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1

Electrically Conductive And Infrared Transparent Thin Metal Film Coatings  

NASA Astrophysics Data System (ADS)

Electrically conductive (EC) and Infrared (IR) transparent thin metal film coatings for the 3 - 5 um and 8 - 12 um wavebands have been developed. Surface resistivity from 5 to 200 ohms/square have been studied. A transmittance value as high as 90% at 10.6 um has been achieved. The performance of these developed coatings are compared with the characteristics of the few IR transparent EC coatings reported in the literature. The fundamental difficulties in producing a highly transparent, wide optical bandwidth coating with low resistivity are discussed. The choice of a semiconductor or metal type EC coating are compared. The optical performance of these two types of IR EC coatings are calculated for equal electrical properties (surface resistivities). Induced transmission optical designs for both EC coating types are presented and the peak transmittance, and bandwidth achieved are compared. Measured results are compared with the calculated values. To date, the developed IR EC coatings have been vacuum deposited on ZnS, ZnSe, Ge, MgF2, Al203 and IR transmitting glass substrates materials. These coatings have also been deposited on a variety of flat optics and on a near hemispherical dome (9" diameter). Some present appli-cations and potential applications of these IR EC coatings are discussed. For example, a 3 - 5 um/millimeter wave aspheric beamsplitter has been produced. Electromagnetic Inter-ference (EMI) shielding of a MgF2 dome with a 3 - 5 um IR EC coating has been accomplished and verified by measurements.

Bright, Clark I.

1986-12-01

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

Thin film metal coated fiber optic hydrophone probe.  

PubMed

Our purpose is to improve the performance sensitivity of a fiber sensor used as a fiber optic hydrophone probe (FOHP) by the addition of nanoscale 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 approximately 9 mum. The performance sensitivity of straight cleaved (i.e., full size core and cladding) uncoated, tapered uncoated, and tapered thin film gold-coated fiber sensors was compared in the frequency range from 1.5 to 20 MHz in the presence of acoustic amplitude pressure levels as high as 6 MPa. An unprecedented voltage sensitivity of -245 dB relative to 1 V/muPa (560 mV/MPa) was measured for a thin film gold-coated FOHP by optimizing the gold coating thickness. PMID:19881652

Gopinath Minasamudram, Rupa; Arora, Piyush; Gandhi, Gaurav; Daryoush, Afshin S; El-Sherif, Mahmoud A; Lewin, Peter A

2009-11-01

4

Ceramic coating effect on liner metal temperatures of film-cooled annular combustor  

NASA Technical Reports Server (NTRS)

An experimental and analytical investigation was conducted to determine the effect of a ceramic coating on the average metal temperatures of full annular, film cooled combustion chamber liner. The investigation was conducted at pressures from 0.50 to 0.062. At all test conditions, experimental results indicate that application of a ceramic coating will result in significantly lower wall temperatures. In a simplified heat transfer analysis, agreement between experimental and calculated liner temperatures was achieved. Simulated spalling of a small portion of the ceramic coating resulted in only small increases in liner temperature because of the thermal conduction of heat from the hotter, uncoated liner metal.

Claus, R. W.; Wear, J. D.; Liebert, C. H.

1979-01-01

5

Coated Aluminized Film Resists Corrosion  

NASA Technical Reports Server (NTRS)

Commercially available corrosion-protection coating allows less costly metals - aluminum in particular used in heat-reflecting films for thermal barriers. Previously, such films had to incorporate gold as reflective layer to withstand humidity, moisture, and salt spray without corroding. This protective coating prevents corrosion of metalized films during evironmental exposure yet remains flexible, thermally stable and clear.

Rockoff, H. J.

1982-01-01

6

Morphology and Optical Properties of Zinc Oxide Films Grown on Metal Coated Glass Substrates by Aqueous Chemical Growth  

NASA Astrophysics Data System (ADS)

Zinc oxide films were deposited on three different metal coated substrates (gold, nickel and platinum) by aqueous chemical growth method. This paper discusses the effect of metal coated substrates on the morphology and optical properties of grown ZnO films. X-Ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FE-SEM) and UV-visible spectroscopy (UV-vis) were employed to characterize the samples. All the as-deposited ZnO films exhibit crystalline hexagonal wurzite structure. The crystallite size of the ZnO films were in the range of 29 to 32 nm. FESEM micrographs revealed hexagonal rod, oval-like and flower-like ZnO structures formed on all metal coated substrates. The Pt coated film contains higher density hexagonal rod as compared to others metal coated substrate. Most probably the Pt lattice parameter is the nearest to ZnO compared to nickel and gold. The optical band gap energy, Eg of ZnO films were estimated to be 3.30 eV which is near to bulk Eg, 3.37 eV. This indicates that the ZnO grown by aqueous chemical growth is able to produce similar quality properties to other conventional method either films or bulk size.

Bakar, M. A.; Hamid, M. A. A.; Jalar, A.; Shamsudin, R.

2013-04-01

7

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

SciTech Connect

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

Nurligareev, D Kh; Usievich, B A; Sychugov, V A; Ivleva, Lyudmila I [A M Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation)

2013-01-31

8

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

NASA Astrophysics Data System (ADS)

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

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

1985-08-01

9

Terahertz surface plasmons excitation by nonlinear mixing of lasers in over ultrathin metal film coated dielectric  

NASA Astrophysics Data System (ADS)

An ultrathin metal film deposited on dielectric plate supports low loss THz surface plasma wave (SPW). The SPW field falls off away from the metal film both inside the dielectric as well as in free space. Two lasers normally incident, from free space on the planar structure, exert a difference frequency ponderomotive force on the free electrons of the film and resonantly excite THz SPW. The ratio of SPW amplitude to lasers is 10-3 at laser intensity of 3 × 1012 W/cm2 at 1 ? m wavelength. The growth rate falls monotonically because at higher frequency the coupling of SPW is weak.

Kumar, Pawan; Tripathi, V. K.

2013-08-01

10

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

11

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

12

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

13

Dip coated ITO thin-films through sol–gel process using metal salts  

Microsoft Academic Search

Indium tin oxide (ITO) thin-films were deposited on soda-lime-silicate glass using sols prepared from alcoholic solutions of indium chloride and stannic chloride with different In:Sn atomic ratios, namely 95\\/5, 90\\/10, 85\\/15 and 80\\/20. The electrical properties, structure and morphology of the thin-films were investigated. All the films studied, with a thickness range of 10–490 nm were polycrystalline with grain sizes

Sutapa Roy Ramanan

2001-01-01

14

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

15

RF-PACVD of water repellent and protective HMDSO coatings on bell metal surfaces: Correlation between discharge parameters and film properties  

NASA Astrophysics Data System (ADS)

Hexamethyldisiloxane (HMDSO) films have been deposited on bell metal using radiofrequency plasma assisted chemical vapor deposition (RF-PACVD) technique. The protective performances of the HMDSO films and their water repellency have been investigated as a function of DC self-bias voltage on the substrates during deposition. Plasma potential measurements during film deposition process are carried out by self-compensated emissive probe. Optical emission spectroscopy (OES) analyses of the plasma during deposition reveal no significant change in the plasma composition within the DC self-bias voltage range of -40 V to -160 V that is used. Raman and X-ray photoelectron spectroscopy (XPS) studies are carried out for film chemistry analysis and indicate that the impinging ion energy on the substrates influences the physio-chemical properties of the HMDSO films. At critical ion energy of 113 qV (corresponding to DC self-bias voltage of -100 V), the deposited HMDSO film exhibits least defective Si-O-Si chemical structure and highest inorganic character and this contributes to its best corrosion resistance behavior. The hardness and elastic modulus of the films are found to be bias dependent and are 1.27 GPa and 5.36 GPa for films deposited at -100 V. The critical load for delamination is also bias dependent and is 11 mN for this film. The water repellency of the HMDSO films is observed to be dependent on the variation in surface roughness. The results of the investigations suggest that HMDSO films deposited by RF-PACVD can be used as protective coatings on bell metal surfaces.

Choudhury, A. J.; Barve, S. A.; Chutia, Joyanti; Pal, A. R.; Kishore, R.; Jagannath; Pande, M.; Patil, D. S.

2011-08-01

16

Scribable coating for plastic films  

NASA Technical Reports Server (NTRS)

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

Clark, R. T.

1967-01-01

17

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

18

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

19

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

NASA Astrophysics Data System (ADS)

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

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

2010-03-01

20

Metal-Coated Optical Fibers for High Temperature Applications  

NASA Technical Reports Server (NTRS)

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

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

1996-01-01

21

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

22

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

Microsoft Academic Search

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

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

2009-01-01

23

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

24

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

25

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.; Eubank, Lowell D.

2004-07-06

26

Metal dusting behavior of coatings.  

SciTech Connect

Surface modification by preoxidation and/or by coatings and alternative materials are being examined at ANL to alleviate the metal dusting problem. Oxide coatings have the advantage that they can minimize carbon-producing reactions (by reducing the availability of catalytic surface) and can also act as a barrier to minimize carbon ingress and pitting of the substrate alloy. We have selected in-situ development of oxide scales, pack diffusion of Al or Cr/Si, and thermal spray of FeAl as avenues for further study. Preliminary tests showed virtually no carbon in pre-oxidized layers of Al-, Cr-, and Si-enriched layers that were subjected to metal dusting environments.

Natesan, K.; Zeng, Z.; Soppet, W. K.; Rink, D. L.

2002-10-16

27

Transition metal nitride functional coatings  

NASA Astrophysics Data System (ADS)

During the past decade, interest in transition metal nitrides has grown considerably. Nitrides of various elements play an important role in industry, science, and technology for their interesting and useful resilient properties. For example, many transition metal nitrides based on titanium, boron, and nitrogen have stimulated commercial interest because of their extreme hardness, wear and corrosion resistance, and thermal and electrical properties. All of these features are enhanced by the resulting structures and the large degree of covalency exhibited by the transition metal-nitride bonds. Coatings of select nitrides may particularly influence physico-chemical properties in critical surface and interface regions. This article attempts to present a brief overview on transition metal-nitride research for advancement in reliable machine part manufacturing.

Navinsek, B.; Seal, Sudipta

2001-09-01

28

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

29

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. 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.

Buchheit, Rudolph G. (Albuquerque, NM); Martinez, Michael A. (Albuquerque, NM)

1998-01-01

30

Refractory Metal Coatings by Chemical Vapor Deposition.  

National Technical Information Service (NTIS)

The basic processes necessary to manufacture refractory metal coatings using chemical vapor deposition technology were investigated. The processes developed were demonstrated on a typical oxidation resistant coating of titanium-chromium-silicon but would ...

G. F. Wakefield

1966-01-01

31

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

32

UV curable polyurethane acrylate coatings for metal surfaces  

Microsoft Academic Search

Purpose – The purpose of this paper is to synthesise environment friendly UV curable polyurethane acrylate resins for various industrial applications and study the performance properties of the cured coating films applied over metal surfaces. Design\\/methodology\\/approach – The polyurethane acrylate resin was synthesised using polyester polyol (synthesised using ethylene glycol, adipic acid and 1,6 hexane diol), isophorone diisocynate (IPDI) and

A. Srivastava; D. Agarwal; S. Mistry; J. Singh

2008-01-01

33

Antireflective coating using aluminum hydroxide formed by hydrothermal treatment of sputtered aluminum films  

Microsoft Academic Search

Here we have proposed a simple method for forming antireflective coating. By putting a rf sputtered metallic Al film into boiling ultrapure water, the film becomes transparent. Its optical transmittance exceeds the glass substrate itself. In addition, the glass substrate with such coating on both sides shows almost perfect transmittance at specific wavelengths. By electron diffraction, the crystal structure of

Takashi Ishiguro; Toshiyuki Hori; Zhiyong Qiu

2009-01-01

34

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

35

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

36

Bi-metal coated aperture SNOM probes  

NASA Astrophysics Data System (ADS)

Aperture probes of scanning near-field optical microscopes (SNOM) offer resolution which is limited by a sum of the aperture diameter at the tip of a tapered waveguide probe and twice the skin depth in metal used for coating. An increase of resolution requires a decrease of the aperture diameter. However, due to low energy throughput of such probes aperture diameters usually are larger than 50 nm. A groove structure at fiber core-metal coating interface for photon-to-plasmon conversion enhances the energy throughput 5-fold for Al coated probes and 30-fold for Au coated probes due to lower losses in the metal. However, gold coated probes have lower resolution, first due to light coupling from the core to plasmons at the outside of the metal coating, and second due to the skin depth being larger than for Al. Here we report on the impact of a metal bilayer of constant thickness for coating aperture SNOM probes. The purpose of the bilayer of two metals of which the outer one is aluminum and the inner is a noble metal is to assure low losses, hence larger transmission. Using body-of-revolution finite-difference time-domain simulations we analyze properties of probes without corrugations to measure the impact of using a metal bilayer and choose an optimum bi-metal configuration. Additionally we investigate how this type of metalization works in the case of grooved probes.

Antosiewicz, Tomasz J.; Wróbel, Piotr; Szoplik, Tomasz

2011-05-01

37

Defect-free nanostructured alumina coating doped with noble metal nanoparticles  

Microsoft Academic Search

Nanostructured alumina coatings loaded with platinum or gold nanoparticles were prepared by two different methods. In the first method the alumina coatings were prepared in the presence of metal ions, which were reduced using UV irradiation once the film was deposited. In the second method, polyvinylpyrrolidone-stabilized nanoparticles were first synthesized and then incorporated in the coating. The texturation of the

Miroslava Malenovska; Marie-Alexandra Neouze; Ulrich Schubert; Veronique Monnier; Emmanuel Scolan; Raphael Pugin

2009-01-01

38

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

39

Plasma-Spray Metal Coating On Foam  

NASA Technical Reports Server (NTRS)

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

Cranston, J.

1994-01-01

40

Metal fluoride coatings prepared by ion-assisted deposition  

NASA Astrophysics Data System (ADS)

ArF lithography technology requires minimization of optical losses due to scattering and absorption. Consequently, it is necessary to optimize the coating process of metal fluorides. The properties of metal fluoride thin films are mainly affected by the deposition methods, their parameters (temperature and deposition rate) and the vacuum conditions. A substrate temperature of more than 300°C is a condition for high density and low water content of metal fluorides. Therefore, a substrate temperature of 150°C results in inhomogeneous films with high water content. Until now, the best results were achieved by boat evaporation. This paper will demonstrate that most of the common metal fluorides like MgF2, AlF3, and even LaF3 can be deposited by electron beam evaporation. In comparison to other deposition methods, the prepared thin films have the lowest absorption in the VUV spectral range. Furthermore, metal fluoride thin films were prepared by ion assistance. It will be demonstrated, that they have less water content, high packing density, and low absorption in the VUV spectral range. In this study, single layers of LaF3 and AlF3 and antireflection coatings were prepared by electron beam evaporation with and without ion-assistance. The mechanical, structural, and optical properties were examined and discussed.

Bischoff, Martin; Sode, Maik; Gäbler, Dieter; Bernitzki, Helmut; Zaczek, Christoph; Kaiser, Norbert; Tünnermann, Andreas

2008-09-01

41

Superconductive niobium films coating carbon nanotube fibers  

NASA Astrophysics Data System (ADS)

Superconducting niobium (Nb) has been successfully obtained by sputter deposition on carbon nanotube fibers. The transport properties of the niobium coating the fibers are compared to those of niobium thin films deposited on oxidized Si substrates during the same deposition run. For niobium films with thicknesses above 300 nm, the niobium coating the fibers and the thin films show similar normal state and superconducting properties with critical current density, measured at T = 4.2 K, of the order of 105 A cm−2. Thinner niobium layers coating the fibers also show the onset of the superconducting transition in the resistivity versus temperature dependence, but zero resistance is not observed down to T = 1 K. We evidence by scanning electron microscopy (SEM) and current-voltage measurements that the granular structure of the samples is the main reason for the lack of true global superconductivity for thicknesses below 300 nm.

Salvato, M.; Lucci, M.; Ottaviani, I.; Cirillo, M.; Behabtu, N.; Young, C. C.; Pasquali, M.; Vecchione, A.; Fittipaldi, R.; Corato, V.

2014-11-01

42

Systematic Evaluation of Jc Decrease in Thick Film Coated Conductors  

SciTech Connect

Address both thickness dependence of Jc, in thick film YBCO coated conductors through an application of a suite of new measurement techniques to thick film wire samples produced by commercially viable coated conductor technologies.

Alex Ignatiev; Dr. Amit Goyal

2006-05-10

43

Polyvinyl acetate-based film coatings.  

PubMed

Polyvinyl acetate-based colloidal aqueous polymer dispersion Kollicoat(®) SR 30 D results in coatings characterized by moderate swelling behaviour, lipophilicity, pH-independent permeability for actives and high flexibility to withstand mechanical stress and is therefore used for controlled release coating. The colloidal aqueous polymer dispersion of Kollicoat(®) SR 30 D can be easily processed due to an optimal low minimum film forming temperature (MFT) of 18 °C without plasticizer addition and a thermal after-treatment (curing) of coated pellets. The drug release from Kollicoat(®) SR 30 D coated pellets was almost pH independent. Drug release could be easily adjusted by coating level or addition of soluble pore forming polymers. Physically stable Kollicoat(®) SR 30 D dispersions were obtained with the water-soluble polymers Kollidon(®) 30 and Kollicoat(®) IR up to 50% w/w. The addition of only 10% w/w triethyl citrate as plasticizer improved the flexibility of the films significantly and allowed compaction of the pellets. The drug release was almost independent of the compression force and the pellet content of the tablets. The inclusion of various tableting excipients slightly affected the drug release, primarily because of a different disintegration rate of the tablets. A combination of Kollicoat(®) SR 30 D and Kollicoat(®) IR with higher coating levels>10 mg/cm(2) is a relatively new alternative to OROS system which does not require drilling. PMID:24076229

Kolter, K; Dashevsky, A; Irfan, Muhamad; Bodmeier, R

2013-12-01

44

Filiform corrosion in polymer-coated metals  

Microsoft Academic Search

Filiform corrosion is a type of localized corrosion which affects painted metals (usually steel, aluminium and magnesium). Filiform corrosion often occurs in marine environments and it produces protective coating damage and thread-like metal base attack. This paper reviews some of the research on this type of corrosion. The survey describes the phenomenon and the resulting problems, enumerates the most important

A. Bautista

1996-01-01

45

Antibacterial property of DLC film coated on textile material  

Microsoft Academic Search

To evaluate the antibacterial property for diamond-like carbon films (DLC), DLC films were coated on textile material (cotton fibres) using a plasma-based ion implantation (PBII). Raman spectra show the DLC films were successfully coated on the cotton fibres. An antibacterial property of DLC film against two types of bacteria (Staphylococcus aureus, and Klebsiella pneumoniae) was investigated by the standard evaluation

N. Kitahara; T. Sato; H. Isogawa; Y. Ohgoe; S. Masuko; F. Shizuku; K. K. Hirakuri

2010-01-01

46

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

47

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

48

Edible Films and Coatings for Meat and Poultry  

Microsoft Academic Search

\\u000a Edible films and coatings are defined as continuous matrices that can be prepared from proteins, polysaccharides and\\/or lipids\\u000a to alter the surface characteristics of a food. Although the terms films and coatings are used interchangeably, films in general\\u000a are preformed and are freestanding, whereas, coatings are formed directly on the food product. Proteins used in edible films\\u000a include wheat gluten,

Zey Ustunol

49

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

50

Covering solid, film cooled surfaces with a duplex thermal barrier coating  

NASA Technical Reports Server (NTRS)

Thermal barrier coating systems were applied to hardware having passageways in the walls connecting apertures in the surface to a gas supply for film cooling. An inert gas, such as argon, is discharged through the apertures during the application of the thermal barrier coating system by plasma spraying. This flow of inert gas reduces both blocking of the holes and base metal oxidation during the coating operation.

Liebert, C. H. (inventor)

1983-01-01

51

Mode characteristics of metal-coated microcavity  

NASA Astrophysics Data System (ADS)

The mode characteristics (dispersion relation and Q factor) of metal-coated microcylinders are achieved from the analytical resonance eigenequation. Among the resonance modes, two surface plasmon polariton (SPP) modes have completely different characteristics compared to the hybrid plasmonic whispering gallery modes (WGMs). In the metal-coated microcylinder, the Q factor of the asymmetrical SPP mode can be greater than the symmetric mode, and the hybrid plasmonic WGMs have a greater mode index range, extending down to zero. Also, the mode indexes and Q factors of the resonance modes are measured by the attenuated total reflection and resonance linewidth method, respectively. The experimental results agree well with the theoretical.

Gu, Jinyi; Zhang, Zhuo; Li, Mi; Song, Yuejiang

2014-07-01

52

Oxide ferromagnetic semiconductors: coatings and films  

NASA Astrophysics Data System (ADS)

The review concerns the results of studies reported in the last decade and concerning oxide ferromagnetic semiconductors which retain the spin orientation of charge carriers above room temperature. Particular attention is paid to methods of preparation of diluted magnetic semiconductors. Methods of synthesis and peculiarities of the physicochemical properties of films and coatings based on ferromagnetic semiconductors are described and prospects for application of these compounds as materials for spintronics are discussed. The bibliography includes 160 references.

Nipan, G. D.; Stognij, A. I.; Ketsko, Valerii A.

2012-05-01

53

Polyenamines for Films, Coatings, and Adhesives  

NASA Technical Reports Server (NTRS)

Easy process makes polymers with good mechanical properties. Synthesis involves Michael-type addition polymerization of two diacetylenic diketones, with various aromatic diamines in m-cresol at 60 to 130 degrees C. Technique provides synthetic route to high-molecular-weight polyenamines with moderate thermal stability and good mechanical properties. Polyenamines produced exhibit potential for use as films, coatings, adhesives, molding compounds, and composite matrices.

Hergenrother, Paul M.; Bass, Robert G.; Sinsky, Mark S.; Connell, John W.

1987-01-01

54

Antireflective coating using aluminum hydroxide formed by hydrothermal treatment of sputtered aluminum films  

NASA Astrophysics Data System (ADS)

Here we have proposed a simple method for forming antireflective coating. By putting a rf sputtered metallic Al film into boiling ultrapure water, the film becomes transparent. Its optical transmittance exceeds the glass substrate itself. In addition, the glass substrate with such coating on both sides shows almost perfect transmittance at specific wavelengths. By electron diffraction, the crystal structure of the transformed film is confirmed to be boehmite. The refractive index of the transparent film is estimated to be one of the median values of the glass and air.

Ishiguro, Takashi; Hori, Toshiyuki; Qiu, Zhiyong

2009-07-01

55

Sputter deposition of a spongelike morphology in metal coatings  

NASA Astrophysics Data System (ADS)

Metallic films are grown with a ``spongelike'' morphology in the as-deposited condition using planar magnetron sputtering. The morphology of the deposit is characterized by metallic continuity in three dimensions with continuous and open porosity on the submicron scale. The stabilization of the spongelike morphology is found over a limited range of the sputter deposition parameters, that is, of working gas pressure and substrate temperature. This spongelike morphology is an extension of the features as generally represented in the classic zone models of growth for physical vapor deposits. Nickel coatings are deposited with working gas pressures up to 4 Pa and for substrate temperatures up to 1100 K. The morphology of the deposits is examined in plan and in cross section views with scanning electron microscopy. The parametric range of gas pressure and substrate temperature (relative to absolute melt point) under which the spongelike metal deposits are produced appear universal for other metals including gold, silver, and aluminum.

Jankowski, A. F.; Hayes, J. P.

2003-03-01

56

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

57

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

58

Gas discrimination by ZnO nanowire arrays with different metal oxide coatings  

Microsoft Academic Search

Three-dimensional (3D) metal oxide nanowire arrays have large surface area and numerous gas transport channels, which can significantly improve the gas sensing performance, such as sensitivity, response and recovery speed, etc. compared to their thin films counterparts. Furthermore, different metal oxide coatings can be used to diversify the chemical reactivity of the nanowires for gas discrimination. A general route to

Jiajun Chen; Haiqiao Su; Weilie Zhou

2011-01-01

59

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

SciTech Connect

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

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

1993-10-01

60

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

Microsoft Academic Search

This article continues a series of papers that shows how thin (10 nm or less) oxide-free phosphate films can be formed on a number of metals. The films formed have potential as corrosion resistant films. Previous papers have shown that it is possible to extend the range of the surface coatings that can be formed by placing a thin polymer

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

2007-01-01

61

Process for fabrication of metal oxide films  

SciTech Connect

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

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

1990-07-17

62

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

63

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

64

Laser-Induced High-Strain-Rate Superplastic 3-D Microforming of Metallic Thin Films  

Microsoft Academic Search

Microforming of metals has always been a challenge because of the limited formability of metals at the microscale. This paper investigates an innovative microforming technique: microscale laser dynamic forming (??LDF), which induces 3-D superplastic forming in metallic thin films. This forming process proceeds in a sequence of laser irradiation and ionization of ablative coating, shockwave generation and propagation in metallic

Huang Gao; Gary J. Cheng

2010-01-01

65

Growth of Cu 2ZnSnS 4 thin films using sulfurization of stacked metallic films  

Microsoft Academic Search

We fabricated Cu2ZnSnS4 (CZTS) thin films through sulfurization of stacked metallic films. Three types of Cu–Zn–Sn metallic films, i.e., Cu-rich, Cu-correct and Cu-poor precursor films were sputtered onto Mo-coated glass. The sulfurization of stacked Cu–Zn–Sn alloy films was performed at a relatively high temperature, 570°C, with S-powder evaporation. CZTS films from Cu-rich and Cu-correct precursors showed a Cu2?xS phase on

Hyesun Yoo; Junho Kim

2010-01-01

66

Method of producing thermally sprayed metallic coating  

DOEpatents

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

Byrnes, Larry Edward (Rochester Hills, MI); Kramer, Martin Stephen (Clarkston, MI); Neiser, Richard A. (Albuquerque, NM)

2003-08-26

67

Thin films of metal-organic frameworks.  

PubMed

The fabrication of thin film coatings of metal-organic frameworks (MOFs) on various substrates is discussed in this critical review. Interestingly, the relatively few studies on MOF films that have appeared in the literature are limited to the following cases: [Zn4O(bdc)3] (MOF-5; bdc=1,4-benzenedicarboxylate), [Cu3(btc)2] (HKUST-1; btc=1,3,5-benzenetricarboxylate), [Zn2(bdc)2(dabco)] (dabco=1,4-diazabicyclo[2.2.2]octane), [Mn(HCOO)], [Cu2(pzdc)2(pyz)] (CPL-1; pzdc=pyrazine-2,3-dicarboxylate, pyz=pyrazine), [Fe(OH)(bdc)] (MIL-53(Fe)) and [Fe3O(bdc)3(Ac)] (MIL-88B; Ac=CH3COO-). Various substrates and support materials have been used, including silica, porous alumina, graphite and organic surfaces, i.e. self-assembled monolayers (SAMs) on gold, as well as silica surfaces. Most of the MOF films were grown by immersion of the selected substrates into specifically pre-treated solvothermal mother liquors of the particular MOF material. This results in more or less densely packed films of intergrown primary crystallites of sizes ranging up to several microm, leading to corresponding film thicknesses. Alternatively, almost atomically flat and very homogenous films, with thicknesses of up to ca. 100 nm, were grown in a novel stepwise layer-by-layer method. The individual growth steps are separated by removing unreacted components via rinsing the substrate with the solvent. The layer-by-layer method offers the possibility to study the kinetics of film formation in more detail using surface plasmon resonance. In some cases, particularly on SAM-modified substrates, a highly oriented growth was observed, and in the case of the MIL-53/MIL-88B system, a phase selective deposition of MIL-88B, rather than MIL-53(Fe), was reported. The growth of MOF thin films is important for smart membranes, catalytic coatings, chemical sensors and related nanodevices (63 references). PMID:19384445

Zacher, Denise; Shekhah, Osama; Wöll, Christof; Fischer, Roland A

2009-05-01

68

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

69

Peroxotungstic Acid Coated Films for Electrochromic Display Devices  

NASA Astrophysics Data System (ADS)

Peroxotungstic acid coated films were investigated for applications to electrochromic display devices. Films coated with peroxotungstic acid aqueous solutions exhibited electrochromism in non-aqueous electrolyte solutions containing Li-salts. A good reversibility for the electrochromic reaction was attained after several writing-erasing cycles involving linear sweeps when the films had been heat-treated at about 120°C for 1 h. Cathodic polarization of the coated films irreversibly reduced the peroxotungstic acid to tungsten trioxide in the electrolyte. This resulted in the devices having poor initial response characteristics. After several aging cycles, however, the coloring efficiency and response rate of the coated films were favorable and comparable to those of tungsten trioxide evaporated films.

