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Sample records for multilayer coating facility

  1. Multilayer optical dielectric coating

    DOEpatents

    Emmett, John L.

    1990-01-01

    A highly damage resistant, multilayer, optical reflective coating includes alternating layers of doped and undoped dielectric material. The doping levels are low enough that there are no distinct interfaces between the doped and undoped layers so that the coating has properties nearly identical to the undoped material. The coating is fabricated at high temperature with plasma-assisted chemical vapor deposition techniques to eliminate defects, reduce energy-absorption sites, and maintain proper chemical stoichiometry. A number of differently-doped layer pairs, each layer having a thickness equal to one-quarter of a predetermined wavelength in the material are combined to form a narrowband reflective coating for a predetermined wavelength. Broadband reflectors are made by using a number of narrowband reflectors, each covering a portion of the broadband.

  2. Multilayer thermal barrier coating systems

    DOEpatents

    Vance, Steven J.; Goedjen, John G.; Sabol, Stephen M.; Sloan, Kelly M.

    2000-01-01

    The present invention generally describes multilayer thermal barrier coating systems and methods of making the multilayer thermal barrier coating systems. The thermal barrier coating systems comprise a first ceramic layer, a second ceramic layer, a thermally grown oxide layer, a metallic bond coating layer and a substrate. The thermal barrier coating systems have improved high temperature thermal and chemical stability for use in gas turbine applications.

  3. Multilayer diamond coated WC tools

    SciTech Connect

    Fan, W.D.; Jagannaham, K.; Narayan, J.

    1995-12-31

    To increase adhesion of diamond coatings, a multilayer structure was developed. The multilayer diamond coating consisted of a first discontinuous diamond layer, an interposing layer, and a top continuous diamond layer. The diamond layer was grown on WC substrates by hot filament chemical vapor deposition and the interposing layer was grown by pulsed laser deposition. Machining tests were used to characterize adhesion properties of the multilayer diamond coatings on WC(Co) substrates. Results indicate that diamond coatings exhibit good adhesion on the WC tool substrates. The wear resistance of the WC tool is improved significantly by the diamond coatings.

  4. Rapid replication and facile modulation of subwavelength antireflective polymer film using injection nanomolding and optical property of multilayer coatings

    NASA Astrophysics Data System (ADS)

    Fuh, Yiin-Kuen; Peng, Cheng-Chang; Huang, Chieh-Tse

    2013-10-01

    A rapid, cost-effective and high-throughput process for nanotexturing subwavelength structures with high uniformity using the polycarbonate (PC) is realized via injection nanomolding. The process enables the precise control of nanohole array (NHA) surface topography (nanohole depth, diameter, and periodicity) over large areas thereby presenting a highly versatile platform for fabricating substrates with user-defined, functional performance. Specifically, the optical property of the PC substrates were systematically characterized and tuned through the modulation of the depths of NHA. The aspect ratio submicron holes can be easily modulated and experimentally proven by simply adjusting the molding temperature. The nanotextured depths were reliably fabricated in the range of 200 to 400 nm with a period of approximately 700 nm. The fabricated PC films can reduce the reflectivity from an original bare film of 10.2% and 8.9% to 1.4% and 2.1% with 400-nm depth of nanoholes at the wavelength of 400 and 550 nm, respectively. Compared with conventional moth-like nanostructures with nanopillar arrays with heights adjustable only by an etching process, this paper proposes a facile route with submicron holes to achieve a similar antireflective function, with a significantly reduced time and facile height modulation capability. Furthermore, the effects of multilayer coatings of dielectric and metallic layers on the nanomolded NHA have been performed and potential sensing application is explored.

  5. Rapid replication and facile modulation of subwavelength antireflective polymer film using injection nanomolding and optical property of multilayer coatings

    PubMed Central

    2013-01-01

    A rapid, cost-effective and high-throughput process for nanotexturing subwavelength structures with high uniformity using the polycarbonate (PC) is realized via injection nanomolding. The process enables the precise control of nanohole array (NHA) surface topography (nanohole depth, diameter, and periodicity) over large areas thereby presenting a highly versatile platform for fabricating substrates with user-defined, functional performance. Specifically, the optical property of the PC substrates were systematically characterized and tuned through the modulation of the depths of NHA. The aspect ratio submicron holes can be easily modulated and experimentally proven by simply adjusting the molding temperature. The nanotextured depths were reliably fabricated in the range of 200 to 400 nm with a period of approximately 700 nm. The fabricated PC films can reduce the reflectivity from an original bare film of 10.2% and 8.9% to 1.4% and 2.1% with 400-nm depth of nanoholes at the wavelength of 400 and 550 nm, respectively. Compared with conventional moth-like nanostructures with nanopillar arrays with heights adjustable only by an etching process, this paper proposes a facile route with submicron holes to achieve a similar antireflective function, with a significantly reduced time and facile height modulation capability. Furthermore, the effects of multilayer coatings of dielectric and metallic layers on the nanomolded NHA have been performed and potential sensing application is explored. PMID:24088185

  6. Rapid replication and facile modulation of subwavelength antireflective polymer film using injection nanomolding and optical property of multilayer coatings.

    PubMed

    Fuh, Yiin-Kuen; Peng, Cheng-Chang; Huang, Chieh-Tse

    2013-01-01

    A rapid, cost-effective and high-throughput process for nanotexturing subwavelength structures with high uniformity using the polycarbonate (PC) is realized via injection nanomolding. The process enables the precise control of nanohole array (NHA) surface topography (nanohole depth, diameter, and periodicity) over large areas thereby presenting a highly versatile platform for fabricating substrates with user-defined, functional performance. Specifically, the optical property of the PC substrates were systematically characterized and tuned through the modulation of the depths of NHA. The aspect ratio submicron holes can be easily modulated and experimentally proven by simply adjusting the molding temperature. The nanotextured depths were reliably fabricated in the range of 200 to 400 nm with a period of approximately 700 nm. The fabricated PC films can reduce the reflectivity from an original bare film of 10.2% and 8.9% to 1.4% and 2.1% with 400-nm depth of nanoholes at the wavelength of 400 and 550 nm, respectively. Compared with conventional moth-like nanostructures with nanopillar arrays with heights adjustable only by an etching process, this paper proposes a facile route with submicron holes to achieve a similar antireflective function, with a significantly reduced time and facile height modulation capability. Furthermore, the effects of multilayer coatings of dielectric and metallic layers on the nanomolded NHA have been performed and potential sensing application is explored. PMID:24088185

  7. Multi-layer coatings

    DOEpatents

    Maghsoodi, Sina; Brophy, Brenor L.; Abrams, Ze'ev R.; Gonsalves, Peter R.

    2016-06-28

    Disclosed herein are coating materials and methods for applying a top-layer coating that is durable, abrasion resistant, highly transparent, hydrophobic, low-friction, moisture-sealing, anti-soiling, and self-cleaning to an existing conventional high temperature anti-reflective coating. The top coat imparts superior durability performance and new properties to the under-laying conventional high temperature anti-reflective coating without reducing the anti-reflectiveness of the coating. Methods and data for optimizing the relative thickness of the under-layer high temperature anti-reflective coating and the top-layer thickness for optimizing optical performance are also disclosed.

  8. Ultrahard Multilayer Coatings

    SciTech Connect

    Chrzan, D.C.; Dugger, M.; Follstaedt, D.M.; Friedman, Lawrence H.; Friedmann, T.A.; Knapp, J.A.; McCarty, K.F.; Medlin, D.L.; Mirkarimi, P.B.; Missert, N.; Newcomer, P.P.; Sullivan, J.P.; Tallant, D.R.

    1999-05-01

    We have developed a new multilayer a-tC material that is thick stress-free, adherent, low friction, and with hardness and stiffness near that of diamond. The new a-tC material is deposited by J pulsed-laser deposition (PLD) at room temperature, and fully stress-relieved by a short thermal anneal at 600°C. A thick multilayer is built up by repeated deposition and annealing steps. We measured 88 GPa hardness, 1100 GPa Young's modulus, and 0.1 friction coefficient (under high load). Significantly, these results are all well within the range reported for crystalline diamond. In fact, this material, if considered separate from crystalline diamond, is the 2nd hardest material known to man. Stress-free a-tC also has important advantages over thin film diamond; namely, it is smooth, processed at lower temperature, and can be grown on a much broader range of substrates. This breakthrough will enable a host of applications that we are actively pursuing in MEMs, sensors, LIGA, etc.

  9. Figure correction of multilayer coated optics

    DOEpatents

    Chapman; Henry N. , Taylor; John S.

    2010-02-16

    A process is provided for producing near-perfect optical surfaces, for EUV and soft-x-ray optics. The method involves polishing or otherwise figuring the multilayer coating that has been deposited on an optical substrate, in order to correct for errors in the figure of the substrate and coating. A method such as ion-beam milling is used to remove material from the multilayer coating by an amount that varies in a specified way across the substrate. The phase of the EUV light that is reflected from the multilayer will be affected by the amount of multilayer material removed, but this effect will be reduced by a factor of 1-n as compared with height variations of the substrate, where n is the average refractive index of the multilayer.

  10. Repair of high performance multilayer coatings

    SciTech Connect

    Gaines, D.P. . Dept. of Physics and Astronomy); Ceglio, N.M. ); Vernon, S.P. ); Krumrey, M.; Mueller, P. . VUV Radiometric Lab.)

    1991-07-01

    Fabrication and environmental damage issues may require that the multilayer x-ray reflection coatings used in soft x-ray projection lithography be replaced or repaired. Two repair strategies were investigated. The first was to overcoat defective multilayers with a new multilayer. The feasibility of this approach was demonstrated by depositing high reflectivity (61% at 130 {Angstrom}) molybdenum silicon (Mo/Si) multilayers onto fused silica figured optics that had already been coated with a Mo/Si multilayer. Because some types of damage mechanisms and fabrication errors are not repairable by this method, a second method of repair was investigated. The multilayer was stripped from the optical substrate by etching a release layer which was deposited onto the substrate beneath the multilayer. The release layer consisted of a 1000 {Angstrom} aluminum film deposited by ion beam sputtering or by electron beam evaporation, with a 300 {Angstrom} SiO{sub 2} protective overcoat. The substrates were superpolished zerodur optical flats. The normal incidence x-ray reflectivity of multilayers deposited on these aluminized substrates was degraded, presumably due to the roughness of the aluminum films. Multilayers, and the underlying release layers, have been removed without damaging the substrates.

  11. Repair of high-performance multilayer coatings

    NASA Astrophysics Data System (ADS)

    Gaines, David P.; Ceglio, Natale M.; Vernon, Stephen P.; Krumrey, Michael K.; Mueller, Peter

    1992-01-01

    Fabrication and environmental damage issues may require that the multilayer x-ray reflection coatings used in soft x-ray projection lithography be replaced or repaired. Two repair strategies were investigated. The first was to overcoat defective multilayers with a new multilayer. The feasibility of this approach was demonstrated by depositing high reflectivity (61% at 130 A) molybdenum silicon (Mo/Si) multilayers onto fused silica figured optics that had already been coated with a Mo/Si multilayer. Because some types of damage mechanisms and fabrication errors are not repairable by this method, a second method of repair was investigated. The multilayer was stripped from the optical substrate by etching a release layer which was deposited onto the substrate beneath the multilayer. The release layer consisted of a 1000 A aluminum film deposited by ion beam sputtering or by electron beam evaporation, with a 300 A SiO protective overcoat. The substrates were superpolished zerodur optical flats. The normal incidence x-ray reflectivity of multilayers deposited on these aluminized substrates was degraded, presumably due to roughness of the aluminum films. Multilayers, and the underlying release layers, have been removed without damaging the substrates.

  12. Supplemental multilayer insulation research facility

    SciTech Connect

    Dempsey, P.J.; Stochl, R.J.

    1996-12-31

    The Supplemental Multilayer Insulation Research Facility (SMIRF) provides a small scale test bed for conducting cryogenic experiments in a vacuum environment. The facility vacuum system is capable of simulating a Space Shuttle launch pressure profile as well as providing a steady space vacuum environment of 1.3{times}10{sup -4} N/m{sup 2}(1 x 10{sup -6} torr). Warm side boundary temperatures can be maintained constant between 111 K(200 R) and 361 K(650 R) using a temperature controlled shroud. The shroud can also simulate a typical lunar day-night temperature profile. The test hardware consists of a cryogenic calorimeter supported by the lid of the vacuum chamber. A 0.45 m{sup 3} (120 gal) vacuum jacketed storage/supply tank is available for conditioning the cryogen prior to use in the calorimeter. The facility was initially designed to evaluate the thermal performance of insulation systems for long-term storage in space. The facility has recently been used to evaluate the performance of various new insulation systems for LH{sub 2} and LN{sub 2} ground storage dewars.

  13. Supplemental multilayer insulation research facility

    SciTech Connect

    Dempsey, P.J.; Stochl, R.J.

    1995-07-01

    The Supplemental Multilayer Insulation Research Facility (SMIRF) provides a small scale test bed for conducting cryogenic experiments in a vacuum environment. The facility vacuum system is capable of simulating a Space Shuttle launch pressure profile as well as providing a steady space vacuum environment of 1.3 x 10(exp -4) Newton/sq meter (1 x 10(exp -6) torr). Warm side boundary temperatures can be maintained constant between 111 K (200 R) and 361 K (650 R) using a temperature controlled shroud. The shroud can also simulate a typical lunar day-night temperature profile. The test hardware consists of a cryogenic calorimeter supported by the lid of the vacuum chamber. A 0.45 cu meter (120 gallon) vacuum jacketed storage/supply tank is available for conditioning the cryogen prior to use in the calorimeter. The facility was initially designed to evaluate the thermal performance of insulation systems for long-term storage in space. The facility has recently been used to evaluate the performance of various new insulation systems for LH2 and LN2 ground storage dewars.

  14. Supplemental multilayer insulation research facility

    NASA Technical Reports Server (NTRS)

    Dempsey, P. J.; Stochl, R. J.

    1995-01-01

    The Supplemental Multilayer Insulation Research Facility (SMIRF) provides a small scale test bed for conducting cryogenic experiments in a vacuum environment. The facility vacuum system is capable of simulating a Space Shuttle launch pressure profile as well as providing a steady space vacuum environment of 1.3 x 10(exp -4) Newton/sq meter (1 x 10(exp -6) torr). Warm side boundary temperatures can be maintained constant between 111 K (200 R) and 361 K (650 R) using a temperature controlled shroud. The shroud can also simulate a typical lunar day-night temperature profile. The test hardware consists of a cryogenic calorimeter supported by the lid of the vacuum chamber. A 0.45 cu meter (120 gallon) vacuum jacketed storage/supply tank is available for conditioning the cryogen prior to use in the calorimeter. The facility was initially designed to evaluate the thermal performance of insulation systems for long-term storage in space. The facility has recently been used to evaluate the performance of various new insulation systems for LH2 and LN2 ground storage dewars.

  15. Brownian thermal noise in multilayer coated mirrors

    NASA Astrophysics Data System (ADS)

    Hong, Ting; Yang, Huan; Gustafson, Eric K.; Adhikari, Rana X.; Chen, Yanbei

    2013-04-01

    We analyze the Brownian thermal noise of a multilayer dielectric coating used in high-precision optical measurements, including interferometric gravitational-wave detectors. We assume the coating material to be isotropic, and therefore study thermal noises arising from shear and bulk losses of the coating materials. We show that coating noise arises not only from layer thickness fluctuations, but also from fluctuations of the interface between the coating and substrate, driven by fluctuating shear stresses of the coating. Although thickness fluctuations of different layers are statistically independent, there exists a finite coherence between the layers and the substrate-coating interface. In addition, photoelastic coefficients of the thin layers (so far not accurately measured) further influence the thermal noise, although at a relatively low level. Taking into account uncertainties in material parameters, we show that significant uncertainties still exist in estimating coating Brownian noise.

  16. Multilayer coatings for solar energy control applications

    SciTech Connect

    Kivaisi, R.T.; Mbise, G.

    1993-12-31

    This work presents some results for window coatings that are suitable for solar control applications. Selected research results are given for metal/dielectric based coatings optimized for normal incidence. These coatings can be used to improve the performance of windows both for architectural and automobile sectors. Surface coatings which are transparent at 0.3 < {lambda} < 0.7 {micro}m can be used to solar control windows. A thin homogeneous noble metal film (eg Ag) can combine short wavelength transmittance with high long wavelength reflectance. By embedding the metal film between high refractive index dielectric layers one can optimize the transmittance in the desired spectral region. Transmittance data for multilayer stacks designed for normal and non normal incidence to the coating are presented.

  17. Optics and multilayer coatings for EUVL systems

    SciTech Connect

    Soufli, R; Bajt, S; Hudyma, R M; Taylor, J S

    2008-03-21

    EUV lithography (EUVL) employs illumination wavelengths around 13.5 nm, and in many aspects it is considered an extension of optical lithography, which is used for the high-volume manufacturing (HVM) of today's microprocessors. The EUV wavelength of illumination dictates the use of reflective optical elements (mirrors) as opposed to the refractive lenses used in conventional lithographic systems. Thus, EUVL tools are based on all-reflective concepts: they use multilayer (ML) coated optics for their illumination and projection systems, and they have a ML-coated reflective mask.

  18. Multilayer Coatings for UV Spectral Range

    NASA Astrophysics Data System (ADS)

    Miloushev, Ilko; Tenev, Tihomir; Peyeva, Rumiana; Panajotov, Krassimir

    2010-01-01

    Optical coatings for the UV spectral range play currently a significant role in the modern optical devices. For reducing of manufacturing cost the reliable design is essential. Therefore, better understanding of the optical properties of the used materials is indispensable for the proper design and manufacturing of the multilayer UV coatings. In this work we present some results on the preparation of reflective UV coatings. The implemented materials are magnesium fluoride and lanthanum fluoride. Their optical constants are determined from spectral characteristics of single layers in the 200-800 nm spectral range, obtained by thermal boat evaporation in high vacuum conditions. These results are subsequently used for the analysis of high reflection (HR) stack made of 40 layers deposited by the same deposition process.

  19. Synthesis and Characterization of Multilayered Diamond Coatings for Biomedical Implants

    PubMed Central

    Booth, Leigh; Catledge, Shane A.; Nolen, Dustin; Thompson, Raymond G.; Vohra, Yogesh K.

    2011-01-01

    With incredible hardness and excellent wear-resistance, nanocrystalline diamond (NCD) coatings are gaining interest in the biomedical community as articulating surfaces of structural implant devices. The focus of this study was to deposit multilayered diamond coatings of alternating NCD and microcrystalline diamond (MCD) layers on Ti-6Al-4V alloy surfaces using microwave plasma chemical vapor deposition (MPCVD) and validate the multilayer coating’s effect on toughness and adhesion. Multilayer samples were designed with varying NCD to MCD thickness ratios and layer numbers. The surface morphology and structural characteristics of the coatings were studied with X-ray diffraction (XRD), Raman spectroscopy, and atomic force microscopy (AFM). Coating adhesion was assessed by Rockwell indentation and progressive load scratch adhesion tests. Multilayered coatings shown to exhibit the greatest adhesion, comparable to single-layered NCD coatings, were the multilayer samples having the lowest average grain sizes and the highest titanium carbide to diamond ratios. PMID:21603588

  20. Multilayered Polymer Coated Carbon Nanotubes to Deliver Dasatinib

    PubMed Central

    Moore, Thomas L.; Grimes, Stuart W.; Lewis, Robert L.; Alexis, Frank

    2014-01-01

    Multilayered, multifunctional polymer coatings were grafted onto carbon nanotubes (CNT) using a one-pot, ring-opening polymerization in order to control the release kinetic and therapeutic efficacy of dasatinib. Biocompatible, biodegradable multilayered coatings composed of poly(glycolide) (PGA), and poly(lactide) (PLA) were polymerized directly onto hydroxyl-functionalized CNT surfaces. Sequential addition of monomers into the reaction vessel enabled multilayered coatings of PLA-PGA, or PGA-PLA. Poly(ethylene glycol) capped the polymer chain ends, resulting in a multifunctional amphiphilic coating. Multilayer polymer coatings on CNTs enabled control of anticancer dasatinib’s release kinetics and enhanced the in vitro therapeutic efficacy against U-87 glioblastoma compared to monolayer polymer coatings. PMID:24294824

  1. Development of High Resolution Hard X-Ray Telescope with Multilayer Coatings

    NASA Technical Reports Server (NTRS)

    Gorenstein, Paul; Brinton, John C. (Technical Monitor)

    2003-01-01

    The activities that occurred during the first year of the grant were: a) completed construction of the large multilayer deposition facility; b) Coated a large number of flat substrates and the interiors of cylindrical X-ray telescope shell substrates with uniform period and depth graded periods of tungsten-silicon (W/Is) bi-layers and other coatings; c) studied the influence of various factors affecting the quality of the multilayer coatings by measuring their reflection efficiency at 8 keV and higher energy X-rays.

  2. The New ESRF Multilayer Facility: Progress and Perspectives

    SciTech Connect

    Morawe, Ch.; Friedrich, K.; Peffen, J.-C.; Osterhoff, M.

    2010-06-23

    In view of the increasing need for high quality multilayer based x-ray optics the ESRF decided to upgrade its multilayer facility. During the last years a new deposition system was designed, installed, and commissioned. Since 2008 the new laboratory is operational and has produced its first optical elements for ESRF beamlines. The deposition system is based on magnetron sputtering and can cover optical surfaces up to 1000x150 mm{sup 2} with uniform or graded coatings. Four cathodes allow the use of conducting, insulating, and ferromagnetic target materials. This work will provide an overview on the machine conception and its overall performance, including a comparison with the formerly used system. It will be complemented by first fabrication results and perspectives for future projects in the framework of the ESRF Upgrade Programme.

  3. Characterization of Multilayer Reflective Coatings for Extreme Ultraviolet Lithography

    SciTech Connect

    Wedowski, M.; Gullikson, E.M.; Underwood, J.H.; Spiller, E.A.; Montcalm, C.; Kearney, P.A.; Bajt, S.; Schmidt, M.A.; Folta, J.A.

    1999-11-01

    The synchrotron-based reflectometer at beamline 6.3.2 of the Advanced Light Source (ALS) in Berkeley is an important metrology tool within the current Extreme Ultraviolet Lithography (EUVL) program. This program is a joint activity of three National Laboratories and a consortium of leading semiconductor manufacturers. Its goal is the development of a technology for routine production of sub-100 nm feature sizes for microelectronic circuits. Multilayer-coated normal-incidence optical surfaces reflecting in the Extreme Ultraviolet (EUV) spectral range near 13 nm are the basis for this emerging technology. All optical components of EUV lithographic steppers need to be characterized at-wavelength during their development and manufacturing process. Multilayer coating uniformity and gradient, accurate wavelength matching and high peak reflectances are the main parameters to be optimized. The mechanical and optical properties of the reflectometer at ALS beamline 6.3.2 proved to be well suited for the needs of the current EUVL program. In particular the facility is highly precise in its wavelength calibration and the determination of absolute EUV reflectance. The reproducibility of results of measurements at ALS beamline 6.3.2 is 0.2 % for reflectivity and 0.002 nm for wavelength.

  4. REPLY TO COMMENT: Photoacoustic studies on multilayer dielectric coatings

    NASA Astrophysics Data System (ADS)

    Philip, Annieta; Radhakrishnan, P.; Nampoori, V. P.; Vallabhan, C. P. G.

    1996-05-01

    We provide here point by point reply to the comments made on our earlier paper which describes photoacoustic studies on multilayer dielectric films. We clearly establish that the experimental data published by us are indeed correct and the results of simple computations used as the basis for criticism are not applicable in the case of multilayer dielectric coatings.

  5. Modeling of thermal stresses in elastic multilayer coating systems

    NASA Astrophysics Data System (ADS)

    Gao, Chunxue; Zhao, Zhiwei; Li, Xuehua

    2015-02-01

    The performance and reliability of multilayer coating systems are strongly influenced by thermal stresses. The present study develops an alternative analytical model to predict the thermal stresses in elastic multilayer coating systems. An exact closed-form solution is obtained which is independent of the number of coating layers. In addition, with the definition of the coordinate system, the closed-form solution is concisely formulated. Specific results are calculated for thermal stresses in HfO2/SiO2 multilayer optical coatings, and a finite element analysis is performed to confirm the analytical results. The two results agree fairly well with each other. Also, when the thicknesses of the coating layers are much less than the substrate thickness, the approximate solution is obtained based on the exact closed-form solution, and its accuracy is examined.

  6. WC-Co/Al Multilayer Coatings by Warm Spray Deposition

    NASA Astrophysics Data System (ADS)

    Watanabe, Makoto; Komatsu, Masayuki; Kuroda, Seiji

    2012-06-01

    WC-Co/aluminum multilayer coatings have been developed by using warm spray deposition to improve fracture toughness and damage tolerance of conventional WC-Co coatings and to investigate the effects of ductile layer addition on their fracture properties. Prior to depositing the multilayer coatings, the mechanical properties of three metal coatings of aluminum, copper, and titanium, which were deposited by warm spraying, were evaluated. The aluminum coating showed excellent ductility among them and was selected for use as ductile layers for the multilayer coatings. The fracture behavior of WC-Co/Al coatings was examined by the four-point bending test. The multilayer coatings did not break in a brittle manner after reaching maximum load, but exhibited a plateau as a result of the ductility of the aluminum layers. The fracture behavior was compared with the finite element analysis results, and they showed good agreement in a general trend. It has been concluded that ductile metal reinforcements, by advanced thermal spray techniques such as warm spray deposition, are very effective to enhance the toughness and damage tolerance of sprayed cermet coatings.

  7. EUV multilayer coatings for solar imaging and spectroscopy

    NASA Astrophysics Data System (ADS)

    Windt, David L.

    2015-09-01

    This paper describes recent progress in the development of new EUV multilayer coatings for solar physics. In particular, we present results obtained with Pd/B4C/Y, Al/Zr, and Al-Mg/SiC multilayers, designed for normal incidence operation in the 9 - 50 nm wavelength range. We describe the development of both periodic multilayer films designed for narrowband imaging, and non-periodic multilayers designed to have a broad-spectral response for spectroscopy. The higher EUV reflectance provided by these new coatings, relative to older-generation coatings such as Si/Mo, Mo/Y, and others, will facilitate the development of future solar physics instruments for both imaging and spectroscopy having higher spatial and spectral resolution, while supporting the exposure times and cadences necessary to capture the evolution of flares, jets, CMEs and other dynamic processes in the solar atmosphere.

  8. Multilayer reflective coatings for extreme-ultraviolet lithography

    SciTech Connect

    Montcalm, C., LLNL

    1998-03-10

    Multilayer mirror coatings which reflect extreme ultraviolet (EUV) radiation are a key enabling technology for EUV lithography. Mo/Si multilayers with reflectances of 67.5% at 13.4 nm are now routinely achieved and reflectances of 70 2% at 11.4 nm were obtained with MO/Be multilayers. High reflectance is achieved with careful control of substrate quality, layer thicknesses, multilayer materials, interface quality, and surface termination. Reflectance and film stress were found to be stable relative to the requirements for application to EUV lithography. The run-to-run reproducibility of the reflectance peak position was characterized to be better than 0.2%, providing the required wavelength matching among the seven multilayer-coated mirrors used in the present lithography system design. Uniformity of coating was improved to better than 0.5% across 150 mm diameter substrates. These improvements in EUV multilayer mirror technology will enable us to meet the stringent specifications for coating the large optical substrates for our next-generation EUV lithography system.

  9. Near-infrared radiation curable multilayer coating systems and methods for applying same

    DOEpatents

    Bowman, Mark P; Verdun, Shelley D; Post, Gordon L

    2015-04-28

    Multilayer coating systems, methods of applying and related substrates are disclosed. The coating system may comprise a first coating comprising a near-IR absorber, and a second coating deposited on a least a portion of the first coating. Methods of applying a multilayer coating composition to a substrate may comprise applying a first coating comprising a near-IR absorber, applying a second coating over at least a portion of the first coating and curing the coating with near infrared radiation.

  10. Facile synthesis of multilayered polysaccharidic vesicles.

    PubMed

    Kwag, Dong Sup; Oh, Kyung Taek; Lee, Eun Seong

    2014-08-10

    In this study, we developed facile synthesis method of multilayered polysaccharidic vesicles (hereafter termed 'mPSVs') using polysaccharides such as starch, hyaluronate (HA), and glycol chitosan (GC) via simple chemistry and using enzymatic reactions among polysaccharides. The enzymatic degradation of the HA shell by hyaluronidase (HYAL) enzyme contributed to accelerate the release of protein/peptide from the mPSVs. The mPSVs containing folate ligand and apoptotic cell death-inducing D-(KLAKLAK)2 peptide were effectively accumulated in in vivo KB tumor cells, primarily owing to passive tumor penetration via the enhanced permeability and retention (EPR) effect and active targeting via specific binding to folate receptors expressed on KB tumor cells. These mPSVs resulted in a significant increase in the in vivo tumor inhibition. This vesicle system is expected to exhibit great potential as an advanced platform technology for biomedical applications involving small molecular drugs with protein/gene targets. PMID:24878178

  11. Selective emission multilayer coatings for a molybdenum thermophotovoltaic radiator

    DOEpatents

    Cockeram, Brian Vern

    2004-01-27

    Multilayer coating designs have been developed to provide selective emission for a molybdenum thermophotovoltaic (TPV) radiator surface. These coatings increase the surface emissivity of a molybdenum TPV radiator substrate in the wavelength range that matches the bandgap of the TPV cells to increase the power density of the TPV system. Radiator emission at wavelengths greater than the bandgap energy of the TPV cells is greatly reduced through the use of these coatings, which significantly increases the efficiency of the TPV system. The use of this coating greatly improves the performance of a TPV system, and the coating can be tailored to match the bandgap of any practical TPV system.

  12. 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.

  13. Boron containing multilayer coatings and method of fabrication

    DOEpatents

    Makowiecki, Daniel M.; Jankowski, Alan F.

    1997-01-01

    Hard coatings are fabricated from multilayer boron/boron carbide, boron carbide/cubic boron nitride, and boron/boron nitride/boron carbide, and the fabrication thereof involves magnetron sputtering in a selected atmosphere. These hard coatings may be applied to tools and engine and other parts, as well to reduce wear on tribological surfaces and electronic devices. These boron coatings contain no morphological growth features. For example, the boron and boron carbide used in forming the multilayers are formed in an inert (e.g. argon) atmosphere, while the cubic boron nitride is formed in a reactive (e.g. nitrogen) atmosphere. The multilayer boron/boron carbide, and boron carbide/cubic boron nitride is produced by depositing alternate layers of boron, cubic boron nitride or boron carbide, with the alternate layers having a thickness of 1 nanometer to 1 micrometer, and at least the interfaces of the layers may be of a discrete or a blended or graded composition.

  14. Sol-gel multilayers applied by a meniscus coating process

    SciTech Connect

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

    1992-03-19

    We describe a meniscus coating method to produce high-laser damage threshold, silica/alumina sol-gel multilayer reflectors on 30 {plus} cm substrates for laser-fusion applications. This process involves forcing a small suspension flow through a porous applicator tube, forming a falling film on the tube. A substrate contacts this film to form a meniscus. Motion of the substrate relative to the applicator entrains a thin film on the substrate, which leaves behind a porous, optical quality film upon solvent evaporation. We develop a solution for the entrained film thickness as a function of geometry, flow and fluid properties by an analysis similar to that of the classical dip-coating problem. This solution is compared with experimental measurements. Also, preliminary results of multilayer coating experiments with a prototype coater are presented, which focus on coating uniformity and laser damage threshold (LDT).

  15. Influence of high temperatures on optical fibers coated with multilayer protective coatings

    NASA Astrophysics Data System (ADS)

    Stanczyk, T.; Fidelus, J.; Wysokinski, K.; Lipinski, S.; Tenderenda, T.; Kuklińska, M.; Kołakowska, A.; Rodriguez Garcia, J.; Canadas Martinez, I.; Nasiłowski, T.

    2015-12-01

    In this work we present an innovative method of enhancing optical fibers' resistance to extremely high temperatures by deposition of a multilayer metal coating on the fibers' surface. Such multilayer coating is necessary because of the silica degradation at elevated temperatures. Despite the fact that copper coated fibers work well at temperatures up to 400°C, at higher temperatures copper oxidizes and can no longer protect the fiber. To hold back the copper oxidation and silica degradation processes we developed a dedicated multilayer coating which allows fibers to operate at temperatures up to 700°C. The optimal protective layer has been chosen after numerous high-temperature tests, where copper plates coated with different kinds of coatings were evaluated. What is more, we present results of the high-temperature reliability tests of copper coated fibers protected with our multilayer coating. Performed tests proved that our solution significantly improved optical fibers' reliability to both: elevated temperatures and rapid changes of temperature. Furthermore the developed metal coatings allow fibers' to be electrolytically bonded to other metal elements (e.g. sensor transducers) what makes them great candidates for harsh environment fiber optic sensor applications.

  16. Reactively evaporated multilayer antireflection coatings for Ge optical window

    NASA Astrophysics Data System (ADS)

    Asghar, M. H.; Placido, F.; Naseem, S.

    2007-04-01

    Two multilayer antireflection (AR) coating configurations are designed, prepared and characterized. These AR coatings are designed for a 1 mm thick Ge optical window in the 3.25-5.25 µm band. Ta2O5 and TiO2 are used as high index materials along with SiO2 as low index material. Configuration 1 comprises nine alternating layers of SiO2 and Ta2O5, whereas configuration 2 comprises seven alternating layers of SiO2 and TiO2. Post-deposition annealing is also carried out in the temperature range 150-450 °C for 10 h. The prepared multilayered structures are characterized optically and structurally using a spectrophotometer, an atomic force microscope, x-ray diffraction and a scanning electron microscope. Optical characterization shows that multilayered structures have high absorption for as-deposited samples. A considerable improvement in the transmission profiles for the two multilayered configurations is observed at 350 °C with peak and average transmission for both the configurations exceeding 90%. The as-prepared samples show predominantly amorphous-like structure with pronounced peaks for configuration 2 only. Delamination (for configuration 1) and cracking (for configuration 2) of the multilayered structures are witnessed at an annealing temperature of 450 °C.

  17. Thermal stress prediction in mirror and multilayer coatings.

    PubMed

    Cheng, Xianchao; Zhang, Lin; Morawe, Christian; Sanchez Del Rio, Manuel

    2015-03-01

    Multilayer optics for X-rays typically consist of hundreds of periods of two types of alternating sub-layers which are coated on a silicon substrate. The thickness of the coating is well below 1 µm (tens or hundreds of nanometers). The high aspect ratio (∼10(7)) between the size of the optics and the thickness of the multilayer can lead to a huge number of elements (∼10(16)) for the numerical simulation (by finite-element analysis using ANSYS code). In this work, the finite-element model for thermal-structural analysis of multilayer optics has been implemented using the ANSYS layer-functioned elements. The number of meshed elements is considerably reduced and the number of sub-layers feasible for the present computers is increased significantly. Based on this technique, single-layer coated mirrors and multilayer monochromators cooled by water or liquid nitrogen are studied with typical parameters of heat-load, cooling and geometry. The effects of cooling-down of the optics and heating of the X-ray beam are described. It is shown that the influences from the coating on temperature and deformation are negligible. However, large stresses are induced in the layers due to the different thermal expansion coefficients between the layer and the substrate materials, which is the critical issue for the survival of the optics. This is particularly true for the liquid-nitrogen cooling condition. The material properties of thin multilayer films are applied in the simulation to predict the layer thermal stresses with more precision. PMID:25723932

  18. Single layer and multilayer tip coatings in magnetic force microscopy

    NASA Astrophysics Data System (ADS)

    Casey, S. M.; Lord, D. G.; Grundy, P. J.; Slade, M.; Lambrick, D.

    1999-04-01

    Interactions between the imaging tip and the sample in magnetic force microscopy (MFM) have been investigated by studying the magnetic microstructure of a range of epitaxial garnet films. Etched silicon cantilever probes, coated with CoPt alloy films and Co/Pt multilayers, provided a range of MFM probes for this study. Resonant torque magnetometry was used to characterize their magnetic properties. Phase change images were found to vary considerably in terms of relative "domain volumes" at the surface depending on which probe was used. Decreasing the moment of the alloy coated tips by using thinner layers reduces the "magnetizing" interaction of the tip field but also reduced the signal to noise ratio. By coating the tip with a multilayer a good signal to noise ratio could be obtained with very little interaction. Force-distance curves were used to study the response of the tips at various lift heights. The tips coated with alloy films gave a significant decrease in signal to noise ratio as the lift height increased whereas the multilayer tips maintained a signal which varied little with lift height.

  19. Multilayer ultra-high-temperature ceramic coatings

    DOEpatents

    Loehman, Ronald E.; Corral, Erica L.

    2012-03-20

    A coated carbon-carbon composite material with multiple ceramic layers to provide oxidation protection from ultra-high-temperatures, where if the carbon-carbon composite material is uninhibited with B.sub.4C particles, then the first layer on the composite material is selected from ZrB.sub.2 and HfB.sub.2, onto which is coated a layer of SiC coated and if the carbon-carbon composite material is inhibited with B.sub.4C particles, then protection can be achieved with a layer of SiC and a layer of either ZrB.sub.2 and HfB.sub.2 in any order.

  20. Biocatalytic material comprising multilayer enzyme coated fiber

    DOEpatents

    Kim, Jungbae [Richland, WA; Kwak, Ja Hun [Richland, WA; Grate, Jay W [West Richland, WA

    2009-11-03

    The present invention relates generally to high stability, high activity biocatalytic materials and processes for using the same. The materials comprise enzyme aggregate coatings having high biocatalytic activity and stability useful in heterogeneous environment. These new materials provide a new biocatalytic immobilized enzyme system with applications in bioconversion, bioremediation, biosensors, and biofuel cells.

  1. Production and performance of multilayer-coated conical x-ray mirrors

    NASA Astrophysics Data System (ADS)

    Ulmer, Melville P.; Altkorn, Robert; Graham, Michael E.; Madan, Anita; Chu, Yong S.

    2003-12-01

    A method of fabricating replica figured x-ray optics with integral multilayer coatings is presented. With the intact electroforming multilayer process (IEMP) technique, we sputter multilayers onto a reusable superpolished mandrel, electroform nickel over the multilayers, and remove the multilayer-coated nickel shell intact from the mandrel. This approach offers advantages over more traditional, original, and segmented-replica fabrication techniques, including low cost; compatibility with a wide range of mirror designs, diameters, and focal lengths; simple integration with multilayer sputtering processes; and the ability to produce complete shells of revolution. The fabrication of W/Si multilayer-coated 10-cm-diameter conical x-ray mirrors is described, as are reflectivity measurements at 10 and 30 keV. The measured reflectivity of the IEMP multilayers at the 10-keV primary Bragg peak was 17%. Measurements of multiple points on the cone showed multilayer uniformity to within a few percent around the mirror.

  2. Vacuum arc deposition of nanostructured multilayer coatings for biomedical applications.

    PubMed

    Vladescu, A; Kiss, A; Braic, M; Cotrut, C M; Drob, P; Balaceanu, M; Vasilescu, C; Braic, V

    2008-02-01

    In recent years, the smart materials have attracted much attention due to their unusual properties such as shape memory effect and pseudoelasticity, being widely used for biomedical implants. These materials contain certain amounts of nickel, titanium and others which are not adequate for surgical implants and prosthesis. In the work reported here, two types of nonostructured multilayer coatings (TiN/ZrN, ZrN/Zr) used to prevent the ions release from shape memory alloys were investigated. For comparison, the TiN and ZrN monolayers were also examined. The films were deposited onto nickel-titanium based alloy (Ti-Ni-Nb) and Ni substrates by vacuum arc deposition technique under various deposition conditions. The concentrations of dissolved ions in Ringer solution for uncoated and coated Ni samples were determined to examine the benefic barrier effect of these coatings for ions release from shape memory alloys. In order to have a more complete characterization of the investigated coatings, other properties such as elemental and phase composition, morphology, texture, microhardness, and adhesion were studied. For all coatings, the concentrations of dissolved ions were lower that those measured in the case of the uncoated specimens. The nanostructured multilayer films exhibited the best mechanical and anticorrosive properties. PMID:18464399

  3. Modeling of light intensification by conical pits within multilayer coatings

    SciTech Connect

    Qiu, S R; Wolfe, J E; Monterrosa, A; Feit, M D; Pistor, T V; Stolz, C J

    2009-11-02

    Removal of laser-induced damage sites provides a possible mitigation pathway to improve damage resistance of coated multilayer dielectric mirrors. In an effort to determine the optimal mitigation geometry which will not generate secondary damage precursors, the electric field distribution within the coating layers for a variety of mitigation shapes under different irradiation angles has been estimated using the finite difference time domain (FDTD) method. The coating consists of twenty-four alternating layers of hafnia and silica with a quarter-wave reflector design. A conical geometrical shape with different cone angles is investigated in the present study. Beam incident angles range from 0{sup o} to 60{sup o} at 5{sup o} increments. We find that light intensification (square of electric field, |E|{sup 2}) within the multilayers depends strongly on the beam incident direction and the cone angle. By comparing the field intensification for each cone angle under all angles of incidence, we find that a 30{sup o} conical pit generates the least field intensification within the multilayer film. Our results suggest that conical pits with shallow cone angles ({le} 30{sup o}) can be used as potential optimal mitigation structures.

  4. Boron containing multilayer coatings and method of fabrication

    DOEpatents

    Makowiecki, D.M.; Jankowski, A.F.

    1997-09-23

    Hard coatings are fabricated from multilayer boron/boron carbide, boron carbide/cubic boron nitride, and boron/boron nitride/boron carbide, and the fabrication thereof involves magnetron sputtering in a selected atmosphere. These hard coatings may be applied to tools and engine and other parts, as well to reduce wear on tribological surfaces and electronic devices. These boron coatings contain no morphological growth features. For example, the boron and boron carbide used in forming the multilayers are formed in an inert (e.g. argon) atmosphere, while the cubic boron nitride is formed in a reactive (e.g. nitrogen) atmosphere. The multilayer boron/boron carbide, and boron carbide/cubic boron nitride is produced by depositing alternate layers of boron, cubic boron nitride or boron carbide, with the alternate layers having a thickness of 1 nanometer to 1 micrometer, and at least the interfaces of the layers may be of a discrete or a blended or graded composition. 6 figs.

  5. High reflectance-low stress Mo-Si multilayer reflective coatings

    DOEpatents

    Montcalm, Claude; Mirkarimi, Paul B.

    2000-01-01

    A high reflectance-low stress Mo-Si multilayer reflective coating particularly useful for the extreme ultraviolet (EUV) wavelength region. While the multilayer reflective coating has particular application for EUV lithography, it has numerous other applications where high reflectance and low stress multilayer coatings are utilized. Multilayer coatings having high near-normal incidence reflectance (R.gtoreq.65%) and low residual stress (.ltoreq.100 MPa) have been produced using thermal and non-thermal approaches. The thermal approach involves heating the multilayer coating to a given temperature for a given time after deposition in order to induce structural changes in the multilayer coating that will have an overall "relaxation" effect without reducing the reflectance significantly.

  6. Process for fabricating high reflectance-low stress Mo--Si multilayer reflective coatings

    DOEpatents

    Montcalm, Claude; Mirkarimi, Paul B.

    2001-01-01

    A high reflectance-low stress Mo--Si multilayer reflective coating particularly useful for the extreme ultraviolet (EUV) wavelength region. While the multilayer reflective coating has particular application for EUV lithography, it has numerous other applications where high reflectance and low stress multilayer coatings are utilized. Multilayer coatings having high near-normal incidence reflectance (R.gtoreq.65%) and low residual stress (.ltoreq.100 MPa) have been produced using thermal and non-thermal approaches. The thermal approach involves heating the multilayer coating to a given temperature for a given time after deposition in order to induce structural changes in the multilayer coating that will have an overall "relaxation" effect without reducing the reflectance significantly.

  7. Residual stress analysis of multilayer environmental barrier coatings.

    SciTech Connect

    Harder, B.; Almer, J.; Weyant, C.; Lee, K.; Faber, K.; Northwestern Univ.; Rolls-Royce Corp.

    2009-02-01

    Silicon-based ceramics (SiC, Si{sub 3}N{sub 4}) are promising materials systems for high-temperature structural applications in gas turbine engines. However, the silica layer that forms on these materials is susceptible to attack from water vapor present in combustion environments. To protect against this degradation, environmental barrier coatings (EBCs) have been developed to shield the underlying substrate and prevent degradation. Here we report on elastic and thermal properties, as well as internal stresses of candidate multilayer coatings, as measured in situ using microfocused high-energy X-rays in a transmission diffraction geometry. Doped aluminosilicate coatings were investigated for their stability on a SiC/SiC melt-infiltrated substrate. The coatings consisted of a Ba{sub 1-x}Sr{sub x}Al{sub 2}Si{sub 2}O{sub 8} topcoat with a mullite or mullite+SrAl{sub 2}Si{sub 2}O{sub 8} interlayer, and a silicon bond coat. A numerical model was used to compare the stress results with an ideal coating system. Experiments were carried out on as-sprayed and heat-treated samples in order to analyze the strain and phase evolution as a function of multilayer depth and temperature. The phase transformation of the topcoat promoted healing of cracks in the EBC and reduced stresses in the underlying layers and the addition of SAS to the interlayer reduced stresses in thermally cycled coatings, but did not stop cracks from forming.

  8. Multilayer hydrogel coatings to combine hemocompatibility and antimicrobial activity.

    PubMed

    Fischer, Marion; Vahdatzadeh, Maryam; Konradi, Rupert; Friedrichs, Jens; Maitz, Manfred F; Freudenberg, Uwe; Werner, Carsten

    2015-07-01

    While silver-loaded catheters are widely used to prevent early-onset catheter-related infections [1], long term antimicrobial protection of indwelling catheters remains to be achieved [2] and antiseptic functionalization of coatings often impairs their hemocompatibility characteristics. Therefore, this work aimed to capitalize on the antimicrobial properties of silver nanoparticles, incorporated in anticoagulant poly(ethylene glycol) (PEG)-heparin hydrogel coatings [3] on thermoplastic polyurethane materials. For prolonged antimicrobial activity, the silver-containing starPEG-heparin hydrogel layers were shielded with silver-free hydrogel layers of otherwise similar composition. The resulting multi-layered gel coatings showed long term antiseptic efficacy against Escherichia coli and Staphylococcus epidermidis strains in vitro, and similarly performed well when incubated with freshly drawn human whole blood with respect to hemolysis, platelet activation and plasmatic coagulation. The introduced hydrogel multilayer system thus offers a promising combination of hemocompatibility and long-term antiseptic capacity to meet an important clinical need. PMID:25934292

  9. Reflectance Profile of BaTiO3 on Multilayer Antireflection Coating Systems

    NASA Astrophysics Data System (ADS)

    Karaomerlioglu, Filiz

    2011-05-01

    Antireflection (AR) coating systems are very important technology for optoelectronic devices. The optical characteristics of the system can be regulated by external electric or thermal field, and designed broadband ultra low reflection coating systems. It is investigated optical properties of multilayer AR coatings based on different ferroelectric materials to reduce reflectance in other studies. In this study, reflectance profile of BaTiO3 on multilayer AR coating systems has been developed in the visible region. It has been used ZnSe and ZrO2 as multilayer AR coatings, and BaTiO3 as the substrate. Fortran program has been simulated on Fresnell equations base.

  10. Surface parameters modification by multilayer coatings deposition for biomedical applications

    NASA Astrophysics Data System (ADS)

    Zykova, A.; Safonov, V.; Virva, O.; Luk'yanchenko, V.; Walkowich, J.; Rogowska, R.; Yakovin, S.

    2008-05-01

    Studies are presented of the surface parameters of various multilayer coatings, namely, TiN, CrN, (Ti, Cr)N, TiN/TiC10N90, TiN/TiC20N80 deposited by means of Arc-PVD on stainless steel (1H18N9), as well as of the same coatings with an additional Al2O3 film deposited by reactive magnetron sputtering (RMS). The surface thickness, roughness and topography are estimated. Other parameters, such as the surface free energy (SFE) and fractional polarity are determined by means of the Wu and the Owens-Wendt-Rabel-Kaelble methods. Experiments are carried out on the in vitro cell/material interaction (in a fibroblasts culture) in order to determine the materials biomedical response. The results show some correlation between the surface properties and cell adhesion. The best biological response parameters (cell number, proliferation function, morphology) are obtained in the case of coatings with the highest values of the polar part component of the SFE and the fractional polarity, such as TiN, TiN/TiC10N90 and oxide coatings.

  11. Transition mode long period grating biosensor with functional multilayer coatings.

    PubMed

    Pilla, Pierluigi; Malachovská, Viera; Borriello, Anna; Buosciolo, Antonietta; Giordano, Michele; Ambrosio, Luigi; Cutolo, Antonello; Cusano, Andrea

    2011-01-17

    We report our latest research results concerning the development of a platform for label-free biosensing based on overlayered Long Period Gratings (LPGs) working in transition mode. The main novelty of this work lies in a multilayer design that allows to decouple the problem of an efficient surface functionalization from that of the tuning in transition region of the cladding modes. An innovative solvent/nonsolvent strategy for the dip-coating technique was developed in order to deposit on the LPG multiple layers of transparent polymers. In particular, a primary coating of atactic polystyrene was used as high refractive index layer to tune the working point of the device in the so-called transition region. In this way, state-of-the-art-competitive sensitivity to surrounding medium refractive index changes was achieved. An extremely thin secondary functional layer of poly(methyl methacrylate-co-methacrylic acid) was deposited onto the primary coating by means of an original identification of selective solvents. This approach allowed to obtain desired functional groups (carboxyls) on the surface of the device for a stable covalent attachment of bioreceptors and minimal perturbation of the optical design. Standard 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide / N-hydrosuccinimide (EDC / NHS) coupling chemistry was used to link streptavidin on the surface of the coated LPG. Highly sensitive real-time monitoring of multiple affinity assays between streptavidin and biotinylated bovine serum albumin was performed by following the shift of the LPGs attenuation bands. PMID:21263591

  12. Structural and Morphological Difference Between Ti/TiN/TiCN Coatings Grown in Multilayer and Graded Form

    SciTech Connect

    Restrepo, E.; Baena, A.; Agudelo, C.; Castillo, H.; Devia, A.; Marino, A.

    2006-12-04

    Thin films can be grown in super-lattice, multilayers and graded form, having each one advantages and disadvantages. The difference between multilayer and graded coatings is the interface. In multilayers the interface is abrupt and in graded coatings it is diffuse. The interface influences many chemical and physical properties of the materials, and its choice depends on the application. Graded coatings have the advantage of having gradual properties such as thermal expansion coefficient and lattice parameter, avoiding adherence problems due to good match between their component materials. In this work the comparison between some properties of coatings grown as multilayer and graded is performed. The materials are produced using the sputtering DC technique because of its facility to control the deposition parameters and generate a slow growth. The target is a disc of titanium and the samples are made of stainless steel 304. The working gases are argon, nitrogen and methane, which are mixed according to the material to be produced, i.e. Ti layer is grown with argon, the TiN film is produced with a mixture of argon and nitrogen, and the TiCN material is obtained mixing argon, nitrogen and methane. These materials are characterized with AFM in order to determine grain size and with XPS studying the chemical composition and performing depth profiles.

  13. Ablation behavior of monolayer and multilayer Ir coatings under carburizing and oxidizing oxyacetylene flames

    NASA Astrophysics Data System (ADS)

    Wu, Wangping; Jiang, Jinjin; Chen, Zhaofeng

    2016-06-01

    Iridium is one of the most promising candidates for protective barrier of refractory materials to endure high service temperature. The multilayer iridium coating was produced by a double glow plasma process on the polished tungsten carbide substrates, compared with monolayer. The ablation behaviors of the monolayer on the unpolished and polished substrates were investigated under carburizing and oxidizing oxyacetylene flames, respectively, at the same time the multilayer coating ablated under oxidizing flames. Multilayer coating was a polycrystalline phase with the preferential (220) orientation. Monolayer on the unpolished substrate had fine coarse grains and some small microcracks were present. Multilayer consisted of columnar grains with some voids between the grains boundaries. The formation of a WIr phase in the as-deposited multilayer was attributed to high deposition temperature. The monolayer could endure high temperature up to 1800 °C in carburizing flame. The substrates could be protected more effectively by multilayer than monolayer at 2000- 2200 °C in oxidizing flame.

  14. Optimization of multilayer antireflection coating for photovoltaic applications

    NASA Astrophysics Data System (ADS)

    Sikder, Urmita; Zaman, Mohammad Asif

    2016-05-01

    Multilayer antireflection coating (ARC) for photovoltaics is optimized using Differential Evolution (DE) algorithm. A general transfer-matrix based mathematical formulation is used for evaluating reflection spectra of the system. Exact and complete values of refractive indices are used in the analysis to provide higher accuracy of the results. The proposed optimization method takes into account the solar irradiance spectra, absorption characteristics of semiconductors and angle of incidence to maximize efficiency. This method is found to reduce the average reflectance for a wide range of angles of incidence. The proposed method is used to design ARC for silicon solar cell and a multi-junction AlGaAs/GaAs/Ge solar cell. Finally, comparative analysis of different ARC designs is provided in terms of corresponding solar cell characteristics.

  15. Characteristics of multi-layer coating formed on commercially pure titanium for biomedical applications.

    PubMed

    Teker, Dilek; Muhaffel, Faiz; Menekse, Meryem; Karaguler, Nevin Gul; Baydogan, Murat; Cimenoglu, Huseyin

    2015-03-01

    An innovative multi-layer coating comprising a bioactive compound layer (consisting of hydroxyapatite and calcium titanate) with an underlying titanium oxide layer (in the form of anatase and rutile) has been developed on Grade 4 quality commercially pure titanium via a single step micro-arc oxidation process. Deposition of a multi-layer coating on titanium enhanced the bioactivity, while providing antibacterial characteristics as compared its untreated state. Furthermore, introduction of silver (4.6wt.%) into the multi-layer coating during micro-arc oxidation process imposed superior antibacterial efficiency without sacrificing the bioactivity. PMID:25579960

  16. Fabrication, characterization, and biological assessment of multilayer laminin γ2 DNA coatings on titanium surfaces

    PubMed Central

    Yang, Guoli; Zhang, Jing; Dong, Wenjing; Liu, Li; Shi, Jue; Wang, Huiming

    2016-01-01

    The purpose of this work was to fabricate a multilayer laminin γ2 DNA coating on a titanium surface and evaluate its biological properties. A multilayer laminin γ2 DNA coating was fabricated on titanium using a layer-by-layer assembly technique. The rate of coating degradation was evaluated by detecting the amount of cDNA remaining. Surface analysis using X-ray photoelectron spectroscopy, atomic force microscopy, and surface contact angle measurements revealed the multilayer structure to consist of cationic lipid and confirmed that a laminin γ2 DNA layer could be fabricated on titanium via the layer-by-layer assembly process. The transfection efficiency was highest for five layers in the multilayer structure. HEK293 cells cultured on the multilayer films displayed significantly higher adhesion activity than the control group. The expression of laminin γ2 and the co-localization of integrin β4 and plectin were more obvious in HN4 cells cultured on the multilayer laminin γ2 DNA coating, while weak immunoreactivities were observed in the control group. We concluded that the DNA-loaded multilayer provided a surface with good biocompatibility and that the multilayer laminin γ2 DNA coating might be effective in improving cell adhesion and the formation of hemidesmosomes on titanium surfaces. PMID:26996815

  17. Lifetime studies of Mo/Si and Mo/Be multilayer coatings for extreme ultraviolet lithography

    SciTech Connect

    Bajt, S; Clift, W M; Folta, J A; Gullikson, E M; Klebanoff, L E; Kleineberg, U; Malinowski, M E; Wedowski, M

    1999-08-05

    Extreme Ultraviolet Lithography (EUVL) is a candidate for future application by the semiconductor industry in the production of sub-100 nm feature sizes in integrated circuits. Using multilayer reflective coatings optimized at wavelengths ranging from 11 to 14 nm, EUVL represents a potential successor to currently existing optical lithography techniques. In order to assess lifetimes of the multilayer coatings under realistic conditions, a series of radiation stability tests has been performed. In each run a dose of EUV radiation equivalent to several months of lithographic operation was applied to Mo/Si and MO/Be multilayer coatings within a few days. Depending on the residual gas concentration in the vacuum environment, surface deposition of carbon during the exposure lead to losses in the multilayer reflectivity. However, in none of the experimental runs was structural damage within the bulk of the multilayers observed. Mo/Si multilayer coatings recovered their full original reflectivity after removal of the carbon layer by an ozone cleaning method. Auger depth profiling on MO/Be multilayers indicate that carbon penetrated into the Be top layer during illumination with high doses of EUV radiation. Subsequent ozone cleaning fully removed the carbon, but revealed enhanced oxidation of the area illuminated, which led to an irreversible loss in reflectance on the order of 1%. Keywords: Extreme ultraviolet (EUV) lithography, multilayer reflective coatings, radiation stability, surface contamination

  18. Fabrication, characterization, and biological assessment of multilayer laminin γ2 DNA coatings on titanium surfaces

    NASA Astrophysics Data System (ADS)

    Yang, Guoli; Zhang, Jing; Dong, Wenjing; Liu, Li; Shi, Jue; Wang, Huiming

    2016-03-01

    The purpose of this work was to fabricate a multilayer laminin γ2 DNA coating on a titanium surface and evaluate its biological properties. A multilayer laminin γ2 DNA coating was fabricated on titanium using a layer-by-layer assembly technique. The rate of coating degradation was evaluated by detecting the amount of cDNA remaining. Surface analysis using X-ray photoelectron spectroscopy, atomic force microscopy, and surface contact angle measurements revealed the multilayer structure to consist of cationic lipid and confirmed that a laminin γ2 DNA layer could be fabricated on titanium via the layer-by-layer assembly process. The transfection efficiency was highest for five layers in the multilayer structure. HEK293 cells cultured on the multilayer films displayed significantly higher adhesion activity than the control group. The expression of laminin γ2 and the co-localization of integrin β4 and plectin were more obvious in HN4 cells cultured on the multilayer laminin γ2 DNA coating, while weak immunoreactivities were observed in the control group. We concluded that the DNA-loaded multilayer provided a surface with good biocompatibility and that the multilayer laminin γ2 DNA coating might be effective in improving cell adhesion and the formation of hemidesmosomes on titanium surfaces.

  19. In-situ stress analysis of multilayer environmental barrier coatings.

    SciTech Connect

    Harder, B. J.; Almer, J.; Lee, K. N.; Faber, K. T.; Northwestern Univ.; Rolls-Royce Corp.

    2009-06-01

    The biaxial stress and thermal expansion of multilayer doped-aluminosilicate environmental barrier coatings were measured in situ during cooling using microfocused high-energy X-rays in transmission. Coating stresses during cooling from 1000 C were measured for as-sprayed and thermally cycled samples. In the as-sprayed state, tensile stresses as high as 75 MPa were measured in the doped-aluminosilicate topcoat at 375 C, after which a drop in the stress occurred accompanied by through-thickness cracking of the two outermost layers. After thermally cycling the samples, the stress in the topcoat was reduced to approximately 50 MPa, and there was no drop in stress upon cooling. This stress reduction was attributed to a crystallographic phase transformation of the topcoat and the accompanying change in thermal expansion coefficient. The addition of a doped aluminosilicate to the mullite layer did not lower the stress in the topcoat, but may offer increased durability due to an increased compressive stress.

  20. Nanostructured multilayer polyelectrolyte films with silver nanoparticles as antibacterial coatings.

    PubMed

    Kruk, Tomasz; Szczepanowicz, Krzysztof; Kręgiel, Dorota; Szyk-Warszyńska, L; Warszyński, Piotr

    2016-01-01

    Ultrathin polyelectrolyte films containing silver nanoparticles appear to be a promising material for antimicrobial coatings used in the medical area. The present work is focused on the formation of multilayer polyelectrolyte films using: polyethyleneimine (PEI) as polycation, Poly(sodium 4-styrenesulfonate) (PSS) as polyanions and negatively charged silver nanoparticles (AgNPs), which led to the polyelectrolyte-silver nanocomposite coatings. The film thickness and mass were measured by ellipsometry and quartz crystal microbalance with dissipation monitoring (QCM-D) and the structure and morphology of films were visualized using scanning electron microscopy (SEM). Systematic increase of the UV-Vis absorption confirmed formation of the consecutive layers of the film. The analysis of bacteria cell adhesion to films surface was done by the luminometry measurement. Three gram-negative bacterial strains with strong adhesive properties were used in this study: Escherichia coli, Aeromonas hydrophila, and Asaia lannenesis. It was found that nanocomposite films have antimicrobial properties, which makes them very interesting for a number of practical applications, e.g. for the prevention of microbial colonization on treated surfaces. PMID:26193773

  1. Characterization of multilayer nitride coatings by electron microscopy and modulus mapping

    SciTech Connect

    Pemmasani, Sai Pramod; Rajulapati, Koteswararao V.; Ramakrishna, M.; Valleti, Krishna; Gundakaram, Ravi C.; Joshi, Shrikant V.

    2013-07-15

    This paper discusses multi-scale characterization of physical vapour deposited multilayer nitride coatings using a combination of electron microscopy and modulus mapping. Multilayer coatings with a triple layer structure based on TiAlN and nanocomposite nitrides with a nano-multilayered architecture were deposited by Cathodic arc deposition and detailed microstructural studies were carried out employing Energy Dispersive Spectroscopy, Electron Backscattered Diffraction, Focused Ion Beam and Cross sectional Transmission Electron Microscopy in order to identify the different phases and to study microstructural features of the various layers formed as a result of the deposition process. Modulus mapping was also performed to study the effect of varying composition on the moduli of the nano-multilayers within the triple layer coating by using a Scanning Probe Microscopy based technique. To the best of our knowledge, this is the first attempt on modulus mapping of cathodic arc deposited nitride multilayer coatings. This work demonstrates the application of Scanning Probe Microscopy based modulus mapping and electron microscopy for the study of coating properties and their relation to composition and microstructure. - Highlights: • Microstructure of a triple layer nitride coating studied at multiple length scales. • Phases identified by EDS, EBSD and SAED (TEM). • Nanolayered, nanocomposite structure of the coating studied using FIB and TEM. • Modulus mapping identified moduli variation even in a nani-multilayer architecture.

  2. Development of multilayer oxidation resistant coatings on Cr-50Nb alloy

    NASA Astrophysics Data System (ADS)

    Zheng, Haizhong; Xiong, Lingling; Luo, Qinhao; Lu, Shiqiang

    2015-12-01

    To protect Cr-50Nb alloys from high-temperature oxidation, the Al2O3/Si-Al multilayer coatings were produced by pack cementation process, followed by sol-gel process and hot pressing. The results indicate that the multilayer coating is dense and exhibits good adherence to the substrate, which consists of a compact Al2O3 outer layer and an inner layer composed of Si, Al, Cr, Nb. Uncoated Cr-50Nb alloy occurs catastrophic oxidation at the initial oxidation stage at 1200 °C. However, the scale spalling resistance of the multilayer coating is improved significantly, and the multilayer coating exhibits good resistance to oxidation. During cyclic oxidation in air at 1200 °C for 100 h, the weight loss is 0.13 mg/cm2 and the mass gain is 3.38 mg/cm2.

  3. Improving the oxidation protection of niobium and tantalum by the use of multilayer coatings

    NASA Astrophysics Data System (ADS)

    Dzyadykevich, Y. V.; Kytskay, L. I.

    1997-01-01

    This article examines how the applicability of the refractory metals niobium and tantalum in high-temperature applications can be improved through the use of high-temperature, multilayer coatings based on molybdenum disilicide for oxidation resistance.

  4. Novel Investigation on Nanostructured Multilayer and Functionally Graded Ni-P Electroless Coatings on Stainless Steel

    NASA Astrophysics Data System (ADS)

    Anvari, S. R.; Monirvaghefi, S. M.; Enayati, M. H.

    2015-06-01

    In this study, step-wise multilayer and functionally graded Ni-P coatings were deposited with electroless in which the content of phosphorus and nickel would be changed gradually and step-wise through the thickness of the coatings, respectively. To compare the properties of these coatings with Ni-P single-layer coatings, three types of coatings with different phosphorus contents were deposited. Heat treatment of coatings was performed at 400 °C for 1 h. The microstructure and phase transformation of coatings were characterized by SEM/EDS, TEM, and XRD. The mechanical properties of coatings were studied by nanoindentation test. According to the results of the single-layer coatings, low P coating had the maximum hardness and also the ratio of hardness ( H) to elasticity modulus ( E) for the mentioned coating was maximum. In addition, low and medium P coatings had crystalline and semi-crystalline structure, respectively. The mentioned coatings had <111> texture and after heat treatment their texture didn't change. While high P coating had amorphous structure, after heat treatment it changed to crystalline structure with <100> texture for nickel grains. Furthermore, the results showed that functionally graded and step-wise multilayer coatings were deposited successfully by using the same initial bath and changing the temperature and pH during deposition. Nanoindentation test results showed that the hardness of the mentioned coatings changed from 670 Hv near the substrate to 860 Hv near the top surface of coatings. For functionally graded coating the hardness profile had gradual changes, while step-wise multilayer coating had step-wise hardness profile. After heat treatment trend of hardness profiles was changed, so that near the substrate, hardness was measured 1400 Hv and changed to 1090 Hv at the top coat.

  5. New Approach to Ceramic/Metal-Polymer Multilayered Coatings for High Performance Dry Sliding Applications

    NASA Astrophysics Data System (ADS)

    Rempp, A.; Killinger, A.; Gadow, R.

    2012-06-01

    The combination of thermally sprayed hard coatings with a polymer based top coat leads to multilayered coating systems with tailored functionalities concerning wear resistance, friction, adhesion, wettability or specific electrical properties. The basic concept is to combine the mechanical properties of the hard base coating with the tribological or chemical abilities of the polymer top coat suitable for the respective application. This paper gives an overview of different types of recently developed multilayer coatings and their application in power transmission under dry sliding conditions. State of the art coatings for dry sliding applications in power transmission are mostly based on thin film coatings like diamond-like carbon or solid lubricants, e.g. MoS2. A new approach is the combination of thin film coatings with combined multilayer coatings. To evaluate the capability of these tribological systems, a multi-stage investigation has been carried out. In the first stage the performance of the sliding lacquers and surface topography of the steel substrate has been evaluated. In the following stage thermally sprayed hard coatings were tested in combination with different sliding lacquers. Wear resistance and friction coefficients of combined coatings were determined using a twin disc test-bed.

  6. Innovative methods for optimization and characterization of multilayer coatings

    NASA Astrophysics Data System (ADS)

    Pelizzo, M. G.; Suman, M.; Monaco, G.; Windt, D. L.; Nicolosi, P.

    2009-05-01

    A numerical method to design multilayer coating (ML) is presented. The mathematical tool is based on an "evolutive strategy" algorithm which provides aperiodic solutions by maximizing input merit functions. It allows the optimization of any kind of structures, comprising interlayers and capping layers, and modelling also inter-diffusion and interface roughness. It has been applied to the design of MLs for different applications, as photolithography, space instrumentation and short pulse preservation/compression. The optimization allows the control of the standing wave distribution inside the ML. When the EUV radiation interacts with the structure, the superposition of the incident and reflected electromagnetic wave generates a standing wave field distribution in the ML. An aperiodic design allows the regulation of the distribution of this field, attributing specific properties to the ML. An experimental technique to recover standing wave intensity on top of the ML is also cited. The technique is based on electron photoemission measurements, which allow to determine both reflectivity as well as phase on top of ML. Thanks to this technique, both tests of the ML performances compliance with expected theoretical ones and of degradation through time can be carried on.

  7. Calcium Binding-Mediated Sustained Release of Minocycline from Hydrophilic Multilayer Coatings Targeting Infection and Inflammation

    PubMed Central

    Zhang, Zhiling; Nix, Camilla A.; Ercan, Utku K.; Gerstenhaber, Jonathan A.; Joshi, Suresh G.; Zhong, Yinghui

    2014-01-01

    Infection and inflammation are common complications that seriously affect the functionality and longevity of implanted medical implants. Systemic administration of antibiotics and anti-inflammatory drugs often cannot achieve sufficient local concentration to be effective, and elicits serious side effects. Local delivery of therapeutics from drug-eluting coatings presents a promising solution. However, hydrophobic and thick coatings are commonly used to ensure sufficient drug loading and sustained release, which may limit tissue integration and tissue device communications. A calcium-mediated drug delivery mechanism was developed and characterized in this study. This novel mechanism allows controlled, sustained release of minocycline, an effective antibiotic and anti-inflammatory drug, from nanoscale thin hydrophilic polyelectrolyte multilayers for over 35 days at physiologically relevant concentrations. pH-responsive minocycline release was observed as the chelation between minocycline and Ca2+ is less stable at acidic pH, enabling ‘smart’ drug delivery in response to infection and/or inflammation-induced tissue acidosis. The release kinetics of minocycline can be controlled by varying initial loading, Ca2+ concentration, and Ca2+ incorporation into different layers, enabling facile development of implant coatings with versatile release kinetics. This drug delivery platform can potentially be used for releasing any drug that has high Ca2+ binding affinity, enabling its use in a variety of biomedical applications. PMID:24409292

  8. Measurement of thermal noise in multilayer coatings with optimized layer thickness

    SciTech Connect

    Villar, Akira E.; Black, Eric D.; DeSalvo, Riccardo; Libbrecht, Kenneth G.; Michel, Christophe; Morgado, Nazario; Pinard, Laurent; Pinto, Innocenzo M.; Pierro, Vincenzo; Galdi, Vincenzo; Principe, Maria; Taurasi, Ilaria

    2010-06-15

    A standard quarter-wavelength multilayer optical coating will produce the highest reflectivity for a given number of coating layers, but in general it will not yield the lowest thermal noise for a prescribed reflectivity. Coatings with the layer thicknesses optimized to minimize thermal noise could be useful in future generation interferometric gravitational wave detectors where coating thermal noise is expected to limit the sensitivity of the instrument. We present the results of direct measurements of the thermal noise of a standard quarter-wavelength coating and a low noise optimized coating. The measurements indicate a reduction in thermal noise in line with modeling predictions.

