

    2014-01-01

    In this work, we report simulation evidence that the graphene surface decorated by carbon nanotube pillars shows strong dewettability, which can give it great advantages in dewetting and detaching metallic nanodroplets on the surfaces. Molecular dynamics (MD) simulations show that the ultrathin liquid film first contracts then detaches from the graphene on a time scale of several nanoseconds, as a result of the inertial effect. The detaching velocity is in the order of 10 m/s for the droplet with radii smaller than 50 nm. Moreover, the contracting and detaching behaviors of the liquid film can be effectively controlled by tuning the geometric parameters of the liquid film or pillar. In addition, the temperature effects on the dewetting and detaching of the metallic liquid film are also discussed. Our results show that one can exploit and effectively control the dewetting properties of metallic nanodroplets by decorating the surfaces with nanotube pillars. PMID:24487279

  3. Metal-insulator transition in films of doped semiconductor nanocrystals.

    PubMed

    Chen, Ting; Reich, K V; Kramer, Nicolaas J; Fu, Han; Kortshagen, Uwe R; Shklovskii, B I

    2016-03-01

    To fully deploy the potential of semiconductor nanocrystal films as low-cost electronic materials, a better understanding of the amount of dopants required to make their conductivity metallic is needed. In bulk semiconductors, the critical concentration of electrons at the metal-insulator transition is described by the Mott criterion. Here, we theoretically derive the critical concentration nc for films of heavily doped nanocrystals devoid of ligands at their surface and in direct contact with each other. In the accompanying experiments, we investigate the conduction mechanism in films of phosphorus-doped, ligand-free silicon nanocrystals. At the largest electron concentration achieved in our samples, which is half the predicted nc, we find that the localization length of hopping electrons is close to three times the nanocrystals diameter, indicating that the film approaches the metal-insulator transition.

  4. Dewetting properties of metallic liquid film on nanopillared graphene.

    PubMed

    Li, Xiongying; He, Yezeng; Wang, Yong; Dong, Jichen; Li, Hui

    2014-02-03

    In this work, we report simulation evidence that the graphene surface decorated by carbon nanotube pillars shows strong dewettability, which can give it great advantages in dewetting and detaching metallic nanodroplets on the surfaces. Molecular dynamics (MD) simulations show that the ultrathin liquid film first contracts then detaches from the graphene on a time scale of several nanoseconds, as a result of the inertial effect. The detaching velocity is in the order of 10 m/s for the droplet with radii smaller than 50 nm. Moreover, the contracting and detaching behaviors of the liquid film can be effectively controlled by tuning the geometric parameters of the liquid film or pillar. In addition, the temperature effects on the dewetting and detaching of the metallic liquid film are also discussed. Our results show that one can exploit and effectively control the dewetting properties of metallic nanodroplets by decorating the surfaces with nanotube pillars.

  5. An investigation of thin-film coating/substrate systems by nanoindentation

    SciTech Connect

    Li, J.; Thostenson, E.T.; Chou, T.W.; Riester, L.

    1998-04-01

    The indentation load-displacement behavior of three material systems tested with a Berkovich indenter has been examined. The materials studied were the substrate materials--silicon and polycarbonate, and the coating/substrate systems--diamond-like carbon (DLC) coating on silicon, and DLC coating on polycarbonate. They represent three material systems, namely, bulk, soft-coating/hard-substrate, and hard-coating on soft-substrate. Delaminations in the soft-coating/hard-substrate (DLC/Si) system and cracking in the hard-coating/soft-substrate system (DLC/Polycarbonate) were observed. Parallel to the experimental work, an elastic analytical effort has been made to examine the influence of the film thickness and the properties of the coating/substrate systems. Comparisons between the experimental data and analytical solutions of the load-displacement curves during unloading show good agreement. The analytical solution also suggests that the Young`s modulus and hardness of the thin film can not be measured accurately using Sneddon`s solution for bulk materials when the thickness of the film is comparable to the loading contact radius of the indenter. The elastic stress field analysis provides a basis for understanding the experimentally observed delaminations and cracking of the coating/substrate systems.

  6. Listeria monocytogenes inhibition by whey protein films and coatings incorporating lysozyme.

    PubMed

    Min, Seacheol; Harris, Linda J; Han, Jung H; Krochta, John M

    2005-11-01

    The effects of whey protein isolate (WPI) films and coatings incorporating lysozyme (LZ) on the inhibition of Listeria monocytogenes both in and on microbial media, as well as on cold-smoked salmon, were studied. The antimicrobial effects of LZ were examined using various growth media by turbidity and plate counting tests. Disc-covering and disc-surface-spreading tests were also used to evaluate the effects of WPI films incorporating LZ. Smoked salmon was used as a model food to test the antimicrobial effects of WPI coatings incorporating LZ, both initially and during storage at 4 and 10 degrees C for 35 days. Tensile properties (elastic modulus, tensile strength, and percentage of elongation), oxygen permeability, and color (Hunter L, a, and b) of WPI films with and without LZ were also compared. LZ inhibited L. monocytogenes in broth and on agar media. The number of cells surviving after LZ treatments depended on the type of media. WPI films incorporating 204 mg of LZ per g of film (dry basis) inhibited the growth of a preparation of 4.4 log CFU/cm2 L. monocytogenes. WPI coatings prepared with 25 mg of LZ per g of coating solution initially inactivated more than 2.4, 4.5, and 3.0 log CFU/g of L. monocytogenes, total aerobes, and yeasts and molds in smoked salmon samples, respectively. The WPI coatings incorporating LZ efficiently retarded the growth of L. monocytogenes at both 4 and 10 degrees C. The anti-L. monocytogenes effect of LZ-WPI coating was more noticeable when the coating was applied before inoculation than when the coating was applied after inoculation. Significantly higher elastic modulus values and lower percentage of elongation and oxygen permeability values were measured with the WPI films incorporating LZ than with the plain WPI films.

  7. Hierarchical opal grating films prepared by slide coating of colloidal dispersions in binary liquid media.

    PubMed

    Lee, Wonmok; Kim, Seulgi; Kim, Seulki; Kim, Jin-Ho; Lee, Hyunjung

    2015-02-15

    There are active researches on well ordered opal films due to their possible applications to various photonic devices. A recently developed slide coating method is capable of rapid fabrication of large area opal films from aqueous colloidal dispersion. In the current study, the slide coating of polystyrene colloidal dispersions in water/i-propanol (IPA) binary media is investigated. Under high IPA content in a dispersing medium, resulting opal film showed a deterioration of long range order, as well as a decreased film thickness due to dilution effect. From the binary liquid, the dried opal films exhibited the unprecedented topological groove patterns with varying periodic distances as a function of alcohol contents in the media. The groove patterns were consisted of the hierarchical structures of the terraced opal layers with periodic thickness variations. The origin of the groove patterns was attributed to a shear-induced periodic instability of colloidal concentration within a thin channel during the coating process which was directly converted to a groove patterns in a resulting opal film due to rapid evaporation of liquid. The groove periods of opal films were in the range of 50-500 μm, and the thickness differences between peak and valley of the groove were significantly large enough to be optically distinguishable, such that the coated films can be utilized as the optical grating film to disperse infra-red light. Utilizing a lowered hydrophilicity of water/IPA dispersant, an opal film could be successfully coated on a flexible Mylar film without significant dewetting problem. PMID:25460710

  8. Hierarchical opal grating films prepared by slide coating of colloidal dispersions in binary liquid media.

    PubMed

    Lee, Wonmok; Kim, Seulgi; Kim, Seulki; Kim, Jin-Ho; Lee, Hyunjung

    2015-02-15

    There are active researches on well ordered opal films due to their possible applications to various photonic devices. A recently developed slide coating method is capable of rapid fabrication of large area opal films from aqueous colloidal dispersion. In the current study, the slide coating of polystyrene colloidal dispersions in water/i-propanol (IPA) binary media is investigated. Under high IPA content in a dispersing medium, resulting opal film showed a deterioration of long range order, as well as a decreased film thickness due to dilution effect. From the binary liquid, the dried opal films exhibited the unprecedented topological groove patterns with varying periodic distances as a function of alcohol contents in the media. The groove patterns were consisted of the hierarchical structures of the terraced opal layers with periodic thickness variations. The origin of the groove patterns was attributed to a shear-induced periodic instability of colloidal concentration within a thin channel during the coating process which was directly converted to a groove patterns in a resulting opal film due to rapid evaporation of liquid. The groove periods of opal films were in the range of 50-500 μm, and the thickness differences between peak and valley of the groove were significantly large enough to be optically distinguishable, such that the coated films can be utilized as the optical grating film to disperse infra-red light. Utilizing a lowered hydrophilicity of water/IPA dispersant, an opal film could be successfully coated on a flexible Mylar film without significant dewetting problem.

  9. Surface modification of metallic cardiovascular stents by strongly adhering aliphatic polyester coatings.

    PubMed

    Jérôme, Christine; Aqil, Abdelhafid; Voccia, Samuël; Labaye, David-Emmanuel; Maquet, Véronique; Gautier, Sandrine; Bertrand, Olivier F; Jérôme, Robert

    2006-03-01

    This article reports on a novel two-step strategy for the coating of cardiovascular stents by strongly adhering biocompatible and biodegradable aliphatic polyesters. First, a precoating of poly(ethylacrylate) (PEA) was electrografted onto the metallic substrate by cathodic reduction of the parent monomer in dimethylformamide (DMF). The electrodeposition of PEA, in a good solvent of it, was confirmed by both Infra-red and Raman spectroscopies. The pendant ester groups of PEA were then chemically reduced into aluminum alkoxides, able to initiate the ring-opening polymerization (ROP) of either D,L-lactide (LA) or epsilon-caprolactone (CL). Growth of biodegradable PLA or PCL coatings from the adhering precoating was confirmed by both Infra-red and Raman spectroscopies, and directly observed by scanning electron microscopy (SEM). This type of coating can act as an anchoring layer for the subsequent casting of drug-loaded polyester films allowing the controlled release of antiproliferative agents for the treatment of in-stent restenosis. PMID:16317721

  10. Polyelectrolyte multilayer-calcium phosphate composite coatings for metal implants.

    PubMed

    Elyada, Alon; Garti, Nissim; Füredi-Milhofer, Helga

    2014-10-13

    The preparation of organic-inorganic composite coatings with the purpose to increase the bioactivity of bioinert metal implants was investigated. As substrates, glass plates and rough titanium surfaces (Ti-SLA) were employed. The method comprises the deposition of polyelectrolyte multilayers (PEMLs) followed by immersion of the coated substrate into a calcifying solution of low supersaturation (MCS). Single or mixed PEMLs were constructed from poly-L-lysine (PLL) alternating with poly-L-glutamate, (PGA), poly-L-aspartate (PAA), and/or chondroitin sulfate (CS). ATR-FTIR spectra reveal that (PLL/PGA)10 multilayers and mixed multilayers with a (PLL/PGA)5 base contain intermolecular β-sheet structures, which are absent in pure (PLL/PAA)10 and (PLL/CS)10 assemblies. All PEML coatings had a grainy topography with aggregate sizes and size distributions increasing in the order: (PLL/PGA)n < (PLL/PAA)n < (PLL/CS)n. In mixed multilayers with a (PLL/PGA)n base and a (PLL/PAA)n or (PLL/CS)n top, the aggregate sizes were greatly reduced. The PEMLs promoted calcium phosphate nucleation and early crystal growth, the intensity of the effect depending on the composition of the terminal layer(s) of the polymer. In contrast, crystal morphology and structure depended on the supersaturation, pH, and ionic strength of the MCS, rather than on the composition of the organic matrix. Crystals grown on both uncoated and coated substrates were mostly platelets of calcium deficient carbonate apatite, with the Ca/P ratio depending on the precipitation conditions. PMID:25105729

  11. Polyelectrolyte multilayer-calcium phosphate composite coatings for metal implants.

    PubMed

    Elyada, Alon; Garti, Nissim; Füredi-Milhofer, Helga

    2014-10-13

    The preparation of organic-inorganic composite coatings with the purpose to increase the bioactivity of bioinert metal implants was investigated. As substrates, glass plates and rough titanium surfaces (Ti-SLA) were employed. The method comprises the deposition of polyelectrolyte multilayers (PEMLs) followed by immersion of the coated substrate into a calcifying solution of low supersaturation (MCS). Single or mixed PEMLs were constructed from poly-L-lysine (PLL) alternating with poly-L-glutamate, (PGA), poly-L-aspartate (PAA), and/or chondroitin sulfate (CS). ATR-FTIR spectra reveal that (PLL/PGA)10 multilayers and mixed multilayers with a (PLL/PGA)5 base contain intermolecular β-sheet structures, which are absent in pure (PLL/PAA)10 and (PLL/CS)10 assemblies. All PEML coatings had a grainy topography with aggregate sizes and size distributions increasing in the order: (PLL/PGA)n < (PLL/PAA)n < (PLL/CS)n. In mixed multilayers with a (PLL/PGA)n base and a (PLL/PAA)n or (PLL/CS)n top, the aggregate sizes were greatly reduced. The PEMLs promoted calcium phosphate nucleation and early crystal growth, the intensity of the effect depending on the composition of the terminal layer(s) of the polymer. In contrast, crystal morphology and structure depended on the supersaturation, pH, and ionic strength of the MCS, rather than on the composition of the organic matrix. Crystals grown on both uncoated and coated substrates were mostly platelets of calcium deficient carbonate apatite, with the Ca/P ratio depending on the precipitation conditions.

  12. Germanium Lift-Off Masks for Thin Metal Film Patterning

    NASA Technical Reports Server (NTRS)

    Brown, Ari

    2012-01-01

    A technique has been developed for patterning thin metallic films that are, in turn, used to fabricate microelectronics circuitry and thin-film sensors. The technique uses germanium thin films as lift-off masks. This requires development of a technique to strip or undercut the germanium chemically without affecting the deposited metal. Unlike in the case of conventional polymeric lift-off masks, the substrate can be exposed to very high temperatures during processing (sputter deposition). The reason why polymeric liftoff masks cannot be exposed to very high temperatures (greater than 100 C) is because (a) they can become cross linked, making lift-off very difficult if not impossible, and (b) they can outgas nitrogen and oxygen, which then can react with the metal being deposited. Consequently, this innovation is expected to find use in the fabrication of transition edge sensors and microwave kinetic inductance detectors, which use thin superconducting films deposited at high temperature as their sensing elements. Transition edge sensors, microwave kinetic inductance detectors, and their circuitry are comprised of superconducting thin films, for example Nb and TiN. Reactive ion etching can be used to pattern these films; however, reactive ion etching also damages the underlying substrate, which is unwanted in many instances. Polymeric lift-off techniques permit thin-film patterning without any substrate damage, but they are difficult to remove and the polymer can outgas during thin-film deposition. The outgassed material can then react with the film with the consequence of altered and non-reproducible materials properties, which, in turn, is deleterious for sensors and their circuitry. The purpose of this innovation was to fabricate a germanium lift-off mask to be used for patterning thin metal films.

  13. Plasma-Etching of Spray-Coated Single-Walled Carbon Nanotube Films for Biointerfaces

    NASA Astrophysics Data System (ADS)

    Kim, Joon Hyub; Lee, Jun-Yong; Min, Nam Ki

    2012-08-01

    We present an effective method for the batch fabrication of miniaturized single-walled carbon nanotube (SWCNT) film electrodes using oxygen plasma etching. We adopted the approach of spray-coating for good adhesion of the SWCNT film onto a pre-patterned Pt support and used O2 plasma patterning of the coated films to realize efficient biointerfaces between SWCNT surfaces and biomolecules. By these approaches, the SWCNT film can be easily integrated into miniaturized electrode systems. To demonstrate the effectiveness of plasma-etched SWCNT film electrodes as biointerfaces, Legionella antibody was selected as analysis model owing to its considerable importance to electrochemical biosensors and was detected using plasma-etched SWCNT film electrodes and a 3,3',5,5'-tetramethyl-benzidine dihydrochloride/horseradish peroxidase (TMB/HRP) catalytic system. The response currents increased with increasing concentration of Legionella antibody. This result indicates that antibodies were effectively immobilized on plasma-etched and activated SWCNT surfaces.

  14. Effect of thermal cycling on stress in metallic films on ceramic substrates

    NASA Technical Reports Server (NTRS)

    Mattison, Edward M.; Vessot, Robert F. C.

    1990-01-01

    The hydrogen maser is the most stable frequency standard currently available for averaging intervals of hours to weeks. A major contributor to maser frequency variations is the maser's microwave resonant cavity: by means of the cavity pulling effect, a change in the cavity's resonance frequency produces a proportional change in the maser's output frequency. To minimize variations in the cavity's dimensions, and thus in its resonance frequency, maser cavities are often constructed of a low-expansivity glass-ceramic material coated on its surface with a conductive metallic film. It was previously shown that silver films like those used in SAO maser cavities develop tensile stress when cooled to room temperature after being fired onto the cavity, and that the stress in such films relaxes with time at a rate proportional to the level of stress. Stress relaxation in maser cavity coatings can alter the shape, and hence the resonance frequency, of the cavity, resulting in a slow variation in the maser's output frequency. The possibility was investigated of reversing the initial tensile stress by precooling the coated cavity material. It was hypothesized that cooling the material well below its normal working temperature and then warming it to its normal temperature would result in a lower tensile stress or even a compressive stress. Under such a condition stress relaxation, and thus any consequent frequency drifts, might be reduced or reversed.