Yamanaka, Kazusuke; Oakamoto, Hiroshi; Kidou, Hirokazu; Kudo, Tetsuichi

1986-09-01

70

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

71

Multilayer thin-film coatings for optical communication systems  

Microsoft Academic Search

Recent developments in thin-film coatings for optical communication systems are reviewed. Particular emphasis is given to thin-film designs with dispersion related to the photonic crystal superprism effect. A single dispersive coating may be used for multiplexing or demultiplexing several wavelength channels by spatial beam shifting. ?2004 Optical Society of America OCIS codes: (310.0310) Thin films, (060.2340) Fiber optics components; (260.2030)

Martina Gerken; David A. B. Miller

2004-01-01

72

Wear Resistance of Coating Films on Hob Teeth  

NASA Astrophysics Data System (ADS)

The wear resistance of coating films on hob teeth is investigated through the simulated hobbing tests with a flytool. The coating films on hob teeth are titanium family ceramics such as TiN, TiCN, TiSiN and TiAlN and aluminum chromium family ceramics such as AlCrN and AlCrSiN. The wear of coated tools is shown about film thickness, film materials, ingredient ratio in a film component and the oxidization of coating films. The oxidization is clarified from a result of the influence on the crater wear progress through wear cutting tests in atmosphere of nitrogen gas or oxygen gas. The oxidization of TiAlN coating films produces oxide products on the tool rake face, and this oxidation relates to the amount of crater wear. The increase of aluminum concentration in the TiAlN film improves the crater wear resistance in air atmosphere, while it has a reverse effect in nitrogen gases. The AlCrSiN film has effective wear resistance against the abrasive wear and/or oxidization wear. The oxidation film formed on the AlCrSiN film is very firm and this suppresses the oxidation wear on the rake face and works against the abrasive wear advantageously.

Umezaki, Yoji; Funaki, Yoshiyuki; Kurokawa, Syuhei; Ohnishi, Osamu; Doi, Toshiro

73

One-step graphene coating of heteroepitaxial GaN films.  

PubMed

Today, state-of-the-art III-Ns technology has been focused on the growth of c-plane nitrides by metal-organic chemical vapor deposition (MOCVD) using a conventional two-step growth process. Here we show that the use of graphene as a coating layer allows the one-step growth of heteroepitaxial GaN films on sapphire in a MOCVD reactor, simplifying the GaN growth process. It is found that the graphene coating improves the wetting between GaN and sapphire, and, with as little as ~0.6 nm of graphene coating, the overgrown GaN layer on sapphire becomes continuous and flat. With increasing thickness of the graphene coating, the structural and optical properties of one-step grown GaN films gradually transition towards those of GaN films grown by a conventional two-step growth method. The InGaN/GaN multiple quantum well structure grown on a GaN/graphene/sapphire heterosystem shows a high internal quantum efficiency, allowing the use of one-step grown GaN films as 'pseudo-substrates' in optoelectronic devices. The introduction of graphene as a coating layer provides an atomic playground for metal adatoms and simplifies the III-Ns growth process, making it potentially very useful as a means to grow other heteroepitaxial films on arbitrary substrates with lattice and thermal mismatch. PMID:23059535

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

2012-11-01

74

One-step graphene coating of heteroepitaxial GaN films  

NASA Astrophysics Data System (ADS)

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

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

2012-11-01

75

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

76

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

77

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

NASA Technical Reports Server (NTRS)

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

Ross, B.

1981-01-01

78

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

79

High-reflectance composite metal coatings for planar-integrated free-space optics.  

PubMed

For planar-integrated free-space optical (PIFSO) systems high-reflectance thin-film coatings are crucial. Evaporated metal films are preferred for their relative technological simplicity. We propose a three-layer Al-Ag-Al coating composition that combines the high reflectance of Ag with the chemical passivity of Al and its good adherence to glass. Two special measures are taken to prevent delamination: one is an anchoring of the edges of the coating in narrow ditches that are etched into the substrate and the other is the use of an adhesive Al underlayer; to reduce absorption this underlayer is implemented only in sparsely distributed discrete areas. The optical properties of such composite coatings are investigated theoretically. The fabrication complexity is only slightly increased compared to PIFSO systems with one-layer Al reflectors. In experimental tests we verified a reflectance of approximately 98% and an adherence comparable to that of simple Al coatings. PMID:16485677

Gruber, Matthias; Seiler, Thomas; Wei, An-Chi

2006-02-01

80

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

81

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

NASA Astrophysics Data System (ADS)

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

Wang, Jing; Zhu, Yaofeng; Fu, Yaqin

2013-11-01

82

Very long nuclear relaxation times of spin polarized helium 3 in metal coated cells  

Microsoft Academic Search

We obtained very long relaxation times T1 of up to 120 h for the nuclear polarization of an optically pumped helium 3 gas. The glass containers were internally coated with metallic films such as bismuth or cesium. These findings will have applications in the field of helium magnetometers and polarized targets.

Werner Heil; Hubert Humblot; Ernst Otten; Matthias Schafer; Reinhard Sarkau; Michèle Leduc

1995-01-01

83

Improvement of corrosion resistance of transparent conductive multilayer coating consisting of silver layers and transparent metal oxide layers  

SciTech Connect

An optical filter for plasma display panel (PDP) requires an electromagnetic shield with very high ability. The authors investigated a transparent conductive multilayer coating consisting of silver (Ag) layers and transparent metal oxide layers. The durability of the multilayer sputter coating, including the silver layer, is very sensitive to the surrounding atmosphere. For example, after an exposure test they found discolored points on the multilayer sputter coatings, possibly caused by migration of silver atoms in the silver layers. In their investigation, they modified the top surface of the multilayer sputter coatings with transition metals to improve the corrosion resistance of the multilayer coating. Specifically, they deposited transition metals 0.5-2 nm thick on the top surface of the multilayer coatings by sputtering. They chose indium tin oxide (ITO) as the transparent metal oxide. They applied the multilayer sputter coatings of seven layers to a polyethylene terephthalate (PET) film substrate. A cross-sectional structure of the film with the multilayer coatings is PET film/ITO/Ag/ITO/Ag/ITO/Ag/ITO. They evaluated the corrosion resistance of the films by a salt-water immersion test. In the test, they immersed the film with multilayer coatings into salt water, and then evaluated the appearance, transmittance, and electrical resistance of the multilayer coatings. They investigated several transition metals as the modifying material, and found that titanium and tantalum drastically improved the resistance of the multilayer coatings to the salt-water exposure without a significant decline in transmittance. They also investigated the relation between elapsed time after deposition of the modifying materials and resistance to the salt water. Furthermore, they investigated the effects of a heat treatment and an oxide plasma treatment on resistance to the salt water.

Koike, Katsuhiko; Yamazaki, Fumiharu; Okamura, Tomoyuki; Fukuda, Shin [Mitsui Chemicals, Inc., Sodegaura, Chiba 299-0265 (Japan)

2007-05-15

84

Aluminum oxynitride coatings for oxidation resistance of epoxy films  

Microsoft Academic Search

Aluminum nitride (AlN) and aluminum oxynitride (AlNO) films were sputter deposited onto epoxy coated silicon substrates. The films were characterized by: electron microscopy; atomic force microscopy; ?-2? X-ray diffractometry; and profilometry. The surface morphology of the films was a function of the feed gas oxygen content. Amorphous aluminum oxynitride films formed with oxygen flows of more than 0.5 sccm yielded

N. J Ianno; H Enshashy; R. O Dillon

2002-01-01

85

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

Microsoft Academic Search

Hollow waveguides have been developed for many years but their losses are still much greater than those for solid-core fiber optics. The primary emphasis in this work is the development of new metallic and dielectric coatings which may be used as coatings for lower loss hollow waveguides. Much of the work involves the use of polymer tubing coated with Ag

Roshan J. George

2004-01-01

86

Water soluble cellulose acetate: a versatile polymer for film coating.  

PubMed

The objective of this study was to investigate the use of water soluble cellulose acetate (WSCA) as a film coating material for tablets. Aspirin (ASA) tablets were prepared by direct compression and coated with either WSCA or HPMC (hydroxypropyl methylcellulose) dispersions. Coatings of 1-3%, depending on the intended application, were applied to the model drug (ASA) tablets employing a side-vented coating pan. Free films of WSCA, prepared by cast method, are crystal clear and, depending on the viscosity grade, are flexible, strong and durable. WSCA has the capability of forming free films without plasticizers and the films dry at room temperature. Glass transition temperature, Tg, was determined by differential scanning calorimetry. The Tg of WSCA is significantly higher relative to HPMC. Inclusion of plasticizer lowers the Tg of WSCA and effective plasticizers were PEG 400 and glycerin. Low viscosity WSCA was more soluble in water (25-30%) relative to medium viscosity WSCA (10-15%). WSCA solutions exhibited no increase in viscosity with an increase in temperature. Samples of coated (WSCA and HPMC) tablets and uncoated ASA cores were packaged for stability studies at room and elevated temperature storage. Physical stability of ASA tablets coated with 2:1 LV: MV (low viscosity: medium viscosity) WSCA formulations was better when compared to tablets coated with HPMC. Dissolution stability of WSCA coated ASA was similar to the physical stability results. After three months at elevated temperature (35 and 45 degrees C), the WSCA coated tablets complied with USP dissolution requirements for ASA, while the HPMC coated tablets did not. There was no difference in moisture (weight) gain of ASA tablets coated with either WSCA or HPMC. The WSCA coated tablets were not sticky or tacky, while the HPMC coated tablets were tacky and stuck together. PMID:17454061

Wheatley, Thomas A

2007-03-01

87

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

88

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

89

Improving the detection performance of heavy metal halides films by surface treatment  

Microsoft Academic Search

Films of three heavy metal halides (BiI3, HgBr2, HgI2) were grown by the PVD method on Pd-coated glass substrates 1”x1” in size. Before the growth substrates were cut in the diagonal direction in order to obtain two representative films for each set. Films were grown under the most appropriate conditions for each material. Film thicknesses ranged between 50 and 200

L. Fornaro; I. Aguiar; N. Sasen; M. Perez; A. Noguera

2010-01-01

90

Experimental and Analytical Studies on the High Cycle Fatigue of Thin Film Metal on PET Substrate for Flexible Electronics Applications  

Microsoft Academic Search

This paper addresses the behavior of thin-film metal coated flexible substrates under high cyclic bending fatigue loading. Polyethylene terephthalate (PET) and polyethylene naphthalate (PEN) are widely used substrates in the fabrication of microelectronic devices. Factors affecting the fatigue life of thin-film coated on a flexible PET substrates were studied, in- cluding thin-film thickness, film material, bending radius, temper- ature, and

Khalid Alzoubi; Susan Lu; Bahgat Sammakia; Mark Poliks

2011-01-01

91

Coalescence and percolation in thin metal films  

Microsoft Academic Search

Metals thermally evaporated onto warm insulating substrates evolve to the thin-film state via the morphological sequence: compact islands, elongated islands, percolation, hole filling, and finally the thin-film state. The coverage at which the metal percolates (pc) is often considerably higher than that predicted by percolation models, such as inverse swiss cheese or lattice percolation. Using a simple continuum model, we

X. Yu; P. M. Duxbury; G. Jeffers; M. A. Dubson

1991-01-01

92

Cation Enhancement of Internally Coated Metal Container Corrosion Failure  

Microsoft Academic Search

The effect of different cations on corrosion rates of internally coated metal containers at rest potential was studied. Time before the failure of 30% of the internally coated metal containers (T[sub 30]) decreased in the order: deionized water > lithium cation > sodium cation > potassium cation > calcium cation for salt concentrations from 0.0 M to 0.1 M. This

W. S. Tait; K. A. Handrich

1994-01-01

93

Sol–gel coatings on metals for corrosion protection  

Microsoft Academic Search

Sol–gel protective coatings have shown excellent chemical stability, oxidation control and enhanced corrosion resistance for metal substrates. Further, the sol–gel method is an environmentally friendly technique of surface protection and had showed the potential for the replacement of toxic pretreatments and coatings which have traditionally been used for increasing corrosion resistance of metals. This review covers the recent developments and

Duhua Wang; Gordon. P. Bierwagen

2009-01-01

94

Colored coatings on eye glass lenses by noble metal colloids  

Microsoft Academic Search

Metal colloids in glass coatings are suitable for preparation of colored transparent coatings with thicknesses of about 0.2 to l ?m due to their high molar coefficient of absorbance (? 106 l\\/(mol cm)). The absorbance of these metallic particles in a dielectric environment is caused by a surface plasmon resonance effect of the conductive electrons of the colloids. Therefore, it

M. Mennig; K. Endres; M. Schmitt; H. Schmidt

1997-01-01

95

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

Code of Federal Regulations, 2011 CFR

...Knee joint patellofemorotibial metal/polymer porous-coated uncemented prosthesis...Knee joint patellofemorotibial metal/polymer porous-coated uncemented prosthesis...knee joint patellofemorotibial metal/polymer porous-coated uncemented...

2011-04-01

96

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

Code of Federal Regulations, 2010 CFR

...Knee joint patellofemorotibial metal/polymer porous-coated uncemented prosthesis...Knee joint patellofemorotibial metal/polymer porous-coated uncemented prosthesis...knee joint patellofemorotibial metal/polymer porous-coated uncemented...

2010-04-01

97

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

98

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

99

Laser damage in thin film optical coatings  

Microsoft Academic Search

A review of laser damage resistant coatings for optical elements to be employed in military systems using lasers or encountering lasers used as weapons or countermeasures is provided. It provides an extensive data base of damage thresholds for oxide, fluoride, and chalcogenide single layer and multilayer coatings. The data base is supported by a detailed description of how the coatings

Kent J. Kogler

1992-01-01

100

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

101

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

102

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

103

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

104

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., <1000.degree. C.). The substrate can be coated by immersing it in the above mentioned solution at ambient temperature. The substrate is then withdrawn from the solution. Next, the coated substrate is heated for a time sufficient and at a temperature sufficient to yield a solid coating. The coated substrate is then heated for a time sufficient, and temperature sufficient to produce a polymetallicsiloxane coating.

Sugama, Toshifumi (Mastic Beach, NY)

1992-01-01

105

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., <1000.degree. C.). The substrate can be coated by immersing it in the above mentioned solution at ambient temperature. The substrate is then withdrawn from the solution. Next, the coated substrate is heated for a time sufficient and at a temperature sufficient to yield a solid coating. The coated substrate is then heated for a time sufficient, and temperature sufficient to produce a polymetallicsiloxane coating.

Sugama, Toshifumi (Mastic Beach, NY)

1993-01-01

106

Hot-melt coating: water sorption behavior of excipient films.  

PubMed

Hot-melt coating allows encapsulation of water-labile, drug-laden substrates to form a barrier that resists moisture ingress. To understand the interaction of water with excipients that can form moisture-protective coatings, sorption behavior of films of lipidic (glyceryl behenate) and polymeric (polyvinyl alcohol) coating excipients was investigated. A simple and rapid method using a new, fully automated instrumental technique to investigate the sorption/desorption behavior of excipient films is reported. Further, the influence of temperature and film thickness on the sorption behavior of films is examined. Both excipient films displayed sorption isotherms that were classified as type III and demonstrated hysteresis during desorption. The sorption data for both films did not follow the Langmuir model, and the BET model could only be used restrictively. The GAB model fitted the sorption data at all conditions and over the entire range of water activity studied. The ability of the Young and Nelson model to explain the hysteresis behavior, from analytical and mechanistic perspectives, is evaluated. Temperature and film thickness were found to profoundly influence the nature of moisture interaction and distribution of moisture in the excipient films. An Arrhenius-type relationship was observed between equilibrium moisture content of excipient films and temperature at constant water activity. PMID:11291204

Achanta, A S; Adusumilli, P S; James, K W; Rhodes, C T

2001-01-01

107

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

108

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

109

Biofouling of Cr-Nickel Spray Coated Films on Steel Surfaces  

NASA Astrophysics Data System (ADS)

Nowadays, corrosion of metals brings us serious economic loss and it often reaches several percentage of GNP. Particularly the marine corrosion was serious and the counter measure was very hard to be established, since the number of factors is huge and complicated. One of the complicated factors in marine corrosion is biofouling. Biofouling was classified into two main categories, microfouling and macrofouling. The former is composed of biofilm formation mainly. Marine bacteria are attached to material surfaces, seeking for nutrition in oligotrophic environment and they excrete polysaccharide to form biofilm on metal surfaces. Then larger living matters are attached on the biofilms to develop biofouling on metal surfaces, which often lead loss and failures of metals in marine environments. From the viewpoint of corrosion protection and maintenance of marine structures, biofouling should be mitigated as much as possible. In this study, we applied spray coating to steels and investigated if chromium-nickel spray coating could mitigate the biofouling, being compared with the conventional aluminium-zinc spray coating in marine environments. The specimens used for this investigation are aluminium, zinc, aluminium-zinc, stacked chromium/nickel and those films were formed on carbon steel (JIS SS400). And the pores formed by spray coating were sealed by a commercial reagent for some specimens. All of those specimens were immersed into sea water located at Marina Kawage (854-3, Chisato, Tsu, Mie Prefecture) in Ise Bay for two weeks. The depth of the specimen was two meter from sea water surface and the distance was always kept constant, since they were suspended from the floating pier. The temperature in sea water changed from 10 to 15 degrees Celsius during the immersion test. The biofouling behavior was investigated by low vacuum SEM (Hitachi Miniscope TM1000) and X-ray fluorescent analysis. When the spray coated specimens with and without sealing agents were compared, the former showed higher antifouling properties generally. Aluminium-zinc alloy spray coated films had higher antifouling property. And the anti-property decreased in this order: Al-Zn alloy spray coating > Zinc spray coating > Aluminium spray coating > Stacked chromium/nickel spray coating. Aluminium and zinc spray coating has been evaluated high conventionally for anti-biofouling in marine environment. However, the Cr/Ni spray coating showed pretty high anti-fouling property.

Yoshida, Kento; Kanematsu, Hideyuki; Kuroda, Daisuke; Ikigai, Hajime; Kogo, Takeshi; Yokoyama, Seiji

2012-03-01

110

Curing of aqueous polymeric film coatings: Importance of the coating level and type of plasticizer.  

PubMed

The aim of this study was to better understand the effects of the curing conditions on the resulting drug release patterns from pellets coated with aqueous polymer dispersions. Diltiazem HCl was used as model drug, ethylcellulose as polymer, triethyl citrate (TEC), dibutyl sebacate (DBS), and distilled acetylated monoglycerides (Myvacet) as plasticizers. Interestingly, the effects of the curing conditions strongly depended on the coating level and the type of plasticizer: in the case of TEC, the drug release rate monotonically decreased with increasing harshness of the curing conditions (time, temperature, and relative humidity), irrespective of the coating level. In contrast, in the case of DBS and Myvacet, this type of relationship was only observed at low coating levels (5%). At intermediate coating levels (around 7.5%), the curing conditions had virtually no effect on drug release. At high coating levels (10%), the release rate initially increased and then decreased with increasing harshness of the curing conditions. This more complex behavior might be attributable to the superposition of two competing phenomena: improved film formation and drug migration into the polymeric membrane. Furthermore, it could be shown that the type of plasticizer had a major effect on drug release in not fully coalesced and equilibrated film coatings, whereas the release profiles were similar for all plasticizers in the case of completely formed and equilibrated film coatings. Importantly, the latter systems were stable for long term even during storage under stress conditions. PMID:19895886

Yang, Q W; Flament, M P; Siepmann, F; Busignies, V; Leclerc, B; Herry, C; Tchoreloff, P; Siepmann, J

2010-02-01

111

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

112

High temperature glass coatings for superalloys and refractory metals  

NASA Technical Reports Server (NTRS)

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

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

1970-01-01

113

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

114

Plasma-sprayed ceramic coatings for molten metal environments.  

SciTech Connect

Coating porosity is an important parameter to optimize for plasma-sprayed ceramics which are intended for service in molten metal environments. Too much porosity and the coatings may be infiltrated by the molten metal causing corrosive attack of the substrate or destruction of the coating upon solidification of the metal. Too little porosity and the coating may fail due to its inability to absorb thermal strains. This study describes the testing and analysis of tungsten rods coated with aluminum oxide, yttria-stabilized zirconia, yttrium oxide, and erbium oxide deposited by atmospheric plasma spraying. The samples were immersed in molten aluminum and analyzed after immersion. One of the ceramic materials used, yttrium oxide, was heat treated at 1000 C and 2000 C and analyzed by X-ray diffractography and mercury intrusion porosimetry. Slight changes in crysl nl structure and significant changes in porosity were observed after heat treatments.

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

2002-01-01

115

Radiation Damage in Nanostructured Metallic Films  

E-print Network

with favorable microstructures and to investigate their response to radiation. The goals of this thesis are to study the radiation responses of several nanostructured metallic thin film systems, including Ag/Ni multilayers, nanotwinned Ag and nanocrystalline Fe...

Yu, Kaiyuan

2013-04-15

116

Study on corrosion protection of organic coatings using electrochemical techniques: Thermal property characterization, film thickness investigation, and coating performance evaluation  

NASA Astrophysics Data System (ADS)

As an initial effort to establish a rapid, accurate, and comprehensive testing protocol for performance evaluation and lifetime prediction of corrosion protective coatings, the effects of coating thermal characteristics, coating application parameters, and coating formulation variations on corrosion protection have been explored. The study has been accomplished primarily through modern electrochemical techniques, such as Electrochemical Noise Methods (ENM) and Electrochemical Impedance Spectroscopy (EIS), with the aid of traditional thermal analysis, surface characterization, and appearance inspection. The employed electrochemical techniques have exhibited usefulness as powerful testing tools that have provided valuable results in good agreement with field observations and other measures by traditional methods. Thermal property characterization on fusion bonded epoxy (FBE) pipeline coatings has shown that coating electrical resistances decreased as temperature rose with a distinct thermal transition point corresponding to glass transition temperature (Tg) of the immersed coatings. The change in coating capacitance with temperature revealed the irreversible process of water ingress and the effects of electrolyte plasticization in the coating films. Film thickness investigation on marine coating systems has demonstrated that film thickness has significant influences on coating corrosion protection. Better performance is expected for a coating system with thicker film thickness as well as with more coating layers when applied at a constant film thickness. The results indicate that there was a possible critical minimum film thickness above which coating protective performance was greatly enhanced and that there was also a maximum limiting film thickness above which increasing film thickness made little contribution to corrosion protection. Coating performance evaluation on aircraft coating systems has offered accurate performance ranking and reasonable lifetime prediction for high-quality, anticorrosive coatings. The mechanisms of corrosion protection by several coating systems with various types of polymers and pigment volume concentrations (PVC) have been discovered. Future work will consider a broader selection of materials, different test conditions, and a greater variety of characterization techniques. More sophisticated data analysis methods also need to be developed.

Li, Junping

2002-08-01

117

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

118

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

NASA Astrophysics Data System (ADS)

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

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

2012-12-01

119

Behaviour of coatings on reinforcements in some metal matrix composites  

Microsoft Academic Search

Coating on reinforcements affects the interface bonding of a composite, and is therefore usually used for improving the composite's properties. The behaviour of SiC coating on carbon fibre in reinforced aluminium metal castings, Fe on carbon fibre-reinforced copper and alumina coating on K2O · 6TiO2 whisker-reinforced aluminium composites were investigated, respectively, by modern techniques such as TEM, SEM etc. with

Yu-Qing Wang; Ben-Lian Zhou

1996-01-01

120

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

121

Optical coatings and thin films for display technologies using closed-field magnetron sputtering  

NASA Astrophysics Data System (ADS)

"Closed field" magnetron (CFM) sputtering offers high throughput, flexible deposition process for optical coatings and thin films required in display technologies. CFM sputtering uses two or more different metal targets to deposit multilayers comprising a wide range of dielectrics, metals and conductive oxides. CFM provides a room temperature deposition process with high ion current density, low bias voltage and reactive oxidation in the entire volume around the rotating substrate drum carrier, depositing films over a large surface area at a high rate with excellent and reproducible properties. Machines based on CFM are scaleable to meet a range of batch and in-line size requirements. Thin film thickness control to <+/-1% is accomplished using time, although quartz crystal or optical monitoring are used for more demanding applications. Fine layer thickness control and deposition of graded index layers is also assisted with a special rotating shutter mechanism. This paper presents data on optical properties for CFM deposited coatings relevant to displays, including anti-reflection, IR blocker and color and thermal control filters, graded coatings, barrier coatings as well as conductive transparent oxides such as indium tin oxide. Benefits of the CFM process for a range of display technologies; OLED, EL and projection are described.

Gibson, Desmond R.; Brinkley, Ian; Walls, J. M.

2004-11-01

122

Enhanced gas sensing of Au nanocluster-doped or -coated zinc oxide thin films  

Microsoft Academic Search

We demonstrated that doping or covering with Au nanoclusters boosts gas sensing effectiveness of optical metal oxide sensors. The sensing response of pulsed laser deposited ZnO films as sensing element was tested by m-line technique for low concentration (1000 ppm) of butane in environmental N2. The optical interrogation was performed for three types of coatings: undoped ZnO, undoped ZnO structures

G. Socol; E. Axente; C. Ristoscu; F. Sima; A. Popescu; N. Stefan; I. N. Mihailescu; L. Escoubas; J. Ferreira; S. Bakalova; A. Szekeres

2007-01-01

123

Metal flame spray coating protects electrical cables in extreme environment  

NASA Technical Reports Server (NTRS)

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

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

1967-01-01

124

Mechanisms, Models, and Simulations of Metal-Coated Fiber Consolidation  

E-print Network

Mechanisms, Models, and Simulations of Metal-Coated Fiber Consolidation R. VANCHEESWARAN, J of Ti-6Al-4V­coated SiC fibers contained in cylindrical canisters have revealed an unexpectedly high plastic and power-law creeping cylinders that contain an elastic ceramic core. Final stage densification

Wadley, Haydn

125

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

126

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

127

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

128

Film coatings for oral pulsatile release.  

PubMed

Pulsatile delivery is generally intended as a release of the active ingredient that is delayed for a programmable period of time to meet particular chronotherapeutic needs and, in the case of oral administration, also target distal intestinal regions, such as the colon. Most oral pulsatile delivery platforms consist in coated formulations wherein the applied polymer serves as the release-controlling agent. When exposed to aqueous media, the coating initially performs as a protective barrier and, subsequently, undergoes a timely failure based on diverse mechanisms depending on its physico-chemical and formulation characteristics. Indeed, it may be ruptured because of the gradual expansion of the core, swell and/or erode due to the glassy-rubbery polymer transition or become permeable thus allowing the drug molecules to diffuse outwards. Otherwise, when the coating is a semipermeable membrane provided with one or more orifices, the drug is released through the latter as a result of an osmotic water influx. The vast majority of pulsatile delivery systems described so far have been prepared by spray-coating, which offers important versatility and feasibility advantages over other techniques such as press- and dip-coating. In the present article, the design, manufacturing and performance of spray-coated pulsatile delivery platforms is thus reviewed. PMID:23506956

Maroni, Alessandra; Zema, Lucia; Loreti, Giulia; Palugan, Luca; Gazzaniga, Andrea

2013-12-01

129

On the use of ceramic PVD coatings to replace metallic coatings in electrical contacts  

Microsoft Academic Search

In electrical contacts the combination of high normal pressures and soft contact materials results in large contact areas and low contact resistance, but also in massive plastic deformation and wear. This paper examines some of the potential advantages and disadvantages of replacing one of the soft metallic coatings in electrical power connectors with a hard ceramic coating. Three ceramic PVD

Åsa Kassman Rudolphi; Staffan Jacobson

1997-01-01

130

Thick film sol gel PZT transducer using dip coating  

Microsoft Academic Search

A sol gel process has been used to develop a 30 ?m thick PZT coating on a sapphire wafer. The sol gel film was removed and plated with platinum electrodes. The free-standing film had a free dielectric constant (?T) of 820, a thickness-mode coupling coefficient (kt) of 0.17, a speed of sound (c) of 3700 m\\/s, and an acoustic impedance

Kenneth L. Gentry; Jason M. Zara; Sang-Don Bu; Chang-Beom Eom; Stephen W. Smith

2000-01-01

131

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

132

Simple push coating of polymer thin-film transistors  

PubMed Central

Solution processibility is a unique advantage of organic semiconductors, permitting the low-cost production of flexible electronics under ambient conditions. However, the solution affinity to substrate surfaces remains a serious dilemma; liquid manipulation is more difficult on highly hydrophobic surfaces, but the use of such surfaces is indispensable for improving device characteristics. Here we demonstrate a simple technique, which we call ‘push coating’, to produce uniform large-area semiconducting polymer films over a hydrophobic surface with eliminating material loss. We utilize a poly(dimethylsiloxane)-based trilayer stamp whose conformal contact with the substrate enables capillarity-induced wetting of the surface. Films are formed through solvent sorption and retention in the stamp, allowing the stamp to be peeled perfectly from the film. The planar film formation on hydrophobic surfaces also enables subsequent fine film patterning. The technique improves the crystallinity and field-effect mobility of stamped semiconductor films, constituting a major step towards flexible electronics production. PMID:23132026

Ikawa, Mitsuhiro; Yamada, Toshikazu; Matsui, Hiroyuki; Minemawari, Hiromi; Tsutsumi, Jun'ya; Horii, Yoshinori; Chikamatsu, Masayuki; Azumi, Reiko; Kumai, Reiji; Hasegawa, Tatsuo

2012-01-01

133

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

134

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

135

Mesoscopically structured nanocrystalline metal oxide thin films.  