  9. Modeling Multilayer Antireflection Coating Systems Based on LiNbO3

    NASA Astrophysics Data System (ADS)

    Karaomerlioglu, Filiz

    Antireflection coatings have had the greatest impact on optics. The antireflection (AR) coating is the critically important technology in obtaining high performance of optoelectronic devices. In the present paper, characteristics of the ferroelectric based multilayered antireflection coating systems are investigated. Multilayer antireflection coatings consisting of insulator thin films have been modeled in the region between the 400 nm and 800 nm visible bands of electromagnetic spectrum to reduce reflectance from ferroelectric based substrate. In this type of antireflection coating we can regulate the optical properties of a system by external electric (or thermal field) and design a broadband low reflection coating system for optoelectronic devices. In order to design and simulate the normal incidence wideband visible multilayer AR coatings, we have developed a Fortran software program based upon Fresnell equations. Different types of layers which are two-different materials like ZnSe and ZrO2 for even-folded multilayer (two-, four-, six-, eight-, ten-, and twelve-layer) antireflection coatings are used. Ferroelectric material, LiNbO3 is used as the substrate. The optical thicknesses of each layer are equal to a quarter-wave thick at a certain wavelength.

  10. Effects of a multilayered DNA/protamine coating on titanium implants on bone responses.

    PubMed

    Sakurai, Toshitsugu; Yoshinari, Masao; Toyama, Takeshi; Hayakawa, Tohru; Ohkubo, Chikahiro

    2016-06-01

    DNA coating on dental titanium (Ti) implants is attracting attention due to its osteogenic properties. The aim of the present study was to evaluate in vitro and in vivo bioactivities of a multilayered DNA/protamine (D/P) coating on Ti implant by simulated body fluid (SBF) immersion experiments and implantation experiments into extracted sockets of rat molars. Two types of DNA, 300 base pair (bp) and 7000 bp fragments, were used. Protamine was initially immobilized onto Ti implants using a tresyl chloride-activated method and DNA and protamine were then alternatively deposited after the immobilization of protamine by a layer-by-layer technique. A multilayered D/P-coating was confirmed by X-ray photoelectron spectroscopy and Fourier-transform infrared spectroscopy measurements. The deposition of apatite progressed more on the surfaces of multilayered D/P-coated Ti implants than on those of nontreated Ti implants in SBF immersion experiments. Animal implantation experiments showed that multilayered D/P-coated Ti implants provided a significantly higher bone-to-implant (BIC) contact ratio 3 weeks after implantation. No significant difference was observed in the BIC ratio 9 weeks after implantation. The results of the present study demonstrated that a multilayered D/P-coating promoted new bone formation at the early stages of the bone healing process. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1500-1509, 2016. PMID:26860353

  11. Self-forming TiBN Nanocomposite Multilayer Coating Prepared by Pulse Cathode Arc Method.

    PubMed

    Cao, Yongzhi; Hu, Zhenjiang; Yan, Leilei; Yu, Fuli; Tu, Wendi

    2016-12-01

    Novel multilayer structured TiBN coatings were deposited on Si (100) substrate using TiBN complex cathode plasma immersion ion implantation and deposition technique (PIIID). The coatings were characterized by X-ray diffraction (XRD), high-resolution transmission electron microcopy (HRTEM), energy-dispersive spectrometer (EDS) and ball-on-disk test. XRD results reveal that both samples of TiBN coatings have the main diffraction peak of TiN (200) and (220). Cross-section TEM images reveal that these coatings have the character of self-forming multilayer and consists of face-centered cubic TiN and hexagonal BN nanocrystalline embedded in amorphous matrix. Because of the existence of hexagonal BN, the friction coefficient of the new TiBN coating in room temperature is obviously lower than that of the monolithic TiN nanocrystalline coating. PMID:27460597

  12. Self-forming TiBN Nanocomposite Multilayer Coating Prepared by Pulse Cathode Arc Method

    NASA Astrophysics Data System (ADS)

    Cao, Yongzhi; Hu, Zhenjiang; Yan, Leilei; Yu, Fuli; Tu, Wendi

    2016-07-01

    Novel multilayer structured TiBN coatings were deposited on Si (100) substrate using TiBN complex cathode plasma immersion ion implantation and deposition technique (PIIID). The coatings were characterized by X-ray diffraction (XRD), high-resolution transmission electron microcopy (HRTEM), energy-dispersive spectrometer (EDS) and ball-on-disk test. XRD results reveal that both samples of TiBN coatings have the main diffraction peak of TiN (200) and (220). Cross-section TEM images reveal that these coatings have the character of self-forming multilayer and consists of face-centered cubic TiN and hexagonal BN nanocrystalline embedded in amorphous matrix. Because of the existence of hexagonal BN, the friction coefficient of the new TiBN coating in room temperature is obviously lower than that of the monolithic TiN nanocrystalline coating.

  13. Polyelectrolyte multilayer coatings for the separation of proteins by capillary electrophoresis: Influence of polyelectrolyte nature and multilayer crosslinking.

    PubMed

    Bekri, Samya; Leclercq, Laurent; Cottet, Hervé

    2015-06-19

    The present work aims at studying the influence of the nature of the polyelectrolytes used in successive multiple ionic polymers on the performances of protein separation in acetic acid volatile background electrolyte. A broad library of polyelectrolyte multilayers was compared on the basis of 9 different weak/strong polyanions and 8 different weak/strong polycations. More than 20 couples of different polyelectrolytes were investigated. The separation efficiencies (expressed as the N/l ratio, where N is the plate number and l is the capillary effective length) were systematically compared for the separation of a protein test mixture. The coating stability was evaluated by the relative standard deviation of the migration times. For weak polyelectrolyte multilayers, the influence of the polymer crosslinking on the coating stability and separation efficiency has been studied. Intra-day repeatability of 100 successive runs, and capillary-to-capillary reproducibility were tested on coatings of each category (crosslinked and non crosslinked). The main (not obvious) result rising from this study is that the nature of the polyanion constituting the multilayers is of primary importance for the performance in terms of separation efficiency and stability, even when the mulilayers finish with a polycation. PMID:25976124

  14. Passivating overcoat bilayer for multilayer reflective coatings for extreme ultraviolet lithography

    DOEpatents

    Montcalm, Claude; Stearns, Daniel G.; Vernon, Stephen P.

    1999-01-01

    A passivating overcoat bilayer is used for multilayer reflective coatings for extreme ultraviolet (EUV) or soft x-ray applications to prevent oxidation and corrosion of the multilayer coating, thereby improving the EUV optical performance. The overcoat bilayer comprises a layer of silicon or beryllium underneath at least one top layer of an elemental or a compound material that resists oxidation and corrosion. Materials for the top layer include carbon, palladium, carbides, borides, nitrides, and oxides. The thicknesses of the two layers that make up the overcoat bilayer are optimized to produce the highest reflectance at the wavelength range of operation. Protective overcoat systems comprising three or more layers are also possible.

  15. Large-area sol-gel multilayer laser reflectors applied by meniscus coating

    SciTech Connect

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

    1992-03-19

    A meniscus coating method to produce multilayer laser reflectors on 30+ cm substrates is described. These high-laser damage threshold (LDT) dielectric coatings are deposited from colloidal suspensions of silica and alumina nanometer-scale particles. The deposition process involves forcing a slow suspension flow through a porous applicator tube, forming a falling film on the tube. A substrate contacts this film to form a meniscus, and then moves relative to the applicator to entrain a film upon itself, which thins to optical dimensions upon solvent evaporation. The fluid dynamics of meniscus coating are briefly described, and optically measured dried film thicknesses are compared to theoretical predictions. Deviations from the theory are traced to non-Newtonian rheology of one of the suspensions used. Preliminary multilayer coating results which focus on large-scale uniformity and LDT are presented.

  16. [The electrochemical indices of soldered dentures with titanium nitride-based multilayered coatings].

    PubMed

    Kotliar, A M; Panchokha, V P; Sevidova, E K; Steglik, T V; Zhivkova, L V; Tarasov, Iu A

    1990-01-01

    Development of an optimal design of multilayer dentures has involved studies of the effects of the material used to make the intermediate layer, its thickness and mode of application on the corrosive electrochemical behavior of orthodontic articles. Application of intermediate layers was found to reduce the magnitude of polarization current and improve the corrosion resistance of a soldered structure. The best effect was achieved with the design with a protective coating of Cr-Ti composition of stainless steel, applied by vacuum method, and galvanic Cr. The corrosion protecting characteristics of this sublayer were found to depend on the quality of the soldered junction: if it is defective, the protective effect is poor whatever the type of coating. The study has confirmed the necessity of protective coatings application to soldered half-finished articles and the efficacy of multilayer coatings with the surface layer of titanium nitride. PMID:1980755

  17. The ion beam sputtering facility at KURRI: Coatings for advanced neutron optical devices

    NASA Astrophysics Data System (ADS)

    Hino, Masahiro; Oda, Tatsuro; Kitaguchi, Masaaki; Yamada, Norifumi L.; Tasaki, Seiji; Kawabata, Yuji

    2015-10-01

    We describe a film coating facility for the development of multilayer mirrors for use in neutron optical devices that handle slow neutron beams. Recently, we succeeded in fabricating a large neutron supermirror with high reflectivity using an ion beam sputtering system (KUR-IBS), as well as all neutron supermirrors in two neutron guide tubes at BL06 at J-PARC/MLF. We also realized a large flexible self-standing m=5 NiC/Ti supermirror and very small d-spacing (d=1.65 nm) multilayer sheets. In this paper, we present an overview of the performance and utility of non-magnetic neutron multilayer mirrors fabricated with the KUR-IBS

  18. Recovery of Mo/Si multilayer coated optical substrates

    DOEpatents

    Baker, S.L.; Vernon, S.P.; Stearns, D.G.

    1997-12-16

    Mo/Si multilayers are removed from superpolished ZERODUR and fused silica substrates with a dry etching process that, under suitable processing conditions, produces negligible change in either the substrate surface figure or surface roughness. The two step dry etching process removes SiO{sub 2} overlayer with a fluroine-containing gas and then moves molybdenum and silicon multilayers with a chlorine-containing gas. Full recovery of the initial normal incidence extreme ultra-violet (EUV) reflectance response has been demonstrated on reprocessed substrates. 5 figs.

  19. Recovery of Mo/Si multilayer coated optical substrates

    DOEpatents

    Baker, Sherry L.; Vernon, Stephen P.; Stearns, Daniel G.

    1997-12-16

    Mo/Si multilayers are removed from superpolished ZERODUR and fused silica substrates with a dry etching process that, under suitable processing conditions, produces negligible change in either the substrate surface figure or surface roughness. The two step dry etching process removes SiO.sub.2 overlayer with a fluroine-containing gas and then moves molybdenum and silicon multilayers with a chlorine-containing gas. Full recovery of the initial normal incidence extreme ultra-violet (EUV) reflectance response has been demonstrated on reprocessed substrates.

  20. Multilayer thin film coatings for reduced infrared loss in hollow glass waveguides

    NASA Astrophysics Data System (ADS)

    Bledt, Carlos M.; Kopp, Daniel V.; Harrington, James A.; Kriesel, Jason M.

    2011-09-01

    Hollow glass waveguides (HGWs) are an attractive alternative to traditional solid-core and 2D photonic crystal, infrared transmissive fibers. Applications for HGWs at wavelengths longer than 2 microns include use of the guides for the delivery of laser power and for use as chemical and thermal sensors. To date, the most common HGW is one with an inner coating of Ag followed by a single-dielectric layer of AgI. These single-layer dielectric coated HGWs have losses for a 700-micron bore guide as low as 0.2 dB/m at 10.6 microns. However, if a multilayer stack of alternating high/low index thin films is deposited instead of a single dielectric layer then the loss can be reduced substantially. In the present study, multilayer dielectric thin films have been deposited inside silica tubing using a liquid-phase deposition method. High index coating materials used include metal sulfides such as PbS while the low index materials include polystyrene (PS) and some sulfides. To date it has been possible to deposit two-layer coatings using, for example, CdS and PS but a lower loss is possible if the coating stack is composed of three dielectric layers. In past work CdS/PbS/CdS coatings were deposited and found to have a measured a loss at λ = 10.6 microns that is approximately two times lower than that for a single dielectric layer. In this paper the theory of multilayer coatings will be presented along with the optical loss measurements from λ = 2 to 12 microns for the multilayer dielectric coatings.

  1. Impact of substrate surface scratches on the laser damage resistance of multilayer coatings

    SciTech Connect

    Qiu, S; Wolfe, J; Monterrosa, A; Teslich, N; Feit, M; Pistor, T; Stolz, C

    2010-11-03

    Substrate scratches can limit the laser resistance of multilayer mirror coatings on high-peak-power laser systems. To date, the mechanism by which substrate surface defects affect the performance of coating layers under high power laser irradiation is not well defined. In this study, we combine experimental approaches with theoretical simulations to delineate the correlation between laser damage resistance of coating layers and the physical properties of the substrate surface defects including scratches. A focused ion beam technique is used to reveal the morphological evolution of coating layers on surface scratches. Preliminary results show that coating layers initially follow the trench morphology on the substrate surface, and as the thickness increases, gradually overcoat voids and planarize the surface. Simulations of the electrical-field distribution of the defective layers using the finite-difference time-domain (FDTD) method show that field intensification exists mostly near the top surface region of the coating near convex focusing structures. The light intensification could be responsible for the reduced damage threshold. Damage testing under 1064 nm, 3 ns laser irradiation over coating layers on substrates with designed scratches show that damage probability and threshold of the multilayer depend on substrate scratch density and width. Our preliminary results show that damage occurs on the region of the coating where substrate scratches reside and etching of the substrate before coating does not seem to improve the laser damage resistance.

  2. Weightless Environment Training Facility (WETF) materials coating evaluation, volume 2

    NASA Technical Reports Server (NTRS)

    1995-01-01

    This volume consists of Appendices A and B to the report on the Weightless Environment Training Facility Materials Coating Evaluation project. The project selected 10 coating systems to be evaluated in six separate exposure environments, and subject to three tests for physical properties. Appendix A holds the coating system, surface preparation, and application data. Appendix B holds the coating material infrared spectra.

  3. Tribological behavior and wear mechanisms of TiN/TiCN/TiN multilayer coatings

    SciTech Connect

    Su, Y.L.; Kao, W.H.

    1998-10-01

    This work employs the PVD process to deposit coatings of single layer TiN, binary layer TiN/TiCN, multilayer TiN/Ti/TiN, and sequenced TiN/TiCN/TiN multilayer coatings with variable individual TiN-layer and TiCN-layer thicknesses on tungsten carbide disks and inserts. Also investigated are the fracture mechanisms and the influence of sequence and thickness of these coatings on cylinder-on-disk, line-contact wear mode and ball-on-disk, point-contact wear mode through SRV reciprocating wear tests. Actual milling tests identify wear performance. Experimental results indicate that the coating with a total thickness of 7 {micro}m and layer sequence TiN/TiCN/TiN exhibits good wear resistance on SRV wear test and milling test. The thickest multilayer TiN/Ti/TiN coating, although having the highest hardness, has the worst wear resistance for all tests. Notably zero-wear performance was observed for all coating disks under cutting fluid lubricated condition due to the transferred layers formed between the contact interface.

  4. Influence of layer type and order on barrier properties of multilayer PECVD barrier coatings

    NASA Astrophysics Data System (ADS)

    Bahroun, K.; Behm, H.; Mitschker, F.; Awakowicz, P.; Dahlmann, R.; Hopmann, Ch

    2014-01-01

    Due to their macromolecular structure, plastics are limited in their scope of application whenever high barrier functionality against oxygen and water vapour permeation is required. One solution is the deposition of thin silicon oxide coatings in plasma-enhanced chemical vapour deposition (PECVD) processes. A way to improve performance of barrier coatings is the use of multilayer structures built from dyad layers, which combine an inorganic barrier layer and an organic intermediate layer. In order to investigate the influence of type and number of dyads on the barrier performance of coated 23 µm PET films, different dyad setups are chosen. The setups include SiOCH interlayers and SiOx-barrier layers deposited using the precursor hexamethyldisiloxane (HMDSO). A single reactor setup driven in pulsed microwave plasma (MW) mode as well as capacitively coupled plasma (CCP) mode is chosen. In this paper the effects of a variation in intermediate layer recipe and stacking order using dyad setups on the oxygen barrier properties of multilayer coatings are discussed with regard to the chemical structure, morphology and activation energy of the permeation process. Changes in surface nano-morphology of intermediate layers have a strong impact on the barrier properties of subsequent glass-like coatings. Even a complete failure of the barrier is observed. Therefore, when depositing multilayer barrier coatings, stacking order has to be considered.

  5. Laser engineered multilayer coating of biphasic calcium phosphate/titanium nanocomposite on metal substrates.

    PubMed

    Zhang, Martin Yi; Ye, Chang; Erasquin, Uriel Joseph; Huynh, Toan; Cai, Chengzhi; Cheng, Gary J

    2011-02-01

    In this work, laser coating of biphasic calcium phosphate/titanium (BCP/Ti) nanocomposite on Ti-6Al-4 V substrates was developed. A continuous wave neodymium-doped yttrium aluminium garnet (Nd:YAG) laser was used to form a robust multilayer of BCP/Ti nanocomposite starting from hydroxyapatite and titanium nanoparticles. In this process, low power coating is realized because of the strong laser-nanoparticle interaction and good sinterability of nanosized titanium. To guide the optimization of laser processing conditions for the coating process, a multiphysics model coupling electromagnetic module with heat transfer module was developed. This model was validated by laser coating experiments. Important features of the coated samples, including microstructures, chemical compositions, and interfacial bonding strength, were characterized. We found that a multilayer of BCP, consisting of 72% hydroxyapatite (HA) and 28% beta-tricalcium phosphate (β-TCP), and titanium nanocomposite was formed on Ti-6Al-4 V substrates. Significantly, the coating/substrate interfacial bonding strength was found to be two times higher than that of the commercial plasma sprayed coatings. Preliminary cell culture studies showed that the resultant BCP/Ti nanocomposite coating supported the adhesion and proliferation of osteoblast-like UMR-106 cells. PMID:21207950

  6. Multilayer coatings for flexible high-barrier materials

    NASA Astrophysics Data System (ADS)

    Vaško, Karol; Noller, Klaus; Mikula, Milan; Amberg-Schwab, Sabine; Weber, Ulrike

    2009-06-01

    A multilayer, flexible, and transparent high-barrier system based on flexible plastic foils, polyethyleneterephthalate (PET) and ethylene-tetrafluoroethylene-copolymer (ETFE), combined with vacuum-deposited, inorganic SiOx layers and hybrid ORMOCER® varnish layers were prepared in different orders on a semiproduction level. Barrier properties of prepared systems, as water vapour transmission (WVTR) and oxygen transmission (OTR), were measured and studied in connection with surface energy, surface topography, and water vapour adsorption properties. Correlations among layers sequence, barrier properties, and other parameters are presented, including some basic principles of permeation of substances through multilayer barrier systems. A combination of several inorganic and hybrid varnish layers is necessary to achieve the technological demands from a barrier standpoint. It is easier to suppress the oxygen transport than the water transport, due to the additional active penetration of water through hydrogen bonds and silanol creations at oxide interfaces, capillary condensation, and swelling with high internal pressure, leading to new defects.

  7. Multilayer coatings for flexible high-barrier materials

    NASA Astrophysics Data System (ADS)

    Vaško, Karol; Noller, Klaus; Mikula, Milan; Amberg-Schwab, Sabine; Weber, Ulrike

    2009-06-01

    A multilayer, flexible, and transparent high-barrier system based on flexible plastic foils, polyethyleneterephthalate (PET) and ethylene-tetrafluoroethylene-copolymer (ETFE), combined with vacuum-deposited, inorganic SiOx layers and hybrid ORMOCER® varnish layers were prepared in different orders on a semiproduction level. Barrier properties of prepared systems, as water vapour transmission (WVTR) and oxygen transmission (OTR), were measured and studied in connection with surface energy, surface topography, and water vapour adsorption properties. Correlations among layers sequence, barrier properties, and other parameters are presented, including some basic principles of permeation of substances through multilayer barrier systems. A combination of several inorganic and hybrid varnish layers is necessary to achieve the technological demands from a barrier standpoint. It is easier to suppress the oxygen transport than the water transport, due to the additional active penetration of water through hydrogen bonds and silanol creations at oxide interfaces, capillary condensation, and swelling with high internal pressure, leading to new defects.

  8. Multi-layer carbon-based coatings for field emission

    DOEpatents

    Sullivan, John P.; Friedmann, Thomas A.

    1998-01-01

    A multi-layer resistive carbon film field emitter device for cold cathode field emission applications. The multi-layered film of the present invention consists of at least two layers of a conductive carbon material, preferably amorphous-tetrahedrally coordinated carbon, where the resistivities of adjacent layers differ. For electron emission from the surface, the preferred structure can be a top layer having a lower resistivity than the bottom layer. For edge emitting structures, the preferred structure of the film can be a plurality of carbon layers, where adjacent layers have different resistivities. Through selection of deposition conditions, including the energy of the depositing carbon species, the presence or absence of certain elements such as H, N, inert gases or boron, carbon layers having desired resistivities can be produced.

  9. Multi-layer carbon-based coatings for field emission

    DOEpatents

    Sullivan, J.P.; Friedmann, T.A.

    1998-10-13

    A multi-layer resistive carbon film field emitter device for cold cathode field emission applications is disclosed. The multi-layered film of the present invention consists of at least two layers of a conductive carbon material, preferably amorphous-tetrahedrally coordinated carbon, where the resistivities of adjacent layers differ. For electron emission from the surface, the preferred structure can be a top layer having a lower resistivity than the bottom layer. For edge emitting structures, the preferred structure of the film can be a plurality of carbon layers, where adjacent layers have different resistivities. Through selection of deposition conditions, including the energy of the depositing carbon species, the presence or absence of certain elements such as H, N, inert gases or boron, carbon layers having desired resistivities can be produced. 8 figs.

  10. Enhancement of biocompatibility of metal implants by nanoscale tiN/NbN multilayer coatings.

    PubMed

    Subramanian, B

    2013-07-01

    Titanium nitride (TiN)/niobium nitride (NbN) nanostructured multilayer coatings were prepared by DC reactive magnetron sputtering method using the combination of a titanium and niobium target and an Ar-N2 mixture discharge gas on to 316L stainless steel substrates. The coatings showed a polycrystalline structure with (111) for TiN and (101) for NbN preferential growth. Raman spectroscopy measurements on the multilayer films exhibited the characteristic peaks at 212, 303, 458 and 578 cm-1. A higher hardness of 38 GPa was observed for TiN/NbN coatings. Electrochemical polarization tests were performed in simulated biological fluid solutions at 37 degreesC in order to determine and compare the corrosion behavior of the coated and uncoated 316L SS substrates. The TiN/NbN multilayer coatings could improve the corrosion resistance of 316L SS substrate. The bacterial culture experiments were performed and the bacteria treated samples were examined by epi fluorescence microscope measurements. PMID:23901475

  11. Electrofabrication of multilayer Fe-Ni alloy coatings for better corrosion protection

    NASA Astrophysics Data System (ADS)

    Ullal, Yathish; Hegde, A. Chitharanjan

    2014-09-01

    Electrofabrication of multilayer Fe-Ni alloy coatings were accomplished successfully on mild steel and their corrosion behaviors were studied. Multilayer comprised of alternatively formed `nano-size' layers of Fe-Ni alloy of different composition have been produced from a single bath having Fe2+and Ni2+ ions using modulated (i.e. periodic pulse control) current density (cd). The deposition conditions were optimized for both composition and thickness of individual layers for best performance of the coatings against corrosion. The deposits were analyzed using scanning electron microscopy (SEM), powder X-ray diffraction (PXRD), Hardness Tester, electrochemical AC and DC methods respectively. The multi layered deposits showed better corrosion resistances compared to the monolayer Fe-Ni (CR = 3.77 mm year-1) coating deposited using DC from the same bath; the maximum corrosion resistance being shown by the coating having 300 layers, deposited at cyclic cathodic current densities of 2.0 and 4.0 A dm-2 (CR = 0.03 mm year-1). Drastic improvement in the corrosion performance of multilayer coatings were explained in the light of changed kinetics of mass transfer at cathode and increased surface area due to modulation and layering.

  12. Short-Pulse Laser Sintering of Multilayer Hard Metal Coatings: Structure and Wear Behavior

    NASA Astrophysics Data System (ADS)

    Kharanzhevskiy, Evgeny; Ipatov, Alexey; Nikolaeva, Irina; Zakirova, Raushaniya

    2015-06-01

    This paper reports on the phase composition and properties of multilayer hard metal coatings deposited on steel by a process variant of Selective laser melting (SLM). The process is based on layer-wise short-pulse laser sintering of high-dispersive WC-Co powder on a steel substrate. High temperature in the molten zone and chemical interaction with the substrate explain high level of adhesion strength between the coating and the substrate. The technique allows obtaining both high quality hard-metal multilayer gradient coatings with thickness up to 200 μm, density near to the theoretical density (TD), hardness up to 21 GPa and complex 3D objects by layer-wise powder based process such as SLM.

  13. Fabrication and characterization of ultra-high resolution multilayer-coated blazed gratings

    SciTech Connect

    Voronov,, Dmitriy; Anderson, Erik; Cambie, Rossana; Dhuey, Scott; Gullikson, Eric; Salmassi, Farhad; Yashchuk, Tony; Padmore, Howard

    2011-07-26

    Multilayer coated blazed gratings with high groove density are the most promising candidate for ultra-high resolution soft x-ray spectroscopy. They combine the ability of blazed gratings to concentrate almost all diffraction energy in a desired high diffraction order with high reflectance soft x-ray multilayers. However in order to realize this potential, the grating fabrication process should provide a near perfect groove profile with an extremely smooth surface of the blazed facets. Here we report on successful fabrication and testing of ultra-dense saw-tooth substrates with 5,000 and 10,000 lines/mm.

  14. Progress Toward Light Weight High Angular Resolution Multilayer Coated Optics

    NASA Astrophysics Data System (ADS)

    Ulmer, M. P.; Graham, M. E.; Vaynman, S.; Echt, J.; Farber, M.; Ehlert, S.; Varlese, S.

    2005-12-01

    We have been working on 3 separate projects that together will give us the ability to make 1 arc second, light weightWolter I optics that work above 40 keV. The three separate tasks are: (a) plasma spraying of metal-coated micro-balloons; (b) coating of the inside of Wolter I mirrors, (c) actuator designs for improving figure quality.We give a progress report on our work on all three areas.

  15. Development of multilayer coatings (Ni/C-Pt/C) for hard x-ray telescopes by e-beam evaporation with ion assistance

    NASA Astrophysics Data System (ADS)

    Spiga, Daniele; Pareschi, Giovanni; Citterio, Oberto; Banham, Robert; Basso, Stefano; Cassanelli, Marco; Cotroneo, Vincenzo; Negri, Barbara; Grisoni, Gabriele; Valsecchi, Giuseppe; Vernani, Dervis

    2004-10-01

    A number of X-ray astronomical missions of near future (XEUS, Constellation-X, SIMBOL-X, HEXIT-SAT, NEXT) will make use of hard X-ray (10-100 keV) optics with broad-band multilayer coatings. To this aim we are developing a multilayer deposition technique for large substrates based on the e-beam deposition technique, improved by the implementation of an ion beam assistance device, in order to reduce the interfacial roughness and improve the reflectivity. The e-beam deposition with ion assistance keeps the film smoothness at a good level and takes the advantage of a reduction of the interlayer stresses. This approach is well suited for the manufacturing of high-reflectance multilayer mirrors for hard X-rays space telescopes where, in addition to a high quality of the deposited films, a volume production is also requested. Moreover, we are also up-grading the replication technique by nickel electroforming, already successfully used for the gold coated soft X-ray mirrors of Beppo-SAX, XMM, JET-X/SWIFT missions, to the case of multilayer coated mirrors. In this paper we will present the technique under development and the implemented deposition facility. Some preliminary, very encouraging, results achieved with the X-ray (8.05 and 17.4 keV) and topographic characterization on flat samples will be discussed.

  16. Sintering Characteristics of Multilayered Thermal Barrier Coatings Under Thermal Gradient and Isothermal High Temperature Annealing Conditions

    NASA Technical Reports Server (NTRS)

    Rai, Amarendra K.; Schmitt, Michael P.; Bhattacharya, Rabi; Zhu, Dongming; Wolfe, Douglas E.

    2014-01-01

    Pyrochlore oxides have most of the relevant attributes for use as next generation thermal barrier coatings such as phase stability, low sintering kinetics and low thermal conductivity. One of the issues with the pyrochlore oxides is their lower toughness and therefore higher erosion rate compared to the current state-of-the-art TBC material, yttria (6 to 8 wt%) stabilized zirconia (YSZ). In this work, sintering characteristics were investigated for novel multilayered coating consisted of alternating layers of pyrochlore oxide viz Gd2Zr2O7 and t' low k (rare earth oxide doped YSZ). Thermal gradient and isothermal high temperature (1316 C) annealing conditions were used to investigate sintering and cracking in these coatings. The results are then compared with that of relevant monolayered coatings and a baseline YSZ coating.

  17. Approach to the development of CAD/CAM system for multilayer optical coatings

    NASA Astrophysics Data System (ADS)

    Mohan Rao, G. R.; Nagendra, C. L.; Thutupalli, G. K. M.

    1990-08-01

    CADCAM system is very vital in the development and production of high efficiency optical coatings, in which in-situ analysis and optiniizatfrxi is the nucleus. A new algoritlin for in-situ analysis and optimization of coatings has been proposed, which has provision for precise determination of optical parameters, namely refractive index n, and gearetrical thickness d, of any layer :tt the multilayered configuration and, to account for adverse effect of the deviaticxs in the optical pareters through global re-optimization of the coatings. It has been implemented on 8086/8087 microprocessor systn in which 8086 is a 16 bit microprocessor and 8087, a coprocessor for high speed floating point operatixs. The validity of the algorithn has been established through a wide range of hypothetical case studies and experimental deve1opint of a few coatings such as wideband antireflecticx coatings (ARCs).

  18. Application of germanium carbide in durable multilayer IR coatings

    NASA Astrophysics Data System (ADS)

    Kelly, Chris J.; Orr, James S.; Gordon, H.; Traub, Leonard T.; Lettington, Alan H.

    1990-08-01

    Infrared transparent amorphous hydrogenated alloys of germanium and carbon (germanium carbide) have been deposited by plasma assisted chemical vapour deposition (PACVD) using germane (GeH4 ) and butane (C 4Hid as the feedstocks and by reactive sputtering of germanium with a CH1g-Ar plasma. The effects of varying various deposition conditions have been assessed on a number of coating properties . Germanium Carbide has good environmental durability and can be deposited in thick layers. Using PACVD it can be deposited with any refractive index in the range 2 to 4 while the sputtering process is limited to indices in the range 3 to 4 . One advantage of the sputtering process is the high deposition rates achievable which can be up to '-lOum/h compared with lum/h for the PACVD process. When used in conjunction with "diamond-like" carbon (a-'C:H) , germanium carbide offers the prospect of rnultilayer antireflection coatings for 8 to 12 urn optics with durabilities which hitherto have been impossible to achieve. Antireflection coatings for zinc sulphide windows which are subject to hostile environmental conditions have been investigated and the performance of the coatings is presented. The factors affecting the practical realisation of these coatings on a production scale are discussed.

  19. Wideband antireflection coatings combining interference multilayers and subwavelength structures prepared by reactive ion etching

    NASA Astrophysics Data System (ADS)

    Bruynooghe, S.; Helgert, M.; Challier, M.; Tonova, D.; Sundermann, M.; Koch, T.; Gatto, A.; Schulze, M.; Kley, E.-B.

    2015-08-01

    To further reduce the intensity of the Fresnel reflections of optical components, subwavelength structures prepared by reactive ion etching of SiO2 thin films are combined as outermost layer with a multilayer system made of conventional thin film materials and prepared by magnetron sputtering. In this approach, a hybrid coating is realized in which the nanoscaled structured outermost layer is expected to further improve the antireflection properties of common interference stacks. The subwavelength structures are examined by spectroscopic ellipsometry, spectral photometry and scanning electron microscopy. The microscopic and optical spectroscopic analysis revealed that pillar-shaped nanostructures are formed during etching which exhibit low-index properties and have a depth-dependent refractive index. To take into account the index gradient in the coating design, the optical properties of the nanostructures are modeled using the effective medium approximation. The calculated average effective refractive index is 1.11 at 500 nm wavelength. A hybrid coating was designed to minimize the residual reflectance in the 400 - 900 nm spectral range for BK7 glass substrate. Experimental results showed that the hybrid coating achieves a low residual reflectance with very good omni-directional properties, owing to the properties of its nanostructured surface. The residual reflection of the hybrid coating is found to be two times smaller than the reflection obtained by applying a common interference multilayer system which demonstrates the benefit of the use of hybrid systems for the realization of broadband antireflective coatings with wide-angle properties.

  20. Mechanical Characterization of CrN/CrAlN Multilayer Coatings Deposited by Magnetron Sputtering System

    NASA Astrophysics Data System (ADS)

    Kaouther, Khlifi; Hafedh, Dhiflaoui; Lassaad, Zoghlami; Ahmed, Ben Cheikh Larbi

    2015-10-01

    Chromium-based coatings are deposited on a 100Cr6 (AISI 52100) substrate by a physical vapor deposition magnetron sputtering system. The coatings have different structures, such as a CrN monolayer and CrAlN multilayer. The structural and morphological compositions of the coatings were evaluated using glow discharge optical emission spectroscopy, atomic force microscopy, and cross-sectional scanning electron microscopy. Nano-indentation tests were performed to investigate the mechanical properties. Domes and craters are shown to be uniformly distributed over the entire surfaces of the two coatings. Additionally, the CrN/CrAlN multilayer coating exhibits a rough surface, attractive mechanical properties, a high compressive stress, and a high plastic and elastic deformation resistance. The improvement of the mechanical properties of the CrN/CrAlN coating is mainly attributed to a reduction in the crystallite size. We found that this reduction was related to three factors: (1) the compositional change resulting from the substitution of aluminum for chromium, which can produce a decrease in the interatomic distance; (2) the structure of CrN/CrAlN, which was characterized by grain size refinement; and (3) the high number of interfaces, which explains the widely accepted concept of dislocation blocking by the layer interfaces.

  1. Substrate recovery of Mo-Si multilayer coated optics

    SciTech Connect

    Stearns, D.G.; Baker, S.L.

    1993-06-01

    Imaging optics in a soft x-ray projection lithography (SXPL) system must meet stringent requirements to achieve high throughput and diffraction limited performance. Errors in the surface figure must be kept to less than {approximately}1 nm and the rms surface roughness must be less than 0.1 nm. The ML coatings must provide high reflectivity (> 60%) at wavelengths in the vicinity of 13 nm. The reflectivity bandpasses of the optics must be aligned within 0.05 nm. Each coating must be uniform across the surface of the optic to within 0.5%. These specifications challenge the limits of the current capabilities in optics fabrication and ML deposition. Consequently a set of qualified SXPL imaging optics is expected to be expensive, costing in the range of 100--250 k$. If the lifetime of the imaging optics is short, the replacement cost could significantly impact the economic competitiveness of the technology. The most likely failure modes for the imaging optics are mechanisms that degrade the ML coatings, but which leave the substrates intact. A potentially low cost solution for salvaging the imaging optics could be to strip the damaged ML coating to recover the substrate and then deposit a new coating. In this paper the authors report on the use of reactive ion etching (RIE) to remove Mo-Si ML coatings from precision optical substrates. The goal of this work was to characterize the etching process both in the ML film and at the substrate, and to determine the effects of the etching on the surface figure and finish of the substrate.

  2. The role of defects in laser damage of multilayer coatings

    SciTech Connect

    Kozlowski, M.R.; Chow, R.

    1993-12-21

    Laser induced damage to optical coatings is generally a localized phenomenon associated with coating defects. The most common of the defect types are the well-known nodule defect. This paper reviews the use of experiments and modeling to understand the formation of these defects and their interaction with laser light. Of particular interest are efforts to identify which defects are most susceptible to laser damage. Also discussed are possible methods for stabilizing these defects (laser conditioning) or preventing their initiation (source stabilization, spatter particle trapping).

  3. Spontaneously intermixed Al-Mg barriers enable corrosion-resistant Mg/SiC multilayer coatings

    NASA Astrophysics Data System (ADS)

    Soufli, Regina; Fernández-Perea, Mónica; Baker, Sherry L.; Robinson, Jeff C.; Alameda, Jennifer; Walton, Christopher C.

    2012-07-01

    Magnesium/silicon carbide (Mg/SiC) has the potential to be the best-performing reflective multilayer coating in the 25-80 nm wavelength region but suffers from Mg-related corrosion, an insidious problem which completely degrades reflectance. We have elucidated the origins and mechanisms of corrosion propagation within Mg/SiC multilayers. Based on our findings, we have demonstrated an efficient and simple-to-implement corrosion barrier for Mg/SiC multilayers. The barrier consists of nanometer-scale Mg and Al layers that intermix spontaneously to form a partially amorphous Al-Mg layer and is shown to prevent atmospheric corrosion while maintaining the unique combination of favorable Mg/SiC reflective properties.

  4. Photoreactive azido-containing silica nanoparticle/polycation multilayers: durable superhydrophobic coating on cotton fabrics.

    PubMed

    Zhao, Yan; Xu, Zhiguang; Wang, Xungai; Lin, Tong

    2012-04-17

    In this study, we report the functionalization of silica nanoparticles with highly photoreactive phenyl azido groups and their utility as a negatively charged building block for layer-by-layer (LbL) electrostatic assembly to produce a stable silica nanoparticle coating. Azido-terminated silica nanoparticles were prepared by the functionalization of bare silica nanoparticles with 3-aminopropyltrimethoxysilane followed by the reaction with 4-azidobenzoic acid. The azido functionalization was confirmed by FTIR and XPS. Poly(allylamine hydrochloride) was also grafted with phenyl azido groups and used as photoreactive polycations for LbL assembly. For the photoreactive silica nanoparticle/polycation multilayers, UV irradiation can induce the covalent cross-linking within the multilayers as well as the anchoring of the multilayer film onto the organic substrate, through azido photochemical reactions including C-H insertion/abstraction reactions with surrounding molecules and dimerization of azido groups. Our results show that the stability of the silica nanoparticle/polycation multilayer film was greatly improved after UV irradiation. Combined with a fluoroalkylsilane post-treatment, the photoreactive LbL multilayers were used as a coating for superhydrophobic modification of cotton fabrics. Herein the LbL assembly method enables us to tailor the number of the coated silica nanoparticles through the assembly cycles. The superhydrophobicity of cotton fabrics was durable against acids, bases, and organic solvents, as well as repeated machine wash. Because of the unique azido photochemistry, the approach used here to anchor silica nanoparticles is applicable to almost any organic substrate. PMID:22462539

  5. Repair of localized defects in multilayer-coated reticle blanks for extreme ultraviolet lithography

    DOEpatents

    Stearns, Daniel G.; Sweeney, Donald W.; Mirkarimi, Paul B.

    2004-11-23

    A method is provided for repairing defects in a multilayer coating layered onto a reticle blank used in an extreme ultraviolet lithography (EUVL) system. Using high lateral spatial resolution, energy is deposited in the multilayer coating in the vicinity of the defect. This can be accomplished using a focused electron beam, focused ion beam or a focused electromagnetic radiation. The absorbed energy will cause a structural modification of the film, producing a localized change in the film thickness. The change in film thickness can be controlled with sub-nanometer accuracy by adjusting the energy dose. The lateral spatial resolution of the thickness modification is controlled by the localization of the energy deposition. The film thickness is adjusted locally to correct the perturbation of the reflected field. For example, when the structural modification is a localized film contraction, the repair of a defect consists of flattening a mound or spreading out the sides of a depression.

  6. Preparation and properties of DLC/MoS2 multilayer coatings for high humidity tribology

    NASA Astrophysics Data System (ADS)

    Zhao, Xiaoyu; Lu, Zhibin; Wu, Guizhi; Zhang, Guangan; Wang, Liping; Xue, Qunji

    2016-06-01

    The DLC/MoS2 multilayer coatings with different modulus ratios were deposited by magnetron sputtering in this study. The morphology, structure, composition, mechanical properties and tribological properties were investigated using several analytical techniques (FESEM, AFM, TEM, AES, XPS, nanoindentation and high humidity tribological test). The results showed that the well-defined multilayer coatings were composed of densely packed particles in which many nanocrystallines with some kinds of defects were distributed in matrix. The incorporation of oxygen into the lattice led to the degraded chemical stability. The coating’s hardness and elastic modulus were almost in the same range. Moderate improvement on the high humidity tribological properties were obtained, which was important for the extension of the service life of MoS2 in humid air.

  7. Use of a TiBN Multilayer Coating for Wear Reduction

    SciTech Connect

    Behrens, Bernd-Arno; Bistron, Marcus; Bach, Friedrich-Wilhelm; Moehwald, Kai; Deisser, Todd Alexander

    2007-05-17

    The near surface area of forging dies is exposed to high mechanical loads. Additionally thermal and chemical stresses occur during the forging process. Depending on the number of forged parts, several kinds of damage develop in the surface area, which lead to failures of forging dies. Die wear is the main reason of failure with a 70% ratio. The abrasion resistance of the surface area of forging dies has to be increased in order to reduce wear. Therefore different methods were examined such as the increase of the abrasion resistance by plasma nitriding and by coating with ceramic layers (TiN, TiCN, TiC, CrN). These layers are applied to the forging die by using PACVD or PAPVD treatment. At the Institute of Metal Forming and Metal-Forming Machines of the University of Hanover a wear reduction by factor 3.5 compared to nitrided forging dies for forging helical gears was achieved. This was possible by using a coating compound of 18 ceramic layers. These excellent results for the multilayer system can be explained through the energy reduction at the inner boundaries and a crack deflection effect at the phase transitions. The layer support of neighboring layers and a stress relaxation through the stacked construction of the layer system are also improving the durability of the coating. This multilayer coating consists of a TiN-TiCN-TiC layer system with an overall thickness of 1.8 {mu}m. This paper presents investigations of this multilayer compound and further research to reduce wear through an additional TiBN coating layer. With this additional top coating an increase of the thermal resistance and the oxidation resistance can be achieved. As a result of this enhancement a further increase of the wear reduction was expected.

  8. Analysis of Counterfeit Coated Tablets and Multi-Layer Packaging Materials Using Infrared Microspectroscopic Imaging.

    PubMed

    Winner, Taryn L; Lanzarotta, Adam; Sommer, André J

    2016-06-01

    An effective method for detecting and characterizing counterfeit finished dosage forms and packaging materials is described in this study. Using attenuated total internal reflection Fourier transform infrared spectroscopic imaging, suspect tablet coating and core formulations as well as multi-layered foil safety seals, bottle labels, and cigarette tear tapes were analyzed and compared directly with those of a stored authentic product. The approach was effective for obtaining molecular information from structures as small as 6 μm. PMID:27068491

  9. Corrosion-resistant multilayer coatings for the 28-75 nm wavelength region

    SciTech Connect

    Soufli, R; Fernandez-Perea, M; Al, E T

    2011-11-08

    Corrosion has prevented use of SiC/Mg multilayers in applications requiring good lifetime stability. We have developed Al-based barrier layers that dramatically reduce corrosion, while preserving high reflectance and low stress. The aforementioned advances may enable the implementation of corrosion-resistant, high-performance SiC/Mg coatings in the 28-75 nm region in applications such as tabletop EUV/soft x-ray laser sources and solar physics telescopes. Further study and optimization of corrosion barrier structures and coating designs is underway.

  10. Test station development for laser-induced optical damage performance of broadband multilayer dielectric coatings

    NASA Astrophysics Data System (ADS)

    Kafka, K. R. P.; Chowdhury, E. A.; Negres, R. A.; Stolz, C. J.; Bude, J. D.; Bayramian, A. J.; Marshall, C. D.; Spinka, T. M.; Haefner, C. L.

    2015-11-01

    Laser-induced damage threshold (LIDT) testing was performed on commercially-available multilayer dielectric coatings to qualify for use in the High Repetition-Rate Advanced Petawatt Laser System (HAPLS) for Extreme Light Infrastructure Beamlines. Various tests were performed with uncompressed pulses (150 ps) from a 780 nm-centered Ti:Sapphire regenerative ampliflier, and the raster scan method was used to determine the best-performing coatings. Performance varied from 2-8 J/cm2 across samples from 6 different manufacturers.

  11. Influence of polyelectrolyte multilayer coating on the degree and type of biofouling in freshwater environment.

    PubMed

    Frueh, Johannes; Gai, Meiyu; Yang, Zhibo; He, Qiang

    2014-06-01

    Biofouling is one of the biggest problems of water-borne systems. Since not only marine but also freshwater-based structures are affected, the biofouling in this environment is studied. The focus of this study lies on the antifouling properties of novel coating materials like polyelectrolyte multilayers (PEM) compared with currently used silicon rubber (PDMS) based fouling release coatings. The following article contains the results of a systematical screening of the mechanical, surface charge and surface nano-heterogeneous properties of the investigated PEM and PDMS systems. The results show that negatively charged non crosslinked and crosslinked PEM coated PDMS can surpass current PDMS based fouling release coatings. The PEM films are not only able to reduce the biofouling, but are additionally able to control the type of settled bacteria (gram positive or negative). The negative terminated surfaces inhibit the settlement of gram positive bacteria, whereby the positive terminated surfaces inhibit the settlement of gram negative bacteria. PMID:24738394

  12. Optimization of hybrid antireflection structure integrating surface texturing and multi-layer interference coating

    NASA Astrophysics Data System (ADS)

    Kubota, Shigeru; Kanomata, Kensaku; Suzuki, Takahiko; Hirose, Fumihiko

    2014-10-01

    The antireflection structure (ARS) for solar cells is categorized to mainly two different techniques, i.e., the surface texturing and the single or multi-layer antireflection interference coating. In this study, we propose a novel hybrid ARS, which integrates moth eye texturing and multi-layer coat, for application to organic photovoltaics (OPVs). Using optical simulations based on the finite-difference time-domain (FDTD) method, we conduct nearly global optimization of the geometric parameters characterizing the hybrid ARS. The proposed optimization algorithm consists of two steps: in the first step, we optimize the period and height of moth eye array, in the absence of multi-layer coating. In the second step, we optimize the whole structure of hybrid ARS by using the solution obtained by the first step as the starting search point. The methods of the simple grid search and the Hooke and Jeeves pattern search are used for global and local searches, respectively. In addition, we study the effects of deviations in the geometric parameters of hybrid ARS from their optimized values. The design concept of hybrid ARS is highly beneficial for broadband light trapping in OPVs.

  13. Spontaneous changes in contact angle of water and oil on novel flip-flop-type hydrophobic multilayer coatings

    NASA Astrophysics Data System (ADS)

    Kawamura, Go; Ema, Tomoyuki; Sakamoto, Hisatoshi; Wei, Xing; Muto, Hiroyuki; Matsuda, Atsunori

    2014-04-01

    Multilayer structures composed of poly(allylamine hydrochloride) (PAH) and Nafion were fabricated on glass substrates by layer-by-layer assembly. Some of the multilayers demonstrated spontaneous changes in contact angle of water and oil due to flip-flop movements of free sulfo groups in the Nafion layer, and the multilayers eventually possessed water repellency in air and oil repellency in water. The repellencies were enhanced by applying primer layers that were formed using SiO2 fine particles to increase surface roughness. Compared to typical hydrophobic and oleophobic surfaces, the multilayers showed practical levels for a use as soil release coatings.

  14. Immunomodulation with Self-Crosslinked Polyelectrolyte Multilayer-Based Coatings.

    PubMed

    Knopf-Marques, Helena; Singh, Sonali; Htwe, Su Su; Wolfova, Lucie; Buffa, Radovan; Bacharouche, Jalal; Francius, Grégory; Voegel, Jean-Claude; Schaaf, Pierre; Ghaemmaghami, Amir M; Vrana, Nihal Engin; Lavalle, Philippe

    2016-06-13

    This study aims to design an optimal polyelectrolyte multilayer film of poly-l-lysine (PLL) and hyaluronic acid (HA) as an anti-inflammatory cytokine release system in order to decrease the implant failure due to any immune reactions. The chemical modification of the HA with aldehyde moieties allows self-cross-linking of the film and an improvement in the mechanical properties of the film. The cross-linking of the film and the release of immunomodulatory cytokine (IL-4) stimulate the differentiation of primary human monocytes seeded on the films into pro-healing macrophages phenotype. This induces the production of anti-inflammatory cytokines (IL1-RA and CCL18) and the decrease of pro-inflammatory cytokines secreted (IL-12, TNF-α, and IL-1β). Moreover, we demonstrate that cross-linking PLL/HA film using HA-aldehyde is already effective by itself to limit inflammatory processes. Finally, this functionalized self-cross-linked PLL/HA-aldehyde films constitutes an innovative and efficient candidate for immunomodulation of any kind of implants of various architecture and properties. PMID:27183396

  15. Process for preparing multilayer enzyme coating on a fiber

    DOEpatents

    Kim, Jungbae; Kwak, Ja Hun; Grate, Jay W.

    2009-11-03

    A process for preparing high stability, high activity biocatalytic materials is disclosed and processes for using the same. The process involves coating of a material or fiber with enzymes and enzyme aggregate providing a material or fiber with high biocatalytic activity and stability useful in heterogeneous environments. In one illustrative approach, enzyme "seeds" are covalently attached to polymer nanofibers followed by treatment with a reagent that crosslinks additional enzyme molecules to the seed enzymes forming enzyme aggregates thereby improving biocatalytic activity due to increased enzyme loading and enzyme stability. This approach creates a useful new biocatalytic immobilized enzyme system with potential applications in bioconversion, bioremediation, biosensors, and biofuel cells.

  16. Fiber/matrix interfaces for SiC/SiC composites: Multilayer SiC coatings

    SciTech Connect

    Halverson, H.; Curtin, W.A.

    1996-08-01

    Tensile tests have been performed on composites of CVI SiC matrix reinforced with 2-d Nicalon fiber cloth, with either pyrolitic carbon or multilayer CVD SiC coatings [Hypertherm High-Temperature Composites Inc., Huntington Beach, CA.] on the fibers. To investigate the role played by the different interfaces, several types of measurements are made on each sample: (i) unload-reload hysteresis loops, and (ii) acoustic emission. The pyrolitic carbon and multilayer SiC coated materials are remarkably similar in overall mechanical responses. These results demonstrate that low-modulus, or compliant, interface coatings are not necessary for good composite performance, and that complex, hierarchical coating structures may possibly yield enhanced high-temperature performance. Analysis of the unload/reload hysteresis loops also indicates that the usual {open_quotes}proportional limit{close_quotes} stress is actually slightly below the stress at which the 0{degrees} load-bearing fibers/matrix interfaces slide and are exposed to atmosphere.

  17. 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.

  18. Inkjet ink spreading on polyelectrolyte multilayers deposited on pigment coated paper.

    PubMed

    Mielonen, Katriina; Geydt, Pavel; Österberg, Monika; Johansson, Leena-Sisko; Backfolk, Kaj

    2015-01-15

    Mechanisms of inkjet ink spreading and absorption on a coated paper have been studied using a polyelectrolyte multilayering technique. By applying alternating sequences of cationic and anionic polyelectrolyte layers on a mineral coated paper, the role of the interfacial chemistry was evaluated. The polyelectrolyte multilayer was created to imitate a thin resin-like liquid-absorptive layer and to clarify the role of the charge of the protruding polyelectrolyte layer on ink spreading and colorant fixation. The formation of a thin polyelectrolyte layer and coating coverage was confirmed by X-ray photoelectron spectroscopy (XPS). A submolecular mechanical imaging of the polyelectrolyte complexes with an atomic force microscope (AFM) revealed differences in modulus and different nanosize agglomerates were identified which were ascribed to polyion complexes. The polyelectrolyte coatings significantly affect the solid-liquid interaction and particularly the ink spreading revealed as intercolor bleeding and wicking. The interfacial interaction between the ink and the applied polyelectrolyte layers showed differences between dye- and pigment-based colorants, which could be emphasized by the polyelectrolyte chemistry. PMID:25454440

  19. High Temperature Multilayer Environmental Barrier Coatings Deposited Via Plasma Spray-Physical Vapor Deposition

    NASA Technical Reports Server (NTRS)

    Harder, Bryan James; Zhu, Dongming; Schmitt, Michael P.; Wolfe, Douglas E.

    2014-01-01

    Si-based ceramic matrix composites (CMCs) require environmental barrier coatings (EBCs) in combustion environments to avoid rapid material loss. Candidate EBC materials have use temperatures only marginally above current technology, but the addition of a columnar oxide topcoat can substantially increase the durability. Plasma Spray-Physical Vapor Deposition (PS-PVD) allows application of these multilayer EBCs in a single process. The PS-PVD technique is a unique method that combines conventional thermal spray and vapor phase methods, allowing for tailoring of thin, dense layers or columnar microstructures by varying deposition conditions. Multilayer coatings were deposited on CMC specimens and assessed for durability under high heat flux and load. Coated samples with surface temperatures ranging from 2400-2700F and 10 ksi loads using the high heat flux laser rigs at NASA Glenn. Coating morphology was characterized in the as-sprayed condition and after thermomechanical loading using electron microscopy and the phase structure was tracked using X-ray diffraction.

  20. Facility for continuous CVD coating of ceramic fibers

    NASA Technical Reports Server (NTRS)

    Moore, Arthur W.

    1992-01-01

    An inductively heated CVD furnace of pilot-plant scale, whose hot zone is 150 mm in diameter x 300 mm in length, has been adapted for continuous coating of ceramic yarns. Coatings at very low pressures are possible in this facility due to the fact that the entire apparatus, including yarn feeding and collecting equipment, is under vacuum. SiC yarn has been coated with 0.1-0.2 microns of BN at yarn speeds of 60 cm/min; a 500-m spool; was coated in about 14 hrs. Coating capacity was tripled by adding pulleys to allow three yarn passes through the furnace.

  1. Searching for optimal mitigation geometries for laser resistant multilayer high reflector coatings

    SciTech Connect

    Qiu, S R; Wolfe, J E; Monterrosa, A M; Feit, M D; Pistor, T V; STolz, C J

    2011-02-11

    Growing laser damage sites on multilayer high reflector coatings can limit mirror performance. One of the strategies to improve laser damage resistance is to replace the growing damage sites with pre-designed benign mitigation structures. By mitigating the weakest site on the optic, the large aperture mirror will have a laser resistance comparable to the intrinsic value of the multilayer coating. To determine the optimal mitigation geometry, the finite difference time domain method (FDTD) was used to quantify the electric-field intensification within the multilayer, at the presence of different conical pits. We find that the field intensification induced by the mitigation pit is strongly dependent on the polarization and the angle of incidence (AOI) of the incoming wave. Therefore the optimal mitigation conical pit geometry is application specific. Furthermore, our simulation also illustrates an alternative means to achieve an optimal mitigation structure by matching the cone angle of the structure with the AOI of the incoming wave, except for the p-polarization wave at a range of incident angles between 30{sup o} and 45{sup o}.

  2. Functional properties of multilayer vacuum-arc TiN/ZrN coatings

    NASA Astrophysics Data System (ADS)

    Plotnikov, S. V.; Pogrebnyak, A. D.; Tleukenov, Y. O.; Erdybaeva, N. K.

    2016-02-01

    Nanostructured multilayer Ti/ZrN coatings were synthesized by vacuum-arc deposition with a number of layers 134-533 and an average thickness 20-125nm of layers. A good planarity was revealed resulting in a range of nanometer layer from plasma streams in a reactive environment. Phase-structural changes mechanisms were established as a model of critical operating coatings’ conditions of in the surface layers under the action of an aggressive oxygen atmosphere at high temperature (700°C). The thickness parameter effect on its hardness of the multilayer system was shown. It was found that the maximum hardness of 42 GPa and the lowest abrasion of coating 1,3×10-5 mm3×H-1×mm-and counterbody 1,9×10-6 mm3×H-1×mm-1 inherent in TiN/ZrN system with the smallest layer thickness of 20 nm in the period. The results are explained by the influence of the size factor interphase boundaries magnified in a multilayer system with a nanometer thick layers.

  3. PUA/PSS multilayer coated CaCO3 microparticles as smart drug delivery vehicles.

    PubMed

    Du, Chao; Shi, Jun; Shi, Jin; Zhang, Li; Cao, Shaokui

    2013-10-01

    Hybrid CaCO3 microparticles coated by sodium poly(styrene sulfonate) (PSS) and aliphatic poly(urethane-amine) (PUA) were developed as thermal-/pH-responsive drug delivery vehicles via LbL self-assembly technique. The DOX release from the CaCO3 microparticles was higher than 60% within 36 h, whereas the value of PUA/PSS-coated microparticles was only 20%. The results demonstrated that the PUA/PSS multilayer coating could reduce the drug release rate and significantly assuage the initial burst release of DOX. In addition, the drug release of the hybrid microparticles was found to be thermal-/pH-dual responsive. More interestingly, more than 90% of DOX was released in 36 h at pH2.1 and 55 °C owing to the combined action of the dissolution of the CaCO3 core and the shrinkage of aliphatic PUA. PMID:23910272

  4. Friction Modifier Using Adherent Metallic Multilayered or Mixed Element Layer Conversion Coatings

    NASA Technical Reports Server (NTRS)

    Schramm, Harry F. (Inventor); Defalco, Francis G. (Inventor); Starks, Lloyd L., Sr. (Inventor)

    2013-01-01

    A process for creating conversion coatings and spin, drawing, and extrusion finishes for surfaces, wherein the conversion coatings and spin, drawing, and extrusion finishes contain potassium, phosphorus, nitrogen, and one or more non-alkaline metals and/or one or more metalloids. The process comprises forming an aqueous solution of water, phosphoric acid or sulfuric acid, ammonium hydroxide, an alkali metal hydroxide, and one or more non-alkaline metals and/or one or more metalloids. The aqueous solution forms an anti-friction multilayer conversion and/or mixed element coating or a spin, drawing, and extrusion finish on a surface when applied to the surface, either directly without the use of applied external electromotive force, or as an additive in lubricating fluids.

  5. Friction modifier using adherent metallic multilayered or mixed element layer conversion coatings

    NASA Technical Reports Server (NTRS)

    Schramm, Harry F. (Inventor); Defalco, Frank G. (Inventor); Starks, Sr., Lloyd L. (Inventor)

    2012-01-01

    A process for creating conversion coatings and spin, drawing, and extrusion finishes for surfaces, wherein the conversion coatings and spin, drawing, and extrusion finishes contain potassium, phosphorus, nitrogen, silicon, and one or more non-alkaline metals. The process comprises forming a first aqueous solution of silicate, potassium hydroxide, and ammonium hydroxide; forming a second aqueous solution of water, phosphoric acid, ammonium hydroxide, an alkali metal hydroxide, and one or more non-alkaline metals, and then combining the first solution with the second solution to form a final solution. This final solution forms an anti-friction multi-layer conversion coating or a spin, drawing, and extrusion finish on a surface when applied to the surface, either directly or as an additive in lubricating fluids.

  6. Multilayer coatings of 10x projection for extreme-ultraviolet lithography

    SciTech Connect

    Folta, J A; Montcalm, C; Spiller, E; Wedowski, M

    1999-03-09

    Two new sets of projections optics for the prototype 10X reduction EUV lithography system were coated with Mo/Si multilayers. The coating thickness was graded across the optics by using shadow masks to ensure maximum throughput at all incidence angles in the camera. The overall deviation of the (normalized) wavelength response across the clear aperture of each mirror is below 0.01% RMS. However, the wavelength mismatch between two optics coated in different runs is up to 0.07 nm. Nevertheless, this is still within the allowed tolerances, and the predicted optical throughput loss in the camera due to such wavelength mismatch is about 4%. EUV reflectances of 63-65% were measured around 13.40 nm for the secondary optics, which is in good agreement with the expected reflectance based on the substrate finish as measured with AFM.

  7. Weightless Environment Training Facility (WETF) materials coating evaluation, volume 3

    NASA Technical Reports Server (NTRS)

    1995-01-01

    This volume consists of Appendices C, D, E, and F to the report on the Weightless Environment Training Facility Materials Coating Evaluation project. The project selected 10 coating systems to be evaluated in six separate exposure environments, and subject to three tests for physical properties. Appendix C is the photographic appendix of the test panels. Appendix D details methods and procedures. Appendix E lists application equipment costs. Appendix F is a compilation of the solicitation of the candidate coating systems.

  8. High-efficiency 5000 lines/mm multilayer-coated blazed grating for EUV wavelengths

    SciTech Connect

    Voronov, Dmitriy; Ahn, Minseung; Anderson, Erik; Cambie, Rossana; Chang, Chih-Hao; Gullikson, Eric; Heilmann, Ralf; Salmassi, Farhad; Schattenburg, Mark; Warwick, Tony; Yashchuk, Valeriy; Zipp, Lucas; Padmore, Howard A.

    2010-04-19

    Volume x-ray gratings consisting of a multilayer coating deposited on a blazed substrate can diffract with very high efficiency even in high orders if diffraction conditions in-plane (grating) and out-of-plane (Bragg multilayer) are met simultaneously. This remarkable property however depends critically on the ability to create a structure with near atomic perfection. In this work we report on a method to produce these structures. We report measurements that show, for a 5000 l/mm grating diffracting in the 3rd order, a diffraction efficiency of 37.6percent at a wavelength of 13.6 nm, close to the theoretical maximum. This work now shows a direct route to achieving high diffraction efficiency in high order at wavelengths throughout the soft x-ray energy range.

  9. Crack Driving Forces in a Multilayered Coating System for Ceramic Matrix Composite Substrates

    NASA Technical Reports Server (NTRS)

    Ghosn, Louis J.; Zhu, Dongming; Miller, Robert A.

    2005-01-01

    The effects of the top coating thickness, modulus and shrinkage strains on the crack driving forces for a baseline multilayer Yttria-Stabilized-Zirconia/Mullite/Si thermal and environment barrier coating (TEBC) system for SiC/SiC ceramic matrix composite substrates are determined for gas turbine applications. The crack driving forces increase with increasing modulus, and a low modulus thermal barrier coating material (below 10 GPa) will have no cracking issues under the thermal gradient condition analyzed. Since top coating sintering increases the crack driving forces with time, highly sintering resistant coatings are desirable to maintain a low tensile modulus and maintain a low crack driving force with time. Finite element results demonstrated that an advanced TEBC system, such as ZrO2/HfO2, which possesses improved sintering resistance and high temperature stability, exhibited excellent durability. A multi-vertical cracked structure with fine columnar spacing is an ideal strain tolerant coating capable of reducing the crack driving forces to an acceptable level even with a high modulus of 50 GPa.

  10. Innovative Coatings Potentially Lower Facility Maintenance Costs

    NASA Technical Reports Server (NTRS)

    2013-01-01

    Through extensive testing at Stennis Space Center, Nanocepts Inc. of Lexington, Kentucky, received key validation of the effectiveness of its photocatalytic coatings. Now a NASA Dual Use Technology partner, the company s commercial coatings offer unique environmental and medical benefits, and their self-cleaning properties help limit grime buildup on buildings.

  11. 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.

  12. Hard X-ray multilayer coated astronomical mirrors by e-beam deposition

    NASA Astrophysics Data System (ADS)

    Spiga, Daniele; Pareschi, Giovanni; Grisoni, Gabriele; Valsecchi, Giuseppe

    2004-10-01

    A number of X-ray astronomical missions of near future (Constellation-X, XEUS, Simbol-X) will make use of hard X-rays (10-100 keV) optics with broad-band multilayer coatings. A possible technique under development is based on an extension of the already tested replication of a coated mandrel by e-beam deposition and nickel electroforming already successfully used for the soft (0.1 - 10 keV) X-ray mirrors of the Beppo-SAX, XMM, JET-X/Swift missions. In this case graded multilayers are deposited and replicated from the mandrel replicated instead of a single layer. The roughness reduction in order to improve the coating reflectivity could be achieved by an ion assistance during the e-beam deposition. The e-beam deposition with ion assistance is a technique that allows to reach comparable (if not better) smoothness levels with respect to other methods (e.g. ion sputtering), taking the advantage of a stress mitigation between the layers and of a further improvement in reflectivity due to the low density of the e-beam evaporated Carbon, which is used as bilayer spacer. In this paper we discuss the adopted deposition technique and its implementation: we present topographic (AFM) tests and X-ray reflectivity tests performed on preliminary samples.

  13. A multilayer innovative solution to improve the adhesion of nanocrystalline diamond coatings

    NASA Astrophysics Data System (ADS)

    Poulon-Quintin, A.; Faure, C.; Teulé-Gay, L.; Manaud, J. P.

    2015-03-01

    Nano-crystalline diamond (NCD) films grown under negative biased substrates by chemical vapor deposition (CVD) are widely used as surface overlay coating onto cermet WC-Co cutting tools to get better performances. To improve the diamond adhesion to the cermet substrate, suitable multi-layer systems have been added. They are composed of a cobalt diffusion barrier close to the substrate (single and sequenced nitrides layers) coated with a nucleation extra layer to improve the nucleus density of diamond during CVD processing. For all systems, before and after diamond deposition, transmission electron microscopy (TEM) has been performed for a better understanding of the diffusion phenomena occurring at the interfaces and to evaluate the presence of graphitic species at the interface with the diamond. Innovative multilayer system dedicated to the regulation of cobalt diffusion coated with a bilayer system optimized for the carbon diffusion control, is shown as an efficient solution to significantly reduce the graphite layer formation at the interface with the diamond down to 10 nm thick and to increase the adhesion of NCD diamond layer as scratch-tests confirm.

  14. Deformation sensor based on polymer-supported discontinuous graphene multi-layer coatings

    SciTech Connect

    Carotenuto, G.; Schiavo, L.; Romeo, V.; Nicolais, L.

    2014-05-15

    Graphene can be conveniently used in the modification of polymer surfaces. Graphene macromolecules are perfectly transparent to the visible light and electrically conductive, consequently these two properties can be simultaneously provided to polymeric substrates by surface coating with thin graphene layers. In addition, such coating process provides the substrates of: water-repellence, higher surface hardness, low-friction, self-lubrication, gas-barrier properties, and many other functionalities. Polyolefins have a non-polar nature and therefore graphene strongly sticks on their surface. Nano-crystalline graphite can be used as graphene precursor in some chemical processes (e.g., graphite oxide synthesis by the Hummer method), in addition it can be directly applied to the surface of a polyolefin substrate (e.g., polyethylene) to cover it by a thin graphene multilayer. In particular, the nano-crystalline graphite perfectly exfoliate under the application of a combination of shear and friction forces and the produced graphene single-layers perfectly spread and adhere on the polyethylene substrate surface. Such polymeric materials can be used as ITO (indium-tin oxide) substitute and in the fabrication of different electronic devices. Here the fabrication of transparent resistive deformation sensors based on low-density polyethylene films coated by graphene multilayers is described. Such devices are very sensible and show a high reversible and reproducible behavior.

  15. Sub-diffraction-limited multilayer coatings for the 0.3-NA Micro-Exposure Tool for extreme ultraviolet lithography

    SciTech Connect

    Soufli, R; Hudyma, R M; Spiller, E; Gullikson, E M; Schmidt, M A; Robinson, J C; Baker, S L; Walton, C C; Taylor, J S

    2007-01-03

    This manuscript discusses the multilayer coating results for the primary and secondary mirrors of the Micro Exposure Tool (MET): a 0.30-numerical aperture (NA) lithographic imaging system with 200 x 600 {micro}m{sup 2} field of view at the wafer plane, operating in the extreme ultraviolet (EUV) wavelength region. Mo/Si multilayers were deposited by DC-magnetron sputtering on large-area, curved MET camera substrates, and a velocity modulation technique was implemented to consistently achieve multilayer thickness profiles with added figure errors below 0.1 nm rms to achieve sub-diffraction-limited performance. This work represents the first experimental demonstration of sub-diffraction-limited multilayer coatings for high-NA EUV imaging systems.

  16. In situ Synthesis of Oligonucleotide Arrays on Surfaces Coated with Crosslinked Polymer Multilayers.

    PubMed

    Broderick, Adam H; Lockett, Matthew R; Buck, Maren E; Yuan, Yuan; Smith, Lloyd M; Lynn, David M

    2012-03-13

    We report an approach to the in situ synthesis of oligonucleotide arrays on surfaces coated with crosslinked polymer multilayers. Our approach makes use of methods for the 'reactive' layer-by-layer assembly of thin, amine-reactive multilayers using branched polyethyleneimine (PEI) and the azlactone-functionalized polymer poly(2-vinyl-4,4'-dimethylazlactone) (PVDMA). Post-fabrication treatment of film-coated glass substrates with d-glucamine or 4-amino-1-butanol yielded hydroxyl-functionalized films suitable for the Maskless Array Synthesis (MAS) of oligonucleotide arrays. Glucamine-functionalized films yielded arrays of oligonucleotides with fluorescence intensities and signal-to-noise ratios (after hybridization with fluorescently labeled complementary strands) comparable to those of arrays fabricated on conventional silanized glass substrates. These arrays could be exposed to multiple hybridization-dehybridization cycles with only moderate loss of hybridization density. The versatility of the layer-by-layer approach also permitted synthesis directly on thin sheets of film-coated poly(ethylene terephthalate) (PET) to yield flexible oligonucleotide arrays that could be readily manipulated (e.g., bent) and cut into smaller arrays. To our knowledge, this work presents the first use of polymer multilayers as a substrate for the multi-step synthesis of complex molecules. Our results demonstrate that these films are robust and able to withstand the ~450 individual chemical processing steps associated with MAS (as well as manipulations required to hybridize, image, and dehybridize the arrays) without large-scale cracking, peeling, or delamination of the thin films. The combination of layer-by-layer assembly and MAS provides a means of fabricating functional oligonucleotide arrays on a range of different materials and substrates. This approach may also prove useful for the fabrication of supports for the solid-phase synthesis and screening of other macromolecular or small

  17. Hollow glass waveguides with multilayer polystyrene and metal sulfide thin film coatings for improved infrared transmission

    NASA Astrophysics Data System (ADS)

    Johnson, Valencia S.

    2007-12-01

    The overall goal of this project was to improve transmission of infrared radiation in hollow waveguides. First, polystyrene was studied as a new dielectric material for silver-coated hollow glass waveguides. The deposition and performance of polystyrene, as a single dielectric layer, were investigated. The potential of polystyrene as the low index of refraction material in a multilayer coating was also demonstrated. Cadmium sulfide and lead sulfide were each considered as the high index material in the multilayer stack. Multilayer silver coated hollow glass waveguides can be formed using polystyrene and either cadmium sulfide or lead sulfide. These material pairs are interesting because they form a multilayer structure with high index contrast, which can significantly lower the loss of a waveguide. The deposition of lead sulfide was also optimized in this project. Lead sulfide, as a single layer dielectric coating, is an attractive material for transmission of longer wavelength radiation, especially 10.6 mum. It is also of interest for emerging applications such as metals processing by lasers because hollow waveguides with silver and lead sulfide can make a low loss waveguide. Losses as low as 0.1dB/m were achieved. The deposition of zinc sulfide and zinc selenide was also investigated in this project. They are of interest because of their small extinction coefficients at longer wavelengths and potential for use in waveguides used for materials processing. The numerous simultaneous chemical reactions occurring during deposition of these materials makes obtaining pure films difficult. Gold was evaluated as a replacement for silver as the highly reflecting metallic layer. It was considered an attractive alternative because it has greater resistance to degradation in high temperature and corrosive environments. All samples were made using an electroless process. Characterization of the samples was performed using the optical techniques of FTIR and UV

  18. Multilayer (TiN, TiAlN) ceramic coatings for nuclear fuel cladding

    NASA Astrophysics Data System (ADS)

    Alat, Ece; Motta, Arthur T.; Comstock, Robert J.; Partezana, Jonna M.; Wolfe, Douglas E.