  15. Amorphous metal formulations and structured coatings for corrosion and wear resistance

    DOEpatents

    Farmer, Joseph C.

    2011-12-13

    A system for coating a surface comprising providing a source of amorphous metal that contains more than 11 elements and applying the amorphous metal that contains more than 11 elements to the surface by a spray. Also a coating comprising a composite material made of amorphous metal that contains more than 11 elements. An apparatus for producing a corrosion-resistant amorphous-metal coating on a structure comprises a deposition chamber, a deposition source in the deposition chamber that produces a deposition spray, the deposition source containing a composite material made of amorphous metal that contains more than 11 elements, and a system that directs the deposition spray onto the structure.

  16. Amorphous metal formulations and structured coatings for corrosion and wear resistance

    DOEpatents

    Farmer, Joseph C.

    2014-07-15

    A system for coating a surface comprising providing a source of amorphous metal that contains more than 11 elements and applying the amorphous metal that contains more than 11 elements to the surface by a spray. Also a coating comprising a composite material made of amorphous metal that contains more than 11 elements. An apparatus for producing a corrosion-resistant amorphous-metal coating on a structure comprises a deposition chamber, a deposition source in the deposition chamber that produces a deposition spray, the deposition source containing a composite material made of amorphous metal that contains more than 11 elements, and a system that directs the deposition spray onto the structure.

  17. Aging of metal/hard-carbon films

    NASA Astrophysics Data System (ADS)

    Biederman, Hynek; Hlidek, Pavel; Pesicka, Josef; Slavinska, Danka; Stundzia, Virgilijus; Zemek, Joseph

    1996-04-01

    Unbalanced electromagnetron operated in Ar/n-hexane mixture was employed for deposition of composite Ag/C:H films. For comparison composite Ni/C:H films were prepared in a similar way using unbalanced planar magnetron with permanent magnets. Optical transmission measurements, TEM micrographs, and dc electrical measurements, were used to study ageing effects of the composites in the ambient atmosphere.

  18. Synthesis and characterization of ZnO nanostructures on noble-metal coated substrates

    NASA Astrophysics Data System (ADS)

    Dikovska, A. Og.; Atanasova, G. B.; Avdeev, G. V.; Nedyalkov, N. N.

    2016-06-01

    In this work, ZnO nanostructures were fabricated on noble-metal (Au, Ag and Au-Ag alloys) coated silicon substrates by applying pulsed laser deposition. The samples were prepared at a substrate temperature of 550 °C, an oxygen pressure of 5 Pa, and a laser fluence of 2 J cm-2 - process parameters usually used for deposition of smooth and dense thin films. The metal layer's role is substantial for the preparation of nanostructures. Heating of the substrate changed the morphology of the metal layer and, subsequently, nanoparticles were formed. The use of different metal particles resulted in different morphologies and properties of the ZnO nanostructures synthesized. The morphology of the ZnO nanostructures was related to the Au-Ag alloy's content of the catalyst layer. It was found that the morphology of the ZnO nanostructures evolved from nanorods to nanobelts as the ratio of Au/Ag in the alloy catalyst was varied. The use of a small quantity of Ag in the Au-Ag catalyst (Au3Ag) layer resulted predominantly in the deposition of ZnO nanorods. A higher Ag content in the catalyst alloy (AuAg2) layer resulted in the growth of a dense structure of ZnO nanobelts.

  19. Undercutting of defects in thin film protective coatings on polymer surfaces exposed to atomic oxygen

    NASA Technical Reports Server (NTRS)

    Rutledge, Sharon K.; Mihelcic, Judith A.

    1989-01-01

    Protection for polymeric surfaces is needed to make them durable in the low Earth orbital environment, where oxidation by atomic oxygen is the predominant failure mechanism. Thin film coatings of oxides such as silicon dioxide are viable candidates to provide this protection, but concern has been voiced over the ability of these coatings to protect when defects are present in the coating due to surface anomalies occurring during the deposition process, handling, or micrometeoroid and debris bombardment in low Earth orbit. When a defected coating protecting a polymer substrate is exposed to atomic oxygen, the defect provides a pathway to the underlying polymer allowing oxidation and subsequent undercutting to occur. Defect undercutting was studied for sputter deposited coatings of silicon dioxide on polyimide Kapton. Preliminary results indicate that undercutting may be limited as long as the coating remains intact with the substrate. Therefore, coatings may not need to be defect free to give protection to the underlying surface.

  20. Undercutting of defects in thin film protective coatings on polymer surfaces exposed to atomic oxygen

    NASA Technical Reports Server (NTRS)

    Rutledge, Sharon K.; Mihelcic, Judith A.

    1989-01-01

    Protection for polymeric surfaces is needed to make them durable in the low earth orbital environment. Thin film coatings of oxides such as SiO2 are viable candidates to provide this protection, but concern has been voiced over the ability of these coatings to protect when defects are present in the coating due to surface anomalies. When a defected coating protecting a polymer substrate is exposed to atomic oxygen, the defect provides a pathway to the underlying polymer allowing oxidation and subsequent undercutting to occur. Defect undercutting was studied for sputter deposited coatings of SiO2 on polyimide Kapton. Preliminary results indicate that undercutting may be limited as long as the coating remains intact with the substrate. Therefore, coatings may not need to be defect free to give protection to the underlying surface.

  1. Growth of lanthanum manganate buffer layers for coated conductors via a metal-organic decomposition process

    NASA Astrophysics Data System (ADS)

    Venkataraman, Kartik

    LaMnO3 (LMO) was identified as a possible buffer material for YBa2Cu3O7-x conductors due to its diffusion barrier properties and close lattice match with YBa2Cu 3O7-x. Growth of LMO films via a metal-organic decomposition (MOD) process on Ni, Ni-5at.%W (Ni-5W), and single crystal SrTiO3 substrates was investigated. Phase-pure LMO was grown via MOD on Ni and SrTiO 3 substrates at temperatures and oxygen pressures within a thermodynamic "process window" wherein LMO, Ni, Ni-5W, and SrTiO3 are all stable components. LMO could not be grown on Ni-5W in the "process window" because tungsten diffused from the substrate into the overlying film, where it reacted to form La and Mn tungstates. The kinetics of tungstate formation and crystallization of phase-pure LMO from the La and Mn acetate precursors are competitive in the temperature range explored (850--1100°C). Temperatures <850°C might mitigate tungsten diffusion from the substrate to the film sufficiently to obviate tungstate formation, but LMO films deposited via MOD require temperatures ≥850°C for nucleation and grain growth. Using a Y2O3 seed layer on Ni-5W to block tungsten from diffusing into the LMO film was explored; however, Y2O3 reacts with tungsten in the "process window" at 850--1100°C. Tungsten diffusion into Y2O3 can be blocked if epitaxial, crack-free NiWO4 and NiO layers are formed at the interface between Ni-5W and Y2O3. NiWO 4 only grows epitaxially if the overlying NiO and buffer layers are thick enough to mechanically suppress (011)-oriented NiWO4 grain growth. This is not the case when a bare 75 nm-thick Y2O3 film on Ni-5W is processed at 850°C. These studies show that the Ni-5W substrate must be at a low temperature to prevent tungsten diffusion, whereas the LMO precursor film must be at elevated temperature to crystallize. An excimer laser-assisted MOD process was used where a Y2O 3-coated Ni-5W substrate was held at 500°C in air and the pulsed laser photo-thermally heated the Y2O3 and LMO

  2. Formation mechanism and anticorrosive properties of thin siloxane films on metal surfaces

    SciTech Connect

    Petrunin, M.A.; Nazarov, A.P.; Mikhailovski, Yu.N.

    1996-01-01

    The adsorption of different ethoxysilanes on Al was studied. It was established that during polymolecular adsorption of ethoxysilanes from the vapor phase on aluminum the first monolayer is adsorbed irreversibly with adsorption van der Waals bonds between silane molecules and the aluminum surface. The covalent bonding of silanes with the surface (Al-O-Si bonds) occurs in the presence of adsorbed water on the aluminum surface. The presence of a silane monolayer on Al decreases water adsorption on the surface, and inhibits hydration of the oxide metal film. The formation of a negatively charged siloxane film on the aluminum surface inhibits local metal corrosion, and a positively charged layer activates it in chloride containing media. The formation of the surface siloxane polymer by the modification of metals inhibits the metal dissolution under polymer coatings. It is caused by silane chemisorption and negative charging of the metal surface. The presence of negatively charged groups causes difficulties of an electrostatic character for the migration of aggressive ions to the metal surface.

  3. Biodegradability of regenerated cellulose films coated with polyurethane/natural polymers interpenetrating polymer networks

    SciTech Connect

    Zhang, L.; Zhou, J.; Huang, J.; Gong, P. Zhou, Q.; Zheng, L.; Du, Y.

    1999-11-01

    Interpenetrating polymer network (IPN) coatings synthesized from castor-oil-based polyurethane (PU) with chitosan, nitrocellulose, or elaeostearin were coated on regenerated cellulose (RC) film for curing at 80--100 C for 2--5 min, providing biodegradable, water-resistant cellulose films coded, respectively, as RCCH, RCNC, and RCEs. The coated films were buried in natural soil for decaying and inoculated with a spore suspension of fungi on the agar medium, respectively, to test biodegradability. The viscosity-average molecular weight, M{sub {eta}}, and the weight of the degraded films decreased sharply with the progress of degradation. The degradation half-lifes, t{sub 1/2}, of the films in soil at 30 C were found to be 19 days for RC, 25 days for RCNC, 32 days for RCCH, and 45 days for the RCEs films. Scanning electron microscopy (SEM) showed that the extent of decay followed in the order RC {gt} RCNC {gt} RCCH {gt} RCEs. SEM, infrared (IR), high-performance liquid chromatography (HPLC), and CO{sub 2} evolution results indicated that the microorganisms directly attacked the water-resistant coating layer and then penetrated into the cellulose to speedily metabolize, while accompanying with producing CO{sub 2}, H{sub 2}O, glucose cleaved from cellulose, and small molecules decomposed from the coatings.

  4. Silver activation on thin films of Ag-ZrCN coatings for antimicrobial activity.

    PubMed

    Ferreri, I; Calderon V, S; Escobar Galindo, R; Palacio, C; Henriques, M; Piedade, A P; Carvalho, S

    2015-10-01

    Nowadays, with the increase of elderly population and related health problems, knee and hip joint prosthesis are being widely used worldwide. However, failure of these invasive devices occurs in a high percentage thus demanding the revision of the chirurgical procedure. Within the reasons of failure, microbial infections, either hospital or subsequently-acquired, contribute in high number to the statistics. Staphylococcus epidermidis (S. epidermidis) has emerged as one of the major nosocomial pathogens associated with these infections. Silver has a historic performance in medicine due to its potent antimicrobial activity, with a broad-spectrum on the activity of different types of microorganisms. Consequently, the main goal of this work was to produce Ag-ZrCN coatings with antimicrobial activity, for the surface modification of hip prostheses. Thin films of ZrCN with several silver concentrations were deposited onto stainless steel 316 L, by DC reactive magnetron sputtering, using two targets, Zr and Zr with silver pellets (Zr+Ag target), in an atmosphere containing Ar, C2H2 and N2. The antimicrobial activity of the modified surfaces was tested against S. epidermidis and the influence of an activation step of silver was assessed by testing samples after immersion in a 5% (w/v) NaClO solution for 5 min. The activation procedure revealed to be essential for the antimicrobial activity, as observed by the presence of an inhibition halo on the surface with 11 at.% of Ag. The morphology analysis of the surface before and after the activation procedure revealed differences in silver distribution indicating segregation/diffusion of the metallic element to the film's surface. Thus, the results indicate that the silver activation step is responsible for an antimicrobial effect of the coatings, due to silver oxidation and silver ion release.

  5. Silver activation on thin films of Ag-ZrCN coatings for antimicrobial activity.

    PubMed

    Ferreri, I; Calderon V, S; Escobar Galindo, R; Palacio, C; Henriques, M; Piedade, A P; Carvalho, S

    2015-10-01

    Nowadays, with the increase of elderly population and related health problems, knee and hip joint prosthesis are being widely used worldwide. However, failure of these invasive devices occurs in a high percentage thus demanding the revision of the chirurgical procedure. Within the reasons of failure, microbial infections, either hospital or subsequently-acquired, contribute in high number to the statistics. Staphylococcus epidermidis (S. epidermidis) has emerged as one of the major nosocomial pathogens associated with these infections. Silver has a historic performance in medicine due to its potent antimicrobial activity, with a broad-spectrum on the activity of different types of microorganisms. Consequently, the main goal of this work was to produce Ag-ZrCN coatings with antimicrobial activity, for the surface modification of hip prostheses. Thin films of ZrCN with several silver concentrations were deposited onto stainless steel 316 L, by DC reactive magnetron sputtering, using two targets, Zr and Zr with silver pellets (Zr+Ag target), in an atmosphere containing Ar, C2H2 and N2. The antimicrobial activity of the modified surfaces was tested against S. epidermidis and the influence of an activation step of silver was assessed by testing samples after immersion in a 5% (w/v) NaClO solution for 5 min. The activation procedure revealed to be essential for the antimicrobial activity, as observed by the presence of an inhibition halo on the surface with 11 at.% of Ag. The morphology analysis of the surface before and after the activation procedure revealed differences in silver distribution indicating segregation/diffusion of the metallic element to the film's surface. Thus, the results indicate that the silver activation step is responsible for an antimicrobial effect of the coatings, due to silver oxidation and silver ion release. PMID:26117788

  6. Fastness and Homogeneous Character of Coating Film on Big Telescope

    NASA Astrophysics Data System (ADS)

    Qin, Songnian; Li, Rufeng; Gao, Cai

    Technical indices of primary mirror coating for telescopes in Yunnan Observatory are presented. The optical homogeneity is less than 1/20, reflectivity 92% and scattered light less than 1% primary mirror is coated with a good firmness. The paper describes in detail the technological procedures for achieving the indices, including the cleaning method of primary mirror surface, cleaning coating chamber, ion-shooting intensity and time selection, necessary for fast reach to high-vaccuum, effects of evaporation rate on coating quality and selection of protective coat.

  7. Mixed polyvalent-monovalent metal coating for carbon-graphite fibers

    NASA Technical Reports Server (NTRS)

    Harper-Tervet, J.; Tervet, F. W.; Humphrey, M. F. (Inventor)

    1982-01-01

    An improved coating of gasification catalyst for carbon-graphite fibers is provided comprising a mixture of a polyvalent metal such as calcium and a monovalent metal such as lithium. The addition of lithium provides a lighter coating and a more flexible coating when applied to a coating of a carboxyl containing resin such as polyacrylic acid since it reduces the crosslink density. Furthermore, the presence of lithium provides a glass-like substance during combustion which holds the fiber together resulting in slow, even combustion with much reduced evolution of conductive fragments. The coated fibers are utilized as fiber reinforcement for composites.

  8. Conductivity of PEDOT:PSS on Spin-Coated and Drop Cast Nanofibrillar Cellulose Thin Films

    NASA Astrophysics Data System (ADS)

    Valtakari, Dimitar; Liu, Jun; Kumar, Vinay; Xu, Chunlin; Toivakka, Martti; Saarinen, Jarkko J.

    2015-10-01

    Aqueous dispersion of conductive polymer poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) was deposited on spin-coated and drop cast nanofibrillar cellulose (NFC)-glycerol (G) matrix on a glass substrate. A thin glycerol film was utilized on plasma-treated glass substrate to provide adequate adhesion for the NFC-glycerol (NFC-G) film. The effects of annealing temperature, the coating method of NFC-G, and the coating time intervals on the electrical performance of the PEDOT:PSS were characterized. PEDOT:PSS on drop cast NFC-G resulted in 3 orders of magnitude increase in the electrical conductivity compared to reference PEDOT:PSS film on a reference glass substrate, whereas the optical transmission was only slightly decreased. The results point out the importance of the interaction between the PEDOT:PSS and the NFC-G for the electrical and barrier properties for thin film electronics applications.

  9. Antibacterial effectiveness of chitosan-propolis coated polypropylene films against foodborne pathogens.

    PubMed

    Torlak, Emrah; Sert, Durmuş

    2013-09-01

    Antibacterial properties of chitosan are well documented in the literature. However its antibacterial effectiveness in the film form is controversial due to the methodological differences in test methods used. In this study, antibacterial effectiveness of chitosan-coated polypropylene films alone and incorporating ethanolic extract of propolis (EEP) were evaluated against six foodborne pathogens (Bacillus cereus, Cronobacter sakazakii, Escherichia coli O157:H7, Listeria monocytogenes, Salmonella typhimurium and Staphylococcus aureus) using the ISO 22196 method designed for the antibacterial treated plastic products. The results demonstrated that chitosan coated film exhibited the broad-spectrum antibacterial activity. Incorporation of EPP to coating at 10% (propolis resin/chitosan) enhanced antibacterial activity against all pathogens tested. Results of this study revealed that chitosan has antibacterial activity in the film form and that propolis is a promising antimicrobial for the food packaging applications.