PubMed

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. PMID:25224841

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

2014-11-01

136

Process optimization of ultrasonic spray coating of polymer films.  

PubMed

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

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

2013-06-11

137

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

138

Method of producing metal-filled organic coating  

SciTech Connect

This invention is directed to a coating method. In the preferred practice of this invention, the method includes the steps of selecting a ferrous substrate, such as steel sheet preferably containing a first coating having certain corrosion resistant and adhesion-promoting characteristics, applying thereto an outer coating of an organic resin containing a particulate metal selected from the group consisting of Al, Ni, Cr, Fe, Mn, Cu, Mo, Co, Ag, Au and alloys thereof, where the particle size of said metal or alloy is prefereably no more than about 10 microns, and applying thereover a cathodic electrophoretic coating at voltages of at least 300 V. The product of such method is corrosion resistant, free of craters or pores, and is readily welable prior to the application of said cathodic electrophoretic coating.

Hart, R.G.; Townsend, H.E.

1985-02-19

139

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

SciTech Connect

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

John, S.; Srinivasan, K.N.; Selvam, M. [Central Electrochemical Research Inst., Tamilnadu (India); Anuradha, S.; Rajendran, S. [Alagappa Univ., Tamilnadu (India). Dept. of Physics

1994-12-31

140

Improved vapor selectivity and stability of localized surface plasmon resonance with a surfactant-coated Au nanoparticles film.  

PubMed

Here, we report the use of tetraoctylammonium bromide (TOABr)-coated Au nanoparticles (NPs) for the optical sensing of volatile organic compounds (VOCs). We find that the film responded selectively to the presence of polar and nonpolar vapors by changes in the maximum wavelength (?(max)) toward higher and lower wavelengths, respectively, as determined by UV-visible spectroscopy. We also observed that the organic coating reorganizes when vapors partition into the film indicated by FT-IR and the film contracts in the presence of water indicated by scanning electron microscopy (SEM). In the present sensor, the metallic Au core serves as the plasmonic signal while the organic coating acts as the receptor material providing vapor selectivity and sensor stability. Correlating changes in (?(max)) with changes in the refractive index (RI) and nanoparticle-to-nanoparticle separation in the film is important both fundamentally and for improving selectivity in localized surface plasmon resonance (LSPR) sensors. PMID:22559724

Dalfovo, María C; Salvarezza, Roberto C; Ibañez, Francisco J

2012-06-01

141

Increased photo- and electroluminescence by zone annealing of spin-coated and vacuum-sublimed amorphous films producing crystalline thin films  

NASA Astrophysics Data System (ADS)

Spin-coated and vacuum sublimed amorphous thin films (˜100 nm thick) were converted into single crystalline films with a simple moving-zone-annealing technique, in which a heated metal wire generated a narrow annealed zone in the film as it is moved across the sample. This annealing resulted in both the photoluminescence and electroluminescence to increase dramatically (by 3-4 times), for example with Ru(bpy)3(ClO4)2 and aluminum 8-hydroxyquinoline, (Alq3), as light emitting devices. This technique is of interest in improving the behavior of highly luminescent thin film optoelectronic devices.

Liu, Chong-Yang; Bard, Allen J.

2003-12-01

142

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

143

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

144

Effects of Glass-Forming Metallic Film on the Fatigue Behavior of C-2000 Ni-Based Alloy , C. L. Chiang1,2  

E-print Network

Effects of Glass-Forming Metallic Film on the Fatigue Behavior of C-2000 Ni-Based Alloy F. X. Liu1 the fatigue life. INTRODUCTION Bulk metallic glass (BMG) materials show enhanced plasticity behavior when to use a glass-forming metallic thin film as a coating material with anticipated high ductile properties

Gao, Yanfei

145

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

Code of Federal Regulations, 2010 CFR

...2010-04-01 false Hip joint metal/polymer/metal semi-constrained porous-coated...Devices § 888.3358 Hip joint metal/polymer/metal semi-constrained porous-coated...Identification. A hip joint metal/polymer/metal...

2010-04-01

146

Spin coated cellulose nanocrystal/silver nanoparticle films.  

PubMed

In this study, thin films of cellulose nanocrystals (CNC) and silver nanoparticles (Ag) were assembled on different substrates by spin coating. The effect of substrates, deposition parameters, and nanocrystal modification on the topographical and hydrophilic properties of the obtained layers was investigated. Dilute concentrations of pristine cellulose nanocrystals (CNC) and surfactant modified crystals (s-CNC) were used in order to evaluate the effect of modification and concentration on the uniformity of the spin coated cellulose/silver layers. Morphological investigations by field emission scanning electron microscopy and atomic force microscopy were performed in order to prove the uniformity of the obtained films, while the wettability of different surfaces were studied and correlated to the cellulose modification and content. The ability of s-CNC to form a stable dispersion in chloroform permits the formation of a uniform cellulose film on the substrate surfaces generating regular films during the spin coating process. Topographical investigations show, on the other hand, that the CNC/Ag suspension produces a non-uniform distribution. These effects can be mainly attributed to the surfactant action rather than to the chemical and electrical properties of the substrate surface. Finally, contact angle studies, underline the hydrophilic nature of s-CNC/Ag based films highlighting that the wettability properties are strongly influenced by the cellulose nanocrystal nature. PMID:25256500

Fortunati, E; Mattioli, S; Armentano, I; Kenny, J M

2014-11-26

147

Graded coatings for metallic implant alloys  

Microsoft Academic Search

Graded glass and glass-hydroxyapatite coatings on Ti-based and Co-Cr alloys have been prepared using a simple enameling technique. The composition of the glasses has been tailored to match the thermal expansion of the alloys. By controlling the firing time, and temperature, it has been possible to control the reactivity between the glass and the alloy and to fabricate coatings (25

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

2002-01-01

148

Sensing using nanostructured metal oxide thin films  

NASA Astrophysics Data System (ADS)

Metal oxides gas sensing properties particularly for In IIO 3 and ZnO nanostructures and nanostructured thin films are reviewed. Fabrication methods for these most commonly used metal oxides are presented, followed by a study on how growth techniques lead to nanostructures and nanostructured polycrystalline films with surface features of nanometer scale for film thickness bellow 1?m. The study continues with a discussion on how, a broad range of morphological parameters, affect the thin film response to various gases. After an overview, the study focus on thin films prepared by reactive dc magnetron sputtering and pulsed laser deposition in different growth conditions. In IIO 3 and ZnO thin films prepared for ozone sensing exhibit resistivity changes of five to eight orders of magnitude at room temperature after exposure to UV light and subsequent ozone treatment. Structural properties, i.e., crystallinity and microstructure investigated by X-ray diffraction (XRD) and Atomic Force Microscopy (AFM) are studied. The nanostructure and nanostructured surfaces are highly controlled by the deposition parameters, which, control the transport properties, and thus the sensing characteristics as measured by conductometric techniques. Analyses on the sensing response of nanostructures and nanostructured In IIO 3 and ZnO films for different gases are presented. Experiments on Surface Acoustic Wave (SAW) devices based on In IIO 3 and ZnO thin films fabricated on LiNbO3 substrates indicate the capability of achieving sensing levels in the low ppb range.

Kiriakidis, G.; Dovinos, D.; Suchea, M.

2006-10-01

149

Method for nondestructive testing of the film coating behavior of surface acoustic wave (SAW) sensors  

Microsoft Academic Search

This paper presents a practical non-destructive method for studying the film coating behavior of SAW devices by using a water soluble dielectric film (manitol) deposited on the SAW device surface by resistive evaporation. After measuring the electrical parameters of the film coated SAW device, the film can easily be removed from its surface by water rinsing without causing any damage

M. A. Taslakov; I. D. Avramov

2010-01-01

150

Spray forming polymer membranes, coatings and films  

DOEpatents

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

McHugh, Kevin M. (Idaho Falls, ID); Watson, Lloyd D. (Rigby, ID); McAtee, Richard E. (Idaho Falls, ID); Ploger, Scott A. (Rigby, ID)

1993-01-01

151

Spray forming polymer membranes, coatings and films  

DOEpatents

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

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

1993-10-12

152

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

NASA Astrophysics Data System (ADS)

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

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

2009-09-01

153

On the manufacture of very thin elastomeric films by spin-coating  

E-print Network

I present a process for manufacturing poly-dimethylsiloxane (PDMS) films of thicknesses down to 50 microns. PDMS films are currently fabricated by spin-coating the polymer on a wafer and then manually peeling the film after ...

Krishnan, Sriram, 1978 May-

2007-01-01

154

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

155

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

SciTech Connect

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

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

1990-04-01

156

Stability of aqueous polymeric controlled release film coatings.  

PubMed

Aqueous polymeric film coatings provide a great potential to accurately control the release rate of a drug from a pharmaceutical dosage form, while avoiding the various disadvantages associated with the use of organic solvents. However, long term instability of drug release, due to imperfect film formation during coating and curing, can be a serious concern. If the coalescence of the particles continues during storage, the film permeability can decrease, slowing down drug release. Different strategies can be used to effectively avoid this phenomenon, including optimized curing conditions, the addition of appropriate additives and the use of specific packaging materials. This article gives an overview on the current state of the art in this field. Various practical examples are described, covering different types of polymer coatings and drugs. The aims are: (i) to provide a better understanding of the release patterns and potential changes thereof, and (ii) to help identifying strategies allowing for improved long term stability for specific types of polymer coatings. PMID:24126037

Siepmann, J; Siepmann, F

2013-12-01

157

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

158

Liquid metal film flow for fusion application  

SciTech Connect

Liquid metal film flow with a free surface is promising for application in Tokamak reactor diverter targets. Experiments with film flow of the eutectic alloy In-Ga-Sn on an inclined chute in a coplanar magnetic field have been conducted as a first step toward such target development. The chute width and length were, respective, 90 and 620 mm, the initial film thickness 4 mm, the mean velocity 0.18-1.25 m/s, and the magnetic field induction up to 0.6 T. The film mean thickness over the chute width and length was measured as well as the surface wave amplitude. The measured distribution of the film thickness over the length was compared with the calculated one based on one-and two-dimensional models. The correlation is satisfactory in the range of experimental characteristic parameters.

Baranov, V.V.; Kirillov, I.R.; Firsova, E.V. [I.I. Polzunov Central Boiler and Turbine Inst., St. Petersburg (Russian Federation)] [and others

1995-04-01

159

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

160

Graded coatings for metallic implant alloys  

SciTech Connect

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

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

2002-08-01

161

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

162

Recent innovations in the area of edible films and coatings.  

PubMed

Edible films/coatings have been considered as one of the potential technologies that can be used to increase the storability of foods and to improve the existent packaging technology, helping to ensure the microbial safety and the preservation of food from the influence of external factors. Innovations constantly appear in food packaging, always aiming at creating a more efficient quality preservation system while improving foods' attractiveness and marketability. The utilization of renewable sources for packaging materials, such as hydrocolloids and lipids from biological origin, is one the main trends of the industry. These films should have acceptable sensory characteristics, appropriate barrier properties (CO2, O2, water, oil), microbial, biochemical and physicochemical stability, they should be safe, and produced by simple technology in low cost. Also they can act as effective carrier for antioxidant, flavor, color and nutritional or anti-microbial additives. Nowadays, a great discussion exists about the potential applications of edible films/coatings on food products. The general trend is to find the correct combination between the food product and the edible film/coating, which will ensure the success of the technology. PMID:24294943

Maftoonazad, Neda; Badii, Fojan; Shahamirian, Maryam

2013-12-01

163

Metallic Bipolar Plates with Composite Coatings  

E-print Network

Work Patent application filed by Argonne: "Corrosion Resistant Bipolar Plate for Polymer Electrolyte Timeline Go/No-Go decisions: ­ Sept. 30, 2010: Composite coatings that are >100 S/cm, corrosion resistant, & Testing Formal Cost Analysis Post-testing Analysis 8 -- Go/No-Go decision1 1 -- Milestone 2 3 4 7 5 6 FY09

164

Water vapour barrier performance of corn-zein coated polypropylene (PP) packaging films  

Microsoft Academic Search

The novel film structure of corn-zein coated on polypropylene (PP) synthetic film for packaging industry was developed to\\u000a examine the feasibility of resulting coated films as an alternative water barrier performance for food packaging. The effects\\u000a of coating formulation (solvent, corn-zein, plasticizer concentration and plasticizer type) on final properties of films were\\u000a observed. Corn-zein is the most important protein of

?sa Do?an Atik; B. Özen; F. T?hm?nl?o?lu

2008-01-01

165

Chitosan based edible films and coatings: a review.  

PubMed

Chitosan is a biodegradable biocompatible polymer derived from natural renewable resources with numerous applications in various fields, and one of which is the area of edible films and coatings. Chitosan has antibacterial and antifungal properties which qualify it for food protection, however, its weak mechanical properties, gas and water vapor permeability limit its uses. This review discusses the application of chitosan and its blends with other natural polymers such as starch and other ingredients for example essential oils, and clay in the field of edible films for food protection. The mechanical behavior and the gas and water vapor permeability of the films are also discussed. References dealing with the antimicrobial behavior of these films and their impact on food protection are explored. PMID:23498203

Elsabee, Maher Z; Abdou, Entsar S

2013-05-01

166

Sputter deposition of a spongelike morphology in metal coatings  

Microsoft Academic Search

Metallic films are grown with a ``spongelike'' morphology in the as-deposited condition using planar magnetron sputtering. The morphology of the deposit is characterized by metallic continuity in three dimensions with continuous and open porosity on the submicron scale. The stabilization of the spongelike morphology is found over a limited range of the sputter deposition parameters, that is, of working gas

A. F. Jankowski; J. P. Hayes

2003-01-01

167

Surface plasmon resonant scattering in metal-coated dielectric nanocylinders  

NASA Astrophysics Data System (ADS)

The scattering of TE polarized plane wave by metal-coated dielectric nanocylinders is investigated with a particular emphasis on the enhancement of the near fields. If the wavelength of illumination is properly chosen, two unique near field distributions can be excited through the surface plasmon resonances. The enhanced near fields are localized along the inner or outer interface of the coating metal, being dependent on the wavelengths. It is shown that the scattering cross-section of the nanocylinders is also enhanced when the illuminating field resonates to the surface plasmons of the structures.

Meng, Peiwen; Yasumoto, Kiyotoshi; Liu, Yunfei

2014-12-01

168

Tribological behavior of aluminum-CNT coated metal composite under dry and water lubricated conditions.  

PubMed

Carbon nanotubes are considered the best material in the field of composites because of their mechanical and tribological properties. In this study, carbon nanotubes coated metal was dispersed in aluminum, the base metal, to improve the wettability between aluminum and carbon nanotubes. The friction and wear behaviors of the aluminum-carbon nanotube coated metal, which is a nickel and copper composite, were investigated using a pin-on-disk wear tester under dry sliding and water lubricated conditions and evaluated using SEM and EDX analysis. All the results demonstrated that the addition of the carbon nanotubes coated metal significantly improved the wettability of CNTs in the aluminum. And the distribution of CNTs prevented the propagation of micro cracks on the surface of the aluminum base metal sample, resulting in enhanced friction characteristics and wear resistance of the nano composite. The composite exhibited lower friction coefficient and wear resistance under the water lubricated condition than the dry sliding condition. Although the lubrication and cooling effect of water contributed to the reduction of the friction coefficient of the composite, the separation of wear particles from the sliding surface changed the wear type from three-body to two-body, resulting in very high wear rate. Also the concentration of oxide under water lubricated condition contributed to the increase of the wear rate because the amount of oxide film removed in terms of thickness exceeded the critical thickness of real contact area. PMID:21446451

Kim, Il-Young; Lee, Young-Ze

2011-01-01

169

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

NASA Technical Reports Server (NTRS)

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

Jaworske, Don A.

2003-01-01

170

Barrier Coatings for Refractory Metals and Superalloys  

Microsoft Academic Search

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

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

2006-01-01

171

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

172

Film coatings for taste masking and moisture protection.  

PubMed

Taste masking and moisture protection of oral dosage forms contribute significantly to the therapeutic effect of pharmaceutical and nutraceutical formulations either by ensuring patient compliance or by providing stability through shelf life of the dosage form. Among different types of taste, bitter taste is the most relevant for patient acceptance because of the extremely high sensitivity. As hydrolysis is the most common mode of degradation of an active ingredient, moisture protection plays a vital role in the stability of the active during manufacturing and storage. Optimized oral dosage forms need to reliably hinder the release of bitter drug molecules in the mouth or ensure stability of the active compound, while also ensuring fast drug release in the stomach to enable early therapeutic onset. Besides different formulation concepts, film coating is found to be the most effective and commonly used approach for taste masking and moisture protection. Film coating can be achieved through the use of water-soluble, cationic, anionic or neutral insoluble polymers from different chemical structures. Cationic polymers provide efficient moisture protection as well as taste masking without influencing the release of the drug in the gastric fluids. Polymers may be sprayed onto various types of cores from dispersions or solutions in organic, solvents or water in drum or fluidzed bed coaters. Applied quantities need insuring complete coating thickness ranging from 0.5 to 50 ?m or more finally. Insulating excipients, such as hydrophobic plasticizers, lipids, pigments or other insoluble substances will influence the functionality of films. Organoleptic tests are still common in testing the quality of taste-masked formulations. Recently, multi-channel taste sensors have been developed to quantify different types of taste. Dynamic vapor sorption technique and studies at elevated temperature provide effective concepts study the efficacy of the formulations. Efficient taste masking and reliable moisture protection of solid oral dosage forms can be achieved by film coating implementing the options of pharmaceutical polymers and processes. PMID:24148666

Joshi, S; Petereit, H-U

2013-12-01

173

Enhanced electrochemical properties of fluoride-coated LiCoO2 thin films  

NASA Astrophysics Data System (ADS)

The electrochemical properties of fluoride-coated lithium cobalt oxide [LiCoO2] thin films were characterized. Aluminum fluoride [AlF3] and lanthanum fluoride [LaF3] coating layers were fabricated on a pristine LiCoO2 thin film by using a spin-coating process. The AlF3- and LaF3-coated films exhibited a higher rate capability, cyclic performance, and stability at high temperature than the pristine film. This indicates that the AlF3 and LaF3 layers effectively protected the surface of the pristine LiCoO2 film from the reactive electrolyte.

Lee, Hye Jin; Kim, Seuk Buom; Park, Yong Joon

2012-01-01

174

Deformation behavior of metallic glass thin films  

NASA Astrophysics Data System (ADS)

We report room-temperature deformation behavior of damage-free metallic glass films characterized by nanoindentation and atomic force microscopy. The glass films with thicknesses ranging from 5 ?m down to ˜60 nm plastically deform by shear bands when subjected to both spherical and sharp Berkovich indenters. Importantly, we found that gallium contamination from focus ion beam (FIB) milling significantly suppresses shear band formation, indicating that the absence of shear bands in FIB milled samples may be caused by gallium irradiation damage, rather than sample size effect. Finite element simulation reveals that a high stress gradient at the film/substrate interface promotes the plastic deformation of the thin films but does not give rise to significant strain inhomogeneity.

Liu, Y. H.; Zhao, F.; Li, Y. L.; Chen, M. W.

2012-09-01

175

21 CFR 888.3535 - Knee joint femorotibial (uni-compartmental) metal/polymer porous-coated uncemented prosthesis.  

Code of Federal Regulations, 2010 CFR

...femorotibial (uni-compartmental) metal/polymer porous-coated uncemented prosthesis...femorotibial (uni-compartmental) metal/polymer porous-coated uncemented prosthesis...femorotibial (uni-compartmental) metal/polymer porous-coated uncemented...

2010-04-01

176

21 CFR 888.3535 - Knee joint femorotibial (uni-compartmental) metal/polymer porous-coated uncemented prosthesis.  

Code of Federal Regulations, 2011 CFR

...femorotibial (uni-compartmental) metal/polymer porous-coated uncemented prosthesis...femorotibial (uni-compartmental) metal/polymer porous-coated uncemented prosthesis...femorotibial (uni-compartmental) metal/polymer porous-coated uncemented...

2011-04-01

177

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

SciTech Connect

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

Panda, Kalpataru; Sundaravel, B.; Panigrahi, B. K. [Materials Physics Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102 (India); Huang, Pin-Chang; Shih, Wen-Ching [Graduate Institute in Electro-Optical Engineering, Tatung University, Taipei 104, Taiwan (China); Chen, Huang-Chin; Lin, I-Nan [Department of Physics, Tamkang University, New-Taipei 251, Taiwan (China)

2012-06-15

178

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

SciTech Connect

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

Sebring, R.; Arendt, P.; Imai, B.; Bradbury, E.M.; Gatewood, J. [Los Alamos National Lab., NM (United States); Panitz, J. [Univ. of New Mexico, Albuquerque, NM (United States). Dept. of Physics and Astronomy; Yau, P. [Univ. of California, Davis, CA (United States)

1997-10-30

179

Investigation of thermally oxidised Mn–Co thin films for application in SOFC metallic interconnects  

Microsoft Academic Search

Thin metallic Mn–Co films (0.3?m thickness) were produced by RF-magnetron co-sputtering on SiO2\\/Si and on ZMG232L steel substrates. The deposition was followed by a heat treatment in order to convert the metallic coatings to (Mn,Co)3O4 spinel oxides. All steel samples were analyzed after 1h heat treatment in order to confirm the presence of the spinel structure on top of the

Cezarina C. Mardare; Henrik Asteman; Michael Spiegel; Alan Savan; Alfred Ludwig

2008-01-01

180

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

181

Modelling the dip coating process for hot metal castings  

E-print Network

Modelling the dip coating process for hot metal castings Mark J. McGuinness #3; A.J. Roberts y The Problem 3 2 Fluidised Beds 4 3 Material properties 6 4 Time to heat castings in furnace 6 4.1 Sensitivity Transfer CoeÃ?cient . . . . . . . . . . . . . . . . . . . . 12 5.2 Change in temperature of castings

McGuinness, Mark

182

Development and application of multicomponent edible coatings and films: A review  

Microsoft Academic Search

Combining the advantages of polysaccharides, proteins and\\/or lipids offers multicomponent edible films and coatings good mass transfer barrier properties. Multicomponent edible films and coatings could be beneficial to the food industry by leading to innovative applications. The barrier properties of these systems strongly depend upon their structure and chemistry, the interaction between different film components as well as surrounding environment

Marilynn Schnepf

2002-01-01

183

Novel chitosan-magnesium aluminum silicate nanocomposite film coatings for modified-release tablets.  

PubMed

Chitosan (CS), a positively charged polysaccharide, and magnesium aluminum silicate (MAS), a negatively charged clay with silicate layers, can electrostatically interact to form nanocomposite films. In this study, CS-MAS nanocomposite films were evaluated for use in tablet film coating. Effects of CS-MAS ratio and coating level on water uptake and drug release from the coated tablets were investigated. Surface and film matrix morphology of the coated film and the effect of enzymes in the simulated gastro-intestinal fluid on drug release were also examined. The results demonstrated that the CS-MAS coated tablets had a rough surface and a layered matrix film, whereas a smooth surface and dense matrix film on the CS coated tablets was found. However, the CS-MAS coated tablets provided fewer film defects than the CS coated tablets. Nanocomposite formation between CS and MAS could retard swelling and erosion of CS in the composite films in acidic medium. The higher MAS ratio of the CS-MAS coated tablets gave lower water uptake and slower drug release when compared with the CS coated tablets. Moreover, the CS-MAS films on the tablets presented good stability towards enzymatic degradation in simulated intestinal fluid. The release of drug from the CS-MAS coated tablets could be modulated by varying CS-MAS ratios and coating levels. Additionally, drug solubility also influenced drug release characteristics of the CS-MAS coated tablets. These findings suggest that the CS-MAS nanocomposites displays a strong potential for use in tablet film coating intended for modifying drug release from tablets. PMID:21291977

Khunawattanakul, Wanwisa; Puttipipatkhachorn, Satit; Rades, Thomas; Pongjanyakul, Thaned

2011-04-01

184

Atmospheric RF plasma coating of indium and tin oxide films  

SciTech Connect

Indium tin oxide (ITO) thin films on soda-lime-silicate (SLS) and silica glasses were fabricated using an RF plasma mist deposition process. SEM analysis showed that the ITO films consisted of uniform particle size with a size ranging from 50 to 200 nm. XRD revealed that In{sub 2}O{sub 3} phase is present in the film when In : Sn ratio is 5 : 5 and higher. The resistivity of the ITO films was between 1--10 ohm-cm. The structural change near the surface of the glass was investigated by DRIFT (Diffuse reflectance infrared Fourier transform) spectroscopy. The infrared results indicated that the structure near the surface was significantly changed with higher indium concentration. The coating materials create non-bridging oxygen near the surfaces. The effects of deposition time and substrate temperature were also studied. Applications of such coatings are conductive filters for use as shields against low frequency interference, flat panel liquid crystal displays, anti-static packaging, heat reflector, resistive heaters to defrost auto windshields, and electrochromic ``smart windows`` which can be utilized to regulate temperature in homes and automobiles.

Williams, J.A.A.; Lee, D.H.; Vuong, K.D.; Tenpas, E.; Wu, V.; Moss, R.; Condrate, R.A. Sr.; Wang, X.W. [Alfred Univ., NY (United States)

1995-12-31

185

Electromagnetic fluctuations near thin metallic films  

NASA Astrophysics Data System (ADS)

We compute the electromagnetic fluctuations due to evanescent-wave Johnson noise in the vicinity of a thin conducting film, such as a metallic gate or a two-dimensional electron gas. This noise can decohere a nearby qubit, and it is also responsible for heat transfer and Casimir forces. We have improved on previous calculations of decoherence rates by including the nonlocal dielectric response of the film, which is an important correction at short distances. Remarkably, the fluctuations responsible for decoherence of charge qubits from a thin film are greatly enhanced over those arising from a conducting half space. The decoherence times can be reduced by over an order of magnitude by decreasing the film thickness. This appears to be due to the leakage into the vacuum of modes that are well localized in the perpendicular direction. There is no corresponding effect for spin qubits (magnetic field fluctuations). We also show that a nonlocal dielectric function naturally removes the divergence in the Casimir force at vanishing separation between two metallic sheets or half spaces. In the separation regime where local and nonlocal treatments are noticeably distinct, the Casimir attraction between two thin sheets and two half spaces is practically indistinguishable for any physical film thickness.