    2016-09-01

    In an attempt to develop an accident-tolerant fuel (ATF) that can delay the deleterious consequences of loss-of-coolant-accidents (LOCA), multilayer coatings were deposited onto ZIRLO® coupon substrates by cathodic arc physical vapor deposition (CA-PVD). Coatings were composed of alternating TiN (top) and Ti1-xAlxN (2-layer, 4-layer, 8-layer and 16-layer) layers. The minimum TiN top coating thickness and coating architecture were optimized for good corrosion and oxidation resistance. Corrosion tests were performed in static pure water at 360 °C and 18.7 MPa for up to 90 days. The optimized coatings showed no spallation/delamination and had a maximum of 6 mg/dm2 weight gain, which is 6 times smaller than that of a control sample of uncoated ZIRLO® which showed a weight gain of 40.2 mg/dm2. The optimized architecture features a ∼1 μm TiN top layer to prevent boehmite phase formation during corrosion and a TiN/TiAlN 8-layer architecture which provides the best corrosion performance.

  19. Functional multilayer coated long period grating tuned in transition region for life science applications

    NASA Astrophysics Data System (ADS)

    Pilla, P.; Malachovská, V.; Borriello, A.; Giordano, M.; Ambrosio, L.; Cutolo, A.; Cusano, A.

    2010-09-01

    We report preliminary results on the development of multilayer coated long period gratings (LPGs) for life science applications. The dip-coating technique and a solvent/nonsolvent strategy were exploited to deposit double-layer polymeric film onto a LPG. A primary coating of atactic polystyrene was used as high refractive index layer to tune the working point of the device in the so-called transition region thus achieving remarkable surrounding medium refractive index sensitivity. A secondary layer of atactic poly(methyl methacrylate-co-methacrylic acid) containing functional carboxyl groups, characterized by a lower refractive index, was deposited onto the primary coating in order to have the desired functional groups on the surface of the device. Commonly used covalent immobilization procedure, NHS/EDC coupling method, was exploited to link streptavidin on the surface of the functionalized coated device. Finally, real-time detection of biotinylated bovine serum albumin affinity binding on immobilized streptavidin was performed by monitoring the shift of the LPG attenuation bands.

  20. Analysis of microstructure and properties of multilayer coatings produced by laser cladding

    NASA Astrophysics Data System (ADS)

    Bykovskiy, D. P.; Petrovskiy, V. N.; Dzhumaev, P. S.; Polskiy, V. I.; Yermachenko, V. M.

    2016-02-01

    Purpose of the work is to prepare multilayer coatings corresponding to specified requirements to recovery and improvement of surface details. Requirements to coatings: providing durable and reliable adhesion base and filler materials, absence of pores, cracks, delaminations, reducing mixing metal base and cladding. We used iron-based PR-10R6M5 and tungsten carbide Hoganas 44712 powders. Experimental determination of the optimal technological mode of application of the single track, the coefficient of overlapping tracks to create a full layer, the angle of the second cladding layer, relative to the first one and, finally, the determination of the optimal additive tungsten carbide to achieve increased durability were produced to fulfill these requirements.

  1. Multifunctional cantilever-free scanning probe arrays coated with multilayer graphene.

    PubMed

    Shim, Wooyoung; Brown, Keith A; Zhou, Xiaozhu; Rasin, Boris; Liao, Xing; Mirkin, Chad A

    2012-11-01

    Scanning probe instruments have expanded beyond their traditional role as imaging or "reading" tools and are now routinely used for "writing." Although a variety of scanning probe lithography techniques are available, each one imposes different requirements on the types of probes that must be used. Additionally, throughput is a major concern for serial writing techniques, so for a scanning probe lithography technique to become widely applied, there needs to be a reasonable path toward a scalable architecture. Here, we use a multilayer graphene coating method to create multifunctional massively parallel probe arrays that have wear-resistant tips of uncompromised sharpness and high electrical and thermal conductivities. The optical transparency and mechanical flexibility of graphene allow this procedure to be used for coating exceptionally large, cantilever-free arrays that can pattern with electrochemical desorption and thermal, in addition to conventional, dip-pen nanolithography. PMID:23086161

  2. Multifunctional cantilever-free scanning probe arrays coated with multilayer graphene

    PubMed Central

    Shim, Wooyoung; Brown, Keith A.; Zhou, Xiaozhu; Rasin, Boris; Liao, Xing; Mirkin, Chad A.

    2012-01-01

    Scanning probe instruments have expanded beyond their traditional role as imaging or “reading” tools and are now routinely used for “writing.” Although a variety of scanning probe lithography techniques are available, each one imposes different requirements on the types of probes that must be used. Additionally, throughput is a major concern for serial writing techniques, so for a scanning probe lithography technique to become widely applied, there needs to be a reasonable path toward a scalable architecture. Here, we use a multilayer graphene coating method to create multifunctional massively parallel probe arrays that have wear-resistant tips of uncompromised sharpness and high electrical and thermal conductivities. The optical transparency and mechanical flexibility of graphene allow this procedure to be used for coating exceptionally large, cantilever-free arrays that can pattern with electrochemical desorption and thermal, in addition to conventional, dip-pen nanolithography. PMID:23086161

  3. Thermal property measurement for thermal barrier coatings using pulsed thermal imaging - multilayer analysis method

    NASA Astrophysics Data System (ADS)

    Sun, J. G.; Tao, N.

    2016-02-01

    Thermal barrier coatings (TBCs) are extensively used on hot gas-path components in gas turbines to improve engine performance and extend component life. TBC thermal properties, specifically the thermal conductivity and heat capacity (the product of density and specific heat), are important parameters in these applications. These TBC properties are usually measured by destructive methods with specially prepared TBC samples. Nondestructive evaluation (NDE) methods have been developed in recently years that can measure TBC properties on natural TBC samples. However, many have limitations when examining TBCs on engine components. One exception is the pulsed thermal imaging - multilayer analysis (PTI-MLA) method, which can be applied to essentially any TBC samples with one or more coating layers and can determine TBC property distributions over the entire TBC surface. This paper describes its basic theories and implementations and discusses its potential applications to all areas of TBC studies.

  4. Development of High Resolution Hard X-Ray Telescope with Multilayer Coatings

    NASA Technical Reports Server (NTRS)

    Brinton, John C. (Technical Monitor); Gorenstein, Paul

    2004-01-01

    The major objective of this program is the development of a focusing hard X-ray telescope with moderately high angular resolution, i .e. comparable to the telescopes of XMM-Newton. The key ingredients of the telescope are a depth graded multilayer coatings and electroformed nickel substrates that are considerably lighter weight than those of previous missions such as XMM-Newton, which have had conventional single metal layer reflective coatings and have operated at much lower energy X-rays. The ultimate target mission for this technology is the Hard X-Ray Telescope (HXT) of the Constellation X-Ray Mission. However, it is applicable to potential SMEX and MIDEX programs as well.

  5. Thermal stability of TiAlN/CrN multilayer coatings studied by atom probe tomography.

    PubMed

    Choi, Pyuck-Pa; Povstugar, Ivan; Ahn, Jae-Pyeong; Kostka, Aleksander; Raabe, Dierk

    2011-05-01

    This study is about the microstructural evolution of TiAlN/CrN multilayers (with a Ti:Al ratio of 0.75:0.25 and average bilayer period of 9 nm) upon thermal treatment. Pulsed laser atom probe analyses were performed in conjunction with transmission electron microscopy and X-ray diffraction. The layers are found to be thermally stable up to 600 °C. At 700 °C TiAlN layers begin to decompose into Ti- and Al-rich nitride layers in the out-of-plane direction. Further increase in temperature to 1000 °C leads to a strong decomposition of the multilayer structure as well as grain coarsening. Layer dissolution and grain coarsening appear to begin at the surface. Domains of AlN and TiCrN larger than 100 nm are found, together with smaller nano-sized AlN precipitates within the TiCrN matrix. Fe and V impurities are detected in the multilayers as well, which diffuse from the steel substrate into the coating along columnar grain boundaries. PMID:21146308

  6. Theory and practical considerations of multilayer dielectric thin-film stacks in Ag-coated hollow waveguides.

    PubMed

    Bledt, Carlos M; Melzer, Jeffrey E; Harrington, James A

    2014-02-01

    This analysis explores the theory and design of dielectric multilayer reflection-enhancing thin film stacks based on high and low refractive index alternating layers of cadmium sulfide (CdS) and lead sulfide (PbS) on silver (Ag)-coated hollow glass waveguides (HGWs) for low loss transmission at midinfrared wavelengths. The fundamentals for determining propagation losses in such multilayer thin-film-coated Ag hollow waveguides is thoroughly discussed, and forms the basis for further theoretical analysis presented in this study. The effects on propagation loss resulting from several key parameters of these multilayer thin film stacks is further explored in order to bridge the gap between results predicted through calculation under ideal conditions and deviations from such ideal models that often arise in practice. In particular, the effects on loss due to the number of dielectric thin film layers deposited, deviation from ideal individual layer thicknesses, and surface roughness related scattering losses are presented and thoroughly investigated. Through such extensive theoretical analysis the level of understanding of the underlying loss mechanisms of multilayer thin-film Ag-coated HGWs is greatly advanced, considerably increasing the potential practical development of next-generation ultralow-loss mid-IR Ag/multilayer dielectric-coated HGWs. PMID:24514252

  7. Stabilized hemocompatible coating of nitinol devices based on photo-cross-linked alginate/heparin multilayer.

    PubMed

    Liu, Meng; Yue, Xiuli; Dai, Zhifei; Xing, Lei; Ma, Fang; Ren, Nanqi

    2007-08-28

    A novel stabilized hemocompatible multicomponent coating was engineered by consecutive alternating adsorption of two polysaccharides, alginate (Alg) and heparin (Hep), onto a Nitinol surface via electrostatic interaction in combination with photoreaction in situ. For this purpose, a photosensitive cross-linker, p-diazonium diphenyl amine polymer (PA), was used as an interlayer between alginate and heparin. The optical intensity of UV/vis spectra increased linearly with the number of layers, indicating the buildup of a multilayer structure and uniform coating. Photo-cross-linking resulted in higher stability without compromising its catalytic capacity to promote antithrombin III (ATIII)-mediated thrombin inactivation. Chromogenic assays for heparin activity proved definitively that anticoagulation activity really comes from surface-bound heparin in multilayer film, not from solution-phase free heparin that has leaked from multilayer film. The activated partial thromboplastin time (aPTT) assay showed that both (PA/Hep)8- and (PA/Alg/PA/Hep)4-coated Nitinol were less thrombogenic than the uncoated one. Yet, the latter was found to be more stable under a continuous shaken wash. In addition, (PA/Alg/PA/Hep)4 film exhibited lower surface roughness and higher hydrophilicity than (PA/Hep)8. As a result, hemolysis of (PA/Alg/PA/Hep)4 (0.34 +/- 0.064%) was lower than (PA/Hep)8 (0.52 +/- 0.241%). The naked Nitinol and (PA/Hep)8-coated Nitinol showed relatively strong platelet adhesion. On the contrary, no sign of any cellular matter was seen on the (PA/Alg/PA/Hep)4 surface. It is believed that the phenomenon of interlayer diffusion resulted in blended structures, hence, the enhanced wettability and antifouling properties after the incorporation of alginate layers. It is likely that the cooperative effect of alginate and heparin led to the excellent blood compatibility of the (PA/Alg/PA/Hep)4 coating. To simplify, there is greater advantage in utilizing cross-linked alginate

  8. Antireflection coatings with SiOx-TiO2 multilayer structures

    NASA Astrophysics Data System (ADS)

    Lu, Jong-Hong; Luo, Jen-Wei; Chuang, Shiou-Ruei; Chen, Bo-Ying

    2014-11-01

    In this study, we used SiOx-TiO2 multilayer antireflective coatings to achieve optical average transmittances of 94.93 and 98.07% for one-sided and double-sided coatings on a glass substrate, respectively. A SiOx film was employed as the material with a low refractive index and a TiO2 film as the material with a high refractive index. Results showed that when any layer thickness of the SiOx-TiO2 nano-multilayer (NML) structure is much less than the wavelength of visible light, the SiOx-TiO2 thickness ratio can be used to adjust the optical refractive index of the entire NML film. In this study, we produced dense antireflective coatings of three layers (SiOx, TiO2, and SiOx-TiO2 NML/glass substrate) and four layers (SiOx, TiO2, SiOx, and TiO2/glass substrate) with film thicknesses and refractive indices controlled by reactive magnetron sputtering. Thermal treatment at 600 °C in an air atmosphere was also shown to reduce the absorption of visible light, resolving the issue of degraded transparency caused by increasing sputtering speed. The microhardness of the antireflective film was 8.44 GPa, similar to that of the glass substrate. Process window analysis demonstrated the feasibility of the antireflective coating process window from an engineering standpoint. The thickness of the film deviated by less than 10% from the ideal thickness, corresponding to a 98% transmittance range, and the simulation and experimental results were relatively consistent.

  9. Colored hard coatings with AlN–TiN multilayer structures

    SciTech Connect

    Hong Lu, Jong Ying Chen, Bo

    2014-03-15

    AlN–TiN multilayer structures can be used to extend the color gamut of hard coatings while maintaining good hardness and corrosion resistance. This study used reactive magnetron sputtering on a glass substrate to produce coatings with a microhardness of 19 GPa as well as optical reflectance exceeding 80% and controllable saturation (chroma) for various hues of red, yellow, green, blue, and purple. The authors characterized the complex index of refraction of the TiN films using ellipsometry; the real refractive indices of the AlN films were derived from the reflectance values obtained using photometry. Finally, the colors of the samples were quantified using CIE-1931 chromaticity coordinates in the L*a*b* color space, and the microhardness of the films was measured using a nanoindenter. Simulation results using a multiple-beam-interference recursive method presented good consistency with experimental measurements with regard to the optical reflective spectra of AlN–TiN multilayer thin film samples.

  10. Testing multilayer-coated polarizing mirrors for the LAMP soft X-ray telescope

    NASA Astrophysics Data System (ADS)

    Spiga, D.; Salmaso, B.; She, R.; Tayabaly, K.; Wen, M.; Banham, R.; Costa, E.; Feng, H.; Giglia, A.; Huang, Q.; Muleri, F.; Pareschi, G.; Soffitta, P.; Tagliaferri, G.; Valsecchi, G.; Wang, Z.

    2015-09-01

    The LAMP (Lightweight Asymmetry and Magnetism Probe) X-ray telescope is a mission concept to measure the polarization of X-ray astronomical sources at 250 eV via imaging mirrors that reflect at incidence angles near the polarization angle, i.e., 45 deg. Hence, it will require the adoption of multilayer coatings with a few nanometers dspacing in order to enhance the reflectivity. The nickel electroforming technology has already been successfully used to fabricate the high angular resolution imaging mirrors of the X-ray telescopes SAX, XMM-Newton, and Swift/XRT. We are investigating this consolidated technology as a possible technique to manufacture focusing mirrors for LAMP. Although the very good reflectivity performances of this kind of mirrors were already demonstrated in grazing incidence, the reflectivity and the scattering properties have not been tested directly at the unusually large angle of 45 deg. Other possible substrates are represented by thin glass foils or silicon wafers. In this paper we present the results of the X-ray reflectivity campaign performed at the BEAR beamline of Elettra - Sincrotrone Trieste on multilayer coatings of various composition (Cr/C, Co/C), deposited with different sputtering parameters on nickel, silicon, and glass substrates, using polarized X-rays in the spectral range 240 - 290 eV.

  11. Multilayer-coated micro-grating array for x-ray phase-contrast imaging

    NASA Astrophysics Data System (ADS)

    Lynch, Susanna K.; Liu, Chian; Assoufid, Lahsen; Morgan, Nicole Y.; Mazilu, Dumitru; Bennett, Eric; Kemble, Camille K.; Wen, Han H.

    2011-05-01

    X-ray imaging techniques based on grating interferometers rely on transmission gratings to detect x-ray refraction and scattering in a sample. Gratings periods below 2 microns are challenging to realize due to the high aspect ratio of the structures. We propose a method to fabricate transmission gratings with sub-micron periods over centimeter areas by multilayer coating of a staircase (echelle) substrate. The advantage of this approach is the high aspect ratio of multilayer coating and the large area of the echelle substrate. The staircase pattern is etched on the surface of a silicon wafer through anisotropic etching. Multiple layers are deposited on the horizontal surfaces of the stairs by magnetron sputtering in a single run. The layers alternate between two materials of different absorption coefficients or refractive indices. The layer thickness d is designed to be (stair height)/2N, where 2N is the total number of layers. The incident xray beam is parallel to the layers and oblique to the wafer surface. Each stair of the echelle substrate forms a micro grating of period 2d, and the array of micro gratings together act as a single grating over a large area given the right continuity conditions. The grating period potentially can be below 100 nm. We present theoretical description of wave diffraction by the grating array, and results of the first fabrication test with magnetron sputtering deposition.

  12. Corrosion resistance and electrical properties of carbon/chromium-titanium-nitride multilayer coatings on stainless steel

    NASA Astrophysics Data System (ADS)

    Feng, Kai; Li, Zhuguo; Lu, Fenggui; Huang, Jian; Cai, Xun; Wu, Yixiong

    2014-03-01

    High electrical conductivity and corrosion resistance are central to advances in wider application of metallic bipolar plates in polymer electrolyte membrane fuel cell (PEMFC). In this study, C/Cr-Ti-N multilayer coatings are deposited by physical vapor deposition and the effect of Cr:Ti ratio on the corrosion resistance and interfacial contact resistance (ICR) are systematically investigated. Scanning electron microscopy (SEM) result shows that the carbon layer is compact and uniform. Excellent corrosion resistance of 0.127 μA cm-2 current density at operating voltage in PEMFC cathode environment and low ICR of 2.03 mΩ-cm2 at compaction force of 150 N cm-2 are achieved when Cr:Ti ratio is 2:4 and 3:3, respectively. The significant enhancement in surface conductivity is probably because that the current comes from carbon paper is homogenized by two electrically conductive layers and flows to the passive film with much more contact area. After polarization, ICR increase to 3.07 mΩ-cm2 and 3.02 mΩ-cm2 in the simulated PEMFC cathode and anode environment, respectively. However, the Raman spectroscopy results disclose that the bonding type of top carbon film before and after polarization shows little difference. The results indicate that C/Cr-Ti-N multilayer coating with Cr:Ti ratio of 2:4 achieves the optimal composition.

  13. Microstructure and corrosion behavior of TiC/Ti(CN)/TiN multilayer CVD coatings on high strength steels

    NASA Astrophysics Data System (ADS)

    Zhang, Jin; Xue, Qi; Li, Songxia

    2013-09-01

    Titanium carbide/titanium carbonitride/titanium nitride (TiC/Ti(CN)/TiN) multilayer coatings are prepared on the surface of three high-strength steels (35CrMo, 42CrMo, and 40CrNiMo) by chemical vapor deposition method. The fracture morphology, elemental distribution, phase composition, micro-hardness, and adhesion of the multilayer film are analyzed. The hydrogen sulfide stress corrosion resistance of the coating is evaluated by the National Association of Corrosion Engineers saturated hydrogen sulfide solution immersion test. A test simulating the environment of the natural gas wells with high temperature and pressure in Luojiazhai in Sichuan is also performed. The results show that the multilayer coatings have dense structures, ∼11 μm thickness, 24.5 ± 2.0 GPa nano-hardness, and ∼70 N adhesion. The corrosion sample also shows no brittle failure induced by stress corrosion after treatment with the coating. Gravimetric analysis shows that the deposition of TiC/Ti(CN)/TiN multilayer coatings results in a corrosion rate reduction of at least 50 times compared with the high-strength steel substrate. A preliminary analysis on this phenomenon is conducted.

  14. Enzyme multilayer coatings inhibit Pseudomonas aeruginosa biofilm formation on urinary catheters.

    PubMed

    Ivanova, Kristina; Fernandes, Margarida M; Mendoza, Ernest; Tzanov, Tzanko

    2015-05-01

    Bacteria use a signaling mechanism called quorum sensing (QS) to form complex communities of surface-attached cells known as biofilms. This protective mode of growth allows them to resist antibiotic treatment and originates the majority of hospital-acquired infections. Emerging alternatives to control biofilm-associated infections and multidrug resistance development interfere with bacterial QS pathways, exerting less selective pressure on bacterial population. In this study, biologically stable coatings comprising the QS disrupting enzyme acylase were built on silicone urinary catheters using a layer-by-layer technique. This was achieved by the alternate deposition of negatively charged enzyme and positively charged polyethylenimine. The acylase-coated catheters efficiently quenched the QS in the biosensor strain Chromobacterium violaceum CECT 5999, demonstrated by approximately 50% inhibition of violacein production. These enzyme multilayer coatings significantly reduced the Pseudomonas aeruginosa ATCC 10145 biofilm formation under static and dynamic conditions in an in vitro catheterized bladder model. The quorum quenching enzyme coatings did not affect the viability of the human fibroblasts (BJ-5ta) over 7 days, corresponding to the extended useful life of urinary catheters. Such enzyme-based approach could be an alternative to the conventional antibiotic treatment for prevention of biofilm-associated urinary tract infections. PMID:25582561

  15. Release of Plasmid DNA from Intravascular Stents Coated with Ultrathin Multilayered Polyelectrolyte Films

    PubMed Central

    Jewell, Christopher M.; Zhang, Jingtao; Fredin, Nathaniel J.; Wolff, Matthew R.; Hacker, Timothy A.; Lynn, David M.

    2008-01-01

    Materials that permit control over the release of DNA from the surfaces of topologically complex implantable devices, such as intravascular stents, could contribute to the development of new approaches to the localized delivery of DNA. We report the fabrication of ultrathin, multilayered polyelectrolyte films that permit both the immobilization and controlled release of plasmid DNA from the surfaces of stainless steel intravascular stents. Our approach makes use of an aqueous-based, layer-by-layer method for the assembly of nanostructured thin films consisting of alternating layers of plasmid DNA and a hydrolytically degradable polyamine. Characterization of coated stents using scanning electron microscopy (SEM) demonstrated that stents were coated uniformly with an ultrathin film ca. 120 nm thick that adhered conformally to the surfaces of stent struts. These ultrathin films did not crack, peel, or delaminate substantially from the surface after exposure to a range of mechanical challenges representative of those encountered during stent deployment (e.g., balloon expansion). Stents coated with eight bilayers of degradable polyamine and a plasmid encoding enhanced green fluorescent protein sustained the release of DNA into solution for up to four days when incubated in phosphate buffered saline at 37 °C, and coated stents were capable of mediating the expression of EGFP in a mammalian cell line without the aid of additional transfection agents. The approach reported here could, with further development, contribute to the development of localized gene-based approaches to the treatment of cardiovascular diseases or related conditions. PMID:16961308

  16. Pd/B4C/Y multilayer coatings for extreme ultraviolet applications near 10  nm wavelength.

    PubMed

    Windt, David L; Gullikson, Eric M

    2015-06-20

    A new extreme ultraviolet (EUV) multilayer coating has been developed comprising Pd and Y layers with thin B4C barrier layers at each interface, for normal incidence applications near 10 nm wavelength. Periodic, nonperiodic, and dual-stack coatings have been investigated and compared with similar structures comprising either Mo/Y or Pd/B4C bilayers. We find that Pd/B4C/Y multilayers provide higher reflectance than either Mo/Y or Pd/B4C, with much lower film stress than Pd/B4C. We have also investigated the performance of periodic multilayers comprising repetitions of Pd/Y, Ru/Y, or Ru/B4C/Y, as well as Pd/B4C multilayers deposited using reactive sputtering with an Ar:N2 gas mixture in order to reduce stress: these material combinations were all found to provide poor EUV performance. The temporal stability of a periodic Pd/B4C/Y multilayer stored in air was investigated over a period of 16 months, and a slight reduction in peak reflectance was observed. Periodic Pd/B4C/Y multilayers were also found to be thermally stable up to 100°C; at higher temperatures (200°C and 300°C) we observe a slight reduction in peak reflectance and a slight increase in multilayer period. High-resolution transmission electron microscopy and selected area diffraction of an as-deposited Pd/B4C/Y film indicates a fully amorphous structure, with interfaces that are both smoother and more abrupt than those observed in a comparable Pd/B4C multilayer in which the Pd layers are polycrystalline. The new Pd/B4C/Y multilayers are suitable for normal-incidence imaging and spectroscopy applications, including solar physics, plasma physics, high-brightness EUV light sources, and others. PMID:26193039

  17. Tissue Integration of Growth Factor-Eluting Layer-by-Layer Polyelectrolyte Multilayer Coated Implants

    PubMed Central

    Macdonald, Mara L.; Samuel, Raymond E.; Shah, Nisarg J.; Padera, Robert; Beben, Yvette M.; Hammond, Paula T.

    2011-01-01

    Drug eluting coatings that can direct the host tissue response to implanted medical devices have the potential to ameliorate both the medical and financial burden of complications from implantation. However, because many drugs useful in this arena are biologic in nature, a paucity of delivery strategies for biologics, including growth factors, currently limits the control that can be exerted on the implantation environment. Layer-by-Layer (LbL) polyelectrolyte multilayer films are highly attractive as ultrathin biologic reservoirs, due to conformal coating of difficult geometries, aqueous processing likely to preserve fragile protein function, and tenability of incorporation and release profiles. Herein, we describe the first LbL films capable of microgram-scale release of the biologic Bone Morphogenetic Protein 2 (BMP-2), which is capable of directing the host tissue response to create bone from native progenitor cells. Ten micrograms of BMP-2 are released over a period of two weeks in vitro; less than 1% is released in the first 3 hours (compared with commercial collagen matrices which can release up to 60% of BMP-2, too quickly to induce differentiation). BMP-2 released from LbL films retains its ability to induce bone differentiation in MC3T3 E1S4 preosteoblasts, as measured by induction of alkaline phosphatase and stains for calcium (via Alizarin Red) and calcium matrix (via Von Kossa). In vivo, BMP-2 film coated scaffolds were compared with film coated scaffolds lacking BMP-2. BMP-2 coatings implanted intramuscularly were able to initiate host progenitor cells to differentiate into bone, which matured and expanded from four to nine weeks as measured by MicroCT and histology. Such LbL films represent new steps towards controlling and tuning host response to implanted medical devices, which may ultimately increase the success of implanted devices, provide alternative new approaches toward bone wound healing, and lay the foundation for development of a multi

  18. Corrosion resistance of multilayer hybrid sol-gel coatings deposited on the AISI 316L austenitic stainless steel

    NASA Astrophysics Data System (ADS)

    Caballero, Y. T.; Rondón, E. A.; Rueda, L.; Hernández Barrios, C. A.; Coy, A.; Viejo, F.

    2016-02-01

    In the present work multilayer hybrid sol-gel coatings were synthesized on the AISI 316L austenitic stainless steel employed in the fabrication of orthopaedic implants. Hybrid sols were obtained from a mixture of inorganic precursor, TEOS, and organic, GPTMS, using ethanol as solvent, and acetic acid as catalyst. The characterization of the sols was performed using pH measurements, rheological tests and infrared spectroscopy (FTIR) for different ageing times. On the other hand, the coatings were characterized by scanning electron microscopy (SEM), while the corrosion resistance was evaluated using anodic potentiodynamic polarization in SBF solution at 37±2°C. The results confirmed that sol-gel synthesis employing TEOS-GPTMS systems produces uniform and homogeneous coatings, which enhanced the corrosion resistance with regard to the parent alloy. Moreover, corrosion performance was retained after applying more than one layer (multilayer coatings).

  19. Maskless deposition technique for the physical vapor deposition of thin film and multilayer coatings with subnanometer precision and accuracy

    DOEpatents

    Vernon, Stephen P.; Ceglio, Natale M.

    2000-01-01

    The invention is a method for the production of axially symmetric, graded and ungraded thickness thin film and multilayer coatings that avoids the use of apertures or masks to tailor the deposition profile. A motional averaging scheme permits the deposition of uniform thickness coatings independent of the substrate radius. Coating uniformity results from an exact cancellation of substrate radius dependent terms, which occurs when the substrate moves at constant velocity. If the substrate is allowed to accelerate over the source, arbitrary coating profiles can be generated through appropriate selection and control of the substrate center of mass equation of motion. The radial symmetry of the coating profile is an artifact produced by orbiting the substrate about its center of mass; other distributions are obtained by selecting another rotation axis. Consequently there is a direct mapping between the coating thickness and substrate equation of motion which can be used to tailor the coating profile without the use of masks and apertures.

  20. Experimental demonstration of a Fresnel-reflection based optical fiber biosensor coated with polyelectrolyte multilayers

    NASA Astrophysics Data System (ADS)

    Yu, Wenjie; Lang, Tingting

    2014-11-01

    We report that the end facet of an optical fiber can be coated with polyelectrolyte multilayers (PEM) of polycation (diallyldimethyl ammonium chloride) and polyanion (styrenesulfonate sodium salt) (PDDA+PSS)n (n is the number of bilayers), which functions effectively as a Fresnel-reflection based biosensor. The experimental setup includes a broadband light source, a 3dB coupler, and an optical spectrum analyzer. Biotin and streptavidin are deposited onto the multilayers-coated end facet sequentially. The light intensity change due to variation of external refractive index is monitored. When the concentrations of streptavidin changes from 0.1mg/ml to 1mg/ml, a linear relationship between the concentration of streptavidin and the reflected optical power at the wavelength of 1530nm is observed. The sensitivity increases from -1.6262×10-3 dB/ppm to -4.7852 ×10-3 dB/ppm, when the number of PEM increases from 1 to 2. Then we confirm the optimized numbers of bilayers of PEM are 5 through experiment. Selectivity and repeatability of our proposed optical fiber biosensor are verified. When bovine serum albumin (BSA) is added instead of streptavidin, the obtained spectra overlaps with that of biotin's. The final end facet coated with PEM and biotin-streptavidin can be cleaned using microwave vibration or aqua regia. The microwave vibration method is utilized due to security concern. The optical spectra changes back to the initial one of the optical fiber in air. In conclusion, a Fresnel-reflection based optical fiber biosensor with good sensitivity, selectivity and repeatability is proposed. This biosensor has the advantages of simple structure, low cost and reliability.

  1. Development of High Resolution Hard X-Ray Telescope with Multi-Layer Coatings

    NASA Technical Reports Server (NTRS)

    Gorenstein, Paul; Brinton, John C. (Technical Monitor)

    2005-01-01

    This is the annual report for the third year of a three-year program. Previous annual reports have described progress achieved in the first and second years. The major objective of this program is the development of a focusing hard X-ray telescope with moderately high angular resolution, i.e. comparable to the telescopes of XMM-Newton. The key ingredients of the telescope are a depth graded multilayer coatings and electroformed nickel substrates that are considerably lighter weight than those of previous missions such as XMM-Newton, which have had conventional single metal layer reflective coatings and have operated at much lower energy X-rays. The ultimate target mission for this technology is the Hard X-Ray Telescope (HXT) of the Constellation X-Ray Mission. However, it is applicable to potential SMEX and MIDEX programs as well. We are building upon technology that has proven to be successful in the XMM-Newton and SWIFT missions. The improvements that we are adding are a significant reduction in mass without much loss of angular resolution and an order of magnitude extension of the bandwidth through the use of multilayer coatings. The distinctive feature of this approach compared to those of other hard X-ray telescope programs is that we expect the angular resolution to be superior than telescopes made by other methods thanks to the structural integrity of the substrates. They are thin walled complete cylinders of revolution with a Wolter Type 1 figure; the front half is a parabola, the rear half a hyperbola.

  2. Preparation of a novel adenovirus formulation with artificial envelope of multilayer polymer-coatings: therapeutic effect on metastatic ovarian cancer.

    PubMed

    Yoshihara, Chieko; Hamada, Katsuyuki; Koyama, Yoshiyuki

    2010-03-01

    Layer-by-layer deposition of the ionic polymers onto adenovirus particles afforded the multilayer-coated virus vectors. The infectivity of the virus in the presence of anti-adenovirus antibody increased as the layer number and the viruses with five or six polymer layers allowed relatively high efficiency of reporter gene expression in vitro. Therapeutic effect of the intraperitoneal injection of the oncolytic adenovirus with quintal polymer multilayers on the mice bearing intraperitoneal metastatic ovarian cancer was examined. All the control mice injected with PBS died within 21 days after the tumor inoculation. On the other hand, the mice injected with the multilayer-coated oncolytic virus lived much longer and seven eighths of them lived >60 days without apparent accumulation of ascites. These approaches would open a new way to create a novel, safe and efficient viral gene therapy. PMID:20127013

  3. 'One-component' ultrathin multilayer films based on poly(vinyl alcohol) as stabilizing coating for phenytoin-loaded liposomes.

    PubMed

    Zasada, Katarzyna; Łukasiewicz-Atanasov, Magdalena; Kłysik, Katarzyna; Lewandowska-Łańcucka, Joanna; Gzyl-Malcher, Barbara; Puciul-Malinowska, Agnieszka; Karewicz, Anna; Nowakowska, Maria

    2015-11-01

    Ultrathin "one-component" multilayer polymeric films for potential biomedical applications were designed based on polyvinyl alcohol,-a non-toxic, fully degradable synthetic polymer. Good uniformity of the obtained film and adequate adsorption properties of the polymeric layers were achieved by functional modification of the polymer, which involved synthesis of cationic and anionic derivatives. Synthesized polymers were characterized by FTIR, NMR spectroscopy, dynamic light scattering measurements and elemental analysis. The layer by layer assembly technique was used to build up a multilayer film and this process was followed using UV-Vis spectroscopy and ellipsometry. The morphology and thickness of the obtained multilayered film material was evaluated by atomic force microscopy (AFM). Preliminary studies on the application of the obtained multilayer film for coating of liposomal nanocarriers containing phenytoin, an antiarrhythmic drug, were performed. The coating effectively stabilizes liposomes and the effect increases with an increasing number of deposited layers until the polymeric film reaches the optimal thickness. The obtained release profiles suggest that bilayer-coated liposomes release phenytoin less rapidly than uncoated ones. The cytotoxicity studies performed for all obtained nanocarriers confirmed that none of them has negative effect on cell viability. All of the performed experiments suggest that liposomes coated with ultrathin film obtained from PVA derivatives can be attractive drug nanocarriers. PMID:26253533

  4. High-Reflectivity Multi-Layer Coatings for the CLASP Sounding Rocket Project

    NASA Technical Reports Server (NTRS)

    Narukage, Noriyuki; Kano, Ryohei; Bando, Takamasa; Ishikawa, Ryoko; Kubo, Masahito; Katsukawa, Yukio; Ishikawa, Shin-nosuke; Kobiki, Toshihiko; Giono, Gabriel; Auchere, Frederic; Winebarger, Amy; Kobayashi, Ken; Tsuneta, Saku

    2015-01-01

    We are planning an international rocket experiment Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP) is (2015 planned) that Lyman alpha line (Ly alpha line) polarization spectroscopic observations from the sun. The purpose of this experiment, detected with high accuracy of the linear polarization of the Ly alpha lines to 0.1% by using a Hanle effect is to measure the magnetic field of the chromosphere-transition layer directly. For polarization photometric accuracy achieved that approximately 0.1% required for CLASP, it is necessary to realize the monitoring device with a high throughput. On the other hand, Ly alpha line (vacuum ultraviolet rays) have a sensitive characteristics that is absorbed by the material. We therefore set the optical system of the reflection system (transmission only the wavelength plate), each of the mirrors, subjected to high efficiency of the multilayer coating in accordance with the role. Primary mirror diameter of CLASP is about 30 cm, the amount of heat about 30,000 J is about 5 minutes of observation time is coming mainly in the visible light to the telescope. In addition, total flux of the sun visible light overwhelmingly large and about 200 000 times the Ly alpha line wavelength region. Therefore, in terms of thermal management and 0.1% of the photometric measurement accuracy achieved telescope, elimination of the visible light is essential. We therefore, has a high reflectivity (greater than 50%) in Ly alpha line, visible light is a multilayer coating be kept to a low reflectance (less than 5%) (cold mirror coating) was applied to the primary mirror. On the other hand, the efficiency of the polarization analyzer required chromospheric magnetic field measurement (the amount of light) Conventional (magnesium fluoride has long been known as a material for vacuum ultraviolet (MgF2) manufactured ellipsometer; Rs = 22%) about increased to 2.5 times were high efficiency reflective polarizing element analysis. This device, Bridou et al

  5. Laser-resistance sensitivity to substrate pit size of multilayer coatings

    PubMed Central

    Chai, Yingjie; Zhu, Meiping; Wang, Hu; Xing, Huanbin; Cui, Yun; Sun, Jian; Yi, Kui; Shao, Jianda

    2016-01-01

    Nanosecond laser-resistance to dielectric multilayer coatings on substrate pits was examined with respect to the electric-field (E-field) enhancement and mechanical properties. The laser-induced damage sensitivity to the shape of the substrate pits has not been directly investigated through experiments, thus preventing clear understanding of the damage mechanism of substrate pits. We performed a systematic and comparative study to reveal the effects of the E-field distributions and localized stress concentration on the damage behaviour of coatings on substrates with pits. To obtain reliable results, substrate pits with different geometries were fabricated using a 520-nm femtosecond laser-processing platform. By using the finite element method, the E-field distribution and localized stress of the pitted region were well simulated. The 1064-nm damage morphologies of the coated pit were directly compared with simulated E-field intensity profiles and stress distributions. To enable further understanding, a simplified geometrical model was established, and the damage mechanism was introduced. PMID:27252016

  6. Delamination analysis of metal-ceramic multilayer coatings subject to nanoindentation

    DOE PAGESBeta

    Jamison, Ryan Dale; Shen, Yu -Lin

    2016-01-22

    Internal damage has been experimentally observed in aluminum (Al)/silicon carbide (SiC) multilayer coatings subject to nanoindentation loading. Post-indentation characterization has identified that delamination at the coating/substrate interface is the most prominent form of damage. In this study the finite element method is employed to study the effect of delamination on indentation-derived hardness and Young's modulus. The model features alternating Al/SiC nanolayers above a silicon (Si) substrate, in consistence with the actual material system used in earlier experiments. Cohesive elements with a traction–separation relationship are used to facilitate delamination along the coating/substrate interface. Delamination is observed numerically to be sensitive tomore » the critical normal and shear stresses that define the cohesive traction–separation behavior. Axial tensile stress below the edge of indentation contact is found to be the largest contributor to damage initiation and evolution. Delamination results in a decrease in both indentation-derived hardness and Young's modulus. As a result, a unique finding is that delamination can occur during the unloading process of indentation, depending on the loading condition and critical tractions.« less

  7. A new insight into defect-induced laser damage in UV multilayer coatings

    SciTech Connect

    Reichling, M.; Bodemann, A.; Kaiser, N.

    1995-12-31

    High performance Al{sub 2}O{sub 3}SiO{sub 2} mirror coatings for 248 nm have been investigated with respect to their excimer laser damage resistivity. Global damage thresholds (in the range of 10-20 J/cm{sup 2}) averaged over large areas were determined with the pulsed photoacoustic mirage detection method. With a raster scanning technique utilizing the same detection scheme, the local damage behaviour was studied with 100 {mu}m spatial resolution. It was found that the local damage threshold at specific sites was lower than the global damage threshold and it was assumed that this phenomenon was associated with micrometer-scale defects in the multilayer coating. To test this hypothesis photothermal displacement microscopy with {mu}m lateral resolution was performed on the investigated regions prior to excimer laser light irradiation. Photothermal images revealed an extremely small background absorption and a small number of absorbing defect sites. For a number of such sites a clear correlation between the local absorption and the onset of laser damage at that specific location was found. We conclude that the crucial factor determining the damage resistivity of the high quality coating systems are defects and contaminants and that it will be possible to predict their damage thresholds by a complete microscopic photothermal inspection.

  8. Laser-resistance sensitivity to substrate pit size of multilayer coatings.

    PubMed

    Chai, Yingjie; Zhu, Meiping; Wang, Hu; Xing, Huanbin; Cui, Yun; Sun, Jian; Yi, Kui; Shao, Jianda

    2016-01-01

    Nanosecond laser-resistance to dielectric multilayer coatings on substrate pits was examined with respect to the electric-field (E-field) enhancement and mechanical properties. The laser-induced damage sensitivity to the shape of the substrate pits has not been directly investigated through experiments, thus preventing clear understanding of the damage mechanism of substrate pits. We performed a systematic and comparative study to reveal the effects of the E-field distributions and localized stress concentration on the damage behaviour of coatings on substrates with pits. To obtain reliable results, substrate pits with different geometries were fabricated using a 520-nm femtosecond laser-processing platform. By using the finite element method, the E-field distribution and localized stress of the pitted region were well simulated. The 1064-nm damage morphologies of the coated pit were directly compared with simulated E-field intensity profiles and stress distributions. To enable further understanding, a simplified geometrical model was established, and the damage mechanism was introduced. PMID:27252016

  9. Laser-resistance sensitivity to substrate pit size of multilayer coatings

    NASA Astrophysics Data System (ADS)

    Chai, Yingjie; Zhu, Meiping; Wang, Hu; Xing, Huanbin; Cui, Yun; Sun, Jian; Yi, Kui; Shao, Jianda

    2016-06-01

    Nanosecond laser-resistance to dielectric multilayer coatings on substrate pits was examined with respect to the electric-field (E-field) enhancement and mechanical properties. The laser-induced damage sensitivity to the shape of the substrate pits has not been directly investigated through experiments, thus preventing clear understanding of the damage mechanism of substrate pits. We performed a systematic and comparative study to reveal the effects of the E-field distributions and localized stress concentration on the damage behaviour of coatings on substrates with pits. To obtain reliable results, substrate pits with different geometries were fabricated using a 520-nm femtosecond laser-processing platform. By using the finite element method, the E-field distribution and localized stress of the pitted region were well simulated. The 1064-nm damage morphologies of the coated pit were directly compared with simulated E-field intensity profiles and stress distributions. To enable further understanding, a simplified geometrical model was established, and the damage mechanism was introduced.

  10. Multilayer-based soft X-ray polarimeter at the Beijing Synchrotron Radiation Facility

    NASA Astrophysics Data System (ADS)

    Sun, Li-Juan; Cui, Ming-Qi; Zhu, Jie; Zhao, Yi-Dong; Zheng, Lei; Wang, Zhan-Shan; Zhu, Jing-Tao

    2013-07-01

    A compact high precision eight-axis automatism and two-axis manual soft-ray polarimeter with a multilayer has been designed, constructed, and installed in 3W1B at the Beijing Synchrotron Radiation Facility (BSRF). Four operational modes in the same device, which are double-reflection, double-transmission, front-reflection-behind-transmission and front-transmission-behind-reflection, have been realized. It can be used for the polarization analysis of synchrotron radiation. It also can be used to characterize the polarization properties of the optical elements in the soft X-ray energy range. Some experiments with Mo/Si and Cr/C multilayers have been performed by using this polarimeter with good results obtained.

  11. Calculated performance of a Wolter type I X-ray telescope coated by multilayers

    NASA Technical Reports Server (NTRS)

    Catura, R. C.; Brown, W. A.; Joki, E. G.; Nobles, R. A.

    1982-01-01

    Deposition of multilayered diffraction coatings on the reflecting surfaces of a Wolter type I X-ray telescope offers the potential of using Bragg reflection to achieve enhanced effective area in selected high energy bandpasses. The structure of a gold-carbon multilayer has been optimized for study of 1.8 A iron-line emission with an X-ray telescope designed for observations from Spacelab. The response of this mirror assembly has been calculated as a function of X-ray energy and the resulting effective area is enhanced by a factor of 10 and peaks at 160 sq cm with a bandpass of 0.4 keV FWHM. This enhanced response is sufficient to allow study of the angular distribution of iron-line emission from the 20 brightest cluster X-ray sources during a 7 day Spacelab mission. The possibility of achieving X-ray imaging in narrow bandpasses at even higher energies has been investigated. It is concluded that it should be possible to achieve effective areas of approximately 5 sq cm in bandpasses approximately 1 keV wide for energies in the 15-25 keV range, a spectral region of much importance during the impulsive phase of solar flares.

  12. A 10,000 groove/mm multilayer coated grating for EUV spectroscopy

    SciTech Connect

    Voronov, Dmytro; Anderson, Erik; Cambie, Rossana; Cabrini, Stefano; Dhuey, Scott; Goray, Leonid; Gullikson, Eric; Salmassi, Farhad; Warwick, Tony; Yashchuk, Valeriy; Padmore, Howard

    2011-02-07

    Ultra-high spectral resolution in the EUV and soft x-ray energy ranges requires the use of very high line density gratings with optimal design resulting in use of a Blazed Multilayer Grating (BMG) structure. Here we demonstrate the production of near-atomically perfect Si blazed substrates with an ultra-high groove density (10,000 l/mm) together with the measured and theoretical performance of an Al/Zr multilayer coating on the grating. A 1st order absolute efficiency of 13percent and 24.6percent was achieved at incidence angles of 11o and 36o respectively. Cross-sectional TEM shows the effect of smoothing caused by the surface mobility of deposited atoms and we correlate this effect with a reduction in peak diffraction efficiency. This work shows the high performance that can be achieved with BMGs based on small-period anisotropic etched Si substrates, but also the constraints imposed by the surface mobility of deposited species.

  13. Angle-resolved scattering and reflectance of extreme-ultraviolet multilayer coatings: measurement and analysis

    SciTech Connect

    Schroeder, Sven; Herffurth, Tobias; Trost, Marcus; Duparre, Angela

    2010-03-20

    Roughness-induced light scattering critically affects the performance of optical components, in particular at short wavelengths. We present a stand-alone instrument for angle-resolved scattering and reflectance measurements at 13.5 nm in the extreme-ultraviolet (EUV) spectral range. The achieved dynamic range allows even the scattering of high-quality EUV mirrors on extremely smooth substrates to be investigated. For Mo/Si multilayers, total scatter losses of several percent have been observed, depending on the substrate qualities as well as on roughening and smoothing effects during coating. Different approximate models for estimating the impact of roughness on scatter losses are discussed and compared with experimental results.

  14. Full spin-coated multilayer structure hybrid light-emitting devices

    NASA Astrophysics Data System (ADS)

    Cheng, Gang; Mazzeo, Marco; Carallo, Sonia; Wang, Huiping; Ma, Yuguang; Gigli, Giuseppe

    2010-09-01

    We report on a multilayer structure hybrid light-emitting device (HLED) using a water/alcohol-soluble polymer poly(9,9-bis{30-[(N,N-dimethyl)-N-ethylammonium}-propyl]-2,7-fluorene dibromide) as an electron-transporting layer and a close-packed quantum dot-layer (QD-layer) as an emitting layer. The device was realized by full spin-coating technology without thermal evaporation process for the deposition of organic layers. The QD-layer was a mixture of QDs with two different sizes, in which large size QD-emitters were dispersed in small size QDs to weaken the concentration quenching. The device achieved a maximum power efficiency of 0.58 lm/W, which nearly quadrupled that of the HLED with a plain large size QD-EML.

  15. Weightless Environment Training Facility (WETF) materials coating evaluation, volume 1

    NASA Technical Reports Server (NTRS)

    1995-01-01

    The Weightless Environment Training Facility Material Coating Evaluation project has included preparing, coating, testing, and evaluating 800 test panels of three differing substrates. Ten selected coating systems were evaluated in six separate exposure environments and subject to three tests for physical properties. Substrate materials were identified, the manner of surface preparation described, and exposure environments defined. Exposure environments included immersion exposure, cyclic exposure, and field exposure. Cyclic exposures, specifically QUV-Weatherometer and the KTA Envirotest were found to be the most agressive of the environments included in the study when all three evaluation criteria are considered. This was found to result primarily from chalking of the coatings under ultraviolet (UV) light exposure. Volumes 2 and 3 hold the 5 appendices to this report.

  16. High temperature performance of high-efficiency, multi-layer solar selective coatings for tower applications

    SciTech Connect

    Gray, M. H.; Tirawat, R.; Kessinger, K. A.; Ndione, P. F.

    2015-05-01

    The roadmap to next-generation concentrating solar power plants anticipates a progression to central towers with operating temperatures in excess of 650°C. These higher temperatures are required to drive higher power-cycle efficiencies, resulting in lower cost energy. However, these conditions also place a greater burden on the materials making up the receiver. Any novel absorber material developed for next-generation receivers must be stable in air, cost effective, and survive thousands of heating and cooling cycles. The collection efficiency of a power tower plant can be increased if the energy absorbed by the receiver is maximized while the heat loss from the receiver to the environment is minimized. Thermal radiation losses can be significant (>7% annual energy loss) with receivers at temperatures above 650°C. We present progress toward highly efficient and durable solar selective absorbers (SSAs) intended for operating temperatures from 650°C to 1000°C. Selective efficiency (ηsel) is defined as the energy retained by the absorber, accounting for both absorptance and emittance, relative to the energy incident on the surface. The low emittance layers of multilayer SSAs are binary compounds of refractory metals whose material properties indicate that coatings formed of these materials should be oxidation resistant in air to 800-1200°C. On this basis, we initially developed a solar selective coating for parabolic troughs. This development has been successfully extended to meet the absorptance and emittance objectives for the more demanding, high temperature regime. We show advancement in coating materials, processing and designs resulting in the initial attainment of target efficiencies ηsel > 0.91 for proposed tower conditions. Additionally, spectral measurements show that these coatings continue to perform at targeted levels after cycling to temperatures of 1000°C in environments of nitrogen and forming gas.

  17. High temperature performance of high-efficiency, multi-layer solar selective coatings for tower applications

    DOE PAGESBeta

    Gray, M. H.; Tirawat, R.; Kessinger, K. A.; Ndione, P. F.

    2015-05-01

    The roadmap to next-generation concentrating solar power plants anticipates a progression to central towers with operating temperatures in excess of 650°C. These higher temperatures are required to drive higher power-cycle efficiencies, resulting in lower cost energy. However, these conditions also place a greater burden on the materials making up the receiver. Any novel absorber material developed for next-generation receivers must be stable in air, cost effective, and survive thousands of heating and cooling cycles. The collection efficiency of a power tower plant can be increased if the energy absorbed by the receiver is maximized while the heat loss from themore » receiver to the environment is minimized. Thermal radiation losses can be significant (>7% annual energy loss) with receivers at temperatures above 650°C. We present progress toward highly efficient and durable solar selective absorbers (SSAs) intended for operating temperatures from 650°C to 1000°C. Selective efficiency (ηsel) is defined as the energy retained by the absorber, accounting for both absorptance and emittance, relative to the energy incident on the surface. The low emittance layers of multilayer SSAs are binary compounds of refractory metals whose material properties indicate that coatings formed of these materials should be oxidation resistant in air to 800-1200°C. On this basis, we initially developed a solar selective coating for parabolic troughs. This development has been successfully extended to meet the absorptance and emittance objectives for the more demanding, high temperature regime. We show advancement in coating materials, processing and designs resulting in the initial attainment of target efficiencies ηsel > 0.91 for proposed tower conditions. Additionally, spectral measurements show that these coatings continue to perform at targeted levels after cycling to temperatures of 1000°C in environments of nitrogen and forming gas.« less

  18. Fine tuning of the pH-sensitivity of laponite-doxorubicin nanohybrids by polyelectrolyte multilayer coating.

    PubMed

    Xiao, Shili; Castro, Rita; Maciel, Dina; Gonçalves, Mara; Shi, Xiangyang; Rodrigues, João; Tomás, Helena

    2016-03-01

    Despite the wide research done in the field, the development of advanced drug delivery systems with improved drug delivery properties and effective anticancer capability still remains a great challenge. Based on previous work that showed the potentialities of the nanoclay Laponite as a pH-sensitive doxorubicin (Dox) delivery vehicle, herein we report a simple method to modulate its extent of drug release at different pH values. This was achieved by alternate deposition of cationic poly(allylamine) hydrochloride and anionic poly(sodium styrene sulfonate) (PAH/PSS) polyelectrolytes over the surface of Dox-loaded Laponite nanoparticles using the electrostatic layer-by-layer (LbL) self-assembly approach. The successful formation of polyelectrolyte multilayer-coated Dox/Laponite systems was confirmed by Dynamic Light Scattering and zeta potential measurements. Systematic studies were performed to evaluate their drug release profiles and anticancer efficiency. Our results showed that the presence of the polyelectrolyte multilayers improved the sustained release properties of Laponite and allowed a fine tuning of the extension of drug release at neutral and acidic pH values. The cytotoxicity presented by polyelectrolyte multilayer-coated Dox/Laponite systems towards MCF-7 cells was in accordance with the drug delivery profiles. Furthermore, cellular uptake studies revealed that polyelectrolyte multilayer-coated Dox/Laponite nanoparticles can be effectively internalized by cells conducting to Dox accumulation in cell nucleus. PMID:26706540

  19. Narrow-band EUV Multilayer Coating for the MOSES Sounding Rocket

    NASA Technical Reports Server (NTRS)

    Owens, Scott M.; Gum, Jeffery S.; Tarrio, Charles; Dvorak, Joseph; Kjornrattanawanich, Benjawan; Keski-Kuha, Ritva; Thomas, Roger J.; Kankelborg, Charles C.

    2005-01-01

    The Multi-order Solar EUV Spectrograph (MOSES) is a slitless spectrograph designed to study solar He II emission at 303.8 Angstroms, to be launched on a sounding rocket payload. One difference between MOSES and other slitless spectrographs is that the images are recorded simultaneously at three spectral orders, m = -1,0, +l. Another is the addition of a narrow-band multilayer coating on both the grating and the fold flat, which will reject out-of-band lines that normally contaminate the image of a slitless instrument. The primary metrics f a the mating were high peak reflectivity and suppression of Fe XV and XVI emission lines at 284 Angstroms and 335 Angstroms, respectively. We chose B4C/Mg2Si for our material combination since it provides better values for all three metrics together than the other leading candidates Si/Ir, Si/B4C or Si/SiC. Measurements of witness flats at NIST indicate the peak reflectivity at 303.6 is 38.5% for a 15 bilayer stack, while the suppression at 284 Angstroms, is 4.5x and at 335 Angstroms is 18.3x for each of two reflections in the instrument. We present the results of coating the MOSES flight gratings and fold flat, including the spectral response of the fold flat and grating as measured at NIST's SURF III and Brookhaven's X24C beamline.

  20. Improved Ru/Si multilayer reflective coatings for advanced extreme-ultraviolet lithography photomasks

    NASA Astrophysics Data System (ADS)

    Wood, Obert; Wong, Keith; Parks, Valentin; Kearney, Patrick; Meyer-Ilse, Julia; Luong, Vu; Philipsen, Vicky; Faheem, Mohammad; Liang, Yifan; Kumar, Ajay; Chen, Esther; Bennett, Corbin; Fu, Bianzhu; Gribelyuk, Michael; Zhao, Wayne; Mangat, Pawitter; Van der Heide, Paul

    2016-03-01

    Extreme ultraviolet (EUV) lithography with reflective photomasks continues to be a potential patterning technology for high volume manufacturing at the 7 nm technology node and beyond. EUV photomasks with alternative materials to the commonly used Mo/Si multilayer (ML) reflector and patterned Ta-based absorber (both of which are known to require shadow effect corrections and lead to large through-focus pattern placement errors) are being actively explored. Because the reflective bandwidth of a Ru/Si ML is significantly wider than the reflective bandwidth of a Mo/Si ML and the effective reflectance plane in Ru/Si is closer to the ML surface, Ru/Si ML coatings may be viable alternatives to the Mo/Si ML coatings that are commercially available today because they will lead to smaller mask 3D effects. In this paper, increases in the peak reflectivity and the reflective bandwidth of Ru/Si ML reflectors by using B4C interlayers to improve the Ru-Si interfaces are discussed. The conclusions of this paper are supported with the results of both experimental measurements and rigorous simulations.

  1. Synthesis, mechanical and tribological properties, and thermal stability of sputter-deposited titanium nickel-based and titanium diboride/titanium carbide multilayer hard coatings

    NASA Astrophysics Data System (ADS)

    Chen, Yu-Hsia

    This thesis is focused on the synthesis of hard and smooth multilayer coatings with low internal stress and equiaxed structure using dual-cathode unbalanced reactive magnetron sputtering system. The studied materials include TiN-based and TiB2/TiC multilayer coatings. These as-deposited coatings and after annealing at elevated temperature were characterized and compared in terms of microstructure, structural, mechanical, and tribological properties. TiN coatings have been widely used in various tribological applications. However, TiN coatings predominantly grow with a columnar grain structure, and these columnar grain boundaries become the sites for crack initiation, resulting in premature failure of TiN coatings. In this research, we report the use of CNx and SiNx to periodically interrupt the growth of TiN in order to suppress the columnar structure. The effect of TiN buffer layer with (111) texture, substrate bias, CNx layer thickness on mechanical properties of TiN/CNx coatings are discussed. The columnar grain structure is partially suppressed in these TiN/CNx coatings. TiN/SiNx multilayer coatings, when deposited under optimum conditions, are smooth and exhibit an equiaxed grain structure with no evidence of columnar growth. These TiN/SiNx multilayer coatings also show better mechanical and tribological properties than those of TiN coatings. Lubricated block-on-ring wear tests show that the wear rate of TiN/SiNx coatings is three times better than that of TiN coatings. The fatigue life of the rod coated with 0.75mum thick TiN/SiNx multilayer coating is more than 10 times better than that of uncoated ones and 5 times better than rods coated with TiN coatings. With proper control of the SiNx thickness, TiN/SiN x multilayer coatings achieved good thermal stability and high hardness ˜37 GPa after annealing at 1000C. Both as-deposited and annealed TiB2/TiC multilayer coatings are examined. These TiB2/TiC coatings exhibit excellent wear resistance under dry block

  2. Using CrAlN multilayer coatings to improve oxidation resistance of steel interconnects for solid oxide fuel cell stacks

    NASA Astrophysics Data System (ADS)

    Smith, R. J.; Tripp, C.; Knospe, A.; Ramana, C. V.; Kayani, A.; Gorokhovsky, Vladimir; Shutthanandan, V.; Gelles, D. S.

    2004-06-01

    The requirements of low-cost and high-temperature corrosion resistance for bipolar interconnect plates in solid oxide fuel cell stacks has directed attention to the use of metal plates with oxidation resistant coatings. The performance of steel plates with multilayer coatings, consisting of CrN for electrical conductivity and CrAlN for oxidation resistance, was investigated. The coatings were deposited using large area filtered arc deposition technology, and subsequently annealed in air for up to 25 hours at 800 °C. The composition, structure, and morphology of the coated plates were characterized using Rutherford backscattering, nuclear reaction analysis, atomic force microscopy, and transmission electron microscopy techniques. By altering the architecture of the layers within the coatings, the rate of oxidation was reduced by more than an order of magnitude. Electrical resistance was measured at room temperature.

  3. Electrically driven ion separations and nanofiltration through membranes coated with polyelectrolyte multilayers

    NASA Astrophysics Data System (ADS)

    White, Nicholas

    Polyelectrolyte multilayer (PEM) films deposited using the layer-by-layer (LBL) method are attractive for their simple deposition, tailorable nature, scalability, and charge or size-based selectivity for solutes. This dissertation explores ion separations in electrodialysis (ED) and solute removal through nanofiltration with PEMs deposited on polymer membranes. ED membranes typically exhibit modest selectivities between monovalent and divalent ions. In contrast, this work shows that K+/Mg 2+ ED selectivities reach values >1000 when using Nafion 115 cation-exchange membranes coated with multilayer poly(4-styrenesulfonate) (PSS)/protonated poly(allylamine) (PAH) films. For comparison, the corresponding K+ /Mg2+ selectivity of bare Nafion 115 is <2. However, water-splitting at strongly overlimiting current densities may lead to a local pH increase close to the membrane surface and alter film permeability or allow passage of Mg(OH)x species to decrease selectivity. When the source phase contains high salt concentrations, the K+ transference number approaches unity and the K+/Mg2+ selectivity is >20,000, presumably because the applied current is below the limiting value for K+ and H+ transport is negligible at this high K+ concentration. The high selectivities of these membranes may enable electrodialysis applications such as purification of salts that contain divalent or trivalent ions. The high ED selectivities of (PAH/PSS)5PAH-coated Nafion membranes translate to separations with Li+/Co2+ and K +/La3+. Even with adsorption of only 3 polyelectrolyte layers, Nafion membranes exhibit a Li+/Co2+ selectivity >23. However, the resistance to monovalent-ion passage does not decrease significantly with fewer polyelectrolyte layers. At overlimiting currents, hydroxides from water splitting form insoluble metal hydroxides to foul the membrane. With 0.1 M source-phase salt concentrations, transference numbers for monovalent cations approach unity and selectivities are >5000

  4. Single-chamber plasma enhanced chemical vapor deposition of transparent organic/inorganic multilayer barrier coating at low temperature

    SciTech Connect

    Park, S. M.; Kim, D. J.; Kim, S. I.; Lee, N.-E.

    2008-07-15

    Deposition of organic/inorganic multilayers is usually carried out by two different process steps by two different deposition methods. A single-chamber process for the deposition of multilayer stacks can make the process and deposition system simpler. In this work, SiOCH and plasma-polymerized methylcyclohexane (pp-MCH) films and their multilayer stacks for application to transparent diffusion barrier coatings were deposited in a single low-temperature plasma enhanced chemical vapor deposition reactor using hexamethyldisilazane/N{sub 2}O/O{sub 2}/Ar and methylcyclohexane/Ar mixtures for SiOCH and pp-MCH layers, respectively. The deposition rates of the SiOCH and pp-MCH layers were increased with increasing the N{sub 2}O:O{sub 2} gas flow ratio and rf plasma power, respectively. Oxygen concentration in the SiOCH films was decreased and carbon and hydrogen incorporation was increased when increasing the N{sub 2}O:O{sub 2} gas flow ratio from 0:1 to 3:1. In this work, the water vapor transmission rate of polyester sulfone substrate could be reduced from a level of 50 (bare substrate) to 0.8 g/m{sup 2} day after deposition of a pp-MCH/SiOCH/pp-MCH multilayer coating.

  5. Heparin-mimicking multilayer coating on polymeric membrane via LbL assembly of cyclodextrin-based supramolecules.

    PubMed

    Deng, Jie; Liu, Xinyue; Ma, Lang; Cheng, Chong; Shi, Wenbin; Nie, Chuanxiong; Zhao, Changsheng

    2014-12-10

    In this study, multifunctional and heparin-mimicking star-shaped supramolecules-deposited 3D porous multilayer films with improved biocompatibility were fabricated via a layer-by-layer (LbL) self-assembly method on polymeric membrane substrates. Star-shaped heparin-mimicking polyanions (including poly(styrenesulfonate-co-sodium acrylate; Star-PSS-AANa) and poly(styrenesulfonate-co-poly(ethylene glycol)methyl ether methacrylate; Star-PSS-EGMA)) and polycations (poly(methyl chloride-quaternized 2-(dimethylamino)ethyl methacrylate; Star-PMeDMA) were first synthesized by atom transfer radical polymerization (ATRP) from β-cyclodextrin (β-CD) based cores. Then assembly of 3D porous multilayers onto polymeric membrane surfaces was carried out by alternating deposition of the polyanions and polycations via electrostatic interaction. The surface morphology and composition, water contact angle, blood activation, and thrombotic potential as well as cell viability for the coated heparin-mimicking films were systematically investigated. The results of surface ATR-FTIR spectra and XPS spectra verified successful deposition of the star-shaped supramolecules onto the biomedical membrane surfaces; scanning electron microscopy (SEM) and atomic force microscopy (AFM) observations revealed that the modified substrate had 3D porous surface morphology, which might have a great biological influence on the biointerface. Furthermore, systematic in vitro investigation of protein adsorption, platelet adhesion, human platelet factor 4 (PF4, indicates platelet activation), activate partial thromboplastin time (APTT), thrombin time (TT), coagulation activation (thrombin-antithrombin III complex (TAT, indicates blood coagulant)), and blood-related complement activation (C3a and C5a, indicates inflammation potential) confirmed that the heparin-mimicking multilayer coated membranes exhibited ultralow blood component activations and excellent hemocompatibility. Meanwhile, after surface coating

  6. Multilayer-coated laminar grating with 16{percent} normal-incidence efficiency in the 150-{Angstrom} wavelength region

    SciTech Connect

    Seely, J. F.; Kowalski, M. P.; Cruddace, R. G.; Rife, J. C.; Osterried, K.; Kleineberg, U.; Menke, D. Hunter, W. R.

    1997-11-01

    We characterized a laminar grating with a Mo/Si multilayer coating by using synchrotron radiation and atomic force microscopy. The grating substitute had 2400 grooves/mm, 40-{Angstrom} groove depth, and 2080-{Angstrom} groove width. The microroughness of the grating substrate was 5 {Angstrom} rms. The multilayer coating was optimized to have peak normal-incidence reflectance at a wavelength near 150 {Angstrom}. For an angle of incidence of 10{degree} the peak grating efficiency was 16.3{percent} in the +1 order and 15.0{percent} in the {minus}1 order. The efficiency in the zero order was lower by a factor of 40 owing to the excellent matching of the groove depth and groove width to the wavelength of the incident radiation. By dividing the grating efficiencies by the measured reflectance of the multilayer coating, we obtained inferred groove efficiencies of 34{percent} and 32{percent} in the +1 and {minus}1 orders, respectively. {copyright} 1997 Optical Society of America

  7. Coating of Nafion membranes with polyelectrolyte multilayers to achieve high monovalent/divalent cation electrodialysis selectivities.

    PubMed

    White, Nicholas; Misovich, Maria; Yaroshchuk, Andriy; Bruening, Merlin L

    2015-04-01

    Electrodialysis (ED) membranes typically exhibit modest selectivities between monovalent and divalent ions. This paper reports a dramatic enhancement of the monovalent/divalent cation selectivities of Nafion 115 membranes through coating with multilayer poly(4-styrenesulfonate) (PSS)/protonated poly(allylamine) (PAH) films. Remarkably, K(+)/Mg(2+) ED selectivities reach values >1000, and similar monovalent/divalent cation selectivities occur with feed solutions containing K(+) and Ca(2+). For comparison, the corresponding K(+)/Mg(2+) selectivity of bare Nafion 115 is only 1.8 ± 0.1. However, with 0.01 M KNO3 and 0.01 M Mg(NO3)2 in the source phase, as the applied current density increases from 1.27 to 2.54 mA cm(-2), the K(+)/Mg(2+) selectivities of coated membranes decrease from >1000 to 22. Water-splitting at strongly overlimiting current densities may lead to a local pH increase close to the membrane surface and alter film permeability or allow passage of Mg(OH)x species to decrease selectivity. When the source phase contains 0.1 M KNO3 and 0.1 M Mg(NO3)2, the K(+) transference number approaches unity and the K(+)/Mg(2+) selectivity is >20,000, presumably because the applied current is below the limiting value for K(+) and H(+) transport is negligible at this high K(+) concentration. The high selectivities of these membranes may enable electrodialysis applications such as purification of salts that contain divalent or trivalent ions. PMID:25738468

  8. Improving blood-compatibility of titanium by coating collagen-heparin multilayers

    NASA Astrophysics Data System (ADS)

    Chen, J. L.; Li, Q. L.; Chen, J. Y.; Chen, C.; Huang, N.

    2009-05-01

    This work deals with improving the blood-compatibility of titanium by coating it with heparin (Hep) and collagen (Col) using a layer-by-layer (LBL) self-assembly technique. In the work described here, LBL-produced Hep-Col film growth is initialized by deposition of a layer of positively charged poly L-Lysine (PLL) on a titanium surface, which is negatively charged after treatment with NaOH, followed by formation of a multilayer thin film formed by alternating deposition of negatively charged heparin and positively charged collagen utilizing electrostatic interaction. The chemical composition, wettability, surface topography, mass and thickness of the film were investigated by Fourier transform infrared spectroscopy, water contact angle measurement, scanning electron microscopy, atomic force microscopy, electronic analytical semi-microbalances, and XP stylus profilometry. The in vitro platelet adhesion and activation were investigated by a static platelet adhesion test probing the lactate dehydrogenase (LDH) release of adherent platelets after lysis and by a P-selectin assay. The clotting time was examined by activated partial thromboplastin time (APTT) and prothrombin time (PT) assays. All obtained data showed that the LBL film can significantly decrease platelet adhesion and activation, and prolong clotting time of APTT and PT compared to untreated titanium. LBL-produced Hep-Col films on titanium display more excellent anticoagulation performance than on the surface of titanium.

  9. Fabrication and in vitro evaluation of stable collagen/hyaluronic acid biomimetic multilayer on titanium coatings

    PubMed Central

    Ao, Haiyong; Xie, Youtao; Tan, Honglue; Yang, Shengbing; Li, Kai; Wu, Xiaodong; Zheng, Xuebin; Tang, Tingting

    2013-01-01

    Layer-by-layer (LBL) self-assembly technique has been proved to be a highly effective method to immobilize the main components of the extracellular matrix such as collagen and hyaluronic acid on titanium-based implants and form a polyelectrolyte multilayer (PEM) film by electrostatic interaction. However, the formed PEM film is unstable in the physiological environment and affects the long-time effectiveness of PEM film. In this study, a modified LBL technology has been developed to fabricate a stable collagen/hyaluronic acid (Col/HA) PEM film on titanium coating (TC) by introducing covalent immobilization. Scanning electron microscopy, diffuse reflectance Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy were used to characterize the PEM film. Results of Sirius red staining demonstrated that the chemical stability of PEM film was greatly improved by covalent cross-linking. Cell culture assays further illustrated that the functions of human mesenchymal stem cells, such as attachment, spreading, proliferation and differentiation, were obviously enhanced by the covalently immobilized Col/HA PEM on TCs compared with the absorbed Col/HA PEM. The improved stability and biological properties of the Col/HA PEM covalently immobilized TC may be beneficial to the early osseointegration of the implants. PMID:23635490

  10. Polyelectrolyte coated multilayered liposomes (nanocapsules) for the treatment of Helicobacter pylori infection.

    PubMed

    Jain, Parul; Jain, Sanyog; Prasad, K N; Jain, S K; Vyas, Suresh P

    2009-01-01

    Helicobacter pylori infection is one of the major causes of gastric cancers. A number of systems have already been reported, but 100% eradication has never been achieved. The present invention designs a gastro-retentive drug delivery system incorporated with amoxicillin and metronidazole, specifically suited for the eradication of Helicobacter pylori infections due to its mucoadhesiveness in the presence of polyelectrolyte polymers. The system possesses the advantages of both vesicular and particulate carriers, and it was prepared by alternative coating of polyanion (poly(acrylic acid), PAA) and polycation (poly(allylamine hydrochloride), PAH) using liposomes as the core. Compared with the conventional liposomes, the polyelectrolyte based multilayered system (nanocapsules) gave prolonged drug release in simulated gastric fluid, which is well suited for drug delivery against H. pylori infection in the stomach. In vitro growth inhibition study, agglutination assay, and in situ adherence assay in cultured H. pylori suggested the successful in vitro activity and binding propensity of the system. In vivo bacterial clearance study carried out in a H. pylori infected mouse model finally confirmed the success of the developed novel nanocapsule system. Thus, the newly developed composite nanocapsules along with the use of combination therapy proved to have commendable potential in Helicobacter pylori eradication as compared to already existing conventional and novel drug delivery systems. PMID:19718807

  11. Morphologies of laser-induced damage in hafnia-silica multilayer mirror and polarizer coatings

    SciTech Connect

    Genin, F.Y.; Stolz, C.J.