  10. Laser-Induced Fabrication of Metallic Interlayers and Patterns in Polyimide Films

    NASA Technical Reports Server (NTRS)

    Miner, Gilda A. (Inventor); Stoakley, Diane M. (Inventor); Gaddy, Gregory A. (Inventor); Koplitz, Brent D. (Inventor); Simpson, Steven M. (Inventor); Lynch, Michael F. (Inventor); Ruffner, Samuel C. (Inventor)

    2010-01-01

    Self-metallizing polyimide films are created by doping polyamic acid solutions with metallic ions and solubilizing agents. Upon creating a film, the film is exposed to coherent light for a specific time and then cured. The resulting film has been found to have a metallic surface layer and a metallic subsurface layer (interlayer). The layer separating the metallic layer has a uniform dispersion of small metal particulates within the polymer. The layer below the interlayer has larger metal particulates uniformly distributed within the polymer. By varying the intensity or time of exposure to the coherent light, three-dimensional control of metal formation within the film is provided.

  11. Fabrication of biomimetic high performance antireflective and antifogging film by spin-coating.

    PubMed

    Zhang, Liang; Lü, Changli; Li, Yunfeng; Lin, Zhe; Wang, Zhanhua; Dong, Heping; Wang, Tieqiang; Zhang, Xuemin; Li, Xiao; Zhang, Junhu; Yang, Bai

    2012-05-15

    In this paper, we report a facile way to fabricate biomimetic high performance optical hybrid films with excellent antireflective and antifogging properties by one-step spin-coating the mixture of mesoporous SiO(2) particles and SiO(2) sol. The production process of the films is easy, low-cost, and time-efficient. Mesoporous SiO(2) particles containing surfactants disperse in SiO(2) sol stably without any chemical modification, which decrease the effective refractive index and increase the transmittance of the films. In addition, such films possess superhydrophilic properties and exhibit high performance antifogging properties. Due to the good film forming performance of SiO(2) sol, mesoporous SiO(2) particles are embedded in the films and impart the films high mechanical stability and durability. The surface morphology of the films can maintain well after repeated friction, and the performances of antireflective and antifogging also do not change as well.

  12. Evenly distributed thin-film Ag coating on stainless plate by tricomponent Ag/silicate/PU with antimicrobial and biocompatible properties.

    PubMed

    Huang, Yi-Hsiu; Chen, Mark Hung-Chih; Lee, Bing-Heng; Hsieh, Kuo-Huang; Tu, Yuan-Kun; Lin, Jiang-Jen; Chang, Chih-Hao

    2014-11-26

    A tricomponent nanohybrid dispersion in water comprising silver nanoparticles (AgNP), nanometer-thick silicate platelets (NSP), and water-based polyurethane (PU) was developed for surface coating on orthopedic metal plates. The previously developed AgNP-on-NSP nanohybrid was homogeneously blended into a selected waterborne PU dispersion at varied weight ratios from 1/0.1 to 1/10 (w/w). PU was used to adhere the Ag nanohybrid to the metal surface. The resultant dispersions were analyzed and found to contain AgNP 2-18 nm in diameter and characterized by using UV absorption and TEM micrograph. The subsequent coating of AgNP/NSP-PU dispersion generated a film of 1.5 μm thickness on the metal plate surface, further characterized by an energy dispersive spectroscope (EDS) to show the homogeneous distribution of Ag, Si, and C elements on the metal plates. The surface antimicrobial efficacy was proven for the coating composition of AgNP/NSP to PU ranging from 1/1 to 1/5 by weight ratio but irrelevant to the thickness of the coated materials. The metal plate coated with the high Ag content at 1/1 (w/w) ratio was shown to have very low cytotoxicity toward the contacted mammal fibroblasts. Overall, the optimized tricomponent Ag/silicate/PU in water dispersion from 1/2 to 1/3 (w/w) could generate a stable film on a metal surface exhibiting both antimicrobial and biocompatible properties. The facile coating technique of the AgNP/NSP in waterborne PU is proven to be viable for fabricating infection- and cytotoxicity-free medical devices.

  13. Bi-directional terahertz-to-infrared emission from metal-coated nanostructures upon femtosecond laser irradiation.

    PubMed

    Zhang, Liangliang; Wu, Tong; Zhao, Ji; Zhang, Cunlin; Zhang, X-C

    2015-09-21

    We report on the investigation of bi-directional terahertz-to-infrared (THz-to-IR) radiation from a metal film coated on a substrate with randomly ordered pore arrays by irradiation of femtosecond laser pulses. THz-to-IR radiation was observed both for front-side excitation (laser incident on the metal surface) and for rear-side excitation (laser incident on the substrate). In both cases, the radiation was observed both in the propagation direction of the laser beam and in the reverse direction. Considering these findings, we propose a thermal emission mechanism based on the production of surface plasmons, either delocalized (through phase-matched excitation) or localized (through surface roughness) at the air/metal and metal/substrate interfaces.

  14. Bi-directional terahertz-to-infrared emission from metal-coated nanostructures upon femtosecond laser irradiation.

    PubMed

    Zhang, Liangliang; Wu, Tong; Zhao, Ji; Zhang, Cunlin; Zhang, X-C

    2015-09-21

    We report on the investigation of bi-directional terahertz-to-infrared (THz-to-IR) radiation from a metal film coated on a substrate with randomly ordered pore arrays by irradiation of femtosecond laser pulses. THz-to-IR radiation was observed both for front-side excitation (laser incident on the metal surface) and for rear-side excitation (laser incident on the substrate). In both cases, the radiation was observed both in the propagation direction of the laser beam and in the reverse direction. Considering these findings, we propose a thermal emission mechanism based on the production of surface plasmons, either delocalized (through phase-matched excitation) or localized (through surface roughness) at the air/metal and metal/substrate interfaces. PMID:26406717

  15. Fabrication of electrically bistable organic semiconducting/ferroelectric blend films by temperature controlled spin coating.

    PubMed

    Hu, Jinghang; Zhang, Jianchi; Fu, Zongyuan; Weng, Junhui; Chen, Weibo; Ding, Shijin; Jiang, Yulong; Zhu, Guodong

    2015-03-25

    Organic semiconducting/ferroelectric blend films attracted much attention due to their electrical bistability and rectification properties and thereof the potential in resistive memory devices. During film deposition from the blend solution, spinodal decomposition induced phase separation, resulting in discrete semiconducting phase whose electrical property could be modulated by the continuous ferroelectric phase. However, blend films processed by common spin coating method showed extremely rough surfaces, even comparable to the film thickness, which caused large electrical leakage and thus compromised the resistive switching performance. To improve film roughness and thus increase the productivity of these resistive devices, we developed temperature controlled spin coating technique to carefully adjust the phase separation process. Here we reported our experimental results from the blend films of ferroelectric poly(vinylidene fluoride-trifluoroethylene (P(VDF-TrFE)) and semiconducting poly(3-hexylthiophene) (P3HT). We conducted a series of experiments at various deposition temperatures ranging from 20 to 90 °C. The resulting films were characterized by AFM, SEM, and VPFM to determine their structure and roughness. Film roughness first decreased and then increased with the increase of deposition temperature. Electrical performance was also characterized and obviously improved insulating property was obtained from the films deposited between 50 and 70 °C. By temperature control during film deposition, it is convenient to efficiently fabricate ferroelectric/semiconducting blend films with good electrical bistability.

  16. Effects of lamination and coating with drying oils on tensile and barrier properties of zein films.

    PubMed

    Rakotonirainy, A M; Padua, G W

    2001-06-01

    Zein films plasticized with oleic acid have been considered potentially useful for biodegradable packaging applications. However, moisture was found to affect their tensile and gas barrier properties. We investigated the effects of two converting processes, fusion lamination and coating with drying oils, on tensile properties and gas permeability of zein films. Zein films were laminated to 4-ply sheets in a Carver press and coated with tung oil, linseed oil, or a mixture of tung and soybean oils. Tensile properties and permeability to water vapor, oxygen, and carbon dioxide were measured according to ASTM methods. Laminated films were clearer, tougher, and more flexible, and had a smoother finish than nontreated sheets. Lamination decreased O(2) and CO(2) permeability by filling in voids and pinholes in the film structure. Coating increased tensile strength and elongation and decreased water vapor permeability. Coatings acted as a composite layer preventing crack propagation and increasing film strength. They also formed a highly hydrophobic surface that prevented film wetting.

  17. The applied research and solar simulation spectral design based on pulse xenon lamp with coating film

    NASA Astrophysics Data System (ADS)

    Chen, Wenzhi; Cheng, Qijin; Zhang, Fengyan

    2014-09-01

    In the paper the spectrum of realistic sunlight and pulse xenon lamp were compared to each other, the result shows that the infrared part of luminescence spectrum of xenon lamp without coating film occupies the total spectrum's 57.4%, but the infrared part of the standard solar spectrum only reaches to 28.3%. The transmittance curve of pulse xenon lamp is got by fitting. Using appropriate method and coating film parameter, the film is done to pulse xenon lamp, and the negative film coefficient transmittance is 16% is got at 935nm central wavelength. At the range of 400-760nm wavelength the average transmittance is more than 86%, and the average transmittance is more than 96% at the range of 400-760nm wavelength. A portion of infrared light can be filtered after coating film. By the spectral testing of two coating film xenon lamp, it can be found that the spectral matching rate is from 0.792 to 1.176 and it is satisfied to A grade standard request. By using A and C grade pulse xenon lamp electric performance of 40.5W thin film cell is tested and the power value by C grade simulative light source is lower than real power for 11.2W. The result indicates the spectral matching rate of solar simulator is very important for cell electric performance.

  18. Preparation and antimicrobial assay of ceramic brackets coated with TiO2 thin films

    PubMed Central

    Cao, Shuai; Wang, Ye; Cao, Lin; Wang, Yu; Lin, Bingpeng; Lan, Wei

    2016-01-01

    Objective Different methods have been utilized to prevent enamel demineralization and other complications during orthodontic treatment. However, none of these methods can offer long-lasting and effective prevention of orthodontic complications or interventions after complications occur. Considering the photocatalytic effect of TiO2 on organic compounds, we hoped to synthesize a novel bracket with a TiO2 thin film to develop a photocatalytic antimicrobial effect. Methods The sol-gel dip coating method was used to prepare TiO2 thin films on ceramic bracket surfaces. Twenty groups of samples were composed according to the experimental parameters. Crystalline structure and surface morphology were characterized by X-ray diffraction and scanning electron microscopy, respectively; film thickness was examined with a surface ellipsometer. The photocatalytic properties under ultraviolet (UV) light irradiation were analyzed by evaluating the degradation ratio of methylene blue (MB) at a certain time. Antibacterial activities of selected thin films were also tested against Lactobacillus acidophilus and Candida albicans. Results Films with 5 coating layers annealed at 700℃ showed the greatest photocatalytic activity in terms of MB decomposition under UV light irradiation. TiO2 thin films with 5 coating layers annealed at 700℃ exhibited the greatest antimicrobial activity under UV-A light irradiation. Conclusions These results provide promising guidance in prevention of demineralization by increasing antimicrobial activities of film coated brackets. PMID:27226960

  19. Low frictional property of copper oxide thin films optimised using a combinatorial sputter coating system

    NASA Astrophysics Data System (ADS)

    Goto, Masahiro; Kasahara, Akira; Tosa, Masahiro

    2006-01-01

    A combinatorial sputter coating system has been developed that can optimize the crystal preferred orientation of coating films. With this system, it is possible to synthesize various kinds of coatings whilst precisely controlling conditions such as the sputter gas, the gas pressure, the gas partial pressure, the r.f. power, the substrate temperature, the distance between the substrate and target, etc. In this way, we successfully synthesized copper oxide coatings with different crystal preferred orientations, and low frictional property was obtained by optimizing the crystal preferred orientation.

  20. XUV spectroscopy of laser plasma from molecular coated metal targets

    NASA Astrophysics Data System (ADS)

    Papanyan, Valeri O.; Nersisyan, Gagik T.; Tittel, Frank K.

    1999-12-01

    Metal targets covered by micrometer layers of metal- phthalocyanines or fullerenes are studied here. An increase in XUV yield due to the optimized absorption of the laser field is reported. Effects of high-temperature plasma rapid expansion (velocity about 106 cm/s) were observed. Moderate power nanosecond and picosecond neodymium lasers are used to produce an incident intensity of 1011 to 1013 W/cm2 on the targets. The plasma electron density was measured by fitting observed spectral profiles to the theoretical profiles. Collisional, Doppler, and Stark broadening mechanisms were considered in the calculations. Our measurement technique permits us to determine the electron density and temperature dependence on distances from the target surface from 1 mm (where Ne approximately equals 1018 cm-3 and Te approximately equals 14 eV are measured for aluminum plasma) up to approximately 5 mm (where Ne coated targets is greater by a factor of approximately 1.5 than measured from bulk solid metal targets.

  1. XUV spectroscopy of laser plasma from molecular coated metal targets

    NASA Astrophysics Data System (ADS)

    Papanyan, Valeri O.; Nersisyan, Gagik T.; Tittel, Frank K.

    1999-10-01

    Metal targets covered by micrometer layers of metal- phthalocyanines are studied here. An increase in EUV yield due to optimized absorption of the laser field is reported. Effects of high-temperature plasma rapid expansion (velocity about 106 cm/s) were observed. Moderate power nanosecond and picosecond neodymium lasers are used to product an incident intensity of 1011 to 1013 W/cm2 on the targets. The plasma electron density was measured by fitting observed spectral profiles to theoretical profiles. Collisional, Doppler, and Stark broadening mechanisms were considered in the calculations. Our measurement technique makes it possible to determine the electron density and temperature dependence on distances from the target surface from 1 mm (where Ne equals 2.0 (+/- 0.5)1018 cm-3 and Te equals 14 eV are measured for aluminum plasma) up to approximately 5 mm (where Ne coated targets is greater by a factor of approximately 1.5 than measured from bulk solid metal targets.

  2. Molecular Interactions Between Alcohols and Metal Phthalocyanine Thin Films for Optical Gas Sensor Applications

    NASA Astrophysics Data System (ADS)

    Uttiya, Sureeporn; Kladsomboon, Sumana; Chamlek, Onanong; Suwannet, Wiriya; Osotchan, Tanakorn; Kerdcharoen, Teerakiat; Brinkmann, Martin; Pratontep, Sirapat

    Optically active organic gas sensors represent a promising molecular sensing device with low power consumption. We report experimental and computational investigations into the molecular interactions of metal phthalocyanine thin films with alcohol vapor. In the gas-sensing regime, the interactions of zinc phthalocyanine and alcohol molecules were studied by the Density Functional Theory (DFT) calculations, in comparison to the x-ray absorption spectroscopy. The DFT results reveal a reversible charge interaction mechanism between the zinc atom and the oxygen atom in the alcohol OH group, which corresponds to a shift in the x-ray absorption edge of the zinc atom. In the irreversible interaction regime, the effect of saturated alcohol vapor on spin-coated zinc phthalocyanine films was studied by the phase contrast microscopy, the optical absorption spectroscopy, and the transmission electron microscopy. Annealing the spin-coated films in saturated methanol vapor was found to induce an irreversible structural transformation from an amorphous to a crystalline phase, similar to the effect of a thermal annealing process. These crystallization processes of the zinc phthalocyanine films were also found to enhance their stability and alcohol sensing performance.

  3. Electrical and optical characterization of metal oxide/metal/polymer multilayer thin films

    NASA Astrophysics Data System (ADS)

    Fryc, Irena

    1998-01-01

    A new procedure for depositing three-layer structures [doped metal oxide/metal/metal oxide (In2O3/Ag/TiO2)] on a glass substrate by applying different methods of film deposition was developed. To obtain the first film -- In2O3:Sn, the spray hydrolysis method was employed and for the second, a thin Ag film, the vacuum evaporation technique was used. The third film -- TiO2 was obtained by the organic oxide compound polymerization method. The electrical and optical properties of the films and the multilayer structure thus obtained were investigated. The studies showed that the three-layer structure could be used as a broad-band infrared filter.

  4. Removal of copper ions from aqueous solution by adsorption onto novel polyelectrolyte film-coated nanofibrous silk fibroin non-wovens

    NASA Astrophysics Data System (ADS)

    Zhou, Weitao; Huang, Haitao; Du, Shan; Huo, Yingdong; He, Jianxin; Cui, Shizhong

    2015-08-01

    In this approach, polyelectrolyte film-coated nanofibrous silk fibroin (SF) nonwovens were prepared from the alternate deposition of positively charged polyethylenimine (PEI) and negatively charged SF using electrostatic layer-by-layer (LBL) self-assembled technology. The composite membranes were characterized by scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectrometer. The SF-PEI multilayer-assembled nanofibers (less than five layers) were fine and uniform with the fiber diameter from 400 nm to 600 nm, and had very large surface area and high porosity (more than 70%). The amino groups of PEI were proved to be deposited onto SF nonwovens, which granted the coated nonwovens with potential applicability for copper ions adsorption. The PEI films coated SF substrate showed much higher copper ions adsorption capacity than that of ethanol treated SF nanofibers. Adding the number of PEI coated could enhance the Cu2+ adsorption capacity significantly. The maximum milligrams per gram of copper ions adsorbed reached 59.7 mg/g when the SF substrate was coated with 5 bilayers of SF-PEI. However, the copper ions adsorption capacity had no obvious change as the number of PEI continued to increase. These results suggest potential for PEL film-coated nanofibrous nonwovens as a new adsorbent for metal ions.

