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1

Metal sulfide thin films on glass as solar control, solar absorber, decorative, and photographic coatings  

Microsoft Academic Search

An overview of the optical transmittance and reflectance characteristics of selected metal sulfide thin-film coatings obtained on glass substrates by chemical bath deposition is presented. The focus is on their application as solar control coatings, solar absorber coatings, decorative coatings, and as an imaging medium. Coatings of PbS-CuxS, Bi2S3- CuxS, SnS-CuxS, and ZnS-CuxS offer a range of solar control characteristics.

Padmanabhan K. Nair; Santhamma M. Nair; A. M. Fernandez; V. M. Garcia; A. B. Hernandez

1991-01-01

2

Thin Film Metal Coated Fiber Optic Hydrophone Probe  

PubMed Central

The purpose of this work was to improve on sensitivity performance of fiber sensor employed as Fiber Optic Hydrophone Probe (FOHP) by nano-scale thin film gold coating. The fiber is designed to provide a uniform and spatial averaging free response up to 100 MHz by etching down to an active diameter of about 9 ?m. The sensitivity performance of straight cleaved (i.e. full size core and cladding) uncoated, tapered uncoated and tapered thin film gold coated fiber sensors were compared in the frequency range of 1.5 MHz to 20 MHz in the presence of acoustic pressure amplitude levels of up to 6 MPa. An unprecedented voltage sensitivity of ?245 dB re 1V/uPa (560 mV/ MPa) was measured for thin film gold coated FOHP by optimizing the gold coating thickness. PMID:19881652

Gopinath, R.; Arora, P.; Gandhi, G.; Daryoush, A.S.; El-Sherif, M.; Lewin, P.A.

2010-01-01

3

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

NASA Technical Reports Server (NTRS)

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

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

1997-01-01

4

Metal Coatings  

NASA Technical Reports Server (NTRS)

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

1994-01-01

5

Localization of folds and cracks in thin metal films coated on flexible elastomer foams.  

PubMed

Thin metal films coated on soft elastomeric foam substrates exhibit enhanced electromechanical performance. The open-cell foam structure conveys highly anisotropic mechanical properties within the top, thin capping elastomer at the surface of the foam. Upon stretching, large strain fields inducing cracks and folds localize above the foam cells, while the surrounding cell ligaments remain almost strain-free, enabling stable electrical conduction in the metallic coating. PMID:23629920

Vandeparre, Hugues; Liu, Qihan; Minev, Ivan R; Suo, Zhigang; Lacour, Stéphanie P

2013-06-11

6

The interfacial chemistry of metallized, oxide coated, and nanocomposite coated polymer films  

Microsoft Academic Search

Aluminium, aluminium oxide, and aluminium\\/aluminium oxide nanocomposite coated polymer substrates have been characterized by X-ray photoelectron spectroscopy, transmission electron microscopy, argon ion sputter depth profiling, and gas permeation measurements. A comparison of the similarities and differences between these coatings has provided a detailed insight into the physicochemical origins of gas barrier associated with metallized plastics.

C. P. Barker; K.-H. Kochem; K. M. Revell; R. S. A. Kelly; J. P. S. Badyal

1995-01-01

7

Transfer printing of patterned metal films using parylene C coated surfaces J. Bavier a,b  

E-print Network

Transfer printing of patterned metal films using parylene C coated surfaces J. Bavier a,b , J October 2012 Available online 24 November 2012 Keywords: Transfer printing Flexible electronics Surface treatments a b s t r a c t Successful transfer printing of aluminum (Al), copper (Cu), silver (Ag), nickel

Rubloff, Gary W.

8

Microwave bonding of thin film metal coated substrates  

NASA Technical Reports Server (NTRS)

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

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

2004-01-01

9

Optical properties of ultrafine line and space polymeric nanogratings coated with metal and metal-dielectric-metal thin films  

NASA Astrophysics Data System (ADS)

Noble metal and metal-dielectric-metal ultrathin films were deposited on the surfaces of ultrafine polymeric nanogratings, which were fabricated using nanoimprint lithography. Experimental results showed dramatic differences of the surface morphologies for single metal and triple metal-dielectric-metal films deposited on flat and corrugated polymeric surfaces. The effect of the surface morphology on the optical properties was hence investigated and analyzed under linearly polarized light. The surface plasmon resonances of single metal and triple metal-dielectric-metal films deposited on polymeric nanograting surfaces were also characterized based on the Kretschmann prism-coupling method. The single metal and triple metal-dielectric-metal films deposited on polymeric nanograting surfaces are important for the study of photon-plasmon interactions (i.e. couplings and conversions) at the interfaces between a nanograting and metal films.

Leong, Eunice Sok Ping; Wu, Siji; Zhang, Nan; Loh, Wei Wei; Huat Khoo, Eng; Si, Guang Yuan; Dai, Hai Tao; Liu, Yan Jun

2014-02-01

10

Optical properties of ultrafine line and space polymeric nanogratings coated with metal and metal-dielectric-metal thin films.  

PubMed

Noble metal and metal-dielectric-metal ultrathin films were deposited on the surfaces of ultrafine polymeric nanogratings, which were fabricated using nanoimprint lithography. Experimental results showed dramatic differences of the surface morphologies for single metal and triple metal-dielectric-metal films deposited on flat and corrugated polymeric surfaces. The effect of the surface morphology on the optical properties was hence investigated and analyzed under linearly polarized light. The surface plasmon resonances of single metal and triple metal-dielectric-metal films deposited on polymeric nanograting surfaces were also characterized based on the Kretschmann prism-coupling method. The single metal and triple metal-dielectric-metal films deposited on polymeric nanograting surfaces are important for the study of photon-plasmon interactions (i.e. couplings and conversions) at the interfaces between a nanograting and metal films. PMID:24406796

Leong, Eunice Sok Ping; Wu, Siji; Zhang, Nan; Loh, Wei Wei; Khoo, Eng Huat; Si, Guang Yuan; Dai, Hai Tao; Liu, Yan Jun

2014-02-01

11

Metallic Films with Fullerene-Like WS2 (MoS2) Nanoparticles: Self-Lubricating Coatings with Potential Applications  

NASA Astrophysics Data System (ADS)

Metallic films impregnated with fullerene-like-WS2 (MoS2) nanoparticles were fabricated on stainless steel and Ti-Ni substrates using galvanic and electroless deposition. The coatings were obtained from aqueous suspensions containing the metallic salts as well as the dispersed nanoparticles. Tribological tests showed that the films have low friction and wear. Such coatings could be useful for numerous civilian and defense-related applications.

Eidelman, O.; Friedman, H.; Tenne, R.

12

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

NASA Astrophysics Data System (ADS)

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-visible spectroscopy. Loss measurements were performed in the laboratory using Er:YAG and CO2 infrared lasers. Profilometry measurements were conducted to quantify the roughness of the polymer films and the metal sulfide films. Polymer films had roughness values between 25 and 40 nm and when overcoated with CdS the roughness increased to 240 nm.

Johnson, Valencia S.

2007-12-01

13

On calculating the energy characteristics of a metal film with a dielectric coating  

NASA Astrophysics Data System (ADS)

A method for calculating the characteristics of a metal film in a dielectric surroundings is suggested. The most interesting case of asymmetric metal-dielectric sandwiches, in which the dielectrics on both sides of the film are different, is considered in the context of the Kohn-Sham modified method. The spectrum, the electron work function, and the surface energy of polycrystalline and single-crystal films placed into passive insulators are calculated for the first time. In general, the dielectric surroundings leads to a negative change in the electron work function and the surface energy. In addition to size-effect-related changes, the shift of the work function is determined by the arithmetic mean of the dielectric constants of the surrounding media. Calculations have been performed for Na, Al, and Pb.

Babich, A. V.

2014-02-01

14

Scanning electron microscopy at macromolecular resolution in low energy mode on biological specimens coated with ultra thin metal films.  

PubMed

In this report, conditions for attaining high resolution in scanning electron microscopy with soft biological specimens are described using the currently available high resolution scanning electron microscopes in emission mode of low energy electrons (secondary and charging electrons). Retinal rod outer segments, red blood cells, intestinal mucosa, and ferritin molecules were all used as biological test specimens. From uncoated specimens a new source of signal, referred to as a discharge signal, can provide a high yield of low energy electrons from an excitation area approximately the size of the beam's cross section. Additionally, under these conditions sufficient topographic contrast can be achieved by applying ultra thin metal coatins. A 0.5 nm thick gold film is found sufficient for generating the total signal, whereas increased coating thickness causes additional topographic background signal. However, a 2.0 nm film is needed for imaging surface details with the present instrument. Ultra thin, even, and grainless tantalum films have been found effective in eliminating the charging artifacts caused by external fields, and the decoration artifacts caused by crystal growth as seen in gold films. To improve, in high magnification work on ultra thin coated specimen, signal-to-noise ratio, methods for obtaining saturation of the signal with discharge electrons are shown. The necessity of confirming the information obtained in SEM by independent techniques (TEM of stereo-replicas or ultra thin sections) is discussed. PMID:392703

Peters, K R

1979-01-01

15

Thin Film Optical Coatings  

NASA Astrophysics Data System (ADS)

Within the scientific conception of the modern world, thin film optical coatings can be interpreted as one-dimensional photonic crystals. In general, they are composed of a sequence of single layers which consist of different transparent dielectrics with a thickness in the nanometer scale according to the operation wavelength range. The major function of these photonic structures is to adapt the properties of an optical surface to the needs of specific applications. By application of optical thin film coatings with optimized designs, the spectral characteristics of a surface can be modified to practically any required transfer function for a certain wavelength range. For example, the Fresnel reflection of a lens or a laser window can be suppressed for a broad wavelength range by depositing an antireflective coating containing only a few single layers. On the basis of a layer stack with alternating high- and low-refracting materials, high reflectance values up to 99.999% can be achieved for a certain laser wavelength. In addition to these basic functions, optical coatings can realize a broad variety of spectral filter characteristics according to even extremely sophisticated demands in modern precision optics and laser technology. Moreover, recent developments in optical thin film technology provide the means to combine selected optical properties with other features concerning, for instance, the thermal, mechanical or chemical stability of a surface. The latest progress in ophthalmic coatings even includes the integration of self-cleaning, photoactive or anti-fogging functions in antireflective coatings on glass.

Ristau, Detlev; Ehlers, Henrik

16

Interfacial interactions of polymer coatings with oxide-free phosphate films on metal surfaces  

NASA Astrophysics Data System (ADS)

A method for producing thin oxide-free phosphate films using an easier process than those previously reported is described. The process is carried out under ambient conditions using aqueous phosphoric acid. The chemistry of the phosphated surface prepared by the process and the interaction of this surface with a thin film of polyvinyl alcohol (PVA) are examined with the purpose of evaluating the potential of this film to serve as an adhesion promoting layer. The surface chemical changes are monitored by core and valence band x-ray photoelectron spectroscopy and ultraviolet photoelectron spectroscopy, with the resultant spectra compared to those from band structure calculations. Valance band photoemission interpreted by band structure calculations can be used to study the interfaces involved, and proves to be a very effective tool for conclusively identifying the surface species present. The process for forming oxide-free phosphate films forms the same surface chemistry as previously reported for other processes. PVA is found to strongly interact with the oxide-free phosphate film on aluminum metal illustrating the potential of such films as adhesion promoters.

Wang, Yuqing; Sherwood, Peter M. A.

2003-07-01

17

Ultra-High-Sensitivity Measurement of Metal Thin Film Thickness by Photothermal Mirage Detection Method through Sample Surface Coating and Use of SemiCylindrical Lens  

Microsoft Academic Search

Methods to achieve ultra-high-sensitivity measurement of metal thin-film thickness by photothermal mirage detection are proposed. These methods apply 1) sample surface coating and 2) a semi-cylindrical lens for pumping beam focusing. Consequently, successful measurements are taken for thicknesses of less than several hundred nm. The semi-cylindrical lens plays a critical role in the measurements, and the sample surface coating significantly

Yoshitsugu Okamoto; Masanori Kurobe; Atsushi Yarai; Takuji Nakanishi

2005-01-01

18

CuInSe? thin-film solar cells with 7.72?% efficiency prepared via direct coating of a metal salts/alcohol-based precursor solution.  

PubMed

A simple direct solution coating process for forming CuInSe? (CIS) thin films was described, employing a low-cost and environmentally friendly precursor solution. The precursor solution was prepared by mixing metal acetates, ethanol, and ethanolamine. The facile formation of a precursor solution without the need to prefabricate nanoparticles enables a rapid and easy processing, and the high stability of the solution in air further ensures the precursor preparation and the film deposition in ambient conditions without a glove box. The thin film solar cell fabricated with the absorber film prepared by this route showed an initial conversion efficiency of as high as 7.72?%. PMID:22890958

Ahn, Sejin; Son, Tae Hwa; Cho, Ara; Gwak, Jihye; Yun, Jae Ho; Shin, Keeshik; Ahn, Seoung Kyu; Park, Sang Hyun; Yoon, Kyunghoon

2012-09-01

19

Effect of thin condensate films of a metal working fluid of an electric propulsion engine on the integral optical coefficients of a spacecraft's thermal control coating  

NASA Astrophysics Data System (ADS)

Materials on experimental studies to determine the effect of thin condensate films of cesium (used as a model working medium for electric propulsion engines and some spacecraft power sources) on integral optical coefficients of spacecraft thermal control coatings are presented. A technique modified by the author and employing the regular thermal regime of a thin metal plate is used. Measurement results demonstrate that films with thicknesses of 100-1000 Å can seriously degrade the integral optical coefficients of thermal control coatings and thus disturb the heat balance of some spacecraft systems.

Chirov, A. A.

2014-05-01

20

Physical deposition of carbon doped titanium nitride film by DC magnetron sputtering for metallic implant coating use  

NASA Astrophysics Data System (ADS)

Alloys exposed to tissue environment are at risk to corrosive breakdown. The corrosion behaviour of carbon doped titanium nitride films was studied. The C-TiN films were deposited by DC magnetron sputtering. The obtained films were investigated to be used as protective layers for medical implants. The films were analysed using XRD, SEM with EDX, FTIR, Raman, UV-vis and potentiodynamic polarization. Analysis indicated that doping with carbon in low concentration led to form titanium carbide. The measured values of corrosion current densities (Icorr, substrate = 2.020 ?A/cm2, Icorr, coating = 0.175 ?A/cm2) indicate that the deposited films improved the corrosion resistance of the pure titanium. Comparison between the corrosion current densities of two samples (uncoated and coated pure titanium) showed a reduction of 91% in corrosion current density for coated Ti compared to the uncoated one.

Sedira, Sofiane; Achour, Slimane; Avci, Ahmet; Eskizeybek, Volkan

2014-03-01

21

Carbonaceous film coating  

DOEpatents

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

Maya, L.

1988-04-27

22

Carbonaceous film coating  

DOEpatents

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

Maya, Leon (Oak Ridge, TN)

1989-01-01

23

Thin film ion conducting coating  

DOEpatents

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

Goldner, Ronald B. (Lexington, MA); Haas, Terry (Sudbury, MA); Wong, Kwok-Keung (Watertown, MA); Seward, George (Arlington, MA)

1989-01-01

24

Performance improvement of an ionic polymer metal composite actuator by parylene thin film coating  

Microsoft Academic Search

IPMC (ionic polymer-metal composite) is a kind of ionic EAP (electroactive polymer) which is actuated by the movement of cations combined with water molecules in the polymer. The cations and water molecules move due to the applied voltage on the metal electrodes which are located on both sides of the polymer. However, water contained in the polymer gradually evaporates during

Seong Jun Kim; In Taek Lee; Ho-Young Lee; Yong Hyup Kim

2006-01-01

25

Performance improvement of an ionic polymer–metal composite actuator by parylene thin film coating  

Microsoft Academic Search

IPMC (ionic polymer–metal composite) is a kind of ionic EAP (electroactive polymer) which is actuated by the movement of cations combined with water molecules in the polymer. The cations and water molecules move due to the applied voltage on the metal electrodes which are located on both sides of the polymer. However, water contained in the polymer gradually evaporates during

Seong Jun Kim; In Taek Lee; Ho-Young Lee; Yong Hyup Kim

2006-01-01

26

Coatings decrease metal fatigue failure  

NASA Technical Reports Server (NTRS)

Metal test specimens were coated with suitable materials to limit the rate of attack of fresh metal surfaces by the atmosphere. The fatigue properties of coated metals were superior to those which were uncoated and approached the properties observable in vacuum.

Sumsion, H. T.

1969-01-01

27

Metal oxide films on metal  

DOEpatents

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

Wu, Xin D. (Los Alamos, NM); Tiwari, Prabhat (Los Alamos, NM)

1995-01-01

28

Polymer-assisted aqueous deposition of metal oxide films  

DOEpatents

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

Li, DeQuan (Los Alamos, NM); Jia, Quanxi (Los Alamos, NM)

2003-07-08

29

Barrier Coatings for Refractory Metals and Superalloys  

SciTech Connect

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

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

2006-02-23

30

Tuning deposition of magnetic metallic nanoparticles from periodic pattern to thin film entrainment by dip coating method.  

PubMed

In this work, we report on the self-assembly of bimetallic CoFe carbide magnetic nanoparticles (MNPs) stabilized by a mixture of long chain surfactants. A dedicated setup, coupling dip coating and sputtering chamber, enables control of the self-assembly of MNPs from regular stripe to continuous thin films under inert atmosphere. The effects of experimental parameters, MNP concentration, withdrawal speed, amount, and nature of surfactants, as well as the surface state of the substrates are discussed. Magnetic measurements revealed that the assembled particles were not oxidized, confirming the high potentiality of our approach for the controlled deposition of highly sensitive MNPs. PMID:25000178

Dugay, J; Tan, R P; Loubat, A; Lacroix, L-M; Carrey, J; Fazzini, P F; Blon, T; Mayoral, A; Chaudret, B; Respaud, M

2014-08-01

31

Tailoring Thin Film-Lacquer Coatings for Space Application  

NASA Technical Reports Server (NTRS)

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

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

1998-01-01

32

Magnetron-Sputtered Amorphous Metallic Coatings  

NASA Technical Reports Server (NTRS)

Amorphous coatings of refractory metal/metalloid-based alloys deposited by magnetron sputtering provide extraordinary hardness and wear resistance. Sputtering target fabricated by thoroughly mixing powders of tungsten, rhenium, and boron in stated proportions and pressing at 1,200 degrees C and 3,000 lb/in. to second power (21 MPa). Substrate lightly etched by sputtering before deposition, then maintained at bias of - 500 V during initial stages of film growth while target material sputtered onto it. Argon gas at pressure used as carrier gas for sputter deposition. Coatings dense, pinhole-free, extremely smooth, and significantly resistant to chemical corrosion in acidic and neutral aqueous environments.

Thakoor, A. P.; Mehra, M.; Khanna, S. K.

1985-01-01

33

Selective Radiation Shielding And Solar Control Applications Of Multilayer Metal And Dielectric Coatings  

NASA Astrophysics Data System (ADS)

Thin metal coatings have been used for several years as selective radiation filters in architectural window applications. These coatings are usually produced by vacuum deposition techniques such as evaporation or sputtering, and coatings are deposited either directly onto glass, or onto polyester film which is then laminated to glass. Recently, metal coatings have begun to be used as reflectors in lighting and other applications.

Ritchie, Ian; Kittler, Wilfred C.

1987-11-01

34

Block copolymer directed nanoporous metal thin films.  

PubMed

Porous metal thin films have high potential for use in applications such as catalysis, electrical contacts, plasmonics, as well as energy storage and conversion. Structuring metal thin films on the nanoscale to generate high surface areas poses an interesting challenge as metals have high surface energy. In this communication, we demonstrate direct access to nanostructured metal nanoparticle hybrid thin films with high nanoparticle loadings through spin coating of a mixture of block copolymer and ligand stabilized platinum and palladium nanoparticles. Plasma cleaning to remove the organics results in a conductive metal thin film. We expect that the methods described here can be generalized to other metals, mixtures of metal nanoparticles, and intermetallics. PMID:21567618

Arora, Hitesh; Li, Zihui; Sai, Hiroaki; Kamperman, Marleen; Warren, Scott C; Wiesner, Ulrich

2010-11-15

35

Metal-Coated Optical Fibers for High Temperature Applications  

NASA Technical Reports Server (NTRS)

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

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

1996-01-01

36

Thin film-coated polymer webs  

DOEpatents

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

Wenz, Robert P. (Cottage Grove, MN); Weber, Michael F. (Shoreview, MN); Arudi, Ravindra L. (Woodbury, MN)

1992-02-04

37

Method of coating metal surfaces to form protective metal coating thereon  

DOEpatents

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

Krikorian, Oscar H. (Danville, CA); Curtis, Paul G. (Tracy, CA)

1992-01-01

38

Method of coating metal surfaces to form protective metal coating thereon  

DOEpatents

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

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

1992-03-31

39

Coated metal articles and method of making  

DOEpatents

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

Boller, Ernest R. (Van Buren Township, IN); Eubank, Lowell D. (Wilmington, DE)

2004-07-06

40

NUCLEAR TRANSMUTATIONS IN THIN-FILM NICKEL COATINGS UNDERGOING ELECTROLYSIS  

Microsoft Academic Search

Experiments using 1-mm plastic and glass microspheres coated with single and multilayers of thin films of various metals such as palladium and nickel, used in a packed-bed electrolytic cell (Patterson Power Cell ™ configuration), have apparently produced a variety of nuclear reaction products. The analysis of a run with 650-Å film of Ni is presented here. Following a two-week electrolytic

George H. Miley; James A. Patterson

41

Corrosion protective coating for metallic materials  

DOEpatents

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

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

1998-05-26

42

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

SciTech Connect

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

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

2006-10-01

43

Overlay metallic-cermet alloy coating systems  

NASA Technical Reports Server (NTRS)

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

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

1984-01-01

44

Tailoring Thin Film-Lacquer Coatings for Space Applications  

NASA Technical Reports Server (NTRS)

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

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

1998-01-01

45

Tantalum-based thin film coatings for wear resistant arthroprostheses.  

PubMed

Cobalt-chromium-molybdenum alloys with high carbon content (HC-CoCrMo) are widely used as materials for arthroprosthesis, in particular in metal-on-metal (MoM) hip joints. In spite of their good wear and corrosion resistance, production of metallic wear particles and metal ion release will occur on a large time-scale. An enhancement of the metal ion level in the patient's blood and urine is often reported in clinical data. Hypersensitivity, inflammatory response and cell necrosis can occur as consequence. So implants on young patients and women on childbearing age are not so widespread. The aim of this research is the realization of a thin film coating in order to improve the biocompatibility of Co-based alloys and to reduce debris production, ion release and citotoxicity. The innovative process consists of a thermal treatment in molten salts, in order to obtain a tantalum enriched thin film coating. Tantalum is chosen because it is considered a biocompatible metal with high corrosion resistance and low ion release. Three HC-CoCrMo alloys, produced by different manufacturing processes, are tested as substrates. The coating is a thin film of TaC or it can be composed by a multilayer of two tantalum carbides and metallic tantalum, depending on the temperature of the treatment and on the carbon content of the substrate. The thin films as well the substrates are characterized from the structural, chemical and morphological point of view. Moreover mechanical behaviour of treated and untreated materials is analyzed by means of nanohardness, scratch and ball-on-disc wear tests. The coating increases the mechanical and tribological properties of HC-CoCrMo. PMID:22400292

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

2011-10-01

46

Transmission characteristics of germanium thin-film-coated metallic hollow waveguides for high-powered CO2 laser light  

Microsoft Academic Search

Various losses such as straight waveguide losses, coupling losses from a CO2 laser, and bending losses are studied. The authors studied the fact that high-powered CO2 laser light could be transmitted through germanium-coated waveguides and investigated beam profiles from straight or bent waveguides. To ascertain the application of the waveguide in wavelengths other than 10.6 ?m, the authors investigated the

Akihito Hongo; Ken-Ichi Morosawa; Tsuneo Shiota; Yuji Matsuura; Mitsunobu Miyagi

1990-01-01

47

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

NASA Astrophysics Data System (ADS)

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

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

2013-06-01

48

Method of producing adherent metal oxide coatings on metallic surfaces  

DOEpatents

Provided is a process of producing an adherent synthetic corrosion product (sludge) coating on metallic surfaces. The method involves a chemical reaction between a dry solid powder mixture of at least one reactive metal oxide with orthophosphoric acid to produce a coating in which the particles are bound together and the matrix is adherent to the metallic surface.

Lane, Michael H. (Clifton Park, NY); Varrin, Jr., Robert D. (McLean, VA)

2001-01-01

49

Aluminum oxide coating on nickel substrate by metal organic chemical vapor deposition  

Microsoft Academic Search

Aluminum oxide thin films were coated onto nickel substrates via chemical vapor deposition. The aluminum oxide was produced by pyrolysis of a metal acetylacetonate precursor. This reaction was done at relatively low temperatures, from 435 to 550 °C to deposit a thin film of aluminum oxide. The coating provided protection against isothermal oxidation at elevated temperatures. Resistance to oxidation was

Jun Nable; Malgorzata Gulbinska; Steven L Suib; Francis Galasso

2003-01-01

50

Metallic Bipolar Plates with Composite Coatings  

E-print Network

Metallic Bipolar Plates with Composite Coatings Jennifer Mawdsley Argonne National Laboratory Fuel Cell Projects Kickoff Meeting Washington DC October 1, 2009 #12;2 Metallic Bipolar Plates with Composite Coatings Project Objective Make aluminum-based bipolar plates an option for replacing machined

51

Amorphous metallic films in silicon metallization systems  

NASA Technical Reports Server (NTRS)

The general objective was to determine the potential of amorphous metallic thin films as a means of improving the stability of metallic contacts to a silicon substrate. The specific objective pursued was to determine the role of nitrogen in the formation and the resulting properties of amorphous thin-film diffusion barriers. Amorphous metallic films are attractive as diffusion barriers because of the low atomic diffusivity in these materials. Previous investigations revealed that in meeting this condition alone, good diffusion barriers are not necessarily obtained, because amorphous films can react with an adjacent medium (e.g., Si, Al) before they recrystallize. In the case of a silicon single-crystalline substrate, correlation exists between the temperature at which an amorphous metallic binary thin film reacts and the temperatures at which the films made of the same two metallic elements react individually. Amorphous binary films made of Zr and W were investigated. Both react with Si individually only at elevated temperatures. It was confirmed that such films react with Si only above 700 C when annealed in vacuum for 30 min. Amorphous W-N films were also investigated. They are more stable as barriers between Al and Si than polycrystalline W. Nitrogen effectively prevents the W-Al reaction that sets in at 500 C with polycrystalline W.

Nicolet, M. A.; Kattelus, H.; So, F.

1984-01-01

52

Epitaxial growth of Pb(Zr0.53Ti0.47)O3 films on Pt coated magnetostrictive amorphous metallic substrates toward next generation multiferroic heterostructures  

NASA Astrophysics Data System (ADS)

Piezoelectric films of Pb(Zr0.53Ti0.47)O3 (PZT) were deposited by pulsed laser deposition onto metallic magnetostrictive substrates. In order to optimize the growth of PZT films, a buffer layer of Pt was employed, as well as variation of deposition temperature, pressure, and laser energy. Room temperature ?-2? x-ray diffraction measurements indicate all diffraction features correspond to reflections indexed to a single PZT phase of space group P4mm. Scanning electron microscopy images reveal pinhole-free dense films of pyramidal shaped crystal arrangements whose orientation and size were controlled by variation of oxygen pressures during deposition. The resulting PZT films had a value of d33 ˜ 46 pm/V representing a 53% increase over previous efforts to realize a piezoelectric/Metglas™ film heterostructure.

Hu, B.; Chen, Y.; Yang, A.; Gillette, S.; Fitchorov, T.; Geiler, A.; Daigle, A.; Su, X. D.; Wang, Z.; Viehland, D.; Harris, V. G.

2012-03-01

53

Improvement of the partial discharge resistance of polymer films by coating with plasma-polymerized films  

Microsoft Academic Search

The surface of polytetrafluoroethylene (PTFE) and polyethylene terephthalate films was coated with plasma-polymerized hexamethyldisiloxane (PPHMDS) film in a triode glow discharge system. The dielectric properties of PPHMDS films and their durability, the partial discharge characteristics and the surface morphology of coated polymer films were investigated. The lifetime of the coated PTFE films was longer than that of the uncoated PTFE

Minoru Kusabiraki; Masao Aozasa

1996-01-01

54

Flexible thin metal film thermal sensing system  

NASA Technical Reports Server (NTRS)

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

Thomsen, Donald L. (Inventor)

2010-01-01

55

Film coatings for oral colon delivery.  

PubMed

Oral colon delivery is pursued through a number of formulation strategies with the aim of enabling effective and well-tolerated treatments for large bowel pathologies or enhancing the intestinal absorption of peptide and protein drugs. According to such strategies, coated dosage forms for colonic release may be provided with microbiota, pH, pressure or time-dependent polymeric films. Microbiota-activated coatings are mostly obtained from polysaccharides of natural origin mixed with insoluble structuring excipients. Alternatively, synthetic azo compounds have been employed, generally requiring organic solvents for use as spray-coating agents. On the other hand, pH-sensitive films show responsiveness to pH changes in the lower gut, such as the rise generally observed in the terminal ileum and distal colon or the slight acidification of caecal contents by bacterial fermentation products. Pressure-sensitive coatings are intended for rupturing because of the relatively elevated pressure that may affect solid dosage forms in the large bowel. Finally, time-dependent films are expected to undergo timed erosion, break-up or permeabilization processes irrespective of the aforementioned physiological variables. In this review, the differing films applied for colon delivery purposes are surveyed, and details on their composition, manufacturing and performance are reported. PMID:23727142

Maroni, Alessandra; Del Curto, Maria Dorly; Zema, Lucia; Foppoli, Anastasia; Gazzaniga, Andrea

2013-12-01

56

Introduction: Edible Coatings and Films to Improve Food Quality  

Technology Transfer Automated Retrieval System (TEKTRAN)

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

57

Molecular Level Coating for Metal Oxide Particles  

NASA Technical Reports Server (NTRS)

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

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

2000-01-01

58

Molecular Level Coating of Metal Oxide Particles  

NASA Technical Reports Server (NTRS)

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

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

2002-01-01

59

THe influence of copper-nickel multilayered thin film coatings on the fatigue behavior of copper  

NASA Astrophysics Data System (ADS)

Multilayered metallic thin films often display enhanced mechanical properties, such as hardness and yield stress, as the bilayer repeat length is reduced below about 100 run. This behavior suggests that surface coatings of such films on metallic substrates may lead to other mechanical property improvements, such as enhanced fatigue life. Unlike other hard coatings that have been used to improve fatigue life, which are often brittle, multilayered thin films display a substantial amount of ductility, and this feature may also have a significant impact on the surface deformation during cyclic loading. Rotating bending fatigue experiments were conducted on bare cylindrical copper substrates as well as substrates coated with monolithic copper films, monolithic nickel films, and multilayered Cu-Ni films with a bilayer repeat length on 40 run. Electrochemical deposition was used to produce the surface films, and each of the coatings had a total thickness of 5mum. No significant difference in the fatigue life of the bare substrates and substrates with the monolithic copper films was observed, and only a modest improvement in fatigue life was measured in the substrates coated with the monolithic nickel films. However, the substrates with the multilayered films showed a substantial increase in the fatigue life, by at least a factor of 33, compared to that of the bare substrates. These results strongly suggest that it is the layered nature of the Cu-Ni composite films that is responsible for the improvement in the fatigue behavior. Microstructural characterization indicated that the multilayered films inhibited both surface crack initiation and propagation. Based on this work, it is proposed that multilayered metallic thin films may be applicable as fatigue resistant surface coatings.

Stoudt, Mark Richard

60

Experimental analysis of metal coated dielectric waveguides  

Microsoft Academic Search

This paper addresses the experimental characteristics of metal-coated dielectric waveguides with a rectangular surface corrugation. Waveguides are designed to operate at a second Bragg frequency of 90 GHz. The period, height, and the duty cycle of a rectangular grating were calculated using the chosen frequency. A metallic layer of aluminum is sputtered on one side of the slab waveguide. The

C. S. Yeh; N. Urimindi; Jin Liu; G. A. Evans; J. K. Butler

1993-01-01

61

Experimental analysis of metal coated dielectric waveguides  

Microsoft Academic Search

This paper concerns the experimental characteristics of metal coated dielectric waveguides with a rectangular surface corrugation. Waveguide are designed to operate at a second Bragg frequency of 90 GHz. The period, height and the duty cycle of a rectangular grating were calculated using the chosen frequency. A metallic layer of aluminum is sputtered on one side of the slab waveguide.

C. S. Yeh; N. Urimindi; Jin Liu; G. A. Evans; J. K. Butler

1993-01-01

62

Metal/dielectric/metal sandwich film for broadband reflection reduction  

PubMed Central

A film comprising randomly distributed metal/dielectric/metal sandwich nanopillars with a distribution of cross-sectional diameters, displayed extremely low reflectance over the blue-to-red regime, when coated on glass and illuminated normally. When it is illuminated by normally incident light, this sandwich film (SWF) has a low extinction coefficient, its phase thickness is close to a negative wavelength in the blue-to-red spectral regime, and it provides weakly dispersive forward and backward impedances, so that reflected waves from the two faces of the SWF interfere destructively. Broadband reflection-reduction, over a wide range of incidence angles and regardless of the polarization state of the incident light, was observed when the SWF was deposited on polished silicon. PMID:23591704

Jen, Yi-Jun; Lakhtakia, Akhlesh; Lin, Meng-Jie; Wang, Wei-Hao; Wu, Huang-Ming; Liao, Hung-Sheng

2013-01-01

63

Optoacoustic technique for thickness measurement of submicron metal coatings  

NASA Astrophysics Data System (ADS)

The new nondestructive method for thickness measurement of submicron metal coatings on transparent substrate is developed. The method is based on the optoacoustic (OA) transformation in the system, where the coating is covered by an optically transparent liquid. Theoretical treatment of the problem consists of two steps. At the first step laser-induced thermal field in the system is calculated, taking into account the large thermal conductivity of the metal film and partial heat diffusion into the liquid. At the second step the system of wave equations for scalar potential of vibration velocities is solved. Heat sources, determined at the first step, are free form of wave equations. Three chrome coatings of different thickness (approximately 0.2, 0.3, and 0.6 ?m) deposited on the quartz substrate are tested experimentally. Two different organic liquids (acetone and ethanol) are used to cover chrome coatings. Nanosecond diode-pumped Nd:YAG laser operated at the main harmonic is used to perform OA transformation (laser pulse duration is ? L = 12 ns, the laser energy is about 0.2 mJ). Two detection modes are used. In forward mode laser pulse irradiates the film from the side of the substrate and in backward mode—from the side of the liquid. Detection of induced ultrasonic pulses is performed by the wide-band piezoelectric transducer in the liquid in both cases. The thickness of the coatings is determined by the least squares fitting of the theoretical dependencies of spectral transfer functions of OA transformation to experimental data. It is demonstrated, that the developed technique can be used for measurement of metal coatings thickness within the range from 50 nm to 5 ?m with the error about 50 nm.

Pelivanov, I. M.; Kopylova, D. S.; Podymova, N. B.; Karabutov, A. A.

2009-06-01

64

Thin-film metal hydrides.  

PubMed

The goal of the medieval alchemist, the chemical transformation of common metals into nobel metals, will forever be a dream. However, key characteristics of metals, such as their electronic band structure and, consequently, their electric, magnetic and optical properties, can be tailored by controlled hydrogen doping. Due to their morphology and well-defined geometry with flat, coplanar surfaces/interfaces, novel phenomena may be observed in thin films. Prominent examples are the eye-catching hydrogen switchable mirror effect, the visualization of solid-state diffusion and the formation of complex surface morphologies. Thin films do not suffer as much from embrittlement and/or decrepitation as bulk materials, allowing the study of cyclic absorption and desorption. Therefore, thin-metal hydride films are used as model systems to study metal-insulator transitions, for high throughput combinatorial research or they may be used as indicator layers to study hydrogen diffusion. They can be found in technological applications as hydrogen sensors, in electrochromic and thermochromic devices. In this review, we discuss the effect of hydrogen loading of thin niobium and yttrium films as archetypical examples of a transition metal and a rare earth metal, respectively. Our focus thereby lies on the hydrogen induced changes of the electronic structure and the morphology of the thin films, their optical properties, the visualization and the control of hydrogen diffusion and on the study of surface phenomena and catalysis. PMID:18980236

Remhof, Arndt; Borgschulte, Andreas

2008-12-01

65

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

Microsoft Academic Search

A battery structure including a cathode, a lithium metal anode and an electrolyte disposed between the lithium anode and the cathode utilizes a thin-film layer of lithium phosphorus oxynitride overlying so as to coat the lithium anode and thereby separate the lithium anode from the electrolyte. If desired, a preliminary layer of lithium nitride may be coated upon the lithium

John B

1994-01-01

66

Metal alloy coatings and methods for applying  

DOEpatents

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

Merz, Martin D. (Richland, WA); Knoll, Robert W. (Kennewick, WA)

1991-01-01

67

Development of metal based thermal barrier coatings  

Microsoft Academic Search

In this work, metal-based thermal barrier coatings (MBTBCs) have been produced, using high frequency induction plasma spraying (IPS) of iron-based nanostructured alloy powders. Important advances have been made over recent years to the development of ceramic-based thermal barrier coatings (TBCs) for internal combustion engines application, but they are not yet applied in mass production situations. Besides the important economic considerations,

Dong-Il Shin

2005-01-01

68

Metal seated ball valves with carbide coatings  

SciTech Connect

Valvtechnologies valves utilize Alloy Carbide HVOF Sprayed RAM{reg_sign} Hardcoatings such as Chrome Carbide and Tungsten Carbide Coatings. The coatings are applied using a Proprietary Gun combusting Hydrogen and Oxygen. The powders are heated and accelerated toward the valve component forming a tenaciously bonded coating. Each coating is chosen depending upon the environment the valve will operate in. These valves have solved many Petro-Chemical service life problems. Free from the temperature limits of elastomers, the only sealing materials are metal, the carbides and grafoils (carbons). Operating temperatures to 982 C (1,800 F) are typical limits; 649 C (1,200 F) is common. Lower temperatures are also common, even in the cryogenic range. Even though the coatings have low thermal expansion rates, RAM{reg_sign} Hardcoatings can expand and contract with the base material and still maintain a seal.

Manuel, R. [Alloy Carbide Co., Houston, TX (United States); Yung, E. [Valvtechnologies, Inc., Houston, TX (United States)

1994-12-31

69

Metallic seal for thermal barrier coating systems  

NASA Technical Reports Server (NTRS)

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

Miller, Robert A. (inventor)

1990-01-01

70

Thin film coatings with variable emittance  

NASA Astrophysics Data System (ADS)

The temperature of a nanosatellite in orbit varies strongly as it goes into earth shadow or solar radiation. A variable emittance panel built with an electrochromic material, could improve the temperature control by providing an adaptive thermal control. The active function is due to an electrochromic layer, WO3, deposited by sputtering. Intercalation of Li+ leads to a change in the electron configuration, which modulates the radiation properties. Thin WO3 films were deposited onto Indium Tin Oxide (ITO) coated glass by reactive dc sputtering. IR measurements were done in a Perkin-Elmer 983 spectrophotometer. The IR emittance modulation, (Delta) (epsilon) of WO3 films, deposited on ITO coated glass, has been investigated. The emittance, (epsilon) , is computed from the reflectance, at 25 degrees C. Initial results show emittances in the range from 0.2 to 0.5 crystalline film has (Delta) (epsilon) equals 0.12, and the amorphous film has (Delta) (epsilon) equals 0.3. IR properties of WO3 need to be further investigated as well as the construction of a whole device.

Larsson, Anna-Lena; Niklasson, Gunnar A.; Stenmark, Lars

1999-09-01

71

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

PubMed

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

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

2009-07-01

72

Aerosol chemical vapor deposition of metal oxide films  

DOEpatents

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

Ott, Kevin C. (4745 Trinity Dr., Los Alamos, NM 87544); Kodas, Toivo T. (5200 Noreen Dr. NE., Albuquerque, NM 87111)

1994-01-01

73

INELASTIC CONTACT DEFORMATION OF METAL COATED FIBERS  

E-print Network

) which are evaluated using the ®nite element method. A simple model for the consolidation of coated Si composites (MMCs) [1±4]. By applying reactive metals such as titanium via a vapor phase process allows and ®ber microbending/damage during the consolidation of titanium matrix composite (TMC) monotapes produced

Wadley, Haydn

74

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

SciTech Connect

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.

Long, Rong, E-mail: rlongmech@gmail.com [Department of Mechanical Engineering, University of Alberta, Edmonton, Alberta T6G 2G8 (Canada); Department of Mechanical Engineering, University of Colorado, Boulder, Colorado 80309 (United States); Dunn, Martin L. [Department of Mechanical Engineering, University of Colorado, Boulder, Colorado 80309 (United States); Singapore University of Technology and Design, Singapore 138682 (Singapore)

2014-06-21

75

The spraying of coating by supersonic metalization  

SciTech Connect

A technology and a specialized equipment complex based on a supersonic arc spraying gun, where a supersonic stream of combustion products of hydrocarbon-gas (HC-gas) with air is used as an atomizing gas, have been developed. Durable and safe work of coated parts functioning under conditions of intensive loading is determined (except general requirements to coatings: wear resistance, hardness, adhesion) to a large extent by the fatigue strength and the stability of the properties of coatings. New possibilities for satisfying all the requirements to coatings on parts type are opened up by a high speed spraying of wire. This is provided at the expanse of raising the kinetic energy of particles under spray, increase of their concentration in a metal stream, lowering of the spread of parameters (velocity, temperature, sizes) in the vicinity of a substrate. This, in its turn, determines the increase of adhesive and cohesive strength of a coating, the decrease of oxidizability, the improvement of stability and reproducibility of its properties. The results of the investigations of the influence of the variable parameters of the process on the listed above properties of coatings are presented. A procedure of computer evaluation of the degree of the reproducibility of structural peculiarities of sprayed coatings is worked out. An industrial installation and examples of its use for the strengthening of automobile parts are described.