    1996-08-01

    Hafnium-silica multilayer mirrors and polarizers were deposited by e-beam evaporation onto BK7 glass substrates. The mirrors and polarizers were coated for operation at 1053 nm at 45{degree} and at Brewster`s angle (56{degree}), respectively. They were tested with a single 3-ns laser pulse. Morphology of the laser-induced damage was characterized by optical and scanning electron microscopy. Four distinct damage morphologies were found: pits, flatbottom pits, scalds, and delaminates. The pits and flat bottom pits (<30{mu}m dia) were detected at lower fluences (as low as 5 J/cm{sup 2}). The pits seemed to result from ejection of nodular defects by causing local enhancement of the electric field. Scalds and delaminates could be observed at higher fluences (above 13 J/cm{sup 2}) and seemed to result from the formation of plasmas on the surface. These damage types often originated at pits and were less than 300 {mu}m diameter; their size increased almost linearly with fluence. Finally, effects of the damage on the beam (reflectivity degradation and phase modulations) were measured.

  12. Facile cell patterning on an albumin-coated surface.

    PubMed

    Yamazoe, Hironori; Uemura, Toshimasa; Tanabe, Toshizumi

    2008-08-19

    Fabrication of micropatterned surfaces to organize and control cell adhesion and proliferation is an indispensable technique for cell-based technologies. Although several successful strategies for creating cellular micropatterns on substrates have been demonstrated, a complex multistep process and requirements for special and expensive equipment or materials limit their prevalence as a general experimental tool. To circumvent these problems, we describe here a novel facile fabrication method for a micropatterned surface for cell patterning by utilizing the UV-induced conversion of the cell adhesive property of albumin, which is the most abundant protein in blood plasma. An albumin-coated surface was prepared by cross-linking albumin with ethylene glycol diglycidyl ether and subsequent casting of the cross-linked albumin solution on the cell culture dish. While cells did not attach to the albumin surface prepared in this way, UV exposure renders the surface cell-adhesive. Thus, surface micropatterning was achieved simply by exposing the albumin-coated surface to UV light through a mask with the desired pattern. Mouse fibroblast L929 cells were inoculated on the patterned albumin substrates, and cells attached and spread in a highly selective manner according to the UV-irradiated pattern. Although detailed investigation of the molecular-level mechanism concerning the change in cell adhesiveness of the albumin-coated surface is required, the present results would give a novel facile method for the fabrication of cell micropatterned surfaces. PMID:18627191

  13. Multilayered coating on titanium for controlled release of antimicrobial peptides for the prevention of implant-associated infections.

    PubMed

    Kazemzadeh-Narbat, Mehdi; Lai, Benjamin F L; Ding, Chuanfan; Kizhakkedathu, Jayachandran N; Hancock, Robert E W; Wang, Rizhi

    2013-08-01

    Prevention of bacterial colonization and formation of a bacterial biofilm on implant surfaces has been a challenge in orthopaedic surgery. The treatment of implant-associated infections with conventional antibiotics has become more complicated by the emergence of multi-drug resistant bacteria. Antimicrobial eluting coatings on implants is one of the most promising strategies that have been attempted. This study reports a controlled release of an antimicrobial peptide (AMP) from titanium surface through a non-cytotoxic multilayered coating. Three layers of vertically oriented TiO2 nanotubes, a thin layer of calcium phosphate coating and a phospholipid (POPC) film were impregnated with a potent broad-spectrum AMP (HHC-36). The coating with controlled and sustained release of AMP was highly effective against both Gram-positive (Staphylococcus aureus) and Gram-negative (Pseudomonas aeruginosa) bacteria. No cytotoxicity to osteoblast-like cells (MG-63) was observed. Moderate platelet activation and adhesion on the implant surface with no observable activation in solution, and very low red blood cell lysis was observed on the implant. This multi-layer assembly can be a potential approach to locally deliver AMPs to prevent peri-implant infection in orthopaedics without being toxic to host cells. PMID:23680363

  14. Influence of the multilayer coating obtained by the HVOF method on behavior of the steel barrier at dynamic loading

    NASA Astrophysics Data System (ADS)

    Radchenko, Pavel; Radchenko, Andrey; Batuev, Stanislav

    2013-06-01

    The high velocity (supersonic) oxy-fuel (HVOF) thermal spray technology is a rather recent addition to family of thermal spray processes. This technique is considered most modern of technologies of spraying. The increase in velocity of the particles at lower temperatures allowed reducing level of oxidation of the particles and to increase the density of a powder coating. In HVOF dry dusting applicators of the first and second generations was used the cylindrical nozzle, whereas in the third generation expanding Laval nozzles are used. This method allows the velocity of a gas flow to exceed to 2000 m/sec, and the velocities of the powder particles 800 m/sec. Recently many results on elastic and strength properties of the multilayer coatings obtained by supersonic flame spraying method are received. But the main part of works on research of the coating obtained by the HVOF method is devoted to research of their stress-strain state at static loadings. In this work the behavior of the steel barrier with the multilayer coating applied by HVOF is researched, at dynamic loading of projectile structure at different velocities of interaction. The problem was solved numerically within Lagrangian approach, a finite element method with the use of the explicit finite difference scheme of G. Johnson.

  15. Microstructure and Wear Behavior of Laser Clad Multi-layered Fe-based Amorphous Coatings on Steel Substrates

    NASA Astrophysics Data System (ADS)

    Paul, Tanaji; Alavi, S. Habib; Biswas, Sourabh; Harimkar, Sandip P.

    2015-12-01

    Single and multi-layered (with two and three layers) coatings of Fe48Cr15Mo14Y2C15B6 amorphous alloy were applied to AISI 1018 steel substrates via laser cladding. XRD analysis indicated partial retention of the amorphous phase along with the formation of oxide and carbide phases. Cross-sectional SEM micrographs revealed relatively sound coatings laser clad with single layer of amorphous alloy; however, cracks and voids were observed in the two and three layered amorphous coatings. The specimens with single and two layered amorphous coatings exhibited surface hardness of about 650 VHN while the hardness of the specimens with three layered amorphous coatings (~1100 VHN) nearly equaled the hardness of previously reported sintered amorphous alloys of similar compositions. The ball-on-disc wear analysis demonstrated a reverse trend wherein the single and two layered amorphous coatings exhibited lower weight loss during the wear test cycle due to superior surface soundness while the three layered amorphous coatings showed aggravated wear due to internal voids and cracks.

  16. A single-step enzyme immunoassay capillary sensor composed of functional multilayer coatings for the diagnosis of marker proteins.

    PubMed

    Funano, Shun-ichi; Sugahara, Masato; Henares, Terence G; Sueyoshi, Kenji; Endo, Tatsuro; Hisamoto, Hideaki

    2015-03-01

    A single-step, easy-to-use enzyme immunoassay capillary sensor, composed of functional multilayer coatings, was developed in this study. The coatings were composed of substrate-immobilized hydrophobic coating, hydrogel coating, and soluble coating containing an enzyme-labeled antibody. The response mechanism involved a spontaneous immunoreaction triggered by capillary action-mediated introduction of a sample antigen solution and subsequent separation of unreacted enzyme-labeled antibodies and antigen-enzyme-labeled antibody complexes by the molecular sieving effect of the hydrogel. An enzyme reaction at the substrate-immobilized hydrophobic coating/hydrogel coating interface resulted in a protein-selective fluorescence response. An antigen concentration-dependent response was obtained for diagnostic marker protein samples (hemoglobin A1c (HbA1c), 7.14-16.7 mg mL(-1); alpha-fetoprotein (AFP), 1.4-140 ng mL(-1); C-reactive protein (CRP), 0.5-10 μg mL(-1)) that cover a clinically important concentration range. The successful measurement of CRP in diluted serum samples demonstrated the application of this capillary sensor. PMID:25599100

  17. Multilayered nanocrystalline CrN/TiAlN/MoS2 tribological thin film coatings: preparation and characterization

    NASA Astrophysics Data System (ADS)

    Papp, S.; Kelemen, A.; Jakab-Farkas, L.; Vida-Simiti, I.; Biró, D.

    2013-12-01

    Nanocrystalline multilayer thin film coatings, composed of nanometer-scale thick CrN, TiAlN and MoS2 tri-layer systems, were prepared by reactive co-sputtering processes. The self-lubricated multilayer coating structures were deposited by one-fold oscillating movement of substrates in front of the sputter sources. Three independently operated direct current (dc) excited unbalanced magnetrons (UM) with rectangular cathodes of TiAl alloy (50/50%), pure chromium and MoS2 were used as sputter sources. The reactive sputtering process was performed in a mixture of Ar-N2 atmosphere. Hardened high-speed-steel (HSS) and thin oxide covered Si (100) wafers were used as substrates for tribological- and microstructure investigations, respectively. According to results of the chemical composition evaluated by Auger-electron spectroscopy (AES) and microstructure investigation by cross sectional transmission electron microscopy (XTEM), the CrN, TiAlN and the MoS2 phases form practically continuous layers with large gradient transition of composition. The as-deposited CrN/ (Al,Ti)N/MoS2 coatings have shown good friction behaviour, tested at room temperature in dry sliding condition with a ball-on-disk tribometer.

  18. Recovery of Multilayer-Coated Zerodur and ULE Optics for Extreme-Ultraviolet Lithography by Recoating, Reactive-Ion Etching, and Wet-Chemical Processes.

    PubMed

    Mirkarimi, P B; Baker, S L; Montcalm, C; Folta, J A

    2001-01-01

    Extreme-ultraviolet lithography requires expensive multilayer-coated Zerodur or ULE optics with extremely tight figure and finish specifications. Therefore it is desirable to develop methods to recover these optics if they are coated with a nonoptimum multilayer films or in the event that the coating deteriorates over time owing to long-term exposure to radiation, corrosion, or surface contamination. We evaluate recoating, reactive-ion etching, and wet-chemical techniques for the recovery of Mo/Si and Mo/Be multilayer films upon Zerodur and ULE test optics. The recoating technique was successfully employed in the recovery of Mo/Si-coated optics but has the drawback of limited applicability. A chlorine-based reactive-ion etch process was successfully used to recover Mo/Si-coated optics, and a particularly large process window was observed when ULE optics were employed; this is an advantageous for large, curved optics. Dilute HCl wet-chemical techniques were developed and successfully demonstrated for the recovery of Mo/Be-coated optics as well as for Mo/Si-coated optics when Mo/Be release layers were employed; however, there are questions about the extendability of the HCl process to large optics and multiple coat and strip cycles. The technique of using carbon barrier layers to protect the optic during removal of Mo/Si in HF:HNO(3) also showed promise. PMID:18356974

  19. Biodegradable, multi-layered coatings for controlled release of small molecules†

    PubMed Central

    Amir, Elizabeth; Antoni, Per; Campos, Luis M.; Damiron, Denis; Gupta, Nalini; Amir, Roey J.; Pesika, Noshir; Drockenmuller, Eric

    2014-01-01

    Incorporation of orthogonal functional groups into biodegradable polymers permits the fabrication of multi-layered thin films with improved adhesion and tunable degradation profiles. The bi-layer structure also allows for accurate control over small molecule release. PMID:22499161

  20. Comparison in mechanical and tribological properties of CrTiAlMoN and CrTiAlN nano-multilayer coatings deposited by magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Wang, Tao; Zhang, Guojun; Jiang, Bailing

    2016-02-01

    CrTiAlN and CrTiAlMoN nano-multilayer coatings were deposited by closed field unbalanced magnetron sputtering. TiMoN and CrTiMoN nano-multilayer coatings with same Mo2N layer thickness were also prepared for comparison. The structure of these coatings is investigated by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). The mechanical and tribological properties were characterized and compared by nano-indentation and ball-on-disc test. It was found that these coatings were structured by fcc metal nitride phases (including CrN, TiN, AlN and Mo2N) and the preferred orientation changed from (1 1 1) to (2 0 0) with the increase of Mo content. The TEM results showed that the coatings exhibited typical columnar structure and nano-multilayer structure with modulation periods ranged from 3.2 nm to 7.6 nm. Among these coatings, CrTiAlMoN coatings presented the highest hardness, lowest coefficient of friction (COF) and wear rate. The hardness of these nano-multilayer coatings were determined by layer interfaces: TiN/Mo2N and AlN/Mo2N layer interface showed benefit on hardness enhancement while CrN/Mo2N layer interface led to a great hardness decrement. In comparison with the other as-deposited coatings, the low COF of CrTiAlMoN coatings was not only affected by Mo addition but also related to its oxidation behaviors.

  1. Controllable in situ synthesis of silver nanoparticles on multilayered film-coated silk fibers for antibacterial application.

    PubMed

    Meng, Mei; He, Huawei; Xiao, Jing; Zhao, Ping; Xie, Jiale; Lu, Zhisong

    2016-01-01

    Layer-by-layer (LbL) assembly is a versatile technique for the preparation of multilayered polymeric films. However, fabrication of LbL polymetic film on silk for the in situ growth of high-density silver nanoparticles (AgNPs) has not been realized. Herein poly(acrylic acid) (PAA)/poly(dimethyldiallylammonium chloride) (PDDA) multilayers are constructed on silk via the LbL approach, subsequently serving as a 3-dimensional matrix for in situ synthesis of AgNPs. After 8 rounds of LbL assembly, the silk is fully covered with a layer of polymeric film. AgNPs with good crystalline structures could be in-situ generated in the silk-coated multilayers and their amount could be tailored by adjusting the bilayer numbers. The as-prepared silk could effectively kill the existing bacteria and inhibit the bacterial growth, demonstrating the antimicrobial activity. Moreover, the release of Ag(+) from the modified silk can last for 120 h, rendering the modified silk sustainable antimicrobial activity. This work may provide a novel method to prepare AgNPs-functionalized antimicrobial silk for potential applications in textile industry. PMID:26414419

  2. Grazing-incidence efficiencies in the 28{endash}42-{Angstrom} wavelength region of replicas of the Skylab 3600-line/mm concave grating with multilayer and gold coatings

    SciTech Connect

    Hunter, W.R.,; Barbee, T.W. Jr.; Seely, J.F.; Kowalski, M.P.; Rife, J.C.,

    1997-09-01

    The efficiencies of replicas of the Skylab 3600-line/mm concave grating with multilayer and gold coatings were measured by using synchrotron radiation at an angle of incidence of 79{degree} and in the 28{endash}42-{Angstrom} wavelength range. The blaze angle of the grating facets that faced the incident radiation was 3.1{degree}, and the average angle of the opposite facets was 6{degree}. For the gold grating, the {minus}1 outside order had the highest efficiency of any diffracted order (excluding the zero order) over the entire wavelength range. Calculations of the grating efficiency indicated that the high efficiency in the {minus}1 order resulted from the rather small angle (6{degree}) of the facets opposite the incident radiation. For the multilayer grating, the efficiency in the on-blaze +2 inside order was enhanced in the 30{endash}34-{Angstrom} wavelength region as a result of the high reflectance of the multilayer coating. The maximum efficiency in the +2 order occurred at the wavelength (32 {Angstrom}) corresponding to the peak of the reflectance of the multilayer coating on the facets facing the incident radiation. These results further demonstrate that a multilayer coating can be used to enhance the efficiency, in a selected wavelength range and in the on-blaze order, of a grating operating at a small grazing angle (11{degree}). {copyright} 1997 Optical Society of America

  3. Effect of surface fluorination of TiO2 particles on photocatalitytic activity of a hybrid multilayer coating obtained by sol-gel method.

    PubMed

    Zhu, Yunfeng; Piscitelli, Filomena; Buonocore, Giovanna G; Lavorgna, Marino; Amendola, Eugenio; Ambrosio, Luigi

    2012-01-01

    A multilayer photoactive coating containing surface fluorinated TiO(2) nanoparticles and hybrid matrices by sol gel approach based on renewable chitosan was applied on poly(lactic acid) (PLA) film by a step wise spin-coating method. The upper photoactive layer contains nano-sized functionalized TiO(2) particles dispersed in a siloxane based matrix. For the purpose of improving TiO(2) dispersion at the air interface coating surface, TiO(2) nanoparticles were modified by silane coupling agent 1H,1H,2H,2H-perfluorooctyltriethoxysilane (FTS) with fluoro-organic side chains. An additional hybrid material consisting of chitosan (CS) cross-linked with 3-glycidyloxypropyl trimethoxy silane (GOTMS) was applied as interlayer between the PLA substrate and the upper photoactive coating to increase the adhesion and reciprocal affinity. The multilayer TiO(2)/CS-GOTMS coatings on PLA films showed a thickness of ~4-6 μm and resulted highly transparent. Their structure was exhaustively characterized by SEM, optical microscope, UV-vis spectroscopy and contact angle measurements. The photocatalytic activity of the multilayer coatings were investigated using methyl orange (MeO) as a target pollutant; the results showed that PLA films coated with surface fluorinated particles exhibit higher activity than films with neat particles, because of a better dispersion of TiO(2) particles. The mechanical properties of PLA and films coated with fluorinated particles, irradiated by UV light were also investigated; the results showed that the degradation of PLA substrate was markedly suppressed because of the UV adsorptive action of the multilayer coating. PMID:22117597

  4. Surface Modifications of Titanium Implants by Multilayer Bioactive Coatings with Drug Delivery Potential: Antimicrobial, Biological, and Drug Release Studies

    NASA Astrophysics Data System (ADS)

    Ordikhani, Farideh; Zustiak, Silviya Petrova; Simchi, Abdolreza

    2016-04-01

    Recent strategies to locally deliver antimicrobial agents to combat implant-associated infections—one of the most common complications in orthopedic surgery—are gaining interest. However, achieving a controlled release profile over a desired time frame remains a challenge. In this study, we present an innovative multifactorial approach to combat infections which comprises a multilayer chitosan/bioactive glass/vancomycin nanocomposite coating with an osteoblastic potential and a drug delivery capacity. The bioactive drug-eluting coating was prepared on the surface of titanium foils by a multistep electrophoretic deposition technique. The adopted deposition strategy allowed for a high antibiotic loading of 1038.4 ± 40.2 µg/cm2. The nanocomposite coating exhibited a suppressed burst release with a prolonged sustained vancomycin release for up to 6 weeks. Importantly, the drug release profile was linear with respect to time, indicating a zero-order release kinetics. An in vitro bactericidal assay against Staphylococcus aureus confirmed that releasing the drug reduced the risk of bacterial infection. Excellent biocompatibility of the developed coating was also demonstrated by in vitro cell studies with a model MG-63 osteoblast cell line.

  5. Rapid release of plasmid DNA from surfaces coated with polyelectrolyte multilayers promoted by the application of electrochemical potentials.

    PubMed

    Aytar, Burcu S; Prausnitz, Mark R; Lynn, David M

    2012-05-01

    We report an approach to the rapid release of DNA based on the application of electrochemical potentials to surfaces coated with polyelectrolyte-based thin films. We fabricated multilayered polyelectrolyte films (or "polyelectrolyte multilayers", PEMs) using plasmid DNA and a model hydrolytically degradable cationic poly(β-amino ester) (polymer 1) on stainless steel substrates using a layer-by-layer approach. The application of continuous reduction potentials in the range of -1.1 to -0.7 V (vs a Ag/AgCl electrode) to film-coated electrodes in PBS at 37 °C resulted in the complete release of DNA over a period of 1-2 min. Film-coated electrodes incubated under identical conditions in the absence of applied potentials required 1-2 days for complete release. Control over the magnitude of the applied potential provided control over the rate at which DNA was released. The results of these and additional physical characterization experiments are consistent with a mechanism of film disruption that is promoted by local increases in pH at the film/electrode interface (resulting from electrochemical reduction of water or dissolved oxygen) that disrupt ionic interactions in these materials. The results of cell-based experiments demonstrated that DNA was released in a form that remains intact and able to promote transgene expression in mammalian cells. Finally, we demonstrate that short-term (i.e., non-continuous) electrochemical treatments can also be used to promote faster film erosion (e.g., over 1-2 h) once the potential is removed. Past studies demonstrate that PEMs fabricated using polymer 1 can promote surface-mediated transfection of cells and tissues in vitro and in vivo. With further development, the electrochemical approaches reported here could thus provide new methods for the rapid, triggered, or spatially patterned transfer of DNA (or other agents) from surfaces of interest in a variety of fundamental and applied contexts. PMID:22551230

  6. 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

  7. High-Temperature TEM investigation of the phase composition and structure of the Zr-Y-O/Si-Al-N multilayer coatings

    NASA Astrophysics Data System (ADS)

    Fedorischeva, M.; Kalashnikov, M.; Sergeev, V.; Bozhko, I.

    2016-04-01

    Deposition of nanostructured multi-layered coatings on the basis of Zr-Y-0 was implemented by the pulse magnetron methods. Structural-phase states and morphology of the nanostructured coatings were investigated by SEM and the high-temperature TEM method. The high-temperature TEM revealed the presence of reversible phase transition of the tetragonal phase to the monoclinic phase, which can ensure stress relaxation and closure of surface cracks.

  8. A Facile Approach to Functionalize Cell Membrane-Coated Nanoparticles

    PubMed Central

    Zhou, Hao; Fan, Zhiyuan; Lemons, Pelin K.; Cheng, Hao

    2016-01-01

    Convenient strategies to provide cell membrane-coated nanoparticles (CM-NPs) with multi-functionalities beyond the natural function of cell membranes would dramatically expand the application of this emerging class of nanomaterials. We have developed a facile approach to functionalize CM-NPs by chemically modifying live cell membranes prior to CM-NP fabrication using a bifunctional linker, succinimidyl-[(N-maleimidopropionamido)-polyethyleneglycol] ester (NHS-PEG-Maleimide). This method is particularly suitable to conjugate large bioactive molecules such as proteins on cell membranes as it establishes a strong anchorage and enable the control of linker length, a critical parameter for maximizing the function of anchored proteins. As a proof of concept, we show the conjugation of human recombinant hyaluronidase, PH20 (rHuPH20) on red blood cell (RBC) membranes and demonstrate that long linker (MW: 3400) is superior to short linker (MW: 425) for maintaining enzyme activity, while minimizing the changes to cell membranes. When the modified membranes were fabricated into RBC membrane-coated nanoparticles (RBCM-NPs), the conjugated rHuPH20 can assist NP diffusion more efficiently than free rHuPH20 in matrix-mimicking gels and the pericellular hyaluronic acid matrix of PC3 prostate cancer cells. After quenching the unreacted chemical groups with polyethylene glycol, we demonstrated that the rHuPH20 modification does not reduce the ultra-long blood circulation time of RBCM-NPs. Therefore, this surface engineering approach provides a platform to functionlize CM-NPs without sacrificing the natural function of cell membranes. PMID:27217834

  9. Advances in the reduction and compensation of film stress in high-reflectance multilayer coatings for extreme ultraviolet lithography applications

    SciTech Connect

    Mirkarimi, P.B., LLNL

    1998-02-20

    Due to the stringent surface figure requirements for the multilayer-coated optics in an extreme ultraviolet (EUV) projection lithography system, it is desirable to minimize deformation due to the multilayer film stress. However, the stress must be reduced or compensated without reducing EUV reflectivity, since the reflectivity has a strong impact on the throughput of a EUV lithography tool. In this work we identify and evaluate several leading techniques for stress reduction and compensation as applied to Mo/Si and Mo/Be multilayer films. The measured film stress for Mo/Si films with EUV reflectances near 67.4% at 13.4 nm is approximately - 420 MPa (compressive), while it is approximately +330 MPa (tensile) for Mo/Be films with EUV reflectances near 69.4% at 11.4 nm. Varying the Mo-to-Si ratio can be used to reduce the stress to near zero levels, but at a large loss in EUV reflectance (> 20%). The technique of varying the base pressure (impurity level) yielded a 10% decrease in stress with a 2% decrease in reflectance for our multilayers. Post-deposition annealing was performed and it was observed that while the cost in reflectance is relatively high (3.5%) to bring the stress to near zero levels (i.e., reduce by 1 00%), the stress can be reduced by 75% with only a 1.3% drop in reflectivity at annealing temperatures near 200{degrees}C. A study of annealing during Mo/Si deposition was also performed; however, no practical advantage was observed by heating during deposition. A new non-thermal (athermal) buffer-layer technique was developed to compensate for the effects of stress. Using this technique with amorphous silicon and Mo/Be buffer-layers it was possible to obtain Mo/Be and Mo/Si multilayer films with a near zero net film stress and less than a 1% loss in reflectivity. For example a Mo/Be film with 68.7% reflectivity at 11.4 nm and a Mo/Si film with 66.5% reflectivity at 13.3 nm were produced with net stress values less than 30 MPa.

  10. Structure of multilayered Cr(Al)N/SiO{sub x} nanocomposite coatings fabricated by differential pumping co-sputtering

    SciTech Connect

    Kawasaki, Masahiro; Nose, Masateru; Onishi, Ichiro; Shiojiri, Makoto

    2013-11-11

    A Cr(Al)N/38 vol. % SiO{sub x} hard coating was prepared on a (001) Si substrate at 250 °C in a differential pumping co-sputtering system, which has two chambers for radio frequency (RF) sputtering and a substrate holder rotating on the chambers. The composite coating was grown by alternate sputter-depositions from CrAl and SiO{sub 2} targets with flows of N{sub 2}+Ar and Ar at RF powers of 200 and 75 W, respectively, on transition layers grown on the substrate. Analytical electron microscopy reveled that the Cr(Al)N/SiO{sub x} coating had a multilayered structure of Cr(Al)N crystal layers ∼1.6 nm thick and two-dimensionally dispersed amorphous silicon oxide (a-SiO{sub x}) particles with sizes of ∼1 nm or less. The a-SiO{sub x} particles were enclosed with the Cr(Al)N layers. The coating had a low indentation hardness of ∼25 GPa at room temperature, due to a high oxide fraction of 38 vol. % and a low substrate rotational speed of 1 rpm. Faster rotation and lower oxide fraction would make a-SiO{sub x} particles smaller, resulting in the formation of Cr(Al)N crystal including the very fine a-SiO{sub x} particles with small number density. They would work as obstacles for the lattice deformation of the Cr(Al)N crystals. We have fabricated a superhard coating of Cr(Al)N/17 vol. % SiO{sub x} with a hardness of 46 GPa prepared at 12 rpm.

  11. Structure of multilayered Cr(Al)N/SiOx nanocomposite coatings fabricated by differential pumping co-sputtering

    NASA Astrophysics Data System (ADS)

    Kawasaki, Masahiro; Nose, Masateru; Onishi, Ichiro; Shiojiri, Makoto

    2013-11-01

    A Cr(Al)N/38 vol. % SiOx hard coating was prepared on a (001) Si substrate at 250 °C in a differential pumping co-sputtering system, which has two chambers for radio frequency (RF) sputtering and a substrate holder rotating on the chambers. The composite coating was grown by alternate sputter-depositions from CrAl and SiO2 targets with flows of N2+Ar and Ar at RF powers of 200 and 75 W, respectively, on transition layers grown on the substrate. Analytical electron microscopy reveled that the Cr(Al)N/SiOx coating had a multilayered structure of Cr(Al)N crystal layers ˜1.6 nm thick and two-dimensionally dispersed amorphous silicon oxide (a-SiOx) particles with sizes of ˜1 nm or less. The a-SiOx particles were enclosed with the Cr(Al)N layers. The coating had a low indentation hardness of ˜25 GPa at room temperature, due to a high oxide fraction of 38 vol. % and a low substrate rotational speed of 1 rpm. Faster rotation and lower oxide fraction would make a-SiOx particles smaller, resulting in the formation of Cr(Al)N crystal including the very fine a-SiOx particles with small number density. They would work as obstacles for the lattice deformation of the Cr(Al)N crystals. We have fabricated a superhard coating of Cr(Al)N/17 vol. % SiOx with a hardness of 46 GPa prepared at 12 rpm.

  12. Correlation of Predicted and Observed Optical Properties of Multilayer Thermal Control Coatings

    NASA Technical Reports Server (NTRS)

    Jaworske, Donald A.

    1998-01-01

    Thermal control coatings on spacecraft will be increasingly important, as spacecraft grow smaller and more compact. New thermal control coatings will be needed to meet the demanding requirements of next generation spacecraft. Computer programs are now available to design optical coatings and one such program was used to design several thermal control coatings consisting of alternating layers of WO3 and SiO2. The coatings were subsequently manufactured with electron beam evaporation and characterized with both optical and thermal techniques. Optical data were collected in both the visible region of the spectrum and the infrared. Predictions of solar absorptance and infrared emittance were successfully correlated to the observed thermal control properties. Functional performance of the coatings was verified in a bench top thermal vacuum chamber.

  13. Quorum-Quenching and Matrix-Degrading Enzymes in Multilayer Coatings Synergistically Prevent Bacterial Biofilm Formation on Urinary Catheters.

    PubMed

    Ivanova, Kristina; Fernandes, Margarida M; Francesko, Antonio; Mendoza, Ernest; Guezguez, Jamil; Burnet, Michael; Tzanov, Tzanko

    2015-12-16

    Bacteria often colonize in-dwelling medical devices and grow as complex biofilm communities of cells embedded in a self-produced extracellular polymeric matrix, which increases their resistance to antibiotics and the host immune system. During biofilm growth, bacterial cells cooperate through specific quorum-sensing (QS) signals. Taking advantage of this mechanism of biofilm formation, we hypothesized that interrupting the communication among bacteria and simultaneously degrading the extracellular matrix would inhibit biofilm growth. To this end, coatings composed of the enzymes acylase and α-amylase, able to degrade bacterial QS molecules and polysaccharides, respectively, were built on silicone urinary catheters using a layer-by-layer deposition technique. Multilayer coatings of either acylase or amylase alone suppressed the biofilm formation of corresponding Gram-negative Pseudomonas aeruginosa and Gram-positive Staphylococcus aureus. Further assembly of both enzymes in hybrid nanocoatings resulted in stronger biofilm inhibition as a function of acylase or amylase position in the layers. Hybrid coatings, with the QS-signal-degrading acylase as outermost layer, demonstrated 30% higher antibiofilm efficiency against medically relevant Gram-negative bacteria compared to that of the other assemblies. These nanocoatings significantly reduced the occurrence of single-species (P. aeruginosa) and mixed-species (P. aeruginosa and Escherichia coli) biofilms on silicone catheters under both static and dynamic conditions. Moreover, in an in vivo animal model, the quorum quenching and matrix degrading enzyme assemblies delayed the biofilm growth up to 7 days. PMID:26593217

  14. Formation of blade and slot die coated small molecule multilayers for OLED applications studied theoretically and by XPS depth profiling

    NASA Astrophysics Data System (ADS)

    Peters, Katharina; Raupp, Sebastian; Hummel, Helga; Bruns, Michael; Scharfer, Philip; Schabel, Wilhelm

    2016-06-01

    Slot die coaters especially designed for low material consumption and doctor blades were used to process small molecule solutions for organic light-emitting diodes (OLEDs). Optimum process parameters were developed for the large-scale coating techniques to generate stable single and multiple layers only a few nanometers thick. Achieving a multilayer architecture for solution-processed OLEDs is the most challenging step. X-ray photoelectron spectroscopy sputter depth profiling was performed to determine defined interfaces between coated organic layers. Commercially available small molecules NPB (N,N'-Di(1-naphthyl)-N,N'-diphenyl-(1,1'-biphenyl)-4,4'-diamine) and BAlq (Bis(8-hdroxy-2methylquinoline)-(4-phenylphenoxy)aluminum), originally developed for vacuum deposition, were used as hole, respectively electron transport material. Defined double-layers were processed with both scalable coating methods using the orthogonal solvent approach. The use of non-orthogonal solvents resulted in complete intermixing of the material. The results are explained by calculations of solubilities and simulating drying and diffusion kinetics of the small molecule solutions.

  15. Production of low fat french-fries with single and multi-layer hydrocolloid coatings.

    PubMed

    Daraei Garmakhany, A; Mirzaei, H O; Maghsudlo, Y; Kashaninejad, M; Jafari, S M

    2014-07-01

    In this study the influence of coating with different hydrocolloids on the oil absorption and quality attributes of French fries was investigated. Our results revealed that hydrocolloid coatings reduced the moisture loss during frying, and hence, reduced the oil uptake of French fries. Among the studied gums as a single layer coating, combination of carboxy methyl cellulose and pectin (0.5 and 1% w/w) lead to the lowest oil uptake of French fries. In samples coated with two and three-layer hydrocolloids, the oil absorption reduced further and the moisture content of final products was higher than the blank samples. PMID:24966427

  16. Design and fabrication of multi-layers infrared antireflection coating consisting of ZnS and Ge on ZnS substrate

    NASA Astrophysics Data System (ADS)

    Zarei Moghadam, R.; Ahmadvand, H.; Jannesari, M.

    2016-03-01

    We have designed, fabricated and characterized a multi-layers antireflection coating on multispectral ZnS substrate, suitable for the infrared range of 8-12 μm. The 4-layers coating (Ge/ZnS/Ge/ZnS) with optimized thicknesses was fabricated by PVD technique and studied by FTIR, nanoindentation and AFM. From FTIR spectroscopy it was found that, in the wavelength range of 8-12 μm, the average transmittance of the double-side coated sample increases by about 26% and its maximum reaches about 98%. To improve the mechanical hardness, a bilayer of Y2O3/carbon was deposited on the coating. Nanoindentation test shows that the coating enhances the mechanical properties. The final coating have successfully passed durability and environmental tests.

  17. Multi-layer laser solid forming of Zr65Al7.5Ni10Cu17.5 amorphous coating: Microstructure and corrosion resistance

    NASA Astrophysics Data System (ADS)

    Gan, Yu; Wang, Wenxian; Guan, Zhuosen; Cui, Zeqin

    2015-06-01

    Multi-layer Zr65Al7.5Ni10Cu17.5 amorphous coatings were produced by laser solid forming on A283 substrate. The coatings with few pores and free of cracks had good metallurgical bonding with the substrate. The microstructural characterization, phase composition, chemical component distribution and corrosion behavior of the coatings were investigated. The results revealed that the amorphization degree increased from the substrate to the coating surface mainly due to the dilution and stir influence from the melted substrate. In the five layers coating, the volume fraction of amorphous phase in the 5th layer, 3rd layer and 1st layer was about 77%, 64% and 49% respectively. With regard to corrosion property, potentiodynamic polarization plots, Nyquist plots and the equivalent circuits were employed in 3.5 wt% sodium chloride solution. Attributing to the presence of amorphous phase and passivation, the LSF coatings exhibit excellent corrosion resistance.

  18. pH-responsive drug delivery system based on hollow silicon dioxide micropillars coated with polyelectrolyte multilayers

    PubMed Central

    2014-01-01

    We report on the fabrication of polyelectrolyte multilayer-coated hollow silicon dioxide micropillars as pH-responsive drug delivery systems. Silicon dioxide micropillars are based on macroporous silicon formed by electrochemical etching. Due to their hollow core capable of being loaded with chemically active agents, silicon dioxide micropillars provide additional function such as drug delivery system. The polyelectrolyte multilayer was assembled by the layer-by-layer technique based on the alternative deposition of cationic and anionic polyelectrolytes. The polyelectrolyte pair poly(allylamine hydrochloride) and sodium poly(styrene sulfonate) exhibited pH-responsive properties for the loading and release of a positively charged drug doxorubicin. The drug release rate was observed to be higher at pH 5.2 compared to that at pH 7.4. Furthermore, we assessed the effect of the number of polyelectrolyte bilayers on the drug release loading and release rate. Thus, this hybrid composite could be potentially applicable as a pH-controlled system for localized drug release. PMID:25221455

  19. Mo/Si multilayer-coated amplitude-division beam splitters for XUV radiation sources

    PubMed Central

    Sobierajski, Ryszard; Loch, Rolf Antonie; van de Kruijs, Robbert W. E.; Louis, Eric; von Blanckenhagen, Gisela; Gullikson, Eric M.; Siewert, Frank; Wawro, Andrzej; Bijkerk, Fred

    2013-01-01

    Amplitude-division beam splitters for XUV radiation sources have been developed and extensively characterized. Mo/Si multilayer coatings were deposited on 50 nm-thick SiN membranes. By changing the multilayer structure (periodicity, number of bilayers, etc.) the intensity of the reflected and transmitted beams were optimized for selected incident radiation parameters (wavelength, incident angle). The developed optical elements were characterized by means of XUV reflectometry and transmission measurements, atomic force microscopy and optical interferometry. Special attention was paid to the spatial homogeneity of the optical response and reflected beam wavefront distortions. Here the results of the characterization are presented and improvements required for advanced applications at XUV free-electron lasers are identified. A flatness as low as 4 nm r.m.s. on 3 × 3 mm beam splitters and 22 nm r.m.s. on 10 × 10 mm beam splitters has been obtained. The high-spatial-frequency surface roughness was about 0.7–1 nm r.m.s. The middle-spatial-frequency roughness was in the range 0.2–0.8 nm r.m.s. The reflection and transmission of the beam splitters were found to be very homogeneous, with a deviation of less than 2% across the full optical element. PMID:23412481

  20. Structure, mechanical, tribological properties, and high temperature stability of titanium diboride/titanium carbide and titanium oxide/aluminum oxide multilayer coatings synthesized by magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Lee, Kitty W.

    The focus of this research is the synthesis and characterization of TiB 2/TiC multilayer and TiO2/Al2O3 composite coatings for possible elevated-temperature machining applications. Coatings were synthesized using a dual-cathode, unbalanced magnetron sputtering system. They were characterized as deposited and after annealing, in terms of structure, mechanical, and tribological properties. TiB2/TiC multilayer coatings are composed of polycrystalline TiB2(001) and amorphous TiC. Coatings synthesized with stationary substrates have high compressive stress (4--7 GPa), and their hardness is slightly enhanced (˜25%) over the rule-of mixture value. Coatings grown with substrate rotation have much lower compressive stress (<2 GPa) and high hardness (>60 GPa). After annealing in an inert environment at 1273 K, these multilayer coatings retain their layer structure. From dry block-on-ring tribotesting, the 3:0.5 multilayer (i.e., the layer thickness is 3.0 nm for TiB2 and 0.5 nm for TiC) provides 4 times improvement in wear resistance over the uncoated M2 steel substrate. Monolithic TiB2 and 3:1 multilayer have flank wear reduction in dry machining by about a factor of ten compared with the uncoated tool after a cutting distance of 600 m. When machining against aluminum, the 3:1 multilayer tool has negligible buildup on the rake face. TiO2/Al2O3 composite coatings were deposited in the same sputtering chamber with an Ar-O2 (75% argon and 25% oxygen) mixture as the reactive gas. Stoichiometric TiO2/Al 2O3 composites were synthesized in the target-poisoned regime with constant TiO2 volume and decreasing Al2O3 volume. TiO2 has a strong rutile (101) preferred orientation and Al2O3 remains amorphous. Hardness of these TiO 2/Al2O3 coatings approaches 15 GPa, comparing to hardness values of pure TiO2 and Al2O3 of ˜8 GPa and ˜7 GPa, respectively. Films remain intact after annealing in air for 1 hour at 1273 K. Hardness of annealed films remains higher than the monolithic

  1. Electric-Field Enhancement by Nodular Defects in Multilayer Coatings Irradiated at Normal and 45 (degree) Incidence

    SciTech Connect

    Stolz, C J; Genin, F Y; Pistor,T V

    2003-09-18

    The standing-wave electric-field profile within multilayer coatings is significantly perturbated by a nodular defect. The intensity, which is proportional to the electric field squared, is increased in the high index material by {>=}3x at normal incidence and {>=}12x at 45 degrees incidence angle. Therefore it is not surprising that nodular defects are initiation sites of laser-induced damage. In this study, the impact of reflectance-band centering and incident angle are explored for a 1 {micro}m diameter nodular defect seed overcoated with a 24 layer high-reflector constructed of quarter-wave thick alternating layers of hafnia and silica. The modeling was performed using a three-dimensional finite-element analysis code.

  2. An acoustic metamaterial composed of multi-layer membrane-coated perforated plates for low-frequency sound insulation

    NASA Astrophysics Data System (ADS)

    Fan, Li; Chen, Zhe; Zhang, Shu-yi; Ding, Jin; Li, Xiao-juan; Zhang, Hui

    2015-04-01

    Insulating against low-frequency sound (below 500 Hz ) remains challenging despite the progress that has been achieved in sound insulation and absorption. In this work, an acoustic metamaterial based on membrane-coated perforated plates is presented for achieving sound insulation in a low-frequency range, even covering the lower audio frequency limit, 20 Hz . Theoretical analysis and finite element simulations demonstrate that this metamaterial can effectively block acoustic waves over a wide low-frequency band regardless of incident angles. Two mechanisms, non-resonance and monopolar resonance, operate in the metamaterial, resulting in a more powerful sound insulation ability than that achieved using periodically arranged multi-layer solid plates.

  3. Interference multilayer antireflection coatings for two wavelengths in the near infrared

    NASA Astrophysics Data System (ADS)

    Pencheva, Tamara G.; Nenkov, Milen; Michev, Javor

    2001-04-01

    The investigation deals with analysis of antireflection coatings of two transparent materials with high (H) and low (L) refractive index for two wavelengths 1.30 micrometer and 1.55 micrometer in the near IR on glass/silica substrates. The results are obtained by numerical optimization approach which algorithms are realized using programming language DELPHI. The initial structures of LHL three-layer and LHLH four-layer coating (optimized for both wavelengths) are modifications of double-layer antireflection coating for one wavelength 1.4 micrometer. It is shown that the highest transmittance near 1.30 and 1.55 micrometer (practically equal to 100%) shows LHLH four-layer coating structure. The total physical and optical thickness of optimized LHLH four-layer coating is smaller than corresponding value for optimized LHL three-layer coating. Four-layer LHLH coating is more stable with respect to small n and d variations and corresponding transmittance changes are less than in case of LHL three-layer coating.

  4. Spontaneously intermixed Al-Mg barriers enable corrosion-resistant Mg/SiC multilayer coatings

    SciTech Connect

    Soufli, Regina; Fernandez-Perea, Monica; Baker, Sherry L.; Robinson, Jeff C.; Alameda, Jennifer; Walton, Christopher C.

    2012-07-24

    Magnesium/silicon carbide (Mg/SiC) has the potential to be the best-performing reflective multilayercoating in the 25–80 nm wavelength region but suffers from Mg-related corrosion, an insidious problem which completely degrades reflectance. We have elucidated the origins and mechanisms of corrosion propagation within Mg/SiC multilayers. Based on our findings, we have demonstrated an efficient and simple-to-implement corrosion barrier for Mg/SiC multilayers. In conclusion, the barrier consists of nanometer-scale Mg and Al layers that intermix spontaneously to form a partially amorphous Al-Mg layer and is shown to prevent atmospheric corrosion while maintaining the unique combination of favorable Mg/SiC reflective properties.

  5. Method of depositing multi-layer carbon-based coatings for field emission

    DOEpatents

    Sullivan, J.P.; Friedmann, T.A.

    1999-08-10

    A novel field emitter device is disclosed for cold cathode field emission applications, comprising a multi-layer resistive carbon film. The multi-layered film of the present invention is comprised of at least two layers of a resistive carbon material, preferably amorphous-tetrahedrally coordinated carbon, such that the resistivities of adjacent layers differ. For electron emission from the surface, the preferred structure comprises a top layer having a lower resistivity than the bottom layer. For edge emitting structures, the preferred structure of the film comprises a plurality of carbon layers, wherein adjacent layers have different resistivities. Through selection of deposition conditions, including the energy of the depositing carbon species, the presence or absence of certain elements such as H, N, inert gases or boron, carbon layers having desired resistivities can be produced. Field emitters made according the present invention display improved electron emission characteristics in comparison to conventional field emitter materials. 8 figs.

  6. Method of depositing multi-layer carbon-based coatings for field emission

    DOEpatents

    Sullivan, John P.; Friedmann, Thomas A.

    1999-01-01

    A novel field emitter device for cold cathode field emission applications, comprising a multi-layer resistive carbon film. The multi-layered film of the present invention is comprised of at least two layers of a resistive carbon material, preferably amorphous-tetrahedrally coordinated carbon, such that the resistivities of adjacent layers differ. For electron emission from the surface, the preferred structure comprises a top layer having a lower resistivity than the bottom layer. For edge emitting structures, the preferred structure of the film comprises a plurality of carbon layers, wherein adjacent layers have different resistivities. Through selection of deposition conditions, including the energy of the depositing carbon species, the presence or absence of certain elements such as H, N, inert gases or boron, carbon layers having desired resistivities can be produced. Field emitters made according the present invention display improved electron emission characteristics in comparison to conventional field emitter materials.

  7. Laser-induced damage of intrinsic and extrinsic defects by picosecond pulses on multilayer dielectric coatings for petawatt-class lasers

    DOE PAGESBeta

    Negres, Raluca A.; Carr, Christopher W.; Laurence, Ted A.; Stanion, Ken; Guss, Gabe; Cross, David A.; Wegner, Paul J.; Stolz, Christopher J.

    2016-08-01

    Here, we describe a damage testing system and its use in investigating laser-induced optical damage initiated by both intrinsic and extrinsic precursors on multilayer dielectric coatings suitable for use in high-energy, large-aperture petawatt-class lasers. We employ small-area damage test methodologies to evaluate the intrinsic damage resistance of various coatings as a function of deposition methods and coating materials under simulated use conditions. In addition, we demonstrate that damage initiation by raster scanning at lower fluences and growth threshold testing are required to probe the density of extrinsic defects, which will limit large-aperture optics performance.

  8. Antibacterial copper-nickel bilayers and multilayer coatings by pulsed laser deposition on titanium.

    PubMed

    Vishwakarma, Vinita; Josephine, J; George, R P; Krishnan, R; Dash, S; Kamruddin, M; Kalavathi, S; Manoharan, N; Tyagi, A K; Dayal, R K

    2009-11-01

    Biofouling, especially microfouling, is a major concern with the use of titanium (Ti) in the marine environment as a condenser material in cooling water systems. Earlier, copper-nickel (Cu/Ni) alloys were extensively used in marine environments due to their high corrosion and biofouling resistance. However, the choice of condenser material for the new fast breeder reactor in Kalpakkam is Ti to avoid steam side corrosion problems, which may pose a threat to steam generator parts having sodium as the secondary coolant. This study evaluates the surface modification of Ti using nano films of copper (Cu) and nickel (Ni) to utilize the antibacterial property of copper ions in reducing microfouling. The surface modification of Ti was carried out by the deposition of a Cu/Ni bilayer and (Cu/Ni)(10) multilayer films using a pulsed laser deposition technique. Various surface characterization studies revealed that the deposited Cu/Ni films were thin and nanocrystalline in nature. The antibacterial properties were evaluated using total viable count and epifluorescence microscopic techniques. The results showed an apparent decrease in bacterial attachment on multilayered and bilayered Cu/Ni thin films on Ti surfaces. Comparative studies between the two types of films showed a bigger reduction in numbers of microorganisms on the multilayers. PMID:20183129

  9. Multilayer Coating of Tetrandrine-loaded PLGA nanoparticles: Effect of surface charges on cellular uptake rate and drug release profile.

    PubMed

    Meng, Rui; Li, Ke; Chen, Zhe; Shi, Chen

    2016-02-01

    The effect of surface charges on the cellular uptake rate and drug release profile of tetrandrine-loaded poly(lactic-co-glycolic acid) (PLGA) nanoparticles (TPNs) was studied. Stabilizer-free nanoprecipitation method was used in this study for the synthesis of TPNs. A typical layer-by-layer approach was applied for multi-coating particles' surface with use of poly(styrene sulfonate) sodium salt (PSS) as anionic layer and poly(allylamine hydrochloride) (PAH) as cationic layer. The modified TPNs were characterized by different physicochemical techniques such as Zeta sizer, scanning electron microscopy and transmission electron microscopy. The drug loading efficiency, release profile and cellular uptake rate were evaluated by high performance liquid chromatography and confocal laser scanning microscopy, respectively. The resultant PSS/PAH/PSS/PAH/TPNs (4 layers) exhibited spherical-shaped morphology with the average size of 160.3±5.165 nm and zeta potential of-57.8 mV. The encapsulation efficiency and drug loading efficiency were 57.88% and 1.73%, respectively. Multi-layer coating of polymeric materials with different charges on particles' surface could dramatically influence the drug release profile of TPNs (4 layers vs. 3 layers). In addition, variable layers of surface coating could also greatly affect the cellular uptake rate of TPNs in A549 cells within 8 h. Overall, by coating particles' surface with those different charged polymers, precise control of drug release as well as cellular uptake rate can be achieved simultaneously. Thus, this approach provides a new strategy for controllable drug delivery. PMID:26838734

  10. Design of broadband multilayer dichroic coating for a high-efficiency solar energy harvesting system.

    PubMed

    Jiachen, Wang; Lee, Sang Bae; Lee, Kwanil

    2015-05-20

    We report on the design and performance of a broadband dichroic coating for a solar energy conversion system. As a spectral beam splitter, the coating facilitates a hybrid system that combines a photovoltaic cell with a thermal collector. When positioned at a 45° angle with respect to incident light, the coating provides high reflectance in the 40-1100 nm and high transmission in the 1200-2000 nm ranges for a photovoltaic cell and a thermal collector, respectively. Numerical simulations show that our design leads to a sharp transition between the reflection and transmission bands, low ripples in both bands, and slight polarization dependence. PMID:26192518

  11. The (PrS/HGF-pDNA) multilayer films for gene-eluting stent coating: Gene-protecting, anticoagulation, antibacterial properties, and in vivo antirestenosis evaluation.

    PubMed

    Chang, Hao; Ren, Ke-feng; Zhang, He; Wang, Jin-lei; Wang, Bai-liang; Ji, Jian

    2015-02-01

    Vascular gene-eluting stents (GES) is a promising strategy for treatment of cardiovascular disease. Very recently, we have proved that the (protamine sulfate/plasmid DNA encoding hepatocyte growth factor) (PrS/HGF-pDNA) multilayer can serve as a powerful tool for enhancing competitiveness of endothelial cell over smooth muscle cell, which opens perspectives for the regulation of intercellular competitiveness in the field of interventional therapy. However, before the gene multilayer films could be used in vascular stents for real clinical application, the preservation of gene bioactivity during the industrial sterilization and the hemocompatibility of film should be taken into account. Actually, both are long been ignored issues in the field of gene coating for GES. In this study, we demonstrate that the (PrS/HGF-pDNA) multilayer film exhibits the good gene-protecting abilities, which is confirmed by using the industrial sterilizations (gamma irradiation and ethylene oxide) and a routine storage condition (dry state at 4°C for 30 days). Furthermore, hemocompatible measurements (such as platelet adhesion and whole blood coagulation) and antibacterial assays (bacteria adhesion and growth inhibition) indicate the good anticoagulation and antibacterial properties of the (PrS/HGF-pDNA) multilayer film. The in vivo preliminary data of angiography and histological analysis suggest that the (PrS/HGF-pDNA) multilayer coated stent can reduce the in-stent restenosis. This work reveals that the (PrS/HGF-pDNA) multilayer film could be a promising candidate as coating for GES, which is of great potential in future clinic application. PMID:24909849

  12. Analysis on laser-induced transient damage behavior in multilayer coating

    NASA Astrophysics Data System (ADS)

    Lifeng, Du; Bo, Fu; Fengyu, Li; Rongzhu, Zhang

    2016-01-01

    Based on the ionization theory and the Drude model of free electron gas, transient damage principle of the anti-reflection coating under ultrashort pulses are analyzed. Specifically, the damage of an anti-reflection coating designed by ZnS/SiO2 materials is calculated. The results show that during the irradiation process the parameters, such as the refractive index, the electric field and the free electron density, should impact on each other. The coupling relationship between these parameters causes the change in the refractive index, which further leads to the decrease of transmittance of anti-reflection coating from 0.96 to 0.01. In addition, the coupling relationship causes the repartition of free electron density constantly, which eventually leads to the external damage of anti-reflection coating.

  13. Effects of post-deposition annealing on the mechanical and chemical properties of the Si 3N 4/NbN multilayer coatings

    NASA Astrophysics Data System (ADS)

    Jeong, J. J.; Lee, C. M.

    2003-05-01

    Multilayered thin films consisting of alternate layers of silicon nitride (Si 3N 4) and niobium nitride (NbN) have been prepared by a dc reactive sputtering technique in nitrogen and argon atmosphere using high purity Nb and Si targets for various flow ratios of N 2/Ar. It has been found that the hardness of the multilayered system is higher than that of the constituent individual layers of equal thickness. Although a single layer of amorphous Si 3N 4 has higher hardness compared with a single layer of nanocrystalline NbN at all the deposition conditions used in this experiment, the hardness of the multilayer coatings consisting of consecutive Si 3N 4/NbN layers strongly follows the hardness variation of the polycrystalline NbN. When the multilayer coatings are subjected to post-deposition annealing at high temperatures, it has been found that both the hardness and the adhesion strength of the coating decrease with increasing annealing temperature. X-ray photoelectron spectroscopy (XPS) results reveal that oxidation of the coatings during annealing plays a crucial role behind such deterioration in mechanical properties. Further, it has been noted that NbN is a more oxidation resistant material than Si 3N 4. Therefore, it has been proposed that during preparation of multilayers with consecutive thin layers of NbN and Si 3N 4, the topmost layer should be made of NbN, instead of Si 3N 4, to prevent the oxygen diffusion from the top surface layer to the next layer underneath.

  14. Thermal Performance of a Customized Multilayer Insulation (MLI). Design and Fabrication of Test Facility Hardware

    NASA Technical Reports Server (NTRS)

    Leonhard, K. E.

    1975-01-01

    The design, fabrication, and assembly of hardware for testing the performance of a customized multilayer insulation are discussed. System components described include the thermal payload simulator, the modified cryoshroud, and a tank back pressure control device designed to maintain a constant liquid boiling point during the thermal evaluation of the multilayer insulation. The thermal payload simulator will provide a constant temperature surface in the range of 20.5 to 417K (37 to 750R) for the insulated tank to view. The cryoshroud was modified to establish a low temperature black body cavity while limiting liquid hydrogen usage to a minimum feasible rate.

  15. Reflection-enhancing coatings from layer-by-layer self-assembled polyelectrolyte/colloidal TiO2 multilayers

    NASA Astrophysics Data System (ADS)

    Yu, Haihu; Jiang, Desheng; Li, Xiaofu; Yu, Dingshan; Zhou, Lingde

    2005-01-01

    Colloidal TiO2 was prepared by hydrolyzing tetra-n-butyl titauate. Composite multilayer films of Poly(sodium 4-styrensulfonate), PSS, and colloidal TiO2 particles were electrostatically self-assembled onto optic fibers and microscope glass slides. As the PSS/TiO2 film was deposited onto the end face of a glass fiber, the reflected optic intensity periodically oscillated as the bilayer number of the film increased. After a 24-bilayer film was coated onto the both sides of a glass slide, the transmittance at 850 nm decreased more than 20%, which means that the film could serve the function as a reflection-enhancing coating. Data of X-ray diffraction and TEM electron diffraction analysis show that the main crystalline phase of the colloidal TiO2 particles is brookite and that the PSS/TiO2 films are polycrystalline films. Scratching experiments indicate that the composite films are of relatively high hardness.

  16. Accuracy of Young's Modulus of Thermal Barrier Coating Layer Determined by Bending Resonance of a Multilayered Specimen

    NASA Astrophysics Data System (ADS)

    Waki, Hiroyuki; Takizawa, Kensuke; Kato, Masahiko; Takahashi, Satoru

    2016-04-01

    The Young's modulus of individual layer in thermal barrier coating (TBC) system is an important mechanical property because it allows determining the parameters of materials mechanics in the TBC system. In this study, we investigated the accuracy of the evaluation method for the Young's modulus of a TBC layer according to the first bending resonance of a multilayered specimen comprising a substrate, bond coating, and TBC. First, we derived a closed-form solution for the Young's modulus of the TBC layer using the equation of motion for the bending vibration of a composite beam. The solution for the three-layered model provided the Young's modulus of the TBC layer according to the measured resonance frequency and the known values for the dimensions, mass, and Young's moduli of all the other layers. Next, we analyzed the sensitivity of these input errors to the evaluated Young's modulus and revealed the important inputs for accurate evaluation. Finally, we experimentally confirmed that the Young's modulus of the TBC layer was obtained accurately by the developed method.

  17. Improved wettability and adhesion of polylactic acid/chitosan coating for bio-based multilayer film development

    NASA Astrophysics Data System (ADS)

    Gartner, Hunter; Li, Yana; Almenar, Eva

    2015-03-01

    The objective of this study was to investigate the effect of methyldiphenyl diisocyanate (MDI) concentration (0, 0.2, 1, 2, and 3%) on the wettability and adhesion of blend solutions of poly(lactic acid) (PLA) and chitosan (CS) when coated on PLA film for development of a bio-based multi-layer film suitable for food packaging and other applications. Characterization was carried out by attenuated total reflectance infrared spectrometry (ATR-FTIR), contact angle (θ), mechanical adhesion pull-off testing, and scanning electron microscopy (SEM). The θ of the PLA/CS blend shifted to a lower value (41-35°) with increasing MDI concentration showing that the surface tension was modified between the PLA/CS blend solution and PLA film and better wettability was achieved. The increase in MDI also resulted in an increased breaking strength (228-303 kPa) due to the increased H-bonding resulting from the more urethane groups formed within the PLA/CS blend as shown by ATR-FTIR. The improved adhesion was also shown by the increased number of physical entanglements observed by SEM. It can be concluded that MDI can be used to improve wettability and adhesion between PLA/CS coating and PLA film.

  18. Fabrication of BaTiO3-Based Dielectrics for Ultrathin-Layer Multilayer Ceramic Capacitor Application by a Modified Coating Approach

    NASA Astrophysics Data System (ADS)

    Tian, Zhibin; Wang, Xiaohui; Zhang, Yichi; Song, Tae-Ho; Hur, Kang Heon; Li, Longtu

    2011-02-01

    The development of multilayer ceramic capacitor (MLCC) with base metal electrode (BME) requires precise controlling of the microstructure in a very thin dielectric layer (<1 µm). In this paper, a modified coating approach for high coverage of BaTiO3 powder for further MLCC application has been developed. The well dispersed and coated BaTiO3 powders are prepared and the relative mechanism has been discussed. Furthermore, the ultrafine grained X7R dielectric ceramics were produced by both conventional mixing and modified coating methods. Compared with the conventional mixing method, the ceramics prepared by the coating approach exhibited better TCC (the temperature coefficient of capacitance) performance, with dielectric constant over 2000 and grain size below 150 nm. In addition, it is found through the coating method the content of additives can be reduced to a relatively smaller amount than that required in conventional mixing method.

  19. Facile Synthesis of Photofunctional Nanolayer Coatings on Titanium Substrates

    PubMed Central

    Choi, Kyong-Hoon; Kim, Jung-Gil; Kang, Byungman; Kim, Ho-Joong; Park, Bong Joo

    2016-01-01

    We developed a two-step chemical bonding process using photosensitizer molecules to fabricate photofunctional nanolayer coatings on hematoporphyrin- (HP-) coated Ti substrates. In the first step, 3-aminopropyltriethoxysilane was covalently functionalized onto the surface of the Ti substrates to provide heterogeneous sites for immobilizing the HP molecules. Then, HP molecules with carboxyl groups were chemically attached to the amine-terminated nanolayer coatings via a carbodiimide coupling reaction. The microstructure and elemental and phase composition of the HP-coated Ti substrates were investigated using field-emission scanning electron microscopy and energy-dispersive X-ray spectrometry. The photophysical properties of the photofunctional nanolayer coatings were confirmed using reflectance ultraviolet-visible absorption and emission spectrophotometry. The singlet oxygen generation efficiency of the photofunctional nanolayer coatings was determined using the decomposition reaction of 1,3-diphenylisobenzofuran. The HP-coated Ti substrates exhibited good biocompatibility without any cytotoxicity, and these nanolayer coatings generated singlet oxygen, which can kill microorganisms using only visible light. PMID:27110564

  20. Status of Optical Coatings for the National Ignition Facility

    SciTech Connect

    Stolz, C J; Weinzapfel, C; Rogowski, G T; Smith, D; Rigatti, A; Oliver, J; Taniguchi, J; von Gunten, M; Bevis, R; Smith, M; Ivan, V

    2001-03-05

    Optical coatings are a crucial part of the pulse trapping and extraction in the NIF multipass amplifiers. Coatings also steer the 192 beams from four linear arrays to four converging cones entering the target chamber. There are a total of 1600 physical vapor deposited coatings on NIF consisting of 576 mirrors within the multipass cavity, 192 polarizers that work in tandem with a Pockels cell to create an optical switch, and 832 transport mirrors. These optics are of sufficient size so that they are not aperture-limiting for the 40-cm x 40 cm beams over an incident range of 0 to 56.4 degrees. These coatings must withstand laser fluences up to 25 J/cm{sup 2} at 1053 nm (1 {omega}) and 3-ns pulse length and are the 1{omega} fluence-limiting component on NIF. The coatings must have a minimal impact on the beam wavefront and phase to maintain beam focusability, minimize scattered loss, and minimize nonlinear damage mechanisms. This is achieved by specifications ranging from <50 MPa coating stress, <1% coating nonuniformity, <4{angstrom} RMS surface roughness, and a PSD specification to control the amplitude of periodic spatial frequencies. Finally, the primary mission of optical coatings is efficient beam steering so reflection and transmission losses are specified as R>99.5% and >99% for mirrors and polarizers, respectively, and T>98% for polarizers.

  1. Polyelectrolyte multilayer coating of 3D scaffolds enhances tissue growth and gene delivery: non-invasive and label-free assessment.

    PubMed

    Holmes, Christina; Daoud, Jamal; Bagnaninchi, Pierre O; Tabrizian, Maryam

    2014-04-01

    Layer-by-layer (LbL) deposition is a versatile technique which is beginning to be be explored for inductive tissue engineering applications. Here, it is demonstrated that a polyelectrolyte multilayer film system composed of glycol-chitosan (Glyc-CHI) and hyaluronic acid (HA) can be used to coat 3D micro-fabricated polymeric tissue engineering scaffolds. In order to overcome many of the limitations associated with conventional techniques for assessing cell growth and viability within 3D scaffolds, two novel, real-time, label-free techniques are introduced: impedance monitoring and optical coherence phase microscopy. Using these methods, it is shown that LbL-coated scaffolds support in vitro cell growth and viability for a period of at least two weeks at levels higher than uncoated controls. These polyelectrolyte multilayer coatings are then further adapted for non-viral gene delivery applications via incorporation of DNA carrier lipoplexes. Scaffold-based delivery of the enhanced green fluorescent protein (EGFP) marker gene from these coatings is successfully demonstrated in vitro, achieving a two-fold increase in transfection efficiency compared with control scaffolds. These results show the great potential of Glyc-CHI/HA polyelectrolyte multilayer films for a variety of gene delivery and inductive tissue engineering applications. PMID:24030932

  2. CASE STUDY PROJECT: THE USE OF LOW-VOC/HAP COATINGS AT WOOD FURNITURE MANUFACTURING FACILITIES

    EPA Science Inventory

    The paper discusses a study of pollution prevention and the use of low-VOC/HAP (volatile organic compound/hazardous air pollutant) coatings at wood furniture manufacturing facilities. The study is to identify wood furniture and cabinet manufacturing facilities that have converted...

  3. POLLUTION PREVENTION AND THE USE OF LOW-VOC/HAP COATINGS AT WOOD FURNITURE MANUFACTURING FACILITIES

    EPA Science Inventory

    The paper discusses a study of pollution prevention and the use of low-VOC/HAP (volatile organic compound/hazardous air pollutant) coatings at wood furniture manufacturing facilities. The study is to identify wood furniture and cabinet manufacturing facilities that have converted...

  4. Stresses in the material with multilayered coating under impulse thermal loading

    NASA Astrophysics Data System (ADS)

    Shanin, S. A.

    2016-04-01

    The two-dimensional model of mechanical behavior of the specimen with multi layered coating is formulated. The parametric analysis was carried out for various types of boundary conditions. Stress intensity depending on time was studied. The influence of impulse parameters on the temperature and stresses was investigated. It was revealed that radiation heat losses reduces the action of external loading.

  5. Stress analysis for multilayered coating systems using semi-analytical BEM with geometric non-linearities

    NASA Astrophysics Data System (ADS)

    Zhang, Yao-Ming; Gu, Yan; Chen, Jeng-Tzong

    2011-05-01

    For a long time, most of the current numerical methods, including the finite element method, have not been efficient to analyze stress fields of very thin structures, such as the problems of thin coatings and their interfacial/internal mechanics. In this paper, the boundary element method for 2-D elastostatic problems is studied for the analysis of multi-coating systems. The nearly singular integrals, which is the primary obstacle associated with the BEM formulations, are dealt with efficiently by using a semi-analytical algorithm. The proposed semi-analytical integral formulas, compared with current analytical methods in the BEM literature, are suitable for high-order geometry elements when nearly singular integrals need to be calculated. Owing to the employment of the curved surface elements, only a small number of elements need to be divided along the boundary, and high accuracy can be achieved without increasing more computational efforts. For the test problems studied, very promising results are obtained when the thickness of coated layers is in the orders of 10-6-10-9, which is sufficient for modeling most coated systems in the micro- or nano-scales.

  6. Atomic scale elemental mapping of light elements in multilayered perovskite coatings

    NASA Astrophysics Data System (ADS)

    Negrea, R. F.; Teodorescu, V. S.; Ghica, C.

    2015-11-01

    Spherical aberration corrected transmission electron microscopes offer unprecedented capabilities in materials structural characterization down to atomic resolution. Electron energy loss spectroscopy (EELS) - spectrum imaging (SI) and annular bright field (ABF) imaging allow to simultaneously identify both the position and nature of the atomic species in a crystalline material. These techniques, along with conventional high-resolution transmission electron microscopy are particularly useful in heterostructures interfaces like epitaxial multilayers characterization, for identifying possible atomic interdiffusion at sub-nanometric scale. This paper presents the structural and compositional microanalysis down to atomic resolution of an epitaxial BaTiO3/SrRuO3/SrTiO3 ferroelectric heterostructure using complex complementary analytical electron microscopy techniques. The atomic arrangement of both heavy and light atomic species across the interfaces in the BaTiO3/SrRuO3/SrTiO3 heterostructures is revealed.

  7. Geometrical characteristics and damage morphology of nodules grown from artificial seeds in multilayer coating

    SciTech Connect

    Shan Yongguang; He Hongbo; Wei Chaoyang; Li Shuhong; Zhou Ming; Li Dawei; Zhao Yuan'an

    2010-08-01

    Nodules have been planted in an HfO2/SiO2 multilayer system with absorptive gold nanoparticle seeds located on the surface of a substrate. The topography of nodules was scanned by an atomic force microscope and imaged by a scanning electron microscope. The underlying characteristics of nodules were revealed by a focused ion beam. The cross-sectional profiles reveal that nodules grown from small seeds have a continuous boundary and better mechanical stability. A laser-induced damage test shows that nodules decrease the laser-induced damage threshold by up to 3 times. The damage pits are exclusively caused by nodular ejection and triggered by the absorptive seeds. The distribution of electric field and average temperature rise in the nodules were analyzed. Theoretical results met experimental results very well. The strong absorptive seed and microlens effect of the nodule play important roles in laser-induced damage of a planted nodule.

  8. TiO2/SiO2 multilayer as an antireflective and protective coating deposited by microwave assisted magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Mazur, M.; Wojcieszak, D.; Domaradzki, J.; Kaczmarek, D.; Song, S.; Placido, F.

    2013-06-01

    In this paper designing, preparation and characterization of multifunctional coatings based on TiO2/SiO2 has been described. TiO2 was used as a high index material, whereas SiO2 was used as a low index material. Multilayers were deposited on microscope slide substrates by microwave assisted reactive magnetron sputtering process. Multilayer design was optimized for residual reflection of about 3% in visible spectrum (450-800 nm). As a top layer, TiO2 with a fixed thickness of 10 nm as a protective film was deposited. Based on transmittance and reflectance spectra, refractive indexes of TiO2 and SiO2 single layers were calculated. Ultra high vacuum atomic force microscope was used to characterize the surface properties of TiO2/SiO2 multilayer. Surface morphology revealed densely packed structure with grains of about 30 nm in size. Prepared samples were also investigated by nanoindentation to evaluate their protective performance against external hazards. Therefore, the hardness of the thin films was measured and it was equal to 9.34 GPa. Additionally, contact angle of prepared coatings has been measured to assess the wetting properties of the multilayer surface.

  9. Fabrication, performance, and figure metrology of epoxy-replicated aluminum foils for hard x-ray focusing multilayer-coated segmented conical optics

    NASA Astrophysics Data System (ADS)

    Jimenez-Garate, Mario A.; Craig, William W.; Hailey, Charles J.; Christensen, Finn E.; Hussain, Ahsen M.

    2000-11-01

    We fabricated x-ray mirrors for hard x-ray (>= 10 keV) telescopes using multilayer coatings and an improved epoxy- replicated aluminum foil (ERAF) nonvacuum technology. The ERAF optics have approximately 1 arcmin axial figure half- power diameter (HPD) and passed environmental testing. Reflectivity measurements at 8 keV on ERAFs with and without multilayer coatings show a 4.4 to 4.8 angstroms room mean square microroughness for correlation lengths

  10. Efficiency of a multilayer-coated, ion-etched laminar holographic grating in the 14.5{endash}16.0-nm wavelength region

    SciTech Connect

    Kowalski, M.P.; Cruddace, R.G.; Seely, J.F.; Rife, J.C.; Heidemann, K.F.; Heinzmann, U.; Kleineberg, U.; Osterried, K.; Menke, D.; Hunter, W.R.