  5. Development of technique for AR coating and nickel and copper metallization of solar cells. FPS Project: Product development

    NASA Astrophysics Data System (ADS)

    Taylor, W.

    1982-04-01

    Printed nickel overplated with copper and applied on top of a predeposited silicon nitride antireflective coating system for metallizing solar cells was analyzed. The ESL D and E paste formulations, and the new formulations F, G, H, and D-1 were evaluated. The nickel thick films were tested after firing for stability in the cleaning and plating solutions used in the Vanguard-Pacific brush plating process. It was found that the films are very sensitive to the leaning and alkaline copper solutions. Less sensitivity was displayed to the neutral copper solution. Microscopic and SEM observations show segregation of frit at the silicon nitride thick film interface with loose frit residues after lifting off plated grid lines.

  6. Development of technique for AR coating and nickel and copper metallization of solar cells. FPS Project: Product development

    NASA Technical Reports Server (NTRS)

    Taylor, W.

    1982-01-01

    Printed nickel overplated with copper and applied on top of a predeposited silicon nitride antireflective coating system for metallizing solar cells was analyzed. The ESL D and E paste formulations, and the new formulations F, G, H, and D-1 were evaluated. The nickel thick films were tested after firing for stability in the cleaning and plating solutions used in the Vanguard-Pacific brush plating process. It was found that the films are very sensitive to the leaning and alkaline copper solutions. Less sensitivity was displayed to the neutral copper solution. Microscopic and SEM observations show segregation of frit at the silicon nitride thick film interface with loose frit residues after lifting off plated grid lines.

  7. The Tribological Behaviors of Three Films Coated on Biomedical Titanium Alloy by Chemical Vapor Deposition

    NASA Astrophysics Data System (ADS)

    Wang, Song; Liao, Zhenhua; Liu, Yuhong; Liu, Weiqiang

    2015-11-01

    Three thin films (DLC, a-C, and TiN) were performed on Ti6Al4V by chemical vapor deposition. Carbon ion implantation was pretreated for DLC and a-C films while Ti transition layer was pretreated for TiN film to strengthen the bonding strength. X-ray diffraction, Raman measurement, nano-hardness and nano-scratch tester, and cross-section etching by FIB method were used to analyze film characteristics. Tribological behaviors of these coatings were studied by articulation with both ZrO2 and UHMWPE balls using ball-on-disk sliding. The thickness values reached ~0.46, ~0.33, and ~1.67 μm for DLC, a-C, and TiN film, respectively. Nano-hardness of the coatings compared with that of untreated and bonding strength (critical load in nano-scratch test) values of composite coatings compared with that of monolayer film all increased significantly, respectively. Under destructive test (ZrO2 ball conterface) in bovine serum lubrication, TiN coating revealed the best wear resistance while DLC showed the worst. Film failure was mainly attributed to the plowing by hard ZrO2 ball characterized by abrasive and adhesive wear. Under normal test (UHMWPE ball conterface), all coatings showed significant improvement in wear resistance both in dry sliding and bovine serum lubrication. Both DLC and a-C films showed less surface damage than TiN film due to the self-lubricating phenomenon in dry sliding. TiN film showed the largest friction coefficient both in destructive and normal tests, devoting to the big TiN grains thus leading to much rougher surface and then a higher value. The self-lubricating film formed on DLC and a-C coating could also decrease their friction coefficients. The results indicated that three coatings revealed different wear mechanisms, and thick DLC or a-C film was more promising in application in lower stress conditions such as artificial cervical disk.

  8. Ultra-smooth metal surfaces generated by pressure-induced surface deformation of thin metal films

    NASA Astrophysics Data System (ADS)

    Logeeswaran, V. J.; Chan, M.-L.; Bayam, Y.; Saif Islam, M.; Horsley, D. A.; Li, X.; Wu, W.; Wang, S. Y.; Williams, R. S.

    2007-05-01

    We present a mechanical pressing technique for generating ultra-smooth surfaces on thin metal films by flattening the bumps, asperities, rough grains and spikes of a freshly vacuum deposited metal film. The method was implemented by varying the applied pressure from 100 MPa to 600 MPa on an e-beam evaporated silver film of thickness 1000 Å deposited on double-polished (100)-oriented silicon surfaces, resulting in a varying degree of film smoothness. The surface morphology of the thin film was studied using atomic force microscopy. Notably, at a pressure of ˜600 MPa an initial silver surface with 13-nm RMS roughness was plastically deformed and transformed to an ultra-flat plane with better than 0.1 nm RMS. Our demonstration with the e-beam evaporated silver thin film exhibits the potential for applications in decreasing the scattering-induced losses in optical metamaterials, plasmonic nanodevices and electrical shorts in molecular-scale electronic devices.

  9. Metal matrix coated fiber composites and the methods of manufacturing such composites

    DOEpatents

    Weeks, J.K. Jr.; Gensse, C.

    1993-09-14

    A fiber coating which allows ceramic or metal fibers to be wetted by molten metals is disclosed. The coating inhibits degradation of the physical properties caused by chemical reaction between the fiber and the coating itself or between the fiber and the metal matrix. The fiber coating preferably includes at least a wetting layer, and in some applications, a wetting layer and a barrier layer between the fiber and the wetting layer. The wetting layer promotes fiber wetting by the metal matrix. The barrier layer inhibits fiber degradation. The fiber coating permits the fibers to be infiltrated with the metal matrix resulting in composites having unique properties not obtainable in pure materials. 8 figures.

  10. Determination of Modulus of Metal Films Using Thermoreflectance

    NASA Astrophysics Data System (ADS)

    Jagannadham, K.

    2015-01-01

    The acoustic displacements in a film of indium pressed on to a sapphire wafer were generated by incidence of a Q-switched Nd-YAG laser beam. Acoustic displacements from tungsten film deposited on silicon substrate were also measured by the same technique. Thermoreflectance from a continuous red laser incident on the surface was used simultaneously to measure the acoustic oscillations. The acoustic oscillations were simulated using the solution to the modified wave equation. The acoustic velocity and the modulus of the metal film were determined from the simulation of the experimental results. It is shown that this technique provides a nondestructive method of determination of acoustic velocity and modulus in the metal films.

  11. Optical reflectivity improvement by upgrading metallic glass film quality

    SciTech Connect

    Wang, W. H.; Hsu, J. H.; Huang, J. C.

    2013-10-14

    The effects of atomic-defect and free-volume amounts of metallic glassy film on the optical reflectivity and mechanical properties of the sputtered metallic glass thin films are explored. With a lower Ar working pressure and the proper post-annealing at temperatures slightly lower than the glass-transition temperature T{sub g}, film free volumes and defects would reduce, resulting in better atomic bonding and higher film hardness/modulus, which in turn leads to lower electric resistivity and higher optical reflectivity. Annealing above T{sub g} would induce crystalline structure which would lead to competition with the optical transition of the Drude free electrons and hinder the optical reflectivity in the visible range.

  12. METAL-MATRIX COMPOSITES AND THERMAL SPRAY COATINGS FOR EARTH MOVING MACHINES

    SciTech Connect

    D. Trent Weaver; Matthew T. Kiser

    2003-10-01

    In the 11th quarter, further testing was performed on thermal spray coatings. A component coated and fused in the 9th quarter underwent high-stress abrasive wear testing. The test successfully showed this coating could survive in a high stress, sliding wear environment as the base layer in an FGM design coating. Work on the ferrous metal-matrix composites was completed in previous quarter and therefore no update is provided.

  13. Young's Moduli of Cold and Vacuum Plasma Sprayed Metallic Coatings

    NASA Technical Reports Server (NTRS)

    Raj, S. V.; Pawlik, R.; Loewenthal, W.

    2009-01-01

    Monolithic metallic copper alloy and NiCrAlY coatings were fabricated by either the cold spray (CS) or the vacuum plasma spray (VPS) deposition processes. Dynamic elastic modulus property measurements were conducted on these monolithic coating specimens between 300 K and 1273 K using the impulse excitation technique. The Young's moduli decreased almost linearly with increasing temperature at all temperatures except in the case of the CS Cu-23%Cr-5%Al and VPS NiCrAlY, where deviations from linearity were observed above a critical temperature. It was observed that the Young's moduli for VPS Cu-8%Cr were larger than literature data compiled for Cu. The addition of 1%Al to Cu- 8%Cr significantly increased its Young's modulus by 12 to 17% presumably due to a solid solution effect. Comparisons of the Young s moduli data between two different measurements on the same CS Cu- 23%Cr-5%Al specimen revealed that the values measured in the first run were about 10% higher than those in the second run. It is suggested that this observation is due to annealing of the initial cold work microstructure resulting form the cold spray deposition process.

  14. Fabrication of Metal Oxide Thin Films Using the Langmuir-Blodgett Deposition Technique.

    NASA Astrophysics Data System (ADS)

    Johnson, David John

    studied in some detail, using two processes: thermal decomposition and decomposition via ultraviolet/ozone exposure. The second technique was found to reduce LB arachidate multilayers to a metal carbonate (at a rate of less than 1 minute per layer), which could be further decomposed into an oxide via a thermal treatment. The ultraviolet/ozone process allowed uniform films of CdO to be produced in addition to the thin films of Y_2O_3 , Er_2O_3 and La_2O_3 fabricated via either thermal or ultraviolet/ozone processing. Applications of the LB produced metal oxides were investigated. Electrical characterization of Y _2O_3 dielectric layers gave a permittivity of varepsilon~ 11.5 +/- 0.9 and good quality metal -oxide-semiconductor structures of <10 nm in thickness. Y_2O_3 coatings on 304 stainless steel were found to significantly reduce thermal oxidation of the steel at 800^ circC. Finally, La_2O _3 interface layers in PZT/Pt structures were found to have a significant effect on the nucleation and growth of the ferroelectric.

  15. Growth of thin metal films studied by spectromicroscopy

    NASA Astrophysics Data System (ADS)

    Schmidt, Th.; Ressel, B.; Heun, S.; Prince, K. C.; Bauer, E.

    2000-05-01

    The many possibilities of SPELEEM are particularly interesting for the study of thin film growth processes. This is demonstrated for the heteroepitaxial growth of thin metal films in the presence of co-adsorbates. Two model systems are chosen:. Fe on W(100) and Pb on Si(111). The Stranski-Krastanov growth mode of both systems is changed to a quasi-Frank-van der Merwe growth mode by a surfactant (Pb) and an interfactant (Au), respectively.

  16. Indium tin oxide films prepared by atmospheric plasma annealing and their semiconductor-metal conductivity transition around room temperature

    NASA Astrophysics Data System (ADS)

    Li, Yali; Li, Chunyang; He, Deyan; Li, Junshuai

    2009-05-01

    We report the synthesis of indium tin oxide (ITO) films using the atmospheric plasma annealing (APA) technique combined with the spin-coating method. The ITO film with a low resistivity of ~4.6 × 10-4 Ω cm and a high visible light transmittance, above 85%, was achieved. Hall measurement indicates that compared with the optimized ITO films deposited by magnetron sputtering, the above-mentioned ITO film has a higher carrier concentration of ~1.21 × 1021 cm-3 and a lower mobility of ~11.4 cm2 V-1 s-1. More interestingly, these electrical characteristics result in the semiconductor-metal conductivity transition around room temperature for the ITO films prepared by APA.

  17. Metal Matrix Composite Coatings Manufactured by Thermal Spraying: Influence of the Powder Preparation on the Coating Properties

    NASA Astrophysics Data System (ADS)

    Aussavy, D.; Costil, S.; El Kedim, O.; Montavon, G.; Bonnot, A.-F.

    2014-01-01

    The purpose of this study is to manufacture metal matrix composite coatings by thermal spraying. In order to improve coating's mechanical properties, it is necessary to increase homogeneity. To meet this objective, the chosen approach was to optimize the powder morphology by mechanical alloying. Indeed, the mechanical alloying method (ball milling) was implemented to synthesize NiCr-Cr3C2 and NiCrBSi-WC composite powders by using cold spraying and high-velocity oxygen fuel process, respectively. After optimizing the process parameters on powder grain size, the composite coatings were compared with standard coatings manufactured from mixed powders. SEM observations, hardness measurements, and XRD analyses were the first technologies implemented to characterize the metal matrix composite coatings. Different characteristics were then observed. When mechanical alloying process is employed to synthesize composite powders strengthened by particle dispersion, the powders tend to fracture into small segments, especially when high content of hard particles is added. Powder microstructures were then refined, which induced thinner coating morphologies and reduced porosity rate. Once an improved microstructure is obtained, manufacturing of coating using milled powders was found suitable in comparison with coatings manufactured only with mixed powders.

  18. Fabricating thin-film photovoltaic devices using ultra-sonic spray-coating (Presentation Recording)

    NASA Astrophysics Data System (ADS)

    Lidzey, David G.

    2015-10-01

    The scale-up of thin-film electronic devices requires a manufacture tool set that is capable of fabricating thin films at high speed over large areas. One such technique capable of such a task is ultra-sonic spray coating. Here, a target solution is fed onto a vibrating tip that breaks the solution up into very fine droplets, with such droplets being carried to a surface by a gas stream. Such ultra-sonic coating processes are already widely used in Electronics, Medical and Displays industries to create films having excellent smoothness and homogeneity. In this talk, I describe the use of ultra-sonic spray-coating to deposit a range of materials for thin-film optoelectronics. As our spray-coating system operates in air, it was first necessary to explore the relative sensitivity of various conjugated polymer / fullerene blends to an air-based process route. It is found that carbazole based co-polymers are particularly stable, and can be processed in air (by spin-coating) into organic photovoltaic devices (OPV) without any apparent loss in device efficiency. I then show that spray-coating can be used to deposit a range of semiconductor materials into smooth, thin-films, including PEDOT:PSS, MoOx (from a precursor) and a series of polymer:fullerene blends. Using such a technique, we are able to scale up an array of devices having an area of 7 cm2, and using a PBDTTT-EFT:PC70BM blend, obtain OPVs having a power conversion efficiency (PCE) of 8.7%. I then discuss spray-coating as a method to fabricate photovoltaic devices based on CH3NH3PbI(3-x)Clx perovskite films. Here, by optimization of deposition parameters, devices are created having a PCE of 11.1%.

  19. Thin film coating process using an inductively coupled plasma

    DOEpatents

    Kniseley, Richard N.; Schmidt, Frederick A.; Merkle, Brian D.

    1990-01-30

    Thin coatings of normally solid materials are applied to target substrates using an inductively coupled plasma. Particles of the coating material are vaporized by plasma heating, and pass through an orifice to a first vacuum zone in which the particles are accelerated to a velocity greater than Mach 1. The shock wave generated in the first vacuum zone is intercepted by the tip of a skimmer cone that provides a second orifice. The particles pass through the second orifice into a second zone maintained at a higher vacuum and impinge on the target to form the coating. Ultrapure coatings can be formed.

  20. Multilayer coatings on flexible substrates

    SciTech Connect

    Martin, P.M.; Affinito, J.D.; Gross, M.E.; Coronado, C.A.; Bennett, W.D.; Stewart, D.C.

    1995-04-01

    Thin-film optical and non-optical multilayer coatings are deposited onto flexible substrates using a vacuum web coater developed at Pacific Northwest Laboratory. The coater`s primary application is rapid prototyping of multilayer (1) polymer coatings, (2) polymer/metal coatings, (3) ceramic/metal coatings, and (4) hybrid polymer, ceramic, and metal coatings. The coater is fully automated and incorporates polymer evaporation and extrusion heads, high-rate magnetron sputtering cathodes, and e-beam evaporation sources. Polymer electrolytes are deposited by extrusion techniques. Flexible plastic, metal, and ceramic substrates can be coated using roll-to-roll or closed-loop configurations. Examples of multilayer optical coatings demonstrated to date are solar reflectors, heat mirrors, Fabry-Perot filters, and alpha particle sensors. Nonoptical coatings include multilayer magnetic metal/ceramic and lamellar composites.

  1. UV laser deposition of metal films by photogenerated free radicals

    NASA Technical Reports Server (NTRS)

    Montgomery, R. K.; Mantei, T. D.

    1986-01-01

    A novel photochemical method for liquid-phase deposition of metal films is described. In the liquid phase deposition scheme, a metal containing compound and a metal-metal bonded carbonyl complex are dissolved together in a polar solvent and the mixture is irradiated using a UV laser. The optical arrangement consists of a HeCd laser which provides 7 mW of power at a wavelength of 325 nm in the TEM(OO) mode. The beam is attenuated and may be expanded to a diameter of 5-20 mm. Experiments with photochemical deposition of silver films onto glass and quartz substrates are described in detail. Mass spectrometric analysis of deposited silver films indicated a deposition rate of about 1 A/s at incident power levels of 0.01 W/sq cm. UV laser-induced copper and palladium films have also been obtained. A black and white photograph showing the silver Van Der Pauw pattern of a solution-deposited film is provided.