Karp, I.N.; Petrov, S.V.; Rudoy, A.P.; Komissarenko, A.A. [Academy of Sciences of Ukraine, Kiev (Ukraine). Gas Inst.

1994-12-31

76

Amorphous metallic films in silicon metallization systems  

NASA Technical Reports Server (NTRS)

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

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

1985-01-01

77

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

PubMed

In recent years, magnesium and its alloys have been investigated as biodegradable metallic materials in cardiovascular stents and bone implants. However, rapid corrosion rate in the early stage of the degradation process greatly influences the cytocompatibility and hinters their application. In this research, biodegradable polymer films are prepared under same coating condition by spin coating in order to improve the early corrosion resistance and cytocompatibility of Mg. The results present that uniform, nonporous, amorphous PLLA and semi-crystalline PCL films are coated on Mg. PLLA film shows better adhesion strength to Mg substrate than that of PCL film. For both PLLA and PCL, low molecular weight (LMW) film is thinner and exhibits better adhesion strength than high molecular weight (HMW) one. SaOS-2 cells show significantly good attachment and high growth on the polymer-coated Mg, demonstrating that all the polymer films can significantly improve the cytocompatibility in the 7-day incubation. The pH measurement of the immersion medium and the quantification of released Mg(2+) during the cell culture clearly indicate that the corrosion resistance of Mg substrate is improved by the polymer films to different extents. It can be concluded that both PLLA and PCL films are promising protective coatings for improving the initial corrosion resistance and cytocompatibility. PMID:22225942

Xu, Liping; Yamamoto, Akiko

2012-05-01

78

Protective coatings of metal surfaces by cold plasma treatment  

NASA Technical Reports Server (NTRS)

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

Manory, R.; Grill, A.

1985-01-01

79

Surfaces: More than they seem. [Coating technologies extend metals' capabilities  

SciTech Connect

Developing surface treatment techniques for metals, ceramics and plastics is becoming big business. As tight budgets hold back new materials development and data and new analytical techniques allow users to predict performance, more companies are either licensing or collaborating on new surface modification techniques or buying surface-engineered products. Most of the developments are now going on in diamond and diamond-like carbon coatings, since diamond offers more hardness, thermal and electrical conductivity and corrosion resistance than other materials. The paper discusses the technical problems involved in working with diamond and other carbon films. The paper also discusses the old-fashioned liquid counting methods which are also being improved.

Grinthal, W.; Ondrey, G.; Parkinson, G.

1994-04-01

80

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

SciTech Connect

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

Shaik, Ummar Pasha [ACRHEM, University of Hyderabad, Hyderabad-500046 (India); Krishna, M. Ghanashyam, E-mail: mgksp@uohyd.ac.in [ACRHEM and School of Physics, University of Hyderabad, Hyderabad-500046 (India)

2014-04-24

81

Bioactive glass coatings for orthopedic metallic implants  

SciTech Connect

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

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

2003-06-30

82

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

ERIC Educational Resources Information Center

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

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

2013-01-01

83

Liquid Galvanic Coatings for Protection of Imbedded Metals  

NASA Technical Reports Server (NTRS)

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

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

2003-01-01

84

Plasma sprayed and electrospark deposited zirconium metal diffusion barrier coatings  

Microsoft Academic Search

Zirconium metal coatings applied by plasma spraying and electrospark deposition (ESD) have been investigated for use as diffusion barrier coatings on low enrichment uranium fuel for research nuclear reactors. The coatings have been applied to both stainless steel as a surrogate and to simulated nuclear fuel uranium-molybdenum alloy substrates. Deposition parameter development accompanied by coating characterization has been performed. The

Kendall J Hollis; Maria I Pena

2010-01-01

85

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

SciTech Connect

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

Pelivanov, Ivan M.; Kopylova, Daria S.; Podymova, Natalia B.; Karabutov, Alexander A. [International Laser Center, M. V. Lomonosov Moscow State University, Moscow 119991 (Russian Federation)

2009-07-01

86

Development of alloy-film coated dispenser cathode for terahertz vacuum electron devices application  

NASA Astrophysics Data System (ADS)

High power terahertz vacuum electron devices demand high current density and uniform emission dispenser cathode. It was found that the coating of noble metals e.g., Os, Ir, and Re on the surface of tungsten dispenser cathodes enhances the emission capabilities and uniformity. Hence metal coated cathode might be the best candidate for terahertz devices applications. In this study, ternary-alloy-film cathode (2Os:2Re:1 W) and Os coated cathode have been developed and the results are presented. The cathodes made out of this alloy coating showed 1.5 times higher emission and 0.02 eV emission uniformity as compared to those of simply Os coated cathodes which can be used in terahertz devices application.

Barik, R. K.; Bera, A.; Raju, R. S.; Tanwar, A. K.; Baek, I. K.; Min, S. H.; Kwon, O. J.; Sattorov, M. A.; Lee, K. W.; Park, G.-S.

2013-07-01

87

Polymer-assisted conformal coating of TiO2 thin films  

NASA Astrophysics Data System (ADS)

Conformal coating of nanofabricated structures with a high-index dielectric material is a common problem for a diverse set of integrated photonic and plasmonic devices such as planar waveguides, on-chip spectrometers, gratings, flat panel displays, optical sensors, and integrated optical devices. In this paper we were recently able to demonstrate an alternate method for conformally coating photonic nanostructures using a low cost, polymer-assisted deposition (PAD) process for the metal-oxide TiO2. In a PAD process a thermally curable, hybrid high refractive index polymer solution is spin-coated onto a substrate. The polymer controls the viscosity and binds the metal ions, resulting in a homogeneous distribution of the precursor in solution. When cured at elevated temperature, the hybrid polymer coating decomposes to form a metal oxide-rich film that has a high refractive index that conformally fills the voids in nanofabricated structures. The resulting films have refractive indices higher than 1.83 in the visible region and film thicknesses between 250-500 nm depending on the level of metal-oxide loading, cure temperature, and number of coatings.

Gillman, E. S.; Costello, D.; Moreno, M.; Raspopin, A.; Kasica, R.; Chen, L.

2010-08-01

88

Evaluation of a non-catalytic coating for metallic TPS  

NASA Technical Reports Server (NTRS)

A commercially available ceramic coating was evaluated for application to metallic heat shields for Shuttle-type entry vehicles. Coated Inconel 617 specimens were subjected to thermal shock cycles, surface emittances were measured, and surface equilibrium temperatures were measured for coated and oxidized specimens exposed to an arc-tunnel environment. The coating adhered very well to the metal and appeared to be very non-catalytic.

Pittman, C. M.; Brown, R. D.; Shideler, J. L.

1984-01-01

89

A shape-recovery polymer coating for the corrosion protection of metallic surfaces.  

PubMed

Self-healing polymer coatings are a type of smart material aimed for advanced corrosion protection of metals. This paper presents the synthesis and characterization of two new UV-cure self-healing coatings based on acrylated polycaprolactone polyurethanes. On a macroscopic scale, the cured films all show outstanding mechanical properties, combining relatively high Young's modulus of up to 270 MPa with a strain at break above 350%. After thermal activation the strained films recover up to 97% of their original length. Optical and electron microscopy reveals the self-healing properties of these coatings on hot dip galvanized steel with scratches and microindentations. The temperature-induced closing of such defects restores the corrosion protection and barrier properties of the coating as shown by electrochemical impedance spectroscopy and scanning vibrating electrode technique. Therefore, such coatings are a complementary option for encapsulation-based autonomous corrosion protection systems. PMID:25517028

Lutz, Alexander; van den Berg, Otto; Van Damme, Jonas; Verheyen, Karen; Bauters, Erwin; De Graeve, Iris; Du Prez, Filip E; Terryn, Herman

2015-01-14

90

Sputtered metallic coatings for optical fibers used in high-temperature environments  

NASA Astrophysics Data System (ADS)

Rf and dc planar magnetron sputtering systems were used to deposit high-temperature nickel- based super alloys, INCONEL 617, 625, Haynes 214, and thin films of palladium, as coatings on optical fibers for use in temperatures approaching 1000 degree(s)C. The nickel-based alloy coatings were applied on-line as the optical fiber was drawn, minimizing the exposure of the fiber to the deleterious effects of humidity. The thin film coatings of pure metals were sputtered using a new rf magnetron sputtering system custom designed and built for the Fiber and Electro Optics Research Center. The resulting coatings were analyzed using scanning electron microscopy, Auger electron microscopy, and energy dispersive x-ray spectroscopy. The coated fibers exhibit promise for embedded sensors in high temperature, high load composites used for advanced aerospace and energy applications.

Gunther, Michael F.; Zeakes, Jason S.; Lieber, Donald E.; May, Russell G.; Claus, Richard O.

1994-05-01

91

Temperature Sensing of Metal-Coated Fiber Bragg Grating  

Microsoft Academic Search

Optical fiber Bragg grating (FBG) sensors have attracted considerable interest due to their special wavelength-encoded nature, small size, lightness, and immunity to electric-magnetic interference. Before being embedded into metal structures, FBG sensors must be protected and metal coating is one of the most efficient protective methods. The fluctuation of temperature induces thermal stresses between metal coating and the optical fiber

Yan Feng; Hua Zhang; Yu-Long Li; Chun-Fang Rao

2010-01-01

92

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

DOEpatents

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

Adzic, Radoslav; Harris, Alexander

2014-04-15

93

Thin films of mixed metal compounds  

DOEpatents

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

Mickelsen, Reid A. (Bellevue, WA); Chen, Wen S. (Seattle, WA)

1985-01-01

94

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

DOEpatents

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

Branagan, Daniel J. (Idaho Falls, ID); Hyde, Timothy A. (Idaho Falls, ID); Fincke, James R. (Los Alamos, NM)

2008-03-11

95

Thin film hydrous metal oxide catalysts  

DOEpatents

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

Dosch, Robert G. (Albuquerque, NM); Stephens, Howard P. (Albuquerque, NM)

1995-01-01

96

Epoxy and Polyurethane Networks in Thin Films On Metals—Formation, Structure, Properties  

Microsoft Academic Search

Thin adhesive films on metals are used as an appropriate model for the characterization of the interphase in polymer?metal compounds. This interphase is a result of the specific interactions between the adhesive partners. It is particularly relevant for the performance, and the long?term stability of adhesively bonded structures and coatings. The influence of the metal substrate affects the formation of

Carsten Wehlack; Wulff Possart; Jan K. Krüger; Ullrich Müller

2007-01-01

97

Dip-coated YBa 2Cu 3O 7- x film by metalorganic deposition using trifluoroacetate  

NASA Astrophysics Data System (ADS)

Metalorganic deposition using trifluoroacetates (TFA-MOD) with dip coating was applied for the preparation of YBCO coated conductor. The thickness of the dip-coated films increases with the 0.364th power of the withdrawal speed of substrates. This relationship is common to the case on either single crystal or metal substrate. A 3 cm long dipped YBCO tape on CeO 2/YSZ(IBAD)/hastelloy-C is formed at a 5 mm/s withdrawal speed. The tape of 2000 Å in thickness has Jc of 1.0-1.3 MA/cm 2 (77 K, 0 T) measured by the four-probe-method.

Araki, T.; Kurosaki, H.; Yuasa, T.; Iijima, Y.; Saitoh, T.; Yamada, Y.; Hirabayashi, I.

2002-08-01

98

Developing metal coated mesh filters for mid-infrared astronomy  

NASA Astrophysics Data System (ADS)

A metal mesh filter is appropriate to a band-pass filter for astronomy in the long mid-infrared between 25 and 40 ?m, where most of optical materials are opaque. The mesh filter does not require transparent dielectric materials unlike interference filters because the transmission characteristics bare determined by surface plasmon-polariton (SPP) resonances excited on a metal surface with a periodic structure. In this study, we have developed the mesh filters optimized to atmospheric windows at 31.8 and 37.5 ?m accessible from the Chajnantor site of 5,640 m altitude. First, mesh filters made of a gold film of 2 ?m thickness have been fabricated. Four identical film-type filters are stacked incoherently to suppress leakages at stop-bands. The transmissions of the stacked filters have been measured to be 0.8 at the peaks and below 1 x 10-3 at the stop-bands at 4 K. The ground-based mid-infrared camera MAX38 has been equipped with the stacked filters and successfully obtained diffraction-limited stellar images at the Chajnantor site. The film-type mesh filter does not have sufficient mechanical strength for a larger aperture and for use in space. We have developed mesh filters with higher strength by applying the membrane technology for x-ray optics. The membrane-type mesh filter is made of SiC and coated with a thin gold layer. The optical performance of the mesh filter is independent of internal materials in principle because the SPP resonances are excited only on the metal surface. The fabricated membrane-type mesh filter has been confirmed to provide comparable optical performance to the film-type mesh filter.

Sako, Shigeyuki; Miyata, Takashi; Kamizuka, Takafumi; Nakamura, Tomohiko; Asano, Kentaro; Uchiyama, Mizuho; Onaka, Takashi; Sakon, Itsuki; Wada, Takehiko

2012-09-01

99

Process for ultra smooth diamond coating on metals and uses thereof  

NASA Technical Reports Server (NTRS)

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

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

2001-01-01

100

Structure and Properties of Regenerated Cellulose Film with Fluorocarbon Coating  

NASA Astrophysics Data System (ADS)

Fluorocarbon coatings were deposited on the surface of regenerated cellulose films by RF magnetron sputtering, using polytetrafluoroethylene targets. Argon was used as the working gas. The coatings were characterized by X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, atomic force microscopy, static contact angle and oxygen permeability measurements. It was found that the coatings were made up of the four components -CF3, -CF2-, -CF- and -C-. The [F]/[C] ratio varied with sputtering conditions. The surface of fluorocarbon coatings had an undulate island structure. The static contact angle of the coatings was greater than 90° at lower power and higher pressure, and the substrate material was transformed from hydrophilic to hydrophobic character. The fluorocarbon coatings were porous and did not influence the oxygen permeability of the cellulose film substrates.

Zhang, Yuhui; Ji, Quan; Qi, Hongjin; Liu, Zengji

101

Increase in the DSSC efficiency when using metal-coated carbon nanowall counter electrodes  

NASA Astrophysics Data System (ADS)

This research was conducted to improve the efficiency of dye-sensitized solar cells (DSSCs) using metal-layer-coated carbon nanowalls (CNWs) as counter electrodes. The CNWs were synthesized on a fluorine-doped tin-oxide (FTO) glass substrate in a microwave plasma-enhanced chemical vapor deposition (PECVD) system using methane (CH4), and the CNWS were sputter-coated with metal films several times by using an RF magnetron sputtering system and four-inch metal targets (Cu, W and Ni, separately). Then, the metal-layer-coated CNWs were used as counter electrodes for manufacturing the DSCCs. The vertical and the surface conditions of the metal-coated CNWs used as the DSCC electrodes were characterized by their electrical variations through field-emission scanning electron microscopy (FE-SEM) and Hall measurements. Their optical characteristics were analyzed using UV-Vis equipment, and the energy conversion efficiencies of the DSSCs manufactured using the metal-layer-coated CNWs as the counter electrodes were measured. The results confirmed that the efficiency improved when the W-coated CNW was used as the counter electrode.

Lee, Sangjoon; Choi, Won Seok; Lim, Dong-Gun; Choi, Eun Chang; Hong, Byungyou

2014-08-01

102

Assessment of ceramic coatings for metal fuel melting crucible  

SciTech Connect

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

Kim, Ki-Hwan; Song, Hoon; Kim, Jong-Hwan; Oh, Seok-Jin; Kim, Hyung-Tae; Lee, Chan-Bock [Korea Atomic Energy Research Institute, Yuseong, Daejeon 305-600 (Korea, Republic of)

2013-07-01

103

Film Coating Process Research and Characterization of TiN Coated Racetrack-type Ceramic Pipe  

E-print Network

TiN film was coated on the internal face of racetrack-type ceramic pipe by three different methods: radio-frequency sputtering, DC sputtering and DC magnetron sputtering. The deposition rates of TiN film under different coating methods were compared. According to the AFM, SEM, XPS test results,these properties were analyzed, such as TiN film roughness and surface morphology. At the same time, the deposition rates were studied under two types' cathode, Ti wires and Ti plate. According to the SEM test results, Ti plate cathode can improve the TiN/Ti film deposition rate obviously.

Wang, Jie; Zhang, Bo; Wei, Wei; Fan, Le; Pei, Xiangtao; Hong, Yuanzhi; Wang, Yong

2015-01-01

104

Ion-beam-assisted deposition of biaxially aligned yttria-stabilized zirconia template films on metallic substrates for YBCO-coated conductors  

NASA Astrophysics Data System (ADS)

Biaxially textured yttria-stabilized zirconia (YSZ) films were grown on mechanically polished Hastelloy C276 (HC) substrates by ion-beam-assisted deposition and electron-beam evaporation. The surface root-mean-square (RMS) roughness of the polished HC substrates was ?3 nm, as measured by atomic force microscopy (AFM). A water-cooled sample stage was used to hold the substrate temperature below 100 °C during deposition. RMS roughness of ?3.3 nm was measured on the deposited YSZ films by AFM. X-ray pole figures were conducted for texture analysis; in-plane texture measured from YSZ (111) ?-scan FWHM was 13.2° and out-of-plane texture from the YSZ (002) ?-scan FWHM was 7.7°. An ?10 nm thick CeO2 buffer layer was deposited on the YSZ film at 800 °C before YBCO films were ablated by pulsed laser deposition at 780 °C in a 250 mTorr flowing oxygen environment. Good in-plane texture with FWHM ? 7° was observed in YBCO films. Tc = 90 K, with sharp transition, and transport Jc of ?2.2 × 106 A cm-2 were observed in a 0.5 ?m thick, 5 mm wide, and 1 cm long sample at 77 K in self-field.

Ma, B.; Li, M.; Fisher, B. L.; Balachandran, U.

2002-07-01

105

Surface Potential of Insulating Plate Coated by Metallic Paint Spray  

Microsoft Academic Search

Surface potential of insulating plate coated by metallic paint spray has been investigated for improving coating system using an air spray gun. The metallic paint contained aluminum flakes with a thickness of about 30 nm in organic solvent. The paint was sprayed on a test target by the air spray gun at a pressure of 0.2 MPa. The target was

Toshiyuki Sugimoto; Noriyuki Shirahata; Yoshio Higashiyama; Koichi Takeda

2007-01-01

106

Thin film heater for removable volatile protecting coatings.  

PubMed

Freshly coated aluminum mirrors have excellent reflectivity at far ultraviolet wavelengths. However, reflectivity rapidly degrades when the mirror surfaces are exposed to atmosphere. In order to avoid this problem, freshly coated aluminum surface can be protected by over-coating of a removable volatile protecting coating. This protecting coating can be re-evaporated by controlled heating or by some other methods when required. This type of removable coating has immediate application in UV space astronomy. The purpose of this paper is to demonstrate the feasibility of re-evaporation of removable volatile Zn protecting coating using a NiCr thin film heater without affecting the reflection properties of Al mirror surfaces. PMID:24327809

Karim, Abid

2013-01-01

107

Thin Film Heater for Removable Volatile Protecting Coatings  

PubMed Central

Freshly coated aluminum mirrors have excellent reflectivity at far ultraviolet wavelengths. However, reflectivity rapidly degrades when the mirror surfaces are exposed to atmosphere. In order to avoid this problem, freshly coated aluminum surface can be protected by over-coating of a removable volatile protecting coating. This protecting coating can be re-evaporated by controlled heating or by some other methods when required. This type of removable coating has immediate application in UV space astronomy. The purpose of this paper is to demonstrate the feasibility of re-evaporation of removable volatile Zn protecting coating using a NiCr thin film heater without affecting the reflection properties of Al mirror surfaces. PMID:24327809

Karim, Abid

2013-01-01

108

40 CFR 52.253 - Metal surface coating thinner and reducer.  

...2014-07-01 false Metal surface coating thinner and reducer. 52...California § 52.253 Metal surface coating thinner and reducer. (a...of the organics in all metal surface coating thinners and reducers that...

2014-07-01

109

40 CFR 52.253 - Metal surface coating thinner and reducer.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 false Metal surface coating thinner and reducer. 52...California § 52.253 Metal surface coating thinner and reducer. (a...of the organics in all metal surface coating thinners and reducers that...

2011-07-01

110

40 CFR 52.253 - Metal surface coating thinner and reducer.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false Metal surface coating thinner and reducer. 52...California § 52.253 Metal surface coating thinner and reducer. (a...of the organics in all metal surface coating thinners and reducers that...

2012-07-01

111

40 CFR 52.253 - Metal surface coating thinner and reducer.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Metal surface coating thinner and reducer. 52...California § 52.253 Metal surface coating thinner and reducer. (a...of the organics in all metal surface coating thinners and reducers that...

2013-07-01

112

Nanostructures versus thin films in the design of antireflection coatings  

NASA Astrophysics Data System (ADS)

It is shown how the discussion about antireflection coatings for the visible and near infrared region has been changed dramatically with recent experimental applications of nanostructures that realize media with effective refractive indices less than the 'magic border' of 1.34. Using the so-called binary optics as an example, a glass-like nanostructure similar to the moth-eye structure is theoretically designed as antireflection coating for the visible and near infrared region. With the aim of this example and considering only known design principles of thin-film optics, a connection between nanostructures and thin films regarding their alternative or combined application as antireflection coatings is presented. As summary regarding the nanostructures vs. thin film discussion, a reference list is presented that cited different types of antireflection coatings presented in the past 70 years with respect to their applications, designs, and deposition technologies.

Schallenberg, Uwe B.

2011-09-01

113

Process for forming a metal compound coating on a substrate  

DOEpatents

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

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

1988-06-29

114

Process for forming a metal compound coating on a substrate  

DOEpatents

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

Sharp, Donald J. (Albuquerque, NM); Vernon, Milton E. (Albuquerque, NM); Wright, Steven A. (Albuquerque, NM)

1991-01-01

115

Adherence of ion beam sputter deposited metal films on H-13 steel  

NASA Technical Reports Server (NTRS)

An electron bombardment argon ion source was used to sputter deposit 17 different metal and metal oxide films ranging in thickness from 1 to 8 micrometers on H-13 steel substrates. The film adherence to the substrate surface was measured using a tensile test apparatus. Comparisons in bond strength were made between ion beam, ion plating, and RF deposited films. A protective coating to prevent heat checking in H-13 steel dies used for aluminum die casting was studied. The results of exposing the coated substrates to temperatures up to 700 degrees are presented.

Mirtich, M. J.

1980-01-01

116

Novel microstructure in spin coated polyaniline thin films  

NASA Astrophysics Data System (ADS)

Polyaniline (Pani) thin films doped with camphor sulfonic acid (CSA) have been deposited on glass substrates using the spin coating technique. Pani is chemically synthesized by an oxidation method at ~0 °C. Pani-CSA films show a hexagonal structure in scanning electron micrographs, which occurs due to the crystalline growth of CSA. A dense hexagonal structure is visible for film deposited at 800 rpm, but it becomes sparser as the revolutions per minute are increased (1200, 1500 and 2000 rpm). Electronic transition of quinoid units cause an absorption shoulder at ~900 nm for films deposited at 1200, 1500 and 2000 rpm, which is not observed for film deposited at 800 rpm.

Verma, Deepak; Dutta, V.

2007-05-01

117

Thin film coatings for space electrical power system applications  

NASA Technical Reports Server (NTRS)

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

Gulino, Daniel A.

1988-01-01

118

Thin film coatings for space electrical power system applications  

NASA Technical Reports Server (NTRS)

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

Gulino, Daniel A.

1989-01-01

119

Flexible Thin Metal Film Thermal Sensing System  

NASA Technical Reports Server (NTRS)

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

Thomsen, Donald Laurence (Inventor)

2012-01-01

120

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

DOEpatents

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

Toshifumi Sugama.

1993-04-06

121

FTIR spectra of thin inorganic coatings on metals  

NASA Astrophysics Data System (ADS)

FTIR spectroscopy has been applied in the study of coatings on aluminium, iron and silicon steel sheets. The following coatings have been investigated: on aluminium—oxide, anodic oxide, phosphate and chromate; on iron or steel—oxide, silicate and phosphate. From good quality IR spectra of these coatings much important information has been obtained, for example: quantitative phase composition of the coatings and their structure, metal-coating chemical bonding, mechanism of the coating formation and correlation between coating spectra and their properties. The phenomena and the interpretation of the reflectance IR spectra are discussed, i.e. TO-LO mode splitting for thin coatings and light interference on the sample. The presented FTIR spectra show that these measurement techniques can be applied as a non-destructive research method in different fields of the coating industries and in corrosion science.

Handke, M.; Paluszkiewicz, C.

1984-05-01

122

Suppression of Cobalt Dissolution from the LiCoO2 Cathodes with Various Metal-Oxide Coatings  

E-print Network

-7,9-19 Recent re- ports by Cho et al. on the nanoscale coating of cathode materials with metal oxides (Al2O3-gel coating of metal oxides, which have a wide range of fracture toughness (ZrO2 Al2O3 TiO2 B2O3 SiO2 of lattice constants of LiCoO2 thin films depends on the conditions of sputtering deposi- tion, substrate

Park, Byungwoo

123

Bottom Extreme-Ultraviolet-Sensitive Coating for Evaluation of the Absorption Coefficient of Ultrathin Film  

NASA Astrophysics Data System (ADS)

A bottom extreme-ultraviolet-sensitive coating (BESC) for evaluation of the absorption coefficients of ultrathin films such as extreme ultraviolet (EUV) resists was developed. This coating consists of a polymer, crosslinker, acid generator, and acid-responsive chromic dye and is formed by a conventional spin-coating method. By heating the film after spin-coating, a crosslinking reaction is induced and the coating becomes insoluble. A typical resist solution can be spin-coated on a substrate covered with the coating film. The evaluation of the linear absorption coefficients of polymer films was demonstrated by measuring the EUV absorption of BESC substrates on which various polymers were spin-coated.

Hijikata, Hayato; Kozawa, Takahiro; Tagawa, Seiichi; Takei, Satoshi

2009-06-01

124

Process for coating tungsten carbide with cobalt metal  

SciTech Connect

A process is described for coating tungsten carbide with cobalt metal, the process comprising: (a) forming an aqueous slurry of tungsten carbide having a particle size of no greater than - 100 mesh, and zinc metal powder; (b) adding ammonia to the slurry with the amount of the ammonia being sufficient so that the slurry is basic after the subsequent addition of cobalt chloride in step c; (c) adding to the resulting ammoniated slurry, a solution of cobalt chloride with agitation, to form a coating of partially reduced cobalt on the tungsten carbide; (d) removing the resulting cobalt coated tungsten carbide from the resulting liquor; and (e) heating the cobalt coated tungsten carbide in a reducing atmosphere to effect the essentially complete reduction of the cobalt and to produce a cobalt metal coating on the tungsten carbide, the coating making up no greater than about 15% of weight of the tungsten carbide.

Ritsko, J.E.; Lee, J.S.

1989-01-31

125

Aerosol chemical vapor deposition of metal oxide films  

DOEpatents

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

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

1994-01-11

126

Terahertz surface plasmon excitation via nonlinear mixing of lasers in a metal-coated optical fiber.  

PubMed

Terahertz (THz) surface plasmon generation via nonlinear mixing of laser eigenmodes in an optical fiber coated with ultrathin metal foil and possessing a dielectric constant ripple of wave number q is investigated. The fiber supports THz surface plasma wave (SPW) with plasmon resonance in the THz domain and is controllable by film thickness. The lasers exert a difference frequency ponderomotive force on the electrons of the metal film. The ponderomotive force induces a nonlinear current driving the difference frequency THz SPW. THz amplitude to laser amplitude ratio of the order ?10(-2) can be achieved by CO2 laser in megawatt range. PMID:24104791

Kumar, Pawan; Tripathi, V K

2013-09-15

127

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

PubMed

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

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

2014-01-01

128

Adherence of ion beam sputter deposited metal films on H-13 steel  

NASA Technical Reports Server (NTRS)

An electron bombardment argon ion source sputter deposited 17 metals and metal oxides on H-13 steel. The films ranged 1 to 8 micrometers in thickness and their adherence was generally greater than the capacity of the measuring device; adherence quality depended on proper precleaning of the substrate before deposition. N2 or air was introduced for correct stoichiometry in metallic compounds. Au, Ag, MgO, and Ta5Si3 films 8 microns thick have bond strength equal to 1 micron coatings; the bond strength of pure metallic films up to 5 microns thick was greater than the epoxy to film bond (8000 psi). The results of exposures of coated material to temperatures up to 700 C are presented.

Mirtich, M. J.

1980-01-01

129

Reflective Self-Metallizing Polyimide Films  

NASA Technical Reports Server (NTRS)

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

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

1997-01-01

130

Multilayer silver / dielectric thin-film coated hollow waveguides for sensor and laser power delivery applications  

NASA Astrophysics Data System (ADS)

Hollow Glass Waveguides (HGWs) incorporating single dielectric thin film designs deposited on silver coated silica hollow waveguides have been used for low-loss transmission of infrared radiation in the 2 - 14 micrometer region. Silver iodide has traditionally been the material of choice as a dielectric thin film in HGWs, with other dielectric thin film materials such as cadmium sulfide and lead sulfide being used as well. The incorporation of multilayer stacks of alternating low and high refractive index dielectric thin films in HGWs has been theoretically shown to further reduce the optical attenuation. Theoretically, lower losses are achieved when the refractive index contrast of the two thin film materials used is high and the number of films incorporated in the HGW film structure increases. Theoretically, such multilayer dielectric stack designs can give rise to the appearance of 1-D photonic bandgap structures with omnidirectional reflection properties as long as critical design parameters are met and scattering contributions due to surface roughness and similar defects are sufficiently low. This study involves the practical design of multilayer dielectric stacks in HGWs, with lead sulfide as a high refractive index material and cadmium sulfide as low refractive index material. The design, optimization, and processing methodology for achieving low-loss multilayer dielectric stacks in HGWs at desired infrared wavelengths is discussed. Characterization of multilayer dielectric coated HGWs includes FTIR spectroscopy for determining the optical response and infrared laser measurements for determining the optical attenuation properties of said multilayer dielectric stack coated HGWs. The experimental loss dependency of dielectric coated HGWs incorporating such metal chalcogenide materials on the particular thin film materials used and number of dielectric layers incorporated is presented and challenges in the current fabrication methodology are discussed.

Bledt, Carlos M.; Harrington, James A.; Kriesel, Jason M.

2012-01-01

131

Development of metal based thermal barrier coatings  

NASA Astrophysics Data System (ADS)

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

Shin, Dong-Il

132

Metallic glass thin films for potential biomedical applications.  

PubMed

We introduce metallic glass thin films (TiCuNi) as biocompatible materials for biomedical applications. TiCuNi metallic glass thin films were deposited on the Si substrate and their structural, surface, and mechanical properties were investigated. The fabricated films showed good biocompatibility upon exposure to muscle cells. Also, they exhibited an average roughness of <0.2 nm, high wear resistance, and high mechanical properties (hardness ?6.9 GPa and reduced modulus ?130 GPa). Top surface of the TiCuNi films was shown to be free from Ni and mainly composed of a thin titanium oxide layer, which resulted in the high surface biocompatibility. In particular, there was no cytotoxicity effect of metallic glass films on the C2C12 myoblasts and the cells were able to proliferate well on these substrates. Low cost, viscoelastic behavior, patternability, high electrical conductivity, and the capability to coat various materials (e.g., nonbiocompatible materials) make TiCuNi as an attractive material for biomedical applications. PMID:24610895

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

2014-10-01

133

Durable silver thin film coating for diffraction gratings  

DOEpatents

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

Wolfe, Jesse D. (Discovery Bay, CA); Britten, Jerald A. (Oakley, CA); Komashko, Aleksey M. (San Diego, CA)

2006-05-30

134

Patterning of polymer-supported metal films by microcutting  

PubMed

The ability to micropattern materials is of great importance for manufacturing advanced electronic, optical and mechanical devices ranging from displays to biosensors. For this purpose a variety of methods have been developed, including X-ray, electron-beam and photo-lithography, microcontact printing, embossing, micromouldings and cold welding. But these techniques are often of restricted applicability, involve a multitude of elaborate and cumbersome processing steps, or require aggressive chemistry. Here we describe a simple and versatile way to create well resolved metallic structures on polymer substrates, which is based on solid-state embossing of metal-coated polymer films. Ductility of both the metal layer and the polymer substrate permits the metal to be cut into surprisingly regular, micrometre-size structures. We illustrate the method by preparing patterned electrically conducting structures, highly efficient infrared polarizers and polarization-dependent colour filters. PMID:11034206

Stutzmann; Tervoort; Bastiaansen; Smith

2000-10-01

135

Laser cladding of wear resistant metal matrix composite coatings  

Microsoft Academic Search

A number of coatings with wear-resistant properties as well as with a low friction coefficient are produced by laser cladding. The structure of these coatings is determined by required performance and realized as metal matrix composite (MMC), where solid lubricant serves as a ductile matrix (e.g. CuSn), reinforced by appropriate ceramic phase (e.g. WC\\/Co). One of the engineered coating with

A. Yakovlev; Ph. Bertrand; I. Smurov

2004-01-01

136

Space radiation testing of thin film and multilayer optical coatings  

NASA Astrophysics Data System (ADS)

With the increasing complexity of optical designs flown on satellites, specialty thin film and multilayer filter coatings are being implemented more often. Unfortunately, very little ionizing radiation testing has actually been performed on such coatings, and certainly not completed to very high doses as might be experienced by an unshielded space optic in orbit for many years. In this paper we present results of gamma irradiation testing on the transmission properties of selected multilayer filters and optical coatings performed in an inert argon environment.

Thayer, Gayle E.; Blansett, Ethan L.; Keeler, Bianca E. N.

2009-08-01

137

Cellular response to titanium discs coated with polyelectrolyte multilayer films  

NASA Astrophysics Data System (ADS)

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 ?/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.

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

2014-09-01

138

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

Code of Federal Regulations, 2012 CFR

...Vinylidene chloride copolymer coatings for polycarbonate film. Vinylidene chloride copolymer coatings identified in this section...safely used as food-contact surfaces, in accordance with the following...prescribed conditions: (a) The coating is applied as a...

2012-04-01

139

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

Code of Federal Regulations, 2013 CFR

...Vinylidene chloride copolymer coatings for nylon film. Vinylidene chloride copolymer coatings identified in this section...used as food-contact surfaces, in accordance with the...conditions: (a) The coating is applied as a...

2013-04-01

140

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

Code of Federal Regulations, 2010 CFR

...Vinylidene chloride copolymer coatings for polycarbonate film. Vinylidene chloride copolymer coatings identified in this section...safely used as food-contact surfaces, in accordance with the following...prescribed conditions: (a) The coating is applied as a...

2010-04-01

141

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

Code of Federal Regulations, 2012 CFR

...Vinylidene chloride copolymer coatings for nylon film. Vinylidene chloride copolymer coatings identified in this section...used as food-contact surfaces, in accordance with the...conditions: (a) The coating is applied as a...

2012-04-01

142

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

Code of Federal Regulations, 2011 CFR

...Vinylidene chloride copolymer coatings for polycarbonate film. Vinylidene chloride copolymer coatings identified in this section...safely used as food-contact surfaces, in accordance with the following...prescribed conditions: (a) The coating is applied as a...

2011-04-01

143

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

Code of Federal Regulations, 2011 CFR

...Vinylidene chloride copolymer coatings for nylon film. Vinylidene chloride copolymer coatings identified in this section...used as food-contact surfaces, in accordance with the...conditions: (a) The coating is applied as a...

2011-04-01

144

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

Code of Federal Regulations, 2013 CFR

...Vinylidene chloride copolymer coatings for polycarbonate film. Vinylidene chloride copolymer coatings identified in this section...safely used as food-contact surfaces, in accordance with the following...prescribed conditions: (a) The coating is applied as a...

2013-04-01

145

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

...Vinylidene chloride copolymer coatings for polycarbonate film. Vinylidene chloride copolymer coatings identified in this section...safely used as food-contact surfaces, in accordance with the following...prescribed conditions: (a) The coating is applied as a...

2014-04-01

146

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

...Vinylidene chloride copolymer coatings for nylon film. Vinylidene chloride copolymer coatings identified in this section...used as food-contact surfaces, in accordance with the...conditions: (a) The coating is applied as a...

2014-04-01

147

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

Code of Federal Regulations, 2010 CFR

...Vinylidene chloride copolymer coatings for nylon film. Vinylidene chloride copolymer coatings identified in this section...used as food-contact surfaces, in accordance with the...conditions: (a) The coating is applied as a...

2010-04-01

148

PLD fabrication of ZnO nanostructures on metal-coated substrates  

NASA Astrophysics Data System (ADS)

In this work, ZnO nanostructures were fabricated on metal (a metal alloy containing Fe, Cr, Mn and Ni) coated silicon substrates by applying pulsed laser deposition. The samples were prepared at substrate temperatures in the range of 550 - 650 °C, oxygen pressure of 5 Pa, and laser fluence <= 1 J cm-2 i.e., process parameters usually used for thin-film deposition. We found that the metal layer's role is substantial in the preparation of nanostructures, the morphology of the catalyst layer determines the growth of the ZnO nanowalls and the increase of the process temperature leads to nanorods formation on the nanowalls.

Dikovska, A. Og; Koleva, M. E.; Atanasova, G. B.; Stoyanchov, T. R.; Nedyalkov, N. N.; Atanasov, P. A.

2014-05-01

149

Adhesion and friction of thin metal films  

NASA Technical Reports Server (NTRS)

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

Buckley, D. H.

1976-01-01

150

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

NASA Technical Reports Server (NTRS)

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

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

1985-01-01

151

Superhydrophobic ceramic coatings enabled by phase-separated nanostructured composite TiO2-Cu2O thin films  

NASA Astrophysics Data System (ADS)

By exploiting phase-separation in oxide materials, we present a simple and potentially low-cost approach to create exceptional superhydrophobicity in thin-film based coatings. By selecting the TiO2-Cu2O system and depositing through magnetron sputtering onto single crystal and metal templates, we demonstrate growth of nanostructured, chemically phase-segregated composite films. These coatings, after appropriate chemical surface modification, demonstrate a robust, non-wetting Cassie-Baxter state and yield an exceptional superhydrophobic performance, with water droplet contact angles reaching to ˜172° and sliding angles <1°. As an added benefit, despite the photo-active nature of TiO2, the chemically coated composite film surfaces display UV stability and retain superhydrophobic attributes even after exposure to UV (275 nm) radiation for an extended period of time. The present approach could benefit a variety of outdoor applications of superhydrophobic coatings, especially for those where exposure to extreme atmospheric conditions is required.

Aytug, Tolga; Bogorin, Daniela F.; Paranthaman, Parans M.; Mathis, John E.; Simpson, John T.; Christen, David K.

2014-06-01

152

STRIP TEMPERATURE IN A METAL COATING LINE ANNEALING FURNACE  

E-print Network

STRIP TEMPERATURE IN A METAL COATING LINE ANNEALING FURNACE Mark McGuinness1 and Stephen Taylor2 We continuously through the furnace, to certain temperatures and then cooling it, resulting in a change prior to being coated, by heating to a predeter- mined temperature for a definite time. Annealing

McGuinness, Mark

153

Precious-Metal Salt Coatings for Detecting Hydrazines  

NASA Technical Reports Server (NTRS)

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

Dee, Louis A.; Greene, Benjamin

2004-01-01

154

Electron grafted barrier coatings for packaging film modification  

NASA Astrophysics Data System (ADS)

The O 2 barrier performance of organosilane films, coated, dried and electron beam grafted to polyolefin film has been studied. Excellent anti-scalping properties based upon limonene (dipentene) transmission measurements have also been observed. Results are also reported on O 2 permeability reduction when the process is applied to common barrier polymers such as EVOH and acrylonitrile. Experience with its in-line application on LDPE is discussed.

Rangwalla, Imtiaz J.; Nablo, Sam V.

1993-07-01

155

Metal current collect protected by oxide film  

DOEpatents

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

Jacobson, Craig P. (Lafayette, CA); Visco, Steven J. (Berkeley, CA); DeJonghe, Lutgard C. (Lafayette, CA)

2004-05-25

156

Evaluation of colorless polyimide film for thermal control coating applications  

NASA Technical Reports Server (NTRS)

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

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

1985-01-01

157

Surface Plasmons in Thin Metallic Films  

E-print Network

For the first time it is shown that for thin metallic films thickness of which not exceed thickness of skin -- layer, the problem of description of surface plasma oscillations allows analytical solution by arbitrary ratio between length of electrons free path and thickness of a film. The dependance of frequency surface plasma oscillations on wave number is carry out.

A. V. Latyshev; A. A. Yushkanov

2010-10-11

158

Application of terahertz pulsed imaging to analyse film coating characteristics of sustained-release coated pellets.  