    1997-06-01

    The efficiency of an ion-etched laminar holographic grating was measured at near-normal incidence in the 14.5{endash}16.0-nm wavelength range. The grating had an electron-beam-evaporated Mo/Si multilayer coating matched to the grating groove depth. The efficiency peaked at 16.3{percent} in the first inside order at 15.12nm and 15.0{percent} in the first outside order at 14.94nm. These are believed to be the highest efficiencies obtained to date from a multilayer-coated laminar grating at near-normal incidence in the EUV ({lambda}{lt}30.0 nm). Zero and even orders were almost completely suppressed. The grating groove efficiency in the first order approached the theoretical limit of 40.5{percent}. {copyright} {ital 1997} {ital Optical Society of America}

  11. Comparative studies of singlet oxygen generation by fullerenes and single- and multilayer carbon nanotubes in the form of solid-phase film coatings

    NASA Astrophysics Data System (ADS)

    Bagrov, I. V.; Kiselev, V. M.; Kislyakov, I. M.; Starodubtsev, A. M.; Burchinov, A. N.

    2015-03-01

    Four types of carbon nanoparticles: C60 fullerene (crystalline and amorphized) and single- and multilayer carbon nanotubes were studied in the form of solid-phase film coatings for the purpose of obtaining singlet oxygen generation in the process of irradiation of these materials by continuous-wave broadband light-emitting diodes in the visible region spectra and by a monopulse 532-nm neodymium laser.

  12. Impact of residual stress on the adhesion and tensile fracture of TiN/CrN multi-layered coatings from first principles

    NASA Astrophysics Data System (ADS)

    Yin, Deqiang; Peng, Xianghe; Qin, Yi; Wang, Zhongchang

    2012-06-01

    Multilayered TiN/CrN coatings find a wide range of technological applications where their internal hetero-interfaces and corresponding residual stress have been long suspected as capable of influencing their intriguing mechanical and chemical performances such as the thermal stability, hardness, and corrosion, tribological and wear resistance. Here, we investigate, by first-principles calculations, atomic and electronic structures of the TiN/CrN interface and how the residual stress influences the adhesion and ideal tensile strength of the multilayered coatings. We find that calculated adhesion energies of the interfaces with (1 1 1) and (0 0 1) orientations are small under no residual stress, yet increase almost linearly when the residual stress is imposed, suggesting that the residual stress plays a dominant role in affecting adhesion. The strengthened adhesion affected by the residual stress is found to be attributable to the stress-induced shrinkage of bonds, which results in enhanced interactions between the bonds in the TiN/CrN coatings. Using several analytic techniques, we have characterized the electronic structure of the interface carefully and determined the interfacial bonding to be primarily ionic with a small degree of covalency. The tensile simulations reveal that the interface with the (1 1 1) texture is more brittle than that with the (0 0 1), although the former presents greater ideal tensile strength. The findings presented here shed light on the impact of residual stress on the adhesion and ideal tensile strength of the TiN/CrN multi-layers, which information could be hard to obtain by means of experiments alone but which is of practical importance for further understanding and improvement of the multi-layered coatings at atomic scale.

  13. A facile hydrothermal approach for construction of carbon coating on TiO2 nanoparticles

    PubMed Central

    Olurode, Kehinde; Neelgund, Gururaj M.; Oki, Aderemi; Luo, Zhiphing

    2012-01-01

    Herein a facile hydrothermal approach is used to construct carbon coated TiO2 nanoparticles employing dextrose as the source of carbon. The procedure is operated at a low temperature of 200 °C. Fourier infrared spectroscopy demonstrated the successful coating of carbon on TiO2 nanoparticles. The phase composition of TiO2 and carbon coated TiO2 nanoparticles were studied using X-ray diffraction and the surface morphology was analyzed by scanning and transmission electron microscopy. The existence of carbon coating on TiO2 nanoparticles was revealed by thermogravimetric analysis through different thermograms exhibited for TiO2 and carbon coated TiO2 nanoparticles. The reported method offers a simple and efficient approach for production of carbon coating TiO2 nanoparticles. PMID:22297036

  14. Multilayer Thermal Barrier Coating (TBC) Architectures Utilizing Rare Earth Doped YSZ and Rare Earth Pyrochlores

    NASA Technical Reports Server (NTRS)

    Schmitt, Michael P.; Rai, Amarendra K.; Bhattacharya, Rabi; Zhu, Dongming; Wolfe, Douglas E.

    2014-01-01

    To allow for increased gas turbine efficiencies, new insulating thermal barrier coatings (TBCs) must be developed to protect the underlying metallic components from higher operating temperatures. This work focused on using rare earth doped (Yb and Gd) yttria stabilized zirconia (t' Low-k) and Gd2Zr2O7 pyrochlores (GZO) combined with novel nanolayered and thick layered microstructures to enable operation beyond the 1200 C stability limit of current 7 wt% yttria stabilized zirconia (7YSZ) coatings. It was observed that the layered system can reduce the thermal conductivity by approximately 45 percent with respect to YSZ after 20 hr of testing at 1316 C. The erosion rate of GZO is shown to be an order to magnitude higher than YSZ and t' Low-k, but this can be reduced by almost 57 percent when utilizing a nanolayered structure. Lastly, the thermal instability of the layered system is investigated and thought is given to optimization of layer thickness.

  15. Enhanced water vapor barrier properties for biopolymer films by polyelectrolyte multilayer and atomic layer deposited Al 2 O 3 double-coating

    NASA Astrophysics Data System (ADS)

    Hirvikorpi, Terhi; Vähä-Nissi, Mika; Harlin, Ali; Salomäki, Mikko; Areva, Sami; Korhonen, Juuso T.; Karppinen, Maarit

    2011-09-01

    Commercial polylactide (PLA) films are coated with a thin (20 nm) non-toxic polyelectrolyte multilayer (PEM) film made from sodium alginate and chitosan and additionally with a 25-nm thick atomic layer deposited (ALD) Al 2O 3 layer. The double-coating of PEM + Al 2O 3 is found to significantly enhance the water vapor barrier properties of the PLA film. The improvement is essentially larger compared with the case the PLA film being just coated with an ALD-grown Al 2O 3 layer. The enhanced water vapor barrier characteristics of the PEM + Al 2O 3 double-coated PLA films are attributed to the increased hydrophobicity of the surface of these films.

  16. Performance of multilayer optical coatings under long-term 532nm laser exposure

    NASA Astrophysics Data System (ADS)

    Poulios, D.; Konoplev, O.; Chiragh, F.; Vasilyev, A.; Stephen, M.; Strickler, K.

    2013-11-01

    The effects of long-term exposure to high intensity 532 nm radiation on various dielectric-coated optics are studied. To investigate potential photodarkening effects on optical surfaces, an accelerated life test platform was constructed where optics were exposed to 532 nm radiation from a short-pulse, high repetition rate fiber amplifier at total doses up to 1 trillion shots. The first run of trillion-shot tests were conducted on e-beam deposited and ion beam sputtering (IBS) coated high reflecting mirrors with onsurface intensities ranging from 1.0-1.4 GW/cm2. It was found that the e-beam coated mirrors failed catastrophically at less than 150 billion shots, while the IBS coated mirror was able to complete the trillionshot test with no measurable loss of reflectivity. Profiling the IBS mirror surface with a high-resolution white light interferometer post-irradiation revealed a ~10 nm high photocontamination deposit at the irradiation site that closely matched the intensity profile of the laser spot. Trillion-shot surface exposure tests were also conducted at multiple surface sites of an LBO frequency doubling crystal at ~1.5 GW/cm2 at multiple surface sites. The transmitted power and on-surface beam size were monitored throughout the tests, and periodic measurements of the beam quality and waist location of the transmitted light were also made using an M2 meter. No changes in transmitted power or M2 were observed in any of the tests, but 3D surface profiling revealed laser-induced contamination deposits at each site tested.

  17. Oxygen permeation, mechanical and structural properties of multilayer diffusion barrier coatings on polypropylene

    NASA Astrophysics Data System (ADS)

    Körner, L.; Sonnenfeld, A.; Heuberger, R.; Waller, J. H.; Leterrier, Y.; Månson, J. A. E.; von Rohr, Ph Rudolf

    2010-03-01

    To improve temperature durability for autoclaving of SiOx diffusion barrier coatings on polypropylene, plasma polymerized hexamethyldisiloxane (pp-HMDSO) is applied by plasma enhanced chemical vapour deposition as interlayer material and compared with results obtained with amorphous hydrogenated carbon-nitrogen (a-C : N : H) and a-Si : C : O : N : H interlayers. The influence of the O2/HMDSO ratio on the chemical structure and related mechanical and oxygen barrier properties is investigated by fragmentation tests, dilatometry, oxygen transmission rate, internal stress and mass density measurements as well as Fourier transform infrared and x-ray photoelectron spectroscopy. Carbon-rich, polymer-like coatings with low density, low internal stress and excellent adhesive and cohesive properties are found for pp-HMDSO at the expense of barrier performance. In the SiOx/pp-HMDSO coating a broad transition in chemical composition was observed, explaining improved mechanical properties responsible for good barrier performance after thermal cycling or autoclaving.

  18. Healable, Transparent, Room-Temperature Electronic Sensors Based on Carbon Nanotube Network-Coated Polyelectrolyte Multilayers.

    PubMed

    Bai, Shouli; Sun, Chaozheng; Yan, Hong; Sun, Xiaoming; Zhang, Han; Luo, Liang; Lei, Xiaodong; Wan, Pengbo; Chen, Xiaodong

    2015-11-18

    Transparent and conductive film based electronics have attracted substantial research interest in various wearable and integrated display devices in recent years. The breakdown of transparent electronics prompts the development of transparent electronics integrated with healability. A healable transparent chemical gas sensor device is assembled from layer-by-layer-assembled transparent healable polyelectrolyte multilayer films by developing effective methods to cast transparent carbon nanotube (CNT) networks on healable substrates. The healable CNT network-containing film with transparency and superior network structures on self-healing substrate is obtained by the lateral movement of the underlying self-healing layer to bring the separated areas of the CNT layer back into contact. The as-prepared healable transparent film is assembled into healable transparent chemical gas sensor device for flexible, healable gas sensing at room temperature, due to the 1D confined network structure, relatively high carrier mobility, and large surface-to-volume ratio. The healable transparent chemical gas sensor demonstrates excellent sensing performance, robust healability, reliable flexibility, and good transparency, providing promising opportunities for developing flexible, healable transparent optoelectronic devices with the reduced raw material consumption, decreased maintenance costs, improved lifetime, and robust functional reliability. PMID:26395971

  19. Fabrication of Optical Multilayer Devices from Porous Silicon Coatings with Closed Porosity by Magnetron Sputtering.

    PubMed

    Caballero-Hernández, Jaime; Godinho, Vanda; Lacroix, Bertrand; Jiménez de Haro, Maria C; Jamon, Damien; Fernández, Asunción

    2015-07-01

    The fabrication of single-material photonic-multilayer devices is explored using a new methodology to produce porous silicon layers by magnetron sputtering. Our bottom-up methodology produces highly stable amorphous porous silicon films with a controlled refractive index using magnetron sputtering and incorporating a large amount of deposition gas inside the closed pores. The influence of the substrate bias on the formation of the closed porosity was explored here for the first time when He was used as the deposition gas. We successfully simulated, designed, and characterized Bragg reflectors and an optical microcavity that integrates these porous layers. The sharp interfaces between the dense and porous layers combined with the adequate control of the refractive index and thickness allowed for excellent agreement between the simulation and the experiments. The versatility of the magnetron sputtering technique allowed for the preparation of these structures for a wide range of substrates such as polymers while also taking advantage of the oblique angle deposition to prepare Bragg reflectors with a controlled lateral gradient in the stop band wavelengths. PMID:26046812

  20. Ionic Driven Embedment of Hyaluronic Acid Coated Liposomes in Polyelectrolyte Multilayer Films for Local Therapeutic Delivery

    NASA Astrophysics Data System (ADS)

    Hayward, Stephen L.; Francis, David M.; Sis, Matthew J.; Kidambi, Srivatsan

    2015-10-01

    The ability to control the spatial distribution and temporal release of a therapeutic remains a central challenge for biomedical research. Here, we report the development and optimization of a novel substrate mediated therapeutic delivery system comprising of hyaluronic acid covalently functionalized liposomes (HALNPs) embedded into polyelectrolyte multilayer (PEM) platform via ionic stabilization. The PEM platform was constructed from sequential deposition of Poly-L-Lysine (PLL) and Poly(Sodium styrene sulfonate) (SPS) “(PLL/SPS)4.5” followed by adsorption of anionic HALNPs. An adsorption affinity assay and saturation curve illustrated the preferential HALNP deposition density for precise therapeutic loading. (PLL/SPS)2.5 capping layer on top of the deposited HALNP monolayer further facilitated complete nanoparticle immobilization, cell adhesion, and provided nanoparticle confinement for controlled linear release profiles of the nanocarrier and encapsulated cargo. To our knowledge, this is the first study to demonstrate the successful embedment of a translatable lipid based nanocarrier into a substrate that allows for temporal and spatial release of both hydrophobic and hydrophilic drugs. Specifically, we have utilized our platform to deliver chemotherapeutic drug Doxorubicin from PEM confined HALNPs. Overall, we believe the development of our HALNP embedded PEM system is significant and will catalyze the usage of substrate mediated delivery platforms in biomedical applications.

  1. Ionic Driven Embedment of Hyaluronic Acid Coated Liposomes in Polyelectrolyte Multilayer Films for Local Therapeutic Delivery

    PubMed Central

    Hayward, Stephen L.; Francis, David M.; Sis, Matthew J.; Kidambi, Srivatsan

    2015-01-01

    The ability to control the spatial distribution and temporal release of a therapeutic remains a central challenge for biomedical research. Here, we report the development and optimization of a novel substrate mediated therapeutic delivery system comprising of hyaluronic acid covalently functionalized liposomes (HALNPs) embedded into polyelectrolyte multilayer (PEM) platform via ionic stabilization. The PEM platform was constructed from sequential deposition of Poly-L-Lysine (PLL) and Poly(Sodium styrene sulfonate) (SPS) “(PLL/SPS)4.5” followed by adsorption of anionic HALNPs. An adsorption affinity assay and saturation curve illustrated the preferential HALNP deposition density for precise therapeutic loading. (PLL/SPS)2.5 capping layer on top of the deposited HALNP monolayer further facilitated complete nanoparticle immobilization, cell adhesion, and provided nanoparticle confinement for controlled linear release profiles of the nanocarrier and encapsulated cargo. To our knowledge, this is the first study to demonstrate the successful embedment of a translatable lipid based nanocarrier into a substrate that allows for temporal and spatial release of both hydrophobic and hydrophilic drugs. Specifically, we have utilized our platform to deliver chemotherapeutic drug Doxorubicin from PEM confined HALNPs. Overall, we believe the development of our HALNP embedded PEM system is significant and will catalyze the usage of substrate mediated delivery platforms in biomedical applications. PMID:26423010

  2. Focusing X-rays to a 1-{mu}m spot using elastically bent, graded multilayer coated mirrors

    SciTech Connect

    Underwood, J.H.; Thompson, A.C.; Kortright, J.B.

    1997-04-01

    In the x-ray fluorescent microprobe at beamline 10.3.1, the ALS bending magnet source is demagnified by a factor of several hundred using a pair of mirrors arranged in the Kirkpatrick-Baez (K-B) configuration. These are coated with multilayers to increase reflectivity and limit the pass band of the x-rays striking the sample. The x-rays excite characteristic fluorescent x-rays of elements in the sample, which are analyzed by an energy dispersive Si-Li detector, for a sensitive assay of the elemental content. By scanning the focal spot the spatial distribution of the elements is determined; the spatial resolution depends on the size of this spot. When spherical mirrors are used, the spatial resolution is limited by aberrations to 5 or 10 {mu}m. This has been improved to 1 {mu}m through the use of an elliptical mirror formed by elastically bending a plane mirror of uniform width and thickness with the optimum combination of end couples.

  3. Facile fabrication of self-repairing superhydrophobic coatings.

    PubMed

    Chen, Kunlin; Zhou, Shuxue; Wu, Limin

    2014-10-14

    A self-repairing superhydrophobic organic coating comprising polystyrene, fluorinated poly(methylsiloxane), fluorinated alkyl silane modified silica nanoparticles and photocatalytic titania nanoparticles shows self-repairing ability after mechanical damage, photocatalytic self-cleaning performance, and thus long-term outdoor durability. PMID:25157381

  4. Glutathione-Responsive Multilayer Coated Gold Nanoparticles for Targeted Gene Delivery.

    PubMed

    Yu, Feifei; Huang, Jingbin; Yu, Yuan; Lu, Ying; Chen, Yan; Zhang, He; Zhou, Guichen; Sun, Zhiguo; Liu, Junjie; Sun, Duxin; Zhang, Guoqing; Zou, Hao; Zhong, Yanqiang

    2016-03-01

    Efficient gene release after intracellular uptake is very important for non-viral gene delivery systems. To construct a glutathione-responsive gene delivery system, we developed gold-cysteamine (AuCM)/plasmid DNA (pDNA)/poly TAT (pTAT)/hyaluronic acid (HA) nanocomplexes (AuCM/pDNA/pTAT/HA) in this study. The AuCM/pDNA/pTAT/HA nanocomplexes possessed a small size less than 200 nm and negative zeta potential of -17 ± 4 mV. The multilayer structure was verified by UV-Vis spectra, surface charges, dynamic light scattering. Morphology was observed by transmission electron microscope. The AuCM/pDNA/pTAT/HA nanocomplexes could completely protect pDNA against enzymatic degradation. These nanocomplexes showed effective cellular uptake in CD44 receptors over-expressed HepG 2 cells in a HA/CD44 interaction dependent manner. Moreover, transfection efficacy was significantly enhanced in AuCM/pDNA/pTAT/HA treated HepG 2 cells compared with AuCM/pDNA/pTAT, and was further enhanced in the presence of GSH, indicating that AuCM/pDNA/pTAT/HA was glutathione-responsive. Biodistribution revealed that AuCM/pDNA/pTAT/HA nanocomplexes mainly accumulated in liver. In conclusion, AuCM/pDNA/pTAT/HA nanocomplexes may serve as glutathione-responsive gene carriers for actively targeting gene delivery to CD44 receptors over-expressed liver cancers. PMID:27280248

  5. The effect of ion irradiation and elevated temperature on the microstructure and the properties of C/W/C/B multilayer coating

    NASA Astrophysics Data System (ADS)

    Vlcak, Petr

    2016-03-01

    C/W/C/B multi-layer PVD coating with a layer period of 10 nm and 500 nm in thickness was irradiated with 45 keV N ions at fluence of 1 × 1017 cm-2. Ion irradiation was performed at room temperature or at an elevated temperature of 500 °C. The microstructure was investigated by X-ray diffraction, by X-ray photoelectron spectroscopy, and by Raman spectroscopy. The results showed that implanted N ions bond both with W atoms and with C atoms. N ion irradiation induced the formation of WC and WC1-x phases. The energetic ions transformed the C bonds in defect sp2 and defect sp3 hybridizations, resulting in graphitization of the carbon fraction in the multilayer coating. Ion irradiation reduced the cohesive strength of the monolayers, reduced hardness of the C/W/C/B coating, increased its surface roughness and increased its friction coefficient. An elevated temperature during ion irradiation caused a better arrangement of the WC phase and further graphitization of the carbon fraction, in comparison with a coating treated by ion irradiation at room temperature. There is discussion of the causes of the observed changes in surface properties.

  6. Biosynthesis of calcium hydroxylapatite coating on sputtered Ti/TiN nano multilayers and their corrosion behavior in simulated body solution.

    PubMed

    Subramanian, Balasubramanian; Dhandapani, Perumal; Maruthamuthu, Sundaram; Jayachandran, Muthirulandi

    2012-02-01

    Titanium/titanium nitride (Ti/TiN) nanoscale multilayered films were deposited onto 316L stainless steel substrates by reactive magnetron sputtering using a Ti target. Coatings characterized by X-ray diffraction showed that the stack possesses centered cubic structure. The X-ray photoelectron spectroscopy survey spectra on the etched surfaces of the stack film on steel exhibited the characteristic Ti2p, N1s, and O1s peaks at the corresponding binding energies 454.5, 397.0, and 530.6 eV, respectively. Platelet adhesion experiments were carried out to examine the interaction between blood and the materials in vitro. The results indicated that the smoothness and lower isoelectric point contribute to better hemocompatibility of the Ti/TiN nanoscale multilayered coating. The biomediated synthesis of calcium hydroxylapatite (HA) was carried out on coated substrates using calcium-depositing bacteria. The observation of low corrosion current density (I(corr)) for the calcium HA-coated Ti/TiN specimens in simulated body fluid confirmed their highly resistive nature under the testing condition. PMID:20819919

  7. Facile nanocoating method: From B-doped to BN-coated one-dimensional nanostructures

    NASA Astrophysics Data System (ADS)

    Tang, C. C.; Bando, Y.; Golberg, D.; Mitome, M.; Ding, X. X.; Qi, S. R.

    2004-07-01

    B-doped MgO nanowires were synthesized through impurity-assisted physical evaporation of a mixture of B and MgO with a small amount of Ga2O3. The B content in the mixture affectsthe morphology of MgO nanowires. B-doped MgO nanotubes and cubes were formed when B-rich mixtures were utilized. Ammonothermal treatment of as-synthesized B-doped products resulted in the formation of uniform BN coatings adherent to nanowire and nanotube surfaces. Thus a facile BN coating method was developed. Finally the growth mechanism of the present BN-coated one-dimensional nanostructures was proposed.

  8. Influence of ion energies on the structure, composition, and properties of multilayer Ti-Al-Si-N ion-plasma-deposited coatings

    NASA Astrophysics Data System (ADS)

    Blinkov, I. V.; Volkhonskii, A. O.; Belov, D. S.; Sergevnin, V. S.; Chernogor, A. V.

    2016-05-01

    It is established that the energy of deposited particles influences the structure, composition, and properties of multilayer nitride coatings consisting of alternating layers of nanocrystalline TiN and amorphous Si3N4 phases with inclusions of nanocrystalline hexagonal AlN formed at energies of titanium, aluminum, and silicon ions exceeding ~317 × 10-19, 267 × 10-19, and 230 × 10-19 J, respectively. As the energy of titanium ions bombarding the substrate increases above ~512 × 10-19 J, the phase transition from disordered TiN x to Ti3N2 and the appearance of 2- to 3-nm-thick sublayers in 15-nm-thick nanocrystalline TiN x layers take place in the coating. The maximum hardness of such coatings reaches a level of ~54 GPa.

  9. Effect of Rare Earth Oxide Content on Nanograined Base Metal Electrode Multilayer Ceramic Capacitor Powder Prepared by Aqueous Chemical Coating Method

    NASA Astrophysics Data System (ADS)

    Zhang, Yichi; Wang, Xiaohui; Kim, Jinyong; Li, Longtu

    2013-02-01

    The aqueous chemical coating route is highly effective in preparing BaTiO3 nanoparticles uniformly coated with additives. Such nanoparticles can be used to produce nano-grained temperature stable BaTiO3 ceramics with core-shell structure, fulfilling the need of next-generation ultrathin layer base metal electrode (BME) multilayer ceramic capacitors (MLCCs). Rare earth oxides are an important class of additives owing to their ability to fulfill both donor and acceptor roles. In this paper, the effects of Y2O3 and Ho2O3 co-dopant content on dielectric and microstructural properties were investigated. By applying chemical coating, BaTiO3-based high performance temperature stabilized ceramics with the average grain size of about 130 nm, which met the requirement of next generation BME MLCCs, were obtained.

  10. In vivo vascularization of MSC-loaded porous hydroxyapatite constructs coated with VEGF-functionalized collagen/heparin multilayers

    PubMed Central

    Jin, Kai; Li, Bo; Lou, Lixia; Xu, Yufeng; Ye, Xin; Yao, Ke; Ye, Juan; Gao, Changyou

    2016-01-01

    Rapid and adequate vascularization is vital to the long-term success of porous orbital enucleation implants. In this study, porous hydroxyapatite (HA) scaffolds coated with vascular endothelial growth factor (VEGF)-functionalized collagen (COL)/heparin (HEP) multilayers (porosity 75%, pore size 316.8 ± 77.1 μm, VEGF dose 3.39 ng/mm3) were fabricated to enhance vascularization by inducing the differentiation of mesenchymal stem cells (MSCs) to endothelial cells. The in vitro immunofluorescence staining, quantitative real-time polymerase chain reaction (qRT-PCR), and western blotting results demonstrated that the expression of the endothelial differentiation markers CD31, Flk-1, and von Willebrand factor (vWF) was significantly increased in the HA/(COL/HEP)5/VEGF/MSCs group compared with the HA/VEGF/MSCs group. Moreover, the HA/(COL/HEP)5 scaffolds showed a better entrapment of the MSCs and accelerated cell proliferation. The in vivo assays showed that the number of newly formed vessels within the constructs after 28 d was significantly higher in the HA/(COL/HEP)5/VEGF/MSCs group (51.9 ± 6.3/mm2) than in the HA (26.7 ± 2.3/mm2) and HA/VEGF/MSCs (38.2 ± 2.4/mm2) groups. The qRT-PCR and western blotting results demonstrated that the HA/(COL/HEP)5/VEGF/MSCs group also had the highest expression of CD31, Flk-1, and vWF at both the mRNA and protein levels. PMID:26794266

  11. AlSiTiN and AlSiCrN multilayer coatings: Effects of structure and surface composition on tribological behavior under dry and lubricated conditions

    NASA Astrophysics Data System (ADS)

    Faga, Maria Giulia; Gautier, Giovanna; Cartasegna, Federico; Priarone, Paolo C.; Settineri, Luca

    2016-03-01

    Nanocomposite coatings have been widely studied over the last years because of their high potential in several applications. The increased interest for these coatings prompted the authors to study the tribological properties of two nanocomposites under dry and lubricated conditions (applying typical MQL media), in order to assess the influence of the surface and bulk properties on friction evolution. To this purpose, multilayer and nanocomposite AlSiTiN and AlSiCrN coatings were deposited onto tungsten carbide-cobalt (WC-Co) samples. Uncoated WC-Co materials were used as reference. Coatings were analyzed in terms of hardness and adhesion. The structure of the samples was assessed by X-ray diffraction (XRD), while the surface composition was studied by XPS analysis. Friction tests were carried out under both dry and lubricated conditions using an inox ball as counterpart. Both coatings showed high hardness and good adhesion to the substrate. As far as the friction properties are concerned, in dry conditions the surface properties affect the sliding contact at the early beginning, while bulk structure and tribolayer formation determine the main behavior. Only AlSiTiN coating shows a low and stable coefficient of friction (COF) under dry condition, while the use of MQL media results in a rapid stabilization of the COF for all the materials.

  12. Tribological and mechanical properties of Ti/TiAlN/TiAlCN nanoscale multilayer PVD coatings deposited on AISI H11 hot work tool steel

    NASA Astrophysics Data System (ADS)

    AL-Bukhaiti, M. A.; Al-hatab, K. A.; Tillmann, W.; Hoffmann, F.; Sprute, T.

    2014-11-01

    A new [Ti/TiAlN/TiAlCN]5 multilayer coatings were deposited onto polished substrate AISI H11 (DIN 1.2343) steel by an industrial magnetron sputtering device. The tribological performance of the coated system was investigated by a ball-on-disk tribometer against 100Cr6 steel and Al2O3 balls. The friction coefficients and specific wear rates were measured at various normal loads (2, 5, 8, and 10 N) and sliding velocities (0.2, 0.4, and 0.8 m/s) in ambient air and dry conditions. The phase structure, composition, wear tracks morphologies, hardness, and film/substrate adhesion of the coatings were characterized by light-microscopy, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), 3D-surface analyzer, nanoindentation, and scratch tests. Results showed that the deposited coatings showed low wear rates in the scale of 10-15 m3/N m, low friction coefficients against 100Cr6 and Al2O3 balls in the range of 0.25-0.37, and good hardness in the range of 17-20 GPa. Results also revealed that the friction coefficients and disc wear rates decrease and increase, respectively with the increase in normal load and sliding velocity for both coating/Al2O3 and coating/100Cr6 sliding system. Compared with the uncoated-H11 substrate, the deposited coating exhibited superior tribological and mechanical properties. The dominant wear mechanism was abrasive wear for coating/Al2O3 pair, while for coating/100Cr6 pair, a combination of mild adhesive wear, severe adhesive wear, and abrasive wear (extensive plowing) were the dominant wear mechanisms at different applied normal loads.

  13. Corrosion behaviour of sintered NdFeB coated with Al/Al 2O 3 multilayers by magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Mao, Shoudong; Yang, Hengxiu; Huang, Feng; Xie, Tingting; Song, Zhenlun

    2011-02-01

    Al/Al2O3 multilayers were deposited on sintered NdFeB magnets to improve the corrosion resistance. The amorphous Al2O3 films were used to periodically interrupt the columnar growth of the Al layers. The structure of the multilayers was investigated by Scanning Electron Microscopy (SEM) and High Resolution Transmission Electron Microscopy (HRTEM). It was found that the columnar structure was effectively inhibited in the multilayers. Subsequent corrosion testing by potentiodynamic polarization in 3.5 wt.% NaCl and neutral salt spray test (NSS) revealed that the Al/Al2O3 multilayers had much better corrosion resistance than the Al single layer. Furthermore, for multilayers with similar thickness, the corrosion resistance was improved as the period decreased.

  14. Materials selection of surface coatings in an advanced size reduction facility. [For decommissioned stainless steel equipment

    SciTech Connect

    Briggs, J. L.; Younger, A. F.

    1980-06-02

    A materials selection test program was conducted to characterize optimum interior surface coatings for an advanced size reduction facility. The equipment to be processed by this facility consists of stainless steel apparatus (e.g., glove boxes, piping, and tanks) used for the chemical recovery of plutonium. Test results showed that a primary requirement for a satisfactory coating is ease of decontamination. A closely related concern is the resistance of paint films to nitric acid - plutonium environments. A vinyl copolymer base paint was the only coating, of eight paints tested, with properties that permitted satisfactory decontamination of plutonium and also performed equal to or better than the other paints in the chemical resistance, radiation stability, and impact tests.

  15. Efficiency calibration of the first multilayer-coated holographic ion-etched flight grating for a sounding rocket high-resolution spectrometer

    SciTech Connect

    Kowalski, Michael P.; Barbee, Troy W. Jr.; Heidemann, Klaus F.; Gursky, Herbert; Rife, Jack C.; Hunter, William R.; Fritz, Gilbert G.; Cruddace, Raymond G.

    1999-11-01

    We have fabricated the four flight gratings for a sounding rocket high-resolution spectrometer using a holographic ion-etching technique. The gratings are spherical (4000-nm radius of curvature), large (160 mmx90 mm), and have a laminar groove profile of high density (3600 grooves/mm). They have been coated with a high-reflectance multilayer of Mo/Si. Using an atomic force microscope, we examined the surface characteristics of the first grating before and after multilayer coating. The average roughness is approximately 3 Aa rms after coating. Using synchrotron radiation, we completed in efficiency calibration map over the wavelength range 225-245 Aa. At an angle of incidence of 5 degree sign and a wavelength of 232 Aa, the average efficiency in the first inside order is 10.4{+-}0.5%, and the derived groove efficiency is 34.8{+-}1.6%. These values exceed all previously published results for a high-density grating. (c) 1999 Optical Society of America.

  16. Technologies for manufacturing of high angular resolution multilayer coated optics for the New Hard X-ray Mission: a status report II

    NASA Astrophysics Data System (ADS)

    Vernani, D.; Borghi, G.; Binda, R.; Citterio, O.; Grisoni, G.; Kools, J.; Marioni, F.; Orlandi, A.; Ritucci, A.; Sironi, G.; Valsecchi, G.; Basso, S.; Pareschi, G.; Spiga, D.; Tagliaferri, G.; Negri, B.

    2010-07-01

    Focusing mirrors manufactured via galvanic replication process from negative shape mandrels is the candidate solution for some of next future X-ray missions. Media Lario Technologies (MLT) is the industrial enabler developing, in collaboration with Brera Astronomical Observatory (INAF/OAB) and Italian Space Agency, the Optical Payload for the New Hard X-ray Mission (NHXM) Italian project. The current and ongoing development activities in Media Lario Technologies complement the electroforming technology with a suite of critical manufacturing and assembly of the Mirror Module Unit. In this paper, the progress on mandrels manufacturing, mirror shell replication, multilayer coating deposition and mirror module integration, leading to the manufacturing and testing of some astronomical Hard X-ray Engineering Models, is reported. Mandrel production is a key point in terms of performances and schedule; the results from mandrels fabricated using a proprietary multistep surface finishing process are reported. The progress in the replication of ultrathin Nickel and Nickel-Cobalt substrates gold coated mirror shells is reported together with the results of MLT Magnetron Sputtering multilayer coating technology for the hard x-ray waveband and its application to Pt/C.

  17. Technologies for manufacturing of high angular resolution multilayer coated optics for future new hard x-ray missions: a status report

    NASA Astrophysics Data System (ADS)

    Borghi, G.; Vernani, D.; Marchi Boscolo, E.; Citterio, O.; Grisoni, G.; Kools, J.; Marioni, F.; Orlandi, A.; Ritucci, A.; Rossi, M.; Salmaso, G.; Valsecchi, G.; Basso, S.; Pareschi, G.; Spiga, D.; Tagliaferri, G.; Negri, B.

    2009-08-01

    High throughput lightweight Hard X-ray Optics manufactured via electroforming replication process from supersmooth mandrels are the primary candidate for some of future New Hard X-ray missions. Media Lario Technologies (MLT) is the industrial enabler exploiting the electroforming technology initially applied for the ESA XMM-Newton mission and further developed in cooperation with Brera Astronomical Observatory (INAF/OAB). The current and ongoing development activities in Media Lario Technologies complement the electroforming technology with a suite of critical manufacturing and assembly of the Mirror Module Unit. In this paper, the progress on mandrels manufacturing, mirror shell replication, multilayer coating deposition, mirror module integration, and relevant metrology is reported in view of the upcoming production phase. Mandrel production is a key point in terms of performances and schedule; the results from of NiP prototype mandrels fabricated using a proprietary multistep surface finishing process are reported. The progress in the replication of ultrathin Nickel and Nickel-Cobalt substrates gold coated mirror shells is reported together with the results of MLT Magnetron Sputtering multilayer coating technology for the hard x-ray waveband and its application to W/Si. Due to the criticality of low thickness mirror handling, the integration concept has been refined and tested on prototype mechanical structures under full illumination UV vertical optical bench.

  18. Silicon carbide multilayer protective coating on carbon obtained by thermionic vacuum arc method

    NASA Astrophysics Data System (ADS)

    Ciupină, Victor; Lungu, Cristian Petrica; Vladoiu, Rodica; Prodan, Gabriel; Porosnicu, Corneliu; Belc, Marius; Stanescu, Iuliana M.; Vasile, Eugeniu; Rughinis, Razvan

    2014-01-01

    Thermionic vacuum arc (TVA) method is currently developing, in particular, to work easily with heavy fusible material for the advantage presented by control of directing energy for the elements forming a plasma. The category of heavy fusible material can recall C and W (high-melting point materials), and are difficult to obtain or to control by other means. Carbon is now used in many areas of special mechanical, thermal, and electrical properties. We refer in particular to high-temperature applications where unwanted effects may occur due to oxidation. Changed properties may lead to improper functioning of the item or device. For example, increasing the coefficient of friction may induce additional heat on moving items. One solution is to protect the item in question by coating with proper materials. Silicon carbide (SiC) was chosen mainly due to compatibility with coated carbon substrate. Recently, SiC has been used as conductive transparent window for optical devices, particularly in thin film solar cells. Using the TVA method, SiC coatings were obtained as thin films (multilayer structures), finishing with a thermal treatment up to 1000°C. Structural properties and oxidation behavior of the multilayer films were investigated, and the measurements showed that the third layer acts as a stopping layer for oxygen. Also, the friction coefficient of the protected films is lower relative to unprotected carbon films.

  19. Stratospheric Observatory for Infrared Astronomy (SOPHIA) Mirror Coating Facility

    NASA Astrophysics Data System (ADS)

    Austin, Ed

    The joint US and German project, Stratospheric Observatory for Infrared Astronomy (SOFIA), to develop and operate a 2.5 meter infrared airborne telescope in a Boeing 747-SP began late last year. Universities Space Research Association (USRA), teamed with Raytheon E-Systems and United Airlines, was selected by NASA to develop and operate SOPHIA. The 2.5 meter telescope will be designed and built by a consortium of German companies. The observatory is expected to operate for over 29 years with the first science flights beginning in 2001. The SOPHIA Observatory will fly at and above 12.5 km, where the telescope will collect radiation in the wavelength range from 0.3 micrometers to a 1.6 millimeters. Universities Space Research Association (USRA) with support from NASA is currently evaluating methods of recoating the primary mirror in preparation for procurement of mirror coating equipment. The decision analysis technique, decision criteria and telescope specifications will be discussed.

  20. Facile preparation of superhydrophobic candle soot coating and its wettability under condensation

    NASA Astrophysics Data System (ADS)

    Yuan, Zhiqing; Huang, Juan; Peng, Chaoyi; Wang, Menglei; Wang, Xian; Bin, Jiping; Xing, Suli; Xiao, Jiayu; Zeng, Jingcheng; Xiao, Ximei; Fu, Xin; Gong, Huifang; Zhao, Dejian; Chen, Hong

    2016-02-01

    A facile method was developed to prepare a superhydrophobic candle soot coating by burning candle and simple deposition on a low-density polyethylene substrate. The water contact angle and sliding angle of the as-prepared superhydrophobic candle soot coating were, respectively, 160 ± 2° and 1° under common condition. ESEM images showed that the superhydrophobic candle soot coating was comprised of many nanoparticles with the size range of about 30-50 nm. After condensation for 30 min, the average contact angle of the condensed water droplets was 150° ± 2°, showing excellent superhydrophobicity under condensation. The mechanism of the candle soot coating remaining superhydrophobicity under condensation was analyzed. This work is helpful for the design and preparation of superhydrophobic surface which can remain superhydrophobicity in future.

  1. Possibilities of structural engineering in multilayer vacuum-arc ZrN/CrN coatings by varying the nanolayer thickness and application of a bias potential

    NASA Astrophysics Data System (ADS)

    Sobol', O. V.; Andreev, A. A.; Gorban', V. F.; Stolbovoy, V. A.; Melekhov, A. A.; Postelnyk, A. A.

    2016-07-01

    The possibility of attaining an superhard state in multilayer vacuum-arc ZrN/CrN coatings with a layer thickness of about 20 nm has been established. It has been shown that the application of a constant negative potential for structural engineering during deposition leads to the formation of solid solutions due to mixing of interfaces. The hardness of these systems exceeds 30 GPa. The application of a pulsed high-voltage bias potential at which the ordering of atoms stimulated by elevated mobility is observed makes it possible to suppress the mixing of the interfaces and to attain elevated hardness (up to 42 GPa) for nanometer layer thicknesses.

  2. New multilayer coating using quaternary ammonium chitosan and κ-carrageenan in capillary electrophoresis: application in fast analysis of betaine and methionine.

    PubMed

    Vitali, Luciano; Della Betta, Fabiana; Costa, Ana Carolina O; Vaz, Fernando Antonio Simas; Oliveira, Marcone Augusto Leal; Vistuba, Jacqueline Pereira; Fávere, Valfredo T; Micke, Gustavo A

    2014-06-01

    The aim of this study was to develop a new multilayer coating with crosslinked quaternary ammonium chitosan (hydroxypropyltrimethyl ammonium chloride chitosan; HACC) and κ-carrageenan for use in capillary electrophoresis. A new semi-permanent multilayer coating was formed using the procedure developed and the method does not require the presence of polymers in the background electrolyte (BGE). The new capillary multilayer coating showed a cathodic electroosmotic flow (EOF) of around 30×10(-9) m(2) V(-1) s(-1) which is pH-independent in the range of pH 2 to 10. The enhanced EOF at low pH obtained contributed significantly to the development of a fast method of separation. The multilayer coating was then applied in the development of a fast separation method to determine betaine and methionine in pharmaceutical formulations by capillary zone electrophoresis (CZE). The BGE used to determine the betaine and methionine concentrations was composed of 10 mmol L(-1) tris(hydroxymethyl) aminomethane, 40 mmol L(-1) phosphoric acid and 10% (v/v) ethanol, at pH 2.1. A fused-silica capillary of 32 cm (50 µm ID×375 µm OD) was used in the experiments and samples and standards were analyzed employing the short-end injection procedure (8.5 cm effective length). The instrumental analysis time of the optimized method was 1.53 min (approx. 39 runs per hour). The validation of the proposed method for the determination of betaine and methionine showed good linearity (R(2)>0.999), adequate limit of detection (LOD <8 mg L(-1)) for the concentration in the samples and inter-day precision values lower than 3.5% (peak area and time migration). The results for the quantification of the amino acids in the samples determined by the CZE-UV method developed were statistically equal to those obtained with the comparative LC-MS/MS method according to the paired t-test with a confidence level of 95%. PMID:24725863

  3. Tri-material multilayer coatings with high reflectivity and wide bandwidth for 25 to 50 nm extreme ultraviolet light.

    PubMed

    Aquila, A; Salmassi, F; Liu, Yanwei; Gullikson, E M

    2009-11-23

    Magnesium/silicon carbide (Mg/SiC) multilayers have been fabricated with normal incidence reflectivity in the vicinity of 40% to 50% for wavelengths in the 25 to 50 nm wavelength range. However many applications, for example solar telescopes and ultrafast studies using high harmonic generation sources, desire larger bandwidths than provided by high reflectivity Mg/SiC multilayers. We investigate introducing a third material, Scandium, to create a tri-material Mg/Sc/SiC multilayer allowing an increase the bandwidth while maintaining high reflectivity. PMID:19997456

  4. Tri-material multilayer coatings with high reflectivity and wide bandwidth for 25 to 50 nm extreme ultraviolet light

    SciTech Connect

    Aquila, Andrew; Salmassi, Farhad; Liu, Yanwei; Gullikson, Eric M.

    2009-09-09

    Magnesium/silicon carbide (Mg/SiC) multilayers have been fabricated with normal incidence reflectivity in the vicinity of 40% to 50% for wavelengths in the 25 to 50 nm wavelength range. However many applications, for example solar telescopes and ultrafast studies using high harmonic generation sources, desire larger bandwidths than provided by high reflectivity Mg/SiC multilayers. We investigate introducing a third material, Scandium, to create a tri-material Mg/Sc/SiC multilayer allowing an increase the bandwidth while maintaining high reflectivity.

  5. Mechanical loss of a multilayer tantala/silica coating on a sapphire disk at cryogenic temperatures: Toward the KAGRA gravitational wave detector

    NASA Astrophysics Data System (ADS)

    Hirose, Eiichi; Craig, Kieran; Ishitsuka, Hideki; Martin, Iain W.; Mio, Norikatsu; Moriwaki, Shigenori; Murray, Peter G.; Ohashi, Masatake; Rowan, Sheila; Sakakibara, Yusuke; Suzuki, Toshikazu; Waseda, Kouichi; Watanabe, Kyohei; Yamamoto, Kazuhiro

    2014-11-01

    We report the results of a new experimental setup to measure the mechanical loss of coating layers on a thin sapphire disk at cryogenic temperatures. Some of the authors previously reported that there was no temperature dependence of the mechanical loss from a multilayer tantala/silica coating on a sapphire disk, both before and after heat treatment, although some reports indicate that Ta2O5 and SiO2 layers annealed at 600 °C have loss peaks near 20 K. Since KAGRA—the Japanese gravitational-wave detector, currently under construction—will be operated at 20 K and have coated sapphire mirrors, it is very important to clarify the mechanical loss behavior of tantala/silica coatings around this temperature. We carefully investigate a tantala/silica-coated sapphire disk with the new setup, anneal the disk, and then investigate the annealed disk. We find that there is no distinct loss peak both before and after annealing under particular conditions. The mechanical loss for the unannealed disk at 20 K is about 5 ×10-4 , as previously reported, while that for the annealed disk is approximately 6.4 ×10-4 .

  6. Multilayer Insulation Material Guidelines

    NASA Technical Reports Server (NTRS)

    Finckenor, M. M.; Dooling, D.

    1999-01-01

    Multilayer Insulation Material Guidelines provides data on multilayer insulation materials used by previous spacecraft such as Spacelab and the Long-Duration Exposure Facility and outlines other concerns. The data presented in the document are presented for information only. They can be used as guidelines for multilayer insulation design for future spacecraft provided the thermal requirements of each new design and the environmental effects on these materials are taken into account.

  7. Design, Fabrication and Testing of Multilayer Coated X-Ray Optics for the Water Window Imaging X-Ray Microscope

    NASA Technical Reports Server (NTRS)

    Spencer, Dwight C.

    1996-01-01

    Hoover et. al. built and tested two imaging Schwarzschild multilayer microscopes. These instruments were constructed as prototypes for the "Water Window Imaging X-Ray Microscope," which is a doubly reflecting, multilayer x-ray microscope configured to operate within the "water window." The "water window" is the narrow region of the x-ray spectrum between the K absorption edges of oxygen (lamda = 23.3 Angstroms) and of carbon (lamda = 43.62 Angstroms), where water is relatively highly transmissive and carbon is highly absorptive. This property of these materials, thus permits the use of high resolution multilayer x-ray microscopes for producing high contrast images of carbon-based structures within the aqueous physiological environments of living cells. We report the design, fabrication and testing of multilayer optics that operate in this regime.

  8. In-depth optical and structural study of silver-based low-emissivity multilayer coatings for energy-saving applications

    NASA Astrophysics Data System (ADS)

    Martín-Palma, R. J.; Gago, R.; Vinnichenko, M.; Martínez-Duart, J. M.

    2004-06-01

    Low-emissivity coatings on glass, which provide highly efficient heat isolation, are nowadays extensively used in windows in offices and residential buildings for the purpose of saving energy in air conditioning. In this paper, multilayer low-emissivity coatings with the structure glass/SnO2/Ni-Cr/Ag/Ni-Cr/SnO2 were deposited onto large glass substrates in an industrial sputtering system. The extremely low thickness of the layers which compose such structures, as well as the large substrate area, causes the structure and impurity content of the films and interfaces to play an important role in providing efficient energy-saving performance as well as high optical transmittance. Thus, in-depth characterization was performed by spectroscopic ellipsometry, Rutherford backscattering spectroscopy and Auger electron spectroscopy. The use of these characterization techniques provides the great advantage of allowing the investigation of the whole multilayer system, including the interfaces. However, the properties of the individual layers (density, composition and optical behaviour) were also determined independently and compared to the values of corresponding bulk materials. Special attention is devoted to inter-diffusion of species.

  9. Qualification of Coatings for Launch Facilities and Ground Support Equipment Through the NASA Corrosion Technology Laboratory

    NASA Technical Reports Server (NTRS)

    Kolody, Mark R.; Curran, Jerome P.; Calle, Luz Marina

    2014-01-01

    Corrosion protection at NASA's Kennedy Space Center is a high priority item. The launch facilities at the Kennedy Space Center are located approximately 1000 feet from the Atlantic Ocean where they are exposed to salt deposits, high humidity, high UV degradation, and acidic exhaust from solid rocket boosters. These assets are constructed from carbon steel, which requires a suitable coating to provide long-term protection to reduce corrosion and its associated costs.

  10. OMEGA: A NEW COLD X-RAY SIMULATION FACILITY FOR THE EVALUATION OF OPTICAL COATINGS

    SciTech Connect

    Fisher, J H; Newlander, C D; Fournier, K B; Beutler, D E; Coverdale, C A; May, M J; Tobin, M; Davis, J F; Shiekh, D

    2007-04-27

    We report on recent progress for the development of a new cold X-ray optical test capability using the Omega Facility located at the Laboratory for Laser Energetics (LLE) at the University of Rochester. These tests were done on the 30 kJ OMEGA laser at the Laboratory for Laser Energetics (LLE) at the University of Rochester, Rochester, NY. We conducted a six-shot series called OMEGA II on 14 July 2006 in one eight-hour day (supported by the Defense Threat Reduction Agency). The initial testing was performed using simple protected gold optical coatings on fused silica substrates. PUFFTFT analyses were completed and the specimen's thermal lateral stress and transverse stress conditions were calculated and interpreted. No major anomalies were detected. Comparison of the pre- and posttest reflective measurements coupled with the TFCALC analyses proved invaluable in guiding the analyses and interpreting the observed damage. The Omega facility is a high quality facility for performing evaluation of optical coatings and coupons and provides experience for the development of future National Ignition Facility (NIF) testing.

  11. Role of EIS in Materials and Coatings Selection for NASA's Launch Facilities

    NASA Technical Reports Server (NTRS)

    Calle, Luz Marina

    2004-01-01

    Corrosion studies began at NASA's John F. Kennedy Space Center (KSC) in 1966, during the Gemini/Apollo Programs, with the evaluation of long-term anti-corrosion coatings for carbon steel structures. NASAIKSC's Atmospheric Exposure Test Site was established at that time on the beach near the launch pad. In the years that followed, numerous studies at the site have identified materials, coatings, and maintenance procedures for launch hardware and equipment exposed to the highly corrosive environment at the launch pad. The atmosphere at the launch pad is highly corrosive due to the proximity of the Atlantic Ocean, high heat from rocket exhaust, and since the introduction of the Space Shuttle, the acidic combustion products of the Solid Rocket Boosters (SRBs). Currently, NASAIKSC maintains about $2 billion worth of unique equipment and facilities, not including the orbiters, each valued at about $1.8 billion. Among the items: two launch complexes, two crawler transporters, three mobile launch platforms, and specialized testing equipment. Atmospheric exposure provides very valuable data but it takes a long time and relies on human visual inspection. NASA Technical Standard for Protective Coatings requires 18 months of good performance at the Atmospheric Exposure Test Site for preliminary approval and continued good performance for 5 years for final approval of a coating system. The use of electrochemical impedance spectroscopy (EIS) was introduced at KSC in 1989 as a supplement to the traditional dc electrochemical techniques and atmospheric exposure studies. This paper presents and overview of several projects in which EIS was used in order to select materials and coatings to be used at NASA's launch facilities [1-2].

  12. Assembly of bioactive multilayered nanocoatings on pancreatic islet cells: incorporation of α1-antitrypsin into the coatings.

    PubMed

    Zhi, Zheng-Liang; Singh, Jashandeep; Austin, Amazon L F; Hope, David C D; King, Aileen J; Persaud, Shanta J; Jones, Peter M

    2015-07-01

    A spontaneous multilayer deposition approach for presenting therapeutic proteins onto pancreatic islet surfaces, using a heparin polyaldehyde and glycol chitosan alternating layering scheme, has been developed to enable the nanoscale engineering of a microenvironment for transplanted cells. The nanocoating incorporating α1-antitrypsin, an anti-inflammatory protein, exhibited effective anti-coagulant activities in vitro. PMID:26051448

  13. Build-up of an antimicrobial multilayer coating on a textile support based on a methylene blue-poly(cyclodextrin) complex.

    PubMed

    Martin, Adeline; Tabary, Nicolas; Chai, Feng; Leclercq, Laurent; Junthip, Jatupol; Aubert-Viard, François; Neut, Christel; Weltrowski, Marek; Blanchemain, Nicolas; Martel, Bernard

    2013-12-01

    The aim of this work was to develop an antibacterial multilayer coating activated with methylene blue (MB) and based on chitosan (CHT) and cyclodextrin polyelectrolyte (polyCD) onto a non-woven polyethylene terephthalate (PET) textile support. The MB-free and MB-loaded systems were built-up by applying the dip-coating technique, alternating soak cycles of the PET textile preliminarily modified with carboxylate groups in CHT and in polyCD or polyCD/MB complex solutions. The layer-by-layer assembly build-up was followed by optical waveguide lightmode spectroscopy on the one hand and by gravimetry once it was applied on the textile substrate on the other hand. Two chitosan grades were used, low molecular weight (CHT-L) and medium molecular weight (CHT-M). The influence of the molar ratio CD/MB in the polyCD solutions was varied and finally the system underwent a post reticulation with genipin. Such parameters influences were investigated with regard to the loading capacity in MB of the systems, the release kinetics profiles of MB in pure water, phosphate buffer and MEM media, and the degradation of the self-assembled coating in the same media. Finally, biological and microbiological tests were performed to demonstrate the cytocompatibility of the systems and their ability to display a sustained antibacterial effect of the device through the MB prolonged release. PMID:24280742

  14. Significant degradability enhancement in multilayer coating of polycaprolactone-bioactive glass/gelatin-bioactive glass on magnesium scaffold for tissue engineering applications

    NASA Astrophysics Data System (ADS)

    Yazdimamaghani, Mostafa; Razavi, Mehdi; Vashaee, Daryoosh; Pothineni, Venkata Raveendra; Rajadas, Jayakumar; Tayebi, Lobat

    2015-05-01

    Magnesium (Mg) is a promising candidate to be used in medical products especially as bone tissue engineering scaffolds. The main challenge for using Mg in biomedical applications is its high degradation rate in the body. For this reason, in this study, a multilayer polymeric layer composed of polycaprolactone (PCL) and gelatin (Gel) reinforced with bioactive glass (BaG) particles has been applied on the surface of Mg scaffolds. The materials characteristics of uncoated Mg scaffold, Mg scaffold coated only with PCL-BaG and Mg scaffold coated with PCL-BaG and Gel-BaG have been analyzed and compared in detail. Scanning electron microscope (SEM) equipped with energy dispersive spectroscopy (EDS), and Fourier transform infrared spectroscopy (FTIR) were utilized for microstructural studies. In vitro bioactivity and biodegradation evaluations were carried out by submerging the scaffolds in simulated body fluid (SBF) at pre-determined time points. The results demonstrated that Mg scaffold coated with PCL-BaG and Gel-BaG exhibited significant improvement in biodegradability.

  15. Non Evaporable Getter (NEG) Coatings for Vacuum Systems in Synchrotron Radiation Facilities

    SciTech Connect

    Manini, Paolo; Conte, Andrea; Raimondi, Stefano; Bonucci, Antonio

    2007-01-19

    Non evaporable Getter (NEG) films, sputter deposited onto the internal surfaces of vacuum chambers, have been proposed by CERN to substantially reduce the gas pressure in UHV-XHV systems. The NEG film acts as a conductance-free distributed pump inside a chamber. Being a barrier for gases it also reduces thermal out-gassing, thus allowing the achievement of very demanding pressure conditions. These features are ideal for very narrow, conductance limited chambers, like Insertion Devices, which cannot be always efficiently pumped by ordinary means. Recent investigations have also shown that NEG coatings do present additional interesting features, like low secondary electron yield and low gas de-sorption rates under ions, electrons and photons bombardment, compared to traditional technical surfaces. Experimental tests, carried out in several high energy machines and synchrotron radiations facilities have so far confirmed the benefits of NEG films in term of better vacuum, longer beam life time and stability, simplified machine design, reduced conditioning time and overall improved machine performances. For these reasons, NEG coating technology is now gaining increasing attention and it is seriously considered for upgrades in a number of machines and for future projects. In the present paper, we report SAES getters experience on NEG coating of chambers of different geometries, materials and sizes for a variety of projects related to synchrotron radiation facilities. Examples of applications in various machines, as well as typical issues related to chambers preparation, film deposition, quality control and characterization, are given.

  16. Non Evaporable Getter (NEG) Coatings for Vacuum Systems in Synchrotron Radiation Facilities

    NASA Astrophysics Data System (ADS)

    Manini, Paolo; Conte, Andrea; Raimondi, Stefano; Bonucci, Antonio

    2007-01-01

    Non evaporable Getter (NEG) films, sputter deposited onto the internal surfaces of vacuum chambers, have been proposed by CERN to substantially reduce the gas pressure in UHV-XHV systems. The NEG film acts as a conductance-free distributed pump inside a chamber. Being a barrier for gases it also reduces thermal out-gassing, thus allowing the achievement of very demanding pressure conditions. These features are ideal for very narrow, conductance limited chambers, like Insertion Devices, which cannot be always efficiently pumped by ordinary means. Recent investigations have also shown that NEG coatings do present additional interesting features, like low secondary electron yield and low gas de-sorption rates under ions, electrons and photons bombardment, compared to traditional technical surfaces. Experimental tests, carried out in several high energy machines and synchrotron radiations facilities have so far confirmed the benefits of NEG films in term of better vacuum, longer beam life time and stability, simplified machine design, reduced conditioning time and overall improved machine performances. For these reasons, NEG coating technology is now gaining increasing attention and it is seriously considered for upgrades in a number of machines and for future projects. In the present paper, we report SAES getters experience on NEG coating of chambers of different geometries, materials and sizes for a variety of projects related to synchrotron radiation facilities. Examples of applications in various machines, as well as typical issues related to chambers preparation, film deposition, quality control and characterization, are given.

  17. Non-Evaporable Getter Coatings at the European Synchrotron Radiation Facility

    NASA Astrophysics Data System (ADS)

    Hahn, Michael

    A large majority of insertion device (ID) vacuum sectors on the European Synchrotron Radiation Facility (ESRF) electron storage ring for the production of intense synchrotron radiation are equipped with flat vacuum vessels made of extruded aluminum using a non-evaporable Getter (NEG) coating to reduce the vacuum pressure bump along the chamber during the operation of the accelerator. After the in-situ activation of the sputtered film by bake-out of the vacuum system the NEG pumps gases such as H2, CO and CO2 while CH4 and noble gases are not pumped. Because a low activation temperature for the NEG is necessary to be compatible with the mechanical limitations of the aluminum alloy, the NEG composition of TiZrV has been chosen. During operation of the ESRF electron storage ring a few hundreds of watts of synchrotron radiation fall on the walls of the ID chambers leading to photodesorption and photo-conditioning. The NEG coating is intended to provide distributed pumping and reduced photodesorption to keep the generation of unwanted Bremsstrahlung radiation following the installation of a new vessel low. The deposit of the NEG coating takes place at a dedicated facility in the ESRF.

  18. Heat transfer from localized absorbing defects to the host coating material in HfO{sub 2}/SiO{sub 2} multilayer systems

    SciTech Connect

    Papernov, S.; Schmid, A.W.

    1997-12-01

    Finite-element analysis was applied in calculating the heat-transfer effects from localized absorbing defects to the host coating material in multilayer HfO{sub 2}/SiO{sub 2} system, irradiated by 1-ns laser pulses. Thermoconductivity was considered the major heat-transfer mechanism. A comparison with high-resolution laser-damage morphology studies carried out by means of atomic-force microscopy allowed estimating peak temperatures reached by the absorbing defects. These peak-temperature values as well as the lateral length scales of the empirically found laser-damage features point toward the importance of radiative energy transfer from the heated defect as the driving mechanism of laser-damage initiation.

  19. High-speed growth of YBa2Cu3O7-δ superconducting films on multilayer-coated Hastelloy C276 tape by laser-assisted MOCVD

    NASA Astrophysics Data System (ADS)

    Zhao, Pei; Ito, Akihiko; Kato, Takeharu; Yokoe, Daisaku; Hirayama, Tsukasa; Goto, Takashi

    2013-05-01

    The high-speed epitaxial growth of YBa2Cu3O7-δ (YBCO) superconducting films on multilayer (CeO2/LaMnO3/MgO/Gd2Zr2O7)-coated Hastelloy C276 tape was demonstrated using laser-assisted metal-organic chemical vapour deposition (laser-assisted MOCVD). The preferred orientation of the YBCO films changed from a-axis to c-axis as the deposition temperature was increased from 769 to 913 K. The c-axis-oriented YBCO film exhibited a high critical temperature of 90 K and a high critical current density of 0.5 MA cm-2 even at a high deposition rate of 55 μm h-1.

  20. 5000 groove/mm multilayer-coated blazed grating with 33percent efficiency in the 3rd order in the EUV wavelength range

    SciTech Connect

    Advanced Light Source; Voronov, Dmitriy L.; Anderson, Erik; Cambie, Rossana; Salmassi, Farhad; Gullikson, Eric; Yashchuk, Valeriy; Padmore, Howard; Ahn, Minseung; Chang, Chih-Hao; Heilmann, Ralf; Schattenburg, Mark

    2009-07-07

    We report on recent progress in developing diffraction gratings which can potentially provide extremely high spectral resolution of 105-106 in the EUV and soft x-ray photon energy ranges. Such a grating was fabricated by deposition of a multilayer on a substrate which consists ofa 6-degree blazed grating with a high groove density. The fabrication of the substrate gratings was based on scanning interference lithography and anisotropic wet etch of silicon single crystals. The optimized fabrication process provided precise control of the grating periodicity, and the grating groove profile, together with very short anti-blazed facets, and near atomically smooth surface blazed facets. The blazed grating coated with 20 Mo/Si bilayers demonstrated a diffraction efficiency in the third order as high as 33percent at an incidence angle of 11? and wavelength of 14.18 nm.

  1. Effect Of The Plasma Deposition Parameters On The Properties Of Ti/TiN Multilayers For Hard Coatings Applications

    SciTech Connect

    Saoula, N.; Henda, K.; Kesri, R.

    2008-09-23

    In this study, we present the effect of the plasma deposition parameters on the mechanical properties of Ti/TiN multilayers. The elaboration of our films has been carried out by RF-Magnetron Sputtering (13.56 MHz) under nitrogen and argon reactive plasma at low pressure. The film depositions have been done on steel substrates. The first step of our study was the optimization of the depositions conditions in order to obtain good quality films. The amount of nitrogen in the sputtering gases being fixed at 10%. The total pressure was set between 2mTorr to 10mTorr. The deposited multilayers were characterized by X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), atomic force microscopy (AFM) and micro-indentation.

  2. Facile incorporation of hydroxyapatite onto an anodized Ti surface via a mussel inspired polydopamine coating

    NASA Astrophysics Data System (ADS)

    Zhe, Wang; Dong, Chaofang; Sefei, Yang; Dawei, Zhang; Kui, Xiao; Xiaogang, Li

    2016-08-01

    Inspired by the porous morphology of anodized Ti and the adhesive versatility of polydopamine (PDA), which can induce apatite mineralization, we fabricated a novel interface by coating a porous anodized TiO2 layer with PDA to rapidly immobilize HA on Ti-based substrates. It was found that the as-prepared PDA/anodized (HD) surface exhibited nanoscale roughness, which possessed an excellent ability to form apatite when immersed in 1.5× simulated body fluid (SBF), as observed by AFM and FE-SEM. The morphology and composition of each layer were further confirmed by XPS, XRD and FTIR. The corrosion resistance of the multilayer was investigated using potentiodynamic polarization curve and electrochemical impedance spectra (EIS) measurements in a 0.9 wt% NaCl solution, the results suggested that the HA/PDA/anodized (HDA) layer increased the corrosion resistance of pure Ti with higher corrosion potential and lower passive current, the surface wettability was also enhanced with the incorporation of HA. In vitro cellular assays showed that the HDA layer stimulated cell attachment and improved the alkaline phosphate (ALP) activity. Overall, the PDA/anodized treatment provided a viable method to quickly integrate HA, and the obtained HDA layer improved both corrosion resistance and biocompatibility of the Ti surface.

  3. Electrochromism and electrocatalysis in viologen polyelectrolyte multilayers

    SciTech Connect

    Stepp, J.; Schlenoff, J.B.

    1997-06-01

    Polyelectrolyte multilayers were constructed from a polyviologen and poly(styrene sulfonate) using an alternating polyion solution deposition technique. In situ absorption spectroscopy showed multilayers to be strongly electrochromic. Oxygen reduction at multilayer-coated conducting glass electrodes was also shown to be facilitated.

  4. Demonstration/Validation of Environmentally-Preferable Coatings for Launch Facilities

    NASA Technical Reports Server (NTRS)

    Lewis, Pattie

    2011-01-01

    Kennedy Space Center (KSC) is responsible for a number of facilities/structures with metallic structural and non-structural components in a highly corrosive environment. Metals require periodic maintenance activity to guard against the insidious effects of corrosion and thus ensure that structures meet or exceed design or performance life. The standard practice for protecting metallic substrates in atmospheric environments is the application of an applied coating system. Applied coating systems work via a variety of methods (barrier, galvanic and/or inhibitor) and adhere to the substrate through a combination of chemical and physical bonds. Maintenance at KSC and other NASA Centers is governed by NASA-STD-50088 (Protective Coating of Carbon Steel, Stainless Steel, and Aluminum on Launch Structures, Facilities, and Ground Support Equipment) which establishes practices for the protective coating of ground support equipment and related facilities used by or for NASA programs and projects. The Standard is for the design of non-flight hardware used to support the operations of receiving, transportation, handling, assembly, inspection, test, checkout, service, and launch of space vehicles and payloads at NASA launch, landing, or retrieval sites. These criteria and practices contained within the Standard may be used for items used at the manufacturing, development, and test sites upstream of the launch, landing, or retrieval sites. The objective of this effort is to demonstrate and validate environmentally-preferable alternatives in accordance with NASA-STD-50088 and KSC requirements which can then be added to the Approved Products List. This Test Protocol contains the critical requirements and tests necessary to qualify alternatives for structural steel applications. These tests were derived from engineering, performance, and operational impact (supportability) requirements defined by a consensus of KSC participants. A Test Report will document the results of the testing

  5. A novel class of potential prion drugs: preliminary in vitro and in vivo data for multilayer coated gold nanoparticles

    NASA Astrophysics Data System (ADS)

    Ai Tran, Hoang Ngoc; Sousa, Fernanda; Moda, Fabio; Mandal, Subhra; Chanana, Munish; Vimercati, Chiara; Morbin, Michela; Krol, Silke; Tagliavini, Fabrizio; Legname, Giuseppe

    2010-12-01

    Gold nanoparticles coated with oppositely charged polyelectrolytes, such as polyallylamine hydrochloride and polystyrenesulfonate, were examined for potential inhibition of prion protein aggregation and prion (PrPSc) conversion and replication. Different coatings, finishing with a positive or negative layer, were tested, and different numbers of layers were investigated for their ability to interact and reduce the accumulation of PrPSc in scrapie prion infected ScGT1 and ScN2a cells. The particles efficiently hampered the accumulation of PrPSc in ScN2a cells and showed curing effects on ScGT1 cells with a nanoparticle concentration in the picomolar range. Finally, incubation periods of prion-infected mice treated with nanomolar concentrations of gold nanoparticles were significantly longer compared to untreated controls.Gold nanoparticles coated with oppositely charged polyelectrolytes, such as polyallylamine hydrochloride and polystyrenesulfonate, were examined for potential inhibition of prion protein aggregation and prion (PrPSc) conversion and replication. Different coatings, finishing with a positive or negative layer, were tested, and different numbers of layers were investigated for their ability to interact and reduce the accumulation of PrPSc in scrapie prion infected ScGT1 and ScN2a cells. The particles efficiently hampered the accumulation of PrPSc in ScN2a cells and showed curing effects on ScGT1 cells with a nanoparticle concentration in the picomolar range. Finally, incubation periods of prion-infected mice treated with nanomolar concentrations of gold nanoparticles were significantly longer compared to untreated controls. Electronic supplementary information (ESI) available: HRTEM image of a 2A coated nanogold particle; Western blot of cell lysate from ScGT1 cells treated with nanoparticles (a) 2A, (b) 2A-46 nm, (c) 5S, and (d) 5S-46 nm. See DOI: 10.1039/c0nr00551g

  6. Facile method for stiff, tough, and strong nanocomposites by direct exfoliation of multilayered graphene into native nanocellulose matrix.

    PubMed

    Malho, Jani-Markus; Laaksonen, Päivi; Walther, Andreas; Ikkala, Olli; Linder, Markus B

    2012-04-01

    Nanofibrillated cellulose (NFC) is a natural fibrillar material with exceptionally high mechanical properties. It has, however, been exceedingly difficult to achieve nanocomposites with drastically improved mechanical properties by dispersing NFC as random networks to polymer matrices, even using compatibilization. We show nanocomposites consisting of aligned assemblies of multilayered graphene and NFC with excellent tensile mechanical properties without any surface treatments. The optimum composition was found at 1.25 wt % graphene multilayers, giving a Young's modulus of 16.9 GPa, ultimate strength of 351 MPa, strain of 12%, and work-of-fracture of 22.3 MJ m(-3). This combines high strength with relatively high toughness and is obtained by direct exfoliation of graphite within aqueous hydrogels of NFC where an optimum sonication power is described. The results suggest the existence of an attractive interaction between multilayered graphene flakes and cellulose. Aligned assemblies are obtained by removal of water by filtration. The concept can be beneficial for applications because it results in high mechanical properties by a simple and environmentally green process. PMID:22372697

  7. Coatings.

    ERIC Educational Resources Information Center

    Anderson, Dennis G.

    1989-01-01

    This review covers analytical techniques applicable to the examination of coatings, raw materials, and substrates upon which coatings are placed. Techniques include chemical and electrochemical methods, chromatography, spectroscopy, thermal analysis, microscopy, and miscellaneous techniques. (MVL)

  8. Study and modeling of the ironing process on a multi-layered polymer coated low-carbon steel

    NASA Astrophysics Data System (ADS)

    Selles Canto, Miguel Angel

    The ironing process is the most crucial step in the manufacture of cans. Sheet steel covered by three polymer layers can be used as the starting material, but this coating must neither break nor fail in any manner in order to be considered as a viable and effective alternative to traditional practice. During ironing, the deformations are severe and high pressures exist at the tool-workpiece interface. Thickness reductions inherent in ironing require a large amount of surface generation. Deterioration of the coating in this delicate operation might enable direct contact of the stored food or drink with the metal. As can be appreciated, the key to the use of polymer-coated steel sheets in the manufacture of cans lies in the survival of these layers during the ironing process. Another important issue is the roughness of the newly-generated surface, because it should be possible to decorate the can without any difficulty. Changing the traditional manufacture of metallic containers such as cans and using this new coated material permits great reduction in environmental contaminants produced as a result of avoiding the formation of Volatile Organic Compounds (VOCs) during the manufacture of the polymer layers. This reduction is even greater because of not using additional lubricants due to the self-lubricanting property of the solid polymer coating layers during the drawing process. These objectives, together with the improvement of the mechanical characteristics and the adhesion of the painting or decorative priming, are realized by the use of the proposed material. In the existing bibliography about ironing processes on coated materials, some authors propose the use of the Upper Bound Theorem for modeling the material behavior. The present research shows for the first time the modeling of the ironing process on a three-layer polymer coated material. In addition, it takes into account the cases in which successful ironing is produced and those in which ones the ironing

  9. Space environmental effects on coated optics

    NASA Technical Reports Server (NTRS)

    Donovan, T. M.; Bennett, J. M.; Gyetvay, S. R.