  2. How many electrons make a semiconductor nanocrystal film metallic

    NASA Astrophysics Data System (ADS)

    Reich, Konstantin; Chen, Ting; Kramer, Nicolaas; Fu, Han; Kortshagen, Uwe; Shklovskii, Boris

    For films of semiconductor nanocrystals to achieve their potential as novel, low-cost electronic materials, a better understanding of their doping to tune their conductivity is required. So far, it not known how many dopants will turn a nanocrystal film from semiconducting to metallic. In bulk semiconductors, the critical concentration nM of electrons at the metal-insulator transition is described by the famous Mott criterion: nMaB3 ~= 0 . 02 , where aB is the effective Bohr radius. We show theoretically that in a dense NC film, where NCs touch each other by small facets, the concentration of electrons nc >>nM at the metal-insulator transition satisfies the condition: ncρ3 ~= 0 . 3 , where ρ is a radius of contact facets. In the accompanying experiments, we investigate the conduction mechanism in films of phosphorus-doped, ligand-free silicon nanocrystals. At the largest electron concentration achieved in our samples, which is half the predicted nc, we find that the localization length of hopping electrons is close to three times the nanocrystals diameter, indicating that the film approaches the metal-insulator transition. This work was supported primarily by the National Science Foundation through the University of Minnesota MRSEC under Award No. DMR-1420013.

  3. Optically Thin Metallic Films for High-Radiative-Efficiency Plasmonics

    NASA Astrophysics Data System (ADS)

    Yang, Yi; Zhen, Bo; Hsu, Chia Wei; Miller, Owen D.; Joannopoulos, John D.; Soljačić, Marin

    2016-07-01

    Plasmonics enables deep-subwavelength concentration of light and has become important for fundamental studies as well as real-life applications. Two major existing platforms of plasmonics are metallic nanoparticles and metallic films. Metallic nanoparticles allow efficient coupling to far field radiation, yet their synthesis typically leads to poor material quality. Metallic films offer substantially higher quality materials, but their coupling to radiation is typically jeopardized due to the large momentum mismatch with free space. Here, we propose and theoretically investigate optically thin metallic films as an ideal platform for high-radiative-efficiency plasmonics. For far-field scattering, adding a thin high-quality metallic substrate enables a higher quality factor while maintaining the localization and tunability that the nanoparticle provides. For near-field spontaneous emission, a thin metallic substrate, of high quality or not, greatly improves the field overlap between the emitter environment and propagating surface plasmons, enabling high-Purcell (total enhancement > $10^4$), high-quantum-yield (> 50 %) spontaneous emission, even as the gap size vanishes (3$\\sim$5 nm). The enhancement has almost spatially independent efficiency and does not suffer from quenching effects that commonly exist in previous structures.

  4. Optically Thin Metallic Films for High-Radiative-Efficiency Plasmonics.

    PubMed

    Yang, Yi; Zhen, Bo; Hsu, Chia Wei; Miller, Owen D; Joannopoulos, John D; Soljačić, Marin

    2016-07-13

    Plasmonics enables deep-subwavelength concentration of light and has become important for fundamental studies as well as real-life applications. Two major existing platforms of plasmonics are metallic nanoparticles and metallic films. Metallic nanoparticles allow efficient coupling to far field radiation, yet their synthesis typically leads to poor material quality. Metallic films offer substantially higher quality materials, but their coupling to radiation is typically jeopardized due to the large momentum mismatch with free space. Here, we propose and theoretically investigate optically thin metallic films as an ideal platform for high-radiative-efficiency plasmonics. For far-field scattering, adding a thin high-quality metallic substrate enables a higher quality factor while maintaining the localization and tunability that the nanoparticle provides. For near-field spontaneous emission, a thin metallic substrate, of high quality or not, greatly improves the field overlap between the emitter environment and propagating surface plasmons, enabling high-Purcell (total enhancement >10(4)), high-quantum-yield (>50%) spontaneous emission, even as the gap size vanishes (3-5 nm). The enhancement has almost spatially independent efficiency and does not suffer from quenching effects that commonly exist in previous structures.

  5. Materials Analysis of CED Nb Films Being Coated on Bulk Nb Single Cell SRF Cavities

    SciTech Connect

    Zhao, Xin; Reece, Charles; Palczewski, Ari; Ciovati, Gianluigi; Krishnan, Mahadevan; James, Colt; Irfan, Irfan

    2013-09-01

    This study is an on-going research on depositing a Nb film on the internal wall of bulk Nb single cell SRF cavities, via a cathodic arc Nb plasma ions source, an coaxial energetic condensation (CED) facility at AASC company. The motivation is to firstly create a homoepitaxy-like Nb/Nb film in a scale of a ~1.5GHz RF single cell cavity. Next, through SRF measurement and materials analysis, it might reveal the baseline properties of the CED-type homoepitaxy Nb films. Literally, a top-surface layer of Nb films which sustains SRF function, always grows up in homo-epitaxy mode, on top of a Nb nucleation layer. Homo-epitaxy growth of Nb must be the final stage (a crystal thickening process) of any coatings of Nb film on alternative cavity structure materials. Such knowledge of Nb-Nb homo-epitaxy is useful to create future realistic SRF cavity film coatings, such as hetero-epitaxy Nb/Cu Films, or template-layer-mitigated Nb films. One large-grain, and three fine grain bulk Nb cavities were coated. They went through cryogenic RF measurement. Preliminary results show that the Q0 of a Nb film could be as same as the pre-coated bulk Nb surface (which received a chemically-buffered polishing plus a light electro-polishing); but quality factor of two tested cavities dropped quickly. We are investigating if the severe Q-slope is caused by hydrogen incorporation before deposition, or is determined by some structural defects during Nb film growth.

  6. Resistivity minimum in granular composites and thin metallic films

    NASA Astrophysics Data System (ADS)

    Gerber, A.; Kishon, I.; Bartov, D.; Karpovski, M.

    2016-09-01

    We analyze the temperature dependence of conductivity in thick granular ferromagnetic compounds NiSi O2 and in thin weakly coupled films of Fe, Ni, and Py in the vicinity of the metal-to-insulator transition. Development of a resistivity minimum followed by a logarithmic variation of conductivity at lower temperatures is attributed to the granular structure of compounds and thin films fabricated by conventional deposition techniques. The resistivity minimum is identified as a transition between temperature dependent intragranular metallic conductance and thermally activated intergranular tunneling.

  7. Thin film application device and method for coating small aperture vacuum vessels

    SciTech Connect

    Walters, Dean R; Este, Grantley O

    2015-01-27

    A device and method for coating an inside surface of a vessel is provided. In one embodiment, a coating device comprises a power supply and a diode in electrical communication with the power supply, wherein electrodes comprising the diode reside completely within the vessel. The method comprises reversibly sealing electrodes in a vessel, sputtering elemental metal or metal compound on the surface while maintaining the surface in a controlled atmosphere.

  8. Structured nanoporous surfaces from hybrid block copolymer micelle films with metal ions

    NASA Astrophysics Data System (ADS)

    Kim, Minsoo P.; Kim, Hyeong Jun; Kim, Bumjoon J.; Yi, Gi-Ra

    2015-03-01

    We present a novel method for producing structured nanoporous thin films using block copolymer (BCP) micelles loaded with metallic ions. The BCP micellar thin films containing gold (Au) ions were prepared by spin-coating poly(styrene-block-4-vinylpyridine) (PS-b-P4VP) micelle solutions in which Au precursors (AuCl4-) were selectively loaded onto the P4VP core. When the micellar films were exposed to cetyltrimethylammonium bromide (CTAB) solutions, the Au precursors were selectively extracted from the P4VP domains due to their strong electrostatic interaction with CTAB, leading to the formation of pores in the micelles. Consequently, regularly patterned nanoporous surfaces were formed. By controlling the molecular weight (Mn) of PS-b-P4VP and the amount of Au precursors (λ) that were loaded in the P4VP domains, the pore size and depth could be tuned precisely. In particular, when a sufficient amount of Au precursors was loaded (λ ≥ 0.3), the porous surface nanostructure was well developed. In addition, the pore size and depth of the nanostructure increased as the λ value increased. For instance, when the λ value increased from 0.3 to 1.0, the pore size increased from 22.8 nm to 28.8 nm, and the pore depth increased from 2.1 nm to 3.2 nm. Interestingly, the transition from the nonporous structures to the porous structures in the micellar film could be reversibly controlled by adding and removing the Au precursors in the film. Moreover, our method for the preparation of nanoporous films can be extended to micellar film by incorporating other metal ions such as silver (Ag) and iron (Fe).

  9. Polymer-assisted deposition of films

    DOEpatents

    McCleskey, Thomas M.; Burrell, Anthony K.; Jia, Quanxi; Lin, Yuan

    2008-04-29

    A polymer assisted deposition process for deposition of metal oxide films is presented. The process includes solutions of one or more metal precursor and soluble polymers having binding properties for the one or more metal precursor. After a coating operation, the resultant coating is heated at high temperatures to yield metal oxide films. Such films can be epitaxial in structure and can be of optical quality. The process can be organic solvent-free.

  10. Polymer-assisted deposition of films

    DOEpatents

    McCleskey, Thomas M.; Burrell; Anthony K.; Jia; Quanxi; Lin; Yuan

    2009-10-20

    A polymer assisted deposition process for deposition of metal oxide films and the like is presented. The process includes solutions of one or more metal precursor and soluble polymers having binding properties for the one or more metal precursor. After a coating operation, the resultant coating is heated at high temperatures to yield metal oxide films and the like. Such films can be epitaxial in structure and can be of optical quality. The process can be organic solvent-free.

  11. Tackiness of acrylic and cellulosic polymer films used in the coating of solid dosage forms.

    PubMed

    Wesseling, M; Kuppler, F; Bodmeier, R

    1999-01-01

    The objective was to determine the tackiness of acrylic and cellulosic polymer films in order to make predictions on the tackiness (agglomeration) of coated dosage forms during coating and curing. Force-displacement curves of the detachment process of two polymeric films were used as a measure of tackiness. Various polymers (cellulosic (Aquacoat and acrylics (Eudragit RS 30D, L 30D, NE 30D)), plasticizers (triacetin, triethyl citrate, tributyl citrate, acetyltributyl citrate) and anti-tacking agents (talc and glyceryl monostearate) were investigated. The order of tackiness for films prepared from the different aqueous polymer dispersions was in order of Eudragit NE 30D > RS 30D > RL 30D > Aquacoat. The tackiness increased with increasing plasticizer concentration due to the softening of the polymer. A correlation between the minimum film formation temperature and the tackiness was observed, however, no correlation between the tackiness and the lipophilicity of the plasticizer was seen. Talc and glyceryl monostearate (GMS) reduced the tackiness of the films significantly, with GMS being effective at much lower concentrations. Curing of Eudragit RS 30D-coated theophylline beads at temperatures higher than 40 degrees C in an irreversible agglomeration of the beads and damage of the coating upon separation of the beads. This resulted in a faster release than with uncured beads. Blending the beads with talc just prior to the curing step eliminated the agglomeration and therefore film damage, even at a curing temperature of 60 degrees C. PMID:10234529

  12. Tackiness of acrylic and cellulosic polymer films used in the coating of solid dosage forms.

    PubMed

    Wesseling, M; Kuppler, F; Bodmeier, R

    1999-01-01

    The objective was to determine the tackiness of acrylic and cellulosic polymer films in order to make predictions on the tackiness (agglomeration) of coated dosage forms during coating and curing. Force-displacement curves of the detachment process of two polymeric films were used as a measure of tackiness. Various polymers (cellulosic (Aquacoat and acrylics (Eudragit RS 30D, L 30D, NE 30D)), plasticizers (triacetin, triethyl citrate, tributyl citrate, acetyltributyl citrate) and anti-tacking agents (talc and glyceryl monostearate) were investigated. The order of tackiness for films prepared from the different aqueous polymer dispersions was in order of Eudragit NE 30D > RS 30D > RL 30D > Aquacoat. The tackiness increased with increasing plasticizer concentration due to the softening of the polymer. A correlation between the minimum film formation temperature and the tackiness was observed, however, no correlation between the tackiness and the lipophilicity of the plasticizer was seen. Talc and glyceryl monostearate (GMS) reduced the tackiness of the films significantly, with GMS being effective at much lower concentrations. Curing of Eudragit RS 30D-coated theophylline beads at temperatures higher than 40 degrees C in an irreversible agglomeration of the beads and damage of the coating upon separation of the beads. This resulted in a faster release than with uncured beads. Blending the beads with talc just prior to the curing step eliminated the agglomeration and therefore film damage, even at a curing temperature of 60 degrees C.

  13. Effects of a ceramic coating on metal temperatures of an air-cooled turbine vane

    NASA Astrophysics Data System (ADS)

    Gladden, H. J.; Liebert, C. H.

    1980-02-01

    The metal temperatures of air cooled turbine vanes both uncoated and coated with the NASA thermal barrier system were studied experimentally. Current and advanced gas turbine engine conditions were simulated at reduced temperatures and pressures. Airfoil metal temperatures were significantly reduced, both locally and on the average, by use of the the coating. However, at low gas Reynolds number, the ceramic coating tripped a laminar boundary layer on the suction surface, and the resulting higher heat flux increased the metal temperatures. Simulated coating loss was also investigated and shown to increase local metal temperatures. However, the metal temperatures in the leading edge region remained below those of the uncoated vane tested at similar conditions. Metal temperatures in the trailing edge region exceeded those of the uncoated vane.

  14. Effects of a ceramic coating on metal temperatures of an air-cooled turbine vane

    NASA Technical Reports Server (NTRS)

    Gladden, H. J.; Liebert, C. H.

    1980-01-01

    The metal temperatures of air cooled turbine vanes both uncoated and coated with the NASA thermal barrier system were studied experimentally. Current and advanced gas turbine engine conditions were simulated at reduced temperatures and pressures. Airfoil metal temperatures were significantly reduced, both locally and on the average, by use of the the coating. However, at low gas Reynolds number, the ceramic coating tripped a laminar boundary layer on the suction surface, and the resulting higher heat flux increased the metal temperatures. Simulated coating loss was also investigated and shown to increase local metal temperatures. However, the metal temperatures in the leading edge region remained below those of the uncoated vane tested at similar conditions. Metal temperatures in the trailing edge region exceeded those of the uncoated vane.

  15. Trace metal ion partitioning at polymer film-metal oxide interfaces: long-period X-ray standing wave study.

    PubMed

    Yoon, Tae Hyun; Trainor, Thomas P; Eng, Peter J; Bargar, John R; Brown, Gordon E

    2005-05-10

    The distributions of Pb(II) and As(V)O4(3-) ions in the interfacial region between thin poly(acrylic acid) (PAA) coatings and aalpha-A12O3(0001), alpha-Al2O3(1-102), and alpha-Fe2O3(0001) single-crystal substrates were studied using long-period X-ray standing wave fluorescent yield (XSW-FY) and X-ray reflectivity techniques. The PAA film serves as a simplified analogue of natural organic matter (NOM) coatings on mineral surfaces. Such coatings are often assumed to play an important role in the partitioning and speciation of trace heavy metals in soils and aquatic systems. On the alpha-Al2O3(1-102) surface, Pb(II) ions were found to preferentially bind to the PAA coating, even at sub-micromolar Pb(II) concentrations, and to partition increasingly onto the metal oxide surface as the Pb(II) concentration was increased ([Pb(II)] = 5 x 10(-8) to 2 x 10(-5) M, pH = 4.5; 0.01 M NaCl background electrolyte). This observation suggests that the binding sites in the PAA coating outcompete those on the alpha-Al2O3(1-102) surface for Pb(II) under these conditions. The As(V)O4(3-) oxoanion partitions preferentially to the L-Al2O3(1-102) surface for the As(V)O4(3-) concentrations examined (1 x 10(-7) to 5 x 10(-7) M, pH = 4.5; 0.01 M NaCl background electrolyte). Partitioning of Pb(II) (at 1 x 10(-7) M and pH 4.5) was also examined at PAA/alpha-Al2O3(0001), and PAA/alpha-Fe2O3(0001) interfaces using XSW-FY measurements. Our results show that the PAA coating was the dominant sink for Pb(II) in all three samples; however, the relative order of reactivity of these metal oxide surfaces with respect to Pb(II) sorption is alpha-Fe2O3(0001) > alpha-Al2O3(1-102) > alpha-Al2O3(0001). This order is consistent with that found in previous studies of the PAA-free surfaces. These XSW results strongly suggest that the characteristics of the organic film (i.e., binding affinity, type, and density of binding sites) as well as metal oxide substrate reactivity are key factors determining the

  16. SnS thin films deposited by chemical bath deposition, dip coating and SILAR techniques

    NASA Astrophysics Data System (ADS)

    Chaki, Sunil H.; Chaudhary, Mahesh D.; Deshpande, M. P.

    2016-05-01

    The SnS thin films were synthesized by chemical bath deposition (CBD), dip coating and successive ionic layer adsorption and reaction (SILAR) techniques. In them, the CBD thin films were deposited at two temperatures: ambient and 70 °C. The energy dispersive analysis of X-rays (EDAX), X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM) and optical spectroscopy techniques were used to characterize the thin films. The electrical transport properties studies on the as-deposited thin films were done by measuring the I-V characteristics, DC electrical resistivity variation with temperature and the room temperature Hall effect. The obtained results are deliberated in this paper.