PubMed

Terahertz pulsed imaging (TPI) was employed to explore its suitability for detecting differences in the film coating thickness and drug layer uniformity of multilayered, sustained-release coated, standard size pellets (approximately 1mm in diameter). Pellets consisting of a sugar starter core and a metoprolol succinate layer were coated with a Kollicoat(®) SR:Kollicoat(®) IR polymer blend for different times giving three groups of pellets (batches I, II and III), each with a different coating thickness according to weight gain. Ten pellets from each batch were mapped individually to evaluate the coating thickness and drug layer thickness between batches, between pellets within each batch, and across individual pellets (uniformity). From the terahertz waveform the terahertz electric field peak strength (TEFPS) was used to define a circular area (approximately 0.13 mm(2)) in the TPI maps, where no signal distortion was found due to pellet curvature in the measurement set-up used. The average coating thicknesses were 46 ?m, 71 ?m and 114 ?m, for batches I, II and III respectively, whilst no drug layer thickness difference between batches was observed. No statistically significant differences in the average coating thickness and drug layer thickness within batches (between pellets) but high thickness variability across individual pellets was observed. These results were confirmed by scanning electron microscopy (SEM). The coating thickness results correlated with the subsequent drug release behaviour. The fastest drug release was obtained from batch I with the lowest coating thickness and the slowest from batch III with the highest coating thickness. In conclusion, TPI is suitable for detailed, non-destructive evaluation of film coating and drug layer thicknesses in multilayered standard size pellets. PMID:23721891

Haaser, M; Karrout, Y; Velghe, C; Cuppok, Y; Gordon, K C; Pepper, M; Siepmann, J; Rades, T; Taday, P F; Strachan, C J

2013-12-01

159

Microtribological Performance of Metal-doped Molybdenum Disulfide Coatings  

NASA Astrophysics Data System (ADS)

The mechanical and tribological properties of pure MoS2, pure Au, Au-MoS2 and Ti-MoS2 coatings were evaluated and examined at a microscopic scale. The metal doped MoS2 coatings had varying metal content, 5-10at% for Ti and 10-90% for Au. Reciprocating sliding wear tests were performed with a range of initial Hertzian contact pressures from 0.41 to 3.5 GPa and in air at two humidity levels (i.e. "low" being 3-5%RH and "high" being 30-40%RH). Titanium and gold were chosen for this study as metal additives due to their positive influence on the mechanical properties of the coating. The friction and wear behavior at the micro-scale were directly compared to tribological properties at the macro-scale, which were performed using an in situ tribometer. Reciprocating micro- and macro- wear tests were performed with spherical diamond tip (with 10 and 50 mum radii) and a sapphire tip (with a radius of 3.175 mm), respectively. The range of initial Hertzian contact pressures for macro-scale (i.e. between 0.41GPa and 1.2GPa) overlapped with that for micro-scale. However, the initial Hertzian contact diameters (2*a) were very different (i.e. 0.8-2.3 mum for micro-scale and 60-180 mum for macro-scale). It was observed that the small addition of Ti or Au to MoS2 improved the microtribological properties (i.e. lower friction and less wear) compared to pure MoS2 coatings. The improved microtribological properties with metal additions were attributed to an increase in the mechanical properties, decrease in adhesion, and a decrease in the interfacial shear strength. In terms of the different length scales, lower steady state friction was observed for macrotribology compared to microtribology. The higher friction at the micro- scale was explained by the greater adhesion effects and additional velocity accommodation modes (e.g. microplowing or plowing). The microplowing or plowing at the microscopic scale was attributed to the tip roughness and the inability to sustain a stable transferfilm throughout the tests at high humidity. In addition, using in situ and ex situ techniques, three different stages for solid lubrication were identified based on differences in contact area, tip shapes, and environmental conditions. The first stage has been previously observed with macrotribology on MoS 2 coatings at low humidity levels. The second stage, on the other hand, was observed for micro-tribology where the contact size is significantly smaller compared to stage one. The main wear mechanism is still adhesion, but there is also some micro-plowing. The final stage was observed for humid sliding in microtribology, where no transfer films were observed and therefore the main wear mechanism was plowing.

Stoyanov, Pantcho

2011-07-01

160

Effect of edible wheat gluten-based films and coatings on refrigerated strawberry ( Fragaria ananassa) quality  

Microsoft Academic Search

Edible coatings and films can provide an alternative for extending the postharvest life of fresh fruits and vegetables. The effect of different wheat gluten-based coatings and films on refrigerated strawberry quality and shelf life was studied. Coatings were formed directly on the surface of the fruit and films were previously formed (on Teflon surfaces) and then used to pack fruit.

Patrícia S. Tanada-Palmu; Carlos R. F. Grosso

2005-01-01

161

Polarization Phase-Compensating Coats for Metallic Mirrors  

NASA Technical Reports Server (NTRS)

A method of compensating for or minimizing phase differences between orthogonal polarizations of light reflected from metallic mirrors at oblique incidence, as, for example, from weakly curved mirrors, is undergoing development. The method is intended to satisfy a need to maintain precise polarization phase relationships or minimum polarization differences needed for proper operation of telescopes and other scientific instruments that include single or multiple mirrors. The basic idea of the method is to optimally coat mirrors with thin engineered layers of materials that introduce phase differences that, as nearly precisely as possible, are opposite of the undesired phase differences arising in reflection with non-optimum coatings. Depending on the specific optical system, the method could involve any or all of the following elements: a) Optimization of a single coat on all the mirrors in the system. b) Optimization of a unique coat for each mirror such that the polarization phase effects of the coat on one mirror compensate, to an acceptably high degree over an acceptably wide wavelength range, for those of the coat on another mirror. c) Tapering the coat on each mirror. Optimization could involve the choice of a single dielectric coating material and its thickness, or design of a more complex coat consisting of multiple layers of different dielectric materials and possibly some metallic materials. Such designs and coatings are particularly significant and needed for obtaining very high quality of wavefront required in high-contrast imaging instruments such as the NASA Terrestrial Planet Finder Coronagraph.

Balasubramanian, Kunjithapatham

2006-01-01

162

Method for improving the oxidation-resistance of metal substrates coated with thermal barrier coatings  

DOEpatents

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

Thompson, Anthony Mark (Niskayuna, NY); Gray, Dennis Michael (Delanson, NY); Jackson, Melvin Robert (Niskayuna, NY)

2002-01-01

163

Effect of Doping on beta-Tricalcium Phosphate Bioresorbable Bulk Material and Thin Film Coatings  

NASA Astrophysics Data System (ADS)

Magnesium has emerged as a revolutionary biodegradable metal for use as an orthopedic material, it has several advantages over the current metallic materials in use, including eliminating the effects of stress shielding, improving biocompatibility and inhibiting degradation rates, thus removing the requirement of a second surgery for implant removal. Due to the rapid degradation of magnesium, it is necessary to control the corrosion rates of the materials to match the rates of bone healing. This dissertation reports on the effect of doping on the properties of beta-tricalcium phosphate (beta-TCP). It also reports on its application as a thin film coating on magnesium alloys for implant applications. Adding various dopants to beta-TCP significantly influences critical properties. In this study, discs were fabricated in two compositions: (i) undoped beta-TCP, (ii) beta-TCP doped with 1.0 wt % MgO, 0.5 wt % ZnO, and 1.0 wt % TiO2. Films were fabricated from these compositions using the pulsed laser deposition (PLD) technique. These coatings were then characterized for corrosive, hardness, and cytocompatibility. The XRD patterns of the coating confirm the amorphous nature of the films. The presence of the metal oxides in beta-TCP improved ceramic densification. The application of these doped coatings was also found to increase the hardness by 88 %, the modulus of elasticity by 66 %, and improve corrosion resistance of the magnesium alloy substrate; with a 2.4 % improvement in Ecorr and 95 % decrease in icorr. Cell viability was studied using an osteoblast precursor cell line MC3T3-E1 to assure that the biocompatibility of these ceramics was not altered due to the dopants. Long-term biodegradation studies were conducted by measuring weight change and surface microstructure as a function of time in simulated body fluid. The results suggest that these coatings could be used for bioresorbable implants with improved corrosion resistance and increased hardness.

Abdalla, Suhaila

164

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

DOEpatents

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

Bates, John B. (Oak Ridge, TN)

1994-01-01

165

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

PubMed Central

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

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

166

The drag-out problem in film coating theory  

Microsoft Academic Search

An important step towards the understanding of many industrial coating processes is a solution of the dragout problem, which is to determine the thickness of the film of liquid which clings to a plate when it is drawn steadily out of a bath of the liquid. An approximate solution, valid for small capillary numbers, was given by Landau and Levich,

S. D. R. Wilson

1982-01-01

167

Antireflective coating for ITO films deposited on glass substrate  

Microsoft Academic Search

The refractive index n of radio-frequency (r.f.) magnetron sputtered indium tin oxide (ITO) films varies with sputtering parameters, such as sputtering power and oxygen percentage in the sputtering ambient. In this study, the feasibility to fabricate multilayer antireflective (AR) coating with a single ITO target by controlling the sputtering conditions is explored. Reduction in the reflectance can be achieved by

Bi-Shiou Chiou; Jen-Huan Tsai

1999-01-01

168

Interfacial bond strength of electrophoretically deposited hydroxyapatite coatings on metals.  

PubMed

Hydroxyapatite (HAp) coatings were deposited onto substrates of metal biomaterials (Ti, Ti6Al4V, and 316L stainless steel) by electrophoretic deposition (EPD). Only ultra-high surface area HAp powder, prepared by the metathesis method 10Ca(NO3)2 + 6(NH4)2HPO4 + 8NH4OH), could produce dense coatings when sintered at 875-1000degreesC. Single EPD coatings cracked during sintering owing to the 15-18% sintering shrinkage, but the HAp did not decompose. The use of dual coatings (coat, sinter, coat, sinter) resolved the cracking problem. Scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS) inspection revealed that the second coating filled in the "valleys" in the cracks of the first coating. The interfacial shear strength of the dual coatings was found, by ASTM F1044-87, to be approximately 12 MPa on a titanium substrate and approximately 22 MPa on 316L stainless steel, comparing quite favorably with the 34 MPa benchmark (the shear strength of bovine cortical bone was found to be 34 MPa). Stainless steel gave the better result since -316L (20.5 microm mK(-1)) > alpha-HAp (approximately 14 microm mK(-1)), resulting in residual compressive stresses in the coating, whereas alpha-titanium (approximately 10.3 microm mK(-1)) < alpha-HAp, resulting in residual tensile stresses in the coating. PMID:15348125

Wei, M; Ruys, A J; Swain, M V; Kim, S H; Milthorpe, B K; Sorrell, C C

1999-07-01

169

Coatings and films made of silk proteins.  

PubMed

Silks are a class of proteinaceous materials produced by arthropods for various purposes. Spider dragline silk is known for its outstanding mechanical properties, and it shows high biocompatibility, good biodegradability, and a lack of immunogenicity and allergenicity. The silk produced by the mulberry silkworm B. mori has been used as a textile fiber and in medical devices for a long time. Here, recent progress in the processing of different silk materials into highly tailored isotropic and anisotropic coatings for biomedical applications such as tissue engineering, cell adhesion, and implant coatings as well as for optics and biosensors is reviewed. PMID:25004395

Borkner, Christian B; Elsner, Martina B; Scheibel, Thomas

2014-09-24

170

Thin films of mixed metal compounds  

DOEpatents

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

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

1985-06-11

171

Nanostructured thin films as functional coatings  

NASA Astrophysics Data System (ADS)

Nanostructured thin films is one of the highly exploiting research areas particularly in applications such as photovoltaics, photocatalysis and sensor technologies. Highly tuned thin films, in terms of thickness, crystallinity, porosity and optical properties, can be fabricated on different substrates using the sol-gel method, chemical solution deposition (CSD), electrochemical etching, along with other conventional methods such as chemical vapour deposition (CVD) and physical vapour deposition (PVD). The above mentioned properties of these films are usually characterised using surface analysis techniques such as XRD, SEM, TEM, AFM, ellipsometry, electrochemistry, SAXS, reflectance spectroscopy, STM, XPS, SIMS, ESCA, X-ray topography and DOSY-NMR. This article presents a short review of the preparation and characterisation of thin films of nanocrystalline titanium dioxide and modified silicon as well as their application in solar cells, water treatment, water splitting, self cleaning fabrics, sensors, optoelectronic devices and lab on chip systems.

Lazar, Manoj A.; Tadvani, Jalil K.; Sze Tung, Wing; Lopez, Lorena; Daoud, Walid A.

2010-06-01

172

Mesoscopically structured nanocrystalline metal oxide thin films  

NASA Astrophysics Data System (ADS)

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

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

2014-11-01

173

Low Temperature Growth of Nanostructured Diamond Films on Metals  

NASA Technical Reports Server (NTRS)

The field of nanocrystalline diamond and tetrahedral amorphous carbon films has been the focus of intense experimental activity in the last few years for applications in field emission display devices, optical windows, and tribological coatings, The choice of substrate used in most studies has typically been silicon. For metals, however, the thermal expansion mismatch between the diamond film and substrate gives rise to thermal stress that often results in delamination of the film. To avoid this problem in conventional CVD deposition low substrate temperatures (less than 700 C) have been used, often with the incorporation of oxygen or carbon monoxide to the feedgas mixture. Conventionally grown CVD diamond films are also rough and would require post-deposition polishing for most applications. Therefore, there is an obvious need to develop techniques for deposition of well-adhered, smooth nano-structured diamond films on metals for various tribological applications. In our work, nanostructured diamond films are grown on a titanium alloy substrate using a two-step deposition process. The first step is performed at elevated temperature (820 C) for 30 minutes using a H2/CH4/N2 gas mixture in order to grow a thin (approx. 600 nm) nanostructured diamond layer and improve film adhesion. The remainder of the deposition involves growth at low temperature (less than 600 C) in a H2/CH4/O2 gas mixture. Laser reflectance Interferometry (LRI) pattern during growth of a nanostructured diamond film on Ti-6Al-4V alloy. The first 30 minutes are at a high temperature of 820 C and the rest of the film is grown at a low temperature of 580 T. The fringe pattern is observed till the very end due to extremely low surface roughness of 40 nm. The continuation of the smooth nanostructured diamond film growth during low temperature deposition is confirmed by in-situ laser reflectance interferometry and by post-deposition micro-Raman spectroscopy and surface profilometry. Similar experiments performed without the starting nanostructured diamond layer resulted in poorly adhered films with a more crystalline appearance and a higher surface roughness. This low temperature deposition of nanostructured diamond films on metals offers advantages in cases where high residual thermal stress leads to delamination at high temperatures.

Baker, Paul A.; Catledge, Shane A.; Vohra, Yogesh K.

2001-01-01

174

Coatings Preserve Metal, Stone, Tile, and Concrete  

NASA Technical Reports Server (NTRS)

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

2014-01-01

175

Plasma-sprayed ceramic coatings for protection against molten metal.  

SciTech Connect

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

Hollis, K. J. (Kendall J.); Peters, M. I. (Maria I.); Bartram, B. D. (Brian D.)

2002-01-01

176

Evaluating the effect of coating equipment on tablet film quality using terahertz pulsed imaging.  

PubMed

In this study, terahertz pulsed imaging (TPI) was employed to investigate the effect of the coating equipment (fluid bed and drum coater) on the structure of the applied film coating and subsequent dissolution behaviour. Six tablets from every batch coated with the same delayed release coating formulation under recommended process conditions (provided by the coating polymer supplier) were mapped individually to evaluate the effect of coating device on critical coating characteristics (coating thickness, surface morphology and density). Although the traditional coating quality parameter (weight gain) indicated no differences between both batches, TPI analysis revealed a lower mean coating thickness (CT) for tablets coated in the drum coater compared to fluid bed coated tablets (p<0.05). Moreover, drum coated tablets showed a more pronounced CT variation between the two sides and the centre band of the biconvex tablets, with the CT around the centre band being 22.5% thinner than the top and bottom sides for the drum coated tablets and 12.5% thinner for fluid bed coated tablets. The TPI analysis suggested a denser coating for the drum coated tablets. Dissolution testing confirmed that the film coating density was the drug release governing factor, with faster drug release for tablets coated in the fluid bed coater (98 ± 4% after 6h) compared to drum coated tablets (72 ± 6% after 6h). Overall, TPI investigation revealed substantial differences in the applied film coating quality between tablets coated in the two coaters, which in turn correlated with the subsequent dissolution performance. PMID:23563103

Haaser, Miriam; Naelapää, Kaisa; Gordon, Keith C; Pepper, Michael; Rantanen, Jukka; Strachan, Clare J; Taday, Philip F; Zeitler, J Axel; Rades, Thomas

2013-11-01

177

40 CFR 52.253 - Metal surface coating thinner and reducer.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Metal surface coating thinner and reducer...IMPLEMENTATION PLANS California § 52.253 Metal surface coating thinner and reducer... (iii) This section is rescinded for metal parts and products coaters which...

2010-07-01

178

Infrared reflection-absorption spectra of metal-effect coatings.  

PubMed

The results of studies of infrared reflection-absorption spectra of metal-effect coatings are presented in this paper. Such coatings consist of metallic flakes that are dispersed in a polymer binder. The spectra show two distinct phenomena. One is due to the polymer matrix. The other is due to metallic flakes that are dispersed inside the layer. The polymer binder causes narrow spectral lines that give a thickness-dependent intensity and position. Metallic flakes change the average baseline of this spectrum over the entire infrared spectral region. This particular effect was evaluated using a simple rough-surface model. Two parameters of the model, the root-mean-square roughness and the correlation length of the rough surface, described the reflection of the partial beams on the metal flake surfaces and scattering on flakes boundaries. The other two parameters are the specular reflectance and the diffuse reflectance of the plane untextured interface between the polymer matrix and the metal flake surface. Various metal-effect coatings within the same polymer binder were analyzed. The effect of each metal flake dispersion was evaluated by the parameters within the rough-surface model. The results were analyzed in terms of the size and the loadings of flakes that were used in the coatings. PMID:14639756

Gunde, Marta Klanjsek; Kunaver, Matjaz

2003-10-01

179

THz surface wave collapse on coated metal Mufei Gong1  

E-print Network

THz surface wave collapse on coated metal surfaces Mufei Gong1 , Tae-In Jeon2 and D. Grischkowsky1-791 Korea *daniel.grischkowsky@okstate.edu Abstract: The Zenneck THz surface wave (Z-TSW) on metals of the THz surface wave on an aluminum surface covered with a 12.5 µm thick dielectric layer have completely

Oklahoma State University

180

Polymer leaching from film coating: effects on the coating transport properties.  

PubMed

The release mechanism of metoprolol succinate pellets coated with a blend of a water-insoluble polymer, ethyl cellulose (EC), and a water-soluble polymer, hydroxypropyl cellulose (HPC), is mechanistically explained. The kinetics of drug release and HPC leaching were followed for drug doses. The coating was initially not permeable to the drug, and release started only after a critical amount of the HPC had been leached out. Drug release occurred mainly through pores created in the coating by the HPC dissolution. Single-pellet release experiments were also performed. The coating thickness and size of each pellet were measured. In order to quantitatively characterize the transport properties of the coating of the individual pellets, and to determine the effective diffusion coefficient (D(e)) of the drug in the coating, a mechanistic model was used to fit the single-pellet release data. It was found that D(e) increased with time due to an increase in the amount of HPC leached. It was also found that D(e) was dependent on the coating thickness, and increased more slowly with a thicker coating. This agreed well with the finding that the HPC leaching rate decreased with increasing film thickness. PMID:21421031

Marucci, Mariagrazia; Ragnarsson, Gert; von Corswant, Christian; Welinder, Anette; Jarke, Annica; Iselau, Frida; Axelsson, Anders

2011-06-15

181

Preparation and characterization of super-water-repellent Al2O3 coating films with high transparency  

NASA Astrophysics Data System (ADS)

Alumina thin films with a roughness of 20 to 50 nm were formed by immersing the porous alumina gel films prepared by the sol- gel method in boiling water. When hydrolyzed fluoroalkyltrimethoxysilane was coated on the alumina films, the films showed super-water-repellency and high transparency; the contact angle for water of the film was 165 degrees and the transmittance for visible light was higher than 92%. When the fluoroalkyltrimethoxysilane-coated thin films were heat- treated at temperatures higher than 500 degrees Celsius, the films became super-hydrophilic; the contact angle for water on the films was less than 5 degrees. It was shown the existence of air in the pores on the surface caused the super-water- repellency and that of water in the pores caused the super- hydrophilic property. The transparent, super water-repellent and super-hydrophilic coating films formed on glasses, metals, and ceramics have practical applications such as optical lenses, eye-glasses, cover glasses for solar cells, windshields of automobiles, and so on.

Minami, Tsutomu; Katata, Noriko; Tadanaga, Kiyoharu

1997-10-01

182

Growth and engineering of microporous zeolite films and coatings  

SciTech Connect

Developing very thin molecular sieve films (< 1 {micro}m), required by many zeolite film-based applications, has been found continually to be a technical challenge. The synthesis strategy of this work is to elucidate some of the parameters that influence the morphology, orientation, surface cover density and thickness of Si-ZSM-5 films on supported substrates. Three different methods to growth zeolite coatings on fused silica have been studied and compared. The zeolite films have been characterized by field emission-SEM, XRD, sorption study and transmitting spectroscopy. At the early stage of crystal growth, the gel layer spontaneously condensed on the substrate surface may have a large porosity of 15%. The strong affinity to grow the (010) faces along the substrate surface is possibly responsible for the preferred orientation of the films. The conditions for synthesis of closely packed coatings, consisting of sub-micron crystals with preferred orientation, are also identified. Engineering issues for fabrication of low optical scattering zeolitic films will also be discussed for designing molecular sieve optical devices.

Yan, Y.; Chaudhuri, S.R.; Sarkar, A. [YTC America Inc., Camarillo, CA (United States)

1996-12-31

183

Dynamics of discontinuous coating and drying of nanoparticulate films.  

SciTech Connect

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

Schunk, Peter Randall; Dunphy, Darren Robert (University of New Mexico, Albuquerque, NM); Brinker, C. Jeffrey; Tjiptowidjojo, Kristianto (University of New Mexico, Albuquerque, NM)

2010-09-01

184

Diamond-like carbon coatings for the protection of metallic artefacts: effect on the aesthetic appearance  

NASA Astrophysics Data System (ADS)

Plasma-enhanced chemical vapour deposition (PECVD) is an environmentally friendly process used to deposit a variety of nano-structured coatings for the protection or the surface modification of metallic artefacts like the SiO2-like films that have been successfully tested on ancient silver, bronze and iron artefacts as barriers against aggressive agents. This paper deals with the preliminary results of a wider investigation aimed to the development of eco-sustainable coatings for the protection of Cu and Ag-based artefacts of archaeological and historic interest. Diamond-like carbon (DLC) coatings have been deposited by PECVD in different experimental conditions, in a capacitively coupled asymmetric plasma reactor, placing the substrates either on electrically powered electrode (cathodic mode) or grounded electrode (anodic mode) with and without hydrogen addition in the gas mixture. The final goal is to develop a coating with good protective effectiveness against aggressive atmospheres and contemporarily with negligible effects on the aesthetic appearance of the artefacts. The evaluation of possible colour changes of the surface patinas, due to coating process, was performed by optical microscopy and colorimetric measurements. Furthermore, to evaluate the reversibility of the thin DLC layer, an etching treatment in oxygen plasma has been successfully carried out and optimized. The chemical-physical characterization of the deposited DLC coatings was performed by means of the combined use of micro-Raman and XPS spectroscopies. The results show that the DLC films obtained in the anodic mode, may be proposed as a viable alternative to polymeric coatings for the protection of metallic ancient objects.

Faraldi, Federica; Angelini, Emma; Caschera, Daniela; Mezzi, Alessio; Riccucci, Cristina; Caro, Tilde De

2014-03-01

185

Performance improvement by metal-dielectric HR coating in laterally coupled DFB laser with metal surface gratings  

NASA Astrophysics Data System (ADS)

We report the device characteristics of the metal-dielectric high-reflectivity (HR) coated 1.55 ?m laterally coupled distributed feedback (DFB) laser with metal surface gratings by using holographic lithography. The HR coating films are composed of Au/Ti/SiO2. It provides a variety of advantages compared to the uncoated DFB laser on the same processed wafer while there is no degradation on current-voltage characteristics. For 3 ?m wide and 300 ?m long HR coated DFB laser, it exhibits a maximum output power of ˜17 mW and a threshold current of 14.2 mA at 20°C under continuous-wave mode. It is clear that the threshold current and slope efficiency are improved by 36% and 96%, respectively, due to the reduction of mirror loss. The metal-dielectric HR coating on one facet of DFB laser is found to have significantly increased characteristic temperature (i.e., T 0˜88 K). Furthermore, the stable single-mode operation with an increased single-mode suppression ratio was achieved.

Jang, S. J.; Yeo, C. I.; Yu, J. S.; Lee, Y. T.

2010-09-01

186

Corrosion-resistant amorphous metallic films of Mo49Cr33B18 alloy  

NASA Technical Reports Server (NTRS)

Corrosion-resistant amorphous metallic alloy films of Mo49Cr33B18 with a crystallization temperature of 590 C were deposited onto glass and quartz substrates by magnetron sputter-quench technique. The amorphous nature of the films was confirmed by their diffuse X-ray diffraction patterns. The deposited films are densely packed (zone T) and exhibit low stress and good adhesion to the substrate. Corrosion current of as-deposited coating of MoCrB amorphous metallic alloy is approximately three orders of magnitude less than the corrosion current of 304 stainless steel in 1N H2SO4 solution.

Ramesham, R.; Distefano, S.; Fitzgerald, D.; Thakoor, A. P.; Khanna, S. K.

1987-01-01

187

Erratum to: “Effect of target material on deposition and properties of metal-containing DLC (Me-DLC) coatings  

Microsoft Academic Search

Metal containing diamond-like carbon (Me-DLC) coatings were prepared by magnetron sputter deposition using tungsten, tungsten carbide, niobium and titanium as target materials. An essential parameter for the process characterization is the target voltage. The substrate heating during the film growth depends on the target material. For the tungsten target, the contribution of energetic neutrals to the heat flux is quite

K Bewilogua; C. V Cooper; C Specht; J Schröder; R Wittorf; M Grischke

2000-01-01

188

Effect of target material on deposition and properties of metal-containing DLC (Me-DLC) coatings  

Microsoft Academic Search

Metal containing diamond-like carbon (Me-DLC) coatings were prepared by magnetron sputter deposition using tungsten, tungsten carbide, niobium and titanium as target materials. An essential parameter for the process characterization is the target voltage. The substrate heating during the film growth depends on the target material. For the tungsten target, the contribution of energetic neutrals to the heat flux is quite

K Bewilogua; C. V Cooper; C Specht; J Schröder; R Wittorf; M Grischke

2000-01-01

189

Metal-doped magnetite thin films.  

PubMed

This paper investigates magnetite (Fe3O4) thin film containing a small amount of a metal element. The films are prepared by rf sputtering with a composite target of ceramic iron oxide with metal chips. Low-temperature magnetization of magnetite containing 5.3%Ge reveals that the film contains some magnetically weak coupling grains. The metal element Mg reduces both hematite (alpha-Fe2O3) and magnetite, resulting in single-phase wüstite (Fe1-xO). In contrast, adding Ge selectively reduces hematite, while magnetite remains unreactive. According to the free energy of reaction, the element Ge is able to reduce hematite only, whereas the element Mg is capable of reducing both hematite and magnetite. This property is in good agreement with the experiment results. PMID:22905582

Abe, Seishi; Ping, De Hai; Nakamura, Shintaro; Ohnuma, Masato; Ohnuma, Shigehiro

2012-06-01

190

Electrical conductivity measurements of polymer thin films on metal substrates  

SciTech Connect

Topographical measurements by AFM and other manometer scanning probes often do not adequately distinguish between phases along composite surfaces. In the case of insulator structures (e.g., thin films; particles) on metal substrates, manometer scans of electrical conductivity offer a convenient tool for interpreting topography. Electrical contact is made with commercial Si{sub 3}N{sub 4} AFM tips coated with Au, Ag, W, or Au-Pd. Voltages ranging from 100 mV to 10 volts are applied to the tip and the metal substrate is grounded through an electrometer to measure the resulting current. The tips are mounted in a commercial AFM (Digital Instruments Nanoscope III); topographical and current scans are acquired simultaneously in the contact mode. Freshly grown, 300-nm thick, polytetrafluoroethylene (PTFE) films on stainless steel substrates yield no measurable current. Thinner films or those exposed to mechanical abrasion exhibit numerous patches with two current levels-sub {mu}A and > {mu}A signals - which often correlate with topography. We interpret these signals and discuss possible applications to thin film characterization and tribology.

Hipps, K.; Dickinson, J.T.; Jensen, L.C. [Washington State Univ., Pullman, WA (United States)

1995-12-01

191

Measurements and Diagnostics of Diamond Films and Coatings  

NASA Technical Reports Server (NTRS)

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

Miyoshi, Kazuhisa; Wu, Richard L. C.

1999-01-01

192

Nanoindentation of functionally graded hybrid polymer/metal thin films  

NASA Astrophysics Data System (ADS)

Hybrid functionally graded coatings (2D-FGC) were deposited by magnetron co-sputtering from poly(tetrafluoroethylene) (PTFE) and AISI 316L stainless steel (316L) targets. The carbon and fluorine content varied from 7.3 to 23.7 at.% and from 0 to 57 at.%, respectively. The surface modification was developed to change the surface of 316L vascular stents in order to improve the biocompatibility of the outmost layer of the metallic biomaterial. In-depth XPS analysis revealed the presence of a graded chemical composition accompanied by the variation of the film structure. These results were complemented by those of transmission electron microscopy (TEM) analysis that highlighted the nanocomposite nature of the coatings. The nanomechanical characterization of 2D-FGC was performed by nanoindentation at several loads on the thin films deposited onto two different steel substrates: 316L and AISI M2. The study allowed establishing 0.7 mN as the load that characterized the coatings without substrate influence. Both hardness and Young modulus decrease with the increase of fluorine content due to the evolution in chemical composition, chemical bonds and structure.

Nunes, J.; Piedade, A. P.

2013-11-01

193

Development of insulating coatings for liquid metal blankets  

SciTech Connect

It is shown that self-cooled liquid metal blankets are feasible only with electrically insulating coatings at the duct walls. The requirements on the insulation properties are estimated by simple analytical models. Candidate insulator materials are selected based on insulating properties and thermodynamic consideration. Different fabrication technologies for insulating coatings are described. The status of the knowledge on the most crucial feasibility issue, the degradation of the resisivity under irradiation, is reviewed.

Malang, S.; Borgstedt, H.U. [Kernforschungszentrum Karlsruhe GmbH (Germany); Farnum, E.H. [Los Alamos National Lab., NM (United States); Natesan, K. [Argonne National Lab., IL (United States); Vitkovski, I.V. [Efremov Inst., St. Petersburg (Russian Federation). MHD-Machines Lab.

1994-07-01

194

Micro-Scratch Study of a Magnetron-Sputtered Zr-Based Metallic-Glass Film  

SciTech Connect

Using the micro-scratch technique, the tribological behavior of ZrCuAlNi metallic-glass coatings on 316L stainless steel was studied. With the application of ramping normal loads, the critical normal loads of about 110 mN were determined, at which the coefficient of friction increased sharply and the indenter penetration depth exceeded the film thickness. No clear evidence of coating debonding has been found, which, together with the observation of multiple shear bands, indicates good adhesion and ductility of the metallic-glass coating. When subjected to constant normal loads, the coefficient of friction increased rapidly once the critical normal load was passed. The scratch results and the scanning-electron microscopy observations indicated good adhesion between the coating and the substrate, which may be due to the good interfacial bonding and low coating residual stress.

Liu, F. X. [University of Tennessee, Knoxville (UTK); Yang, F. Q. [University of Kentucky; Gao, Yanfei [ORNL; Jiang, W. H. [University of Tennessee, Knoxville (UTK); Guan, Y F [University of Tennessee, Knoxville (UTK); Rack, P. D. [University of Tennessee, Knoxville (UTK); Sergic, O. [CSM Instruments Inc.; Liaw, Peter K [University of Tennessee, Knoxville (UTK)

2009-01-01

195

Deposition and characteristics of chromium nitride thin film coatings on precision balls for tribological applications  

Microsoft Academic Search

Thin film hard coatings on rolling element surfaces can enhance the overall wear resistance of rolling element bearings, as demonstrated previously for coated tapered, cylindrical, and spherical roller bearings. Hard coatings in ball bearings are less common because of the difficulty in achieving uniform film thickness on a ball surface. This limitation is overcome by a new process for depositing

Michael D. Drory; Ryan D. Evans

196

Uniform Carbon Nano-Coating on an Anodic Aluminum Oxide Film Properties and Applications  

Microsoft Academic Search

Uniform carbon coating on nanochannels of an anodic aluminum oxide film drastically changes its optical property and, as a result, the resulting carbon-coated film exhibits brilliant colors. The carbon deposited on the inner walls of the nanochannels plays a major role in this phenomenon. In addition, the coating makes the channel walls electro-conductive, hydrophobic and much more chemically stable. These

Hironori Orikasa; Xiao-Hui Wang; Takashi Kyotani

2009-01-01

197

Studies on the spin coating process of silica films  

Microsoft Academic Search

Silica xerogel films with good uniformity and various thicknesses were successfully prepared by a two-step acid-base catalyst procedure and spin coating. After the addition of ammonia catalyst, the sol changes gradually from a Newtonian fluid to a shear-thinning one due to the progress of polymerization reactions. An empirical equation using the relative ratio of reaction time to gel time can

Ya-Yu Huang; Kan-Sen Chou

2003-01-01

198

Effect of sputtered lanthanum hexaboride film thickness on field emission from metallic knife edge cathodes  

SciTech Connect

We report experiments and analysis of field emission from metallic knife-edge cathodes, which are sputter-coated with thin films of lanthanum hexaboride (LaB{sub 6}), a low-work function material. The emission current is found to depend sensitively on the thickness of the LaB{sub 6} layer. We find that films thinner than 10 nm greatly enhance the emitted current. However, cathodes coated with a thicker layer of LaB{sub 6} are observed to emit less current than the uncoated metallic cathode. This result is unexpected due to the higher work function of the bare metal cathode. We show, based on numerical calculation of the electrostatic potential throughout the structure, that the external (LaB{sub 6}/vacuum) barrier is reduced with respect to uncoated samples for both thin and thick coatings. However, this behavior is not exhibited at the internal (metal/LaB{sub 6}) barrier. In thinly coated samples, electrons tunnel efficiently through both the internal and external barrier, resulting in current enhancement with respect to the uncoated case. In contrast, the thick internal barrier in thickly coated samples suppresses current below the value for uncoated samples in spite of the lowered external barrier. We argue that this coating thickness variation stems from a relatively low (no higher than 10{sup 18} cm{sup -3}) free carrier density in the sputtered polycrystalline LaB{sub 6}.

Kirley, M. P.; Novakovic, B.; Sule, N.; Weber, M. J.; Knezevic, I.; Booske, J. H. [Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States)

2012-03-15

199

Synthesis and characterization of sol-gel-derived nanomaterials and nanocrystalline electroless metal coatings  

NASA Astrophysics Data System (ADS)

CuS (minimum size of 2.5 nm), Ag2S (minimum and average size of 2.5 nm and 26 nm respectively), and Au (with minimum size of <10 nm) nanoparticles dispersed within the sol-gel derived hydroxypropyl cellulose (HPC)-silica films are synthesized using the gas diffusion technique. The effectiveness of HPC polymer, as a 'compatibilizer', to synthesize semiconductor and metal nanoparticles distributed uniformly within the silica film is demonstrated. The sol-gel derived HPC-silica films containing dispersed nanoparticles are characterized using x-ray photoelectron spectroscopy (XPS) to understand the mechanism of formation of nanoparticles within the film. The XPS core-level binding energies (B.E.) for the nanoparticles are observed to be sensitive to the variation in the chemical composition at the surface and their size. The 'cluster size effect' is shown to be useful in predicting the average nanoparticle size. Nanocrystalline ZrO2 particles are successfully synthesized using sol-gel technique utilizing HPC polymer as a 'steric barrier'. The use of HPC polymer is demonstrated to synthesize submicron-sized, non-agglomerated, and spherical as well as nanocrystalline ZrO2 particles by adjusting the sol-gel synthesis parameters. The effect of sol-gel synthesis parameters on ZrO2 nanocrystallite size, its distribution, and the phase evolution behavior of ZrO2 is studied. The optimum sol-gel synthesis parameters for synthesizing nanocrystalline ZrO2 with 100% tetragonal phase are identified. Cu/CuO-ZrO2 composite powder is synthesized using the electroless metal deposition technique. The mechanism of electroless deposition of Cu over ZrO2 particle surface is investigated using XPS. On the basis of 'cluster size effect', it is suggested that, the electroless metal deposition process activates the non-catalytic ceramic substrate surface by depositing metallic Pd0 clusters and not by the accepted Pd-Sn alloy catalyst. Fly ash cenosphere particle surface is also activated by metallic Pd0 clusters under similar coating conditions. The cenosphere particles are further coated with Ag using Pd-activation. The Cu and Ag-coated cenosphere particles find application in manufacturing conducting polymers used for electromagnetic interference (EMI) shielding application. The use of cost-effective activator (AgNO3) is demonstrated for coating the cenosphere particles with Cu for commercialization. The use of Focussed Ion Beam (FIB) microscopy technique is demonstrated to directly measure the coating-thickness.

Shukla, Satyajit Vishnu

200

Pentek metal coating removal system: Baseline report  

SciTech Connect

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

NONE

1997-07-31

201

Optimum antireflection coating for Antireflection-coated Metal-Oxide-Semiconductor /AMOS/ solar cells  

NASA Technical Reports Server (NTRS)

Consideration is given to the design of a single-layer optimum antireflection coating for AMOS (antireflection-coated metal-oxide-semiconductor) solar cells to match the entire sunlight spectrum. The energy conversion efficiency is maximized by maximizing the open-circuit voltage and the short-circuit current. The former is maximized by oxidation techniques and the latter is maximized by the light-coupling into the solar cell. With reference to the effective index of refraction as obtained by ellipsometry, examples of optimum antireflection coatings for 60-A Au-GaAs solar cells are presented.

Yeh, Y. C. M.; Ernest, F. P.; Stirn, R. J.

1977-01-01

202

Preparing oxidizer coated metal fuel particles  

NASA Technical Reports Server (NTRS)

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

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

1974-01-01

203

Vacuum deposition of high-quality metal films on porous substrates  

SciTech Connect

A composite mandrel has been developed consisting of a core of low density polymethylpentene foam overcoated with a thin layer of film forming polymer. The surface tension and viscosity of the coating solution are important parameters in obtaining a polymer film which forms a continuous, smooth skin over the core without penetrating into the foam matrix. Water soluble film formers with surface tensions in the range of 45 dynes/cm and minimum viscosities of a few hundred centipoises have been found most satisfactory for coating polymethylpentene foam. By means of this technique, continuous polymer films with thicknesses of 10 to 20 ..mu..m have been formed on the surface of machined polymethylpentene foam blanks. Aluminum has been vacuum deposited onto these composite mandrels to produce metal films which appear smooth and generally defect free even at 10,000 times magnification.

Barthell, B.L.; Duchane, D.V.

1981-01-01

204

Zinc oxide films prepared by sol-gel spin-coating  

Microsoft Academic Search

The d.c. electrical conductivity and optical properties of undoped zinc oxide films prepared by the sol-gel process using a spin-coating technique were investigated. The ZnO films were obtained by 10 cycle spin-coated and dried zinc acetate films followed by annealing in air at 500–575°C. The films deposited on the Pyrex glass substrate were polycrystalline and c-axis oriented. A minimum film

Y. Natsume; H Sakata

2000-01-01

205

One and two-photon induced growth of ligand coated nanoparticles for 2 &3D metal patterning  

Microsoft Academic Search

Ligand-coated metallic nanoparticles are powerful new materials for nano-electronic and photonics applications. They can be readily synthesized and their stability and solubility allows them to be cast in complex composite materials or self-assembled into quasi-ordered films. We demonstrate that, in the presence of reducing dyes with a large two-photon cross-section and metal salts, it is possible to induce the growth

Francesco Stellacci; Christina A. Bauer; Timo Meyer-Friedrichsen; Wim Wenseleers; Valérie Alain; Stephen M. Kuebler; Stephanie J. Pond; Yadong Zhang; Seth R. Marder; Joseph W. Perry

2002-01-01

206

Coating of porous polytetrafluoroethylene films with other polymers for electret applications  

Microsoft Academic Search

Porous polytetrafluoroethylene (PTFE) films are attractive for electret applications because of their unusual mechanical properties and their excellent charge-storage capabilities. The direct application of electrodes is facilitated and the charge stability of the open-porous films is improved, if the porous PTFE films are coated with layers of other suitable polymers. Here, we report on the preparation of coated porous PTFE

M. Wegener; W. Wirges; W. Kiinstler; R. Gerhard-Multhaupt; B. Elling; M. Pinnow; R. Danz

2001-01-01

207

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

NASA Astrophysics Data System (ADS)

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

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

1994-09-01

208

Polymer-Metal Nanocomposites via Polymer Thin Film  

E-print Network

Polymer-Metal Nanocomposites via Polymer Thin Film T. P. Radhakrishnan School of Chemistry, University of Hyderabad Polymer-metal nanocomposite thin films are versatile materials that not only characteristics of the components, but also manifest mutualistic effects. Soft c film is a facile in situ of metal

Shyamasundar, R.K.