Langsjoen, Luke S.; Poudel, Amrit; Vavilov, Maxim G.; Joynt, Robert

2014-03-01

186

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

187

INELASTIC CONTACT DEFORMATION OF METAL COATED FIBERS  

E-print Network

by plasma spray deposition [11±13]. After experimental testing, these models have been used to successfully Metallurgica Inc. 1. INTRODUCTION Physical vapor deposition (PVD) processes are beginning to be used to produce composites (MMCs) [1±4]. By applying reactive metals such as titanium via a vapor phase process allows

Wadley, Haydn

188

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

189

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

PubMed

Behaviors of silicon nitride films and their relation to blood compatibility and biomechanical have been interesting subjects to researchers. A systematic blood compatibility and biomechanical property investigation on the deposition of silicon-nitride films under varying N? and CF? flows was carried out by direct current unbalanced magnetron sputtering techniques. Significant role of surface property, chemical bonding state of silicon nitride film and blood compatibility, mechanical properties for the films were observed. The chemical bonding configurations, surface topography, contact angle and mechanical properties were characterized by means of X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and nano-indentation technique and CSEM pin-on-disk tribometer. Blood compatibility of the films was evaluated by platelet adhesion investigation. The results of the platelet adhesion tests shown that the effect of fluorine and nitrogen-doped revealed an intimate relationship between the ratio of polar component and dispersion component of the surface energy and its hemocompatibility. Si-N-O coating can be a great candidate for developing antithrombogenic surfaces in blood contacting materials. The chemical bonding state made an adjustment in microstructured surfaces, once in the totally wettable configuration, may improve the initial contact between platelet and biomedical materials, due to the appropriate ratio of dispersion component and polar component. To resist wear, biomedical components require coatings that are tough and hard, have low friction, and are bio-inert. The study suggests that by Si-N coating the metal surfaces could be a choice to prolong the life of the sliding pair Co-Cr-Mo alloy/UHMWPE implants. PMID:23137618

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

2012-12-01

190

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

191

[Dental implantations of ceramics-coated metals].  

PubMed

Recent studies and personal experience of the Authors in the field of dental implants have encountered the same fundamental problem which arises with orthopedic prosthesis procedures. The basic problem is that of adhesion between the bone tissue and the metal implant. Chrome-cobalt alloy, Tantalum and Titanium are the metals of most recent use. The Authors therefore proceeded to investigate the behaviour of alveolar bone tissue in the proximity of artificial teeth made of alloy (platinum-gold) covered with ceramic, as used in prosthetic dentistry. The experiment was carried out in a dog and a man. In the dog, two of its mandibular teeth were substituted with the same ceramic-gold implants: the first, a replica of natural tooth, was placed in the socket and held in place by metal splint and mandibular circumferential wirings. The other implant, without a replicated crown, was left free, within the alveolus, without contacting the near or opposing teeth. A solid smooth surfaced alumina device, shaped like a small cylinder, was implanted in the upper femoral epiphysis of the same animal. PMID:1105133

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

1975-01-01

192

Phonon emission spectra of thin metallic films  

Microsoft Academic Search

Thin metallic films evaporated on an Al2O3-single crystal and cooled to liquid helium temperatures are heated by short electric current pulses. The high frequency part\\u000a of the emitted phonons is detected by calibrated superconductive tunneling junctions on the opposite surface of the substrate.\\u000a The observed phonon detector signal amplitude is compared with theoretical models taking account of the boundary conditions

Wolfgang Frick; Dieter Waldmann; Wolfgang Eisenmenger

1975-01-01

193

Bismuth film electrodes for heavy metals determination  

Microsoft Academic Search

Bismuth film electrodes (BiFEs) have a potential to replace toxic mercury used most frequently for determination of heavy\\u000a metals (Cd, Pb, Zn) by anodic stripping voltammetry. We prepared a graphite disc electrode (0.5 mm in diameter) from a pencil-lead\\u000a rod and developed a nitrogen doped diamond-like carbon (NDLC) microelectrode array consisting of 50,625 microdiscs with 3 ?m\\u000a in diameter and interelectrode distances

Vlastimil Rehacek; Ivan Hotovy; Marian Vojs; Fedor Mika

2008-01-01

194

Bismuth film electrodes for heavy metals determination  

Microsoft Academic Search

Bismuth film electrodes (BiFEs) have a potential to replace toxic mercury used most frequently for determination of heavy metals (Cd, Pb, Zn) by anodic stripping voltammetry. We prepared a graphite disc electrode (0.5 mm in diameter) from a pencil-lead rod and developed a nitrogen doped diamond-like carbon (NDLC) microelectrode array consisting of 50 625 microdiscs with 3 mum in diameter

Vlastimil Rehacek; Ivan Hotovy; Marian Vojs; Fedor Mika

2007-01-01

195

Silicide coating on refractory metals in molten salt  

NASA Astrophysics Data System (ADS)

For better oxidation resistance of refractory metals in air, the electroless coating of silicide in the molten salt was developed in open air at 973 1173 K. The molten salt consists of NaCl, KCl, Na2SiF6 and Si powder, where the proportional reaction between Si and Si4+ ions forms Si2+ ions. Si2+ deposits on the metal substrate and forms the metal silicide. The deposited silicide layers were classified into two categories depending on the metal substrates: (1) Nb, Mo and Cr mainly formed silicon-rich disilicide (MSi2) layer. (2) Fe, Ni and Co formed silicon-poor silicide layer (MSin, n<2), such as Fe3Si. This difference was described by the diffusivity of Si through the silicide layer into the metal.

Tatemoto, K.; Ono, Y.; Suzuki, R. O.

2005-02-01

196

Dynamics of polymer film formation during spin coating  

NASA Astrophysics Data System (ADS)

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

2014-09-01

197

Bare and protected sputtered-noble-metal films for surface-enhanced Raman spectroscopy  

NASA Astrophysics Data System (ADS)

Sputtered silver and gold films with different surface morphologies have been prepared and coated with a benzenethiol self-assembled monolayer. Rough noble metal films showed strong Raman features assigned to adsorbed benzenethiol molecules upon irradiation over a wide energy range in the visible spectrum, which disclosed the occurrence of a significant surface-enhanced Raman scattering with maximal enhancement factors as high as 6 × 106. In addition, the adsorption of ethanethiol onto silver surfaces hinders their corrosion over days while preserving mostly intact enhancement properties of naked silver. This study may be applied to develop stable and efficient metalized probes for tip-enhanced Raman spectroscopy.

Talaga, David; Bonhommeau, Sébastien

2014-11-01

198

Antibacterial Performance of Alginic Acid Coating on Polyethylene Film  

PubMed Central

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

Karbassi, Elika; Asadinezhad, Ahmad; Lehocký, Marian; Humpolí?ek, Petr; Vesel, Alenka; Novák, Igor; Sáha, Petr

2014-01-01

199

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

200

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

201

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

202

Process for the preparation of metal-containing nanostructured films  

NASA Technical Reports Server (NTRS)

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

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

2006-01-01

203

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

SciTech Connect

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

Nordman, Olli; Nordman, Nina; Pashkevich, Valfrid

2001-08-01

204

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

205

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

206

Soluble aromatic polyimides for film and coating applications  

NASA Technical Reports Server (NTRS)

Linear all-aromatic polyimides have been synthesized and characterized which show much potential as films and coatings for electronic applications. Structure-property relations with regard to methods for obtaining solubility of fully imidized polymers will be discussed. Methods used to obtain solubility include variation of polymer molecular structure, variation of isomerism of the diamine monomer, modification of cure time/temperature and atmosphere. Other properties of soluble polyimides will be presented which include glass transition temperatures, thermooxidative stabilities, UV-visible spectra, and refractive indices.

St.clair, Anne K.; St.clair, Terry L.

1986-01-01

207

Soluble aromatic polyimides for film and coating applications  

NASA Technical Reports Server (NTRS)

Linear all-aromatic polyimides have been synthesized and characterized which show much potential as films and coatings for electronic applications. Structure-property relations with regard to methods for obtaining solubility of fully imidized polymers will be discussed. Methods used to obtain solubility include variation of polymer molecular structure, variation of isomerism of the diamine monomer, modification of cure time/temperature and atmosphere. Other properties of soluble polyimides will be presented which include glass transition temperatures, thermooxidative stabilities, UV-visible spectra, and refractive indices.

St.clair, Anne K.; St.clair, Terry L.

1987-01-01

208

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

Microsoft Academic Search

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

Y. Liu; D. Beckett; D. Hawthorne

2011-01-01

209

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

210

Quantitative Analysis of Electroplated Nickel Coating on Hard Metal  

PubMed Central

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

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

2013-01-01

211

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

212

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

NASA Technical Reports Server (NTRS)

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

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

1991-01-01

213

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

214

Rolling and sliding of a sphere down a plane coated with a thin fluid film  

Microsoft Academic Search

When a sphere rolls down an inclined plane which is coated with a thin film of viscous liquid, it reaches a state where it translates and rotates at constant rates. We consider theoretical explanations for the experimentally observed translational and rotational speeds. Due to the effects of the thin film on the plate, this problem is related to coating flows;

J. Ashmore; J. Bico; Ha Stone; Gh McKinley

2002-01-01

215

Investigation of adhesive strength of metallized-polymer coatings of pump rods  

Microsoft Academic Search

ant steel should be used. The selection of zinc and aluminum as a coating is dictated by the protective properties of these metals with respect to steel. One of the major inadequacies of these coatings, however, is low resistance to mechanical wear, as a result of which they fail rapidly, especially in inclined holes. Moreover, metallized coatings, exhibiting significant porosity

R. M. Bikchentaev; K. V. Zvezdinskii; V. V. Pugach; N. P. Umanchik; I. B. Kabal'nikova

1990-01-01

216

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

217

Evaluation of coated metallic bipolar plates for polymer electrolyte membrane fuel cells  

Microsoft Academic Search

Metallic bipolar plates for polymer electrolyte membrane (PEM) fuel cells typically require coatings for corrosion protection. Other requirements for the corrosion protective coatings include low electrical contact resistance, good mechanical robustness, low material and fabrication cost. The authors have evaluated a number of protective coatings deposited on stainless steel substrates by electroplating and physical vapor deposition (PVD) methods. The coatings

Wonseok Yoon; Xinyu Huang; Paul Fazzino; Kenneth L. Reifsnider; Michael A. Akkaoui

2008-01-01

218

Self-optimized metal coatings for fiber plasmonics by electroless deposition.  

PubMed

We present a novel method to prepare optimized metal coatings for infrared Surface Plasmon Resonance (SPR) sensors by electroless plating. We show that Tilted Fiber Bragg grating sensors can be used to monitor in real-time the growth of gold nano-films up to 70 nm in thickness and to stop the deposition of the gold at a thickness that maximizes the SPR (near 55 nm for sensors operating in the near infrared at wavelengths around 1550 nm). The deposited films are highly uniform around the fiber circumference and in spite of some nanoscale roughness (RMS surface roughness of 5.17 nm) the underlying gratings show high quality SPR responses in water. PMID:21996817

Bialiayeu, A; Caucheteur, C; Ahamad, N; Ianoul, A; Albert, J

2011-09-26

219

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

220

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

221

Flexible ceramic-reinforced polyurethane composite coatings on synthetic fibres: Process of continuous liquid film coating and its influence on the coating thickness  

Microsoft Academic Search

A concept for the realisation of composite layers on the surface of synthetic fibres by continuous liquid film coating of spread roving or monofilaments with a slurry containing ceramic particles and a polymeric binder is successfully demonstrated. Polyamide 6 monofilaments were coated with alumina particles and a polyurethane elastomer based binder system to achieve higher abrasion resistance. Under frictional load,

Felix A. Reifler; Felipe A. L. Sánchez; Frank J. Clemens; Ksenija Varga; Rudolf Hufenus

2010-01-01

222

Fabrication of metal dielectric metal multilayer thin film: Color filter  

NASA Astrophysics Data System (ADS)

A highly efficient color filters based on a multilayer thin film Ag/MgF2/Ag were deposited on a glass substrate using thermal evaporation technique. They were designed by taking into account the influence of the dispersion characteristics and the thickness of silver (Ag) metal and magnesium fluoride (MgF2) dielectric layer. The cavity thickness for the blue, green and red color filter was 273, 334, and 170 nm respectively, while the metal layer was fixed at 32 nm. The center wavelength were found to be 460, 540, 620 nm for the blue, green and red devices and the corresponding peak transmission were 73.12%, 69.18% and 63.19%, respectively and provided a satisfactory color image. The spectral response of the device was also analyzed for the oblique light incidence as the tilt angle varied up to 70° and it was found to be angular dependent.

Kedawat, Garima; Jain, Vipin Kumar; Vijay, Y. K.

2014-04-01

223

Radiation damage in nanostructured metallic films  

NASA Astrophysics Data System (ADS)

High energy neutron and charged particle radiation cause microstructural and mechanical degradation in structural metals and alloys, such as phase segregation, void swelling, embrittlement and creep. Radiation induced damages typically limit nuclear materials to a lifetime of about 40 years. Next generation nuclear reactors require materials that can sustain over 60 - 80 years. Therefore it is of great significance to explore new materials with better radiation resistance, to design metals with favorable microstructures and to investigate their response to radiation. The goals of this thesis are to study the radiation responses of several nanostructured metallic thin film systems, including Ag/Ni multilayers, nanotwinned Ag and nanocrystalline Fe. Such systems obtain high volume fraction of boundaries, which are considered sinks to radiation induced defects. From the viewpoint of nanomechanics, it is of interest to investigate the plastic deformation mechanisms of nanostructured films, which typically show strong size dependence. By controlling the feature size (layer thickness, twin spacing and grain size), it is applicable to picture a deformation mechanism map which also provides prerequisite information for subsequent radiation hardening study. And from the viewpoint of radiation effects, it is of interest to explore the fundamentals of radiation response, to examine the microstructural and mechanical variations of irradiated nanometals and to enrich the design database. More importantly, with the assistance of in situ techniques, it is appealing to examine the defect generation, evolution, annihilation, absorption and interaction with internal interfaces (layer interfaces, twin boundaries and grain boundaries). Moreover, well-designed nanostructures can also verify the speculation that radiation induced defect density and hardening show clear size dependence. The focus of this thesis lies in the radiation response of Ag/Ni multilayers and nanotwinned Ag subjected to charged particles. The radiation effects in irradiated nanograined Fe are also investigated for comparison. Radiation responses in these nanostructured metallic films suggest that immiscible incoherent Ag/Ni multilayers are more resistant to radiation in comparison to their monolithic counterparts. Their mechanical properties and radiation response show strong layer thickness dependence in terms of radiation hardening and defect density. Coherent twin boundaries can interact with stacking fault tetrahedral and remove them effectively. Twin boundaries can actively absorb radiation induced defects and defect clusters resulting in boundary migration. Size dependence is also found in nanograins where fewer defects exhibit in films with smaller grains.

Yu, Kaiyuan

224

Thin Semiconductor/Metal Films For Infrared Devices  

NASA Technical Reports Server (NTRS)

Spectral responses of absorbers and reflectors tailored. Thin cermet films composites of metals and semiconductors undergoing development for use as broadband infrared reflectors and absorbers. Development extends concepts of semiconductor and dielectric films used as interference filters for infrared light and visible light. Composite films offer advantages over semiconductor films. Addition of metal particles contributes additional thermal conductivity, reducing thermal gradients and associated thermal stresses, with resultant enhancements of thermal stability. Because values of n in composite films made large, same optical effects achieved with lesser thicknesses. By decreasing thicknesses of films, one not only decreases weights but also contributes further to reductions of thermal stresses.

Lamb, James L.; Nagendra, Channamallappa L.

1995-01-01

225

Method for nondestructive testing of the film coating behavior of surface acoustic wave (SAW) sensors  

NASA Astrophysics Data System (ADS)

This paper presents a practical non-destructive method for studying the film coating behavior of SAW devices by using a water soluble dielectric film (manitol) deposited on the SAW device surface by resistive evaporation. After measuring the electrical parameters of the film coated SAW device, the film can easily be removed from its surface by water rinsing without causing any damage to it. The SAW device can then be used over and over again in a large number of film depositions. The method was tested on a 1 GHz surface transverse wave (STW) resonator coated with manitol of varying thickness. After each coating and evaluation, the STW device was successfully recovered without significant performance degradation. Data is presented on the electrical changes of the STW device as a result of depositing manitol coatings of various thicknesses.

Taslakov, M. A.; Avramov, I. D.

2010-04-01

226

Delivery of Flavor and Active Ingredients Using Edible Films and Coatings  

Microsoft Academic Search

\\u000a Edible films and coatings are promising systems for improvement of food quality, shelf life, safety, and functionality. They\\u000a can be used as individual packaging materials, food coating materials, and active ingredient carriers. They can also be used\\u000a to separate the compartments of heterogeneous ingredients within foods. In fact, edible films and coatings can incorporate\\u000a food additives, such as anti-browning agents,

Olga Martín-Belloso; M. Alejandra Rojas-Graü; Robert Soliva-Fortuny

227

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

228

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/cm 2 by the polarization measurement.

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

2011-02-01

229

Dielectric interlayers for increasing the transparency of metal films for mid-infrared attenuated total reflection spectroscopy.  

PubMed

By depositing a continuous, thin metal film on a substrate coated with a mid-infrared (IR) transparent dielectric film that fulfils the role of an index-matching, anti-reflective coating for the metal, the transparency of the metal in the IR wavelength range can be significantly enhanced. This effect is used to yield enhanced absorption in attenuated total internal reflection infrared (ATR-IR) spectroscopy in the presence of continuous thin metal films. The main limitation of the ATR technique when using continuous metal films is the low transparency of metals, especially for infrared light. Computations and experiments show an enhancement in the absorbance of a sample in contact with the metal at certain wavenumbers when the dielectric interlayer is present. The realisation of the setup is the stratified system consisting of zinc selenide-germanium (~1 ?m)-gold (40 nm and 20 nm) using the organic solvent acetonitrile as sample. Enhancement is stronger in s- than in p-polarisation. In s-polarisation, enhancement factors of up to 4 have been observed so far in experiments, but calculations show a route to higher enhancements. In addition to the increased absorption, the absorbance spectra show interference fringes which are due to a mismatch in the real part of the refractive index of the sample in contact with the metal film compared to a reference measurement. PMID:20941445

Reithmeier, Martina; Erbe, Andreas

2010-11-28

230

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

231

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

232

The evaluation of the corrosion resistance of metallic substrates protected by a hydrophobic coating  

E-print Network

the performance of hydrophobic materials in corrosion service, metallic substrates of aluminum, copper, and steel were coated with a hydrophobic coating termed conformal and subjected to a variety of intensive analytical examinations including Electrochemical...

Lee, Daniel G

2012-06-07

233

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

234

Preparation of cobalt doped nickel ferrite thin films on optical fibers by dip-coating technique  

Microsoft Academic Search

Cobalt doped NiFe2O4 thin films were synthesized using dip-coating wet-chemical process using a solution of iron (III) nitrate dissolved in ethylene glycol and 2-methoxyethanol. Films coated on flat (alumina plates, fused silica, slide glass) substrates and optical fibers were dense and without defects. The onset of the film crystallization was between 450 and 500 °C and crystallinity increased with increasing

Miroslav Sedlar; Ladislav Pust

1995-01-01

235

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

SciTech Connect

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

Asunskis, A. L.; Sherwood, P. M. A. [Department of Physics, 145 Physical Sciences, Oklahoma State University, Stillwater, Oklahoma 74078-3072 (United States)

2007-07-15

236

Electrical Characterization of Metal-Coated Carbon Nanotube Tips Shinya YOSHIMOTO, Yuya MURATA1  

E-print Network

using an acrylic adhesive,5) (2) growing a CNT directly on a metal tip apex by chemical vapor deposition of coating the CNT tips uniformly with metal thin layers by pulsed laser deposition (PLD),17Electrical Characterization of Metal-Coated Carbon Nanotube Tips Shinya YOSHIMOTO, Yuya MURATA1

Hasegawa, Shuji

237

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

238

Resistivity of thin Cu films coated with Ta, Ti, Ru, Al, and Pd barrier layers from first principles  

NASA Astrophysics Data System (ADS)

We present an atomistic first-principles calculation for the resistivity of rough Cu thin films coated with barrier layers of Ta, Ti, Ru, Al, and Pd. A significant difference in resistivity due to different barrier metals is found. Ti, Ta, and Ru barriers increase the resistivity whereas Al and Pd lower the resistivity, in comparison with that of bare Cu films having the same degree of roughness disorder. It is found that Al/Pd barrier atoms produce density of states (DOS) that match rather well with the DOS of Cu atoms on a Cu film with a perfectly flat surface while the DOS of Ti, Ta, and Ru do not match. Our results suggest that the geometrical roughness on the Cu film that causes diffuse scattering, can be “smoothed” out electronically by certain barriers such that the surface scattering becomes more specular.

Zahid, Ferdows; Ke, Youqi; Gall, Daniel; Guo, Hong

2010-01-01

239

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

240

Fabrication and Electromagnetic Characterization of Novel Self-Metallized Thin Films.  

National Technical Information Service (NTIS)

Unique, self-metallized films were investigated for deployable reflector antenna applications at L-band. Polyamic acid resins or soluble polyimides were doped with metal complexes, cast into films, and thermally cured. Each resulting film had a metallic l...

A. I. Mackenzie, R. L. Cravey, K. L. Dudley, D. T. Fralick, G. A. Miner, D. M. Stoakley

2002-01-01

241

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

NASA Astrophysics Data System (ADS)

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

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

1996-01-01

242

Planar plasmonic terahertz waveguides based on periodically corrugated metal films  

Microsoft Academic Search

We demonstrate that a one-dimensional periodically corrugated metal film can be used to create planar terahertz (THz) waveguides. The periodic corrugation is in the form of rectangular blind holes (i.e. holes that do not completely perforate the metal film) that are fabricated using a multilayer construction. The approach allows for the creation of structures in which the hole depth can

Gagan Kumar; Shashank Pandey; Albert Cui; Ajay Nahata

2011-01-01

243

The role of size and coating in Au nanoparticles incorporated into bi-component polymeric thin-film transistors  

NASA Astrophysics Data System (ADS)

We describe the effect of blending poly(3-hexylthiophene) (P3HT) with Au nanoparticles (AuNPs) on the performance of organic thin-film transistors. To this end we have used AuNPs of two different sizes coated with chemisorbed SAMs of oligophenyl-thiols possessing increasing lengths. The electrical characteristics of the hybrid materials revealed changes in the field-effect mobility depending primarily on the AuNP size, as a result of the variable energy level of the coated metallic nanocluster and by the degree of modification of the P3HT crystalline structure.We describe the effect of blending poly(3-hexylthiophene) (P3HT) with Au nanoparticles (AuNPs) on the performance of organic thin-film transistors. To this end we have used AuNPs of two different sizes coated with chemisorbed SAMs of oligophenyl-thiols possessing increasing lengths. The electrical characteristics of the hybrid materials revealed changes in the field-effect mobility depending primarily on the AuNP size, as a result of the variable energy level of the coated metallic nanocluster and by the degree of modification of the P3HT crystalline structure. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr00076e

Mosciatti, Thomas; Orgiu, Emanuele; Raimondo, Corinna; Samorì, Paolo

2014-04-01

244

High-barrier coated bacterial cellulose nanowhiskers films with reduced moisture sensitivity.  

PubMed

This study reports on the development and characterization of bacterial cellulose (BCNW) films coated with hydrophobic layers, presenting enhanced barrier properties. Pure BCNW films showed good transparency and thermal stability, high rigidity and extremely low oxygen permeability at 0%RH. The dramatic increase in oxygen permeability at 80%RH, due to the hydrophilic character of BCNW, was counteracted through coating the films with annealed PLA electrospun nanostructured fibres or hydrophobic silanes. The use of electrospinning was crucial to attain a good adhesion between the hydrophilic BCNW and the hydrophobic PLA layer. After electrospinning, the fibres were homogenised by annealing, thus obtaining a uniform and continuous coating. Coated systems showed a hydrophobic surface and protected the BCNW from moisture, thus reducing ca. 70% the water permeability and up to 97% the oxygen permeability at 80%RH. Furthermore, this novel approach was seen to protect BCNW films from moisture more efficiently than coating with hydrophobic silanes. PMID:23987449

Martínez-Sanz, Marta; Lopez-Rubio, Amparo; Lagaron, Jose M

2013-10-15

245

Nano Fabrication of Functional Transition Metal Oxide Thin Films  

Microsoft Academic Search

Transition metal oxide films show a rich variety of peculiar properties, such as ferroelectricity, ferromagnetism, high Tc superconductivity, colossal magnetoresistance, and so on. The method to process the oxide films down to nano scale is still under development. In this paper we introduce several techniques to process oxide films on the basis of AFM lithography and nanoimprint lithography. Using AFM

Naoki Suzuki; Hidekazu Tanaka; Yoshihiko Yanagisawa; Satoru Yamanaka; Luca Pellegrino; Bong Kuk Lee; Hea Yeon Lee; Tomoji Kawai

2008-01-01

246

Metal-enhanced fluorescence: effect of surface coating  

NASA Astrophysics Data System (ADS)

Metal Enhanced Fluorescence (MEF), a phenomenon arising when a fluorophore is in closed proximity to a metallic structure such as metallic films or nanostructures, is seen as a way to increase the amount of reactive oxygen species produced by the irradiation of the protoporphyrin IX (PpIX), a photosensitizer commonly used in photodynamic therapy. Here, we show a study of the distance-dependent of MEF by applying multiple layers of polyelectrolyte (PE) on silver nanoparticles (AgNPs) to progressively increase the distance between AgNPs and PpIX, covalently bond to the last polyelectrolyte layer as well as exploring the use of AgNPs of different sizes ranging from 40 to 100 nm. Up to four fold increase of PpIX fluorescence was observed when this photosensitizing agent is bounded onto 100 nm sized Ag NPs. The effective corresponding distance between AgNPs and PpIX is three layers of PE.

Lismont, M.; François, A.; Dreesen, L.; Monro, T. M.

2014-03-01

247

Ethanol-resistant polymeric film coatings for controlled drug delivery.  

PubMed

The sensitivity of controlled release dosage forms to the presence of ethanol in the gastro intestinal tract is critical, if the incorporated drug is potent and exhibits severe side effects. This is for instance the case for most opioid drugs. The co-ingestion of alcoholic beverages can lead to dose dumping and potentially fatal consequences. For these reasons the marketing of hydromorphone HCl extended release capsules (Palladone) was suspended. The aim of this study was to develop a novel type of controlled release film coatings, which are ethanol-resistant: even the presence of high ethanol concentrations in the surrounding bulk fluid (e.g., up to 40%) should not affect the resulting drug release kinetics. Interestingly, blends of ethylcellulose and medium or high viscosity guar gums provide such ethanol resistance. Theophylline release from pellets coated with the aqueous ethylcellulose dispersion Aquacoat® ECD 30 containing 10 or 15% medium and high viscosity guar gum was virtually unaffected by the addition of 40% ethanol to the release medium. Furthermore, drug release was shown to be long term stable from this type of dosage forms under ambient and stress conditions (without packaging material), upon appropriate curing. PMID:23570984

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

2013-07-10

248

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

249

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

NASA Astrophysics Data System (ADS)

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

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

2014-11-01

250

Preparation and photo-catalytic activity of Fe?TiO 2 thin films prepared by sol–gel dip coating  

Microsoft Academic Search

Thin films of iron (Fe) doped titanium dioxide (Fe?TiO2) were prepared on a variety of substrates by using Ti-peroxy sol–gel dip coating method. The surface structure of the film was modified by adding different concentrations of polyethylene glycol (PEG) into the TiO2 sol. Most of the metal ion doped entered TiO2 lattice resulting the shift in optical absorption edge towards

R. S. Sonawane; B. B. Kale; M. K. Dongare

2004-01-01

251

Enhanced electrochemical properties of fluoride-coated LiCoO2 thin films.  