    1991-01-01

    Several multilayer coated mirror designs developed for potential space applications were tested on the Long Duration Exposure Facility (LDEF) along with single layer witness coatings deposited on fused silica and a coated CaF2 window. Performance requirements included high mirror reflectivity, low absorption, low scatter, environmental durability, and radiation hardness. The designs were selected in screening tests using combined electron, proton, and simulated solar UV radiation. The purpose of the space test was to validate the above test results and determine the effects of atomic oxygen and contamination on mirror performance.

  10. Coatings for large-area low-cost solar concentrators and reflectors

    SciTech Connect

    Martin, P.M.; Affinito, J.D.; Gross, M.E.; Bennett, W.D.

    1994-07-01

    Seven years ago, Pacific Northwest Laboratory constructed a large-optics coating facility to develop and fabricate high-performance multilayer laser-mirror coatings on large substrates. With the reduction of DoD funding for the development of optical coatings for large optics, new applications for this chamber were sought. In addition to new DoD applications, the facility is now being used to fabricate multilayer enhanced-metal reflectors for low-cost large-area solar concentrators using both magnetron-sputtered metal and dielectric coatings, with future extension to vacuum-evaporated polymer coatings. Other new applications include: Ti/Ti:Al lamellar composites on flexible webs; EMI cladding for heater wire; EMI-shielding coatings on flexible webs; microwave-absorbing coatings on flexible webs; heat mirrors; bulk micromachining; and protective coatings on cylindrical substrates and webs. The facility has also been established as a DoD user facility for development and experimentation in large-area optical coatings. This paper describes important changes in the large-optics coating chamber and additional deposition equipment that has been added to pursue these new non-DoD technological areas. Solar reflectors and the resulting new coatings will be described. Future work and new technological areas being pursued will also be discussed.

  11. A novel class of potential prion drugs: preliminary in vitro and in vivo data for multilayer coated gold nanoparticles.

    PubMed

    Ai Tran, Hoang Ngoc; Sousa, Fernanda; Moda, Fabio; Mandal, Subhra; Chanana, Munish; Vimercati, Chiara; Morbin, Michela; Krol, Silke; Tagliavini, Fabrizio; Legname, Giuseppe

    2010-12-01

    Gold nanoparticles coated with oppositely charged polyelectrolytes, such as polyallylamine hydrochloride and polystyrenesulfonate, were examined for potential inhibition of prion protein aggregation and prion (PrPSc) conversion and replication. Different coatings, finishing with a positive or negative layer, were tested, and different numbers of layers were investigated for their ability to interact and reduce the accumulation of PrPSc in scrapie prion infected ScGT1 and ScN2a cells. The particles efficiently hampered the accumulation of PrPSc in ScN2a cells and showed curing effects on ScGT1 cells with a nanoparticle concentration in the picomolar range. Finally, incubation periods of prion-infected mice treated with nanomolar concentrations of gold nanoparticles were significantly longer compared to untreated controls. PMID:20944860

  12. Synthesis and characterization of titanium carbide, titanium boron carbonitride, titanium boride/titanium carbide and titanium carbide/chromium carbide multilayer coatings by reactive and ion beam assisted, electron beam-physical vapor deposition (EB-PVD)

    NASA Astrophysics Data System (ADS)

    Wolfe, Douglas Edward

    The purpose of the present work was to investigate the synthesis of titanium carbide, TiBCN, TiB2/TiC and TiC/Cr23C6 multilayer coatings by several methods of electron beam-physical vapor deposition (EB-PVD) and examine the affects of various processing parameters on the properties and microstructures of the coatings. TiC was successfully deposited by reactive ion beam assisted (RIBA), EB-PVD and the results were compared to various titanium carbide coatings deposited by a variety of techniques. The affects of substrate temperature and ion beam current density were correlated with composition, hardness, changes in the lattice parameter, degree of crystallographic texture, residual stress, surface morphology, and microstructure. The average Vicker's hardness number was found to increase with increasing ion beam current density and increase over the substrate temperature range of 250°C to 650°C. The average Vicker's hardness number decreased at a substrate temperature of 750°C as a result of texturing and microstructure. The present investigation shows that the average Vicker's hardness number is not only a function of the composition, but also the microstructure including the degree of crystallographic texture. TiB2/TiC multilayer coatings were deposited by argon ion beam assisted, EB-PVD with varying number of total layers to two different film thicknesses under slightly different deposition conditions. In both cases, the hardness of the coatings increased with increasing number of total layers. The adhesion of the coatings ranged from 30 N to 50 N, with the better adhesion values obtained with the thinner coatings. The crystallographic texture coefficients of both the TiC and TiB2 layers were found to change with increasing number of total layers. The multilayer design was found to significantly affect the microstructure and grain size of the deposited coatings. The fracture toughness was found to decrease with increasing number of total layers and was

  13. Development of Ni-based multilayers for future focusing soft gamma ray telescopes

    NASA Astrophysics Data System (ADS)

    Girou, David A.; Massahi, Sonny; Sleire, Erlend K.; Jakobsen, Anders C.; Christensen, Finn E.

    2015-09-01

    Ni-based multilayers are a possible solution to extend the upper energy range of hard X-ray focusing telescopes currently limited at ≈79:4 keV by the Pt-K absorption edge. In this study 10 bilayers multilayers with a constant bilayer thickness were coated with the DC magnetron sputtering facility at DTU Space, characterized at 8 keV using X-ray reectometry and fitted using the IMD software. Ni/C multilayers were found to have a mean interface roughness ≈ 1:5 times lower than Ni/B4C multilayers. Reactive sputtering with ≈ 76% of Ar and ≈ 24% of N2 reduced the mean interface roughness by a factor of ≈ 1:7. It also increased the coating rate of C by a factor of ≈ 3:1 and lead to a coating process going ≈ 1:6 times faster. Honeycomb collimation proved to limit the increase in mean interface roughness when the bilayer thickness increases at the price of a coating process going ≈ 1:9 times longer than with separator plates. Finally a Ni/C 150 bilayers depth-graded mutilayer was coated with reactive sputtering and honeycomb collimation and then characterized from 10 keV to 150 keV. It showed 10% reectance up to 85 keV.

  14. Carbon-Coated Gold Nanorods: A Facile Route to Biocompatible Materials for Photothermal Applications.

    PubMed

    Kaneti, Yusuf Valentino; Chen, Chuyang; Liu, Minsu; Wang, Xiaochun; Yang, Jia Lin; Taylor, Robert Allen; Jiang, Xuchuan; Yu, Aibing

    2015-11-25

    Gold nanorods and their core-shell nanocomposites have been widely studied because of their well-defined anisotropy and unique optical properties and applications. This study demonstrates a facile hydrothermal synthesis strategy for generating carbon coating on gold nanorods (AuNRs@C) under mild conditions (<200 °C), where the carbon shell is composed of polymerized sugar molecules (glucose). The structure and composition of the produced core-shell nanocomposites were characterized using advanced microscopic and spectroscopic techniques. The functional properties, particularly the photothermal and biocompatibility properties of the produced AuNRs@C, were quantified to assess their potential in photothermal hyperthermia. These AuNRs@C were tested in vitro (under representative treatment conditions) using near-infrared (NIR) light irradiation. It was found that the AuNRs produced here exhibit exemplary heat generation capability. Temperature changes of 10.5, 9, and 8 °C for AuNRs@C were observed with carbon shell thicknesses of 10, 17, and 25 nm, respectively, at a concentration of 50 μM, after 600 s of irradiation with a laser power of 0.17 W/cm(2). In addition, the synthesized AuNRs@C also exhibit good biocompatibility toward two soft tissue sarcoma cell lines (HT1080, a fibrosarcoma; and GCT, a fibrous histiocytoma). The cell viability study shows that AuNRs@C (at a concentration of <0.1 mg/mL) core-shell particles induce significantly lower cytotoxicity on both HT1080 and GCT cell lines, as compared with cetyltrimethylammonium bromide (CTAB)-capped AuNRs. Furthermore, similar to PEG-modified AuNRs, they are also safe to both HT1080 and GCT cell lines. This biocompatibility results from a surface full of -OH or -COH groups, which are suitable for linking and are nontoxic Therefore, the AuNRs@C represent a viable alternative to PEG-coated AuNRs for facile synthesis and improved photothermal conversion. Overall, these findings open up a new class of carbon-coated

  15. Tribological and cutting behavior of silicon nitride tools coated with monolayer- and multilayer-microcrystalline HFCVD diamond films

    NASA Astrophysics Data System (ADS)

    Chen, Naichao; Shen, Bin; Yang, Guodong; Sun, Fanghong

    2013-01-01

    Monolayer-micrometric (MN-MCD), monolayer-submicrometric (MN-SMCD) and multilayer-micrometric (MT-MCD) diamond films are grown on silicon nitride substrates by hot filament chemical vapor deposition (HFCVD) technique. The as-deposited diamond films are characterized with scanning electron microscope (SEM), X-ray diffraction (XRD), energy-dispersive X-ray spectrometer (EDS), Raman spectrum and 3D surface topography. Tribological properties are assessed by the sliding tests using a reciprocal motion ball-on-flat (BOF) configuration. The friction coefficients are measured as 0.126 for the MN-MCD films, 0.076 for the MN-SMCD films and 0.071 for the MT-MCD films during dry sliding against silicon nitride counterface. The different carbon content of the films may result in the visible diminution of friction coefficient for the MT-MCD films relative to the MN-MCD films. The results show that the MN-MCD and MT-MCD films present the much higher wear resistance than the MN-SMCD films. Meanwhile, the cutting performances of as-deposited diamond films are evaluated by machining aluminum-silicon alloy material. The experimental results show that the MT-MCD insert presents the best behavior regarding the tool wear.

  16. Preparation and Evaluation of Diclofenac Sodium Tablet Coated with Polyelectrolyte Multilayer Film Using Hypromellose Acetate Succinate and Polymethacrylates for pH-Dependent, Modified Release Drug Delivery.

    PubMed

    Jeganathan, Balamurugan; Prakya, Vijayalakshmi; Deshmukh, Abhijit

    2016-06-01

    Polyelectrolyte multilayer (PEM) film formed due to the electrostatic interaction between oppositely charged polyelectrolytes is of considerable interest because of their potential applications as both drug carriers and surface-modifying agents. In this study, in vitro studies were carried out on polyelectrolyte complexes formulated with Eudragit E (EE) and hypromellose acetate succinate (HPMCAS). The complexes of EE and HPMCAS were formulated by non-stoichiometric method. The prepared IPCs were investigated using Fourier transform infrared spectroscopy. Diclofenac sodium (DS) tablets were prepared and were coated with polymer solution of HPMCAS and EE to achieve pH-dependent and sustained-release tablets. Tablets were evaluated for their physical characteristics and in vitro drug release. The results of pharmacokinetic studies in rabbits showed that the selected formulation (F6) exhibited a delayed peak plasma concentration and marked sustained-release effect of drug in the in vivo drug release in comparison with marketed tablet. The suitable combination of PEM film based on EE and HPMCAS demonstrated potential candidate for targeted release of DS in the lower part of the gastrointestinal (GI) tract. PMID:26283195

  17. Facile, high efficiency immobilization of lipase enzyme on magnetic iron oxide nanoparticles via a biomimetic coating

    PubMed Central

    2011-01-01

    Background Immobilization of lipase on appropriate solid supports is one way to improve their stability and activity, and can be reused for large scale applications. A sample, cost- effective and high loading capacity method is still challenging. Results A facile method of lipase immobilization was developed in this study, by the use of polydopamine coated magnetic nanoparticles (PD-MNPs). Under optimal conditions, 73.9% of the available lipase was immobilized on PD-MNPs, yielding a lipase loading capacity as high as 429 mg/g. Enzyme assays revealed that lipase immobilized on PD-MNPs displayed enhanced pH and thermal stability compared to free lipase. Furthermore, lipase immobilized on PD-MNPs was easily isolated from the reaction medium by magnetic separation and retained more than 70% of initial activity after 21 repeated cycles of enzyme reaction followed by magnetic separation. Conclusions Immobilization of enzyme onto magnetic iron oxide nanoparticles via poly-dopamine film is economical, facile and efficient. PMID:21649934

  18. New facilities for Al+MgF2 coating for 2-m class mirrors for UV

    NASA Astrophysics Data System (ADS)

    Zhupanov, Valery; Vlasenko, Oleg; Sachkov, Mikhail; Fedoseev, Viktor

    2014-07-01

    above 120 nm [19] with reflectivity more than 90% at wavelength longer than 200 nm, but the spectral range from 700 to 900 nm, where it's lowest value of reflectivity is 86% at 850 nm. That makes aluminum one of the best coating materials in the creating a mirror for operations in vacuum ultraviolet. However, the aluminum membrane is prone to oxidization, so applying the protecting coating is essential. Magnesium fluoride is one of the few materials transparent in the UV range [20]. In this contribution, capacities of new facilities in LUCH company that are created for World Space Observatory - Ultraviolet (WSO-UV) project are described in Section 2, the process of applying Al + MgF2 coating workout is presented in Section 3, results of applying Al+MgF2 coating for WSO-UV primary mirror are presented in Section 4 and a brief summary are provided in the concluding Section 5.

  19. Facile transition from hydrophilicity to superhydrophilicity and superhydrophobicity on aluminum alloy surface by simple acid etching and polymer coating

    NASA Astrophysics Data System (ADS)

    Liu, Wenyong; Sun, Linyu; Luo, Yuting; Wu, Ruomei; Jiang, Haiyun; Chen, Yi; Zeng, Guangsheng; Liu, Yuejun

    2013-09-01

    The transition from the hydrophilic surface to the superhydrophilic and superhydrophobic surface on aluminum alloy via hydrochloric acid etching and polymer coating was investigated by contact angle (CA) measurements and scanning electron microscope (SEM). The effects of etching and polymer coating on the surface were discussed. The results showed that a superhydrophilic surface was facilely obtained after acid etching for 20 min and a superhydrophobic surface was readily fabricated by polypropylene (PP) coating after acid etching. When the etching time was 30 min, the CA was up to 157̊. By contrast, two other polymers of polystyrene (PS) and polypropylene grafting maleic anhydride (PP-g-MAH) were used to coat the aluminum alloy surface after acid etching. The results showed that the CA was up to 159̊ by coating PP-g-MAH, while the CA was only 141̊ by coating PS. By modifying the surface with the silane coupling agent before PP coating, the durability and solvent resistance performance of the superhydrophobic surface was further improved. The micro-nano concave-convex structures of the superhydrophilic surface and the superhydrophobic surface were further confirmed by scanning electron microscope (SEM). Combined with the natural hydrophilicity of aluminum alloy, the rough micro-nano structures of the surface led to the superhydrophilicity of the aluminum alloy surface, while the rough surface structures led to the superhydrophobicity of the aluminum alloy surface by combination with the material of PP with the low surface free energy.

  20. Facile microemulsion route to coat carbonized glucose on upconversion nanocrystals as high luminescence and biocompatible cell-imaging probes.

    PubMed

    Li, Zhengquan; Guo, Huichen; Qian, Haisheng; Hu, Yong

    2010-08-01

    Surface modification of lanthanide-doped upconversion nanocrystals is crucial to make them useful for various biological applications. Unfortunately, the current methods available to achieve a desirable surface exhibiting both high luminescence and good biocompatibility are limited. In this work, we present a facile microemulsion route to coat carbonized glucose on hydrophobic NaYF(4) nanocrystals. Owing to the particular structure of the carbonized shell, glucose coating on these UCNs is not only able to preserve strong fluorescence from the core nanocrystals, but it also confers good water solubility and bears various functional groups for conjugating to biomolecules. Compared to 10 nm silica-coated UCNs, these glucose-coated nanocrystals possess better cell biocompatibility, and can be rapidly internalized into cells. Such unique features of glucose-coated UCNs may find promising applications in imaging, diagnosis and therapeutic purposes. Besides, this facile surface-modification route has the potential to be extended to a broad range of other hydrophobic nanocrystals. PMID:20634574

  1. Multilayered Graphene in Microwaves

    NASA Astrophysics Data System (ADS)

    Kuzhir, P.; Volynets, N.; Maksimenko, S.; Kaplas, T.; Svirko, Yu.

    2013-05-01

    We report on the experimental study of electromagnetic (EM) properties of multilayered graphene in Ka-band synthesized by catalytic chemical vapor deposition (CVD) process in between nanometrically thin Cu catalyst film and dielectric (SiO2) substrate. The quality of the produced multilayered graphene samples were monitored by Raman spectroscopy. The thickness of graphene films was controlled by atomic force microscopy (AFM) and was found to be a few nanometers (up to 5 nm). We discovered, that the fabricated graphene provided remarkably high EM shielding efficiency caused by absorption losses at the level of 35-43% of incident power. Being highly conductive at room temperature, multi-layer graphene emerges as a promising material for manufacturing ultrathin microwave coatings to be used in aerospace applications.

  2. Multilayer Hydrophilic Poly(phenol-formaldehyde resin)-Coated Magnetic Graphene for Boronic Acid Immobilization as a Novel Matrix for Glycoproteome Analysis.

    PubMed

    Wang, Jiaxi; Wang, Yanan; Gao, Mingxia; Zhang, Xiangmin; Yang, Pengyuan

    2015-07-29

    Capturing glycopeptides selectively and efficiently from mixed biological samples has always been critical for comprehensive and in-depth glycoproteomics analysis, but the lack of materials with superior capture capacity and high specificity still makes it a challenge. In this work, we introduce a way first to synthesize a novel boronic-acid-functionalized magnetic graphene@phenolic-formaldehyde resin multilayer composites via a facile process. The as-prepared composites gathered excellent characters of large specific surface area and strong magnetic responsiveness of magnetic graphene, biocompatibility of resin, and enhanced affinity properties of boronic acid. Furthermore, the functional graphene composites were shown to have low detection limit (1 fmol) and good selectivity, even when the background nonglycopeptides has a concentration 100 fold higher. Additionally, enrichment efficiency of the composites was still retained after being used repeatedly (at least three times). Better yet, the practical applicability of this approach was evaluated by the enrichment of human serum with a low sample volume of 1 μL. All the results have illustrated that the magG@PF@APB has a great potential in glycoproteome analysis of complex biological samples. PMID:26161682

  3. Improved equipment cleaning in coated and laminated substrate manufacturing facilities (phase 2). Final report, November 1992-November 1993

    SciTech Connect

    Vitas, J.B.; McMinn, B.W.; McMinn, G.D.

    1995-07-01

    The report discusses EPA efforts to identify, demonstrate, and publish pollution prevention information and opportunites for equipment cleaning for the coated and laminated substrate manufacturing industry. It summarizes initial data collected and summarized during industry observation and demonstration visits. Demonstration took place at a small batch facility and a small dedicated-line facility. The focus at the batch facility was to decrease the number of solvents used for cleaning, reducing the quantity of material used for cleaning, and standardizing cleaning practices. While consolidating from three chemicals (toluene, xylene, and methyl ethyl ketone) to a single solvent for cleaning may not be feasible because of the varied product mix, the facility could eliminate one solvent, thereby reducing handling and disposal costs.

  4. Facile one-step coating approach to magnetic submicron particles with poly(ethylene glycol) coats and abundant accessible carboxyl groups

    PubMed Central

    Long, Gaobo; Yang, Xiao-lan; Zhang, Yi; Pu, Jun; Liu, Lin; Liu, Hong-bo; Li, Yuan-li; Liao, Fei

    2013-01-01

    Purpose Magnetic submicron particles (MSPs) are pivotal biomaterials for magnetic separations in bioanalyses, but their preparation remains a technical challenge. In this report, a facile one-step coating approach to MSPs suitable for magnetic separations was investigated. Methods Polyethylene glycol) (PEG) was derived into PEG-bis-(maleic monoester) and maleic monoester-PEG-succinic monoester as the monomers. Magnetofluids were prepared via chemical co-precipitation and dispersion with the monomers. MSPs were prepared via one-step coating of magnetofluids in a water-in-oil microemulsion system of aerosol-OT and heptane by radical co-polymerization of such monomers. Results The resulting MSPs contained abundant carboxyl groups, exhibited negligible nonspecific adsorption of common substances and excellent suspension stability, appeared as irregular particles by electronic microscopy, and had submicron sizes of broad distribution by laser scattering. Saturation magnetizations and average particle sizes were affected mainly by the quantities of monomers used for coating magnetofluids, and steric hindrance around carboxyl groups was alleviated by the use of longer monomers of one polymerizable bond for coating. After optimizations, MSPs bearing saturation magnetizations over 46 emu/g, average sizes of 0.32 μm, and titrated carboxyl groups of about 0.21 mmol/g were obtained. After the activation of carboxyl groups on MSPs into N-hydroxysuccinimide ester, biotin was immobilized on MSPs and the resulting biotin-functionalized MSPs isolated the conjugate of streptavidin and alkaline phosphatase at about 2.1 mg/g MSPs; streptavidin was immobilized at about 10 mg/g MSPs and retained 81% ± 18% (n = 5) of the specific activity of the free form. Conclusion The facile approach effectively prepares MSPs for magnetic separations. PMID:23589687

  5. A facile and controllable strategy to synthesize Au-Ag alloy nanoparticles within polyelectrolyte multilayer nanoreactors upon thermal reduction.

    PubMed

    Shang, Li; Jin, Lihua; Guo, Shaojun; Zhai, Junfeng; Dong, Shaojun

    2010-05-01

    A new synthesis strategy has been developed for the preparation of bimetallic gold-silver (Au-Ag) alloy nanoparticles by the virtue of polyelectrolyte multilayer (PEM) nanoreactors. By controlling the assembly conditions, gold and silver ions can be effectively loaded onto the PEM composed of polyethylenimine (PEI) and poly(acrylic acid) (PAA) simultaneously. Upon further thermal treatment, Au-Ag alloy nanoparticles with sizes of ca. 3.8 nm formed in the PEM, which were characterized in detail by UV-vis absorption spectroscopy, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and energy-dispersive X-ray (EDX) analysis. Appearance of a single plasmon band in the visible region and lack of apparent core-shell structures in the TEM images confirm the formation of homogeneous Au-Ag alloy nanoparticles. In addition, the surface plasmon absorption band of the Au-Ag alloy nanoparticles shows linear blue-shift with increasing Ag content, which also supported the formation of alloy nanoparticles. Several key parameters of the present strategy have been investigated, which showed that pH of both the assembly solution and gold salt solution and the choice of polymers for constructing PEM, as well as the reduction approach, all played an important role in successfully synthesizing bimetallic Au-Ag nanoparticles. The formation mechanism of alloy nanoparticles has also been discussed based on the spectral evolution during the thermal reduction. PMID:20017511

  6. Facile synthesis of multilayer-like Si thin film as high-performance anode materials for lithium-ion batteries

    NASA Astrophysics Data System (ADS)

    Wang, Mingxu; Geng, Zhongrong

    2016-05-01

    For the silicon anodes in lithium-ion batteries, it is well known that the enormous volumetric expansion/contraction is also the mainly reason for the capacity fading. In this manuscript, a new kind of Si thin films was prepared with a radio frequency magnetron sputtering method. By using a periodic modulation negative bias on the substrate, a density-modulated multilayer-like silicon thin films with different layer densities were used as anode materials of lithium-ion batteries, and which displayed a high capacity and stable cycling performances. The reason for the charming electrochemical performances may be owned to the particular density modulated microstructure of the Si thin films. It is conjectured that the lower density can as compliant layers and which provided the volume for the higher-density layer expansion in the process of the lithiation/delithiation. In contrast to the conventional silicon anodes, the density modulated microstructure in this work could exploit a new approach to silicon thin-film anode materials with outstanding electrochemical properties and mechanical stability. And these reports may be provide a new way to prepare the Si thin films for the high-energy, safe, and low-cost batteries.

  7. Pulsed-Plasma Physical Vapor Deposition Approach Toward the Facile Synthesis of Multilayer and Monolayer Graphene for Anticoagulation Applications.

    PubMed

    Vijayaraghavan, Rajani K; Gaman, Cezar; Jose, Bincy; McCoy, Anthony P; Cafolla, Tony; McNally, Patrick J; Daniels, Stephen

    2016-02-01

    We demonstrate the growth of multilayer and single-layer graphene on copper foil using bipolar pulsed direct current (DC) magnetron sputtering of a graphite target in pure argon atmosphere. Single-layer graphene (SG) and few-layer graphene (FLG) films are deposited at temperatures ranging from 700 °C to 920 °C within <30 min. We find that the deposition and post-deposition annealing temperatures influence the layer thickness and quality of the graphene films formed. The films were characterized using atomic force microscopy (AFM), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and optical transmission spectroscopy techniques. Based on the above studies, a diffusion-controlled mechanism was proposed for the graphene growth. A single-step whole blood assay was used to investigate the anticoagulant activity of graphene surfaces. Platelet adhesion, activation, and morphological changes on the graphene/glass surfaces, compared to bare glass, were analyzed using fluorescence microscopy and SEM techniques. We have found significant suppression of the platelet adhesion, activation, and aggregation on the graphene-covered surfaces, compared to the bare glass, indicating the anticoagulant activity of the deposited graphene films. Our production technique represents an industrially relevant method for the growth of SG and FLG for various applications including the biomedical field. PMID:26808203

  8. Multilayer Dye Adsorption in Activated Carbons-Facile Approach to Exploit Vacant Sites and Interlayer Charge Interaction.

    PubMed

    Hadi, Pejman; Guo, Jiaxin; Barford, John; McKay, Gordon

    2016-05-17

    Altering the textural properties of activated carbons (ACs) via physicochemical techniques to increase their specific surface area and/or to manipulate their pore size is a common practice to enhance their adsorption capacity. Instead, this study proposes the utilization of the vacant sites remaining unoccupied after dye uptake saturation by removing the steric hindrance and same-charge repulsion phenomena via multilayer adsorption. Herein, it has been shown that the adsorption capacity of the fresh AC is a direct function of the dye molecular size. As the cross-sectional area of the dye molecule increases, the steric hindrance effect exerted on the neighboring adsorbed molecules increases, and the geometrical packing efficiency is constrained. Thus, ACs saturated with larger dye molecules render higher concentrations of vacant adsorption sites which can accommodate an additional layer of dye molecules on the exhausted adsorbent through interlayer attractive forces. The second layer adsorption capacity (60-200 mg·g(-1)) has been demonstrated to have a linear relationship with the uncovered surface area of the exhausted AC, which is, in turn, inversely proportional to the adsorbate molecular size. Unlike the second layer adsorption, the third layer adsorption is a direct function of the charge density of the second layer. PMID:27088796

  9. Antimicrobial polypeptide multilayer nanocoatings.

    PubMed

    Rudra, Jai S; Dave, Komal; Haynie, Donald T

    2006-01-01

    A multilayer coating (or film) of nanometer-thick layers can be made by sequential adsorption of oppositely charged polyelectrolytes on a solid support. The method is known as layer-by-layer assembly (LBL). No special apparatus is required for LBL and nanofilms can be prepared under mild, physiological conditions. A multilayer nanofilm in which at least one of the constituent species is a polypeptide is a polypeptide multilayer nanofilm. The present work was aimed at assessing whether polypeptide multilayer nanofilms with specific antimicrobial properties could be prepared by incorporation of a known antimicrobial agent in the film structure, in this case the edible protein hen egg white lysozyme (HEWL). The chicken enzyme is widely employed as a human food preservative. An advantage of LBL in this context is that the nanofilm is fabricated directly on the surface of interest, eliminating the need to incorporate the antimicrobial in other packaging materials. Here, nanofilms were made of poly(L-glutamic acid) (PLGA), which is highly negatively charged in the mildly acidic pH range, and HEWL, which has a high net positive charge at acidic pH. We show that PLGA/HEWL nanofilms inhibit growth of the model microbe Microccocus luteus in the surrounding liquid medium. The amount of HEWL released from PLGA/HEWL films depends on the number of HEWL layers and therefore on the total quantity of HEWL in the films. This initial study provides a sketch of the scope for further development of LBL in the area of antimicrobial polypeptide multilayer films. Potential applications of such films include strategies for food preservation and coatings for implant devices. PMID:17176751

  10. Facile Synthesis of Smart Nanocontainers as Key Components for Construction of Self-Healing Coating with Superhydrophobic Surfaces.

    PubMed

    Liang, Yi; Wang, MingDong; Wang, Cheng; Feng, Jing; Li, JianSheng; Wang, LianJun; Fu, JiaJun

    2016-12-01

    SiO2-imidazoline nanocomposites (SiO2-IMI) owning high loading capacity of corrosion inhibitor, 1-hexadecyl-3-methylimidazolium bromide (HMID), and a special acid/alkali dual-stimuli-accelerated release property have been synthesized via a one-step modified Stöber method. SiO2-IMI were uniformly distributed into the hydrophobic SiO2 sol to construct "host"-"guest" feedback active coating with a superhydrophobic surface (SiO2-IMI@SHSC) on aluminium alloy, AA2024, by dip-coating technique. SiO2-IMI as "guest" components have good compatibility with "host" sol-gel coating, and more importantly, once localized corrosion occurs on the surface of AA2024, SiO2-IMI can simultaneously respond to the increase in environmental pH around corrosive micro-cathodic regions and decrease in pH near micro-anodic regions, promptly releasing HMID to form a compact molecular film on the damaged surface, inhibiting corrosion spread and executing a self-healing function. The scanning vibrating electrode technique (SVET) was applied to illustrate the suppression process of cathodic/anodic corrosion activities. Furthermore, benefiting from the superhydrophobic surface, SiO2-IMI@SHSC remained its protective ability after immersion in 0.5 M NaCl solution for 35 days, which is far superior to the conventional sol-gel coating with the same coating thickness. The facile fabrication method of SiO2-IMI simplifies the construction procedure of SiO2-IMI@SHSC, which have great potential to replace non-environmental chromate conversion coatings for practical use. PMID:27121439

  11. Facile Synthesis of Smart Nanocontainers as Key Components for Construction of Self-Healing Coating with Superhydrophobic Surfaces

    NASA Astrophysics Data System (ADS)

    Liang, Yi; Wang, MingDong; Wang, Cheng; Feng, Jing; Li, JianSheng; Wang, LianJun; Fu, JiaJun

    2016-04-01

    SiO2-imidazoline nanocomposites (SiO2-IMI) owning high loading capacity of corrosion inhibitor, 1-hexadecyl-3-methylimidazolium bromide (HMID), and a special acid/alkali dual-stimuli-accelerated release property have been synthesized via a one-step modified Stöber method. SiO2-IMI were uniformly distributed into the hydrophobic SiO2 sol to construct "host"-"guest" feedback active coating with a superhydrophobic surface (SiO2-IMI@SHSC) on aluminium alloy, AA2024, by dip-coating technique. SiO2-IMI as "guest" components have good compatibility with "host" sol-gel coating, and more importantly, once localized corrosion occurs on the surface of AA2024, SiO2-IMI can simultaneously respond to the increase in environmental pH around corrosive micro-cathodic regions and decrease in pH near micro-anodic regions, promptly releasing HMID to form a compact molecular film on the damaged surface, inhibiting corrosion spread and executing a self-healing function. The scanning vibrating electrode technique (SVET) was applied to illustrate the suppression process of cathodic/anodic corrosion activities. Furthermore, benefiting from the superhydrophobic surface, SiO2-IMI@SHSC remained its protective ability after immersion in 0.5 M NaCl solution for 35 days, which is far superior to the conventional sol-gel coating with the same coating thickness. The facile fabrication method of SiO2-IMI simplifies the construction procedure of SiO2-IMI@SHSC, which have great potential to replace non-environmental chromate conversion coatings for practical use.

  12. Tunable photonic multilayer sensors from photo-crosslinkable polymers

    NASA Astrophysics Data System (ADS)

    Chiappelli, Maria; Hayward, Ryan

    2014-03-01

    The fabrication of tunable photonic multilayer sensors from stimuli-responsive, photo-crosslinkable polymers will be described. Benzophenone is covalently incorporated as a pendent photo-crosslinker, allowing for facile preparation of multilayer films by sequential spin-coating and crosslinking processes. Copolymer chemistries and layer thicknesses are selected to provide robust multilayer sensors which can show color changes across nearly the full visible spectrum due to the specific stimulus-responsive nature of the hydrated film stack. We will describe how this approach is extended to alternative sensor designs by tailoring the thickness and chemistry of each layer independently, allowing for the preparation of sensors which depend not only on the shift in wavelength of a reflectance peak, but also on the transition between Bragg mirrors and filters. Device design is optimized by photo-patterning sensor arrays on a single substrate, providing more efficient fabrication time as well as multi-functional sensors. Finally, radiation-sensitive multilayers, designed by choosing polymers which will preferentially degrade or crosslink under ionizing radiation, will also be described.

  13. High efficiency carbon-based multilayers for LAMP at 250 eV

    NASA Astrophysics Data System (ADS)

    Wen, Mingwu; Huang, Qiushi; She, Rui; Jiang, Li; Zhang, Zhong; Wang, Zhanshan; Feng, Hua; Spiga, Daniele; Giglia, Angelo

    2015-09-01

    X-ray reflection near the Brewster's angle by multilayer mirrors can be used to detect the polarization from X-ray sources. The photon emission spectra from some isolated neutron stars and AGN/blazars etc. show that their emission is peaked at low energies near 250eV, which is just below carbon K-absorption edge. The Lightweight Asymmetry and Magnetism Probe (LAMP) is proposed as a micro-satellite mission dedicated for astronomical X-ray polarimetry working at 250 eV and is currently under early phase study. Co/C multilayers are selected and designed at the energy near 250eV with a grazing incident angle of 45°. The carbon layer thickness ratio is optimized to get the highest integral reflectivity which means larger effective signals in the astrophysics observation. The multilayer coatings were manufactured by direct current magnetron sputtering on D263 glasses and electroformed nickels and characterized using Grazing incidence X-ray reflectometry at 8keV. Reactive sputtering with 4%, 6% and 8% nitrogen were used to improve the Co/C multilayer interfaces respectively. Reflectivity for s-polarization and p-polarization light was measured at BEAR beamline in Elettra synchtron facility. Co/C multilayer deposited with 6% nitrogen exhibits the best performance comparing to other multilayers with different nitrogen content.

  14. A facile and general route to synthesize silica-coated SERS tags with the enhanced signal intensity

    NASA Astrophysics Data System (ADS)

    Zhang, Youlin; Li, Xiaokun; Xue, Bin; Kong, Xianggui; Liu, Xiaomin; Tu, Langping; Chang, Yulei

    2015-10-01

    Silica-coated SERS tags have been attracting greater attention in recent years. However, the reported methods to synthesize these tags are tedious, and often subjected to the limited signal intensity. Here, we report a facile and general method to prepare the silica-coated Ag SERS tags with the enhanced signal intensity by no introducing the primers. This approach mainly depends on the colloidal stability of the Ag NPs in alcohol solution. By decreasing the concentration of salt in Ag NP solution, the citrate-stabilized Ag NPs can be well dispersed in alcohol solution. Based on this, the Ag SERS tags can be directly coated with thickness-controlled and homogeneous silica shells. This approach is highly reproducible for silica shell growth and signal intensity, not depending on the properties of Raman molecules, proved by 7 kinds of the Raman molecules. Moreover, this kind of SERS tags coated with silica hold the stronger SERS signals than the traditional method due to no interference from the priming molecules.

  15. A facile and general route to synthesize silica-coated SERS tags with the enhanced signal intensity

    PubMed Central

    Zhang, Youlin; Li, Xiaokun; Xue, Bin; Kong, Xianggui; Liu, Xiaomin; Tu, Langping; Chang, Yulei

    2015-01-01

    Silica-coated SERS tags have been attracting greater attention in recent years. However, the reported methods to synthesize these tags are tedious, and often subjected to the limited signal intensity. Here, we report a facile and general method to prepare the silica-coated Ag SERS tags with the enhanced signal intensity by no introducing the primers. This approach mainly depends on the colloidal stability of the Ag NPs in alcohol solution. By decreasing the concentration of salt in Ag NP solution, the citrate-stabilized Ag NPs can be well dispersed in alcohol solution. Based on this, the Ag SERS tags can be directly coated with thickness-controlled and homogeneous silica shells. This approach is highly reproducible for silica shell growth and signal intensity, not depending on the properties of Raman molecules, proved by 7 kinds of the Raman molecules. Moreover, this kind of SERS tags coated with silica hold the stronger SERS signals than the traditional method due to no interference from the priming molecules. PMID:26450559

  16. Facile approach in fabricating superhydrophobic coatings from silica-based nanocomposite

    NASA Astrophysics Data System (ADS)

    Guo, Yonggang; Wang, Qihua

    2010-10-01

    This study develops a one-step technique to synthesize various super water-repellent coatings with addition of modified silica nanoparticles. Surface topography observation showed that stacking of spherical silica nanoparticles formed primary surface roughness. The wettability of the products was investigated. It was found that the as-prepared surface possesses superhydrophobic properties not only for pure water but also for corrosive water under both acidic and basic conditions. The silica-based nanocomposite coatings can be fabricated on glass substrates and other functional engineering material surfaces, such as copper, iron, aluminum alloy, to form self-cleaning coatings.

  17. MoRu/Be multilayers for extreme ultraviolet applications

    DOEpatents

    Bajt, Sasa C.; Wall, Mark A.

    2001-01-01

    High reflectance, low intrinsic roughness and low stress multilayer systems for extreme ultraviolet (EUV) lithography comprise amorphous layers MoRu and crystalline Be layers. Reflectance greater than 70% has been demonstrated for MoRu/Be multilayers with 50 bilayer pairs. Optical throughput of MoRu/Be multilayers can be 30-40% higher than that of Mo/Be multilayer coatings. The throughput can be improved using a diffusion barrier to make sharper interfaces. A capping layer on the top surface of the multilayer improves the long-term reflectance and EUV radiation stability of the multilayer by forming a very thin native oxide that is water resistant.

  18. Multilayer infrared beamsplitter film system

    NASA Technical Reports Server (NTRS)

    Bastien, R. C.; Heinrich, P. L.

    1969-01-01

    Multilayer infrared beamsplitter film system on a potassium bromide crystal substrate is operational over a wavelength range of 2.5 to 25 microns with nearly equal broadband reflectance and transmittance. It is useful in optical coating, vacuum deposition, radiometry, interferometry, and spectrometry.

  19. Optical multilayers with an amorphous fluoropolymer

    SciTech Connect

    Chow, R.; Loomis, G.E.; Lindsey, E.F.

    1994-07-01

    Multilayered coatings were made by physical vapor deposition (PVD) of a perfluorinated amorphous polymer, Teflon AF2400, together with other optical materials. A high reflector at 1064 run was made with ZnS and AF2400. An all-organic 1064-nm reflector was made from AF2400 and polyethylene. Oxide (HfO{sub 2}, SiO{sub 2}) compatibility was also tested. Each multilayer system adhered to itself. The multilayers were influenced by coating stress and unintentional temperature rises during PVD deposition.

  20. A facile fabrication of light diffusing film with LDP/polyacrylates composites coating for anti-glare LED application

    NASA Astrophysics Data System (ADS)

    Song, Shisen; Sun, Yaojie; Lin, Yandan; You, Bo

    2013-05-01

    In this paper, we present a facile coating technique to fabricate the light diffusing film with hemispherical surface convex micro-structure. The coating was prepared by different ratio of light-diffusing particles (LDP)/polyacrylates composites via in situ radical polymerization, with the H2SO4 and vinyl triethoxysilane (A-151) pretreatment made the LDP better dispersed and incorporated with polyacrylate polymer chains. When the mass ratio (LDP/polyacrylate) was 0.5, the film obtained the highest light-diffusing effect and more than 90% transmittance due to the formation of hemispherical surface convex micro-structure. The light diffusing films have excellent anti-glare property if applied to LED light system.

  1. IMPROVED EQUIPMENT CLEANING IN COATED AND LAMINATED SUBSTRATE MANUFACTURING FACILITIES (PHASE I)

    EPA Science Inventory

    The report gives results of a Phase I study to characterize current equipment cleaning practices in the coated and laminated substrate manufacturing industry, to identify alternative cleaning technologies, and to identify demonstrable technologies and estimate their emissions imp...

  2. IMPROVED EQUIPMENT CLEANING IN COATED AND LAMINATED SUBSTRATE MANUFACTURING FACILITIES (PHASE II)

    EPA Science Inventory

    The report discusses EPA efforts to identify, demonstrate, and publish pollution prevention information and opportunities for equipment cleaning for the coated and laminated substrate manufacturing industry. It summarizes initial data collected and summarized during industry obse...

  3. Four space application material coatings on the Long-Duration Exposure Facility (LDEF)

    NASA Technical Reports Server (NTRS)

    Scialdone, John J.; Clatterbuck, Carroll

    1995-01-01

    Four material coatings of different thicknesses were flown on the LDEF to determine their ability to perform in the harsh space environment. The coatings, located in the ram direction of the spacecraft, were exposed for 10 months to the low-Earth orbit (LEO) environments experienced by the LDEF at an orbit of 260 nautical miles. They consisted of indium oxide (In2O3), silicon oxide (SiO(x)), clear RTV silicone, and silicone with silicate-treated zinc oxide (ZnO). These coatings were flown to assess their behavior when exposed to atomic oxygen and to confirm their good radiative properties, stability, electrical conductivity, and resistance to UV exposure. The flown samples were checked and compared with the reference unflown samples using high-magnification optical inspection, ESCA analysis, weight changes, and dimensional changes. These comparisons indicated the following. The 1000 A SiO(x) coating eroded uniformly, with minor changes in its radiative properties. The 100 A In2O3 coating eroded completely down to the Kapton backing, with resultant losses of reflectance. The RTV-615 showed erosion, with carbon (C) content losses, while the Si remained constant, with a doubling of the oxygen (O) concentration. The RTV-615 silicone with K2SiO3-treated ZnO changed from flat to glossy white in appearance. It lost C, was etched, and increased its O content. The upper layers showed no remaining Zn or K. Losses of reflectance occurred within certain wavelength bands. It was not possible to evaluate the experimental oxygen reaction rate using the calculated atomic oxygen fluence of 2.6 x 10(exp 20) atoms/cm(exp 2) for the exposure of these coatings during the flight. The bakeout of the coatings was not carried out prior to the flight. Hence, the coating weight and dimensional losses included losses by outgassing products.

  4. Facile synthesis of novel two-dimensional silver-coated layered double hydroxide nanosheets as advanced anode material for Ni-Zn secondary batteries

    NASA Astrophysics Data System (ADS)

    Yang, Bin; Yang, Zhanhong; Wang, Ruijuan

    2014-04-01

    Silver-coated layered double hydroxide (Ag-coated LDH) nanosheets are successfully prepared by a facile silver mirror reaction and their electrochemical performance has been evaluated as anode materials for Ni-Zn secondary batteries. The microstructure and morphology of as-prepared Ag-coated Zn/Al-LDH are investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). As anode material for Ni-Zn secondary batteries, Ag-coated Zn/Al-LDH exhibits high specific capacity (400 mAh g-1), good charge-discharge properties and excellent cycling performance, which is attributed to the effect of the electron conductivity improvement by the Ag coating on the surface of Zn/Al-LDH nanosheet. This newly designed Ag-coated Zn/Al-LDH may offer a promising anode candidate for high-performance Ni-Zn secondary batteries.

  5. Facile preparation of superamphiphobic epoxy resin/modified poly(vinylidene fluoride)/fluorinated ethylene propylene composite coating with corrosion/wear-resistance

    NASA Astrophysics Data System (ADS)

    Wang, Huaiyuan; Liu, Zhanjian; Wang, Enqun; Zhang, Xiguang; Yuan, Ruixia; Wu, Shiqi; Zhu, Yanji

    2015-12-01

    A robust superamphiphobic epoxy resin (EP)/modified poly(vinylidene fluoride) (MPVDF)/fluorinated ethylene propylene (FEP) composite coating has been prepared through the combination of chemical modification and spraying technique. Nanometer silica (SiO2, 2.5 wt.%) and carbon nanotubes (CNTs, 2.5 wt.%) were added in the coating to construct the necessary reticulate papillae structures for superamphiphobic surface. The prepared EP composite coating demonstrated high static contact angles (166°, 155°) and low sliding angles (3°, 5°) to water and glycerol, respectively. Moreover, the prepared coating can also retain superhydrophobicity under strongly acidic and alkaline conditions. The brittleness of EP can be avoided by introducing the malleable MPVDF. The wear life of the EP composite coating with 25 wt.% FEP was improved to 18 times of the pure EP coating. The increased wear life of the coating can be attributed to the designed nano/micro structures, the self-lubrication of FEP and the chemical reaction between EP and MPVDF. The anti-corrosion performance of the coatings was investigated in 3.5% NaCl solution using potentiodynamic polarization. The results showed that the prepared superamphiphobic composite coating was most effective in corrosion resistance, primarily due to the barrier effect for the diffusion of O2 and H2O molecules. It is believed that this robust superamphiphobic EP/MPVDF/FEP composite coating prepared by the facile spray method can pave a way for the large-scale application in pipeline transport.

  6. Facile and General Method for Synthesis of Sugar Coated Gold Nanoparticles

    PubMed Central

    Katti, Kavita K.; Kattumuri, Vijaya; Bhaskaran, Sharanya; Katti, Kattesh V.; Kannan, Raghuraman

    2009-01-01

    This letter describes a general method for the preparation of carbohydrate coated gold nanoparticles. The generality of this method has been demonstrated by surface coating AuNPs with the following sugars: glucose (monosaccharide); sucrose, maltose, or lactose (disaccharides); raffinose (trisaccharide); and starch (polysaccharide). The non-toxic, water-soluble phosphino aminoacid P(CH2NHCH(CH3-)COOH)3, THPAL, has been used as a reducing agent in this process. The sizes of sugar coated AuNPs that have been generated in this study are: 30 ± 8 nm (Glucose), 10 ± 6 nm (sucrose), 8 ± 2 nm (maltose), 3 ± 1 nm (lactose), 6 ± 2 nm (raffinose), and 39 ± 9 nm (starch). PMID:20011668

  7. Facile approach in the development of icephobic hierarchically textured coatings as corrosion barrier

    NASA Astrophysics Data System (ADS)

    Momen, G.; Farzaneh, M.

    2014-04-01

    An anti-corrosion superhydrophobic film with water contact angle greater than 160° on aluminum alloy 6061 substrate was fabricated simply through the spin-coating method applied to Al2O3 nanoparticles doped in silicone rubber solution. The as-obtained sample was characterized by scanning electron microscopy (SEM) and water contact angle/surface energy measurement. The corrosion behaviour of such coating in the NaCl solutions was investigated using the potentiodynamic polarization. The results show that the corrosion resistance of the developed superhydrophobic surface is improved greatly due to the composite wetting states or interfaces with numerous air pockets between its surface and the NaCl solution. This superhydrophobic coating could serve as an effective barrier against aggressive medium. Ice adhesion strength of the as-prepared superhydrophobic coating was also evaluated by measuring its ice adhesion force which was found to have reduced by 4.8 times compared to that of aluminum substrate as reference test.

  8. Facile synthesis of pectin coated Fe3O4 nanospheres by the sonochemical method

    NASA Astrophysics Data System (ADS)

    Dai, Junjun; Wu, Shixi; Jiang, Wei; Li, Pingyun; Chen, Xiaolong; Liu, Li; Liu, Jie; Sun, Danping; Chen, Wei; Chen, Binhua; Li, Fengsheng

    2013-04-01

    Pectin coated Fe3O4 magnetic nanospheres (PCMNs) were synthesized by the sonochemical method. The Fe3O4 nanoparticles were prepared by chemical precipitation as reported in the previous articles, and the PCMNs were characterized by transmission electron microscopy, dynamic light scattering, thermogravimetric analysis, Fourier-transform infrared spectroscopy, a vibrating sample magnetometer and energy dispersive X-ray spectrum. The results indicated that the magnetic nanoparticles have been coated by pectin, magnetite content of which was up to 63%, with the saturation magnetization being 32.69 emu/g. The formation mechanism and further application of PCMNs have also been discussed. The results show that the PCMNs can be applied to biomedical applications.

  9. Facile and generalized encapsulations of inorganic nanocrystals with nitrogen-doped carbonaceous coating for multifunctionality

    NASA Astrophysics Data System (ADS)

    Yang, Yong; Zhang, Jingchao; Wang, Shitong; Xu, Xiaobin; Zhang, Zhicheng; Wang, Pengpeng; Tang, Zilong; Wang, Xun

    2015-02-01

    A simple strategy toward versatile encapsulations of inorganic nanocrystals, through a green hydrothermal treatment of commercial polyurethane sponge, was developed. This approach enables us to realize a general method to form a surface-adherent, N-doped coating with a controllable thickness for well-defined structures. These composites exhibit active properties in optical applications and energy storage. For example, N-doped carbon encapsulated Fe2O3 nanoboxes show a very high discharge capacity and outstanding cyclability, and the capacity still remained at 1086 mA h g-1 at a current density of 400 mA g-1 after 200 cycles. Our results described here provide a simple surface coating technique to design various functional nanostructures.A simple strategy toward versatile encapsulations of inorganic nanocrystals, through a green hydrothermal treatment of commercial polyurethane sponge, was developed. This approach enables us to realize a general method to form a surface-adherent, N-doped coating with a controllable thickness for well-defined structures. These composites exhibit active properties in optical applications and energy storage. For example, N-doped carbon encapsulated Fe2O3 nanoboxes show a very high discharge capacity and outstanding cyclability, and the capacity still remained at 1086 mA h g-1 at a current density of 400 mA g-1 after 200 cycles. Our results described here provide a simple surface coating technique to design various functional nanostructures. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr07181f

  10. A novel and facile synthesis of porous SiO2-coated ultrasmall Se particles as a drug delivery nanoplatform for efficient synergistic treatment of cancer cells

    NASA Astrophysics Data System (ADS)

    Liu, Xijian; Deng, Guoying; Wang, Yeying; Wang, Qian; Gao, Zhifang; Sun, Yangang; Zhang, Wenlong; Lu, Jie; Hu, Junqing

    2016-04-01

    A novel and facile synthetic route has been developed to fabricate porous SiO2-coated ultrasmall Se particles (Se@SiO2 nanospheres) as a drug delivery nanoplatform which combines Se quantum dots and doxorubicin (DOX) for efficient synergistic treatment of cancer cells.A novel and facile synthetic route has been developed to fabricate porous SiO2-coated ultrasmall Se particles (Se@SiO2 nanospheres) as a drug delivery nanoplatform which combines Se quantum dots and doxorubicin (DOX) for efficient synergistic treatment of cancer cells. Electronic supplementary information (ESI) available. See DOI: 10.1039/c6nr02298g

  11. Study of multilayer-reflected beam profiles and their coherence properties using beamlines ID19 (ESRF) and 32-ID (APS)

    SciTech Connect

    Rack, A.; Assoufid, L.; Dietsch, R.; Weitkamp, T.; Trabelsi, S. Bauer; Rack, T.; Siewert, F.; Kraemer, M.; Holz, Th.; Zanette, I.; Le, W.-K.; Cloetens, P.; Ziegler, E.

    2012-05-17

    The use of multilayer mirrors is an interesting alternative for reflective X-ray monochromatization with respect to reflection from crystal optics. The increased photon flux density due to the multilayers' larger bandwidth is of crucial importance for, e.g, full-field X-ray imaging applications. Drawbacks are the introduced modifications of the reflected beam profile as well as a certain loss of coherence, summarized as wavefront degradation. Our recent work has shown that the modification of the beam profile can vary with, e.g., the material composition of the coating applied. In order to verify our findings, a beamline round-robin has been initiated, comparing the wavefront profiles after reflection by selected multilayers at beamlines 32-ID (Advanced Photon Source) and ID19 (European Synchrotron Radiation Facility) with our initial results acquired at BM05 (ESRF) [1].

  12. Cylindrical multilayer metal-dielectric structures

    NASA Astrophysics Data System (ADS)

    Sasin, M. E.; Il'inskaya, N. D.; Zadiranov, Yu. M.; Kaliteevskaya, N. A.; Lazarenko, A. A.; Mazlin, V. A.; Brunkov, P. N.; Pavlov, S. I.; Kaliteevski, M. A.

    2015-11-01

    A method of creating a cylindrical structures consisting of thin metallic layer and dielectric multilayer Bragg reflector is described. Formation of the structures is observed experimentally as a result of separation and twisting away from the substrate a thin layer of gold coated with a multilayer SiO2/TiO2 Bragg reflector. It is suggested that such structures may be of interest for the creation of novel optoelectronic devices.

  13. Spherical cloaking with homogeneous isotropic multilayered structures.

    PubMed

    Qiu, Cheng-Wei; Hu, Li; Xu, Xiaofei; Feng, Yijun

    2009-04-01

    We propose a practical realization of electromagnetic spherical cloaking by layered structure of homogeneous isotropic materials. By mimicking the classic anisotropic cloak by many alternating thin layers of isotropic dielectrics, the permittivity and permeability in each isotropic layer can be properly determined by effective medium theory in order to achieve invisibility. The model greatly facilitates modeling by Mie theory and realization by multilayer coating of dielectrics. Eigenmode analysis is also presented to provide insights of the discretization in multilayers. PMID:19518392

  14. Design and Performance of Capping Layers for EUV Multilayer Mirrors

    SciTech Connect

    Bajt, S; Chapman, H N; Nuygen, N; Alameda, J; Robinson, J C; Malinowski, M; Gullikson, E; Aquila, A; Tarrio, C; Grantham, S

    2003-03-10

    The reflectance stability of multilayer coatings for extreme ultraviolet lithography (EUVL) in a commercial tool environment is of uttermost importance to ensure continuous exposures with minimum maintenance cost. We have made substantial progress in designing the protective capping layer coatings, understanding their performance and estimating their lifetimes based on accelerated electron beam and EUV exposure studies. Our current capping layer coatings have about 40 times longer lifetimes than Si-capped multilayer optics. Nevertheless, the lifetime of current Ru-capped multilayers is too short to satisfy commercial tool requirements and further improvements are essential.

  15. A facile fabrication of superhydrophobic nanocomposite coating with contact angles approaching the theoretical limit

    NASA Astrophysics Data System (ADS)

    Hancer, Mehmet; Arkaz, Harun

    2015-11-01

    Although there are many viable approaches to induce hydrophobicity, a superhydrophobic surface could only be fabricated by combination of surface chemistry modification and roughness enhancement. In this study, surface roughness was obtained by 12 nm SiO2 nanoparticles (NPs) which were chemically modified using a self-assembled monolayer of perfluorodecyltrichlorosilane. The SiO2 NPs which were rendered hydrophobic, then successfully dispersed into a poly silicon (silsesquioxane) matrix at varying concentrations from 0.5 to 4%. The NPs dispersed polymer suspension was then spray coated on to glass and aluminum coupons in order to achieve polymer thin film nanocomposites. The results were revealed a superhydrophobic surface with a water contact angle exceeding 178° with low hysteresis and bouncing water droplet behavior. Furthermore the composite film reliability (hot-humid and ice build-up) was tested in an environmental control chamber by precisely adjusting both temperature (85 °C) and relative humidity (85 RH). Taber abrasion testing was applied in order to gain insights into the abrasion resistance of nanocomposite film. Finally, ice formation was simulated at -20 °C on the superhydrophobic nanocomposite film coated substrates.

  16. Facile preparation and applications of graphitic carbon nitride coating in solid-phase microextraction.

    PubMed

    Xu, Na; Wang, Yiru; Rong, Mingcong; Ye, Zhifeng; Deng, Zhuo; Chen, Xi

    2014-10-17

    In this study, graphitic carbon nitride (g-C3N4) was used as a coating material for solid-phase microextraction (SPME) applications. Coupled to gas chromatography (GC), the extraction ability of the SPME fiber was investigated and compared with the commercial fibers of 100 μm PDMS and 85 μm CAR/PDMS using six target analytes including deltamethrin, nerolidol, amphetamine, dodecane, ametryn and acrylamide. The g-C3N4 coating revealed excellent extraction ability and durability comparing with those of the commercial fibers due to its loose structure and unique physicochemical properties. The repeatability for each single fiber was found to be 3.46% and reproducibility for fiber to fiber was 8.53%. The g-C3N4 SPME fiber was applied to the determination of acrylamide in potato chips, the linearity and detection limit was 0.5-250 μg g(-1) and 0.018 μg g(-1), respectively. PMID:25218628

  17. Facile preparation of mesoporous carbon-silica-coated graphene for the selective enrichment of endogenous peptides.

    PubMed

    Zhang, Quanqing; Zhang, Qinghe; Xiong, Zhichao; Wan, Hao; Chen, Xiaoting; Li, Hongmei; Zou, Hanfa

    2016-01-01

    A sandwich-like composite composed of ordered mesoporous carbon-silica shell-coated graphene (denoted as graphene@mSiO2-C) was prepared by an in-situ carbonation strategy. A mesoporous silica shell was synthesized by a sol-gel method, and cetyltrimethyl ammonium bromide inside the mesopores were in-situ carbonized as a carbon source to obtain a carbon-silica shell. The resulting mesoporous carbon-silica material with a sandwich structure possesses a high surface area (600 m(2) g(-1)), large pore volume (0.587 cm(3) g(-1)), highly ordered mesoporous pore (3 nm), and high carbon content (30%). This material shows not only high hydrophobicity of graphene and mesoporous carbon but also a hydrophilic silica framework that ensures excellent dispersibility in aqueous solution. The material can capture many more peptides from bovine serum albumin tryptic digests than mesoporous silica shell-coated graphene, demonstrating great enrichment efficiency for peptides. Furthermore, the prepared composite was applied to the enrichment of low-abundance endogenous peptides in human serum. Based on Matrix-Assisted Laser Desorption/ Ionization Time of Flight Mass Spectrometry identification, the graphene@mSiO2-C could efficiently size-exclude proteins and enriches the low-abundant peptides on the graphene and mesoporous carbon. And based on the LC-MS/MS results, 892 endogenous peptides were obtained by graphene@mSiO2-C, hinting at its great potential in peptides analysis. PMID:26695263

  18. Effects of Aerospace MACT Standard on coating operations at DoD facilities

    SciTech Connect

    Pelton, D.J.; Narayanan, R.

    1997-12-31

    DoD facilities that are a major source of HAPs and that manufacture, repair or rework any aerospace vehicle will have to contend with the aerospace National Emission Standard for Hazardous Air Pollutants (NESHAP). The rule which becomes effective September 1, 1998 requires reductions in volatile organic compounds (VOC) and organic hazardous air pollutants (HAP). Reductions will be achieved by use of primers and topcoats that meet regulatory limits for VOC or organic HAP or using air pollution control systems. At some DoD facilities preparations have been made to comply with the standard when the standard is in effect. The requirements of 40 CFR Part 63 Subpart GG (aerospace NESHAP) are briefly summarized. The impacts that have been experienced at an Air Force base that is currently practicing most of the NESHAP requirements in order to comply with existing state requirements are discussed.

  19. Microstructure characterization of advanced protective Cr/CrN+a-C:H/a-C:H:Cr multilayer coatings on carbon fibre composite (CFC).

    PubMed

    Major, L; Janusz, M; Lackner, J M; Kot, M; Major, B

    2016-06-01

    Studies of advanced protective chromium-based coatings on the carbon fibre composite (CFC) were performed. Multidisciplinary examinations were carried out comprising: microstructure transmission electron microscopy (TEM, HREM) studies, micromechanical analysis and wear resistance. Coatings were prepared using a magnetron sputtering technique with application of high-purity chromium and carbon (graphite) targets deposited on the CFC substrate. Selection of the CFC for surface modification in respect to irregularities on the surface making the CFC surface more smooth was performed. Deposited coatings consisted of two parts. The inner part was responsible for the residual stress compensation and cracking initiation as well as resistance at elevated temperatures occurring namely during surgical tools sterilization process. The outer part was responsible for wear resistance properties and biocompatibility. Experimental studies revealed that irregularities on the substrate surface had a negative influence on the crystallites growth direction. Chromium implanted into the a-C:H structure reacted with carbon forming the cubic nanocrystal chromium carbides of the Cr23 C6 type. The cracking was initiated at the coating/substrate interface and the energy of brittle cracking was reduced because of the plastic deformation at each Cr interlayer interface. The wear mechanism and cracking process was described in micro- and nanoscale by means of transmission electron microscope studies. Examined materials of coated CFC type would find applications in advanced surgical tools. PMID:26788794

  20. Normal incidence multilayer mirrors for extreme ultraviolet astronomy

    NASA Technical Reports Server (NTRS)

    Stern, R. A.; Haisch, B. M.; Joki, E. G.; Catura, R. C.

    1984-01-01

    Sputtered multilayer coatings allow the use of normal incidence optics in the extreme ultraviolet (EUV) region below 500 A. Multilayer mirrors can be tailored to provide images at strong EUV lines in the sun and stars, in many cases making more efficient use of the telescope aperture than grazing incidence optics. Alternatively, the bandpass can be broadened at the expense of peak effective area, by varying the multilayer structure over the mirror surface. Such mirrors can also serve as optical elements in spectrographs for investigation of specific emission and absorption line complexes, and are self-filtering in that they reject nearby geocoronal and cosmic resonance line backgrounds. Current efforts at the Lockheed Palo Alto Research Laboratory in the design, fabrication, and testing of EUV multilayer mirrors are discussed. This program includes the design and fabrication of normal incidence EUV multilayer mirrors, and the deposition of multilayers on lacquer-coated substrates.

  1. Radiation control coatings on rough-surfaced roofs at a federal facility: Two summers of monitoring plus roof and whole building modeling

    SciTech Connect

    Petrie, T.W.; Childs, P.W.; Christian, J.E.

    1998-01-01

    Support of the federal New Technology Demonstration Program (NTDP) allowed the authors to learn the effect of radiation control coatings on roofs at a federal facility in the Panhandle of Florida. Two rough-surfaced, moderately well-insulated, low solar reflectance built-up roofs (BURs) were spray coated with a white, latex-based product with ceramic beads. Samples of the coated roofs were brought periodically to the laboratory to measure the solar reflectance as the coatings weathered. The authors monitored the power demand of the all-electric buildings that the roofs covered and temperatures and heat fluxes for two instrumented areas on each roof. Average decreases in the sunlit temperatures of the coated vs. the uncoated surfaces show weathering effects. They also show that the shading enhanced the effect of the coating on the significantly shaded roof because the coated instrumented area on it was preferentially shaded near noon of sunny days. Whole building models were constructed for DOE 2.1E and model predictions were compared to measurements of total electrical power for each all-electric building. The building with the significantly shaded roof had very high internal loads. The effect of the shading on annual energy use for cooling was twice that of the coating but the coating decreased annual cooling energy needs only by 0.5%. The building with the heavyweight concrete-decked roof had small internal loads. For it, the DOE 2.1E model predicted a 7.4% decrease in annual cooling energy use due to the coating and a comparatively small effect of the less extensive shading.

  2. Etched-multilayer phase shifting masks for EUV lithography

    DOEpatents

    Chapman, Henry N.; Taylor, John S.

    2005-04-05

    A method is disclosed for the implementation of phase shifting masks for EUV lithography. The method involves directly etching material away from the multilayer coating of the mask, to cause a refractive phase shift in the mask. By etching into the multilayer (for example, by reactive ion etching), rather than depositing extra material on the top of the multilayer, there will be minimal absorption loss associated with the phase shift.

  3. High temperature stability multilayers for EUV condenser optics

    SciTech Connect

    Bajt, S; Stearns, D G

    2005-05-03

    We investigate the thermal stability of Mo/SiC multilayer coatings at elevated temperatures. Transmission electron microscopy and x-ray diffraction studies show that upon annealing a thermally-induced structural relaxation occurs that transforms the polycrystalline Mo and amorphous SiC layers in as-deposited multilayers into amorphous Mo-Si-C alloy and crystalline SiC, respectively. After this relaxation process is complete the multilayer is stable at temperatures up to 400 C.

  4. Facile Synthesis of Au-Coated Magnetic Nanoparticles and Their Application in Bacteria Detection via a SERS Method.

    PubMed

    Wang, Junfeng; Wu, Xuezhong; Wang, Chongwen; Rong, Zhen; Ding, Hongmei; Li, Hui; Li, Shaohua; Shao, Ningsheng; Dong, Peitao; Xiao, Rui; Wang, Shengqi

    2016-08-10

    This study proposes a facile method for synthesis of Au-coated magnetic nanoparticles (AuMNPs) core/shell nanocomposites with nanoscale rough surfaces. MnFe2O4 nanoparticles (NPs) were first modified with a uniform polyethylenimine layer (2 nm) through self-assembly under sonication. The negatively charged Au seeds were then adsorbed on the surface of the MnFe2O4 NPs through electrostatic interaction for Au shell formation. Our newly developed sonochemically assisted hydroxylamine seeding growth method was used to grow the adsorbed gold seeds into large Au nanoparticles (AuNPs) to form a nanoscale rough Au shell. Au-coated magnetic nanoparticles (AuMNPs) were obtained from the intermediate product (Au seeds decorated magnetic core) under sonication within 5 min. The AuMNPs were highly uniform in size and shape and exhibited satisfactory surface-enhanced Raman scattering (SERS) activity and strong magnetic responsivity. PATP was used as a probe molecule to evaluate the SERS performance of the synthesized AuMNPs with a detection limit of 10(-9) M. The synthesized AuMNPs were conjugated with Staphylococcus aureus (S. aureus) antibody for bacteria capture and separation. The synthesized plasmonic AuNR-DTNB NPs, whose LSPR wavelength was adjusted to the given laser excitation wavelength (785 nm), were conjugated with S. aureus antibody to form a SERS tag for specific recognition and report of the target bacteria. S. aureus was indirectly detected through SERS based on sandwich-structured immunoassay, with a detection limit of 10 cells/mL. Moreover, the SERS intensity at Raman peak of 1331 cm(-1) exhibited a linear relationship to the logarithm of bacteria concentrations ranging from 10(1) cells/mL to 10(5) cells/mL. PMID:27420923

  5. Wormlike micelle assisted rod coating: a general method for facile fabrication of large-area conductive nanomaterial thin layer onto flexible plastics.

    PubMed

    Xie, Jingyi; Wang, Huan; Bai, Huadong; Yang, Peng; Shi, Mengxue; Guo, Peng; Wang, Chen; Yang, Wantai; Song, Huaihe

    2012-06-27

    Through combined application of wormlike-micelle and rod-coating technique, a general method was demonstrated for the facile reparation of thin transparent conductive films (TCF) of various nanomaterials and their hybrids on flexible plastics. The cetyltrimethylammonium hydroxide (CTAOH)/p-toluenesulfonic acid (CTAT) wormlike micelle system was selected for both the dispersion of different nanomaterials and the enhancement of viscosities of the coating fluids. With the single-walled carbon nanotubes (SWNTs)/wormlike micelle aqueous dispersions as coating fluid, TCFs of SWNTs on flexible poly(ethylene terephthalate) (PET) substrates made by rod-coating method were demonstrated. After doping by immersion into thionyl chloride solution, the sheet resistance of SWNTs thin films, which had a transmittance of about 78%, was as low as 480Ω/sq. This coating method was extended to the preparation of thin films or networks of other materials such as reduced graphene oxide and Ag nanowires. The obtained TCF from Ag nanowire networks has a low sheet resistance of 17Ω/sq, which is comparable to the value of best indium tin oxide (ITO) coating on plastic substrates. Finally, hybrid thin films of different nanomaterials were demonstrated by this method. PMID:22551382

  6. Flow Characterization of a Detonation Gun Facility and First Coating Experiments

    NASA Astrophysics Data System (ADS)

    Henkes, C.; Olivier, H.

    2014-06-01

    A computer-controlled detonation gun based spraying device has been designed and tested to obtain particle velocities over 1200 m/s. The device is able to be operated in two modes based on different flow-physical principles. In one mode, the device functions like a conventional detonation gun in which the powder is accelerated in a blast wave. In the other mode, an extension of the facility with a nozzle uses the detonated gas for an intermittently operated shock tunnel process in which the particles are injected into and accelerated by a quasi-steady high enthalpy nozzle flow with high reservoir conditions. Presented are experimental results of the operation without nozzle in which the device generates moderate to high particle velocities in an intermittent process with a frequency of 5 Hz. A hydrogen/oxygen mixture and Cu and WC-Co (88/12) powders are used in the experiments. Operation performance and tube outflow are characterized by time-resolved Schlieren images and pressure measurements. The particle velocities in the outflow are obtained by laser Doppler anemometry. Different substrate/powder combinations (Al/Cu, Steel/Cu, Al/WC-Co, and Steel/WC-Co) have been investigated by light microscopy and measurements of microhardness.

  7. Magnetic multilayer structure

    DOEpatents

    Herget, Philipp; O'Sullivan, Eugene J.; Romankiw, Lubomyr T.; Wang, Naigang; Webb, Bucknell C.

    2016-07-05

    A mechanism is provided for an integrated laminated magnetic device. A substrate and a multilayer stack structure form the device. The multilayer stack structure includes alternating magnetic layers and diode structures formed on the substrate. Each magnetic layer in the multilayer stack structure is separated from another magnetic layer in the multilayer stack structure by a diode structure.

  8. Facile synthesis of pH sensitive polymer-coated mesoporous silica nanoparticles and their application in drug delivery.

    PubMed

    Tang, Hongyan; Guo, Jia; Sun, Yang; Chang, Baisong; Ren, Qingguang; Yang, Wuli

    2011-12-15

    pH-responsive polymer shell chitosan/poly (methacrylic acid) (CS-PMAA) was coated on mesoporous silica nanoparticles (MSN) through the facile in situ polymerization method. The resultant composite microspheres showed a flexible control over shell thickness, surface charges and hydrodynamic size by adjusting the feeding amount of MSN and the molar ratio of [-NH(2)]/MAA. The MSN/CS-PMAA composite microspheres were stable in the pH range of 5-8 as well as in the physiological saline (0.15M NaCl). Doxorubicin hydrochloride (DOX) was applied as a model drug to investigate the drug storage and release behavior. The results demonstrated that DOX could be effectively loaded into the composite microspheres. The cumulative release of DOX-loaded composite microspheres was pH dependent and the release rate was much faster at low pH (5.5) than that of pH 7.4. The cytotoxicity test by MTT assay showed that the blank carrier MSN/CS-PMAA microspheres were suitable as drug carriers. The cellular uptake of composite microspheres was investigated by confocal laser scanning microscopy (CLSM), which indicated that MSN/CS-PMAA could deliver the drugs into HeLa cell. The above results imply that the composite microspheres are a promising drug delivery system for cancer therapy. PMID:22001840

  9. X-ray Reflectivity by Rough Multilayers

    NASA Astrophysics Data System (ADS)

    Baumbach, Tilo; Mikulik, Petr

    One tendency in present material research is the increasing ability to structure solids in one, two and three dimensions at a sub-micrometer scale. Based on various material systems artificial mesoscopic layered superstructures such as multilayers, superlattices, layered gratings, quantum wires and dots have been fabricated successfully. This has opened new perspectives for manifold technological applications (e.g. for anticorrosion coating and hard coating, micro and optoelectronic devices, neutron and x-ray optical elements, magnetooptical recording).