209

Reduced graphene oxide coated thin aluminum film as an optoacoustic transmitter for high pressure and high frequency ultrasound generation  

NASA Astrophysics Data System (ADS)

We demonstrate that reduced graphene oxide (rGO) coated thin aluminum film is an effective optoacoustic transmitter for generating high pressure and high frequency ultrasound previously unattainable by other techniques. The rGO layer of different thickness is deposited between a 100 nm-thick aluminum film and a glass substrate. Under a pulsed laser excitation, the transmitter generates enhanced optoacoustic pressure of 64 times the aluminum-alone transmitter. A promising optoacoustic wave generation is possible by optimizing thermoelasticity of metal film and thermal conductivity of rGO in the proposed transmitter for laser-induced ultrasound applications.

Hwan Lee, Seok; Park, Mi-ae; Yoh, Jack J.; Song, Hyelynn; Yun Jang, Eui; Hyup Kim, Yong; Kang, Sungchan; Seop Yoon, Yong

2012-12-01

210

SERS-applicable silver nanoisland film grown under protective coating  

NASA Astrophysics Data System (ADS)

We have used recently developed out-diffusion technique of growing silver nanoisland films on glass surface to grow silver nanoislands under TiO2 layer deposited on the glass. After covering the surface of silver ion-exchanged glasses with TiO2 film using atomic layer deposition technique and subsequent thermal processing of the samples in hydrogen their optical absorption spectra demonstrate the absorption peak corresponding to surface plasmon resonance in grown silver nanoislands. The spectral position of the peak is shifted relatively to the peak observed in the spectra of the nanoisland film grown on the surface of ion exchanged and annealed glass samples without dielectric cover. The applicability of the silver nanoislands grown under several nm thick protective TiO2 coating in surface-enhanced Raman scattering spectroscopy is demonstrated.

Reduto, I.; Chervinskii, S.; Matikainen, A.; Baklanov, A.; Kamenskii, A.; Lipovskii, A.

2014-10-01

211

Superhydrophobic anti-ultraviolet films by doctor blade coating  

NASA Astrophysics Data System (ADS)

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

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

2014-11-01

212

Near-field optical writing on azo-polymethacrylate spin-coated films  

NASA Astrophysics Data System (ADS)

We report on near-field optical writing and topographic reading of spin-coated azo-polymethacrylate films with subwavelength resolution. The sample is functionalized with photosensitive side chain azobenzene groups. These photochromes are locally illuminated at 325 and 488 nm through the aperture of a metalized tapered optical fiber. The printing on subwavelength scale is due to optically induced cooperative rearranging of the polymeric chain. It is read in situ in the surface topography imaged by shear-force microscopy. The stability of the optically produced pattern and the cycling characteristics of the photoisomerization of the azobenzene molecules make these samples suitable for optical nanolithography and high density optical data storage.

Patanè, S.; Arena, A.; Allegrini, M.; Andreozzi, L.; Faetti, M.; Giordano, M.

2002-09-01

213

Thickness-Dependent Mechanical Behaviour of Aluminium-Coated Polyethylene Terephthalate (PET) Films  

Microsoft Academic Search

Mechanical behaviour of aluminium-coated PET films has been investigated through Dynamic Mechanical Analyser. Aluminium is coated on PET substrate by vacuum thermal evaporation method. As thickness of aluminium coating increases from 150 nm to 350 nm, tensile strength decreases from 108.88 MPa to 99.25 MPa. This mechanical behaviour is correlated with microstructure and its evolution with the thickness of aluminium coating. Al-PET film consists

Sandhya Gupta; Manasvi Dixit; Mahesh Baboo; Kananbala Sharma; N. S. Saxena

2009-01-01

214

Hypervelocity impact on silicon wafers with metallic and polymeric coatings  

Microsoft Academic Search

Current and near future developments in microsystem technologies (MST, also known as MEMS) are defining a new trend towards lower mass, smaller volume spacecraft, without loss of functionality. The MST spacecraft components are etched onto silicon wafers coated with different metallic or polymeric material layers (typically 1-2 microns in thickness). These silicon wafers are then integrated to provide the spacecraft

E. A. Taylor; H. J. Scott; M. Abraham; A. T. Kearsley

2001-01-01

215

COATING ALTERNATIVES GUIDE (CAGE) FOR METAL PARTS AND PRODUCTS PAINTING  

EPA Science Inventory

The paper discusses the initial development of a Coating Alternatives Guide (CAGE) for metal parts and products painting. t is an innovative technology transfer approach that provides a tool to improve technology diffusion and assistance. t will provide vital, user-accessible inf...

216

Intergranular metal phase increases thermal shock resistance of ceramic coating  

NASA Technical Reports Server (NTRS)

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

Carpenter, H. W.

1966-01-01

217

Coated metal sintering carriers for fuel cell electrodes  

SciTech Connect

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

Donelson, R.; Bryson, E.S.

1998-11-10

218

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

DOEpatents

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

Thompson, Anthony Mark (Niskayuna, NY); Gray, Dennis Michael (Delanson, NY); Jackson, Melvin Robert (Niskayuna, NY)

2003-05-13

219

Non-destructive determination of the coating film thickness by X-ray powder diffractometry and correlation with the dissolution behavior of film-coated tablets.  

PubMed

The goal of this project was to determine the effect of the thickness of the coating film on the dissolution behavior of tablets. Commercially available film-coated tablets containing aspirin, acetaminophen and caffeine, were used as the model system. First, a non-destructive X-ray microdiffractometric technique was developed to quantify the thickness of the film-coating in intact tablets. The same tablets were then subjected to dissolution tests. There was an inverse correlation between the cumulative amount of drug in solution at 5min and the thickness of the coating film. As the coating thickness increased, the initiation of tablet dissolution was delayed, resulting in a decrease in the cumulative amount of drug in solution. Finally, the technique was applied to formulations marketed by different companies. The X-ray microdiffractometric technique has the potential to predict the dissolution behavior of tablets. PMID:19945243

Yamada, Hiroyuki; Terada, Katsuhide; Suryanarayanan, Raj

2010-03-11

220

Self-dissolution assisted coating on magnesium metal for biodegradable bone fixation devices  

NASA Astrophysics Data System (ADS)

An attempt was made to develop a self-dissolution assisted coating on a pure magnesium metal for potential bone fixation implants. Magnesium phosphate cement (MPC) was coated successfully on the magnesium metal in ammonium dihydrogen phosphate solution. The in vitro degradation behaviour of the MPC coated metal was evaluated using electrochemical techniques. The MPC coating increased the polarisation resistance (RP) of the metal by ?150% after 2 h immersion in simulated body fluid (SBF) and reduced the corrosion current density (icorr) by ?80%. The RP of the MPC coated metal remained relatively high even after 8 h immersion period. However, post-degradation analysis of the MPC coated metal revealed localized attack. Hence, the study suggests that MPC coating alone may not be beneficial, but this novel coating could provide additional protection if used as a precursor for other potential coatings such as biodegradable polymers or calcium phosphates.

Khakbaz, Hadis; Walter, Rhys; Gordon, Timothy; Bobby Kannan, M.

2014-12-01

221

Coloured paints based on coated flakes of metal as the pigment, for enhanced solar reflectance and cooler interiors: description and theory  

Microsoft Academic Search

Flakes of metal coated with thin dielectric films, when used as various coloured paint pigments, can reflect much more of the near infra red component of solar radiation than standard paints of equivalent colour, which makes them attractive for reducing cooling loads in cars and under metal roofs, while maintaining a wide range of decorative options. Spectral responses, solar absorptance

G. B. Smith; A. Gentle; P. Swift; A. Earp; N. Mronga

2003-01-01

222

Preparation of pure boron coating film and its characterization by XPS and TDS  

NASA Astrophysics Data System (ADS)

A PACVD apparatus was designed and fabricated at Shizuoka University in order to prepare high-pure boron coating films. In the present study, some parameters, especially feeding gas concentration, substrate temperature and CVD input power, have been optimized to prepare pure boron coating films. It was found that the purity of boron coating film was controlled by the decaborane concentration of feeding gas and substrate temperature during the PACVD process, and each optimized values were 0.4 and 473 K, respectively. The atomic composition of boron in the boron coating film under the optimized condition has been achieved to be 0.94.

Oyaidzu, M.; Yoshikawa, A.; Kodama, H.; Oya, Y.; Sagara, A.; Noda, N.; Okuno, K.

2005-05-01

223

Liquid metal embrittlement of steel with galvanized coatings  

NASA Astrophysics Data System (ADS)

Article presents the state of knowledge relating occurrences of liquid metals embrittlement. The results of experimental investigations of the LME phenomenon, reasons of its formation and influence of different parameters are described. Selected ideas of the applied research methods accessible in different works are presented. Samples made of C70D steel with tensions stretching (400-800 MPa) at different values and kinds of loading during the hot dip metallization were investigated. Coating processes in two bath: zinc and zinc with 2 % tin addition were made. The processes of hot dip metallization were done at 450 °C temperature and immersion time 180 s. Coated samples were investigated by light microscope to specify possibility appear of LME effect.

Mendala, J.

2012-05-01

224

Investigation of cadmium alternatives in thin-film coatings  

NASA Astrophysics Data System (ADS)

The health risks associated with the inhalation or ingestion of cadmium are well documented. During the past 18 years, EU legislation has steadily been introduced to restrict its use, leaving a requirement for the development of replacement materials. This paper looks at possible alternatives to various cadmium II-VI dielectric compounds used in the deposition of optical thin-films for various opto-electronic devices. Application areas of particular interest are for infrared multilayer interference filter fabrication and solar cell industries, where cadmium-based coatings currently find widespread use. The results of single and multilayer designs comprising CdTe, CdS, CdSe and PbTe deposited onto group IV and II-VI materials as interference filters for the mid-IR region are presented. Thin films of SnN, SnO II, SnS and SnSe are fabricated by plasma assisted CVD, reactive RF sputtering and thermal evaporation. Examination of these films using FTIR spectroscopy, SEM, EDX analysis and optical characterisation methods provide details of material dispersion, absorption, composition, refractive index, energy band gap and layer thicknesses. The optimisation of deposition parameters in order to synthesise coatings with similar optical and semiconductor properties as those containing cadmium has been investigated. Results of environmental, durability and stability trials are also presented.

Wakeham, S. J.; Hawkins, G. J.

2006-08-01

225

Dynamics of polymer film formation during spin coating  

SciTech Connect

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

Mouhamad, Y.; Clarke, N.; Jones, R. A. L.; Geoghegan, M., E-mail: geoghegan@sheffield.ac.uk [Department of Physics and Astronomy, The University of Sheffield, Hicks Building, Hounsfield Road, Sheffield S3 7RH (United Kingdom); Mokarian-Tabari, P. [Materials Research Group, Department of Chemistry and the Tyndall National Institute, University College Cork, Cork (Ireland)

2014-09-28

226

The Electronic Structure of Transition Metal Coated Fullerenes  

NASA Astrophysics Data System (ADS)

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

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

1998-03-01

227

Thermal barrier coating system having improved adhesion  

NASA Technical Reports Server (NTRS)

The adherence between a ceramic thermal barrier coating and a metal bond coating is improved by ion sputtering a ceramic film on the bond cost. A ceramic thermal barrier coating is then plasma-sprayed onto this primer film. This improves the integrity and strength of the interface between the plasma-sprayed ceramic layer and metallic bond coat which insures stronger adherence between the metal and the ceramic.

Bill, R. C.; Sovey, J. S. (inventors)

1982-01-01

228

Robotic burnishing system for solid film lubricant coated parts  

SciTech Connect

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

Fureigh, M.L.

1986-05-01

229

Sol-gel preparation and characterization of SiO2 coated VO2 films with enhanced transmittance and high thermochromic performance  

NASA Astrophysics Data System (ADS)

Vanadium dioxide (VO2) films prepared at low-temperature with a low cost are considerable for energy-saving applications. Here, SiO2 coated VO2 films with clearly enhanced visible transmittance by introducing antireflection coatings (ARCs) and excellent thermochromic performance were present. The VO2 films have been prepared via a stable and low-cost sol-gel synthesis route using vanadium pentaoxide powder as precursor, and their structural, morphological, optical and electrical properties and thermochromic performance were systemically characterized. The resistance of VO2 films varies by 4 orders of magnitude and the transmittance changes from 11.8% to 69.3% at 2500 nm while no significant deviation appears in the visible region during metal-insulator transition (MIT). Nanoporous SiO2 coating with good optical transparency was coated on the surface of VO2 film via sol-gel dip-coating technique to enhance its optical transmittance, and the visible transmittance is increased by 14.6% due to the significantly decreased reflectance. The critical transition temperature (63 °C) and infrared switching properties of VO2 films are not much deteriorated by applying SiO2 layer. The synergistic effect of antireflection and thermochromism on SiO2 coated VO2 films was investigated.

Li, Dezeng; Shan, Yongkui; Huang, Fuqiang; Ding, Shangjun

2014-10-01

230

Heterojunction thin films based on multifunctional metal oxides for photovoltaic application  

SciTech Connect

Metal oxides based multifunctional heterojunction thin films of ZnO/SnO{sub 2} and ZnO/SnO{sub 2}/CuO QDs were prepared by spin-coating technique. The crystallographic properties and the surface morphologies of the films were studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The optical absorption studies revealed that the film thickness has considerable effect on the band gap values and is found to be in the range of 3.73–3.48 eV. The photoluminescence spectra showed several weak visible emission peaks related to the deep level defects (450-575 nm). Finally, the current density-voltage (J-V) characteristic of ZnO/SnO{sub 2}/CuO QDs (ZSCI) based heterojunction thin film coated on ITO is also reported.

Prabhu, M.; Soundararajan, N.; Ramachandran, K. [School of Physics, Madurai Kamaraj University, Madurai - 625021 (India); Marikkannan, M.; Mayandi, J. [School of Chemistry, Madurai Kamaraj University, Madurai - 625021 (India)

2014-04-24

231

Ni-based Metal Matrix Composite Functionally Graded Coatings  

NASA Astrophysics Data System (ADS)

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

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

232

A preconcentrator chip employing ?-SPME array coated with in-situ-synthesized carbon adsorbent film for VOCs analysis.  

PubMed

We report the design, fabrication, and evaluation of a ?-preconcentrator chip that utilizes an array of solid-phase microextraction (SPME) needles coated with in-situ-grown carbon adsorbent film. The structure of the SPME needle (diameter=100 ?m, height=250 ?m) array inside the sampling chamber was fabricated using a deep reactive-ion etching (DRIE) process to enhance the attachable surface area for adsorbent film. Heaters and temperature sensors were fabricated onto the back of a ?-preconcentrator chip using lithography patterning and a metal lift-off process. The devices were sealed by anodic bonding and diced prior to the application of the adsorbent film. An adsorbent precursor, cellulose was dissolved in water and dynamically coated onto the SPME needle array. The coated cellulose film was converted into a porous carbon film via pyrolysis at 600 °C in a N(2) atmosphere. The surface area of the carbon adsorbent film was 308 m(2)/g, which is higher than that of a commercial adsorbent Carbopack X. A preconcentration factor as high as 13,637-fold was demonstrated using toluene. Eleven volatile organic compounds (VOCs) of different volatilities and functional groups were sampled and analyzed by GC-FID, and the desorption peak widths at half height were all less than 2.6 s after elution from a 15m capillary GC column. There was no sign of performance degradation after continuous operation for 50 cycles in air. PMID:23158327

Wong, Ming-Yee; Cheng, Wei-Rui; Liu, Mao-Huang; Tian, Wei-Cheng; Lu, Chia-Jung

2012-11-15

233

Physical Properties of Granular Metal Thin Films  

NASA Astrophysics Data System (ADS)

Granular metal films consisting of small Bi, Sn, and Ni particles, typically ranging from less than 10 nm to several hundred nm in size and embedded in a SiO _2 matrix, have been fabricated over a range of metal compositions by magnetron sputter deposition. Both transmission electron microscopy and x-ray diffraction measurements have shown that the average particle size decreases and the particle size distribution becomes more narrow as the nominal metal fraction in the film is reduced. The melting behavior of the (Bi,Sn)-SiO _2 systems has been studied by differential scanning calorimetry (DSC). The melting temperature becomes increasingly depressed as the particle size is reduced, with relative reductions of about 15% of the bulk melting temperature occurring in the smallest particles. The melting point depression is consistent with several thermodynamic models which predict a linear reduction in the melting point with inverse particle size. The freezing transition has also been studied for the Bi-SiO_2 system, using both DSC cooling measurements and isothermal measurements carried out at various undercoolings. These measurements have revealed strong fluctuations in the freezing onset with repeated scanning. The distribution of freezing times obtained during isothermal measurements is strongly dependent on the undercooling, broadening and shifting to higher values in time as the undercooling is reduced. The electrical transport behavior of the Ni-SiO _2 system has been studied between room temperature and 100 mK and in magnetic fields up to 6 Tesla. The resistivity of the films increases systematically as the Ni concentration is reduced. Films with Ni concentrations greater than about 70 atomic percent are metallic, displaying positive temperature coefficients of resistance at room temperature. The resistance of these films first decreases with temperature and then increases logarithmically at low temperature. The resistivities of films in the insulating regime, corresponding to Ni concentration of less than 70 atomic percent, were of the form rho(T) = rho_0exp((T_0 /T)^{1/2}) above about 5 K, with values of T_0 which increase rapidly with decreasing Ni concentration. Below 1 K, there is a crossover to a weaker, common temperature dependence. The magnetoresistance of all films is small and negative.

Patterson, Brian Mark

234

A 15% efficient antireflection-coated metal-oxide-semiconductor solar cell  

NASA Technical Reports Server (NTRS)

A new effect is being developed which significantly improves the conversion efficiency of antireflection-coated metal-oxide-semiconductor (AMOS) solar cells. The effect, a marked increase in the open-circuit voltage, is produced by the addition of an oxide layer to the semiconductor. Cells using gold on n-type gallium arsenide have been made with efficiencies up to 15% in terrestrial sunlight. All processing steps are amenable to the use of low-cost polycrystalline films of GaAs in place of the single crystals now used.

Stirn, R. J.; Yeh, Y. C. M.

1975-01-01

235

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

DOEpatents

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

Weeks, Jr., Joseph K. (Salt Lake City, UT); Gensse, Chantal (Salt Lake City, UT)

1993-01-01

236

Metal-AlN cermet solar selective coatings deposited by direct current magnetron sputtering technology  

NASA Astrophysics Data System (ADS)

A series of metal-aluminium nitride (M-AlN) cermet materials for solar selective coatings was deposited by a novel direct current (d.c.) magnetron sputtering technology. Aluminium nitride was used as the ceramic component in the cermets, and stainless steel (SS), nickel-based alloy 0022-3727/31/4/003/img1 (NiCr), molybdenum-based alloy 0022-3727/31/4/003/img2 (TZM) and tungsten were used as the metallic components. The aluminium nitride ceramic and metallic components of the cermets were deposited by simultaneously running both an aluminium target and another metallic target in a gas mixture of argon and nitrogen. The ceramic component was deposited by d.c. reactive sputtering and the metallic component by d.c. non-reactive sputtering. The total sputtering gas pressure was 0.8-1.0 Pa and the partial pressure of reactive nitrogen gas was set at 0.020-0.025 Pa which is sufficiently high to ensure that a nearly pure AlN ceramic sublayer was deposited by d.c. reactive sputtering. Because of the excellent nitriding resistance of stainless steel and the other alloys and metal, a nearly pure metallic sublayer was deposited by d.c. sputtering at this low nitrogen partial pressure. A multilayered system, consisting of alternating metallic and AlN ceramic sublayers, was deposited by substrate rotation. This multisublayer system can be considered as a macrohomogeneous cermet layer with metal volume fraction determined by controlling the thicknesses of metallic and ceramic sublayers. Following this procedure, M-AlN cermet solar selective coatings with a double cermet layer structure were deposited. The films of these selective surfaces have the following structure: a low metal volume fraction cermet layer is placed on a high metal volume fraction cermet layer which in turn is placed on an aluminium metal infrared reflection layer. The top surface layer consists of an aluminium nitride antireflection layer. A solar absorptance of 0.92-0.96 and a normal emittance of 0.03-0.05 at room temperature have been achieved for these M-AlN cermet solar selective coatings.

Zhang, Qi-Chu

1998-02-01

237

Plasmonic enhancement of thin-film solar cells using gold-black coatings  

NASA Astrophysics Data System (ADS)

Coatings of conducting gold-black nano-structures on commercial thin-film amorphous-silicon solar cells enhance the short-circuit current by 20% over a broad spectrum from 400 to 800 nm wavelength. The efficiency, i.e. the ratio of the maximum electrical output power to the incident solar power, is found to increase 7% for initial un-optimized coatings. Metal blacks are produced cheaply and quickly in a low-vacuum process requiring no lithographic patterning. The inherently broad particle-size distribution is responsible for the broad spectrum enhancement in comparison to what has been reported for mono-disperse lithographically deposited or self-assembled metal nano-particles. Photoemission electron microscopy reveals the spatial-spectral distribution of hot-spots for plasmon resonances, where scattering of normally-incident solar flux into the plane increases the effective optical path in the thin film to enhance light harvesting. Efficiency enhancement is correlated with percent coverage and particle size distribution, which are determined from histogram and wavelet analysis of scanning electron microscopy images. Electrodynamic simulations reveal how the gold-black particles scatter the radiation and locally enhance the field strength.

Fredricksen, C. J.; Panjwani, D. R.; Arnold, J. P.; Figueiredo, P. N.; Rezaie, F. K.; Colwell, J.; Baillie, K.; Peppernick, S. J.; Joly, A. G.; Beck, K. M.; Hess, W. P.; Peale, R. E.

2011-09-01

238

Antimicrobial beeswax coated polylactide films with silver control release capacity.  

PubMed

Although the application of silver based antimicrobial systems is a widespread technology, its implementation in areas such as food packaging is still challenging. The present paper describes the fabrication of poly(lactic acid) (PLA) coated with beeswax with controlled release properties for sustained antimicrobial performance. Release of silver ions from the polymers was monitored voltammetrically under various conditions (surface contact, immersion in various liquid media and at different pH values) throughout at least 7days. A higher release was noted with decreasing pH while surface release was much slower than the release when immersed in liquid medium. While uncoated films demonstrated a high burst release which in some instances implied surpassing some current migration restrictions (<0.05mg/kg food), the addition of a beeswax layer allowed a sustained release of the antimicrobial compound. Increasing the thickness of the beeswax layer resulted in an increase in the water barrier properties of the films while reducing the relatively constant values of sustained release. Antimicrobial performance was correlated with the release of silver ions, indicating threshold concentrations for biocide action of <6?g/L and 9-14?g/L for surface contact and in liquid media, respectively. Either by surface contact or by immersion in growth medium or vegetable soup, the coated films displayed a strong bactericidal effect against Salmonella enterica. The application of this functional barrier thus offers the possibility of tuning the release profiles of the films to suit a specific application and puts forth the possible suitability of these materials for food packaging or other migration sensitive applications. PMID:24448276

Martínez-Abad, Antonio; Lagarón, Jose Maria; Ocio, María Jose

2014-03-17

239

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

NASA Astrophysics Data System (ADS)

Highly textured MgO films were grown by the inclined-substrate deposition (ISD) technique at a high deposition rate. A columnar grain with a roofing-tile-shaped surface was observed in these MgO films. X-ray pole figure, and ?- and ?-scan were used to characterize in-plane and out-of-plane textures. MgO films deposited when the incline angle ? was 55° and 30° exhibited the best in-plane and out-of-plane texture, respectively. High-quality YBCO films were epitaxially grown on ISD-MgO-buffered Hastelloy C substrates by pulsed laser deposition. Tc=88 K, with sharp transition, and jc values of ?2×10 5 A/cm 2 at 77 K in zero field were observed on films 5 mm wide and 1 cm long. This work has demonstrated that biaxially textured ISD MgO buffer layers deposited on metal substrates are excellent candidates for fabrication of high-quality YBCO coated conductors.

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

2002-02-01

240

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

SciTech Connect

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

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

2002-02-01

241

Hot-Dipped Metal Films as Epitaxial Substrates  

NASA Technical Reports Server (NTRS)

Multistep process forms semiconductor devices on macrocrystalline films of cadmium or zinc. Solar-cell fabrication processes use hot-dipped macrocrystalline films on low-cost sheet-metal base as substrates for epitaxy. Epitaxial layers formed by variety of methods of alternative sequence paths. Solar cells made economically by forming desired surface substance directly on metal film by chemical reactions.

Shlichta, P. J.

1985-01-01

242

Pulsed-laser deposited transition-metal carbides for field-emission cathode coatings.  

PubMed

Thin films of transition-metal carbides ZrC, HfC, and TiC were deposited by pulsed-laser deposition under vacuum. The surface chemistry of the films was characterized with ultraviolet photoelectron spectroscopy, X-ray photoelectron spectroscopy, and Auger electron spectroscopy in situ. X-ray diffraction was used to characterize the film structure. TiC was shown to be nearly stoichiometric and polycrystalline. The TiC was applied to a vertically aligned carbon nanotube sample and characterized by field emission. Field-emission results showed enhanced current and current density at a film thickness, 5 nm, not previously reported in the literature. Emission from TiC films was also shown to be less affected by adsorbates during field emission. Pulsed-laser deposition of TiC offers a distinct advantage over other techniques in that high-quality films can be obtained under ultrahigh vacuum conditions without the use of a reactive background gas or excessively high annealing temperatures. The application of TiC by pulsed-laser deposition as a cathode coating shows potential for integration into a fabrication process. PMID:23988076

Back, Tyson; Fairchild, Steven B; Averett, Kent; Maruyama, Benji; Pierce, Neal; Cahay, Marc; Murray, P Terrence

2013-09-25

243

Tantalum-cadmium film coatings: Preparation, phase composition, and structure  

NASA Astrophysics Data System (ADS)

Ion-plasma sputtering and codeposition of ultrafine Ta and Cd particles were used for the first time to prepare solid solutions, namely, alloys with up to 66.2 at % Cd in the form of coatings; the fact of such a production confirms the thermal-fluctuation melting and coalescence of small particles. When the coatings are formed by tantalum and cadmium nanolayers, the mutual dissolution of the components takes place, which is accompanied by the formation of solid solutions of one metal in the other. When the cadmium concentration is above 44 at %, the ?-Ta tetragonal lattice transforms into the ?-Ta body-centered cubic lattice. Beginning from 74.4 at % Cd, a hexagonal structure typical of cadmium is formed, and tantalum is present in the coatings in the form of amorphous phase. The formation of ?-Ta- and Cd-based interstitial and ?-Ta-based substitute solid solutions is stated. At 700°C, cadmium evaporates from Ta-based solid solutions, and porous tantalum is formed. The evaporation of cadmium from coatings, which consist of the mixture of tantalum solid solution in cadmium and amorphous tantalum, leads to the formation of tantalum characterized by a highly developed surface. The prepared Ta-based materials assume the technological application of the results of the investigation.

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

2015-01-01

244

The effect of film thickness on the failure strain of polymer-supported metal films  

E-print Network

The effect of film thickness on the failure strain of polymer-supported metal films Nanshu Lu-supported copper films with a strong (1 1 1) fiber texture and with thicknesses varying from 50 nm to 1 lm. Films with thicknesses below 200 nm fail by intergranular fracture at elongations of only a few percent. Thicker films

Suo, Zhigang

245

Metal oxide coatings for piezoelectric exhaust gas sensors  

SciTech Connect

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

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

1996-06-01

246

Method of producing solution-derived metal oxide thin films  

DOEpatents

A method of preparing metal oxide thin films by a solution method. A .beta.-metal .beta.-diketonate or carboxylate compound, where the metal is selected from groups 8, 9, 10, 11, and 12 of the Periodic Table, is solubilized in a strong Lewis base to form a homogeneous solution. This precursor solution forms within minutes and can be deposited on a substrate in a single layer or a multiple layers to form a metal oxide thin film. The substrate with the deposited thin film is heated to change the film from an amorphous phase to a ceramic metal oxide and cooled.

Boyle, Timothy J. (Albuquerque, NM); Ingersoll, David (Albuquerque, NM)

2000-01-01

247

Multilayer silver / dielectric thin-film coated hollow waveguides for sensor and laser power delivery applications  

E-print Network

Multilayer silver / dielectric thin-film coated hollow waveguides for sensor and laser power thin film designs deposited on silver coated silica hollow waveguides have been used for low-loss transmission of infrared radiation in the 2 ­ 14 micrometer region. Silver iodide has traditionally been

248

Antimicrobial Edible Films and Coatings for Fresh and Minimally Processed Fruits and Vegetables: a Review  

Microsoft Academic Search

The use of edible films and coatings is an environmentally friendly technology that offers substantial advantages for shelf-life increase of many food products including fruits and vegetables. The development of new natural edible films and coatings with the addition of antimicrobial compounds to preserve fresh and minimally processed fruits and vegetables is a technological challenge for the industry and a

SILVIA A. VALENCIA-CHAMORRO; LLUÍS PALOU; MIGUEL A. DEL RÍO; MARÍA B. PÉREZ-GAGO

2011-01-01

249

Repairing Chipped Silicide Coatings on Refractory Metal Substrates  

NASA Technical Reports Server (NTRS)

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

Youngquist, Robert

2006-01-01

250

film across metal to insulator transition  

NASA Astrophysics Data System (ADS)

We have proposed a method to probe metal to insulator transition in VO2 measuring photoluminescence response of colloidal quantum dots deposited on the VO2 film. In addition to linear luminescence intensity decrease with temperature that is well known for quantum dots, temperature ranges with enhanced photoluminescence changes have been found during phase transition in the oxide. Corresponding temperature derived from luminescence dependence on temperature closely correlates with that from resistance measurement during heating. The supporting reflectance data point out that photoluminescence response mimics a reflectance change in VO2 across metal to insulator transition. Time-resolved photoluminescence study did not reveal any significant change of luminescence lifetime of deposited quantum dots under metal to insulator transition. It is a strong argument in favor of the proposed explanation based on the reflectance data.

Kuznetsov, Sergey N.; Cheremisin, Alexander B.; Stefanovich, Genrikh B.

2014-11-01

251

Interfacial Reactions between Oxide Films and Refractory Metal Substrates  

E-print Network

Interfacial Reactions between Oxide Films and Refractory Metal Substrates X. Xu, W. S. Oh, and D. W,thelatterbeingencapsulatedbythemolybdenum oxides. Above 1200 K, both metallic nickel and molybdenum oxides are evolved from the surface-grown oxide thin films on various metal substrates [for example, NiO/Mo(100), MgO/Mo(100) and Al2O3/Ta(110

Goodman, Wayne

252

Metal-matrix composite coatings by PTA surfacing  

Microsoft Academic Search

Metal-matrix composite (MMC) coatings are deposited onto ferrous and non-ferrous substrates by three conventional techniques, namely laser cladding, thermal spraying and plasma transferred-arc (PTA) surfacing. In this paper PTA surfacing technology is reviewed with reference to current surface modification applications. The main rationale behind this technology has been focussed towards enhancing the tribological properties of the substrate. Little effort has

R. L. Deuis; J. M. Yellup; C. Subramanian

1998-01-01

253

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

PubMed

A series of moisture-resistant konjac glucomannan films were prepared by coating shellac/stearic acid emulsion on deacetylated konjac glucomannan films (dKGM). The effect of stearic acid content on structure and properties of the coated films were investigated by field emission scanning electron microscopy (FE SEM), Fourier transform infrared spectroscopy (FT-IR), ultraviolet spectroscopy (UV), water vapor permeability (WVP), water uptake, water contact angle, and tensile testing. The results revealed that shellac in the coating adhered intimately to the surface of dKGM film, and provided a substrate for the dispersion of stearic acid which played an important role in enhancement of the moisture barrier properties and mechanical properties of the coated films. The WVP of the coated films decreased from 2.63×10(-11) to 0.37×10(-11)g/(msPa) and the water contact angle increased from 68° to 101.2° when stearic acid content increased from 0wt% to 40wt%, showing the potential applications in food preservation. PMID:25542116

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

2015-03-15

254

Electrochemical corrosion behavior of composite coatings of sealed MAO film on magnesium alloy AZ91D  

Microsoft Academic Search

Protective composite coatings were prepared on magnesium alloy AZ91D by micro-arc oxidation (MAO) treatment plus a top coating with sealing agent using multi-immersion technique under low-pressure conditions. The corrosion resistance of AZ91D alloy with composite coatings was superior evidently to that with merely MAO film. SEM observations revealed that the sealing agent was integrated with MAO film by physically interlocking;

Hongping Duan; Keqin Du; Chuanwei Yan; Fuhui Wang

2006-01-01

255

Effect of heat treatment, top coatings and conversion coatings on the corrosion properties of black electroless Ni-P films  

NASA Astrophysics Data System (ADS)

Electroless black nickel-phosphorus plating is an advanced electroless nickel plating process formulated to deposit a black finish when processed through an oxidizing acid solution. Heat treatment, five types of top organic coating techniques and one conversion coating technique with three different experimental conditions were investigated to stabilize the black film and increase the hardness and corrosion resistance. Morphology and compositions of electroless nickel-phosphorous films with or without heat treatment, with five types of top organic coatings, and with three conversion coatings were compared to examine nickel, phosphorus, oxygen, carbon, silicon and chrome contents on the corrosion resistance of black surfaces by energy dispersive X-ray microanalysis and scanning electron microscope. Corrosion resistance of black electroless nickel-phosphorus coatings with or without heat treatment, with five types of top organic coatings, and with three conversion coatings was investigated by the polarization measurements and the salt spray test in 5% NaCl solution, respectively. HydroLac as the top organic coating from MacDermid showed the excellent corrosion resistance and the black EN film did not lose the black color after 48 h salt spray test. Electrotarnil B process with 0.5 ASD for 1 min stabilized the black Ni-P film immediately and increased the hardness and corrosion performance of the black Ni-P film. The black Ni-P coating with Electroarnil B process passed the 5% NaCl salt spray test for 3000 h in the black color and had a minimal corrosion current 0.8547 ?A/cm2 by the polarization measurement.

Liu, Y.; Beckett, D.; Hawthorne, D.

2011-02-01

256

Corrosion behavior of rare earth metal (REM) conversion coatings on aluminum alloy LY12  

Microsoft Academic Search

The processes of the double layer rare earth metal (REM) conversion coating on aluminum alloy LY12 (2024) were introduced. The results of polarization tests showed that the corrosion resistance of the double layer REM conversion coating was superior to that of chromate conversion coating. The corrosion behavior of REM conversion coatings on LY12 alloy was studied with optical microscopy and

Yu Xingwen; Cao Chunan; Yao Zhiming; Zhou Derui; Yin Zhongda

2000-01-01

257

Detection of volatile organic compounds by weight-detectable sensors coated with metal-organic frameworks.  

PubMed

Detection of volatile organic compounds (VOCs) using weight-detectable quartz microbalance and silicon-based microcantilever sensors coated with crystalline metal-organic framework (MOF) thin films is described in this paper. The thin films of two MOFs were grown from COOH-terminated self-assembled monolayers onto the gold electrodes of sensor platforms. The MOF layers worked as the effective concentrators of VOC gases, and the adsorption/desorption processes of the VOCs could be monitored by the frequency changes of weight-detectable sensors. Moreover, the MOF layers provided VOC sensing selectivity to the weight-detectable sensors through the size-selective adsorption of the VOCs within the regulated nanospace of the MOFs. PMID:25175808

Yamagiwa, Hiroki; Sato, Seiko; Fukawa, Tadashi; Ikehara, Tsuyoshi; Maeda, Ryutaro; Mihara, Takashi; Kimura, Mutsumi

2014-01-01

258

Detection of Volatile Organic Compounds by Weight-Detectable Sensors coated with Metal-Organic Frameworks  

NASA Astrophysics Data System (ADS)

Detection of volatile organic compounds (VOCs) using weight-detectable quartz microbalance and silicon-based microcantilever sensors coated with crystalline metal-organic framework (MOF) thin films is described in this paper. The thin films of two MOFs were grown from COOH-terminated self-assembled monolayers onto the gold electrodes of sensor platforms. The MOF layers worked as the effective concentrators of VOC gases, and the adsorption/desorption processes of the VOCs could be monitored by the frequency changes of weight-detectable sensors. Moreover, the MOF layers provided VOC sensing selectivity to the weight-detectable sensors through the size-selective adsorption of the VOCs within the regulated nanospace of the MOFs.

Yamagiwa, Hiroki; Sato, Seiko; Fukawa, Tadashi; Ikehara, Tsuyoshi; Maeda, Ryutaro; Mihara, Takashi; Kimura, Mutsumi

2014-09-01

259

Detection of Volatile Organic Compounds by Weight-Detectable Sensors coated with Metal-Organic Frameworks  

PubMed Central

Detection of volatile organic compounds (VOCs) using weight-detectable quartz microbalance and silicon-based microcantilever sensors coated with crystalline metal-organic framework (MOF) thin films is described in this paper. The thin films of two MOFs were grown from COOH-terminated self-assembled monolayers onto the gold electrodes of sensor platforms. The MOF layers worked as the effective concentrators of VOC gases, and the adsorption/desorption processes of the VOCs could be monitored by the frequency changes of weight-detectable sensors. Moreover, the MOF layers provided VOC sensing selectivity to the weight-detectable sensors through the size-selective adsorption of the VOCs within the regulated nanospace of the MOFs. PMID:25175808

Yamagiwa, Hiroki; Sato, Seiko; Fukawa, Tadashi; Ikehara, Tsuyoshi; Maeda, Ryutaro; Mihara, Takashi; Kimura, Mutsumi

2014-01-01

260

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

PubMed

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

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

1989-12-15

261

Laser Forming of Thin Film Metallic Glass  

NASA Astrophysics Data System (ADS)

Palladium based thin film metallic glasses were plastically bent by laser forming process. Thin films of Pd77Cu6Si17 with a thickness of 0.028mm and Pd40Ni40P20 with a thickness of 0.017mm were used for specimen. A 50W YAG laser was employed for forming. Variation of bending angle was investigated by changing working conditions such as laser power, laser operation mode (continuous wave and Q-switch pulsed modes), Q-sw frequency, scanning velocity and scanning number. From the experimental results, both thin films of Pd77Cu6Si17 and Pd40Ni40P20 were successfully bent for more than 85°. The formed thin films did not crystallize but were amorphous. As scanning number increased, bending angle also increased but increasing rate decreased. When laser power and scanning velocity were changed, bending angle had a peak. When Q-sw frequency was changed, bending angle had a broad peak in Pd77Cu6Si17 case, but that was larger as frequency was smaller in Pd40Ni40P20 case.

Otsu, Masaaki; Ide, Yuki; Sakurai, Junpei; Hata, Seiichi; Takashima, Kazuki

262

Metallic oxide switches using thick film technology  

NASA Technical Reports Server (NTRS)

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

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

1974-01-01

263

Evaluation of Adhesive Behaviors of Chromium Nitride Coating Films Produced by Arc Ion Plating Method  

Microsoft Academic Search

Scratch tests and pin-on-disk wear tests were performed to clarify the cracking and delaminating behavior of CrN coatings. The CrN films were coated onto an aluminum alloy substrate, JIS A2024, by an arc ion plating method. Eight types of single-layered coating and multilayered coatings were prepared by changing the bias voltage during the deposition. LCI and LCII values were not

Ri-Ichi Murakami; Yun-Hae Kim; Kazushi Kimura; Daisuke Yonekura; Do-Hoon Shin

2006-01-01

264

Thin film pc-Si by aluminium induced crystallization on metallic substrate  

NASA Astrophysics Data System (ADS)

Thin film polycrystalline silicon (pc-Si) on flexible metallic substrates is promising for low cost production of photovoltaic solar cells. One of the attractive methods to produce pc-Si solar cells consists in thickening a large-grained seed layer by epitaxy. In this work, the deposited seed layer is made by aluminium induced crystallization (AIC) of an amorphous silicon (a-Si) thin film on metallic substrates (Ni/Fe alloy) initially coated with a tantalum nitride (TaN) conductive diffusion barrier layer. Effect of the thermal budget on the AIC grown pc-Si seed layer was investigated in order to optimize the process (i.e. the quality of the pc-Si thin film). Structural and optical characterizations were carried out using optical microscopy, ?-Raman and Electron Backscatter Diffraction (EBSD). At optimal thermal annealing conditions, the continuous AIC grown pc-Si thin film showed an average grain size around 15 ?m. The grains were preferably (001) oriented which is favorable for its epitaxial thickening. This work proves the feasibility of the AIC method to grow large grains pc-Si seed layer on TaN coated metal substrates. These results are, in terms of grains size, the finest obtained by AIC on metallic substrates.

Delachat, F.; Antoni, F.; Prathap, P.; Slaoui, A.; Cayron, C.; Ducros, C.

2013-04-01

265

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

PubMed

Mechanical properties of orthopedic implants play important role in the regeneration and cell growth of the diseased body part. The present investigation was aimed at the development of a biocompatible, biodegradable and mechanically stable coating of chitosan (CS)-polyvinyl alcohol (PVA) polymer composite on Titanium (Ti) metal by employing a simple methodology at ambient conditions. The PVA to CS concentrations were maintained in fixed ratios of 1:4 weight/weight (w/w) for the development of all the coatings on Ti metal. Four different concentrations of the polymers ranging in the order of 5%, 10%, 15% and 20% weight/volume (w/v) solution of CS were selected in an aim to test their efficacy on mechanical stability. The results obtained from the analysis confirmed considerable improvement in mechanical properties of the composite polymer film comprising CS and PVA on Ti metal with the four different concentrations showing variable elastic modulus and hardness. The difference in mechanical properties of both dehydrated and hydrated coatings demonstrates the effective and efficient shielding of high mechanical properties of Ti metal in physiological conditions. The scratch tests performed on the coated specimens also indicated a good adhesion of the polymer on the Ti metal surface. PMID:25265031

Mishra, Sandeep K; Kannan, S

2014-12-01

266

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

NASA Technical Reports Server (NTRS)

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

Sliney, H. E.