PubMed

The electrochemical properties of fluoride-coated lithium cobalt oxide [LiCoO2] thin films were characterized. Aluminum fluoride [AlF3] and lanthanum fluoride [LaF3] coating layers were fabricated on a pristine LiCoO2 thin film by using a spin-coating process. The AlF3- and LaF3-coated films exhibited a higher rate capability, cyclic performance, and stability at high temperature than the pristine film. This indicates that the AlF3 and LaF3 layers effectively protected the surface of the pristine LiCoO2 film from the reactive electrolyte. PMID:22221488

Lee, Hye Jin; Kim, Seuk Buom; Park, Yong Joon

2012-01-01

252

Enhanced electrochemical properties of fluoride-coated LiCoO2 thin films  

PubMed Central

The electrochemical properties of fluoride-coated lithium cobalt oxide [LiCoO2] thin films were characterized. Aluminum fluoride [AlF3] and lanthanum fluoride [LaF3] coating layers were fabricated on a pristine LiCoO2 thin film by using a spin-coating process. The AlF3- and LaF3-coated films exhibited a higher rate capability, cyclic performance, and stability at high temperature than the pristine film. This indicates that the AlF3 and LaF3 layers effectively protected the surface of the pristine LiCoO2 film from the reactive electrolyte. PMID:22221488

2012-01-01

253

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

254

Conductive Perovskite-type Metal Oxide Thin Films Prepared by Chemical Solution Deposition Technique  

NASA Astrophysics Data System (ADS)

Metal oxide electrode have been widely developed for high-performance electric device because they possess some attractive characteristic such as thermal/chemical stabilities and change compensation for oxygen vacancies in interconnected dielectric layers, etc., which is often hardly achieved by convention metal electrodes. As almost all metal oxide electrodes were usually fabricated by some vapour deposition techniques which require large-scale equipments, power, resources and costs, film deposition via solution technique would be worthy for familiarizing the metal oxide electrodes. In this research, thin films of conductive perovskite-type oxides, (La,Sr)CoO3 [LSCO], were fabricated by chemical solution deposition technique. The precursor solution for LSCO was prepared using metal nitrate, acetates, and iso-propoxide and 2-methoxyethanol. The solution was spin-coated on substrates, followed by drying, pyrolysis and RTA-treatment for crystallization at 500-750°C, for 5 min in air. These processes were repeated to obtain desired film thickness. (100)Si and (100)SrTiO3 were used as substrate. XRD analysis indicated that both of LSCO films fabricated on (100)SrTiO3 and (100)Si substrates were crystallized at and above 600°C. The films on (100)SrTiO3 had preferential crystal orientation of (100)LSCO normal to the substrate surface, while random crystal orientation was confirmed for the films on (100)Si. Electrical resistivity of the both films fabricated at 700°C were 6.09 × 10-5 ? cm and 1.12 × 10-4 ? cm, respectively, which is almost same as the LSCO films fabricated by conventional vapour deposition technique.

Sasajima, K.; Uchida, H.

2011-10-01

255

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

256

Characterization of a novel super-hydrophilic coating film as a function of different spin coating speeds  

NASA Astrophysics Data System (ADS)

In this paper, the mechanical and the optical characteristics of a novel super-hydrophilic coating material (Wellture Finetech, Korea) are introduced according to the film thickness. Because a waterbased SiO2-abundant material has perfect transparency, as does glass, and a super-hydrophilic property, it can be used as a protection glass for a solar cell module. The film thickness was controlled by selecting several spin speeds in the coating process. After the coating process, the material was cured at around 290 °C for 20 minutes. The hardness of the film was measured using the ASTM D3363 test method, and the adhesion of the film was tested using the ASTM D3359 method. The surface conditions of the film were analyzed via scanning electron microscopy (SEM) and contact-angle measurements. A UV-visible spectrometer was used to measure the optical transmittance of the film. The anti-pollution property of the film (700 rpm) was also tested by pouring regular water on a permanent marker scratch.

Joung, Yeun-Ho; Choi, Won Seok; Shin, Yongtak; Lee, Minji; Kim, Heekon; Song, Woochang

2013-07-01

257

A Investigation Into the Relaxation Behavior of Pharmaceutical Film Coatings.  

NASA Astrophysics Data System (ADS)

Polymeric materials utilized as film coatings exhibit many different time dependent relaxations which can yield relevant information regarding their use. In this dissertation research, the effect of additives on the primary relaxation behavior and the effect of physical aging, a relaxation to the lowest free energy state, on the physical properties of glassy polymeric materials was investigated. Glassy polymeric materials were chosen in this study since they are widely utilized in the pharmaceutical industry. The observation of the aging process using a creep compliance technique was confirmed with polystyrene, a material whose aging behavior has been well studied. Results from both hydroxypropyl methylcellulose phthalate, HP-55, and cellulose acetate indicate that these materials physically age in their sub-Tg temperature ranges. The mechanical data in both cases was successfully fit to a model which describes the relaxation behavior of condensed amorphous materials. The aging time and temperature dependence of key parameters from this model show that physical aging is thermally activated and thermoreversible. Aging time and temperature dependent reductions in the water permeability of cellulose acetate were observed. The reductions were correlated with calculations, based on the mechanical property changes, which describe the aging -induced relaxation of the glass. These results indicate that a structural change due to aging may be responsible for the observed reductions in water mobility in cellulose acetate. The dissolution rate of HP-55 was found to decrease to a limiting rate when physically aged. Mechanical measurements performed on film samples which were subjected to the same thermal history utilized in the dissolution experiments confirmed the observed aging effect. The effect of the addition of the plasticizers dibutyl phthalate and polyethylene glycol 200 on the primary relaxation behavior of Eudragit S100, an enteric coating, was also evaluated in this dissertation. Creep compliance measurements were performed on films in the glass transition region. Both plasticizers were found to increase the mechanical rate of response of the polymer. A free volume approach was used to describe plasticizing efficiency and it was found that dibutyl phthalate was more effective at changing the mechanical rate of response of Eudragit S100 than polyethylene glycol 200.

Sinko, Christopher Michael

258

Investigation of a methodology for in-film defects detection on film coated blank wafers  

NASA Astrophysics Data System (ADS)

Multi-patterning is one of the commonly used processes to shrink device node dimensions. With the miniaturization of the device node and the increasing number of coated layers and lithography processes, needs for defect reduction and control are getting stronger. Although there are needs for detecting in-film defects during the lithography process, it is difficult to verify in-film defects detected by an optical inspection tool because in-film defects usually appear as SEM Non-Visuals (SNV) during defect review using a scanning electron microscope (SEM). This makes the tuning of optical inspection tools difficult since these defects may be considered as noise. However, if these defects are "real defects", they will have a negative impact to manufacturing yield. In this paper, we investigate a new methodology to detect in-film defects with high sensitivity utilizing a broadband plasma inspection tool. This methodology is expected to allow the early detection of in-film defects before the pattern formation, hence improving device manufacturing yield.

Kiyotomi, Akiko; Dauendorffer, Arnaud; Shimura, Satoru; Miyazaki, Shinobu; Miyagi, Takemasa; Ota, Shigeru; Haneda, Koji; Baris, Oksen; Wei, Junwei

2014-04-01

259

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

260

Understanding plasmon resonances of metal-coated colloidal crystal monolayers  

NASA Astrophysics Data System (ADS)

Metal films deposited over two-dimensional colloidal crystals (MFoCC) constitute a low-cost periodic structure with interesting photonic and plasmonic properties. It has previously been shown that this structure exhibits a behaviour similar to the well-known Extraordinary Optical Transmission (EOT) of metallic hole arrays in planar films. Here, we explore the transmission characteristics of AgFoCC by systematic comparison with that of the bare CC. Furthermore with additional reflectivity measurements we evaluate the AgFoCC overall plasmonic response, which, notably, exhibits a strong plasmon absorption band at wavelengths larger than those of the transmitted maximum. By corroborating these results with finite-difference time-domain electromagnetic simulations, we identify a hybrid metal-dielectric propagative mode in the transmission mechanism. On the contrary a strongly localized mode is responsible for the maximum light absorption by this structure. These results shed new light on the current understanding of this highly promising plasmonic structure, being useful for the design of surface-enhanced Raman scattering and enhanced fluorescence substrates.

Farcau, C.; Giloan, M.; Vinteler, E.; Astilean, S.

2012-03-01

261

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

262

Influence of film additives on stabilizing drug release rates from pellets coated with acrylic polymers.  

PubMed

The objective of this study was to investigate the influence of talc and triethyl citrate (TEC) on stabilizing the drug release rates following curing and storage at elevated temperature of pellets coated with an aqueous acrylic polymeric dispersion. Core pellets containing anhydrous theophylline (20%), microcrystalline cellulose, and polyvinylpyrrolidone were prepared by extrusion-spheronization. The aqueous dispersions were prepared by adding up to 30% TEC as a plasticizer and talc up to 200% as an antiadherent to a mixture of Eudragit RS 30D/RL 30D (95:5). The theophylline pellets were coated in a fluidized-bed coating unit and then cured at elevated temperatures. Theophylline pellets were successfully coated with the Eudragit dispersions that contained up to 200% talc, based on the dry polymer weight, and the coating efficiency was greater than 93%. Our results demonstrated that the polymer, which was plasticized by TEC, was able to function as a film-forming agent for dispersions containing high levels of talc. No sticking of the coated pellets was observed during the coating process or during the curing or equilibrating phase, even with high levels of TEC in the film. The dissolution rate of theophylline from the coated pellets was delayed when the film coating dispersion contained high levels of talc. Additionally, the stability of the drug release profiles from the coated pellets after storage was significantly improved. Furthermore, a modified dissolution testing used to simulate mechanical stresses that may be encountered in vivo showed the film coated pellets would have sufficient strength. The results of this study demonstrated that high levels of film additives in the acrylic dispersion contributed to the stabilization of the drug release rates as well as the reproducibility of the coating process. PMID:11416995

Maejima, T; McGinity, J W

2001-01-01

263

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

264

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

265

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

266

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

SciTech Connect

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

Rao Nanxia; Xie Xin; Wielizcka, David; Zhu Daming [Department of Physics, University of Missouri-Kansas City, 5110 Rockhill Road, Kansas City, Missouri 64110 (United States)

2006-11-15

267

Deposition of alloy films. [on irregulary shaped metal object  

NASA Technical Reports Server (NTRS)

An invention is described which deposits metal alloy films on a metal object. A glow discharge is established by applying a high voltage between an anode and a cathode object disposed in an inert gas atmosphere. An alloy of two or more metals is vaporized and the vapor injected into the glow discharge causing the alloy to be plated onto the cathode object.

Spalvins, T. (inventor)

1973-01-01

268

Metallization of CVD diamond films by cathodic arc deposition  

Microsoft Academic Search

Reliable metallization schemes for chemical vapor deposited diamond are critical for expanding the use of diamond components in electronics and optics. We present here the results of our investigation of several metallization schemes produced by cathodic arc deposition. The deposition process also allows the control of the metal ion energy, and this is used to promote good adhesion between film

O. R. Monteiro; M. C. Salvadori; M. Cattani; V Mammaana; I. G. Brown

1997-01-01

269

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

270

Bismuth film electrodes for heavy metals determination  

NASA Astrophysics Data System (ADS)

Bismuth film electrodes (BiFEs) have a potential to replace toxic mercury used most frequently for determination of heavy metals (Cd, Pb, Zn) by anodic stripping voltammetry. We prepared a graphite disc electrode (0.5 mm in diameter) from a pencil-lead rod and developed a nitrogen doped diamond-like carbon (NDLC) microelectrode array consisting of 50 625 microdiscs with 3 ?m in diameter and interelectrode distances of 20 ?m on a highly conductive silicon substrate as a support for BiFEs. The disc graphite BiFE was used for simultaneous determination of Pb(II), Cd(II) and Zn(II) by square wave voltammetry (SWV) in an aqueous solution. We found the optimum bismuth-to-metal concentration ratio in the solution to be 20. The dependence of the stripping responses on the concentration of target metals was linear in the range from 1×10 -8 to 1.2×10 -7 mol/L. Detection limits 2.4×10 -9 mol/L for Pb(II), 2.9×10 -9 mol/L for Cd(II) and 1.2×10 -8 mol/L for Zn(II) were estimated. A bismuth-plated NDLC microelectrode array was used for Pb(II) determination by differential pulse voltammetry (DPV) in an aqueous solution. We found that the stripping current for bismuth-plated NDLC array was linear in the concentration range of Pb(II) from 2×10 -8 to 1.2×10 -7 mol/L. The detection limit 2.2×10 -8 mol/L was estimated from a calibration plot.

Rehacek, Vlastimil; Hotovy, Ivan; Vojs, Marian; Mika, Fedor

2007-05-01

271

Heat-Induced Precipitation and Light-Induced Dissolution of Metal (Ag & Au) Nanoparticles in Hybrid Film  

Microsoft Academic Search

Metal nanoparticle-doped materials have attracted much attention because of their enhanced third-order nonlinear optical susceptibility. In their application, (1) controllable precipitation and (2) stability against photo-irradiation are essential concerns. Silver or gold nanoparticle-doped films were made from hybrid sol containing metal ions with their stabilizer on silica glass substrates by the sol-gel dip-coating technique and their heat-induced precipitation and photo-stability

S. Shibata; K. Miyajima; Y. Kimura; T. Yano

2004-01-01

272

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

273

Determination of silica coating efficiency on metal particles using multiple digestion methods.  

PubMed

Nano-sized metal particles, including both elemental and oxidized metals, have received significant interest due to their biotoxicity and presence in a wide range of industrial systems. A novel silica technology has been recently explored to minimize the biotoxicity of metal particles by encapsulating them with an amorphous silica shell. In this study, a method to determine silica coating efficiency on metal particles was developed. Metal particles with silica coating were generated using gas metal arc welding (GMAW) process with a silica precursor tetramethylsilane (TMS) added to the shielding gas. Microwave digestion and Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES) were employed to solubilize the metal content in the particles and analyze the concentration, respectively. Three acid mixtures were tested to acquire the appropriate digestion method targeting at metals and silica coating. Metal recovery efficiencies of different digestion methods were compared through analysis of spiked samples. HNO(3)/HF mixture was found to be a more aggressive digestion method for metal particles with silica coating. Aqua regia was able to effectively dissolve metal particles not trapped in the silica shell. Silica coating efficiencies were thus calculated based on the measured concentrations following digestion by HNO(3)/HF mixture and aqua regia. The results showed 14-39% of welding fume particles were encapsulated in silica coating under various conditions. This newly developed method could also be used to examine the silica coverage on particles of silica shell/metal core structure in other nanotechnology areas. PMID:21962698

Wang, Jun; Topham, Nathan; Wu, Chang-Yu

2011-10-15

274

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

275

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

276

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

277

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

Park, Jong Hee (Clarendon Hills, IL)

1998-01-01

278

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

279

Super elastic strain limit in metallic glass films  

PubMed Central

On monolithic Ni-Nb metallic glass films, we experimentally revealed 6.6% elastic strain limit by in-situ transmission electron microscopy observations. The origin of high elastic strain limit may link with high free volume in the film, causing the rearrangement of loosely bonded atomic clusters (or atoms) upon elastic deformation. This high elastic limit of metallic glass films will shed light on new application fields for metallic glasses, and also trigger more studies for deformation mechanism of amorphous materials in general. PMID:23152943

Jiang, Q. K.; Liu, P.; Ma, Y.; Cao, Q. P.; Wang, X. D.; Zhang, D. X.; Han, X. D.; Zhang, Z.; Jiang, J. Z.

2012-01-01

280

Evolution of potential distributions during the charging of nano-structured metal oxide films in air as response to sudden voltage application  

Microsoft Academic Search

Using metal oxide film structures, which were originally designed for gas sensing applications, we measured the charging and discharge currents and potential distributions on several metal oxide coatings after the application of an electrical potential against earth. The potential distributions show a specific charging of the surface with oxygen ions through the gas phase. The accumulated charge corresponds to that

I. Kiselev; M. Sommer

2010-01-01

281

Superconductivity enhancement in screened ultrathin metal films  

Microsoft Academic Search

We have studied superconductivity in thin quench-condensed bismuth films deposited on a 3 nm oxide layer covering a thick aluminium film. It was found that these Bi films have superconducting transition temperatures significantly larger than those of similar films deposited directly on glass. The enhancement of superconductivity is attributed to partial screening of the Coulomb interaction between conduction electrons in

E. G. Astrakharchik; C. J. Adkins

1998-01-01

282

A molecular dynamics study of metal coating on SWNT Teppei Matsuo, Junichiro Shiomi and Shigeo Maruyama  

E-print Network

-8656, Japan Metal coating on an SWNT is an important element technology in CNT-based electric and thermal on the static energetics. However, in order to grasp the full picture of the coating mechanism, one would also for various metal kinds, temperatures, and deposition conditions such as initial cluster sizes and deposition

Maruyama, Shigeo

283

Water vapor and oxygen-barrier performance of corn–zein coated polypropylene films  

Microsoft Academic Search

A novel corn–zein coating structure on polypropylene (PP) films was developed to examine its feasibility as an alternative water vapor and oxygen-barrier for flexible packaging industry. The barrier properties of the resulting films were evaluated as affected by coating formulation (solvent, corn–zein, plasticizer concentration and plasticizer type). Corn–zein with different amounts (5% and 15%) was dissolved in 70% and 95%

Funda Tihminlioglu; ?sa Do?an Atik; Banu Özen

2010-01-01

284

Application of dip-coating process for depositing conducting polypyrrole films  

Microsoft Academic Search

The formation and electrical properties of vapour phase polymerised polypyrrole films on dip-coated polyethylene oxide (PEO)-cupric chloride substrates have been studied with respect to different deposition parameters. The substrate speed (U) during the dip-coating process affects the film thickness (d) and a relationship of the type d?Un with n = 0.27 is followed. The X-ray diffraction studies reveal a distinct

Sachin P. Khedkar; S. Radhakrishnan

1997-01-01

285

Preparation of titanium(IV) oxide thin film photocatalyst by sol–gel dip coating  

Microsoft Academic Search

Thin films of titanium dioxide (TiO2) were deposited on variety of substrates by a simple sol–gel dip coating technique. The substrates were coated with titanium peroxide precursor solution of controlled viscosity at a constant pulling rate of 1mms?1, air-dried and further heated at 400°C to obtain uniform films with good adhesion to the substrate. The change in viscosity of the

R. S Sonawane; S. G Hegde; M. K Dongare

2003-01-01

286

Analysis of IBAD silicon oxynitride film for anti-reflection coating application  

Microsoft Academic Search

A SOI-based optoelectronic device needs a high-quality anti-reflection coating on both faces of the device to minimize the optical reflectance from the face. In this work amorphous silicon oxynitride films were deposited on silicon substrates by ion beam assisted deposition (IBAD). The main purpose was to use silicon oxynitride film as single layer anti-reflection coating for SOI-based optoelectronic devices. This

Yongjin Wang; Xinli Cheng; Zhilang Lin; Changsheng Zhang; Haibo Xiao; Feng Zhang; Shichang Zou

2004-01-01

287

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

288

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

289

Development and application of multicomponent edible coatings and films: a review.  

PubMed

Combining the advantages of polysaccharides, proteins and/or lipids offers multicomponent edible films and coatings good mass transfer barrier properties. Multicomponent edible films and coatings could be beneficial to the food industry by leading to innovative applications. The barrier properties of these systems strongly depend upon their structure and chemistry, the interaction between different film components as well as surrounding environment conditions. Future researches on these multicomponent systems need to concentrate on the following goals: (1) investigation of the optimal film compositions and specific film-forming conditions for different food systems; (2) study of the film responses in their barrier properties to environmental factors such as RH and temperature; (3) fundamental research of the mechanism of mass transfer and the interaction of different films components and foods; (4) exploration of the feasibility of potential applications in the food industry. PMID:11885140

Wu, Yi; Weller, Curtis L; Hamouz, Fayrene; Cuppett, Susan L; Schnepf, Marilynn

2002-01-01

290

An analytical description of the jet finishing process for hot-dip metallic coatings on strip  

Microsoft Academic Search

An analytical study of the jet finishing of hot-dip metallic coated strip which relates the final solidified coating thickness\\u000a to strip speed, jet nozzle operating parameters, and coating metal and finishing fluid properties is described. The results\\u000a of laboratory and mill tests are compared with the predictions of the analytical model and engineering considerations for\\u000a jet nozzle operation to reduce

John A. Thornton; Hart F. Graff

1976-01-01

291

Coating of a stainless steel tube-wall catalytic reactor with thermally treated polysiloxane thick films  

E-print Network

Coating of a stainless steel tube-wall catalytic reactor with thermally treated polysiloxane thick. The organosilicon films were then thermally treated under air and the influence of calcinations conditions remains coated and hidden despite visible but non penetrating cracks of the upper layer of the physical

Paris-Sud XI, Université de

292

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

293

Characterisation and wear response of metal-boride coated WC–Co  

Microsoft Academic Search

Wear resistant transition metal boride coatings have received comparatively little investigation. In the present work, a series of CrB2, Mo2B5 and WB coatings were successfully applied to WC–6wt.%Co cutting tool inserts using unbalanced magnetron sputtering technology. The CrB2 coatings were fully crystalline and had a {101} preferred orientation, while the Mo2B5 coatings although containing some crystallinity were mainly amorphous. The

Peter A Dearnley; Martin Schellewald; Karl L Dahm

2005-01-01

294

Corrosion and drug release properties of EN-plating\\/PLGA composite coating on MAO film  

Microsoft Academic Search

The electroless nickel plating\\/poly(dl-lactide-co-glycolide) composite coating (EN-plating\\/PLGA composite coating) was fabricated on the surface of the micro-arc oxidation (MAO) film of the magnesium alloy AZ81 to double control the corrosion and drug release in the hanks' solution. The EN-plating was fabricated on the MAO coating to improve the corrosion resistance by overlaying most pores and micro-cracks on the surface of

Ping Lu; Yin Liu; Meiqing Guo; Haidong Fang; Xinhua Xu

2011-01-01

295

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.

2014-08-01

296

Plasma treatment of thin film coated with graphene flakes for the reduction of sheet resistance.  

PubMed

We investigated the effects of plasma treatment on the sheet resistance of thin films spray-coated with graphene flakes on polyethylene terephthalate (PET) substrates. Thin films coated with graphene flakes show high sheet resistance due to defects within graphene edges, domains, and residual oxygen content. Cl2 plasma treatment led to decreased sheet resistance when treatment time was increased, but when thin films were treated for too long the sheet resistance increased again. Optimum treatment time was related to film thickness. The reduction of sheet resistance may be explained by the donation of holes due to forming pi-type covalent bonds of Cl with carbon atoms on graphene surfaces, or by C--Cl bonding at the sites of graphene defects. However, due to radiation damage caused by plasma treatment, sheet resistance increased with increased treatment time. We found that the sheet resistance of PET film coated with graphene flakes could be decreased by 50% under optimum conditions. PMID:24266197

Kim, Sung Hee; Oh, Jong Sik; Kim, Kyong Nam; Seo, Jin Seok; Jeon, Min Hwan; Yang, Kyung Chae; Yeom, Geun Young

2013-12-01

297

Properties of two biological glasses used as metallic prosthesis coatings and after an implantation in body  

E-print Network

Properties of two biological glasses used as metallic prosthesis coatings and after an implantation the mechanical properties of the supporting metal. Such as hydroxyapatites ceramics, biological glasses are good prostheses are made with metal or metallic alloys. A successful long-term implant requires biocompatibility

Paris-Sud XI, Université de

298

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. 8 figures.

Weeks, J.K. Jr.; Gensse, C.

1993-09-14

299

Electrophoretic Deposition Applied to Thick Metal-Ceramic Coatings  

SciTech Connect

Electrophoretic deposition was used to fabricate thick (4 mm) metal–ceramic deposits from a non-aqueous slurry of nickel and alumina particles. A high solid volume in the slurry was identified as the primary parameter for depositing thick cermet coatings rather than the applied electric potential or ionic additive concentration. Ionic additives (MgCl2, AlCl3, etc.) were found to adequately suspend the alumina particles and provide rapid deposition rates. The nickel particles proved to be more difficult to suspend in solution, thereby sacrificing control of the deposition composition. The use of small (3.0 µm) particles and continuously pumping the slurry alleviated the suspension problems but small electric potentials (100 V/cm) were required to avoid the formation of rough, columnar deposits on the depositing electrode.

Windes, William Enoch; Zimmerman, Jeramy; Reimanis, Ivar E.

2002-08-01

300

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

301

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

302

Squeezed mode conversion in hybrid plasmon polariton waveguide using spin-coated silver film.  

PubMed

We designed, fabricated, and characterized a hybrid surface plasmon polariton waveguide (SPP_wg) for mode conversion. The 20-nm-thick silver SPP_wg was fabricated via spin-coating with an aqueous silver ionic complex solution. The structure of the SPP_wg consists of a straight Insulator-Metal-Insulator waveguide (IMl_wg), a lateral tapered Insulator-Metal-Insulator-Metal-Insulator waveguide (tapered_IMIMI_wg), and a straight IMIMI waveguide (IMIMI_wg). An s0 mode size of 12.90 microm x 8.08 microm at a 6-microm-wide IMI_wg was excited by a butt-coupling method at a wavelength of 1550 nm. The s0 mode was converted into an Ss0 mode size of 8.08 microm x 5.65 microm at a 3-microm-wide IMIMI_wg. The mode size was squeezed by approximately 2/3 via a 15-microm-long lateral tapered_IMIMI_wg with a 500-nm-thick central insulator. The coupling loss for mode conversion between the straight IMI_wg and the straight IMIMI_wg was 5.49 dB. The hybrid SPP_wg for mode conversion has the potential to bridge the gap between micron and sub-micron scales in nano plasmonic integrated circuits. In addition, the use of the spin coating method is very cost-effective because films are formed at a low temperature in a short period of time without the need for a vacuum system. PMID:22966593

Ha, Thi-Vu-Anh; Park, Hae-Ryeong; Son, Jung-Han; Lee, Myung-Hyun

2012-07-01

303

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

304

Shear-alignment of metal-containing block copolymer thin films for nanofabrication  

NASA Astrophysics Data System (ADS)

Cylinder-forming block copolymers can be used as etch masks for the fabrication of nanowire grids, with both fine resolution and scalability. However, achieving a high aspect ratio in these nanostructures, where reactive ion etching is employed for pattern transfer, requires strong etch contrast between two blocks of the copolymer. We achieve this strong contrast by using metal-containing block copolymers: materials which either contain metal as synthesized, or which can be selectively metallized after deposition as thin films. In the first case, iron-containing polystyrene-b-poly(ferrocenylisopropylmethylsilane) (PS-PFS) forming PFS cylinders was employed, and a spin-coated film was aligned by shearing with a polydimethylsiloxane pad. In the second case, polystyrene-b-poly-2-vinylpyridine (PS-P2VP) was deposited as a film, shear-aligned, and then platinum was selectively sequestered within the P2VP cylinders by brief soaking in an aqueous solution of a Pt salt. In both cases, shear stress produced alignment over centimeter-scale areas; this alignment was retained for PS-P2VP during the selective metallization. The line pattern in these aligned block copolymer thin films is then transferred via reactive ion etching into amorphous silicon deposited onto a quartz wafer to fabricate silicon nanowire grid polarizers which can operate at deep ultraviolet wavelengths.

Kim, So Youn; Register, Richard; Gwyther, Jessica; Manners, Ian; Chaikin, Paul

2013-03-01

305

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

306

Effects of asymmetric surface corrugations on fully metal-coated scanning near field optical microscopy tips.  

PubMed

We propose a new configuration for a fully metal coated scanning near field (SNOM) probe based on asymmetric corrugations in the metal coating. The variation in the metal surface induces coupling mechanisms leading to the creation of a localized hot spot under linearly polarized excitation. Field localization is an effect of paramount importance for resolution but cannot be achieved with standard axisymmetric fully metal-coated probes, unless a more cumbersome radially polarized excitation is used. Our simulations show that this promising structure allows one to simplify the mode injection procedures circumventing the need for a radially polarized beam. PMID:20588716

Lotito, Valeria; Sennhauser, Urs; Hafner, Christian

2010-04-12

307

Thick film silver metallizations for silicon solar cells  

Microsoft Academic Search

Thick film conductor compositions containing silver powder and lead bismuthate glass frit powder and an organic vehicle\\/solvent system are presented for use as grid metallizations to the n-type layers of n- on p- silicon solar cells.

Needes

1980-01-01

308

Photon Generation by Joule Heating in Metal Films  

Microsoft Academic Search

We calculate the evolution of the coupled electron-phonon system in a metal film subjected to an electric field. The detailed form of the phonon distribution is presented, and is shown to deviate significantly from a Bose distribution.