  17. Nanocomposites biodegradable coating on BOPET films to enhance hot seal strength properties

    NASA Astrophysics Data System (ADS)

    Barbaro, G.; Galdi, M. R.; Di Maio, L.; Incarnato, L.

    2015-12-01

    The coating technology is a strategic solution to improve the properties of flexible packaging films. Indeed, additional functional layers are often designed and added as coating on the substrate, in order to improve the characteristic of the flexible packaging and to meet the requirements for the desired gas or vapour barrier, for adhesion and sealing, or for improving the film printability, its aesthetics and durability. Moreover, this technology allows to functionalize a polymeric substrate applying materials with different chemistry, rheology, thermal and structural characteristics. BOPET films are widely used for food packaging applications thanks to their good gas barrier and mechanical properties, high transparency and for the excellent printability. In regard to sealing performance, BOPET films show poor sealing properties so they are mostly submitted to lamination processes with polyethylene. Nevertheless, this solution compromises the PET recyclability and influences the gas permeability of the multilayer PET based structures. The aim of this work is to investigate on the effect of nanocomposite biodegradable coatings for BOPET substrates in enhancing the heat sealing strength of eco-compatible PET/PLA films. At this regards, different percentages of Cloisite C30B (0%, 2% and 4%wt/wt) have been added to PLA by solution intercalation technique and the nanocomposite biodegradable materials produced have been applied on BOPET commercial films by casting. The BOPET coated films have been characterized in order to evaluate the heat sealing strength and the mechanical, gas permeability and surface properties. The results have shown that the addition of nanoclay in PLA coating significantly enhance the hot tack properties of the PET/PLA system produced, while the oxygen and water vapour permeability are slightly increased if compared to pure BOPET films.

  18. Nanocomposites biodegradable coating on BOPET films to enhance hot seal strength properties

    SciTech Connect

    Barbaro, G. Galdi, M. R. Di Maio, L. Incarnato, L.

    2015-12-17

    The coating technology is a strategic solution to improve the properties of flexible packaging films. Indeed, additional functional layers are often designed and added as coating on the substrate, in order to improve the characteristic of the flexible packaging and to meet the requirements for the desired gas or vapour barrier, for adhesion and sealing, or for improving the film printability, its aesthetics and durability. Moreover, this technology allows to functionalize a polymeric substrate applying materials with different chemistry, rheology, thermal and structural characteristics. BOPET films are widely used for food packaging applications thanks to their good gas barrier and mechanical properties, high transparency and for the excellent printability. In regard to sealing performance, BOPET films show poor sealing properties so they are mostly submitted to lamination processes with polyethylene. Nevertheless, this solution compromises the PET recyclability and influences the gas permeability of the multilayer PET based structures. The aim of this work is to investigate on the effect of nanocomposite biodegradable coatings for BOPET substrates in enhancing the heat sealing strength of eco-compatible PET/PLA films. At this regards, different percentages of Cloisite C30B (0%, 2% and 4%{sub wt/wt}) have been added to PLA by solution intercalation technique and the nanocomposite biodegradable materials produced have been applied on BOPET commercial films by casting. The BOPET coated films have been characterized in order to evaluate the heat sealing strength and the mechanical, gas permeability and surface properties. The results have shown that the addition of nanoclay in PLA coating significantly enhance the hot tack properties of the PET/PLA system produced, while the oxygen and water vapour permeability are slightly increased if compared to pure BOPET films.

  19. Insights on Capacitive Interdigitated Electrodes Coated with MOF Thin Films: Humidity and VOCs Sensing as a Case Study

    PubMed Central

    Sapsanis, Christos; Omran, Hesham; Chernikova, Valeriya; Shekhah, Osama; Belmabkhout, Youssef; Buttner, Ulrich; Eddaoudi, Mohamed; Salama, Khaled N.

    2015-01-01

    A prototypical metal-organic framework (MOF), a 2D periodic porous structure based on the assembly of copper ions and benzene dicarboxylate (bdc) ligands (Cu(bdc)·xH2O), was grown successfully as a thin film on interdigitated electrodes (IDEs). IDEs have been used for achieving planar CMOS-compatible low-cost capacitive sensing structures for the detection of humidity and volatile organic compounds (VOCs). Accordingly, the resultant IDEs coated with the Cu(bdc)·xH2O thin film was evaluated, for the first time, as a capacitive sensor for gas sensing applications. A fully automated setup, using LabVIEW interfaces to experiment conduction and data acquisition, was developed in order to measure the associated gas sensing performance. PMID:26213943

  20. Growth of CdS thin films on indium coated glass substrates via chemical bath deposition and subsequent air annealing

    NASA Astrophysics Data System (ADS)

    Ghosh, Biswajit; Kumar, Kamlesh; Singh, Balwant Kr; Banerjee, Pushan; Das, Subrata

    2014-11-01

    In the present work attempts were made to synthesize indium doped CdS films by fabricating In/CdS bilayers using CBD-CdS on vacuum evaporated In thin films and subsequent air annealing. 135 nm CdS films were grown onto 20 nm and 35 nm indium coated glass substrate employing chemical bath deposition technique. The In/CdS bilayers thus formed were subjected to heat treatment at the temperatures between 200 and 400 °C for 4 min in the muffle furnace to facilitate indium to diffuse into the CdS films. XRD pattern ascertained no noticeable shift in lattice constant implying grain boundary metal segregation, while secondary ion mass spectrometry indicated the diffusion profile of indium into CdS matrices. Mass spectrometry results showed that substantial diffusion of indium had been taken place within CdS at 400 °C. Dark and photocurrent with different illumination time were measured to ascertain the photosensitivity of pure and composite CdS films.

  1. Nucleation and growth of epitaxial metal-oxide films based on polymer-assisted deposition.

    PubMed

    McCleskey, T M; Shi, P; Bauer, E; Highland, M J; Eastman, J A; Bi, Z X; Fuoss, P H; Baldo, P M; Ren, W; Scott, B L; Burrell, A K; Jia, Q X

    2014-04-01

    Polymer-assisted deposition (PAD) is one of the chemical solution deposition methods which have been successfully used to grow films, form coatings, and synthesize nanostructured materials. In comparison with other conventional solution-based deposition techniques, PAD differs in its use of water-soluble polymers in the solution that prevent the metal ions from unwanted chemical reactions and keep the solution stable. Furthermore, filtration to remove non-coordinated cations and anions in the PAD process ensures well controlled nucleation, which enables the growth of high quality epitaxial films with desired structural and physical properties. The precursor solution is prepared by mixing water-soluble polymer(s) with salt(s). Thermal treatment of the precursor films in a controlled environment leads to the formation of desired materials. Using BaTiO3 grown on SrTiO3 and LaMnO3 on LaAlO3 as model systems, we show the effect of filtration on the nucleation and growth of epitaxial complex metal-oxide films based on the PAD process. PMID:24158602

  2. High sensitive mesoporous TiO2-coated love wave device for heavy metal detection.

    PubMed

    Gammoudi, I; Blanc, L; Moroté, F; Grauby-Heywang, C; Boissière, C; Kalfat, R; Rebière, D; Cohen-Bouhacina, T; Dejous, C

    2014-07-15

    This work deals with the design of a highly sensitive whole cell-based biosensor for heavy metal detection in liquid medium. The biosensor is constituted of a Love wave sensor coated with a polyelectrolyte multilayer (PEM). Escherichia coli bacteria are used as bioreceptors as their viscoelastic properties are influenced by toxic heavy metals. The acoustic sensor is constituted of a quartz substrate with interdigitated transducers and a SiO2 guiding layer. However, SiO2 shows some degradation when used in a saline medium. Mesoporous TiO2 presents good mechanical and chemical stability and offers a high active surface area. Then, the addition of a thin titania layer dip-coated onto the acoustic path of the sensor is proposed to overcome the silica degradation and to improve the mass effect sensitivity of the acoustic device. PEM and bacteria deposition, and heavy metal influence, are real time monitored through the resonance frequency variations of the acoustic device. The first polyelectrolyte layer is inserted through the titania mesoporosity, favouring rigid link of the PEM on the sensor and improving the device sensitivity. Also, the mesoporosity of surface increases the specific surface area which can be occupied and favors the formation of homogeneous PEM. It was found a frequency shift near -20±1 kHz for bacteria immobilization with titania film instead of -7±3 kHz with bare silica surface. The sensitivity is highlighted towards cadmium detection. Moreover, in this paper, particular attention is given to the immobilization of bacteria and to biosensor lifetime. Atomic Force Microscopy characterizations of the biosurface have been done for several weeks. They showed significant morphological differences depending on the bacterial life time. We noticed that the lifetime of the biosensor is longer in the case of using a mesoporous TiO2 layer.

  3. Thin film thermoelectric devices as thermal control coatings: A study

    NASA Technical Reports Server (NTRS)

    Clemons, J. M.; Krupnick, A. C.

    1973-01-01

    Peltier effect, Thomson effect, and Seeback effect are utilized in design of thermal control coating that serves as versatile means for controlling heat absorbed and radiated by surface. Coatings may be useful in extreme temperature environment enclosures or as heat shields.

  4. Applications of edible films and coatings to processed foods

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Edible coatings have been successfully applied in processed foods such as meat, cereals, confectionaries, dried fruits, nuts and fresh and fresh-cut fruits and vegetables. These coatings are used to improve the quality and shelf-life of foods. Furthermore, different food ingredients, derived from ...

  5. Synthesis and characterisation of pack cemented aluminide coatings on metals

    NASA Astrophysics Data System (ADS)

    Houngninou, C.; Chevalier, S.; Larpin, J. P.

    2004-09-01

    The exposition of metallic materials to high temperature environments leads to their corrosion because of oxidation or sulphidation. One way to protect such materials is to produce an Al 2O 3 layer which needs to be continuous enough to limit diffusion of oxygen or metallic elements, and withstand this corrosion. Since a few years, it has been proved that aluminide compounds are one of the most effective materials to achieve this goal. Indeed, they possess sufficient Al and many beneficial mechanical properties when exposed to high temperature conditions to make possible the formation of a protective Al 2O 3 scale. This study is aimed at the elaboration of iron, nickel and molybdenum aluminides by modification of the surface of the base materials by a pack cementation process. The as-cemented alloys were analysed by means of SEM coupled with EDX and by XRD. Cross-section examinations showed, in each case, a progressive diffusion of aluminium through the substrates. The diffusion thickness layer was more or less important depending on the base material and on the coating conditions.

  6. Development of metal-coated ceramic anodes for molten carbonate fuel cells

    SciTech Connect

    Khandkar, A.C.; Elangovan, S.; Marianowski, L.G.

    1990-03-01

    This report documents the developmental efforts on metal coating of various ceramic substrates (LiAlO{sub 2}, SrTiO{sub 3}, and LiFeO{sub 2}) and the critical issues associated with fabricating anodes using metal-coated LiAlO{sub 2} substrates. Electroless Ni and Cu coating technology was developed to achieve complete metal coverage on LiAlO{sub 2} powder substrates. Metal coated SrTiO{sub 3} powders were fabricated into anodes by a process identical to that reported in the GE literature. Microstructural examination revealed that the grains of the ceramic had fused together, with the metal having dewetted from the surface of the ceramic. Alternate substrates that might allow for better wetting of the metal on the ceramic such as LiFeO{sub 2} and Li{sub 2}MnO{sub 3} were identified. Cu/Ni-coated (50:50 mol ratio, 50 w/o metal loading) LiFeO{sub 2} anodes were optimized to meet the MCFC anode specifications. Metal-coated gamma-LiAlO{sub 2} substrates were also developed. By using suitable chemical surface modification methods, the gamma-UAlO{sub 2} substrate surface may be modified to allow a stable metal coated anode to be fabricated. Creep testing of the metal coated ceramic anodes were conducted at IGT. It was determined that the predominant creep mechanism is due to particle rearrangement. The anode porosity, and mean pore size had significant effect on the creep of the anode. Lower porosity and pore size consistent with performance criteria are desired to reduce creep. Lower metal loading with uniformity of coverage will result in lower creep behavior of the anode. Of the two substrates evaluated, LiFeO{sub 2} in general exhibited lower creep which was attributed to superior metal adhesion.

  7. Development of metal-coated ceramic anodes for molten carbonate fuel cells. Final report

    SciTech Connect

    Khandkar, A.C.; Elangovan, S.; Marianowski, L.G.

    1990-03-01

    This report documents the developmental efforts on metal coating of various ceramic substrates (LiAlO{sub 2}, SrTiO{sub 3}, and LiFeO{sub 2}) and the critical issues associated with fabricating anodes using metal-coated LiAlO{sub 2} substrates. Electroless Ni and Cu coating technology was developed to achieve complete metal coverage on LiAlO{sub 2} powder substrates. Metal coated SrTiO{sub 3} powders were fabricated into anodes by a process identical to that reported in the GE literature. Microstructural examination revealed that the grains of the ceramic had fused together, with the metal having dewetted from the surface of the ceramic. Alternate substrates that might allow for better wetting of the metal on the ceramic such as LiFeO{sub 2} and Li{sub 2}MnO{sub 3} were identified. Cu/Ni-coated (50:50 mol ratio, 50 w/o metal loading) LiFeO{sub 2} anodes were optimized to meet the MCFC anode specifications. Metal-coated gamma-LiAlO{sub 2} substrates were also developed. By using suitable chemical surface modification methods, the gamma-UAlO{sub 2} substrate surface may be modified to allow a stable metal coated anode to be fabricated. Creep testing of the metal coated ceramic anodes were conducted at IGT. It was determined that the predominant creep mechanism is due to particle rearrangement. The anode porosity, and mean pore size had significant effect on the creep of the anode. Lower porosity and pore size consistent with performance criteria are desired to reduce creep. Lower metal loading with uniformity of coverage will result in lower creep behavior of the anode. Of the two substrates evaluated, LiFeO{sub 2} in general exhibited lower creep which was attributed to superior metal adhesion.

  8. Orthopaedic metal devices coated with a novel antiseptic dye for the prevention of bacterial infections.

    PubMed

    Bahna, Paul; Dvorak, Tanya; Hanna, Hend; Yasko, Alan W; Hachem, Ray; Raad, Issam

    2007-05-01

    Gendine is a novel antiseptic dye with broad-spectrum antimicrobial activity that may be used to coat plastics and metal devices. Our objective was to determine the efficacy of gendine-coated orthopaedic metal devices in preventing methicillin-resistant Staphylococcus aureus (MRSA) colonisation. Stainless steel and titanium Schanz rods were coated with gendine. The zone of inhibition (ZoI) around the rods with and without gamma-irradiation was determined by a modified Kirby-Bauer method. A previously published bioprosthetic biofilm colonisation model, modified Kuhn's method, was used to determine the adherence of MRSA to coated and uncoated rods, with and without irradiation, after insertion into bovine bone and after 3 months shelf life followed by 2 weeks of immersion in serum. The gendine-coated Schanz metal rods showed a net ZoI of 16 mm against MRSA before and after irradiation. Gendine-coated rods showed no biofilm formation (0 colony-forming units (CFU)), which was a significant reduction (P<0.001) compared with uncoated controls (>5000 CFU). Coated rods exposed to high-dose gamma-irradiation and coated rods drilled into bone also showed significant efficacy (P<0.001) in preventing biofilm adherence. After 2 weeks, gendine-coated rods maintained significant durability (P<0.01), resulting in 90% reduction in MRSA biofilm adherence compared with uncoated control rods. Results indicate that gendine-coated metal rods are highly efficacious in the prevention of MRSA biofilm.

  9. Metal-organic chemical vapor deposition of cerium oxide, gallium-indium-oxide, and magnesium oxide thin films: Precursor design, film growth, and film characterization

    NASA Astrophysics Data System (ADS)

    Edleman, Nikki Lynn

    A new class of volatile, low-melting, fluorine-free lanthanide metal-organic chemical vapor deposition (MOCVD) precursors has been developed. The neutral, monomeric cerium, neodymium, gadolinium, and erbium complexes are coordinatively saturated by a versatile, multidentate, ether-functionalized beta-ketoiminate ligand, and complex melting point and volatility characteristics can be tuned by altering the alkyl substituents on the ligand periphery. Direct comparison with lanthanide beta-diketonate complexes reveals that the present precursor class is a superior choice for lanthanide oxide MOCVD. Epitaxial CeO 2 buffer layer films have been grown on (001) YSZ substrates by MOCVD at significantly lower temperatures than previously reported using one of the newly developed cerium precursors. High-quality YBCO films grown on these CeO2 buffer layers by POMBE exhibit very good electrical transport properties. The cerium complex has therefore been explicitly demonstrated to be a stable and volatile precursor and is attractive for low-temperature growth of coated conductor multilayer structures by MOCVD. Gallium-indium-oxide thin films (GaxIn2-xO 3), x = 0.0˜1.1, have been grown by MOCVD using the volatile metal-organic precursors In(dpm)3 and Ga(dpm)3. The films have a homogeneously Ga-substituted, cubic In2O3 microstructure randomly oriented on quartz or heteroepitaxial on (100) YSZ single-crystal substrates. The highest conductivity of the as-grown films is found at x = 0.12. The optical transmission window and absolute transparency of the films rivals or exceeds that of the most transparent conductive oxides known. Reductive annealing results in improved charge transport characteristics with little loss of optical transparency. No significant difference in electrical properties is observed between randomly oriented and heteroepitaxial films, thus arguing that carrier scattering effects at high-angle grain boundaries play a minor role in the film conductivity mechanism

  10. Effect of the manufacturing conditions on the structure and permeability of polymer films intended for coating undergoing phase separation.