1974-01-01

267

Application of the dielectric barrier discharge to detect defects in a teflon coated metal surface  

Microsoft Academic Search

In the semiconductor industry, flexible stainless steel tubes, the inside of which are coated with thick Teflon films, by the splay coating method, have been used to prevent their degradation and erosion by organic solvents. We have developed an inspection system to detect pinholes and cracks in the deposited Teflon films, and the dielectric barrier discharge (DBD) was employed to

Kenji Ebihara; Takahiro Tanaka; Tomoaki Ikegami; Yukihiko Yamagata; Toru Matsunaga; Kazutaka Yamashita; Yoshifumi Oyama

2003-01-01

268

A soft metal hydride actuator using LaNi5 alloy and a laminate film bellows  

Microsoft Academic Search

Rehabilitation systems and assistive technology devices for people with motor disabilities caused by stroke or the aging process require a human-friendly actuator that is soft, compact, slow, noiseless, and environmentally benign. In order to realize these kinds of actuators, we designed a soft metal hydride (MH) actuator using a copper-coated LaNi5 alloy and a laminate film bellows. For the purpose

S. Ino; M. Hosono; M. Sato; S. Nakajima; K. Yamashita; T. Izumi

2009-01-01

269

Alginate-magnesium aluminum silicate films: effect of plasticizers on film properties, drug permeation and drug release from coated tablets.  

PubMed

The effect of hydrophilic plasticizers, namely glycerin and polyethylene glycol 400 (PEG400), on physicochemical properties of sodium alginate-magnesium aluminum silicate (SA-MAS) microcomposite films was characterized and application of the films for controlling drug release from tablets was evaluated as well. The plasticizers could possibly interact with SA or MAS by formation of hydrogen bonding, as revealed using FTIR spectroscopy. PXRD studies presented that glycerin or PEG400 could intercalate into the silicate layers of MAS and higher crystallinity of the films with PEG400 was obtained. This led to a different thermal behavior of the films. Glycerin gave more flexibility of the films than PEG400. Incorporation of plasticizers into the films did not affect water uptake in acid medium, but increasing an erosion of the films because of the leaching of the plasticizers. Water vapor permeability of the films decreased with increasing amount of plasticizers in the range of 10-30% (w/w). Diffusion coefficient (D) of acetaminophen (ACT) across the films in acid medium increased with addition of the plasticizers because the leaching of plasticizers could reduce tortuosity of aqueous pore channels of the films. The tablets coated with plasticized films had a quite smooth surface without defect as shown by SEM. The ACT release profiles from the coated tablets showed a zero-order release kinetic with drug diffusion mechanism across in situ insoluble composite films in acid medium, and coating film swelling and erosion mechanism in pH 6.8 phosphate buffer. Moreover, neither the release rate nor the release pattern of the ACT coated tablets was obviously changed. The findings show that glycerin or PEG400 could improve physicochemical properties of the SA-MAS films and the plasticized films could control the drug release from tablets in gastro-intestinal condition. PMID:17056214

Pongjanyakul, Thaned; Puttipipatkhachorn, Satit

2007-03-21

270

Formation of carbonated hydroxyapatite films on metallic surfaces using dihexadecyl phosphate-LB film as template.  

PubMed

Hydroxyapatite serves as a bioactive material for biomedical purposes, because it shares similarities with the inorganic part of the bone. However, how this material deposits on metallic surfaces using biomimetic matrices remains unclear. In this study, we deposited dihexadecyl phosphate, a phospholipid that bears a simple chemical structure, on stainless steel and titanium surfaces using the Langmuir-Blodgett (LB) technique; we employed the resulting matrix to grow carbonated hydroxyapatite. We obtained the calcium phosphate coating via a two-step process: we immersed the surfaces modified with the LB films into phosphate buffer, and then, we exposed the metal to a solution that simulated the concentration of ions in the human plasma. The latter step generated carbonated hydroxyapatite, the same mineral existing in the bone. The free energy related to the surface roughness and composition increased after we modified the supports. We investigated the film morphology by scanning electron and atomic force microscopies and determined surface composition by infrared spectroscopy and energy dispersive X-ray. We also studied the role of the surface roughness and the surface chemistry on cell viability. The surface-modified Ti significantly increased osteoblastic cells proliferation, supporting the potential use of these surfaces as osteogenic materials. PMID:24727116

de Souza, Israel D; Cruz, Marcos A E; de Faria, Amanda N; Zancanela, Daniela C; Simão, Ana M S; Ciancaglini, Pietro; Ramos, Ana P

2014-06-01

271

Preparation and selective laser sintering of nylon-12 coated metal powders and post processing  

Microsoft Academic Search

A dissolution–precipitation process was successfully developed to prepare nylon-12 coated carbon steel powders. The SEM and laser diffraction particle size analysis results show that the metal particles are well coated by nylon-12 resin; therefore, an effective method for preparing nylon-12 coated metal powders is provided. Green parts were formed from the coated powders by selective laser sintering (SLS) process, and

Chunze Yan; Yusheng Shi; Jingsong Yang; Jinhui Liu

2009-01-01

272

Superhydrophobic ceramic coatings enabled by phase-separated nanostructured composite TiO2-Cu2O thin films.  

PubMed

By exploiting phase-separation in oxide materials, we present a simple and potentially low-cost approach to create exceptional superhydrophobicity in thin-film based coatings. By selecting the TiO2-Cu2O system and depositing through magnetron sputtering onto single crystal and metal templates, we demonstrate growth of nanostructured, chemically phase-segregated composite films. These coatings, after appropriate chemical surface modification, demonstrate a robust, non-wetting Cassie-Baxter state and yield an exceptional superhydrophobic performance, with water droplet contact angles reaching to ~172° and sliding angles <1°. As an added benefit, despite the photo-active nature of TiO2, the chemically coated composite film surfaces display UV stability and retain superhydrophobic attributes even after exposure to UV (275 nm) radiation for an extended period of time. The present approach could benefit a variety of outdoor applications of superhydrophobic coatings, especially for those where exposure to extreme atmospheric conditions is required. PMID:24857856

Aytug, Tolga; Bogorin, Daniela F; Paranthaman, Parans M; Mathis, John E; Simpson, John T; Christen, David K

2014-06-20

273

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

NASA Astrophysics Data System (ADS)

Cyclic nanoindentation tests were carried out to study the influence of the chromium nitride thin films on the mechanical properties of Zr-based metallic glass. Chromium nitride thin coatings have been deposited on Zr50Cu40Al10 metallic glass substrate by RF sputtering. The deposition process was done at room temperature under nitrogen reactive gas using a metallic chromium target. The CrN films have a thickness of 300 nm. Several cyclic nanoindentation measurements were conducted on CrN films and Zr50Cu40Al10 metallic glass substrate samples at various loading rate values. We have found that the coated metallic glass sample shows high mechanical properties such as hardness and reduced elastic modulus. Cyclic nanoindentation results show a hardening behaviour for these CrN coatings. Moreover, the CrN coated on Zr-based metallic glass was found to have a high value of resistance to crack propagation, as being analysed through the SEM pictures of the residual Vickers indentation impressions.

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

2011-01-01

274

Personal Thermal Management by Metallic Nanowire-Coated Textile Po-Chun Hsu,  

E-print Network

Personal Thermal Management by Metallic Nanowire-Coated Textile Po-Chun Hsu, Xiaoge Liu, Chong Liu to traditional indoor heaters. KEYWORDS: metallic nanowires, textile, low-emissivity materials, thermal demonstrate that solution-processed metallic nanowire mesh can be easily coated onto existing textiles

Cui, Yi

275

Western blotting by thin-film direct coating.  

PubMed

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

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

2014-05-20

276

Tribological performance of ceramic coatings deposited on metal surfaces for micro-bearing biomedical applications  

NASA Astrophysics Data System (ADS)

Modification of metal materials by means of ceramic coating deposition is an effective way of forming alternative bearing surfaces. Ceramic AlN, Al2O3 and nanocomposite oxynitride coatings are widely used as protective coatings against wear, diffusion and corrosion. The enhancement of the mechanical properties, such as hardness parameters, effective Young's modulus, toughness, elastic recovery and wear resistance of the coatings, is very important for the tribological performance of the next generation of ceramic-coated ball bearing devices.

Donkov, N.; Zykova, A.; Safonov, V.; Smolik, J.; Rogowska, R.; Luk'yanchenko, V.; Yakovin, S.

2014-05-01

277

REMOVAL OF METAL IONS FROM WATER SOLUTIONS BY IRON\\/COBALT OXIDE COATED KERAMZITE  

Microsoft Academic Search

A method for coating hydrated iron, cobalt and iron\\/cobalt oxide on the surface of keramzite sand was developed. The coating parameters (pH, amount of coated metal, molar ratio Co\\/Fe, temperature of modification and time of treatment) controlling sorption ability of the coated layer were determined. The iron\\/cobalt coated keramzite thermally activated at 450°C obtained at a molar ratio Co\\/Fe-0.516 is

R. Y. Stefanova

2001-01-01

278

In vitro corrosion behavior of bioceramic, metallic, and bioceramic–metallic coated stainless steel dental implants  

Microsoft Academic Search

Objectives: The most common metals and alloys used in dentistry may be exposed to a process of corrosion in vivo that make them cytotoxic. The biocompatibility of dental alloys is primarily related to their corrosion behavior. The aim of this work was to evaluate the corrosion behavior and thus the biocompatibility of the uncoated and coated stainless steels and compare

M. H Fathi; M Salehi; A Saatchi; V Mortazavi; S. B Moosavi

2003-01-01

279

Soldering of Thin Film-Metallized Glass Substrates  

SciTech Connect

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

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

1999-03-31

280

Highly Conductive Group VI Transition Metal Dichalcogenide Films by Solution-Processed Deposition  

SciTech Connect

A new soluble synthetic route was developed to fabricate thin films of layered structure transition metal dichalcogendies, MoS{sub 2} and WS{sub 2}. High-quality thin films of the dichalcogenides were prepared using new soluble precursors, (CH{sub 3}NH{sub 3}){sub 2}MS{sub 4} (M = Mo, W). The precursors were dissolved in organic solvents and spun onto substrates via both single- and multistep spin coating procedures. The thin films were formed by the thermal decomposition of the coatings under inert atmosphere. Structural, electrical, optical absorption, thermal, and transport properties of the thin films were characterized. Surface morphology of the films was analyzed by atomic force microscopy and scanning electron microscopy. Highly conductive and textured n-type MoS{sub 2} films were obtained. The measured room temperature conductivity {approx}50 O-1 cm-1 is substantially higher than the previously reported values. The n-type WS{sub 2} films were prepared for the first time using solution-processed deposition. WS{sub 2} displays a conductivity of {approx}6.7 O-1 cm-1 at room temperature.

Ki, W.; Huang, X.; Li, J.; Young, D. L.; Zhang, Y.

2007-05-01

281

Optical and electrical transport properties of semicontinuous metallic films  

Microsoft Academic Search

Semicontinuous metallic films posses unique optical and electrical transport properties. The strong localization and large enhancement of electric fields demonstrated by these films make them interesting in terms of a fundamental understanding of these phenomena as well as potentially useful in a large variety of applications. The field distributions and electrical transport properties of these films depend on the structural

Katyayani Seal

2003-01-01

282

Effect of surface ZnO coatings on oxidation and thermal stability of zinc films  

NASA Astrophysics Data System (ADS)

The effect of thin ZnO coatings grown on Zn films on further oxidation and thermal stability of Zn films deposited on Mo(110) substrate was in situ investigated under ultrahigh vacuum by photoelectron spectrometries and low-energy electron diffraction. The results indicated that ZnO layers formed by oxidizing Zn films had at least a thickness of 3-5 monolayers. Further oxidation of Zn films was confined by as-formed ZnO coatings due to a surface passivation. It was of advantage to explain the difficulty in growing low oxygen-deficient ZnO films. The surface ZnO coatings strongly enhanced the thermal stability of Zn films, which was useful for understanding the underlying application of Zn/ZnO materials, such as Zn/ZnO nanocables with Zn core and ZnO shell.

Xue, M. S.; Li, W.; Wang, F. J.

2010-08-01

283

New Synthetic Routes to Metal Boride Thin Films and Metallaboranes  

NASA Astrophysics Data System (ADS)

This dissertation describes the investigation of the chemical vapor deposition of metal/metal boride thin films of transition and rare earth elements from metal halides and boron hydride precursors. Also reported are thermal routes to the synthesis of new metallaborane complexes. A systematic approach to the chemical vapor deposition of metal/metal boride thin films of the first row transition elements has been developed. Metal/metal boride thin films of scandium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel and copper were prepared using metal halides, pentaborane(9) and decaborane(14) precursors between 450 -870^circC. The analyzed films were compositionally uniform as a function of thickness. Both metal-rich and boron-rich films were formed. Mixed metal films were also deposited containing Fe-Co-B and Cu-Ni -B. The metal boride films were characterized by scanning electron microscopy (SEM), X-ray thin film diffraction (XRD), transmission electron diffraction (TED), atomic absorption spectrophotometry (AA), auger electron spectroscopy (AES), X-ray emission spectrometry (XES), Laser microprobe mass analysis (LAMMA), glow discharge mass spectrometry (GDMS) and elemental analysis. The chemical vapor deposition of rare earth boride films is presented in chapter two. Thin films of LaB _6, GdB_6 and NdB _6 were deposited from the corresponding metal chlorides, pentaborane(9) and decaborane(14) precursors. The rare earth boride films possessed unusual microstructures and their compositions were relatively uniform as a function of thickness. Mixed metal films containing Co-Nd-B were also prepared. The films were characterized by scanning electron microscopy, X-ray thin film diffraction, reflection high energy electron diffraction, energy dispersive and wavelength dispersive X-ray emission spectrometry and glow discharge mass spectrometry. The reactions of the metal halide thermal dissociation species and neutral pentaborane(9) are described. mu-2,3,2^',3 ^'-rm Fe(B _5H_8)_2, 1, and mu -2,3,2^',3 ^'-rm Ti(B_5H _8)_2, 2, were synthesized by condensing the thermal products of FeCl_2 and TiCl_4, respectively, with pentaborane(9) at -78^circC followed by warming to room temperature. A thermal reaction of NiCl _2 and rm B_5H_9 produced compound 3 proposed as rm B_{10}H_8Ni_2Cl_2. The compounds were characterized by ^ {11}B NMR spectroscopy, mass spectrometry and 2D ^{11}B- ^{11}B NMR spectroscopy.

Kher, Shreyas Suresh

284

An in vitro method to investigate food effects on drug release from film-coated beads.  

PubMed

The influence of simulated high-fat meals on drug release from beads coated with modified-release ethylcellulose coating formulations was investigated as a function of plasticizer type and concentration, and coating level. Ethylcellulose-coated beads were soaked in peanut oil prior to testing to simulate the influence of concomitant administration of the dosage form with ingestion of fatty meals. The USP apparatus 3 dissolution procedure was employed to study the drug release properties of the beads. It was found that the ethylcellulose-coated beads plasticized with either triethyl citrate (TEC) or dibutyl sebacate (DBS) had faster drug release rates after the peanut oil treatment. Scanning electron microscopy (SEM) revealed that the peanut oil soak caused the polymeric films to detach from the surface of the bead, producing a series of uneven ridges and cracks in the coating. Modulated differential scanning calorimetry (DSC) demonstrated that the glass transition temperature was increased for DBS-plasticized films soaked in peanut oil, and that it was not influenced for TEC plasticized films. Similar results were found for the puncture strength, percent elongation, and modulus of elasticity for the DBS- and TEC-plasticized films soaked in peanut oil. The results verified that the DBS was solubilized and extracted from the plasticized film during the peanut oil soak, and that the film plasticized with the TEC was not significantly affected by the peanut oil soak. Drug release was influenced by the plasticizer type and concentration, and coating level applied to the beads. PMID:9552426

Williams, R O; Sriwongjanya, M; Liu, J

1997-02-01

285

Sol-gel antireflective coating on plastics  

DOEpatents

An antireflection film made from a reliquified sol-gel hydrolyzation, condensation polymeric reaction product of a silicon, alkoxides and/or metal alkoxides, or mixtures thereof. The film is particularly useful for coating plastics.

Ashley, Carol S. (Albuquerque, NM); Reed, Scott T. (Albuquerque, NM)

1990-01-01

286

Sol-gel antireflective coating on plastics  

DOEpatents

An antireflection film made from reliquified sol-gel hydrolyzation, condensation polymeric reaction product of a silicon, alkoxides and/or metal alkoxides, or mixtures thereof. The film is particularly useful for coating plastics.

Ashley, C.S.; Reed, S.T.

1988-01-26

287

Promising antimicrobial capability of thin film metallic glasses.  

PubMed

Thin film metallic glasses (TFMGs) are demonstrated to exhibit excellent surface flatness, high corrosion resistance and satisfactory hydrophobic properties. Moreover, the antimicrobial and biocompatibility abilities of TFMGs are examined and the results are compared with the behavior of pure Ag and 316L stainless steel. Three TFMGs, Al48Ag37Ti15, Zr54Ti35Si11, and Zr59Ti22Ag19, are prepared by sputtering to assess the antimicrobial performance against Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa, which are the most common nosocomial infection pathogens. Experimental results show that the antimicrobial effect of the Al- or Ag-containing AlAgTi and ZrTiAg TFMGs is similar to that of the pure Ag coating. The ZrTiSi TFMG with no Ag or Al shows poor antimicrobial capability. The physical properties of highly smooth surface and hydrophobic nature alone are not sufficient to result in promising antimicrobial ability. The chemical metal ion release still plays a major role, which should be born in mind in designing biomedical devices. PMID:24433907

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

2014-03-01

288

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

PubMed Central

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

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

2011-01-01

289

Engineering the interface characteristics of ultrananocrystalline diamond films grown on Au-coated Si substrates.  

PubMed

Enhanced electron field emission (EFE) properties have been observed for ultrananocrystalline diamond (UNCD) films grown on Au-coated Si (UNCD/Au-Si) substrates. The EFE properties of UNCD/Au-Si could be turned on at a low field of 8.9 V/?m, attaining EFE current density of 4.5 mA/cm(2) at an applied field of 10.5 V/?m, which is superior to that of UNCD films grown on Si (UNCD/Si) substrates with the same chemical vapor deposition process. Moreover, a significant difference in current-voltage curves from scanning tunneling spectroscopic measurements at the grain and the grain boundary has been observed. From the variation of normalized conductance (dI/dV)/(I/V) versus V, bandgap of UNCD/Au-Si is measured to be 2.8 eV at the grain and nearly metallic at the grain boundary. Current imaging tunneling spectroscopy measurements show that the grain boundaries have higher electron field emission capacity than the grains. The diffusion of Au into the interface layer that results in the induction of graphite and converts the metal-to-Si interface from Schottky to Ohmic contact is believed to be the authentic factors, resulting in marvelous EFE properties of UNCD/Au-Si. PMID:22823911

Sankaran, Kamatchi Jothiramalingam; Panda, Kalpataru; Sundaravel, Balakrishnan; Chen, Huang-Chin; Lin, I-Nan; Lee, Chi-Young; Tai, Nyan-Hwa

2012-08-01

290

Oxygen and oil barrier properties of microfibrillated cellulose films and coatings  

Microsoft Academic Search

The preparation of carboxymethylated microfibrillated cellulose (MFC) films by dispersion-casting from aqueous dispersions\\u000a and by surface coating on base papers is described. The oxygen permeability of MFC films were studied at different relative\\u000a humidity (RH). At low RH (0%), the MFC films showed very low oxygen permeability as compared with films prepared from plasticized\\u000a starch, whey protein and arabinoxylan and

Christian Aulin; Mikael Gällstedt; Tom Lindström

2010-01-01

291

Pentek metal coating removal system: Baseline report; Summary  

SciTech Connect

The Pentek metal coating removal system consists of the ROTO-PEEN Scaler, CORNER-CUTTER(R), and VAC-PAC(R). The system is designed to remove coatings from steel, concrete, brick, and wood. The Scaler uses 3M ROTO-PEEN tungsten carbide cutters, while the CORNER-CUTTER(R) uses solid needles for descaling activities. These are used with the VAC-PAC(R) vacuum system to capture dust and debris as removal of the coating takes place. The safety and health evaluation during the testing demonstration focused on two main areas of exposure: dust and noise. Dust exposure was minimal, but noise exposure was significant. Further testing for each exposure is recommended, since the outdoor environment where the testing demonstration took place may skew the results. It is feasible that dust and noise levels will be higher in an enclosed operating environment. Other areas of concern found were arm-hand vibration, whole-body vibration, ergonomics, heat stress, tripping hazards, electrical hazards, machine guarding, and lockout/tagout.

NONE

1997-07-31

292

Insulator coating for high temperature alloys method for producing insulator coating for high temperature alloys  

DOEpatents

A method for fabricating an electrically insulating coating on a surface is disclosed comprising coating the surface with a metal, and reacting the metal coated surface with a nonmetal so as to create a film on the metal-coated surface. Alternatively, the invention provides for a method for producing a noncorrosive, electrically insulating coating on a surface saturated with a nonmetal comprising supplying a molten fluid, dissolving a metal in the molten fluid to create a mixture, and contacting the mixture with the saturated surface. Lastly, the invention provides an electrically insulative coating comprising an underlying structural substrate coated with an oxide or nitride compound. 2 figs.

Park, J.H.

1998-06-23

293

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

NASA Technical Reports Server (NTRS)

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

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

1995-01-01

294

Tamarindus indica pectin blend film composition for coating tablets with enhanced adhesive force strength.  

PubMed

Tablet coating is the most useful method to improve tablet texture, odour and mask taste. Thus, the present investigation was aimed at developing an industrially acceptable aqueous tablet coating material. The physico-chemical, electrical and SEM investigations ensures that blending of Tamarindus indica (Linn.) pectin (TP) with chitosan gives water resistant film texture. Therefore, CH-TP (60:40) spray coated tablets were prepared. The evaluation of CH-TP coated tablets showed enhanced adhesive force strength (between tablet surface to coat) and negligible cohesive force strength (between two tablets) both evaluated using texture analyzer. The comparison of CH-TP coated tablets with Eudragit coated tablets further supported superiority of the former material. Thus, the findings pointed towards the potential of CH-TP for use as a tablet coating material in food as well as pharmaceutical industry. PMID:24507255

Khurana, Rajneet; Singh, Kuldeep; Sapra, Bharti; Tiwary, A K; Rana, Vikas

2014-02-15

295

Metallic NEMS components fabricated from nanocomposite Al–Mo films  

Microsoft Academic Search

We have fabricated fully released nano-electro-mechanical system (NEMS) cantilevers of various geometries from metallic alloy nanocomposite films. At thicknesses of 4.3 and 20.0nm, these are the thinnest released metal cantilevers reported in the literature to date. Such device dimensions are very difficult to achieve using conventional metal films. We were able to overcome this limitation by using room-temperature co-sputtering to

Z Lee; C Ophus; L M Fischer; N Nelson-Fitzpatrick; K L Westra; S Evoy; V Radmilovic; U Dahmen; D Mitlin

2006-01-01

296

Evaluation of the film-coating properties of a hydroxyethyl cellulose/hydroxypropyl methylcellulose polymer system.  

PubMed

The effect of different grades of hydroxyethyl cellulose (HEC) and hydroxypropyl methllcellulose (HPMC) on the film-formation and taste-masking ability for ibuprofen granules was evaluated. Three batches of coated ibuprofen granules were prepared using a roto-granulator, each with a different coating composition. Two grades of HEC [MW300,000 (H) and MW90,000 (L)] were combined with three different grades of HPMC [MW 11,000 (L), MW 25,000 (M) and MW 35,000 (H)] to prepare the coating solutions. Mechanical strength and physical properties of the polymer films were evaluated. Films made from HPMC (L)/HEC (H), HPMC (M)/HEC (H), and HPMC (H)/HEC (H) were stronger and more flexible than the HPMC (L) HEC (L) films. The assay, dissolution, particle size distribution, and environmental scanning electron microscopy (ESEM) data of the three batches of the coated ibuprofen granules were similar. PMID:12056532

Li, Shun Por; Martellucci, Stephen A; Bruce, Richard D; Kinyon, Adam C; Hay, Michael B; Higgins, John D

2002-04-01

297

Evaluation of polyelectrolyte multilayer thin-film coated microneedle arrays for transcutaneous vaccine delivery  

E-print Network

The skin is an ideal organ for the safe and convenient delivery of vaccines, small molecules, and other biologics. Members of the Irvine and Hammond groups have developed a polyelectrolyte multilayer thin film-coated ...

Fung, Peter W. (Peter Waitak)

2011-01-01

298

Chemical vapor deposition thin films as biopassivation coatings and directly patternable dielectrics  

E-print Network

Organosilicon thin films deposited by pulsed plasma-enhanced chemical vapor deposition (PPECVD) and hot-filament chemical vapor deposition (HFCVD) were investigated as potential biopassivation coatings for neural probes. ...

Pryce Lewis, Hilton G. (Hilton Gavin), 1973-

2001-01-01

299

Polyelectrolyte multilayer-calcium phosphate composite coatings for metal implants.  

PubMed

The preparation of organic-inorganic composite coatings with the purpose to increase the bioactivity of bioinert metal implants was investigated. As substrates, glass plates and rough titanium surfaces (Ti-SLA) were employed. The method comprises the deposition of polyelectrolyte multilayers (PEMLs) followed by immersion of the coated substrate into a calcifying solution of low supersaturation (MCS). Single or mixed PEMLs were constructed from poly-L-lysine (PLL) alternating with poly-L-glutamate, (PGA), poly-L-aspartate (PAA), and/or chondroitin sulfate (CS). ATR-FTIR spectra reveal that (PLL/PGA)10 multilayers and mixed multilayers with a (PLL/PGA)5 base contain intermolecular ?-sheet structures, which are absent in pure (PLL/PAA)10 and (PLL/CS)10 assemblies. All PEML coatings had a grainy topography with aggregate sizes and size distributions increasing in the order: (PLL/PGA)n < (PLL/PAA)n < (PLL/CS)n. In mixed multilayers with a (PLL/PGA)n base and a (PLL/PAA)n or (PLL/CS)n top, the aggregate sizes were greatly reduced. The PEMLs promoted calcium phosphate nucleation and early crystal growth, the intensity of the effect depending on the composition of the terminal layer(s) of the polymer. In contrast, crystal morphology and structure depended on the supersaturation, pH, and ionic strength of the MCS, rather than on the composition of the organic matrix. Crystals grown on both uncoated and coated substrates were mostly platelets of calcium deficient carbonate apatite, with the Ca/P ratio depending on the precipitation conditions. PMID:25105729

Elyada, Alon; Garti, Nissim; Füredi-Milhofer, Helga

2014-10-13

300

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

NASA Astrophysics Data System (ADS)

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

Sinha, Sumona; Mukherjee, M.

2013-08-01

301

Amorphous metal formulations and structured coatings for corrosion and wear resistance  

DOEpatents

A system for coating a surface comprising providing a source of amorphous metal that contains more than 11 elements and applying the amorphous metal that contains more than 11 elements to the surface by a spray. Also a coating comprising a composite material made of amorphous metal that contains more than 11 elements. An apparatus for producing a corrosion-resistant amorphous-metal coating on a structure comprises a deposition chamber, a deposition source in the deposition chamber that produces a deposition spray, the deposition source containing a composite material made of amorphous metal that contains more than 11 elements, and a system that directs the deposition spray onto the structure.

Farmer, Joseph C.

2014-07-15

302

Influence of semiconducting properties of nanoparticle coating on the electrochemical actuation of liquid metal marble  

NASA Astrophysics Data System (ADS)

Semiconducting properties of nanoparticle coating on liquid metal marbles can present opportunities for an additional dimension of control on these soft objects with functional surfaces in aqueous environments. We show the unique differences in the electrochemical actuation mechanisms of liquid metal marbles with n- and p-type semiconducting nanomaterial coating. A systematic study on such liquid metal marbles shows voltage dependent nanoparticle cluster formation and morphological changes of the liquid metal core during electrochemical actuations and these observations are unique to p-type nanomaterial coated liquid metal marbles.

Sivan, Vijay; Tang, Shi-Yang; O'Mullane, Anthony P.; Petersen, Phred; Kalantar-zadeh, Kourosh; Khoshmanesh, Khashayar; Mitchell, Arnan

2014-09-01

303

Amorphous metal formulations and structured coatings for corrosion and wear resistance  

DOEpatents

A system for coating a surface comprising providing a source of amorphous metal that contains more than 11 elements and applying the amorphous metal that contains more than 11 elements to the surface by a spray. Also a coating comprising a composite material made of amorphous metal that contains more than 11 elements. An apparatus for producing a corrosion-resistant amorphous-metal coating on a structure comprises a deposition chamber, a deposition source in the deposition chamber that produces a deposition spray, the deposition source containing a composite material made of amorphous metal that contains more than 11 elements, and a system that directs the deposition spray onto the structure.

Farmer, Joseph C. (Tracy, CA)

2011-12-13

304

Tackiness of acrylic and cellulosic polymer films used in the coating of solid dosage forms  

Microsoft Academic Search

The objective was to determine the tackiness of acrylic and cellulosic polymer films in order to make predictions on the tackiness (agglomeration) of coated dosage forms during coating and curing. Force-displacement curves of the detachment process of two polymeric films were used as a measure of tackiness. Various polymers (cellulosic (Aquacoat®) and acrylics (Eudragit® RS 30D, L 30D, NE 30D)),

Martin Wesseling; Frank Kuppler; Roland Bodmeier

1999-01-01

305

Structure and Function of Protein-Based Edible Films and Coatings  

Microsoft Academic Search

\\u000a Research and development on films and coatings made from various agricultural proteins has been conducted over the past 20\\u000a years, but is of heightened interest, due to the demand for environmentally-friendly, renewable replacements for petroleum-based\\u000a polymeric materials and plastics. To address this demand, films and coatings have been made from renewable resources, such\\u000a as casein, whey, soy, corn zein, collagen,

Kirsten Dangaran; Peggy M. Tomasula; Phoebe Qi

306

Effect of the composition of film-forming solutions and the temperature and time regimes on the colorimetric characteristics of film coatings  

SciTech Connect

The calorimetric characteristics of film coatings obtained from iron-containing industrial waste are determined by instrumental methods. The relationship between the composition of the film-forming solution, the temperature and time regimes of treatment and the calorimetric characteristics of film coatings such as lightness, brightness, and intensity (purity) of hue is described.

Sytnik, R.D.; Kiuila, I.G.; Ignatyuk, O.A. [Kharkov State Polytechnical Univ., Kharkov (Ukraine)

1995-11-01

307

Effect of a dielectric coating on terahertz surface plasmon polaritons on metal wires  

E-print Network

Effect of a dielectric coating on terahertz surface plasmon polaritons on metal wires Nick C. J pulses propagate along the wire as surface waves, and show how a thin coating of a non We present measurements and calculations on the effect of thin dielec- tric coatings

308

Study of double layer rare earth metal conversion coating on aluminum alloy LY12  

Microsoft Academic Search

The process of the double layer rare earth metal (REM) conversion coating on aluminum alloy LY12 (2024) was introduced in this paper. The corrosion resistance of REM conversion coating was examined by electrochemical impedance spectroscopy. The results showed that the coating increased the corrosion resistance (Rp) of the alloy surface, thus reducing the driving force of corrosion. The morphologies of

Yu Xingwen; Cao Chunan; Yao Zhiming; Zhou Derui; Yin Zhongda

2001-01-01

309

The structure of ion plated films in relation to coating properties  

NASA Technical Reports Server (NTRS)

Ion plating is an ion assisted or glow discharge deposition technique, where ions or energetic atoms transfer energy, momentum and charge to the substrate and the growing film in a manner which can be controlled to favorably modify surface, subsurface chemistry, and microstructure. The glow discharge energizing effects from the initial nucleation stages to the final film growth are discussed. As a result, adherence, coherence, internal stresses, density and morphology of the coatings are significantly improved, over the conventional (nonion-assisted) techniques which in turn favorably affect the surface initiated failures caused by friction, wear, erosion, corrosion and fatigue. Ion plated films because of their graded coating/substrate interface, fine, uniform, densely packed film structure also induce a surface strengthening effect which improved the mechanical properties such as yield, tensile strength and fatigue life. Since a uniform, continuous film can be obtained at lower nominal film thickness, this effect is of great importance in solid film lubrication and in corrosion protection.

Spalvins, T.

1985-01-01

310

Stabilized chromium oxide film  

Microsoft Academic Search

This patent describes a coated ceramic RF window and metal sleeve of a klystron comprising a stabilized chromium oxide film less than 200 angstroms thick deposited on a ceramic RF window and metal sleeve.

E. L. Garwin; A. R. Nyaiesh

1988-01-01

311

Cutting performance increasing in gear hobbing by means of HSS hobs, coated with effective PVD films  

Microsoft Academic Search

Coated tools experience a rapid development due to the increased demands towards cutting performance improvement and production cost diminishing. In order to meet corresponding requirements in gear manufacturing, impressive developments, among others, in the area of coating technology, have been realized. In order to investigate the effectiveness of various innovative PVD films, fly hobbing wear experiments in individual generating positions

K.-D. Bouzakis; S. Kombogiannis; O. Friderikos; J. Anastopoulos

312

Spin-coating deposition of PbS and CdS thin films for solar cell application  

NASA Astrophysics Data System (ADS)

In this work, we describe a simple spin-coating deposition technique for lead sulphide (PbS) and cadmium sulphide (CdS) films from a methanolic metal-thiourea complex. The characterization of the films by X-ray diffraction and X-ray photoelectron spectroscopy techniques revealed that pure cubic phase PbS and CdS layers were formed via this method. As shown by atomic force microscopy and scanning electron microscopy results, both films were homogeneous and presented a smooth surface. Optical properties showed that the energy band gap of PbS and CdS films were around 1.65 and 2.5 eV, respectively. The PbS film is p-type in nature with an electrical conductivity of around 0.8 S/cm. The hole concentration and mobility were 2.35 × 1018 cm-3 and 2.16 × 10-3 cm2/V/s, respectively, as determined from Hall measurement. Both films were used to develop a thin film solar cell device of graphite/PbS/CdS/ITO/glass. Device characterization showed the power conversion efficiency of around 0.24 %. The corresponding open circuit voltage, short circuit current and fill factor were 0.570 V, 1.32 mA/cm2 and 0.32, respectively.

Patel, Jayesh; Mighri, Frej; Ajji, Abdellah; Tiwari, Devendra; Chaudhuri, Tapas K.

2014-12-01

313

Bioequivalence study of 400 and 100 mg imatinib film-coated tablets in healthy volunteers.  

PubMed

The aim of the study was to investigate the bioavailability of a generic product of 100 mg and 400 mg imatinib film-coated tablets (test) as compared to that of a branded product (reference) at the same strength to determine bioequivalence. The secondary objective of the study was to evaluate tolerability of both products. An open-label, randomized, crossover, two-period, single-dose, comparative study was conducted in 43 (Imatynib-Biofarm 100 mg film-coated tablet) and in 42 (Imatynib-Biofarm 400 mg film-coated tablet), brand name Imatenil, Caucasian healthy volunteers in fed conditions. A single oral dose administration of the test or reference product was separated by 14-day washout period. The imatinib and its metabolite N-desmethyl imatinib concentrations were determined using a validated LC MS/MS method. The results of the single-dose study in healthy volunteers indicated that the film-coated tablets of Imatynib-Biofarm 100 mg and 400 mg film-coated tablets manufactured by Biofarm Sp. z o.o. (test products) are bioequivalent to those of Glivec 100 mg and 400 mg film-coated tablets manufactured by Novartis Pharma GmbH (reference products). Both products in the two doses of imatinib were well tolerated. PMID:25362813

Ostrowicz, Andrzej; Miko?ajczak, Przemys?aw L; Wierzbicka, Marzena; Boguradzki, Piotr

2014-01-01

314

Mixed polyvalent-monovalent metal coating for carbon-graphite fibers  

NASA Technical Reports Server (NTRS)

An improved coating of gasification catalyst for carbon-graphite fibers is provided comprising a mixture of a polyvalent metal such as calcium and a monovalent metal such as lithium. The addition of lithium provides a lighter coating and a more flexible coating when applied to a coating of a carboxyl containing resin such as polyacrylic acid since it reduces the crosslink density. Furthermore, the presence of lithium provides a glass-like substance during combustion which holds the fiber together resulting in slow, even combustion with much reduced evolution of conductive fragments. The coated fibers are utilized as fiber reinforcement for composites.

Harper-Tervet, J.; Tervet, F. W.; Humphrey, M. F. (inventors)

1982-01-01

315

New synthetic routes to metal boride thin films and metallaboranes  

SciTech Connect

This dissertation describes the investigation of chemical vapor deposition of metal/metal boride thin films of transition and rare earth elements from metal halides and boron hydride precursors. Also reported are thermal routes to synthesis of new metallaborane complexes. An approach to the chemical vapor deposition of metal/metal boride thin films of the first row transition elements has been developed. Metal/metal boride thin films of scandium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, and copper were prepared using metal halides, pentaborane (9) and decaborane (14) precursors. Mixed metal films were also deposited containing Fe-Co-B and Cu-Ni-B. The metal boride films were characterized by scanning electron microscopy (SEM), X-ray thin film diffraction (XRD), transmission electron diffraction (TED), atomic absorption spectrophotometry (AA), auger electron spectroscopy (AES), X-ray emission spectrometry (XES), Laser microprobe mass analysis (LAMMA), glow discharge mass spectrometry (GDMS) and elemental analysis. The chemical vapor deposition of rare earth boride films is presented. Thin films of LaB[sub 6], GdB[sub 6], and NdB[sub 6] were deposited from the corresponding metal chlorides, pentaborane(9) and decaborane(14) precursors. The rare earth boride films possessed unusual microstructures. Mixed metal films containing Co-Nd-B were also prepared. The films were characterized by scanning electron microscopy, X-ray thin film diffraction, reflection high energy electron diffraction, energy dispersive and wavelength dispersive X-ray emission spectrometry and glow discharge mass spectrometry. The reactions of the metal halide thermal dissociation species and neutral pentaborane(9) are described. [mu]-2,3,2',3'-Fe(B[sub 5]H[sub 8])[sub 2], 1, and [mu]-2,3,2',3'-Ti(B[sub 5]H[sub 8])[sub 2] 2, were synthesized. A thermal reaction of NiCl[sub 2] and B[sub 5]H[sub 9] produced compound 3 proposed as B[sub 10]H[sub 8]Ni[sub 2]Cl[sub 2].

Kher, S.S.

1993-01-01

316

In situ forming, metal-adhesive heparin hydrogel surfaces for blood-compatible coating.  

PubMed

Durable and blood-compatible coating of metallic biomaterials remains a major issue in biomedical fields despite its long history of development. In this study, in situ forming, metal-adhesive heparin hydrogels were developed to coat metallic substrates to enhance blood compatibility. The hydrogels are composed of metal-adhesive and enzyme-reactive amphiphilic block copolymer (Tetronic-tyramine/dopamine; TTD) and enzyme-reactive heparin derivatives (heparin-tyramine or heparin-polyethylene glycol-tyramine), which are cross-linkable in situ via an enzyme reaction. The combinations of heparin and Tetronic formed hydrogels with relatively high mechanical strengths of 300-5000 Pa within several tens of seconds; this was also confirmed by observing a dried porous structure as coated on a metal surface. The introduction of dopamine to the hydrogel network enhanced the durability of the hydrogel layers coated on metal, such that more than 60% heparin remained for 7 days. Compared to bare metal surfaces, hydrogel-coated metal surfaces exhibited significantly enhanced blood compatibility. Reduced fibrinogen adsorption and platelet adhesion showed that blood compatibility was 3-5-fold-enhanced on coated hydrogel layers than on the bare metal surface. In conclusion, hydrogels containing heparin and dopamine prepared by enzyme reaction have the potential to be an alternative coating method for enhancing blood compatibility of metallic biomaterials. PMID:22100384

Joung, Yoon Ki; You, Seung Soo; Park, Kyung Min; Go, Dong Hyun; Park, Ki Dong

2012-11-01

317

Refractory amorphous metallic (W/0.6/ Re/0.4/)76B24 coatings on steel substrates  

NASA Technical Reports Server (NTRS)

Refractory metallic coatings of (W/0.6/ Re/0.4/)76B24 (WReB) have been deposited onto glass, quartz, and heat-treated AISI 52100 bearing steel substrates by dc magnetron sputtering. As-deposited WReB films are amorphous, as shown by their diffuse X-ray diffraction patterns; chemically homogeneous, according to secondary ion mass spectrometry (SIMS) analysis; and they exhibit a very high (approximately 1000 C) crystallization temperature. Adhesion strength of these coatings on heat-treated AISI 52100 steel is in excess of approximately 20,000 psi and they possess high microhardness (approximately 2400 HV50). Unlubricated wear resistance of such hard and adherent amorphous metallic coatings on AISI 52100 steel is studied using the pin-on-disc method under various loading conditions. Amorphous metallic WReB coatings, about 4 microns thick, exhibit an improvement of more than two and a half orders of magnitude in the unlubricated wear resistance over that of the uncoated AISI 52100 steel.