N. Perrin; H. Budd

1972-01-01

309

Combustion zone durability program-B. Task VIII. Sputter deposited ceramic and metallic coatings. Executive summary. [Graded metal; metal/ceramic layered; dense surface ceramic  

SciTech Connect

The graded metal coatings are of the CoCrAlY type modified by including high Cr surface compositions, gradients in Cr and Al composition, underlayers and graded Pt additions, and Hf substitutions for Y. The metal ceramic layered coatings consist of alternate metal (Ni, Ni-Cr, CoCrAlY or Pt) and ceramic (Al/sub 2/O/sub 3/ or ZrO/sub 2/ + Y) layers. Investigations of dense surface ceramic coatings are directed towards methods for obtaining adherent impermeable ceramic protective coatings for gas turbine hot section components. Increased coating adherence is being sought through two coating designs intended to accomodate expansion and modulus mismatches at the coating-substrate interface.

Patten, J. W.; Moss, R. W.; Hays, D. D.

1980-11-01

310

Multilayer coatings on flexible substrates  

SciTech Connect

Thin-film optical and non-optical multilayer coatings are deposited onto flexible substrates using a vacuum web coater developed at Pacific Northwest Laboratory. The coater`s primary application is rapid prototyping of multilayer (1) polymer coatings, (2) polymer/metal coatings, (3) ceramic/metal coatings, and (4) hybrid polymer, ceramic, and metal coatings. The coater is fully automated and incorporates polymer evaporation and extrusion heads, high-rate magnetron sputtering cathodes, and e-beam evaporation sources. Polymer electrolytes are deposited by extrusion techniques. Flexible plastic, metal, and ceramic substrates can be coated using roll-to-roll or closed-loop configurations. Examples of multilayer optical coatings demonstrated to date are solar reflectors, heat mirrors, Fabry-Perot filters, and alpha particle sensors. Nonoptical coatings include multilayer magnetic metal/ceramic and lamellar composites.

Martin, P.M.; Affinito, J.D.; Gross, M.E.; Coronado, C.A.; Bennett, W.D.; Stewart, D.C.

1995-04-01

311

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

312

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

313

Transverse fracture in thin-film coatings under spherical indentation  

Microsoft Academic Search

The competition between transverse surface and sub-surface cracks in a thin, hard coating bonded to polycarbonate substrate due to spherical indentation is investigated in real-time as a function of coating thickness and indenter radius. Fine grain (Y-TZP) and medium grain (alumina) ceramics and pre-abraded amorphous glass are used for the coating. As the coating thickness is reduced, the familiar star-shape

Herzl Chai

2005-01-01

314

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

NASA Technical Reports Server (NTRS)

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.

1980-01-01

315

Mesoporous sandwiches: towards mesoporous multilayer films of crystalline metal oxides.  

PubMed

Alternating multilayers of ordered mesoporous films of different metal oxides were prepared with the EISA (evaporation-induced self-assembly) method, using block copolymer templates. Selecting certain metal oxides, as exemplified with TiO2 and WO3 in this work, a high mesoscopic order could be achieved and preserved during crystallization. In addition to standard characterizations, the electrochromism of the multilayer film was studied, proving good accessibility of the single layers. PMID:19421475

Ostermann, Rainer; Sallard, Sébastien; Smarsly, Bernd M

2009-05-21

316

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

317

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

318

Water repellent porous silica films by sol-gel dip coating method.  

PubMed

The wetting of solid surfaces by water droplets is ubiquitous in our daily lives as well as in industrial processes. In the present research work, water repellent porous silica films are prepared on glass substrate at room temperature by sol-gel process. The coating sol was prepared by keeping the molar ratio of methyltriethoxysilane (MTES), methanol (MeOH), water (H(2)O) constant at 1:12.90:4.74, respectively, with 2M NH(4)OH throughout the experiments and the molar ratio (M) of MTES/Ph-TMS was varied from 0 to 0.22. A simple dip coating technique is adopted to coat silica films on the glass substrates. The static water contact angle as high as 164° and water sliding angle as low as 4° was obtained for silica film prepared from M=0.22. The surface morphological studies of the prepared silica film showed the porous structure with pore sizes typically ranging from 200nm to 1.3?m. The superhydrophobic silica films prepared from M=0.22 retained their superhydrophobicity up to a temperature of 285°C and above this temperature the films became superhydrophilic. The porous and water repellent silica films are prepared by proper alteration of the Ph-TMS in the coating solution. The prepared silica films were characterized by surface profilometer, scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier Transform Infrared (FT-IR) spectroscopy, humidity tests, chemical aging tests, static and dynamic water contact angle measurements. PMID:20822773

Rao, A Venkateswara; Gurav, Annaso B; Latthe, Sanjay S; Vhatkar, Rajiv S; Imai, Hiroaki; Kappenstein, Charles; Wagh, P B; Gupta, Satish C

2010-12-01

319

Nonmetallic Conduction in Thin Metal Films at Low Temperatures  

Microsoft Academic Search

Resistance measurements were made on high-resistivity thin-film metal strips at temperatures as low as 10 mK. Unexpected logarithmic variations of the resistance with temperature and applied electric field were observed for strips with sheet resistance below R□~10 kOmega\\/□ and widths >~ 1 mum. Exponential increases in resistance were observed for similar films when the film width was decreased to about

G. J. Dolan; D. D. Osheroff

1979-01-01

320

Measurement of yield strength of thin metal film  

Microsoft Academic Search

Based on measurement of the load-depth curve in nanoindentation, the yield strength of thin metal film on Si substrate can be determined with the model of finite element analysis. An example is given of thin Cu film and the result shows that the yield strength thus determined can eventually reflect changes of processing condition both in deposition and in post-treatment.

Fei Wang; Kewei Xu

2004-01-01

321

Negative index metamaterial combining magnetic resonators with metal films  

Microsoft Academic Search

We present simulation results of a design for negative index materials that\\u000auses magnetic resonators to provide negative permeability and metal film for\\u000anegative permittivity. We also discuss the possibility of using semicontinuous\\u000ametal films to achieve better manufacturability and enhanced impedance\\u000amatching.

Uday K. Chettiar; Alexander V. Kildishev; Thomas A. Klar; Vladimir M. Shalaev

2006-01-01

322

Yielding and strain hardening of thin metal films on substrates  

Microsoft Academic Search

The author has shown that the very high strengths and high strain hardening rates exhibited by thin metal films on substrates can be understood by considering the effects of confinement on the motion of dislocations. Both the substrate and passivation and the obstacle dislocations already present in the film narrow the channels through which dislocations can move and this leads

William D. Nix

1998-01-01

323

Synthesis and characterisation of pack cemented aluminide coatings on metals  

NASA Astrophysics Data System (ADS)

The exposition of metallic materials to high temperature environments leads to their corrosion because of oxidation or sulphidation. One way to protect such materials is to produce an Al 2O 3 layer which needs to be continuous enough to limit diffusion of oxygen or metallic elements, and withstand this corrosion. Since a few years, it has been proved that aluminide compounds are one of the most effective materials to achieve this goal. Indeed, they possess sufficient Al and many beneficial mechanical properties when exposed to high temperature conditions to make possible the formation of a protective Al 2O 3 scale. This study is aimed at the elaboration of iron, nickel and molybdenum aluminides by modification of the surface of the base materials by a pack cementation process. The as-cemented alloys were analysed by means of SEM coupled with EDX and by XRD. Cross-section examinations showed, in each case, a progressive diffusion of aluminium through the substrates. The diffusion thickness layer was more or less important depending on the base material and on the coating conditions.

Houngninou, C.; Chevalier, S.; Larpin, J. P.

2004-09-01

324

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

325

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

326

Chemical vapor deposition of ceramic coatings on metals and ceramic fibers  

Microsoft Academic Search

The research presented in this study consists of two major parts. The first part is about the development of ceramic coatings on metals by chemical vapor deposition (CVD) and metal-organic chemical vapor deposition (MOCVD). Ceramics such as Al2O3 and Cr2O3, are used as protective coatings for materials used at elevated temperatures (>700°C). These metal oxides either exhibit oxidation resistance or

Jun Co Nable

2005-01-01

327

Broadly tunable thin-film intereference coatings: active thin films for telecom applications  

NASA Astrophysics Data System (ADS)

Thin film interference coatings (TFIC) are the most widely used optical technology for telecom filtering, but until recently no tunable versions have been known except for mechanically rotated filters. We describe a new approach to broadly tunable TFIC components based on the thermo-optic properties of semiconductor thin films with large thermo-optic coefficients 3.6X10[-4]/K. The technology is based on amorphous silicon thin films deposited by plasma-enhanced chemical vapor deposition (PECVD), a process adapted for telecom applications from its origins in the flat-panel display and solar cell industries. Unlike MEMS devices, tunable TFIC can be designed as sophisticated multi-cavity, multi-layer optical designs. Applications include flat-top passband filters for add-drop multiplexing, tunable dispersion compensators, tunable gain equalizers and variable optical attenuators. Extremely compact tunable devices may be integrated into modules such as optical channel monitors, tunable lasers, gain-equalized amplifiers, and tunable detectors.

Domash, Lawrence H.; Ma, Eugene Y.; Lourie, Mark T.; Sharfin, Wayne F.; Wagner, Matthias

2003-06-01

328

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.

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

2012-08-01

329

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

330

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

331

Fundamental Adsorption Properties for Low Molecular Weight Alcohols in Fluorocarbon Thin Films Deposited onto Quartz Crystal Microbalance Electrode by an R.F. Sputtering and Spin Coating  

NASA Astrophysics Data System (ADS)

Highly sensitive detection methods for volatile organic compounds (VOCs) are needed in working environment handling the VOCs. The use of a quartz crystal microbalance (QCM) is one such method, and many studies have been carried out on the deposition of metallic, inorganic and organic thin films onto QCM surfaces for use as sensors. In this paper, we report on adsorption properties of fluorocarbon thin films deposited onto the QCM electrode by an r.f. sputtering and spin coating for low molecular weight VOCs such as aliphatic alcohols and acetone. Adsorption mass of these VOC molecules in the fluorocarbon thin film deposited by the r.f. sputtering were much higher than that in the thin film deposited by the spin coating. It is known that molecular structures of fluorocarbon thin films sputtered with a Poly(tetrafluoroethylene) (PTFE) target were quite different from pristine PTFE. It is considered that this is one of reasons why the adsorption mass in the thin film deposited by the r.f. sputtering was higher than that in the thin film deposited by the spin coating.

Iwamori, Satoru; Miyamoto, Takaaki; Ikeda, Yuki; Ohnishi, Yasutaka; Noda, Kazutoshi

332

Organic hydrogen gas sensor with palladium-coated ?-phase poly(vinylidene fluoride) thin films  

NASA Astrophysics Data System (ADS)

We have proposed an organic hydrogen gas sensor in which palladium (Pd)-coated ?-phase poly(vinylidene fluoride) (PVDF) films are utilized. Volume expansion of the Pd thin film caused by absorption of hydrogen gas is monitored by a piezoelectric thin film of PVDF attached to the Pd films. We have developed a simple method of synthesizing ?-phase PVDF films from ?-phase PVDF powder by using a wet process in which a mixture of acetone and hexamethylphosphoric triamide is used as the solvent for the PVDF powder. The sensor works by itself at room temperature without a power source.

Imai, Yuji; Kimura, Yasuo; Niwano, Michio

2012-10-01

333

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

334

Application of diamond films from CO-H 2 plasma to tool blade coating  

Microsoft Academic Search

Diamond films were coated on WC-Co alloy tool blades using a microwave plasma of CO-H2 mixed gas. Diamond film prepared at a CO concentration of 10% had good properties: Vickers hardness % 8500 kg mm-2 and adhesion force ˜ 1.7 kg mm-2. No peel-off of the diamond film was observed after a cutting test of an Al-Si alloy rod at

Yukio Saito; Kouji Sato; Shinpei Matuda; Hideomi Koinuma

1991-01-01

335

High-performance carbon nanotube transparent conductive films by scalable dip coating.  

PubMed

Transparent conductive carbon nanotube (CNT) films were fabricated by dip-coating solutions of pristine CNTs dissolved in chlorosulfonic acid (CSA) and then removing the CSA. The film performance and morphology (including alignment) were controlled by the CNT length, solution concentration, coating speed, and level of doping. Using long CNTs (?10 ?m), uniform films were produced with excellent optoelectrical performance (?100 ?/sq sheet resistance at ?90% transmittance in the visible), in the range of applied interest for touch screens and flexible electronics. This technique has potential for commercialization because it preserves the length and quality of the CNTs (leading to enhanced film performance) and operates at high CNT concentration and coating speed without using surfactants (decreasing production costs). PMID:23038980

Mirri, Francesca; Ma, Anson W K; Hsu, Tienyi T; Behabtu, Natnael; Eichmann, Shannon L; Young, Colin C; Tsentalovich, Dmitri E; Pasquali, Matteo

2012-11-27

336

Antibacterial effectiveness of chitosan-propolis coated polypropylene films against foodborne pathogens.  

PubMed

Antibacterial properties of chitosan are well documented in the literature. However its antibacterial effectiveness in the film form is controversial due to the methodological differences in test methods used. In this study, antibacterial effectiveness of chitosan-coated polypropylene films alone and incorporating ethanolic extract of propolis (EEP) were evaluated against six foodborne pathogens (Bacillus cereus, Cronobacter sakazakii, Escherichia coli O157:H7, Listeria monocytogenes, Salmonella typhimurium and Staphylococcus aureus) using the ISO 22196 method designed for the antibacterial treated plastic products. The results demonstrated that chitosan coated film exhibited the broad-spectrum antibacterial activity. Incorporation of EPP to coating at 10% (propolis resin/chitosan) enhanced antibacterial activity against all pathogens tested. Results of this study revealed that chitosan has antibacterial activity in the film form and that propolis is a promising antimicrobial for the food packaging applications. PMID:23707735

Torlak, Emrah; Sert, Durmu?

2013-09-01

337

Functional properties of ZnO films prepared by thermal oxidation of metallic films  

NASA Astrophysics Data System (ADS)

We have prepared ZnO films by thermal oxidation of Zn metallic films and analyzed their structure, morphology, wettability, and gas sensing properties. Films structure and surface morphology were derived from X-ray diffraction and atomic force microscopy data. XRD analysis indicates that obtained ZnO films posses a crystalline structure. An increase of the surface roughness was observed, once the oxidation time increases. Surface wettability investigations showed that under UV-illumination, ZnO films present a reversible switching between hydrophobic and hydrophilic states. The gas response to methane, acetone, and formaldehyde was investigated, and experimental results indicate that tested films are selective to methane. Also, the gas response was found to increase, as the oxidation time of metallic films increases. This behavior was attributed to the structural changes (crystallite sizes, surface roughness), which take place during oxidation process.

Rambu, A. P.; Tiron, V.; Nica, V.; Iftimie, N.

2013-06-01

338

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

339

Ceramic plasma-sprayed coating of melting crucibles for casting metal fuel slugs  

SciTech Connect

Thermal cycling and melt reaction studies of ceramic coatings plasma-sprayed on Nb substrates were carried out to evaluate the performance of barrier coatings for metallic fuel casting applications. Thermal cycling tests of the ceramic plasma-sprayed coatings to 1450 degrees C showed that HfN, TiC, ZrC, and Y2O3 coating had good cycling characteristics with few interconnected cracks even after 20 cycles. Interaction studies by 1550 degrees C melt dipping tests of the plasma-sprayed coatings also indicated that HfN and Y2O3 do not form significant reaction layer between U–20 wt.% Zr melt and the coating layer. Plasma-sprayed Y2O3 coating exhibited the most promising characteristics among HfN, TiC, ZrC, and Y2O3 coating.

K.H. Kim; C.T. Lee; C.B. Lee; R.S. Fielding; J.R. Kennedy

2013-10-01

340

Ceramic plasma-sprayed coating of melting crucibles for casting metal fuel slugs  

NASA Astrophysics Data System (ADS)

Thermal cycling and melt reaction studies of ceramic coatings plasma-sprayed on Nb substrates were carried out to evaluate the performance of barrier coatings for metallic fuel casting applications. Thermal cycling tests of the ceramic plasma-sprayed coatings to 1450 °C showed that HfN, TiC, ZrC, and Y2O3 coating had good cycling characteristics with few interconnected cracks even after 20 cycles. Interaction studies by 1550 °C melt dipping tests of the plasma-sprayed coatings also indicated that HfN and Y2O3 do not form significant reaction layer between U-20 wt.% Zr melt and the coating layer. Plasma-sprayed Y2O3 coating exhibited the most promising characteristics among HfN, TiC, ZrC, and Y2O3 coating.

Kim, Ki Hwan; Lee, Chong Tak; Lee, Chan Bock; Fielding, R. S.; Kennedy, J. R.

2013-10-01

341

Comparison of Release-Controlling Efficiency of Polymeric Coating Materials Using Matrix-type Casted Films and Diffusion-Controlled Coated Tablet  

Microsoft Academic Search

Polymeric coating materials have been widely used to modify release rate of drug. We compared physical properties and release-controlling\\u000a efficiency of polymeric coating materials using matrix-type casted film and diffusion-controlled coated tablet. Hydroxypropylmethyl\\u000a cellulose (HPMC) with low or high viscosity grade, ethylcellulose (EC) and Eudragit® RS100 as pH-independent polymers and\\u000a Eudragit S100 for enteric coatings were chosen to prepare the

Zong-Zhu Piao; Kyoung-Ho Lee; Dong-Jin Kim; Hong-Gu Lee; Jaehwi Lee; Kyung Taek Oh; Beom-Jin Lee

2010-01-01

342

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

343

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

344

Understanding Organic Film Behavior on Alloy and Metal Oxides  

PubMed Central

Native oxide surfaces of stainless steel 316L and Nitinol alloys and their constituent metal oxides namely, nickel, chromium, molybdenum, manganese, iron and titanium were modified with long chain organic acids to better understand organic film formation. The adhesion and stability of films of octadecylphosphonic acid, octadecylhydroxamic acid, octadecylcarboxylic acid and octadecylsulfonic acid on these substrates was examined in this study. The films formed on these surfaces were analyzed by diffuse reflectance infrared Fourier transform spectroscopy, contact angle goniometry, atomic force microscopy and matrix assisted laser desorption ionization mass spectrometry. The effect of the acidity of the organic moiety and substrate composition on the film characteristics and stability is discussed. Interestingly, on the alloy surfaces, the presence of less reactive metal sites does not inhibit film formation. PMID:20039608

Raman, Aparna; Quinones, Rosalynn; Barriger, Lisa; Eastman, Rachel; Parsi, Arash

2010-01-01

345

ELECTROCHEMICAL PERFORMANCE OF Ni\\/Cu-METALLIZED & CARBON-COATED GRAPHITES FOR LITHIUM BATTERIES  

Microsoft Academic Search

Synthetic and natural graphites were metallized with Cu or Ni using a fluidized bed coating and annealing process. With this method, crystalline nanometer-sized metal islands (~ 50 nm diameter) were deposited onto the surface of graphite. Post-metallization, the graphite materials were cycled in lithium coin cells to determine their electrochemical properties in a propylene carbonate (PC) solvent based electrolyte. Better

Christopher S. Johnson; Kevin Lauzze; Nick Kanakaris; Arthur Kahaian; Michael Thackeray; Khalil Amine; Giselle Sandí-Tapia; Stephen Hackney; Robert Rigney

346

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 on the propagation of terahertz pulses along the surface of metal wires. Our measurements show that propagation over in the measurements. Our results show the potential of tera- hertz surface plasmon polaritons on metal wires

347

Ceramics reinforced metal base composite coatings produced by CO2 laser cladding  

Microsoft Academic Search

Due to the excellent performance in high strength, anti-temperature and anti-wear, ceramics reinforced metal base composite material was used in some important fields of aircraft, aerospace, automobile and defense. The traditional bulk metal base composite materials are the expensive cost, which is limited in its industrial application. Development of laser coating of ceramics reinforced metal base composite is very interesting

Xichen Yang; Yu Wang; Nan Yang

2008-01-01

348

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

349

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

350

Novel layer-by-layer structured nanofibrous mats coated by protein films for dermal regeneration.  

PubMed

Layer-by-layer coating technique is effective in modifying the surface of nanofibrous mats, but overmuch film-coating makes the mats less porous to hardly suit the condition for tissue engineering. We developed novel nanofibrous mats layer-by-layer coated by silk fibroin and lysozyme on the cellulose electrospun template via electrostatic interaction. The film-coating assembled on the mats was not excessive because the charge of the proteins varied in the coating process due to different pH value. In addition, pure nature materials made the mats nontoxic, biodegradable and low-cost. The morphology and composition variation during layer-by-layer coating process was investigated and the results showed that the structure and thickness of film-coatings could be well-controlled. The antibacterial assay and in vitro cell experiments indicated that the mats could actively inhibit bacteria and exhibit excellent biocompatibility. In vivo implant assay further verified the mats cultured with human epidermal cells could promote wound healing and avoid wound infection. Therefore, these mats showed promising prospects when performed for dermal reconstruction. PMID:24734533

Xin, Shangjing; Li, Xueyong; Wang, Qun; Huang, Rong; Xu, Xiaoli; Lei, Zhanjun; Deng, Hongbing

2014-05-01

351

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

352

Production of strontium sulfide coatings by metal organic chemical vapor deposition  

SciTech Connect

This work was focused on the MOCVD of the cerium-doped strontium sulfide (SrS:Ce) phosphor for use in thin film electroluminescent displays (TFELs). Following previous research on a small scale reactor, a feasibility scale-up using a commercially available reactor enlarged the size of the deposition area to a 4`` diameter wafer or a 2`` by 2`` glass slide. Films were deposited from the reaction of Sr(thd){sub 2}, Ce(thd){sub 4}, and H{sub 2}S at 450{degrees}C and 5 torr. This system employed a liquid delivery system for the accurate and repeatable delivery of the metal organic reagents. The deposition from this reactor was shown to be crystalline-as-deposited SrS with a (200) orientation, possibly a result of the thin nature of the coating and the involvement of (200) grains in the initial nucleation process. The wafers showed good uniformity, but had some thickness variation near the outer radius of the wafer resulting from the addition of H{sub 2}S from the outer edge. There were eighteen total deposition experiments, of which nine were characterized for EL performance. The highest brightness observed was 5 fL.. The samples were exceedingly thin as a result of the fifteen fold increase in the surface area between the deposition reactors. Increasing the sample thickness to 7,000{angstrom} or higher will dramatically increase the brightness of the emission.

Moss, T.S.; Dye, R.C.; Tuenge, R.T.

1998-11-01

353

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; Diaz, Luis A.; Prado, Catuxa; Cabal, Belen; Torrecillas, Ramon; Moya, Jose S.

2014-01-01

354

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

355

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

356

Photoresist dip coating on thin film networks. Final report  

SciTech Connect

Application of liquid photoresist by dip coating was investigated as potentially more reliable and repeatable than the current roller coating process. Resist viscosity, extraction rate, and substrate orientation were found to affect applied resist thickness and uniformity. The data accumulated in this effort will be used in future work to develop an improved photoresist application process.

Hughs, R.W.; Barner, G.E.

1980-07-01

357

On Coating Durability of Polymer Coated Sheet Metal under Plastic Deformation  

E-print Network

-off apparatus that measures the coating pull-off stress was used to indicate the coating adhesion strength. Several types of specimen were designed to obtain uniaxial tension, biaxial tension, and tension-compression deformation modes on pre-coated sheet...

Huang, Yu-Hsuan

2011-08-08

358

Tensile and Adhesion Properties of Metal Thin Films Deposited onto Polyester Film Substrate Prepared by a Conventional Vacuum Evaporator  

NASA Astrophysics Data System (ADS)

Four kinds of metal, such as aluminum, copper, indium and tin, thin films were deposited onto polyester (PET) substrate by a conventional vacuum evaporator and evaluated their tensile and adhesion properties. The tensile property was estimated by observations of micro-cracks of the thin films due to the tensile test at 150°C. The tensile property of the metal thin films seems to relate with Brinell hardness and thickness of the thin film. The adhesion property of these metal thin films was estimated by measuring the pull strength. Aluminum thin film showed highest pull strength of all the thin films, and the pull strength increased with increase of the thickness.

Kita, Takuya; Saitoh, Shou; Iwamori, Satoru

359

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

360

Maximal Transmission with Dielectric/Metal Coated Hollow Flexible Terahertz Waveguides  

NASA Astrophysics Data System (ADS)

Hollow, flexible, dielectric (Polystyrene), metal (Silver/Gold) coated polycarbonate waveguides have been designed and fabricated for maximal transmission of Terahertz radiation (THz). Attenuation characteristics of Terahertz radiation in metal coated waveguides with bore diameters 4.1mm, 3.2mm, 2 mm were studied at 215?m wavelength and the maximal transmission was obtained by coupling the lowest loss TE11 mode from an optically pumped terahertz laser. Transmission loss can be reduced substantially by creating corrugation in metal coated waveguides and by coupling HE11 mode into it. Minimal propagation loss of less than 1dB/m was achieved in metal coated waveguide with the addition of dielectric layer that causes corrugation. Polystyrene was chosen to be the dielectric, due to its lowest extinction coefficient, which enhances the transmission through the waveguide. The results will be presented during APS meeting.

Doradla, Pallavi; Joseph, C. S.; Kumar, Jayant; Giles, Robert H.

2011-04-01

361

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

Microsoft Academic Search

The authors present measurements and calculations on the effect of thin dielectric coatings on the propagation of terahertz pulses along the surface of metal wires. Our measurements show that propagation over only a few centimeters of wire having a thin dielectric coating, strongly distorts the terahertz pulse, which results in a several tens of picoseconds long chirped signal. We demonstrate

Paul C. M. Planken

2005-01-01

362

Metal-coated Si springs: Nanoelectromechanical actuators J. P. Singh,a)  

E-print Network

with substrate rotation, and were rendered conductive by coating with a 10-nm-thick Co layer using chemical vapor the chemical vapor deposition CVD technique. A dc current is passed through the nano- spring by a conductiveMetal-coated Si springs: Nanoelectromechanical actuators J. P. Singh,a) D.-L. Liu, D.-X. Ye, R. C

Wang, Gwo-Ching

363

Theory of percolation and tunneling regimes in nanogranular metal films  

NASA Astrophysics Data System (ADS)

Nanogranular metal composites, consisting of immiscible metallic and insulating phases deposited on a substrate, are characterized by two distinct electronic transport regimes depending on the relative amount of the metallic phase. At sufficiently large metallic loadings, granular metals behave as percolating systems with a well-defined critical concentration above which macroscopic clusters of physically connected conductive particles span the entire sample. Below the critical loading, granular metal films are in the dielectric regime, where current can flow throughout the composite only via hopping or tunneling processes between isolated nanosized particles or clusters. In this case transport is intrinsically nonpercolative in the sense that no critical concentration can be identified for the onset of transport. It is shown here that, although being very different in nature, these two regimes can be described by treating percolation and hopping on equal footing. By considering general features of the microstructure and of the electrical connectedness, the concentration dependence of the dc conductivity of several nanogranular metal films is reproduced to high accuracy within an effective-medium approach. In particular, fits to published experimental data enable us to extract the values of microscopic parameters that govern the percolation and tunneling regimes, explaining thus the transport properties observed in nanogranular metal films.

Grimaldi, Claudio

2014-06-01

364

Growth of CdS thin films on indium coated glass substrates via chemical bath deposition and subsequent air annealing  

NASA Astrophysics Data System (ADS)

In the present work attempts were made to synthesize indium doped CdS films by fabricating In/CdS bilayers using CBD-CdS on vacuum evaporated In thin films and subsequent air annealing. 135 nm CdS films were grown onto 20 nm and 35 nm indium coated glass substrate employing chemical bath deposition technique. The In/CdS bilayers thus formed were subjected to heat treatment at the temperatures between 200 and 400 °C for 4 min in the muffle furnace to facilitate indium to diffuse into the CdS films. XRD pattern ascertained no noticeable shift in lattice constant implying grain boundary metal segregation, while secondary ion mass spectrometry indicated the diffusion profile of indium into CdS matrices. Mass spectrometry results showed that substantial diffusion of indium had been taken place within CdS at 400 °C. Dark and photocurrent with different illumination time were measured to ascertain the photosensitivity of pure and composite CdS films.

Ghosh, Biswajit; Kumar, Kamlesh; Singh, Balwant Kr; Banerjee, Pushan; Das, Subrata

2014-11-01

365

New approach toward reflective films and fibers using cholesteric liquid-crystal coatings.  