  10. Facile formation of a Li3PO4 coating layer during the synthesis of a lithium-rich layered oxide for high-capacity lithium-ion batteries

    NASA Astrophysics Data System (ADS)

    Lee, Yongho; Lee, Jieun; Lee, Kwan Young; Mun, Junyoung; Lee, Joong Kee; Choi, Wonchang

    2016-05-01

    The facile surface modification of transition-metal hydroxide precursors with ammonium dihydrogen phosphate was performed by ball-milling before the calcination process. The prepared precursors were mixed with the required amount of lithium hydroxide and then simply calcined to obtain lithium-phosphate-coated lithium transition metal oxide cathodes during the one-pot calcination process. A thin, homogeneous Li3PO4 coating is firstly formed on the surface of the precursor owing to the abundance of lithium at a lower-temperature range, and subsequent formation of lithium transition metal oxide is achieved at a higher-temperature range during the calcination process. The Li3PO4-coated cathode electrode with the high loading level over 12 mg cm-1 exhibits a discharge capacity of 106 mAh g-1 at 5C at ambient temperature. Furthermore, it delivers 90% capacity retention after 50 cycles at 60 °C.

  11. Imaging Schwarzschild multilayer X-ray microscope

    NASA Astrophysics Data System (ADS)

    Hoover, Richard B.; Baker, Phillip C.; Shealy, David L.; Core, David B.; Walker, Arthur B. C., Jr.; Barbee, Troy W., Jr.; Kerstetter, Ted

    1993-01-01

    We have designed, analyzed, fabricated, and tested Schwarzschild multilayer X-ray microscopes. These instruments use flow-polished Zerodur mirror substrates which have been coated with multilayers optimized for maximum reflectivity at normal incidence at 135 A. They are being developed as prototypes for the Water Window Imaging X-Ray Microscope. Ultrasmooth mirror sets of hemlite grade sapphire have been fabricated and they are now being coated with multilayers to reflect soft X-rays at 38 A, within the biologically important 'water window'. In this paper, we discuss the fabrication of the microscope optics and structural components as well as the mounting of the optics and assembly of the microscopes. We also describe the optical alignment, interferometric and visible light testing of the microscopes, present interferometrically measured performance data, and provide the first results of optical imaging tests.

  12. Method and system using power modulation for maskless vapor deposition of spatially graded thin film and multilayer coatings with atomic-level precision and accuracy

    DOEpatents

    Montcalm, Claude; Folta, James Allen; Tan, Swie-In; Reiss, Ira

    2002-07-30

    A method and system for producing a film (preferably a thin film with highly uniform or highly accurate custom graded thickness) on a flat or graded substrate (such as concave or convex optics), by sweeping the substrate across a vapor deposition source operated with time-varying flux distribution. In preferred embodiments, the source is operated with time-varying power applied thereto during each sweep of the substrate to achieve the time-varying flux distribution as a function of time. A user selects a source flux modulation recipe for achieving a predetermined desired thickness profile of the deposited film. The method relies on precise modulation of the deposition flux to which a substrate is exposed to provide a desired coating thickness distribution.

  13. Atomic oxygen undercutting of LDEF aluminized Kapton multilayer insulation

    NASA Astrophysics Data System (ADS)

    Degroh, Kim K.

    1991-06-01

    Atomic oxygen undercutting is a potential threat to vulnerable spacecraft materials which have been shielded with an atomic oxygen protective coating. This is due to atomic oxygen attack of oxidizable materials at the point of microscopic defects in the protective coatings which occur during fabrication and handling, or from micrometeoroid and debris bombardment in space. An aluminized Kapton multilayer insulation sample which was flown on the leading edge of the Long Duration Exposure Facility (LDEF) was used to study low Earth orbit (LEO) directed ram oxygen undercutting. Cracks in the aluminized coatings around the vent holes provided excellent locations for evaluation of atomic oxygen undercutting. The undercutting profiles were compared to Monte Carlo models which predict LEO ram atomic oxygen attack. The shape of the undercurrent profile was found to vary with crack width, which is proportional to the number of atomic oxygen atoms entering the crack. The resulting atomic oxygen undercut profiles which occurred on LDEF indicated wide undercut cavities in spite of the fixed ram orientation. Potential causes of the observed undercutting profiles will be presented. Implications of the undercutting profiles relevant to Space Station Freedom will also be discussed.

  14. Fabrication of mullite-bonded porous SiC ceramics from multilayer-coated SiC particles through sol-gel and in-situ polymerization techniques

    NASA Astrophysics Data System (ADS)

    Ebrahimpour, Omid

    In this work, mullite-bonded porous silicon carbide (SiC) ceramics were prepared via a reaction bonding technique with the assistance of a sol-gel technique or in-situ polymerization as well as a combination of these techniques. In a typical procedure, SiC particles were first coated by alumina using calcined powder and alumina sol via a sol-gel technique followed by drying and passing through a screen. Subsequently, they were coated with the desired amount of polyethylene via an in-situ polymerization technique in a slurry phase reactor using a Ziegler-Natta catalyst. Afterward, the coated powders were dried again and passed through a screen before being pressed into a rectangular mold to make a green body. During the heating process, the polyethylene was burnt out to form pores at a temperature of about 500°C. Increasing the temperature above 800°C led to the partial oxidation of SiC particles to silica. At higher temperatures (above 1400°C) derived silica reacted with alumina to form mullite, which bonds SiC particles together. The porous SiC specimens were characterized with various techniques. The first part of the project was devoted to investigating the oxidation of SiC particles using a Thermogravimetric analysis (TGA) apparatus. The effects of particle size (micro and nano) and oxidation temperature (910°C--1010°C) as well as the initial mass of SiC particles in TGA on the oxidation behaviour of SiC powders were evaluated. To illustrate the oxidation rate of SiC in the packed bed state, a new kinetic model, which takes into account all of the diffusion steps (bulk, inter and intra particle diffusion) and surface oxidation rate, was proposed. Furthermore, the oxidation of SiC particles was analyzed by the X-ray Diffraction (XRD) technique. The effect of different alumina sources (calcined Al2O 3, alumina sol or a combination of the two) on the mechanical, physical, and crystalline structure of mullite-bonded porous SiC ceramics was studied in the

  15. Fabrication of mullite-bonded porous SiC ceramics from multilayer-coated SiC particles through sol-gel and in-situ polymerization techniques

    NASA Astrophysics Data System (ADS)

    Ebrahimpour, Omid

    In this work, mullite-bonded porous silicon carbide (SiC) ceramics were prepared via a reaction bonding technique with the assistance of a sol-gel technique or in-situ polymerization as well as a combination of these techniques. In a typical procedure, SiC particles were first coated by alumina using calcined powder and alumina sol via a sol-gel technique followed by drying and passing through a screen. Subsequently, they were coated with the desired amount of polyethylene via an in-situ polymerization technique in a slurry phase reactor using a Ziegler-Natta catalyst. Afterward, the coated powders were dried again and passed through a screen before being pressed into a rectangular mold to make a green body. During the heating process, the polyethylene was burnt out to form pores at a temperature of about 500°C. Increasing the temperature above 800°C led to the partial oxidation of SiC particles to silica. At higher temperatures (above 1400°C) derived silica reacted with alumina to form mullite, which bonds SiC particles together. The porous SiC specimens were characterized with various techniques. The first part of the project was devoted to investigating the oxidation of SiC particles using a Thermogravimetric analysis (TGA) apparatus. The effects of particle size (micro and nano) and oxidation temperature (910°C--1010°C) as well as the initial mass of SiC particles in TGA on the oxidation behaviour of SiC powders were evaluated. To illustrate the oxidation rate of SiC in the packed bed state, a new kinetic model, which takes into account all of the diffusion steps (bulk, inter and intra particle diffusion) and surface oxidation rate, was proposed. Furthermore, the oxidation of SiC particles was analyzed by the X-ray Diffraction (XRD) technique. The effect of different alumina sources (calcined Al2O 3, alumina sol or a combination of the two) on the mechanical, physical, and crystalline structure of mullite-bonded porous SiC ceramics was studied in the

  16. Facile fabrication of core-shell Pr6O11-ZnO modified silane coatings for anti-corrosion applications

    NASA Astrophysics Data System (ADS)

    Jeeva Jothi, K.; Palanivelu, K.

    2014-01-01

    In this work, we have developed a facile and inexpensive method to fabricate anti-corrosive and hydrophobic surface with hierarchical micro and nano structures. We demonstrate for the first time the use of praseodymium oxide doped zinc oxide (Pr6O11-ZnO) nanocomposites loaded in a hybrid sol-gel (SiOx/ZrOx) layer, to effectively protect the underlying steel substrate from corrosion attack. The influence of Pr6O11-ZnO gives the surprising aspects based on active anti-corrosion and hydrophobic coatings. The spherical SiO2 particles have been successfully coated with Pr6O11-ZnO layer through sol-gel process. The resulted SiO2@Pr6O11-ZnO core-shell was characterized by Transmission Electron Microscopy (TEM), X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), and X-ray Photoelectron Spectroscopy (XPS). The barrier properties of the intact coatings were assessed by Electrochemical Impedance Spectroscopy (EIS). The fabrication of SiO2@Pr6O11-ZnO shows dual properties of hydrophobic and anti-corrosion micro/nanostructured sol-gel coatings follows a single/simple step coating procedure. This study has led to a better understanding factor influencing the anti-corrosion performance with embedded nanocomposites. These developments are particularly for silane network@ Pr6O11-ZnO for self-healing and self-cleaning behavior which can be designed for new protective coating system.

  17. Optical multilayer films based on an amorphous fluoropolymer

    SciTech Connect

    Chow, R.; Loomis, G.E.; Ward, R.L.

    1996-01-01

    Multilayered coatings were made by physical vapor deposition (PVD) of a perfluorinated amorphous polymer, Teflon AF2400, and with other optical materials. A high reflector for 1064 nm light was made with ZnS and AF2400. An all-organic 1064 nm reflector was made from AF2400 and polyethylene. Oxide (HfO{sub 2} and SiO{sub 2}) compatibility with AF2400 was also tested. The multilayer morphologies were influenced by coating stress and unintentional temperature rises from the PVD process. Analysis by liquid nuclear magnetic resonance of the thin films showed slight compositional variations between the coating and starting materials of perfluorinated amorphous polymers.

  18. Nonvolatile resistive switching memory properties of thermally annealed titania precursor/polyelectrolyte multilayers.

    PubMed

    Lee, Chanwoo; Kim, Inpyo; Shin, Hyunjung; Kim, Sanghyo; Cho, Jinhan

    2009-10-01

    We describe a novel and versatile approach for preparing resistive switching memory devices based on transition metal oxides. A titania precursor and poly(allyamine hydrochloride) (PAH) layers were deposited alternately onto platinum (Pt)-coated silicon substrates using electrostatic interactions. The multilayers were then converted to TiO2 nanocomposite (TiO2 NC) films after thermal annealing. A top electrode was coated on the TiO2 NC films to complete device fabrication. When an external bias was applied to the devices, a switching phenomenon independent of the voltage polarity (i.e., unipolar switching) was observed at low operating voltages (approximately 0.4 VRESET and 1.3 VSET), which is comparable to that observed in conventional devices fabricated by sputtering or metal organic chemical vapor deposition processes. The reported approach offers new opportunities for preparing inorganic material-based resistive switching memory devices with tailored electronic properties, allowing facile solution processing. PMID:19725555

  19. Exposure to space radiation of high-performance infrared multilayer filters

    NASA Technical Reports Server (NTRS)

    Seeley, J. S.; Hawkins, G. J.; Hunneman, R.

    1991-01-01

    The University of Reading experiment exposed IR interference filters and crystal substrates on identical earth facing and leading-edge sites of the Long Duration Exposure Facility (LDEF). Filters mostly comprised multilayer coatings of lead telluride (PbTe)/II-IV on germanium (Ge) and other substrates: crystals comprised CdTe, MgF2, sapphire, quartz, silicon, and some softer materials. Identical control samples were maintained in the laboratory throughout the experiment. The filters were novel in their design, construction and manufacture, and categorized high-performance because of their ability to resolve emission spectra of the important atmospheric gases for various purposes in remote sensing. No significant changes were found in the spectra of the hard-coated filters or in the harder crystals (the softer materials were degraded to an extent). By virtue of this well-documented and long exposure in LDEF, the qualification of the filter type is significantly improved for its future requirements.

  20. Biomedical applications of polypeptide multilayer nanofilms and microcapsules

    NASA Astrophysics Data System (ADS)

    Rudra, Jai Simha S.

    The past few years have witnessed considerable growth in synthetic polymer chemistry and physics, biomaterials science, and nano-scale engineering. Research on polypeptide multilayer films, coatings, and microcapsules is located at the intersection of these areas and are promising materials for applications in medicine, biotechnology, environmental science. Most envisioned applications of polypeptide multilayers have a biomedical bent. This dissertation on polypeptide multilayer film applications covers key points of polypeptides as materials, means of polymer production, film preparation, film characterization methods, and key points of current research in basic science. Both commercial and designed peptides have been used to fabricate films for in-vitro applications such as antimicrobial coatings and cell culture coatings and also microcapsules for drug delivery applications. Other areas of product development include artificial red blood cells, anisotropic coatings, enantioselective membranes, and artificial viruses.

  1. Hardness Study of the Pulse Electrodeposited Nanoscale Multilayers of CR-NI

    NASA Astrophysics Data System (ADS)

    Etminanfar, M. R.; Heydarzadeh Sohi, M.

    Nanoscale multilayers of Cr-Ni coatings were deposited on low carbon steel by pulse electroplating and agitation modulation in chromium (III)-nickel (II) bath. The coatings were characterized by using SEM, EDS, XRD and microhardness techniques. For hardness measurement, the total thickness of the coatings was fixed at 5 μm and the thickness of the monolayers in the coatings varied from 20 to 100 nm. Single chromium and single nickel coatings with similar thickness of 5 μm were also produced by using DC electroplating. Microhardness testing was carried out on the surface of the coatings by using a range of loads from 25 to 1000 gf. A composite hardness model was used to estimate and compare the hardness of the single and multilayer coatings. It was shown that multilayer deposition significantly increases the hardness of the coating and the hardness increases further as the thickness of the nano- monolayers is reduced.

  2. Facile synthesis of mesoporous ZnCo2O4 coated with polypyrrole as an anode material for lithium-ion batteries

    NASA Astrophysics Data System (ADS)

    Zhong, Xiao-Bin; Wang, Hui-Yuan; Yang, Zhi-Zheng; Jin, Bo; Jiang, Qi-Chuan

    2015-11-01

    Although many research efforts have been devoted to improving the electrochemical performance of ZnCo2O4, there is still a great need for a facile, low cost and time-saving method to synthesize ZnCo2O4. Herein, we first report a facile method to prepare mesoporous ZnCo2O4 with polypyrrole (PPy) coating (ZnCo2O4/PPy). The facile strategy involves a reflux method and a subsequent chemical polymerization method. The mesoporous ZnCo2O4/PPy shows an outstanding electrochemical performance. The discharge capacity of the ZnCo2O4/PPy is 615 mAh g-1 after 100 cycles at a current density of 0.1 A g-1. When the current density increases to 0.2 A g-1, the discharge capacity still retains 458 mAh g-1 after 100 cycles. The improved electrochemical performance is attributed to the coating of PPy layer, which acts as a conductive agent and buffer during charge/discharge. Our results demonstrate that the ZnCo2O4/PPy has potential as a high-energy anode material for lithium-ion batteries.

  3. A facile and cost-effective method for separation of oil-water mixtures using polymer-coated iron oxide nanoparticles.

    PubMed

    Palchoudhury, Soubantika; Lead, Jamie R

    2014-12-16

    Catastrophic oil spills and oil from waste waters such as bilge and fracking waters pose major environmental concerns. The limitations of existing cleanup techniques for benign oil remediation has inspired a recent scientific impetus to develop oil-absorbing smart nanomaterials. Magnetic nanocomposites were here designed to allow easy recovery from various systems. In this study, sorption of reference MC252 oil with easy-to-synthesize and low-cost hydrophilic polyvinylpyrrolidone-coated iron oxide nanoparticles is reported for the first time. The one-step modified polyol synthesis in air directly generates water-soluble nanoparticles. Stable polyvinylpyrrolidone-coatings are known to minimize environmental alterations of nanoparticles from aggregation and other processes. Iron oxide provides effective magnetic actuation, while both PVP and iron oxide have low toxicity. These nanoparticles gave quantitative (near 100%) oil removal under optimized conditions. The facile synthesis and ease of use represents a significant improvement over existing techniques. PMID:25409536

  4. Nanoassemblies constructed from bimodal mesoporous silica nanoparticles and surface-coated multilayer pH-responsive polymer for controlled delivery of ibuprofen.

    PubMed

    Guo, Yueyue; Sun, Jihong; Bai, Shiyang; Jin, Xiaoqi

    2016-09-01

    The pH-sensitive poly(D-A) grafted amine-functionalized bimodal mesoporous silica (D-A/BMMs) was prepared by a facile method used as a drug delivery vehicle. They exhibited superior properties such as good dispersion in aqueous medium, high drug loading efficiency, improved stability and high drug release rates. Meanwhile, its structural features and performances in a controlled delivery of ibuprofen (IBU) were systematically investigated by using XRD, N2 adsorption and desorption, SEM, TEM, FT-IR, elemental analysis and TG techniques. The results demonstrated that the obtained nanocomposite presented a flexible control over drug release by controlling the grafting amount of D-A onto the mesopores surface of aminated BMMs. The cumulative percent release of IBU from D-A/BMMs was found to be much higher at pH 7.4 than at pH 2.0. The release rate was very slow in an acidic medium but became faster in a neutral medium, owing to hydrogen bonding in an acidic medium and electrostatic repulsion between negatively charged carboxyl groups in an alkaline medium. PMID:27278781

  5. A facile method of fabricating mechanical durable anti-icing coatings based on CeO2 microparticles

    NASA Astrophysics Data System (ADS)

    Wang, Pengren; Peng, Chaoyi; Wu, Binrui; Yuan, Zhiqing; Yang, Fubiao; Zeng, Jingcheng

    2015-07-01

    Compromising between hydrophobicity and mechanical durability may be a feasible approach to fabricating usable anti-icing coatings. This work improves the contact angle of current commercial anti-icing coatings applied to wind turbine blades dramatically and keeps relatively high mechanical durability. CeO2 microparticles and diluent were mixed with fluorocarbon resin to fabricate high hydrophobic coatings on the glass fiber reinforced epoxy composite substrates. The proportion of CeO2 microparticles and diluent influences the contact angles significantly. The optimum mass ratio of fluorocarbon resin to CeO2 microparticles to diluent is 1:1.5:1, which leads to the highest contact angle close to 140°. The microscopy analysis shows that the CeO2 microparticles form nano/microscale hierarchical structure on the surface of the coatings.

  6. Multilayer films with sharp, stable interfaces for use in EUV and soft X-ray application

    DOEpatents

    Barbee, Jr., Troy W.; Bajt, Sasa

    2002-01-01

    The reflectivity and thermal stability of Mo/Si (molybdenum/silicon) multilayer films, used in soft x-ray and extreme ultraviolet region, is enhanced by deposition of a thin layer of boron carbide (e.g., B.sub.4 C) between alternating layers of Mo and Si. The invention is useful for reflective coatings for soft X-ray and extreme ultraviolet optics, multilayer for masks, coatings for other wavelengths and multilayers for masks that are more thermally stable than pure Mo/Si multilayers

  7. Facile synthesis and intraparticle self-catalytic oxidation of dextran-coated hollow Au-Ag nanoshell and its application for chemo-thermotherapy.

    PubMed

    Jang, Hongje; Kim, Young-Kwan; Huh, Hyun; Min, Dal-Hee

    2014-01-28

    Galvanic replacement reaction is a useful method to prepare various hollow nanostructures. We developed fast and facile preparation of biocompatible and structurally robust hollow Au-Ag nanostructures by using dextran-coated Ag nanoparticles. Oxidation of the surface dextran alcohols was enabled by catalytic activity of the core Au-Ag nanostructure, introducing carbonyl groups that are useful for further bioconjugation. Subsequent doxorubicin (Dox) conjugation via Schiff base formation was achieved, giving high payload of approximately 35 000 Dox per particle. Near-infrared-mediated photothermal conversion showed high efficacy of the Dox-loaded Au-Ag nanoshell as a combinational chemo-thermotherapy to treat cancer cells. PMID:24383549

  8. Laser bonding of multilayer polymer microfluidic chips

    NASA Astrophysics Data System (ADS)

    Lai, Jianjun; Yuan, Hui; Yi, Xin-Jian; Liu, Sheng

    2005-01-01

    Polymer microfluidic chips have stimulated great instrests in the field of biochemical and medical analysis due to their low prices, easy fabrication and biocompatibility. Recently multilayer microfluidic chips have been fabricated by adhesive bonding to form 3-D multilayer laminate. However adhesive bonding may introduce pollution as well as complexity in coating. A bonding system with compact diode laser is introduced and a novel method based on transparent bonding line for multilayer microfluidic chips is developed. This bonding method is based on transmission laser microwelding technique. In this method, a special colorless dye as laser absorber, thus transparent polymer sheets can be stacked and bonded layer by layer. Initial results and bonding performance have demonstrate the feasibility of this method.

  9. A new facility for manufacturing and testing very large narrow bandpass filters and other high performance optical coatings

    NASA Astrophysics Data System (ADS)

    Mooney, Thomas; Pawlewicz, Walter; Merrill, Michael; Leclerc, David; Hurd, Kerry

    2014-07-01

    Optical coatings are key elements of any optical system. They can reduce surface reflection loss, isolate spectral bands, re-direct the light path and split light beams by wavelength. For decades, astronomers have made use of these special characteristics embodied in Anti-Reflection (AR) coatings, Band Pass (BP) filters, mirrors and Dichroic Beamsplitters (DBS). In the last several years, a need has arisen for much larger high performance filters and coatings. This is being driven by the ever increasing size of new and planned telescopes with their correspondingly larger focal planes. Typical Broadband filters require modest wavelength uniformity and can be produced in legacy (existing) coating chambers, even in fairly large formats. However, some new instruments require narrow BP (NBP) filters of 60 cm or greater diameter in order to perform efficiently. Some planned systems will even require filters in the 75 cm diameter range. The implications for coating such large, very expensive optics are that the equipment must not only accommodate a large optic, but the process must achieve excellent uniformity over broad areas. It must also exhibit excellent performance, reproducibility and reliability in depositions consisting of well over one hundred layers and many hours duration. And finally, the spectral performance must be verifiable, not through an indirect method, but directly of the science optic itself. To address these challenges, Materion designed, built, tested and put into production a purposebuilt laboratory. This paper will describe in detail the elements of the lab creation and initial achievements.

  10. Corrosion protected, multi-layer fuel cell interface

    DOEpatents

    Feigenbaum, Haim; Pudick, Sheldon; Wang, Chiu L.

    1986-01-01

    An improved interface configuration for use between adjacent elements of a fuel cell stack. The interface is impervious to gas and liquid and provides resistance to corrosion by the electrolyte of the fuel cell. The multi-layer configuration for the interface comprises a non-cupreous metal-coated metallic element to which is film-bonded a conductive layer by hot pressing a resin therebetween. The multi-layer arrangement provides bridging electrical contact.

  11. Degradation of electro-optic components aboard LDEF. [long duration exposure facility

    NASA Technical Reports Server (NTRS)

    Blue, M. D.

    1992-01-01

    Re-measurement of the properties of a set of electro-optic components exposed to the low earth orbital environment aboard the Long Duration Exposure Facility (LDEF) indicates that most components survived quite well. Typical components showed some effects related to the space environment unless well protected. The effects were often small but significant. Results for semiconductor infrared detectors, lasers, LED's, filter, mirrors, and black paints will be presented. Semiconductor detectors and emitters were scarred but reproduced their original characteristics. Spectral characteristics of multi-layer dielectric filters and mirrors were found to be altered and degraded. Increased absorption in black paints indicates an increase in absorption sites, giving rise to enhanced performance as coatings for baffles and sunscreens. We find plastics and multi-layer dielectric coatings to be potentially unstable. Semiconductor devices, metal, and glass are more likely to be stable.

  12. Ultra-thin multilayer capacitors.

    SciTech Connect

    Renk, Timothy Jerome; Monson, Todd C.

    2009-06-01

    The fabrication of ultra-thin lanthanum-doped lead zirconium titanate (PLZT) multilayer ceramic capacitors (MLCCs) using a high-power pulsed ion beam was studied. The deposition experiments were conducted on the RHEPP-1 facility at Sandia National Laboratories. The goal of this work was to increase the energy density of ceramic capacitors through the formation of a multilayer device with excellent materials properties, dielectric constant, and standoff voltage. For successful device construction, there are a number of challenging requirements including achieving correct stoichiometric and crystallographic composition of the deposited PLZT, as well as the creation of a defect free homogenous film. This report details some success in satisfying these requirements, although 900 C temperatures were necessary for PLZT perovskite phase formation. These temperatures were applied to a previously deposited multi-layer film which was then post-annealed to this temperature. The film exhibited mechanical distress attributable to differences in the coefficient of thermal expansion (CTE) of the various layers. This caused significant defects in the deposited films that led to shorts across devices. A follow-on single layer deposition without post-anneal produced smooth layers with good interface behavior, but without the perovskite phase formation. These issues will need to be addressed in order for ion beam deposited MLCCs to become a viable technology. It is possible that future in-situ heating during deposition may address both the CTE issue, and result in lowered processing temperatures, which in turn could raise the probability of successful MLCC formation.

  13. Multi-layered oriented polyfluorene films.

    PubMed

    Nagamatsu, Shuichi; Misaki, Masahiro; Yoshida, Yuji; Azumi, Reiko; Tanigaki, Nobutaka; Yase, Kiyoshi

    2009-04-30

    Multilayered oriented polyfluorene (PF) films were obtained by applying thermal treatment procedure to a multilayered PF film constructed with fluorene derivatives layer formed on top of a highly oriented friction-transferred crystalline poly(9,9-dioctylfluorene) (PF8) film. The orientations in the multilayered PF films were investigated by polarized photoluminescence (PL) spectroscopy and grazing incident X-ray diffraction (GIXD) analysis. The results of the multilayered PF film constructed with spin-coated PF8 on friction-transferred PF8 indicate that the rearrangement of the upper PF8 layer is induced from the orientation of lower PF8 layer by thermal treatment at the nematic phase temperature. Polarized green emission from the multilayered oriented PF film was demonstrated using the blend of PF8 and poly(9,9-dioctylfluorene-co-benzothiadiazol) (F8BT) as green light emitter for upper layer. By this method, the polarized emission color can be tuned using polymer blends for upper layer similar to the liquid-crystalline polymer arrangement without using different materials as an underlying layer such as the rubbed polyimide. PMID:19351119

  14. Facile fabrication of ionic liquid doped polycarbazole coating for the headspace solid-phase microextraction of some environmental pollutants.

    PubMed

    Feng, Yuanyuan; Wu, Mian; Zhao, Faqiong; Zeng, Baizhao

    2016-02-01

    A novel polycarbazole (PCz)-ionic liquid (IL, i.e. 1-hydroxyethyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide, [HOEMIm][NTf2]) composite coating (PCz-IL) was fabricated by electrodeposition. The IL could facilitate the electrodeposition of poor-conductive PCz and a more porous coating was obtained. The composite coating exhibited enhanced extraction capacity for some environmental pollutants (i.e. o-chlorotoluene, p-bromotoluene, o-nitrotoluene, m-nitrotoluene, p-nitrotoluene), as they could interact through π-π and hydrophobic interactions. Compared with [HOEMIm][NTf2] coated fiber, some other PCz-IL fibers (here IL=1-hydroxyethyl-3-methylimidazolium hexafluorophosphate and 1-methyl-3-octylimidazolium hexafluorophosphate) and commercial fibers (i.e. polydimethylsiloxane and polyacrylate), the PCz-IL fiber showed better performance. It was used for the determination of the environmental pollutants by coupling with gas chromatography, the limits of detection were 47.8-65.9 ng L(-1) under the optimized conditions and the linear ranges were 0.1-500 μg L(-1) with correlation coefficients above 0.9947 for different compounds. The relative standard deviations (RSDs) were 3.4-4.6% for five successive extractions with single fiber, and the RSDs for inter-fiber were 6.5-10.4% (n=5). The fiber was successfully applied to the detection of real samples and the recoveries for standards added were 88.6-108.8% with RSDs below 9.7%. PMID:26653460

  15. Facile Layer-by-Layer Self-Assembly toward Enantiomeric Poly(lactide) Stereocomplex Coated Magnetite Nanocarrier for Highly Tunable Drug Deliveries.

    PubMed

    Li, Zibiao; Yuan, Du; Jin, Guorui; Tan, Beng H; He, Chaobin

    2016-01-27

    A highly tunable nanoparticle (NP) system with multifunctionalities was developed as drug nanocarrier via a facile layer-by-layer (LbL) stereocomplex (SC) self-assembly of enantiomeric poly(l-lactic acid) (PLLA) and poly(d-lactic acid) (PDLA) in solution using silica-coated magnetite (Fe3O4@SiO2) as template. The poly(lactide) (PLA) SC coated NPs (Fe3O4@SiO2@-SC) were further endowed with different stimuli-responsiveness by controlling the outermost layer coatings with respective pH-sensitive poly(lactic acid)-poly(2-dimethylaminoethyl methacrylate) (PLA-D) and temperature-sensitive poly(lactic acid)-poly(N-isopropylacrylamide) (PLA-N) diblock copolymers to yield Fe3O4@SiO2@SC-D and Fe3O4@SiO2@SC-N NPs, respectively, while the superparamagnetic properties of Fe3O4 were maintained. TEM images show a clearly resolved core-shell structure with a silica layer and sequential PLA SC co/polymer coating layers in the respective NPs. The well-designed NPs possess a size distribution in a range of 220-270 nm and high magnetization of 70.8-72.1 emu/g [Fe3O4]. More importantly, a drug release study from the as-constructed stimuli-responsive NPs exhibited sustained release profiles and the rates of release can be tuned by variation of external environments. Further cytotoxicity and cell culture studies revealed that PLA SC coated NPs possessed good cell biocompatibility and the doxorubicin (DOX)-loaded NPs showed enhanced drug delivery efficiency toward MCF-7 cancer cells. Together with the strong magnetic sensitivity, the developed hybrid NPs demonstrate a great potential of control over the drug release at a targeted site. The developed coating method can be further optimized to finely tune the nanocarrier size and operating range of pHs and temperatures for in vivo applications. PMID:26717323

  16. Fabrication of multilayer nanowires

    NASA Astrophysics Data System (ADS)

    Kaur, Jasveer; Singh, Avtar; Kumar, Davinder; Thakur, Anup; Kaur, Raminder

    2016-05-01

    Multilayer nanowires were fabricated by potentiostate ectrodeposition template synthesis method into the pores of polycarbonate membrane. In present work layer by layer deposition of two different metals Ni and Cu in polycarbonate membrane having pore size of 600 nm were carried out. It is found that the growth of nanowires is not constant, it varies with deposition time. Scanning electron microscopy (SEM) is used to study the morphology of fabricated multilayer nanowires. An energy dispersive X-ray spectroscopy (EDS) results confirm the composition of multilayer nanowires. The result shows that multilayer nanowires formed is dense.

  17. Facile synthesis of low crystalline MoS2 nanosheet-coated CNTs for enhanced hydrogen evolution reaction.

    PubMed

    Yan, Ya; Ge, Xiaoming; Liu, Zhaolin; Wang, Jing-Yuan; Lee, Jong-Min; Wang, Xin

    2013-09-01

    In this work, a networked MoS2/CNT nanocomposite has been synthesized by a facile solvothermal method. The as-prepared sample exhibits high catalytic activity for electrocatalytic hydrogen evolution. PMID:23884193

  18. Long Duration Exposure Facility M0003-5 thermal control coatings on DoD flight experiment

    NASA Technical Reports Server (NTRS)

    Hurley, Charles J.; Lehn, William L.

    1992-01-01

    The M0003-5 thermal control coatings and materials orbited on the LDEF M0003 Space Environment Effects on Spacecraft Materials were a part of a Wright Laboratories Materials Directorate larger experiment. They were selected from new materials which emerged from development programs during the 1978-1982 time frame. Included were materials described in the technical literature which were being considered or had been applied to satellites. Materials that had been exposed on previous satellite materials experiments were also included to provide data correlation with earlier space flight experiments. The objective was to determine the effect of the LDEF environment on the physical and optical properties of thermal control coatings and materials. One hundred and two specimens of various pigmented organic and inorganic coatings, metallized polymer thin films, optical solar reflectors, and mirrors were orbited on LDEF. The materials were exposed in four separate locations on the vehicle. The first set was exposed on the direct leading edge of the satellite. The second set was exposed on the direct trailing edge of the vehicle. The third and fourth sets were exposed in environmental exposure control canisters (EECC) located 30 degrees off normal to the leading and trailing edges. The purpose of the experiment was to understand the changes in the properties of materials before and after exposure to the space environment and to compare the changes with predictions based on laboratory experiments. The basic approach was to measure the optical and physical properties of materials before and after long-term exposure to a low earth orbital environment comprised of UV, VUV, electrons, protons, atomic oxygen, thermal cycling, vacuum, debris, and micrometeoroids. Due to the unanticipated extended orbital flight of LDEF, the thermal control coatings and materials in the direct leading and trailing edge were exposed for a full five years and ten months to the space environment and the

  19. Mitigation of substrate defects in reflective reticles using sequential coating and annealing

    DOEpatents

    Mirkanimi, Paul B.

    2002-01-01

    A buffer-layer to minimize the size of defects on a reticle substrate prior to deposition of a reflective coating on the substrate. The buffer-layer is formed by either a multilayer deposited on the substrate or by a plurality of sequentially deposited and annealed coatings deposited on the substrate. The plurality of sequentially deposited and annealed coating may comprise multilayer and single layer coatings. The multilayer deposited and annealed buffer layer coatings may be of the same or different material than the reflecting coating thereafter deposited on the buffer-layer.

  20. Recent Developments of Multilayer Mirror Optics for Laboratory X-ray Instrumentation

    NASA Astrophysics Data System (ADS)

    Michaelsen, Carsten; Wiesmann, Jörg; Hoffmann, C.; Wulf, K.; Brugemann, Lutz; Storm, A.

    2002-12-01

    In this paper we review various improvements that we made in the development of multilayer mirror optics for home-lab x-ray analytical equipment in recent years. For the detection of light elements using x-ray fluorescence spectrometry, we developed a number of new multilayers with improved detection limits. In detail, we found that La/B4C multilayers improve the detection limit of boron by 29 % compared to the previous Mo/B4C multilayers. For the detection of carbon, TiO2/C multilayers improve the detection limit also by 29 % compared to the V/C multilayers previously used. For the detection of aluminum, WSi2/Si or Ta/Si multilayers can lead to detection limit improvements over the current W/Si multilayers of up to 60 % for samples on silicon wafers. For the use as beam-conditioning elements in x-ray diffractometry, curved optics coated with laterally d-spacing graded multilayers give rise to major improvements concerning usable x-ray intensity and beam quality. Recent developments lead to a high quality of these multilayer optics concerning beam intensity, divergence, beam uniformity and spectral purity. For example, x-ray reflectometry instruments equipped with such multilayer optics have dynamic ranges previously only available at synchrotron sources. Two-dimensional focusing multilayer optics are shown to become essential optical elements in protein crystallography and structural proteomics.

  1. An amorphous fluoropolymer: Next generation optical coating candidate

    SciTech Connect

    Chow, R.; Loomis, G.E.; Spragge, M.K.; Lindsey, E.L.; Rainer, F.; Ward, R.L.; Kozlowski, M.R.

    1994-05-01

    Anti-reflective (AR) and high reflector (HR) optical coatings were made by physical vapor deposition (PVD) of Teflon AF2400, a perfluorinated amorphous polymer. The AR had the highest laser damage thresholds recorded for PVD coatings at the Lawrence Livermore National Laboratory damage facility. The HR was a multilayer of ZnS and AF2400. The bandwidth was 550 mn, centered at 1064 mn. Single layers of Teflon AF2400 deposited by PVD were characterized optically. The refractive index could be intentionally reduced below the bulk value by varying either deposition rate or substrate temperature. Scanning electron microscopy and nuclear magnetic resonance observations indicated that morphological changes caused the variations in the refractive index rather than compositional changes.

  2. Facile synthesis of gold coated copper(II) hydroxide pine-needle-like micro/nanostructures for surface-enhanced Raman scattering

    NASA Astrophysics Data System (ADS)

    Long, Kailin; Du, Deyang; Luo, Xiaoguang; Zhao, Weiwei; Wu, Zhangting; Si, Lifang; Qiu, Teng

    2014-08-01

    This work reports a facile method to fabricate gold coated copper(II) hydroxide pine-needle-like micro/nanostructures for surface-enhanced Raman scattering (SERS) application. The effects of reaction parameters on the shape, size and surface morphology of the products are systematically investigated. The as-prepared 3D hierarchical structures have the advantage of a large surface area available for the formation of hot spots and the adsorption of target analytes, thus dramatically improving the Raman signals. The finite difference time domain calculations indicate that the pine-needle-like model pattern may demonstrate a high quality SERS property owing to the high density and abundant hot spot characteristic in closely spaced needle-like arms.

  3. A Facile and Effective Approach to Fabricate Chitosan/Hydroxyapatite Nanocomposite Coating on the Surface of Wood from Chinese Glossy Privet.

    PubMed

    Wang, Ning; Cai, Chuanjie; Cheng, Junjie; Li, Shengli; Cai, Dongqing; Wu, Zhengyan

    2016-06-01

    A chitosan/hydroxyapatite nanocomposite coating was fabricated on the surface of wood from Chinese Glossy Privet (CGP) and could adhere compactly to the wood surface. Fourier transform infrared spectra analysis indicated that the interaction between chitosan and hydroxyapatite might exist. In addition, sodium bicarbonate was added into the nanocomposite during the preparation process making the boating porous in acidic surrounding through effervescence effect. Field emission scanning electron microscope characterizations showed the nanocomposite (M(CS):M(HA) = 1:1, with 30% NaHCO3) was optimal and such composite was stable, which was verified by thermal analysis and in vitro degradation study. This work could provide a facile and effective fabricating approach of biocompatible material which may have some potential applications as bone-repairing material. PMID:27427648

  4. Influence of gas humidity on the reflection coefficient of multilayer dielectric mirrors.

    PubMed

    Serdyukov, V I; Sinitsa, L N; Lugovskoi, A A

    2016-06-10

    The influence of water vapor on the reflection coefficient of multilayer mirrors was studied using a gas cell with multiple reflections from the mirrors. A strong change in the reflection coefficient of the mirrors (up to 0.9%) was found when water vapor under a pressure of 23 mbar was injected into the cell, which was interpreted as a change in the refraction index of the layers of multilayer coatings when water vapor penetrated into the porous coating structure. PMID:27409037

  5. Facile synthesis of superhydrophobic surface of ZnO nanoflakes: chemical coating and UV-induced wettability conversion

    NASA Astrophysics Data System (ADS)

    Yao, Lujun; Zheng, Maojun; Li, Changli; Ma, Li; Shen, Wenzhong

    2012-04-01

    This work reports an oriented growth process of two-dimensional (2D) ZnO nanoflakes on aluminum substrate through a low temperature hydrothermal technique and proposes the preliminary growth mechanism. A bionic superhydrophobic surface with excellent corrosion protection over a wide pH range in both acidic and alkaline solutions was constructed by a chemical coating treatment with stearic acid (SA) molecules on ZnO nanoflakes. It is found that the superhydrophobic surface of ZnO nanoflake arrays shows a maximum water contact angle (CA) of 157° and a low sliding angle of 8°, and it can be reversibly switched to its initial superhydrophilic state under ultraviolet (UV) irradiation, which is due to the UV-induced decomposition of the coated SA molecules. This study is significant for simple and inexpensive building of large-scale 2D ZnO nanoflake arrays with special wettability which can extend the applications of ZnO films to many other important fields.

  6. Facile synthesis of biocompatible cysteine-coated CuS nanoparticles with high photothermal conversion efficiency for cancer therapy.

    PubMed

    Liu, Xijian; Li, Bo; Fu, Fanfan; Xu, Kaibing; Zou, Rujia; Wang, Qian; Zhang, Bingjie; Chen, Zhigang; Hu, Junqing

    2014-08-14

    The semiconductor compounds have been proven to be promising candidates as a new type of photothermal therapy agent, but unsatisfactory photothermal conversion efficiencies limit their widespread application in photothermal therapy (PTT). Herein, we synthesized cysteine-coated CuS nanoparticles (Cys-CuS NPs) as highly efficient PTT agents by a simple aqueous solution method. The Cys-CuS NPs have a good biocompatibility owing to their biocompatible cysteine coating and exhibit a strong absorption in the near-infrared region due to the localized surface plasma resonances of valence-band free carriers. The photothermal conversion efficiency of Cys-CuS NPs reaches 38.0%, which is much higher than that of the recently reported Cu9S5 and Cu(2-x)Se nanocrystals. More importantly, tumor growth can be efficiently inhibited in vivo by the fatal heat arising from the excellent photothermal effect of Cys-CuS NPs at a low concentration under the irradiation of a 980 nm laser with a safe power density of 0.72 W cm(-2). Therefore, the Cys-CuS NPs have great potential as ideal photothermal agents for cancer therapy. PMID:24950757

  7. Plasma deposition of thin film multilayers for surface engineering

    NASA Astrophysics Data System (ADS)

    Bhattacharyya, R.; Kumar, Sushil

    2012-06-01

    Plasma surface Engineering for enhancing optical and tribological behaviour of a surface is discussed. Specifically, it is shown how optimized PECVD processing can produce sophisticated Rugate filters and AR coatings on plastic lenses. It is found that multilayer Diamond Like Carbon coatings (DLC), in a functionally graded geometry, obtained by a combination of plasma intensive processing, not only can impart high value of hardness to a surface but also wear protection at high contact loads.

  8. Multilayer dielectric diffraction gratings

    DOEpatents

    Perry, Michael D.; Britten, Jerald A.; Nguyen, Hoang T.; Boyd, Robert; Shore, Bruce W.

    1999-01-01

    The design and fabrication of dielectric grating structures with high diffraction efficiency used in reflection or transmission is described. By forming a multilayer structure of alternating index dielectric materials and placing a grating structure on top of the multilayer, a diffraction grating of adjustable efficiency, and variable optical bandwidth can be obtained. Diffraction efficiency into the first order in reflection varying between 1 and 98 percent has been achieved by controlling the design of the multilayer and the depth, shape, and material comprising the grooves of the grating structure. Methods for fabricating these gratings without the use of ion etching techniques are described.

  9. Multilayer dielectric diffraction gratings

    DOEpatents

    Perry, M.D.; Britten, J.A.; Nguyen, H.T.; Boyd, R.; Shore, B.W.

    1999-05-25

    The design and fabrication of dielectric grating structures with high diffraction efficiency used in reflection or transmission is described. By forming a multilayer structure of alternating index dielectric materials and placing a grating structure on top of the multilayer, a diffraction grating of adjustable efficiency, and variable optical bandwidth can be obtained. Diffraction efficiency into the first order in reflection varying between 1 and 98 percent has been achieved by controlling the design of the multilayer and the depth, shape, and material comprising the grooves of the grating structure. Methods for fabricating these gratings without the use of ion etching techniques are described. 7 figs.

  10. Enhancing Casimir repulsion via topological insulator multilayers

    NASA Astrophysics Data System (ADS)

    Zeng, Ran; Chen, Liang; Nie, Wenjie; Bi, Meihua; Yang, Yaping; Zhu, Shiyao

    2016-08-01

    We propose to observe the enhanced Casimir repulsion between two parallel multilayer walls made of alternating layers of a topological insulator (TI) and a normal insulator. Based on the transfer matrix method, the Fresnel coefficients matrix is generalized to apply to the TI multilayer structure. The Casimir repulsion under the influence of the magnetization orientation in the magnetic coatings on TI layer surfaces, the layer thicknesses, and the topological magnetoelectric polarizability, is investigated. We show that, for the multilayer structures with parallel magnetization on the TI layer surfaces, it is possible to enhance the repulsion by increasing the TI layer number, which is due to the accumulation of the contribution to the repulsion from the polarization rotation effect occurring on each TI layer surface. Generally, in the distance region where there is Casimir attraction between semi-infinite TIs, the force may turn into repulsion in TI multilayer structure, and in the region of repulsion for semi-infinite TI, the repulsive force can be enhanced in magnitude, the enhancement tends to a maximum while the structure contains sufficiently many layers.

  11. Heat Transfer in High Temperature Multilayer Insulation

    NASA Technical Reports Server (NTRS)

    Daryabeigi, Kamran; Miller, Steve D.; Cunnington, George R.

    2007-01-01

    High temperature multilayer insulations have been investigated as an effective component of thermal-protection systems for atmospheric re-entry of reusable launch vehicles. Heat transfer in multilayer insulations consisting of thin, gold-coated, ceramic reflective foils and Saffil(TradeMark) fibrous insulation spacers was studied both numerically and experimentally. A finite volume numerical thermal model using combined conduction (gaseous and solid) and radiation in porous media was developed. A two-flux model with anisotropic scattering was used for radiation heat transfer in the fibrous insulation spacers between the reflective foils. The thermal model was validated by comparison with effective thermal conductivity measurements in an apparatus based on ASTM standard C201. Measurements were performed at environmental pressures in the range from 1x10(exp -4) to 760 torr over the temperature range from 300 to 1300 K. Four multilayer samples with nominal densities of 48 kg/cu m were tested. The first sample was 13.3 mm thick and had four evenly spaced reflective foils. The other three samples were 26.6 mm thick and utilized either one, two, or four reflective foils, located near the hot boundary with nominal foil spacing of 1.7 mm. The validated thermal model was then used to study relevant design parameters, such as reflective foil spacing and location in the stack-up and coating of one or both sides of foils.

  12. Facile synthesis of polyaniline-coated SiO₂ nanofiber and its application in enrichment of fluoroquinolones from honey samples.

    PubMed

    He, Xiao-Mei; Zhu, Gang-Tian; Zheng, Hao-Bo; Xu, Sheng-Nan; Yuan, Bi-Feng; Feng, Yu-Qi

    2015-08-01

    In this study, polyaniline coated SiO2 nanofibers (PANI/SiO2) was prepared by combining electrospinning technique with in-situ polymerization. The proposed strategy for the preparation of PANI/SiO2 can eliminate the aggregation of PANI and the yield of PANI/SiO2 was high. Scanning electron microscopy (SEM) images showed that PANI nanoparticles were uniformly coated on the surface of SiO2 nanofibers. The as-prepared PANI/SiO2 nanofibers were then applied as the sorbent for in-syringe dispersive solid-phase extraction (dSPE) for the extraction of fluoroquinolones (FQs) from honey samples. The influence of SiO2 amount on the formation of PANI/SiO2 and several parameters that affect the extraction efficiency were investigated. Under optimized conditions, a rapid, simple and effective method for the determination of FQs in honey sample was developed by coupling with liquid chromatography-fluorescence detector (LC-FLD) analysis. Due to the fast extraction equilibrium, the whole sample pretreatment process could be accomplished within 4 min. The limits of detection (LODs) for the target FQs were found to be 0.1-1.3 ng/g. The recoveries in honey sample were in the range of 81.4-118.1% with the RSDs of 0.8-14.4% (intra-day) and 1.4-14.9% (inter-day). This study offers a new strategy for the preparation of functional SiO2 nanofibers using post-electrospinning modification by in-situ polymerization, which could be generally applied in the preparation of various separation materials with electrospun nanofibers. PMID:26048819

  13. EUV-multilayers on grating-like topographies

    SciTech Connect

    van Boogaard, A. J. R.; Louis, E.; Goldberg, K. A.; Mochi, I.; Bijkerk, F.

    2010-03-12

    In this study, multilayer morphology near the key anomalies in grating-like structures, namely sharp step-edges and steep walls, are examined. Different deposition schemes are employed. Based on cross section TEM analysis an explanatory model describing the morphology of the successive layers is developed. A further insight into the periodicity and the general performance of the multilayer is obtained by EUV microscopy. The main distortions in multilayer structure and hence EUV performance are found to be restricted to a region within a few hundred nanometers from the anomalies, which is very small compared to the proposed grating period (50-100 {micro}m). These multilayer coated blazed gratings can thus be considered a viable option for spectral purity enhancement of EUV light sources.

  14. Photo-crosslinkable polymers for fabrication of photonic multilayer sensors

    NASA Astrophysics Data System (ADS)

    Chiappelli, Maria; Hayward, Ryan C.

    2013-03-01

    We have used photo-crosslinkable polymers to fabricate photonic multilayer sensors. Benzophenone is utilized as a covalently incorporated pendent photo-crosslinker, providing a convenient means of fabricating multilayer films by sequential spin-coating and crosslinking processes. Colorimetric temperature sensors were designed from thermally-responsive, low-refractive index poly(N-isopropylacrylamide) (PNIPAM) and high-refractive index poly(para-methyl styrene) (P pMS). Copolymer chemistries and layer thicknesses were selected to provide robust multilayer sensors which show color changes across nearly the full visible spectrum due to changes in temperature of the hydrated film stack. We have characterized the uniformity and interfacial broadening within the multilayers, the kinetics of swelling and de-swelling, and the reversibility over multiple hydration/dehydration cycles. We also describe how the approach can be extended to alternative sensor designs through the ability to tailor each layer independently, as well as to additional stimuli by selecting alternative copolymer chemistries.

  15. Spray Deposition of Multilayer Gas Barrier Thin Films

    NASA Astrophysics Data System (ADS)

    Givens, Tara; Xiang, Fangming; Grunlan, Jaime

    2015-03-01

    Dip-assisted assembly is the norm for making multilayer thin films (also known as layer-by-layer [LbL] assembly). Spray-based deposition possesses several advantages over dipping, but has not been studied in great detail, especially for gas barrier layers. In this study, polyethylenimine [PEI]/poly(acylic acid) [PAA] bilayers were deposited with varying spray parameters. Spraying time was found to be the most influential parameter to control the roughness, thickness, and gas barrier of the PEI/PAA assembly. A spray-coated sample was prepared using optimized parameters and compared to a dip-coated sample using the same deposition time (5s). The sprayed sample was better in terms of thickness, roughness, and gas barrier. This study is the first report showing that a sprayed multilayer assembly has better properties than its dipped counterpart. These findings could revolutionize the multilayer deposition process, making it more commercially-friendly.

  16. Mitigation of substrate defects in reticles using multilayer buffer layers

    DOEpatents

    Mirkarimi, Paul B.; Bajt, Sasa; Stearns, Daniel G.

    2001-01-01

    A multilayer film is used as a buffer layer to minimize the size of defects on a reticle substrate prior to deposition of a reflective coating on the substrate. The multilayer buffer layer deposited intermediate the reticle substrate and the reflective coating produces a smoothing of small particles and other defects on the reticle substrate. The reduction in defect size is controlled by surface relaxation during the buffer layer growth process and by the degree of intermixing and volume contraction of the materials at the multilayer interfaces. The buffer layers are deposited at near-normal incidence via a low particulate ion beam sputtering process. The growth surface of the buffer layer may also be heated by a secondary ion source to increase the degree of intermixing and improve the mitigation of defects.

  17. Multilayer refractory nozzles produced by plasma-spray process

    NASA Technical Reports Server (NTRS)

    Bliton, J. L.; Rausch, J. L.

    1966-01-01

    Multilayer rocket nozzles formed by plasma spraying have good thermal shock resistance and can be reheated in an oxidizing environment without loss of coating adherence. Suggested application of this process are for the production of refractory components, which can be formed as surfaces of revolution.

  18. Influence of microstructure on laser damage threshold of IBS coatings

    SciTech Connect

    Stolz, C.J.; Genin, F.Y.; Kozlowski, M.R.; Long, D.; Lalazari, R.; Wu, Z.L.; Kuo, P.K.

    1996-01-05

    Ion-beam sputtering (IBS) coatings were developed for the laser gyro industry to meet significantly different requirements than those of fusion lasers. Laser gyro mirrors are small (< 25 mm) and require low losses (< 30 ppm typical) and high stability with long exposures to low power laser energy. In contrast, fusion laser optics are large (< 1 meter), have significantly reduced loss requirements (< 5,000 ppm) and high damage thresholds (> 26 J/cm{sup 2} at 1,064 nm with 3-ns pulses). As part of the National Ignition Facility (NIF) coating development effort, IBS coatings are being studied to explore the possible benefits of this technology to NIF optics. As an initial step to achieving the NIF size and damage threshold requirements, the coating process is being scaled to uniformly coat a 20 x 40 cm{sup 2} area with reduced spectral, reflected wavefront, and laser damage threshold requirements. Here, multilayer coatings deposited by ion-beam sputtering with amorphous layers were found to have lower damage thresholds at 1,064 nm than similar coatings with crystalline layers. Interestingly, at higher fluences the damage was less severe for the amorphous coatings. The magnitude of the difference in damage thresholds between the two different microstructures was strongly influenced by the size of the tested area. To better understand the microstructure effects, single layers of HfO{sub 2} with different microstructures were studied using transmission electron microscopy, ellipsometry, and a photothermal deflection technique. Since the laser damage initiated at defects, the influence of thermal diffusivity on thermal gradients in nodular defects is also presented.

  19. Multilayer heterostructures and their manufacture

    SciTech Connect

    Hammond, Scott R; Reese, Matthew; Rupert, Benjamin; Miedaner, Alexander; Curtis, Clavin; Olson, Dana; Ginley, David S

    2015-11-04

    A method of synthesizing multilayer heterostructures including an inorganic oxide layer residing on a solid substrate is described. Exemplary embodiments include producing an inorganic oxide layer on a solid substrate by a liquid coating process under relatively mild conditions. The relatively mild conditions include temperatures below 225.degree. C. and pressures above 9.4 mb. In an exemplary embodiment, a solution of diethyl aluminum ethoxide in anhydrous diglyme is applied to a flexible solid substrate by slot-die coating at ambient atmospheric pressure, and the diglyme removed by evaporation. An AlO.sub.x layer is formed by subjecting material remaining on the solid substrate to a relatively mild oven temperature of approximately 150.degree. C. The resulting AlO.sub.x layer exhibits relatively high light transmittance and relatively low vapor transmission rates for water. An exemplary embodiment of a flexible solid substrate is polyethylene napthalate (PEN). The PEN is not substantially adversely affected by exposure to 150.degree. C

  20. Advances in Low-Defect Multilayers for EUVL Mask Blanks

    SciTech Connect

    Folta, J A; Davidson, J C; Larson, C C; Walton, C C; Kearney, P A

    2002-04-15

    Low-defect multilayer coatings are required to fabricate mask blanks for Extreme Ultraviolet Lithography (EUVL). The mask blanks consist of high reflectance E W multilayers on low thermal expansion substrates. A defect density of 0.0025 printable defects/cm{sup 2} for both the mask substrate and the multilayer is required to provide a mask blank yield of 60%. Current low defect multilayer coating technology allows repeated coating-added defect levels of 0.05/cm{sup 2} for defects greater than 90 nm polystyrene latex sphere (PSL) equivalent size for lots of 20 substrates. Extended clean operation of the coating system at levels below 0.08/cm{sup 2} for 3 months of operation has also been achieved. Two substrates with zero added defects in the quality area have been fabricated, providing an existence proof that ultra low defect coatings are possible. Increasing the ion source-to-target distance from 410 to 560 mm to reduce undesired coating of the ion source caused the defect density to increase to 0.2/cm{sup 2}. Deposition and etching diagnostic witness substrates and deposition pinhole cameras showed a much higher level of ion beam spillover (ions missing the sputter target) than expected. Future work will quantify beam spillover, and test designs to reduce spillover, if it is confirmed to be the cause of the increased defect level. The LDD system will also be upgraded to allow clean coating of standard format mask substrates. The upgrade will confirm that the low defect process developed on Si wafers is compatible with the standard mask format 152 mm square substrates, and will provide a clean supply of EUVL mask blanks needed to support development of EUVL mask patterning processes and clean mask handling technologies.

  1. Templated biomimetic multifunctional coatings

    NASA Astrophysics Data System (ADS)

    Sun, Chih-Hung; Gonzalez, Adriel; Linn, Nicholas C.; Jiang, Peng; Jiang, Bin

    2008-02-01

    We report a bioinspired templating technique for fabricating multifunctional optical coatings that mimic both unique functionalities of antireflective moth eyes and superhydrophobic cicada wings. Subwavelength-structured fluoropolymer nipple arrays are created by a soft-lithography-like process. The utilization of fluoropolymers simultaneously enhances the antireflective performance and the hydrophobicity of the replicated films. The specular reflectivity matches the optical simulation using a thin-film multilayer model. The dependence of the size and the crystalline ordering of the replicated nipples on the resulting antireflective properties have also been investigated by experiment and modeling. These biomimetic materials may find important technological application in self-cleaning antireflection coatings.

  2. Advancements in hard x-ray multilayers for x-ray astronomy

    NASA Astrophysics Data System (ADS)

    Windt, David L.

    2015-09-01

    This paper is focused on recent progress in the development of broad-band multilayer coatings designed for hard X-ray energies, for use in future astronomical telescopes. We describe a new laboratory-based hard X-ray reflectometer for atwavelength characterization of multilayer films, we present the results of an experimental comparison of the hard X-ray performance of several W-based periodic multilayer coatings, and we describe the optimization and experimental performance of new non-periodic Co-based multilayer coatings (both depth-graded and aperiodic), designed for continuous response through the W and Pt K-edges near 70 and 80 keV, respectively. We discuss future research directions in light of these new results.

  3. Lubricant Coating Process

    NASA Technical Reports Server (NTRS)

    1989-01-01

    "Peen Plating," a NASA developed process for applying molybdenum disulfide, is the key element of Techniblast Co.'s SURFGUARD process for applying high strength solid lubricants. The process requires two machines -- one for cleaning and one for coating. The cleaning step allows the coating to be bonded directly to the substrate to provide a better "anchor." The coating machine applies a half a micron thick coating. Then, a blast gun, using various pressures to vary peening intensities for different applications, fires high velocity "media" -- peening hammers -- ranging from plastic pellets to steel shot. Techniblast was assisted by Rural Enterprises, Inc. Coating service can be performed at either Techniblast's or a customer's facility.

  4. Effect of hydrogen concentration in conventional and IAD coatings on the absorption and laser-induced damage at 10.6 μm

    NASA Astrophysics Data System (ADS)

    Rahe, Manfred; Ristau, Detlev; Schmidt, Holger

    1993-06-01

    In this paper, data of single layers of YbF3, BaF2, YF3, and NaF and multilayer coatings produced by conventional thermal evaporation (boat, e-beam) and ion assisted deposition (IAD) are compared. Hydrogen concentration depth profiling was performed using nuclear reaction analysis based on the reaction 1H(15N, (alpha) (gamma) )12C. Absorption was measured with the aid of a laser calorimeter and a cw CO2 laser. A computer-controlled test facility with a TEA CO2 laser was used for determining the 1-on-1 damage thresholds of the coatings. The results point out that the absorption and damage behavior of coatings for the CO2 laser wavelength are related to the total amount of species containing hydrogen. Most of the IAD coatings exhibit a lower hydrogen contamination than conventional thin films.

  5. Carbon and oxide coatings on continuous ceramic fibers

    SciTech Connect

    Hay, R.S.; Cinibulk, M.K.; Petry, M.D.; Keller, K.A.; Welch, J.R.

    1995-10-01

    Oxide-carbon multilayer coatings were continuously applied to various fibers of nominal SiC composition. A liquid-phase coating system that allows application of the coatings in a controlled atmosphere at relatively rapid rates was employed. Sugar-ammonium hydroxide solutions were used for carbon coatings, and aqueous sols were used for the oxides. Carbon was also deposited simultaneously with alumina by chemical vapor deposition of a hydrocarbon in the coating furnace. The coatings were extensively characterized by optical microscopy and TEM. Problems with embrittlement by oxide coatings and poor adherence of oxide coatings on carbon, and some possible solutions to these problems, are discussed.

  6. High-performance multilayer composite membranes with mussel-inspired polydopamine as a versatile molecular bridge for CO2 separation.

    PubMed

    Li, Panyuan; Wang, Zhi; Li, Wen; Liu, Yanni; Wang, Jixiao; Wang, Shichang

    2015-07-22

    It is desirable to develop high-performance composite membranes for efficient CO2 separation in CO2 capture process. Introduction of a highly permeable polydimethylsiloxane (PDMS) intermediate layer between a selective layer and a porous support has been considered as a simple but efficient way to enhance gas permeance while maintaining high gas selectivity, because the introduced intermediate layer could benefit the formation of an ultrathin defect-free selective layer owing to the circumvention of pore penetration phenomenon. However, the selection of selective layer materials is unfavorably restricted because of the low surface energy of PDMS. Various highly hydrophilic membrane materials such as amino group-rich polyvinylamine (PVAm), a representative facilitated transport membrane material for CO2 separation, could not be facilely coated over the surface of the hydrophobic PDMS intermediate layer uniformly. Inspired by the hydrophilic nature and strong adhesive ability of polydopamine (PDA), PDA was therefore selected as a versatile molecular bridge between hydrophobic PDMS and hydrophilic PVAm. The PDA coating endows a highly compatible interface between both components with a large surface energy difference via multiple-site cooperative interactions. The resulting multilayer composite membrane with a thin facilitated transport PVAm selective layer exhibits a notably enhanced CO2 permeance (1887 GPU) combined with a slightly improved CO2/N2 selectivity (83), as well as superior structural stability. Similarly, the multilayer composite membrane with a hydrophilic CO2-philic Pebax 1657 selective layer was also developed for enhanced CO2 separation performance. PMID:26121208

  7. Control of Multilayer Networks

    PubMed Central

    Menichetti, Giulia; Dall’Asta, Luca; Bianconi, Ginestra

    2016-01-01

    The controllability of a network is a theoretical problem of relevance in a variety of contexts ranging from financial markets to the brain. Until now, network controllability has been characterized only on isolated networks, while the vast majority of complex systems are formed by multilayer networks. Here we build a theoretical framework for the linear controllability of multilayer networks by mapping the problem into a combinatorial matching problem. We found that correlating the external signals in the different layers can significantly reduce the multiplex network robustness to node removal, as it can be seen in conjunction with a hybrid phase transition occurring in interacting Poisson networks. Moreover we observe that multilayer networks can stabilize the fully controllable multiplex network configuration that can be stable also when the full controllability of the single network is not stable. PMID:26869210

  8. Magnetic multilayer interface anisotropy

    SciTech Connect

    Pechan, M.J.

    1992-01-01

    Ni/Mo and Ni/V multilayer magnetic anisotropy has been investigated as a function of Ni layer thickness, frequency and temperature. Variable frequency ferromagnetic resonance (FMR) measurements show, for the first time, significant frequency dependence associated with the multilayer magnetic anisotropy. The thickness dependence allows one to extract the interface contribution from the total anisotropy. Temperature dependent FMR (9 GHz) and room temperature magnetization indicate that strain between Ni and the non-magnetic layers is contributing significantly to the source of the interface anisotropy and the state of the interfacial magnetization. In order to examine the interface properties of other transition metal multilayer systems, investigations on Fe/Cu are underway and CoCr/Ag is being proposed. ESR measurements have been reported on Gd substituted YBaCuO superconductors and a novel quasi-equilibrium method has been developed to determine quickly and precisely the ransition temperature.

  9. Multilayer mirror with enhanced spectral selectivity for the next generation extreme ultraviolet lithography

    SciTech Connect

    Medvedev, V. V. Kruijs, R. W. E. van de; Yakshin, A. E.; Novikova, N. N.; Krivtsun, V. M.; Louis, E.; Bijkerk, F.; Yakunin, A. M.

    2013-11-25

    We have demonstrated a hybrid extreme ultraviolet (EUV) multilayer mirror for 6.x nm radiation that provides selective suppression for infrared (IR) radiation. The mirror consists of an IR-transparent LaN∕B multilayer stack which is used as EUV-reflective coating and antireflective (AR) coating to suppress IR. The AR coating can be optimized to suppress CO{sub 2} laser radiation at the wavelength of 10.6 μm, which is of interest for application in next-generation EUV lithography systems.

  10. Analysis of selected materials flown on interior locations of the Long Duration Exposure Facility

    NASA Technical Reports Server (NTRS)

    Smith, H. A.; Nelson, K. M.; Eash, D.; Pippin, H. G.

    1994-01-01

    This report documents the post-flight condition of selected hardware taken from interior locations on the Long Duration Exposure Facility (LDEF). This hardware was generally in excellent condition. Outgassing data is presented for heat shrink tubing and fiberglass composite shims. Variation in total mass loss (TML) values for heat shrink tubing were correlated with location. Nylon grommets were evaluated for mechanical integrity; slight embrittlement was observed for flight specimens. Multi-layer insulation blankets, wire bundles, and paints in non-exposed interior locations were all in visibly good condition. Silicon-containing contaminant films were observed on silver-coated hex nuts at the space- and Earth-end interior locations.

  11. Adherent dielectric coating of diamond-turned mirrors.

    PubMed

    Saito, T T; Esposito, R R; Johnson, F E

    1978-01-01

    Adherent, high-reflectivity infrared, and multilayer dielectric coatings have been applied to diamond-turned aluminum, copper, and electroless nickel substrates. Samples passed cheesecloth, Scotch tape, salt fog, and humidity tests. PMID:19680392

  12. X-ray multilayer optics for Indus synchrotrons application

    NASA Astrophysics Data System (ADS)

    Nayak, Maheswar; Pradhan, P. C.; Lodha, G. S.

    2015-06-01

    We present the state-of-the-art X-ray multilayer optics fabrication facilities at Indus synchrotrons complex. The facilities are regularly used for fabrication of high quality x-ray multilayer structures. The results on two representative materials combination of Mo/Si and W/B4C are presented. In Mo/Si multilayer system, we have achieved ˜70% of reflectivity (near normal incidence angle) at soft x-ray region. Large area (300mm×50mm) Mo/Si multilayers are also successively fabricated for monochromator application in hard x-ray region. Whereas in W/B4C system, we demonstrate the capability of these facilities to fabricate ultra short period multilayer (periodicity ˜15-20 Å) with large number of layer pairs in the range of 200-400 for transmission polarizer near Fe L-edge and for monochromator application in hard x-ray region. Hard x-ray reflectivity of ˜54% is achieved from W/B4C MLs with periodicity ˜20 Å and number of layer pairs 300.

  13. Recent developments in highly durable protective/antireflection coatings for Ge and ZnS substrates

    NASA Astrophysics Data System (ADS)

    Hasan, Wasim; Propst, Steven H.

    1994-11-01

    Antireflection coated ZnS and Ge substrates erode under severe operational environmental conditions. High velocity water drop impact and high velocity sand particle impact are primarily military concerns that originated with the advent of faster aircraft. High speed flight through rain and sand storms seriously erodes forward facing components such as infrared transmitting windows and/or domes. This erosion of windows and/or domes causes reduction in transmission, resulting in the reduction of detection and recognition sensitivity of the electro-optical sensor. A single film of one quarterwave thick hard-carbon coating has been used on germanium to increase optical transmission (reducing Fresnel's reflection losses on Ge surface) as well as to reduce rain and sand impact damage to some extent, at a lower speed. At high speed, the damage becomes more severe, resulting in unacceptable large transmission losses. Recently, new hard carbon coatings have been developed for Ge which have substantially increased the damage threshold of the coated substrates. The rain erosion test was performed at Wright-Patterson AFB facility in Dayton, Ohio, and the sand tests were performed at PDA Engineering in Santa Ana, California. In addition, a multilayer AR coating utilizing hard carbon film as one of the low index films has also been developed at Hughes for ZnS substrates. The optical properties, rain erosion, sand erosion, and sand abrasion test results of these coatings are also presented in this paper.

  14. Advanced materials for multilayer mirrors for extreme ultraviolet solar astronomy.

    PubMed

    Bogachev, S A; Chkhalo, N I; Kuzin, S V; Pariev, D E; Polkovnikov, V N; Salashchenko, N N; Shestov, S V; Zuev, S Y

    2016-03-20

    We provide an analysis of contemporary multilayer optics for extreme ultraviolet (EUV) solar astronomy in the wavelength ranges: λ=12.9-13.3  nm, λ=17-21  nm, λ=28-33  nm, and λ=58.4  nm. We found new material pairs, which will make new spaceborne experiments possible due to the high reflection efficiencies, spectral resolution, and long-term stabilities of the proposed multilayer coatings. In the spectral range λ=13  nm, Mo/Be multilayer mirrors were shown to demonstrate a better ratio of reflection efficiency and spectral resolution compared with the commonly used Mo/Si. In the spectral range λ=17-21  nm, a new multilayer structure Al/Si was proposed, which had higher spectral resolution along with comparable reflection efficiency compared with the commonly used Al/Zr multilayer structures. In the spectral range λ=30  nm, the Si/B4C/Mg/Cr multilayer structure turned out to best obey reflection efficiency and long-term stability. The B4C and Cr layers prevented mutual diffusion of the Si and Mg layers. For the spectral range λ=58  nm, a new multilayer Mo/Mg-based structure was developed; its reflection efficiency and long-term stability have been analyzed. We also investigated intrinsic stresses inherent for most of the multilayer structures and proposed possibilities for stress elimination. PMID:27140543

  15. The NSLS-II Multilayer Laue Lens Deposition System

    SciTech Connect

    Conley, R.; Bouet, N.; Biancarosa, J.; Shen, Q.; Boas, L.; Feraca, J.; Rosenbaum, L.

    2009-08-02

    The NSLS-II[1] program has a requirement for an unprecedented level of x-ray nanofocusing and has selected the wedged multilayer Laue lens[2,3] (MLL) as the optic of choice to meet this goal. In order to fabricate the MLL a deposition system is required that is capable of depositing depth-graded and laterally-graded multilayers with precise thickness control over many thousands of layers, with total film growth in one run up to 100m thick or greater. This machine design expounds on the positive features of a rotary deposition system[4] constructed previously for MLLs and will contain multiple stationary, horizontally-oriented magnetron sources where a transport will move a substrate back and forth in a linear fashion over shaped apertures at well-defined velocities to affect a multilayer coating.