Thakoor, A. P.; Lamb, J. L.; Khanna, S. K.; Mehra, M.; Johnson, W. L.

1985-01-01

318

Thermoelastic response of thin metal films and their adjacent materials  

SciTech Connect

A pulsed laser beam applied to a thin metal film is capable of launching an acoustic wave due to thermal expansion. Heat transfer from the thin metal film to adjacent materials can also induce thermal expansion; thus, the properties of these adjacent materials (as well as the thin metal film) should be considered for a complete description of the thermoelastic response. Here, we show that adjacent materials with a small specific heat and large thermal expansion coefficient can generate an enhanced acoustic wave and we demonstrate a three-fold increase in the peak pressure of the generated acoustic wave on substitution of parylene for polydimethylsiloxane.

Kang, S.; Yoon, Y.; Kim, J.; Kim, W. [Samsung Electronics Co., Yongin-Si, 446-712 Gyeonggi-do (Korea, Republic of)] [Samsung Electronics Co., Yongin-Si, 446-712 Gyeonggi-do (Korea, Republic of)

2013-01-14

319

METAL-MATRIX COMPOSITES AND THERMAL SPRAY COATINGS FOR EARTH MOVING MACHINES  

SciTech Connect

In the 11th quarter, further testing was performed on thermal spray coatings. A component coated and fused in the 9th quarter underwent high-stress abrasive wear testing. The test successfully showed this coating could survive in a high stress, sliding wear environment as the base layer in an FGM design coating. Work on the ferrous metal-matrix composites was completed in previous quarter and therefore no update is provided.

D. Trent Weaver; Matthew T. Kiser

2003-10-01

320

METAL-MATRIX COMPOSITES AND THERMAL SPRAY COATINGS FOR EARTH MOVING MACHINES  

Microsoft Academic Search

In the 11th quarter, further testing was performed on thermal spray coatings. A component coated and fused in the 9th quarter underwent high-stress abrasive wear testing. The test successfully showed this coating could survive in a high stress, sliding wear environment as the base layer in an FGM design coating. Work on the ferrous metal-matrix composites was completed in previous

D. Trent Weaver; Matthew T. Kiser

2003-01-01

321

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

NASA Astrophysics Data System (ADS)

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.

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

2012-06-01

322

Hierarchical opal grating films prepared by slide coating of colloidal dispersions in binary liquid media.  

PubMed

There are active researches on well ordered opal films due to their possible applications to various photonic devices. A recently developed slide coating method is capable of rapid fabrication of large area opal films from aqueous colloidal dispersion. In the current study, the slide coating of polystyrene colloidal dispersions in water/i-propanol (IPA) binary media is investigated. Under high IPA content in a dispersing medium, resulting opal film showed a deterioration of long range order, as well as a decreased film thickness due to dilution effect. From the binary liquid, the dried opal films exhibited the unprecedented topological groove patterns with varying periodic distances as a function of alcohol contents in the media. The groove patterns were consisted of the hierarchical structures of the terraced opal layers with periodic thickness variations. The origin of the groove patterns was attributed to a shear-induced periodic instability of colloidal concentration within a thin channel during the coating process which was directly converted to a groove patterns in a resulting opal film due to rapid evaporation of liquid. The groove periods of opal films were in the range of 50-500 ?m, and the thickness differences between peak and valley of the groove were significantly large enough to be optically distinguishable, such that the coated films can be utilized as the optical grating film to disperse infra-red light. Utilizing a lowered hydrophilicity of water/IPA dispersant, an opal film could be successfully coated on a flexible Mylar film without significant dewetting problem. PMID:25460710

Lee, Wonmok; Kim, Seulgi; Kim, Seulki; Kim, Jin-Ho; Lee, Hyunjung

2015-02-15

323

ZnS films for infrared optical coatings: improvement of adhesion to Ge substrates  

NASA Astrophysics Data System (ADS)

In this work, physical and optical properties of ZnS films grown at different evaporation conditions have been studied. ZnS 3000 nm thick films have been deposited on Ge substrates at 200°C, 120°C and without substrate heating. In addition, evaporation rates of 4, 2 and 1 nm/s have been considered. The structural and morphological properties of the films have been analysed by XRD and AFM, respectively and the refractive index in the 2.4-11.5 microns range has been determined from transmittance spectra through reverse synthesis. From this analysis, the most suitable evaporation conditions for ZnS thin films deposition have been defined in terms of film properties and intended applications on thermal IR multilayer coatings. Afterwards, adhesion properties of ZnS films deposited under the optimised conditions have been analysed. ZnS films deposited at 120°C and 4 nm/s peeled off when subjected to MIL-F-48616 standard surface durability testing. The use of a MgO bonding layer to enhance the ZnS film adherence to the substrate has been proposed and its effect on the ZnS film properties has been studied. Finally, the mechanical stability of the ZnS coating under MIL-F-48616 standard testing has been confirmed for films grown onto MgO coated substrates.

Sánchez-Agudo, M.; Génova, I.; Orr, H. J. B.; Harris, G.; Pérez, G.

2008-09-01

324

Surface chemistry of coated lithium manganese nickel oxide thin film cathodes studied by XPS  

SciTech Connect

The effect of coating high voltage LiMn1.5Ni0.5O4 spinel cathode thin films with three metal oxide thin layers is discussed. The changes in surface chemistry of the electrodes are measured by X-ray photoelectron spectroscopy. ZnO is found to decompose during the first charge whereas Al2O3 and ZrO2 are stable for more than 100 cycles. ZrO2, however, importantly limits the available Li storage capacity of the electrochemical reaction due to poorer kinetics. Al2O3 offers the best results in term of capacity retention. Upon cycling, the evidence of a signal at 75.4 eV in the Al2p binding energy spectrum indicates the partial conversion of Al2O3 into Al2O2F2. Moreover, the continuous formation of PEO , esters and LixPOyFz compounds on the surface of the electrodes is found for all coating materials.

Baggetto, Loic [ORNL] [ORNL; Dudney, Nancy J [ORNL] [ORNL; Veith, Gabriel M [ORNL] [ORNL

2013-01-01

325

Metal Matrix Composite Coatings Manufactured by Thermal Spraying: Influence of the Powder Preparation on the Coating Properties  

NASA Astrophysics Data System (ADS)

The purpose of this study is to manufacture metal matrix composite coatings by thermal spraying. In order to improve coating's mechanical properties, it is necessary to increase homogeneity. To meet this objective, the chosen approach was to optimize the powder morphology by mechanical alloying. Indeed, the mechanical alloying method (ball milling) was implemented to synthesize NiCr-Cr3C2 and NiCrBSi-WC composite powders by using cold spraying and high-velocity oxygen fuel process, respectively. After optimizing the process parameters on powder grain size, the composite coatings were compared with standard coatings manufactured from mixed powders. SEM observations, hardness measurements, and XRD analyses were the first technologies implemented to characterize the metal matrix composite coatings. Different characteristics were then observed. When mechanical alloying process is employed to synthesize composite powders strengthened by particle dispersion, the powders tend to fracture into small segments, especially when high content of hard particles is added. Powder microstructures were then refined, which induced thinner coating morphologies and reduced porosity rate. Once an improved microstructure is obtained, manufacturing of coating using milled powders was found suitable in comparison with coatings manufactured only with mixed powders.

Aussavy, D.; Costil, S.; El Kedim, O.; Montavon, G.; Bonnot, A.-F.

2014-01-01

326

Magnetic sensor based on side-polished fiber Bragg grating coated with iron film  

Microsoft Academic Search

A novel optical fiber magnetic sensor based on a side-polished fiber Bragg grating (FBG) coated with thin iron film was investigated. The sensor consists of a side-polished 10 mm FBG and two-layer thin iron films deposited on an interaction section 20 mum in diameter.

C. Tien; C. Hung; H. Chen; W. Liu; S. Lin

2006-01-01

327

Effect of flame spray coating on falling film evaporation for multi effect distillation system  

Microsoft Academic Search

Horizontal tube falling film evaporators find various applications like multi effect distillation for sea water desalination, power and process applications, refrigeration applications, etc. In this system, latent heat released inside the tube due to condensation is transferred to the falling film on the tube surface resulting in convective evaporation. Among many heat transfer enhancement techniques, thermal spray coatings enjoy diverse

Raju Abraham; A. Mani

2012-01-01

328

Pulsed laser deposition of YBCO films on ISD MgO buffered metal tapes  

NASA Astrophysics Data System (ADS)

Biaxially textured magnesium oxide (MgO) films deposited by inclined-substrate deposition (ISD) are desirable for rapid production of high-quality template layers for YBCO-coated conductors. High-quality YBCO films were grown on ISD MgO buffered metallic substrates by pulsed laser deposition (PLD). Columnar grains with a roof-tile surface structure were observed in the ISD MgO films. X-ray pole figure analysis revealed that the (002) planes of the ISD MgO films are tilted at an angle from the substrate normal. A small full-width at half maximum (FWHM) of approx9° was observed in the phi-scan for ISD MgO films deposited at an inclination angle of 55°. In-plane texture in the ISD MgO films developed in the first approx0.5 mum from the substrate surface, and then stabilized with further increases in film thickness. Yttria-stabilized zirconia and ceria buffer layers were deposited on the ISD MgO grown on metallic substrates prior to the deposition of YBCO by PLD. YBCO films with the c-axis parallel to the substrate normal have a unique orientation relationship with the ISD MgO films. An orientation relationship of YBCOlangle100rangleparallelMgOlangle111rangle and YBCOlangle010rangleparallelMgOlangle110rangle was measured by x-ray pole figure analyses and confirmed by transmission electron microscopy. A Tc of 91 K with a sharp transition and transport Jc of 5.5 × 105 A cm-2 at 77 K in self-field were measured on a YBCO film that was 0.46 mum thick, 4 mm wide and 10 mm long.

Ma, B.; Li, M.; Koritala, R. E.; Fisher, B. L.; Markowitz, A. R.; Erck, R. A.; Baurceanu, R.; Dorris, S. E.; Miller, D. J.; Balachandran, U.

2003-04-01

329

Application of the Scanning Kelvin Probe for the study of the corrosion resistance of interfacial thin organosilane films at adhesive\\/metal interfaces  

Microsoft Academic Search

The Scanning Kelvin Probe is introduced as a real time non-destructive in situ technique for the detection of de-adhesion at adhesive\\/metal oxide interfaces. Iron substrates and an epoxy adhesive served as model systems. Iron surfaces were coated with ultra-thin organosilane plasma polymer films from a microwave discharge and 3-(trimethoxysilyl)-propylamine films from dilute water based solutions. Surface and film characterisation was

K. Wapner; M. Stratmann; G. Grundmeier

2005-01-01

330

Young's Moduli of Cold and Vacuum Plasma Sprayed Metallic Coatings  

NASA Technical Reports Server (NTRS)

Monolithic metallic copper alloy and NiCrAlY coatings were fabricated by either the cold spray (CS) or the vacuum plasma spray (VPS) deposition processes. Dynamic elastic modulus property measurements were conducted on these monolithic coating specimens between 300 K and 1273 K using the impulse excitation technique. The Young's moduli decreased almost linearly with increasing temperature at all temperatures except in the case of the CS Cu-23%Cr-5%Al and VPS NiCrAlY, where deviations from linearity were observed above a critical temperature. It was observed that the Young's moduli for VPS Cu-8%Cr were larger than literature data compiled for Cu. The addition of 1%Al to Cu- 8%Cr significantly increased its Young's modulus by 12 to 17% presumably due to a solid solution effect. Comparisons of the Young s moduli data between two different measurements on the same CS Cu- 23%Cr-5%Al specimen revealed that the values measured in the first run were about 10% higher than those in the second run. It is suggested that this observation is due to annealing of the initial cold work microstructure resulting form the cold spray deposition process.

Raj, S. V.; Pawlik, R.; Loewenthal, W.

2009-01-01

331

Recent status of chemical bath deposited metal chalcogenide and metal oxide thin films  

Microsoft Academic Search

Presently nanocrystalline materials have opened a new chapter in the field of electronic applications, since material properties could be changed by changing the crystallite size and\\/or thickness of the film. The synthesis of nanocrystalline metal chalcogenide and metal oxide thin films by chemical bath deposition (CBD) method is currently attracting considerable attention as it is relatively inexpensive, simple and convenient

S. M. Pawar; B. S. Pawar; J. H. Kim; Oh-Shim Joo; C. D. Lokhande

2011-01-01

332

Plasma-Etching of Spray-Coated Single-Walled Carbon Nanotube Films for Biointerfaces  

NASA Astrophysics Data System (ADS)

We present an effective method for the batch fabrication of miniaturized single-walled carbon nanotube (SWCNT) film electrodes using oxygen plasma etching. We adopted the approach of spray-coating for good adhesion of the SWCNT film onto a pre-patterned Pt support and used O2 plasma patterning of the coated films to realize efficient biointerfaces between SWCNT surfaces and biomolecules. By these approaches, the SWCNT film can be easily integrated into miniaturized electrode systems. To demonstrate the effectiveness of plasma-etched SWCNT film electrodes as biointerfaces, Legionella antibody was selected as analysis model owing to its considerable importance to electrochemical biosensors and was detected using plasma-etched SWCNT film electrodes and a 3,3',5,5'-tetramethyl-benzidine dihydrochloride/horseradish peroxidase (TMB/HRP) catalytic system. The response currents increased with increasing concentration of Legionella antibody. This result indicates that antibodies were effectively immobilized on plasma-etched and activated SWCNT surfaces.

Hyub Kim, Joon; Lee, Jun-Yong; Min, Nam Ki

2012-08-01

333

Surfactant-induced rigidity of interfaces: a unified approach to free and dip-coated films  

E-print Network

The behavior of thin liquid films is known to be strongly affected by the presence of surfactants at the interfaces. The detailed mechanism by which the latter enhance film stability is still a matter of debate, in particular concerning the influence of surface elastic effects on the hydrodynamic boundary condition at the liquid/air interfaces. In the present work, "twin" hydrodynamic models neglecting surfactant transport to the interfaces are proposed to describe the coating of films onto a solid plate (Landau-Levich-Derjaguin configuration) as well as soap film pulling (Frankel configuration). Experimental data on the entrained film thickness in both configurations can be fitted very well using a single value of the surface elasticity, which is in good agreement with independent measurements by mean of surface expansion experiments in a Langmuir through. The analysis shows how and when the soap films or dip coating experiments may be used to precisely and sensitively measure the surface elasticity of surfactant solutions.

Lorène Champougny; Benoit Scheid; Frédéric Restagno; Jan Vermant; Emmanuelle Rio

2014-02-19

334

Evenly Distributed Thin-Film Ag Coating on Stainless Plate by Tricomponent Ag/Silicate/PU with Antimicrobial and Biocompatible Properties.  

PubMed

A tricomponent nanohybrid dispersion in water comprising silver nanoparticles (AgNP), nanometer-thick silicate platelets (NSP), and water-based polyurethane (PU) was developed for surface coating on orthopedic metal plates. The previously developed AgNP-on-NSP nanohybrid was homogeneously blended into a selected waterborne PU dispersion at varied weight ratios from 1/0.1 to 1/10 (w/w). PU was used to adhere the Ag nanohybrid to the metal surface. The resultant dispersions were analyzed and found to contain AgNP 2-18 nm in diameter and characterized by using UV absorption and TEM micrograph. The subsequent coating of AgNP/NSP-PU dispersion generated a film of 1.5 ?m thickness on the metal plate surface, further characterized by an energy dispersive spectroscope (EDS) to show the homogeneous distribution of Ag, Si, and C elements on the metal plates. The surface antimicrobial efficacy was proven for the coating composition of AgNP/NSP to PU ranging from 1/1 to 1/5 by weight ratio but irrelevant to the thickness of the coated materials. The metal plate coated with the high Ag content at 1/1 (w/w) ratio was shown to have very low cytotoxicity toward the contacted mammal fibroblasts. Overall, the optimized tricomponent Ag/silicate/PU in water dispersion from 1/2 to 1/3 (w/w) could generate a stable film on a metal surface exhibiting both antimicrobial and biocompatible properties. The facile coating technique of the AgNP/NSP in waterborne PU is proven to be viable for fabricating infection- and cytotoxicity-free medical devices. PMID:25307230

Huang, Yi-Hsiu; Chen, Mark Hung-Chih; Lee, Bing-Heng; Hsieh, Kuo-Huang; Tu, Yuan-Kun; Lin, Jiang-Jen; Chang, Chih-Hao

2014-11-26

335

Development of technique for AR coating and nickel and copper metallization of solar cells. FPS Project: Product development  

NASA Technical Reports Server (NTRS)

Printed nickel overplated with copper and applied on top of a predeposited silicon nitride antireflective coating system for metallizing solar cells was analyzed. The ESL D and E paste formulations, and the new formulations F, G, H, and D-1 were evaluated. The nickel thick films were tested after firing for stability in the cleaning and plating solutions used in the Vanguard-Pacific brush plating process. It was found that the films are very sensitive to the leaning and alkaline copper solutions. Less sensitivity was displayed to the neutral copper solution. Microscopic and SEM observations show segregation of frit at the silicon nitride thick film interface with loose frit residues after lifting off plated grid lines.

Taylor, W.

1982-01-01

336

Green Thin Polymer Film Metallization using Supercritical Carbon Dioxide  

SciTech Connect

It is shown that low-density polymer layers created by supercritical carbon dioxide (scCO{sub 2}) processing can be exploited to enhance metallization of thin polymer films. Spun-cast thin films were exposed to scCO{sub 2} within the narrow temperature and pressure regime known as the 'density fluctuation ridge', where excess swelling of the polymer thin films was induced, and the swollen structures could be subsequently preserved by quick evaporation of CO{sub 2}. X-ray reflectivity (XR) measurements proved that the 'expanded' films had a broader interfacial width between the polymer and deposited metal layers, regardless of the polymer film thickness or choice of polymers. Furthermore, standard peel test showed a drastic enhancement in adhesion between the polymer and metal layers, which correlates with the XR result: the broader interfacial width indicates increased adhesion.

Koga,T.; Kugler, B.; Loewenstein, J.; Jermone, J.; Rafailovich, M.

2007-01-01

337

Biodegradability of regenerated cellulose films coated with polyurethane/natural polymers interpenetrating polymer networks  

SciTech Connect

Interpenetrating polymer network (IPN) coatings synthesized from castor-oil-based polyurethane (PU) with chitosan, nitrocellulose, or elaeostearin were coated on regenerated cellulose (RC) film for curing at 80--100 C for 2--5 min, providing biodegradable, water-resistant cellulose films coded, respectively, as RCCH, RCNC, and RCEs. The coated films were buried in natural soil for decaying and inoculated with a spore suspension of fungi on the agar medium, respectively, to test biodegradability. The viscosity-average molecular weight, M{sub {eta}}, and the weight of the degraded films decreased sharply with the progress of degradation. The degradation half-lifes, t{sub 1/2}, of the films in soil at 30 C were found to be 19 days for RC, 25 days for RCNC, 32 days for RCCH, and 45 days for the RCEs films. Scanning electron microscopy (SEM) showed that the extent of decay followed in the order RC {gt} RCNC {gt} RCCH {gt} RCEs. SEM, infrared (IR), high-performance liquid chromatography (HPLC), and CO{sub 2} evolution results indicated that the microorganisms directly attacked the water-resistant coating layer and then penetrated into the cellulose to speedily metabolize, while accompanying with producing CO{sub 2}, H{sub 2}O, glucose cleaved from cellulose, and small molecules decomposed from the coatings.

Zhang, L.; Zhou, J.; Huang, J.; Gong, P. Zhou, Q.; Zheng, L.; Du, Y.

1999-11-01

338

Delivery of Food Additives and Antimicrobials Using Edible Films and Coatings  

Microsoft Academic Search

\\u000a Functional efficiency of edible films and coatings strongly depends on the nature of film components and physical structure.\\u000a Choice of a film-forming substance and\\/or active additive depends on the desired objective, nature of the food product, and\\u000a specific application. Thus, lipids or hydrophobic substances such as resins, waxes or some insoluble proteins are most efficient\\u000a for retarding moisture transfer. On

Jesus-Alberto Quezada-Gallo

339

Imprint Behavior of Piezoelectric PZT Thin Films Deposited onto Cu-Coated Polymer Substrates  

Microsoft Academic Search

In this work, we investigate the imprint behavior of lead-rich Pb(Zr, Ti)O3 (PZT) thin films deposited onto copper-coated Kapton® substrates by piezoresponse force microscopy. As-deposited films, consisting of a mixture of PZT and lead and zirconium oxides, had a strongly imprinted polarization state with a polarization vector pointing toward the film surface. Above a threshold field of about 10 V\\/?m,

G. Suchaneck; Z. Hubi?ka; M. ?ada; D. A. Kiselev; I. Bdikin; A. A. Levin; L. Jastrabík; A. L. Kholkin; G. Gerlach; A. Dejneka

2011-01-01

340

Conductive metal oxide film and method of making  

DOEpatents

The present invention is a method for reducing a dopant in a film of a metal oxide wherein the dopant is reduced and the first metal oxide is substantially not reduced. The method of the present invention relies upon exposing the film to reducing conditions for a predetermined time and reducing a valence of the metal from a positive valence to a zero valence and maintaining atoms with a zero valence in an atomic configuration within the lattice structure of the metal oxide. According to the present invention, exposure to reducing conditions may be achieved electrochemically or achieved in an elevated temperature gas phase.

Windisch, Jr., Charles F. (Kennewick, WA); Exarhos, Gregory J. (Richland, WA)

1999-01-01

341

Film condensation of liquid metals -- precision of measurement  

E-print Network

Major differences exist in results published by investigators of film condensation of liquid metal vapors. In particular, the reported dependence of the condensation coefficient on pressure has raised questions about both ...

Wilcox, Stanley James

1969-01-01

342

Relationship between microindentation response and film composition and microstructure for some novel amorphous alloy coatings  

SciTech Connect

A number of amorphous alloy coatings have been deposited onto Ni substrates by decomposing metal carbonyls (Ni(CO)/sub 4/ and Fe(CO)/sub 5/) and metalloid hydrides (PH/sub 3/ and B/sub 2/H/sub 6/) by using a combination of heat (chemical vapor deposition) and high-energy electron and ion bombardment (radio frequency plasma deposition). The chemical composition of these films has been determined using Auger electron spectroscopy and the hybridization (i.e., bonding character) of the metalloids (phosphorus, boron and carbon) has been evaluated by using Auger lineshape analysis. The amorphous/crystalline nature of these alloys has been evaluated by using x-ray and electron diffraction techniques. The microindentation load-depth response of these films has been measured with an ultra-low-load hardness tester capable of testing at loads less than 10 grams and at penetration depths less than 1 micrometer. The results of these measurements are discussed in the light of theories which attempt to relate mechanical properties of amorphous alloys to the bonding character of the outer electrons of the component elements. 14 refs., 6 figs., 1 tab.

Bourcier, R.J.; Nelson, G.C.; Hays, A.K.; Romig, A.D. Jr.

1986-01-01

343

Effect of film composition and microstructure on microindentation response in amorphous alloy coatings  

SciTech Connect

Amorphous alloy coatings were deposited onto Ni substrates by decomposing metal carbonyls (Ni(CO)/sub 4/ and Fe(CO)/sub 5/) and metalloid hydrides (PH/sub 3/ and B/sub 2/H/sub 6/) by chemical vapor deposition in an rf plasma. The chemical composition of these films was determined using Auger electron spectroscopy and the hybridization (i.e., bonding character) of the metalloids (phosphorus, boron, and carbon) has been evaluated by using Auger line-shape analysis. The amorphous/crystalline nature of these alloys was evaluated using x-ray and electron diffraction techniques. The microindentation load-depth response of these films was measured with an ultralow-load hardness tester capable of testing at loads less than 10 g and at penetration depths less than 1 ..mu..m. The results of these measurements are discussed in the light of theories which attempt to relate mechanical properties of amorphous alloys to the bonding character of the outer electrons of the component elements.

Bourcier, R.J.; Nelson, G.C.; Hays, A.K.; Romig A.D. Jr.

1986-11-01

344

Effects of a ceramic coating on metal temperatures of an air-cooled turbine vane  

NASA Astrophysics Data System (ADS)

The metal temperatures of air cooled turbine vanes both uncoated and coated with the NASA thermal barrier system were studied experimentally. Current and advanced gas turbine engine conditions were simulated at reduced temperatures and pressures. Airfoil metal temperatures were significantly reduced, both locally and on the average, by use of the the coating. However, at low gas Reynolds number, the ceramic coating tripped a laminar boundary layer on the suction surface, and the resulting higher heat flux increased the metal temperatures. Simulated coating loss was also investigated and shown to increase local metal temperatures. However, the metal temperatures in the leading edge region remained below those of the uncoated vane tested at similar conditions. Metal temperatures in the trailing edge region exceeded those of the uncoated vane.

Gladden, H. J.; Liebert, C. H.

1980-02-01

345

Spintronics in metal–insulator nanogranular magnetic thin films  

Microsoft Academic Search

Magnetic and electrical properties of metal–insulator nanogranular thin films are overviewed, from the spintronics point of view, by presenting our recent results. (1) The metal-rich ferromagnetic ones possess ultrahigh-frequency (MHz–GHz) permeabilities ??, ??, mainly owing to large induced magnetic anisotropy field Hk. They are useful for various magnetic devices, such as thin-film inductors and noise suppressors. (2) The insulator-rich superpramagnetic

Hiroyasu Fujimori; Shigehiro Ohnuma; Nobukiyo Kobayashi; Tsuyosi Masumoto

2006-01-01

346

Method of synthesizing metal doped diamond-like carbon films  

NASA Technical Reports Server (NTRS)

A method of synthesizing metal doped carbon films by placing a substrate in a chamber with a selected amount of a metalorganic compound. An electron cyclotron resonance is applied to the chamber in order to vaporize the metalorganic compound. The resonance is applied to the chamber until a metal doped carbon film is formed. The metalorganic compound is preferably selected from the group consisting of an organic salt of ruthenium, palladium, gold or platinum.

Ueno, Mayumi (Inventor); Sunkara, Mahendra Kumar (Inventor)

2003-01-01

347

Development of metal-coated ceramic anodes for molten carbonate fuel cells  

SciTech Connect

This report documents the developmental efforts on metal coating of various ceramic substrates (LiAlO{sub 2}, SrTiO{sub 3}, and LiFeO{sub 2}) and the critical issues associated with fabricating anodes using metal-coated LiAlO{sub 2} substrates. Electroless Ni and Cu coating technology was developed to achieve complete metal coverage on LiAlO{sub 2} powder substrates. Metal coated SrTiO{sub 3} powders were fabricated into anodes by a process identical to that reported in the GE literature. Microstructural examination revealed that the grains of the ceramic had fused together, with the metal having dewetted from the surface of the ceramic. Alternate substrates that might allow for better wetting of the metal on the ceramic such as LiFeO{sub 2} and Li{sub 2}MnO{sub 3} were identified. Cu/Ni-coated (50:50 mol ratio, 50 w/o metal loading) LiFeO{sub 2} anodes were optimized to meet the MCFC anode specifications. Metal-coated gamma-LiAlO{sub 2} substrates were also developed. By using suitable chemical surface modification methods, the gamma-UAlO{sub 2} substrate surface may be modified to allow a stable metal coated anode to be fabricated. Creep testing of the metal coated ceramic anodes were conducted at IGT. It was determined that the predominant creep mechanism is due to particle rearrangement. The anode porosity, and mean pore size had significant effect on the creep of the anode. Lower porosity and pore size consistent with performance criteria are desired to reduce creep. Lower metal loading with uniformity of coverage will result in lower creep behavior of the anode. Of the two substrates evaluated, LiFeO{sub 2} in general exhibited lower creep which was attributed to superior metal adhesion.

Khandkar, A.C.; Elangovan, S.; Marianowski, L.G.

1990-03-01

348

Development of metal-coated ceramic anodes for molten carbonate fuel cells. Final report  

SciTech Connect

This report documents the developmental efforts on metal coating of various ceramic substrates (LiAlO{sub 2}, SrTiO{sub 3}, and LiFeO{sub 2}) and the critical issues associated with fabricating anodes using metal-coated LiAlO{sub 2} substrates. Electroless Ni and Cu coating technology was developed to achieve complete metal coverage on LiAlO{sub 2} powder substrates. Metal coated SrTiO{sub 3} powders were fabricated into anodes by a process identical to that reported in the GE literature. Microstructural examination revealed that the grains of the ceramic had fused together, with the metal having dewetted from the surface of the ceramic. Alternate substrates that might allow for better wetting of the metal on the ceramic such as LiFeO{sub 2} and Li{sub 2}MnO{sub 3} were identified. Cu/Ni-coated (50:50 mol ratio, 50 w/o metal loading) LiFeO{sub 2} anodes were optimized to meet the MCFC anode specifications. Metal-coated gamma-LiAlO{sub 2} substrates were also developed. By using suitable chemical surface modification methods, the gamma-UAlO{sub 2} substrate surface may be modified to allow a stable metal coated anode to be fabricated. Creep testing of the metal coated ceramic anodes were conducted at IGT. It was determined that the predominant creep mechanism is due to particle rearrangement. The anode porosity, and mean pore size had significant effect on the creep of the anode. Lower porosity and pore size consistent with performance criteria are desired to reduce creep. Lower metal loading with uniformity of coverage will result in lower creep behavior of the anode. Of the two substrates evaluated, LiFeO{sub 2} in general exhibited lower creep which was attributed to superior metal adhesion.

Khandkar, A.C.; Elangovan, S.; Marianowski, L.G.

1990-03-01

349

In vitro biocompatibility response of Ti-Zr-Si thin film metallic glasses  

NASA Astrophysics Data System (ADS)

In this study, the bio-electrochemical response of the Ti-Zr-Si thin film metallic glasses (TFMGs) in simulated body fluid with different contents of titanium is measured via potentiostat. According to the results of bio-corrosion potential and current, as well as the polarization resistance, it is concluded that the Ti66Zr25Si9 TFMGs possess the highest bio-electrochemical resistance. With increasing content of titanium, the corrosion resistance becomes progressively higher. The passive current results reveal that amorphous alloys can form a more protective and denser passive film on the metallic glass surface than the crystalline materials. In addition, the mechanical performance of the Ti-Zr-Si TFMGs is better than the crystalline counterparts. As a result, the Ti-based TFMGs are considered to be potential materials for bio-coating applications.

Ke, J. L.; Huang, C. H.; Chen, Y. H.; Tsai, W. Y.; Wei, T. Y.; Huang, J. C.

2014-12-01

350

Chemical solution deposition of epitaxial metal-oxide nanocomposite thin films.  

PubMed

Epitaixial metal-oxide nanocomposite films, which possess interesting multifunctionality, have found applications in a wide range of devices. However, such films are typically produced by using high-vacuum equipment, like pulse-laser deposition, molecular-beam epitaxy, and chemical vapor deposition. As an alternative approach, chemical solution methods are not only cost-effective but also offer several advantages, including large surface coating, good control over stoichiometry, and the possible use of dopants. Therefore, in this Personal Account, we review the chemistry behind several of the main solution-based approaches, that is, sol-gel techniques, metal-organic decomposition, chelation, polymer-assisted deposition, and hydrothermal methods, including the seminal works that have been reported so far, to demonstrate the advantages and disadvantages of these different routes. PMID:23389886

Fei, Ling; Naeemi, Maitham; Zou, Guifu; Luo, Hongmei

2013-02-01

351

Brilliant and tunable color by changing pore diameter of metal-coated porous anodic alumina  

NASA Astrophysics Data System (ADS)

Porous anodic alumina (PAA), with highly ordered microstructures, has attracted much attention due to some unique physical and optical characteristics. In recent years, PAA is also used to obtain different colors by methods such as growing nanowires, tuning pore depth, or sputtering metal on PAA surface. In this paper, we report a simple and precisely controllable method to tune color by changing the pore diameter of PAA. In order to obtain PPA with different pore diameter, we first prepare the PPA membrane by two step anodization of high purity aluminium foil in acidic solutions and then immerse the fabricated PPA membrane into phosphoric acid to enlarge pore diameter. The different pore diameters of PAA are controlled by immersed time in phosphoric acid. After sputtering metal on surface of PAA, the brilliant color can be seen on the surface of PAA. Different colors of PAA film with metal-coated are obtained using this method and colorful patterns are successfully fabricated. The physical model of the PAA is constructed and the mechanism of tuning color is analyzed. It is concluded that the color can be tuned by changing pore diameter of the PAA membrane. This method will be of potential use in decoration, color displays and anti-counterfeiting technology.

Li, Jiawen; Zhu, Zhiqiang; Deng, Ping; Hu, Yanlei; Chu, Jiaru; Huang, Wenhao

2012-11-01

352

Chemical vapor deposition of anisotropic ultrathin gold films on optical fibers: real-time sensing by tilted fiber Bragg gratings and use of a dielectric pre-coating  

NASA Astrophysics Data System (ADS)

Tilted fiber Bragg gratings (TFBGs) are refractometry-based sensor platforms that have been employed herein as devices for the real-time monitoring of chemical vapour deposition (CVD) in the near-infrared range (NIR). The coreguided light launched within the TFBG core is back-reflected off a gold mirror sputtered onto the fiber-end and is scattered out into the cladding where it can interact with a nucleating thin film. Evanescent fields of the growing gold nanostructures behave differently depending on the polarization state of the core-guided light interrogating the growing film, therefore the resulting spectral profile is typically decomposed into two separate peak families for the orthogonal S- and P-polarizations. Wavelength shifts and attenuation profiles generated from gold films in the thickness regime of 5-100 nm are typically degenerate for deposition directly onto the TFBG. However, a polarization-dependence can be imposed by adding a thin dielectric pre-coating onto the TFBG prior to using the device for CVD monitoring of the ultrathin gold films. It is found that addition of the pre-coating enhances the sensitivity of the P-polarized peak family to the deposition of ultrathin gold films and renders the films optically anisotropic. It is shown herein that addition of the metal oxide coating can increase the peak-to-peak wavelength separation between orthogonal polarization modes as well as allow for easy resonance tracking during deposition. This is also the first reporting of anisotropic gold films generated from this particular gold precursor and CVD process. Using an ensemble of x-ray techniques, the local fine structure of the gold films deposited directly on the TFBG is compared to gold films of similar thicknesses deposited on the Al2O3 pre-coated TFBG and witness slides.

Mandia, David J.; Zhou, Wenjun; Ward, Matthew J.; Joress, Howie; Giorgi, Javier B.; Gordon, Peter; Albert, Jacques; Barry, Seán. T.

2014-09-01

353

High sensitive mesoporous TiO2-coated love wave device for heavy metal detection.  

PubMed

This work deals with the design of a highly sensitive whole cell-based biosensor for heavy metal detection in liquid medium. The biosensor is constituted of a Love wave sensor coated with a polyelectrolyte multilayer (PEM). Escherichia coli bacteria are used as bioreceptors as their viscoelastic properties are influenced by toxic heavy metals. The acoustic sensor is constituted of a quartz substrate with interdigitated transducers and a SiO2 guiding layer. However, SiO2 shows some degradation when used in a saline medium. Mesoporous TiO2 presents good mechanical and chemical stability and offers a high active surface area. Then, the addition of a thin titania layer dip-coated onto the acoustic path of the sensor is proposed to overcome the silica degradation and to improve the mass effect sensitivity of the acoustic device. PEM and bacteria deposition, and heavy metal influence, are real time monitored through the resonance frequency variations of the acoustic device. The first polyelectrolyte layer is inserted through the titania mesoporosity, favouring rigid link of the PEM on the sensor and improving the device sensitivity. Also, the mesoporosity of surface increases the specific surface area which can be occupied and favors the formation of homogeneous PEM. It was found a frequency shift near -20±1 kHz for bacteria immobilization with titania film instead of -7±3 kHz with bare silica surface. The sensitivity is highlighted towards cadmium detection. Moreover, in this paper, particular attention is given to the immobilization of bacteria and to biosensor lifetime. Atomic Force Microscopy characterizations of the biosurface have been done for several weeks. They showed significant morphological differences depending on the bacterial life time. We noticed that the lifetime of the biosensor is longer in the case of using a mesoporous TiO2 layer. PMID:24583687

Gammoudi, I; Blanc, L; Moroté, F; Grauby-Heywang, C; Boissière, C; Kalfat, R; Rebière, D; Cohen-Bouhacina, T; Dejous, C

2014-07-15

354

Modeling emissivity of low-emissivity coating containing horizontally oriented metallic flake particles  

NASA Astrophysics Data System (ADS)

The scattering and absorption cross sections of horizontally oriented metallic flake particles are estimated by extended geometric optics that includes diffraction and edge effects. Emissivity of the coating containing those particles is calculated using Kubelka-Munk theory. The dependence of emissivity of the coating on the radius, thickness, content of metallic flake particles and coating thickness is discussed. Finally, theoretical results are compared with the experimental measurements with Al/acrylic resin coating system and the results show that simulation values are in good agreement with experimental ones.

Chen, Shuai; Yuan, Le; Weng, Xiaolong; Deng, Longjiang

2014-11-01

355

Effect of thermal cycling on stress in metallic films on ceramic substrates  

NASA Technical Reports Server (NTRS)

The hydrogen maser is the most stable frequency standard currently available for averaging intervals of hours to weeks. A major contributor to maser frequency variations is the maser's microwave resonant cavity: by means of the cavity pulling effect, a change in the cavity's resonance frequency produces a proportional change in the maser's output frequency. To minimize variations in the cavity's dimensions, and thus in its resonance frequency, maser cavities are often constructed of a low-expansivity glass-ceramic material coated on its surface with a conductive metallic film. It was previously shown that silver films like those used in SAO maser cavities develop tensile stress when cooled to room temperature after being fired onto the cavity, and that the stress in such films relaxes with time at a rate proportional to the level of stress. Stress relaxation in maser cavity coatings can alter the shape, and hence the resonance frequency, of the cavity, resulting in a slow variation in the maser's output frequency. The possibility was investigated of reversing the initial tensile stress by precooling the coated cavity material. It was hypothesized that cooling the material well below its normal working temperature and then warming it to its normal temperature would result in a lower tensile stress or even a compressive stress. Under such a condition stress relaxation, and thus any consequent frequency drifts, might be reduced or reversed.

Mattison, Edward M.; Vessot, Robert F. C.

1990-01-01

356

The dependence of erosion-corrosion wastage on carbide\\/metal binder proportion for HVOF carbide-metal cerment coatings  

Microsoft Academic Search

A series of erosion-corrosion (E-C) tests was carried out on hypersonic velocity oxygen fuel (HVOF) carbide-metal cement coatings specimens at elevated temperature under conditions that attempted to simulate the errosion conditions found in fossil-fired boilers. The coatings included tungsten carbide, niobium carbide, and titanium carbide with different fractions of metal binder phase. Angular SiO2 quarts particles were used as the

Bu-Qian Wang

1996-01-01

357

A comparative study of aqueous and organic-based films and coatings of PEGylated rosin derivative.  

PubMed

Rosin was partially esterified with polyethylene glycol 400 and reacted with maleic-anhydride to form an ester-adduct derivative. Derivative and native rosin were characterized for physicochemical properties. Aqueous coating system of derivative was developed by ammonia neutralization method. Organic-based films were produced using acetone. Aqueous and organic-based films were comparatively evaluated. Derivative exhibited an excellent coat-forming ability on spherical-units. Aqueous-based film exhibited very high water vapor transmission rate, wettability, water uptake, and leaching at pH 6.8. A 20% w/w aqueous-based coat could sustain diclofenac sodium release for 8 h, whereas, 20% w/w organic-based coat released 20.11% of drug in 8 h. In conclusion, aqueous coating system of synthesized rosin derivative can be developed; however, aqueous-coats are less efficient to retard the drug release rate. Instead, the organic-based coatings can efficiently be used for sustained drug delivery. PMID:18214752

Morkhade, Dinesh Mahadeorao; Nande, Vishwanath Sundar; Barabde, Umesh Vinayak; Kamble, Manish U; Patil, Arun T; Joshi, Siddheshwar B

2008-01-01

358

Characterization of electrically conductive transition metal dichalcogenide lubricant films  

NASA Astrophysics Data System (ADS)

Groups VB and VIB transition metal dichalcogenides with layered structures, are intrinsic solid lubricants, and constitute a class of materials with unique and unusual properties based on their extreme anisotropy. The primary objective of this investigation was to conduct a comprehensive study on the tribological and electrical properties of burnished and sputtered transition metal dichalcogenide films, and characterize the performance under sliding electrical contact conditions. Evaluation was done using a pin-on-disc tribometer, modified to allow simultaneous monitoring of friction and contact resistance. Resistivities were measured using a static four point probe. The optimal conditions for sputter depositing transition metal dichalcogenides using the DV-602 sputtering system were determined as 10 microns of argon pressure and a rf power of 200 W. Some of the dichalcogenides did not form adherent films on stainless steel substrates under the experimental conditions. A dual source cosputtering (Cu/NbTesb2) technique is discussed, which improved the film-substrate adherence significantly, and provides a new way for the development of other thin film materials. The cosputtered Cu appears to alter the lattice parameters in the dichalcogenide crystal structure and consequently leads to improved adhesion and electrical properties. The sliding contact electrical behavior of the films was found to be related to the electronic configuration, crystal packing and structure. The group VB (Nb, Ta) metal dichalcogenides exhibited better electrical properties than the group VIB (Mo, W) metal dichalcogenide films, because of the presence of delocalized nonbonding electrons in the group VB compounds. Sputtered films with better adherence to the substrate illustrated improved friction and wear life in comparison to the burnished films. The sputtered films with greater amount of metallic character, purity, crystallinity and better adhesion reduced the contributions to the overall contact resistance. The increased metallic character of the sputtered films implies that the free electrons in the valency band are closer to the fermi level of the metal, and hence illustrate lower sliding contact resistance as compared to the burnished films. A conduction-lubrication-wear mechanism is presented, which was derived from the asperity flash temperature rise. The ohmic heating affects on the conduction-lubrication-wear mechanism of films are also discussed. The coefficient of friction, sliding contact resistance, wear rates, static four point resistivities and the asperity flash temperature estimates are presented.