    PubMed

    Marucci, Mariagrazia; Arnehed, Johan; Jarke, Annica; Matic, Hanna; Nicholas, Mark; Boissier, Catherine; von Corswant, Christian

    2013-02-01

    The major aim of this work was to study the effect of two process parameters, temperature and coating flow, on permeability to water and structure of free films sprayed from mixtures of ethyl cellulose (EC), hydroxypropyl cellulose (HPC), and ethanol. The films were sprayed in a new spraying setup that was developed to mimic the film coating process in a fluid bed and to provide well controlled conditions. EC and HPC phase separated during the film drying process, and EC- and HPC-rich domains were formed. The process parameters had a great impact on the structure and the permeability to water of the films. The longer the time before the film structure was locked by a high film viscosity, that is, the lower the temperature and the higher the coating flow, the larger the domains and the lower the film permeability. The effective diffusion coefficient of water in the films varied by about six times within the range of the process parameters studied. Structures of sprayed films and water effective diffusion coefficients in sprayed films were compared to those of cast films. For the cast films, the domains were bigger, and the permeability to water was significantly lower compared to those of the sprayed films. The results indicate that the process parameters can be used as a mean to regulate structure and permeability of coating films undergoing phase separation.

  11. Development and characterization of crosslinked hyaluronic acid polymeric films for use in coating processes.

    PubMed

    Sgorla, Débora; Almeida, Andreia; Azevedo, Claudia; Bunhak, Élcio Jose; Sarmento, Bruno; Cavalcanti, Osvaldo Albuquerque

    2016-09-10

    The aim of this work was to develop and characterize new hyaluronic acid-based responsive materials for film coating of solid dosage forms. Crosslinking of hyaluronic acid with trisodium trimetaphosphate was performed under controlled alkaline aqueous environment. The films were produced through casting process by mixing crosslinked or bare biopolymer in aqueous dispersion of ethylcellulose, at different proportions. Films were further characterized regarding morphology by scanning electron microscopy, robustness by permeation to water vapor transmission, and ability to hydrate in simulated gastric and intestinal physiological fluids. The safety and biocompatibility of films were assessed against Caco-2 and HT29-MTX intestinal cells. The permeation to water vapor transmission was favored by increasing hyaluronic acid content in the final formulation. When in simulated gastric fluid, films exhibited lower hydration ability compared to more extensive hydration in simulated intestinal fluids. Simultaneously, in simulated intestinal fluids, films partially lost weight, revealing ability for preventing drug release at gastric pH, but tailoring the release at higher intestinal pH. The physiochemical characterization suggests thermal stability of films and physical interaction between compounds of formulation. Lastly, cytotoxicity tests demonstrated that films and individual components of the formulations, when incubated for 4h, were safe for intestinal cells Overall, these evidences suggest that hyaluronic acid-based responsive films, applied as coating material of oral solid dosage forms, can prevent the premature release of drugs in harsh stomach conditions, but control the release it in gastrointestinal tract distal portion, assuring safety to intestinal mucosa. PMID:27436707

  12. Starch acetate--a novel film-forming polymer for pharmaceutical coatings.

    PubMed

    Tarvainen, Maarit; Sutinen, Riitta; Peltonen, Soili; Tiihonen, Päivi; Paronen, Petteri

    2002-01-01

    Starch acetates (SA) have been investigated as novel, multifunctional excipients for the direct compression tableting process. In this study, the film-forming ability of SA (DS 2.8) and the effect of commonly used plasticizers on the physical properties of SA films were evaluated. The results were compared with the properties of ethylcellulose (EC). Free films were prepared by a solvent-cast method. Mechanical studies, water vapor and drug permeability tests, and thermal analysis (DSC) were used to characterize the film-forming ability of SA and efficiency of tested plasticizers. SA films were tougher and stronger than EC films at the same plasticizer concentration. Also, in most cases, the water vapor permeability of SA films was lower than that of EC films. DSC thermograms supported the findings of the tensile test: plasticizers with several small ester groups (e.g., triacetin and triethyl citrate) were the most compatible with SA. Due to the good mechanical properties, low water vapor, and drug permeabilities of the films, SA seems to be a promising film-former for pharmaceutical coatings. The toughness of SA films may result from their dense film structure, which is due to strong interaction forces between adjacent SA molecular chains. PMID:11782918

  13. Physical properties of whey protein coating solutions and films containing antioxidants.

    PubMed

    Han, J H; Krochta, J M

    2007-06-01

    Antioxidants (ascorbyl palmitate and alpha-tocopherol) were incorporated into 10% (w/w) whey protein isolate (WPI) coating solution containing 6.67% (w/w) glycerol (WPI:glycerol = 6:4). Before incorporation, the antioxidants were mixed using either powder blending (Process 1) or ethanol solvent-mixing (Process 2). After the antioxidant mixtures were incorporated into heat-denatured WPI solution, viscosity and turbidity of the WPI solutions were determined. The WPI solutions were dried on a flat surface to produce WPI films. The WPI films were examined to determine transparency and oxygen-barrier properties (permeability, diffusivity, and solubility). WPI solution containing antioxidants produced by Process 1 and Process 2 did not show any difference in viscosity and turbidity, but viscosity was greater for the WPI solution with rather than without antioxidants. WPI films produced by Process 2 were more transparent than the films produced by Process 1. Oxygen permeability of Process 1 film was lower than Process 2 film. However, both the diffusivity and solubility of oxygen were statistically the same in Process 1 and Process 2 films. Both control WPI films and antioxidant-containing WPI films had very low oxygen solubility, comparable to polyethylene terephthalate films. Permeability of antioxidant-incorporated films was not enhanced compared to control WPI films.

  14. Thick, low-stress films, and coated substrates formed therefrom

    DOEpatents

    Henager, Jr., Charles H.; Knoll, Robert W.

    1991-01-01

    Stress-induced deformation, and the damage resulting therefrom, increases with film thickness. The overcoming of excessive stress by the use of the film material of the present invention, permits the formation of thick films that are necessary for certain of the above described applications. The most likely use for the subject film materials, other than their specialized views as an optical film, is for microelectronic packaging of components on silicon substrates. In general, the subject Si-Al-O-N films have excellent adherence to the underlying substrate, a high degree of hardness and durability, and are excellent insulators. Prior art elevated temperature deposition processes cannot meet the microelectronic packaging temperature formation constraints. The process of the present invention is conducted under non-elevated temperature conditions, typically 500# C. or less.

  15. Electron stimulated hydroxylation of a metal supported silicate film.

    PubMed

    Yu, Xin; Emmez, Emre; Pan, Qiushi; Yang, Bing; Pomp, Sascha; Kaden, William E; Sterrer, Martin; Shaikhutdinov, Shamil; Freund, Hans-Joachim; Goikoetxea, Itziar; Wlodarczyk, Radoslaw; Sauer, Joachim

    2016-02-01

    Water adsorption on a double-layer silicate film was studied by using infrared reflection-absorption spectroscopy, thermal desorption spectroscopy and scanning tunneling microscopy. Under vacuum conditions, small amounts of silanols (Si-OH) could only be formed upon deposition of an ice-like (amorphous solid water, ASW) film and subsequent heating to room temperature. Silanol coverage is considerably enhanced by low-energy electron irradiation of an ASW pre-covered silicate film. The degree of hydroxylation can be tuned by the irradiation parameters (beam energy, exposure) and the ASW film thickness. The results are consistent with a generally accepted picture that hydroxylation occurs through hydrolysis of siloxane (Si-O-Si) bonds in the silica network. Calculations using density functional theory show that this may happen on Si-O-Si bonds, which are either parallel (i.e., in the topmost silicate layer) or vertical to the film surface (i.e., connecting two silicate layers). In the latter case, the mechanism may additionally involve the reaction with a metal support underneath. The observed vibrational spectra are dominated by terminal silanol groups (ν(OD) band at 2763 cm(-1)) formed by hydrolysis of vertical Si-O-Si linkages. Film dehydroxylation fully occurs only upon heating to very high temperatures (∼ 1200 K) and is accompanied by substantial film restructuring, and even film dewetting upon cycling hydroxylation/dehydroxylation treatment.

  16. High Performance Optical Coatings Utilizing Tailored Refractive Index Nanoporous Thin Films

    NASA Astrophysics Data System (ADS)

    Poxson, David J.

    Refractive index is perhaps the most important quantity in optics. It is particularly relevant in the field of optical coatings, where the refractive index appears in virtually every optics equation as a figure of merit. Recently it has been demonstrated through control of the deposition angle during oblique-angle electron-beam deposition, nanoporous films of virtually any desired porosity may be accurately deposited. As the porosity of a nanoporous film directly relates to its effective refractive index, the refractive index value of a film may be tailored to any value between that of the bulk material and close to that of air. These two characteristics, namely; (i) tailored-refractive index and (ii) very low-refractive index values close to that of air, offer significant advantages in the design and optical performance in all optical coating applications. In this dissertation we explore optical coating applications whose performance can be greatly enhanced by utilization of a tailored- and low-refractive index nanoporous material system. One such important application is in the design and fabrication of broadband, omnidirectional antireflection (AR) coatings on solar cell devices. To harness the full spectrum of solar energy, Fresnel reflections at the surface of a photovoltaic cell must be reduced as much as possible over the relevant solar wavelength range and over a wide range of incident angles. However, the development of AR coatings embodying omni-directionality over a wide range of wavelengths is challenging. By utilizing the tailored- and low-refractive index properties of the nanoporous material system, in conjunction with a computational genetic algorithm and a predictive quantitative model for the porosity of such nanoporous films, truly optimized AR coatings can be designed and fabricated on solar cells. Here we show that these optimized AR structures demonstrate significant improvement to overall device efficiency. Traditionally, nanoporous films

  17. Metallic amorphous electrodeposited molybdenum coating from aqueous electrolyte: Structural, electrical and morphological properties under current density

    NASA Astrophysics Data System (ADS)

    Nemla, Fatima; Cherrad, Djellal

    2016-07-01

    Molybdenum coatings are extensively utilized as back contact for CIGS-based solar cells. However, their electrodeposition from aqueous electrolyte still sophisticates, since long time, owing to the high reactivity with oxygen. In this study, we present a successful 30 min electrodeposition experiment of somewhat thick (∼0.98-2.9 μm) and of moderate surface roughness RMS (∼47-58 nm), metallic bright Mo coating from aqueous electrolyte containing molybdate ions. XRD analysis and Hall Effect measurements have been used to confirm the presence of Mo. The crystal structure of deposits was slightly amorphous in nature to body centred cubic structure (bcc) Mo (110), (211) and (220) face. Lattice parameters exhibit some weak fluctuated tensile stress when compared to the reference lattice parameter. Additionally, our calculated lattice parameters are in good agreement with some previous works from literature. Discussions on the grain growth prove that they are constrained by grain boundary energy not the thickness effect. Further discussions were made on the electrical resistivity and surface morphology. Resonance scattering of Fermi electrons are expected to contribute towards the variation in the film resistivity through the carrier mobility limitation. However, studied samples might be qualified as candidates for solar cell application.

  18. Erosion of mylar and protection by thin metal films

    NASA Technical Reports Server (NTRS)

    Fraundorf, P.; Lindstrom, D.; Sandford, S.; Swan, P.; Walker, R.; Zinner, E.; Pailer, N.

    1983-01-01

    Mylar strips, 2.5 microns thick, uncoated and coated with 50A, 100A and 200A of Al, Pd, and Au/Pd were exposed on STS-5 in order to measure the erosion of mylar and to test means of protecting thin plastic foils commonly used for space experiments in low earth orbit. Analysis by optical microscopy, SEM and STEM investigation, EDX measurements, FTIR spectroscopy and weight loss measurements showed that while up to 75 percent of the uncoated mylar was eroded during exposure, thin coatings of the above metals can protect mylar for integrated oxygen-fluxes of at least 10 to the 21st atoms/sq cm.

  19. Modeling emissivity of low-emissivity coating containing horizontally oriented metallic flake particles

    NASA Astrophysics Data System (ADS)

    Chen, Shuai; Yuan, Le; Weng, Xiaolong; Deng, Longjiang

    2014-11-01

    The scattering and absorption cross sections of horizontally oriented metallic flake particles are estimated by extended geometric optics that includes diffraction and edge effects. Emissivity of the coating containing those particles is calculated using Kubelka-Munk theory. The dependence of emissivity of the coating on the radius, thickness, content of metallic flake particles and coating thickness is discussed. Finally, theoretical results are compared with the experimental measurements with Al/acrylic resin coating system and the results show that simulation values are in good agreement with experimental ones.

  20. CCD imaging sensor with flashed backside metal film

    NASA Technical Reports Server (NTRS)

    Janesick, James R. (Inventor)

    1991-01-01

    A backside illuminated CCD imaging sensor for reading out image charges from wells of the array of pixels is significantly improved for blue, UV, far UV and low energy x-ray wavelengths (1-5000.ANG.) by so overthinning the backside as to place the depletion edge at the surface and depositing a thin transparent metal film of about 10.ANG. on a native-quality oxide film of less than about 30.ANG. grown on the thinned backside. The metal is selected to have a higher work function than that of the semiconductor to so bend the energy bands (at the interface of the semiconductor material and the oxide film) as to eliminate wells that would otherwise trap minority carriers. A bias voltage may be applied to extend the frontside depletion edge to the interface of the semiconductor material with the oxide film in the event there is not sufficient thinning. This metal film (flash gate), which improves and stabilizes the quantum efficiency of a CCD imaging sensor, will also improve the QE of any p-n junction photodetector.

  1. Producing CCD imaging sensor with flashed backside metal film

    NASA Technical Reports Server (NTRS)

    Janesick, James R. (Inventor)

    1988-01-01

    A backside illuminated CCD imaging sensor for reading out image charges from wells of the array of pixels is significantly improved for blue, UV, far UV and low energy x-ray wavelengths (1-5000.ANG.) by so overthinning the backside as to place the depletion edge at the surface and depositing a thin transparent metal film of about 10.ANG. on a native-quality oxide film of less than about 30.ANG. grown on the thinned backside. The metal is selected to have a higher work function than that of the semiconductor to so bend the energy bands (at the interface of the semiconductor material and the oxide film) as to eliminate wells that would otherwise trap minority carriers. A bias voltage may be applied to extend the frontside depletion edge to the interface of the semiconductor material with the oxide film in the event there is not sufficient thinning. This metal film (flash gate), which improves and stabilizes the quantum efficiency of a CCD imaging sensor, will also improve the QE of any p-n junction photodetector.

  2. Electrosprayed Metal Oxide Semiconductor Films for Sensitive and Selective Detection of Hydrogen Sulfide

    PubMed Central

    Ghimbeu, Camelia Matei; Lumbreras, Martine; Schoonman, Joop; Siadat, Maryam

    2009-01-01

    Semiconductor metal oxide films of copper-doped tin oxide (Cu-SnO2), tungsten oxide (WO3) and indium oxide (In2O3) were deposited on a platinum coated alumina substrate employing the electrostatic spray deposition technique (ESD). The morphology studied with scanning electron microscopy (SEM) and atomic force microscopy (AFM) shows porous homogeneous films comprising uniformly distributed aggregates of nano particles. The X-ray diffraction technique (XRD) proves the formation of crystalline phases with no impurities. Besides, the Raman cartographies provided information about the structural homogeneity. Some of the films are highly sensitive to low concentrations of H2S (10 ppm) at low operating temperatures (100 and 200 °C) and the best response in terms of Rair/Rgas is given by Cu-SnO2 films (2500) followed by WO3 (1200) and In2O3 (75). Moreover, all the films exhibit no cross-sensitivity to other reducing (SO2) or oxidizing (NO2) gases. PMID:22291557

  3. Electrosprayed metal oxide semiconductor films for sensitive and selective detection of hydrogen sulfide.

    PubMed

    Ghimbeu, Camelia Matei; Lumbreras, Martine; Schoonman, Joop; Siadat, Maryam

    2009-01-01

    Semiconductor metal oxide films of copper-doped tin oxide (Cu-SnO(2)), tungsten oxide (WO(3)) and indium oxide (In(2)O(3)) were deposited on a platinum coated alumina substrate employing the electrostatic spray deposition technique (ESD). The morphology studied with scanning electron microscopy (SEM) and atomic force microscopy (AFM) shows porous homogeneous films comprising uniformly distributed aggregates of nano particles. The X-ray diffraction technique (XRD) proves the formation of crystalline phases with no impurities. Besides, the Raman cartographies provided information about the structural homogeneity. Some of the films are highly sensitive to low concentrations of H(2)S (10 ppm) at low operating temperatures (100 and 200 °C) and the best response in terms of R(air)/R(gas) is given by Cu-SnO(2) films (2500) followed by WO(3) (1200) and In(2)O(3) (75). Moreover, all the films exhibit no cross-sensitivity to other reducing (SO(2)) or oxidizing (NO(2)) gases. PMID:22291557

  4. Drug release from film-coated chlorpheniramine maleate nonpareil beads: effect of water-soluble polymer, coating level, and soluble core material.