  16. Multi-layer surface profiling using gated wavefront sensing

    NASA Astrophysics Data System (ADS)

    Wang, Xin; Nordin, Nur Dalilla; Tik, Eddy Chow Mun; Tan, ChingSeong; Chew, Kuew Wai; Menoni, Carmen

    2015-01-01

    Recently, multi-layer surface profiling and inspection has been considered an emerging topic that can be used to solve various manufacturing inspection problems, such as graded index lenses, TSV (Thru-Silicon Via), and optical coating. In our study, we proposed a gated wavefront sensing approach to estimate the multi-layer surface profile. In this paper, we set up an experimental platform to validate our theoretical models and methods. Our test bed consists of pulse laser, collimator, prism, well-defined focusing lens, testing specimen, and gated wavefront sensing assembly (e.g., lenslet and gated camera). Typical wavefront measurement steps are carried out for the gated system, except the reflectance is timed against its time of flight as well as its intensity profile. By synchronizing the laser pulses to the camera gate time, it is possible to discriminate a multi-layer wavefront from its neighbouring discrete layer reflections.

  17. Construction of heparinylated multilayer films on Tisbnd O via streptavidin/biotin interaction

    NASA Astrophysics Data System (ADS)

    Weng, Y. J.; Jing, F. J.; Chen, J. Y.; Huang, N.

    2012-06-01

    Construction of heparinylated multilayer films on Tisbnd O via streptavidin/biotin interaction was conducted in the present study. An organic layer of 3-aminopropylphosphonic acid (APP) was first introduced on Tisbnd O by self-assembling, and then biotin was immobilized by photochemical methods. So streptavidin and biotinylated heparin were assembling through biorecognition, and a desired 6-layer heparinylated multilayer was obtained through layer-by-layer driven by streptavidin/biotin interaction. The in vitro platelet adhesion and activation were investigated by a static platelet adhesion test. The clotting time was examined by activated partial thromboplastin time (APTT). Results show that the heparinylated multilayer coated Tisbnd O can significantly decrease platelet adhesion and activation, and prolong clotting time of APTT compared to untreated Tisbnd O, which indicates the heparinylated multilayer coated Tisbnd O displays more excellent anticoagulation performance than that of the bare Tisbnd O.

  18. Antireflective Coatings for Glass and Transparent Polymers.

    PubMed

    Buskens, Pascal; Burghoorn, Marieke; Mourad, Maurice Christian Danho; Vroon, Zeger

    2016-07-12

    Antireflective coatings (ARCs) are applied to reduce surface reflections. We review coatings that reduce the reflection of the surface of the transparent substrates float glass, polyethylene terephthalate, poly(methyl methacrylate), and polycarbonate. Three main coating concepts exist to lower the reflection at the interface of a transparent substrate and air: multilayer interference coatings, graded index coatings, and quarter-wave coatings. We introduce and discuss these three concepts, and zoom in on porous quarter-wave coatings comprising colloidal particles. We extensively discuss the four routes for introducing porosity in quarter-wave coatings through the use of colloidal particles, which have the highest potential for application: (1) packing of dense nanospheres, (2) integration of voids through hollow nanospheres, (3) integration of voids through sacrificial particle templates, and (4) packing of nonspherical nanoparticles. Finally, we address the remaining challenges in the field of ARCs, and elaborate on potential strategies for future research in this area. PMID:27187719

  19. Coatings on reflective mask substrates

    DOEpatents

    Tong, William Man-Wai; Taylor, John S.; Hector, Scott D.; Mangat, Pawitter J. S.; Stivers, Alan R.; Kofron, Patrick G.; Thompson, Matthew A.

    2002-01-01

    A process for creating a mask substrate involving depositing: 1) a coating on one or both sides of a low thermal expansion material EUVL mask substrate to improve defect inspection, surface finishing, and defect levels; and 2) a high dielectric coating, on the backside to facilitate electrostatic chucking and to correct for any bowing caused by the stress imbalance imparted by either other deposited coatings or the multilayer coating of the mask substrate. An film, such as TaSi, may be deposited on the front side and/or back of the low thermal expansion material before the material coating to balance the stress. The low thermal expansion material with a silicon overlayer and a silicon and/or other conductive underlayer enables improved defect inspection and stress balancing.

  20. 40 CFR 60.460 - Applicability and designation of affected facility.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Performance for Metal Coil Surface Coating § 60.460 Applicability and designation of affected facility. (a... coating operation: each prime coat operation, each finish coat operation, and each prime and finish coat operation combined when the finish coat is applied wet on wet over the prime coat and both coatings...

  1. Multilayer bioactive glass/zirconium titanate thin films in bone tissue engineering and regenerative dentistry

    PubMed Central

    Mozafari, Masoud; Salahinejad, Erfan; Shabafrooz, Vahid; Yazdimamaghani, Mostafa; Vashaee, Daryoosh; Tayebi, Lobat

    2013-01-01

    Surface modification, particularly coatings deposition, is beneficial to tissue-engineering applications. In this work, bioactive glass/zirconium titanate composite thin films were prepared by a sol-gel spin-coating method. The surface features of the coatings were studied by scanning electron microscopy, atomic force microscopy, and spectroscopic reflection analyses. The results show that uniform and sound multilayer thin films were successfully prepared through the optimization of the process variables and the application of carboxymethyl cellulose as a dispersing agent. Also, it was found that the thickness and roughness of the multilayer coatings increase nonlinearly with increasing the number of the layers. This new class of nanocomposite coatings, comprising the bioactive and inert components, is expected not only to enhance bioactivity and biocompatibility, but also to protect the surface of metallic implants against wear and corrosion. PMID:23641155

  2. Multilayer bioactive glass/zirconium titanate thin films in bone tissue engineering and regenerative dentistry.

    PubMed

    Mozafari, Masoud; Salahinejad, Erfan; Shabafrooz, Vahid; Yazdimamaghani, Mostafa; Vashaee, Daryoosh; Tayebi, Lobat

    2013-01-01

    Surface modification, particularly coatings deposition, is beneficial to tissue-engineering applications. In this work, bioactive glass/zirconium titanate composite thin films were prepared by a sol-gel spin-coating method. The surface features of the coatings were studied by scanning electron microscopy, atomic force microscopy, and spectroscopic reflection analyses. The results show that uniform and sound multilayer thin films were successfully prepared through the optimization of the process variables and the application of carboxymethyl cellulose as a dispersing agent. Also, it was found that the thickness and roughness of the multilayer coatings increase nonlinearly with increasing the number of the layers. This new class of nanocomposite coatings, comprising the bioactive and inert components, is expected not only to enhance bioactivity and biocompatibility, but also to protect the surface of metallic implants against wear and corrosion. PMID:23641155

  3. Optical properties of gold-silica-gold multilayer nanoshells.

    PubMed

    Hu, Ying; Fleming, Ryan C; Drezek, Rebekah A

    2008-11-24

    The spectral and angular radiation properties of gold-silica-gold multilayer nanoshells are investigated using Mie theory for concentric multilayer spheres. The spectral tunability of multilayer nanoshells is explained and characterized by a plasmon hybridization model and a universal scaling principle. A thinner intermediate silica layer, scaled by particle size, red shifts the plasmon resonance. This shift is relatively insensitive to the overall particle size and follows the universal scaling principle with respect to the resonant wavelength of a conventional silica-gold core-shell nanoshell. The extra tunability provided by the inner core further shifts the extinction peak to longer wavelengths, which is difficult to achieve on conventional sub-100 nm nanoshells due to limitations in synthesizing ultrathin gold coatings. We found multilayer nanoshells to be more absorbing with a larger gold core, a thinner silica layer, and a thinner outer gold shell. Both scattering intensity and angular radiation pattern were found to differ from conventional nanoshells due to spectral modulation from the inner core. Multilayer nanoshells may provide more backscattering at wavelengths where silica-gold core-shell nanoshells predominantly forward scatter. PMID:19030045

  4. Analysis of the spatial filter of a dielectric multilayer film reflective cutoff filter-combination device

    NASA Astrophysics Data System (ADS)

    Zhang, Ying; Qi, Hong-Ji; Yi, Kui; Wang, Yan-Zhi; Sui, Zhan; Shao, Jian-Da

    2015-10-01

    The experiment setup of a reflecting combination device, which has more advantages than a transmitting combination device, is designed in this study. To achieve angular spectrum selectivity, only one type of reflective component is needed, so difficulties of design and preparation are reduced. A dielectric multilayer film is applied to the reflective component, and the long wave-pass coating stacks of the structure are designed. To achieve high stopband transmittance and reduce electric field intensity at a wavelength of 1053 nm, an objective function is proposed for designing an optimized coating. The final optimized coating has good spectral characteristics and a high laser-induced damage threshold. A dielectric multilayer film with high reflectance plays an important role in preparing and applying a dielectric multilayer film reflecting cutoff filter-combination device.

  5. [Method of multilayer assembly as alternative to antibacterial coverings of medicobiological implants].

    PubMed

    Ospanova, A K; Omarova, R A; Abdurazakov, U A; Jartybaev, R N; Iskakova, M K; Savdenbekova, B E; Amkhadova, M A

    2016-01-01

    Department of Traumatology and Orthopedics Almaty Kazakh Medical University of Continuing Education; 4. Moscow Regional Research Clinical Institute, Russia Resume: in this report we present the results on the use of the method of layer-by-layer (LbL) for obtaining antimicrobial coatings for biomedical implants. As the substrates were used silicon titanium implants and silicon plate. For the obtaining multilayer coatings on the surfaces of the samples were used as the polycation--chitosan and polyanion--carboxymethylcellulose sodium. On the surface multilayer were deposited antibacterial preparations: Triclosan-2,4,4'trichloro-2' hydroxyphenyl ether, silver ions and iodine. Microbiological studies were conducted on the museum strains: E. coli, Candida and Staf. Preliminary antibacterial studies on these microorganisms showed high activity multilayer coating containing triclosan. PMID:26925557

  6. Analysis of selected materials flown on interior locations of the Long Duration Exposure Facility. Report, October 1989-December 1993

    SciTech Connect

    Smith, H.A.; Nelson, K.M.; Eash, D.; Pippin, H.G.

    1994-04-01

    This report documents the post-flight condition of selected hardware taken from interior locations on the Long Duration Exposure Facility (LDEF). This hardware was generally in excellent condition. Outgassing data is presented for heat shrink tubing and fiberglass composite shims. Variation in total mass loss (TML) values for heat shrink tubing were correlated with location. Nylon grommets were evaluated for mechanical integrity; slight embrittlement was observed for flight specimens. Multi-layer insulation blankets, wire bundles, and paints in non-exposed interior locations were all in visibly good condition. Silicon-containing contaminant films were observed on silver-coated hex nuts at the space- and Earth-end interior locations.

  7. Reactive multilayer synthesis of hard ceramic foils and films

    DOEpatents

    Makowiecki, D.M.; Holt, J.B.

    1996-02-13

    A method is disclosed for synthesizing hard ceramic materials such as carbides, borides and aluminides, particularly in the form of coatings provided on another material so as to improve the wear and abrasion performance of machine tools, for example. The method involves the sputter deposition of alternating layers of reactive metals with layers of carbon, boron, or aluminum and the subsequent reaction of the multilayered structure to produce a dense crystalline ceramic. The material can be coated on a substrate or formed as a foil which can be coiled as a tape for later use.

  8. Reactive multilayer synthesis of hard ceramic foils and films

    DOEpatents

    Makowiecki, Daniel M.; Holt, Joseph B.

    1996-01-01

    A method for synthesizing hard ceramic materials such as carbides, borides nd aluminides, particularly in the form of coatings provided on another material so as to improve the wear and abrasion performance of machine tools, for example. The method involves the sputter deposition of alternating layers of reactive metals with layers of carbon, boron, or aluminum and the subsequent reaction of the multilayered structure to produce a dense crystalline ceramic. The material can be coated on a substrate or formed as a foil which can be coild as a tape for later use.

  9. Reactive multilayer synthesis of hard ceramic foils and films

    SciTech Connect

    Makowiecki, D.M.; Holt, J.B.

    1993-12-31

    Disclosed is method for synthesizing hard ceramic materials such as carbides, borides and aluminides, particularly in the form of coatings provided on another material so as to improve the wear and abrasion performance of machine tools, for example. Method involves the sputter deposition of alternating layers of reactive metals with layers of carbon, boron, or aluminum and the subsequent reaction of the multilayered structure to produce a dense crystalline ceramic. The material can be coated on a substrate or formed as a foil which can be coiled as a tape for later use.

  10. Interfacial thiol-ene photoclick reactions for forming multilayer hydrogels.

    PubMed

    Shih, Han; Fraser, Andrew K; Lin, Chien-Chi

    2013-03-13

    Interfacial visible light-mediated thiol-ene photoclick reactions were developed for preparing step-growth hydrogels with multilayer structures. The effect of a noncleavage type photoinitiator eosin-Y on visible-light-mediated thiol-ene photopolymerization was first characterized using in situ photorheometry, gel fraction, and equilibrium swelling ratio. Next, spectrophotometric properties of eosin-Y in the presence of various relevant macromer species were evaluated using ultraviolet-visible light (UV-vis) spectrometry. It was determined that eosin-Y was able to reinitiate the thiol-ene photoclick reaction, even after light exposure. Because of its small molecular weight, most eosin-Y molecules readily leached out from the hydrogels. The diffusion of residual eosin-Y from preformed hydrogels was exploited for fabricating multilayer step-growth hydrogels. Interfacial hydrogel coating was formed via the same visible-light-mediated gelation mechanism without adding fresh initiator. The thickness of the thiol-ene gel coating could be easily controlled by adjusting visible light exposure time, eosin-Y concentration initially loaded in the core gel, or macromer concentration in the coating solution. The major benefits of this interfacial thiol-ene coating system include its simplicity and cytocompatibility. The formation of thiol-ene hydrogels and coatings neither requires nor generates any cytotoxic components. This new gelation chemistry may have great utilities in controlled release of multiple sensitive growth factors and encapsulation of multiple cell types for tissue regeneration. PMID:23384151

  11. Development and testing of coatings for orbital space radiation environments.

    PubMed

    Pellicori, Samuel F; Martinez, Carol L; Hausgen, Paul; Wilt, David

    2014-02-01

    Specific coating processes and materials were investigated in the quest to develop multilayer coatings with greater tolerance to space radiation exposure. Ultraviolet reflection (UVR) and wide-band antireflection (AR) multilayer coatings were deposited on solar cell covers and test substrates and subsequently exposed to simulated space environments and also flown on the Materials International Space Station Experiment-7 (MISSE-7) to determine their space environment stability. Functional solar cells integrated with these coatings underwent simulated UV and MISSE-7 low earth orbit flight exposure. The effects of UV, proton, and atomic oxygen exposure on coatings and on assembled solar cells as related to the implemented deposition processes and material compositions were small. The UVR/AR coatings protected flexible polymer substrate materials that are intended for future flexible multijunction cell arrays to be deployed from rolls. Progress was made toward developing stable and protective coatings for extended space-mission applications. Test results are presented. PMID:24514237

  12. Ferroelectric properties of PZT/BFO multilayer thin films prepared using the sol-gel method

    PubMed Central

    2012-01-01

    In this study, Pb(Zr0.52Ti0.48)O3/BiFeO3 [PZT/BFO] multilayer thin films were fabricated using the spin-coating method on a Pt(200 nm)/Ti(10 nm)/SiO2(100 nm)/p-Si(100) substrate alternately using BFO and PZT metal alkoxide solutions. The coating-and-heating procedure was repeated several times to form the multilayer thin films. All PZT/BFO multilayer thin films show a void-free, uniform grain structure without the presence of rosette structures. The relative dielectric constant and dielectric loss of the six-coated PZT/BFO [PZT/BFO-6] thin film were approximately 405 and 0.03%, respectively. As the number of coatings increased, the remanent polarization and coercive field increased. The values for the BFO-6 multilayer thin film were 41.3 C/cm2 and 15.1 MV/cm, respectively. The leakage current density of the BFO-6 multilayer thin film at 5 V was 2.52 × 10-7 A/cm2. PMID:22221519

  13. Facile, soot free approach toward synthesis of carbon nanoropes via chemical vapor deposition of acetylene in the presence of MnFe2O4 coated on stainless steel

    NASA Astrophysics Data System (ADS)

    Dhand, Vivek; Bharadwaj, S.; Amareshwari, K.; Himabindu, V.; Rhee, Kyong Yop; Park, Soo-Jin; Hui, David

    2015-12-01

    High density, soot free, novel and a facile approach toward synthesis of carbon nanoropes (CNRs) were successfully carried out in a chemical vapor deposition (CVD) process. Manganese ferrite (MnFe2O4) coated on stainless steel foil (SS 316 grade) was used as a catalyst to initiate the growth of CNR. The coated catalyst was introduced into the CVD and the chamber temperature was set at 700 °C later followed with the release of acetylene (50 sccm) and nitrogen (500 sccm) gas, respectively. Total reaction continued until 30 min. No purification or oxidation process of the soot was involved. Analysis reveals the presence of intermingled CNRs with semi crystalline nature of the sample. The elemental analysis confirms the presence of manganese and iron whereas Raman spectrum shows the characteristic narrow G and D bands. The sample displays a super-paramagnetic behavior and is thermally stable up to 500-550 °C presenting a strong exothermic reaction.

  14. The Multi-Spectral Solar Telescope Array. II - Soft X-ray/EUV reflectivity of the multilayer mirrors

    NASA Technical Reports Server (NTRS)

    Barbee, Troy W., Jr.; Weed, J. W.; Hoover, Richard B. C., Jr.; Allen, Max J.; Lindblom, Joakim F.; O'Neal, Ray H.; Kankelborg, Charles C.; Deforest, Craig E.; Paris, Elizabeth S.; Walker, Arthur B. C.

    1992-01-01

    We have developed seven compact soft X-ray/EUV (XUV) multilayer coated and two compact FUV interference film coated Cassegrain and Ritchey-Chretien telescopes for a rocket borne observatory, the Multi-Spectral Solar Telescope Array. We report here on extensive measurements of the efficiency and spectral bandpass of the XUV telescopes carried out at the Stanford Synchrotron Radiation Laboratory.

  15. Architecture and Assembly of the Bacillus subtilis Spore Coat

    PubMed Central

    Plomp, Marco; Carroll, Alicia Monroe; Setlow, Peter; Malkin, Alexander J.

    2014-01-01

    Bacillus spores are encased in a multilayer, proteinaceous self-assembled coat structure that assists in protecting the bacterial genome from stresses and consists of at least 70 proteins. The elucidation of Bacillus spore coat assembly, architecture, and function is critical to determining mechanisms of spore pathogenesis, environmental resistance, immune response, and physicochemical properties. Recently, genetic, biochemical and microscopy methods have provided new insight into spore coat architecture, assembly, structure and function. However, detailed spore coat architecture and assembly, comprehensive understanding of the proteomic composition of coat layers, and specific roles of coat proteins in coat assembly and their precise localization within the coat remain in question. In this study, atomic force microscopy was used to probe the coat structure of Bacillus subtilis wild type and cotA, cotB, safA, cotH, cotO, cotE, gerE, and cotE gerE spores. This approach provided high-resolution visualization of the various spore coat structures, new insight into the function of specific coat proteins, and enabled the development of a detailed model of spore coat architecture. This model is consistent with a recently reported four-layer coat assembly and further adds several coat layers not reported previously. The coat is organized starting from the outside into an outermost amorphous (crust) layer, a rodlet layer, a honeycomb layer, a fibrous layer, a layer of “nanodot” particles, a multilayer assembly, and finally the undercoat/basement layer. We propose that the assembly of the previously unreported fibrous layer, which we link to the darkly stained outer coat seen by electron microscopy, and the nanodot layer are cotH- and cotE- dependent and cotE-specific respectively. We further propose that the inner coat multilayer structure is crystalline with its apparent two-dimensional (2D) nuclei being the first example of a non-mineral 2D nucleation crystallization

  16. Process for manufacturing multilayer capacitors

    DOEpatents

    Lauf, R.J.; Holcombe, C.E.; Dykes, N.L.

    1996-01-02

    The invention is directed to a method of manufacture of multilayer electrical components, especially capacitors, and components made by such a method. High capacitance dielectric materials and low cost metallizations layered with such dielectrics may be fabricated as multilayer electrical components by sintering the metallizations and the dielectrics during the fabrication process by application of microwave radiation. 4 figs.

  17. Process for manufacturing multilayer capacitors

    DOEpatents

    Lauf, Robert J.; Holcombe, Cressie E.; Dykes, Norman L.

    1996-01-01

    The invention is directed to a method of manufacture of multilayer electrical components, especially capacitors, and components made by such a method. High capacitance dielectric materials and low cost metallizations layered with such dielectrics may be fabricated as multilayer electrical components by sintering the metallizations and the dielectrics during the fabrication process by application of microwave radiation.

  18. Large optics for the National Ignition Facility

    SciTech Connect

    Baisden, P.

    2015-01-12

    The National Ignition Facility (NIF) laser with its 192 independent laser beams is not only the world’s largest laser, it is also the largest optical system ever built. With its 192 independent laser beams, the NIF requires a total of 7648 large-aperture (meter-sized) optics. One of the many challenges in designing and building NIF has been to carry out the research and development on optical materials, optics design, and optics manufacturing and metrology technologies needed to achieve NIF’s high output energies and precision beam quality. This paper describes the multiyear, multi-supplier, development effort that was undertaken to develop the advanced optical materials, coatings, fabrication technologies, and associated process improvements necessary to manufacture the wide range of NIF optics. The optics include neodymium-doped phosphate glass laser amplifiers; fused silica lenses, windows, and phase plates; mirrors and polarizers with multi-layer, high-reflectivity dielectric coatings deposited on BK7 substrates; and potassium di-hydrogen phosphate crystal optics for fast optical switches, frequency conversion, and polarization rotation. Also included is a discussion of optical specifications and custom metrology and quality-assurance tools designed, built, and fielded at supplier sites to verify compliance with the stringent NIF specifications. In addition, a brief description of the ongoing program to improve the operational lifetime (i.e., damage resistance) of optics exposed to high fluence in the 351-nm (3ω) is provided.

  19. Optical coatings for document security

    NASA Astrophysics Data System (ADS)

    Phillips, Roger W.; Bleikolm, Anton F.

    1996-10-01

    Optical coatings that shift color with viewing angle have been adapted into optically variable foils, pigments, and inks to prevent color copying by color copiers, printers, cameras, or lithographic reproduction. Metal-dielectric multilayer thin-film structures have large color shifts with angle, high chroma, a large color gamut, and light fastness that make them uniquely suited for security inks. World currencies are now protected by these structures.

  20. Strain-tolerant ceramic coated seal

    DOEpatents

    Schienle, James L.; Strangman, Thomas E.

    1994-01-01

    A metallic regenerator seal is provided having multi-layer coating comprising a NiCrAlY bond layer, a yttria stabilized zirconia (YSZ) intermediate layer, and a ceramic high temperature solid lubricant surface layer comprising zinc oxide, calcium fluoride, and tin oxide. An array of discontinuous grooves is laser machined into the outer surface of the solid lubricant surface layer making the coating strain tolerant.

  1. Symmetric multilayer megampere X-pinch

    SciTech Connect

    Shelkovenko, T. A.; Pikuz, S. A.; McBride, R. D.; Knapp, P. F.; Wilhelm, G.; Sinars, D. B.; Hammer, D. A.; Orlov, N. Yu.

    2010-01-15

    Raising the power of X-ray emission from an X-pinch by increasing the pinch current to the megampere level requires the corresponding increase in the initial linear mass of the load. This can be achieved by increasing either the number of wires or their diameter. In both cases, special measures should be undertaken to prevent the formation of a complicated configuration with an uncontrolled spatial structure in the region of wire crossing, because such a structure breaks the symmetry of the neck formed in the crossing region, destabilizes plasma formation, and degrades X-ray generation. To improve the symmetry of the wire crossing region, X-pinch configurations with a regular multilayer arrangement of wires in this region were proposed and implemented. The results of experiments with various symmetric X-pinch configurations on the COBRA facility at currents of {approx}1MA are presented. It is shown that an X-pinch with a symmetric crossing region consisting of several layers of wires made of different materials can be successfully used in megampere facilities. The most efficient combinations of wires in symmetric multilayer X-pinches are found in which only one hot spot forms and that are characterized by a high and stable soft X-ray yield.

  2. Synthesis and photocatalytic property of multilayered Co3O4

    NASA Astrophysics Data System (ADS)

    Zhang, Dong En; Ren, Li Zheng; Hao, Xiao Yun; Pan, Bin Bin; Wang, Ming Yan; Ma, Juan Juan; Li, Feng; Li, Shu An; Tong, Zhi Wei

    2015-11-01

    Co3O4 multilayered structures were successfully synthesized by a facile poly (ethylene glycol 20000) (PEG-20000) assisted hydrothermal technique in combination with calcination method. The final Co3O4 multilayered structures inherited perfectly the morphology of the preliminarily hydrothermal products. Experimental results obtained from the different growth stages demonstrate that the as-prepared precursor exhibit an interesting time-dependent evolution of building blocks, from urchin to multilayer. The possible formation mechanism for the hierarchical structures with various architectures is presented on account of the self-assembled growth induced by Ostwald ripening. Because of the unique structured composed of slices, the photocatalytic activity of the products was examined by measuring the photodecolourisation of methyl violet solution with ultraviolet radiation. The result shows that our products have a good photocatalytic activity.

  3. Wrapped Multilayer Insulation

    NASA Technical Reports Server (NTRS)

    Dye, Scott A.

    2015-01-01

    New NASA vehicles, such as Earth Departure Stage (EDS), Orion, landers, and orbiting fuel depots, need improved cryogenic propellant transfer and storage for long-duration missions. Current cryogen feed line multilayer insulation (MLI) performance is 10 times worse per area than tank MLI insulation. During each launch, cryogenic piping loses approximately 150,000 gallons (equivalent to $300,000) in boil-off during transfer, chill down, and ground hold. Quest Product Development Corp., teaming with Ball Aerospace, developed an innovative advanced insulation system, Wrapped MLI (wMLI), to provide improved thermal insulation for cryogenic feed lines. wMLI is high-performance multilayer insulation designed for cryogenic piping. It uses Quest's innovative discrete-spacer technology to control layer spacing/ density and reduce heat leak. The Phase I project successfully designed, built, and tested a wMLI prototype with a measured heat leak 3.6X lower than spiral-wrapped conventional MLI widely used for piping insulation. A wMLI prototype had a heat leak of 7.3 W/sq m, or 27 percent of the heat leak of conventional MLI (26.7 W/sq m). The Phase II project is further developing wMLI technology with custom, molded polymer spacers and advancing the product toward commercialization via a rigorous testing program, including developing advanced vacuuminsulated pipe for ground support equipment.

  4. Wrapped Multilayer Insulation

    NASA Technical Reports Server (NTRS)

    Dye, Scott A.

    2015-01-01

    New NASA vehicles, such as Earth Departure Stage (EDS), Orion, landers, and orbiting fuel depots, need improved cryogenic propellant transfer and storage for long-duration missions. Current cryogen feed line multilayer insulation (MLI) performance is 10 times worse per area than tank MLI insulation. During each launch, cryogenic piping loses approximately 150,000 gallons (equivalent to $300,000) in boil-off during transfer, chill down, and ground hold. Quest Product Development Corp., teaming with Ball Aerospace, developed an innovative advanced insulation system, Wrapped MLI (wMLI), to provide improved thermal insulation for cryogenic feed lines. wMLI is high-performance multilayer insulation designed for cryogenic piping. It uses Quest's innovative discrete-spacer technology to control layer spacing/ density and reduce heat leak. The Phase I project successfully designed, built, and tested a wMLI prototype with a measured heat leak 3.6X lower than spiral-wrapped conventional MLI widely used for piping insulation. A wMLI prototype had a heat leak of 7.3 W/m2, or 27 percent of the heat leak of conventional MLI (26.7 W/m2). The Phase II project is further developing wMLI technology with custom, molded polymer spacers and advancing the product toward commercialization via a rigorous testing program, including developing advanced vacuuminsulated pipe for ground support equipment.

  5. Magnetic metallic multilayers

    SciTech Connect

    Hood, R.Q.

    1994-04-01

    Utilizing self-consistent Hartree-Fock calculations, several aspects of multilayers and interfaces are explored: enhancement and reduction of the local magnetic moments, magnetic coupling at the interfaces, magnetic arrangements within each film and among non-neighboring films, global symmetry of the systems, frustration, orientation of the various moments with respect to an outside applied field, and magnetic-field induced transitions. Magnetoresistance of ferromagnetic-normal-metal multilayers is found by solving the Boltzmann equation. Results explain the giant negative magnetoresistance encountered in these systems when an initial antiparallel arrangement is changed into a parallel configuration by an external magnetic field. The calculation depends on (1) geometric parameters (thicknesses of layers), (2) intrinsic metal parameters (number of conduction electrons, magnetization, and effective masses in layers), (3) bulk sample properties (conductivity relaxation times), (4) interface scattering properties (diffuse scattering versus potential scattering at the interfaces, and (5) outer surface scattering properties (specular versus diffuse surface scattering). It is found that a large negative magnetoresistance requires considerable asymmetry in interface scattering for the two spin orientations. Features of the interfaces that may produce an asymmetrical spin-dependent scattering are studied: varying interfacial geometric random roughness with no lateral coherence, correlated (quasi-periodic) roughness, and varying chemical composition of the interfaces. The interplay between these aspects of the interfaces may enhance or suppress the magnetoresistance, depending on whether it increases or decreases the asymmetry in the spin-dependent scattering of the conduction electrons.

  6. Magneto-optic multilayers

    NASA Astrophysics Data System (ADS)

    Bader, Samuel D.

    1992-08-01

    Magneto-optical multilayers are of interest to the optical data storage community as a possible second-generation medium of the future. The important Co/Pt-superlattice system is introduced in this respect, and an extensive reference listing is provided to previous research. Magneto-optical modeling studies of Co/Pt are presented, and it is concluded that the interfacial Pt is magnetized and is magneto-optically active at the short wavelengths of interest (approximately 4 eV) for applications. Magneto-optics in the ultrathin limit are discussed, and an additivity law is presented and verified experimentally utilizing data for epitaxial Fe/Ag(111) superlattices. Finally, the surface magnetic anisotropy that provides the vertical easy axes of magnetization in candidate superlattice systems is discussed and illustrated experimentally using ultrathin epitaxial films of Fe grown on a variety of substrates. It is concluded that magneto-optic multilayers will provide many stimulating basic and applied challenges in the years ahead.

  7. Finite element analysis of multilayer coextrusion.

    SciTech Connect

    Hopkins, Matthew Morgan; Schunk, Peter Randall; Baer, Thomas A.; Mrozek, Randy A.; Lenhart, Joseph Ludlow; Rao, Rekha Ranjana; Collins, Robert; Mondy, Lisa Ann

    2011-09-01

    Multilayer coextrusion has become a popular commercial process for producing complex polymeric products from soda bottles to reflective coatings. A numerical model of a multilayer coextrusion process is developed based on a finite element discretization and two different free-surface methods, an arbitrary-Lagrangian-Eulerian (ALE) moving mesh implementation and an Eulerian level set method, to understand the moving boundary problem associated with the polymer-polymer interface. The goal of this work is to have a numerical capability suitable for optimizing and troubleshooting the coextrusion process, circumventing flow instabilities such as ribbing and barring, and reducing variability in layer thickness. Though these instabilities can be both viscous and elastic in nature, for this work a generalized Newtonian description of the fluid is used. Models of varying degrees of complexity are investigated including stability analysis and direct three-dimensional finite element free surface approaches. The results of this work show how critical modeling can be to reduce build test cycles, improve material choices, and guide mold design.

  8. Polymer multilayer tattooing for enhanced DNA vaccination

    NASA Astrophysics Data System (ADS)

    Demuth, Peter C.; Min, Younjin; Huang, Bonnie; Kramer, Joshua A.; Miller, Andrew D.; Barouch, Dan H.; Hammond, Paula T.; Irvine, Darrell J.

    2013-04-01

    DNA vaccines have many potential benefits but have failed to generate robust immune responses in humans. Recently, methods such as in vivo electroporation have demonstrated improved performance, but an optimal strategy for safe, reproducible, and pain-free DNA vaccination remains elusive. Here we report an approach for rapid implantation of vaccine-loaded polymer films carrying DNA, immune-stimulatory RNA, and biodegradable polycations into the immune-cell-rich epidermis, using microneedles coated with releasable polyelectrolyte multilayers. Films transferred into the skin following brief microneedle application promoted local transfection and controlled the persistence of DNA and adjuvants in the skin from days to weeks, with kinetics determined by the film composition. These ‘multilayer tattoo’ DNA vaccines induced immune responses against a model HIV antigen comparable to electroporation in mice, enhanced memory T-cell generation, and elicited 140-fold higher gene expression in non-human primate skin than intradermal DNA injection, indicating the potential of this strategy for enhancing DNA vaccination.

  9. Polyelectrolyte multilayers: An odyssey through interdisciplinary science

    NASA Astrophysics Data System (ADS)

    Jaber, Jad A.

    . Positive polyelectrolytes were investigated as new surface coatings for promoting in vitro actomyosin motility. Two surface arrangements were studied: a monolayer of the polyelectrolyte PAH, and multilayers consisting of 11-41 layers of alternating polypositive PAH/polynegative PSS electrolytes. For in vitro motility assays, rabbit skeletal muscle heavy meromyosin (HMM) was applied to the PAH surface of both polyelectrolyte mono and multilayers. Myosin driven motion of actin filaments labeled with rhodamine-phalloidin was recorded at 30°C using epifluorescence microscopy. Actin filaments were found to have a mean speed of 2.9+/-0.08 mum sec-1 on the multilayer surface compared to 2.5+/-0.06 mum sec-1 on the monolayer surface. Average filament's length and speed increased respectively when nonionic surfactant was added to HMM and ionic strength of the motility buffer increased. Micro-contact printing with a water-insoluble charged block copolymer on PAH produced patterned surfaces that restricted filament motion to PAH tracks.

  10. Chitin nanocrystal-xyloglucan multilayer thin films.

    PubMed

    Villares, Ana; Moreau, Céline; Capron, Isabelle; Cathala, Bernard

    2014-01-13

    For the first time, the adsorption of xyloglucan (XG) on chitin nanocrystals (ChiNC) surface was proved using quartz crystal microbalance with dissipation (QCM-D) and by successfully building up spin-coated assisted layer-by-layer (LbL) structures on solid substrates. Several parameters in the adsorption process, such as ChiNC concentrations (0.5-3.0 g L(-1)), number of layers, or the outmost layer material (ChiNC or XG), were investigated to better understand the fabrication process of multilayer films. The thickness of the homogeneous film increased linearly with the number of bilayers, with an average thickness per bilayer of 12.3 nm. Additionally surface morphology was studied by atomic force microscopy (AFM), which revealed an almost completely covered surface after the adsorption of ChiNC. The final structures were found to have semireflective properties capable of being tuned by adjusting the ChiNC dispersion parameters. PMID:24328307

  11. A Kirkpatrick-Baez microscope for the National Ignition Facility.

    PubMed

    Pickworth, L A; McCarville, T; Decker, T; Pardini, T; Ayers, J; Bell, P; Bradley, D; Brejnholt, N F; Izumi, N; Mirkarimi, P; Pivovaroff, M; Smalyuk, V; Vogel, J; Walton, C; Kilkenny, J

    2014-11-01

    Current pinhole x ray imaging at the National Ignition Facility (NIF) is limited in resolution and signal throughput to the detector for Inertial Confinement Fusion applications, due to the viable range of pinhole sizes (10-25 μm) that can be deployed. A higher resolution and throughput diagnostic is in development using a Kirkpatrick-Baez microscope system (KBM). The system will achieve <9 μm resolution over a 300 μm field of view with a multilayer coating operating at 10.2 keV. Presented here are the first images from the uncoated NIF KBM configuration demonstrating high resolution has been achieved across the full 300 μm field of view. PMID:25430187

  12. A Kirkpatrick-Baez microscope for the National Ignition Facility

    SciTech Connect

    Pickworth, L. A. McCarville, T.; Decker, T.; Pardini, T.; Ayers, J.; Bell, P.; Bradley, D.; Brejnholt, N. F.; Izumi, N.; Mirkarimi, P.; Pivovaroff, M.; Smalyuk, V.; Vogel, J.; Walton, C.; Kilkenny, J.

    2014-11-15

    Current pinhole x ray imaging at the National Ignition Facility (NIF) is limited in resolution and signal throughput to the detector for Inertial Confinement Fusion applications, due to the viable range of pinhole sizes (10–25 μm) that can be deployed. A higher resolution and throughput diagnostic is in development using a Kirkpatrick-Baez microscope system (KBM). The system will achieve <9 μm resolution over a 300 μm field of view with a multilayer coating operating at 10.2 keV. Presented here are the first images from the uncoated NIF KBM configuration demonstrating high resolution has been achieved across the full 300 μm field of view.

  13. Ultra-precision fabrication of 500 mm long and laterally graded Ru/C multilayer mirrors for X-ray light sources.

    PubMed

    Störmer, M; Gabrisch, H; Horstmann, C; Heidorn, U; Hertlein, F; Wiesmann, J; Siewert, F; Rack, A

    2016-05-01

    X-ray mirrors are needed for beam shaping and monochromatization at advanced research light sources, for instance, free-electron lasers and synchrotron sources. Such mirrors consist of a substrate and a coating. The shape accuracy of the substrate and the layer precision of the coating are the crucial parameters that determine the beam properties required for various applications. In principal, the selection of the layer materials determines the mirror reflectivity. A single layer mirror offers high reflectivity in the range of total external reflection, whereas the reflectivity is reduced considerably above the critical angle. A periodic multilayer can enhance the reflectivity at higher angles due to Bragg reflection. Here, the selection of a suitable combination of layer materials is essential to achieve a high flux at distinct photon energies, which is often required for applications such as microtomography, diffraction, or protein crystallography. This contribution presents the current development of a Ru/C multilayer mirror prepared by magnetron sputtering with a sputtering facility that was designed in-house at the Helmholtz-Zentrum Geesthacht. The deposition conditions were optimized in order to achieve ultra-high precision and high flux in future mirrors. Input for the improved deposition parameters came from investigations by transmission electron microscopy. The X-ray optical properties were investigated by means of X-ray reflectometry using Cu- and Mo-radiation. The change of the multilayer d-spacing over the mirror dimensions and the variation of the Bragg angles were determined. The results demonstrate the ability to precisely control the variation in thickness over the whole mirror length of 500 mm thus achieving picometer-precision in the meter-range. PMID:27250371

  14. The synthesis and characterization of monodispersed chitosan-coated Fe3O4 nanoparticles via a facile one-step solvothermal process for adsorption of bovine serum albumin.

    PubMed

    Shen, Mao; Yu, Yujing; Fan, Guodong; Chen, Guang; Jin, Ying Min; Tang, Wenyuan; Jia, Wenping

    2014-01-01

    Preparation of magnetic nanoparticles coated with chitosan (CS-coated Fe3O4 NPs) in one step by the solvothermal method in the presence of different amounts of added chitosan is reported here. The magnetic property of the obtained magnetic composite nanoparticles was confirmed by X-ray diffraction (XRD) and magnetic measurements (VSM). Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) allowed the identification of spherical nanoparticles with about 150 nm in average diameter. Characterization of the products by Fourier transform infrared spectroscopy (FTIR) demonstrated that CS-coated Fe3O4 NPs were obtained. Chitosan content in the obtained nanocomposites was estimated by thermogravimetric analysis (TGA). The adsorption properties of the CS-coated Fe3O4 NPs for bovine serum albumin (BSA) were investigated under different concentrations of BSA. Compared with naked Fe3O4 nanoparticles, the CS-coated Fe3O4 NPs showed a higher BSA adsorption capacity (96.5 mg/g) and a fast adsorption rate (45 min) in aqueous solutions. This work demonstrates that the prepared magnetic nanoparticles have promising applications in enzyme and protein immobilization. PMID:24994954

  15. Deposition- controlled uniformity of multilayer mirrors

    NASA Astrophysics Data System (ADS)

    Jankowski, Alan F.; Makowiecki, Daniel M.; McKernan, M. A.; Foreman, R. J.; Patterson, R. G.

    1991-02-01

    The widely used physical vapor deposition techniques to produce multilayer x-ray optics with uniform layer pair spacings (<1% variation) over large areas (> 10cm x 10 cm) have all been limited by the geometry of the vapor source. Magnetron sputtering sources, geometrically a convolution of point sources in a circular or rectangular array, provide uniformly thick regions of coating only within the boundaries of the erosion track. To maximize uniformity over large regins requires target materials equally as large, proving a costly proposition. Electron beam or molecular beam sources are similarly limited by the size of the melt pooi or effusion cell diameter. For ion beam deposition, spatial divergence from typical ion sources results in coating thickness variations of 5%or more for large areas as previously described. To minimize the ultimate expense of designing a necessarily large, single deposition source to provide a small thickness variation (without the use of compensating substrate motion or elaborate shielding over the deposition sources), several small sources arranged in an appropiate array may provide a viable alternative. To this end, the use of a linear array of one-inch magnetron sources has proven effective. Material has been deposited within the limitations of 1.5% thickness variation, along the axis of a linear gun array, over 15cm in length. The feasibility of using two linear arrays of magnetron sources is investigated to prepare large area multilayer mirrors with minimal layer pair spacing variations. Such a deposition system also allows for gradually varying the layer pair spacings across the surface of an optic, in a designed manner, which proves useful for focusing applications.

  16. Enhancing the Thermal and Upper Voltage Performance of Ni-Rich Cathode Material by a Homogeneous and Facile Coating Method: Spray-Drying Coating with Nano-Al2O3.

    PubMed

    Du, Ke; Xie, Hongbin; Hu, Guorong; Peng, Zhongdong; Cao, Yanbing; Yu, Fan

    2016-07-13

    The electrochemical performance of Ni-rich cathode material at high temperature (>50 °C) and upper voltage operation (>4.3 V) is a challenge for next-generation lithium-ion batteries (LIBs) because of the rapid capacity degradation over cycling. Here we report improved performance of LiNi0.8Co0.15Al0.05O2 materials via a LiAlO2 coating, which was prepared from a Ni0.80Co0.15Al0.05(OH)2 precursor by spray-drying coating with nano-Al2O3. Investigations by X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and transmission electron microscopy revealed that an Al2O3 layer is uniformly distributed on the precursor and a LiAlO2 layer on the as-prepared cathode material. Such a coating shell acts as a scavenger to protect the cathode material from attack by HF and serious side reactions, which remarkably enhances the cycle performance at 55 °C and upper operating voltage (4.4 and 4.5 V). In particular, the sample with a 2% Al2O3 coating shows capacity retentions of 90.40%, 85.14%, 87.85%, and 81.1% after 150 cycles at a rate of 1.0C at room temperature, 55 °C, 4.4 V, and 4.5 V, respectively, which are significantly higher than those of the pristine one. This is mainly due to the significant improvement of the structural stability led by the effective coating technique, which could be extended to other cathode materials to obtain LIBs with enhanced safety and excellent cycling stability. PMID:27328728

  17. Probing aggregation and fibril formation of insulin in polyelectrolyte multilayers.

    PubMed

    Koo, Juny; Czeslik, Claus

    2012-06-01

    Ultrathin films are useful for coating materials and controlling drug delivery processes. Here, we explore the use of polyelectrolyte multilayers as templates for the formation of two-dimensional protein networks, which represent biocompatible and biodegradable ultrathin films. In a first step, we have studied the lateral aggregation and amyloid fibril formation of bovine insulin that is adsorbed at and confined within planar polyelectrolyte multilayers, assembled with poly(diallyldimethylammonium chloride) (PDDA), poly(styrenesulfonic acid) (PSS), and hyaluronic acid (HA). Si-PDDA-PSS-(insulin-PSS)(x) and Si-PDDA-PSS-(insulin-HA)(x) multilayers (x=1-4) have been prepared and characterized in the fully hydrated state by using X-ray reflectometry, attenuated total reflection-Fourier transform infrared spectroscopy and confocal fluorescence microscopy. The obtained data demonstrate a successful build-up of the insulin-polyelectrolyte multilayers on silicon wafers that grow strongly in thickness upon insulin adsorption on PSS and HA layers. The secondary structure analysis of insulin, based on the vibrational amide I'-band, indicates an enhanced intermolecular β-sheet formation within the multilayers at 70°C and pD=2, i.e. at conditions that promote insulin amyloid fibrils rich in β-sheet contents. However, insulin that is confined between two polyelectrolyte layers rather forms amorphous aggregates as can be inferred from confocal fluorescence images. Remarkably, when insulin is deposited as the top-layer, a partial conversion into a two-dimensional fibrillar network can be induced by adding amyloid seeds to the solution. Thus, the results of this study illustrate the capability of polyelectrolyte multilayers as templates for the growth of protein networks. PMID:22369752

  18. Thin-Film Design for Multilayer Diffraction Gratings

    SciTech Connect

    Oliver, J.B.; Kessler, T.J.; Huang, H.; Keck, J.; Rigatti, A.L.; Schmid, A.W.; Kozlov, A.; Kosc, T.Z.

    2006-03-01

    Multilayer dielectric (MLD) diffraction gratings are a key component for the construction of high-peak-power, pulse-compressed laser systems. While a great deal of effort has been devoted to the design of optimal grating structures and the etching of these structures into the MLD coating, there has not been the same effort put into the optimization of the MLD coating itself. The primary characteristics of the multilayer that must be considered during design include minimization of the standing wave created in the photoresist because of the reflectivity of the coated optical surface, creation of a sufficiently high reflectivity at the use wavelength and incidence angle in a dry environment, proper balance of the individual layer materials to yield a coating with an overall neutral or slightly compressive stress, and a high laser-damage threshold for the wavelength and pulse duration of use. This work focuses on the modification of a standard MLD mirror, while considering these characteristics, to allow the fabrication of a diffraction grating with higher efficiency and laser-damage threshold than is typically achieved.

  19. Fabrication of multilayered thin films via spin-assembly

    DOEpatents

    Chiarelli, Peter A.; Robinson, Jeanne M.; Casson, Joanna L.; Johal, Malkiat S.; Wang, Hsing-Lin

    2007-02-20

    An process of forming multilayer thin film heterostructures is disclosed and includes applying a solution including a first water-soluble polymer from the group of polyanionic species, polycationic species and uncharged polymer species onto a substrate to form a first coating layer on the substrate, drying the first coating layer on the substrate, applying a solution including a second water-soluble polymer from the group of polyanionic species, polycationic species and uncharged polymer species onto the substrate having the first coating layer to form a second coating layer on the first coating layer wherein the second water-soluble polymer is of a different material than the first water-soluble polymer, and drying the second coating layer on the first coating layer so as to form a bilayer structure on the substrate. Optionally, one or more additional applying and drying sequences can be repeated with a water-soluble polymer from the group of polyanionic species, polycationic species and uncharged polymer species, so that a predetermined plurality of layers are built up upon the substrate.

  20. Ultrasonic NDE of Multilayered Structures

    SciTech Connect

    Quarry, M J; Fisher, K A; Lehman, S K

    2005-02-14

    This project developed ultrasonic nondestructive evaluation techniques based on guided and bulk waves in multilayered structures using arrays. First, a guided wave technique was developed by preferentially exciting dominant modes with energy in the layer of interest via an ultrasonic array. Second, a bulk wave technique uses Fermat's principle of least time as well as wave-based properties to reconstruct array data and image the multilayered structure. The guided wave technique enables the inspection of inaccessible areas of a multilayered structure without disassembling it. Guided waves propagate using the multilayer as a waveguide into the inaccessible areas from an accessible position. Inspecting multi-layered structures with a guided wave relies on exciting modes with sufficient energy in the layer of interest. Multilayered structures are modeled to determine the possible modes and their distribution of energy across the thickness. Suitable modes were determined and excited by designing arrays with the proper element spacing and frequency. Bulk wave imaging algorithms were developed to overcome the difficulties of multiple reflections and refractions at interfaces. Reconstruction algorithms were developed to detect and localize flaws. A bent-ray algorithm incorporates Fermat's principle to correct time delays in the ultrasonic data that result from the difference in wave speeds in each layer and refractions at the interfaces. A planar wave-based algorithm was developed using the Green function for the multilayer structure to enhance focusing on reception for improved imaging.

  1. Synthesis and tribology of doped carbon films and oxide multilayers

    NASA Astrophysics Data System (ADS)

    Freyman, Christina A.

    The focus of this research is to synthesize thin films coatings by reactive magnetron sputtering with properties that will result in energy savings. Tailoring of hydrogenated carbon film properties to minimize environment effects on friction is accomplished by sulfur doping. Synthesis results in smooth surfaces and mid-range hardness. The stabilization of ultra-low friction in humid air can be attributed to the reduction of water adsorption on the surface, which is verified by results of quartz crystal microbalance and temperature-programmed desorption experiments. Even at 90% relative humidity, sulfur-doped films have less than one monolayer of water adsorbed on the surface. This reduction in water coverage is due to the decrease in residence time of water on the surface, which is related to the strength of the bonding between water molecules and the sulfur-doped surface. These results indicate that sulfur doping results in weaker bonding between water and the film surface due to a reduction in the polar nature of the surface. Metal nitrides, carbides, and borides are widely used as protective coatings due to their high hardness, but are not stable above 600°C due to coating oxidation. Hardness enhancement techniques have been applied to thermally stable oxide multilayers for use at high temperatures. Amorphous Al2 O3 and crystalline TiO2 nanoscale layers have been deposited using reactive d.c. magnetron sputtering at different partial pressures of oxygen. Hardness enhancement of twice the rule of mixtures has been observed in oxide multilayers for the first time due to clear interfaces and large difference in modulus between amorphous Al2O3 and crystalline TiO2 layers. Multilayer films with majority bilayer component of Al2O3 showed greater resistance to wear due to increased elastic recovery and H/E ratio over monolithic films and TiO2 majority phase multilayers. Multilayer films retain their high hardness up to ˜800°C in air; some hardness enhancement in the

  2. Sub-picosecond laser induced damage test facility for petawatt reflective optical components characterizations

    NASA Astrophysics Data System (ADS)

    Sozet, Martin; Néauport, Jérôme; Lavastre, Eric; Roquin, Nadja; Gallais, Laurent; Lamaignère, Laurent

    2015-05-01

    While considering long pulse or short pulse high power laser facilities, optical components performances and in particular laser damage resistance are always factors limiting the overall system performances. Consequently, getting a detailed knowledge of the behavior of these optical components under irradiations with large beam in short pulse range is of major importance. In this context, a Laser Induced Damage Threshold test facility called DERIC has been developed at the Commissariat à l'Energie Atomique et aux Energies Alternatives, Bordeaux. It uses an Amplitude Systemes laser source which delivers Gaussian pulses of 500 fs at 1053 nm. 1-on-1, S-on-1 and RasterScan test procedures are implemented to study the behavior of monolayer and multilayer dielectric coatings.

  3. Structure of lipid multilayers via drop casting of aqueous liposome dispersions.

    PubMed

    Sironi, Beatrice; Snow, Tim; Redeker, Christian; Slastanova, Anna; Bikondoa, Oier; Arnold, Thomas; Klein, Jacob; Briscoe, Wuge H

    2016-05-01

    Understanding the structure of solid supported lipid multilayers is crucial to their application as a platform for novel materials. Conventionally, they are prepared from drop casting or spin coating of lipids dissolved in organic solvents, and lipid multilayers prepared from aqueous media and their structural characterisation have not been reported previously, due to their extremely low lipid solubility (i.e.∼10(-9) M) in water. Herein, using X-ray reflectivity (XRR) facilitated by a "bending mica" method, we have studied the structural characteristics of dioleoylphosphatidylcholine (DOPC) multilayers prepared via drop casting aqueous small unilamellar and multilamellar vesicle or liposome (i.e. SUV and MLV) dispersions on different surfaces, including mica, positively charged polyethylenimine (PEI) coated mica, and stearic trimethylammonium iodide (STAI) coated mica which exposes a monolayer of hydrocarbon tails. We suggest that DOPC liposomes served both as a delivery matrix where an appreciable lipid concentration in water (∼25 mg mL(-1) or 14 mM) was feasible, and as a structural precursor where the lamellar structure was readily retained on the rupture of the vesicles at the solid surface upon solvent evaporation to facilitate rapid multilayer formation. We find that multilayers on mica from MLVs exhibited polymorphism, whereas the SUV multilayers were well ordered and showed stronger stability against water. The influence of substrate chemistry (i.e. polymer coating, charge and hydrophobicity) on the multilayer structure is discussed in terms of lipid-substrate molecular interactions determining the bilayer packing proximal to the solid-liquid interface, which then had a templating effect on the structure of the bilayers distal from the interface, resulting in the overall different multilayer structural characteristics on different substrates. Such a fundamental understanding of the correlation between the physical parameters that characterise liposomes

  4. A multilayer sonic film

    NASA Astrophysics Data System (ADS)

    Munteanu, L.; Chiroiu, V.; Sireteanu, T.; Dumitriu, D.

    2015-10-01

    A non-periodic multilayer film was analyzed to show that, despite its non-periodicity, the film exhibits full band-gaps and localized modes at its interfaces, as well as in the sonic composites. The film consists of alternating layers of two different materials that follow a triadic Cantor sequence. The Cantor structure shows extremely low thresholds for subharmonic generation of ultrasonic waves, compared with homogeneous and periodic structures. The coupling between the extended-mode (phonon) and the localized-mode (fracton) vibration regimes explains the generation of full band-gaps, for which there are no propagating Lamb waves. The large enhancement of the nonlinear interaction results from a more favorable frequency and spatial matching of coupled modes. A full band-gap that excludes Love waves is also analyzed.

  5. Multilayer graphene condenser microphone

    NASA Astrophysics Data System (ADS)

    Todorović, Dejan; Matković, Aleksandar; Milićević, Marijana; Jovanović, Djordje; Gajić, Radoš; Salom, Iva; Spasenović, Marko

    2015-12-01

    Vibrating membranes are the cornerstone of acoustic technology, forming the backbone of modern loudspeakers and microphones. Acoustic performance of a condenser microphone is derived mainly from the membrane’s size, surface mass and achievable static tension. The widely studied and available nickel has been a dominant membrane material for professional microphones for several decades. In this paper we introduce multilayer graphene as a membrane material for condenser microphones. The graphene device outperforms a high end commercial nickel-based microphone over a significant part of the audio spectrum, with a larger than 10 dB enhancement of sensitivity. Our experimental results are supported with numerical simulations, which also show that a 300 layer thick graphene membrane under maximum tension would offer excellent extension of the frequency range, up to 1 MHz.

  6. Integrated Multilayer Insulation

    NASA Technical Reports Server (NTRS)

    Dye, Scott

    2009-01-01

    Integrated multilayer insulation (IMLI) is being developed as an improved alternative to conventional multilayer insulation (MLI), which is more than 50 years old. A typical conventional MLI blanket comprises between 10 and 120 metallized polymer films separated by polyester nets. MLI is the best thermal- insulation material for use in a vacuum, and is the insulation material of choice for spacecraft and cryogenic systems. However, conventional MLI has several disadvantages: It is difficult or impossible to maintain the desired value of gap distance between the film layers (and consequently, it is difficult or impossible to ensure consistent performance), and fabrication and installation are labor-intensive and difficult. The development of IMLI is intended to overcome these disadvantages to some extent and to offer some additional advantages over conventional MLI. The main difference between IMLI and conventional MLI lies in the method of maintaining the gaps between the film layers. In IMLI, the film layers are separated by what its developers call a micro-molded discrete matrix, which can be loosely characterized as consisting of arrays of highly engineered, small, lightweight, polymer (typically, thermoplastic) frames attached to, and placed between, the film layers. The term "micro-molded" refers to both the smallness of the frames and the fact that they are fabricated in a process that forms precise small features, described below, that are essential to attainment of the desired properties. The term "discrete" refers to the nature of the matrix as consisting of separate frames, in contradistinction to a unitary frame spanning entire volume of an insulation blanket.

  7. High reflectance coatings for space applications in the EUV

    NASA Astrophysics Data System (ADS)

    Keski-Kuha, Ritva A. M.; Gum, Jeffrey S.; Osantowski, John F.; Fleetwood, Charles M.

    1993-01-01

    Advances in optical coating and materials technology have made possible the development of instruments with substantially improved efficiency and made possible to consider more complex optical designs in the EUV. The importance of recent developments in chemical vapor deposited silicon carbide (CVD-SiC), SiC films and multilayer coatings is discussed in the context of EUV instrumentation design. The EUV performance of these coatings as well as some strengths and problem areas for their use in space will be addressed.

  8. Heat Transfer In High-Temperature Multilayer Insulation

    NASA Technical Reports Server (NTRS)

    Daryabeigi, Kamran; Miller, Stephen D.; Cunnington, George R.

    2006-01-01

    The combined radiation/conduction heat transfer in high-temperature multilayer insulations for typical reentry of reusable launch vehicles from low Earth orbit was investigated experimentally and numerically. The high-temperature multilayer insulation investigated consisted of gold-coated reflective foils separated by alumina fibrous insulation spacers. The steady-state heat transfer through four multilayer insulation configurations was investigated experimentally over the temperature range of 300-1300 K and environmental pressure range of 1.33 10(exp -5)-101.32 kPa. It was shown that including the reflective foils reduced the effective thermal conductivity compared to fibrous insulation sample at 1.5 times the density of the multilayer sample. A finite volume numerical model was developed to solve the governing combined radiation/conduction heat transfer equations. The radiation heat transfer in the fibrous insulation spacers was modeled using the modified two-flux approximation assuming anisotropic scattering and gray medium. The numerical model was validated by comparison with steady-state experimental data. The root mean square deviation between the predicted and measured effective thermal conductivity of the samples was 9.5%.

  9. Finite element analysis of multilayer DEAP stack-actuators

    NASA Astrophysics Data System (ADS)

    Kuhring, Stefan; Uhlenbusch, Dominik; Hoffstadt, Thorben; Maas, Jürgen

    2015-04-01

    Dielectric elastomers (DE) are thin polymer films belonging to the class of electroactive polymers (EAP). They are coated with compliant and conductive electrodes on each side, which make them performing a relative high amount of deformation with considerable force generation under the influence of an electric field. Because the realization of high electric fields with a limited voltage level requests single layer polymer films to be very thin, novel multilayer actuators are utilized to increase the absolute displacement and force. In case of a multilayer stack-actuator, many actuator films are mechanically stacked in series and electrically connected in parallel. Because there are different ways to design such a stack-actuator, this contribution considers an optimization of some design parameters using the finite element analysis (FEA), whereby the behavior and the actuation of a multilayer dielectric electroactive polymer (DEAP) stack-actuator can be improved. To describe the material behavior, first different material models are compared and necessary material parameters are identified by experiments. Furthermore, a FEA model of a DEAP film is presented, which is expanded to a multilayer DEAP stack-actuator model. Finally, the results of the FEA are discussed and conclusions for design rules of optimized stack-actuators are outlined.

  10. Multilayer Laue Lens Growth at NSLS-II

    NASA Astrophysics Data System (ADS)

    Conley, R.; Bouet, N.; Lauer, K.; Carlucci-Dayton, M.; Biancarosa, J.; Boas, L.; Drannbauer, J.; Feraca, J.; Rosenbaum, L.

    2011-09-01

    The new NSLS-II deposition laboratory has been commissioned to include a variety of thin-film characterization equipment and a next-generation deposition system [1]. The primary goal for this effort is R&D on the multilayer Laue lens (MLL) [2-4], which is a new type of x-ray optic with the potential for an unprecedented level of x-ray nano-focusing. This unique deposition system contains many design features in order to facilitate growth of combined depth-graded and laterally graded multilayers with precise thickness control over many thousands of layers, providing total film growth in one run of up to 100 μm thick or greater. A precision in-vacuum linear motor servo system raster scans a substrate over an array of magnetrons with shaped apertures at well-defined velocities to affect a multilayer coating. The design, commissioning, and performance metrics of the NSLS-II deposition system will be discussed. Latest growth results of both MLL and reflective multilayers in this machine will be presented.

  11. Anti-Corrosion Coating

    NASA Technical Reports Server (NTRS)

    1977-01-01

    NASA-Goddard developed a zinc-rich coating with a special binder that exhibits longer life and booths with the air purifiers. superior adhesion characteristics-so that only a single coat is required. Unlike conventional coatings, . the NASA compound is easy to mix and it requires no straining before application; its materials also cost less. Thus the new coating offers cost advantages in materials, labor hours per application, and fewer applications over a given time span. The NASA coating is now undergoing test on a number of coastal area structures. In a cooperative effort with the Philadelphia Mayor's Science and Technology Council, the coating has been applied to sample sections of the Frankford Elevated System's steel support structure. On the West Coast, it is being tested on facilities of the Pillar Point Satellite Tracking Station, Pillar Point, Cat. and on segments of the Golden Gate Bridge. It is also undergoing evaluation as an undercoating to protect road equipment against de-icing salts; the coating was applied to the underside of a truck and its performance is being recorded periodically by the Vermont Department of Highways. NASA has issued patent licenses to two paint companies and the coating is expected to be commercially available this year.

  12. Ultra-high efficiency multilayer blazed gratings through deposition kinetic control

    SciTech Connect

    Voronov, D. L.; Anderson, Erik H.; Gullikson, Eric M.; Salmassi, Farhad; Warwick, Tony; Yashchuk, Valeriy V.; Padmore, Howard A.

    2012-05-07

    Diffraction efficiency of multilayer coated blazed gratings (MBG) strongly depends on the perfection of the saw-tooth-shaped layers in the overall composite structure. Growth of multilayers on saw-tooth substrates should be carefully optimized in order to reduce groove profile distortion and at the same time to avoid significant roughening of multilayer interfaces. In this work we report on a new way to optimize growth of sputter-deposited Mo/Si multilayers on saw-tooth substrates through variation of the sputtering gas pressure. Lastly, a new record for diffraction efficiency of 44% was achieved for a optimized MBG with groove density of 5250 lines/mm at the wavelength of 13.1 nm.

  13. Multi-Layered Films Containing a Biomimetic Stimuli-Responsive Recombinant Protein

    NASA Astrophysics Data System (ADS)

    Barbosa, J. S.; Costa, R. R.; Testera, A. M.; Alonso, M.; Rodríguez-Cabello, J. C.; Mano, J. F.

    2009-10-01

    Electrostatic self-assembly was used to fabricate new smart multi-layer coatings, using a recombinant elastin-like polymer (ELP) and chitosan as the counterion macromolecule. The ELP was bioproduced, purified and its purity and expected molecular weight were assessed. Aggregate size measurements, obtained by light scattering of dissolved ELP, were performed as a function of temperature and pH to assess the smart properties of the polymer. The build-up of multi-layered films containing ELP and chitosan, using a layer-by-layer methodology, was followed by quartz-crystal microbalance with dissipation monitoring. Atomic force microscopy analysis permitted to demonstrate that the topography of the multi-layered films could respond to temperature. This work opens new possibilities for the use of ELPs in the fabrication of biodegradable smart coatings and films, offering new platforms in biotechnology and in the biomedical area.

  14. Multi-Layered Films Containing a Biomimetic Stimuli-Responsive Recombinant Protein

    PubMed Central

    2009-01-01

    Electrostatic self-assembly was used to fabricate new smart multi-layer coatings, using a recombinant elastin-like polymer (ELP) and chitosan as the counterion macromolecule. The ELP was bioproduced, purified and its purity and expected molecular weight were assessed. Aggregate size measurements, obtained by light scattering of dissolved ELP, were performed as a function of temperature and pH to assess the smart properties of the polymer. The build-up of multi-layered films containing ELP and chitosan, using a layer-by-layer methodology, was followed by quartz-crystal microbalance with dissipation monitoring. Atomic force microscopy analysis permitted to demonstrate that the topography of the multi-layered films could respond to temperature. This work opens new possibilities for the use of ELPs in the fabrication of biodegradable smart coatings and films, offering new platforms in biotechnology and in the biomedical area. PMID:20596391

  15. Development of sputter coatings for the gravity probe B gyroscope housings

    NASA Technical Reports Server (NTRS)

    Zhou, P.; Cheung, S.; Lydic, T.; Turneaure, J. P.

    1988-01-01

    Cu/Ti coatings have been applied by sputter deposition to fused quartz housings to serve as the electrodes and lands of electrostatically supported gyroscopes. Niobium-coated fused quartz gyro rotors have been successfully suspended and spun up in those housings. The Cu/Ti bilayer coating and alternative multilayer coatings (Cu/Mo, Mo/Cu/Ti and Mo/Cu/Mo) with 2-micron thickness produced by sputter deposition on flat, fused quartz substrates have been examined with scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and four-point resistivity measurement techniques. The multilayer coatings with a molybdenum bonding layer appear to produce smoother surfaces than those with a titanium bonding layer. All multilayer coatings survived thermal cycling to 77 K without adhesion failure.

  16. High efficiency multilayer blazed gratings for EUV and soft X-rays: Recent developments

    SciTech Connect

    Voronov, Dmitriy; Ahn, Minseung; Anderson, Erik; Cambie, Rossana; Chang, Chih-Hao; Goray, Leonid; Gullikson, Eric; Heilmann, Ralf; Salmassi, Farhad; Schattenburg, Mark; Warwick, Tony; Yashchuk, Valeriy; Padmore, Howard

    2011-07-26

    Multilayer coated blazed gratings with high groove density are the best candidates for use in high resolution EUV and soft x-ray spectroscopy. Theoretical analysis shows that such a grating can be potentially optimized for high dispersion and spectral resolution in a desired high diffraction order without significant loss of diffraction efficiency. In order to realize this potential, the grating fabrication process should provide a perfect triangular groove profile and an extremely smooth surface of the blazed facets. Here we report on recent progress achieved at the Advanced Light Source (ALS) in fabrication of high quality multilayer coated blazed gratings. The blazed gratings were fabricated using scanning beam interference lithography followed by wet anisotropic etching of silicon. A 200 nm period grating coated with a Mo/Si multilayer composed with 30 bi-layers demonstrated an absolute efficiency of 37.6percent in the 3rd diffraction order at 13.6 nm wavelength. The groove profile of the grating was thoroughly characterized with atomic force microscopy before and after the multilayer deposition. The obtained metrology data were used for simulation of the grating efficiency with the vector electromagnetic PCGrate-6.1 code. The simulations showed that smoothing of the grating profile during the multilayer deposition is the main reason for efficiency losses compared to the theoretical maximum. Investigation of the grating with cross-sectional transmission electron microscopy revealed a complex evolution of the groove profile in the course of the multilayer deposition. Impact of the shadowing and smoothing processes on growth of the multilayer on the surface of the sawtooth substrate is discussed.

  17. High-efficiency multilayer blazed gratings for EUV and soft x-rays: recent developments

    NASA Astrophysics Data System (ADS)

    Voronov, Dmitriy L.; Ahn, Minseung; Anderson, Eric H.; Cambie, Rossana; Chang, Chih-Hao; Goray, Leonid I.; Gullikson, Eric M.; Heilmann, Ralf K.; Salmassi, Farhad; Schattenburg, Mark L.; Warwick, Tony; Yashchuk, Valeriy; Padmore, Howard A.

    2010-09-01

    Multilayer coated blazed gratings with high groove density are the best candidates for use in high resolution EUV and soft x-ray spectroscopy. Theoretical analysis shows that such a grating can be potentially optimized for high dispersion and spectral resolution in a desired high diffraction order without significant loss of diffraction efficiency. In order to realize this potential, the grating fabrication process should provide a perfect triangular groove profile and an extremely smooth surface of the blazed facets. Here we report on recent progress achieved at the Advanced Light Source (ALS) in fabrication of high quality multilayer coated blazed gratings. The blazed gratings were fabricated using scanning beam interference lithography followed by wet anisotropic etching of silicon. A 200 nm period grating coated with a Mo/Si multilayer composed with 30 bi-layers demonstrated an absolute efficiency of 37.6% in the 3rd diffraction order at 13.6 nm wavelength. The groove profile of the grating was thoroughly characterized with atomic force microscopy before and after the multilayer deposition. The obtained metrology data were used for simulation of the grating efficiency with the vector electromagnetic PCGrate-6.1 code. The simulations showed that smoothing of the grating profile during the multilayer deposition is the main reason for efficiency losses compared to the theoretical maximum. Investigation of the grating with cross-sectional transmission electron microscopy revealed a complex evolution of the groove profile in the course of the multilayer deposition. Impact of the shadowing and smoothing processes on growth of the multilayer on the surface of the sawtooth substrate is discussed.

  18. Multilayer sulfur-resistant composite metal membranes and methods of making and repairing the same

    DOEpatents

    Way, J. Douglas; Hatlevik, Oyvind

    2014-07-15

    The invention relates to thin, hydrogen-permeable, sulfur-resistant membranes formed from multi-layers of palladium or palladium-alloy coatings on porous, ceramic or metal supports, methods of making these membranes, methods of repairing layers of these membranes and devices that incorporate these membranes.

  19. Multilayered Magnetic Gelatin Membrane Scaffolds.

    PubMed

    Samal, Sangram K; Goranov, Vitaly; Dash, Mamoni; Russo, Alessandro; Shelyakova, Tatiana; Graziosi, Patrizio; Lungaro, Lisa; Riminucci, Alberto; Uhlarz, Marc; Bañobre-López, Manuel; Rivas, Jose; Herrmannsdörfer, Thomas; Rajadas, Jayakumar; De Smedt, Stefaan; Braeckmans, Kevin; Kaplan, David L; Dediu, V Alek

    2015-10-21

    A versatile approach for the design and fabrication of multilayer magnetic scaffolds with tunable magnetic gradients is described. Multilayer magnetic gelatin membrane scaffolds with intrinsic magnetic gradients were designed to encapsulate magnetized bioagents under an externally applied magnetic field for use in magnetic-field-assisted tissue engineering. The temperature of the individual membranes increased up to 43.7 °C under an applied oscillating magnetic field for 70 s by magnetic hyperthermia, enabling the possibility of inducing a thermal gradient inside the final 3D multilayer magnetic scaffolds. On the basis of finite element method simulations, magnetic gelatin membranes with different concentrations of magnetic nanoparticles were assembled into 3D multilayered scaffolds. A magnetic-gradient-controlled distribution of magnetically labeled stem cells was demonstrated in vitro. This magnetic biomaterial-magnetic cell strategy can be expanded to a number of different magnetic biomaterials for various tissue engineering applications. PMID:26451743

  20. Properties of multilayer filters

    NASA Technical Reports Server (NTRS)

    Baumeister, P. W.

    1973-01-01

    New methods were investigated of using optical interference coatings to produce bandpass filters for the spectral region 110 nm to 200 nm. The types of filter are: triple cavity metal dielectric filters; all dielectric reflection filters; and all dielectric Fabry Perot type filters. The latter two types use thorium fluoride and either cryolite films or magnesium fluoride films in the stacks. The optical properties of the thorium fluoride were also measured.