Waghray, Harish C.

359

Thin film coating process using an inductively coupled plasma  

DOEpatents

Thin coatings of normally solid materials are applied to target substrates using an inductively coupled plasma. Particles of the coating material are vaporized by plasma heating, and pass through an orifice to a first vacuum zone in which the particles are accelerated to a velocity greater than Mach 1. The shock wave generated in the first vacuum zone is intercepted by the tip of a skimmer cone that provides a second orifice. The particles pass through the second orifice into a second zone maintained at a higher vacuum and impinge on the target to form the coating. Ultrapure coatings can be formed.

Kniseley, Richard N. (Ames, IA); Schmidt, Frederick A. (Ames, IA); Merkle, Brian D. (Ames, IA)

1990-01-30

360

Nano polymer Films by Fast Dip Coating Method for Field Effect Transistor Applications  

NASA Astrophysics Data System (ADS)

Nano Polyvinyl alcohol films are prepared by fast dip coating method. Cleaned glass plates are used as substrate to prepare the above said films. The thickness of the films are measured by capacitance method, weighing method and cross checked by electronic measuring instrument (Tesatronic-TTD 20). IR spectrum is used to identify the coated films. The coated films are identified by IR spectrum. No pits and pin holes are found on the surface. The XRD spectrum indicated the amorphous nature of the films studied. Aluminium/PVA/Aluminum sandwich structures are formed to study the dielectric and AC conduction behaviour. The capacitance and dielectric loss of the films are measured in the frequency range of 0.1 kHz to 100 kHz for various temperatures ranging from 290 K to 450 K. The observed increase of capacitance with the decrease of frequency in the lower frequency range can be assigned to charge carriers being blocked at the electrodes. The decrease of capacitance with increasing frequency is also attributed to the increasing inability of the dipoles to orient them selves in a rapidly varying electric field. The AC conductivity is found to vary according to the relation ?ac ? ?n, where the value of n depends on temperature and frequency. The value of activation energy is found to be 0.0015 eV ?0.007 eV for various temperatures confirms the amorphous nature of the film.

Sathish, S.; Shekar, B. Chandar; Sathyamoorthy, R.

361

A comparative study of the morphology of flow and spin coated P3HT:PCBM films  

NASA Astrophysics Data System (ADS)

Polymer solar cells are attractive due to the possibility of using cheaper materials and processing techniques for mass production of solar panels. Previous methods of fabricating polymer solar cells are suitable in laboratory conditions but are not scalable for industrial production. In this study, thin films of the photoactive blend of poly(3-hexylthiophene) (P3HT) and fullerene derivative [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) were prepared by flow coating, which is suitable for industrial manufacturing of solar cells. P3HT:PCBM blends were cast from different solvents, and the morphology of flow coated and spin coated films was compared. The surface morphology and optical properties of P3HT:PCBM films were characterized with optical microscopy, AFM, and UV-vis absorption spectroscopy. The degree of P3HT order was higher in flow coated films, as compared to spin coated films. Films flow coated using chloroform solutions had a higher thermal stability and an enhanced degree of phase separation as compared to spin coated films. Flow coated films from chlorobenzene solutions had a lower thermal stability and a smaller length scale of phase separation. This study demonstrates that flow coating is a suitable alternative technique for fabricating polymer solar cells.

Chapa, Jose; Karim, Alamgir

2013-03-01

362

Performance comparison of dye-sensitized solar cells by using different metal oxide- coated TiO2 as the photoanode  

NASA Astrophysics Data System (ADS)

In order to increase the conversion efficiency of dye-sensitized solar cells, TiO2 photoanode surface is often covered with a metal oxide layer to form a core-shell composite structure. Different metal oxide coating on TiO2 as composite photoanodes can affect the cell efficiency variously. However, there still lacks the crosswise comparison among the effects of different metal oxides on TiO2 photoanode. In this study, TiO2 was coated with Al2O3, CaO, ZnO, MgO, Fe2O3 or Bi2O3 separately by liquid phase deposition method. The results indicated that cells with TiO2/Al2O3, TiO2/ZnO, TiO2/CaO, or TiO2/MgO composite film as a photoanode had higher conversion efficiency than those with un-coated TiO2 films. TiO2/Al2O3 showed the highest efficiency and TiO2/CaO ranked second. On the contrary, cells with TiO2/Bi2O3 or TiO2/Fe2O3 composite film as a photoanode had lower conversion efficiency than those with un-coated TiO2 films. The mechanism of the cell efficiency change was also investigated. To get higher conversion efficiency, matched energy level of the metal oxide with TiO2 is the first prerequisite, and then the optimum coating thickness is also a necessary condition.

Xuhui, Sun; Xinglan, Chang; Wanquan, Tuo; Dong, Wang; Kefei, Li

2014-03-01

363

Preparation, properties and chemistry of glass- and glass-ceramic-to-metal seals and coatings  

Microsoft Academic Search

An overview is given outlining the materials and technologies that have been employed in the preparation of glass- and glass-ceramic-to-metal seals and coatings. Metal\\/non-metal bonding theories are summarized, and the conditions required for the formation of strong chemical bonding are described and discussed. Particular reference is given to the interfacial chemistry involved for individual glass\\/metal and glass-ceramic\\/metal combinations. The major

I. W. Donald

1993-01-01

364

Influence of coating bath chemistry on the deposition of 3-mercaptopropyl trimethoxysilane films deposited on magnesium alloy.  

PubMed

Magnesium alloys have a low specific density and a high strength to weight ratio. This makes them sought after light weight construction materials for automotive and aerospace applications. These materials have also recently become of interest for biomedical applications. Unfortunately, the use of magnesium alloys in many applications has been limited due to its high susceptibility to corrosion. One way to improve the corrosion resistance of magnesium alloys is through the deposition of protective coatings. Many of the current pretreatments/coatings available use toxic chemicals such as chromates and hydrofluoric acid. One possible environmentally friendly alternative is organosilane coatings which have been shown to offer significant corrosion protection to both aluminum alloys and steels. Organosilanes are ambifunctional molecules that are capable of covalent bonding to metal hydroxide surfaces. In order for covalent bonding to occur, the organosilane must undergo hydrolysis in the coating bath followed by a condensation reaction with the surface. There are a number of factors that influence the rates of these reactions such as pH and concentration of reactants. These factors can also influence competing reactions in solution such as oligomerization. The rates of hydrolysis and condensation of 3-mercaptopropyltrimethoxy silane in methanol have been analyzed with (1)H NMR and ATR-FTIR. The results indicate that organosilane oligomers begin to form in solution before the molecules are fully hydrolyzed. The organosilane films deposited on magnesium alloy AZ91 at a variety of concentrations and pre-hydrolysis times were characterized with a combination of ATR-FTIR, ellipsometry and SEM/EDS. The results show that both organosilane film thickness and uniformity are affected by the chemistry occurring in the coating bath prior to deposition. PMID:20064643

Scott, A F; Gray-Munro, J E; Shepherd, J L

2010-03-15

365

Characterization of electrically conductive transition metal dichalcogenide lubricant films  

Microsoft Academic Search

Groups VB and VIB transition metal dichalcogenides with layered structures, are intrinsic solid lubricants, and constitute a class of materials with unique and unusual properties based on their extreme anisotropy. The primary objective of this investigation was to conduct a comprehensive study on the tribological and electrical properties of burnished and sputtered transition metal dichalcogenide films, and characterize the performance

Harish C. Waghray

1997-01-01

366

Chemical deposition method for metal chalcogenide thin films  

Microsoft Academic Search

Metal chalcogenide thin films preparation by chemical methods are currently attracting considerable attention as it is relatively inexpensive, simple and convenient for large area deposition. A variety of substrates such as insulators, semiconductors or metals can be used since these are low temperature processes which avoid oxidation and corrosion of substrate. These are slow processes which facilitates better orientation of

R. S. Mane; C. D. Lokhande

2000-01-01

367

Direct Writing of Metal Nanoparticle Films Inside Sealed Microfluidic Channels  

E-print Network

Direct Writing of Metal Nanoparticle Films Inside Sealed Microfluidic Channels Edward T. Castellana practical strategy available for patterning metals inside sealed microchannels involves the use of arbitrary geometry inside sealed PDMS/ TiO2/glass microfluidic devices. The technique can be employed

368

Materials Analysis of CED Nb Films Being Coated on Bulk Nb Single Cell SRF Cavities  

SciTech Connect

This study is an on-going research on depositing a Nb film on the internal wall of bulk Nb single cell SRF cavities, via a cathodic arc Nb plasma ions source, an coaxial energetic condensation (CED) facility at AASC company. The motivation is to firstly create a homoepitaxy-like Nb/Nb film in a scale of a ~1.5GHz RF single cell cavity. Next, through SRF measurement and materials analysis, it might reveal the baseline properties of the CED-type homoepitaxy Nb films. Literally, a top-surface layer of Nb films which sustains SRF function, always grows up in homo-epitaxy mode, on top of a Nb nucleation layer. Homo-epitaxy growth of Nb must be the final stage (a crystal thickening process) of any coatings of Nb film on alternative cavity structure materials. Such knowledge of Nb-Nb homo-epitaxy is useful to create future realistic SRF cavity film coatings, such as hetero-epitaxy Nb/Cu Films, or template-layer-mitigated Nb films. One large-grain, and three fine grain bulk Nb cavities were coated. They went through cryogenic RF measurement. Preliminary results show that the Q0 of a Nb film could be as same as the pre-coated bulk Nb surface (which received a chemically-buffered polishing plus a light electro-polishing); but quality factor of two tested cavities dropped quickly. We are investigating if the severe Q-slope is caused by hydrogen incorporation before deposition, or is determined by some structural defects during Nb film growth.

Zhao, Xin; Reece, Charles; Palczewski, Ari; Ciovati, Gianluigi; Krishnan, Mahadevan; James, Colt; Irfan, Irfan

2013-09-01

369

Dewetting Properties of Metallic Liquid Film on Nanopillared Graphene  

PubMed Central

In this work, we report simulation evidence that the graphene surface decorated by carbon nanotube pillars shows strong dewettability, which can give it great advantages in dewetting and detaching metallic nanodroplets on the surfaces. Molecular dynamics (MD) simulations show that the ultrathin liquid film first contracts then detaches from the graphene on a time scale of several nanoseconds, as a result of the inertial effect. The detaching velocity is in the order of 10?m/s for the droplet with radii smaller than 50?nm. Moreover, the contracting and detaching behaviors of the liquid film can be effectively controlled by tuning the geometric parameters of the liquid film or pillar. In addition, the temperature effects on the dewetting and detaching of the metallic liquid film are also discussed. Our results show that one can exploit and effectively control the dewetting properties of metallic nanodroplets by decorating the surfaces with nanotube pillars. PMID:24487279

Li, Xiongying; He, Yezeng; Wang, Yong; Dong, Jichen; Li, Hui

2014-01-01

370

Surface Segregation of Substrate Metal on Film Surface  

NASA Astrophysics Data System (ADS)

We studied surface segregation of substrate metal on the top of a deposited film in a vacuum. The specimen was heated in high vacuum chamber of Auger electron spectroscopy (AES) or X-ray photoelectron spectroscopy (XPS) until the substrate metal was observed on the surface of the deposited film and the surface concentration of the substrate metal became saturated. The depth profile of the heated specimen was obtained by measuring AES/XPS with Ar ion etching. Al, Ti, Cr, Ni, Cu, Nb, and Fe were used as substrate materials and Al, Ti, Cr, Zr, Cu, Nb, and Fe were used as film materials. The rule is segregation of a substrate atom occurs if the adsorption energy of a substrate atom on a film is larger than that on the substrate itself. The adsorption energy is estimated from heat of solution, surface energy, and vaporization energy, and those estimated values are used to predict the segregation behavior.

Aparna, Yarrama Reddy; Rao, K. V.; Reddy, G. Balanagi

2011-07-01

371

Dynamics and response of polymer-coated surface acoustic wave devices. Effect of viscoelastic properties and film resonance  

Microsoft Academic Search

The response of polymer-coated surface acoustic wave (SAW) devices to temperature changes and polymer vapor absorption is examined. A perturbational approach is used to relate velocity and attenuation responses to film translational and strain modes generated by the SAW. Two distinct regimes of film behavior arise, causing different SAW responses. For glassy films, displacement is nearly uniform across the film

Stephen J. Martin; Gregory C. Frye; Stephen D. Senturia

1994-01-01

372

Metal oxynitride and diamond hard coatings for infrared windows  

NASA Astrophysics Data System (ADS)

The protection of IR windows in airborne FLIR sensor systems against erosion resulting from raindrop and particle impact is accomplished by means of a front surface coating. The wavelength ranges required are 8-14 micrometers , where diamond competes with boron phosphide based coatings for the protection of multispectral zinc sulphide used as a window for multiple detectors. This paper describes progress in the development of diamond coatings for germanium windows, including selection and deposition of durable front surface antireflection layers. The diamond layers are deposited by microwave plasma CVD techniques at 500 degrees C. For the multispectral application, hard oxynitride coatings have been developed both as stand-alone coatings and as interlayers for diamond coatings. The multispectral coatings and the antireflection coatings are deposited by a sputtering process, applicable to flats and domes. In both cases, structured surfaces at appropriate scales are used to improve optical transmission and mechanical adhesion.

Miller, Andrew J.; Hudson, Martin D.; Dennis, Paul V.; Wilson, Anthony E. J.

1999-07-01

373

Effects of ion beam mixing of silicon carbide film deposited onto metallic materials for application to nuclear hydrogen production  

NASA Astrophysics Data System (ADS)

The effects of ion beam mixing of the SiC film coated on metallic substrates were studied, aiming at developing highly sustainable materials at above 1173 K in SO 3/SO 2 ambience. Firstly, ˜50 nm thick SiC films were deposited by e-beam evaporative method on stainless 316 L, Inconel 800H, Inconel 690, and Hastelloy-X substrates, followed by the 100 keV (Ar and N) ions bombardment to mix the interfacial region. After ion beam mixing, additional ˜500 nm thick SiC film was deposited onto the ion bombarded SiC film. Samples with and without ion beam mixing were immersed in 50% H 2SO 4 solution for 1 h with heating the solution up at 573 K. The film in the as-deposited sample was completely removed during the immersion, while the ion beam mixed sample exhibited no detachment of the deposited film. The corrosion of non-ion beam-mixed sample initiated from non-deposited metallic surface and then propagated to the film deposited region, flaking-off the film from the edge. The interface formed by ion beam mixing seems to be protective against the corrosion. The SiC film/metallic substrates were heated up to 1223 K. The film deposited on the stainless steel substrate was completely peeled off, while the films deposited on Ni-based alloys all sustained. This is due to the difference of thermal stresses between the film and substrate materials. The best materials combination in our experimental scheme is the SiC film and the Hastelloy-X, because their thermal properties are more similar than for the other materials combinations.

Park, Jae-Won; Chun, Youngjin; Chang, Jonghwa

2007-05-01

374

Sorption and filtration of metals using iron-oxide-coated sand  

Microsoft Academic Search

Iron oxides are good adsorbents for uncomplexed metals, some metal-ligand complexes, and many metal oxyanions. However, the adsorbent properties of these oxides are not fully exploited in wastewater treatment operations because of difficulties associated with their separation from the aqueous phase. This paper describes experiments in which iron oxides were coated onto the surface of ordinary filter sand, and this

Mark M. Benjamin; Ronald S. Sletten; Robert P. Bailey; Thomas Bennett

1996-01-01

375

Molten metal containment vessel with rare earth oxysulfide protective coating thereon and method of making same  

DOEpatents

An improved molten metal containment vessel is disclosed in which wetting of the vessel's inner wall surfaces by molten metal is inhibited by coating at least the inner surfaces of the containment vessel with one or more rare earth oxysulfide or rare earth sulfide compounds to inhibit wetting and or adherence by the molten metal to the surfaces of the containment vessel.

Krikorian, Oscar H. (Danville, CA); Curtis, Paul G. (Tracy, CA)

1992-01-01

376

Thin film thermoelectric devices as thermal control coatings: A study  

NASA Technical Reports Server (NTRS)

Peltier effect, Thomson effect, and Seeback effect are utilized in design of thermal control coating that serves as versatile means for controlling heat absorbed and radiated by surface. Coatings may be useful in extreme temperature environment enclosures or as heat shields.

Clemons, J. M.; Krupnick, A. C.

1973-01-01

377

Applications of edible films and coatings to processed foods  

Technology Transfer Automated Retrieval System (TEKTRAN)

Edible coatings have been successfully applied in processed foods such as meat, cereals, confectionaries, dried fruits, nuts and fresh and fresh-cut fruits and vegetables. These coatings are used to improve the quality and shelf-life of foods. Furthermore, different food ingredients, derived from ...

378

Germanium Lift-Off Masks for Thin Metal Film Patterning  

NASA Technical Reports Server (NTRS)

A technique has been developed for patterning thin metallic films that are, in turn, used to fabricate microelectronics circuitry and thin-film sensors. The technique uses germanium thin films as lift-off masks. This requires development of a technique to strip or undercut the germanium chemically without affecting the deposited metal. Unlike in the case of conventional polymeric lift-off masks, the substrate can be exposed to very high temperatures during processing (sputter deposition). The reason why polymeric liftoff masks cannot be exposed to very high temperatures (greater than 100 C) is because (a) they can become cross linked, making lift-off very difficult if not impossible, and (b) they can outgas nitrogen and oxygen, which then can react with the metal being deposited. Consequently, this innovation is expected to find use in the fabrication of transition edge sensors and microwave kinetic inductance detectors, which use thin superconducting films deposited at high temperature as their sensing elements. Transition edge sensors, microwave kinetic inductance detectors, and their circuitry are comprised of superconducting thin films, for example Nb and TiN. Reactive ion etching can be used to pattern these films; however, reactive ion etching also damages the underlying substrate, which is unwanted in many instances. Polymeric lift-off techniques permit thin-film patterning without any substrate damage, but they are difficult to remove and the polymer can outgas during thin-film deposition. The outgassed material can then react with the film with the consequence of altered and non-reproducible materials properties, which, in turn, is deleterious for sensors and their circuitry. The purpose of this innovation was to fabricate a germanium lift-off mask to be used for patterning thin metal films.

Brown, Ari

2012-01-01

379

Polymer-assisted deposition of films  

DOEpatents

A polymer assisted deposition process for deposition of metal oxide films and the like is presented. The process includes solutions of one or more metal precursor and soluble polymers having binding properties for the one or more metal precursor. After a coating operation, the resultant coating is heated at high temperatures to yield metal oxide films and the like. Such films can be epitaxial in structure and can be of optical quality. The process can be organic solvent-free.

McCleskey, Thomas M. (Los Alamos, NM); Burrell; Anthony K. (Los Alamos, NM); Jia; Quanxi (Los Alamos, NM); Lin; Yuan (Los Alamos, NM)

2009-10-20

380

Polymer-assisted deposition of films  

DOEpatents

A polymer assisted deposition process for deposition of metal oxide films is presented. The process includes solutions of one or more metal precursor and soluble polymers having binding properties for the one or more metal precursor. After a coating operation, the resultant coating is heated at high temperatures to yield metal oxide films. Such films can be epitaxial in structure and can be of optical quality. The process can be organic solvent-free.

McCleskey, Thomas M. (Los Alamos, NM); Burrell, Anthony K. (Los Alamos, NM); Jia, Quanxi (Los Alamos, NM); Lin, Yuan (Los Alamos, NM)

2008-04-29

381

Three-reflection halfwave and quarterwave retarders using dielectric-coated metallic mirrors  

NASA Astrophysics Data System (ADS)

A design procedure is described to determine the thicknesses of single-layer coatings of a given dielectric on a given metallic substrate so that a specified net phase retardance (and/or a net relative amplitude attenuation) between the p and s polarizations is achieved after three reflections from a symmetrical arrangement of three mirrors that maintain collinearity of the input and output beams. Examples are presented of halfwave and quarterwave retarders (HWR and QWR) that use a ZnS-Ag film-substrate system at the CO2-laser wavelength of 10.6 microns. The equal net reflectances for the p and s polarizations are computed and found to be high (above 90 percent) for most designs. Sensitivity of the designs (deviation of the magnitude and phase of the ratio of net complex p and s reflection coefficients from design specifications) to small film-thickness and angle-of-incidence errors is examined, and useful operation over a small wavelength range (10-11 microns) is demonstrated.

Thonn, T. F.; Azzam, R. M. A.

1984-08-01

382

Sputter deposition of metallic thin film and directpatterning  

SciTech Connect

A compact apparatus is developed for deposition of metal thin film. The system employs an RF discharge plasma source with a straight RF antenna, which is made of or covered with deposition material, serving as sputtering target at the same time. The average deposition rate of copper thin film is as high as 450nm/min. By properly allocating the metal materials on the sputtering antenna, mixture deposition of multiple metal species is achieved. Using an ion beam imprinting scheme also taking advantage of ion beam focusing technique, two different schemes of direct patterning deposition process are developed: direct depositing patterned metallic thin film and resistless ion beam sputter patterning. Preliminary experiments have demonstrated direct pattern transfer from a template with feature size of micro scale; patterns with more than 10x reduction are achieved by sputtering patterning method.

Ji, L.; Chen, Y.; Jiang, X.; Ji, Q.; Leung, K.-N.

2005-09-09

383

Coatings of Fe/FeAIN Thin Films  

SciTech Connect

We report new results on materials properties of Fe/FeAIN thin films. Films were fabricated via a pulsed DC sputtering technique. Sputtering target materials were FeAl where x varies from 0.025 to 1. Film thickness varied from 0.01 to 4 micrometers, and particle size varied from 5 to 100 nanometers, depending on the fabrication conditions and target materials. A film with 22 layers was also fabricated via the sputtering technique. Materials properties of the films were analyzed by SEM/EDS, XRD, RBS, and ESCA (XPS).

Liu, Yuandan; Miller, Ronald E.; Zhang, Tao; Feng, Qiquan; Votava, W.; Li, Dingqiang; Dunkleberger, L. N.; Wang, Xingwu; Gray, R.; Bibens, T.; Helfer, Jeffrey; Mooney, K.; Nowak, R.; Lubitz, P.; Zhang, Yanwen

2008-08-01

384

Calcium and Zinc Containing Bactericidal Glass Coatings for Biomedical Metallic Substrates  

PubMed Central

The present work presents new bactericidal coatings, based on two families of non-toxic, antimicrobial glasses belonging to B2O3–SiO2–Na2O–ZnO and SiO2–Na2O–Al2O3–CaO–B2O3 systems. Free of cracking, single layer direct coatings on different biomedical metallic substrates (titanium alloy, Nb, Ta, and stainless steel) have been developed. Thermal expansion mismatch was adjusted by changing glass composition of the glass type, as well as the firing atmosphere (air or Ar) according to the biomedical metallic substrates. Formation of bubbles in some of the glassy coatings has been rationalized considering the reactions that take place at the different metal/coating interfaces. All the obtained coatings were proven to be strongly antibacterial versus Escherichia coli (>4 log). PMID:25056542

Esteban-Tejeda, Leticia; Díaz, Luis A.; Prado, Catuxa; Cabal, Belén; Torrecillas, Ramón; Moya, José S.

2014-01-01

385

Calcium and zinc containing bactericidal glass coatings for biomedical metallic substrates.  

PubMed

The present work presents new bactericidal coatings, based on two families of non-toxic, antimicrobial glasses belonging to B2O3-SiO2-Na2O-ZnO and SiO2-Na2O-Al2O3-CaO-B2O3 systems. Free of cracking, single layer direct coatings on different biomedical metallic substrates (titanium alloy, Nb, Ta, and stainless steel) have been developed. Thermal expansion mismatch was adjusted by changing glass composition of the glass type, as well as the firing atmosphere (air or Ar) according to the biomedical metallic substrates. Formation of bubbles in some of the glassy coatings has been rationalized considering the reactions that take place at the different metal/coating interfaces. All the obtained coatings were proven to be strongly antibacterial versus Escherichia coli (>4 log). PMID:25056542

Esteban-Tejeda, Leticia; Díaz, Luis A; Prado, Catuxa; Cabal, Belén; Torrecillas, Ramón; Moya, José S

2014-01-01

386

Birefringence-induced polarization-independent and nearly all-angle transparency through a metallic film  

NASA Astrophysics Data System (ADS)

We propose a birefringence route to perfect electromagnetic (EM) wave tunneling through a metallic film which relies on homogeneous birefringent coatings with moderate and positive parameters only. EM transparency is achieved in such a birefringent-metal-birefringent (BMB) structure for both polarizations and over nearly all incident angles. The stringent restrictions in conventional dielectric-metal-dielectric media, i.e., dielectrics with extremely negative permittivity, high magnetic field and polarization dependence (only for TE waves), are not required in our method. The criterion for perfect transmission is obtained by analyzing the effective medium theory and the EM fields of such a birefringent structure. The solutions hold for lossless and lossy cases in a quite large frequency range.

Gao, D. L.; Gao, L.; Qiu, C. W.

2011-08-01

387

Laser-Induced Fabrication of Metallic Interlayers and Patterns in Polyimide Films  

NASA Technical Reports Server (NTRS)

Self-metallizing polyimide films are created by doping polyamic acid solutions with metallic ions and solubilizing agents. Upon creating a film, the film is exposed to coherent light for a specific time and then cured. The resulting film has been found to have a metallic surface layer and a metallic subsurface layer (interlayer). The layer separating the metallic layer has a uniform dispersion of small metal particulates within the polymer. The layer below the interlayer has larger metal particulates uniformly distributed within the polymer. By varying the intensity or time of exposure to the coherent light, three-dimensional control of metal formation within the film is provided.

Miner, Gilda A. (Inventor); Stoakley, Diane M. (Inventor); Gaddy, Gregory A. (Inventor); Koplitz, Brent D. (Inventor); Simpson, Steven M. (Inventor); Lynch, Michael F. (Inventor); Ruffner, Samuel C. (Inventor)

2010-01-01

388

Terahertz pulsed imaging as an analytical tool for sustained-release tablet film coating.  

PubMed

The ability of terahertz pulsed imaging (TPI) to be employed as an analytical tool for monitoring a film coating unit operation and to assess the success of a subsequent process scale-up was explored in this study. As part of a process scale-up development, a total of 190 sustained-release tablets were sampled at 10% increments of the amount of polymer applied, from a lab-scale and a pilot-scale coating run. These tablets were subjected to TPI analysis, followed by dissolution testing. Information on tablet film coating layer thickness and variations in coating density were extracted using TPI. It was found that both terahertz parameters were more sensitive and informative to product quality when compared with measuring the amount of polymer applied. For monitoring the film coating unit operation, coating layer thickness showed a strong influence on the dissolution behaviour for both the lab-scale and the pilot-scale batches. An R(2) of 0.89, root mean square error (RMSE)=0.22 h (MDT range=3.21-5.48 h) and an R(2) of 0.92, RMSE=0.23 h (MDT range=5.43-8.12 h) were derived from the lab-scale and pilot-scale, respectively. The scale-up process led to significant changes in MDT between the lab-scale and pilot-scale. These changes in MDT could be explained by the differences observed in the film coating density on samples with similar amount of polymer applied between the lab and the pilot-scale. Overall, TPI demonstrated potential to be employed as an analytical tool to help refine the coating unit operation and the scale-up procedure. PMID:18647650

Ho, Louise; Müller, Ronny; Gordon, Keith C; Kleinebudde, Peter; Pepper, Michael; Rades, Thomas; Shen, Yaochun; Taday, Philip F; Zeitler, J Axel

2009-01-01

389

Sputtered Silver Films to Improve Chromium Carbide Based Solid Lubricant Coatings for Use to 900°C  

Microsoft Academic Search

Thin silver films, 25 to 350 nm thick, were sputtered onto PS200, a plasma sprayed, chromium carbide based, solid lubricant coating, to reduce run-in wear and improve tribological properties. The coating contains bonded chromium carbide as the wear resistant “base stock” with silver and barium fluoride\\/calcium flouride eutectic added as low and high temperature lubricants respectively. Potential applications for the

Christopher Dellacorte; Harold E. Sliney; Daniel L. Deadmore

1988-01-01

390

Effect of the manufacturing conditions on the structure and permeability of polymer films intended for coating undergoing phase separation.  

PubMed

The major aim of this work was to study the effect of two process parameters, temperature and coating flow, on permeability to water and structure of free films sprayed from mixtures of ethyl cellulose (EC), hydroxypropyl cellulose (HPC), and ethanol. The films were sprayed in a new spraying setup that was developed to mimic the film coating process in a fluid bed and to provide well controlled conditions. EC and HPC phase separated during the film drying process, and EC- and HPC-rich domains were formed. The process parameters had a great impact on the structure and the permeability to water of the films. The longer the time before the film structure was locked by a high film viscosity, that is, the lower the temperature and the higher the coating flow, the larger the domains and the lower the film permeability. The effective diffusion coefficient of water in the films varied by about six times within the range of the process parameters studied. Structures of sprayed films and water effective diffusion coefficients in sprayed films were compared to those of cast films. For the cast films, the domains were bigger, and the permeability to water was significantly lower compared to those of the sprayed films. The results indicate that the process parameters can be used as a mean to regulate structure and permeability of coating films undergoing phase separation. PMID:23064326

Marucci, Mariagrazia; Arnehed, Johan; Jarke, Annica; Matic, Hanna; Nicholas, Mark; Boissier, Catherine; von Corswant, Christian

2013-02-01

391

Magnetron sputtering of metallic coatings onto elastomeric substrates for a decrease in fuel permeation rate  

NASA Astrophysics Data System (ADS)

The purpose of this research was to investigate the application of a metallic coating by magnetron sputtering onto elastomeric substrates, as an inhibiting layer to permeation transport. The metallic coatings which were deposited were aluminum, titanium, and copper. The substrates used were NBR, FVMQ, and FKM elastomers. The permeating fluids were ASTM Fuel C, isooctane, and toluene. The magnetron sputtering properties of these metallic elements were unique to each material, with the titanium sputtering rate being very low. The sputtering rates of these materials correlated well with their sublimation temperature. It was found that some of the metallic particles which were sputtered onto the substrates, implanted into the surface of the elastomeric membranes, with the total amount and distance of implantation being related to the density of the substrate material. The permeation of these solvents through the composite materials was reduced by the presence of these coatings with the reduction in permeation rate ranging from 12 to 25% for Fuel C. The pervaporation properties of these substrates were also evaluated. It was found from this analysis that for the FVMQ and NBR substrates, the permeation rate of the permeating solute molecules was proportional to the size of the permeation molecule. The substrate materials were not significantly stiffened by the addition of the thin metallic coatings. The coated materials were cohesive and well adhered, as determined by stretching of the substrate materials with the metallic layer in place. Upon stretching, there was no evidence of damage to the metallic coating.

Myntti, Matthew F.

392

Surface-modification of LiMn 2O 4 with a silver-metal coating  

Microsoft Academic Search

Spenel lithium manganese oxides with a nominal composition of LiMn2O4 are prepared by using a conventional ceramic synthesis method and are coated by a chemical deposition of silver particles. The silver-coated nano-particle LiMn2O4 shows excellent cycleability at 2C galvanostatic conditions. The high surface electronic conductivity caused by the metal coating reduces cell polarization. The results indicate that such surface treatment

J. T. Son; K. S. Park; H. G. Kim; H. T. Chung

2004-01-01

393

Thermal property evolution of metal based thermal barrier coatings with heat treatments  

Microsoft Academic Search

Predicting “in-service” lifetime of ceramic thermal barrier coatings (TBCs) is difficult due to the inherent brittle nature\\u000a of ceramics used. Therefore, the study of metal-based thermal barrier coatings (MBTBCs) has been initiated to challenge the\\u000a current problems of ceramic-based TBCs (CBTBCs) and create a new generation of thermal barrier coatings (TBCs). In this work,\\u000a nano\\/amorphous structured MBTBCs, for use in

Dong-Il Shin; François Gitzhofer; Christian Moreau

2007-01-01

394

Comparative studies of sol-gel SiO II thin films prepared by spin-coating and dip-coating techniques  

NASA Astrophysics Data System (ADS)

Silicon dioxide (SiO II) film is an important material for semiconductor industry as the gate dielectric material, and optical industry as antireflective coatings, and so on. The sol-gel method has been widely used for the deposition of oxide thin films due to several advantages such as simple and low-cost equipment, normal atmospheric conditions, and ease control of the precursor composition doping. In this work, SiO II thin film was deposited on BK7 glass substrate by spin-coating and dip-coating techniques, respectively. Three precursor concentrations were investigated, i.e., tetraethylorthosilicate (TEOS): ethanol: water= 1:7:7, 1:10:10 and 1:15:15 (molar ratio). X-Ray Diffraction spectrometry (XRD), scanning electron microscopy (SEM), and UV-VIS-NIR scanning spectrophotometry were used to characterize the crystallinity, morphological and optical properties of deposited SiO II thin films. Results show that all the SiO II thin films deposited by the spin-coating and dip-coating are amorphous. SEM analysis confirms that the deposited SiO II thin films have high surface quality and tight adherence with the substrate. The transmittance measurements indicate that dip-coated SiO II thin film from gel of low precursor concentration represents better transmittance than that from high concentrations at the range of 600-1200nm. SiO II thin film spin-coated from gel of high precursor concentration has better transmittance than that by dip-coating, but of opposite results for the films deposited from gels of low precursor concentrations.

He, Xiliang; Wu, Jiehua; Gao, Xiangdong; Wu, Lingnan; Li, Xiaomin

2007-12-01

395

Metal sulfide thin films by chemical spray pyrolysis  

NASA Astrophysics Data System (ADS)

CdS, ZnS and CuS thin films were prepared by spray pyrolysis method using metal chlorides and thiourea (tu) as starting materials. Metal sulfide films form as products of thermal decomposition of complexes Cd(tu)2Cl2, Zn(tu)2Cl2 and Cu(tu)Cl(DOT)1/2H2O, originally formed in aqueous solution at precursors molar ratio 1:2. The metal-ligand bonding is thermally stable up to 220 degrees Celsius, followed by multistep degradation process of complexes. The TG/DTA analysis show similar thermal behavior of complexes up to 300 degrees Celsius with the formation of metal sulfides in this decomposition step. In air intensive oxidation processes are detected close to 400, 600 and 720 degrees Celsius for Cu, Cd and Zn complexes, respectively. The results of thermoanalytical study and XRD of sprayed films show that CdS and ZnS films could be grown at 450 degrees Celsius even in air while deposition of copper sulfide films should be performed in an inert atmosphere. High total impurities content of 10 wt% in CdS films prepared at 240 degrees Celsius is originated from the precursor and reduced to 2 wt% by increasing the growth temperature up to 400 degrees Celsius.

Krunks, Malle; Mellikov, Enn

2001-04-01

396

Dielectric breakdown of polymer films containing metal clusters  

SciTech Connect

Thin films of gold-containing plasma-polymerized tetrafluoroethylene were prepared in an rf glow discharge. The films thus obtained showed a wide range of conductivities from insulating ( rho>10/sup 16/ ..cap omega.. cm) to metallic ( rhoapprox.3 x 10/sup -6/ ..cap omega.. cm), depending on plasma conditions during synthesis. The synthesis of the polymer is described in detail since it presents several new aspects. The structure and composition of the films were investigated by x-ray photoelectron spectroscopy and transmission electron microscopy. Studies of current-voltage characteristics in the dielectric regime, i.e., below electrical percolation, show that the conduction is volume limited (Poole--Frenkel effect) in non-gold-containing films, and characterized by a bistable switching behavior for gold-rich films. Dielectric breakdown measurements were realized on self-healing metal-insulator-metal structures. The Weibull analysis of breakdown voltages and a statistical treatment of times to breakdown under constant stress give, respectively, the nominal breakdown field E/sub 0/ and the specific breakdown field E/sub c/. These two sets of data follow similar functional behavior as a function of metallic volume fraction in the films. Surprisingly, the breakdown-field values remain relativity high up to the percolation concentration.

Laurent, C.; Kay, E.; Souag, N.

1988-07-01

397

Spectroscopic ellipsometry of metal phthalocyanine thin films  

E-print Network

of the films may be substrate dependent and that lithium Pc films deposited on glass substrates at room fluorine bridged aluminum A. B. Djurisic´ dalek@eee.hku.hk , C. Y. Kwong, T. W. Lau, L. S. M. Lam, and W. K

398

Metal-organic chemical vapor-deposited cobalt oxide films as negative electrodes for thin film Li-ion battery  

NASA Astrophysics Data System (ADS)

In this study, thin films of cobalt oxide (Co3O4) have been grown by the metal-organic chemical vapor deposition (MOCVD) technique on stainless steel substrate at two preferred temperatures (450 °C and 500 °C), using cobalt acetylacetonate dihydrate as precursor. Spherical as well as columnar microstructures of Co3O4 have been observed under controlled growth conditions. Further investigations reveal these films are phase-pure, well crystallized and carbon-free. High-resolution TEM analysis confirms that each columnar structure is a continuous stack of minute crystals. Comparative study between these Co3O4 films grown at 450 °C and 500 °C has been carried out for their application as negative electrodes in Li-ion batteries. Our method of electrode fabrication leads to a coating of active material directly on current collector without any use of external additives. A high specific capacity of 1168 micro Ah cm-2 ?m-1 has been measured reproducibly for the film deposited at 500°C with columnar morphology. Further, high rate capability is observed when cycled at different current densities. The Co3O4 electrode with columnar structure has a specific capacity 38% higher than the electrode with spherical microstructure (grown at 450°C). Impedance measurements on the Co3O4 electrode grown at 500 °C also carried out to study the kinetics of the electrode process.

Jena, Anirudha; Munichandraiah, N.; Shivashankar, S. A.

2015-03-01

399

Ceramic coating of metal by laser heat treatment at ambient pressure and temperature  

NASA Astrophysics Data System (ADS)

Initial results for a new laser based procedure to make ceramic coatings on ferrous metals are described. The procedure is performed at ambient temperature and pressure to avoid the use of a vacuum chamber. An Nd:YAG laser beam (1064 nm) coupled to a mechanical scanner is used to produce coating. The coating precursor materials are sprayed onto the metal sample before the laser-generated heat treatment. A jet of argon gas is used to avoid oxidation of the metallic substrate. The principal ingredients of the coating precursor are sodium tetraborate and a natural clay mineral. The product is a glassy ceramic. The product has been characterized by scanning electron microscopy, optical microscopy and hardness and adhesion tests. The results indicate that the surface material is a micrometric, single layer which adheres to the metal surface.

Picouet, Pierre A.; McStay, Daniel; Hunter, Catherine; Tonge, Kenneth

2000-02-01

400

Mechanical Properties and Microstructure of Plasma Sprayed Ni-Based Metallic Glass Coating  

SciTech Connect

Various developmental research works on the metallic glass have been conducted in order to broaden its application field. Thermal spraying method is one of the potential techniques to enhance the excellent properties such as high toughness and corrosion resistance of the metallic glass material. The gas tunnel type plasma spraying is useful to obtain high quality ceramic coatings such as Al{sub 2}O{sub 3} and ZrO{sub 2} coatings. In this study, the Ni-based metallic glass coatings were produced by the gas tunnel type plasma spraying under various experimental conditions, and their microstructure and mechanical properties were investigated. At the plasma current of 200-300 A, the Ni-based metallic glass coatings of more than 200 {mu}m in thickness were formed densely with Vickers hardness of about Hv = 600.

Kobayashi, Akira; Kuroda, Toshio [Joining and Welding Res. Inst., Osaka University, 11-1 Mihogaoka, Ibaraki, Osaka 567-0047 (Japan); Kimura, Hisamichi; Inoue, Akihisa [Inst. for Materials Res., Tohoku University, Katahira, Sendai 980-8577 (Japan)

2010-10-13

401

High-rate reel-to-reel continuous coating of biaxially textured magnesium oxide thin films for coated conductors  

SciTech Connect

Biaxially textured thin films of magnesium oxide (MgO) were deposited by electron beam evaporation at deposition rates of 0.6 {mu}m/min on moving Ni-based alloy tapes as oriented buffer layers for coated conductors. Moving substrates were inclined with respect to the atomic vapor and translated through collimated dual vapor sources. Growth anisotropy in the MgO and self-shadowing effects due to the inclined angle combine to create biaxial texture in the deposited thin films. MgO films grown to a thickness of 2.0 {mu}m with this inclined-substrate deposition technique have yielded in-plane textures of 10--12{degree} fill-width half-maximum (FWHM). Results of a parametric study on the in-plane texture in short-length static-mode samples are presented, along with preliminary results of long-length samples deposited under translating conditions.

Chudzik, M. P.; Erck, R. A.; Balachandran, U.; Luo, Z. P.; Miller, D. J.; Kannewurf, C. R.