PubMed

A new approach for the production of oriented films and fibers with angular-dependent reflective colors is presented. The process consists of spray coating a solution of cholesteric liquid-crystalline monomers onto a melt-processed and oriented polyamide-6 substrate followed by UV curing. Reflectivity measurements and optical microscopy show that a well-defined liquid-crystalline and planar alignment is obtained. It is further demonstrated that a reflection up to 80% is obtained by coating oriented films on both sides of the oriented substrate with a single-handedness cholesteric liquid-crystal coating. The high reflectivity is attributed to the close to half-wave retardation induced by the anisotropic polymer substrate. Also, polyamide-6 filaments are successfully coated and fibers are obtained with an angular-dependent color in a single dimension along the fiber direction, which originates from the planar cholesteric alignment on a curved surface. PMID:23802918

Picot, Olivier T; Dai, Mian; Broer, Dirk J; Peijs, Ton; Bastiaansen, Cees W M

2013-08-14

366

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

367

Characterization of thermally aged AlPO4-coated LiCoO2 thin films  

PubMed Central

The electrochemical properties and stability during storage of pristine and AlPO4-coated LiCoO2 thin films were characterized. The wide and smooth surface of the thin film electrode might provide an opportunity for one to observe surface reactions with an electrolyte. The rate capability and cyclic performance of the LiCoO2 thin film were enhanced by AlPO4 surface coating. Based on secondary ion mass spectrometry analysis and scanning electron microscopy images of the surface, it was confirmed that the coating layer was successfully protected from the reactive electrolyte during storage at 90°C. In contrast, the surface of the pristine sample was severely damaged after storage. PMID:22221315

2012-01-01

368

Maximal Transmission with Dielectric\\/Metal Coated Hollow Flexible Terahertz Waveguides  

Microsoft Academic Search

Hollow, flexible, dielectric (Polystyrene), metal (Silver\\/Gold) coated polycarbonate waveguides have been designed and fabricated for maximal transmission of Terahertz radiation (THz). Attenuation characteristics of Terahertz radiation in metal coated waveguides with bore diameters 4.1mm, 3.2mm, 2 mm were studied at 215mum wavelength and the maximal transmission was obtained by coupling the lowest loss TE11 mode from an optically pumped terahertz

Pallavi Doradla; C. S. Joseph; Jayant Kumar; Robert H. Giles

2011-01-01

369

Fabrication of Metal Oxide Thin Films Using the Langmuir-Blodgett Deposition Technique.  

NASA Astrophysics Data System (ADS)

The Langmuir Blodgett (LB) deposition of metal arachidates was investigated as a technique for fabrication of metal oxides with emphasis placed on the lanthanide arachidates. Traditionally, these materials are difficult to deposit via the LB process, due to the rigidity of the floating monolayer. Studies on yttrium arachidate have shown that the quality of deposition of these materials is highly dependent on the concentration of the metal salt and the pH of the subphase. Yttrium arachidate was thus deposited at 10^{-5} M YCl_3 over a pH range of 4.0 to 6.9. Uniform multilayer films were produced with films at the higher pH's showing 100% yttrium arachidate. A pK_{rm a} value of 4.9 +/- 0.2 was obtained under these conditions. Fourier transform infrared spectroscopy, Rutherford backscattering spectrometry and x-ray photoelectron spectroscopy data indicate that the metal is being incorporated into the arachidic acid predominantly as Y(OH) ^{2+}. A saturation areal density of (2.0 +/- 0.1) times 10^{14} Y/cm ^2 was measured for one layer of yttrium arachidate. Ellipsometric measurements were performed on films of yttrium arachidate to study order-disorder transitions. Upon heating the films were observed to undergo two transitions at 65^circC and 100 ^circC. At room temperature, the as -deposited films were found to be anisotropic with indices of refraction of N_{rm x} = 1.503 +/- 0.005 and N _{rm z} = 1.554 +/- 0.005 and a monolayer spacing of 2.73 +/- 0.03 nm. Above 100^ circC the films were isotropic with N = 1.440 +/- 0.005 and a thickness of 3.13 +/- 0.03 nm per original layer. The films showed no desorption below 100^circ C. In contrast to films of cadium arachidate, the yttrium arachidate films were observed to undergo supercooling by 35^circC. This may point to a lack of nucleation sites in the yttrium arachidate films explaining why they maintain areal integrity at high temperature while cadmium arachidate films do not. The decomposition of LB films was studied in some detail, using two processes: thermal decomposition and decomposition via ultraviolet/ozone exposure. The second technique was found to reduce LB arachidate multilayers to a metal carbonate (at a rate of less than 1 minute per layer), which could be further decomposed into an oxide via a thermal treatment. The ultraviolet/ozone process allowed uniform films of CdO to be produced in addition to the thin films of Y_2O_3 , Er_2O_3 and La_2O_3 fabricated via either thermal or ultraviolet/ozone processing. Applications of the LB produced metal oxides were investigated. Electrical characterization of Y _2O_3 dielectric layers gave a permittivity of varepsilon~ 11.5 +/- 0.9 and good quality metal -oxide-semiconductor structures of <10 nm in thickness. Y_2O_3 coatings on 304 stainless steel were found to significantly reduce thermal oxidation of the steel at 800^ circC. Finally, La_2O _3 interface layers in PZT/Pt structures were found to have a significant effect on the nucleation and growth of the ferroelectric.

Johnson, David John

370

Interfacial diffusion of metal atoms during air annealing of chemically deposited ZnS-CuS and PbS-CuS thin films  

SciTech Connect

The authors report on the interfacial diffusion of metal ions occurring during air annealing of multilayer CuS films (0.15-0.6[mu]m) deposited on thin coating of ZnS or PbS ([approximately]0.06 [mu]m) on glass substrates. All the films are deposited from chemical baths at room temperature. The interfacial diffusion on the metal atoms during the air annealing is illustrate by X-ray photoelectron spectroscopy studies. A multilayer of 0.3 [mu]m thick CuS film deposited over a thin film of ZnS upon annealing at 150 C shows atomic ratios of Zn to Cu of [approximately]0.15 and [approximately]0.48 at the surface layers of the samples annealed for 12 and 24 h, respectively. In the case of CuS on PbS film, the corresponding Pb to Cu atomic ratios at the surface layers are 0.43 and 0.83. The optical transmittance spectra and sheet resistance of these multilayer films indicate thermal stabilities superior to that of the CuS-only coatings. Application of the interfacial diffusion process in the production of thermally stable solar control coatings, solar absorber coating, or p-type films for solar cell structures is discussed.

Huang, L.; Zingaro, R.A.; Meyers, E.A. (Texas A and M Univ., College Station, TX (United States). Dept. of Chemistry); Nair, P.K.; Nair, M.T.S. (Univ. Nacional Autonoma de Mexico, Morelos (Mexico). Lab. de Energia Solar)

1994-09-01

371

Photovoltaic cell characteristics of hybrid silicon devices with lanthanide complex phosphor-coating film  

Microsoft Academic Search

Conversion efficiency values of silicon photovoltaic cells were significantly enhanced, by surface coating of the organically modified silicate (ORMOSIL) composite phosphor films incorporating europium(III) phenanthroline and terbium(III) bipyridine complexes. Relative maximal outputs of the coated single-crystal (c-Si) and amorphous silicon (a-Si) photovoltaic devices compared with those of the uncoated c-Si and a-Si ones were increased to 118 and 108%, respectively,

Tetsuro Jin; Satoshi Inoue; Kenichi Machida; Ginya Adachi

1997-01-01

372

Effects of edible film coatings on shelf-life of mustafakemalpasa sweet, a cheese based dessert  

Microsoft Academic Search

It was aimed to investigate the shelf-life of single baked (one stage heating at 280–300 °C) mustafakemalpasa (MKP) cheese\\u000a sweets coated with edible films such as ?-carrageenan, chitosan, corn zein and whey protein concentrate (WPC). The sweets\\u000a prepared were coated, packed in polystyrene bags and stored at room temperature (20?±?1 °C). The shelf-life of sweet samples\\u000a was determined by microbiological analyses, aw,

Metin Guldas; Arzu Akpinar Bayizit; Tulay Ozcan Yilsay; Lutfiye Yilmaz-Ersan

2010-01-01

373

Omnidirectional light absorption in thin film silicon solar cell with dual anti-reflection coatings  

Microsoft Academic Search

A theoretical model for an all-in-one thin film silicon solar cell (TFSSC) design with the anti-reflection (AR) coatings, the transparent electrodes, the silicon and the back reflective coatings all deposited on one piece of glass is proposed and the optical performance for the design is numerically simulated. The calculated average reflectance over the wavelength range of 0.4–1.0?m and incident angles

Wenji Yang; Hongchun Yu; Jianping Tang; Yingbing Su; Qing Wan; Yanguo Wang

2011-01-01

374

Optical reflectivity improvement by upgrading metallic glass film quality  

SciTech Connect

The effects of atomic-defect and free-volume amounts of metallic glassy film on the optical reflectivity and mechanical properties of the sputtered metallic glass thin films are explored. With a lower Ar working pressure and the proper post-annealing at temperatures slightly lower than the glass-transition temperature T{sub g}, film free volumes and defects would reduce, resulting in better atomic bonding and higher film hardness/modulus, which in turn leads to lower electric resistivity and higher optical reflectivity. Annealing above T{sub g} would induce crystalline structure which would lead to competition with the optical transition of the Drude free electrons and hinder the optical reflectivity in the visible range.

Wang, W. H.; Hsu, J. H.; Huang, J. C. [Department of Materials and Optoelectronic Science, National Sun Yat-Sen University, Kaohsiung, 804 Taiwan (China)] [Department of Materials and Optoelectronic Science, National Sun Yat-Sen University, Kaohsiung, 804 Taiwan (China)

2013-10-14

375

Characterization of WC\\/Co coatings on metal substrates  

Microsoft Academic Search

In the present work, WC\\/Co coatings were obtained by electro-thermal explosion directional spraying technology. The performances including microstructure, elements distribution, hardness, elastic modulus and wear resistance of the coatings were investigated by means of SEM, EDAX, nano-indentation test, friction and wear test, respectively. Results show that WC\\/Co coatings are characterized by compact construction, good bond, high hardness and elastic modulus.

Guo Jin; Bin-shi Xu; Hai-dou Wang; Qing-fen Li; Shi-cheng Wei

2007-01-01

376

Stabilization of Ba2YCu3O7-? by Surface Coating with Plasma Polymerized Fluorocarbon Film  

NASA Astrophysics Data System (ADS)

High-Tc superconducting Ba2YCu3O7-? pellets were coated with polyfluorocarbon thin films prepared by plasma polymerization of tetrafluoroethene (C2F4). The polymer-coated Ba2YCu3O7-? preserved its high-Tc superconductivity even after it had been kept standing in water at 60°C, whereas the superconductivity of noncoated pellets was completely destroyed under the same condition. The high hydrophobicity of the film originated from high fluorine content is considered to be primarily responsible for the protection of the superconductor from chemical deterioration by preventing the hydrolysis at the surface.

Sato, Kota; Omae, Shinji; Kojima, Kuniharu; Hashimoto, Takuya; Koinuma, Hideomi

1988-11-01

377

Thick, low-stress films, and coated substrates formed therefrom  

DOEpatents

Stress-induced deformation, and the damage resulting therefrom, increases with film thickness. The overcoming of excessive stress by the use of the film material of the present invention, permits the formation of thick films that are necessary for certain of the above described applications. The most likely use for the subject film materials, other than their specialized views as an optical film, is for microelectronic packaging of components on silicon substrates. In general, the subject Si-Al-O-N films have excellent adherence to the underlying substrate, a high degree of hardness and durability, and are excellent insulators. Prior art elevated temperature deposition processes cannot meet the microelectronic packaging temperature formation constraints. The process of the present invention is conducted under non-elevated temperature conditions, typically 500# C. or less.

Henager, Jr., Charles H. (Kennewick, WA); Knoll, Robert W. (Menomonee Falls, WI)

1991-01-01

378

Prediction of film thickness of Bottom Anti-reflective Coating based on in-line viscosity measurement  

Microsoft Academic Search

Tighter fim thickness control is required as the linewidth of semiconductor devices gets smaller. Viscosity is one of the most important parameters to determine film thickness during spin coating. In this paper, we show strong and repeatable correlation between viscosity and film thickness for a Bottom Anti-reflective Coating (BARC) material. Based on results of this work, we have developed a

Woo Sok Chang; Christos Monovoukas; Keith Kahmann; Manuel Arjona; Hang Shi; Darin Collins; Ryan Buschjost

2008-01-01

379

Polymer thin films embedded with in situ grown metal nanoparticles.  

PubMed

Metal nanoparticle-polymer composites are versatile materials which not only combine the unique characteristics of the components, but also manifest mutualistic effects between the two. Embedding inside polymer thin films facilitates immobilization and organization of the metal nanoparticles and tuning of their electronic and optical responses by the dielectric environment. The embedded metal nanoparticles in turn can impact upon the various material attributes of the polymer matrix. Some of the most convenient and attractive routes to the fabrication of metal nanoparticle-embedded polymer thin films involve in situ generation of the nanoparticles through reduction or decomposition of appropriate precursors inside the solid film. In this tutorial review we present an overview of the different methodologies developed using this general concept and describe the environment-friendly protocol we have optimized for the fabrication of noble metal nanostructures inside polymer thin films, using aqueous media for the synthesis and deploying the polymer itself as the reducing as well as stabilizing agent. A variety of techniques that have been exploited to characterize the precursor to product transformation inside the polymer film are discussed. The unique control provided by the in situ fabrication route on the size, shape and distribution of the nanostructures, and application of the polymer thin films with the in situ generated metal nanoparticles in areas such as nonlinear optics, surface enhanced Raman scattering, e-beam lithography, microwave absorption, non-volatile memory devices and random lasers, illustrate the versatility of these materials. A brief appraisal of the avenues for future developments in this area is presented. PMID:19690744

Ramesh, G V; Porel, S; Radhakrishnan, T P

2009-09-01

380

Electrically Conductive, Corrosion-Resistant Coatings Through Defect Chemistry for Metallic Interconnects  

SciTech Connect

The principal objective of this work was to develop oxidation protective coatings for metallic interconnect based on a defect chemistry approach. It was reasoned that the effectiveness of a coating is dictated by oxygen permeation kinetics; the slower the permeation kinetics, the better the protection. All protective coating materials investigated to date are either perovskites or spinels containing metals exhibiting multiple valence states (Co, Fe, Mn, Cr, etc.). As a result, all of these oxides exhibit a reasonable level of electronic conductivity; typically at least about {approx}0.05 S/cm at 800 C. For a 5 micron coating, this equates to a maximum {approx}0.025 {Omega}cm{sup 2} area specific resistance due to the coating. This suggests that the coating should be based on oxygen ion conductivity (the lower the better) and not on electronic conductivity. Measurements of ionic conductivity of prospective coating materials were conducted using Hebb-Wagner method. It was demonstrated that special precautions need to be taken to measure oxygen ion conductivity in these materials with very low oxygen vacancy concentration. A model for oxidation under a protective coating is presented. Defect chemistry based approach was developed such that by suitably doping, oxygen vacancy concentration was suppressed, thus suppressing oxygen ion transport and increasing effectiveness of the coating. For the cathode side, the best coating material identified was LaMnO{sub 3} with Ti dopant on the Mn site (LTM). It was observed that LTM is more than 20 times as effective as Mn-containing spinels. On the anode side, LaCrO3 doped with Nb on the Cr site (LNC) was the material identified. Extensive oxidation kinetics studies were conducted on metallic alloy foils with coating {approx}1 micron in thickness. From these studies, it was projected that a 5 micron coating would be sufficient to ensure 40,000 h life.

Anil V. Virkar

2006-12-31

381

Single Wall Carbon Nano Tube Films and Coatings  

Microsoft Academic Search

Purified single wall carbon nano tubes (SWNTs) produced from the high-pressure carbon monoxide (HiPCO) process have been dissolved \\/dispersed in oleum. These solutions \\/dispersions were optically homogeneous and have been used to form stand-alone SWNT films. The washed, dried, and heat-treated films are isotropic. The scanning electron micrographs of the film surface shows that the nanotube ropes (or fibrils) of

T. V. Sreekumar; Satish Kumar; Lars M. Ericson; Richard E. Smalley

2002-01-01

382

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

383

Valvetrain Friction Reduction through Thin Film Coatings and Polishing  

Microsoft Academic Search

In a direct-acting mechanical bucket tappet–type valvetrain, the cam and tappet contact is responsible for about 85% of the total valvetrain frictional losses. Because this contact operates primarily in a mixed lubrication regime, it offers an opportunity for friction reduction through surface engineering. The friction reduction potential of thin Mn-phosphate coating, diamond-like carbon coating, and polishing on the bucket surface

Arup Gangopadhyay; Douglas G. McWatt; Robert J. Zdrodowski; Steve J. Simko; Steve Matera; Kirk Sheffer; Robert S. Furby

2012-01-01

384

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

385

Nucleation and growth of epitaxial metal-oxide films based on polymer-assisted deposition.  

PubMed

Polymer-assisted deposition (PAD) is one of the chemical solution deposition methods which have been successfully used to grow films, form coatings, and synthesize nanostructured materials. In comparison with other conventional solution-based deposition techniques, PAD differs in its use of water-soluble polymers in the solution that prevent the metal ions from unwanted chemical reactions and keep the solution stable. Furthermore, filtration to remove non-coordinated cations and anions in the PAD process ensures well controlled nucleation, which enables the growth of high quality epitaxial films with desired structural and physical properties. The precursor solution is prepared by mixing water-soluble polymer(s) with salt(s). Thermal treatment of the precursor films in a controlled environment leads to the formation of desired materials. Using BaTiO3 grown on SrTiO3 and LaMnO3 on LaAlO3 as model systems, we show the effect of filtration on the nucleation and growth of epitaxial complex metal-oxide films based on the PAD process. PMID:24158602

McCleskey, T M; Shi, P; Bauer, E; Highland, M J; Eastman, J A; Bi, Z X; Fuoss, P H; Baldo, P M; Ren, W; Scott, B L; Burrell, A K; Jia, Q X

2014-04-01

386

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

387

Preliminary investigations on laminin coatings for flexible polyimide/platinum thin films for PNS applications.  

PubMed

The aim of this work was to investigate the possibility to obtain stable bioactive coatings for polyimide/platinum neural interfaces based on thin film technology for applications into the peripheral nervous system (PNS). Laminin (LI), a glycoprotein of the extracellular matrix, which guides and promotes differentiation and growth of neurons, was selected to deposit bioactive coatings. Dip-coating was performed on dummy structures at different LI concentrations. Indirect methods allowed to identify and characterize laminin on coated samples. Mechanical stability was also confirmed by indirect evaluations. Pilot experiments with differentiated PC12 cells, by the addition of nerve growth factor (NGF), showed improved neurite outgrowth on the coated probes compared to bare polyimide samples. PMID:21096373

Bossi, S; Benvenuto, A; Wieringa, P; Di Pino, G; Guglielmelli, E; Boretius, T; Stieglitz, T; Navarro, X; Micera, S

2010-01-01

388

Electrochemical characteristics of metal oxide-coated lithium manganese oxide (spinel type)  

Microsoft Academic Search

Metal oxide-coated spinel was investigated with respect to electrochemical characteristics. Metal oxide coating on commercial spinel powder (LiMn2?xMxO4, M=Zr, Nikki, Japan) was carried out using the sol–gel method. Al2O3\\/CuOx-coated spinel exhibited stable cycle performance in the range from 3.0 to 4.4V, and it had lower charge transfer resistance and higher double layer capacitance than bare spinel in later cycles. In

Seung-Won Lee; Kwang-Soo Kim; Ki-Lyoung Lee; Hee-Soo Moon; Hyun-Joong Kim; Byung-Won Cho; Won-Il Cho; Jong-Wan Park

2004-01-01

389

Electrochemical and structural characteristics of metal oxide-coated lithium manganese oxide (spinel type)  

Microsoft Academic Search

The electrochemical and structural characteristics of the metal oxide-coated spinel were investigated in the range of 2.5–4.2V. Metal oxide coating on commercial spinel powder (LiMn2?xMxO4, M=Zr, Nikki, Japan) was carried out using the sol–gel method. Al2O3\\/(PtOx or CuOx)-coated spinel exhibited improved cyclability compared to bare spinel. Impedance analysis results indicated that electrochemical resistance value was not consistent with cycle performance.

Seung-Won Lee; Kwang-Soo Kim; Hee-Soo Moon; Jae-Pil Lee; Hyun-Joong Kim; Byung-Won Cho; Won-Il Cho; Jong-Wan Park

2004-01-01

390

Current sharing between the metallic and superconducting layers of high temperature superconductor coated conductors operated above their critical current  

NASA Astrophysics Data System (ADS)

In this contribution, we report and discuss the physical meaning of pulse current measurements carried out on coated conductors (CCs) consisting of a superconducting YBCO film deposited on a Hastelloy substrate and coated with a thin metallic layer. The high current (up to 1000 A) and short duration pulses have allowed us to determine the current-voltage characteristics of two different samples in a situation near that of zero injected energy and therefore remove the bias resulting from the temperature rise during the measurement. The characteristics obtained show a flux creep region and two linear regimes. The first linear regime is the flux flow regime. In this regime, we show that there is a constant vortex velocity that depends on the metal film resistivity. The second linear regime is also a vortex regime, but its precise nature is less clear. We propose models describing both linear regimes, in agreement with the measurements. Finally, we discuss the consequences of these results for the applications of CCs in devices for power systems, especially fault current limiters and power transmission cables.

Bernstein, Pierre; McLoughlin, Conor; Thimont, Yohann; Sirois, Frédéric; Coulombe, Jonathan

2011-02-01

391

Optically optimal wavelength-scale patterned ITO/ZnO composite coatings for thin film solar cells  

E-print Network

Optically optimal wavelength-scale patterned ITO/ZnO composite coatings for thin film solar cells-reflective coating made of ITO or ZnO, or a composite ITO/ZnO coating. These latter structures are realistic and present good performances despite very thin active layers. 1 hal-00672568,version1-21Feb2012 #12;I

Paris-Sud XI, Université de

392

Optically optimal wavelength-scale patterned ITO/ZnO composite coatings for thin film solar cells  

E-print Network

Optically optimal wavelength-scale patterned ITO/ZnO composite coatings for thin film solar cells-reflective coating made of ITO or ZnO, or a composite ITO/ZnO coating. These latter structures are realistic and present good performances despite very thin active layers. 1 hal-00672568,version2-13Mar2012 #12;I

Paris-Sud XI, Université de

393

MULTI-LAYER COATING OF ULTRATHIN POLYMER FILMS ON NANO-PARTICLES OF ALUMINA BY A PLASMA TREATMENT  

E-print Network

MULTI-LAYER COATING OF ULTRATHIN POLYMER FILMS ON NANO- PARTICLES OF ALUMINA BY A PLASMA TREATMENT during the plasma treatment. After single layer coating, hexamethyldisiloxane (HMDSO) was coated again. The deposition mechanisms and the effects of plasma treatment parameters are discussed. INTRODUCTION Surface

Dalal, Vikram

394

Metal ion reactive thin films using spray electrostatic LbL assembly.  

PubMed

By using the spray-layer-by-layer (Spray-LbL) technique, the number of metal counterions trapped within LbL coatings is significantly increased by kinetically freezing the film short of equilibrium, potentially limiting interchain penetration and forcing chains to remain extrinsically compensated to a much greater degree than observed in the traditional dipped LbL technique. The basis for the enhanced entrapment of metal ions such as Cu2+, Fe2+, and Ag+ is addressed, including the equilibrium driving force for extrinsic compensation by soft versus hard metal ions and the impact of Spray-LbL on the kinetics of polymer-ion complexation. These polymer-bound metal-ion coatings are also demonstrated to be effective treatments for air filtration, functionalizing existing filters with the ability to strongly bind toxic industrial compounds such as ammonia or cyanide gases, as well as chemical warfare agent simulants such as chloroethyl ethyl sulfide. On the basis of results reported here, future work could extend this method to include other toxic soft-base ligands such as carbon monoxide, benzene, or organophosphate nerve agents. PMID:18712910

Krogman, Kevin C; Lyon, Katharine F; Hammond, Paula T

2008-11-20

395

Technique for production of calibrated metal hydride films  

SciTech Connect

A technique has been developed for producing calibrated metal hydride films for use in the measurement of high-energy (5--15 MeV) particle reaction cross sections for hydrogen and helium isotopes on hydrogen isotopes. Absolute concentrations of various hydrogen isotopes in the film is expected to be determined to better than {+-}2% leading to the capacity of accurately measuring various reaction cross sections. Hydrogen isotope concentrations from near 100% to 5% can be made accurately and reproducibly. This is accomplished with the use of high accuracy pressure measurements coupled with high accuracy mass spectrometric measurements of each constituent partial pressure of the gas mixture during loading of the metal occluder films. Various techniques are used to verify the amount of metal present as well as the amount of hydrogen isotopes; high energy ion scattering analysis, PV measurements before, during and after loading, and thermal desorption/mass spectrometry measurements. The most appropriate metal to use for the occluder film appears to be titanium but other occluder metals are also being considered. Calibrated gas ratio samples, previously prepared, are used for the loading gas. Deviations from this calibrated gas ratio are measured using mass spectrometry during and after the loading process thereby determining the loading of the various hydrogen isotopes. These techniques are discussed and pertinent issues presented.

Langley, R.A.; Browning, J.F.; Balsley, S.D.; Banks, J.C.; Doyle, B.L.; Wampler, W.R.; Beavis, L.C.

1999-11-11

396

Optical sol-gel coatings : ellipsometry of film formation Alan J. Hurd and C. Jeffrey Brinker  

E-print Network

. France 49 (1988) 1017-1025 JUIN 1988, Classification Physics Abstracts 07.60F - 68.15 - 81.15L - 82.70G 11017 Optical sol-gel coatings : ellipsometry of film formation Alan J. Hurd and C. Jeffrey Brinker ; cette méthode donne l'épaisseur du film et son indice de réfraction en fonction de la position. Les

Boyer, Edmond

397

Chemical solution deposition of YBa2Cu3O7-x films by dip coating  

Microsoft Academic Search

Dense superconducting YBa2Cu3O7-x (YBCO) films were prepared via chemical solution deposition in a trifluoroacetate (TFA) process. The dip coated substrates were treated in a two stage annealing process under wet oxygen below 400 °C and subsequently heated up to 800 °C in a wet nitrogen dominated atmosphere. We obtained epitaxially grown 190 nm thick films on single-crystalline strontium titanate with

Martina Falter; Wolfgang Häßler; Brigitte Schlobach; Bernhard Holzapfel

2002-01-01

398

Tin dioxide based transparent semiconducting films deposited by the dip-coating technique  

Microsoft Academic Search

Undoped and F-doped transparent semiconducting films with tin dioxide as the active material have been prepared by a dip-coating technique. The film is formed in situ by the hydrolysis of stannous chloride which takes place when a substrate is withdrawn vertically from a methanol solution of SnCl2·2H2O and heat treated at a high temperature. F-doping is achieved by adding NH4F

Sekhar C Ray; Malay K Karanjai; Dhruba DasGupta

1998-01-01

399

Preparation and electrical properties of ITO thin films by dip-coating process  

Microsoft Academic Search

Indium tin oxide (ITO) thin films were prepared on quartz glass substrates by a dip-coating process. The starting solution was prepared by mixing indium chloride dissolved in acetylacetone and tin chloride dissolved in ethanol. The ITO thin films containing 0 ~ 20 mol% SnO2 were successfully prepared by heat-treatment at above 400 °C. Chemical stability of sol were investigated by

Keishi Nishio; Tadanori Sei; Toshio Tsuchiya

1996-01-01

400

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

401

Micromechanical estimation of composite hardness using nanoindentation technique for thin-film coated system  

Microsoft Academic Search

The hardness characteristics of thin-film coated composite were analyzed using the plastic-zone volume-law of mixtures theory. In calculating the plastic-zone volumes, the elastic\\/plastic indentation stress field was analyzed; the substrate was assumed to undergo radial deformation, while the cylindrical deformation mode was applied to the film. In addition, the effect of interface was incorporated. The deformation of the softer material

Jeong-Hoon Ahn; Dongil Kwon

2000-01-01

402

Optimization of PECVD silicon oxynitride films for anti-reflection coating  

Microsoft Academic Search

In this work, amorphous silicon oxynitride films were deposited on silicon substrates by plasma-enhanced chemical vapor deposition (PECVD). The main purpose was to use silicon oxynitride film as a single-layer anti-reflection coating for Si-based optoelectronic devices. The chemical information was measured by infrared spectroscopy. Surface and cross-section morphology was determined by a scanning electron microscope. Spectroscopic ellipsometry (SE) was applied

Yongjin Wang; Xinli Cheng; Zhilang Lin; Changsheng Zhang; Feng Zhang

2003-01-01

403

Development of X-Shape Filtered Arc Deposition Apparatus for Thick taC Film Coating  

Microsoft Academic Search

Novel X-shape filtered arc deposition (X-FAD) apparatus is specially designed and newly developed for thick hydrogen-free tetrahedral amorphous-carbon (ta-C) film coating on superhard alloy (or cemented carbide) substrate. The apparatus has a graphite cathode for deposition of hydrogen-free diamond-like carbon (DLC; ta-C and amorphous carbon: a-C) film and a chromium (Cr) cathode for deposition of Cr layer. The filter duct

Hiroki Hikokasa; Yasuhiro Iwasaki; Hirofumi Takikawa; Tateki Sakakibara; Hiroshi Hasegawa; Nobuhiro Tsuji

2006-01-01

404

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

405

Adherent diamond like carbon coatings on metals via plasma source ion implantation  

SciTech Connect

Various techniques are currently used to produce diamond-like carbon (DLC) coatings on various materials. Many of these techniques use metallic interlayers, such as Ti or Si, to improve the adhesion of a DLC coating to a ferrous substrate. An alternative processing route would be to use plasma source ion implantation (PSII) to create a carbon composition gradient in the surface of the ferrous material to serve as the interface for a DLC coating. The need for interlayer deposition is eliminated by using a such a graded interfaces PSII approach has been used to form adherent DLC coatings on magnesium, aluminum, silicon, titanium, chromium, brass, nickel, and tungsten. A PSII process tailored to create a graded interface allows deposition of adherent DLC coatings even on metals that exhibit a positive heat of formation with carbon, such as magnesium, iron, brass and nickel.