    PubMed

    Tang, L; Schwartz, J B; Porter, S C; Schnaare, R L; Wigent, R J

    2000-01-01

    The purpose of this research was to use a new drug release model to study the effects of formulation parameters on drug release from a film-coated chlorpheniramine (CPM) nonpareil system. The film-coated CPM nonpareils were prepared by using a fluid bed apparatus. A hydroxylpropylmethylcellulose (HPMC) solution was blended with an aqueous ethylcellulose dispersion (Surelease) to adjust the permeability of the film. The apparent permeability of samples was obtained from dissolution data using a previously reported drug release equation. The apparent permeability was plotted versus the film coating level or the HPMC concentration in the film. When the natural logarithm of the apparent permeability versus coating level was graphed, a biphasic plot was observed in the group without HPMC in the film, showing the occurrence of a critical coating level. It was suggested that a mechanically formed porous film (due to an incomplete coating) could change to a nonporous film after the bead was completely coated. However, in the group that contained 12% HPMC in the film, the critical coating level was not observed. A porous film, formed by the leaching out of the water-soluble polymer, would not change to a nonporous film even after the bead is completely coated. Through a mathematical derivation, the decrease of apparent permeability versus coating level was related to the reduction of the total hole area. The apparent permeability was found to increase with the HPMC concentration. After a critical concentration was reached, the further addition of HPMC into the film caused a rapid increase in apparent permeability. The critical HPMC concentration was related to a minimum domain formation concentration (MDFC). A rapid increase of the drug release was observed when the dissolution profile of a sample made from a regular sugar nonpareil core (soluble) was compared with the sample made from a precoated nonpareil core (insoluble), which suggests that the drug release can be

  5. Ceramic thin films on plastics: a versatile transfer process for large area as well as patterned coating.

    PubMed

    Kozuka, Hiromitsu; Fukui, Takafumi; Takahashi, Mitsuru; Uchiyama, Hiroaki; Tsuboi, Shohei

    2012-12-01

    A versatile technique for fabricating ceramic thin films on plastics has been proposed. The technique comprises (i) the deposition of a gel film by spin- or dip-coating on a silicon substrate coated beforehand with a release layer, (ii) the firing of the gel film into a ceramic film, and (iii) its transfer onto plastics by melting or softening the plastics surface. Reflective anatase and electrically conductive indium-tin-oxide (ITO) thin films were prepared on acrylic resin and polycarbonate substrates. Patterned ITO thin films could also be fabricated on plastics by using a mother silicon substrate with periodic grooves. PMID:23211312

  6. Ceramic thin films on plastics: a versatile transfer process for large area as well as patterned coating.

    PubMed

    Kozuka, Hiromitsu; Fukui, Takafumi; Takahashi, Mitsuru; Uchiyama, Hiroaki; Tsuboi, Shohei

    2012-12-01

    A versatile technique for fabricating ceramic thin films on plastics has been proposed. The technique comprises (i) the deposition of a gel film by spin- or dip-coating on a silicon substrate coated beforehand with a release layer, (ii) the firing of the gel film into a ceramic film, and (iii) its transfer onto plastics by melting or softening the plastics surface. Reflective anatase and electrically conductive indium-tin-oxide (ITO) thin films were prepared on acrylic resin and polycarbonate substrates. Patterned ITO thin films could also be fabricated on plastics by using a mother silicon substrate with periodic grooves.

  7. Surface plasmon resonance image sensor module of spin-coated silver film with polymer layer.

    PubMed

    Son, Jung-Han; Lee, Dong Hun; Cho, Yong-Jin; Lee, Myung-Hyun

    2013-11-01

    Prism modules of 20 nm-, 40 nm-, and 60 nm-thick spin-coated silver films both without and with an upper 100 nm-thick spin-coated polymer layer were fabricated for surface plasmon resonance (SPR) image sensor applications. The prism modules were applied to an SPR image sensor system. The coefficients of determination (R2s) for the 20 nm-, 40 nm- and 60 nm-thick silver films without the polymer layer were 0.9231, 0.9901, and 0.9889, respectively, and with the polymer layer 0.9228, 0.9951, and 0.9880, respectively when standard ethanol solutions with 0.1% intervals in the range of 20.0% to 20.5% were applied. The upper polymer layer has no effect on the R2. The prism modules of the 40-nm-thick spin-coated silver films had the highest R2 value of approximately 0.99. The durability of the 40 nm-thick spin-coated silver film with the 100 nm-thick polymer layer is much better than that without the upper low-loss polymer layer. The developed SPR image sensor module of the 40 nm-thick spin-coated silver film with the upper 100 nm-thick low-loss polymer film is expected to be a very cost-effective and robust solution because the films are formed at low temperatures in a short period of time without requiring a vacuum system and are very durable.

  8. Effects of water in film boiling over liquid metal melts

    SciTech Connect

    Greene, G.A.; Finfrock, C.; Burson, S.B.

    1986-01-01

    Liquid-liquid boiling experiments have been performed with H/sub 2/O and liquid metal melts in the 100-series test matrix (Runs 121, 126, 127) and the VE test matrix. Some of the pre-explosion unstable film boiling data as well as observations from the explosive series have been previously reported.

  9. Super-hydrophobic surfaces of layer-by-layer structured film-coated electrospun nanofibrous membranes

    NASA Astrophysics Data System (ADS)

    Ogawa, Tasuku; Ding, Bin; Sone, Yuji; Shiratori, Seimei

    2007-04-01

    We have recently fabricated super-hydrophobic membrane surfaces based on the inspiration of self-cleaning silver ragwort leaves. This biomimetic super-hydrophobic surface was composed of fluoroalkylsilane (FAS)-modified layer-by-layer (LBL) structured film-coated electrospun nanofibrous membranes. The rough fibre surface caused by the electrostatic LBL coating of TiO2 nanoparticles and poly(acrylic acid) (PAA) was used to imitate the rough surface of nanosized grooves along the silver ragwort leaf fibre axis. The results showed that the FAS modification was the key process for increasing the surface hydrophobicity of the fibrous membranes. Additionally, the dependence of the hydrophobicity of the membrane surfaces upon the number of LBL coating bilayers was affected by the membrane surface roughness. Moreover, x-ray photoelectron spectroscopy (XPS) results further indicated that the surface of LBL film-coated fibres absorbed more fluoro groups than the fibre surface without the LBL coating. A (TiO2/PAA)10 film-coated cellulose acetate nanofibrous membrane with FAS surface modification showed the highest water contact angle of 162° and lowest water-roll angle of 2°.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  11. Development of an all-metal thick film cost effective metallization system for solar cells

    NASA Technical Reports Server (NTRS)

    Ross, B.; Parker, J.

    1983-01-01

    Improved thick film solar cell contacts for the high volume production of low cost silicon solar arrays are needed. All metal screenable pastes made from economical base metals and suitable for application to low to high conductivity silicon were examined. Silver fluoride containing copper pastes and fluorocarbon containing copper pastes were discussed. The effect of hydrogen on the adhesion of metals to silicon was investigated. A cost analysis of various paste materials is provided.

  12. Surface magnetoelectric effect in ferromagnetic metal films.

    PubMed

    Duan, Chun-Gang; Velev, Julian P; Sabirianov, R F; Zhu, Ziqiang; Chu, Junhao; Jaswal, S S; Tsymbal, E Y

    2008-09-26

    A surface magnetoelectric effect is revealed by density-functional calculations that are applied to ferromagnetic Fe(001), Ni(001), and Co(0001) films in the presence of an external electric field. The effect originates from spin-dependent screening of the electric field which leads to notable changes in the surface magnetization and the surface magnetocrystalline anisotropy. These results are of considerable interest in the area of electrically controlled magnetism and magnetoelectric phenomena. PMID:18851486

  13. Synthesis and Electrochemical Behavior of Ceria Based Bi-Layer Films by Dip Coating Technique.

    PubMed

    Chinnu, M Karl; Anand, K Vijai; Kumar, R Mohan; Alagesan, T; Jayavel, R

    2015-01-01

    Ceria based bi-layer films of CeO2-CdS and CeO2-TiO2 were prepared by sol-gel based hydrothermal route combined with dip-coating. The synthesized samples were subjected to various characterizations such as X-ray diffraction, Field emission scanning electron microscopy, thermo-gravimetric analysis, UV-Vis absorption and photoluminescence studies. The prepared materials were dissolved in naffion solution and disposed as a thin film on glassy carbon electrode by dip coating technique. Electrochemical Li+ intercalation/deintercalation was performed by cyclic voltammetry and these results indicate that the CeO2/LiClO4 system is electrochemically reversible. The total intercalation/deintercalation of the CeO2 film, CeO2-CdS and CeO2-TiO2 bi-layer films was determined by cyclic voltammetry, which showed increased charge storage capacity.

  14. Optical properties of metal oxynitride thin films grown with atmospheric plasma deposition

    NASA Astrophysics Data System (ADS)

    Hovish, Michael Q.; Dauskardt, Reinhold H.

    2016-10-01

    Thin films of tantalum oxynitride (TaO x N y ) and titanium oxynitride (TiO x N y ) are deposited using atmospheric plasma deposition and a suite of optical properties are reported. Tantalum and titanium ethoxide are introduced into the afterglow of a radio-frequency capacitively coupled plasma, facilitating the growth of oxynitride films on silicon and polycarbonate at temperatures below 180 °C. The plasma power and nitrogen flow within the plasma are varied between 60 and 120 W and between 0.1 and 0.3 LPM respectively. We use spectroscopic ellipsometry to show that the optical properties of the metal oxynitride films grown in this study are comparable to those synthesized with sol-gel methods. Measurement of both the extinction coefficient and the transmission on polycarbonate substrates indicates good transparency in the visible wavelengths of light. Additionally, the refractive index increases when increasing the number of reactive nitrogen species within the discharge. We use x-ray photoelectron spectroscopy to correlate the higher indexes observed at large secondary gas flows to the presence of metal oxynitride bonding. Single layer anti-reflection coatings are deposited on silicon, with a five-fold and seven-fold reduction in reflection for TaO x N y and TiO x N y coatings, respectively. In total, we have found that the modulation of nitrogen concentration within the plasma discharge results in good control over optical constants. In addition, we observe similarities between films deposited with atmospheric plasma and those reported for sol-gel, indicating an alternative processing route where solution chemistries are currently applied.

  15. Ceramic plasma-sprayed coating of melting crucibles for casting metal fuel slugs

    NASA Astrophysics Data System (ADS)

    Kim, Ki Hwan; Lee, Chong Tak; Lee, Chan Bock; Fielding, R. S.; Kennedy, J. R.

    2013-10-01

    Thermal cycling and melt reaction studies of ceramic coatings plasma-sprayed on Nb substrates were carried out to evaluate the performance of barrier coatings for metallic fuel casting applications. Thermal cycling tests of the ceramic plasma-sprayed coatings to 1450 °C showed that HfN, TiC, ZrC, and Y2O3 coating had good cycling characteristics with few interconnected cracks even after 20 cycles. Interaction studies by 1550 °C melt dipping tests of the plasma-sprayed coatings also indicated that HfN and Y2O3 do not form significant reaction layer between U-20 wt.% Zr melt and the coating layer. Plasma-sprayed Y2O3 coating exhibited the most promising characteristics among HfN, TiC, ZrC, and Y2O3 coating.

  16. Ceramic plasma-sprayed coating of melting crucibles for casting metal fuel slugs

    SciTech Connect

    K.H. Kim; C.T. Lee; C.B. Lee; R.S. Fielding; J.R. Kennedy

    2013-10-01

    Thermal cycling and melt reaction studies of ceramic coatings plasma-sprayed on Nb substrates were carried out to evaluate the performance of barrier coatings for metallic fuel casting applications. Thermal cycling tests of the ceramic plasma-sprayed coatings to 1450 degrees C showed that HfN, TiC, ZrC, and Y2O3 coating had good cycling characteristics with few interconnected cracks even after 20 cycles. Interaction studies by 1550 degrees C melt dipping tests of the plasma-sprayed coatings also indicated that HfN and Y2O3 do not form significant reaction layer between U–20 wt.% Zr melt and the coating layer. Plasma-sprayed Y2O3 coating exhibited the most promising characteristics among HfN, TiC, ZrC, and Y2O3 coating.

  17. Atomic Layer Deposition of Metal Oxide Thin Films on Metallic Substrates

    NASA Astrophysics Data System (ADS)

    Foroughi Abari, Ali

    Atomic layer deposition (ALD) is a powerful ultra-thin film deposition technique that uses sequential self-limiting surface reactions to provide conformal atomic scale film growth. Deposition of ALD films on many substrate systems has been studied before; however, limited data is available on deposition on metallic surfaces. The investigation of the growth of Al 2O3, HfO2, and ZrO2 as three technologically important metal oxides on metallic substrates is the subject of this thesis. Al2O3, HfO2, and ZrO2 films were grown by ALD on silicon, as a well-studied substrate, in different operating conditions to investigate the effect of process parameters on film properties. To study the growth of oxides on metals, thin metallic substrates were prepared by sputter deposition on silicon wafers and then were transferred to the ALD chamber where the film growth was monitored by in-situ spectroscopic ellipsometry. The transfer was performed via a load lock system without breaking the vacuum to preserve the pristine metal surface. Formation of a thin interfacial layer of metal oxide was observed during the initial moments of plasma enhanced ALD, that was due to the exposure of metal surface to oxygen plasma. In-situ spectroscopic ellipsometry was used to accurately measure the thickness change of the growing films including the interfacial layer. The thickness of this interfacial oxide layer depended on various process parameters including deposition temperature, order of precursors and plasma pulse length. The interfacial oxide layer was absent during the conventional thermal ALD. However, thermal ALD of oxides on metals exhibited substrate-inhibited growth, especially at higher deposition temperatures. With the knowledge of ALD growth characteristics on metals, metal-insulator-metal (MIM) devices were fabricated by both thermal and plasma enhanced ALD and electrically characterized. The presence of the interfacial oxide layer altered the device performance by changing the

  18. Production of strontium sulfide coatings by metal organic chemical vapor deposition

    SciTech Connect

    Moss, T.S.; Dye, R.C.; Tuenge, R.T.

    1998-11-01

    This work was focused on the MOCVD of the cerium-doped strontium sulfide (SrS:Ce) phosphor for use in thin film electroluminescent displays (TFELs). Following previous research on a small scale reactor, a feasibility scale-up using a commercially available reactor enlarged the size of the deposition area to a 4`` diameter wafer or a 2`` by 2`` glass slide. Films were deposited from the reaction of Sr(thd){sub 2}, Ce(thd){sub 4}, and H{sub 2}S at 450{degrees}C and 5 torr. This system employed a liquid delivery system for the accurate and repeatable delivery of the metal organic reagents. The deposition from this reactor was shown to be crystalline-as-deposited SrS with a (200) orientation, possibly a result of the thin nature of the coating and the involvement of (200) grains in the initial nucleation process. The wafers showed good uniformity, but had some thickness variation near the outer radius of the wafer resulting from the addition of H{sub 2}S from the outer edge. There were eighteen total deposition experiments, of which nine were characterized for EL performance. The highest brightness observed was 5 fL.. The samples were exceedingly thin as a result of the fifteen fold increase in the surface area between the deposition reactors. Increasing the sample thickness to 7,000{angstrom} or higher will dramatically increase the brightness of the emission.

  19. Preparation and Basic Properties of BaTiO3-BaPbO3 Multilayer Thin Films by Metal-Alkoxides Method

    NASA Astrophysics Data System (ADS)

    Azuma, Takahiro; Takahashi, Sheiji; Kuwabara, Makoto

    1993-09-01

    Preferentially oriented barium titanate (BTO)-barium metaplumbate (BPO) multilayer thin films were prepared by the metal-alkoxides method on MgO single crystals. The BPO layer is an electrode for the BTO layer. Thin films were deposited on cleaved MgO (100) substrates by spin coating. A BTO film of 0.4 μm thickness on the BPO layer shows a dielectric constant of about 400 at room temperature. No formation of reaction phases between BTO and BPO, fired at 800°C to yield a well-crystallized BTO film, was detected in X-ray diffraction analysis.

  20. High-rate reel-to-reel continuous coating of biaxially textured magnesium oxide thin films for coated conductors

    SciTech Connect

    Chudzik, M. P.; Erck, R. A.; Balachandran, U.; Luo, Z. P.; Miller, D. J.; Kannewurf, C. R.

    2000-01-12

    Biaxially textured thin films of magnesium oxide (MgO) were deposited by electron beam evaporation at deposition rates of 0.6 {mu}m/min on moving Ni-based alloy tapes as oriented buffer layers for coated conductors. Moving substrates were inclined with respect to the atomic vapor and translated through collimated dual vapor sources. Growth anisotropy in the MgO and self-shadowing effects due to the inclined angle combine to create biaxial texture in the deposited thin films. MgO films grown to a thickness of 2.0 {mu}m with this inclined-substrate deposition technique have yielded in-plane textures of 10--12{degree} fill-width half-maximum (FWHM). Results of a parametric study on the in-plane texture in short-length static-mode samples are presented, along with preliminary results of long-length samples deposited under translating conditions.