2000-01-12

402

Biofouling studies on nanoparticle-based metal oxide coatings on glass coupons exposed to marine environment.  

PubMed

Titania, niobia and silica coatings, derived from their respective nanoparticle dispersions or sols and fabricated on soda lime glass substrates were subjected to field testing in marine environment for antimacrofouling applications for marine optical instruments. Settlement and enumeration of macrofouling organisms like barnacles, hydroides and oysters on these nanoparticle-based metal oxide coatings subjected to different heat treatments up to 400 degrees C were periodically monitored for a period of 15 days. The differences observed in the antifouling behaviour between the coated and uncoated substrates are discussed based on the solar ultraviolet light induced photocatalytic activities as well as hydrophilicities of the coatings in case of titania and niobia coatings and the inherent hydrophilicity in the case of silica coating. The effect of heat treatment on the photocatalytic activity of the coatings is also discussed. PMID:19647419

Dineshram, R; Subasri, R; Somaraju, K R C; Jayaraj, K; Vedaprakash, L; Ratnam, Krupa; Joshi, S V; Venkatesan, R

2009-11-01

403

Spin-Coated Erbium-Doped Silica Sol-Gel Films on Silicon  

E-print Network

This work reports optical functionality contained in, as well as and produced by, thin film coatings. A sol-gel process, formulated with precursor active ingredients of erbium oxide and tetraethylorthosilicate (TEOS), was used for spin-coating thin (~130 nm) erbium-doped (~6 at. %) silica films on single-crystal silicon. Annealed films produce infrared emission in the 1.5-micron band from erbium ions in the film, as well as greatly enhancing (~100X) band-gap emission from the underlying silicon. The distinctly different mechanisms for the two modes of optical activities are interpreted in terms of optical emission theory and modeling; prospects for opto-electronic applications are discussed.

Abedrabbo, Sufian; Shet, Sudhakar; Fiory, Anthony; Ravindra, Nuggehalli

2012-01-01

404

Wear of Tools Coated with Various PVD Films: Correlation with Impact Test Results by Means of FEM Simulations  

Microsoft Academic Search

The use of appropriate cutting conditions and coatings is an issue of pivotal signifi- cance since it affects the overall tool performance in manufacturing processes. This paper introduces a quick and innovative procedure for characterizing the coating cutting performance based on the film impact resistance. A correlation between coating impact resistance and cutting performance under various conditions is es- tablished.

Konstantinos-Dionysios Bouzakis; Ioannis Mirisidis; Nikolaos Michailidis; Eleftheria Lili; Anastasios Sampris; Georg Erkens; Rainer Cremer

2007-01-01

405

Diffusion welding of silver interlayers coated onto base metals by planar-magnetron sputtering  

Microsoft Academic Search

Silver has been coated onto various base metals by planar-magnetron (PM) sputtering to provide interlayers for diffusion welding. The vacuum-coating process consisted of two stages: (1) sputter etching of the base metals to remove surface oxide layers, followed by (2) vapor deposition of high-purity silver onto the clean surfaces. The silvers surfaces were diffusion welded at elevated pressure (207 MPa)

R. S. Rosen; M. E. Kassner

1990-01-01

406

The hot erosion behavior of HVOF chromium carbide-metal cermet coatings sprayed with different powders  

Microsoft Academic Search

The high velocity oxygen fuel (HVOF) sprayed chromium carbide-metal cermet coatings have shown some attractive behavior, which makes them superior to arc-sprayed iron base coatings in preventing erosion. While their hot erosion behavior and its dependence on carbide\\/metal matrix proportion have been investigated, the detail study of the hot erosion behavior being dependent on the spraying methods and the starting

Bu Qian Wang; Zheng Rong Shui

2002-01-01

407

Experiment, thermal simulation, and characterizations on transmission laser coating of hydroxyapatite on metal implant.  

PubMed

Coating of bioceramic material, Hydroxyapatite (HAp), on metal implant has attracted many attentions in biomedical industry recently because its combination of good mechanical property and biocompatibility. However, most of current HAp coatings lack coating/substrate interfacial strength, and/or biocompatibility. The cell-tissue attachment is affected by the degraded biocompatibility due to decomposition of HAp during high temperature processing. In this article, an innovative method, transmission laser coating (TLC), is investigated to coat HAp on Ti substrate with low temperature processing. This process enhances the HAp/Metal interfacial property of current coatings, while maintaining good biocompatibility. Experiments are conducted using a continuous neodymium-doped yttrium aluminium garnet (Nd-YAG) laser. Multiphysics simulation is conducted to simulate the temperature distribution in coatings and substrates during TLC processing. X-ray energy dispersion spectrum is used to measure the chemical composition of HAp coatings after TLC process. Pull-out tests are conducted to measure the interfacial strength between the HAp coating and Ti substrate. Cell culture study is conducted to qualitatively evaluate the biocompatibility after TLC of HAp particles. These results show that TLC processing will open new ways of producing biocompatible bioceramic coatings with controlled thickness, and at low processing temperature. PMID:19165793

Cheng, Gary J; Ye, Chang

2010-01-01

408

Use of Precious Metals Coated Titanium Anodes for Industrial Waste Treatment  

E-print Network

he use of precious metals coated titanium anodes for waste treatment and general electrochemical processes has increased substantially during the past ten years because of stringent environmental regulations. The anodes are prepared by applying an electrocatalytic coating (precious metals or oxides of precious metals, typically platinum or indium) on titanium or other valve metal substrates, such as niobium and tantalum. Comparisons are made between titanium anodes and other insoluble anodes such as lead, lead alloy and graphite, in terms of their electrochemical performance and environmental

L. Wang; Electrode Products; Ravi R. Ch

409

Apparatus for coating a surface with a metal utilizing a plasma source  

DOEpatents

An apparatus and method for coating or layering a surface with a metal utilizing a metal vapor vacuum arc plasma source. The apparatus includes a trigger mechanism for actuating the metal vacuum vapor arc plasma source in a pulsed mode at a predetermined rate. The surface or substrate to be coated or layered is supported in position with the plasma source in a vacuum chamber. The surface is electrically biased for a selected period of time during the pulsed mode of operation of the plasma source. Both the pulsing of the metal vapor vacuum arc plasma source and the electrical biasing of the surface are synchronized for selected periods of time.

Brown, Ian G. (Berkeley, CA); MacGill, Robert A. (Richmond, CA); Galvin, James E. (Emeryville, CA)

1991-01-01

410

Can deformation of a polymer film with a rigid coating model geophysical processes?  

PubMed

The structural and mechanical behavior of polymer films with a thin rigid coating is analyzed. The behavior of such systems under applied stress is accompanied by the formation of a regular wavy surface relief and by regular fragmentation of the coating. The above phenomena are shown to be universal. Both phenomena (stress-induced development of a regular wavy surface relief and regular fragmentation of the coating) are provided by the specific features of mechanical stress transfer from a compliant soft support to a rigid thin coating. The above phenomena are associated with a specific structure of the system, which is referred to as "a rigid coating on a soft substratum" system (RCSS). Surface microrelief in RCSS systems is similar to the ocean floor relief in the vicinity of mid-oceanic ridges. Thus, the complex system composed of a young oceanic crust and upper Earth's mantle may be considered as typically "a solid coating on a soft substratum" system. Specific features of the ocean floor relief are analyzed in terms of the approach advanced for the description of the structural mechanical behavior of polymer films with a rigid coating. This analysis allowed to estimate the strength of an ocean floor. PMID:18094934

Volynskii, A L; Bazhenov, S L

2007-12-01

411

Polydopamine film coated controlled-release multielement compound fertilizer based on mussel-inspired chemistry.  

PubMed

This work reports on a facile and reliable method to prepare a polydopamine film coated controlled-release multielement compound fertilizer (PCMCF) based on mussel-inspired chemistry for the first time. The polydopamine (Pdop) film was coated on double copper potassium pyrophosphate trihydrate, providing three essential nutrients (Cu, K, and P) by spontaneous oxidative polymerization of dopamine. The thickness of the polymer coating of the fertilizer was controlled by using the multistep deposition technique. The morphology and composition of the products were characterized by transmission electron microscopy, inductively coupled plasma emission spectrometer, a vis spectrophotometer, and a Kjeltec autoanalyzer. The controlled-release behavior of four elements, including nitrogen from Pdop, was evaluated in water and in soil (sterilized or not). The results revealed that the coated fertilizers had good slow-release properties, incubated in either water or soil. It is noted that the release rate of nutrients of PCMCF can be tailored by the thickness of the Pdop coating, and the Pdop coating can be biodegraded in soil. This coating technology will be effective and promising in the research and development of controlled-release fertilizer. PMID:23464683

Jia, Xin; Ma, Zhi-yuan; Zhang, Guo-xiang; Hu, Jia-mei; Liu, Zhi-yong; Wang, He-yun; Zhou, Feng

2013-03-27

412

Effects of lithium phosphorous oxynitride film coating on electrochemical performance and thermal stability of graphite anodes  

Microsoft Academic Search

In this study, we investigated the effects of lithium phosphorus oxynitride (LiPON) solid electrolyte thin-film deposition on the electrochemical performance and thermal stability of pristine graphite and carbon-coated graphite composite anodes. The LiPON film was deposited by radio frequency (rf) magnetron sputtering. We studied the thermal stability of the lithiated electrodes when immersed in the presence of a liquid electrolyte

Yoon-Soo Park; Sung-Man Lee

2011-01-01

413

Dip coating of PT, PZ and PZT films using an alkoxide-diethanolamine method  

Microsoft Academic Search

Dip-coating of uniform PT, PZ and PZT films was investigated using a solution of titanium tetraisopropoxide (and\\/or zirconiumn-butoxide), diethanolamine, lead acetate trihydrate and isopropanol, where the diethanolamine\\/alkoxide molar ratioR = 1 and the water\\/alkoxide molar ratioW = 3. Perovskite-type PT and PZT films were obtained on glass substrates above 500 to 600 ° C when the solutions with concentrations equal

Yasutaka Takahashi; Yoshihiro Matsuoka; Kouichi Yamaguchi; Michiyasu Matsuki; Keisuke Kobayashi

1990-01-01

414

Comparative study of SnO 2:Sb transparent conducting films produced by various coating and heat treatment techniques  

Microsoft Academic Search

Transparent electrically conducting SnO2:Sb coatings have been prepared by the sol—gel dip-coating process from an ethanolic solution of SnCl2(OAc)2 and SbCl3 (5 mol%). The room temperature resistivity of the dip-coated films heat treated in a furnace or by laser IR irradiation is systematically greater than that obtained for films made by spray pyrolysis. Solution precursors and stabilisers and above all

M. A. Aegerter; A. Reich; D. Ganz; G. Gasparro; J. Pütz; T. Krajewski

1997-01-01

415

Transparent conductive reduced graphene oxide thin films produced by spray coating  

NASA Astrophysics Data System (ADS)

Reduced graphene oxide thin films were fabricated on quartz by spray coating method using a stable dispersion of reduced graphene oxide in N,N-Dimethylformamide. The dispersion was produced by chemical reduction of graphene oxide, and the film thickness was controlled with the amount of spray volume. AFM measurements revealed that the thin films have near-atomically flat surface. The chemical and structural parameters of the samples were analyzed by Raman and XPS studies. It was found that the thin films show electrical conductivity with good optical transparency in the visible to near infrared region. The sheet resistance of the films can be significantly reduced by annealing in vacuum and reach 58 k? with a light transmittance of 68.69% at 550 nm. The conductive transparent properties of the reduced graphene oxide thin films would be useful to develop flexible electronics.

Shi, HongFei; Wang, Can; Sun, ZhiPei; Zhou, YueLiang; Jin, KuiJuan; Yang, GuoZhen

2015-01-01

416

Transparent conductive reduced graphene oxide thin films produced by spray coating  

NASA Astrophysics Data System (ADS)

Reduced graphene oxide thin films were fabricated on quartz by spray coating method using a stable dispersion of reduced graphene oxide in N,N-Dimethylformamide. The dispersion was produced by chemical reduction of graphene oxide, and the film thickness was controlled with the amount of spray volume. AFM measurements revealed that the thin films have near-atomically flat surface. The chemical and structural parameters of the samples were analyzed by Raman and XPS studies. It was found that the thin films show electrical conductivity with good optical transparency in the visible to near infrared region. The sheet resistance of the films can be significantly reduced by annealing in vacuum and reach 58 k? with a light transmittance of 68.69% at 550 nm. The conductive transparent properties of the reduced graphene oxide thin films would be useful to develop flexible electronics.

Shi, HongFei; Wang, Can; Sun, ZhiPei; Zhou, YueLiang; Jin, KuiJuan; Yang, GuoZhen

2014-11-01

417

Fabrication and Evaluation of One-Axis Oriented Lead Zirconate Titanate Films Using Metal-Oxide Nanosheet Interface Layer  

NASA Astrophysics Data System (ADS)

Nanosheet Ca2Nb3O20 (ns-CN) layers with pseudo-perovskite-type crystal configuration were applied on the surface of polycrystalline metal substrates to achieve preferential crystal orientation of Pb(Zr,Ti)O3 (PZT) films for the purpose of enhanced ferroelectricity comparable to that of epitaxial thin films. PZT films with tetragonal symmetry (Zr/Ti=0.40:0.60) were fabricated by chemical solution deposition (CSD) on ns-CN-buffered Inconel 625 and SUS 316L substrates, while ns-CN was applied on the the substrates by dip-coating. The preferential crystal growth on the ns-CN layer can be achieved by favorable lattice matching between (001)/(100)PZT and (001)ns-CN planes. The degree of (001) orientation was increased for PZT films on ns-CN/Inconel 625 and ns-CN/SUS 316L substrates, whereas randomly-oriented PZT films with a lower degree of (001) orientation were grown on bare and Inconel 625 films. Enhanced remanent polarization of 60 µC/cm2 was confirmed for the PZT films on ns-CN/metal substrates, ascribed to the preferential alignment of the polar [001] axis normal to the substrate surface, although it also suffered from higher coercive field above 500 kV/cm caused by PZT/metal interfacial reaction.

Minemura, Yoshiki; Nagasaka, Kohei; Kiguchi, Takanori; Konno, Toyohiko J.; Funakubo, Hiroshi; Uchida, Hiroshi

2013-09-01

418

Structured nanoporous surfaces from hybrid block copolymer micelle films with metal ions.  

PubMed

We present a novel method for producing structured nanoporous thin films using block copolymer (BCP) micelles loaded with metallic ions. The BCP micellar thin films containing gold (Au) ions were prepared by spin-coating poly(styrene-block-4-vinylpyridine) (PS-b-P4VP) micelle solutions in which Au precursors (AuCl4(-)) were selectively loaded onto the P4VP core. When the micellar films were exposed to cetyltrimethylammonium bromide (CTAB) solutions, the Au precursors were selectively extracted from the P4VP domains due to their strong electrostatic interaction with CTAB, leading to the formation of pores in the micelles. Consequently, regularly patterned nanoporous surfaces were formed. By controlling the molecular weight (Mn) of PS-b-P4VP and the amount of Au precursors (?) that were loaded in the P4VP domains, the pore size and depth could be tuned precisely. In particular, when a sufficient amount of Au precursors was loaded (?  ? 0.3), the porous surface nanostructure was well developed. In addition, the pore size and depth of the nanostructure increased as the ? value increased. For instance, when the ? value increased from 0.3 to 1.0, the pore size increased from 22.8 nm to 28.8 nm, and the pore depth increased from 2.1 nm to 3.2 nm. Interestingly, the transition from the nonporous structures to the porous structures in the micellar film could be reversibly controlled by adding and removing the Au precursors in the film. Moreover, our method for the preparation of nanoporous films can be extended to micellar film by incorporating other metal ions such as silver (Ag) and iron (Fe). PMID:25670249

Kim, Minsoo P; Kim, Hyeong Jun; Kim, Bumjoon J; Yi, Gi-Ra

2015-03-01

419

Corrosion resistant coating  

NASA Technical Reports Server (NTRS)

A method of coating a substrate with an amorphous metal is described. A solid piece of the metal is bombarded with ions of an inert gas in the presence of a magnetic field to provide a vapor of the metal which is deposited on the substrate at a sufficiently low gas pressure so that there is formed on the substrate a thin, uniformly thick, essentially pinhole-free film of the metal.

Khanna, S. K.; Thakoor, A. P.; Williams, R. M. (inventors)

1985-01-01

420

Metal-insulator transition in epitaxial vanadium sesquioxide thin films  

NASA Astrophysics Data System (ADS)

Of all the transition metal oxides which exhibit metal-insulator transitions (MIT), one of the most extensively studied in recent years is the vanadium sesquioxide (V2O3), both from experimental and theoretical point of view. At a transition temperature of about 160 K at an ambient pressure of 1 atm, pure V2O3 transforms from a rhombohedral paramagnetic metallic (PM) to a monoclinic antiferromagnetic insulating (AFI) phase upon cooling, with a jump in the resistivity of about seven orders of magnitude. Experimental studies have focused more on bulk V2O3 and recently there have been significant interest in thin film fabrication of this material due to potential applications as thermal sensors, current limiters, Positive Temperature Coefficient (PTC) thermistors, and optical switches. This study addresses the deposition, characterization, and properties of high-quality epitaxial V2O3 thin films grown on a-, c-Al2O3 and c-LiTaO 3 substrates by a straightforward method of pulsed laser deposition (PLD). Various characterization techniques including X-ray diffraction, atomic force microscopy, scanning electron microscopy, and X-ray photoemission spectroscopy were used to examine the structural, crystallographic, and surface properties, while four point probe resistivity measurements were used to examine the electrical properties of the films. V2O3 thin films of different thicknesses ranging from 10-450 nm were deposited on c-Al 2O3 and c-LiTaO3 substrates by PLD to understand also the role of epitaxial strains. Resistivity measurements showed that depending on the thicknesses of films, different electrical transitions were exhibited by the samples. While some of the samples displayed the expected metal-insulator transition typical of bulk V2O3, some showed insulating behavior only and others exhibited metallic characteristics only over the whole temperature range. For example, for films on c-LiTaO3 with increasing film thickness, first an insulator-insulator, then a metal-insulator, followed by a metal-metal transition is observed. Thicker films (>202 nm) remain metallic in the temperature range of the measurements.

Allimi, Bamidele S.

421

Determination of Modulus of Metal Films Using Thermoreflectance  

NASA Astrophysics Data System (ADS)

The acoustic displacements in a film of indium pressed on to a sapphire wafer were generated by incidence of a Q-switched Nd-YAG laser beam. Acoustic displacements from tungsten film deposited on silicon substrate were also measured by the same technique. Thermoreflectance from a continuous red laser incident on the surface was used simultaneously to measure the acoustic oscillations. The acoustic oscillations were simulated using the solution to the modified wave equation. The acoustic velocity and the modulus of the metal film were determined from the simulation of the experimental results. It is shown that this technique provides a nondestructive method of determination of acoustic velocity and modulus in the metal films.

Jagannadham, K.

2015-01-01

422

Generalized coating route to silica and titania films with orthogonally tilted cylindrical nanopore arrays.  

SciTech Connect

We describe a simple, inexpensive coating method to produce thin silica and titania films with surfactant templated, orthogonally tilted cylindrical nanopore arrays. These films can be deposited onto any substrate because orientation of the 2D hexagonally close packed (HCP) mesophases out of the plane of the film is directed by a chemically neutral sacrificial copolymer layer. Orientation of the HCP mesophases through the entire thickness of films cured in open air is achieved by limiting the coating thickness. This generalizes the coating method by making it possible to deposit oriented films on substrates of any curvature and size. We find a critical thickness between 70 and 100 nm, below which the triblock copolymer surfactant-templated HCP phase aligns completely out of the plane of glass and silicon wafer substrates. Above this thickness, the effect of the chemically neutral bottom layer does not propagate across the entire film, and alignment of the HCP mesophases parallel to the (nonpolar) air interface produces a mixed orientation.

Koganti, V. R.; Dunphy, D.; Gowrishankar, V.; McGehee, M. D.; Li, X.; Wang, J.; Rankin, S. E.; X-Ray Science Division; Univ. of Kentucky; SNL; Stanford Univ.

2006-11-08

423

Effect of nanostructured AlN coatings on the oxidation-resistant properties of optical diamond films  

NASA Astrophysics Data System (ADS)

Diamond film is an ultra-durable optical material with high thermal conductivity and good transmission in near-infrared and far-IR (8-14 ?m) wavebands. CVD diamond is subjected to oxidation at temperature higher than 780 °C bared in air for 3 min, while it can be protected from oxidation for extended exposure in air at temperature up to 900 °C by a coating of aluminum nitride. Highly oriented AlN coatings were prepared for infrared windows on diamond films by reactive sputtering method and the average surface roughness ( Ra) of the coatings was about 10 nm. The deposited films were characterized by X-ray diffraction (XRD) and atom force microscope (AFM). XRD confirmed the preferential orientation nature and AFM showed nanostructures. Optical properties of diamond films coated AlN thin film was investigated using infrared spectrum (IR) compared with that for as-grown diamond films.

Zhang, H.; Liu, J. M.; Lu, F. X.

2007-01-01

424

X-ray reflectometry of nanocomposite metal-dielectric films  

Microsoft Academic Search

The technique of X-ray reflectometry used for studying the sizes of metallic and dielectric inclusions in nanocomposite films\\u000a (Fe45Co45Zr10) · (Al2O3)100?x\\u000a depending on their composition is described. The size of isolated metallic inclusions increases with an increase in metallic\\u000a phase concentration and reaches its maximum in the region of the percolation threshold. Above this threshold, metallic inclusions\\u000a merge, thus forming

A. P. Petrakov; L. N. Kotov; Yu. E. Kalinin; A. V. Sitnikov

2009-01-01

425

Porous silica xerogel films as antireflective coatings - Fabrication and characterization  

NASA Astrophysics Data System (ADS)

The paper presents a simple fabrication method of porous silica xerogel films. By adding a surface active agent Triton X-100™ to the starting solution, we can considerably reduce the surface tension, which, in turn, allows to fabricate silica films of high porosity. The paper presents the influence of surfactant content and the influence of heating temperature on the refractive index and thickness of the fabricated films. We fabricated silica films of the minimum refractive index below 1.3 and corresponding porosity ˜50%. Due to low refractive index, the elaborated porous silica xerogel films can be applied to reduce the light reflection coefficient in optical systems. In this work the spectral characteristics of the refractive index, extinction coefficients, the reflection and transmission coefficients and also depolarization factor are presented. The paper also provides results of surface morphology of produced layers, obtained using an atomic force microscope.

Karasi?ski, Pawe?; Jaglarz, Janusz; Reben, Manuela; Skoczek, Edyta; Mazur, Jacek

2011-10-01

426

Size reduction of a semiconductor nanowire laser by using metal coating  

NASA Astrophysics Data System (ADS)

We explore the possibility of coating semiconductor nanowires with metal (Ag) to reduce the size of nanowire lasers operating at photon energies around 0.8-2 eV. Our results show that the material gain of a typical III-V semiconductor in nanowire may be sufficient to compensate Joule losses of such metal as Ag. The most promising mode to achieve lasing is TM 01 near its cutoff. To calculate the guiding properties of metal coated nanowires, we developed a finite-difference discretization approach, the details of which we also present. This approach allowed us to treat accurately the large index contrast of the nanowire/metal interface and to include nonperturbatively the imaginary parts of dielectric constants of the semiconductor core and metal coating.

Maslov, A. V.; Ning, C. Z.

2007-02-01

427

Coated conductor architectures based on IBAD-TiN for high- Jc YBCO films  

NASA Astrophysics Data System (ADS)

Ion-beam assisted deposition (IBAD) is one of the major approaches to realise highly textured templates for YBa 2Cu 3O 7-x (YBCO) coated conductors. Whereas IBAD-MgO is mostly used so far in such buffer architectures, TiN is a suitable alternative for this approach as it is showing a similar textured nucleation required for fast processing. Highly textured TiN films were prepared by ion beam assisted pulsed laser deposition on Hastelloy as well as on stainless steel using a Ta 0.75Ni 0.25 or Y 2O 3 bed layer. The biaxial texture was preserved to a higher thickness using homoepitaxial growth at higher temperatures and transferred to a second SrZrO 3 buffer layer. Finally, YBCO layers with an in-plane and out-of-plane alignment of less than 6° and 3°, respectively, were prepared on the buffered metal tapes leading to critical current densities well above 1 MA/cm 2. The microstructure of the different architectures was studied in detail.

Hühne, R.; Gärtner, R.; Oswald, S.; Schultz, L.; Holzapfel, B.

2011-11-01

428

Improved Cutting Processes with Adapted Coating Systems  

Microsoft Academic Search

Since the introduction of coated metal cutting tools, there has been continuous development and improvement of substrates and coatings. These improvements are invariably aimed at better resistance to the stresses involved in specific cutting tasks like interrupted cutting, machining of adhesive materials or hard and dry machining. Examples of improved performance coatings include multilayer hard thin films or composite hard\\/soft

F. Klocke; T. Krieg; K. Gerschwiler; R. Fritsch; V. Zinkann; M. Pöhls; G. Eisenblätter

1998-01-01

429

Nonstationary hot wire method with silica-coated probe for measuring thermal conductivities of molten metals  

SciTech Connect

The nonstationary hot wire method with a silica-coated probe has been developed to measure thermal conductivities of molten metals at high temperatures. Measurements were carried out on mercury and lead as test liquids. The thermal conductivities of liquid mercury ranged between 7.6 and 8.1 W/m K at temperatures between 273 and 293 K. Factors affecting the thermal conductivity measurement using this method have been discussed. It has been concluded that the nonstationary hot wire method with an insulator-coated probe can be applied to various molten metals, as long as materials for probe coating are pertinent.

Yamasue, Eiji; Susa, Masahiro; Fukuyama, Hiroyuki; Nagata, Kazuhiro [Tokyo Inst. of Tech., Tokyo (Japan)

1999-08-01

430

Laminated solar-control safety glass incorporating chemically deposited metal chalcogenide thin films  

NASA Astrophysics Data System (ADS)

The feasibility of producing safety glass made from 3 mm sheet glass coated with chemically deposited CuS, ZnS-CuS, Sb2S3-CuS, and PbS-CuS thin films are presented. The coatings are produced on the sheet glass from dilute solutions containing metal complexes and a source of sulfide ions such as thiourea, thioacetamide, or thiosulfate. Films of thickness ranging from 0.05 micrometer to 0.3 micrometer are deposited at different temperatures, 10 degrees Celsius - 50 degrees Celsius, with durations of depositions of 1 h to 6 h. These coatings are laminated using commercially available poly(vinyl butyral) based laminating polymer sheets and clear sheet glass at temperatures of 120 degrees Celsius to 140 degrees Celsius under 10 - 12 kg cm-2 pressure in an autoclave. The optical transmittance and reflectance spectra of the safety glasses show that a wide choice of solar control parameters are possible with these glazings: TVIS, 2.5 - 45%; RVIS, 10 - 25%; and shading coefficient (SC), 0.25 - 0.45.

Nair, Padmanabhan K.; Nair, M. T.; Gomez-Daza, O.; Garcia, V. M.; Castillo, A.; Arenas, O. L.; Pena, Y.; Guerrero, L.

1997-10-01

431

Laser generated ultrasound in metals and thin films on silicon  

NASA Astrophysics Data System (ADS)

A study of thermoelastic photoacoustic generation in metals and metallic films on silicon is presented. Results are obtained in thin metal plates and thin films on a silicon substrate. The materials studied are aluminium, copper and chromium. The metallic films on silicon, studied are Al, Cu, and Cr. The laser source is an Nd:YAG laser with second harmonic available. Acoustic waveforms are detected optically using a vibrometer. The generation of acoustic waves in thin plates i.e. Lamb waves can be considered to be comprised of three processes. Absorption of electromagnetic energy by the material, subsequent thermal diffusion into the material and the production of elastic stresses due to thermal expansion. The efficiency of laser generation is investigated in the materials to determine how parameters such as absorption coefficient and optical reflectivity as functions of excitation wavelength influence the generation of Lamb waves. The optical and thermal properties of the thin films are investigated in the same manner to evaluate how the presence of these films influences the production of acoustic waves in the Silicon substrate.

McKee, C.; Culshaw, B.; Thursby, G.; Cleary, A.; Armstrong, I.

2012-05-01

432

UV laser deposition of metal films by photogenerated free radicals  

NASA Technical Reports Server (NTRS)

A novel photochemical method for liquid-phase deposition of metal films is described. In the liquid phase deposition scheme, a metal containing compound and a metal-metal bonded carbonyl complex are dissolved together in a polar solvent and the mixture is irradiated using a UV laser. The optical arrangement consists of a HeCd laser which provides 7 mW of power at a wavelength of 325 nm in the TEM(OO) mode. The beam is attenuated and may be expanded to a diameter of 5-20 mm. Experiments with photochemical deposition of silver films onto glass and quartz substrates are described in detail. Mass spectrometric analysis of deposited silver films indicated a deposition rate of about 1 A/s at incident power levels of 0.01 W/sq cm. UV laser-induced copper and palladium films have also been obtained. A black and white photograph showing the silver Van Der Pauw pattern of a solution-deposited film is provided.

Montgomery, R. K.; Mantei, T. D.

1986-01-01

433

Atomic layer deposition of metal oxide and nitride thin films  

NASA Astrophysics Data System (ADS)

With the continued miniaturization of thin film devices, growth techniques are required that deposit conformal films with atomic layer control. In this thesis, atomic layer deposition (ALD) techniques were developed to achieve conformal and atomic layer controlled film growth. Reactors were constructed and optimized for testing potential precursors and deposition processes. Several methods of volatilization and delivery into the reactor were studied and optimized. All of the ALD methods are based on sequential, self-limiting surface reactions. The research included developing new chemistries and new precursors for ALD, optimizing and characterizing film growth and evaluating properties of ALD films. This thesis is based on experimental work carried out during the years 1999--2002 at Harvard. It will first review ALD in general. Then, the growth and properties of films of metal oxides and nitrides will be described. The self-limiting film growth mechanism in ALD ensures excellent film conformality and uniformity over large areas, and atomic level composition and thickness control. A variety of electronic films have been deposited by ALD. In this thesis, ALD deposition and material characterization of two groups of films will be examined: (i) insulating films and (ii) conductive films. In every case atomic layer controlled growth was shown to occur. In the present work, the deposition of silver-colored, conductive tungsten nitride barrier films by ALD using a novel precursor, bis(tert-butylimido)bis(dimethylamido)tungsten, (t-BuN)2(Me2N)2W, and ammonia at low substrate temperatures (250--350°C) is reported. The basic bulk properties of these films were investigated, as well as their performance as a barrier to the diffusion of copper. The thesis also deals with a new type of ALD reaction, using trimethylaluminum and tris(tert-butoxy)silanol, that deposits dozens of monolayers in cycles less than half a minute long, resulting in a deposition rate more than 100 times faster than previously known ALD reactions for silica nanolaminates. In addition, new deposition processes for metal silicates for hafnium, zirconium, lanthanum and yttrium from metal alkylamides and tris(alkoxy)silanols are reported. Using metal alkylamide precursors and ammonia, films of pure insulating nitrides of hafnium and zirconium were prepared and characterized. The ALD of thin films of Hf3N4 and Zr3N4 using homoleptic tetrakis(dialkylamido)metal(IV) complexes and ammonia at low substrate temperatures (150--250°C) is reported. Hafnium and zirconium oxynitride (HfOxNy and ZrOxN y) dielectrics were also made by ALD using, homoleptic tetrakis(dimethylamido)metal(IV), water and ammonia at low substrate temperatures (200--250°C). The basic bulk properties of these films were investigated, as well as their electrical properties for the application of these materials as gate dielectrics.

Becker, Jill Svenja

434

Superconductivity in Metal-mixed Ion-Implanted Polymer Films  

E-print Network

Ion-implantation of normally insulating polymers offers an alternative to depositing conjugated organics onto plastic films to make electronic circuits. We used a 50 keV nitrogen ion beam to mix a thin 10 nm Sn/Sb alloy film into the sub-surface of polyetheretherketone (PEEK) and report the low temperature properties of this material. We observed metallic behavior, and the onset of superconductivity below 3 K. There are strong indications that the superconductivity does not result from a residual thin-film of alloy, but instead from a network of alloy grains coupled via a weakly conducting, ion-beam carbonized polymer matrix.

A. P. Micolich; E. Tavenner; B. J. Powell; A. R. Hamilton; M. T. Curry; R. E. Giedd; P. Meredith

2005-09-11

435

Effects of humidity during photoprocessing on thin film metallization adhesion  

SciTech Connect

Humidity effects during photoprocessing on tantalum/chromium/gold thin film networks (TFNs) were investigated. Humidity conditions at various process steps were controlled by placing either desiccant or water in handling containers for the TFNs. The TFNs photoprocessed in humid conditions had a much higher occurrence of metallization failures compared to TFNs processed in dry conditions. Ceramic surface defects were shown to cause pores in the thin films, and these pores enhanced corrosion susceptibility for the films. This study resulted in a desiccated storage process for production of TFNs.

Norwood, D.P.

1980-03-01

436

Bi(111) thin film with insulating interior but metallic surfaces.  

PubMed

The electrical conductance of epitaxial Bi thin films grown on BaF(2)(111) by molecular beam epitaxy has been systematically investigated as a function of both film thickness (4-540 nm) and temperature (5-300 K). Unlike bulk Bi as a prototypical semimetal, the Bi thin films up to 90 nm are found to be insulating in the interior but metallic on the surface. This finding not only has unambiguously resolved the long-standing controversy about the existence of the semimetal-semiconductor transition in Bi thin films but also provided a straightforward interpretation for the perplexing temperature dependence of the resistivity of Bi thin films, which in turn might have some potential applications in spintronics. PMID:23215113

Xiao, Shunhao; Wei, Dahai; Jin, Xiaofeng

2012-10-19

437

Fatigue Properties and Fracture Mechanism of Steel Coated with Diamond-Like Carbon Films  

NASA Astrophysics Data System (ADS)

Diamond-like carbon (DLC) films have attracted much attention in many industrial fields because of their excellent tribological properties, high hardness, chemical inertness and biocompatibility. In order to examine the fatigue properties and to clear the fracture mechanism of DLC coated materials, AISI4140 steel coated with DLC films by using unbalanced magnetron sputtering method was prepared and two types of fatigue test were carried out by using a tension and compression testing machine with stress ratio -1 and a bending testing machine with stress ratio -1 with a focused on the fatigue crack behavior in detail. The fracture origin changed from the slip deformation to micro defects at surface whose size didn't affect the fatigue crack initiation behavior in the case of Virgin series because the hard coating like DLC films make the defect sensitivity of coated material higher. However, DLC series indicated higher fatigue strengths in finite life region and fatigue limit compared with Virgin series. From the continuously observation by using a plastic replicas technique, it is clear that there are no noticeable differences on fatigue crack propagation rate between the Virgin and DLC series, however the fatigue crack initiation of DLC series was delayed significantly by existence of DLC films compared with Virgin series.

Akebono, Hiroyuki; Kato, Masahiko; Sugeta, Atsushi

438

Sputtered silver films to improve chromium carbide based solid lubricant coatings for use to 900 C  

NASA Technical Reports Server (NTRS)

Thin silver films, 250 to 3500 A thick, were sputtered onto PS200, a plasma sprayed, chromium carbide based solid lubricant coating, to reduce run-in wear and improve tribological properties. The coating contains bonded chromium carbide as the wear resistant base stock with silver and barium fluoride/calcium fluoride eutectic added as low and high temperature lubricants, respectively. Potential applications for the PS200 coating are cylinder wall/piston ring lubrication for Stirling engines and foil bearing journal lubrication. In this preliminary program, the silver film overlay thickness was optimized based on tests using a pin-on-disk tribometer. The friction and wear studies were performed in a helium atmosphere at temperatures from 25 to 760 C with a sliding velocity of 2.7 m/s under a 4.9 N load. Films between 1000 and 1500 A provide the best lubrication of the counterface material. The films enrich the sliding surface with lubricant and reduce the initial abrasiveness of the as ground, plasma-sprayed coating surface, thus reducing wear.

Dellacorte, Christopher; Sliney, Harold E.; Deadmore, Daniel L.

1988-01-01

439

Sputtered silver films to improve chromium carbide based solid lubricant coatings for use to 900 C  

NASA Technical Reports Server (NTRS)

Thin silver films, 250 to 3500 A thick, were sputtered onto PS200, a plasma sprayed, chromium carbide based solid lubricant coating, to reduce run-in wear and improve tribological properties. The coating contains bonded chromium carbide as the wear resistant base stock with silver and barium fluoride/calcium fluoride eutectic added as low and high temperature lubricants respectively. Potential applications for the PS200 coating are cylinder wall/piston ring lubrication for Stirling engines and foil bearing journal lubrication. In this preliminary program, the silver film overlay thickness was optimized based on tests using a pin-on-disk tribometer. The friction and wear studies were performed in a helium atmosphere at temperatures from 25 to 760 C with a sliding velocity of 2.7 m/s under a 4.9 N load. Films between 1000 and 1500 A provide the best lubrication of the counterface material. The films enrich the sliding surface with lubricant and reduce the initial abrasiveness of the as ground, plasma-sprayed coating surface, thus reducing wear.

Dellacorte, Christopher; Sliney, Harold E.; Deadmore, Daniel L.

1988-01-01

440

Oxygen-scavenging coatings and films based on lignosulfonates and laccase.  

PubMed

Laccase and lignosulfonates were included in coating colors and embedded in latex-based or starch-based films and coatings on foil or board. After 6 days at 23 °C and 100% relative humidity, the oxygen content in airtight chambers decreased from 1.0% (synthetic gas consisting of 99% N(2) and 1% O(2)) to 0.3% in the presence of board coated with lignosulfonate and laccase, while the oxygen content remained unchanged in control experiments without enzyme. The water stability of lignosulfonate-containing latex-based coatings and starch-based films was improved after laccase-catalyzed oxidation of lignosulfonates, which indicates polymerization to products with lower solubility in water. Furthermore, the E' modulus of starch-based films increased with 30%, which indicates laccase-catalyzed polymerization of lignosulfonates resulting in increased stiffness of the film. The results suggest that laccases and lignosulfonates can be used as an oxygen-scavenging system in active packaging and that enzyme-catalyzed polymerization of lignosulfonates contributes to improved water stability and mechanical properties. PMID:22721759

Johansson, Kristin; Winestrand, Sandra; Johansson, Caisa; Järnström, Lars; Jönsson, Leif J

2012-09-15

441

Texture etched ZnO:Al coated glass substrates for silicon based thin film solar cells  

Microsoft Academic Search

ZnO:Al films were r.f.- and d.c.-magnetron sputtered on glass substrates from ceramic (ZnO:Al2O3) and metallic (Zn:Al) targets, respectively. The initially smooth films exhibit high transparencies (T?83% for visible light including all reflection losses) and excellent electrical properties (?=2.7–6×10?4 ? cm). Depending on their structural properties these films develop different surface textures upon post deposition etching in diluted HCl. The light

O. Kluth; B Rech; L Houben; S Wieder; G Schöpe; C Beneking; H Wagner; A Löffl; H. W Schock

1999-01-01

442

Osteogenecity of octacalcium phosphate coatings applied on porous metal implants.  

PubMed

The biomimetic route allows the homogeneous deposition of calcium phosphate (Ca-P) coatings on porous implants by immersion in simulated physiologic solution. In addition, various Ca-P phases, such as octacalcium phosphate (OCP) or bone-like carbonated apatite (BCA), which are stable only at low temperatures, can be deposited. In this pilot study, experiments were designed with a twofold-purpose: (1) to investigate the osteoinduction of OCP-coated and noncoated porous tantalum cylinders and of dense titanium alloy cylinders (5 mm in diameter and 10 mm in length) in the back muscle of goats at 12 and 24 weeks (n = 4); and (2) to compare the osteogenic potentials of BCA-coated, OCP-coated, and bare porous tantalum cylinders in a gap of 1 mm created in the femoral condyle of a goat at 12 weeks (n = 2). In the goat muscle, after 12 weeks the OCP-coated porous cylinder had induced ectopic bone as well as bone within the cavity of the OCP-coated dense titanium cylinder. In the femoral condyle, bone did not fill the gap in any of the porous implants. In contrast with the two other groups, OCP-coated porous cylinders exhibited bone formation in the center of the implant. The nature of the Ca-P coating, via its microstructure, its dissolution rate, and its specific interactions with body fluids, may influence the osteogenecity of the Ca-P biomaterial. PMID:12926029

Barrère, Florence; van der Valk, Chantal M; Dalmeijer, Remco A J; Meijer, Gert; van Blitterswijk, Clemens A; de Groot, Klaas; Layrolle, Pierre

2003-09-15

443

Optical Reflectance Of Metallic Coatings: Effect Of Aluminum Flake Orientation  

Microsoft Academic Search

A set of aluminum-flake pigmented coatings having different flake orientations was pre- pared using various spray conditions. The orientations of individual flakes were determined from images obtained by laser scanning confocal microscopy. Reflectance measurements were carried out to quantify the optical properties of the coatings. A Gaussian orientation distribution or topographic map of the flakes was then used as input

Li-Piin Sung; Maria E. Nadal; Mary E. McKnight; Egon Marx; Brent Laurenti

2001-01-01

444

Propagation loss optimization in metal/dielectric coated hollow flexible terahertz waveguides  

NASA Astrophysics Data System (ADS)

Low-loss hollow flexible metal/dielectric coated polycarbonate waveguides have been designed and fabricated for the maximal tr