Walter, K.C.; Nastasi, M.; Munson, C.P.

1996-12-01

406

Sol-gel film formation by dip coating  

SciTech Connect

In this paper, the physical aspects of sol-gel film formation are discussed. The equations governing the steady state film profile, controlled by hydrodynamic flow, capillary pressure and evaporation, are presented along with representative data obtained by imaging ellipsometry. Some issues concerning capillary collapse are also addressed.

Hurd, A.J.; Brinker, C.J.

1990-01-01

407

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

408

Carboxyl-Ebselen-Based Layer-by-Layer Films as Potential Antithrombotic and Antimicrobial Coatings  

PubMed Central

A carboxyl-ebselen-based layer-by-layer (LbL) film was fabricated by alternatively assembling carboxyl-ebselen immobilized polyethylenimine (e-PEI) and alginate (Alg) onto substrates followed by salt annealing and cross-linking. The annealed films exhibiting significantly improved stability are capable of generating nitric oxide (NO) from endogeneous S-nitrosothiols (RSNOs) in the presence of a reducing agent. The NO generation behaviors of different organoselenium species in solution phase are compared and the annealing mechanism to create stable LbL films is studied in details. An LbL film coated polyurethane catheter is capable of generating physiological levels of NO from RSNOs even after blood soaking for 24 h, indicating potential antithrombotic applications of the coating. Further, the LbL film is also demonstrated to be capable of reducing living bacterial surface attachment and killing a broad spectrum of bacteria, likely through generation of superoxide (O2•?) from oxygen. This type of film is expected to have potential application as an antithrombotic and antimicrobial coating for different biomedical device surfaces. PMID:21794909

Cai, Wenyi; Wu, Jianfeng; Xi, Chuanwu; Ashe, Arthur J.; Mark, E. Meyerhoff

2011-01-01

409

Films loaded with insulin-coated nanoparticles (ICNP) as potential platforms for peptide buccal delivery.  

PubMed

The goal of this investigation was to develop films containing insulin-coated nanoparticles and evaluate their performance in vitro as potential peptide delivery systems. To incorporate insulin into the films, a new antisolvent co-precipitation fabrication process was adapted to obtain insulin-coated nanoparticles (ICNPs). The ICNPs were embedded in polymeric films containing a cationic polymethacrylate derivative (ERL) or a combination of ERL with hydroxypropyl methylcellulose (HPMC). ICNP-loaded films were characterized for morphology, mucoadhesion, and insulin release. Furthermore, in vitro insulin permeation was evaluated using a cultured tridimensional human buccal mucosa model. The antisolvent co-precipitation method was successfully adapted to obtain ICNPs with 40% (w/w) insulin load, achieving 323±8nm particles with a high zeta potential of 32.4±0.8mV, indicating good stability. High yields were obtained after manufacture and the insulin content did not decrease after one month storage. ICNP-embedded films using ERL as the polymer matrix presented excellent mucoadhesive and insulin release properties. A high permeation enhancement effect was observed for ICNP-loaded ERL films in comparison with ICNP-loaded ERL-HPMC films and a control insulin solution. ICNP-loaded ERL formulations were found to be more effective in terms of film performance and insulin permeation through the human buccal mucosa model, and thus are a promising delivery system for buccal administration of a peptide such as insulin. PMID:25016543

Morales, Javier O; Huang, Siyuan; Williams, Robert O; McConville, Jason T

2014-10-01

410

Antimicrobial and enzymatic antibrowning film used as coating for bamboo shoot quality improvement.  

PubMed

Edible films were prepared with varying proportion of alginate and starch in the ratio of 2:0(F1), 2:1(F2), 1:1(F3), 1:1.5(F4), 1:2(F5), 0:2(F6) with added carboxymethyl cellulose (15%, w/w of starch). The film F5 had superior barrier, mechanical and thermal properties over the other films. Water vapor permeability, moisture absorption, water solubility, breakage strength and elongation capacity of F5 film were reported as 1.21 × 10(-9)g/Pa h m, 9.37%, 40%, 977.3g and 14.62 mm respectively. However, surface characteristics showed the smooth and uniform film and thermal decomposition took place above 200 °C. The film forming solution of selected F5 film, added with antioxidant and antimicrobial extracts was coated on bamboo shoots and stored for 5 days. The film was successful in lowering the browning of bamboo shoots, and also successfully inhibited surface microbial load. Moreover, the moisture loss of coated shoot was less compared to uncoated. PMID:24528722

Badwaik, Laxmikant S; Borah, Pallab Kumar; Deka, Sankar C

2014-03-15

411

Nano and microsized metal oxide thin film gas sensors  

Microsoft Academic Search

Functional micro- and nanosized metal oxide thin film structures are very promising candidate for future gas-sensors. Their\\u000a reduced size offers an increased surface to volume ratio thus improving sensitivity and sensor performance. Whilst most experimental\\u000a nanostructures are produced using a bottom-up approach, a top-down sputtering technique for structuring nano-sized gas sensitive\\u000a metal oxide areas is presented in this letter. Oxidised

Stefan Palzer; Emmanuel Moretton; Francisco Hernandez Ramirez; Albert Romano-Rodriguez; Jürgen Wöllenstein

2008-01-01

412

[Analysis of the character of film decomposition of methyl methacrylate (MMA) coated urea by infrared spectrum].  

PubMed

The degradability characteristics of film with 4 kinds of methyl methacrylate coated urea amended with inhibitors were analyzed by FITR, which was purposed to supply theoretical basis for applying the FITR analysis method to film decomposition and methyl methacrylate coated urea fertilizers on farming. The result showed that the chemical component, molecule structure and material form of the membrane were not changed because of adding different inhibitors to urea. the main peaks of expressing film degradation process were brought by the -C-H of CH3 & CH2, -OH, C-O, C-C, C-O-C, C=O, C=C flexing vibrancy in asymmetry and symmetry in 3 479-3 195, 2 993--2 873, 1 741-1 564, 1 461-925 and 850-650 cm(-1). The peak value changed from smooth to tip, and from width to narrow caused by chemical structural transform of film The infrared spectrum of 4 kinds of fertilizers was not different remarkably before 60 days, and the film was slowly degraded. But degradation of the film was expedited after 60 days, it was most quickened at 120 day, and the decomposition rate of film was decreased at 310 day. The substantiality change of film in main molecule structure of 4 kinds of fertilizers didn't happen in 310 days. The main component of film materials was degraded most slowly in brown soil. The speed of film degradation wasn't heavily impacted by different inhibitors. The characteristic of film degradation may be monitored entirely by infrared spectrum. The degradation dynamic, chemical structure change, degradation speed difference of the film could be represented through infrared spectrum. PMID:22582622

Li, Dong-po; Wu, Zhi-jie; Liang, Cheng-hua; Chen, Li-jun; Zhang, Yu-lan; Nie, Yan-xi

2012-03-01

413

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

414

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

415

Electrosprayed metal oxide semiconductor films for sensitive and selective detection of hydrogen sulfide.  

PubMed

Semiconductor metal oxide films of copper-doped tin oxide (Cu-SnO(2)), tungsten oxide (WO(3)) and indium oxide (In(2)O(3)) were deposited on a platinum coated alumina substrate employing the electrostatic spray deposition technique (ESD). The morphology studied with scanning electron microscopy (SEM) and atomic force microscopy (AFM) shows porous homogeneous films comprising uniformly distributed aggregates of nano particles. The X-ray diffraction technique (XRD) proves the formation of crystalline phases with no impurities. Besides, the Raman cartographies provided information about the structural homogeneity. Some of the films are highly sensitive to low concentrations of H(2)S (10 ppm) at low operating temperatures (100 and 200 °C) and the best response in terms of R(air)/R(gas) is given by Cu-SnO(2) films (2500) followed by WO(3) (1200) and In(2)O(3) (75). Moreover, all the films exhibit no cross-sensitivity to other reducing (SO(2)) or oxidizing (NO(2)) gases. PMID:22291557

Ghimbeu, Camelia Matei; Lumbreras, Martine; Schoonman, Joop; Siadat, Maryam

2009-01-01

416

Electrosprayed Metal Oxide Semiconductor Films for Sensitive and Selective Detection of Hydrogen Sulfide  

PubMed Central

Semiconductor metal oxide films of copper-doped tin oxide (Cu-SnO2), tungsten oxide (WO3) and indium oxide (In2O3) were deposited on a platinum coated alumina substrate employing the electrostatic spray deposition technique (ESD). The morphology studied with scanning electron microscopy (SEM) and atomic force microscopy (AFM) shows porous homogeneous films comprising uniformly distributed aggregates of nano particles. The X-ray diffraction technique (XRD) proves the formation of crystalline phases with no impurities. Besides, the Raman cartographies provided information about the structural homogeneity. Some of the films are highly sensitive to low concentrations of H2S (10 ppm) at low operating temperatures (100 and 200 °C) and the best response in terms of Rair/Rgas is given by Cu-SnO2 films (2500) followed by WO3 (1200) and In2O3 (75). Moreover, all the films exhibit no cross-sensitivity to other reducing (SO2) or oxidizing (NO2) gases. PMID:22291557

Ghimbeu, Camelia Matei; Lumbreras, Martine; Schoonman, Joop; Siadat, Maryam

2009-01-01

417

Novel Nanocrystalline Intermetallic Coatings for Metal Alloys in Coal-fired Environments  

SciTech Connect

Intermetallic coatings (iron aluminide and nickel aluminide) were prepared by a novel reaction process. In the process, the aluminide coating is formed by an in-situ reaction between the aluminum powder fed through a plasma transferred arc (PTA) torch and the metal substrate (steel or Ni-base alloy). Subjected to the high temperature within an argon plasma zone, aluminum powder and the surface of the substrate melt and react to form the aluminide coatings. The prepared coatings were found to be aluminide phases that are porosity-free and metallurgically bonded to the substrate. The coatings also exhibit excellent high-temperature corrosion resistance under the conditions which simulate the steam-side and fire-side environments in coal-fired boilers. It is expected that the principle demonstrated in this process can be applied to the preparation of other intermetallic and alloy coatings.

Z. Zak Fang; H. Y. Sohn

2009-08-31

418

Atomic Layer Deposition of Metal Oxide Thin Films on Metallic Substrates  

NASA Astrophysics Data System (ADS)

Atomic layer deposition (ALD) is a powerful ultra-thin film deposition technique that uses sequential self-limiting surface reactions to provide conformal atomic scale film growth. Deposition of ALD films on many substrate systems has been studied before; however, limited data is available on deposition on metallic surfaces. The investigation of the growth of Al 2O3, HfO2, and ZrO2 as three technologically important metal oxides on metallic substrates is the subject of this thesis. Al2O3, HfO2, and ZrO2 films were grown by ALD on silicon, as a well-studied substrate, in different operating conditions to investigate the effect of process parameters on film properties. To study the growth of oxides on metals, thin metallic substrates were prepared by sputter deposition on silicon wafers and then were transferred to the ALD chamber where the film growth was monitored by in-situ spectroscopic ellipsometry. The transfer was performed via a load lock system without breaking the vacuum to preserve the pristine metal surface. Formation of a thin interfacial layer of metal oxide was observed during the initial moments of plasma enhanced ALD, that was due to the exposure of metal surface to oxygen plasma. In-situ spectroscopic ellipsometry was used to accurately measure the thickness change of the growing films including the interfacial layer. The thickness of this interfacial oxide layer depended on various process parameters including deposition temperature, order of precursors and plasma pulse length. The interfacial oxide layer was absent during the conventional thermal ALD. However, thermal ALD of oxides on metals exhibited substrate-inhibited growth, especially at higher deposition temperatures. With the knowledge of ALD growth characteristics on metals, metal-insulator-metal (MIM) devices were fabricated by both thermal and plasma enhanced ALD and electrically characterized. The presence of the interfacial oxide layer altered the device performance by changing the capacitance and current characteristics. Employing this approach, it was shown that ALD can be successfully used in the fabrication process of MIM devices and similar systems where ultra-thin insulating layers need to be uniformly deposited on a metallic surface.

Foroughi Abari, Ali

419

Laser generation of ultrasound in films and coatings  

NASA Astrophysics Data System (ADS)

A model for the pulsed laser generation of ultrasound in an isotropic film on a semi-infinite substrate is presented. The model gives the time domain displacement of the system as a function of the density and mechanical properties of the film and substrate and the thermal properties of the film. The model has been verified experimentally using a 1 ns Nd:YAG laser source for acoustic wave generation and a stabilized Michelson interferometer for detection. Experimental and theoretical signals agree well for both the case of a fast layer on a slow substrate (zirconium nitride/steel) and a slow layer on a fast substrate (titanium/aluminum).

Murray, T. W.; Krishnaswamy, S.; Achenbach, J. D.

1999-06-01

420

Characterization of amorphous silicon carbide and silicon carbonitride thin films synthesized by polymer-source chemical vapor deposition. Mechanical structural and metal-interface properties  

Microsoft Academic Search

Amorphous silicon carbide (a-SiC) and silicon carbonitride thin films have been deposited onto a variety of substrates by Polymer-Source Chemical Vapor Deposition (PS-CVD). The interfacial interaction between the a-SiC films and several substrates including silicon, SiO2, Si3N 4, Cr, Ti and refractory metal-coated silicon has been studied. The effect of thermal annealing on the structural and mechanical properties of the

Yousef Awad

2006-01-01

421

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

422

Hydrogen sensing at room temperature with Pt-coated ZnO thin films and nanorods  

NASA Astrophysics Data System (ADS)

A comparison is made of the sensitivities for detecting hydrogen with Pt-coated single ZnO nanorods and thin films of various thicknesses (20-350 nm). The Pt-coated single nanorods show a current response of approximately a factor of 3 larger at room temperature upon exposure to 500ppmH2 in N2 than the thin films of ZnO. The power consumption with both types of sensors can be very small (in the nW range) when using discontinuous coatings of Pt. Once the Pt coating becomes continuous, the current required to operate the sensors increases to the ?W range. The optimum ZnO thin film thickness under our conditions was between 40-170 nm, with the hydrogen sensitivity falling off outside this range. The nanorod sensors show a slower recovery in air after hydrogen exposure than the thin films, but exhibit a faster response to hydrogen, consistent with the notion that the former adsorb relatively more hydrogen on their surface. Both ZnO thin and nanorods cannot detect oxygen.

Tien, L. C.; Sadik, P. W.; Norton, D. P.; Voss, L. F.; Pearton, S. J.; Wang, H. T.; Kang, B. S.; Ren, F.; Jun, J.; Lin, J.

2005-11-01

423

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

424

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

425

Metallic coatings obtained by Pulsed Laser Deposition through a dynamic prism system  

NASA Astrophysics Data System (ADS)

Metal coatings have been produced using a Pulsed Laser Deposition (PLD) process based on a dynamic prism system. A nanosecond pulsed Nd:YVO4 laser emitting at a wavelength of 1064 nm is steared through a couple of prisms into a metallic target placed inside a vacuum chamber. This work presents the study of the parameters applied to achieve ablation of two metallic targets, aluminum and brass, in order to obtain their respective metallic coatings on glass substrates by pulsed laser deposition. The results obtained allow to standardize the optimal laser and set-up parameters in order to obtain homogeneous layers, tunable thickness and/or semi-transparent mirror behaviour through the formation of an adequate plasma plume. Microstructure and transmittance spectra of these coatings are also reported.

Cambronero-López, F.; Rey-García, F.; Bao-Varela, Carmen; Estepa, L. C.; de La Fuente, G. F.

2014-05-01

426

Excitation of emf in metallic films by a laser pulse  

Microsoft Academic Search

It has been shown that in the interaction of laser pulses with ferromagnetic metals in an external magnetic field, the signal becomes unipolar with decreasing thickness of the specimen and the signal shape approaches that of the laser pulse. Such voltage pulses have been observed in nickel, bismuth, copper, and antimony films. The electric signal is independent of the polarization

A. B. Katrich; Iu. V. Koltok; V. M. Kuzmichev; Iu. M. Latynin

1977-01-01

427

Effects of water in film boiling over liquid metal melts  

SciTech Connect

Liquid-liquid boiling experiments have been performed with H/sub 2/O and liquid metal melts in the 100-series test matrix (Runs 121, 126, 127) and the VE test matrix. Some of the pre-explosion unstable film boiling data as well as observations from the explosive series have been previously reported.

Greene, G.A.; Finfrock, C.; Burson, S.B.

1986-01-01

428

Influence of an acrylic polymer blend on the physical stability of film-coated theophylline pellets.  

PubMed

The purpose of this study was to investigate the physical stability of a coating system consisting of a blend of two sustained release acrylic polymers and its influence on the drug release rate of theophylline from coated pellets. The properties of both free films and theophylline pellets coated with the polymer blend were investigated, and the miscibility was determined via differential scanning calorimetry. Eudragit RS 30 D was plasticized by the addition of Eudragit NE 30 D, and the predicted glass transition temperature (T(g)) of the blend was similar to the experimental values. Sprayed films composed of a blend of Eudragit NE 30 D/Eudragit RS 30 D (1:1) showed a water vapor permeability six times greater than films containing only Eudragit NE 30 D. The presence of quaternary ammonium functional groups from the RS 30 D polymer increased the swellability of the films. The films prepared from the blend exhibited stable permeability values when stored for 1 month at both 25 degrees C and 40 degrees C, while the films which were composed of only Eudragit NE 30 D showed a statistically significant decrease in this parameter when stored under the same conditions. Eudragit NE 30 D/Eudragit RS 30 D (1:1)-sprayed films decreased in elongation from 180% to 40% after storage at 40 degrees C for 1 month, while those stored at 25 degrees C showed no change in elongation. In coated pellets, the addition of Eudragit RS 30 D to the Eudragit NE 30 D increased the theophylline release rate, and the pellets were stable when stored at 25 degrees C for a period of up to 3 months due to maintenance of the physico-mechanical properties of the film. Pellets stored at 40 degrees C exhibited a decrease in drug release rate over time as a result of changes in film physico-mechanical properties which were attributed to further coalescence and densification of the polymer. When the storage temperature was above the T(g) of the composite, instabilities in both drug release rate and physical properties were evident. Stabilization in drug release rate from coated pellets could be correlated with the physico-mechanical stability of the film formulation when stored at temperatures below the T(g) of the polymer. PMID:19568939

Kucera, Shawn; Shah, Navnit H; Malick, A Waseem; Infeld, Martin H; McGinity, James W

2009-01-01

429

Further studies on thin film structures of metal-borosilicate glass-metal  

Microsoft Academic Search

Further work on the electrical and electron emissive behaviour of metal-borosilicate glass-metal (MIM) structures is reported. Differences in behaviour of the samples are found for different electrode materials and a systematic variation of properties with insulator thickness is observed. By means of a technique of coating with SiO2 layers, the behaviour of samples containing more than 50% B2O3 can be

C. A. HOGARTH; E. H. Z. TAHERI

1974-01-01

430

Nanostructured metal coatings on polymers increase osteoblast attachment  

PubMed Central

Bioactive coatings are in high demand to increase the functions of cells for numerous medical devices. The objective of this in vitro study was to characterize osteoblast (bone-forming cell) adhesion on several potential orthopedic polymeric materials (specifically, polyetheretherketone, ultra-high molecular weight polyethylene, and polytetrafluoroethylene) coated with either titanium or gold using a novel Ionic Plasma Deposition process which creates a surface-engineered nanostructure (with features below 100 nm). Results demonstrated that compared to currently-used titanium and uncoated polymers, polymers coated with either titanium or gold using Ionic Plasma Deposition significantly increased osteoblast adhesion. Qualitative cell morphology results supported quantitative adhesion results as increased osteoblast cell spreading was observed on coated polymers compared to uncoated polymers. In this manner, this in vitro study strongly suggests that Ionic Plasma Deposition should be further studied for creating nanometer surface features on a wide variety of materials to enhance osteoblast functions necessary for orthopedic applications. PMID:18019846

Yao, Chang; Storey, Dan; Webster, Thomas J

2007-01-01

431

Evaluation of metallic coatings for the corrosion protection of a uranium-3\\/4 weight percent titanium alloy  

Microsoft Academic Search

Various coatings and coating processes were evaluated in terms of the corrosion protection offered to U-3\\/4 Ti. The metallic coatings considered were electroplated nickel, electroplated cadmium, electroless nickel, ion-plated aluminum, ion-plated zinc, a duplex coating of electroplated zinc over nickel, and the same duplex coating with a chromate finish. Based upon the tests conducted (hot, humid air; dilute salt solutions;

Weirick

1974-01-01

432

Wear behavior of gas tunnel type plasma sprayed Zr-based metallic glass composite coatings  

NASA Astrophysics Data System (ADS)

Gas tunnel type plasma spraying is a prospective method to produce metallic glass composite coatings with high quality due to its noteworthy feature of process controllability. In this study, Zr55Cu30Al10Ni5 metallic glass composite coatings were produced by gas tunnel type plasma spraying torch under optimum spraying conditions with selected plasma currents. The formation mechanism, sliding, and erosive wear behaviors of the coatings with respect to plasma current was examined. The phase and thermal analyses as well as microstructure of the plasma sprayed coatings produced at different plasma currents were characterized using X-ray diffraction (XRD), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDX) techniques. The sliding and erosive wear behaviors of the coatings were studied using a pin-on-disc and a specially designed erosive wear tester, respectively. The results showed that an increase in plasma current increased the crystalline content in the metallic glass composite coatings, which enhanced the hardness and wear resistance of the coatings.

Yugeswaran, S.; Kobayashi, A.; Suresh, K.; Rao, K. P.; Subramanian, B.

2012-09-01

433

Size dependent nonlinear optical properties of spin coated zinc oxide-polystyrene nanocomposite films  

NASA Astrophysics Data System (ADS)

Using simple wet chemical method at room temperature, zinc oxide (ZnO) nanoparticles embedded in polystyrene (PS) matrix were synthesized. The size of the ZnO nanoparticles could be varied by varying the precursor concentration, reaction time and stirring speed. Transparent films of ZnO/PS nanocomposites of thickness around 1 ?m were coated on ultrasonically cleaned glass substrates by spin coating. The optical absorptive nonlinearity in ZnO/PS nanocomposite films was investigated using open aperture Z-scan technique with nanosecond laser pulses at 532 nm. The results indicate optical limiting type nonlinearity in the films due to two-photon absorption in ZnO. These films also show a self-defocusing type negative nonlinear refraction in closed aperture Z-scan experiment. The observed nonlinear absorption is strongly dependent on particle size and the normalized transmittance could be reduced to as low as 0.43 by the suitable choice of the ZnO nanoparticle size. These composite films can hence be used as efficient optical limiters for sensor protection. The much-pronounced nonlinear response of these composite films, compared to pure ZnO, combined with the improved stability of ZnO nanoparticles in the PS matrix offer prospects of application of these composite films in the fabrication of stable non-linear optical devices.

Jeeju, Pullarkat P.; Jayalekshmi, S.; Chandrasekharan, K.; Sudheesh, P.

2012-11-01

434

Interfacial effects on the structure of thin metal films  

NASA Astrophysics Data System (ADS)

Three studies of thin metal films grown on semiconductor and insulator substrates are presented. Thin films grown on a substrate decorated by a periodic array of atomic wires can exhibit unusual properties such as stacking faults and electronic topological phase transitions due to the interfacial modulation. We report a study of Ag films grown on an array of atomic In chains on Si(111). Prior STM studies have suggested an array of stacking faults in the Ag films that allow the film lattice structure to match the interfacial modulations. STM however can only probe the surface. Our work uses x-ray diffraction to elucidate the internal 3-dimensional structure of this system. The measurements are found to be best explained by a model in which the unit cell contains a single stacking fault. When the thickness of a thin film approaches the nanoscale significant changes in its properties can occur known as quantum size effects. Bilayer oscillations in the preferred island heights as a function of thickness in Pb films grown on Si(111) substrates is one example of a quantum size effect that is now well understood. Here we present a study of Pb films grown on sapphire substrates and present evidence of quantum size effects in a metal on insulator system. Intriguing difference between the Pb on Si system and this system are observed. The crossover between preferences for even and odd thicknesses is not observed in this system, over the range of thicknesses studied, as they are in the Pb on Si case. The preferred heights are found to have much greater thermal stability demonstrating a connection between the quantum growth of thin films and the substrate band gap. By growing thin films from materials with substantially different electronic properties interesting changes in the quantum growth behavior should also be observable. In the third study reported surface x-ray diffraction experiments on In films grown on Si substrates are presented. In films are grown on Si(111)-(7x7) and Si(111)-( 3x3 )-In substrates. The Si(111)-(7x7) surface is found to persist upon burial by the film. Although preferences for island heights at low coverages have been observed no observation of preferred island heights above 7 monolayers (ML) have been made in previous studies of this system. Our experiments show that by annealing the sample a preference for islands 13 ML in height can be seen.

Gray, Aaron James

435

Optimizing vanadium pentoxide thin films and multilayers from dip-coated nanofluid precursors.  

PubMed

Using an alkoxide-based precursor, a strategy for producing highly uniform thin films and multilayers of V2O5 is demonstrated using dip coating. Defect-free and smooth films of V2O5 on different surfaces can be deposited from liquid precursors. We show how pinholes are formed due to heterogeneous nucleation during hydrolysis as the precursor forms a nanofluid. Using knowledge of instability formation often found in composite nanofluid films and the influence of cluster formation on the stability of these films, we show how polymer-precursor mixtures provide optimum uniformity and very low surface roughness in amorphous V2O5 and also orthorhombic V2O5 after crystallization by heating. Pinhole and roughness instability formation during the liquid stage of the nanofluid on gold and ITO substrates is suppressed giving a uniform coating. Practically, understanding evolution pathways that involve dewetting processes, nucleation, decomposition, or hydrolysis in complex nanofluids provides a route for improved uniformity of thin films. The method could be extended to improve the consistency in sequential or iterative multilayer deposits of a range of liquid precursors for functional materials and coatings. PMID:24432710

Glynn, Colm; Creedon, Donal; Geaney, Hugh; O'Connell, John; Holmes, Justin D; O'Dwyer, Colm

2014-02-12

436

Planarization of metal films for multilevel interconnects  

DOEpatents

In the fabrication of multilevel integrated circuits, each metal layer is planarized by heating to momentarily melt the layer. The layer